It is generally accepted that adult bone marrow(BM) contains both hematopoietic stem cells(HSCs) and mesenchymal stem cells (MSCs). Recently, a rare population of stem cells different from HSCs and MSCs were ide...It is generally accepted that adult bone marrow(BM) contains both hematopoietic stem cells(HSCs) and mesenchymal stem cells (MSCs). Recently, a rare population of stem cells different from HSCs and MSCs were identified in murine BM and human cord blood (CB), named as very small embryonic like(VSEL) stem cells. These cells are tiny round and CXCR4^+ Sca-1^+ Lin^- CD45^-, expressing SSEA-1/4, Oct-4 and Nanog, which have potent of differentiation into all three germ-layer lineages, such as cardiornyocytes, neural and pancreatic ceils.展开更多
Rhesus monkey embryonic stem(rES) cells have similar characteristics to human ES cells,and might be useful as a substitute model for preclinical research.Notch signaling is involved in the formation of bile ducts,wh...Rhesus monkey embryonic stem(rES) cells have similar characteristics to human ES cells,and might be useful as a substitute model for preclinical research.Notch signaling is involved in the formation of bile ducts,which are composed of cholangiocytes.However,little is known about the role of Notch signaling in cholangiocytic commitment of ES cells.We analyzed the effect of Notch signaling on the induction of cholangiocyte-like cells from rES cells.About 80% of definitive endoderm(DE) cells were generated from rES cells after treatment with activin A.After treatment with BMP4 and FGF1 on matrigel coated wells in serum-free medium,rES-derived DE gave rise to cholangiocyte-like cells by expression of cholangiocytic specific proteins(CK7,CK18,CK19,CK20,and OV-6) and genes(GSTPi,IB4,and HNF1β).At the same time,expression of Notch 1 and Notch 2 mRNA were detected during cell differentiation,as well as their downstream target genes such as Hes 1 and Hes 5.Inhibition of the Notch signal pathway by L-685458 resulted in decreased expression of Notch and their downstream genes.In addition,the proportion of cholangiocyte-like cells declined from ~90% to ~20%.These results suggest that Notch signaling may play a critical role in cholangiocytic development from ES cells.展开更多
Spinal cord injury is a disabling condition with limited treatment options.Multiple studies have provided evidence suggesting that small extracellular vesicles(SEVs)secreted by bone marrow mesenchymal stem cells(MSCs)...Spinal cord injury is a disabling condition with limited treatment options.Multiple studies have provided evidence suggesting that small extracellular vesicles(SEVs)secreted by bone marrow mesenchymal stem cells(MSCs)help mediate the beneficial effects conferred by MSC transplantation following spinal cord injury.Strikingly,hypoxia-preconditioned bone marrow mesenchymal stem cell-derived SEVs(HSEVs)exhibit increased therapeutic potency.We thus explored the role of HSEVs in macrophage immune regulation after spinal cord injury in rats and their significance in spinal cord repair.SEVs or HSEVs were isolated from bone marrow MSC supernatants by density gradient ultracentrifugation.HSEV administration to rats via tail vein injection after spinal cord injury reduced the lesion area and attenuated spinal cord inflammation.HSEVs regulate macrophage polarization towards the M2 phenotype in vivo and in vitro.Micro RNA sequencing and bioinformatics analyses of SEVs and HSEVs revealed that mi R-146a-5p is a potent mediator of macrophage polarization that targets interleukin-1 receptor-associated kinase 1.Reducing mi R-146a-5p expression in HSEVs partially attenuated macrophage polarization.Our data suggest that HSEVs attenuate spinal cord inflammation and injury in rats by transporting mi R-146a-5p,which alters macrophage polarization.This study provides new insights into the application of HSEVs as a therapeutic tool for spinal cord injury.展开更多
BACKGROUND Embryonic stem cells(ESCs)serve as a crucial ex vivo model,representing epiblast cells derived from the inner cell mass of blastocyst-stage embryos.ESCs exhibit a unique combination of self-renewal potency,...BACKGROUND Embryonic stem cells(ESCs)serve as a crucial ex vivo model,representing epiblast cells derived from the inner cell mass of blastocyst-stage embryos.ESCs exhibit a unique combination of self-renewal potency,unlimited proliferation,and pluripotency.The latter is evident by the ability of the isolated cells to differ-entiate spontaneously into multiple cell lineages,representing the three primary embryonic germ layers.Multiple regulatory networks guide ESCs,directing their self-renewal and lineage-specific differentiation.Apoptosis,or programmed cell death,emerges as a key event involved in sculpting and forming various organs and structures ensuring proper embryonic development.How-ever,the molecular mechanisms underlying the dynamic interplay between diffe-rentiation and apoptosis remain poorly understood.AIM To investigate the regulatory impact of apoptosis on the early differentiation of ESCs into cardiac cells,using mouse ESC(mESC)models-mESC-B-cell lym-phoma 2(BCL-2),mESC-PIM-2,and mESC-metallothionein-1(MET-1)-which overexpress the anti-apoptotic genes Bcl-2,Pim-2,and Met-1,respectively.METHODS mESC-T2(wild-type),mESC-BCL-2,mESC-PIM-2,and mESC-MET-1 have been used to assess the effect of potentiated apoptotic signals on cardiac differentiation.The hanging drop method was adopted to generate embryoid bodies(EBs)and induce terminal differentiation of mESCs.The size of the generated EBs was measured in each condition compared to the wild type.At the functional level,the percentage of cardiac differentiation was measured by calculating the number of beating cardiomyocytes in the manipulated mESCs compared to the control.At the molecular level,quantitative reverse transcription-polymerase chain reaction was used to assess the mRNA expression of three cardiac markers:Troponin T,GATA4,and NKX2.5.Additionally,troponin T protein expression was evaluated through immunofluorescence and western blot assays.RESULTS Our findings showed that the upregulation of Bcl-2,Pim-2,and Met-1 genes led to a reduction in the size of the EBs derived from the manipulated mESCs,in comparison with their wild-type counterpart.Additionally,a decrease in the count of beating cardiomyocytes among differentiated cells was observed.Furthermore,the mRNA expression of three cardiac markers-troponin T,GATA4,and NKX2.5-was diminished in mESCs overexpressing the three anti-apoptotic genes compared to the control cell line.Moreover,the overexpression of the anti-apoptotic genes resulted in a reduction in troponin T protein expression.CONCLUSION Our findings revealed that the upregulation of Bcl-2,Pim-2,and Met-1 genes altered cardiac differentiation,providing insight into the intricate interplay between apoptosis and ESC fate determination.展开更多
Parthenogenetic embryonic stem cells have pluripotent differentiation potentials, akin to fertilized embryo-derived embryonic stem cells. The aim of this study was to compare the neuronal differentiation potential of ...Parthenogenetic embryonic stem cells have pluripotent differentiation potentials, akin to fertilized embryo-derived embryonic stem cells. The aim of this study was to compare the neuronal differentiation potential of parthenogenetic and fertilized embryo-derived embryonic stem cells. Before differentiation, karyotype analysis was performed, with normal karyotypes detected in both parthenogenetic and fertilized embryo-derived embryonic stem cells. Sex chromosomes were identified as XX. Immunocytochemistry and quantitative real-time PCR detected high expression of the pluripotent gene, Oct4, at both the mRNA and protein levels, indicating pluripotent differentiation potential of the two embryonic stem cell subtypes. Embryonic stern cells were induced with retinoic acid to form embryoid bodies, and then dispersed into single cells. Single cells were differentiated in N2 differentiation medium for 9 days. Immunocytochemistry showed parthenogenetic and fertilized embryo-derived embryonic stem cells both express the neuronal cell markers nestin, ~lll-tubulin and myelin basic protein. Quantitative real-time PCR found expression of neuregenesis related genes (Sox-1, Nestin, GABA, Pax6, Zic5 and Pitxl) in both types of embryonic stem cells, and Oct4 expression was significantly decreased. Nestin and Pax6 expression in parthenogenetic embryonic stem cells was significantly higher than that in fertilized embryo-derived embryonic stem cells. Thus, our experimental findings indicate that parthenogenetic embryonic stem cells have stronger neuronal differentiation potential than fertilized embryo-derived embryonic stem cells.展开更多
