Chaperone-mediated autophagy (CMA) confers neuroprotection of HBO preconditioning against stroke

Previous attempts to identify neuroprotective targets for acute ischemic stroke by studying ischemic cascades and devising ways to suppress these pathways have failed in translational research. We hypothesized that studying the molecular determinants of endogenous neuroprotection, namely, the tolerance against ischemic stroke conferred by hyperbaric oxygen (HBO) preconditioning, via a well-established paradigm would reveal new neuroprotective targets. By a combination of proteomics, KEGG pathway analysis, lysosome fraction and western blot analysis, we found that chaperone-mediated autophagy (CMA) was activated by HBO preconditioning. In addition, LAMP2A is uniquely decreased in cortical neurons in the early stage of stroke. Suppression of CMA with recombinant adeno-associated viral vector (rAAV)-mediated delivery of short hairpin RNAs (shRNAs) targeting the LAMP2A transcript increased the neuronal susceptibility of apoptosis and abolished the neuroprotection induced by HBO preconditioning. Administration of the clinically utilized FDA-approved drug mycophenolate mofetil induced long-term neuroprotection post-stroke in a CMA-dependent manner. In summary, HBO preconditioning confers neuroprotection against ischemia by inducing CMA, which is a promising translational treatment target for stroke.