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Liang Z, Sun G, Zhang J, Zhang Q, Li X, Qin S, Lv S, Ding J, Zhang Q, Xia Y, Lu D. Protein phosphatase 4 mediates palmitic acid-induced endothelial dysfunction by decreasing eNOS phosphorylation at serine 633 in HUVECs. Exp Cell Res 2024; 437:113998. [PMID: 38513962 DOI: 10.1016/j.yexcr.2024.113998] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Revised: 01/30/2024] [Accepted: 03/10/2024] [Indexed: 03/23/2024]
Abstract
Plasma saturated free fatty acid (FFA)-induced endothelial dysfunction (ED) contributes to the pathogenesis of atherosclerosis and cardiovascular diseases. However, the mechanism underlying saturated FFA-induced ED remains unclear. This study demonstrated that palmitic acid (PA) induced ED by activating the NADPH oxidase (NOX)/ROS signaling pathway to activate protein phosphatase 4 (PP4) and protein phosphatase 2A (PP2A), thereby reducing endothelial nitric oxide synthase (eNOS) phosphorylation at Ser633 and Ser1177, respectively. Okadaic acid (OA) and fostriecin (FST), which are inhibitors of PP2A, inhibited the PA-induced decreases in eNOS phosphorylation at Ser633 and Ser1177. The antioxidants N-acetylcysteine (NAC) and apocynin (APO) or knockdown of gp91phox or p67phox (NOX subunits) restored PA-mediated downregulation of PP4R2 protein expression and eNOS Ser633 phosphorylation. Knockdown of the PP4 catalytic subunit (PP4c) specifically increased eNOS Ser633 phosphorylation, while silencing the PP2A catalytic subunit (PP2Ac) restored only eNOS Ser1177 phosphorylation. Furthermore, PA dramatically decreased the protein expression of the PP4 regulatory subunit R2 (PP4R2) but not the other regulatory subunits. PP4R2 overexpression increased eNOS Ser633 phosphorylation, nitric oxide (NO) production, cell migration and tube formation but did not change eNOS Ser1177 phosphorylation levels. Coimmunoprecipitation (Co-IP) suggested that PP4R2 and PP4c interacted with the PP4R3α and eNOS proteins. In summary, PA decreases PP4R2 protein expression through the Nox/ROS pathway to activate PP4, which contributes to ED by dephosphorylating eNOS at Ser633. The results of this study suggest that PP4 is a novel therapeutic target for ED and ED-associated vascular diseases.
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Affiliation(s)
- Zhengwei Liang
- Department of Pathophysiology, Guizhou Medical University, Guiyang, China; Guizhou Provincial Key Laboratory of Pathogenesis & Drug Research on Common Chronic Diseases, Guizhou Medical University, Guiyang, China
| | - Gang Sun
- Department of Pathophysiology, Guizhou Medical University, Guiyang, China; Guizhou Provincial Key Laboratory of Pathogenesis & Drug Research on Common Chronic Diseases, Guizhou Medical University, Guiyang, China
| | - Junshi Zhang
- Department of Pathophysiology, Guizhou Medical University, Guiyang, China; Guizhou Provincial Key Laboratory of Pathogenesis & Drug Research on Common Chronic Diseases, Guizhou Medical University, Guiyang, China
| | - Qian Zhang
- Department of Pathophysiology, Guizhou Medical University, Guiyang, China; Guizhou Provincial Key Laboratory of Pathogenesis & Drug Research on Common Chronic Diseases, Guizhou Medical University, Guiyang, China
| | - Xiaoyu Li
- Department of Pathophysiology, Guizhou Medical University, Guiyang, China; Guizhou Provincial Key Laboratory of Pathogenesis & Drug Research on Common Chronic Diseases, Guizhou Medical University, Guiyang, China
| | - Si Qin
- Department of Pathophysiology, Guizhou Medical University, Guiyang, China; Guizhou Provincial Key Laboratory of Pathogenesis & Drug Research on Common Chronic Diseases, Guizhou Medical University, Guiyang, China
| | - Sha Lv
- Department of Pathophysiology, Guizhou Medical University, Guiyang, China; Guizhou Provincial Key Laboratory of Pathogenesis & Drug Research on Common Chronic Diseases, Guizhou Medical University, Guiyang, China
| | - Jing Ding
- Department of Pathophysiology, Guizhou Medical University, Guiyang, China; Guizhou Provincial Key Laboratory of Pathogenesis & Drug Research on Common Chronic Diseases, Guizhou Medical University, Guiyang, China
| | - Qifang Zhang
- Key Laboratory of Endemic and Ethnic Diseases, Ministry of Education, Guizhou Medical University, Guiyang, China
| | - Yong Xia
- Davis Heart and Lung Research Institute, The Ohio State University College of Medicine, Columbus, OH, United States.
