title: Adropin induction of lipoprotein lipase expression in tilapia hepatocytes.
abstract: The peptide hormone adropin plays a role in energy homeostasis. However, biological actions of adropin in non-mammalian species are still lacking. Using tilapia as a model, we examined the role of adropin in lipoprotein lipase (LPL) regulation in hepatocytes. To this end, the structural identity of tilapia adropin was established by 5'/3'-rapid amplification of cDNA ends (RACE). The transcripts of tilapia adropin were ubiquitously expressed in various tissues with the highest levels in the liver and hypothalamus. The prolonged fasting could elevate tilapia hepatic adropin gene expression, whereas no effect of fasting was observed on hypothalamic adropin gene levels. In primary cultures of tilapia hepatocytes, synthetic adropin was effective in stimulating LPL release, cellular LPL content, and total LPL production. The increase in LPL production also occurred with parallel rises in LPL gene levels. In parallel experiments, adropin could elevate cAMP production and up-regulate protein kinase A (PKA) and PKC activities. Using a pharmacological approach, cAMP/PKA and PLC/inositol trisphosphate (IP3)/PKC cascades were shown to be involved in adropin-stimulated LPL gene expression. Parallel inhibition of p38MAPK and Erk1/2, however, were not effective in these regards. Our findings provide, for the first time, evidence that adropin could stimulate LPL gene expression via direct actions in tilapia hepatocytes through the activation of multiple signaling mechanisms.
authors.affiliation: Key Laboratory of Bio-Resources and Eco-Environment of Ministry of EducationCollege of Life Sciences, Sichuan University, Chengdu 610065, People's Republic ChinaHepatic SurgeryThird Affiliated Hospital of Sun Yat-sen University, Guangdong, ChinaAnimal Health Research InstituteTongwei Co., Ltd, Chengdu, China.
authors.forename: Anji
authors.initials: A
authors.lastname: Lian
authors.affiliation: Key Laboratory of Bio-Resources and Eco-Environment of Ministry of EducationCollege of Life Sciences, Sichuan University, Chengdu 610065, People's Republic ChinaHepatic SurgeryThird Affiliated Hospital of Sun Yat-sen University, Guangdong, ChinaAnimal Health Research InstituteTongwei Co., Ltd, Chengdu, China.
authors.forename: Keqiang
authors.initials: K
authors.lastname: Wu
authors.affiliation: Key Laboratory of Bio-Resources and Eco-Environment of Ministry of EducationCollege of Life Sciences, Sichuan University, Chengdu 610065, People's Republic ChinaHepatic SurgeryThird Affiliated Hospital of Sun Yat-sen University, Guangdong, ChinaAnimal Health Research InstituteTongwei Co., Ltd, Chengdu, China Key Laboratory of Bio-Resources and Eco-Environment of Ministry of EducationCollege of Life Sciences, Sichuan University, Chengdu 610065, People's Republic ChinaHepatic SurgeryThird Affiliated Hospital of Sun Yat-sen University, Guangdong, ChinaAnimal Health Research InstituteTongwei Co., Ltd, Chengdu, China.
authors.forename: Tianqiang
authors.initials: T
authors.lastname: Liu
authors.affiliation: Key Laboratory of Bio-Resources and Eco-Environment of Ministry of EducationCollege of Life Sciences, Sichuan University, Chengdu 610065, People's Republic ChinaHepatic SurgeryThird Affiliated Hospital of Sun Yat-sen University, Guangdong, ChinaAnimal Health Research InstituteTongwei Co., Ltd, Chengdu, China.
authors.forename: Nan
authors.initials: N
authors.lastname: Jiang
authors.affiliation: Key Laboratory of Bio-Resources and Eco-Environment of Ministry of EducationCollege of Life Sciences, Sichuan University, Chengdu 610065, People's Republic ChinaHepatic SurgeryThird Affiliated Hospital of Sun Yat-sen University, Guangdong, ChinaAnimal Health Research InstituteTongwei Co., Ltd, Chengdu, China jiangqua@gmail.com.
authors.forename: Quan
authors.initials: Q
authors.lastname: Jiang
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002478:Cells, Cultured; D003001:Cloning, Molecular; D017124:Conserved Sequence; D000242:Cyclic AMP / Q000378:metabolism; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism; D004790:Enzyme Induction; D029941:Fish Proteins / Q000502:physiology*; D018628:Gene Dosage; D015870:Gene Expression; D022781:Hepatocytes / Q000201:enzymology*; D007031:Hypothalamus / Q000378:metabolism; D008071:Lipoprotein Lipase / Q000235:genetics / Q000378:metabolism*; D008099:Liver / Q000378:metabolism; D020935:MAP Kinase Signaling System; D008969:Molecular Sequence Data; D009928:Organ Specificity; D036361:Peptide Hormones / Q000502:physiology*; D011493:Protein Kinase C / Q000378:metabolism; D017210:Tilapia
chemical_list: D029941:Fish Proteins; D036361:Peptide Hormones; D000242:Cyclic AMP; D017868:Cyclic AMP-Dependent Protein Kinases; D011493:Protein Kinase C; D008071:Lipoprotein Lipase
keywords: adropin; lipoprotein lipase; signal transduction pathway; tilapia hepatocytes