[Show abstract][Hide abstract] ABSTRACT: Introduction
Bone marrow mesenchymal stem cells (BMSCs) possess low immunogenicity and immunosuppression as an allograft, can differentiate into insulin-producing cells (IPCs) by in vitro induction, and may be a valuable cell source to regenerate pancreatic islets. However, the very low differentiation efficiency of BMSCs towards IPCs under adherent induction has thus far hindered the clinical exploitation of these cells. The aim of this study is to explore a new way to efficiently induce BMSCs into IPCs and lay the groundwork for their clinical exploitation.
In comparison with adherent induction, BMSCs of human first-trimester abortus (hfBMSCs) under a nonadherent state were induced towards IPCs in noncoated plastic dishes using a three-stage induction procedure developed by the authors. Induction effects were evaluated by statistics of the cell clustering rate of induced cells, and ultrastructural observation, dithizone staining, quantitative polymerase chain reaction and immunofluorescence assay, insulin and c-peptide release under glucose stimulus of cell clusters, as well as transplantation test of the cell clusters in diabetic model mice.
With (6.175 ± 0.263) × 105 cells in 508.5 ± 24.5 cell clusters, (3.303 ± 0.331) × 105 single cells and (9.478 ± 0.208) × 105 total cell count on average, 65.08 ± 2.98% hfBMSCs differentiated into pancreatic islet-like cell clusters after nonadherent induction. With (3.993 ± 0.344) × 105 cells in 332.3 ± 41.6 cell clusters, (5.437 ± 0.434) × 105 single cells and (9.430 ± 0.340) × 105 total cell count on average, 42.37 ± 3.70% hfBMSCs differentiated into pancreatic islet-like cell clusters after adherent induction (P < 0.01, n = 10). The former is significantly higher than the latter. Calculated according to the cell clustering rate and IPC percentage in the cell clusters, 29.80 ± 3.95% hfBMSCs differentiated into IPCs after nonadherent induction and 18.40 ± 2.08% hfBMSCs differentiated into IPCs after adherent induction (P < 0.01, n = 10), the former significantly higher than the latter. The cell clusters expressed a broad gene profile related to pancreatic islet cells, released insulin and c-peptide in a glucose concentration-dependent manner, and normalized hyperglycemia of streptozocin-induced mice for at least 80 days following xenograft. Blood glucose of grafted mice rose again after their graft removed. A series of examination of the grafts showed that transplanted cells produced human insulin in recipients.
Our studies demonstrate that nonadherent induction can greatly promote BMSCs to form pancreatic islet-like cell clusters, thereby improving the differentiation efficiency of BMSCs towards IPCs.
Preview · Article · May 2014 · Stem Cell Research & Therapy
[Show abstract][Hide abstract] ABSTRACT: The small molecule 6-bromoindirubin-30-oxime (BIO), a glycogen synthase kinase 3 (GSK3) inhibitor, is a pharmacological agent known to maintain self-renewal in human and mouse embryonic stem cells (ESCs). However, the precise role of GSK3 in immortalized pancreatic mesenchymal stem cells (iPMSCs) growth and survival is not completely understood at present.
To determine whether this molecule is involved in controlling the proliferation of iPMSCs, we examined the effect of BIO on iPMSCs. We found that the inactivation of GSK3 by BIO can robustly stimulate iPMSCs proliferation and mass formation as shown by QRT-PCR, western blotting, 5-Bromo-2-deoxyuridine (BrdU) immunostaining assay and tunel assay. However, we did not find the related roles of BIO on β cell differentiation by immunostaining, QRT-PCR assay, glucose-stimulated insulin release and C-peptide content analysis.
These results suggest that BIO plays a key role in the regulation of cell mass proliferation and maintenance of the undifferentiated state of iPMSCs.
