Adult stem cells have great advantage in tissue reconstruction and regeneration.Transplantation of autologous stem cells into ischemic tissue is a novel therapeutic option for ischemic disorders.This review summarizes the potential role of adipose tissue-derived stromal cells(ADSC) on regenerative cell therapy for ischemic diseases.ADSC can be readily harvested and cultured;under specific condition,they can be induced to differentiate into adipocytes,bone,neurons,and endothelial cells.Moreover,ADSC can secrete a number of angiogenesis-related cytokines which might be suitable for regenerative cell therapy.It has also been reported that ADSC could differentiate into myocardiocytes.ADSC might be an important material for regenerative cell therapy in the near future,replacing bone marrow cells.

Human stem cell is a unique cell population with the ability of self renewal and differentiation. There are many types of stem cells in human embryonic body and adult tissues, and they have crucial functions in human development. The stem cell differentiation is of great importance for the success of stem cell based therapies,whose effectiveness is determined by the intrinsic property of the cells and the cell microenvironment. The studies on the differentiation of human stem cell include the structural property of the cell and the molecular mechanism in vivo and in vitro . The aim of scientists is to gain the renewable and directional differential stem cells in vitro and use them for a variety of human diseases.

All types of blood cells are derived from a common precursor:the hematopoietic stem cell.Hematopoietic stem cells can be found in different locations of the developing vertebrate organism. Hematopoiesis is a dynamic process sustained by cytokine induced production and activities of hematopoietic stem and progenitor cells.A number of different cytokines,cells,and cytokine cell interactions are involved in regulating the hematopoiesis. Some cytokines have more than one functions partially due to their actions on different target cells.These actions are mediated through specific receptors transmiting intracellular signals.These signals give the stem and progenitor cells critical information to survive,proliferate, differentiate or to migrate. This paper is to review recent developments in some of the major signal transduction pathways influencing hematopoietic growth and differentiation with a particular emphasis on myeloid cells.

The Oct4,a POU transcription factor belongs to class Ⅴ of POU proteins, is expressed in mouse totipotent embryonic stem and germ cells. Oct4 plays a critical role in maintaining pluripotency of stem cell when it differentiates into a trophectoderm lineage at early stage of mouse embryo. Oct4 expression appears to be regulated by a positional effect as well as specific regulating elements of Oct4 such as proximal enhancer (PE) and distal enhancer (DE). Oct4 has both repression and activation effects in regulating transcription,and the activation has 3 models: distance dependent transactivation, conformational transactivation and Oct4 dimers dependent transactivation.

Objective:To investigate the regulatory effect of dissociative intracytoplasmic domain of leukemia inhibitory factor receptor ? (LIFR?) subunit on the growth of HL-60 cells and the related signal transduction mechanism. Methods: The constructed recombinant plasmids pcDNA3.0-190CT2+3 and cDNA3.0-190CT3 were identified and transfected into HL-60 cells with liposome FuGene-6. Then the cells were cultured in a medium containing G-418 and the positive clones were selected. Immunohistochemical method and Western blotting were used to detect the expression of the target protein in HL-60 cells and the growth curve of the cells was plotted. The expression of proliferating cell nuclear antigen (PCNA) and the phosphorylation levels of signal transducer and activator of transcription 3 (Stat3) were assayed by Western blotting. Results: Western blotting detected the band of target protein and the cell line stably expressing the target protein was obtained. Compared with that of the wild type group, the cell sizes in 190CT2+3 and 190CT3 group were enlarged. The ratio of leaf cell number to the total cell number increased and the cell proliferation was slowed down. We also found that the expression of PCNA was decreased and the phosphorylation level of STAT3 was increased. Conclusion: The dissociative intracytoplasmic domain of LIFR? subunit can accelerate the differentiation of HL-60 cells, inhibit the proliferation of HL-60 cells, and activate signal molecule STAT3.

