Abstract:
To investigate the effects of overexpressing lipoprotein lipase a gene (
lpl-a) in common carp (
Cyprinid carpio) on fat deposition patterns and lipid metabolism-related genes expression, we analyzed the sequence and structural characteristics of the carp
lpl-a gene and examined its tissue distribution using quantitative real-time (qPCR) in five internal tissues: abdominal fat, liver, kidney, muscle, and intestine. The
lpl-a overexpression plasmid vector was constructed by homologous recombination and introduced into zebrafish (
Danio rerio) and carp liver cells. The impacts of
lpl-a overexpression on total cholesterol (T-CHO), triglyceride (TG) levels, and expressions of lipid metabolism marker genes (
pparγ,
fabp3,
pnpla2, etc.) were assessed in zebrafish (individual level) and carp hepatocytes (cell level). Results showed that the carp
lpl-a was predicted to encode a 507-amino acid protein with 7 open reading frames (ORFs), and it demonstrated high evolutionary conservation in osteichthyes. Tissue-specific expression analysis revealed significantly higher
lpl-a transcript levels in abdominal fat, liver, and kidney compared to muscle and intestine (
P<0.05). In zebrafish, microinjection of the
lpl-a overexpression vector resulted in an approximately 7-fold increase in muscle T-CHO and a 1-fold increase in both T-CHO and TG in liver, accompanied by upregulation of
lpl-a,
ppar γ, and
fabp 3 (
P<0.05). In carp hepatocytes, transfection with the
lpl-a construct for 72h significantly increased
lpl-a and lipolytic gene
pnpla 2 expressions (
P<0.05). Altogether, these findings demonstrate that overexpression of
lpl-a induced distinct lipid metabolism regulations at individual (enhanced muscle fat storage and hepatic lipid accumulation) and cellular (activated lipolysis and inhibited lipogenesis) levels, providing theoretical insights for targeting
lpl-a to modulate lipid deposition in economically important aquatic animals.