[Show abstract][Hide abstract] ABSTRACT: Islet replacement therapy is limited by shortage of donor islet cells. Usage of islet cells derived from porcine pancreatic stem cells (PSCs) is currently viewed as the most promising alternative for human islet transplantation. However, PSCs are rare and have a finite proliferative lifespan. In this study, we isolated and established an immortalized mesenchymal stem cell (MSC) line derived from foetal porcine pancreas, by transfecting human telomerase reverse transcriptase (hTERT) and called these immortalized pancreatic mesenchymal stem cells (iPMSCs). The iPMSCs have been cultured for more than 80 passages and have capacity to differentiate into neurons, cardiomyocytes, germ cells and islet-like cells, analysed by morphology, RT-PCR, western blotting, immunofluorescence, immunocytochemistry and transplantation assay. Islets derived from iPMSCs reversed hyperglycaemia in streptozotocin-induced diabetic mice and secreted insulin and C-peptide in vitro. These results demonstrated that iPMSCs might provide unlimited resources for islet replacement therapy and models for functional cell differentiation.
No preview · Article · Feb 2011 · Cell Proliferation
[Show abstract][Hide abstract] ABSTRACT: Bone marrow mesenchymal stem cells (BMSCs) have been reported to possess low immunogenicity and cause immunosuppression of recipients when allografted. They can differentiate into insulin-producing cells and may be a valuable source for islet formation. However, the extremely low differentiating rate of adult BMSCs toward insulin-producing cells and the insufficient insulin secretion of the differentiated BMSCs in vitro prevent their clinical use in diabetes treatment. Little is known about the potential of cell replacement therapy with human BMSCs. Previously, we isolated and identified human first-trimester fetal BMSCs (hfBMSCs). Under a novel four-step induction procedure established in this study, the hfBMSCs effectively differentiated into functional pancreatic islet-like cell clusters that contained 62 ± 14% insulin-producing cells, expressed a broad gene profile related to pancreatic islet β-cell development, and released high levels of insulin (2.245 ± 0.222 pmol/100 clusters per 30 min) and C-peptide (2.200 ± 0.468 pmol/100 clusters per 30 min) in response to 25 mmol/L glucose stimulus in vitro. The pancreatic islet-like cell clusters normalized the blood glucose level of diabetic model mice for at least 9 weeks when xenografted; blood glucose levels in these mice rose abnormally again when the grafts were removed. Examination of the grafts indicated that the transplanted cells survived in recipients and produced human insulin and C-peptide in situ. These results demonstrate that hfBMSCs derived from a human first-trimester abortus can differentiate into pancreatic islet-like cell clusters following an established four-step induction. The insulin-producing clusters present advantages in cell replacement therapy of type 1 diabetic model mice.
No preview · Article · Dec 2010 · Rejuvenation Research
[Show abstract][Hide abstract] ABSTRACT: The integrity and transparency of cornea plays a key role in vision. Limbal Stem Cells (LSCs) are precursors of cornea, which are responsible for self-renewal and replenishing corneal epithelium. Though it is successful to cell replacement therapy for impairing ocular surface by Limbal Stem Cell Transplantation (LSCT), the mechanism of renew is unclear after LSCT. To real time follow-up the migration and differentiation of corneal transplanted epithelial cells after transplanting, we transfected venus (a fluorescent protein gene) into goat LSCs, selected with G418 and established a stable transfected cell line, named GLSC-V. These cells showed green fluorescence, and which could maintain for at least 3 months. GLSC-V also were positive for anti-P63 and anti-Integrinbeta1 antibody by immunofluorescent staining. We founded neither GLSC-V nor GLSCs expressed keratin3 (k3) and keratinl2 (k12). However, GLSC-V had higher levels in expression of p63, pcna and venus compared with GLSCs. Further, we cultivated the cells on denude amniotic membrane to construct tissue engineered fluorescent corneal epithelial sheets. Histology and HE staining showed that the constructed fluorescent corneal epithelial sheets consisted of 5-6 layers of epithelium. Only the lowest basal cells of fluorescent corneal epithelial sheets expressed P63 analyzed by immunofluorescence, but not superficial epithelial cells. These results showed that our constructed fluorescent corneal epithelial sheets were similar to the normal corneal epithelium in structure and morphology. This demonstrated that they could be transplanted for patents with corneal impair, also may provide a foundation for the study on the mechanisms of corneal epithelial cell regeneration after LSCT.
