Regulation of Glycerol-3-Phosphate Dehydrogenase by Hypoxia-Inducible Factor-1 in WSSV-Infected White Shrimp Litopenaeus vannamei.

Hypoxia-inducible factor-1 (HIF-1) induces the Warburg effect in the Litopenaeus vannamei shrimp infected with white spot syndrome virus (WSSV) to satisfy the energetic and biosynthetic demands required for viral replication. Glycerol-3-phosphate dehydrogenase (GPDH) is a key enzyme linking carbohydrate metabolism, lipid biosynthesis, and cellular redox balance; however, its role during WSSV infection remains poorly understood. In this study, the complete coding sequences of the cytoplasmic (LvGPDHc) and mitochondrial (LvGPDHm) GPDH isoforms were characterized from the hepatopancreas of L. vannamei, and their regulation by HIF-1α during WSSV infection was investigated. Sequence and phylogenetic analyses revealed that both proteins are highly conserved among crustaceans and contain the characteristic domains required for catalytic activity. WSSV infection decreases the mRNA expression of both GPDH isoforms and increases the cytoplasmic GPDH activity. In contrast, HIF-1α silencing increases the mRNA expression of both GPDH isoforms and increases the mitochondrial GPDH activity. The concentrations of glycerol-3-phosphate and citrate increase with WSSV infection and return to basal levels upon HIF-1α silencing. Results suggest that WSSV infection in white shrimp is associated with increased lipid biosynthesis via cytoplasmic GPDH, which contributes to viral replication, whereas mitochondrial GPDH may help maintain cellular redox status. Furthermore, these results demonstrate that the expression of GPDH isoforms is regulated by HIF-1, contributing to metabolic reprogramming in shrimp during WSSV infection.