Periodontal bone defects,primarily caused by periodontitis,are highly prevalent in clinical settings and manifest as bone fenestration,dehiscence,or attachment loss,presenting a significant challenge to oral health.In...Periodontal bone defects,primarily caused by periodontitis,are highly prevalent in clinical settings and manifest as bone fenestration,dehiscence,or attachment loss,presenting a significant challenge to oral health.In regenerative medicine,harnessing developmental principles for tissue repair offers promising therapeutic potential.Of particular interest is the condensation of progenitor cells,an essential event in organogenesis that has inspired clinically effective cell aggregation approaches in dental regeneration.However,the precise cellular coordination mechanisms during condensation and regeneration remain elusive.Here,taking the tooth as a model organ,we employed single-cell RNA sequencing to dissect the cellular composition and heterogeneity of human dental follicle and dental papilla,revealing a distinct Platelet-derived growth factor receptor alpha(PDGFRA)mesenchymal stem/stromal cell(MSC)population with remarkable odontogenic potential.Interestingly,a reciprocal paracrine interaction between PDGFRA^(+)dental follicle stem cells(DFSCs)and CD31^(+)Endomucin^(+)endothelial cells(ECs)was mediated by Vascular endothelial growth factor A(VEGFA)and Platelet-derived growth factor subunit BB(PDGFBB).This crosstalk not only maintains the functionality of PDGFRA^(+)DFSCs but also drives specialized angiogenesis.In vivo periodontal bone regeneration experiments further reveal that communication between PDGFRA+DFSC aggregates and recipient ECs is essential for effective angiogenic-osteogenic coupling and rapid tissue repair.Collectively,our results unravel the importance of MSC-EC crosstalk mediated by the VEGFA and PDGFBB-PDGFRA reciprocal signaling in orchestrating angiogenesis and osteogenesis.These findings not only establish a framework for deciphering and promoting periodontal bone regeneration in potential clinical applications but also offer insights for future therapeutic strategies in dental or broader regenerative medicine.展开更多
BACKGROUND Fibro-adipogenic progenitors(FAPs)are a group of mesenchymal stem cells that cause fibro-fatty degeneration in skeletal muscle in various chronic disease mode-ls.FAPs also play a role in preventing muscle d...BACKGROUND Fibro-adipogenic progenitors(FAPs)are a group of mesenchymal stem cells that cause fibro-fatty degeneration in skeletal muscle in various chronic disease mode-ls.FAPs also play a role in preventing muscle degeneration at acute stages during disease progression.However,few studies have reported the changes in and function of FAPs in the acute phase after tendon rupture.AIM To clarify the changes in the number of FAPs and their impact on skeletal muscle soon after tendon rupture to facilitate future studies targeting FAPs to treat muscle degeneration.METHODS We utilized Pdgfra-H2B::eGFP mice to trace and quantify FAPs in a tibialis anterior tenotomy(TAT)model at 0 and 3 days,1 week,2 weeks,3 weeks,4 weeks,5 weeks,and 6 weeks post-injury,and the results were further validated using fluorescence-activated cell sorting analysis with C57BL/6 mice at the same post-injury timepoints.We subsequently used PdgfraCreERT::RosaDTA mice,and evaluated the severity of post-TAT skeletal muscle degeneration with or without FAP-depletion.RESULTS The number of FAPs peaked at 1 week post-TAT before gradually declining to a level comparable to that pre-TAT.The change in the number of FAPs was potentially temporally correlated with the progression of skeletal muscle degeneration after TAT.FAP-depletion led to more severe degeneration early after TAT,indicating that FAPs potentially alleviate muscle degeneration after tendon rupture in the early post-injury phase.CONCLUSION FAPs potentially alleviate the degeneration of skeletal muscle in the acute stage after tendon rupture.展开更多
AIM： To enrich hepatic progenitors using epithelial cell adhesion molecule （EpCAM） as a marker from human fetal liver and investigate the expression of human leukocyte antigen （HLA） and their markers associated w...AIM： To enrich hepatic progenitors using epithelial cell adhesion molecule （EpCAM） as a marker from human fetal liver and investigate the expression of human leukocyte antigen （HLA） and their markers associated with hepatic progenitor cells. METHODS： EpCAM ＋ve cells were isolated using magnetic cell sorting （MACS） from human fetuses （n = 10） at 15-25 wk gestation. Expression of markers for hepatic progenitors such as albumin, alpha-fetoprotein （AFP）, CD29 （integrin ~1）, CD49f （integrin c^6） and CD90 （Thy 1） was studied by using flow cytometry, immunocytochemistry and RT-PCR; HLA class Ⅰ （A, B, C） and class Ⅱ （DR） expression was studied by flow cytometry only. RESULTS： FACS analysis indicated that EpCAM ＋ve cells were positive for CD29, CD49f, CD90, CD34, HLA class I, albumin and AFP but negative for HLA class Ⅱ （DR） and CD45. RT PCR showed that EpCAM ＋ve cells expressed liver epithelial markers （CK18）, biliary specific marker （CK19） and hepatic markers （albumin, AFP）. On immunocytochemical staining, EpCAM ＋ve cells were shown positive signals for CK18 and albumin. CONCLUSION： Our study suggests that these EpCAM ＋ve cells can be used as hepatic progenitors for cell transplantation with a minimum risk of alloreactivity and these cells may serve as a potential source for enrichment of hepatic progenitor.展开更多
BACKGROUND Retinal organoids serve as excellent human-specific disease models for conditions affecting otherwise inaccessible retinal tissue from patients.They permit the isolation of key cell types affected in variou...BACKGROUND Retinal organoids serve as excellent human-specific disease models for conditions affecting otherwise inaccessible retinal tissue from patients.They permit the isolation of key cell types affected in various eye diseases including retinal ganglion cells(RGCs)and Müller glia.AIM To refine human-induced pluripotent stem cells(hiPSCs)differentiated into threedimensional(3D)retinal organoids to generate sufficient numbers of RGCs and Müller glia progenitors for downstream analyses.METHODS In this study we described,evaluated,and refined methods with which to generate Müller glia and RGC progenitors,isolated them via magnetic-activated cell sorting,and assessed their lineage stability after prolonged 2D culture.Putative progenitor populations were characterized via quantitative PCR and immunocytochemistry,and the ultrastructural composition of retinal organoid cells was investigated.RESULTS Our study confirms the feasibility of generating marker-characterized Müller glia and RGC progenitors within retinal organoids.Such retinal organoids can be dissociated and the Müller glia and RGC progenitor-like cells isolated via magnetic-activated cell sorting and propagated as monolayers.CONCLUSION Enrichment of Müller glia and RGC progenitors from retinal organoids is a feasible method with which to study cell type-specific disease phenotypes and to potentially generate specific retinal populations for cell replacement therapies.展开更多
Cellular transplantation for repair of spinal cord injury is a prom- ising therapeutic strategy that includes the use of a variety of neural and non-neural cells isolated or derived from embryonic and adult tissue as ...Cellular transplantation for repair of spinal cord injury is a prom- ising therapeutic strategy that includes the use of a variety of neural and non-neural cells isolated or derived from embryonic and adult tissue as well as embryonic stem cells and induced plu- ripotent stem cells. In particular, transplants of neural progenitor cells （NPCs） have been shown to limit secondary injury and scar formation and create a permissive environment in the injured spinal cord through the provision of neurotrophic molecules and growth supporting matrices that promote growth of injured host axons. Importantly, transplants of NPC are unique in their poten- tial to replace lost neural cells - including neurons, astrocytes,展开更多