No preview · Article · Dec 2010 · Sheng wu gong cheng xue bao = Chinese journal of biotechnology
[Show abstract][Hide abstract] ABSTRACT: The transcription factors (Oct4, Sox2, c-Myc, and Klf4) play an important role in the generation of induced pluripotent stem cells. These factors are expressed in metaphase II oocytes and embryonic stem cells (ESCs). The mechanisms responsible for the reprogramming of ooplasm during nuclear transfer are expected to be associated with the four factors. Here, we show that different paternal genetic backgrounds are able to influence the in vitro development of parthenogenetic and cloned embryos. Using real- time polymerase chain reaction (PCR) we found that the expression level of Oct4 in oocytes was less than that of ESCs, whereas oocytes from KM x C3H females showed the highest expression level of Sox2 than the other strains tested or in G1 ESCs. c-Myc mRNA levels in oocytes from KM mice were greater than those found in ESCs or oocytes of KM x C3H mice. These data demonstrate that the expression of the four transcription factors was different among the oocytes, which may be a contributing factor for the different efficiencies of parthenogenesis and the development of cloned embryos in vitro.
[Show abstract][Hide abstract] ABSTRACT: Recent results have shown that bone marrow mesenchymal stem cells (BMSCs) from human first-trimester abortus (hfBMSCs) are closer to embryonic stem cells and perform greater telomerase activity and faster propagation than mid- and late-prophase fetal and adult BMSCs. However, no research has been done on the plasticity of hfBMSCs into neuronal cells using single-cell cloned strains without cell contamination. In this study, we isolated five single cells from hfBMSCs and obtained five single-cell cloned strains, and investigated their biological property and neuronal differentiation potential. We found that four of the five strains showed similar expression profile of surface antigen markers to hfBMSCs, and most of them differentiated into neuron-like cells expressing Nestin, Pax6, Sox1, β-III Tubulin, NF-L, and NSE under induction. One strain showed different expression profile of surface antigen markers from the four strains and hfBMSCs, and did not differentiate toward neuronal cells. We demonstrated for the first time that some of single-cell cloned strains from hfBMSCs can differentiate into nerve tissue-like cell clusters under induction in vitro, and that the plasticity of each single-cell cloned strain into neuronal cells is different.
[Show abstract][Hide abstract] ABSTRACT: In order to construct the recombinant retrovirus vector of human ngn3 gene and its packaging cell line, we successfully amplified the open reading frame (ORF) of ngn3 gene from human fetal pancreatic tissue by RT-PCR. The PCR products of human ngn3 gene was subcloned into pMD18-T vectors and sequenced. Results showed that its sequence was fully consistent with the ngn3 gene published in GenBank(GenBank Accession No. BC126468). The correct fragment was digested by EcoR I and Hpa I from recombinant pMD18-T vector and inserted into the same restriction enzyme sites of retroviral vector pMSCV-neo. We got recombinant retrovirus vector pMSCV-ngn3, which was identified by double restriction enzyme digestion and then transfected into PT67 cells by lipofectamine 2000. We established the PT67-ngn3 packaging cell line by G418 selection, which was detected by RT-PCR and immunohistochemistry staining. The detection results showed that the Ngn3 expressed at the mRNA and protein level in the packaging cell line. RT-PCR detection and electronic microscope analysis showed that the recombinant retroviral vector pMSCV-ngn3 was packaged into infectious virus particles and released into the supernatant of the cells. These results demonstrated that a PT67-ngn3 packaging cell line was successfully established, and this could facilitate the study of differentiation of the human fetal pancreatic progenitor cells into insulin-producing cells by using the ngn3 gene.
