The Effect of SIN1 and Microtubules on Insulin Induced PKC ζ Activation.

BACKGROUND Protein kinase C zeta (PKC ζ) plays an important role in insulin induced glycometabolism and insulin receptor (IR) associated signaling pathways. The full activation of PKC ζ depends on its translocation from cytosol to membrane and phosphorylation at Thr410. However, the mechanism of PKC ζ activation remains elusive. In this study, the effect of SIN1 and microtubules on insulin-induced PKC ζ activation was investigated. MATERIAL AND METHODS HepG2 cells were stimulated with insulin for co-immunoprecipitation (co-IP) assay. The immunocomplex was captured by using anti-PKC ζ, anti-SIN1 or anti-FLAG antibodies and was subjected to western blotting analysis for detecting PKC ζ, SIN1, and ß-tubulin protein expression level. The cells were intervened by small interfering RNA (siRNA) that targeted exon regions of SIN1. Then the glucose uptake ratio after cells were stimulated by insulin was measured. The PKC ζ insulin receptor levels in the membranes were analyzed. Cells stained with anti-PKC ζ, anti-SIN1 antibodies and probed with molecular probes were observed by immunofluorescence confocal microscopy. RESULTS SIN1 interacted and co-located with PKC ζ by pleckstrin homology (PH) domain. Downregulation of SIN1 severely impaired PKC ζ translocation and phosphorylation induced by insulin. PKC ζ co-immunoprecipitated with ß-tubulin at different intervals upon insulin stimulus, and the activation of PKC ζ was affected by paclitaxel and nocodazole. CONCLUSIONS PKC ζ translocated from cytosol to membrane depending on SIN1, which suggested that PKC ζ may be activated directly by PI3K and the reaction probably carried out on microtubules in HepG2 cells.

Relation between dampness-heat syndrome of acute period of GBS and neuroendocrine-immunoregulatory network / 中华中医药杂志

Objective: To discuss the relation between dampness-heat syndrome of GBS and neuroendocrine-immunoregulatory network.Methods: 34 patients with GBS were divided into dampness-heat syndrome group and nondampness-heat syndrome group by syndromes differentiation of TCM.The autonomic nerve function,the level of immunoglobulin,cortisol(COR) and adrenocorticotropin(ACTH) of these two groups were detected.The datas were compared with that of normal control group.Results:① There were significant difference in function of autonomic nerve between the two groups(damp-heat syndrome group and nondamp-heat syndrome group) and normal control group.There is difference between dampness-heat syndrome group and nondampness-heat syndrome group,too.Dampness-heat syndrome group mainly showed sympathetic nerve excitement(60.0%).In nondampness-heat syndrome group,the incidence of sympathetic nerve excitement is 35.7%;parasympathetic nerve excitement is 28.6%.② In dampness-heat syndrome group the level of IgG was higher than that in nondampness-heat syndrome group and normal control group.The level of IgA was higher than that in normal control group(P