OBJECTIVETo investigate the role of autophagy inhibitor chloroquine (CQ) in the proliferation of pulmonary arterial smooth muscle cells (PASMCs) in hypoxia conditions.

METHODSThe following groups in this study were set up: control group, hypoxia group, 50 micromol/L CQ + hypoxia group, 50 micromol/L CQ group. The viability of PASMCs in every group was detected by MTT assay. Autophagic vacuoles in the cells were observed by MDC staining. Protein expression of microtubule associated protein light chain 3 (LC3) was measured by Western blot. Migration of PASMCs was detected by wound healing assay.

RESULTSCompared with control group, no effect on the viability of PASMCs was observed treated by CQ alone. In 1% hypoxia group, cell viability increased significantly compared with that in control group. The number of autophagic vacuoles and the rate of cell migration and also protein expression of LC3-II were also markedly increased. Compared with hypoxia group, addition of CQ increased the number of autophagic vacuoles and the levels of LC3-II protein, but decreased the proliferation and migration of PASMCs.

CONCLUSIONHypoxia could activates autophagy and contributes to proliferation and migration of PASMCs, and autophagy inhibitor CQ could decrease the effect of hypoxia on PASMCs through inhibiting autophagy process.

Autophagy ; drug effects ; Cell Hypoxia ; Cell Movement ; Cell Survival ; Cells, Cultured ; Chloroquine ; pharmacology ; Humans ; Microtubule-Associated Proteins ; metabolism ; Myocytes, Smooth Muscle ; drug effects ; Pulmonary Artery ; cytology

Helicobacter pylori (H.pylori) infection is a recognized risk factor of dementia,while its role and mechanism in Alzheimer disease (AD) remained unclarified.Our previous study has identified that injection of soluble H.pylori filtrate could induce AD-like pathologic changes and cognitive impairment in SD rats.In the present study,we further explored the effect of long-term stomach colonization of H.pylori bacteria on the brains of SD rats.The results showed that H.pylori bacteria gavage induced an efficient colonization of H.pylori in the stomach after four weeks.However,there was no significant change of tau phosphorylation at Thr205 (pT205),Thr231 (pT231),Ser396 (pS396) and Ser404 (pS404) sites in the hippocampus and cerebral cortex.The H.pylori-infected rats also showed no cognitive impairment.These observations may result from inefficient release of bacterial pathogenic factors or the overall lack of host inflammatory responses.We conclude that SD rat with long-term H.pylori colonization in the stomach is not a suitable animal model for exploring the effects of H.pylori infection on brain function in human beings;administration of bacterial filtrates may better reveal the systemic pathologic changes induced by bacterial infection in animals which show a negative host response to bacterial colonization.