During rock drilling and blasting activities,stemming blast holes is to prevent high-pressure explosive gases from the holes,thereby enhancing the overall blasting effectiveness.Hence,it is imperative to investigate t...During rock drilling and blasting activities,stemming blast holes is to prevent high-pressure explosive gases from the holes,thereby enhancing the overall blasting effectiveness.Hence,it is imperative to investigate the dynamic mechanical properties of the stem-ming materials.In this study,impact compression tests were conducted on self-swelling cartridges(SSCs)using a split Hopkinson pres-sure bar(SHPB),aiming to evaluate dynamic performances across strain rate range of 20 to 65 s^(−1).Test results indicate that the dynamic compressive strength of SSCs exhibits the following trends:it increases with increasing density of SSC,decreases with an increase in insertion gap,and follows an initial rise and subsequent fall trend with an increase in water absorption.The order of significance among these factors is density>water absorption>insertion gaps.SSCs exhibit a pronounced strain-rate strengthening dependence in dynamic compressive strength.Furthermore,both the compressive peak stress and peak strain of SSCs follow a well-defined quadratic upward trend with increasing strain rates.As the strain rate increases,the degree of fragmentation,absorbed energy,and dynamic increase factor exhibit an upward trend.Model experimental results indicate that,compared to cementitious stemming materials,SSCs can prolong the duration of gas explosion action.Therefore,SSCs are more suitable for high strain-rate applications such as blasting stemming and rock burst control.展开更多
Based on the blasting theory and stress wave theory, stemming mechanism and movement of stemmed material in rock blasting were analyzed and the calculation expression of stemming lengths was deduced. The blasting expe...Based on the blasting theory and stress wave theory, stemming mechanism and movement of stemmed material in rock blasting were analyzed and the calculation expression of stemming lengths was deduced. The blasting experiment with different stemming lengths was carried out and the results show that the theoretical stemming length, which is 0.73 ~ 0.8 time of burden, is in the range of the experiential length, which is O. 63 - O. 88 time of burden. The blasting results of field experiments with theoretical stemming length are satisfactory, which shows the theoretical derivation and analysis are correct and reliable. The results will supply rock blasting with the theoretical gist of parameters design.展开更多
To the Editor：Irreversible electroporation （IRE） is a CE- and FDA- approved treatment modality for pancreatic and liver tumors that is based on the site-confined destruction of tumor tissue by multiple short, high-...To the Editor：Irreversible electroporation （IRE） is a CE- and FDA- approved treatment modality for pancreatic and liver tumors that is based on the site-confined destruction of tumor tissue by multiple short, high-intensity electrical pulses.展开更多
Arabic, as one of the Semitic languages, has a very rich and complex morphology, which is radically different from the European and the East Asian languages. The derivational system of Arabic, is therefore, based on r...Arabic, as one of the Semitic languages, has a very rich and complex morphology, which is radically different from the European and the East Asian languages. The derivational system of Arabic, is therefore, based on roots, which are often inflected to compose words, using a spectacular and a relatively large set of Arabic morphemes affixes, e.g., antefixs, prefixes, suffixes, etc. Stemming is the process of rendering all the inflected forms of word into a common canonical form. Stemming is one of the early and major phases in natural processing, machine translation and information retrieval tasks. A number of Arabic language stemmers were proposed. Examples include light stemming, morphological analysis, statistical-based stemming, N-grams and parallel corpora (collections). Motivated by the reported results in the literature, this paper attempts to exhaustively review current achievements for stemming Arabic texts. A variety of algorithms are discussed. The main contribution of the paper is to provide better understanding among existing approaches with the hope of building an error-free and effective Arabic stemmer in the near future.展开更多
Stemming is used to produce stem or root of words. The process is vital to different research fields such as text mining, sentiment analysis, and text categorization, etc. Several techniques have been proposed to stem...Stemming is used to produce stem or root of words. The process is vital to different research fields such as text mining, sentiment analysis, and text categorization, etc. Several techniques have been proposed to stemming Arabic text and among them, Khoja and light-10 stemmers are the most widely used. In this paper, we propose and evaluate two different stemming techniques to Arabic that are based on light stemming techniques. The new stemmers are compared to best reported light stemmer, which is light-10. Results and experiments, which were conducted using standard collections, reveal that The proposed stemmers yield 5.13% and 13.1% improvement in retrieval performance over light 10 with 0.369 average precision and 0.397, respectively and the improvement is statistically significant.展开更多
Traumatic brain injury can be categorized into primary and secondary injuries.Secondary injuries are the main cause of disability following traumatic brain injury,which involves a complex multicellular cascade.Microgl...Traumatic brain injury can be categorized into primary and secondary injuries.Secondary injuries are the main cause of disability following traumatic brain injury,which involves a complex multicellular cascade.Microglia play an important role in secondary injury and can be activated in response to traumatic brain injury.In this article,we review the origin and classification of microglia as well as the dynamic changes of microglia in traumatic brain injury.We also clarify the microglial polarization pathways and the therapeutic drugs targeting activated microglia.We found that regulating the signaling pathways involved in pro-inflammatory and anti-inflammatory microglia,such as the Toll-like receptor 4/nuclear factor-kappa B,mitogen-activated protein kinase,Janus kinase/signal transducer and activator of transcription,phosphoinositide 3-kinase/protein kinase B,Notch,and high mobility group box 1 pathways,can alleviate the inflammatory response triggered by microglia in traumatic brain injury,thereby exerting neuroprotective effects.We also reviewed the strategies developed on the basis of these pathways,such as drug and cell replacement therapies.Drugs that modulate inflammatory factors,such as rosuvastatin,have been shown to promote the polarization of antiinflammatory microglia and reduce the inflammatory response caused by traumatic brain injury.Mesenchymal stem cells possess anti-inflammatory properties,and clinical studies have confirmed their significant efficacy and safety in patients with traumatic brain injury.Additionally,advancements in mesenchymal stem cell-delivery methods—such as combinations of novel biomaterials,genetic engineering,and mesenchymal stem cell exosome therapy—have greatly enhanced the efficiency and therapeutic effects of mesenchymal stem cells in animal models.However,numerous challenges in the application of drug and mesenchymal stem cell treatment strategies remain to be addressed.In the future,new technologies,such as single-cell RNA sequencing and transcriptome analysis,can facilitate further experimental studies.Moreover,research involving non-human primates can help translate these treatment strategies to clinical practice.展开更多
Stroke,particularly ischemic stroke,is the leading cause of long-term disability and mortality worldwide.It occurs due to the occlusion of the cerebral arteries,which significantly reduces the delivery of blood,oxygen...Stroke,particularly ischemic stroke,is the leading cause of long-term disability and mortality worldwide.It occurs due to the occlusion of the cerebral arteries,which significantly reduces the delivery of blood,oxygen,and essential nutrients to brain tissues.This deprivation triggers a cascade of cellular events that ultimately leads to neuronal death.Recent studies have clarified the multifactorial pathogenesis of ischemic stroke,highlighting the roles of energy failure,excitotoxicity,oxidative stress,neuroinflammation,and apoptosis.This review aimed to provide a comprehensive insight into the fundamental mechanisms driving neuronal death triggered by ischemia and to examine the progress of neuroprotective therapeutic approaches designed to mitigate neuronal loss and promote neurological recovery after a stroke.Additionally,we explored widely accepted findings regarding the potential pathways implicated in neuronal death during ischemic stroke,including the interplay of apoptosis,autophagy,pyroptosis,ferroptosis,and necrosis,which collectively influence neuronal fate.We also discussed advancements in neuroprotective therapeutics,encompassing a range of interventions from pharmacological modulation to stem cell-based therapies,aimed at reducing neuronal injury and enhancing functional recovery following ischemic stroke.Despite these advancements,challenges remain in translating mechanistic insights into effective clinical therapies.Although neuroprotective strategies have shown promise in preclinical models,their efficacy in human trials has been inconsistent,often due to the complex pathology of ischemic stroke and the timing of interventions.In conclusion,this review synthesizes mechanistic insights into the intricate interplay of molecular and cellular pathways driving neuronal death post-ischemia.It sheds light on cutting-edge advancements in potential neuroprotective therapeutics,underscores the promise of regenerative medicine,and offers a forward-looking perspective on potential clinical breakthroughs.The ongoing evolution of precision-targeted interventions is expected to significantly enhance preventative strategies and improve clinical outcomes.展开更多
