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Wang R, Zhong J, Pan X, Su Z, Xu Y, Zhang M, Chen X, Chen N, Yu T, Zhou Q. A novel intronic circular RNA circFGFR1 int2 up-regulates FGFR1 by recruiting transcriptional activators P65/FUS and suppressing miR-4687-5p to promote prostate cancer progression. J Transl Med 2023; 21:840. [PMID: 37993879 PMCID: PMC10664560 DOI: 10.1186/s12967-023-04718-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Accepted: 11/10/2023] [Indexed: 11/24/2023] Open
Abstract
Fibroblast growth factor receptor 1 (FGFR1) is a core component of the FGFs/FGFR pathway that activates multiple signalling pathways, including ERK1/2, PI3K/AKT, PLCγ, and NF-κB. Aberrant expression of FGFR1 due to gene amplification, chromosome rearrangement, point mutation, and epigenetic deregulations, have been reported in various cancers. FGFR1 overexpression has also been reported in prostate cancer (PCa), but the underlining mechanisms are not clear. Here we report a novel circular RNA, circFGFR1int2, derived from intron 2 of FGFR1 gene, which is overexpressed in PCa and associated with tumor progression. Importantly, we show that circFGFR1int2 facilitates FGFR1 transcription by recruiting transcription activators P65/FUS and by interacting with FGFR1 promoter. Moreover, we show that circFGFR1int2 suppresses post-transcriptional inhibitory effects of miR-4687-5p on FGFR1 mRNA. These mechanisms synergistically promote PCa cell growth, migration, and invasion. Overexpression of circFGFR1int2 is significantly correlated with higher tumor grade, Gleason score, and PSA level, and is a significant unfavorable prognosticator for CRPC-free survival (CFS) (RR = 3.277, 95% confidence interval: 1.192-9.009; P = 0.021). These findings unravelled novel mechanisms controlling FGFR1 gene expression by intronic circRNA and its potential clinicopathological utility as a diagnostic or therapeutic target.
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Affiliation(s)
- Ruyue Wang
- Department of Pathology, West China Hospital, Sichuan University, Chengdu, 610041, China
| | - Jinjing Zhong
- Department of Pathology, West China Hospital, Sichuan University, Chengdu, 610041, China
| | - Xiuyi Pan
- Department of Pathology, West China Hospital, Sichuan University, Chengdu, 610041, China
| | - Zhengzheng Su
- Department of Pathology, West China Hospital, Sichuan University, Chengdu, 610041, China
| | - Yunyi Xu
- Department of Pathology, West China Hospital, Sichuan University, Chengdu, 610041, China
| | - Mengni Zhang
- Department of Pathology, West China Hospital, Sichuan University, Chengdu, 610041, China
| | - Xueqin Chen
- Department of Pathology, West China Hospital, Sichuan University, Chengdu, 610041, China
| | - Ni Chen
- Department of Pathology, West China Hospital, Sichuan University, Chengdu, 610041, China
| | - Ting Yu
- Department of Pathology, West China Hospital, Sichuan University, Chengdu, 610041, China.
| | - Qiao Zhou
- Department of Pathology, West China Hospital, Sichuan University, Chengdu, 610041, China.
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Cong J, Cheng B, Liu J, He P. RTEF-1 Inhibits Vascular Smooth Muscle Cell Calcification through Regulating Wnt/β-Catenin Signaling Pathway. Calcif Tissue Int 2021; 109:203-214. [PMID: 33713163 PMCID: PMC8273062 DOI: 10.1007/s00223-021-00833-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2020] [Accepted: 02/25/2021] [Indexed: 12/24/2022]
Abstract
Vascular calcification (VC) is highly prevailing in cardiovascular disease, diabetes mellitus, and chronic kidney disease and, when present, is associated with cardiovascular events and mortality. The osteogenic differentiation of vascular smooth muscle cells (VSMCs) is regarded as the foundation for mediating VC. Related transcriptional enhancer factor (RTEF-1), also named as transcriptional enhanced associate domain (TEAD) 4 or transcriptional enhancer factor-3 (TEF-3), is a nuclear transcriptional factor with a potent effect on cardiovascular diseases, apart from its oncogenic role in the canonical Hippo pathway. However, the role and mechanism of RTEF-1 in VC, particularly in calcification of VSMCs, are poorly understood. Our results showed that RTEF-1 was reduced in calcified VSMCs. RTEF-1 significantly ameliorated β-glycerophosphate (β-GP)-induced VSMCs calcification, as detected by alizarin red staining and calcium content assay. Also, RTEF-1 reduced alkaline phosphatase (ALP) activity and decreased expressions of osteoblast markers such as Osteocalcin and Runt-related transcription factor-2 (Runx2), but increased expression of contractile protein, including SM α-actin (α-SMA). Additionally, RTEF-1 inhibited β-GP-activated Wnt/β-catenin pathway which plays a critical role in calcification and osteogenic differentiation of VSMCs. Specifically, RTEF-1 reduced the levels of Wnt3a, p-β-catenin (Ser675), glycogen synthase kinase-3β (GSK-3β), and p-GSK-3β (Ser9), but increased the levels of p-β-catenin (Ser33/37). Also, RTEF-1 increased the ratio of p-β-catenin (Ser33/37) to β-catenin proteins and decreased the ratio of p-GSK-3β (Ser9) to GSK-3β protein. LiCl, a Wnt/β-catenin signaling activator, was observed to reverse the protective effect of RTEF-1 overexpression on VSMCs calcification induced by β-GP. Accordingly, Dickkopf-1 (Dkk1), a Wnt antagonist, attenuated the role of RTEF-1 deficiency in β-GP-induced VSMCs calcification. Taken together, we concluded that RTEF-1 ameliorated β-GP-induced calcification and osteoblastic differentiation of VSMCs by inhibiting Wnt/β-catenin signaling pathway.