Spermatogonial stem cells (SSCs) divide continuously to support spermatogenesis throughout postnatal life and transmit genetic information to the next generation. Here, we report the successful establishment of the ...Spermatogonial stem cells (SSCs) divide continuously to support spermatogenesis throughout postnatal life and transmit genetic information to the next generation. Here, we report the successful establishment of the method for the isolation and identification of human SSCs from testicular tissue, and to determine the culture conditions required to expand SSCs on human embryonic stem cell-derived fibroblast-like cells (hdFs). Large-scale cultures of SSCs were maintained on hdF feeder layers and expanded in the presence of a combination of cytokines and glial cell line-derived neurotrophic factor for at least 2 months. Cell surface marker analysis showed that SSCs retained high levels of alkaline phosphatase activity and stained strongly for anti-stage-specific embryonic antigen (SSEA)-1, OCT4 and CD49f. They also expressed the genes OCT4, SOX3 and STRA8 as detected by reverse transcription polymerase chain reaction (RT-PCR) analysis. These data clearly illustrate a novel approach for the growth of human SSCs using hdFs as feeder cells, potentially eliminating xenogeneic contaminants. This system provides a new opportunity for the study of the regulatory mechanism of the ‘niche' that governs SSC self-renewal, and will be a valuable source of SSCs for potential clinical applications.展开更多
Objective Vascular smooth muscle cell(VSMC)differentiation from stem cells is one source of the increasing number of VSMCs that are involved in vascular remodeling-related diseases such as hypertension,atherosclerosis...Objective Vascular smooth muscle cell(VSMC)differentiation from stem cells is one source of the increasing number of VSMCs that are involved in vascular remodeling-related diseases such as hypertension,atherosclerosis,and restenosis.MicroRNA-146a(miR-146a)has been proven to be involved in cell proliferation,migration,and tumor metabolism.However,little is known about the functional role of miR-146a in VSMC differentiation from embryonic stem cells(ESCs).This study aimed to determine the role of miR-146a in VSMC differentiation from ESCs.Methods Mouse ESCs were differentiated into VSMCs,and the cell extracts were analyzed by Western blotting and RT-qPCR.In addition,luciferase reporter assays using ESCs transfected with miR-146a/mimic and plasmids were performed.Finally,C57BL/6J female mice were injected with mimic or miR-146a-overexpressing ESCs,and immunohistochemistry,Western blotting,and RT-qPCR assays were carried out on tissue samples from these mice.Results miR-146a was significantly upregulated during VSMC differentiation,accompanied with the VSMC-specific marker genes smooth muscle-alpha-actin(SMαA),smooth muscle 22(SM22),smooth muscle myosin heavy chain(SMMHC),and h1-calponin.Furthermore,overexpression of miR-146a enhanced the differentiation process in vitro and in vivo.Concurrently,the expression of Kruppel-like factor 4(KLF4),predicted as one of the top targets of miR-146a,was sharply decreased in miR-146a-overexpressing ESCs.Importantly,inhibiting KLF4 expression enhanced the VSMC-specific gene expression induced by miR-146a overexpression in differentiating ESCs.In addition,miR-146a upregulated the mRNA expression levels and transcriptional activity of VSMC differentiation-related transcription factors,including serum response factor(SRF)and myocyte enhancer factor 2c(MEF-2c).Conclusion Our data support that miR-146a promotes ESC-VSMC differentiation through regulating KLF4 and modulating the transcription factor activity of VSMCs.展开更多
Our previous study showed that cell cycle exit and neuronal differentiation 1(CEND1)may participate in neural stem cell cycle exit and oriented differentiation.However,whether CEND1-transfected neural stem cells can i...Our previous study showed that cell cycle exit and neuronal differentiation 1(CEND1)may participate in neural stem cell cycle exit and oriented differentiation.However,whether CEND1-transfected neural stem cells can improve the prognosis of traumatic brain injury remained unclear.In this study,we performed quantitative proteomic analysis and found that after traumatic brain injury,CEND1 expression was downregulated in mouse brain tissue.Three days after traumatic brain injury,we transplanted CEND1-transfected neural stem cells into the area surrounding the injury site.We found that at 5 weeks after traumatic brain injury,transplantation of CEND1-transfected neural stem cells markedly alleviated brain atrophy and greatly improved neurological function.In vivo and in vitro results indicate that CEND1 overexpression inhibited the proliferation of neural stem cells,but significantly promoted their neuronal differentiation.Additionally,CEND1 overexpression reduced protein levels of Notch1 and cyclin D1,but increased levels of p21 in CEND1-transfected neural stem cells.Treatment with CEND1-transfected neural stem cells was superior to similar treatment without CEND1 transfection.These findings suggest that transplantation of CEND1-transfected neural stem cells is a promising cell therapy for traumatic brain injury.This study was approved by the Animal Ethics Committee of the School of Biomedical Engineering of Shanghai Jiao Tong University,China(approval No.2016034)on November 25,2016.展开更多
In the eighth decade of the last century extensive clinical delayed-type hypersensitivity (DTH) skin tests to an intradermal injection of a pharmaceutical allogeneic human Placenta Suspension (phPS) performed in obste...In the eighth decade of the last century extensive clinical delayed-type hypersensitivity (DTH) skin tests to an intradermal injection of a pharmaceutical allogeneic human Placenta Suspension (phPS) performed in obstetrical, gynecological and control group patients have shown positive reaction in 239 patients with clinical conditions having been as histopatrhological substratum, a hypoxia-induced adaptive/reactive epithelial cell proliferation, e.g. syncytiotrophoblastic cell hyperplasia, endometrial cell hyperplasia, or different gynecological cancers. Because the immune response against phPS has shown antigenc similarities between normal placental and endometrial hyperplastic cells and different kinds of cancer cells and because many cancers adopt an embryonic stem-like gene expression pattern, it is suggested that the profile of hypoxia-promoting placental and endometrial stem cell proliferation is more embryonic-like, and that the immune respose against phPS is expected to cross-react with tumor cells in vivo. In the process of persistent growth and accelerated oxygen consumption by hyperplastic cytotrophoblastic cells and neoplastic cells in a hypoxic microenvironment, a basic shift in energy metabolism is accompanied by appearance of heat shock proteins (HSPs), of fetal isoenzymes and of membrane glycoproteins (reappearance of oncofetal antigens, OFAs), which, as result of their overexpression/amplification may induce a host immunological response. Thus, it is assumed that phPS prepared from full-term human placentas delivered after a spontaneous labor comprises stem/progenitor cells reverted to a proliferative embryonic stem cell-like-state upon exposure to labor-inducing intrmittent placental hypoxia and that by expressing HSP/OFAs could immunize to generate immune response againjst a variety of antigens that are shared by different kinds of epithelial cancers. This immunological feature of phPS qualifies is as a vaccine-related product that may be used for a preventive cancer vaccine when mixed with a potent adjuvant (BCG-Vaccine) and given normal healthy individuals.展开更多