Blood-brain barrier disruption and the neuroinflammatory response are significant pathological features that critically influence disease progression and treatment outcomes.This review systematically analyzes the curr...Blood-brain barrier disruption and the neuroinflammatory response are significant pathological features that critically influence disease progression and treatment outcomes.This review systematically analyzes the current understanding of the bidirectional relationship between blood-brain barrier disruption and neuroinflammation in traumatic brain injury,along with emerging combination therapeutic strategies.Literature review indicates that blood-brain barrier disruption and neuroinflammatory responses are key pathological features following traumatic brain injury.In the acute phase after traumatic brain injury,the pathological characteristics include primary blood-brain barrier disruption and the activation of inflammatory cascades.In the subacute phase,the pathological features are characterized by repair mechanisms and inflammatory modulation.In the chronic phase,the pathological features show persistent low-grade inflammation and incomplete recovery of the blood-brain barrier.Various physiological changes,such as structural alterations of the blood-brain barrier,inflammatory cascades,and extracellular matrix remodeling,interact with each other and are influenced by genetic,age,sex,and environmental factors.The dynamic balance between blood-brain barrier permeability and neuroinflammation is regulated by hormones,particularly sex hormones and stress-related hormones.Additionally,the role of gastrointestinal hormones is receiving increasing attention.Current treatment strategies for traumatic brain injury include various methods such as conventional drug combinations,multimodality neuromonitoring,hyperbaric oxygen therapy,and non-invasive brain stimulation.Artificial intelligence also shows potential in treatment decision-making and personalized therapy.Emerging sequential combination strategies and precision medicine approaches can help improve treatment outcomes;however,challenges remain,such as inadequate research on the mechanisms of the chronic phase traumatic brain injury and difficulties with technology integration.Future research on traumatic brain injury should focus on personalized treatment strategies,the standardization of techniques,costeffectiveness evaluations,and addressing the needs of patients with comorbidities.A multidisciplinary approach should be used to enhance treatment and improve patient outcomes.展开更多
Traumatic optic neuropathy is a form of optic neuropathy resulting from trauma.Its pathophysiological mechanisms involve primary and secondary injury phases,leading to progressive retinal ganglion cell loss and axonal...Traumatic optic neuropathy is a form of optic neuropathy resulting from trauma.Its pathophysiological mechanisms involve primary and secondary injury phases,leading to progressive retinal ganglion cell loss and axonal degeneration.Contributing factors such as physical trauma,oxidative stress,neuroinflammation,and glial scar formation exacerbate disease progression and retinal ganglion cell death.Multiple forms of cell death—including apoptosis,pyroptosis,necroptosis,and ferroptosis—are involved at different disease stages.Although current treatments,such as corticosteroid therapy and surgical interventions,have limited efficacy,cell-based therapies have emerged as a promising approach that simultaneously promotes neuroprotection and retinal ganglion cell regeneration.This review summarizes recent advances in cell-based therapies for traumatic optic neuropathy.In the context of cell replacement therapy,retinal ganglion cell-like cells derived from embryonic stem cells and induced pluripotent stem cells—via chemical induction or direct reprogramming—have demonstrated the ability to integrate into the host retina and survive for weeks to months,potentially improving visual function.Mesenchymal stem cells derived from various sources,including bone marrow,umbilical cord,placenta,and adipose tissue,have been shown to enhance retinal ganglion cell survival,stimulate axonal regeneration,and support partial functional recovery.Additionally,neural stem/progenitor cells derived from human embryonic stem cells offer neuroprotective effects and function as“neuronal relays,”facilitating reconnection between damaged regions of the optic nerve and the visual pathway.Beyond direct cell transplantation,cell-derived products,such as extracellular vesicles and cell-extracted solutions,have demonstrated promising neuroprotective effects in traumatic optic neuropathy.Despite significant progress,several challenges remain,including limited integration of transplanted cells,suboptimal functional vision recovery,the need for precise timing and delivery methods,and an incomplete understanding of the role of the retinal microenvironment and glial cell activation in neuroprotection and neuroregeneration.Furthermore,studies with longer observation periods and deeper mechanistic insights into the therapeutic effects of cell-based therapies remain scarce.Two Phase I clinical trials have confirmed the safety and potential benefits of cell-based therapy for traumatic optic neuropathy,with reported improvements in visual acuity.However,further studies are needed to validate these findings and establish significant therapeutic outcomes.In conclusion,cell-based therapies hold great promise for treating traumatic optic neuropathy,but critical obstacles must be overcome to achieve functional optic nerve regeneration.Emerging bioengineering strategies,such as scaffold-based transplantation,may improve cell survival and axonal guidance.Successful clinical translation will require rigorous preclinical validation,standardized protocols,and the integration of advanced imaging techniques to optimize therapeutic efficacy.展开更多
Epilepsy is a serious neurological disorder;however,the effectiveness of current medications is often suboptimal.Recently,stem cell technology has demonstrated remarkable therapeutic potential in addressing various ne...Epilepsy is a serious neurological disorder;however,the effectiveness of current medications is often suboptimal.Recently,stem cell technology has demonstrated remarkable therapeutic potential in addressing various neurological diseases,igniting interest in its applicability for epilepsy treatment.This comprehensive review summarizes different therapeutic approaches utilizing various types of stem cells.Preclinical experiments have explored the use and potential therapeutic effects of mesenchymal stem cells,including genetically modified variants.Clinical trials involving patientderived mesenchymal stem cells have shown promising results,with reductions in the frequency of epileptic seizures and improvements in neurological,cognitive,and motor functions reported.Another promising therapeutic strategy involves neural stem cells.These cells can be cultured outside the body and directed to differentiate into specific cell types.The transplant of neural stem cells has the potential to replace lost inhibitory interneurons,providing a novel treatment avenue for epilepsy.Embryonic stem cells are characterized by their significant capacity for self-renewal and their ability to differentiate into any type of somatic cell.In epilepsy treatment,embryonic stem cells can serve three primary functions:neuron regeneration,the maintenance of cellular homeostasis,and restorative activity.One notable strategy involves differentiating embryonic stem cells intoγ-aminobutyric acidergic neurons for transplantation into lesion sites.This approach is currently undergoing clinical trials and could be a breakthrough in the treatment of refractory epilepsy.Induced pluripotent stem cells share the same genetic background as the donor,thereby reducing the risk of immune rejection and addressing ethical concerns.However,research on induced pluripotent stem cell therapy remains in the preclinical stage.Despite the promise of stem cell therapies for epilepsy,several limitations must be addressed.Safety concerns persist,including issues such as tumor formation,and the low survival rate of transplanted cells remains a significant challenge.Additionally,the high cost of these treatments may be prohibitive for some patients.In summary,stem cell therapy shows considerable promise in managing epilepsy,but further research is needed to overcome its existing limitations and enhance its clinical applicability.展开更多