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Affiliation(s)
- Jingjing Cong
- Department of Geriatrics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1277 Jiefang Avenue, Wuhan, 430022, Hubei, China
| | - Bei Cheng
- Department of Geriatrics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1277 Jiefang Avenue, Wuhan, 430022, Hubei, China
| | - Jinyu Liu
- Department of Rehabilitative Medicine, Wuhan NO.1 Hospital, Wuhan, 430022, Hubei Province, China
| | - Ping He
- Department of Geriatrics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1277 Jiefang Avenue, Wuhan, 430022, Hubei, China.
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Abstract
OBJECTIVES Cardiopulmonary bypass-induced endothelial dysfunction has been inferred by changes in pulmonary vascular resistance, alterations in circulating biomarkers, and postoperative capillary leak. Endothelial-dependent vasomotor dysfunction of the systemic vasculature has never been quantified in this setting. The objective of the present study was to quantify acute effects of cardiopulmonary bypass on endothelial vasomotor control and attempt to correlate these effects with postoperative cytokines, tissue edema, and clinical outcomes in infants. DESIGN Single-center prospective observational cohort pilot study. SETTING Pediatric cardiac ICU at a tertiary children's hospital. PATIENTS Children less than 1 year old requiring cardiopulmonary bypass for repair of a congenital heart lesion. INTERVENTION None. MEASUREMENTS AND MAIN RESULTS Laser Doppler perfusion monitoring was coupled with local iontophoresis of acetylcholine (endothelium-dependent vasodilator) or sodium nitroprusside (endothelium-independent vasodilator) to quantify endothelial-dependent vasomotor function in the cutaneous microcirculation. Measurements were obtained preoperatively, 2-4 hours, and 24 hours after separation from cardiopulmonary bypass. Fifteen patients completed all laser Doppler perfusion monitor (Perimed, Järfälla, Sweden) measurements. Comparing prebypass with 2-4 hours postbypass responses, there was a decrease in both peak perfusion (p = 0.0006) and area under the dose-response curve (p = 0.005) following acetylcholine, but no change in responses to sodium nitroprusside. Twenty-four hours after bypass responsiveness to acetylcholine improved, but typically remained depressed from baseline. Conserved endothelial function was associated with higher urine output during the first 48 postoperative hours (R = 0.43; p = 0.008). CONCLUSIONS Cutaneous endothelial dysfunction is present in infants immediately following cardiopulmonary bypass and recovers significantly in some patients within 24 hours postoperatively. Confirmation of an association between persistent endothelial-dependent vasomotor dysfunction and decreased urine output could have important clinical implications. Ongoing research will explore the pattern of endothelial-dependent vasomotor dysfunction after cardiopulmonary bypass and its relationship with biochemical markers of inflammation and clinical outcomes.
