ProCRH in the teleost Ameiurus nebulosus: gene cloning and role in LPS-induced stress response.
The procorticotrophin-releasing hormone (proCRH) gene from the teleost Ameiurus nebulosus was cloned by direct and inverse PCR-based technologies and characterized. The structure of the proCRH gene shows the presence of four exons and three introns giving a total length of 1416bp. Sequence similarity with the corresponding proCRH coding sequences in Tilapia mossambica and Homo sapiens is 97.7 and 78%, respectively. Western blot experiments performed with an anti-human CRH (1-41) antibody revealed the presence of an immunoreactive molecule with an approximate MW of 18kDa, a value comparable to that of the putative catfish proCRH peptide. These data suggest that proCRH could be active in A. nebulosus without any cleavage. ProCRH immunoreactive molecules were found in the central nervous system (CNS) and were immunocytochemically detected in the head kidney and in the pancreatic gland. Western blot and immunocytochemical experiments showed an increase in proCRH expression in the CNS after 15min but not after 120min exposure to LPS. In contrast, the increased immunopositivity was detectable in the pancreas only after 120min of treatment, but in the head kidney throughout the entire period of exposure. Our findings indicate that the CNS responds to the altered conditions for a shorter period of time than the peripheral organs, suggesting a hierarchical and time-regulated stress response. However, an independent response in the peripheral organs cannot be excluded in this scenario.
Malagoli
Davide
D
Department of Animal Biology, University of Modena and Reggio Emilia, Modena, Italy.
Mandrioli
Mauro
M
Ottaviani
Enzo
E
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002490:Central Nervous System / Q000378:metabolism; D003001:Cloning, Molecular; D003346:Corticotropin-Releasing Hormone / Q000235:genetics* / Q000378:metabolism; D029941:Fish Proteins / Q000235:genetics / Q000378:metabolism; D005786:Gene Expression Regulation; D007059:Ictaluridae / Q000235:genetics* / Q000378:metabolism; D007150:Immunohistochemistry; D007668:Kidney / Q000378:metabolism; D008070:Lipopolysaccharides; D008969:Molecular Sequence Data; D010179:Pancreas / Q000378:metabolism; D011498:Protein Precursors / Q000235:genetics* / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012689:Sequence Homology, Nucleic Acid; D013312:Stress, Physiological / Q000139:chemically induced / Q000235:genetics* / Q000503:physiopathology; D014018:Tissue Distribution
D029941:Fish Proteins; D008070:Lipopolysaccharides; D011498:Protein Precursors; D003346:Corticotropin-Releasing Hormone