Objective To investigate the function and mechanism of embryonic stem cells again Lewis non-small cell lung cancer in vivo. Methods Based on the mouse Lewis non-small cell lung cancer model,we have tested some tumor g...Objective To investigate the function and mechanism of embryonic stem cells again Lewis non-small cell lung cancer in vivo. Methods Based on the mouse Lewis non-small cell lung cancer model,we have tested some tumor growth indexes and investigated the immune response of embryonic stem cells against cancer cells. Results Compared with the mice in control group,mice展开更多
[Objective] The paper was to establish embryonic stem cell system of goats. [Method] Numerous primordial germ cell colonies were derived from gonadal ridge and the surrounding tissues in 20 millimeter fetuses of down ...[Objective] The paper was to establish embryonic stem cell system of goats. [Method] Numerous primordial germ cell colonies were derived from gonadal ridge and the surrounding tissues in 20 millimeter fetuses of down producing goat. Primordial germ cells and goats embryonic fibroblasts obtained from conceptus of equivaient gestational age were co-cultured. [Result] The colonies showed some characteristics of embryonic stem cells, such as the morphology of nest-like, they continued to be AKP positive and the ability to be continuously passed [Conclusion] These cells were pluripotent and ES-like cells.展开更多
Spinal cord injury is considered one of the most difficult injuries to repair and has one of the worst prognoses for injuries to the nervous system.Following surgery,the poor regenerative capacity of nerve cells and t...Spinal cord injury is considered one of the most difficult injuries to repair and has one of the worst prognoses for injuries to the nervous system.Following surgery,the poor regenerative capacity of nerve cells and the generation of new scars can make it very difficult for the impaired nervous system to restore its neural functionality.Traditional treatments can only alleviate secondary injuries but cannot fundamentally repair the spinal cord.Consequently,there is a critical need to develop new treatments to promote functional repair after spinal cord injury.Over recent years,there have been seve ral developments in the use of stem cell therapy for the treatment of spinal cord injury.Alongside significant developments in the field of tissue engineering,three-dimensional bioprinting technology has become a hot research topic due to its ability to accurately print complex structures.This led to the loading of three-dimensional bioprinting scaffolds which provided precise cell localization.These three-dimensional bioprinting scaffolds co uld repair damaged neural circuits and had the potential to repair the damaged spinal cord.In this review,we discuss the mechanisms underlying simple stem cell therapy,the application of different types of stem cells for the treatment of spinal cord injury,and the different manufa cturing methods for three-dimensional bioprinting scaffolds.In particular,we focus on the development of three-dimensional bioprinting scaffolds for the treatment of spinal cord injury.展开更多
Human induced pluripotent stem (iPS) cells are similar to embryonic stem (ES) cells, and can proliferate intensively and differentiate into a variety of cell types. However, the hepatic differentiation of human iP...Human induced pluripotent stem (iPS) cells are similar to embryonic stem (ES) cells, and can proliferate intensively and differentiate into a variety of cell types. However, the hepatic differentiation of human iPS cells has not yet been reported. In this report, human iPS cells were induced to differentiate into hepatic cells by a stepwise protocol. The expression of liver cell markers and liver-related functions of the human iPS cell-derived cells were monitored and compared with that of differentiated human ES cells and primary human hepatocytes. Approximately 60% of the differentiated human iPS cells at day 7 expressed hepatic markers alpha fetoprotein and Alb. The differentiated cells at day 21 exhibited liver cell functions including albumin Asecretion, glycogen synthesis, urea production and inducible cytochrome P450 activity. The expression of hepatic markers and fiver-related functions of the iPS cellderived hepatic ceils were comparable to that of the human ES cell-derived hepatic cells. These results show that human iPS cells, which are similar to human ES cells, can be efficiently induced to differentiate into hepatocyte-like cells.展开更多
BACKGROUND: Midbrain-derived neural stem cells (mNSCs) can differentiate into functional mature dopaminergic neurons. The mNSCs are considered the ideal choice for cell therapy of Parkinson's disease. OBJECTIVE: ...BACKGROUND: Midbrain-derived neural stem cells (mNSCs) can differentiate into functional mature dopaminergic neurons. The mNSCs are considered the ideal choice for cell therapy of Parkinson's disease. OBJECTIVE: To isolate rat embryonic mNSCs and to observe the differentiation characteristics of mNSCs induced by cell growth-promoting factors. DESIGN, TIME AND SETTING: An in vitro cell culture study based on the molecular biology of nerve cells was carried out at the Institute of Clinical Medicine, China-Japan Friendship Hospital (China) from March to November 2007. MATERIALS: Sprague Dawley rats at embryonic day 14 were used in this study. Nestin antibody, β-Ⅲ tubulin antibody, glial fibrillary acidic protein (GFAP) antibody and cyclic nucleotide 3'-phosphohydrolase (CNPase) antibody were provided by Abcam; DMEM/F12 medium and N2 supplement were provided by Invitrogen; epidermal growth factor (EGF) and fibroblast growth factor-2 (FGF2) were provided by R&D Systems. METHODS: The ventral mesencephalon was dissected from embryonic day 14 rat embryos. By trypsin digestion and mechanical separation, the brain tissue was triturated into a fine single-cell suspension. The cells were cultured in 5 mL serum-free medium containing DMEM/FI 2, 1% N: supplement, 20 ng/mL EGF and FGF2. The mNSCs at the third generation were coated with 10ug/mL polylysine and induced to differentiate in the DMEM/F12 supplemented with 1% fetal bovine serum and 1% N2. MAIN OUTCOME MEASURES: The neural spheres of the third passage were identified by nestin immunofluorescence; at the same time, the cells were induced to differentiate, and the types of differentiated cell were identified by immunofluorescence for β Ⅲ tubulin, GFAP and CNPase. RESULTS: Seven days after primary culture, a great many neurospheres could be obtained by successive pasage. Immunofluorescence assays showed that the neurospheres were nestin positive, and after differentiation, the cells expressed GFAP, CNPase and β -Ⅲ-tubulin. CONCLUSION: Embryonic day 14 rat mNSCs can differentiate into neuron-like cells and glial cells following induction by EGF, FGF2 and N: additive.展开更多