Preview · Article · Apr 2010 · Sheng wu gong cheng xue bao = Chinese journal of biotechnology
[Show abstract][Hide abstract] ABSTRACT: Diabetes mellitus affects millions of people in the world. Islet replacement strategies are becoming increasingly attractive options for patients at risk for severe diabetic complications. A major limitation of these approaches is the limited number of organs and the efficacy, safety and supply that restrict the available for islet transplantation. Recently, scientists have reported that stem cells promise a plentiful and flexible source for transplantation therapy. Here we used 10 ng/mL hepatocyte growth factor (HGF), 10 μM nicotinamide in PRMI 1640 to induce human embryonic germ cells (hEGCs) to differentiate into insulin producing cells. The results demonstrate that HGF and nicotinamide can promote the efficacy of insulin-secreting cells formation derived from embryoid bodies (EBs) derived hEGCs. The percentage of Dithizone (DTZ) positive, insulin, PDX-1, CK-19, Nestin positive in induced groups were significantly higher than the control. More importantly, levels of insulin-secreting after stimulation with high concentration glucose in inducing cells were significantly higher than the control (P
[Show abstract][Hide abstract] ABSTRACT: In order to construct the recombinant retrovirus vector of bovine sox2 gene and obtain infectious retroviral particles, we successfully amplified the ORF (open reading frame) of bovine sox2 gene from the primodial genital ridges of bovine embryo by RT-PCR. The cDNA of ORF was subcloned to pMD18-T vectors and verified that its sequence was highly homologous to the GenBank counterpart (GenBank Accession No. NM-001105463) by sequencing. The correct fragment was digested by EcoR I/Bgl II from recombinant pMD18-T vector and inserted into the same restriction sites f retroviral vector pMSCVneo. We got recombinant retrovirus vector pMSCV-sox2 which was transfected into PT67 by lipofectamine 2000 with pMIG (including green fluorescence protein) as a control. Flow cytometry analysis showed that its transfected efficiency was 68.3%. Subsequently, we established the stable cell strain by G418 selection which could produce virus. Its viral titer was up to 8.16x10(7) CFU/mL. This greatly facilitates the further study of bovine induced pluripotent stem cells induced from bovine somatic cells by defined factors.
Preview · Article · Oct 2009 · Sheng wu gong cheng xue bao = Chinese journal of biotechnology
[Show abstract][Hide abstract] ABSTRACT: Pluripotent mesenchymal stem-like cell lines were established from lungs of 3-4 months old aborted fetus. The cells present the high ex vivo expansion potential of MSC, a typical fibroblast-like morphology and proliferate up to 15 passages without displaying clear changes in morphology. Immunological localization and flow cytometry analyses showed that these cells are positive for OCT4, c-Kit, CD11, CD29, CD44, telomerase, CD106, CD105, CD166, and SSEA1, weakly expression or negative for SSEA1, SSEA3, SSEA4, CD34, CD105 and CD106. These cells can give rise to the adipogenic as evidenced by accumulation of lipid-rich vacuoles within cells identified by Oil-red O when they were induced with 0.5 mM isobutylmethylxanthine, 200 microM indomethacin, 10(-6)M dexamethasone, and 10 microg/ml of insulin in high-glucose DMEM. Osteogenic lineage cells were generated in 0.1 microM dexamethasone, 50 microg/ml ascorbic acid, 10 mM beta-glycerophosphate, which are shaped as the osteoblastic morphology, expression of alkaline phosphatase (AP), and the formation of a mineralized extracellular matrix identified by Alizarin Red staining. Neural cells are observed when the cultures were induced with 2-mercapometal, which are positive for nestin, NF-100, MBP and GFAP. Additionally, embryoid bodies (EBs) and sperm like cells are obtained in vitro differentiation of these lung MSCs induced with 10(-5)M retinoic acid (RA). These results demonstrated that these MSCs are pluripotent and may provide an in vitro model to study germ-cell formation and also as a potential source of sperms for male infertility.
[Show abstract][Hide abstract] ABSTRACT: To optimize program of bovine somatic nuclear transfer, we used two different enucleation procedures (by Spindle-view system & Hoechst 33342 staining), two different procedures to introduce donor nuclei (by ooplasm microinjection & electrofusion), and three different group electrofusion parameters (group 1: 1.9 kV/cm, 10 micros, two; group 2: 1.5 kV/cm, 25 micros, two; group 3: 0.6 kV/cm, 100 micros, one) to reconstruct bovine cloned embryos. The cleavation rates and blastocyst development rates of cloned embryos were used to assess the efficiency of different operational procedure. Finally, the best combination of operational procedure, that the spindle-viewer system was used for oocytes enucleating, and donor cell was electrofused into ooplasm by electrical pulse (1.9 kV/cm, 10 micros, two) to reconstruct bovine cloned embryos. Then the excellent blastocysts were transferred to fosters for producing cloned cattle 80 high-quality cloned blastocysts were transferred into 33 fosters, two cloned calves were produced. According to the results, the optimized program could be used to produce cloned cattle.