The killing effects of five chemical disinfectants on hepatitis A virus (HAV) were determined by ELISA The results showed that 2% glutaraldehyde completely killed HAV within 10 min and 025% peracetic acid killed 74.5% HAV within 5 min and 40% iodophors killed 60.3% HAV within 5 min. It is suggested that glutaraldehyde, peracetic acid and iodophors are more effective agents to kill HAV.

The germ cell lineage in the mouse is established during gastrulation;sex determination is achieved after germ cell migrating to the site of the future gonads. Germ cells proliferate indefinitely when cultured in vitro . Human embryonic germ(EG) cells have been recently established;these immortalized EG cells are chromosomally stable and pluripotent, raising the hope that their differentiation can be directed to specific cell types, which may be of value in the clinical treatment of degenerative diseases.

Objective To observe the effects of red blood cell lysis buffer on the isolation and culture of human bone marrow mesenchymal stem cells (hMSCs) in vitro.Methods Twenty-two bone marrow samples were randomly divided into 2 groups,including 11 samples of crushed red blood cell prepared with Tris-NH4Cl red blood cell lysis agent and 11 samples prepared without red blood cell lysis agent.The intervals from primary generation to 1,2 and 3 passages and the time of expansion to l07 cells were compared between the two groups.Results The times for P1,P2 and P3 passage was ( 9.3 ± 4.9 ) days vs.( 7.2 ± 1.0 ) days,( 14.4 ±4.7) days vs.( 14.5 ± 3.5 ) days,and ( 18.5 ± 5.0 ) days vs,( 20.1 ± 4.4 ) days,respectively,in crushed red blood cell group and non-crushed red blood cell group.The differences were not significant ( t =1.39,t =0.06,t =0.80,P ＞ O.05 ).The time for expansion to 107 cells in two groups was not significantly different ( t =0.80,P ＞0.05).Conclusion Tris-NH4Cl agent in red blood cell lysis has no significant effects on hMSCs isolation,culture and cell proliferation,which indicates erythrocyte lysing may be not an independent step for hMSCs isolation and expansion in vitro.

Objective To observe the differentiation of bone marrow multipotent adult progenitor cells(MAPCs)into skin tissue cells of rats in vivo. Methods Magnetic activated cell sorting (MACS)was used to remove MAPCs from bone marrow of male rats through negative screening.Tail vein injection with combined with MAPCs Was done in C57BL/6 mice with skin wound and nude mice with immunodeficieney.Immunohistochemical staining was used to examine the expression of MHCI antigen in the healed skin of donor SD rats. Results Positive MHCI cells were found in the epidermal fundus and Some hair follicle-like structures of the healed skin of C57BL/6 mice.Hair follicle-like structure appeared in the healed skin of nude mice group,in which positive MHCI cells were found in the basal epidermal and some hair follicle-like structures. Conclusions During skin damage,MAPCs can migrate to the injured skin area and skin adnexa hair foilicle area,transform into epidermal cells and hence participate in the healing of the wound skin.

Objective To determine the biological characteristics of human embryonic MSC (hMSCs) and their potential ability of differentiation, and to investigate the survival and distribution of hMSCs after transplantation into the kidney of newborn mice. Methods hMSCs were derived from 4-7 week-old embryos, then primary culture was done. The biological characteristics of hMSCs were detected by immunohistochemical methods and flow cytometry. Their differentiation potential was determined by coculture with conditioning medium. The survival and distribution of PKH-26-stained hMSCs in mice were observed by laser scanning confocal microscope. Results Flow cytometry and immunochemistry staining revealed that the expression of CD29, CD44, CD90, SH-2, OCT-4 was positive significantly, and CD34, CD45 was negative. The cells could be induced to differentiate to osteocytes and adipocytes under special conditions. After transplantation for 1 month, PKH-26-stained hMSCs still existed in the kidney of mice and co-localized in tubular epithelium by confocal microscope. Conclusion hMSCs derived from the early human embryo have the ability of proliferation and differentiation with low immunity, and may be involved in the development of renal tubule in newbem mice.