BACKGROUND Chronic liver diseases(CLD)are the major public health burden due to the continuous increasing rate of global morbidity and mortality.The inherent limitations of organ transplantation have led to the develo...BACKGROUND Chronic liver diseases(CLD)are the major public health burden due to the continuous increasing rate of global morbidity and mortality.The inherent limitations of organ transplantation have led to the development of stem cell-based therapy as a supportive and promising therapeutic option.However,identifying the fate of transplanted cells in vivo represents a crucial obstacle.AIM To evaluate the potential applicability of DiD dye as a cell labeling agent for longterm,and non-invasive in vivo tracking of transplanted cells in the liver.METHODS Magnetically sorted,epithelial cell adhesion molecule positive(1×106 cells/mL)fetal hepatic progenitor cells were labeled with DiD dye and transplanted into the livers of CLD-severe combined immunodeficiency(SCID)mice.Near-infrared(NIR)imaging was performed for in vivo tracking of the DiD-labeled transplanted cells along with colocalization of hepatic markers for up to 80 d.The existence of human cells within mouse livers was identified using Alu polymerase chain reaction and sequencing.RESULTS NIR fluorescence imaging of CLD-SCID mice showed a positive fluorescence signal of DiD at days 7,15,30,45,60,and 80 post-transplantation.Furthermore,positive staining of cytokeratin,c-Met,and albumin colocalizing with DiD fluorescence clearly demonstrated that the fluorescent signal of hepatic markers emerged from the DiD-labeled transplanted cells.Recovery of liver function was also observed with serum levels of glutamic-oxaloacetic transaminase,glutamate-pyruvate transaminase,and bilirubin.The detection of human-specific Alu sequence from the transplanted mouse livers provided evidence for the survival of transplanted cells at day 80.CONCLUSION DiD-labeling is promising for long-term and non-invasive in vivo cell tracking,and understanding the regenerative mechanisms incurred by the transplanted cells.展开更多
To understand how the nervous system develops from a small pool of progenitors during early embryonic development,it is fundamentally important to identify the diversity of neuronal subtypes,decode the origin of neuro...To understand how the nervous system develops from a small pool of progenitors during early embryonic development,it is fundamentally important to identify the diversity of neuronal subtypes,decode the origin of neuronal diversity,and uncover the principles governing neuronal specification across different regions.Recent single-cell analyses have systematically identified neuronal diversity at unprecedented scale and speed,leaving the deconstruction of spatiotemporal mechanisms for generating neuronal diversity an imperative and paramount challenge.In this review,we highlight three distinct strategies deployed by neural progenitors to produce diverse neuronal subtypes,including predetermined,stochastic,and cascade diversifying models,and elaborate how these strategies are implemented in distinct regions such as the neocortex,spinal cord,retina,and hypothalamus.Importantly,the identity of neural progenitors is defined by their spatial position and temporal patterning factors,and each type of progenitor cell gives rise to distinguishable cohorts of neuronal subtypes.Microenvironmental cues,spontaneous activity,and connectional pattern further reshape and diversify the fate of unspecialized neurons in particular regions.The illumination of how neuronal diversity is generated will pave the way for producing specific brain organoids to model human disease and desired neuronal subtypes for cell therapy,as well as understanding the organization of functional neural circuits and the evolution of the nervous system.展开更多
Objective: To isolate neural progenitors from midbrain of new born rats. Methods: Cell groups with cloning capability were obtained from midbrain of new-born rats by using serum-free and floating cell culture. Immunoc...Objective: To isolate neural progenitors from midbrain of new born rats. Methods: Cell groups with cloning capability were obtained from midbrain of new-born rats by using serum-free and floating cell culture. Immunocytochemistry was applied to detect antigens such as BrdU, Nestin and specific markers for mature neural cells. Results: Cell groups isolated from midbrain propagated in succession and shaped 'neuro-spheres'. Nestin antigen was expressed in the course of proliferation. After differentiation, epitopes of neuron , astrocyte and oligodendrocyte were all found in the neural progenitors-derived cells, the most majority were astrocyte-epitoped cells. Conclusion: Cell groups expressing Nestin isolated from midbrain of new-born rats have properties of propagating, multi-potency differentiating and self-renewal. It is demonstrated that the cell groups are stem-like neural progenitors in the central nervous system, which are qualified for cell therapy of diseases in central nervous system.展开更多
In the brain, there are hundreds of types of specialized neurons and to generate one type of them we need to have neural progenitors for differentiation to specific neuron type. Mesenchymal stem cells (MSCs) are easil...In the brain, there are hundreds of types of specialized neurons and to generate one type of them we need to have neural progenitors for differentiation to specific neuron type. Mesenchymal stem cells (MSCs) are easily isolated, cultured, manipulated ex vivo, showing great potential for therapeutic applications. The adult MSCs have the potential to produce progeny that differentiate into a variety of cell types such as neurons. This fact suggests that MSCs derived neurons are an important cell type and a deep understanding of the molecular characteristics of it would significantly enhance the advancement of cell therapy for neurological disorders. Therefore, in this study, we isolated, identified, and studied neural progenitors by measuring expression levels through neurogenesis pathway of three neural differentiation markers nestin (NES), neurofilament (NF-L), and microtubule association protein (MAP-2) from mouse bone marrow MSCs (mouse bmMSCs) by using butylated hydroxyanisole (BHA) and diethyl sulfoxide (DMSO) as neural inducers agents. The results of immunocytochemistry and Real Time-PCR showed that in contrast to MSCs, neural differentiated cells showed neural progenitor pattern by showing stable increase in NES gene expression through differentiation process with increasing the protein expression through different exposures times, while NF-L gene and protein expression start to increased after 48 h but not replaced the NES expression completely even when its expression passed NES levels. The maturation marker Map-2 expression was low during the duration of differentiation period in protein and gene expression, which prove that these cells are still progenitors and can be redirected into specific type of neurons by further treatments.展开更多
