Bone morphogenetic proteins in the nervous system

Abstract

Bone morphogenetic proteins (BMPs) belong to the TGF-β superfamily of growth factors and morphogens. BMPs regulate neurulation, the sequence of morphogenetic events that specify neural tissue. Thereafter, BMPs and the closely related Growth/Differentiation Factors (GDFs) are prominently expressed in the central and peripheral nervous systems as well as in target tissues of sensory and motor neurons. The actions of BMPs and GDFs on neural tissue are both profound and diverse. They have been implicated in crucial developmental events such as: specification of neural and glial cell lineages, neural cell survival and proliferation, dorsal-ventral patterning, segmentation, axonal guidance, determination of neurotransmitter phenotype, regulation of dendritic growth and synapse formation. In addition, BMPs and GDFs are neuroprotective in mature animals in models of stroke and Parkinson’s disease. In a previous article, we surveyed the effects of BMPs and GDFs on neural tissue [1]. In this review, we update summaries of some of the more rapidly advancing research areas. Other recent reviews have examined neural actions of TGF-β [2] and the roles of BMPs and their antagonists in neural induction [3, 4], neural crest development [5] and dorsal-ventral patterning [6, 7]. Therefore, these topics are not considered here.