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Sigmund CD. The 2023 Walter B. Cannon Award Lecture: Mechanisms Regulating Vascular Function and Blood Pressure by the PPARγ-RhoBTB1-CUL3 Pathway. FUNCTION 2024; 5:zqad071. [PMID: 38196837 PMCID: PMC10775765 DOI: 10.1093/function/zqad071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Accepted: 12/08/2023] [Indexed: 01/11/2024] Open
Abstract
Human genetic and clinical trial data suggest that peroxisome proliferator activated receptor γ (PPARγ), a nuclear receptor transcription factor plays an important role in the regulation of arterial blood pressure. The examination of a series of novel animal models, coupled with transcriptomic and proteomic analysis, has revealed that PPARγ and its target genes employ diverse pathways to regulate vascular function and blood pressure. In endothelium, PPARγ target genes promote an antioxidant state, stimulating both nitric oxide (NO) synthesis and bioavailability, essential components of endothelial-smooth muscle communication. In vascular smooth muscle, PPARγ induces the expression of a number of genes that promote an antiinflammatory state and tightly control the level of cGMP, thus promoting responsiveness to endothelial-derived NO. One of the PPARγ targets in smooth muscle, Rho related BTB domain containing 1 (RhoBTB1) acts as a substrate adaptor for proteins to be ubiquitinated by the E3 ubiquitin ligase Cullin-3 and targeted for proteasomal degradation. One of these proteins, phosphodiesterase 5 (PDE5) is a target of the Cullin-3/RhoBTB1 pathway. Phosphodiesterase 5 degrades cGMP to GMP and thus regulates the smooth muscle response to NO. Moreover, expression of RhoBTB1 under condition of RhoBTB1 deficiency reverses established arterial stiffness. In conclusion, the coordinated action of PPARγ in endothelium and smooth muscle is needed to maintain NO bioavailability and activity, is an essential regulator of vasodilator/vasoconstrictor balance, and regulates blood vessel structure and stiffness.
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Affiliation(s)
- Curt D Sigmund
- Department of Physiology, Cardiovascular Center, Medical College of Wisconsin, Milwaukee, WI 53226, USA
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2
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Mladenov M, Lubomirov L, Grisk O, Avtanski D, Mitrokhin V, Sazdova I, Keremidarska-Markova M, Danailova Y, Nikolaev G, Konakchieva R, Gagov H. Oxidative Stress, Reductive Stress and Antioxidants in Vascular Pathogenesis and Aging. Antioxidants (Basel) 2023; 12:antiox12051126. [PMID: 37237992 DOI: 10.3390/antiox12051126] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 04/22/2023] [Accepted: 05/15/2023] [Indexed: 05/28/2023] Open
Abstract
This review is focused on the mechanisms that regulate health, disease and aging redox status, the signal pathways that counteract oxidative and reductive stress, the role of food components and additives with antioxidant properties (curcumin, polyphenols, vitamins, carotenoids, flavonoids, etc.), and the role of the hormones irisin and melatonin in the redox homeostasis of animal and human cells. The correlations between the deviation from optimal redox conditions and inflammation, allergic, aging and autoimmune responses are discussed. Special attention is given to the vascular system, kidney, liver and brain oxidative stress processes. The role of hydrogen peroxide as an intracellular and paracrine signal molecule is also reviewed. The cyanotoxins β-N-methylamino-l-alanine (BMAA), cylindrospermopsin, microcystins and nodularins are introduced as potentially dangerous food and environment pro-oxidants.
