Autophagy Induced by Oxygen-Glucose Deprivation Mediates the Injury to the Neurovascular Unit

Med Sci Monit. 2019 Feb 21:25:1373-1382. doi: 10.12659/MSM.915123.

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.

MeSH terms

  • Adenine / analogs & derivatives
  • Adenine / pharmacology
  • Animals
  • Apoptosis / drug effects
  • Autophagy / drug effects
  • Autophagy / physiology
  • Cell Hypoxia / drug effects
  • Cell Line / drug effects
  • Cell Survival / drug effects
  • Cells, Cultured
  • Cerebral Cortex / cytology
  • Endothelial Cells / metabolism
  • Glucose / metabolism
  • Humans
  • Hypoxia-Ischemia, Brain / metabolism*
  • Myocytes, Smooth Muscle / metabolism
  • Neurons / metabolism
  • Neurovascular Coupling / drug effects*
  • Neurovascular Coupling / physiology*
  • Oxygen / metabolism
  • Rats

Substances

  • 3-methyladenine
  • Glucose
  • Adenine
  • Oxygen