Stem volume estimation is crucial in forest ecology and management,particularly for timber harvesting strategies and carbon stock assessments.This study aimed to develop a variable-exponent taper equation specifically...Stem volume estimation is crucial in forest ecology and management,particularly for timber harvesting strategies and carbon stock assessments.This study aimed to develop a variable-exponent taper equation specifically tailored to savanna tree species using close-range photogrammetry(CRP)data and to evaluate its performance against conventional volume equations for stem volume estimation.A dataset of 30 trees across five dominant savanna species was used to fit the taper model,which was validated using a separate dataset of 322 trees from 14 species.The results demonstrated significant improvements in volume estimation accuracy when using the taper equation.At the tree level,the root mean square error(RMSE)decreased by 47%,from 598 to 319 dm^(3),and the mean absolute bias(MAB)by 48%,from 328 to 172 dm3,compared to volume equations.Similarly,at the plot level,RMSE was reduced by 42% and MAB by 40%.The model performed well for species with regular forms.However,species with irregular tapers exhibited higher errors,reflecting the challenges of modeling stem forms of mixed species.The use of CRP proved valuable,providing high-resolution diameter measurements that improved model parameterization.This study underscores the importance of advanced data collection methods for enhancing taper model accuracy and suggests that further species-specific adjustments are needed to improve performance for species with irregular forms.The findings support the broader application of taper equations for improving stem volume estimates in savanna ecosystems,contributing to better forest management and resource monitoring practices.展开更多
Accurate and efficient estimation of forest growth and live biomass is a critical element in assessing potential responses to forest management and environmental change. The objective of this study was to develop mode...Accurate and efficient estimation of forest growth and live biomass is a critical element in assessing potential responses to forest management and environmental change. The objective of this study was to develop models to predict longleaf pine tree diameter at breast height （dbh） and merchantable stem volume （V） using data obtained from field measurements. We used longleaf pine tree data from 3,376 planted trees on 127 permanent plots located in the U.S. Gulf Coastal Plain region to fit equations to predict dbh and V as functions of tree height （H） and crown area （CA）. Prediction of dbh as a function of H improved when CA was added as an additional independent variable. Similarly, predic- tions of V based on H improved when CA was included. Incorporation of additional stand variables such as age, site index, dominant height, and stand density were also evaluated but resulted in only small improvements in model performance. For model testing we used data from planted and naturally-regenerated trees located inside and outside the geographic area used for model fitting. Our results suggest that the models are a robust alternative for dbh and V estimations when H and CA are known on planted stands with potential for naturally-regenerated stands, across a wide range of ages. We discuss the importance of these models for use with metrics derived from remote sensing data.展开更多
This study presents the utility of remote sensing （RS）, GIS and field observation data to estimate above ground biomass （AGB） and stem volume over tropical forest environment. Application of those data for the mod...This study presents the utility of remote sensing （RS）, GIS and field observation data to estimate above ground biomass （AGB） and stem volume over tropical forest environment. Application of those data for the modeling of forest properties is site specific and highly uncertain, thus further study is encouraged. In this study we used 1460 sampling plots collected in 16 transects measuring tree diameter （DBH） and other forest properties which were useful for the biomass assessment. The study was carded out in tropical forest region in East Kalimantan, Indo- nesia. The AGB density was estimated applying an existing DBH - biomass equation. The estimate was superimposed over the modified GIS map of the study area, and the biomass density of each land cover was calculated. The RS approach was performed using a subset of sample data to develop the AGB and stem volume linear equation models. Pearson correlation statistics test was conducted using ETM bands reflectance, vegetation indices, image transform layers, Principal Component Analysis （PCA） bands, Tasseled Cap （TC）, Grey Level Co-Occurrence Matrix （GLCM） texture features and DEM data as the predictors. Two linear