IRE1α inhibition attenuates neuronal pyroptosis via miR-125/NLRP1 pathway in a neonatal hypoxic-ischemic encephalopathy rat model

• Published in: Journal of neuroinflammation Vol. 17; no. 1; p. 152
• Main Authors: Huang, Juan, Lu, Weitian, Doycheva, Desislava Met, Gamdzyk, Marcin, Hu, Xiao, Liu, Rui, Zhang, John H, Tang, Jiping
• Format: Journal Article
• Language: English
• Published: England BioMed Central 06-05-2020; BMC
• Subjects: Animals; Animals, Newborn; Apoptosis; Brain damage; Brain injury; Carotid arteries; Caspase-1; CRISPR; Cytokines; Disease Models, Animal; Encephalopathy; Endoplasmic reticulum; Endoribonucleases - antagonists & inhibitors; Enzymes; Experiments; Gene expression; Hypoxia; Hypoxia-Ischemia, Brain - metabolism; Hypoxia-Ischemia, Brain - pathology; Hypoxic-ischemic encephalopathy; IL-1β; Immunofluorescence; Inflammasome; Inflammasomes; Inflammasomes - drug effects; Inositol; Interleukin 18; IRE1α; Ischemia; Kinases; Laboratory animals; Localization; MicroRNAs; MicroRNAs - metabolism; miR-125; miRNA; Molecular modelling; Multienzyme Complexes - antagonists & inhibitors; Neonates; Nerve Tissue Proteins - metabolism; Neurons - drug effects; Neurons - metabolism; Neurons - pathology; NLPR1; Polymerase chain reaction; Protein-Serine-Threonine Kinases - antagonists & inhibitors; Pyrin protein; Pyroptosis; Pyroptosis - drug effects; Pyroptosis - physiology; Rats; Rats, Sprague-Dawley; Reverse transcription; Rodents; Signal transduction; Signal Transduction - drug effects; Signal Transduction - physiology; Sulfonamides - pharmacology; Surgery; Thiophenes - pharmacology; Traumatic brain injury; miR-125; Inflammasome; Pyroptosis; Hypoxic-ischemic encephalopathy; IRE1α; NLPR1
• ISSN: 1742-2094; 1742-2094
• DOI: 10.1186/s12974-020-01796-3

Inhibition of inositol-requiring enzyme-1 alpha (IRE1α), one of the sensor signaling proteins associated with endoplasmic reticulum (ER) stress, has been shown to alleviate brain injury and improve neurological behavior in a neonatal hypoxic-ischemic encephalopathy (HIE) rat model. However, there is no information about the role of IRE1α inhibitor as well as its molecular mechanisms in preventing neuronal pyroptosis induced by NLRP1 (NOD-, LRR- and pyrin domain-containing 1) inflammasome. In the present study, we hypothesized that IRE1α can degrade microRNA-125-b-2-3p (miR-125-b-2-3p) and activate NLRP1/caspased-1 pathway, and subsequently promote neuronal pyroptosis in HIE rat model.
Ten-day old unsexed rat pups were subjected to hypoxia-ischemia (HI) injury, and the inhibitor of IRE1α, STF083010, was administered intranasally at 1 h after HI induction. AntimiR-125 or NLRP1 activation CRISPR was administered by intracerebroventricular (i.c.v) injection at 24 h before HI induction. Immunofluorescence staining, western blot analysis, reverse transcription quantitative real-time polymerase chain reaction (RT-qPCR), brain infarct volume measurement, neurological function tests, and Fluoro-Jade C staining were performed.
Endogenous phosphorylated IRE1α (p-IRE1α), NLRP1, cleaved caspase-1, interleukin-1β (IL-1β), and interleukin-18 (IL-18) were increased and miR-125-b-2-3p was decreased in HIE rat model. STF083010 administration significantly upregulated the expression of miR-125-b-2-3p, reduced the infarct volume, improved neurobehavioral outcomes and downregulated the protein expression of NLRP1, cleaved caspase-1, IL-1β and IL-18. The protective effects of STF083010 were reversed by antimiR-125 or NLRP1 activation CRISPR.
IRE1α inhibitor, STF083010, reduced neuronal pyroptosis at least in part via miR-125/NLRP1/caspase-1 signaling pathway after HI.