title: Treatment of cerebral ischemia with melanocortins acting at MC4 receptors induces marked neurogenesis and long-lasting functional recovery.
abstract: Melanocortins produce neuroprotection against ischemic stroke with subsequent long-lasting functional recovery, through melanocortin MC(4) receptor activation. Here we investigated whether the long-lasting beneficial effect of melanocortins in stroke conditions is associated with a stimulation of neurogenesis. Gerbils were subjected to transient global cerebral ischemia by occluding both common carotid arteries for 10 min; then, they were prepared for 5-bromo-2'-deoxyuridine (BrdU) labeling of proliferating cells. Delayed treatment (up to 9 h after the ischemic injury) for 11 days with the melanocortin analog [Nle(4),D-Phe(7)]α-melanocyte-stimulating hormone (NDP-α-MSH) improved learning and memory throughout the 50-day observation period. Immunohistochemical examination of the hippocampus on day 50 showed, in the dentate gyrus, an elevated number of BrdU immunoreactive cells colocalized with NeuN (used as indicator of mature neurons) and Zif268 (used as indicator of functionally integrated neurons). Retrospective analysis during the early stage of neural stem/progenitor cell development (days 3 and 4 after stroke) showed, in NDP-α-MSH-treated gerbils, a high degree of daily cell proliferation and revealed that NDP-α-MSH favorably affects Wnt-3A signaling pathways and doublecortin expression. Pharmacologic blockade of MC(4) receptors prevented all effects of NDP-α-MSH. These data indicate that treatment of cerebral ischemia with MC(4) receptor agonists induces, with a broad window of therapeutic opportunity, long-lasting functional recovery associated with a large number of mature and likely functional newborn neurons in brain injured areas. Our findings reveal previously undescribed effects of melanocortins which might have major clinical implications.
authors.affiliation: Department of Biomedical Sciences, Section of Pharmacology, University of Modena and Reggio Emilia, Via G. Campi 287, 41125, Modena, Italy.
authors.forename: Daniela
authors.initials: D
authors.lastname: Giuliani
authors.forename: Davide
authors.initials: D
authors.lastname: Zaffe
authors.forename: Alessandra
authors.initials: A
authors.lastname: Ottani
authors.forename: Luca
authors.initials: L
authors.lastname: Spaccapelo
authors.forename: Maria
authors.initials: M
authors.lastname: Galantucci
authors.forename: Letteria
authors.initials: L
authors.lastname: Minutoli
authors.forename: Alessandra
authors.initials: A
authors.lastname: Bitto
authors.forename: Natasha
authors.initials: N
authors.lastname: Irrera
authors.forename: Miranda
authors.initials: M
authors.lastname: Contri
authors.forename: Domenica
authors.initials: D
authors.lastname: Altavilla
authors.forename: Annibale R
authors.initials: AR
authors.lastname: Botticelli
authors.forename: Francesco
authors.initials: F
authors.lastname: Squadrito
authors.forename: Salvatore
authors.initials: S
authors.lastname: Guarini
mesh_terms: D000818:Animals; D002545:Brain Ischemia / Q000188:drug therapy* / Q000378:metabolism* / Q000473:pathology; D004195:Disease Models, Animal; D005849:Gerbillinae; D008297:Male; D053486:Melanocortins / Q000494:pharmacology / Q000502:physiology*; D009410:Nerve Degeneration / Q000188:drug therapy* / Q000378:metabolism* / Q000473:pathology; D055495:Neurogenesis / Q000502:physiology*; D044105:Receptor, Melanocortin, Type 4 / Q000378:metabolism* / Q000502:physiology; D020127:Recovery of Function / Q000187:drug effects / Q000502:physiology*; D013997:Time Factors
chemical_list: D053486:Melanocortins; D044105:Receptor, Melanocortin, Type 4