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Affiliation(s)
- Mitko Mladenov
- Faculty of Natural Sciences and Mathematics, Institute of Biology, "Ss. Cyril and Methodius" University, P.O. Box 162, 1000 Skopje, North Macedonia
| | - Lubomir Lubomirov
- Institute of Physiology, Brandenburg Medical School Theodor Fontane, 16816 Neuruppin, Germany
| | - Olaf Grisk
- Institute of Physiology, Brandenburg Medical School Theodor Fontane, 16816 Neuruppin, Germany
| | - Dimiter Avtanski
- Friedman Diabetes Institute, Lenox Hill Hospital, Northwell Health, 110 E 59th Street, New York, NY 10003, USA
| | - Vadim Mitrokhin
- Department of Physiology, Pirogov Russian National Research Medical University, 1 Ostrovityanova Street, 117997 Moscow, Russia
| | - Iliyana Sazdova
- Department of Animal and Human Physiology, Faculty of Biology, Sofia University "St. Kliment Ohridski", 8 Dragan Tzankov Blvd., 1164 Sofia, Bulgaria
| | - Milena Keremidarska-Markova
- Department of Animal and Human Physiology, Faculty of Biology, Sofia University "St. Kliment Ohridski", 8 Dragan Tzankov Blvd., 1164 Sofia, Bulgaria
| | - Yana Danailova
- Department of Animal and Human Physiology, Faculty of Biology, Sofia University "St. Kliment Ohridski", 8 Dragan Tzankov Blvd., 1164 Sofia, Bulgaria
| | - Georgi Nikolaev
- Department of Cell and Developmental Biology, Faculty of Biology, Sofia University "St. Kliment Ohridski", 8 Dragan Tsankov Blvd., 1164 Sofia, Bulgaria
| | - Rossitza Konakchieva
- Department of Cell and Developmental Biology, Faculty of Biology, Sofia University "St. Kliment Ohridski", 8 Dragan Tsankov Blvd., 1164 Sofia, Bulgaria
| | - Hristo Gagov
- Department of Animal and Human Physiology, Faculty of Biology, Sofia University "St. Kliment Ohridski", 8 Dragan Tzankov Blvd., 1164 Sofia, Bulgaria
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3
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Kinzenbaw DA, Langmack L, Faraci FM. Angiotensin II-induced endothelial dysfunction: Impact of sex, genetic background, and rho kinase. Physiol Rep 2022; 10:e15336. [PMID: 35681278 PMCID: PMC9184751 DOI: 10.14814/phy2.15336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 05/11/2022] [Accepted: 05/13/2022] [Indexed: 06/15/2023] Open
Abstract
The renin-angiotensin system (RAS) contributes to vascular disease with multiple cardiovascular risk factors including hypertension. As a major effector within the RAS, angiotensin II (Ang II) activates diverse signaling mechanisms that affect vascular biology. Despite the impact of such vascular pathophysiology, our understanding of the effects of Ang II in relation to the function of endothelial cells is incomplete. Because genetic background and biological sex can be determinants of vascular disease, we performed studies examining the direct effects of Ang II using carotid arteries from male and female mice on two genetic backgrounds, C57BL/6J and FVB/NJ. Although FVB/NJ mice are much less susceptible to atherosclerosis than C57BL/6J, the effects of Ang II on endothelial cells in FVB/NJ are poorly defined. Overnight incubation of isolated arteries with Ang II (10 nmol/L), impaired endothelial function in both strains and sexes by approximately one-half (p < 0.05). To examine the potential mechanistic contribution of Rho kinase (ROCK), we treated arteries with SLX-2119, an inhibitor with high selectivity for ROCK2. In both male and female mice of both strains, SLX-2119 largely restored endothelial function to normal, compared to vessels treated with vehicle. Thus, Ang II-induced endothelial dysfunction was observed in both FVB/NJ and C57BL/6J mice. This effect was sex-independent. In all groups, effects of Ang II were reversed by inhibition of ROCK2 with SLX-2119. These studies provide the first evidence that ROCK2 may be a key contributor to Ang II-induced endothelial dysfunction in both sexes and in mouse strains that differ in relation to other major aspects of vascular disease.