models were generated from the significant RS data. To analyze total biomass and stem volume of each land cover, Landsat ETM images from 2000 and 2003 were preprocessed, classified using maximum likelihood method, and filtered with the majority analysis. We found 158±16 m^3.ha^-1 of stem volume and 168±15 t.ha^-1 of AGB estimated from RS approach, whereas the field measurement and GIS estimated 157±92 m^3.ha^-1 and 167±94 t.ha^-1 of stem volume and AGB, respectively. The dynamics of biomass abundance from 2000 to 2003 were assessed from multi temporal ETM data and we found a slightly declining trend of total biomass over these periods. Remote sensing approach estimated lower biomass abundance than did the GIS and field measurement data. The earlier approach predicted 10.5 Gt and 10.3 Gt of total biomasses in 2000 and 2003, while the later estimated 11.9 Gt and 11.6 Gt of total biomasses, respectively. We found that GLCM mean texture features showed markedly strong correlations with stem volume and biomass.展开更多
In this study, compatible taper and stem volume equations were developed for Larix kaempferi species of South Korea. The dataset was split into two groups： 80% of the data were used in model fitting and the remaining...In this study, compatible taper and stem volume equations were developed for Larix kaempferi species of South Korea. The dataset was split into two groups： 80% of the data were used in model fitting and the remaining 2o% were used for validation. The compatible MB76 equations were used to predict the diameter outside bark to a specific height, the height to a specific diameter and the stem volume of the species. The result of the stem volume analysis was compared with the existing stem volume model of Larix kaempferi species of South Korea which was developed by the Korea Forest Research Institute and with a simple volume model that was developed with fitting dataset in this study. The compatible model provided accurate prediction of the total stem volume when compared to the existing stem volume model and with a simple volume model. It is concluded that the compatible taper and stem volume equations are more convenient to use and therefore it is recommended to be applied in the Larix kaempferi species of South Korea.展开更多
Recent applications of digital photogrammetry in forestry have highlighted its utility as a viable mensuration technique.However,in tropical regions little research has been done on the accuracy of this approach for s...Recent applications of digital photogrammetry in forestry have highlighted its utility as a viable mensuration technique.However,in tropical regions little research has been done on the accuracy of this approach for stem volume calculation.In this study,the performance of Structure from Motion photogrammetry for estimating individual tree stem volume in relation to traditional approaches was evaluated.We selected 30 trees from five savanna species growing at the periphery of the W National Park in northern Benin and measured their circumferences at different heights using traditional tape and clinometer.Stem volumes of sample trees were estimated from the measured circumferences using nine volumetric formulae for solids of revolution,including cylinder,cone,paraboloid,neiloid and their respective fustrums.Each tree was photographed and stem volume determined using a taper function derived from tri-dimensional stem models.This reference volume was compared with the results of formulaic estimations.Tree stem profiles were further decomposed into different portions,approximately corresponding to the stump,butt logs and logs,and the suitability of each solid of revolution was assessed for simulating the resulting shapes.Stem volumes calculated using the fustrums of paraboloid and neiloid formulae were the closest to reference volumes with a bias and root mean square error of 8.0%and 24.4%,respectively.Stems closely resembled fustrums of a paraboloid and a neiloid.Individual stem portions assumed different solids as follows:fustrums of paraboloid and neiloid were more prevalent from the stump to breast height,while a paraboloid closely matched stem shapes beyond this point.Therefore,a more accurate stem volumetric estimate was attained when stems were considered as a composite of at least three geometric solids.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
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