The capacity for self-renewal and differentiation of human embryonic stem (ES) cells makes them a potential source for generation of pancreatic beta cells for treating type I diabetes mellitus. Here, we report a new...The capacity for self-renewal and differentiation of human embryonic stem (ES) cells makes them a potential source for generation of pancreatic beta cells for treating type I diabetes mellitus. Here, we report a newly developed and effective method, carried out in a serum-free system, which induced human ES cells to differentiate into insulin-producing cells. Activin A was used in the initial stage to induce definitive endoderm differentiation from human ES cells, as detected by the expression of the definitive endoderm markers Sox17 and Brachyury. Further, all-trans retinoic acid (RA) was used to promote pancreatic differentiation, as indicated by the expression of the early pancreatic transcription factors pdxl and hlxb9. After maturation in DMEM/F12 serum-free medium with bFGF and nicotinamide, the differentiated cells expressed islet specific markers such as C-peptide, insulin, glucagon and glut2. The percentage of C-peptide-positive cells exceeded 15%. The secretion of insulin and C-peptide by these cells corresponded to the variations in glucose levels. When transplanted into renal capsules of Streptozotocin (STZ)-treated nude mice, these differentiated human ES cells survived and maintained the expression of beta cell marker genes, including C-peptide, pdxl, glucokinase, nkx6.1, lAPP, pax6 and Tcfl. Thirty percent of the transplanted nude mice exhibited apparent restoration of stable euglycemia; and the corrected phenotype was sustained for more than six weeks. Our new method provides a promising in vitro differentiation model for studying the mechanisms of human pancreas development and illustrates the potential of using human ES cells for the treatment of type I diabetes mellitus.展开更多
To solve the problem of immune incompatibility, nuclear transplantation has been envisaged as a means to produce cells or tissues for human autologous transplantation. Here we have derived embryonic stem cells by the ...To solve the problem of immune incompatibility, nuclear transplantation has been envisaged as a means to produce cells or tissues for human autologous transplantation. Here we have derived embryonic stem cells by the transfer of human somatic nuclei into rabbit oocytes. The number of blastocysts that developed from the fused nuclear transfer was comparable among nuclear donors at ages of 5, 42, 52 and 60 years, and nuclear transfer (NT) embryonic stem cells (ntES cells) were subsequently derived from each of the four age groups. These results suggest that human somatic nuclei can form ntES cells independent of the age of the donor. The derived ntES cells are human based on karyotype, isogenicity, in situ hybridization, PCR and immunocytochemistry with probes that distinguish between the various species. The ntES cells maintain the capability of sustained growth in an undifferentiated state, and form embryoid bodies, which, on further induction, give rise to cell types such as neuron and muscle, as well as mixed cell populations that express markers representative of all three germ layers. Thus, ntES cells derived from human somatic cells by NT to rabbit eggs retain phenotypes similar to those of conventional human ES cells, including the ability to undergo multilineage cellular differentiation.展开更多
Endothelial cells (TEC_3 cells) derived from mouse embryonic stem (ES) cells were used as seed cells to construct blood vessels. Tissue engineered blood vessels were made by seeding 8 × 10~6 smooth muscle cells (...Endothelial cells (TEC_3 cells) derived from mouse embryonic stem (ES) cells were used as seed cells to construct blood vessels. Tissue engineered blood vessels were made by seeding 8 × 10~6 smooth muscle cells (SMCs) obtained from rabbit arteries onto a sheet of nonwoven polyglycolic acid (PGA) fibers, which was used as a biodegradable polymer scaffold. After being cultured in DMEM medium for 7 days in vitro, SMCs grew well on the PGA fibers, and the cell-PGA sheet was then wrapped around a silicon tube, and implanted subcutaneously into nude mice. After 6~8 weeks, the silicon tube was replaced with another silicon tube in smaller diameter, and then the TEC_3 cells (endothelial cells differentiated from mouse ES cells) were injected inside the engineered vessel tube as the test group. In the control group only culture medium was injected. Five days later, the engineered vessels were harvested for gross observation, histological and immunohistochemical analysis. The preliminary results demonstrated that the SMC-PGA construct could form a tubular structure in 6~8 weeks and PGA fibers were completely degraded. Histological and immunohistochemical analysis of the newly formed tissue revealed a typical blood vessel structure, including a lining of endothelial cells (ECs) on the lumimal surface and the presence of SMC and collagen in the wall. No EC lining was found in the tubes of control group. Therefore, the ECs differentiated from mouse ES cells can serve as seed cells for endothelium lining in tissue engineered blood vessels.展开更多
In our previous study, five homologous feeder cell lines, Monkey ear skin fibroblasts (MESFs), clonally derived fibroblasts from the MESFs (CMESFs), monkey oviductal fibroblasts (MOFs), monkey follicular granulo...In our previous study, five homologous feeder cell lines, Monkey ear skin fibroblasts (MESFs), clonally derived fibroblasts from the MESFs (CMESFs), monkey oviductal fibroblasts (MOFs), monkey follicular granulosa fibroblast-like (MFGs) cells, monkey follicular granulosa epithelium-like (MFGEs) cells, were developed for the maintenance of rhesus embryonic stem cells (rESCs). We found that MESFs, CMESFs, MOFs and MFGs, but not MFGEs, support the growth of rhesus embryonic stem cells. Moreover, we detected some genes that are upregulated in supportive feeder cell lines by semi-quantitative PCR. In the present study, we applied the GeneChip Rhesus Macaque Genome Array of Affymetrix Corporation to study the expression profiles of these five feeder cell lines, in purpose to find out which cytokines and signaling pathways were important in maintaining the rESCs, mRNAs of eight genes, including GREM2, bFGF, KITLG, DKK3, GREM1, AREG, SERPINF1 and LTBP1, were found to be upregulated in supportive feeder cell lines, but not in MFGE. The results indicate that many signaling pathways may play redundant roles in supporting the undifferentiated growth and maintenance of pluripotency in rESCs.展开更多
Pluripotency of embryonic stem cells(ESCs) and induced pluripotent stem cells is regulated by a well characterized gene transcription circuitry. The circuitry is assembled by ESC specific transcription factors, signal...Pluripotency of embryonic stem cells(ESCs) and induced pluripotent stem cells is regulated by a well characterized gene transcription circuitry. The circuitry is assembled by ESC specific transcription factors, signal trans-ducing molecules and epigenetic regulators. Growing understanding of stem-like cells, albeit of more complex phenotypes, present in tumors(cancer stem cells), provides a common conceptual and research frame-work for basic and applied stem cell biology. In this review, we highlight current results on biomarkers, gene signatures, signaling pathways and epigenetic regulators that are common in embryonic and cancer stem cells. We discuss their role in determining the cell phenotype and finally, their potential use to design next generation biological and pharmaceutical approaches for regenerative medicine and cancer therapies.展开更多
文摘It is generally accepted that adult bone marrow(BM) contains both hematopoietic stem cells(HSCs) and mesenchymal stem cells (MSCs). Recently, a rare population of stem cells different from HSCs and MSCs were identified in murine BM and human cord blood (CB), named as very small embryonic like(VSEL) stem cells. These cells are tiny round and CXCR4^+ Sca-1^+ Lin^- CD45^-, expressing SSEA-1/4, Oct-4 and Nanog, which have potent of differentiation into all three germ-layer lineages, such as cardiornyocytes, neural and pancreatic ceils.
