Stem cell research is a innovative technology that focuses on using undifferentiated cells able to self-renew through the asymmetrical or symmetrical divisions. Three types of stem cells have been studied in laboratory including embryonic stem cell, adult stem cells and induced pluripotent stem cells. Embryonic stem cells are pluripotent stem cells derived from the inner cell mass and it can give rise to any fetal or adult cell type. Adult stem cells are multipotent, have the ability to differentiate into a limited number of specialized cell types, and have been obtained from the bone marrow, umbilical cord blood, placenta and adipose tissue. Stem cell therapy is the most promising therapy for several degenerative and devastating diseases including digestive tract disease such as liver failure, inflammatory bowel disease, Celiac sprue, and pancreatitis. Further understanding of biological properties of stem cells will lead to safe and successful stem cell therapies.
Adult Stem Cells/cytology/metabolism/transplantation ; Embryonic Stem Cells/cytology/metabolism/transplantation ; Humans ; Induced Pluripotent Stem Cells/cytology/metabolism/transplantation ; Stem Cells/*cytology/metabolism

OBJECTIVETo investigate the telomerase activity of human adipose derived stem cells (ADSCs) during proliferation and differentiation in vitro.

METHODSADSCs were highly purified and cultured in vitro. The morphology, phenotype and biological properties of the cultured ADSCs were observed by flow cytometer. Then ADSCs were induced to differentiate into adipocytes and osteoblast. The telomerase activity was detected by TRAP.

RESULTSADSCs had the ability of multi-directed differentiation, like adipocytes and osteoblast. It could also express the stem cell-related surface markers. The telomerase activity was negative or lowly expressed in ADSCs in vitro within 12 generations. The telomerase activity was up-regulated when ADSCs was adipogenic differentiated, but deceased 3-6 days later.

CONCLUSIONSThe telomerase activity of ADSCs is not changed during culture in vitro. It is up-regulated when ADSCs are induced to adipogenic differentiation, but decreased later.

Adipocytes ; cytology ; metabolism ; Adult ; Cell Differentiation ; Cell Proliferation ; Cells, Cultured ; Female ; Humans ; Mesenchymal Stromal Cells ; cytology ; metabolism ; Stem Cells ; cytology ; metabolism ; Telomerase ; metabolism ; Young Adult

OBJECTIVETo isolate human adipose tissue-derived stromal cells and study the potential of osteogenic differentiation after inductive culture.

METHODSLiposuction human adipose tissues were minced and digested with collagenase type I. The obtained stromal cells were plated in BGJb medium as primary culture for ten days. The second passage cells were harvested and plated in DMEM/F12 medium supplemented with 10% FBS, 5% horse serum and 50 micromol/L hydrocortisone for myogenic induction culture. The cell-anchored slips were removed and fixed in 4% formaldehydam polymerisatum. Toluidine blue, Mallory's phosphotungstic hematoxylin staining and monoclonal antibody to human skeletal muscle myosin heavy chain immunocytochemical methods were used to assay the differentiation of cells.

RESULTSIt was observed that the size and shape of induced cells were much different from those of non-induced cells. Toluidine blue, Mallory's phosphotungstic hematoxylin staining demonstrated there were many basophilic striations within cytoplasm and multinucleated myotubes were formed. Immunocytochemical stain indicated that characterastic skeletal myosin heavy chain was positive in myogenic induced cells.

CONCLUSIONIt seems that human adipose tissue represents an abundant reservoir of adult stem cells that have multi-germline potential to differentiate into myoblasts. Adipose tissue derived stromal cells will be another alternative source for cell-based tissue engineering in skeletal muscle reconstruction.

Adipose Tissue ; cytology ; Adult Stem Cells ; cytology ; Cell Differentiation ; Cell Separation ; Cells, Cultured ; Culture Media ; Humans ; Myoblasts ; cytology ; Myosin Heavy Chains ; metabolism ; Stromal Cells ; cytology

OBJECTIVETo investigate whether adipose-derived stem cells (ADSCs) induced by retinoic acid (RA) in vitro express primordial germ cell marker alkaline phosphatase (ALP) and vasa.

