DHA Attenuates Hypoxia/Reoxygenation Injury by Activating SSeCKS in Human Cerebrovascular Pericytes

Abstract

Docosahexaenoic acid (DHA) can alleviate cerebral ischemia/reperfusion injury by reducing blood-brain barrier permeability and maintaining its integrity, accompanied by an increased Ang-1/Ang-2 ratio; however, the underlying mechanisms of these effects remain unclear. Src-suppressed C kinase substrates (SSeCKS), a substrate of protein kinase C, plays an important role in maintaining cell junctions and cell morphology and regulating cell permeability. However, whether DHA can increase SSeCKS expression and then mediate the Ang-1/Ang-2 ratio still needs to be studied. Human cerebrovascular pericytes (HBVPs) cultured in vitro were divided into groups, treated with or without DHA along with SSeCKS siRNA to knockdown SSeCKS expression, and then subjected to 24 h of hypoxia followed by 6 h of reoxygenation. Cell viability; lactate dehydrogenase (LDH) release; and Ang-1, Ang-2 and VEGF activity were detected by using ELISA kits. The apoptosis rate was assessed by TUNEL flow cytometry. Expression of the SSeCKS, Ang-1, Ang-2 and VEGF proteins was evaluated by western blotting. Pretreatment with 10 μM or 40 μM DHA efficiently attenuated hypoxia/reoxygenation (H/R) injury by activating SSeCKS to increase the Ang-1/Ang-2 ratio and downregulate VEGF expression in HBVPs, as evidenced by decreased LDH release and apoptotic rates and increased HBVPs viability. Meanwhile, after we used SSeCKS siRNA to knock down SSeCKS protein expression, the protective effect of DHA on HBVPs following H/R injury was reversed. In conclusion, DHA can activate SSeCKS to increase the Ang-1/Ang-2 ratio and downregulate VEGF expression in HBVPs, thus reducing H/R injury.

Ischemic Brain Injury: Involvement of Lipids in the Pathophysiology of Stroke and Therapeutic Strategies

“…In rat brain microvascular endothelial cells under an oxygen- and glucose-deprivation environment (OGD), that mimics ischemic stroke in vitro, DHA was shown to decrease apoptosis, COX-2 protein expression, and the secretion of PGE 2 , PGI 2 , vascular endothelial growth factor (VEGF), and angiopoietin-2 (Ang-2, which has been shown to cause blood–brain barrier damage and to increase endothelial cell apoptosis) [ 123 ]. DHA can also decrease hypoxia/reoxygenation injury by activating Src-suppressed C kinase (SSeCKS), a substrate of protein kinase C that plays a key role in maintaining cell morphology and tight junctions of the blood–brain barrier and regulating cell permeability [ 124 , 125 ].…”

Neural crest cell-derived pericytes act as pro-angiogenic cells in human neocortex development and gliomas

“…Besides the stabilizing role exerted by PCs on ECs [ 52 , 158 ], there is an active angiogenic effect of PCs in secreting pro-regenerative molecules in response to PDGF-B [ 295 , 296 ]. Of particular note is VEGF, which has been immunolocalized in PCs during human cerebral cortex development [ 174 ] and is released by these cells in in vitro models [ 175 , 296 , 297 ]. In a mathematical, biomimetic 3D angiogenesis model, it has been demonstrated that PCs intervene in the VEGF/TNF-α (tumor necrosis factor-α) proangiogenic/antiangiogenic interplay, promoting a proangiogenic effect of TNF-α, thus allowing complete VEGF-induced sprout formation, elongation, and lumenalization, and also ensuring that the efficacy of the reverted TNF-α effect is proportional to the extension of the pericyte coverage.…”

Loss of lncRNA UCA1 ameliorates the injury managed by cerebral ischemia-reperfusion by sponging miR-18a-5p

“…AIS is mainly caused by cerebral vascular occlusion, which leads to focal neurological deficits [13]. At present, the internationally recognized treatment means is to open occluded blood vessels as soon as possible and reduce ischemic injury of brain tissue [28]. The main treatment methods are thrombolysis and arterial thrombectomy after thrombolysis, but the reperfusion injury to brain tissue after recanalization is one of the main reasons for the poor therapeutic effect [1].…”