No preview · Article · Sep 2009 · Sheng wu gong cheng xue bao = Chinese journal of biotechnology
[Show abstract][Hide abstract] ABSTRACT: This study examined the effects of a chemically defined culture medium supplement, knock-out serum replacement (KSR), on the growth and differentiation of human embryonic germ cells (hEgc) and found that the efficiency of the initial establishment of hEGC lines in KSR medium was significantly higher than in fetal calf serum (FCS) medium. The percentage of undifferentiated hEGC colonies growing in KSR medium was significantly higher than in FCS-based medium (P < 0.05). The hEGC colonies showed typical mouse embryonic germ cell-like morphology. They showed normal and stable diploid karyotype and expressed alkaline phosphatase (AP), stage-specific embryonic antigens (SSEA) and other specific markers of pluripotent cells. In addition, hEGC could form simple and cystic embryoid bodies (EB) that consisted of various cell types including neural, epithelial and rhythmically beating cardiac cells, even sperm-like and oocyte-like cells. Tumour-like outgrowths were formed in nude mice and found to contain a variety of cell types, including uterine epithelium, adipocytes, squamous tissue and skin structures. In conclusion, an appropriate serum-free culture system has been developed for the establishment of hEGC lines. This may provide an in-vitro model to study differentiation and can be used as a potential source of therapy for infertility and regenerative medicine.
[Show abstract][Hide abstract] ABSTRACT: The aim of this study is to investigate effects of 5-azacytidine (5-aza) induction duration on differentiation of bone marrow mesenchymal stem cells (MSCs) from human first-trimester abortus (hfMSCs) towards cardiomyocyte-like cells. hfMSCs were stimulated with 10 micromol/l 5-aza for 24 h (group A), 48 h (group B) and 21 days (group C), respectively. During the induction, 30-40% of the cells gradually enlarged, elongated, connected with adjoining cells and formed myotube-like structures, branches and string-bead-like nuclei. Some of the cells congregated into cell clusters or strips. After the induction, numerous myofilaments in the cytoplasm and conjunction of intercalated disc-like structure between adjoining cells were observed. The induced cells expressed messenger ribonucleic acids (mRNAs) and proteins of myocardium-specific alpha-actin, sarcomeric beta-myocin heavy chain and troponin-T. The positive cell percentages for the three antigens in group C were each significantly higher than those antigens in group A and B (P<0.01) and the cell population doubling time (PDT) of group C was longer than those of group A and B (P<0.01). These indicate that 21-d induction with 10 micromol/l 5-aza slows down proliferation speed of hfMSCs but increases differentiation rate of hfMSCs into cardiomyocyte-like cells if compared with 24-48 h induction.
Preview · Article · Sep 2009 · Interactive Cardiovascular and Thoracic Surgery
[Show abstract][Hide abstract] ABSTRACT: Mesenchymal stem cells derived from bone marrow are a well characterized population of adult stem cells that can be maintained and propagated in culture for a long time with the capacity to form a variety of cell types. Reports have shown that murine and human embryonic stem cells can differentiate into primordial germ cells and then to early gametes. Evidence has indicated that some adult stem cells also have the potential to differentiate into germ cells. Currently, there are no reports on directed differentiation of human mesenchymal stem cells into germ cells. This study investigated the ability of retinoic acid and testicular extracts to induce human bone marrow stem cells (hBMSC) to differentiate into male germ cells. It was found that a small population of hBMSC seem to transdifferentiate into male germ cell-like cells. These cells expressed early germ cell markers OCT4, STELLA, NANOG and VASA, and male germ-ceil-specific markers such as DAZL, TH2, c-kit, beta(1)-integrin, ACR, PRMl, FSHR, STRA8 and SCP3, as analysed by reverse transcription-polymerase chain reaction and immunohistochemistry. These results demonstrated that hBMSC may differentiate into male germ cells and the same could be used as a potential source of cells for reproductive toxicological studies.