| | - Deqin Lu
- Department of Pathophysiology, Guizhou Medical University, Guiyang, China; Guizhou Provincial Key Laboratory of Pathogenesis & Drug Research on Common Chronic Diseases, Guizhou Medical University, Guiyang, China.
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2
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Ablooglu AJ, Chen WS, Xie Z, Desai A, Paul S, Lack JB, Scott LA, Eisch AR, Dudek AZ, Parikh SM, Druey KM. Intrinsic endothelial hyperresponsiveness to inflammatory mediators drives acute episodes in models of Clarkson disease. J Clin Invest 2024; 134:e169137. [PMID: 38502192 DOI: 10.1172/jci169137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Accepted: 03/08/2024] [Indexed: 03/21/2024] Open
Abstract
Clarkson disease, or monoclonal gammopathy-associated idiopathic systemic capillary leak syndrome (ISCLS), is a rare, relapsing-remitting disorder featuring the abrupt extravasation of fluids and proteins into peripheral tissues, which in turn leads to hypotensive shock, severe hemoconcentration, and hypoalbuminemia. The specific leakage factor(s) and pathways in ISCLS are unknown, and there is no effective treatment for acute flares. Here, we characterize an autonomous vascular endothelial defect in ISCLS that was recapitulated in patient-derived endothelial cells (ECs) in culture and in a mouse model of disease. ISCLS-derived ECs were functionally hyperresponsive to permeability-inducing factors like VEGF and histamine, in part due to increased endothelial nitric oxide synthase (eNOS) activity. eNOS blockade by administration of N(γ)-nitro-l-arginine methyl ester (l-NAME) ameliorated vascular leakage in an SJL/J mouse model of ISCLS induced by histamine or VEGF challenge. eNOS mislocalization and decreased protein phosphatase 2A (PP2A) expression may contribute to eNOS hyperactivation in ISCLS-derived ECs. Our findings provide mechanistic insights into microvascular barrier dysfunction in ISCLS and highlight a potential therapeutic approach.
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Affiliation(s)
- Ararat J Ablooglu
- Lung and Vascular Inflammation Section, Laboratory of Allergic Diseases, and
| | - Wei-Sheng Chen
- Lung and Vascular Inflammation Section, Laboratory of Allergic Diseases, and
| | - Zhihui Xie
- Lung and Vascular Inflammation Section, Laboratory of Allergic Diseases, and
| | - Abhishek Desai
- Lung and Vascular Inflammation Section, Laboratory of Allergic Diseases, and
| | - Subrata Paul
- Integrative Data Sciences Section, National Institute of Allergy and Infectious Diseases (NIAID), NIH, Bethesda, Maryland, USA
| | - Justin B Lack
- Integrative Data Sciences Section, National Institute of Allergy and Infectious Diseases (NIAID), NIH, Bethesda, Maryland, USA
| | - Linda A Scott
- Lung and Vascular Inflammation Section, Laboratory of Allergic Diseases, and
| | - A Robin Eisch
- Lung and Vascular Inflammation Section, Laboratory of Allergic Diseases, and
| | - Arkadiusz Z Dudek
- Division of Medical Oncology, Mayo Clinic, Rochester, Minnesota, USA
| | - Samir M Parikh
- Division of Nephrology, Departments of Internal Medicine and Pharmacology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Kirk M Druey
- Lung and Vascular Inflammation Section, Laboratory of Allergic Diseases, and
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3
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Thalwieser Z, Fonódi M, Király N, Csortos C, Boratkó A. PP2A Affects Angiogenesis via Its Interaction with a Novel Phosphorylation Site of TSP1. Int J Mol Sci 2024; 25:1844. [PMID: 38339122 PMCID: PMC10855381 DOI: 10.3390/ijms25031844] [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: 01/13/2024] [Revised: 01/30/2024] [Accepted: 02/01/2024] [Indexed: 02/12/2024] Open
Abstract