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Affiliation(s)
- Dale A. Kinzenbaw
- Departments of Internal MedicineFrancois M. Abboud Cardiovascular CenterThe University of Iowa Carver College of MedicineIowa CityIowaUSA
| | - Lucy Langmack
- Departments of Internal MedicineFrancois M. Abboud Cardiovascular CenterThe University of Iowa Carver College of MedicineIowa CityIowaUSA
| | - Frank M. Faraci
- Departments of Internal MedicineFrancois M. Abboud Cardiovascular CenterThe University of Iowa Carver College of MedicineIowa CityIowaUSA
- Departments of Neuroscience and PharmacologyThe University of Iowa Carver College of MedicineIowa CityIowaUSA
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4
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Ertuglu LA, Elijovich F, Laffer CL, Kirabo A. Salt-Sensitivity of Blood Pressure and Insulin Resistance. Front Physiol 2021; 12:793924. [PMID: 34966295 PMCID: PMC8711096 DOI: 10.3389/fphys.2021.793924] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Accepted: 11/18/2021] [Indexed: 12/20/2022] Open
Abstract
Salt sensitivity of blood pressure (SSBP) is an independent risk factor for cardiovascular morbidity and mortality that is seen in both hypertensive and normotensive populations. Insulin resistance (IR) strongly correlates with SSBP and affects nearly 50% of salt sensitive people. While the precise mechanism by which IR and SSBP relate remains elusive, several common pathways are involved in the genesis of both processes, including vascular dysfunction and immune activation. Vascular dysfunction associated with insulin resistance is characterized by loss of nitric oxide (NO)-mediated vasodilation and heightened endothelin-1 induced vasoconstriction, as well as capillary rarefaction. It manifests with increased blood pressure (BP) in salt sensitive murine models. Another common denominator in the pathogenesis of insulin resistance, hypertension, and salt sensitivity (SS) is immune activation involving pro-inflammatory cytokines like tumor necrosis factor (TNF)-α, IL-1β, and IL-6. In the last decade, a new understanding of interstitial sodium storage in tissues such as skin and muscle has revolutionized traditional concepts of body sodium handling and pathogenesis of SS. We have shown that interstitial Na+ can trigger a T cell mediated inflammatory response through formation of isolevuglandin protein adducts in antigen presenting cells (APCs), and that this response is implicated in salt sensitive hypertension. The peroxisome proliferator-activated receptor γ (PPARγ) is a transcription factor that modulates both insulin sensitivity and BP. PPARγ agonists increase insulin sensitivity and ameliorate salt sensitivity, whereas deficiency of PPARγ results in severe insulin resistance and hypertension. These findings suggest that PPARγ plays a role in the common pathogenesis of insulin sensitivity and salt sensitivity, perhaps via effects on the immune system and vascular function. The goal of this review is to discuss those mechanisms that may play a role in both SSBP and in insulin resistance.
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Affiliation(s)
- Lale A Ertuglu
- Division of Nephrology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Fernando Elijovich
- Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Cheryl L Laffer
- Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Annet Kirabo
- Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, United States
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5
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Abdelhafez AT, Gomaa AMS, Ahmed AM, Sayed MM, Ahmed MA. Pioglitazone and/or irbesartan ameliorate COPD-induced endothelial dysfunction in side stream cigarette smoke-exposed mice model. Life Sci 2021; 280:119706. [PMID: 34102190 DOI: 10.1016/j.lfs.2021.119706] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 05/26/2021] [Accepted: 06/03/2021] [Indexed: 01/18/2023]
Abstract
AIMS Cigarette smoking (CS) is the main cause of chronic obstructive pulmonary disease (COPD). Endothelial dysfunction is related to the severity of pulmonary disease in COPD. This study aimed to evaluate the effectiveness of single and combined administration of pioglitazone (Pio) and irbesartan (Irb) against COPD-induced endothelial dysfunction in mice and the involvement of NO and H2S in their effects. MATERIALS AND METHODS Adult male Swiss mice (n = 40, weighing 25-30 g) were assigned into 5 groups. The normal control group received 1% carboxy methyl cellulose (CMC). The CS group was exposed to CS and administered 1% CMC for 3 months. The CS + Pio, CS + Irb, and CS + Pio/Irb groups were subjected to CS and received Pio (60 mg/kg), Irb (50 mg/kg), and their combination respectively, daily orally for 3 months. Body weight gain, mean blood pressure, urinary albumin, serum NO and ET-1 levels with TNF-α and IL-2 levels in lung tissue and bronchoalveolar lavage were measured. Lung H2S and ET-1 levels, protein expression of PPARγ in lung and VEGF in lung and aortic tissues with histological changes were assessed. KEY FINDINGS Our results illustrated that CS induced a model of COPD with endothelial dysfunction in mice. Pio/Irb singly and in combination elicited protective effects against the pathophysiology of the disease with more improvement in the combined group. There is a strong correlation between NO and H2S as well as the other measured parameters. SIGNIFICANCE Collectively, both drugs performed these effects via their anti-inflammatory potential and increasing H2S and NO levels.