Ischemic stroke is a significant global health crisis,frequently resulting in disability or death,with limited therapeutic interventions available.Although various intrinsic reparative processes are initiated within t...Ischemic stroke is a significant global health crisis,frequently resulting in disability or death,with limited therapeutic interventions available.Although various intrinsic reparative processes are initiated within the ischemic brain,these mechanisms are often insufficient to restore neuronal functionality.This has led to intensive investigation into the use of exogenous stem cells as a potential therapeutic option.This comprehensive review outlines the ontogeny and mechanisms of activation of endogenous neural stem cells within the adult brain following ischemic events,with focus on the impact of stem cell-based therapies on neural stem cells.Exogenous stem cells have been shown to enhance the proliferation of endogenous neural stem cells via direct cell-tocell contact and through the secretion of growth factors and exosomes.Additionally,implanted stem cells may recruit host stem cells from their niches to the infarct area by establishing so-called“biobridges.”Furthermore,xenogeneic and allogeneic stem cells can modify the microenvironment of the infarcted brain tissue through immunomodulatory and angiogenic effects,thereby supporting endogenous neuroregeneration.Given the convergence of regulatory pathways between exogenous and endogenous stem cells and the necessity for a supportive microenvironment,we discuss three strategies to simultaneously enhance the therapeutic efficacy of both cell types.These approaches include:(1)co-administration of various growth factors and pharmacological agents alongside stem cell transplantation to reduce stem cell apoptosis;(2)synergistic administration of stem cells and their exosomes to amplify paracrine effects;and(3)integration of stem cells within hydrogels,which provide a protective scaffold for the implanted cells while facilitating the regeneration of neural tissue and the reconstitution of neural circuits.This comprehensive review highlights the interactions and shared regulatory mechanisms between endogenous neural stem cells and exogenously implanted stem cells and may offer new insights for improving the efficacy of stem cell-based therapies in the treatment of ischemic stroke.展开更多
Our previous study demonstrated that combined transplantation of bone marrow mesenchymal stem cells and retinal progenitor cells in rats has therapeutic effects on retinal degeneration that are superior to transplanta...Our previous study demonstrated that combined transplantation of bone marrow mesenchymal stem cells and retinal progenitor cells in rats has therapeutic effects on retinal degeneration that are superior to transplantation of retinal progenitor cells alone.Bone marrow mesenchymal stem cells regulate and interact with various cells in the retinal microenvironment by secreting neurotrophic factors and extracellular vesicles.Small extracellular vesicles derived from bone marrow mesenchymal stem cells,which offer low immunogenicity,minimal tumorigenic risk,and ease of transportation,have been utilized in the treatment of various neurological diseases.These vesicles exhibit various activities,including anti-inflammatory actions,promotion of tissue repair,and immune regulation.Therefore,novel strategies using human retinal progenitor cells combined with bone marrow mesenchymal stem cell-derived small extracellular vesicles may represent an innovation in stem cell therapy for retinal degeneration.In this study,we developed such an approach utilizing retinal progenitor cells combined with bone marrow mesenchymal stem cell-derived small extracellular vesicles to treat retinal degeneration in Royal College of Surgeons rats,a genetic model of retinal degeneration.Our findings revealed that the combination of bone marrow mesenchymal stem cell-derived small extracellular vesicles and retinal progenitor cells significantly improved visual function in these rats.The addition of bone marrow mesenchymal stem cell-derived small extracellular vesicles as adjuvants to stem cell transplantation with retinal progenitor cells enhanced the survival,migration,and differentiation of the exogenous retinal progenitor cells.Concurrently,these small extracellular vesicles inhibited the activation of regional microglia,promoted the migration of transplanted retinal progenitor cells to the inner nuclear layer of the retina,and facilitated their differentiation into photoreceptors and bipolar cells.These findings suggest that bone marrow mesenchymal stem cell-derived small extracellular vesicles potentiate the therapeutic efficacy of retinal progenitor cells in retinal degeneration by promoting their survival and differentiation.展开更多
Bone regeneration for non-load-bearing defects remains a significant clinical challenge requiring advanced biomaterials and cellular strategies.Adiposederived mesenchymal stem cells(AD-MSCs)have garnered significant i...Bone regeneration for non-load-bearing defects remains a significant clinical challenge requiring advanced biomaterials and cellular strategies.Adiposederived mesenchymal stem cells(AD-MSCs)have garnered significant interest in bone tissue engineering(BTE)because of their abundant availability,minimally invasive harvesting procedures,and robust differentiation potential into osteogenic lineages.Unlike bone marrow-derived mesenchymal stem cells,AD-MSCs can be easily obtained in large quantities,making them appealing alternatives for therapeutic applications.This review explores hydrogels containing polymers,such as chitosan,collagen,gelatin,and hyaluronic acid,and their composites,tailored for BTE,and emphasizes the importance of these hydrogels as scaffolds for the delivery of AD-MSCs.Various hydrogel fabrication techniques and biocompatibility assessments are discussed,along with innovative modifications to enhance osteogenesis.This review also briefly outlines AD-MSC isolation methods and advanced embedding techniques for precise cell placement,such as direct encapsulation and three-dimensional bioprinting.We discuss the mechanisms of bone regeneration in the AD-MSC-laden hydrogels,including osteoinduction,vascularization,and extracellular matrix remodeling.We also review the preclinical and clinical applications of AD-MSC-hydrogel systems,emphasizing their success and limitations.In this review,we provide a comprehensive overview of AD-MSC-based hydrogel systems to guide the development of effective therapies for bone regeneration.展开更多
A recently published prospective study marks a breakthrough for congenital olfactory disorders in children.The study provides the first long-term,three-year follow-up data,robustly demonstrating the durable efficacy a...A recently published prospective study marks a breakthrough for congenital olfactory disorders in children.The study provides the first long-term,three-year follow-up data,robustly demonstrating the durable efficacy and safety of autologous nasal epithelial stem cell transplantation.This work reveals immense therapeutic potential for a condition traditionally considered untreatable.However,this milestone achievement also presents new challenges.To translate this pioneering therapy from a single-center success to a global standard,multicenter,controlled clinical trials must be initiated immediately.Only through rigorous validation can we ensure its widespread adoption and ultimately bring hope to millions of children worldwide.展开更多
BACKGROUND The incidence of diabetic atherosclerosis(DMA)is increasing worldwide,but its pathogenesis remains incompletely understood.In addition to cardiovascular complications,bladder dysfunction is one of the commo...BACKGROUND The incidence of diabetic atherosclerosis(DMA)is increasing worldwide,but its pathogenesis remains incompletely understood.In addition to cardiovascular complications,bladder dysfunction is one of the common comorbidities associated with DMA but is often refractory to current treatments.AIM To investigate the therapeutic effect of human amniotic fluid stem cell-derived extracellular vesicles(hAFSC-EVs)on the recovery of bladder dysfunction in DMA rats.METHODS Eighty rats were divided into normal control,streptozotocin-induced diabetic rats,diabetic rats subjected to arterial balloon endothelial injury of common iliac artery(DMA),and DMA rats treated with hAFSC-EVs(DMA+hAFSC-EVs).At 4 weeks and 12 weeks after DMA induction,levels of blood glucose,total cholesterol,triglyceride,high-density lipoprotein cholesterol,low-density lipoprotein cholesterol,homeostasis model assessment(HOMA)-insulin resistance,and HOMA-βwere measured.Cystometry,common iliac artery wall thickness,and bladder tumor necrosis factor(TNF)-α,interleukin(IL)-6,transforming growth factor(TGF)-β1,Smad3,connective tissue growth factor(CTGF)and fibronectin were also evaluated.RESULTS Bladder weight and blood glucose,triglyceride,HOMA-insulin resistance,common iliac artery intima thickness,voided volume,intercontraction interval,bladder capacity,and mRNA expression of TNF-α,IL-6,TGF-β1,Smad3,CTGF and fibronectin were significantly increased at 4 weeks and 12 weeks after induction,while the HOMA-βlevel decreased at 4 weeks and 12 weeks,and the high-density lipoprotein cholesterol level decreased at 12 weeks.hAFSC-EVs treatment in DMA rats significantly reduced bladder weight and blood glucose,thickness of common iliac arterial intima,voided volume,intercontraction interval and bladder capacity at 4 weeks.The mRNA expression of TNF-α,TGF-β1,and CTGF in DMA rats treated with hAFSC-EVs were significantly decreased at 4 weeks,while the mRNA expressions of IL-6 and Smad3 were significantly decreased 12 weeks.CONCLUSION hAFSC-EVs treatment can help restore DMA-induced bladder dysfunction,which is associated with lowered blood glucose levels,reduced arterial wall thickness,and decreased TNF-α,IL-6,TGF-β1,Smad3,and CTGF expression.展开更多
