title: Starvation beneficially influences the liver physiology and nutrient metabolism in Edwardsiella tarda infected red sea bream (Pagrus major).
abstract: Dietary compromises, especially food restrictions, possess species-specific effects on the health status and infection control in several organisms, including fish. To understand the starvation-mediated physiological responses in Edwardsiella tarda infected red sea bream, especially in the liver, we performed a 20-day starvation experiment using 4 treatment (2 fed and 2 starved) groups, namely, fed-placebo, starved-placebo, fed-infected, and starved-infected, wherein bacterial exposure was done on the 11th day. In the present study, the starved groups showed reduced hepatosomatic index and drastic depletion in glycogen storage and vacuole formation. The fed-infected fish showed significant (P<0.05) increase in catalase and superoxide dismutase activity in relation to its starved equivalent. Significant (P<0.05) alteration in glucose and energy metabolism, as evident from hexokinase and glucose-6-phosphate dehydrogenase activity, was recorded in the starved groups. Interestingly, coinciding with the liver histology, PPAR (peroxisome proliferator activated receptors) α transcription followed a time-dependent activation in starved groups while PPARγ exhibited an opposite pattern. The transcription of hepcidin 1 and transferrin, initially increased in 0dai (days after infection) starved fish but reduced significantly (P<0.05) at later stages. Two-color immunohistochemistry and subsequent cell counting showed significant increase in P63-positive cells at 0dai and 5dai but later reduced slightly at 10dai. Similar results were also obtained in the lysosomal (cathepsin D) and non-lysosomal (ubiquitin) gene transcription level. All together, our data suggest that starvation exerts multidirectional responses, which allows for better physiological adaptations during any infectious period, in red sea bream.
authors.affiliation: South Ehime Fisheries Research Center, Ehime University, 798-4206, Matsuyama, Japan.
authors.forename: Sipra
authors.initials: S
authors.lastname: Mohapatra
authors.affiliation: South Ehime Fisheries Research Center, Ehime University, 798-4206, Matsuyama, Japan. Electronic address: chakraborty.tapas.yx@ehime-u.ac.jp.
authors.forename: Tapas
authors.initials: T
authors.lastname: Chakraborty
authors.affiliation: Fisheries Research Division, Ainan Town Office, Ainancho, 798-4211, Matsuyama, Japan.
authors.forename: Sonoko
authors.initials: S
authors.lastname: Shimizu
authors.affiliation: Fisheries Research Division, Ainan Town Office, Ainancho, 798-4211, Matsuyama, Japan.
authors.forename: Shintaro
authors.initials: S
authors.lastname: Urasaki
authors.affiliation: South Ehime Fisheries Research Center, Ehime University, 798-4206, Matsuyama, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Matsubara
authors.affiliation: South Ehime Fisheries Research Center, Ehime University, 798-4206, Matsuyama, Japan; Institution for Collaborative Relations, Ehime University, 790-8577, Matsuyama, Japan.
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Nagahama
authors.affiliation: South Ehime Fisheries Research Center, Ehime University, 798-4206, Matsuyama, Japan. Electronic address: kohta@agr.ehime-u.ac.jp.
authors.forename: Kohei
authors.initials: K
authors.lastname: Ohta
mesh_terms: D000818:Animals; D002374:Catalase / Q000378:metabolism; D020609:Edwardsiella tarda / Q000254:growth & development* / Q000502:physiology; D004734:Energy Metabolism; D004756:Enterobacteriaceae Infections / Q000378:metabolism / Q000382:microbiology / Q000503:physiopathology*; D005393:Fish Diseases / Q000378:metabolism / Q000382:microbiology / Q000503:physiopathology*; D029941:Fish Proteins / Q000235:genetics / Q000378:metabolism; D005502:Food; D015870:Gene Expression; D005947:Glucose / Q000378:metabolism; D006003:Glycogen / Q000378:metabolism; D054884:Host-Pathogen Interactions; D008099:Liver / Q000378:metabolism / Q000382:microbiology / Q000503:physiopathology*; D047493:PPAR alpha / Q000235:genetics; D047495:PPAR gamma / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D021541:Sea Bream / Q000378:metabolism / Q000382:microbiology / Q000502:physiology*; D013217:Starvation; D013482:Superoxide Dismutase / Q000378:metabolism; D014617:Vacuoles / Q000378:metabolism
chemical_list: D029941:Fish Proteins; D047493:PPAR alpha; D047495:PPAR gamma; D006003:Glycogen; D002374:Catalase; D013482:Superoxide Dismutase; D005947:Glucose
keywords: Cell death; Iron homeostasis; Liver; Metabolic enzymes; PPAR; Red sea bream; Starvation