Changes in apolipoprotein abundance dominate proteome responses to prolonged fasting in elephant seals

Authors

• Jane I. Khudyakov, University of the PacificFollow
• Rachel R. Holser, University of California, Santa Cruz
• Craig A. Vierra, University of the PacificFollow
• Serena T. Ly, University of the Pacific
• Theron K. Niel, University of the Pacific
• Basma M. Hasan, University of the Pacific
• Daniel E. Crocker, Sonoma State University
• Daniel P. Costa, University of California, Santa Cruz

Document Type

Article

Publication Title

Journal of Experimental Biology

Department

Biological Sciences

ISSN

14779145

Volume

225

Issue

4

DOI

10.1242/jeb.243572

First Page

1

Last Page

13

Publication Date

2-21-2022

Abstract

Unlike many animals that reduce activity during fasting, northern elephant seals (NES) undergo prolonged fasting during energyintensive life-history stages such as reproduction and molting, fueling fasting energy needs by mobilizing fat stores accrued during foraging. NES display several unique metabolic features such as high fasting metabolic rates, elevated blood lipid and high-density lipoprotein (HDL) cholesterol levels, efficient protein sparing and resistance to oxidative stress during fasting. However, the cellular mechanisms that regulate these adaptations are still not fully understood. To examine how metabolic coordination is achieved during prolonged fasting, we profiled changes in blubber, skeletal muscle and plasma proteomes of adult female NES over a 5 week fast associated with molting. We found that while blubber and muscle proteomes were remarkably stable over fasting, over 50 proteins changed in abundance in plasma, including those associated with lipid storage, mobilization, oxidation and transport. Apolipoproteins dominated the blubber, plasma and muscle proteome responses to fasting. APOA4, APOE and APOC3, which are associated with lipogenesis and triglyceride accumulation, decreased, while APOA1, APOA2 and APOM, which are associated with lipid mobilization and HDL function, increased over fasting. Our findings suggest that changes in apolipoprotein composition may underlie the maintenance of high HDL levels and, together with adipokines and hepatokines that facilitate lipid catabolism, may mediate the metabolic transitions between feeding and fasting in NES. Many of these proteins have not been previously studied in this species and provide intriguing hypotheses about metabolic regulation during prolonged fasting in mammals.

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 International License.

Recommended Citation

Khudyakov, Jane I.; Holser, Rachel R.; Vierra, Craig A.; Ly, Serena T.; Niel, Theron K.; Hasan, Basma M.; Crocker, Daniel E.; and Costa, Daniel P., "Changes in apolipoprotein abundance dominate proteome responses to prolonged fasting in elephant seals" (2022). Pacific Faculty Work. 185.
https://scholarlycommons.pacific.edu/all-faculty/185