title: Elevated cortisol modulates Hsp70 and Hsp90 gene expression and protein in sea bass head kidney and isolated leukocytes.
abstract: In fish, interactions between Hsps and cortisol are involved in stress modulated physiological processes including innate immune responses. Cortisol exerts a role in the regulation of Hsps synthesis. Fish head kidney is a lymphomieloid and endocrine organ releasing cortisol, and it is the central organ for immune-endocrine interactions. In sea bass, cortisol intraperitoneal injection and in vitro treatment of head kidney cells show that inducible Hsp70 and Hsp90 are modulated by this hormone. However, an inverse relationship between mRNA expression (real-time PCR) and Hsp70 and Hsp90 protein levels (densitometric band analysis) was found. Time-course assays indicate a cortisol-mediated regulation. Furthermore, Hsp70 gene modulation appears to be more susceptible to the cortisol action and the mRNA was transcribed within 3h post-injection. The restoration of the homeostatic conditions was observed at a week p.i., when plasma cortisol baseline was reached. Although fish manipulation and injection exerted stressing effects as indicated by serological parameters, differences between cortisol treated specimens compared to untreated or sham fish are statistically significant. Similar results were found by examining in vitro total cells and isolated leukocytes from head kidney cultured for 3h with increasing cortisol concentration. Finally, MTT test and DNA fragmentation experiments showed that the apoptotic effect expected in cortisol-treated cells could be counteracted by high Hsp70 intracellular levels.
authors.affiliation: Laboratory of Marine Immunobiology, Department of Environmental Biology and Biodiversity, Division of Animal Biology and Anthropology, University of Palermo, Via Archirafi 18, Palermo, Italy.
authors.forename: Monica
authors.initials: M
authors.lastname: Celi
authors.forename: Mirella
authors.initials: M
authors.lastname: Vazzana
authors.forename: Maria Antonietta
authors.initials: MA
authors.lastname: Sanfratello
authors.forename: Nicolò
authors.initials: N
authors.lastname: Parrinello
mesh_terms: D000818:Animals; D001492:Bass / Q000378:metabolism*; D002478:Cells, Cultured; D005786:Gene Expression Regulation / Q000187:drug effects*; D018840:HSP70 Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism*; D018841:HSP90 Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism*; D060226:Head Kidney / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D006854:Hydrocortisone / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology*; D066298:In Vitro Techniques; D007274:Injections, Intraperitoneal; D007962:Leukocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D013312:Stress, Physiological / Q000502:physiology
chemical_list: D018840:HSP70 Heat-Shock Proteins; D018841:HSP90 Heat-Shock Proteins; D012333:RNA, Messenger; D006854:Hydrocortisone