Previous research has demonstrated the feasibility of repairing nerve defects through acellular allogeneic nerve grafting with bone marrow mesenchymal stem cells.However,adult tissue–derived mesenchymal stem cells en...Previous research has demonstrated the feasibility of repairing nerve defects through acellular allogeneic nerve grafting with bone marrow mesenchymal stem cells.However,adult tissue–derived mesenchymal stem cells encounter various obstacles,including limited tissue sources,invasive acquisition methods,cellular heterogeneity,purification challenges,cellular senescence,and diminished pluripotency and proliferation over successive passages.In this study,we used induced pluripotent stem cell-derived mesenchymal stem cells,known for their self-renewal capacity,multilineage differentiation potential,and immunomodulatory characteristics.We used induced pluripotent stem cell-derived mesenchymal stem cells in conjunction with acellular nerve allografts to address a 10 mm-long defect in a rat model of sciatic nerve injury.Our findings reveal that induced pluripotent stem cell-derived mesenchymal stem cells exhibit survival for up to 17 days in a rat model of peripheral nerve injury with acellular nerve allograft transplantation.Furthermore,the combination of acellular nerve allograft and induced pluripotent stem cell-derived mesenchymal stem cells significantly accelerates the regeneration of injured axons and improves behavioral function recovery in rats.Additionally,our in vivo and in vitro experiments indicate that induced pluripotent stem cell-derived mesenchymal stem cells play a pivotal role in promoting neovascularization.Collectively,our results suggest the potential of acellular nerve allografts with induced pluripotent stem cell-derived mesenchymal stem cells to augment nerve regeneration in rats,offering promising therapeutic strategies for clinical translation.展开更多
In recent years,exosomes have garnered extensive attention as therapeutic agents and early diagnostic markers in neurodegenerative disease research.Exosomes are small and can effectively cross the blood-brain barrier,...In recent years,exosomes have garnered extensive attention as therapeutic agents and early diagnostic markers in neurodegenerative disease research.Exosomes are small and can effectively cross the blood-brain barrier,allowing them to target deep brain lesions.Recent studies have demonstrated that exosomes derived from different cell types may exert therapeutic effects by regulating the expression of various inflammatory cytokines,mRNAs,and disease-related proteins,thereby halting the progression of neurodegenerative diseases and exhibiting beneficial effects.However,exosomes are composed of lipid bilayer membranes and lack the ability to recognize specific target cells.This limitation can lead to side effects and toxicity when they interact with non-specific cells.Growing evidence suggests that surface-modified exosomes have enhanced targeting capabilities and can be used as targeted drug-delivery vehicles that show promising results in the treatment of neurodegenerative diseases.In this review,we provide an up-to-date overview of existing research aimed at devising approaches to modify exosomes and elucidating their therapeutic potential in neurodegenerative diseases.Our findings indicate that exosomes can efficiently cross the blood-brain barrier to facilitate drug delivery and can also serve as early diagnostic markers for neurodegenerative diseases.We introduce the strategies being used to enhance exosome targeting,including genetic engineering,chemical modifications(both covalent,such as click chemistry and metabolic engineering,and non-covalent,such as polyvalent electrostatic and hydrophobic interactions,ligand-receptor binding,aptamer-based modifications,and the incorporation of CP05-anchored peptides),and nanomaterial modifications.Research into these strategies has confirmed that exosomes have significant therapeutic potential for neurodegenerative diseases.However,several challenges remain in the clinical application of exosomes.Improvements are needed in preparation,characterization,and optimization methods,as well as in reducing the adverse reactions associated with their use.Additionally,the range of applications and the safety of exosomes require further research and evaluation.展开更多
BACKGROUND Gastric cancer(GC)is one of the most common malignant tumors of the digestive system worldwide,the prognosis of patients with advanced GC remains poor.AIM To evaluate the combined expression characteristics...BACKGROUND Gastric cancer(GC)is one of the most common malignant tumors of the digestive system worldwide,the prognosis of patients with advanced GC remains poor.AIM To evaluate the combined expression characteristics of cancer stem cell markers CD24 and CD133 in GC pathological tissues,and to explore their association with patients’clinicopathological parameters and postoperative survival outcomes.METHODS A total of 304 GC patients who underwent surgical treatment in our hospital from January 2018 to January 2020 were retrospectively included.Immunohistochemistry was used to detect the protein expression of CD24 and CD133 in tumor tissues,adjacent tissues,and normal gastric mucosa tissues.Based on staining intensity and the proportion of positive cells,expression levels were classified into low and high expression,while clinicopathological parameters were recorded.χ2 test was used to evaluate the correlation between expression and categorical variables,Spearman rank correlation analysis was performed to assess the correlation between the expression intensities of the two markers,and multivariate regression models were applied to identify independent risk factors influencing co-expression.Kaplan-Meier survival curves and Log-rank test were used to compare survival differences among groups with different expression patterns.RESULTS Among the 304 patients,155 cases(50.99%)were CD24 positive,including 91 low-expression and 64 highexpression;133 cases(43.75%)were CD133 positive,including 81 low-expression and 52 high-expression.There were 74 cases(24.34%)with double positivity and 81 cases(26.64%)with double negativity.Compared with tumor tissues,the positive rates of CD24 and CD133 in normal gastric tissues and adjacent tissues were significantly lower(P<0.05).Univariate analysis showed that co-expression of CD24 and CD133 in GC tissues was significantly correlated with tumor size,Lauren classification,T stage,N stage,and vascular invasion(P<0.05),but not with patient age,gender,tumor site,World Health Organization histological classification,or M stage(P>0.05).Further multivariate regression analysis suggested that tumor size,T stage,N stage,and vascular invasion were independent risk factors promoting CD24 and CD133 double positivity.Spearman rank correlation analysis indicated a moderate positive correlation between their expression intensities(r=0.420,P<0.001).During follow-up,29 of 304 patients were lost(loss rate 9.54%);146 deaths occurred.According to expression combination,there were 89 cases of CD24 single positivity(39 deaths),68 cases of CD133 single positivity(31 deaths),81 cases of double negativity(25 deaths),and 66 cases of double positivity(51 deaths).Log-rank test showed significant differences in overall survival among the four groups(χ2=20.89,P<0.001),with CD24+/CD133+group showing the worst prognosis.CONCLUSION CD24 and CD133 exhibit high positive detection rates in GC tissues,and their co-positivity is closely associated with tumor stage progression and significantly indicates unfavorable survival outcomes.The co-expression of CD24/CD133 may reflect higher aggressiveness and metastatic potential of GC,serving as a potential prognostic marker and a direction for targeted therapeutic strategies.However,as this is a single-center retrospective study with limitations such as patient loss to follow-up and sample size,further prospective,multicenter,and mechanistic studies are required to validate its clinical applicability and biological role.展开更多
Adult neurogenesis continuously produces new neurons critical for cognitive plasticity in adult rodents.While it is known transforming growth factor-βsignaling is important in embryonic neurogenesis,its role in postn...Adult neurogenesis continuously produces new neurons critical for cognitive plasticity in adult rodents.While it is known transforming growth factor-βsignaling is important in embryonic neurogenesis,its role in postnatal neurogenesis remains unclear.In this study,to define the precise role of transforming growth factor-βsignaling in postnatal neurogenesis at distinct stages of the neurogenic cascade both in vitro and in vivo,we developed two novel inducible and cell type-specific mouse models to specifically silence transforming growth factor-βsignaling in neural stem cells in(mGFAPcre-ALK5fl/fl-Ai9)or immature neuroblasts in(DCXcreERT2-ALK5fl/fl-Ai9).Our data showed that exogenous transforming growth factor-βtreatment led to inhibition of the proliferation of primary neural stem cells while stimulating their migration.These effects were abolished in activin-like kinase 5(ALK5)knockout primary neural stem cells.Consistent with this,inhibition of transforming growth factor-βsignaling with SB-431542 in wild-type neural stem cells stimulated proliferation while inhibited the migration of neural stem cells.Interestingly,deletion of transforming growth factor-βreceptor in neural stem cells in vivo inhibited the migration of postnatal born neurons in mGFAPcre-ALK5fl/fl-Ai9 mice,while abolishment of transforming growth factor-βsignaling in immature neuroblasts in DCXcreERT2-ALK5fl/fl-Ai9 mice did not affect the migration of these cells in the hippocampus.In summary,our data supports a dual role of transforming growth factor-βsignaling in the proliferation and migration of neural stem cells in vitro.Moreover,our data provides novel insights on cell type-specific-dependent requirements of transforming growth factor-βsignaling on neural stem cell proliferation and migration in vivo.展开更多
基金supported by the National Natural Science Foundation of China(Nos.51874068 and 52074062)the Open Funds from the Key Laboratory of Ministry of Education on Safe Mining of Deep Metal Mines,Northeastern University,China(No.DM2023B03).
