Novel role for TRPC4 in regulation of macroautophagy by a small molecule in vascular endothelial cells

• Published in: Biochimica et biophysica acta Vol. 1853; no. 2; pp. 377 - 387
• Main Authors: Zhang, Lu, Dai, Fang, Cui, LiuQing, Jing, Hongjuan, Fan, Pei, Tan, Xiaorong, Guo, YuQi, Zhou, GuangZhou
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.02.2015
• Subjects: AMP-Activated Protein Kinases - metabolism; Autophagy - drug effects; Autophagy - genetics; Calcium - metabolism; Calcium-Calmodulin-Dependent Protein Kinase Kinase - metabolism; Human Umbilical Vein Endothelial Cells - cytology; Human Umbilical Vein Endothelial Cells - drug effects; Human Umbilical Vein Endothelial Cells - metabolism; Humans; Intracellular Space - drug effects; Intracellular Space - metabolism; Macroautophagy; Mammalian target of rapamycin; Oligonucleotide Array Sequence Analysis; Stilbenes - pharmacology; TOR Serine-Threonine Kinases - antagonists & inhibitors; TOR Serine-Threonine Kinases - metabolism; Trans-3,5,4′-trimethoxystilbene; Transfection; Transient receptor potential canonical channel 4; TRPC Cation Channels - genetics; TRPC Cation Channels - metabolism; Up-Regulation - drug effects; Up-Regulation - genetics; Vascular endothelial cell; Transient receptor potential canonical channel 4; RES; NO; Vascular endothelial cell; p70S6K; TRPC4; AVOs; CaMKKβ; PVDF; Macroautophagy; AO; FGF-2; AMPKα; Ca2; VECs; Mammalian target of rapamycin; mTOR; HUVEC; 3-MA; 4E-BP1; TMS; SQSTM1; Trans-3,5,4′-trimethoxystilbene
• ISSN: 0167-4889; 0006-3002; 1879-2596
• DOI: 10.1016/j.bbamcr.2014.10.030

Macroautophagy (autophagy) is an important factor affecting the function of vascular endothelial cells (VECs) and must be tightly regulated in these cells. However, the precise mechanisms underlying this process, particularly in the presence of serum, remain obscure. In this study, we identified trans-3,5,4′-trimethoxystilbene (TMS) as a potent small molecule inducer of autophagy in human umbilical vascular endothelial cells (HUVECs) in the presence of serum. Using high-throughput DNA microarray and siRNA transfection technologies, we demonstrated that TMS induced autophagy by up-regulating the expression of the transient receptor potential canonical channel 4 (TRPC4), an important cation channel in HUVECs. In addition, the overexpression of TRPC4 by plasmid transfection also induced autophagy. Mechanistic studies revealed that the up-regulation of TRPC4 increased the intracellular Ca2+ concentration, which, in turn, activated the Ca2+/CaMKKβ/AMPK pathway, leading to mTOR inhibition and autophagy. Our study identifies a novel role for TRPC4 in the regulation of autophagy in VECs. TMS is a useful new tool for investigating the molecular mechanism of autophagy in VECs and may serve as a potential lead compound for developing a class of autophagy inducers to treat autophagy-related diseases. [Display omitted] •TMS is a useful tool to investigate autophagy in VECs in the presence of serum.•TRPC4 is a novel regulator of autophagy in VECs.•TRPC4 overexpression induces autophagy via the downstream Ca2+/CaMKKβ/AMPK/mTOR pathway.