Tuberin levels during cellular differentiation in brain development

Abstract

ABSTRACTTuberin is a member of a large protein complex, Tuberous Sclerosis Complex, and acts as a sensor for nutrient status regulating protein synthesis and cell cycle progression. Mutations in the Tuberin gene, TSC2, lead to the formation of tumors and developmental defects in many organ systems, including the central nervous system. Tuberin is expressed in the brain throughout development and levels of Tuberin have been found to decrease during neuronal differentiation in cell lines in vitro. Our current work investigates the levels of Tuberin at two stages of embryonic development in vivo, and we study the mRNA and protein levels during a time course using immortalized cell lines in vitro. Our results show that Tuberin levels remain stable in the olfactory bulb but decrease in the Purkinje cell layer during embryonic mouse brain development. We show here that Tuberin levels are higher when cells are cultured as neurospheres, and knockdown of Tuberin results in a reduction in the number of neurospheres. These data provide support for the hypothesis that Tuberin is an important regulator of stemness and the reduction of Tuberin levels might support functional differentiation in the central nervous system. Understanding how Tuberin expression is regulated throughout neural development is essential to fully comprehend the role of this protein in several developmental and neural pathologies.HIGHLIGHTSTuberin protein levels are decreased in the Purkinje cell layer in later stages of embryonic development.Tuberin protein and mRNA levels decrease as cells undergo neuronal differentiation.Downregulation of Tuberin impairs neurosphere formation.Tuberin is implicated in the maintenance of stemness in the developing brain.