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Affiliation(s)
- Alaa T Abdelhafez
- Department of Pharmacology, Faculty of Medicine, Assiut University, Assiut, Egypt
| | - Asmaa M S Gomaa
- Department of Medical Physiology, Faculty of Medicine, Assiut University, Assiut, Egypt
| | - Asmaa M Ahmed
- Department of Pathology, Faculty of Medicine, Assiut University, Assiut, Egypt
| | - Manal M Sayed
- Department of Histology and Cell Biology, Faculty of Medicine, Assiut University, Assiut, Egypt
| | - Marwa A Ahmed
- Department of Pharmacology, Faculty of Medicine, Assiut University, Assiut, Egypt.
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6
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Fang S, Livergood MC, Nakagawa P, Wu J, Sigmund CD. Role of the Peroxisome Proliferator Activated Receptors in Hypertension. Circ Res 2021; 128:1021-1039. [PMID: 33793338 DOI: 10.1161/circresaha.120.318062] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Nuclear receptors represent a large family of ligand-activated transcription factors which sense the physiological environment and make long-term adaptations by mediating changes in gene expression. In this review, we will first discuss the fundamental mechanisms by which nuclear receptors mediate their transcriptional responses. We will focus on the PPAR (peroxisome proliferator-activated receptor) family of adopted orphan receptors paying special attention to PPARγ, the isoform with the most compelling evidence as an important regulator of arterial blood pressure. We will review genetic data showing that rare mutations in PPARγ cause severe hypertension and clinical trial data which show that PPARγ activators have beneficial effects on blood pressure. We will detail the tissue- and cell-specific molecular mechanisms by which PPARs in the brain, kidney, vasculature, and immune system modulate blood pressure and related phenotypes, such as endothelial function. Finally, we will discuss the role of placental PPARs in preeclampsia, a life threatening form of hypertension during pregnancy. We will close with a viewpoint on future research directions and implications for developing novel therapies.
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Affiliation(s)
- Shi Fang
- Department of Physiology, Cardiovascular Center (S.F., P.N., J.W., C.D.S.), Medical College of Wisconsin, Milwaukee.,Department of Neuroscience and Pharmacology, University of Iowa (S.F.)
| | - M Christine Livergood
- Department of Obstetrics and Gynecology (M.C.L.), Medical College of Wisconsin, Milwaukee
| | - Pablo Nakagawa
- Department of Physiology, Cardiovascular Center (S.F., P.N., J.W., C.D.S.), Medical College of Wisconsin, Milwaukee
| | - Jing Wu
- Department of Physiology, Cardiovascular Center (S.F., P.N., J.W., C.D.S.), Medical College of Wisconsin, Milwaukee
| | - Curt D Sigmund
- Department of Physiology, Cardiovascular Center (S.F., P.N., J.W., C.D.S.), Medical College of Wisconsin, Milwaukee
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7
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Abstract
PURPOSE OF REVIEW The goal of this review is to evaluate recent advances in understanding the pivotal roles of Cullin-3 (CUL3) in blood pressure regulation with a focus on its actions in the kidney and blood vessels. RECENT FINDINGS Cul3-based ubiquitin ligase regulates renal electrolyte transport, vascular tone, and redox homeostasis by facilitating the normal turnover of (1) with-no-lysine kinases in the distal nephron, (2) RhoA and phosphodiesterase 5 in the vascular smooth muscle, and (3) nuclear factor E2-related factor 2 in antioxidant responses. CUL3 mutations identified in familial hyperkalemic hypertension (FHHt) yield a mutant protein lacking exon 9 (CUL3∆9) which displays dual gain and loss of function. CUL3∆9 acts in a dominant manner to impair CUL3-mediated substrate ubiquitylation and degradation. The consequent accumulation of substrates and overactivation of downstream signaling cause FHHt through increased sodium reabsorption, enhanced vasoconstriction, and decreased vasodilation. CUL3 ubiquitin ligase maintains normal cardiovascular and renal physiology through posttranslational modification of key substrates which regulate blood pressure. Interference with CUL3 disturbs these key downstream pathways. Further understanding the spatial and temporal specificity of how CUL3 functions in these pathways is necessary to identify novel therapeutic targets for hypertension.
