Protective effects and mechanism of Zuogui Jiangtang Jieyu Formulation on hippocampal neuron of NVU induced by autophagy in diabetes mellitus with depression / 中草药

ABSTRACT

Objective: To investigate the protective effects and mechanism of Zuogui Jiangtang Jieyu Formulation (ZGF) on hippocampal neuron of neurovascular unit (NVU) induced by autophagy in diabetes mellitus with depression (DD). Methods Hippocampal neurons, astrocytes and brain microvascular endothelial cells from SD rats were primitively isolated, purified and cultured, and then immunocytochemistry staining was employed to identify primitive cells. The DD model of NVU was established by applying intervention of high glucose (150 mmol/L) and cortisone (200 μmol/L) after co-culture system was built in vitro. The cultured cells were randomly divided into normal group, blank serum group, model group, and medicated serum of ZGF group. Intracellular calcium levels (Ca2+) on hippocampal neuron of NVU was detected by Furo-3/AM staining. The expression of autophagy marker Beclin-1, LC3-II, and GluR2/Ca2+/mTOR signaling pathway key proteins was detected by high content analysis. The apoptosis of hippocampal neurons was observed by Tunel staining. Results:Compared with the normal group, Ca2+ levels was remarkably increased, expression of autophagy marker Beclin-1 and LC3-II was dramatically up-regulated, proteins expression of GluR2 and mTOR was obviously down-regulated while AMPK up-regulated, and the apoptosis in hippocampal neuron of NVU was significantly increased in model and blank serum group. Compared with the model group, intracellular calcium levels was obviously decreased, expression of autophagy marker Beclin-1 and LC3-II was down-regulated, GluR2/Ca2+/mTOR signaling pathway proteins expression of GluR2, mTOR was up-regulated while AMPK down-regulated, furthermore the apoptosis of hippocampal neurons was significantly decreased in ZGF group. Conclusion: ZGF has significant protective effects on hippocampal neuron of NVU induced by autophagy in DD, and its mechanism is related to the GluR2/Ca2+/mTOR signaling pathway and apoptosis.