基金supported by research grants from Zhejiang Natural Sciences Foundation of China (Y2110911 Y2080996)the National Key Technologies R&D Program of China (2007CB947701)
文摘Rhesus monkey embryonic stem(rES) cells have similar characteristics to human ES cells,and might be useful as a substitute model for preclinical research.Notch signaling is involved in the formation of bile ducts,which are composed of cholangiocytes.However,little is known about the role of Notch signaling in cholangiocytic commitment of ES cells.We analyzed the effect of Notch signaling on the induction of cholangiocyte-like cells from rES cells.About 80% of definitive endoderm(DE) cells were generated from rES cells after treatment with activin A.After treatment with BMP4 and FGF1 on matrigel coated wells in serum-free medium,rES-derived DE gave rise to cholangiocyte-like cells by expression of cholangiocytic specific proteins(CK7,CK18,CK19,CK20,and OV-6) and genes(GSTPi,IB4,and HNF1β).At the same time,expression of Notch 1 and Notch 2 mRNA were detected during cell differentiation,as well as their downstream target genes such as Hes 1 and Hes 5.Inhibition of the Notch signal pathway by L-685458 resulted in decreased expression of Notch and their downstream genes.In addition,the proportion of cholangiocyte-like cells declined from ~90% to ~20%.These results suggest that Notch signaling may play a critical role in cholangiocytic development from ES cells.
基金supported by the Fujian Minimally Invasive Medical Center Foundation,No.2128100514(to CC,CW,HX)the Natural Science Foundation of Fujian Province,No.2023J01640(to CC,CW,ZL,HX)。
文摘Spinal cord injury is a disabling condition with limited treatment options.Multiple studies have provided evidence suggesting that small extracellular vesicles(SEVs)secreted by bone marrow mesenchymal stem cells(MSCs)help mediate the beneficial effects conferred by MSC transplantation following spinal cord injury.Strikingly,hypoxia-preconditioned bone marrow mesenchymal stem cell-derived SEVs(HSEVs)exhibit increased therapeutic potency.We thus explored the role of HSEVs in macrophage immune regulation after spinal cord injury in rats and their significance in spinal cord repair.SEVs or HSEVs were isolated from bone marrow MSC supernatants by density gradient ultracentrifugation.HSEV administration to rats via tail vein injection after spinal cord injury reduced the lesion area and attenuated spinal cord inflammation.HSEVs regulate macrophage polarization towards the M2 phenotype in vivo and in vitro.Micro RNA sequencing and bioinformatics analyses of SEVs and HSEVs revealed that mi R-146a-5p is a potent mediator of macrophage polarization that targets interleukin-1 receptor-associated kinase 1.Reducing mi R-146a-5p expression in HSEVs partially attenuated macrophage polarization.Our data suggest that HSEVs attenuate spinal cord inflammation and injury in rats by transporting mi R-146a-5p,which alters macrophage polarization.This study provides new insights into the application of HSEVs as a therapeutic tool for spinal cord injury.
基金Supported by the National Council for Scientific Research in Lebanon,CNRS-L.
文摘BACKGROUND Embryonic stem cells(ESCs)serve as a crucial ex vivo model,representing epiblast cells derived from the inner cell mass of blastocyst-stage embryos.ESCs exhibit a unique combination of self-renewal potency,unlimited proliferation,and pluripotency.The latter is evident by the ability of the isolated cells to differ-entiate spontaneously into multiple cell lineages,representing the three primary embryonic germ layers.Multiple regulatory networks guide ESCs,directing their self-renewal and lineage-specific differentiation.Apoptosis,or programmed cell death,emerges as a key event involved in sculpting and forming various organs and structures ensuring proper embryonic development.How-ever,the molecular mechanisms underlying the dynamic interplay between diffe-rentiation and apoptosis remain poorly understood.AIM To investigate the regulatory impact of apoptosis on the early differentiation of ESCs into cardiac cells,using mouse ESC(mESC)models-mESC-B-cell lym-phoma 2(BCL-2),mESC-PIM-2,and mESC-metallothionein-1(MET-1)-which overexpress the anti-apoptotic genes Bcl-2,Pim-2,and Met-1,respectively.METHODS mESC-T2(wild-type),mESC-BCL-2,mESC-PIM-2,and mESC-MET-1 have been used to assess the effect of potentiated apoptotic signals on cardiac differentiation.The hanging drop method was adopted to generate embryoid bodies(EBs)and induce terminal differentiation of mESCs.The size of the generated EBs was measured in each condition compared to the wild type.At the functional level,the percentage of cardiac differentiation was measured by calculating the number of beating cardiomyocytes in the manipulated mESCs compared to the control.At the molecular level,quantitative reverse transcription-polymerase chain reaction was used to assess the mRNA expression of three cardiac markers:Troponin T,GATA4,and NKX2.5.Additionally,troponin T protein expression was evaluated through immunofluorescence and western blot assays.RESULTS Our findings showed that the upregulation of Bcl-2,Pim-2,and Met-1 genes led to a reduction in the size of the EBs derived from the manipulated mESCs,in comparison with their wild-type counterpart.Additionally,a decrease in the count of beating cardiomyocytes among differentiated cells was observed.Furthermore,the mRNA expression of three cardiac markers-troponin T,GATA4,and NKX2.5-was diminished in mESCs overexpressing the three anti-apoptotic genes compared to the control cell line.Moreover,the overexpression of the anti-apoptotic genes resulted in a reduction in troponin T protein expression.CONCLUSION Our findings revealed that the upregulation of Bcl-2,Pim-2,and Met-1 genes altered cardiac differentiation,providing insight into the intricate interplay between apoptosis and ESC fate determination.
