title: Hypothalamic proline rich polypeptide regulates hematopoiesis.
abstract: The AGAPEPAEPAQPGVY proline-rich polypeptide (PRP-1) was isolated from neurosecretory granules of the bovine neurohypophysis; it is produced by N. supraopticus and N. paraventricularis. It has been shown that PRP-1 has many potentially beneficial biological effects including immunoregulatory, hematopoietic, antimicrobial and anti-neurodegenerative properties. Here we demonstrated that PRP-1 administration influence on redistribution of monocytes, granulocytes and lymphocytes between bone marrow (BM) and peripheral blood and promotes the influx of granulocytes and monocytes/macrophages from BM into peripheral blood and accumulation of immature granulocyte and monocyte in BM and delayed the maturation of T cells in BM. PRP-1 increased colony-forming cell proliferation in rat cells in vivo. In PRP-treated rat BM, the CFU number at day 4, 7 and 14 was considerably increased in comparison with untreated rats BM and no difference was found at day 21 and day 28. We found that PRP-1 enhances erythroid and myeloid colonies formation in human CD34(+) progenitor cell culture in the presence of different growth factors and down-regulates T cells colony formation and specific surface markers expression during induction of human CD34(+) progenitor cells differentiation into T lymphocytes lineage. We suggested that the hypothalamic PRP-1 possibly represents an endogenous peptide whose primary functions are to regulate neuronal survival and differentiation and hematopoiesis within neurosecretory hypothalamus-bone marrow humoral axis.
authors.affiliation: H. Buniatian Institute of Biochemistry, NAS RA, 5/1 Sevag Str., Yerevan, 375014, Republic of Armenia.
authors.forename: Kristina B
authors.initials: KB
authors.lastname: Bezirganyan
authors.forename: Tigran K
authors.initials: TK
authors.lastname: Davtyan
authors.forename: Armen A
authors.initials: AA
authors.lastname: Galoyan
mesh_terms: D000818:Animals; D018952:Antigens, CD34 / Q000378:metabolism; D023181:Antimicrobial Cationic Peptides; D001854:Bone Marrow Cells / Q000166:cytology / Q000187:drug effects; D002417:Cattle; D002454:Cell Differentiation; D002478:Cells, Cultured; D003114:Colony-Forming Units Assay; D003713:Dendritic Cells / Q000166:cytology / Q000187:drug effects; D004912:Erythrocytes / Q000166:cytology / Q000187:drug effects; D006410:Hematopoiesis / Q000187:drug effects*; D006801:Humans; D008214:Lymphocytes / Q000166:cytology / Q000187:drug effects; D010455:Peptides / Q000494:pharmacology* / Q000502:physiology; D010904:Pituitary Gland, Posterior / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D013234:Stem Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism
chemical_list: D018952:Antigens, CD34; D023181:Antimicrobial Cationic Peptides; C540268:PRP-1 peptide; D010455:Peptides