Regulatory effect of GDNF on the proliferation and differentiation of mammalian spermatogonial stem cells / 中华男科学杂志

The glial cell-derived neurotrophic factor (GDNF) is a member of the transforming growth factor beta (Tgf-beta) superfamily, which is produced by Sertoli cells and plays an important role in the proliferation and differentiation of spermatogonial stem cells (SSC). The addition of proper amount of GDNF to the culture media can promote SSC proliferation in vitro. Besides, GDNF regulates the self-renewal and differentiation of SSCs through various signaling pathways. This review focuses on the effects of GDNF on the proliferation and differentiation of mammalian SSCs and GDNF-mediated signaling pathways.

Preparation and characterization of a monoclonal antibody with high affinity for soluble Abeta oligomers.

Amyloid beta-protein (Abeta) has been causally implicated in the neurodegenerative processes that accompany Alzheimer's disease. Soluble oligomers of the Abeta(1-42) fragment are thought to be significantly more neurotoxic than higher molecular weight aggregates. We report the isolation and characterization of a mouse monoclonal antibody (MAb) directed against soluble Abeta(1-42) oligomers. Synthetic Abeta(1-42) oligomers were assembled in vitro; these were used to immunize mice, and hybridomas were isolated following myeloma fusion of splenocytes from immunized animals. Screening for reactivity against Abeta(1-42) resulted in the identification of MAb A8 with high affinity for soluble oligomers. The isotype of A8 was found to be IgG(2b). Experiments using sub-peptides of Abeta(1-42) revealed that the epitope identified by A8 lies within the 1-6 region of Abeta. The antibody displays high affinity for soluble Abeta(1-42) oligomers in the molecular weight range of 16.5-25 kDa, and detected target antigen in brain sections from senescence-accelerated SAMP 8 mice. The sensitivity and optimal titers for the detection of soluble Abeta(1-42) oligomers were determined to be 0.625 microg/mL in indirect ELISA, and 1:10(6), 1:4000, and 1:150 for ELISA, Western blotting, and immunohistochemistry, respectively. The A8 antibody specific for soluble Abeta(1-42) oligomers will provide a valuable tool for Alzheimer's disease research.

Application of IL-13R?2-directed Toxin Fusion Protein in Tumor Therapy / 中国生物工程杂志

The research of interleukin-13 receptor ?2(IL-13R?2) chain is a rising pop these years.Previous studies have shown that many human tumors overexpress IL-13R?2 chain,while normal cells do not express this receptor or express very low level.This difference of express level is significant to diagnose and cure tumors by the IL-13R?2-directed toxin fusion protein.During the past decade,the structure and the function of IL-13R?2 together with the relationship between this receptor and tumors has been further developed.Therefore new therapies and theories can be proposed as the clinical tumor treatments.In this case,the expression in various tumor cell lines was not only focused on but also on the IL-13 and toxin fusion protein killing effect in both the cell level and the in vivo level.Besides,an overview of the mechanism in the treatment of IL-13R?2-directed toxin fusion protein together with the improved methods for fusion protein purification and other relative tumor therapy was given.In conclusion,the current status and progress of IL-13R?2 as well as IL-13R?2-directed toxin fusion protein in tumor therapy were represented.

Migration and differentiation of human bone marrow mesenchymal stem cells in the rat brain / 生理学报

Bone marrow mesenchymal stem cells (MSCs) are multipotent tissue stem cells that can be induced in vitro to differentiate into a variety of cells such as osteoblasts, chondrocytes and adipocytes. MSCs are useful vehicles for both cell and gene therapy for a variety of diseases. Here, we injected human MSCs with enhanced green fluorescent protein (EGFP) into the striatum of Parkinson disease (PD) rat and examined their survival, migration, differentiation, and the behavior changes in PD rats, which will provide a theoretical foundation and technical method for clinic PD therapy by stem cells. The results showed that human bone marrow MSCs can survive in rat brain for a long time (exceeding 70 d). MSCs were found in multiple areas of the rat brain including the striatum, the corpus callosum, contralateral cortex and even the brain vascular wall. Immunocytochemical staining suggested that implanted cells expressed human neurofilament (NF), neuron-specific enolase (NSE) and glial fibrillary acid protein (GFAP). At the same time, remission in abnormal behavior of the PD rats appeared. Rotation scores decreased gradually from 8.86+/-2.09 r/min pre-transplantation to 4.87+/-2.06 r/min 90 d post-transplantation (statistic result showed P<0.05).

Progress on the study of tissue stem cells / 中国实验血液学杂志

Stem cells in the individual life are the cell population with high self-renewal capacity and multiple differentiation potential. At present, embryonic stem cells and tissue stem cells are the major objects for study in the field of stem cell engineering. At the same time, with the development of tissue engineering, cell replacement therapy became a new approach to treat some diseases. Tissue stem cells were tried to expand and committedly induce in vitro to some cells that are needed, then implanted them into patients to repair damage, replace regressive tissue and improve the function of hereditarily defect tissue. Based on recent progress of research on stem cells, this paper reviewed the biological characters and clinic application prospects of tissue stem cells.