METHODSADSCs were isolated from adult female SD rats and cultured in vitro. The third passage of ADSCs was identified by adipogenic differentiation, osteogenic differentiation and cell surface marker detection. The ADSCs were treated with 1×10(-5), 1×10(-6), or 1×10(-7) mol/L RA for 7 or 14 days, and the cellular expression of ALP was detected. vasa mRNA expression in ADSCs treated with 1×10(-5) mol/L RA for 7 days was detected using RT-PCR.

RESULTSThe OD value of ADSCs treated with 1×10(-5), 1×10(-6), or 1×10(-7) mol/L RA was 0.59∓0.04, 0.27∓0.07, and 0.15∓0.03 after a 7-day treatment, and was 0.42∓0.02, 0.34∓0.01, and 0.19∓0.02 after a 14-day treatment, respectively, demonstrating significantly enhanced ALP expression in RA-treated ADSCs compared with that in the control cells (0.07∓0.01 and 0.07∓0.01 at 7 and 14 days, respectively, P<0.01). The ADSCs showed a negative vasa mRNA expression after 1×10(-5) mol/L RA treatment for 7 days.

CONCLUSIONRA-induced ADSCs express ALP, a marker of primordial germ cells, but does not express the primordial germ cell marker vasa.

Adipose Tissue ; cytology ; Adult Stem Cells ; cytology ; enzymology ; Alkaline Phosphatase ; metabolism ; Animals ; Cell Differentiation ; Cells, Cultured ; Female ; Germ Cells ; cytology ; metabolism ; Rats ; Rats, Sprague-Dawley ; Tretinoin ; pharmacology

The purpose of this study was to elucidate the origin and cellular composition of retrocorneal membranes (RCMs) associated with chemical burns using immunohistochemical staining for primitive cell markers. Six cases of RCMs were collected during penetrating keratoplasty. We examined RCMs with hematoxylin and eosin (H&E), periodic acid-Schiff (PAS) staining and immunohistochemical analysis using monoclonal antibodies against hematopoietic stem cells (CD34, CD133, c-kit), mesenchymal stem cells (beta-1-integrin, TGF-beta, vimentin, hSTRO-1), fibroblasts (FGF-beta, alpha-smooth muscle actin), and corneal endothelial cells (type IV collagen, CD133, VEGF, VEGFR1). Histologic analysis of RCMs revealed an organized assembly of spindle-shaped cells, pigment-laden cells, and thin collagenous matrix structures. RCMs were positive for markers of mesenchymal stem cells including beta-1-integrin, TGF-beta, vimentin, and hSTRO-1. Fibroblast markers were also positive, including FGF-beta and alpha-smooth muscle actin (SMA). In contrast, immunohistochemical staining was negative for hematopoietic stem cell markers including CD34, CD133 and c-kit as well as corneal endothelial cell markers such as type IV collagen, CD133 except VEGF and VEGFR1. Pigment-laden cells did not stain with any antibodies. The results of this study suggest that RCMs consist of a thin collagen matrix and fibroblast-like cells and may be a possible neogenetic structure produced from a lineage of bone marrow-derived mesenchymal stem cells.
Adult ; Aged ; Antigens, CD/metabolism ; Cornea/*cytology/pathology ; Cytokines/metabolism ; Endothelial Cells/cytology/metabolism ; Female ; Fibroblasts/cytology/metabolism ; Hematopoietic Stem Cells/cytology/metabolism ; Humans ; Immunohistochemistry ; Intercellular Signaling Peptides and Proteins/metabolism ; Male ; Mesenchymal Stromal Cells/cytology/metabolism ; Middle Aged ; Stem Cells/cytology/*metabolism

