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AMPK affects thermal tolerance in decapod crustaceans
Author(s) -
Lancor Pierce,
Bucicchia Christina,
Frederich Markus
Publication year - 2018
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.2018.32.1_supplement.862.7
Subject(s) - ampk , biology , carcinus maenas , amp activated protein kinase , energy charge , protein kinase a , cellular stress response , medicine , endocrinology , crustacean , ecology , microbiology and biotechnology , adenylate kinase , biochemistry , kinase , decapoda , enzyme , fight or flight response , gene
AMP‐activated protein kinase (AMPK) is a cellular master regulator of energy metabolism, that is activated during stress to ensure a stable ATP pool in the cell. Additional to substantial work on the role of AMPK in mammals, especially humans, it becomes increasingly clear that AMPK is also involved in multiple processes in marine invertebrates, like crustaceans. Following the Oxygen and Capacity‐Limited Thermal Tolerance Hypothesis (OCLTT) marine invertebrates' thermal tolerance is dependent on sufficient oxygen delivery to the tissues and subsequent cellular ATP supply. Recent work has shown AMPK activation during heat stress in the rock crab, Cancer irroratus and the lobster, Homarus americanus . However, heat stress did not activate AMPK in the green crab Carcinus maenas . In the current project we tested whether pharmaceutically activating AMPK prior to a heat stress affects subsequent thermal tolerance. We injected Metformin in C. irroratus and activated AMPK about 3 fold above control levels, without affecting HSP70 protein levels or glucose levels in the hemolymph, indicating that this treatment did not trigger a broader stress response. A subsequent progressive temperature challenge between 11 and 32°C led in the Metformin treated animals to a drop in the maximum heart rate from 150 to 100 BPM at 29 and 23°C (control vs. Metformin treated, respectively), and a drop of the critical temperature, indicated by a switch to anaerobic metabolism and lactate accumulation, from 30 to 26°C. Therefore, AMPK activation diminished thermal tolerance in C. irroratus . Injecting Metformin into C. maenas showed a 30% increase in AMPK activity in the gills, with no substantial increase in AMPK activity in the hepatopancreas or heart. First results on the effect on injecting another AMPK activator, AICAR, don't lead to a substantial increase in AMPK activity yet, and require further adjustments of the treatment protocol. Pharmaceutically activating AMPK and investigating the subsequent effect on stress tolerance will contribute to a mechanistic understanding of energy allocations during stress in the context of the dynamic energy budget framework. Support or Funding Information Supported by a summer research fellowship from the American Physiological Society to P.L., and NSF grant DUE 1431955 to M.F. This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .