Sonic hedgehog induces GLT-1 degradation via PKC delta to suppress its transporter activities. (4th December 2017)

• Record Type: Journal Article
• Authors: Wang, Yuqing; Lu, Shanshan; Qu, Zhongwei; Wu, Lin; Wang, Yizheng
• Is Part Of: Neuroscience. Volume 365(2017)
• Page Start: 217
• Page End: 225
• Publication Date: 2017-12-04
• Subjects: Asp aspartate -- BisII bisindolylmaleimideII -- CYC cyclopamine -- MTT thiazolyl blue tetrazolium bromide -- PKCδ PKC delta -- PMA phorbol 12-myristate 13-acetate -- SHH sonic hedgehog -- Smo Smoothened -- STP straurosporine -- TfR, transferrin receptor -- UCPH UCPH101 -- WAY WAY213613; sonic hedgehog -- GLT-1 -- PKC -- astrocytes; Neurochemistry -- Periodicals; Neurophysiology -- Periodicals; Neurology -- Periodicals; Neurochimie -- Périodiques; Neurophysiologie -- Périodiques; Neurochemistry; Neurophysiology; Electronic journals; Periodicals; Electronic journals; 612.8
• DOI: 10.1016/j.neuroscience.2017.09.051
• Languages: English
• ISSNs: 0306-4522

Abstract

Highlights: Sonic hedgehog induces the degradation of GLT-1 through proteosome in cultured astrocytes. Sonic hedgehog inhibits the GLT-1 activities in cultured astrocytes. PKC delta mediates GLT-1 degradation induced by sonic hedgehog in cultured astrocytes. Abstract: GLT-1 is mainly expressed in astrocytes and has a crucial role in glutamate uptake. Sonic hedgehog (SHH) can inhibit glutamate uptake and its pathway is activated in many brain diseases related with glutamate excitotoxicity. However, whether SHH regulates GLT-1 to affect glutamate uptake is not clear. Here, we use pharmacological and genetic methods to show that SHH induces GLT-1 degradation in astrocytes in a manner that is dependent on PKC delta (PKCδ) to regulate GLT-1 activities. GLT-1 protein levels are reduced as early as 2 hs in astrocytes after incubation with SHH, whereas its mRNA levels are not changed. This reduction is recapitulated when astrocytes are transfected with SmoA1, a constitutively active form of Smoothened (Smo), the mediator of SHH pathway. The reduction of GLT-1 and inhibition of aspartate current are not observed when staurosporine (STP) and BisindolylmaleimideII (BisII), agents known as PKC inhibitors, are present. Further, when PKCδ is knocked down in astrocytes, SHH cannot reduce GLT-1 protein levels. Therefore, SHH induces degradation of GLT-1 through PKCδ to regulate its activities.