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Teng K, Deng C, Xu J, Men Q, Lei T, Di D, Liu T, Li W, Liu X. Nuclear localization of TEF3-1 promotes cell cycle progression and angiogenesis in cancer. Oncotarget 2017; 7:13827-41. [PMID: 26885617 PMCID: PMC4924681 DOI: 10.18632/oncotarget.7342] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Accepted: 01/29/2016] [Indexed: 01/09/2023] Open
Abstract
TEF3-1 (transcriptional enhancer factor 3 isoform 1), also known as TEAD4 (TEA domain family member 4), was recently revealed as an oncogenic character in cancer development. However, the underlying molecular pathogenic mechanisms remain undefined. In this paper, we investigated nuclear TEF3-1 could promote G1/S transition in HUVECs, and the expression levels of cyclins and CDKs were upregulated. Additionally, if TEF3-1 was knocked down, the expression of cyclins and CDKs was downregulated while the expression of P21, a negative regulator of the cell cycle, was upregulated. A microarray analysis also confirmed that TEF3-1 overexpression upregulates genes that are related to cell cycle progression and the promotion of angiogenesis. Moreover, we observed that nuclear TEF3-1 was highly expressed during the formation of vascular structures in gastric cancer (GC). Finally, tumor xenograft experiments indicated that, when TEF3-1 was knocked down, tumor growth and angiogenesis were also suppressed. Taken together, these results demonstrate for the first time that TEF3-1 localization to the nucleus stimulates the cell cycle progression in HUVECs and specifically contributes to tumor angiogenesis. Nuclear TEF3-1 in HUVECs may serve as an oncogenic biomarker, and the suppression of TEF3-1 may be a potential target in anti-tumor therapy.
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Affiliation(s)
- Kaixuan Teng
- Ministry of Education Laboratory of Combinatorial Biosynthesis and Drug Discovery, College of Pharmacy, Wuhan University, Wuhan, 430071, P.R. China
| | - Cuilan Deng
- Ministry of Education Laboratory of Combinatorial Biosynthesis and Drug Discovery, College of Pharmacy, Wuhan University, Wuhan, 430071, P.R. China
| | - Jie Xu
- Ministry of Education Laboratory of Combinatorial Biosynthesis and Drug Discovery, College of Pharmacy, Wuhan University, Wuhan, 430071, P.R. China
| | - Qiuxu Men
- Ministry of Education Laboratory of Combinatorial Biosynthesis and Drug Discovery, College of Pharmacy, Wuhan University, Wuhan, 430071, P.R. China
| | - Tao Lei
- Ministry of Education Laboratory of Combinatorial Biosynthesis and Drug Discovery, College of Pharmacy, Wuhan University, Wuhan, 430071, P.R. China
| | - Da Di
- Ministry of Education Laboratory of Combinatorial Biosynthesis and Drug Discovery, College of Pharmacy, Wuhan University, Wuhan, 430071, P.R. China
| | - Ting Liu
- College of Life Sciences, Wuhan University, Wuhan, 430072, P.R. China
| | - Wenhua Li
- College of Life Sciences, Wuhan University, Wuhan, 430072, P.R. China
| | - Xin Liu
- Ministry of Education Laboratory of Combinatorial Biosynthesis and Drug Discovery, College of Pharmacy, Wuhan University, Wuhan, 430071, P.R. China
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Sun S, Cheng B, Sun PG, Wu XH, Wu QQ, He P. RTEF-1 protects against oxidative damage induced by H2O2 in human umbilical vein endothelial cells through Klotho activation. Exp Biol Med (Maywood) 2015; 240:1606-13. [PMID: 26041389 DOI: 10.1177/1535370215587914] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Accepted: 04/27/2015] [Indexed: 11/15/2022] Open
Abstract
Oxidative stress is a main risk factor of vascular aging, which may lead to age-associated diseases. Related transcriptional enhancer factor-1 (RTEF-1) has been suggested to regulate many genes expression which are involved in the endothelial angiogenesis and vasodilation. However, whether RTEF-1 has a direct role in anti-oxidation and what specific genes are involved in RTEF-1-driven anti-oxidation have not been elucidated. In this study, we found that overexpressing RTEF-1 in H2O2-treated human umbilical vein endothelial cells decreased senescence-associated-β-galactosidase (SA-β-gal)-positive cells and G0/G1 cells population. The expressions of p53 and p21 were decreased in H2O2-treated RTEF-1 o/e human umbilical vein endothelial cells. However, specific small interfering RNA of RTEF-1 totally reversed the anti-oxidation effect of RTEF-1 and inhibited RTEF-1-induced decreased p53 and p21 expressions. It demonstrated that RTEF-1 could protect cells from H2O2-induced oxidative damage. In addition, we demonstrated that RTEF-1 could up-regulate Klotho gene expression and activate its promoter. Furthermore, Klotho small interfering RNA significantly blocked RTEF-1-driven endothelial cell protection from H2O2-induced oxidative damage and increased p53 and p21 expressions. These results reveal that RTEF-1 is a potential anti-oxidation gene and can prevent H2O2-induced endothelial cell oxidative damage by activating Klotho.
