Neuroprotective effects of resveratrol against oxygen glucose deprivation induced mitochondrial dysfunction by activation of AMPK in SH-SY5Y cells with 3D gelatin scaffold

Abstract

Ischemic stroke arising from the sudden blockage of arteries in the brain, is a common and serious brain damaging problem worldwide, often leading to disability or death. The oxygen glucose deprivation (OGD) model was created to improve understanding of hypoxia- and hypoglycemia-induced neuronal cell injury, and provide an in vitro surrogate to assess novel treatments for cerebral hypoxia-ischemia. AMP-activated protein kinase (AMPK) is a critical neuroprotective regulator of energy homeostasis, metabolism and cell survival. However, the neuroprotective mechanisms by which AMPK achieves these beneficial effects in human SH-SY5Y neural cells exposed to OGD are still not well understood. Resveratrol is a potent activator of AMPK suggesting it may have therapeutic potential as a neuroprotective agent. Therefore, we hypothesized the AMPK activator resveratrol protects against OGD-mediated impairment of human SH-SY5Y neuronal cells. The novelty of the experiment using a 3D gelatin scaffold cell culture assay, we have tested the potential of 3D systems to mimic the endogenous neuronal environment and have applied these systems to study the effect of OGD on neuronal cells with/without resveratrol. Here we show resveratrol reverses, via AMPK-dependent downregulation of caspase 3 and 9 activity, the OGD-mediated decreases in SH-SY5Y cell viability on a 3D gelatin scaffold. In addition, treatment with OGD decreases mRNA levels of AMPK and the neuroprotective genes (Bcl-2 and CREB); however, co-treatment with resveratrol significantly normalizes these effects. Importantly, resveratrol improves the expression of AMPK and p-AMPK in OGD-exposed SH-SY5Y cells. Resveratrol also significantly rescues SH-SY5Y cells from OGD-mediated mitochondrial deficiency (lower D-loop level, mitochondrial mass, maximal respiratory function, COX activity, and mitochondrial membrane potential). Resveratrol also rescues the transcript expression levels of PGC1 alpha and mitochondrial genes (NRF-1 and Tfam) in OGD-treated SH-SY5Y cells. These findings extend our mechanistic understanding of the central role of AMPK in OGD-related neuronal impairment, and may serve as basis for implementing new therapeutic strategies in the treatment of ischemic stroke.