Alterations in angiogenic properties play a pivotal role in the manifestation and onset of various pathologies, including vascular diseases and cancer. Thrombospondin-1 (TSP1) protein is one of the master regulators of angiogenesis. This study unveils a novel aspect of TSP1 regulation through reversible phosphorylation. The silencing of the B55α regulatory subunit of protein phosphatase 2A (PP2A) in endothelial cells led to a significant decrease in TSP1 expression. Direct interaction between TSP1 and PP2A-B55α was confirmed via various methods. Truncated TSP1 constructs were employed to identify the phosphorylation site and the responsible kinase, ultimately pinpointing PKC as the enzyme phosphorylating TSP1 on Ser93. The biological effects of B55α-TSP1 interaction were also analyzed. B55α silencing not only counteracted the increase in TSP1 expression during wound closure but also prolonged wound closure time. Although B55α silenced cells initiated tube-like structures earlier than control cells, their spheroid formation was disrupted, leading to disintegration. Cells transfected with phosphomimic TSP1 S93D exhibited smaller spheroids and reduced effectiveness in tube formation, revealing insights into the effects of TSP1 phosphorylation on angiogenic properties. In this paper, we introduce a new regulatory mechanism of angiogenesis by reversible phosphorylation on TSP1 S93 by PKC and PP2A B55α.
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Affiliation(s)
| | | | | | | | - Anita Boratkó
- Department of Medical Chemistry, Faculty of Medicine, University of Debrecen, Egyetem tér 1, H-4032 Debrecen, Hungary; (Z.T.); (M.F.); (C.C.)
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Xia Y, Lu YW, Hao RJ, Yu GR. Catalpol relieved angiotensin II-induced blood-brain barrier destruction via inhibiting the TLR4 pathway in brain endothelial cells. PHARMACEUTICAL BIOLOGY 2022; 60:2210-2218. [PMID: 36369944 PMCID: PMC9665075 DOI: 10.1080/13880209.2022.2142801] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Revised: 09/02/2022] [Accepted: 10/28/2022] [Indexed: 06/16/2023]
Abstract
CONTEXT Catalpol is a major bioactive constituent of Rehmannia glutinosa Libosch (Scrophulariaceae), a traditional Chinese medicine, which is widely used in multiple diseases, including hypertension. OBJECTIVES To explore whether catalpol protects against angiotensin II (Ang II)-triggered blood-brain barrier (BBB) leakage. MATERIALS AND METHODS The bEnd.3 cells and BBB models were pre-treated with or without catalpol (50, 200 and 500 μM) or TAK-242 (1 μM) for 2 h and then with Ang II (0.1 μM) or LPS (1 μg/mL) for 24 h. Cell viability was determined by the MTT assay. The levels of Toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (MyD88), inducible nitric oxide synthase (iNOS), tumour necrosis factor-α (TNF-α), caveolin-1 (Cav-1) and p-eNOS/eNOS were tested by western blot. The BBB permeability was evaluated by the flux of bovine serum albumin-fluorescein isothiocyanate (BSA-FITC) across monolayers. nuclear factor kappa-B (NF-κB) p65 nuclear translocation was explored by immunofluorescence staining. RESULTS Ang II (0.1 μM) decreased the cell viability to 86.52 ± 1.79%, elevated the levels of TLR4, MyD88, iNOS, TNF-α and Cav-1 respectively to 3.7-, 1.5-, 2.3-, 2.2- and 2.7-fold, reduced the level of p-eNOS/eNOS to 1.6-fold in bEnd.3 cells, and eventually increased BBB permeability. Catalpol dose-dependently reversed these changes at 50-500 μM. Meanwhile, catalpol (500 μM) inhibited the upregulated levels of TLR4 pathway-related proteins and NF-κB p65 nuclear translocation, decreased the enhanced transcytosis, and relieved the BBB disruption caused by both LPS (the TLR4 activator) and Ang II. The effects are same as TAK-242 (the TLR4 inhibitor). CONCLUSIONS Catalpol relieved the Ang II-induced BBB damage, which indicated catalpol has high potential for the treatment of hypertension-induced cerebral small vessel disease (cSVD).