Stem cells are pluripotent cells that can divide and differentiate,forming many different types of cells.Stem cells can be obtained from various sources,with embryonic stem cells being the most advantageous as they po...Stem cells are pluripotent cells that can divide and differentiate,forming many different types of cells.Stem cells can be obtained from various sources,with embryonic stem cells being the most advantageous as they possess a broad dividing potential.When the standard treatment proves ineffective,stem cells are typically utilized as a final option.Infections and childhood malignancies are among the significant causes of mortality in the pediatric population.Stem cell therapy has shown a decrease in morbidity and mortality when used in patients with favorable conditions like young age and lack of comorbidities.This review discusses how stem cells are prepared and used in treating pediatric diseases like X-linked agammaglobulinemia,diabetes mellitus,aplastic anemia,infections,and leukemia.Technological advancement has played a significant role in producing more specific stem cells using genetic modification methods like clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9,which produce stem cells that target a particular cell type,e.g.,myocytes and hematopoietic cells,further increasing the effectiveness of the therapy.We address the obstacles faced when conducting research related to stem cells,including ethical and legal issues,which hinder the use of this therapy in some fields.We also indicate recommendations for increasing the efficacy of stem cell therapy in the pediatric population.展开更多
Myelosuppression is a common and severe side effect of cancer chemotherapy,with current treatments hindered by limitations such as depletion of hematopoietic reserves,poor patient compliance,delayed therapeutic onset,...Myelosuppression is a common and severe side effect of cancer chemotherapy,with current treatments hindered by limitations such as depletion of hematopoietic reserves,poor patient compliance,delayed therapeutic onset,and high cost.To overcome these challenges,we developed Epimedium-derived nanovesicles(ENVs)from the traditional Chinese medicinal herb Epimedium,addressing the solubility and bioavailability issues associated with conventional extracts.ENVs encapsulate bioactive constituents,including icariin and hematopoiesis-promoting ceramides.In a cyclophosphamide(CTX)-induced myelosuppression mouse model,prophylactic and therapeutic oral administration of ENVs effectively alleviated hematopoietic suppression,significantly outperforming the Epimedium-based herbal extract“Joungal”(Shengbai Formula)despite equivalent icariin content.Notably,ENVs promoted hematopoietic stem cell(HSC)proliferation—an outcome rarely achieved with existing therapies.Mechanistically,ENVs modulated the gut microbiota,enriching lactobacillus species and enhancing lactate production.This microbiota-driven lactate signaling stimulated LepR+mesenchymal stem cells(MSCs)in the bone marrow niche to secrete stromal cellderived factor-1(SDF-1)and stem cell factor(SCF),thereby supporting HSC expansion and restoring hematopoietic function.In vivo safety evaluations confirmed the excellent biocompatibility of ENVs.Our findings uncover a gut-lactate-bone marrow axis through which ENVs enhance hematopoiesis and promote HSC regeneration.This work introduces a cost-effective,scalable,and orally administrable biomaterial platform with strong translational potential for the prevention and treatment of chemotherapy-induced myelosuppression.展开更多
Effective control of inflammatory cytokines is crucial for controlling ankylosing spondylitis(AS).However,due to the complexity of cytokine networks,current therapies targeting individual cytokines often fall short of...Effective control of inflammatory cytokines is crucial for controlling ankylosing spondylitis(AS).However,due to the complexity of cytokine networks,current therapies targeting individual cytokines often fall short of achieving satisfactory outcomes.Here,we developed mesenchymal stem cell(MSC)-like nanodecoys(denoted“MSC-NDs”)and evaluated their potential as a versatile anti-inflammatory therapeutic for AS.To improve membrane yield,microvesicles derived from MSCs via cytochalasin B(CB)stimulation were employed as substitutes for traditional membrane extractions.Proteomic analysis confirmed that CBinduced microvesicles retained a membrane protein profile comparable to that of conventionally isolated MSC membranes,while offering over twice the production efficiency.The resulting MSC-NDs effectively neutralized multiple proinflammatory cytokines and suppressed cytokine-induced osteogenic differentiation of MSCs in vitro.In a mouse model of AS,MSC-NDs significantly reduced systemic cytokine levels and effectively delayed pathological new bone formation.RNA sequencing of lumbar spine tissue further revealed widespread downregulation of genes involved in bone metabolism and inflammation.These findings underscore the therapeutic potential of MSC-like nanodecoys as a versatile anti-inflammatory platform for the treatment of AS and potentially other inflammatory disorders.展开更多
基金partially funded by the International Foundation for Science(Grant No:I-1-D-6066-1).
