title: The pro-apoptotic action of the peptide hormone Neb-colloostatin on insect haemocytes.
abstract: The gonadoinhibitory peptide hormone Neb-colloostatin was first isolated from ovaries of the flesh fly Neobellieria bullata. This 19-mer peptide is thought to be a cleaved product of a collagen-like precursor molecule that is formed during remodelling of the extracellular matrix. In this study, we report that upon injection of picomolar and nanomolar doses, this peptide exerts a pro-apoptotic action on haemocytes of Tenebrio molitor adults, as visualized by changes in morphology and viability. The F-actin cytoskeleton was found to aggregate into distinctive patches. This may be responsible for the observed inhibition of adhesion of haemocytes and for the stimulation of filopodia formation. However, Neb-colloostatin injection did not induce the formation of autophagic vacuoles. Our results suggest that physiological concentrations of Neb-colloostatin play an important role in controlling the quantity and activity of haemocytes in insect haemolymph. They also suggest that during periods in which Neb-colloostatin is released, this peptide may cause a weakening of the insects' immune system. This is the first report that exposure to a peptide hormone causes apoptosis in insect haemocytes.
authors.affiliation: Department of Animal Physiology and Development, Institute of Experimental Biology, Adam Mickiewicz University, Umultowska 89, 61-614 Poznań, Poland. czarniew@amu.edu.pl
authors.forename: E
authors.initials: E
authors.lastname: Czarniewska
authors.forename: L
authors.initials: L
authors.lastname: Mrówczynska
authors.forename: M
authors.initials: M
authors.lastname: Kuczer
authors.forename: G
authors.initials: G
authors.lastname: Rosinski
mesh_terms: D000818:Animals; D017209:Apoptosis; D006434:Hemocytes / Q000166:cytology* / Q000378:metabolism; D007301:Insect Hormones / Q000378:metabolism*; D013712:Tenebrio / Q000378:metabolism*
chemical_list: D007301:Insect Hormones; C094892:Neb-colloostatin