Pituitary Adenylate Cyclase‐activating Polypeptide‐like Compounds Could Modulate the Activity of Coelomocytes in the Earthworm

Abstract

By means of radioimmunoassay, we studied the concentration of pituitary adenylate cyclase-activating polypeptide (PACAP)-like proteins in intact and regenerating earthworms. Transection of animals increased the concentration of PACAP-like compounds in coelomocytes, and a decreasing rostrocaudal gradient was detected in the regenerating animals. Western blot analysis revealed a range of PAC1-receptor proteins with molecular weights from 40 to 80 kDa. Electron microscopic immunocytochemistry showed that PAC1 receptors were located on distinct sets of coelomocytes (mainly on amebocytes and on some granulocytes). Based on our results we hypothesize a link between PACAP and coelomocytes, suggesting that PACAP modulates the function of amebocytes and certain granulocytes that play a role in tissue remodeling of regenerating earthworms.

Immune system participates in brain regeneration and restoration of reproduction in the earthworm Dendrobaena veneta

“…Somogyi et al (2009) proposed the existence of a functional link between the nervous system and coelomocyte-mediated regenerative capabilities of earthworms. This important insight was supported by the immune-localization of a variety of neuropeptides in the coelomocytes of Eisenia fetida (Wilhelm et al, 2006) and, crucially, the observation that earthworm coelomocytes, especially those located in the vicinity of regenerating tissue, contain pituitary adenylate cyclase-activating polypeptide (PACAP)-like proteins (Somogyi et al, 2009). In vertebrates, PACAP protects cells within the central nervous system against stress-induced apoptosis (Vaudry et al, 2002).…”

PACAP deficiency as a model of aging

“…As PACAP is a remarkably wellconserved neuropeptide, a lot of its actions are also present in lower animals, including invertebrates (Kiss and Pirger 2013;Krajcs et al 2015;Lugo et al 2013;Mertens et al 2007;Ng et al 2012). These include actions that are important in aging processes, like apoptosis (Pirger et al 2008), regeneration (Varhalmi et al 2008), immune (Somogyi et al 2009), and cognitive (Pirger et al 2010) functions. A recent study has described that PACAP is able to decrease the deteriorating effects of rotenone, a neurotoxin inducing parkinsonian effects in mollusks (Maasz et al 2017).…”

Nanobiology and physiology of growth hormone secretion

“…Chordata, Echinoderma, Hemichordata) about one billion years ago. There is strong evidence for the presence of PACAP-like peptide in mollusks, 141 annelids 142 and arthropods/insects. In Drosophila, the amnesiac gene encodes a peptide that is homologous with vertebrate PACAP.…”