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Affiliation(s)
- Shan Sun
- Department of Gerontology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Bei Cheng
- Department of Gerontology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Pan-Ge Sun
- Department of Gerontology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Xiao-Hua Wu
- Department of Gerontology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Qin-Qin Wu
- Department of Gerontology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Ping He
- Department of Gerontology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
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Che P, Liu J, Shan Z, Wu R, Yao C, Cui J, Zhu X, Wang J, Burnett MS, Wang S, Wang J. miR-125a-5p impairs endothelial cell angiogenesis in aging mice via RTEF-1 downregulation. Aging Cell 2014; 13:926-34. [PMID: 25059272 PMCID: PMC4331751 DOI: 10.1111/acel.12252] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/23/2014] [Indexed: 12/05/2022] Open
Abstract
Increasing evidence suggests that microRNAs (miRNAs) play important roles in impaired endothelial cell (EC) angiogenesis during aging. However, their exact roles in the aging process remain unclear. We aimed to determine whether miRNAs cause angiogenesis defects in ECs during aging and to uncover the underlying mechanisms. To study the miRNA-induced changes in ECs during aging, we performed microarray analyses on arterial ECs collected from young and aging mice. Using qRT–PCR, we showed that microRNA-125a-5p (mir-125a-5p) expression was approximately 2.9 times higher in old endothelial cells (OECs) compared with samples collected from young animals. Western blot assays showed a lower expression level of an mir-125a-5p target known as related transcriptional enhancer factor-1 (RTEF-1) in OECs compared with its expression levels in young cells. Overexpression of mir-125a-5p in young endothelial cells (YECs) using pre-mir-125a-5p caused the downregulation of RTEF-1, endothelial nitric oxide synthase (eNOS) and vascular endothelial growth factor (VEGF) and resulted in impaired angiogenesis, as evidenced by spheroid sprouting and tube formation assays in vitro. Conversely, repression of mir-125a-5p in OECs using anti-mir-125a-5p increased RTEF-1, eNOS and VEGF expression and improved EC angiogenesis. Importantly, impaired angiogenesis caused by knock-down of RTEF-1 was not efficiently rescued by anti-mir-125a-5p. Dual-luciferase reporter gene analysis showed that RTEF-1 is a direct target of mir-125a-5p, which regulates angiogenesis by repressing RTEF-1 expression and modulating eNOS and VEGF expression. These findings indicate that mir-125a-5p and RTEF-1 are potential therapeutic targets for improving EC-mediated angiogenesis in elderly individuals.
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Affiliation(s)
- Peng Che
- Department of Vascular Surgery The First Affiliated Hospital of Sun Yat‐sen University NO. 58 Zhongshan Road 2 Guangzhou 510080 China
| | - Jun Liu
- Department of Cardiology The First Affiliated Hospital of Sun Yat‐Sen University NO. 58 Zhongshan Road 2 Guangzhou 510080 China
| | - Zhen Shan
- Department of Vascular Surgery The First Affiliated Hospital of Sun Yat‐sen University NO. 58 Zhongshan Road 2 Guangzhou 510080 China
| | - Ridong Wu
- Department of Vascular Surgery The First Affiliated Hospital of Sun Yat‐sen University NO. 58 Zhongshan Road 2 Guangzhou 510080 China
| | - Chen Yao
- Department of Vascular Surgery The First Affiliated Hospital of Sun Yat‐sen University NO. 58 Zhongshan Road 2 Guangzhou 510080 China
| | - Jin Cui
- Department of Vascular Surgery The First Affiliated Hospital of Sun Yat‐sen University NO. 58 Zhongshan Road 2 Guangzhou 510080 China
| | - Xiaonan Zhu
- Department of Pharmacology Laboratory The First Affiliated Hospital of Sun Yat‐sen University NO.58 Zhongshan Road 2 Guangzhou 510080 China
| | - Junwei Wang
- Department of Vascular Surgery The First Affiliated Hospital of Sun Yat‐sen University NO. 58 Zhongshan Road 2 Guangzhou 510080 China
| | - Mary Susan Burnett
- Cardiovascular Research Institute MedStar Health Research Institute Washington DC 20010 USA
| | - Shenming Wang
- Department of Vascular Surgery The First Affiliated Hospital of Sun Yat‐sen University NO. 58 Zhongshan Road 2 Guangzhou 510080 China
| | - JinSong Wang
- Department of Vascular Surgery The First Affiliated Hospital of Sun Yat‐sen University NO. 58 Zhongshan Road 2 Guangzhou 510080 China
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He P, Philbrick MJ, An X, Wu J, Messmer-Blust AF, Li J. Endothelial differentiation gene-1, a new downstream gene is involved in RTEF-1 induced angiogenesis in endothelial cells. PLoS One 2014; 9:e88143. [PMID: 24520353 PMCID: PMC3919740 DOI: 10.1371/journal.pone.0088143] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2013] [Accepted: 01/03/2014] [Indexed: 11/18/2022] Open