BubR1 mitotic checkpoint kinase monitors attachment of microtubules to kinetochores and links regulation of the chromosome-spindle attachment to mitotic checkpoint signaling. Defects in BubR1-mediated signaling severely perturb checkpoint control and are linked to diseases such as cancer. Studies using BubR1 mouse models suggest that BubR1 activities prevent premature aging and infertility. In this study, we show that BubR1 depletion in human adipose-derived mesenchymal stem cells (ASCs) precedes loss of the differentiation potential and induction of replicative senescence. These effects occur independently of p16(INK4A) expression and may involve DNA methylation. Our results reveal a new and unsuspected feature of BubR1 expression in regulation of adult stem cell differentiation.
*Adipogenesis ; Adipose Tissue/*cytology ; Adult ; Cell Aging ; Cells, Cultured ; DNA Methylation ; Gene Expression Regulation ; Genes, p16 ; Humans ; Mesenchymal Stem Cells/*cytology/metabolism ; Protein-Serine-Threonine Kinases/genetics/*metabolism

OBJECTIVETo observe the distribution of epidermal stem cell (ESC) after soft tissue expansion, and to explore dynamic change in ESC under mechanical stress and kinetic mechanism of skin expansion.

METHODSSkin samples were collected from patients after expansion of the scalp. They were divided into three groups: A group (scalp harvested 3 cm away from the center of dilator), B group (scalp tissues at the edge of dilator), and control group (scalp without dilatation). The tissue structures were observed with optical microscope with HE staining. The distribution and differentiation characteristics of cell keratin 19 (CK19) positive cells were observed with inverted phase contrast microscope after immunohistochemistry staining.

RESULTSHE staining showed that the epidermis was thickened and distributed densely with uneven, rugged and increased layers in A, B groups. With immunohistochemistry staining, CK19 positive cells appeared in multilayers in basal membrane, a few of them were in cluster or dispersed , with" hollowing" structure formation. These phenomena were not seen in control group.

CONCLUSIONESC can proliferate with abnormal distribution and "hollowing" structure formation after mechanical dilatation, which may be related to dynamic changes in basal layer cells.

Adolescent ; Adult ; Cell Proliferation ; Cellular Structures ; Epithelial Cells ; cytology ; Humans ; Keratin-19 ; metabolism ; Male ; Stem Cells ; cytology ; Stress, Mechanical ; Tissue Expansion ; Young Adult

Adipose tissue stem cells (ADSCs) would be an attractive autologous cell source. However, ADSCs require invasive procedures, and has potential complications. Recently, urine stem cells (USCs) have been proposed as an alternative stem cell source. In this study, we compared USCs and ADSCs collected from the same patients on stem cell characteristics and capacity to differentiate into various cell lineages to provide a useful guideline for selecting the appropriate type of cell source for use in clinical application. The urine samples were collected via urethral catheterization, and adipose tissue was obtained from subcutaneous fat tissue during elective laparoscopic kidney surgery from the same patient (n = 10). Both cells were plated for primary culture. Cell proliferation, colony formation, cell surface markers, immune modulation, chromosome stability and multi-lineage differentiation were analyzed for each USCs and ADSCs at cell passage 3, 5, and 7. USCs showed high cell proliferation rate, enhanced colony forming ability, strong positive for stem cell markers expression, high efficiency for inhibition of immune cell activation compared to ADSCs at cell passage 3, 5, and 7. In chromosome stability analysis, both cells showed normal karyotype through all passages. In analysis of multi-lineage capability, USCs showed higher myogenic, neurogenic, and endogenic differentiation rate, and lower osteogenic, adipogenic, and chondrogenic differentiation rate compared to ADSCs. Therefore, we expect that USC can be an alternative autologous stem cell source for muscle, neuron and endothelial tissue reconstruction instead of ADSCs.
Adult Stem Cells/*cytology/*immunology/transplantation ; Biomarkers/metabolism ; Cell Differentiation ; Cell Lineage ; Cell Proliferation ; Cell Separation ; Chromosomal Instability ; Colony-Forming Units Assay ; Humans ; Karyotyping ; Multipotent Stem Cells/cytology/immunology/transplantation ; Subcutaneous Fat, Abdominal/*cytology ; Transplantation, Autologous ; Urine/*cytology