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Affiliation(s)
- Yu Xia
- Department of Neurology, Jiangsu Province Hospital of Chinese Medicine, The Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, China
| | - Yun Wei Lu
- Department of Neurology, Jiangsu Province Hospital of Chinese Medicine, The Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, China
| | - Ren Juan Hao
- Department of Neurology, Jiangsu Province Hospital of Chinese Medicine, The Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, China
| | - Gu Ran Yu
- Department of Neurology, Jiangsu Province Hospital of Chinese Medicine, The Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, China
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Jin J, Liu J, Luo Y, He H, Zheng X, Zheng C, Huang Y, Chen Y. High fructose induces dysfunctional vasodilatation via PP2A-mediated eNOS Ser1177 dephosphorylation. Nutr Metab (Lond) 2022; 19:24. [PMID: 35331293 PMCID: PMC8944156 DOI: 10.1186/s12986-022-00659-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Accepted: 03/08/2022] [Indexed: 11/17/2022] Open
Abstract
Background Processed foods are popular and contain large amounts of industrial fructose, which changes people’s diet and exacerbates the negative health effects of high fructose. Several studies have shown that excessive intake of fructose has a major impact on vascular disease. However, the mechanism of the effect of high fructose on blood vessels is currently unclear. Methods The effect of fructose on the vasodilatation of isolated thoracic aortic rings was observed by using wire myography in wild-type (WT) mice. Cell viability and nitric oxide (NO) production were assessed by the corresponding kits in mouse vascular endothelial cells. The effect of fructose on endothelial nitric oxide synthase (eNOS) and protein phosphatase 2A (PP2A) and their changes in phosphorylation were detected by using Western blots. Moreover, a PP2A inhibitor (okadaic acid, OA) was used to evaluate the relationship between fructose and PP2A. Furthermore, PP2ACα endothelial-specific knockout (PP2A cKO) mice were used to detect the vasodilatation of in vitro fructose-incubated thoracic aortic rings by using wire myography. Results High fructose induced endothelium-dependent dysfunctional vasodilatation. High fructose reduced acetylcholine (Ach)-induced vasodilation but did not affect sodium nitroprusside (SNP)-induced vasodilation. Accordingly, NO production and the phosphorylation level of eNOS at serine (Ser) 1177 (P-eNOS) in vascular endothelial cells were remarkably reduced without changes in cell viability. The expression of protein phosphatase 2A catalytic subunit (PP2AC) was increased and the expression of phosphorylated PP2AC (P-PP2A, tyrosine [Tyr] 307) was significantly decreased. Nevertheless, these effects were reversed by OA. Moreover, knockout of the PP2A gene could recover the response of vessels to Ach under high fructose stimulation. Conclusions Our observations demonstrate an underlying mechanism of fructose-induced dysfunctional vasodilatation. Fructose could activate PP2A, which leads to decrease in the phosphorylation of eNOS at Ser1177 and the reduction of NO release, thus leading to the occurrence of endothelium-dependent dysfunctional vasodilatation.
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Affiliation(s)
- Jiaqi Jin
- School of Pharmaceutical, Guangzhou University of Chinese Medicine, No. 232 Waihuan Dong Rd., Guangzhou University Town, Panyu District, Guangzhou, 510000, China
| | - Jingya Liu
- School of Pharmaceutical, Guangzhou University of Chinese Medicine, No. 232 Waihuan Dong Rd., Guangzhou University Town, Panyu District, Guangzhou, 510000, China
| | - Yong Luo
- School of Pharmaceutical, Guangzhou University of Chinese Medicine, No. 232 Waihuan Dong Rd., Guangzhou University Town, Panyu District, Guangzhou, 510000, China
| | - Hong He
- Department of Obstetrics and Gynecology, Key Laboratory for Major Obstetric Diseases of Guangdong Province, The Third Affiliated Hospital of Guangzhou Medical University, No. 63 Duobao Road, Liwan District, Guangzhou, 510150, China
| | - Xinyue Zheng
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, Hubei, China
| | - Chaoyang Zheng
- Department of Cardiology, The Second Clinical Medical College and Guangdong Provincial Hospital of Chinese Medicine, Guangzhou University of Chinese Medicine, Guangzhou, 510006, China
| | - Yi Huang
- Department of Stomatology, The First Affiliated Hospital, The School of Dental Medicine, Jinan University, No. 613W. Huangpu Avenue, Guangzhou, 510630, China.
| | - Yang Chen
- School of Pharmaceutical, Guangzhou University of Chinese Medicine, No. 232 Waihuan Dong Rd., Guangzhou University Town, Panyu District, Guangzhou, 510000, China.
