Gonadotropin‐releasing hormone‐1 (GnRH‐1) is involved in tooth maturation and biomineralization

Abstract Gonadotropin releasing‐hormone‐1 (GnRH‐1) is expressed in mouse incisors during development. In this report, we identify (1) cell type(s) that express GnRH‐1 throughout tooth development, (2) the GnRH‐1 receptor, and (3) the role of GnRH‐1/GnRH‐1 receptor signaling in tooth maturation. Results show that GnRH‐1‐positive cells in dental epithelium differentiate and populate multiple tooth structures including ameloblast and papillary layers that are involved in enamel formation and mineralization. The GnRH‐1 receptor was present, and in vitro a GnRH‐1 antagonist attenuated incisor GnRH‐1 cell expression. In vivo, in mice lacking GnRH‐1 (−/−), the incisors were discolored, longer, and more curved compared to wildtype. Elemental analysis of calcium, phosphorus, and iron revealed changes in −/− incisors consistent with GnRH‐1 affecting movement of minerals into the dental matrix. In sum, in tooth development a signal transduction pathway exists for GnRH‐1 via the GnRH‐1 receptor and disruption of such signaling affects incisor growth and biomineralization. Developmental Dynamics 236:2980–2992, 2007. Published 2007 Wiley‐Liss, Inc.