PMID- 25914608 OWN - NLM STAT- PubMed-not-MEDLINE DCOM- 20150428 LR - 20201001 IS - 1476-9255 (Print) IS - 1476-9255 (Electronic) IS - 1476-9255 (Linking) VI - 12 DP - 2015 TI - ATF4 is a novel regulator of MCP-1 in microvascular endothelial cells. PG - 31 LID - 10.1186/s12950-015-0076-1 [doi] LID - 31 AB - BACKGROUND: Monocyte chemoattractant protein-1 (MCP-1) is a major chemokine that recruits monocyte/macrophage to the site of tissue injury and plays a critical role in microvascular complications of diabetes. However, the mechanisms underlying the regulation of MCP-1 are not fully understood. The present study aims to explore the role of activating transcription factor 4 (ATF4), an ER stress-inducible transcription factor, in regulation of MCP-1 expression and production in brain and retinal microvascular endothelial cells. METHODS: For in vitro study, primary brain microvascular endothelial cells isolated from ATF4 knockout mice or mouse retinal endothelial cells were treated with lipopolysaccharide (LPS) to induce MCP-1 expression. ATF4 expression/function was manipulated by adenoviruses expressing wild type ATF4 (Ad-ATF4) or a dominant negative mutant of the protein (Ad-ATF4DN). For in vivo study, MCP-1 expression was induced by intravitreal injection of LPS or Ad-ATF4 in heterozygous ATF4 knockout or wild type mice. RESULTS: LPS treatment induced a dose- and time-dependent increase in ATF4 expression, ER stress and MCP-1 production in brain and retinal microvascular endothelial cells. Overexpression of ATF4 in endothelial cells significantly increased the secretion of MCP-1 and promoted THP-1 monocyte-endothelial cell adhesion. Conditioned medium from ATF4-overexpressiing endothelial cells significantly enhanced THP-1 cell migration. Consistently, intravitreal injection of Ad-ATF4 remarkably enhanced retinal levels of MCP-1 and promoted inflammatory cell infiltration into the vitreous and retina. In contrast, LPS-induced MCP-1 upregulation was markedly attenuated in ATF4-deficient endothelial cells and in retinas of ATF4 knockout mice, suggesting that ATF4 is essential for LPS-induced MCP-1 production in endothelial cells and in the retina. Mechanistically, overexpression of ATF4 enhanced, while inhibition of ATF4, attenuated the basal and LPS-stimulated phosphorylation of NF-kappaB, P38, and JNK. Furthermore, pharmacological inhibition of NF-kappaB, P38, or JNK significantly reduced ATF4-stimulated MCP-1 secretion from endothelial cells. CONCLUSIONS: Taken together, our results suggest a critical role of ATF4 in the regulation of MCP-1 production in retinal and brain microvascular endothelial cells, which may contribute to inflammation-related endothelial injury in diseases such as diabetic retinopathy. FAU - Huang, Huibin AU - Huang H AD - Departments of Ophthalmology and Biochemistry, School of Medicine and Biomedical Sciences, University at Buffalo, The State University of New York, Buffalo, NY 14214 USA ; SUNY Eye Institute, The State University of New York, Buffalo, NY 14214 USA ; Department of Endocrinology, The 2nd Affiliated Hospital of Fujian Medical University, Quanzhou, Fujian China. FAU - Jing, Guangjun AU - Jing G AD - Department of Medicine, Endocrinology and Diabetes, Harold Hamm Diabetes Center, University of Oklahoma Health Sciences Center, Oklahoma, 73104 OK USA. FAU - Wang, Joshua J AU - Wang JJ AD - Departments of Ophthalmology and Biochemistry, School of Medicine and Biomedical Sciences, University at Buffalo, The State University of New York, Buffalo, NY 14214 USA ; SUNY Eye Institute, The State University of New York, Buffalo, NY 14214 USA ; Department of Medicine, Endocrinology and Diabetes, Harold Hamm Diabetes Center, University of Oklahoma Health Sciences Center, Oklahoma, 73104 OK USA. FAU - Sheibani, Nader AU - Sheibani N AD - Department of Ophthalmology and Visual Sciences, University of Wisconsin, School of Medicine and Public Health, Madison, Wisconsin USA ; McPherson Eye Research Institute, University of Wisconsin, School of Medicine and Public Health, Madison, WI 53705 USA. FAU - Zhang, Sarah X AU - Zhang SX AD - Departments of Ophthalmology and Biochemistry, School of Medicine and Biomedical Sciences, University at Buffalo, The State University of New York, Buffalo, NY 14214 USA ; SUNY Eye Institute, The State University of New York, Buffalo, NY 14214 USA ; Department of Medicine, Endocrinology and Diabetes, Harold Hamm Diabetes Center, University of Oklahoma Health Sciences Center, Oklahoma, 73104 OK USA. LA - eng GR - R01 EY019949/EY/NEI NIH HHS/United States GR - R21 EY025061/EY/NEI NIH HHS/United States GR - R24 EY022883/EY/NEI NIH HHS/United States PT - Journal Article DEP - 20150417 PL - England TA - J Inflamm (Lond) JT - Journal of inflammation (London, England) JID - 101232234 PMC - PMC4409760 OTO - NOTNLM OT - Activating transcription factor 4 OT - Microvascular endothelial cells OT - Monocyte chemoattractant protein 1 EDAT- 2015/04/29 06:00 MHDA- 2015/04/29 06:01 PMCR- 2015/04/17 CRDT- 2015/04/28 06:00 PHST- 2015/01/06 00:00 [received] PHST- 2015/03/31 00:00 [accepted] PHST- 2015/04/28 06:00 [entrez] PHST- 2015/04/29 06:00 [pubmed] PHST- 2015/04/29 06:01 [medline] PHST- 2015/04/17 00:00 [pmc-release] AID - 76 [pii] AID - 10.1186/s12950-015-0076-1 [doi] PST - epublish SO - J Inflamm (Lond). 2015 Apr 17;12:31. doi: 10.1186/s12950-015-0076-1. eCollection 2015.