基金supported by the National Natural Science Foundation of China,No. 30900155 and 81070496the Research Foundation of Education Bureau of Shaanxi Province,China,No. 09JK785+1 种基金Foundation of Interdisciplinary for Postgraduates from Northwest University,No. 08YJC22the Key Laboratory Funding of Northwestern University,Shaanxi Province in China
文摘Parthenogenetic embryonic stem cells have pluripotent differentiation potentials, akin to fertilized embryo-derived embryonic stem cells. The aim of this study was to compare the neuronal differentiation potential of parthenogenetic and fertilized embryo-derived embryonic stem cells. Before differentiation, karyotype analysis was performed, with normal karyotypes detected in both parthenogenetic and fertilized embryo-derived embryonic stem cells. Sex chromosomes were identified as XX. Immunocytochemistry and quantitative real-time PCR detected high expression of the pluripotent gene, Oct4, at both the mRNA and protein levels, indicating pluripotent differentiation potential of the two embryonic stem cell subtypes. Embryonic stern cells were induced with retinoic acid to form embryoid bodies, and then dispersed into single cells. Single cells were differentiated in N2 differentiation medium for 9 days. Immunocytochemistry showed parthenogenetic and fertilized embryo-derived embryonic stem cells both express the neuronal cell markers nestin, ~lll-tubulin and myelin basic protein. Quantitative real-time PCR found expression of neuregenesis related genes (Sox-1, Nestin, GABA, Pax6, Zic5 and Pitxl) in both types of embryonic stem cells, and Oct4 expression was significantly decreased. Nestin and Pax6 expression in parthenogenetic embryonic stem cells was significantly higher than that in fertilized embryo-derived embryonic stem cells. Thus, our experimental findings indicate that parthenogenetic embryonic stem cells have stronger neuronal differentiation potential than fertilized embryo-derived embryonic stem cells.
文摘Spermatogonial stem cells (SSCs) divide continuously to support spermatogenesis throughout postnatal life and transmit genetic information to the next generation. Here, we report the successful establishment of the method for the isolation and identification of human SSCs from testicular tissue, and to determine the culture conditions required to expand SSCs on human embryonic stem cell-derived fibroblast-like cells (hdFs). Large-scale cultures of SSCs were maintained on hdF feeder layers and expanded in the presence of a combination of cytokines and glial cell line-derived neurotrophic factor for at least 2 months. Cell surface marker analysis showed that SSCs retained high levels of alkaline phosphatase activity and stained strongly for anti-stage-specific embryonic antigen (SSEA)-1, OCT4 and CD49f. They also expressed the genes OCT4, SOX3 and STRA8 as detected by reverse transcription polymerase chain reaction (RT-PCR) analysis. These data clearly illustrate a novel approach for the growth of human SSCs using hdFs as feeder cells, potentially eliminating xenogeneic contaminants. This system provides a new opportunity for the study of the regulatory mechanism of the ‘niche' that governs SSC self-renewal, and will be a valuable source of SSCs for potential clinical applications.
基金funded by the National Natural Science Foundation of China(No.82070376 and No.81873491)the Natural Science Foundation of Zhejiang Province(No.LY21H020005)+1 种基金the Zhejiang Medical Science and Technology Project(No.2019KY376 and No.2018KY071)a Ningbo Science and Technology Project(No.202002N3173).
文摘Objective Vascular smooth muscle cell(VSMC)differentiation from stem cells is one source of the increasing number of VSMCs that are involved in vascular remodeling-related diseases such as hypertension,atherosclerosis,and restenosis.MicroRNA-146a(miR-146a)has been proven to be involved in cell proliferation,migration,and tumor metabolism.However,little is known about the functional role of miR-146a in VSMC differentiation from embryonic stem cells(ESCs).This study aimed to determine the role of miR-146a in VSMC differentiation from ESCs.Methods Mouse ESCs were differentiated into VSMCs,and the cell extracts were analyzed by Western blotting and RT-qPCR.In addition,luciferase reporter assays using ESCs transfected with miR-146a/mimic and plasmids were performed.Finally,C57BL/6J female mice were injected with mimic or miR-146a-overexpressing ESCs,and immunohistochemistry,Western blotting,and RT-qPCR assays were carried out on tissue samples from these mice.Results miR-146a was significantly upregulated during VSMC differentiation,accompanied with the VSMC-specific marker genes smooth muscle-alpha-actin(SMαA),smooth muscle 22(SM22),smooth muscle myosin heavy chain(SMMHC),and h1-calponin.Furthermore,overexpression of miR-146a enhanced the differentiation process in vitro and in vivo.Concurrently,the expression of Kruppel-like factor 4(KLF4),predicted as one of the top targets of miR-146a,was sharply decreased in miR-146a-overexpressing ESCs.Importantly,inhibiting KLF4 expression enhanced the VSMC-specific gene expression induced by miR-146a overexpression in differentiating ESCs.In addition,miR-146a upregulated the mRNA expression levels and transcriptional activity of VSMC differentiation-related transcription factors,including serum response factor(SRF)and myocyte enhancer factor 2c(MEF-2c).Conclusion Our data support that miR-146a promotes ESC-VSMC differentiation through regulating KLF4 and modulating the transcription factor activity of VSMCs.
基金supported by the National Natural Science Foundation of China,No.81701895Shanghai Jiao Tong University Medicine-Engineering Research Fund,China,No.YG2016QN20(both to FY)。
文摘Our previous study showed that cell cycle exit and neuronal differentiation 1(CEND1)may participate in neural stem cell cycle exit and oriented differentiation.However,whether CEND1-transfected neural stem cells can improve the prognosis of traumatic brain injury remained unclear.In this study,we performed quantitative proteomic analysis and found that after traumatic brain injury,CEND1 expression was downregulated in mouse brain tissue.Three days after traumatic brain injury,we transplanted CEND1-transfected neural stem cells into the area surrounding the injury site.We found that at 5 weeks after traumatic brain injury,transplantation of CEND1-transfected neural stem cells markedly alleviated brain atrophy and greatly improved neurological function.In vivo and in vitro results indicate that CEND1 overexpression inhibited the proliferation of neural stem cells,but significantly promoted their neuronal differentiation.Additionally,CEND1 overexpression reduced protein levels of Notch1 and cyclin D1,but increased levels of p21 in CEND1-transfected neural stem cells.Treatment with CEND1-transfected neural stem cells was superior to similar treatment without CEND1 transfection.These findings suggest that transplantation of CEND1-transfected neural stem cells is a promising cell therapy for traumatic brain injury.This study was approved by the Animal Ethics Committee of the School of Biomedical Engineering of Shanghai Jiao Tong University,China(approval No.2016034)on November 25,2016.
