PMID- 30462552 OWN - NLM STAT- MEDLINE DCOM- 20191227 LR - 20240410 IS - 1522-1539 (Electronic) IS - 0363-6135 (Print) IS - 0363-6135 (Linking) VI - 316 IP - 2 DP - 2019 Feb 1 TI - Downregulation of GATA6 in mTOR-inhibited human aortic endothelial cells: effects on TNF-alpha-induced VCAM-1 expression and monocytic cell adhesion. PG - H408-H420 LID - 10.1152/ajpheart.00411.2018 [doi] AB - Increased expression of vascular cell adhesion molecule 1 (VCAM-1) on the aortic endothelium is an early marker of atherogenesis, promoted in part by elevated levels of inflammatory cytokines such as TNF-alpha. Mammalian target of rapamycin (mTOR) is a ubiquitous signaling molecule that has been considered to contribute to diverse cellular processes through mTOR complex 1 (mTORC1) or complex 2 (mTORC2). This study aimed to elucidate the role of mTOR signaling in TNF-alpha-induced VCAM-1 expression by the arterial endothelium. Primary human aortic endothelial cells (HAECs) were treated with low-dose (0.1 ng/ml) TNF-alpha, and VCAM-1 expression was measured by real-time quantitative PCR, Western blot analysis, and flow cytometry. Inhibition of mTOR through siRNA-mediated depletion or treatment with chemical inhibitors rapamycin or torin 1 suppressed VCAM1 transcription, which translated to inhibition of VCAM-1 surface expression by HAECs and concomitant decreased adhesion of monocytes. A promoter luciferase assay and chromatin immunoprecipitation indicated that mTOR regulated VCAM1 transcription through a mechanism involving transcription factor GATA6. Activation of PKC-alpha and an increase in miR-200a-3p expression, caused by mTOR inhibition but not disruption of mTORC1 or mTORC2 singly or together, decreased TNF-alpha-induced GATA6 expression and its enrichment at the VCAM1 promoter. In conclusion, mTOR inhibition activates PKC-alpha independently of disruption of mTORC1 and/or mTORC2, which challenges the conventional wisdom regarding mTOR signaling. Moreover, mTOR signals through transcriptional and posttranscriptional mechanisms to elicit maximal cytokine-induced endothelial inflammation that precedes atherosclerosis. NEW & NOTEWORTHY Both mammalian target of rapamycin (mTOR) complex 1 (mTORC1) and mTORC2 contribute to PKC-alpha activation in the human aortic endothelium. Inhibition of mTOR is not equivalent to disruption of mTORC1 and/or mTORC2 in affecting human aortic endothelial cell signaling. Specifically, inhibition of mTOR causes PKC-alpha activation and miR-200a-3p upregulation, which independently suppresses TNF-alpha-induced transcription factor GATA6 expression and subsequently inhibits VCAM-1 expression and monocytic cell adhesion onto the aortic endothelium. FAU - Fan, Xing AU - Fan X AD - Key Laboratory of Targeted Intervention of Cardiovascular Disease, Collaborative Innovation Center for Cardiovascular Disease Translational Medicine, Nanjing Medical University , Nanjing , China. FAU - Chen, Xiaolin AU - Chen X AD - Key Laboratory of Targeted Intervention of Cardiovascular Disease, Collaborative Innovation Center for Cardiovascular Disease Translational Medicine, Nanjing Medical University , Nanjing , China. FAU - Feng, Qi AU - Feng Q AD - Key Laboratory of Targeted Intervention of Cardiovascular Disease, Collaborative Innovation Center for Cardiovascular Disease Translational Medicine, Nanjing Medical University , Nanjing , China. FAU - Peng, Kai AU - Peng K AD - Key Laboratory of Targeted Intervention of Cardiovascular Disease, Collaborative Innovation Center for Cardiovascular Disease Translational Medicine, Nanjing Medical University , Nanjing , China. FAU - Wu, Qianqian AU - Wu Q AD - Key Laboratory of Targeted Intervention of Cardiovascular Disease, Collaborative Innovation Center for Cardiovascular Disease Translational Medicine, Nanjing Medical University , Nanjing , China. FAU - Passerini, Anthony G AU - Passerini AG AD - Department of Biomedical Engineering, University of California , Davis, California. FAU - Simon, Scott I AU - Simon SI AD - Department of Biomedical Engineering, University of California , Davis, California. FAU - Sun, ChongXiu AU - Sun C AD - Key Laboratory of Targeted Intervention of Cardiovascular Disease, Collaborative Innovation Center for Cardiovascular Disease Translational Medicine, Nanjing Medical University , Nanjing , China. LA - eng GR - P30 CA093373/CA/NCI NIH HHS/United States GR - R01 HL082689/HL/NHLBI NIH HHS/United States PT - Journal Article PT - Research Support, N.I.H., Extramural PT - Research Support, Non-U.S. Gov't DEP - 20181121 PL - United States TA - Am J Physiol Heart Circ Physiol JT - American journal of physiology. Heart and circulatory physiology JID - 100901228 RN - 0 (GATA6 Transcription Factor) RN - 0 (GATA6 protein, human) RN - 0 (Tumor Necrosis Factor-alpha) RN - 0 (Vascular Cell Adhesion Molecule-1) RN - EC 2.7.11.1 (TOR Serine-Threonine Kinases) RN - EC 2.7.11.13 (Protein Kinase C-alpha) SB - IM MH - Aorta/cytology/metabolism MH - Atherosclerosis/*metabolism MH - *Cell Adhesion MH - Cells, Cultured MH - Down-Regulation MH - Endothelial Cells/drug effects/*metabolism/physiology MH - Endothelium, Vascular/cytology/metabolism MH - GATA6 Transcription Factor/genetics/*metabolism MH - Humans MH - Monocytes/physiology MH - Protein Kinase C-alpha/metabolism MH - Signal Transduction MH - TOR Serine-Threonine Kinases/genetics/*metabolism MH - Tumor Necrosis Factor-alpha/pharmacology MH - Vascular Cell Adhesion Molecule-1/genetics/*metabolism PMC - PMC6397389 OTO - NOTNLM OT - GATA6 OT - atherosclerosis OT - endothelium OT - vascular cell adhesion molecule 1 COIS- No conflicts of interest, financial or otherwise, are declared by the authors. EDAT- 2018/11/22 06:00 MHDA- 2019/12/28 06:00 PMCR- 2020/02/01 CRDT- 2018/11/22 06:00 PHST- 2018/11/22 06:00 [pubmed] PHST- 2019/12/28 06:00 [medline] PHST- 2018/11/22 06:00 [entrez] PHST- 2020/02/01 00:00 [pmc-release] AID - H-00411-2018 [pii] AID - 10.1152/ajpheart.00411.2018 [doi] PST - ppublish SO - Am J Physiol Heart Circ Physiol. 2019 Feb 1;316(2):H408-H420. doi: 10.1152/ajpheart.00411.2018. Epub 2018 Nov 21.