文摘Stem volume estimation is crucial in forest ecology and management,particularly for timber harvesting strategies and carbon stock assessments.This study aimed to develop a variable-exponent taper equation specifically tailored to savanna tree species using close-range photogrammetry(CRP)data and to evaluate its performance against conventional volume equations for stem volume estimation.A dataset of 30 trees across five dominant savanna species was used to fit the taper model,which was validated using a separate dataset of 322 trees from 14 species.The results demonstrated significant improvements in volume estimation accuracy when using the taper equation.At the tree level,the root mean square error(RMSE)decreased by 47%,from 598 to 319 dm^(3),and the mean absolute bias(MAB)by 48%,from 328 to 172 dm3,compared to volume equations.Similarly,at the plot level,RMSE was reduced by 42% and MAB by 40%.The model performed well for species with regular forms.However,species with irregular tapers exhibited higher errors,reflecting the challenges of modeling stem forms of mixed species.The use of CRP proved valuable,providing high-resolution diameter measurements that improved model parameterization.This study underscores the importance of advanced data collection methods for enhancing taper model accuracy and suggests that further species-specific adjustments are needed to improve performance for species with irregular forms.The findings support the broader application of taper equations for improving stem volume estimates in savanna ecosystems,contributing to better forest management and resource monitoring practices.
基金supported by the U.S.Department of Defense,through the Strategic Environmental Research and Development Program(SERDP)
文摘Accurate and efficient estimation of forest growth and live biomass is a critical element in assessing potential responses to forest management and environmental change. The objective of this study was to develop models to predict longleaf pine tree diameter at breast height （dbh） and merchantable stem volume （V） using data obtained from field measurements. We used longleaf pine tree data from 3,376 planted trees on 127 permanent plots located in the U.S. Gulf Coastal Plain region to fit equations to predict dbh and V as functions of tree height （H） and crown area （CA）. Prediction of dbh as a function of H improved when CA was added as an additional independent variable. Similarly, predic- tions of V based on H improved when CA was included. Incorporation of additional stand variables such as age, site index, dominant height, and stand density were also evaluated but resulted in only small improvements in model performance. For model testing we used data from planted and naturally-regenerated trees located inside and outside the geographic area used for model fitting. Our results suggest that the models are a robust alternative for dbh and V estimations when H and CA are known on planted stands with potential for naturally-regenerated stands, across a wide range of ages. We discuss the importance of these models for use with metrics derived from remote sensing data.
文摘This study presents the utility of remote sensing （RS）, GIS and field observation data to estimate above ground biomass （AGB） and stem volume over tropical forest environment. Application of those data for the modeling of forest properties is site specific and highly uncertain, thus further study is encouraged. In this study we used 1460 sampling plots collected in 16 transects measuring tree diameter （DBH） and other forest properties which were useful for the biomass assessment. The study was carded out in tropical forest region in East Kalimantan, Indo- nesia. The AGB density was estimated applying an existing DBH - biomass equation. The estimate was superimposed over the modified GIS map of the study area, and the biomass density of each land cover was calculated. The RS approach was performed using a subset of sample data to develop the AGB and stem volume linear equation models. Pearson correlation statistics test was conducted using ETM bands reflectance, vegetation indices, image transform layers, Principal Component Analysis （PCA） bands, Tasseled Cap （TC）, Grey Level Co-Occurrence Matrix （GLCM） texture features and DEM data as the predictors. Two linear models were generated from the significant RS data. To analyze total biomass and stem volume of each land cover, Landsat ETM images from 2000 and 2003 were preprocessed, classified using maximum likelihood method, and filtered with the majority analysis. We found 158±16 m^3.ha^-1 of stem volume and 168±15 t.ha^-1 of AGB estimated from RS approach, whereas the field measurement and GIS estimated 157±92 m^3.ha^-1 and 167±94 t.ha^-1 of stem volume and AGB, respectively. The dynamics of biomass abundance from 2000 to 2003 were assessed from multi temporal ETM data and we found a slightly declining trend of total biomass over these periods. Remote sensing approach estimated lower biomass abundance than did the GIS and field measurement data. The earlier approach predicted 10.5 Gt and 10.3 Gt of total biomasses in 2000 and 2003, while the later estimated 11.9 Gt and 11.6 Gt of total biomasses, respectively. We found that GLCM mean texture features showed markedly strong correlations with stem volume and biomass.