文摘During rock drilling and blasting activities,stemming blast holes is to prevent high-pressure explosive gases from the holes,thereby enhancing the overall blasting effectiveness.Hence,it is imperative to investigate the dynamic mechanical properties of the stem-ming materials.In this study,impact compression tests were conducted on self-swelling cartridges(SSCs)using a split Hopkinson pres-sure bar(SHPB),aiming to evaluate dynamic performances across strain rate range of 20 to 65 s^(−1).Test results indicate that the dynamic compressive strength of SSCs exhibits the following trends:it increases with increasing density of SSC,decreases with an increase in insertion gap,and follows an initial rise and subsequent fall trend with an increase in water absorption.The order of significance among these factors is density>water absorption>insertion gaps.SSCs exhibit a pronounced strain-rate strengthening dependence in dynamic compressive strength.Furthermore,both the compressive peak stress and peak strain of SSCs follow a well-defined quadratic upward trend with increasing strain rates.As the strain rate increases,the degree of fragmentation,absorbed energy,and dynamic increase factor exhibit an upward trend.Model experimental results indicate that,compared to cementitious stemming materials,SSCs can prolong the duration of gas explosion action.Therefore,SSCs are more suitable for high strain-rate applications such as blasting stemming and rock burst control.
文摘Based on the blasting theory and stress wave theory, stemming mechanism and movement of stemmed material in rock blasting were analyzed and the calculation expression of stemming lengths was deduced. The blasting experiment with different stemming lengths was carried out and the results show that the theoretical stemming length, which is 0.73 ~ 0.8 time of burden, is in the range of the experiential length, which is O. 63 - O. 88 time of burden. The blasting results of field experiments with theoretical stemming length are satisfactory, which shows the theoretical derivation and analysis are correct and reliable. The results will supply rock blasting with the theoretical gist of parameters design.
文摘To the Editor：Irreversible electroporation （IRE） is a CE- and FDA- approved treatment modality for pancreatic and liver tumors that is based on the site-confined destruction of tumor tissue by multiple short, high-intensity electrical pulses.
文摘Arabic, as one of the Semitic languages, has a very rich and complex morphology, which is radically different from the European and the East Asian languages. The derivational system of Arabic, is therefore, based on roots, which are often inflected to compose words, using a spectacular and a relatively large set of Arabic morphemes affixes, e.g., antefixs, prefixes, suffixes, etc. Stemming is the process of rendering all the inflected forms of word into a common canonical form. Stemming is one of the early and major phases in natural processing, machine translation and information retrieval tasks. A number of Arabic language stemmers were proposed. Examples include light stemming, morphological analysis, statistical-based stemming, N-grams and parallel corpora (collections). Motivated by the reported results in the literature, this paper attempts to exhaustively review current achievements for stemming Arabic texts. A variety of algorithms are discussed. The main contribution of the paper is to provide better understanding among existing approaches with the hope of building an error-free and effective Arabic stemmer in the near future.
文摘Stemming is used to produce stem or root of words. The process is vital to different research fields such as text mining, sentiment analysis, and text categorization, etc. Several techniques have been proposed to stemming Arabic text and among them, Khoja and light-10 stemmers are the most widely used. In this paper, we propose and evaluate two different stemming techniques to Arabic that are based on light stemming techniques. The new stemmers are compared to best reported light stemmer, which is light-10. Results and experiments, which were conducted using standard collections, reveal that The proposed stemmers yield 5.13% and 13.1% improvement in retrieval performance over light 10 with 0.369 average precision and 0.397, respectively and the improvement is statistically significant.
基金supported by the Natural Science Foundation of Yunnan Province,No.202401AS070086(to ZW)the National Key Research and Development Program of China,No.2018YFA0801403(to ZW)+1 种基金Yunnan Science and Technology Talent and Platform Plan,No.202105AC160041(to ZW)the Natural Science Foundation of China,No.31960120(to ZW)。
文摘Traumatic brain injury can be categorized into primary and secondary injuries.Secondary injuries are the main cause of disability following traumatic brain injury,which involves a complex multicellular cascade.Microglia play an important role in secondary injury and can be activated in response to traumatic brain injury.In this article,we review the origin and classification of microglia as well as the dynamic changes of microglia in traumatic brain injury.We also clarify the microglial polarization pathways and the therapeutic drugs targeting activated microglia.We found that regulating the signaling pathways involved in pro-inflammatory and anti-inflammatory microglia,such as the Toll-like receptor 4/nuclear factor-kappa B,mitogen-activated protein kinase,Janus kinase/signal transducer and activator of transcription,phosphoinositide 3-kinase/protein kinase B,Notch,and high mobility group box 1 pathways,can alleviate the inflammatory response triggered by microglia in traumatic brain injury,thereby exerting neuroprotective effects.We also reviewed the strategies developed on the basis of these pathways,such as drug and cell replacement therapies.Drugs that modulate inflammatory factors,such as rosuvastatin,have been shown to promote the polarization of antiinflammatory microglia and reduce the inflammatory response caused by traumatic brain injury.Mesenchymal stem cells possess anti-inflammatory properties,and clinical studies have confirmed their significant efficacy and safety in patients with traumatic brain injury.Additionally,advancements in mesenchymal stem cell-delivery methods—such as combinations of novel biomaterials,genetic engineering,and mesenchymal stem cell exosome therapy—have greatly enhanced the efficiency and therapeutic effects of mesenchymal stem cells in animal models.However,numerous challenges in the application of drug and mesenchymal stem cell treatment strategies remain to be addressed.In the future,new technologies,such as single-cell RNA sequencing and transcriptome analysis,can facilitate further experimental studies.Moreover,research involving non-human primates can help translate these treatment strategies to clinical practice.
基金supported by the National Natural Science Foundation of China,Nos.82171387 and 31830111(both to SL).
文摘Stroke,particularly ischemic stroke,is the leading cause of long-term disability and mortality worldwide.It occurs due to the occlusion of the cerebral arteries,which significantly reduces the delivery of blood,oxygen,and essential nutrients to brain tissues.This deprivation triggers a cascade of cellular events that ultimately leads to neuronal death.Recent studies have clarified the multifactorial pathogenesis of ischemic stroke,highlighting the roles of energy failure,excitotoxicity,oxidative stress,neuroinflammation,and apoptosis.This review aimed to provide a comprehensive insight into the fundamental mechanisms driving neuronal death triggered by ischemia and to examine the progress of neuroprotective therapeutic approaches designed to mitigate neuronal loss and promote neurological recovery after a stroke.Additionally,we explored widely accepted findings regarding the potential pathways implicated in neuronal death during ischemic stroke,including the interplay of apoptosis,autophagy,pyroptosis,ferroptosis,and necrosis,which collectively influence neuronal fate.We also discussed advancements in neuroprotective therapeutics,encompassing a range of interventions from pharmacological modulation to stem cell-based therapies,aimed at reducing neuronal injury and enhancing functional recovery following ischemic stroke.Despite these advancements,challenges remain in translating mechanistic insights into effective clinical therapies.Although neuroprotective strategies have shown promise in preclinical models,their efficacy in human trials has been inconsistent,often due to the complex pathology of ischemic stroke and the timing of interventions.In conclusion,this review synthesizes mechanistic insights into the intricate interplay of molecular and cellular pathways driving neuronal death post-ischemia.It sheds light on cutting-edge advancements in potential neuroprotective therapeutics,underscores the promise of regenerative medicine,and offers a forward-looking perspective on potential clinical breakthroughs.The ongoing evolution of precision-targeted interventions is expected to significantly enhance preventative strategies and improve clinical outcomes.
基金supported by Open Scientific Research Program of Military Logistics,No.BLB20J009(to YZhao).