文摘In the eighth decade of the last century extensive clinical delayed-type hypersensitivity (DTH) skin tests to an intradermal injection of a pharmaceutical allogeneic human Placenta Suspension (phPS) performed in obstetrical, gynecological and control group patients have shown positive reaction in 239 patients with clinical conditions having been as histopatrhological substratum, a hypoxia-induced adaptive/reactive epithelial cell proliferation, e.g. syncytiotrophoblastic cell hyperplasia, endometrial cell hyperplasia, or different gynecological cancers. Because the immune response against phPS has shown antigenc similarities between normal placental and endometrial hyperplastic cells and different kinds of cancer cells and because many cancers adopt an embryonic stem-like gene expression pattern, it is suggested that the profile of hypoxia-promoting placental and endometrial stem cell proliferation is more embryonic-like, and that the immune respose against phPS is expected to cross-react with tumor cells in vivo. In the process of persistent growth and accelerated oxygen consumption by hyperplastic cytotrophoblastic cells and neoplastic cells in a hypoxic microenvironment, a basic shift in energy metabolism is accompanied by appearance of heat shock proteins (HSPs), of fetal isoenzymes and of membrane glycoproteins (reappearance of oncofetal antigens, OFAs), which, as result of their overexpression/amplification may induce a host immunological response. Thus, it is assumed that phPS prepared from full-term human placentas delivered after a spontaneous labor comprises stem/progenitor cells reverted to a proliferative embryonic stem cell-like-state upon exposure to labor-inducing intrmittent placental hypoxia and that by expressing HSP/OFAs could immunize to generate immune response againjst a variety of antigens that are shared by different kinds of epithelial cancers. This immunological feature of phPS qualifies is as a vaccine-related product that may be used for a preventive cancer vaccine when mixed with a potent adjuvant (BCG-Vaccine) and given normal healthy individuals.
文摘Objective To investigate the function and mechanism of embryonic stem cells again Lewis non-small cell lung cancer in vivo. Methods Based on the mouse Lewis non-small cell lung cancer model,we have tested some tumor growth indexes and investigated the immune response of embryonic stem cells against cancer cells. Results Compared with the mice in control group,mice
基金Supported by Project of Baotou University(BSY2010-23)~~
文摘[Objective] The paper was to establish embryonic stem cell system of goats. [Method] Numerous primordial germ cell colonies were derived from gonadal ridge and the surrounding tissues in 20 millimeter fetuses of down producing goat. Primordial germ cells and goats embryonic fibroblasts obtained from conceptus of equivaient gestational age were co-cultured. [Result] The colonies showed some characteristics of embryonic stem cells, such as the morphology of nest-like, they continued to be AKP positive and the ability to be continuously passed [Conclusion] These cells were pluripotent and ES-like cells.
基金supported by the National Natural Science Foundation of China,No.82171380(to CD)Jiangsu Students’Platform for Innovation and Entrepreneurship Training Program,No.202110304098Y(to DJ)。
文摘Spinal cord injury is considered one of the most difficult injuries to repair and has one of the worst prognoses for injuries to the nervous system.Following surgery,the poor regenerative capacity of nerve cells and the generation of new scars can make it very difficult for the impaired nervous system to restore its neural functionality.Traditional treatments can only alleviate secondary injuries but cannot fundamentally repair the spinal cord.Consequently,there is a critical need to develop new treatments to promote functional repair after spinal cord injury.Over recent years,there have been seve ral developments in the use of stem cell therapy for the treatment of spinal cord injury.Alongside significant developments in the field of tissue engineering,three-dimensional bioprinting technology has become a hot research topic due to its ability to accurately print complex structures.This led to the loading of three-dimensional bioprinting scaffolds which provided precise cell localization.These three-dimensional bioprinting scaffolds co uld repair damaged neural circuits and had the potential to repair the damaged spinal cord.In this review,we discuss the mechanisms underlying simple stem cell therapy,the application of different types of stem cells for the treatment of spinal cord injury,and the different manufa cturing methods for three-dimensional bioprinting scaffolds.In particular,we focus on the development of three-dimensional bioprinting scaffolds for the treatment of spinal cord injury.
基金We thank Dr Zicai Liang and Huang Huang (Institute of Molecular Medicine, Peking University) for their kind help with BioTek Multi-Detection Microplate Reader and Yizhe Zhang for technical support on real-time PCR. We also thank Chengyan Wang, Pengbo Zhang, Pingping Hou, Haisong Liu, Chun Liu and other colleagues in our laboratory for technical assistance and advice in carrying out these experiments. This study was supported by a Bill & Melinda Gates Foundation Grant (37871), a Ministry of Education grant (705001), the National Basic Research Program of China (973 program, 2009CB522502, 2009CB941200 and 2007CB947901), National Natural Science Foundation of China for Creative Research Groups (30421004), the Chinese Science and Technology Key Project (2008zx10002-014, 2008zx10002- 011 and 2009ZX 10004-403) and a 111 Project to Deng H.
文摘Human induced pluripotent stem (iPS) cells are similar to embryonic stem (ES) cells, and can proliferate intensively and differentiate into a variety of cell types. However, the hepatic differentiation of human iPS cells has not yet been reported. In this report, human iPS cells were induced to differentiate into hepatic cells by a stepwise protocol. The expression of liver cell markers and liver-related functions of the human iPS cell-derived cells were monitored and compared with that of differentiated human ES cells and primary human hepatocytes. Approximately 60% of the differentiated human iPS cells at day 7 expressed hepatic markers alpha fetoprotein and Alb. The differentiated cells at day 21 exhibited liver cell functions including albumin Asecretion, glycogen synthesis, urea production and inducible cytochrome P450 activity. The expression of hepatic markers and fiver-related functions of the iPS cellderived hepatic ceils were comparable to that of the human ES cell-derived hepatic cells. These results show that human iPS cells, which are similar to human ES cells, can be efficiently induced to differentiate into hepatocyte-like cells.
基金the National Natural Science Foundation of China,No.30672151
文摘BACKGROUND: Midbrain-derived neural stem cells (mNSCs) can differentiate into functional mature dopaminergic neurons. The mNSCs are considered the ideal choice for cell therapy of Parkinson's disease. OBJECTIVE: To isolate rat embryonic mNSCs and to observe the differentiation characteristics of mNSCs induced by cell growth-promoting factors. DESIGN, TIME AND SETTING: An in vitro cell culture study based on the molecular biology of nerve cells was carried out at the Institute of Clinical Medicine, China-Japan Friendship Hospital (China) from March to November 2007. MATERIALS: Sprague Dawley rats at embryonic day 14 were used in this study. Nestin antibody, β-Ⅲ tubulin antibody, glial fibrillary acidic protein (GFAP) antibody and cyclic nucleotide 3'-phosphohydrolase (CNPase) antibody were provided by Abcam; DMEM/F12 medium and N2 supplement were provided by Invitrogen; epidermal growth factor (EGF) and fibroblast growth factor-2 (FGF2) were provided by R&D Systems. METHODS: The ventral mesencephalon was dissected from embryonic day 14 rat embryos. By trypsin digestion and mechanical separation, the brain tissue was triturated into a fine single-cell suspension. The cells were cultured in 5 mL serum-free medium containing DMEM/FI 2, 1% N: supplement, 20 ng/mL EGF and FGF2. The mNSCs at the third generation were coated with 10ug/mL polylysine and induced to differentiate in the DMEM/F12 supplemented with 1% fetal bovine serum and 1% N2. MAIN OUTCOME MEASURES: The neural spheres of the third passage were identified by nestin immunofluorescence; at the same time, the cells were induced to differentiate, and the types of differentiated cell were identified by immunofluorescence for β Ⅲ tubulin, GFAP and CNPase. RESULTS: Seven days after primary culture, a great many neurospheres could be obtained by successive pasage. Immunofluorescence assays showed that the neurospheres were nestin positive, and after differentiation, the cells expressed GFAP, CNPase and β -Ⅲ-tubulin. CONCLUSION: Embryonic day 14 rat mNSCs can differentiate into neuron-like cells and glial cells following induction by EGF, FGF2 and N: additive.