基金the Korea Forest Service for funding this research(Project No.S211316L020130)
文摘In this study, compatible taper and stem volume equations were developed for Larix kaempferi species of South Korea. The dataset was split into two groups： 80% of the data were used in model fitting and the remaining 2o% were used for validation. The compatible MB76 equations were used to predict the diameter outside bark to a specific height, the height to a specific diameter and the stem volume of the species. The result of the stem volume analysis was compared with the existing stem volume model of Larix kaempferi species of South Korea which was developed by the Korea Forest Research Institute and with a simple volume model that was developed with fitting dataset in this study. The compatible model provided accurate prediction of the total stem volume when compared to the existing stem volume model and with a simple volume model. It is concluded that the compatible taper and stem volume equations are more convenient to use and therefore it is recommended to be applied in the Larix kaempferi species of South Korea.
基金The work was supported by the International Foundation for Science(Grant No:I-1-D-60661).
文摘Recent applications of digital photogrammetry in forestry have highlighted its utility as a viable mensuration technique.However,in tropical regions little research has been done on the accuracy of this approach for stem volume calculation.In this study,the performance of Structure from Motion photogrammetry for estimating individual tree stem volume in relation to traditional approaches was evaluated.We selected 30 trees from five savanna species growing at the periphery of the W National Park in northern Benin and measured their circumferences at different heights using traditional tape and clinometer.Stem volumes of sample trees were estimated from the measured circumferences using nine volumetric formulae for solids of revolution,including cylinder,cone,paraboloid,neiloid and their respective fustrums.Each tree was photographed and stem volume determined using a taper function derived from tri-dimensional stem models.This reference volume was compared with the results of formulaic estimations.Tree stem profiles were further decomposed into different portions,approximately corresponding to the stump,butt logs and logs,and the suitability of each solid of revolution was assessed for simulating the resulting shapes.Stem volumes calculated using the fustrums of paraboloid and neiloid formulae were the closest to reference volumes with a bias and root mean square error of 8.0%and 24.4%,respectively.Stems closely resembled fustrums of a paraboloid and a neiloid.Individual stem portions assumed different solids as follows:fustrums of paraboloid and neiloid were more prevalent from the stump to breast height,while a paraboloid closely matched stem shapes beyond this point.Therefore,a more accurate stem volumetric estimate was attained when stems were considered as a composite of at least three geometric solids.
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.
文摘Stem cells are pluripotent cells that can divide and differentiate,forming many different types of cells.Stem cells can be obtained from various sources,with embryonic stem cells being the most advantageous as they possess a broad dividing potential.When the standard treatment proves ineffective,stem cells are typically utilized as a final option.Infections and childhood malignancies are among the significant causes of mortality in the pediatric population.Stem cell therapy has shown a decrease in morbidity and mortality when used in patients with favorable conditions like young age and lack of comorbidities.This review discusses how stem cells are prepared and used in treating pediatric diseases like X-linked agammaglobulinemia,diabetes mellitus,aplastic anemia,infections,and leukemia.Technological advancement has played a significant role in producing more specific stem cells using genetic modification methods like clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9,which produce stem cells that target a particular cell type,e.g.,myocytes and hematopoietic cells,further increasing the effectiveness of the therapy.We address the obstacles faced when conducting research related to stem cells,including ethical and legal issues,which hinder the use of this therapy in some fields.We also indicate recommendations for increasing the efficacy of stem cell therapy in the pediatric population.