AIM: To investigate the origin of hematopoietic progenitors contained in the stromal vascular fraction(SVF)of human adipose tissue.METHODS: Tissue samples obtained from lipectomies were subjected to enzymatic digestio...AIM: To investigate the origin of hematopoietic progenitors contained in the stromal vascular fraction(SVF)of human adipose tissue.METHODS: Tissue samples obtained from lipectomies were subjected to enzymatic digestion with collagenase to obtain a single-cell suspension. The centrifuged cell pellet, termed SVF, was separated immunomagnetically into CD45+and CD45-cells and cultured in serum-free medium containing hematopoietic cytokines. The freshly isolated and cultured cells were evaluated to determine their ability to form hematopoietic colony-forming units in clonogenic assays and for the expression of certain hematopoietic transcription factors by reversetranscription-polymerase chain reaction; the gene expression level was compared to that in CD34+hematopoietic progenitor cells from cord blood(CB) and adult peripheral blood(PB). To characterize erythroid progenitors, burst-forming units-erythroid(BFU-E) were developed in a semisolid medium under different culture conditions, and the hemoglobin composition and globin gene expression in the erythroid colonies were determined.RESULTS: The transcription factors SCL/TAL1, RUNX1,RUNX2 and GATA2 were expressed in both the CD45+and CD45-SVF populations; however, in contrast to our observations in the CD34+cells from CB and adult PB, GATA1 was not detected. Nevertheless, GATA1could be detected in the SVF cells after seven days in culture, whereas its expression was upregulated in the CB CD34+cells. The analysis of BFU-E-derived colonies revealed that virtually all erythroid cells produced by SVF cells expressed fetal hemoglobin, and the γ-globin mRNA levels ranged between those obtained in the adult- and neonatal-derived erythroid cells. Moreover,the SVF-derived erythroid cells synthesized similar levels of α- and β-globin mRNA, whereas the α-globin transcript levels were consistently higher those ofβ-globin in the cells derived from CB or PB CD34+cells. Furthermore, although the cellular distribution of hemoglobin in the erythroid cells derived from the CD34+cells obtained from hematopoietic tissues was dependent on the presence or absence of serum in the culture medium, this did not affect the SVF-derived erythroid cells.CONCLUSION: Our results demonstrate that hematopoietic progenitors in SVF have molecular and functional features that differ from those exhibited by circulating progenitors, suggesting the possibility of a different origin.展开更多
The establishment of multipotent pancreas progenitors(MPP) should have a significant impact not only on the ontology of the pancreas, but also for the translational research of glucose-responding endocrine b-cells. De...The establishment of multipotent pancreas progenitors(MPP) should have a significant impact not only on the ontology of the pancreas, but also for the translational research of glucose-responding endocrine b-cells. Deficiency of the latter may lead to the pandemic type 1 or type 2 diabetes mellitus, a metabolic disorder. An ideal treatment of which would potentially be the replacement of destroyed or failed b-cells, by restoring function of endogenous pancreatic endocrine cells or by transplantation of donor islets or in vitro generated insulin-secreting cells. Thus, considerable research efforts have been devoted to identify MPP candidates in the preand post-natal pancreas for the endogenous neogenesis or regeneration of endocrine insulin-secreting cells. In order to advance this inconclusive but critical field, we here review the emerging concepts, recent literature and newest developments of potential MPP and propose measures that would assist its forward progression.展开更多
Human adult olfactory epithelium contains neural progenitors (hONPs) which replace damaged cellular components throughout life. Methods to isolate and expand the hONPs which form neurospheres in vitro have been develo...Human adult olfactory epithelium contains neural progenitors (hONPs) which replace damaged cellular components throughout life. Methods to isolate and expand the hONPs which form neurospheres in vitro have been developed in our laboratory. In response to morphogens, the hONPs differentiate along several neural lineages. This study optimized conditions for the differentiation of hONPs towards dopaminergic neurons. The hONPs were treated with Sonic hedgehog (Shh), in the presence or absence of retinoic acid (RA) and/or forskolin (FN). Transcription factors (nurr1, pitx3 and lmx1a) that promote embryonic mouse or chicken dopaminergic development were employed to determine if they would modulate lineage restriction of these adult human progenitors. Four expression vectors (pIRES-pitx3-nurr1, pLN-CX2-pitx3, pLNCX2-nurr1 and pLNCX2-lmx1a) were transfected into the hONPs, respectively. Transcription factor expression and the rate-limiting enzyme in dopamine synthesis tyrosine hydroxylase (TH) were detected in the transfected cells after 4 month-selection with G418, indicating transfected hONPs were stably restricted towards a dopaminergic lineage. Furthermore, a dopamine enzyme immunoassay (EIA) was employed to detect the synthesis and release of dopamine. The most efficient transfection paradigm was determined. Several neurotrophic factors were detected in the pre-transfected hONPs which have potential roles in the maintenance, survival and proliferation of dopaminergic neurons. Therefore the effect of transfection on the neurotrophin synthesis was examined. Transfection did not alter synthesis. The use of olfactory progenitors as a cell-based therapy for Parkinson’s disease (PD) would allow harvest without invasive surgery, provide an autologous cell population, eliminate need for immunosuppression and avoid the ethical concerns associated with embryonic tissues. This study suggests that specific transcription factors and treatment with morphogens can restrict human adult olfactory-derived progenitors to a dopaminergic neuronal lineage. Future studies will evaluate the utility of these unique cells in cell-replacement paradigms for the treatment of PD like animal models.展开更多
There is great interest in the regenerative potential of the neural stem cells and progenitors that populate the subventricular zone（SVZ）. However, a comprehensive understanding of SVZ cell responses to brain injuri...There is great interest in the regenerative potential of the neural stem cells and progenitors that populate the subventricular zone（SVZ）. However, a comprehensive understanding of SVZ cell responses to brain injuries has been hindered by the lack of sensitive approaches to study the cellular composition of this niche. Here we review progress being made in deciphering the cells of the SVZ gleaned from the use of a recently designed flow cytometry panel that allows SVZ cells to be parsed into multiple subsets of progenitors as well as putative stem cells. We review how this approach has begun to unmask both the heterogeneity of SVZ cells as well as the dynamic shifts in cell populations with neonatal and pediatric brain injuries. We also discuss how flow cytometric analyses also have begun to reveal how specific cytokines, such as Leukemia inhibitory factor are coordinating SVZ responses to injury.展开更多
AIM: To enrich putative hepatic progenitors from the developing human fetal liver using CD34 as a marker. METHODS: Aborted fetuses of 13-20 wk were used for the isolation of liver cells. The cells were labeled with an...AIM: To enrich putative hepatic progenitors from the developing human fetal liver using CD34 as a marker. METHODS: Aborted fetuses of 13-20 wk were used for the isolation of liver cells. The cells were labeled with anti CD34; a marker used for isolating progenitor population and the cells were sorted using magnetic cell sorting. The positive fractions of cells were assessed for specific hepatic markers. Further, these cells were cultured in vitro for long term investigation. RESULTS: Flow cytometric and immunocytochemical analysis for alphafetoprotein (AFP) showed that the majority of the enriched CD34 positive cells were positive for AFP. Furthermore, these enriched cells proliferated in the long term and maintained hepatic characteristics in in vitro culture. CONCLUSION: The study shows that aborted human fetal liver is a potential source for isolation of hepatic progenitors for clinical applications. The study also demonstrates that CD34 can be a good marker for the enrichment of progenitor populations.展开更多
