title: Comparison of melatonin with growth factors in promoting precursor cells proliferation in adult mouse subventricular zone.
abstract: Melatonin, secreted mainly by the pineal gland, plays roles in various physiological functions including protecting cell death. We showed in previous study that the proliferation and differentiation of precursor cells from the adult mouse subventricular zone (SVZ) can be modulated by melatonin via the MT1 melatonin receptor. Since melatonin and epidermal growth factor receptor (EGFR) share some signaling pathway components, we investigated whether melatonin can promote the proliferation of precursor cells from the adult mouse SVZ via the extracellular signal-regulated protein kinase /mitogen-activated protein kinase (ERK/MAPK) pathways in comparison with epidermal growth factor (EGF). Melatonin-induced ERK/MAPK pathways compared with EGF were measured by usingin vitroandvivomodels. We used neurosphere proliferation assay, immunocytochemistry, and immuno-blotting to analyze significant differences between melatonin and growth factor treatment. We also used specific antagonist and inhibitors to confirm the exactly signaling pathway including luzindole and U0126. We found that significant increase in proliferation was observed when two growth factors (EGF+bFGF) and melatonin were used simultaneously compared with EGF + bFGF or compared with melatonin alone. In addition, the present result suggested the synergistic effect occurred of melatonin and growth factors on the activating the ERK/MAPK pathway. This study exhibited that melatonin could act as a trophic factor, increasing proliferation in precursor cells mediated through the melatonin receptor coupled to ERK/MAPK signaling pathways. Understanding the mechanism by which melatonin regulates precursor cells may conduct to the development of novel strategies for neurodegenerative disease therapy.
authors.affiliation: Center for Neuroscience, Faculty of Science, Mahidol University, Bangkok, Thailand; Chulabhorn International College of Medicine, Thammasat University, Patumthani, 12120, Thailand.
authors.forename: Areechun
authors.initials: A
authors.lastname: Sotthibundhu
authors.affiliation: Physical therapy, Srinakharinwirot University, Ongkharak, Nakhonnayok 26120, Thailand; Research Center for Neuroscience, Institute of Molecular Biosciences, Mahidol University, Salaya, Nakornpathom, Thailand.
authors.forename: Kasima
authors.initials: K
authors.lastname: Ekthuwapranee
authors.affiliation: Center for Neuroscience, Faculty of Science, Mahidol University, Bangkok, Thailand; Research Center for Neuroscience, Institute of Molecular Biosciences, Mahidol University, Salaya, Nakornpathom, Thailand; Chulabhorn Graduate Institute, Kamphaeng Phet 6 Road, Lak Si, Bangkok 10210, Thailand.
authors.forename: Piyarat
authors.initials: P
authors.lastname: Govitrapong
keywords: epidermal growth factor; extracellular signal-regulated protein kinase; melatonin; mitogen-activated protein kinase; neural stem cells; subventricular zone