基金This research was supported by the Ministry of Science and Technology Grant (2001CB510106);Science and Technology Plan of Beijing Municipal Government (H020220050290);National Natural Science Foundation of China Awards for 0utstanding Young Scientists (30125022);for Creative Research Groups (30421004);Bill & Melinda Gates Foundation Grant (37871) to H Deng.
文摘The capacity for self-renewal and differentiation of human embryonic stem (ES) cells makes them a potential source for generation of pancreatic beta cells for treating type I diabetes mellitus. Here, we report a newly developed and effective method, carried out in a serum-free system, which induced human ES cells to differentiate into insulin-producing cells. Activin A was used in the initial stage to induce definitive endoderm differentiation from human ES cells, as detected by the expression of the definitive endoderm markers Sox17 and Brachyury. Further, all-trans retinoic acid (RA) was used to promote pancreatic differentiation, as indicated by the expression of the early pancreatic transcription factors pdxl and hlxb9. After maturation in DMEM/F12 serum-free medium with bFGF and nicotinamide, the differentiated cells expressed islet specific markers such as C-peptide, insulin, glucagon and glut2. The percentage of C-peptide-positive cells exceeded 15%. The secretion of insulin and C-peptide by these cells corresponded to the variations in glucose levels. When transplanted into renal capsules of Streptozotocin (STZ)-treated nude mice, these differentiated human ES cells survived and maintained the expression of beta cell marker genes, including C-peptide, pdxl, glucokinase, nkx6.1, lAPP, pax6 and Tcfl. Thirty percent of the transplanted nude mice exhibited apparent restoration of stable euglycemia; and the corrected phenotype was sustained for more than six weeks. Our new method provides a promising in vitro differentiation model for studying the mechanisms of human pancreas development and illustrates the potential of using human ES cells for the treatment of type I diabetes mellitus.
基金supported by grants from the Major State Basic Research Development Program of China(No.001CB5099)the National High Technology Research and Development Program of China(No.2001AA216121)+3 种基金National Natural Science Foundation of China(No.30040003)Projects of Shanghai Science&Technology Development Foundation(No.99DJ14002,00DJ14033,01DJ14003)the Chinese Academy of Sciences(No.KSCX-2-3-08)Shanghai Municipal Education Commission and by Shanghai Second Medical University
文摘To solve the problem of immune incompatibility, nuclear transplantation has been envisaged as a means to produce cells or tissues for human autologous transplantation. Here we have derived embryonic stem cells by the transfer of human somatic nuclei into rabbit oocytes. The number of blastocysts that developed from the fused nuclear transfer was comparable among nuclear donors at ages of 5, 42, 52 and 60 years, and nuclear transfer (NT) embryonic stem cells (ntES cells) were subsequently derived from each of the four age groups. These results suggest that human somatic nuclei can form ntES cells independent of the age of the donor. The derived ntES cells are human based on karyotype, isogenicity, in situ hybridization, PCR and immunocytochemistry with probes that distinguish between the various species. The ntES cells maintain the capability of sustained growth in an undifferentiated state, and form embryoid bodies, which, on further induction, give rise to cell types such as neuron and muscle, as well as mixed cell populations that express markers representative of all three germ layers. Thus, ntES cells derived from human somatic cells by NT to rabbit eggs retain phenotypes similar to those of conventional human ES cells, including the ability to undergo multilineage cellular differentiation.
基金supported by the national“973”tissue engineering project of China(G1999054300)Shanghai Science and Technology Development Foundation(03DJ14021)
文摘Endothelial cells (TEC_3 cells) derived from mouse embryonic stem (ES) cells were used as seed cells to construct blood vessels. Tissue engineered blood vessels were made by seeding 8 × 10~6 smooth muscle cells (SMCs) obtained from rabbit arteries onto a sheet of nonwoven polyglycolic acid (PGA) fibers, which was used as a biodegradable polymer scaffold. After being cultured in DMEM medium for 7 days in vitro, SMCs grew well on the PGA fibers, and the cell-PGA sheet was then wrapped around a silicon tube, and implanted subcutaneously into nude mice. After 6~8 weeks, the silicon tube was replaced with another silicon tube in smaller diameter, and then the TEC_3 cells (endothelial cells differentiated from mouse ES cells) were injected inside the engineered vessel tube as the test group. In the control group only culture medium was injected. Five days later, the engineered vessels were harvested for gross observation, histological and immunohistochemical analysis. The preliminary results demonstrated that the SMC-PGA construct could form a tubular structure in 6~8 weeks and PGA fibers were completely degraded. Histological and immunohistochemical analysis of the newly formed tissue revealed a typical blood vessel structure, including a lining of endothelial cells (ECs) on the lumimal surface and the presence of SMC and collagen in the wall. No EC lining was found in the tubes of control group. Therefore, the ECs differentiated from mouse ES cells can serve as seed cells for endothelium lining in tissue engineered blood vessels.
文摘In our previous study, five homologous feeder cell lines, Monkey ear skin fibroblasts (MESFs), clonally derived fibroblasts from the MESFs (CMESFs), monkey oviductal fibroblasts (MOFs), monkey follicular granulosa fibroblast-like (MFGs) cells, monkey follicular granulosa epithelium-like (MFGEs) cells, were developed for the maintenance of rhesus embryonic stem cells (rESCs). We found that MESFs, CMESFs, MOFs and MFGs, but not MFGEs, support the growth of rhesus embryonic stem cells. Moreover, we detected some genes that are upregulated in supportive feeder cell lines by semi-quantitative PCR. In the present study, we applied the GeneChip Rhesus Macaque Genome Array of Affymetrix Corporation to study the expression profiles of these five feeder cell lines, in purpose to find out which cytokines and signaling pathways were important in maintaining the rESCs, mRNAs of eight genes, including GREM2, bFGF, KITLG, DKK3, GREM1, AREG, SERPINF1 and LTBP1, were found to be upregulated in supportive feeder cell lines, but not in MFGE. The results indicate that many signaling pathways may play redundant roles in supporting the undifferentiated growth and maintenance of pluripotency in rESCs.
文摘Pluripotency of embryonic stem cells(ESCs) and induced pluripotent stem cells is regulated by a well characterized gene transcription circuitry. The circuitry is assembled by ESC specific transcription factors, signal trans-ducing molecules and epigenetic regulators. Growing understanding of stem-like cells, albeit of more complex phenotypes, present in tumors(cancer stem cells), provides a common conceptual and research frame-work for basic and applied stem cell biology. In this review, we highlight current results on biomarkers, gene signatures, signaling pathways and epigenetic regulators that are common in embryonic and cancer stem cells. We discuss their role in determining the cell phenotype and finally, their potential use to design next generation biological and pharmaceutical approaches for regenerative medicine and cancer therapies.