A comprehensive understanding of the cellular heterogeneity and molecular mechanisms underlying the development,homeostasis,and disease of human intervertebral disks(IVDs)remains challenging.Here,the transcriptomic la...A comprehensive understanding of the cellular heterogeneity and molecular mechanisms underlying the development,homeostasis,and disease of human intervertebral disks(IVDs)remains challenging.Here,the transcriptomic landscape of 108108 IVD cells was mapped using single-cell RNA sequencing of three main compartments from young and adult healthy IVDs,including the nucleus pulposus(NP),annulus fibrosus,and cartilage endplate(CEP).The chondrocyte subclusters were classified based on their potential regulatory,homeostatic,and effector functions in extracellular matrix(ECM)homeostasis.Notably,in the NP,a PROCR+resident progenitor population showed enriched colony-forming unit-fibroblast(CFU-F)activity and trilineage differentiation capacity.Finally,intercellular crosstalk based on signaling network analysis uncovered that the PDGF and TGF-βcascades are important cues in the NP microenvironment.In conclusion,a single-cell transcriptomic atlas that resolves spatially regulated cellular heterogeneity together with the critical signaling that underlies homeostasis will help to establish new therapeutic strategies for IVD degeneration in the clinic.展开更多
Type II collagen-positive(Col2^(+))cells have been reported as skeletal stem cells(SSCs),but the contribution of Col2^(+)progenitors to skeletal development both prenatally and postnatally during aging remains unclear...Type II collagen-positive(Col2^(+))cells have been reported as skeletal stem cells(SSCs),but the contribution of Col2^(+)progenitors to skeletal development both prenatally and postnatally during aging remains unclear.To address this question,we generated new mouse models with ablation of Col2^(+)cells at either the embryonic or postnatal stages.The embryonic ablation of Col2^(+)progenitors resulted in the death of newborn mice due to a decrease in skeletal blood vessels,loss of all vertebral bones and absence of most other bones except part of the craniofacial bone,the clavicle bone and a small piece of the long bone and ribs,which suggested that intramembranous ossification is involved in long bone development but does not participate in spine development.The postnatal ablation of Col2^(+)cells resulted in mouse growth retardation and a collagenopathy phenotype.Lineage tracing experiments with embryonic or postnatal mice revealed that Col2^(+)progenitors occurred predominantly in the growth plate(GP)and articular cartilage,but a limited number of Col2^(+)cells were detected in the bone marrow.Moreover,the number and differentiation ability of Col2^(+)progenitors in the long bone and knee joints decreased with increasing age.The fate-mapping study further revealed Col2^(+)lineage cells contributed to,in addition to osteoblasts and chondrocytes,CD31^(+)blood vessels in both the calvarial bone and long bone.Specifically,almost all blood vessels in calvarial bone and 25.4%of blood vessels in long bone were Col2^(+)lineage cells.However,during fracture healing,95.5%of CD31^(+)blood vessels in long bone were Col2^(+)lineage cells.In vitro studies further confirmed that Col2^(+)progenitors from calvarial bone and GP could form CD31^(+)vascular lumens.Thus,this study provides the first demonstration that intramembranous ossification is involved in long bone and rib development but not spine development.Col2^(+)progenitors contribute to CD31^(+)skeletal blood vessel formation,but the percentage differs between long bone and skull bone.The number and differentiation ability of Col2^(+)progenitors decreases with increasing age.展开更多
The transcription factor Sox11 plays important roles in retinal neurogenesis during vertebrate eye development.However,its function in retina regeneration remains elusive.Here we report that Sox11 b,a zebrafish Sox11 ...The transcription factor Sox11 plays important roles in retinal neurogenesis during vertebrate eye development.However,its function in retina regeneration remains elusive.Here we report that Sox11 b,a zebrafish Sox11 homolog,regulates the migration and fate determination of Müller glia-derived progenitors(MGPCs)in an adult zebrafish model of mechanical retinal injury.Following a stab injury,the expression of Sox11 b was induced in proliferating MGPCs in the retina.Sox11 b knockdown did not affect MGPC formation at 4 days post-injury,although the nuclear morphology and subsequent radial migration of MGPCs were alte red.At 7 days post-injury,Sox11 b knockdown res ulted in an increased proportion of MGPCs in the inner retina and a decreased propo rtion of MGPCs in the outer nuclear layer,compared with controls.Furthermore,Sox11 b knockdown led to reduced photoreceptor regeneration,while it increased the numbe rs of newborn amacrines and retinal ganglion cells.Finally,quantitative polymerase chain reaction analysis revealed that Sox11 b regulated the expression of Notch signaling components in the retina,and Notch inhibition partially recapitulated the Sox11 b knockdown phenotype,indicating that Notch signaling functions downstream of Sox11 b.Our findings imply that Sox11 b plays key roles in MGPC migration and fate determination during retina regeneration in zebrafish,which may have critical im plications for future explorations of retinal repair in mammals.展开更多
Stem/progenitor cells differentiate into different cell lineages during organ development and morphogenesis.Signaling pathway networks and mechanotransduction are important factors to guide the lineage commitment of s...Stem/progenitor cells differentiate into different cell lineages during organ development and morphogenesis.Signaling pathway networks and mechanotransduction are important factors to guide the lineage commitment of stem/progenitor cells during craniofacial tissue morphogenesis.展开更多
During the development of the central nervous system(CNS),neuroepithelial cells in the ventricular zone are multipotent stem cells that can generate neurons and macroglia(astrocytes or oligodendrocytes).It is generall...During the development of the central nervous system(CNS),neuroepithelial cells in the ventricular zone are multipotent stem cells that can generate neurons and macroglia(astrocytes or oligodendrocytes).It is generally thought that these progenitor cells sequentially produce neurons followed by glia.展开更多
Ciliary neurotrophic factor is the only known neurotrophic factor that can promote differentiation of hippocampal neural progenitor cells to glial cells and neurons in adult rats. This process is similar to spontaneou...Ciliary neurotrophic factor is the only known neurotrophic factor that can promote differentiation of hippocampal neural progenitor cells to glial cells and neurons in adult rats. This process is similar to spontaneous differentiation. Therefore, ciliary neurotrophic factor may be involved in spontaneous differentiation of neural stem cells. To verify this hypothesis, the present study isolated neural progenitor cells from adult male rats and cultured them in vitro. Results showed that when neural progenitor cells were cultured in the absence of mitogen fibroblast growth factor-2 or epidermal growth factor, they underwent spontaneous differentiation into neurons and glial cells. Western blot and immunocytochemical staining showed that exogenous ciliary neurotrophic factor strongly induced adult hippocampal progenitor cells to differentiate into neurons and glial cells. Moreover, passage 4 adult hippocampal progenitor cells expressed high levels of endogenous ciliary neurotrophic factor, and a neutralizing antibody against ciliary neurotrophic factor prevented the spontaneous neuronal and glial differentiation of adult hippocampal progenitor cells. These results suggest that the spontaneous differentiation of adult hippocampal progenitor cells is mediated partially by endogenous ciliary neurotrophic factor.展开更多
基金supported by grants from the National Key Research and Development Program of China(2022YFA1104400)the National Natural Science Foundation of China(82170988,82371020,82301028,82401201,82471011)+5 种基金the Young Science and Technology Rising Star Project of Shaanxi Province(2024ZC-KJXX-122)the China Postdoctoral Science Foundation(BX20230485)the Project of State Key Laboratory of Oral&Maxillofacial Reconstruction and Regeneration(2024MS04)the Shaanxi Provincial Health Research and Innovation Platform Construction Plan(2024PT-04)the“Rapid Response”Research projects(2023KXKT017 and 2023KXKT090)the Intramural Research Program project founded by Fourth Military Medical University(2024QMJJ008).