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Ding J, Yu M, Jiang J, Luo Y, Zhang Q, Wang S, Yang F, Wang A, Wang L, Zhuang M, Wu S, Zhang Q, Xia Y, Lu D. Angiotensin II Decreases Endothelial Nitric Oxide Synthase Phosphorylation via AT 1R Nox/ROS/PP2A Pathway. Front Physiol 2020; 11:566410. [PMID: 33162896 PMCID: PMC7580705 DOI: 10.3389/fphys.2020.566410] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Accepted: 09/08/2020] [Indexed: 12/12/2022] Open
Abstract
Increasing evidences suggest that angiotensin (Ang) II participates in the pathogenesis of endothelial dysfunction (ED) through multiple signaling pathways, including angiotensin type 1 receptor (AT1R) mediated NADPH oxidase (Nox)/reactive oxygen species (ROS) signal transduction. However, the detailed mechanism is not completely understood. In this study, we reported that AngII/AT1R-mediated activated protein phosphatase 2A (PP2A) downregulated endothelial nitric oxide synthase (eNOS) phosphorylation via Nox/ROS pathway. AngII treatment reduced the levels of phosphorylation of eNOS Ser1177 and nitric oxide (NO) content along with phosphorylation of PP2Ac (PP2A catalytic subunit) Tyr307, meanwhile increased the PP2A activity and ROS production in human umbilical vein endothelial cells (HUVECs). These changes could be impeded by AT1R antagonist candesartan (CAN). The pretreatment of 10−8 M PP2A inhibitor okadaic acid (OA) reversed the levels of eNOS Ser1177 and NO content. Similar effects of AngII on PP2A and eNOS were also observed in the mesenteric arteries of Sprague-Dawley rats subjected to AngII infusion via osmotic minipumps for 2 weeks. We found that the PP2A activity was increased, but the levels of PP2Ac Tyr307 and eNOS Ser1177 as well as NO content were decreased in the mesenteric arteries. The pretreatments of antioxidant N-acetylcysteine (NAC) and apocynin (APO) abolished the drop of the levels of PP2Ac Tyr307 and eNOS Ser1177 induced by AngII in HUVECs. The knockdown of p22phox by small interfering RNA (siRNA) gave rise to decrement of ROS production and increment of the levels of PP2Ac Tyr307 and eNOS Ser1177. These results indicated that AngII/AT1R pathway activated PP2A by downregulating its catalytic subunit Tyr307 phosphorylation, which relies on the Nox activation and ROS production. In summary, our findings indicate that AngII downregulates PP2A catalytic subunit Tyr307 phosphorylation to activate PP2A via AT1R-mediated Nox/ROS signaling pathway. The activated PP2A further decreases levels of eNOS Ser1177 phosphorylation and NO content leading to endothelial dysfunction.
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Affiliation(s)
- Jing Ding
- Department of Pathophysiology, Guizhou Medical University, Guiyang, China.,Guizhou Provincial Key Laboratory of Pathogenesis and Drug Research on Common Chronic Diseases, Guizhou Medical University, Guiyang, China
| | - Min Yu
- Department of Pathophysiology, Guizhou Medical University, Guiyang, China.,Guizhou Provincial Key Laboratory of Pathogenesis and Drug Research on Common Chronic Diseases, Guizhou Medical University, Guiyang, China
| | - Juncai Jiang
- Department of Pathophysiology, Guizhou Medical University, Guiyang, China.,Guizhou Provincial Key Laboratory of Pathogenesis and Drug Research on Common Chronic Diseases, Guizhou Medical University, Guiyang, China
| | - Yanbei Luo
- Department of Pathophysiology, Guizhou Medical University, Guiyang, China.,Guizhou Provincial Key Laboratory of Pathogenesis and Drug Research on Common Chronic Diseases, Guizhou Medical University, Guiyang, China
| | - Qian Zhang
- Department of Pathophysiology, Guizhou Medical University, Guiyang, China.,Guizhou Provincial Key Laboratory of Pathogenesis and Drug Research on Common Chronic Diseases, Guizhou Medical University, Guiyang, China
| | - Shengnan Wang
- Department of Pathology, The Second Clinical Medical School of Inner Mongolia University for the Nationalities, Yakeshi, China
| | - Fei Yang
- Department of Cardiology, The Second Provincial People's Hospital of Gansu, Lanzhou, China