基金supported by National Natural Science Foundation of China(Nos.82104445 and 82470182]Basic Scientific Research Funds of Department of Education of Zhejiang Province(No.KYZD2024013)+2 种基金The Startup Foundation of Zhejiang Provincial People’s Hospital(Nos.C-2023-QDJJ12 and C-2024-ZZJJ05)Science and Technology Plan Project of Traditional Chinese Medicine in Zhejiang Province(No.2025ZR007)The National Administration of Traditional Chinese Medicine(No.GZY-ZJ-KJ-24044).
文摘Myelosuppression is a common and severe side effect of cancer chemotherapy,with current treatments hindered by limitations such as depletion of hematopoietic reserves,poor patient compliance,delayed therapeutic onset,and high cost.To overcome these challenges,we developed Epimedium-derived nanovesicles(ENVs)from the traditional Chinese medicinal herb Epimedium,addressing the solubility and bioavailability issues associated with conventional extracts.ENVs encapsulate bioactive constituents,including icariin and hematopoiesis-promoting ceramides.In a cyclophosphamide(CTX)-induced myelosuppression mouse model,prophylactic and therapeutic oral administration of ENVs effectively alleviated hematopoietic suppression,significantly outperforming the Epimedium-based herbal extract“Joungal”(Shengbai Formula)despite equivalent icariin content.Notably,ENVs promoted hematopoietic stem cell(HSC)proliferation—an outcome rarely achieved with existing therapies.Mechanistically,ENVs modulated the gut microbiota,enriching lactobacillus species and enhancing lactate production.This microbiota-driven lactate signaling stimulated LepR+mesenchymal stem cells(MSCs)in the bone marrow niche to secrete stromal cellderived factor-1(SDF-1)and stem cell factor(SCF),thereby supporting HSC expansion and restoring hematopoietic function.In vivo safety evaluations confirmed the excellent biocompatibility of ENVs.Our findings uncover a gut-lactate-bone marrow axis through which ENVs enhance hematopoiesis and promote HSC regeneration.This work introduces a cost-effective,scalable,and orally administrable biomaterial platform with strong translational potential for the prevention and treatment of chemotherapy-induced myelosuppression.
基金supported by funding from the Science and Technology Planning Project of Guangdong Province(No.2023B1111030002)the Guangdong Clinical Research Center of Immune disease(No.2020B1111170008).
文摘Effective control of inflammatory cytokines is crucial for controlling ankylosing spondylitis(AS).However,due to the complexity of cytokine networks,current therapies targeting individual cytokines often fall short of achieving satisfactory outcomes.Here,we developed mesenchymal stem cell(MSC)-like nanodecoys(denoted“MSC-NDs”)and evaluated their potential as a versatile anti-inflammatory therapeutic for AS.To improve membrane yield,microvesicles derived from MSCs via cytochalasin B(CB)stimulation were employed as substitutes for traditional membrane extractions.Proteomic analysis confirmed that CBinduced microvesicles retained a membrane protein profile comparable to that of conventionally isolated MSC membranes,while offering over twice the production efficiency.The resulting MSC-NDs effectively neutralized multiple proinflammatory cytokines and suppressed cytokine-induced osteogenic differentiation of MSCs in vitro.In a mouse model of AS,MSC-NDs significantly reduced systemic cytokine levels and effectively delayed pathological new bone formation.RNA sequencing of lumbar spine tissue further revealed widespread downregulation of genes involved in bone metabolism and inflammation.These findings underscore the therapeutic potential of MSC-like nanodecoys as a versatile anti-inflammatory platform for the treatment of AS and potentially other inflammatory disorders.
