RIP3/MLKL-mediated neuronal necroptosis induced by methamphetamine at 39℃

Methamphetamine is one of the most prevalent drugs abused in the world.Methamphetamine abusers usually present with hyperpyrexia (39℃),hallucination and other psychiatric symptoms.However,the detailed mechanism underlying its neurotoxic action remains elusive.This study investigated the effects of methamphetamine + 39℃ on primary cortical neurons from the cortex of embryonic Sprague-Dawley rats.Primary cortex neurons were exposed to 1 mM methamphetamine + 39℃.Propidium iodide staining and lactate dehydrogenase release detection showed that methamphetamine + 39℃ triggered obvious necrosis-like death in cultured primary cortical neurons,which could be partially inhibited by receptor-interacting protein-1 (RIP1) inhibitor Necrostatin-1 partially.Western blot assay results showed that there were increases in the expressions of receptor-interacting protein-3 (RIP3) and mixed lineage kinase domain-like protein (MLKL) in the primary cortical neurons treated with 1 mM methamphetamine + 39℃ for 3 hours.After pre-treatment with RIP3 inhibitor GSK’872,propidium iodide staining and lactate dehydrogenase release detection showed that neuronal necrosis rate was significantly decreased;RIP3 and MLKL protein expression significantly decreased.Immunohistochemistry staining results also showed that the expressions of RIP3 and MLKL were up-regulated in brain specimens from humans who had died of methamphetamine abuse.Taken together,the above results suggest that methamphetamine + 39℃ can induce RIP3/MLKL regulated necroptosis,thereby resulting in neurotoxicity.The study protocol was approved by the Medical Ethics Committee of the Third Xiangya Hospital of Central South University,China (approval numbers: 2017-S026 and 2017-S033) on March 7,2017.