文摘Blood-brain barrier disruption and the neuroinflammatory response are significant pathological features that critically influence disease progression and treatment outcomes.This review systematically analyzes the current understanding of the bidirectional relationship between blood-brain barrier disruption and neuroinflammation in traumatic brain injury,along with emerging combination therapeutic strategies.Literature review indicates that blood-brain barrier disruption and neuroinflammatory responses are key pathological features following traumatic brain injury.In the acute phase after traumatic brain injury,the pathological characteristics include primary blood-brain barrier disruption and the activation of inflammatory cascades.In the subacute phase,the pathological features are characterized by repair mechanisms and inflammatory modulation.In the chronic phase,the pathological features show persistent low-grade inflammation and incomplete recovery of the blood-brain barrier.Various physiological changes,such as structural alterations of the blood-brain barrier,inflammatory cascades,and extracellular matrix remodeling,interact with each other and are influenced by genetic,age,sex,and environmental factors.The dynamic balance between blood-brain barrier permeability and neuroinflammation is regulated by hormones,particularly sex hormones and stress-related hormones.Additionally,the role of gastrointestinal hormones is receiving increasing attention.Current treatment strategies for traumatic brain injury include various methods such as conventional drug combinations,multimodality neuromonitoring,hyperbaric oxygen therapy,and non-invasive brain stimulation.Artificial intelligence also shows potential in treatment decision-making and personalized therapy.Emerging sequential combination strategies and precision medicine approaches can help improve treatment outcomes;however,challenges remain,such as inadequate research on the mechanisms of the chronic phase traumatic brain injury and difficulties with technology integration.Future research on traumatic brain injury should focus on personalized treatment strategies,the standardization of techniques,costeffectiveness evaluations,and addressing the needs of patients with comorbidities.A multidisciplinary approach should be used to enhance treatment and improve patient outcomes.
基金supported by the National Key Research and Development Program of China,No.2022YFA1105502(to PG)the National Natural Science Foundation of China,Nos.82271123(to PG),32200618(to ZT)。
文摘Traumatic optic neuropathy is a form of optic neuropathy resulting from trauma.Its pathophysiological mechanisms involve primary and secondary injury phases,leading to progressive retinal ganglion cell loss and axonal degeneration.Contributing factors such as physical trauma,oxidative stress,neuroinflammation,and glial scar formation exacerbate disease progression and retinal ganglion cell death.Multiple forms of cell death—including apoptosis,pyroptosis,necroptosis,and ferroptosis—are involved at different disease stages.Although current treatments,such as corticosteroid therapy and surgical interventions,have limited efficacy,cell-based therapies have emerged as a promising approach that simultaneously promotes neuroprotection and retinal ganglion cell regeneration.This review summarizes recent advances in cell-based therapies for traumatic optic neuropathy.In the context of cell replacement therapy,retinal ganglion cell-like cells derived from embryonic stem cells and induced pluripotent stem cells—via chemical induction or direct reprogramming—have demonstrated the ability to integrate into the host retina and survive for weeks to months,potentially improving visual function.Mesenchymal stem cells derived from various sources,including bone marrow,umbilical cord,placenta,and adipose tissue,have been shown to enhance retinal ganglion cell survival,stimulate axonal regeneration,and support partial functional recovery.Additionally,neural stem/progenitor cells derived from human embryonic stem cells offer neuroprotective effects and function as“neuronal relays,”facilitating reconnection between damaged regions of the optic nerve and the visual pathway.Beyond direct cell transplantation,cell-derived products,such as extracellular vesicles and cell-extracted solutions,have demonstrated promising neuroprotective effects in traumatic optic neuropathy.Despite significant progress,several challenges remain,including limited integration of transplanted cells,suboptimal functional vision recovery,the need for precise timing and delivery methods,and an incomplete understanding of the role of the retinal microenvironment and glial cell activation in neuroprotection and neuroregeneration.Furthermore,studies with longer observation periods and deeper mechanistic insights into the therapeutic effects of cell-based therapies remain scarce.Two Phase I clinical trials have confirmed the safety and potential benefits of cell-based therapy for traumatic optic neuropathy,with reported improvements in visual acuity.However,further studies are needed to validate these findings and establish significant therapeutic outcomes.In conclusion,cell-based therapies hold great promise for treating traumatic optic neuropathy,but critical obstacles must be overcome to achieve functional optic nerve regeneration.Emerging bioengineering strategies,such as scaffold-based transplantation,may improve cell survival and axonal guidance.Successful clinical translation will require rigorous preclinical validation,standardized protocols,and the integration of advanced imaging techniques to optimize therapeutic efficacy.
基金supported by the National Natural Science Foundation of China,Nos.82471471(to WJ),82471485(to FY)Shaanxi Province Special Support Program for Leading Talents in Scientific and Technological Innovation,No.tzjhjw(to WJ)+1 种基金Shaanxi Key Research and Development Plan Project,No.2023-YBSF-353(to XW)the Joint Fund Project of Innovation Research Institute of Xijing Hospital,No.LHJJ24JH13(to ZS)。
文摘Epilepsy is a serious neurological disorder;however,the effectiveness of current medications is often suboptimal.Recently,stem cell technology has demonstrated remarkable therapeutic potential in addressing various neurological diseases,igniting interest in its applicability for epilepsy treatment.This comprehensive review summarizes different therapeutic approaches utilizing various types of stem cells.Preclinical experiments have explored the use and potential therapeutic effects of mesenchymal stem cells,including genetically modified variants.Clinical trials involving patientderived mesenchymal stem cells have shown promising results,with reductions in the frequency of epileptic seizures and improvements in neurological,cognitive,and motor functions reported.Another promising therapeutic strategy involves neural stem cells.These cells can be cultured outside the body and directed to differentiate into specific cell types.The transplant of neural stem cells has the potential to replace lost inhibitory interneurons,providing a novel treatment avenue for epilepsy.Embryonic stem cells are characterized by their significant capacity for self-renewal and their ability to differentiate into any type of somatic cell.In epilepsy treatment,embryonic stem cells can serve three primary functions:neuron regeneration,the maintenance of cellular homeostasis,and restorative activity.One notable strategy involves differentiating embryonic stem cells intoγ-aminobutyric acidergic neurons for transplantation into lesion sites.This approach is currently undergoing clinical trials and could be a breakthrough in the treatment of refractory epilepsy.Induced pluripotent stem cells share the same genetic background as the donor,thereby reducing the risk of immune rejection and addressing ethical concerns.However,research on induced pluripotent stem cell therapy remains in the preclinical stage.Despite the promise of stem cell therapies for epilepsy,several limitations must be addressed.Safety concerns persist,including issues such as tumor formation,and the low survival rate of transplanted cells remains a significant challenge.Additionally,the high cost of these treatments may be prohibitive for some patients.In summary,stem cell therapy shows considerable promise in managing epilepsy,but further research is needed to overcome its existing limitations and enhance its clinical applicability.
基金supported by the National Key Research and Development Program of China,No.2018YFA0108602the CAMS Initiative for Innovative Medicine,No.2021-1-I2M-019National High-Level Hospital Clinical Research Funding,No.2022-PUMCH-C-042(all to XB)。
文摘Ischemic stroke is a significant global health crisis,frequently resulting in disability or death,with limited therapeutic interventions available.Although various intrinsic reparative processes are initiated within the ischemic brain,these mechanisms are often insufficient to restore neuronal functionality.This has led to intensive investigation into the use of exogenous stem cells as a potential therapeutic option.This comprehensive review outlines the ontogeny and mechanisms of activation of endogenous neural stem cells within the adult brain following ischemic events,with focus on the impact of stem cell-based therapies on neural stem cells.Exogenous stem cells have been shown to enhance the proliferation of endogenous neural stem cells via direct cell-tocell contact and through the secretion of growth factors and exosomes.Additionally,implanted stem cells may recruit host stem cells from their niches to the infarct area by establishing so-called“biobridges.”Furthermore,xenogeneic and allogeneic stem cells can modify the microenvironment of the infarcted brain tissue through immunomodulatory and angiogenic effects,thereby supporting endogenous neuroregeneration.Given the convergence of regulatory pathways between exogenous and endogenous stem cells and the necessity for a supportive microenvironment,we discuss three strategies to simultaneously enhance the therapeutic efficacy of both cell types.These approaches include:(1)co-administration of various growth factors and pharmacological agents alongside stem cell transplantation to reduce stem cell apoptosis;(2)synergistic administration of stem cells and their exosomes to amplify paracrine effects;and(3)integration of stem cells within hydrogels,which provide a protective scaffold for the implanted cells while facilitating the regeneration of neural tissue and the reconstitution of neural circuits.This comprehensive review highlights the interactions and shared regulatory mechanisms between endogenous neural stem cells and exogenously implanted stem cells and may offer new insights for improving the efficacy of stem cell-based therapies in the treatment of ischemic stroke.