文摘Periodontal bone defects,primarily caused by periodontitis,are highly prevalent in clinical settings and manifest as bone fenestration,dehiscence,or attachment loss,presenting a significant challenge to oral health.In regenerative medicine,harnessing developmental principles for tissue repair offers promising therapeutic potential.Of particular interest is the condensation of progenitor cells,an essential event in organogenesis that has inspired clinically effective cell aggregation approaches in dental regeneration.However,the precise cellular coordination mechanisms during condensation and regeneration remain elusive.Here,taking the tooth as a model organ,we employed single-cell RNA sequencing to dissect the cellular composition and heterogeneity of human dental follicle and dental papilla,revealing a distinct Platelet-derived growth factor receptor alpha(PDGFRA)mesenchymal stem/stromal cell(MSC)population with remarkable odontogenic potential.Interestingly,a reciprocal paracrine interaction between PDGFRA^(+)dental follicle stem cells(DFSCs)and CD31^(+)Endomucin^(+)endothelial cells(ECs)was mediated by Vascular endothelial growth factor A(VEGFA)and Platelet-derived growth factor subunit BB(PDGFBB).This crosstalk not only maintains the functionality of PDGFRA^(+)DFSCs but also drives specialized angiogenesis.In vivo periodontal bone regeneration experiments further reveal that communication between PDGFRA+DFSC aggregates and recipient ECs is essential for effective angiogenic-osteogenic coupling and rapid tissue repair.Collectively,our results unravel the importance of MSC-EC crosstalk mediated by the VEGFA and PDGFBB-PDGFRA reciprocal signaling in orchestrating angiogenesis and osteogenesis.These findings not only establish a framework for deciphering and promoting periodontal bone regeneration in potential clinical applications but also offer insights for future therapeutic strategies in dental or broader regenerative medicine.
基金Supported by National Natural Science Foundation of China,No.82172509.
文摘BACKGROUND Fibro-adipogenic progenitors(FAPs)are a group of mesenchymal stem cells that cause fibro-fatty degeneration in skeletal muscle in various chronic disease mode-ls.FAPs also play a role in preventing muscle degeneration at acute stages during disease progression.However,few studies have reported the changes in and function of FAPs in the acute phase after tendon rupture.AIM To clarify the changes in the number of FAPs and their impact on skeletal muscle soon after tendon rupture to facilitate future studies targeting FAPs to treat muscle degeneration.METHODS We utilized Pdgfra-H2B::eGFP mice to trace and quantify FAPs in a tibialis anterior tenotomy(TAT)model at 0 and 3 days,1 week,2 weeks,3 weeks,4 weeks,5 weeks,and 6 weeks post-injury,and the results were further validated using fluorescence-activated cell sorting analysis with C57BL/6 mice at the same post-injury timepoints.We subsequently used PdgfraCreERT::RosaDTA mice,and evaluated the severity of post-TAT skeletal muscle degeneration with or without FAP-depletion.RESULTS The number of FAPs peaked at 1 week post-TAT before gradually declining to a level comparable to that pre-TAT.The change in the number of FAPs was potentially temporally correlated with the progression of skeletal muscle degeneration after TAT.FAP-depletion led to more severe degeneration early after TAT,indicating that FAPs potentially alleviate muscle degeneration after tendon rupture in the early post-injury phase.CONCLUSION FAPs potentially alleviate the degeneration of skeletal muscle in the acute stage after tendon rupture.
基金Council of Scientific and Industrial Research Network Grant CMM002ICMR Grant (GAP 0215)
文摘AIM： To enrich hepatic progenitors using epithelial cell adhesion molecule （EpCAM） as a marker from human fetal liver and investigate the expression of human leukocyte antigen （HLA） and their markers associated with hepatic progenitor cells. METHODS： EpCAM ＋ve cells were isolated using magnetic cell sorting （MACS） from human fetuses （n = 10） at 15-25 wk gestation. Expression of markers for hepatic progenitors such as albumin, alpha-fetoprotein （AFP）, CD29 （integrin ~1）, CD49f （integrin c^6） and CD90 （Thy 1） was studied by using flow cytometry, immunocytochemistry and RT-PCR; HLA class Ⅰ （A, B, C） and class Ⅱ （DR） expression was studied by flow cytometry only. RESULTS： FACS analysis indicated that EpCAM ＋ve cells were positive for CD29, CD49f, CD90, CD34, HLA class I, albumin and AFP but negative for HLA class Ⅱ （DR） and CD45. RT PCR showed that EpCAM ＋ve cells expressed liver epithelial markers （CK18）, biliary specific marker （CK19） and hepatic markers （albumin, AFP）. On immunocytochemical staining, EpCAM ＋ve cells were shown positive signals for CK18 and albumin. CONCLUSION： Our study suggests that these EpCAM ＋ve cells can be used as hepatic progenitors for cell transplantation with a minimum risk of alloreactivity and these cells may serve as a potential source for enrichment of hepatic progenitor.
基金Innovation Fund Denmark,No.4108-00008BThe Bagenkop NielsensØjen-Fond,No.115227+2 种基金Hørslev-Fonden,No.116967Beckett Fonden,No.116936Velux Foundation,No.1179261001/2.
文摘BACKGROUND Retinal organoids serve as excellent human-specific disease models for conditions affecting otherwise inaccessible retinal tissue from patients.They permit the isolation of key cell types affected in various eye diseases including retinal ganglion cells(RGCs)and Müller glia.AIM To refine human-induced pluripotent stem cells(hiPSCs)differentiated into threedimensional(3D)retinal organoids to generate sufficient numbers of RGCs and Müller glia progenitors for downstream analyses.METHODS In this study we described,evaluated,and refined methods with which to generate Müller glia and RGC progenitors,isolated them via magnetic-activated cell sorting,and assessed their lineage stability after prolonged 2D culture.Putative progenitor populations were characterized via quantitative PCR and immunocytochemistry,and the ultrastructural composition of retinal organoid cells was investigated.RESULTS Our study confirms the feasibility of generating marker-characterized Müller glia and RGC progenitors within retinal organoids.Such retinal organoids can be dissociated and the Müller glia and RGC progenitor-like cells isolated via magnetic-activated cell sorting and propagated as monolayers.CONCLUSION Enrichment of Müller glia and RGC progenitors from retinal organoids is a feasible method with which to study cell type-specific disease phenotypes and to potentially generate specific retinal populations for cell replacement therapies.