| | - Alei Wang
- Department of Pathophysiology, Guizhou Medical University, Guiyang, China.,Guizhou Provincial Key Laboratory of Pathogenesis and Drug Research on Common Chronic Diseases, Guizhou Medical University, Guiyang, China
| | - Lingxiao Wang
- Department of Pathophysiology, Guizhou Medical University, Guiyang, China.,Guizhou Provincial Key Laboratory of Pathogenesis and Drug Research on Common Chronic Diseases, Guizhou Medical University, Guiyang, China
| | - Mei Zhuang
- Department of Cardiology, Affiliated Hospital of Guizhou Medical University, Guiyang, China
| | - Shan Wu
- Department of Neurology, Affiliated Hospital of Guizhou Medical University, Guiyang, China
| | - Qifang Zhang
- Key Laboratory of Medical Molecular Biology, Guizhou Medical University, Guiyang, China
| | - Yong Xia
- Davis Heart and Lung Research Institute, The Ohio State University College of Medicine, Columbus, OH, United States
| | - Deqin Lu
- Department of Pathophysiology, Guizhou Medical University, Guiyang, China.,Guizhou Provincial Key Laboratory of Pathogenesis and Drug Research on Common Chronic Diseases, Guizhou Medical University, Guiyang, China
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7
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Chen B, Zhao Q, Xu T, Yu L, Zhuo L, Yang Y, Xu Y. BRG1 Activates PR65A Transcription to Regulate NO Bioavailability in Vascular Endothelial Cells. Front Cell Dev Biol 2020; 8:774. [PMID: 32903816 PMCID: PMC7443572 DOI: 10.3389/fcell.2020.00774] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Accepted: 07/23/2020] [Indexed: 12/21/2022] Open
Abstract
Vascular endothelial cells contribute to the pathogenesis of cardiovascular diseases by producing and disseminating angiocrine factors. Nitric oxide (NO), catalyzed by endothelial NO synthase (eNOS), is one of the prototypical angiocrine factors. eNOS activity is modulated by site-specific phosphorylation. We have previously shown that endothelial-specific knockdown of BRG1 in Apoe–/– mice attenuates the development of atherosclerosis, in which eNOS-dependent NO catalysis plays an antagonizing role. Here we report that attenuation of atherogenesis in mice by BRG1 knockdown was accompanied by partial restoration of NO biosynthesis by 44% in the arteries and a simultaneous up-regulation of eNOS serine 1177 phosphorylation by 59%. Indeed, BRG1 depletion or inhibition ameliorated oxLDL-induced loss of NO bioavailability and eNOS phosphorylation in cultured endothelial cells. Further analysis revealed that BRG1 regulated eNOS phosphorylation and NO synthesis by activating the transcription of protein phosphatase 2A (PP2A) structural subunit a (encoded by PR65A). BRG1 interacted with ETS1, was recruited by ETS1 to the PR65A promoter, and cooperated with ETS1 to activate PR65A transcription. Finally, depletion of ETS1, similar to BRG1, repressed PR65A induction, normalized eNOS phosphorylation, and rescued NO biosynthesis in endothelial cells treated with oxLDL. In conclusion, our data characterize a novel transcriptional cascade that regulates NO bioavailability in vascular endothelial cells.
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Affiliation(s)
- Baoyu Chen
- Department of Pathophysiology, Nanjing Medical University, Nanjing, China
| | - Qianwen Zhao
- Department of Pathophysiology, Nanjing Medical University, Nanjing, China
| | - Tongchang Xu
- Department of Pathophysiology, Nanjing Medical University, Nanjing, China
| | - Liming Yu
- Department of Pathophysiology, Nanjing Medical University, Nanjing, China
| | - Lili Zhuo
- Department of Geriatrics, The Second Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Yuyu Yang
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, China.,Institute of Biomedical Research, Liaocheng University, Liaocheng, China
| | - Yong Xu
- Department of Pathophysiology, Nanjing Medical University, Nanjing, China.,Institute of Biomedical Research, Liaocheng University, Liaocheng, China
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