PPAR Signaling Maintains Metabolic Homeostasis under Hypothermia in Freshwater Drum (Aplodinotus grunniens)

Ningyuan Wu; Haibo Wen; Pao Xu; Jianxiang Chen; Miaomiao Xue; Jianlin Li; Meiyao Wang; Changyou Song; Hongxia Li

doi:10.3390/metabo13010102

PPAR Signaling Maintains Metabolic Homeostasis under Hypothermia in Freshwater Drum (Aplodinotus grunniens)

Metabolites. 2023 Jan 8;13(1):102. doi: 10.3390/metabo13010102.

Authors

Ningyuan Wu^{1

2}, Haibo Wen^{1

2}, Pao Xu^{1

2}, Jianxiang Chen², Miaomiao Xue², Jianlin Li^{1

2}, Meiyao Wang^{1

2}, Changyou Song^{1

2}, Hongxia Li^{1

2}

Affiliations

¹ Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, No. 9 Shanshui East Road, Wuxi 214081, China.
² Wuxi Fisheries College, Nanjing Agricultural University, Wuxi 214081, China.

Abstract

Aplodinotus grunniens, known as freshwater drum, is a kind of eurythermal freshwater fish that is widely distributed in North America. In 2019, our research group reached a milestone on its artificial breeding and cultivation and have investigated its physiological adaption to the environment, providing a breakthrough and prospects for aquaculture. However, its adaptability and metabolic homeostasis to hypothermia is not fully understood. In this experiment, cold stress was conducted at 18 °C (LT18) and 10 °C (LT10) with 25 °C as control (Con) for 8 days to explore the effects of short-term hypothermia on the physiology and metabolism of freshwater drum. From the results, the level of free essential amino acids in LT18 and LT10 decreased significantly after 2 days cold stress compared with Con. Furthermore, plasma total triglyceride (TG) content and lipase (LPS) activity were decreased at LT10 for 2d. With RNA-seq in the liver, metabolic-related signaling, especially amino acid synthesis and lipid metabolism, was inhibited by hypothermia. Specifically, the PPAR signaling pathway is correlated with the inhibition of lipid and amino acid metabolism induced by hypothermia. These data confirmed that PPAR signaling maintains lipid and amino acid metabolic homeostasis during cold stress. These results give a theoretical foundation for hypothermia resistance in the area of metabolic homeostasis for freshwater drum.

Keywords: Aplodinotus grunniens; PPAR signaling; amino acid metabolism; hypothermia; lipid metabolism.

Grants and funding

This research was funded by the National Nonprofit Institute Research Grant of Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences (2021JBFM13, 2020JBFR03, 2020JBMF02), and the Innovation Project of Jiangsu Agriculture Science and Technology (SCX(20)2025).