基金NIH PO1 NS055976,Craig H.Neilsen Foundation,and Shriner’s Hospital for Children
文摘Cellular transplantation for repair of spinal cord injury is a prom- ising therapeutic strategy that includes the use of a variety of neural and non-neural cells isolated or derived from embryonic and adult tissue as well as embryonic stem cells and induced plu- ripotent stem cells. In particular, transplants of neural progenitor cells （NPCs） have been shown to limit secondary injury and scar formation and create a permissive environment in the injured spinal cord through the provision of neurotrophic molecules and growth supporting matrices that promote growth of injured host axons. Importantly, transplants of NPC are unique in their poten- tial to replace lost neural cells - including neurons, astrocytes,
基金Supported by Department of Science and Technology(DST),Ministry of Science and Technology,Govt.of India and Indian Council of Medical Research(ICMR),New Delhi,Govt.of India Grants to GP,No.GAP-0220 and No.GAP-0383.
文摘BACKGROUND Chronic liver diseases(CLD)are the major public health burden due to the continuous increasing rate of global morbidity and mortality.The inherent limitations of organ transplantation have led to the development of stem cell-based therapy as a supportive and promising therapeutic option.However,identifying the fate of transplanted cells in vivo represents a crucial obstacle.AIM To evaluate the potential applicability of DiD dye as a cell labeling agent for longterm,and non-invasive in vivo tracking of transplanted cells in the liver.METHODS Magnetically sorted,epithelial cell adhesion molecule positive(1×106 cells/mL)fetal hepatic progenitor cells were labeled with DiD dye and transplanted into the livers of CLD-severe combined immunodeficiency(SCID)mice.Near-infrared(NIR)imaging was performed for in vivo tracking of the DiD-labeled transplanted cells along with colocalization of hepatic markers for up to 80 d.The existence of human cells within mouse livers was identified using Alu polymerase chain reaction and sequencing.RESULTS NIR fluorescence imaging of CLD-SCID mice showed a positive fluorescence signal of DiD at days 7,15,30,45,60,and 80 post-transplantation.Furthermore,positive staining of cytokeratin,c-Met,and albumin colocalizing with DiD fluorescence clearly demonstrated that the fluorescent signal of hepatic markers emerged from the DiD-labeled transplanted cells.Recovery of liver function was also observed with serum levels of glutamic-oxaloacetic transaminase,glutamate-pyruvate transaminase,and bilirubin.The detection of human-specific Alu sequence from the transplanted mouse livers provided evidence for the survival of transplanted cells at day 80.CONCLUSION DiD-labeling is promising for long-term and non-invasive in vivo cell tracking,and understanding the regenerative mechanisms incurred by the transplanted cells.
基金supported by the National Key R&D Program of China(2019YFA0801900 and 2018YFA0801104)the National Natural Science Foundation of China(81891002,32070972,31921002,and 31771131)+2 种基金the Strategic Priority Research Program of Chinese Academy of Sciences(XDB32020000)the Hundred-Talent Program(Chinese Academy of Sciences)the Beijing Municipal Science&Technology Commission(Z210010 and Z181100001518001).
文摘To understand how the nervous system develops from a small pool of progenitors during early embryonic development,it is fundamentally important to identify the diversity of neuronal subtypes,decode the origin of neuronal diversity,and uncover the principles governing neuronal specification across different regions.Recent single-cell analyses have systematically identified neuronal diversity at unprecedented scale and speed,leaving the deconstruction of spatiotemporal mechanisms for generating neuronal diversity an imperative and paramount challenge.In this review,we highlight three distinct strategies deployed by neural progenitors to produce diverse neuronal subtypes,including predetermined,stochastic,and cascade diversifying models,and elaborate how these strategies are implemented in distinct regions such as the neocortex,spinal cord,retina,and hypothalamus.Importantly,the identity of neural progenitors is defined by their spatial position and temporal patterning factors,and each type of progenitor cell gives rise to distinguishable cohorts of neuronal subtypes.Microenvironmental cues,spontaneous activity,and connectional pattern further reshape and diversify the fate of unspecialized neurons in particular regions.The illumination of how neuronal diversity is generated will pave the way for producing specific brain organoids to model human disease and desired neuronal subtypes for cell therapy,as well as understanding the organization of functional neural circuits and the evolution of the nervous system.
基金National Natural Science Foundation of China (No. 30170469)
文摘Objective: To isolate neural progenitors from midbrain of new born rats. Methods: Cell groups with cloning capability were obtained from midbrain of new-born rats by using serum-free and floating cell culture. Immunocytochemistry was applied to detect antigens such as BrdU, Nestin and specific markers for mature neural cells. Results: Cell groups isolated from midbrain propagated in succession and shaped 'neuro-spheres'. Nestin antigen was expressed in the course of proliferation. After differentiation, epitopes of neuron , astrocyte and oligodendrocyte were all found in the neural progenitors-derived cells, the most majority were astrocyte-epitoped cells. Conclusion: Cell groups expressing Nestin isolated from midbrain of new-born rats have properties of propagating, multi-potency differentiating and self-renewal. It is demonstrated that the cell groups are stem-like neural progenitors in the central nervous system, which are qualified for cell therapy of diseases in central nervous system.
文摘In the brain, there are hundreds of types of specialized neurons and to generate one type of them we need to have neural progenitors for differentiation to specific neuron type. Mesenchymal stem cells (MSCs) are easily isolated, cultured, manipulated ex vivo, showing great potential for therapeutic applications. The adult MSCs have the potential to produce progeny that differentiate into a variety of cell types such as neurons. This fact suggests that MSCs derived neurons are an important cell type and a deep understanding of the molecular characteristics of it would significantly enhance the advancement of cell therapy for neurological disorders. Therefore, in this study, we isolated, identified, and studied neural progenitors by measuring expression levels through neurogenesis pathway of three neural differentiation markers nestin (NES), neurofilament (NF-L), and microtubule association protein (MAP-2) from mouse bone marrow MSCs (mouse bmMSCs) by using butylated hydroxyanisole (BHA) and diethyl sulfoxide (DMSO) as neural inducers agents. The results of immunocytochemistry and Real Time-PCR showed that in contrast to MSCs, neural differentiated cells showed neural progenitor pattern by showing stable increase in NES gene expression through differentiation process with increasing the protein expression through different exposures times, while NF-L gene and protein expression start to increased after 48 h but not replaced the NES expression completely even when its expression passed NES levels. The maturation marker Map-2 expression was low during the duration of differentiation period in protein and gene expression, which prove that these cells are still progenitors and can be redirected into specific type of neurons by further treatments.
