Rapamycin potentiates cAMP-induced differentiation in NG108-15 cells

• Main Authors: wang, 王秀勻
• Other Authors: 闕小輝
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/69739597164108939347

碩士 === 國防醫學院 === 生物化學研究所 === 97 === NG108-15 cell line fused from N18TG-2 and C6-BU-1 is a good model for investgating neuronal development and differentiation. We found that cell proliferation would be inhibited by treating DMEM with only 1% serum. It has been already known that inhibiting cell proliferation and elevating concentration of cytosolic cyclic adenosine 3',5'-monophosphate (cAMP) would let NG108-15 cell differentiation through activating transcription factor, cAMP response element binding protein (CREB). There are three features when NG108-15 cell differentiate. (1) Neurite outgrowth and Formation of varicosity. (2) Activity of voltage sensitive calcium channel, VSCC, elevates. (3) Neuronal marker protein, Microtubule Associated Protein 2 (MAP2), formate. Rapamycin is an inhibitor of Mammalian Target of Rapamycin Complex 1 (mTORC1). mTOR is a protein kinase that control cell cycle from G1 to S phase, promote proliferation and inhibit autophagy. Therefore, rapamycin would arrest cell cycle in G0/G1 and promote autophagy. We found that treating dibutyryl cAMP (dbcAMP) and rapamycin at the same time would promote NG108-15 cell differentiation earlier than only treating dbcAMP. It would have higher neurite and varicosity number, VSCC activity and MAP2 content. Silencing mTOR would mimic the effect of rapamycin in NG108-15 cells. Furthermore, potentiating differentiation caused by cotreating dbcAMP and rapamycin would be inhibited by adding autophagic inhibitor or silencing Beclin1. Rapamycin could also induce differentiation in NG108-15 cells. Rapamycin would not change phosphorylatic level of ERK and CREB. Besides, dbcAMP would not induce autophagy. In sum, differentiation of NG108-15 cells would be potentiated through inducing autophagy by treating rapamycin or silencing mTOR.