Micromanaging freeze tolerance: the biogenesis and regulation of neuroprotective microRNAs in frozen brains.

摘要: When temperatures plummet below 0 °C, wood frogs (Rana sylvatica) can endure the freezing of up to ~ 65% their body water in extracellular ice masses, displaying no measurable brain activity, breathing, movement, and a flat-lined heart. To aid survival, retreat into state suspended animation characterized by global suppression metabolic functions reprioritization energy usage to essential survival processes that is elicited, part, regulatory controls microRNAs. The present study first investigate miRNA biogenesis regulation freeze tolerant vertebrate. Indeed, proper function adaptations environmental stimuli play crucial role coordinating stress responses. Immunoblotting factors illustrated an overall reduction majority these processing proteins suggesting potential maturation over freeze–thaw cycle. This was coupled with large-scale RT-qPCR analysis relative expression levels 113 microRNA species brains control, 24 h frozen, 8 h thawed R. sylvatica. Of 41 microRNAs differentially regulated during thawing, only two were significantly upregulated. Bioinformatic target enrichment downregulated miRNAs, performed at low experienced predicted involvement activation various neuroprotective such as synaptic signaling, intracellular signal transduction, anoxia/ischemia injury protection. predominantly fingerprint identified herein suggests microRNA-mediated cryoprotective mechanism responsible for maintaining neuronal facilitating successful whole thawing.