Abstract

BACKGROUND: Autophagy is characterized by the degradation of cellular components in autophagosomes. It plays a significant role in cerebral ischemic injury and has a complex functional connection with apoptosis. The neurovascular unit (NVU) is a structural and functional unit of the nervous system presented as a therapeutic target of stroke. This study aimed to investigate the effect of autophagy induced by ischemic damage on NVUs.

MATERIAL AND METHODS: SH-SY5Y cells, C6 cells, and rat brain microvascular endothelial cells were cultured with oxygen-glucose deprivation (OGD) exposure for different time durations, and 3-methyladenine (3-MA) was added as an autophagy inhibitor. In all 3 cell lines, lactate dehydrogenase (LDH) release was measured. Furthermore, apoptosis was detected using Annexin V-fluorescein isothiocyanate/propidium iodide labeling and immunofluorescence staining. Autophagosomes were observed through AO/MDC (acridine orange/monodansycadaverine) double staining. LC3-II expression levels were evaluated by western blot analysis.

RESULTS: In the OGD groups of 3 cell lines, LDH leakage, and apoptotic rates were obviously increased. Remarkable increase in LC3-II expression was found in the OGD groups of SH-SY5Y cells and C6 cells. However, 3-MA decreased the LC3-II expression to varying degrees.

CONCLUSIONS: OGD could induce the over-activation of autophagy and augment the apoptotic activity in neurons and glial cells of NVUs.

Keywords: Hypoxia-Ischemia, Brain, Stroke, Adenine, Cell Hypoxia, Cell Line, Cells, Cultured, Cerebral Cortex, endothelial cells, Glucose, Myocytes, Smooth Muscle, Neurons, Neurovascular Coupling, Oxygen