PPARα activation enhances the ability of nile tilapia (Oreochromis niloticus) to resist Aeromonas hydrophila infection

• Published in: Fish & shellfish immunology 2019-11, Vol.94, p.675-684
• Main Authors: Luo, Yuan, Zhang, Yun-Ni, Zhang, Han, Lv, Hong-Bo, Zhang, Mei-Ling, Chen, Li-Qiao, Du, Zhen-Yu
• Format: Article
• Language: English
• Subjects: Aeromonas hydrophila; Aeromonas hydrophila - physiology; Animal Feed - analysis; Animals; Antioxidation; Cichlids - immunology; Diet - veterinary; Dietary Supplements - analysis; Energy metabolism; Fenofibrate - administration & dosage; Fenofibrate - metabolism; Fish Diseases - immunology; Fish Diseases - microbiology; Gram-Negative Bacterial Infections - immunology; Gram-Negative Bacterial Infections - microbiology; Gram-Negative Bacterial Infections - veterinary; Immune function; Mitochondrial function; Nile tilapia; PPAR alpha - agonists; PPARα activation
• ISSN: 1050-4648; 1095-9947
• DOI: 10.1016/j.fsi.2019.09.062

Peroxisome proliferator-activated receptor α (PPARα) plays critical physiological roles in energy metabolism, antioxidation and immunity of mammals, however, these functions have not been fully understood in fish. In the present study, Nile tilapia (Oreochromis niloticus) were fed with fenofibrate, an agonist of PPARα, for six weeks, and subsequently challenged with Aeromonas hydrophila. The results showed that PPARα was efficiently activated by fenofibrate through increasing mRNA and protein expressions and protein dephosphorylation. PPARα activation increased significantly mitochondrial fatty acid β-oxidation efficiency, the copy number of mitochondrial DNA and expression of monoamine oxidase (MAO), a marker gene of mitochondria. Meanwhile, PPARα activation also increased significantly the expression of NADH dehydrogenase [ubiquinone] 1α subcomplex subunit 9 (NDUFA9, complex I) and mitochondrial cytochrome c oxidase 1 (MTCO1, complex IV). The fenofibrate-fed fish had higher survival rate when exposed to A. hydrophila. Moreover, the fenofibrate-fed fish also had higher activities of immune and antioxidative enzymes, and gene expressions of anti-inflammatory cytokines, while had lower expressions of pro-inflammatory cytokine genes. Taken together, PPARα activation improved the ability of Nile tilapia to resist A. hydrophila, mainly through enhancing mitochondrial fatty acids β-oxidation, immune and antioxidant capacities, as well as inhibiting inflammation. This is the first study showing the regulatory effects of PPARα activation on immune functions through increasing mitochondria-mediated energy supply in fish. •PPARα was efficiently activated by fenofibrate in Nile tilapia.•PPARα activation enhanced antioxidant ability and immune functions in Nile tilapia.•PPARα activation enhanced mitochondrial functions and energy supply in Nile tilapia.•PPARα could be a potential new target in regulating immune functions in fish.