{Reference Type}: Journal Article {Title}: miR-8-3p regulates the antioxidant response and apoptosis in white shrimp, Litopenaeus vannamei under ammonia-N stress. {Author}: Zhuo H;Zhang Y;Fu S;Lin L;Li J;Zhou X;Wu G;Guo C;Liu J; {Journal}: Int J Biol Macromol {Volume}: 274 {Issue}: 0 {Year}: 2024 Aug 22 {Factor}: 8.025 {DOI}: 10.1016/j.ijbiomac.2024.133305 {Abstract}: Exposure to excess ammonia-N (NH3/NH4+) in aquaculture can disrupt physiological function in shrimp leading to enhanced oxidative stress and apoptosis, but little is known concerning the post-transcriptional regulation mechanism. In this study, the first miR-200 family member in crustacean was identified and characterized from Litopenaeus vannamei (designed as Lva-miR-8-3p). Lva-miR-8-3p was highly expressed in eyestalks, brainganglion, and gills. The expression of Lva-miR-8-3p in gills significantly decreased after ammonia-N stress, and Lva-miR-8-3p was confirmed to target IKKβ 3'UTR for negatively regulating IKKβ/NF-κB pathway. Overexpression of miR-8-3p promoted the hemolymph ammonia-N accumulation, total hemocyte count (THC) decrease, and gills tissue damage, thus resulting in a decreased survival rate of ammonia-exposed shrimp. Besides, Lva-miR-8-3p silencing could enhance the antioxidant enzymes activities and reduce the oxidative damage, whereas overexpression of Lva-miR-8-3p exerted the opposite effects. Furthermore, Lva-miR-8-3p overexpression was found to aggravate ammonia-N induced apoptosis in gills. In primarily cultured hemocytes, the cell viability decreased, the ROS content and caspase-3 activity increased after agomiR-8-3p transfection, while antagomiR-8-3p transfection caused the opposite change except the cell viability. These findings indicate that Lva-miR-8-3p acts as a post-transcriptional regulator in ammonia-N induced antioxidant response and apoptosis by negatively regulating IKKβ/NF-κB pathway.