No preview · Article · Feb 2009 · Reproductive biomedicine online
[Show abstract][Hide abstract] ABSTRACT: In order to purify the cardiomyocytes derived stem cells, we constructed an expression vector, alpha -actin-pEGFP-N1 which consists of EGFP gene as reporter markers, and driven by human cardiac alpha-actin promoter, then transfected it into human embryonic germ cells(hEGCs) by Lipofectamine2000. Fluorescent observation and immunocytochemistry staining demonstrated that transfected hEGCs could differentiate into cardiomyocyte like cells and expressed GFP. The results suggest that this system may provide a model for the study of cardiogenesis and differentiation.
[Show abstract][Hide abstract] ABSTRACT: We describe a procedure to construct an artificial corneal epithelium from cryopreserved limbal stem cells (LSCs) for corneal transplantation. The LSCs were separated from limbal tissue of male goats. The primary LSCs were identified by flow cytometry and were expanded. They were examined for stem cell-relevant properties and cryopreserved in liquid nitrogen. Cryopreserved LSCs were thawed and then transplanted onto human amniotic membrane, framed on a nitrocellulose sheet, to construct corneal epithelium sheets. The artificial corneal epithelium was transplanted into the right eye of pathological models of total limbal stem cell deficiency (LSCD). Then, the effects of reconstruction were evaluated by clinical observation and histological examination. Polymerase chain reaction analysis was used to detect the SRY gene. The data showed that transplantation of cryopreserved LSCs, like fresh LSCs, successfully reconstructed damaged goat corneal surface gradually, but the SRY gene expression from male goat cells could only be detected in the first 2 months after transplantation. The therapeutic effect of the transplantation may be associated with the inhibition of inflammation-related angiogenesis after transplantation of cryopreserved LSCs. This study provides the first line of evidence that cryopreserved LSCs can be used for reconstruction of damaged corneas, presenting a remarkable potential source for transplantation in the treatment of corneal disorders.
Preview · Article · Nov 2008 · Molecular Reproduction and Development
[Show abstract][Hide abstract] ABSTRACT: Sodium/proton exchanger 1 (NHE1) plays an important role in the cardiomyocyte development. To study the effect of NHE1 activity in stem cells differentiation into cardiomyocytes, we treated P19 stem cells with dimethyl sulfoxide (DMSO) to initiate cardiomyocyte differentiation. In separate experiments, P19 cells were incubated with NHE1 specific inhibitor EMD87580 during the DMSO induction. The formed embryoid bodies (EBs) were detected with cell morphology detection, immunohistochemisty staining and RT-PCR analysis of expression of cardio-specific gene markers. Results showed that P19 cells were able to differentiate into cardiomyocytes and form the beating cell clusters. However, when cells treated with NHE1 inhibitor EMD87580, they could still form the EBs and proliferate when cell clusters adhered on the culture plate, but cells were unable to differentiate. This observation indicates that inhibition of NHE1 activity affected P19 stem cells differentiating into cardiomyocytes.
No preview · Article · Nov 2008 · Sheng wu gong cheng xue bao = Chinese journal of biotechnology
[Show abstract][Hide abstract] ABSTRACT: To investigate the effect of 1,25(OH)2VD3 on differentiation of embryonic stem cells (ESCs) into osteoblasts.
Osteoblasts were isolated and cultured from calvarium of 2-day-old Kunming white mice, embryoid bodies (EBs) were prepared with modified zur Nieden method. EBs were divided into 4 groups according to different mediums: group A, as the control group, in which EBs medium contained no leukemia inhibitory factor; group B, in which EBs medium contained supplements of Vitamin C (VC, 50 microg/mL) and beta-glycerophosphate (beta-GP, 50 mmol/L); group C, in which EBs medium was the same as that of group B and 5 x 10(4) osteoblasts of 3rd passage were seeded into each well; group D, in which the medium contained supplements of VC (50 microg/mL), beta-GP (50 mmol/L) and 1,25(OH)2VD3 (4 x 10(-9) mol/L), and 5 x 10(4) osteoblasts of 3rd passage were seeded into each well. The ALP activity was determined by ALP reagent kit every 5 days. The RQ-PCR was performed to measure the mRNA expressions of osteocalcin (OCN). Alizarin red S staining was performed to count the bone nodules.
