Activation of Rheb, but not of mTORC1, impairs spine synapse morphogenesis in tuberous sclerosis complex

作者：Yasuda Shin; Sugiura Hiroko; Katsurabayashi Shutaro; Shimada Tadayuki; Tanaka Hidekazu; Takasaki Kotaro; Iwasaki Katsunori; Kobayashi Toshiyuki; Hino Okio; Yamagata Kanato^*

来源：Scientific Reports, 2014, 4(1): 5155.

DOI：10.1038/srep05155

Mutations in the Tsc1 or Tsc2 genes cause tuberous sclerosis complex (TSC). Tsc1 and Tsc2 proteins form a complex that inhibits mammalian target of rapamycin complex 1 (mTORC1) signalling through Rheb-GTPase. We found that Tsc21/2 neurons showed impaired spine synapse formation, which was resistant to an mTORC1 inhibitor. Knockdown of mTOR also failed to restore these abnormalities, suggesting mTORC may not participate in impaired spinogenesis in Tsc21/2 neurons. To address whether Rheb activation impairs spine synapse formation, we expressed active and inactive forms of Rheb in WT and Tsc2(+/-) neurons, respectively. Expression of active Rheb abolished dendritic spine formation in WT neurons, whereas inactive Rheb restored spine synapse formation in Tsc2(+/-) neurons. Moreover, inactivation of Rheb with farnesyl transferase inhibitors recovered spine synapse morphogenesis in Tsc2(+/-) neurons. In conclusion, dendritic spine abnormalities in TSC neurons may be caused through activation of Rheb, but not through of mTORC1.

• 出版日期2014-6-3
• 单位河北医科大学