基金supported by the National Natural Science Foundation of China,Nos.82271132(to YL),82101167(to BB)the Natural Science Foundation of Chongqing,Nos.CSTB2022NSCQ-MSX0020(to BB),cstc2019jcyj-msxmX0473(to FC).
文摘Our previous study demonstrated that combined transplantation of bone marrow mesenchymal stem cells and retinal progenitor cells in rats has therapeutic effects on retinal degeneration that are superior to transplantation of retinal progenitor cells alone.Bone marrow mesenchymal stem cells regulate and interact with various cells in the retinal microenvironment by secreting neurotrophic factors and extracellular vesicles.Small extracellular vesicles derived from bone marrow mesenchymal stem cells,which offer low immunogenicity,minimal tumorigenic risk,and ease of transportation,have been utilized in the treatment of various neurological diseases.These vesicles exhibit various activities,including anti-inflammatory actions,promotion of tissue repair,and immune regulation.Therefore,novel strategies using human retinal progenitor cells combined with bone marrow mesenchymal stem cell-derived small extracellular vesicles may represent an innovation in stem cell therapy for retinal degeneration.In this study,we developed such an approach utilizing retinal progenitor cells combined with bone marrow mesenchymal stem cell-derived small extracellular vesicles to treat retinal degeneration in Royal College of Surgeons rats,a genetic model of retinal degeneration.Our findings revealed that the combination of bone marrow mesenchymal stem cell-derived small extracellular vesicles and retinal progenitor cells significantly improved visual function in these rats.The addition of bone marrow mesenchymal stem cell-derived small extracellular vesicles as adjuvants to stem cell transplantation with retinal progenitor cells enhanced the survival,migration,and differentiation of the exogenous retinal progenitor cells.Concurrently,these small extracellular vesicles inhibited the activation of regional microglia,promoted the migration of transplanted retinal progenitor cells to the inner nuclear layer of the retina,and facilitated their differentiation into photoreceptors and bipolar cells.These findings suggest that bone marrow mesenchymal stem cell-derived small extracellular vesicles potentiate the therapeutic efficacy of retinal progenitor cells in retinal degeneration by promoting their survival and differentiation.
文摘Bone regeneration for non-load-bearing defects remains a significant clinical challenge requiring advanced biomaterials and cellular strategies.Adiposederived mesenchymal stem cells(AD-MSCs)have garnered significant interest in bone tissue engineering(BTE)because of their abundant availability,minimally invasive harvesting procedures,and robust differentiation potential into osteogenic lineages.Unlike bone marrow-derived mesenchymal stem cells,AD-MSCs can be easily obtained in large quantities,making them appealing alternatives for therapeutic applications.This review explores hydrogels containing polymers,such as chitosan,collagen,gelatin,and hyaluronic acid,and their composites,tailored for BTE,and emphasizes the importance of these hydrogels as scaffolds for the delivery of AD-MSCs.Various hydrogel fabrication techniques and biocompatibility assessments are discussed,along with innovative modifications to enhance osteogenesis.This review also briefly outlines AD-MSC isolation methods and advanced embedding techniques for precise cell placement,such as direct encapsulation and three-dimensional bioprinting.We discuss the mechanisms of bone regeneration in the AD-MSC-laden hydrogels,including osteoinduction,vascularization,and extracellular matrix remodeling.We also review the preclinical and clinical applications of AD-MSC-hydrogel systems,emphasizing their success and limitations.In this review,we provide a comprehensive overview of AD-MSC-based hydrogel systems to guide the development of effective therapies for bone regeneration.
文摘A recently published prospective study marks a breakthrough for congenital olfactory disorders in children.The study provides the first long-term,three-year follow-up data,robustly demonstrating the durable efficacy and safety of autologous nasal epithelial stem cell transplantation.This work reveals immense therapeutic potential for a condition traditionally considered untreatable.However,this milestone achievement also presents new challenges.To translate this pioneering therapy from a single-center success to a global standard,multicenter,controlled clinical trials must be initiated immediately.Only through rigorous validation can we ensure its widespread adoption and ultimately bring hope to millions of children worldwide.
基金the Ministry of Science and Technology Taiwan,No.MOST 109-2314-B-182A-091,No.NSTC 112-2314-B-182A-062, No.NSTC 113-2314-B-182A-125.
文摘BACKGROUND The incidence of diabetic atherosclerosis(DMA)is increasing worldwide,but its pathogenesis remains incompletely understood.In addition to cardiovascular complications,bladder dysfunction is one of the common comorbidities associated with DMA but is often refractory to current treatments.AIM To investigate the therapeutic effect of human amniotic fluid stem cell-derived extracellular vesicles(hAFSC-EVs)on the recovery of bladder dysfunction in DMA rats.METHODS Eighty rats were divided into normal control,streptozotocin-induced diabetic rats,diabetic rats subjected to arterial balloon endothelial injury of common iliac artery(DMA),and DMA rats treated with hAFSC-EVs(DMA+hAFSC-EVs).At 4 weeks and 12 weeks after DMA induction,levels of blood glucose,total cholesterol,triglyceride,high-density lipoprotein cholesterol,low-density lipoprotein cholesterol,homeostasis model assessment(HOMA)-insulin resistance,and HOMA-βwere measured.Cystometry,common iliac artery wall thickness,and bladder tumor necrosis factor(TNF)-α,interleukin(IL)-6,transforming growth factor(TGF)-β1,Smad3,connective tissue growth factor(CTGF)and fibronectin were also evaluated.RESULTS Bladder weight and blood glucose,triglyceride,HOMA-insulin resistance,common iliac artery intima thickness,voided volume,intercontraction interval,bladder capacity,and mRNA expression of TNF-α,IL-6,TGF-β1,Smad3,CTGF and fibronectin were significantly increased at 4 weeks and 12 weeks after induction,while the HOMA-βlevel decreased at 4 weeks and 12 weeks,and the high-density lipoprotein cholesterol level decreased at 12 weeks.hAFSC-EVs treatment in DMA rats significantly reduced bladder weight and blood glucose,thickness of common iliac arterial intima,voided volume,intercontraction interval and bladder capacity at 4 weeks.The mRNA expression of TNF-α,TGF-β1,and CTGF in DMA rats treated with hAFSC-EVs were significantly decreased at 4 weeks,while the mRNA expressions of IL-6 and Smad3 were significantly decreased 12 weeks.CONCLUSION hAFSC-EVs treatment can help restore DMA-induced bladder dysfunction,which is associated with lowered blood glucose levels,reduced arterial wall thickness,and decreased TNF-α,IL-6,TGF-β1,Smad3,and CTGF expression.