The expression of ALP witnessed no obvious change in each group within 5 days after adherence of EBs, but increased gradually after 5 days. The expression of ALP in group D reached the peak at 20 days. Red nodules with clear outline and different sizes were evident by microscope. Alizarin red S staining testified the number of bone nodules in groups A, B, C and D was 20 +/- 8, 18 +/- 5, 31 +/- 1 and 50 +/- 1, respectively, indicating significant differences between groups C, D and groups A, B (P < 0.05), no significant difference between group A and group B (P > 0.05), and a significant difference between group C and group D (P < 0.05). The result of RQ-PCR showed that the mRNA expressions of OCN in groups A, B, C and D was 10.18 +/- 1.17, 20.29 +/- 1.03, 18.84 +/- 4.07 and 32.15 +/- 5.23, respectively, indicating significant differences between groups C, D and groups A, B (P < 0.05), no significant difference between group A and group B (P > 0.05), and a significant difference between group C and group D (P < 0.05).
The combined action of 1,25(OH)2VD3 (4 x 10(-9) mol/L), VC, and beta-GP can effectively promote the differentiation of the ESCs-derived osteoblasts.
Preview · Article · Oct 2008 · Zhongguo xiu fu chong jian wai ke za zhi = Zhongguo xiufu chongjian waike zazhi = Chinese journal of reparative and reconstructive surgery
[Show abstract][Hide abstract] ABSTRACT: The major obstacle in using pancreatic islet transplantation to cure type I and some type II diabetes is the shortage of the donors. One of ways to overcome such obstacle is to isolate and clone pancreatic stem cells as "seed cells" and induce their differentiation into functional islets as an abundant transplantation source. In this study, a monoclonal human pancreatic stem cell (mhPSC) line was obtained from abortive fetal pancreatic tissues. Pancreatic tissues were taken from abortive fetus by sterile procedures, and digested into single cells and cell clusters with 0.1% type IV collagenase. Cultured in modified glucose-low DMEM with 10% fetal bovine serum (FBS), these single cells and cell clusters adhered to culture dishes, and then primary epidermal-like pancreatic stem cells started to clone. After digesting with 0.25% trypsin and 0.04% EDTA, fibroblasts and other cells were gradually eliminated and epithelioid pancreatic stem cells were gradually purified during generations. Using clone-ring selection, the mhPSCs were obtained. After addition of 10 ng/mL epidermal growth factor (EGF) in cell culture medium, the mhPSCs quickly grew and formed a gravelstone-like monolayer. Continuously proliferated, a mhPSC line, which was derived from a male abortive fetus of 4 months old, has been passed through 50 generations. More than 1 x 10(9) mhPSCs were cryo-preserved in liquid nitrogen. Karyotype analysis showed that the chromosome set of the mhPSC line was normal diploid. Immunocytochemistry results demonstrated that the mhPSC line was positive for the pdx1, glucagon, nestin and CK19, and negative for the insulin, CD34, CD44 and CD45 protein expression. RT-PCR revealed further that the mhPSCs expressed transcription factors of the pdx1, glucagon, nestin and CK19. Also, in vitro induced with beta-mercaptoethanol, the mhPSCs differentiated into nerve cells that expressed the NF protein. Induced with nicotinamide, the mhPSCs differentiated into functional islet-like clusters, as identified by dithizone staining, which expressed the transcription factor of the insulin and secreted the insulin and C-peptide. Furthermore, the transplantation of mhPSCs-induced pancreatic islets into the subcapsular region of the kidney in streptozotocin-induced diabetic rats could reduce blood glucose levels and prolong the life time.
No preview · Article · Oct 2008 · Science in China Series C Life Sciences