microRNA‐129‐5p involved in the neuroprotective effect of dexmedetomidine on hypoxic‐ischemic brain injury by targeting COL3A1 through the Wnt/β‐catenin signaling pathway in neonatal rats

Our study aims to elucidate the mechanisms how microRNA‐129‐5p (miR‐129‐5p) involved in the neuroprotective effect of dexmedetomidine (DEX) on hypoxic‐ischemic brain injury (HIBI) by targeting the type III procollagen gene (COL3A1) through the Wnt/β‐catenin signaling pathway in neonatal rats. A total of 120 rats were obtained, among which 15 rats were selected as sham group and rest rats as model, DEX, DEX + negative control (DEX + NC), DEX + miR‐129‐5p mimics, DEX + miR‐129‐5p inhibitors, DEX + XAV‐939, and DEX + miR‐129‐5p inhibitors + XAV‐939 groups. A dual‐luciferase reporter assay was performed for the target relationship between miR‐129‐5p and COL3A1. Weight rate and water content of cerebral hemisphere were detected. Quantitative real‐time polymerase chain reaction and Western blot analysis were conducted to detect miR‐129‐5p expression and expressions of COL3A1, E‐cadherin, T‐cell factor (TCF)− 4, and β‐catenin. The DEX, DEX + miR‐129‐5p mimics, DEX + XAV‐939 groups had increased weight rate of the cerebral hemisphere, but decreased water content of left cerebral hemisphere, levels of COL3A1, β‐catenin, TCF‐4, and E‐cadherin in the hippocampus compared with the model and DEX + miR‐129‐5p inhibitors groups. COL3A1 was verified as the target gene of the miR‐129‐5p. Compared with the DEX + NC and DEX + miR‐129‐5p inhibitors + XAV‐939 groups, the DEX + XAV‐939 and DEX + miR‐129‐5p mimics groups had elevated weight rate of the cerebral hemisphere, but reduced water content of left cerebral hemisphere, levels of COL3A1, β‐catenin, TCF‐4, and E‐cadherin in the hippocampus. Our findings demonstrate that miR‐129‐5p improves the neuroprotective role of DEX in HIBI by targeting COL3A1 through the Wnt/β‐catenin signaling pathway in neonatal rats. Our findings demonstrate that microRNA‐129‐5p improves the neuroprotective role of dexmedetomidine in hypoxic‐ischemic brain injury by targeting type III procollagen gene through the Wnt/β‐catenin signaling pathway in neonatal rats.