ABSTRACT
Synaptotagmin 1 (Sytl) is a member of the Synaptotagmin family and plays a role in neurotransmitter vesicle transport and exoeytosis. It has been reported that Sytl appears to be expressed in the intestinal epithelium, but the biological function of Sytl in colitis remains poorly understood. This study aimed to investigate the effects of Sytl in the inflammatory response and intestinal epithelial regeneration in colitis using Sytl transgenic mice and dextran sulfate sodium (DSS)-induced ulcerative colitis mode. qRT-PCR and Western blotting were employed to analyze the dynamic changes of Sytl in colitis. H&E staining, immunostaining and Western blotting were used to explore the roles of Sytl in the inflammatory response and in the regeneration and repair of intestinal epithelium in colitis. The results showed that the expression level of Sytl was indeed high in the colonic epithelium of wild-type mice and the intestinal epithelial cells of the adjacent tissues of colorectal cancer patients. Consistently, DSS-induced inflammation progressively resulted in marked upregulation of Sytl in the colon (P<0.01). In DSS-induced colitis, both the body weight loss and colonic shortening were dampened in Sytl loss-of-function mice compared with the control group (P < 0.05), while the number of regenerated crypts and Ki67 proliferating cells were also increased (P<0.01). Additionally, there were less infiltration of CD45 immune cells and F 4/80 macrophages and the expression of pro-inflammatory cytokines IL-6, TNFα and I L l-β, which were related with the severity of inflammation in the inflammatory bowel disease (I B D), were significantly decreased after Sytl deletion (P<0.05). Immunohistochemistry staining and Western blotting results further showed that IL-6 and p-STAT3 was significantly downregulated in Sytl knockdown mice (P<0.05). Taken together, these results suggested that knocking-down of Sytl may improve colitis by inhibiting the IL6/STAT3 signaling pathway.
ABSTRACT
Objective: Berberine, a cationic alkaloid first isolated in 1917, has been approved by the China Drug Administration for decades. Accumulating evidence demonstrated its antidepressant-like activities in vivo. Our previous study has shown that chronic stress leads to the upregulation of miR-34a in the hippocampus of mice. This study aims to evaluate the underlying miR-34a mediated mechanism of berberine in chronic stress-induced depression in mice. Methods: In the present study, mice were administered with berberine during chronic stress. Levels of miR-34a, dendritic density, mitochondrial morphology, and neurogenesis were assessed in the hippocampus. Subsequently, miR-34a agomir was used as a pharmacological intervention for the investigation of berberine. Results: The results showed that berberine reversed the decrease in sucrose preference and the increase in latency to feed without altering total food consumption. Furthermore, chronic stress-induced overexpression of miR-34a decreased synaptotagmin-1 and Bcl-2 levels, thereby impairing spinal morphology, mitochondria and neurogenesis. Berberine inhibited miR-34a expression, in turn restored synaptotagmin-1 and Bcl-2 levels, and thus improved spinal morphology, mitochondria and neurogenesis in the hippocampus. However, the improvements induced by berberine were totally blocked by the pretreatment of miR-34a agomir, which caused the elevation of miR-34a levels in the hippocampus. Conclusion: This finding demonstrated that miR-34a downregulation was involved in the antidepressant-like effects of berberine in mice exposed to chronic stress.
ABSTRACT
@#Objective To investigate the dynamics of cortical granules exocytosis (CGE), and the role of Synaptotagmin1 (Syt1) in mouse fertilization. Methods The dynamics of mouse CGE were filmed on Perkin Elmer precisely Ulta VIEW VOX confocal Imaging System. The Syt1 functions on mouse fertilization and expression in zygotes were analyzed by immunofluorescence, Western blot assy and qRT-PCR. Results The dynamic process of mouse CGE was observed after oocyte activation, and the exact pot seems to be close to the polar body. The Syt1 expression was gradually increased after fertilization. The mouse fertilization rate after Syt1 knockdown was significantly lower than that of the control group (P＜ 0.05). Conclusion The dynamic process of CGE is studied. It is found that Syt1 is involved in mouse fertilization process.