基金The Ministerio de Ciencia e Innovación,PI08/1716Ministerio de Sanidad y Consumo,EMER07/005Conselleríade Sanidad,Generalitat Valenciana,AP061/09 and AP069/10
文摘AIM: To investigate the origin of hematopoietic progenitors contained in the stromal vascular fraction(SVF)of human adipose tissue.METHODS: Tissue samples obtained from lipectomies were subjected to enzymatic digestion with collagenase to obtain a single-cell suspension. The centrifuged cell pellet, termed SVF, was separated immunomagnetically into CD45+and CD45-cells and cultured in serum-free medium containing hematopoietic cytokines. The freshly isolated and cultured cells were evaluated to determine their ability to form hematopoietic colony-forming units in clonogenic assays and for the expression of certain hematopoietic transcription factors by reversetranscription-polymerase chain reaction; the gene expression level was compared to that in CD34+hematopoietic progenitor cells from cord blood(CB) and adult peripheral blood(PB). To characterize erythroid progenitors, burst-forming units-erythroid(BFU-E) were developed in a semisolid medium under different culture conditions, and the hemoglobin composition and globin gene expression in the erythroid colonies were determined.RESULTS: The transcription factors SCL/TAL1, RUNX1,RUNX2 and GATA2 were expressed in both the CD45+and CD45-SVF populations; however, in contrast to our observations in the CD34+cells from CB and adult PB, GATA1 was not detected. Nevertheless, GATA1could be detected in the SVF cells after seven days in culture, whereas its expression was upregulated in the CB CD34+cells. The analysis of BFU-E-derived colonies revealed that virtually all erythroid cells produced by SVF cells expressed fetal hemoglobin, and the γ-globin mRNA levels ranged between those obtained in the adult- and neonatal-derived erythroid cells. Moreover,the SVF-derived erythroid cells synthesized similar levels of α- and β-globin mRNA, whereas the α-globin transcript levels were consistently higher those ofβ-globin in the cells derived from CB or PB CD34+cells. Furthermore, although the cellular distribution of hemoglobin in the erythroid cells derived from the CD34+cells obtained from hematopoietic tissues was dependent on the presence or absence of serum in the culture medium, this did not affect the SVF-derived erythroid cells.CONCLUSION: Our results demonstrate that hematopoietic progenitors in SVF have molecular and functional features that differ from those exhibited by circulating progenitors, suggesting the possibility of a different origin.
基金Supported by Telethon Perth Child Health Research Foundationthe Diabetes Research Foundation of Western Australia+1 种基金the University of Western Australiathe National Health and Medical Research Council Program,No.53000400
文摘The establishment of multipotent pancreas progenitors(MPP) should have a significant impact not only on the ontology of the pancreas, but also for the translational research of glucose-responding endocrine b-cells. Deficiency of the latter may lead to the pandemic type 1 or type 2 diabetes mellitus, a metabolic disorder. An ideal treatment of which would potentially be the replacement of destroyed or failed b-cells, by restoring function of endogenous pancreatic endocrine cells or by transplantation of donor islets or in vitro generated insulin-secreting cells. Thus, considerable research efforts have been devoted to identify MPP candidates in the preand post-natal pancreas for the endogenous neogenesis or regeneration of endocrine insulin-secreting cells. In order to advance this inconclusive but critical field, we here review the emerging concepts, recent literature and newest developments of potential MPP and propose measures that would assist its forward progression.
文摘Human adult olfactory epithelium contains neural progenitors (hONPs) which replace damaged cellular components throughout life. Methods to isolate and expand the hONPs which form neurospheres in vitro have been developed in our laboratory. In response to morphogens, the hONPs differentiate along several neural lineages. This study optimized conditions for the differentiation of hONPs towards dopaminergic neurons. The hONPs were treated with Sonic hedgehog (Shh), in the presence or absence of retinoic acid (RA) and/or forskolin (FN). Transcription factors (nurr1, pitx3 and lmx1a) that promote embryonic mouse or chicken dopaminergic development were employed to determine if they would modulate lineage restriction of these adult human progenitors. Four expression vectors (pIRES-pitx3-nurr1, pLN-CX2-pitx3, pLNCX2-nurr1 and pLNCX2-lmx1a) were transfected into the hONPs, respectively. Transcription factor expression and the rate-limiting enzyme in dopamine synthesis tyrosine hydroxylase (TH) were detected in the transfected cells after 4 month-selection with G418, indicating transfected hONPs were stably restricted towards a dopaminergic lineage. Furthermore, a dopamine enzyme immunoassay (EIA) was employed to detect the synthesis and release of dopamine. The most efficient transfection paradigm was determined. Several neurotrophic factors were detected in the pre-transfected hONPs which have potential roles in the maintenance, survival and proliferation of dopaminergic neurons. Therefore the effect of transfection on the neurotrophin synthesis was examined. Transfection did not alter synthesis. The use of olfactory progenitors as a cell-based therapy for Parkinson’s disease (PD) would allow harvest without invasive surgery, provide an autologous cell population, eliminate need for immunosuppression and avoid the ethical concerns associated with embryonic tissues. This study suggests that specific transcription factors and treatment with morphogens can restrict human adult olfactory-derived progenitors to a dopaminergic neuronal lineage. Future studies will evaluate the utility of these unique cells in cell-replacement paradigms for the treatment of PD like animal models.
文摘There is great interest in the regenerative potential of the neural stem cells and progenitors that populate the subventricular zone（SVZ）. However, a comprehensive understanding of SVZ cell responses to brain injuries has been hindered by the lack of sensitive approaches to study the cellular composition of this niche. Here we review progress being made in deciphering the cells of the SVZ gleaned from the use of a recently designed flow cytometry panel that allows SVZ cells to be parsed into multiple subsets of progenitors as well as putative stem cells. We review how this approach has begun to unmask both the heterogeneity of SVZ cells as well as the dynamic shifts in cell populations with neonatal and pediatric brain injuries. We also discuss how flow cytometric analyses also have begun to reveal how specific cytokines, such as Leukemia inhibitory factor are coordinating SVZ responses to injury.
基金Supported by Department of Biotechnology, Government of India
文摘AIM: To enrich putative hepatic progenitors from the developing human fetal liver using CD34 as a marker. METHODS: Aborted fetuses of 13-20 wk were used for the isolation of liver cells. The cells were labeled with anti CD34; a marker used for isolating progenitor population and the cells were sorted using magnetic cell sorting. The positive fractions of cells were assessed for specific hepatic markers. Further, these cells were cultured in vitro for long term investigation. RESULTS: Flow cytometric and immunocytochemical analysis for alphafetoprotein (AFP) showed that the majority of the enriched CD34 positive cells were positive for AFP. Furthermore, these enriched cells proliferated in the long term and maintained hepatic characteristics in in vitro culture. CONCLUSION: The study shows that aborted human fetal liver is a potential source for isolation of hepatic progenitors for clinical applications. The study also demonstrates that CD34 can be a good marker for the enrichment of progenitor populations.
基金supported by grants from the National Natural Science Foundation of China(81802165 and 31930054)National Key Research and Development Program of China(2017YFA0103401 and 2019YFA0110201)+2 种基金raining Plan of Talents’Innovation of Army Medical Center of PLA(2019CXJSB013)Postdoctoral Innovative Talent Support Program in Chongqing(2019-298)Fund for Excellent Young Scholars of the State Key Laboratory of Trauma,Burns and Combined Injury(SKLYQ201902).
