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AMP-activated protein kinase (AMPK) is an energy sensor that couples the cellular energy state with basic biological processes. AMPK is thought to be linked with cell division although the underlying mechanisms remain largely unknown. Here, we show that AMPK functionally participates throughout cell division and that AMPK catalytic subunits, especially α2, are sequentially associated with separate mitotic apparatus. Using quantitative phosphoproteomics analysis, we found that the strong direct substrate KIF4A is phosphorylated by AMPK at Ser801. Further analysis revealed that AMPK and Aurora B competitively phosphoregulates KIF4A during mitotic phase due to overlapping recognition motifs, resulting in the elaborate phosphoregulation for KIF4A-dependent central spindle length control. Given the intrinsic energy-sensing function of AMPK, our study links the KIF4A-dependent control of central spindle length with cellular glucose stress.

Aim: To study the effects of CD74 gene on IFN-γR expression in myasthenia gravis thymic epithelial cell(TEC)., Methods: PCMV-CD74 transiently transfect to primary cultured TEC mediated with lipofectamine, the result of transfection and some autoimmune related genes such as IFN-γR were detected by real-time RT-PCR., Results: Real-time quantitative RT-PCR results show that the mRNA expression level of IL-4R, IL-32, IFN-γR, ECGF1, HLA-A, HLA-DR increased significantly, with the high express ion of CD74 gene in thymic epithelial cells., Conclusion: CD74 gene over-expression in TEC can increase IFN-γR mRNA expression.

This study was aimed to investigate the changes of differentiation and gene expression of CD133(+) cells in human umbilical cord blood induced by stem cell factor (SCF) and basic fibroblast growth factor (bFGF) in vitro, and to explore the biological characteristics of CD133(+) cells so as to provide experimental basis for potential use in regenerative medicine. The human umbilical cord blood CD133(+) cells were isolated from umbilical cord blood and purified by MACS magnetic selection. The CD133(+) cells were cultured in DMEM/F12 medium containing SCF, bFGF and B27 for 10 to 15 days. The total RNA of these cells was extracted before and after culture, and the analysis of related gene expression levels of these cells was performed using oligonucleotide microarrays. The results showed that out of 263 genes 21 genes were obviously up-regulated after culture than that before culture, whereas 7 genes were found to be significant down-regulated as compared with fresh-separated CD133(+) cells. These genes were involved in stem cell specific markers, cell cycle regulators, stem cell differentiation markers and signaling pathways that are important for stem cell maintenance. It is concluded that SCF and bFGF can induce differentiation of human cord blood CD133(+) cells through up- or down-regulation of specific genes. This study provides gene expression information for SCF and bFGF-induced human cord blood CD133(+) cells and contributes to understand the effect of SCF and bFGF on proliferation and differentiation CD133(+) cells at gene level, and promotes therapeutic applications of the CD133(+) cells induced by SCF and bFGF.

Aim: To study the relationship between the abnormal differentiation thymocytes and the pathogenesis of myasthenia gravis (MG)., Methods: The gene expression of some ILs, IFN and their receptors was examined by cDNA array. The percentage of CD45RO(+) and D45RA(+) thymocytes was measured by flow cytometry (FCM). The expression and distribution of CD45RA and CD45RO in the samples of thymus tissues were observed by immunohistochemistry., Results: The levels of IL-1R, IL-4R, IFNgammaR1, IFNgammaR2, IL-6 and IL-8 in the patients with MG were lower than those of normal controls and there were significant differences between them. But the levels of IL-1, IL-2, IL-4, IL-10, IL-7, IFN-alpha, IFN-beta and IFN-gamma showed no significant changes in patients with MG in comparison with normal controls. The percentage of CD56(+) thymocytes in MG patients 0.56+/-0.33 was significantly lower than that in normal controls(1.78+/-0.69).The CD45RO(+) and CD1a(+) in MG patients increased more significantly those in normal controls. The immunohistochemistry and RT-PCR showed the same result., Conclusion: Aberrant transformation from CD45R0(+)T to CD45RA(+)T has been found in the development of thymocytes of the patients with MG.

Aim: To explore the roles of abnormalities of thymocytic abnormal apoptosis and its Fas expression in patients with myasthenia gravis (MG) in generation of autoimmune response., Methods: The thymocytes were isolated and thymus extractive was prepared from fresh thymic tissue excised from MG patients. The proliferation of thymocyes was evaluated by MTT colorimetry. The apoptosis of thymocytes were examined by DNA electrophoresis. Expression of Fas was analyzed by a FACScan flow cytometry. Transcription and mutation of Fas gene were detected by RT-PCR and single-stranded conformation polymorphism ( SSCP) analysis., Results: Thymus extractive could inhibit proliferation of normal thymocytes, while had no influence on the thymocytic proliferation of MG patients. The proliferation of thymocytes of both normal persons and MG patients could be inhibited by thymus extractive in the presence of dexamethasone. The inhibition rates were 58. 33% and 54. 26% respectively. The cocultured thymocytes with dexamethasone showed characteristic apoptosis pattern and the DNA electrophoresis exhibited 'ladder' appearance. The abnormal bands in Fas mRNA of partial MG patients' thymocytes were found by RT-PCR-SSCP analysis., Conclusion: Abnormalities of apoptosis and Fas gene expression of MG patients' thymocytes, and Fas gene mutation may be related to the pathogenesis and progression of MG.