RETRACTED: MicroRNA-29a-3p strengthens the effect of dexmedetomidine on improving neurologic damage in newborn rats with hypoxic-ischemic brain damage by inhibiting HDAC4

Abstract

Hypoxic-ischemic brain damage (HIBD) is a common brain injury caused by hypoxia or ischemia of the brain. This study aims to investigate the effect of dexmedetomidine (Dex) post-treatment on neurological impairment of newborn rats with HIBD via modulating microRNA-29a-3p (miR-29a-3p) and histone deacetylase 4 (HDAC4). HIBD model of newborn rats was established. Newborn modeled rats were injected with Dex, miR-29a-3p mimic or HDAC4 siRNA to figure their roles in learning and memory abilities, left hemisphere atrophy, brain tissue injury, inflammatory response and apoptosis rate of nerve cells of rats. The expression of miR-29a-3p and HDAC4 in hippocampal tissues of rats were detected, and the potential relationship between miR-29a-3p and HDAC4 was analyzed. Decreased miR-29a-3p and elevated HDAC4 were found in hippocampal tissues of rats with HIBD. In addition, Dex, elevated miR-29a-3p or declined HDAC4 enhanced spatial learning and memory abilities in rats with HIBD. Moreover, Dex, up-regulated miR-29a-3p or declined HDAC4 alleviated brain atrophy, repressed brain tissue injury, retrained the inflammation, repressed the apoptosis of neurons in the hippocampal region of rats with HIBD. HDAC4 was targeted and negatively regulated by miR-29a-3p. The study concludes that miR-29a-3p strengthened the effect of Dex on improving neurologic damage in newborn rats with HIBD by inhibiting HDAC4.