文摘A comprehensive understanding of the cellular heterogeneity and molecular mechanisms underlying the development,homeostasis,and disease of human intervertebral disks(IVDs)remains challenging.Here,the transcriptomic landscape of 108108 IVD cells was mapped using single-cell RNA sequencing of three main compartments from young and adult healthy IVDs,including the nucleus pulposus(NP),annulus fibrosus,and cartilage endplate(CEP).The chondrocyte subclusters were classified based on their potential regulatory,homeostatic,and effector functions in extracellular matrix(ECM)homeostasis.Notably,in the NP,a PROCR+resident progenitor population showed enriched colony-forming unit-fibroblast(CFU-F)activity and trilineage differentiation capacity.Finally,intercellular crosstalk based on signaling network analysis uncovered that the PDGF and TGF-βcascades are important cues in the NP microenvironment.In conclusion,a single-cell transcriptomic atlas that resolves spatially regulated cellular heterogeneity together with the critical signaling that underlies homeostasis will help to establish new therapeutic strategies for IVD degeneration in the clinic.
基金supported by the National Institute of Dental and Craniofacial Research, the National Institute of Arthritis and Musculoskeletal and Skin Diseases, and the National Institute on Aging, part of the National Institutes of Health, under Award Numbers DE023105, AR066101 and AG048388Department of Defense office of the Congressionally Directed Medical Research Programs (CDMRP), under Award Number of RA210159 to SY+2 种基金sponsored by the Shanghai Sailing Program (21YF1436400)National Natural Science Foundation of China (82102608) to XLsupported by the China Scholarship Council (CSC) Grant #201706260178。
文摘Type II collagen-positive(Col2^(+))cells have been reported as skeletal stem cells(SSCs),but the contribution of Col2^(+)progenitors to skeletal development both prenatally and postnatally during aging remains unclear.To address this question,we generated new mouse models with ablation of Col2^(+)cells at either the embryonic or postnatal stages.The embryonic ablation of Col2^(+)progenitors resulted in the death of newborn mice due to a decrease in skeletal blood vessels,loss of all vertebral bones and absence of most other bones except part of the craniofacial bone,the clavicle bone and a small piece of the long bone and ribs,which suggested that intramembranous ossification is involved in long bone development but does not participate in spine development.The postnatal ablation of Col2^(+)cells resulted in mouse growth retardation and a collagenopathy phenotype.Lineage tracing experiments with embryonic or postnatal mice revealed that Col2^(+)progenitors occurred predominantly in the growth plate(GP)and articular cartilage,but a limited number of Col2^(+)cells were detected in the bone marrow.Moreover,the number and differentiation ability of Col2^(+)progenitors in the long bone and knee joints decreased with increasing age.The fate-mapping study further revealed Col2^(+)lineage cells contributed to,in addition to osteoblasts and chondrocytes,CD31^(+)blood vessels in both the calvarial bone and long bone.Specifically,almost all blood vessels in calvarial bone and 25.4%of blood vessels in long bone were Col2^(+)lineage cells.However,during fracture healing,95.5%of CD31^(+)blood vessels in long bone were Col2^(+)lineage cells.In vitro studies further confirmed that Col2^(+)progenitors from calvarial bone and GP could form CD31^(+)vascular lumens.Thus,this study provides the first demonstration that intramembranous ossification is involved in long bone and rib development but not spine development.Col2^(+)progenitors contribute to CD31^(+)skeletal blood vessel formation,but the percentage differs between long bone and skull bone.The number and differentiation ability of Col2^(+)progenitors decreases with increasing age.
基金supported by the National Key Research and Development Project of China,Nos.2017YFA0104100(to JL),2017YFA0701304(to HX)National Natural Science Foundation of China Nos.81970820(to HX),31930068(to JL)。
文摘The transcription factor Sox11 plays important roles in retinal neurogenesis during vertebrate eye development.However,its function in retina regeneration remains elusive.Here we report that Sox11 b,a zebrafish Sox11 homolog,regulates the migration and fate determination of Müller glia-derived progenitors(MGPCs)in an adult zebrafish model of mechanical retinal injury.Following a stab injury,the expression of Sox11 b was induced in proliferating MGPCs in the retina.Sox11 b knockdown did not affect MGPC formation at 4 days post-injury,although the nuclear morphology and subsequent radial migration of MGPCs were alte red.At 7 days post-injury,Sox11 b knockdown res ulted in an increased proportion of MGPCs in the inner retina and a decreased propo rtion of MGPCs in the outer nuclear layer,compared with controls.Furthermore,Sox11 b knockdown led to reduced photoreceptor regeneration,while it increased the numbe rs of newborn amacrines and retinal ganglion cells.Finally,quantitative polymerase chain reaction analysis revealed that Sox11 b regulated the expression of Notch signaling components in the retina,and Notch inhibition partially recapitulated the Sox11 b knockdown phenotype,indicating that Notch signaling functions downstream of Sox11 b.Our findings imply that Sox11 b plays key roles in MGPC migration and fate determination during retina regeneration in zebrafish,which may have critical im plications for future explorations of retinal repair in mammals.
基金supported by funding from the National Institute of Dental and Craniofacial Research,National Institutes of Health (R01 DE022503 and R01 DE012711 to Yang Chai)。
文摘Stem/progenitor cells differentiate into different cell lineages during organ development and morphogenesis.Signaling pathway networks and mechanotransduction are important factors to guide the lineage commitment of stem/progenitor cells during craniofacial tissue morphogenesis.
基金the Natural Science Foundation of Zhejiang Province(LQ19C090001)the National Natural Science Foundation of China(31900703 and 31771621).
文摘During the development of the central nervous system(CNS),neuroepithelial cells in the ventricular zone are multipotent stem cells that can generate neurons and macroglia(astrocytes or oligodendrocytes).It is generally thought that these progenitor cells sequentially produce neurons followed by glia.
基金supported by the National Natural Science Foundation of China,No. 30770754
文摘Ciliary neurotrophic factor is the only known neurotrophic factor that can promote differentiation of hippocampal neural progenitor cells to glial cells and neurons in adult rats. This process is similar to spontaneous differentiation. Therefore, ciliary neurotrophic factor may be involved in spontaneous differentiation of neural stem cells. To verify this hypothesis, the present study isolated neural progenitor cells from adult male rats and cultured them in vitro. Results showed that when neural progenitor cells were cultured in the absence of mitogen fibroblast growth factor-2 or epidermal growth factor, they underwent spontaneous differentiation into neurons and glial cells. Western blot and immunocytochemical staining showed that exogenous ciliary neurotrophic factor strongly induced adult hippocampal progenitor cells to differentiate into neurons and glial cells. Moreover, passage 4 adult hippocampal progenitor cells expressed high levels of endogenous ciliary neurotrophic factor, and a neutralizing antibody against ciliary neurotrophic factor prevented the spontaneous neuronal and glial differentiation of adult hippocampal progenitor cells. These results suggest that the spontaneous differentiation of adult hippocampal progenitor cells is mediated partially by endogenous ciliary neurotrophic factor.