Abstract
Related Transcriptional Enhancer Factor-1 (RTEF-1) has been suggested to induce angiogenesis through regulating target genes. Whether RTEF-1 has a direct role in angiogenesis and what specific genes are involved in RTEF-1 driven angiogenisis have not been elucidated. We found that over-expressing RTEF-1 in Human dermal microvascular endothelial cells-1 (HMEC-1) significantly increased endothelial cell aggregation, growth and migration while the processes were inhibited by siRNA of RTEF-1. In addition, we observed that Endothelial differentiation gene-1 (Edg-1) expression was up-regulated by RTEF-1 at the transcriptional level. RTEF-1 could bind to Edg-1 promoter and subsequently induce its activity. Edg-1 siRNA significantly blocked RTEF-1-driven increases in endothelial cell aggregation in a Matrigel assay and retarded RTEF-1-induced endothelial cell growth and migration. Pertussis Toxin (PTX), a Gi/Go protein sensitive inhibitor, was found to inhibit RTEF-1 driven endothelial cell aggregation and migration. Our data demonstrates that Edg-1 is a potential target gene of RTEF-1 and is involved in RTEF-1-induced angiogenesis in endothelial cells. Gi/Go protein coupled receptor pathway plays a role in RTEF-1 driven angiogenesis in endothelial cells.
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Affiliation(s)
- Ping He
- Department of Gerontology of Union Hospital, Tongji Medical College of Huazhong University of Science and Technology, Wuhan, China
- Cardiovascular Institute, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Melissa J. Philbrick
- Cardiovascular Institute, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Xiaojin An
- Cardiovascular Institute, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Jiaping Wu
- Cardiovascular Institute, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Angela F. Messmer-Blust
- Cardiovascular Institute, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Jian Li
- Cardiovascular Institute, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, United States of America
- * E-mail:
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Messmer-Blust AF, Philbrick MJ, Guo S, Wu J, He P, Guo S, Li J. RTEF-1 attenuates blood glucose levels by regulating insulin-like growth factor binding protein-1 in the endothelium. Circ Res 2012; 111:991-1001. [PMID: 22843786 DOI: 10.1161/circresaha.112.268110] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
RATIONALE Related transcriptional enhancer factor-1 (RTEF-1) plays an important role in endothelial cell function by regulating angiogenesis; however, the mechanism underlying the role of RTEF-1 in the endothelium in vivo is not well defined. OBJECTIVE We investigated the biological functions of RTEF-1 by disrupting the gene that encodes it in mice endothelium -specific RTEF-1-deficient transgenic mice (RTEF-1(-/-)). METHODS AND RESULTS RTEF-1(-/-) mice showed significantly increased blood glucose levels and insulin resistance, accompanied by decreased levels of insulin-like growth factor binding protein-1 (IGFBP-1) mRNA in the endothelium and decreased serum IGFBP-1 levels. Additionally, the RTEF-1(-/-) phenotype was exacerbated when the mice were fed a high-fat diet, which correlated with decreased IGFBP-1 levels. In contrast, vascular endothelial cadherin/RTEF-1-overexpressing(1) transgenic mice (VE-Cad/RTEF1) demonstrated improved glucose clearance and insulin sensitivity in response to a high-fat diet. Furthermore, we demonstrated that RTEF-1 upregulates IGFBP-1 through selective binding and promotion of transcription from the insulin response element site. Insulin prevented RTEF-1 expression and significantly inhibited IGFBP-1 transcription in endothelial cells in a dose-dependent fashion. CONCLUSIONS To the best of our knowledge, this is the first report demonstrating that RTEF-1 stimulates promoter activity through an insulin response element and also mediates the effects of insulin on gene expression. These results show that RTEF-1-stimulated IGFBP-1 expression may be central to the mechanism by which RTEF-1 attenuates blood glucose levels. These findings provide the basis for novel insights into the transcriptional regulation of IGFBP-1 and contribute to our understanding of the role of vascular endothelial cells in metabolism.
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Affiliation(s)
- Angela F Messmer-Blust
- Division of Cardiovascular Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02115, USA
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