CpG-island margins and non-island-CpG sites round the transcription start sites of CpG-island-positive and -negative genes are methylated to various degrees in a tissue-specific manner. These methylation-variable CpG sites were analyzed to delineate a relationship between the methylation and transcription of the tissue-specific genes. The level of tissue-specific transcription was estimated by counting the number of the total transcripts in the SAGE (serial analysis of gene expression) database. The methylation status of 12 CpG-island margins and 21 non-island CpG sites near the key tissue-specific genes was examined in pluripotent stromal cells obtained from fat and bone marrow samples as well as in lineage-committed cells from marrow bulk, stomach, colon, breast, and thyroid samples. Of the 33 CpG sites examined, 10 non-island-CpG sites, but none of the CpG-island margins were undermethylated concurrent with tissue-specific expression of their nearby genes. The net methylation of the 33 CpG sites and the net amount of non-island-CpG gene transcripts were high in stomach tissues and low in stromal cells. The present findings suggest that the methylation of the non-island-CpG sites is inversely associated with the expression of the nearby genes, and the concert effect of transitional-CpG methylation is linearly associated with the stomach-specific genes lacking CpG-islands.
Adipose Tissue/cytology ; Adolescent ; Adult ; Adult Stem Cells/cytology/*metabolism ; Aged ; CpG Islands/*genetics ; *DNA Methylation ; Female ; Gene Expression Profiling ; Humans ; Male ; Middle Aged ; Polymerase Chain Reaction ; Stomach/cytology/*metabolism ; Stromal Cells/metabolism ; Transcription Initiation Site ; Transcription, Genetic

OBJECTIVETo isolate and characterize the dental follicle cells (DFC) from dental follicle (DF) tissues of normal human impacted third molars.

METHODSDFC were isolated from the DF tissues of healthy young human impacted third molars. A limited dilution culture was used to assess DFC colony-forming efficiency. The expressions of Stro-1, Notch-1 and nestin in DFC were detected by immunohistochemistry analysis. The primary DFC cultures were subjected to a variety of treatment modes: osteogenic, adipogenic and chondrogenic differentiation. DFC and periodontal ligament cells (PDLC) proliferation abilities were compared by methyl thiazolyl tetrazolium (MTT) assay. The expressions of tenascin-N and F-spondin in DFC and PDLC were evaluated by reverse transcriptase polymerase chain reaction (RT-PCR).

RESULTSMost DFC were spindle fibroblast-like cells. DFC cultures formed colonies from passage 1 cells and the frequency of colony forming efficiency (CFE) was 3.70%. Some of the DFC were stained positively for Stro-1 and almost all the DFC were stained positively for Notch-1 and nestin. DFC cultures displayed multipotential characteristics following fate-specific inductions for 21 days. Alizarin red positive condensed nodules were detected following osteogenic induction, oil red-positive lipid vacuoles were generated using adipogenic induction and collagen-II was revealed following chondrogenic induction by immunohistochemistry. On day 3 and 5, DFC (0.20 ± 0.01, 0.51 ± 0.09) showed a better cell activity than PDLC (0.16 ± 0.03, 0.47 ± 0.07) (P > 0.05). On day 7, DFC (1.03 ± 0.11) exhibited a higher proliferation rate than PDLC (0.93 ± 0.09) (P < 0.05). RT-PCR results showed that tenascin-N was not expressed in DFC, but expressed moderately in PDLC. F-spondin was expressed strongly in DFC, while not expressed in PDLC.

CONCLUSIONSDFC from ectomesenchymal tissues showed a good viability and contained cells similar to the mesenchymal stem cells. It may be used as a novel cell source for periodontium regeneration.

Adolescent ; Antigens, Surface ; metabolism ; Cell Differentiation ; Cell Separation ; Cells, Cultured ; Dental Sac ; cytology ; Extracellular Matrix Proteins ; metabolism ; Female ; Humans ; Male ; Molar ; Nestin ; metabolism ; Receptor, Notch1 ; metabolism ; Stem Cells ; cytology ; Tenascin ; metabolism ; Tissue Engineering ; Tooth, Impacted ; Young Adult