Recombinant novel pituitary adenylate cyclase-activating polypeptide from African catfish (Clarias gariepinus) authenticates its biological function as a growth-promoting factor in low vertebrates

Abstract

Nowadays, the studies of pituitary adenylate cyclase-activating polypeptide (PACAP)-related peptide (PRP) and PACAP in non-mammalian vertebrates, especially in fish, have paid attention mainly to the localization, cloning, and structural evolution of the peptides, but very little is known about its biological functions as growth-promoting factors in low vertebrates. In this work, we have cloned and characterized the PRP/PACAP cDNA from the commercially important North African catfish Clarias gariepinus. The sequence obtained agrees with the higher conservation of PACAP than of PRP peptide sequences. We have reported for the first time the recombinant expression of fish PRP and PACAP in mammalian cells and bacteria and also demonstrated that the growth rate of fish is enhanced by both PRP and PACAP recombinant peptides. The results obtained in vivo in three different fish species, catfish (C. gariepinus), tilapia (Oreochromis niloticus), and carp (Cyprinus carpio) support the finding that PACAP rather than PRP plays a primordial role in growth control in teleost fish. This finding could help to elucidate the neuroendocrine axis proposed to explain the hypothalamic regulation of growth in non-mammalian vertebrates.

A novel GH secretagogue, A233, exhibits enhanced growth activity and innate immune system stimulation in teleosts fish

“…Meanwhile, Boaz (2005) observed the stimulating effect of CP-477 335 secretagogue on the secretion of GH by the pituitary gland of Mozambique tilapia (O. mossambicus) by incubating the body for 8 h with the synthetic secretagogue. Other researchers have reported the stimulatory effect of the synthetic peptides GHRP6, PACAP, and PACAP-related peptide from Clarias gariepinus on the release of GH in vitro by the pituitary gland of tilapia (Oreochromis niloticus; Lugo et al 2008).…”

“…The GH secreted in vitro was measured using a noncompetitive ELISA as described by Lugo et al (2008). The 96-well MaxiSorp plates (Nalge Nunc International, Roskilde, Denmark) were coated (3 h at 37 8C) with anti-tilapia GH monoclonal antibody 1 (tiGH1 mAb; CIGB, Santi Spiritus, Cuba) at 10 mg/ml in 0 .…”

Expression and in vitro regulation of pituitary adenylate cyclase-activating polypeptide (pacap38) and its type I receptor (pac1-r) in the gonads of tilapia (Oreochromis mossambicus)

“…Recently, it has been reported that the growth rates of catfish (Clarias gariepinus), tilapia (Oreochromis niloticus), and carp (Cyprinus carpio) were enhanced by the addition of both catfish PACAP-related peptide (PRP) and PACAP recombinant peptides (Lugo et al 2008). However, recombinant grass carp peptide specifically inhibited T98G human glioblastoma cell proliferation (Wang et al 2008).…”

Genomic structure, polymorphism and expression analysis of growth hormone-releasing hormone and pituitary adenylate cyclase activating polypeptide genes in the half-smooth tongue sole (Cynoglossus semilaevis)

“…In fish, PACAP is a pleiotropic hormone as an enhancer which potently stimulates the release of GH (Wong et al, 2000;Rousseau et al, 2001), gonadotropin (Wong et al, 2000), prolactin, adrenocorticotrophic hormone (ACTH) and luteinizing hormone (LH) (Fradinger and Sherwood, 2000). The PACAP mRNA precursor also encodes PACAP-related peptide (PRP), which also enhances the growth rates like PACAP as reported in fish (Lugo et al, 2008).…”