Long non-coding RNA MEG3 attends to morphine-mediated autophagy of HT22 cells through modulating ERK pathway

Gao, Shuibo; Li, Enyao; Gao, Haixia

Morphine is a very effective opiate analgesic drug widely used to ease both acute and chronic pain (Du 2018) . However, morphine has become a commonly abused recreational drug due to its widespread availability and a high potential for addiction (Kim et al. 2016) . Researching the pathogenesis of morphine addiction can provide new ideas and theoretical basis for elucidating the molecular mechanism of opioid addiction and clinical treatment. Earlier experimental studies have indicated that neuronal cell mitochondrial dysfunction happens in morphine addiction process, which in turn induces cell autophagy (Lixia et al. 2010; Cai et al. 2016; Su et al. 2017) . Su et al. (2017) reported that compared to wild-type mice, mice specific knockout of autophagy-related 5 (Atg5) and Atg7 in dopaminergic neurons had lower sensitivities to constructing morphine-induced addictive behaviours. Orexin1 receptor (OX1R) is a G-protein-coupled receptor in central nervous system, which contributed to the establishment of morphine addiction (Baimel et al. 2015) . c-fos is a proto-oncogene that expressed in central neurons after adverse stimulation (Dziopa et al. 2011) . Studies in rats revealed that cfos protein took part in the neurobiological responses to morphine in dopamine neurons (Dziopa et al. 2011) . Besides, both ERK and PKC pathways have been found to participate in the morphine-mediated drug addiction Pena et al. 2018) .