Research Square
Neuronal ABHD6 Exacerbates Ischemic Brain Injury Through 2-AG Depletion and DDIT3/BNIP3-Dependent Autophagy Dysregulation
By Liu D, Cao Z, Zhao L and 9 others.
Abstract
Abstract The endocannabinoid 2-arachidonoylglycerol (2-AG) confers critical neuroprotection against ischemic stroke (IS) by restricting neuronal apoptosis. While monoacylglycerol lipase (MAGL) mediates 85% of central nervous system 2-AG hydrolysis, its chronic inhibition induces severe cannabinoid receptor desensitization. In contrast, postsynaptic alpha/beta hydrolase domain 6 (ABHD6) governs a highly localized 4% pool of 2-AG degradation, uniquely positioning it as a precise, on-demand therapeutic target devoid of off-target effects. However, its exact pathological contribution to ischemic neuronal death remains elusive. This study investigates the molecular mechanisms by which ABHD6 regulates apoptosis and autophagic crosstalk following IS. Utilizing a middle cerebral artery occlusion/reperfusion mouse model and an in vitro oxygen-glucose deprivation followed by 24-hour reoxygenation (OGD/R) model in primary neurons, assays demonstrated that ABHD6 expression and enzymatic activity were significantly upregulated post-ischemia. This elevation accelerated postsynaptic 2-AG hydrolysis, restricted neuroprotective endocannabinoid activation, and aggravated apoptosis. Pharmacological inhibition of ABHD6 with WWL70 and CRISPR/Cas9-mediated genetic ablation effectively suppressed enzymatic activity, preserved endogenous 2-AG levels, and attenuated OGD/R-induced programmed cell death. Mechanistically, ABHD6 impaired neuroprotective autophagy by modulating the DDIT3/BNIP3 pathway; the consequent suppression of autophagic flux directly exacerbated neuronal apoptosis and subcellular structural disintegration. In conclusion, ABHD6 exerts a dual detrimental role in IS by depleting neuroprotective 2-AG and suppressing DDIT3/BNIP3-dependent autophagy. Targeting postsynaptic ABHD6 to restore endocannabinoid homeostasis and autophagic flux represents a highly specific molecular strategy for attenuating ischemia-induced neuronal apoptosis.