基金supported by the National Natural Science Foundation of China,No.32171356(to YW)Self-Support Research Projects of Shihezi University,No.ZZZC2021105(to WJ)+1 种基金Capital Medical University Natural Science Cultivation Fund,No.PYZ23044(to FQM)Beijing Municipal Natural Science Foundation,No.7244410(to JHD)。
文摘Previous research has demonstrated the feasibility of repairing nerve defects through acellular allogeneic nerve grafting with bone marrow mesenchymal stem cells.However,adult tissue–derived mesenchymal stem cells encounter various obstacles,including limited tissue sources,invasive acquisition methods,cellular heterogeneity,purification challenges,cellular senescence,and diminished pluripotency and proliferation over successive passages.In this study,we used induced pluripotent stem cell-derived mesenchymal stem cells,known for their self-renewal capacity,multilineage differentiation potential,and immunomodulatory characteristics.We used induced pluripotent stem cell-derived mesenchymal stem cells in conjunction with acellular nerve allografts to address a 10 mm-long defect in a rat model of sciatic nerve injury.Our findings reveal that induced pluripotent stem cell-derived mesenchymal stem cells exhibit survival for up to 17 days in a rat model of peripheral nerve injury with acellular nerve allograft transplantation.Furthermore,the combination of acellular nerve allograft and induced pluripotent stem cell-derived mesenchymal stem cells significantly accelerates the regeneration of injured axons and improves behavioral function recovery in rats.Additionally,our in vivo and in vitro experiments indicate that induced pluripotent stem cell-derived mesenchymal stem cells play a pivotal role in promoting neovascularization.Collectively,our results suggest the potential of acellular nerve allografts with induced pluripotent stem cell-derived mesenchymal stem cells to augment nerve regeneration in rats,offering promising therapeutic strategies for clinical translation.
基金supported by the National Natural Science Foundation of China,No.22103055(to JG)the Natural Science Foundation of Hebei Province,No.F2024110001(to HC)Open Project of Tianjin Key Laboratory of Optoelectronic Detection Technology and System,Nos.2024LODTS215(to NL),2024LODTS216(to XS).
文摘In recent years,exosomes have garnered extensive attention as therapeutic agents and early diagnostic markers in neurodegenerative disease research.Exosomes are small and can effectively cross the blood-brain barrier,allowing them to target deep brain lesions.Recent studies have demonstrated that exosomes derived from different cell types may exert therapeutic effects by regulating the expression of various inflammatory cytokines,mRNAs,and disease-related proteins,thereby halting the progression of neurodegenerative diseases and exhibiting beneficial effects.However,exosomes are composed of lipid bilayer membranes and lack the ability to recognize specific target cells.This limitation can lead to side effects and toxicity when they interact with non-specific cells.Growing evidence suggests that surface-modified exosomes have enhanced targeting capabilities and can be used as targeted drug-delivery vehicles that show promising results in the treatment of neurodegenerative diseases.In this review,we provide an up-to-date overview of existing research aimed at devising approaches to modify exosomes and elucidating their therapeutic potential in neurodegenerative diseases.Our findings indicate that exosomes can efficiently cross the blood-brain barrier to facilitate drug delivery and can also serve as early diagnostic markers for neurodegenerative diseases.We introduce the strategies being used to enhance exosome targeting,including genetic engineering,chemical modifications(both covalent,such as click chemistry and metabolic engineering,and non-covalent,such as polyvalent electrostatic and hydrophobic interactions,ligand-receptor binding,aptamer-based modifications,and the incorporation of CP05-anchored peptides),and nanomaterial modifications.Research into these strategies has confirmed that exosomes have significant therapeutic potential for neurodegenerative diseases.However,several challenges remain in the clinical application of exosomes.Improvements are needed in preparation,characterization,and optimization methods,as well as in reducing the adverse reactions associated with their use.Additionally,the range of applications and the safety of exosomes require further research and evaluation.
基金National Natural Science Foundation of China,No.82003223and China Postdoctoral Science Foundation,No.2020M671398.
文摘BACKGROUND Gastric cancer(GC)is one of the most common malignant tumors of the digestive system worldwide,the prognosis of patients with advanced GC remains poor.AIM To evaluate the combined expression characteristics of cancer stem cell markers CD24 and CD133 in GC pathological tissues,and to explore their association with patients’clinicopathological parameters and postoperative survival outcomes.METHODS A total of 304 GC patients who underwent surgical treatment in our hospital from January 2018 to January 2020 were retrospectively included.Immunohistochemistry was used to detect the protein expression of CD24 and CD133 in tumor tissues,adjacent tissues,and normal gastric mucosa tissues.Based on staining intensity and the proportion of positive cells,expression levels were classified into low and high expression,while clinicopathological parameters were recorded.χ2 test was used to evaluate the correlation between expression and categorical variables,Spearman rank correlation analysis was performed to assess the correlation between the expression intensities of the two markers,and multivariate regression models were applied to identify independent risk factors influencing co-expression.Kaplan-Meier survival curves and Log-rank test were used to compare survival differences among groups with different expression patterns.RESULTS Among the 304 patients,155 cases(50.99%)were CD24 positive,including 91 low-expression and 64 highexpression;133 cases(43.75%)were CD133 positive,including 81 low-expression and 52 high-expression.There were 74 cases(24.34%)with double positivity and 81 cases(26.64%)with double negativity.Compared with tumor tissues,the positive rates of CD24 and CD133 in normal gastric tissues and adjacent tissues were significantly lower(P<0.05).Univariate analysis showed that co-expression of CD24 and CD133 in GC tissues was significantly correlated with tumor size,Lauren classification,T stage,N stage,and vascular invasion(P<0.05),but not with patient age,gender,tumor site,World Health Organization histological classification,or M stage(P>0.05).Further multivariate regression analysis suggested that tumor size,T stage,N stage,and vascular invasion were independent risk factors promoting CD24 and CD133 double positivity.Spearman rank correlation analysis indicated a moderate positive correlation between their expression intensities(r=0.420,P<0.001).During follow-up,29 of 304 patients were lost(loss rate 9.54%);146 deaths occurred.According to expression combination,there were 89 cases of CD24 single positivity(39 deaths),68 cases of CD133 single positivity(31 deaths),81 cases of double negativity(25 deaths),and 66 cases of double positivity(51 deaths).Log-rank test showed significant differences in overall survival among the four groups(χ2=20.89,P<0.001),with CD24+/CD133+group showing the worst prognosis.CONCLUSION CD24 and CD133 exhibit high positive detection rates in GC tissues,and their co-positivity is closely associated with tumor stage progression and significantly indicates unfavorable survival outcomes.The co-expression of CD24/CD133 may reflect higher aggressiveness and metastatic potential of GC,serving as a potential prognostic marker and a direction for targeted therapeutic strategies.However,as this is a single-center retrospective study with limitations such as patient loss to follow-up and sample size,further prospective,multicenter,and mechanistic studies are required to validate its clinical applicability and biological role.
基金supported by NIH grants,Nos.R01NS125074,R01AG083164,R01NS107365,and R21NS127177(to YL),1F31NS129204-01A1(to KW)and Albert Ryan Fellowship(to KW).
文摘Adult neurogenesis continuously produces new neurons critical for cognitive plasticity in adult rodents.While it is known transforming growth factor-βsignaling is important in embryonic neurogenesis,its role in postnatal neurogenesis remains unclear.In this study,to define the precise role of transforming growth factor-βsignaling in postnatal neurogenesis at distinct stages of the neurogenic cascade both in vitro and in vivo,we developed two novel inducible and cell type-specific mouse models to specifically silence transforming growth factor-βsignaling in neural stem cells in(mGFAPcre-ALK5fl/fl-Ai9)or immature neuroblasts in(DCXcreERT2-ALK5fl/fl-Ai9).Our data showed that exogenous transforming growth factor-βtreatment led to inhibition of the proliferation of primary neural stem cells while stimulating their migration.These effects were abolished in activin-like kinase 5(ALK5)knockout primary neural stem cells.Consistent with this,inhibition of transforming growth factor-βsignaling with SB-431542 in wild-type neural stem cells stimulated proliferation while inhibited the migration of neural stem cells.Interestingly,deletion of transforming growth factor-βreceptor in neural stem cells in vivo inhibited the migration of postnatal born neurons in mGFAPcre-ALK5fl/fl-Ai9 mice,while abolishment of transforming growth factor-βsignaling in immature neuroblasts in DCXcreERT2-ALK5fl/fl-Ai9 mice did not affect the migration of these cells in the hippocampus.In summary,our data supports a dual role of transforming growth factor-βsignaling in the proliferation and migration of neural stem cells in vitro.Moreover,our data provides novel insights on cell type-specific-dependent requirements of transforming growth factor-βsignaling on neural stem cell proliferation and migration in vivo.