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8
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Abstract
PURPOSE OF REVIEW This review provides an up-to-date understanding of how peroxisome proliferator activated receptor γ (PPARγ) exerts its cardioprotective effect in the vasculature through its activation of novel PPARγ target genes in endothelium and vascular smooth muscle. RECENT FINDINGS In vascular endothelial cells, PPARγ plays a protective role by increasing nitric oxide bioavailability and preventing oxidative stress. RBP7 is a PPARγ target gene enriched in vascular endothelial cells, which is likely to form a positive feedback loop with PPARγ. In vascular smooth muscle cells, PPARγ antagonizes the renin-angiotensin system, maintains vascular integrity, suppresses vasoconstriction, and promotes vasodilation through distinct pathways. Rho-related BTB domain containing protein 1 (RhoBTB1) is a novel PPARγ gene target in vascular smooth muscle cells that mediates the protective effect of PPARγ by serving as a substrate adaptor between the Cullin-3 RING ubiquitin ligase and phosphodiesterase 5, thus restraining its activity through ubiquitination and proteasomal degradation. SUMMARY In the vasculature, PPARγ exerts its cardioprotective effect through its transcriptional activity in endothelium and vascular smooth muscle. From the understanding of PPARγ's transcription targets in those pathways, novel hypertension therapy target(s) will emerge.
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9
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Abstract
Cerebral small vessel disease (SVD) is characterized by changes in the pial and parenchymal microcirculations. SVD produces reductions in cerebral blood flow and impaired blood-brain barrier function, which are leading contributors to age-related reductions in brain health. End-organ effects are diverse, resulting in both cognitive and noncognitive deficits. Underlying phenotypes and mechanisms are multifactorial, with no specific treatments at this time. Despite consequences that are already considerable, the impact of SVD is predicted to increase substantially with the growing aging population. In the face of this health challenge, the basic biology, pathogenesis, and determinants of SVD are poorly defined. This review summarizes recent progress and concepts in this area, highlighting key findings and some major unanswered questions. We focus on phenotypes and mechanisms that underlie microvascular aging, the greatest risk factor for cerebrovascular disease and its subsequent effects.
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Affiliation(s)
- T Michael De Silva
- Department of Physiology, Anatomy and Microbiology, School of Life Sciences, La Trobe University, Melbourne Campus, Bundoora, Victoria 3086, Australia;
| | - Frank M Faraci
- Departments of Internal Medicine, Neuroscience, and Pharmacology, Francois M. Abboud Cardiovascular Center, Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242, USA;
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10
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Reho JJ, Guo DF, Morgan DA, Rahmouni K. Smooth Muscle Cell-Specific Disruption of the BBSome Causes Vascular Dysfunction. Hypertension 2019; 74:817-825. [PMID: 31422694 DOI: 10.1161/hypertensionaha.119.13382] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The BBSome-a complex consisting of 8 Bardet-Biedl syndrome proteins-is involved in the regulation of various cellular processes. Recently, the BBSome complex has emerged as an important regulator of cardiovascular function with implications for disease. In this study, we examined the role of the BBSome in vascular smooth muscle and its effects on the regulation of cardiovascular function. Smooth muscle-specific disruption of the BBSome through tamoxifen-inducible deletion of Bbs1 gene-a critical component of the BBSome complex-reduces relaxation and enhances contractility of vascular rings and increases aortic stiffness independent of changes in arterial blood pressure. Mechanistically, we demonstrate that smooth muscle Bbs1 gene deletion increases vascular angiotensinogen gene expression implicating the renin-angiotensin system in these altered cardiovascular responses. Additionally, we report that smooth muscle-specific Bbs1 knockout mice demonstrate enhanced ET-1 (endothelin-1)-induced contractility of mesenteric arteries-an effect reversed by blockade of the AT1 (angiotensin type 1 receptor) with losartan. These findings highlight the importance of the smooth muscle BBSome in the control of vascular function and arterial stiffness through modulation of renin-angiotensin system signaling.
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Affiliation(s)
- John J Reho
- From the Department of Pharmacology (J.J.R., D.-F.G., D.A.M., K.R.), University of Iowa Carver College of Medicine
| | - Deng-Fu Guo
- From the Department of Pharmacology (J.J.R., D.-F.G., D.A.M., K.R.), University of Iowa Carver College of Medicine
| | - Donald A Morgan
- From the Department of Pharmacology (J.J.R., D.-F.G., D.A.M., K.R.), University of Iowa Carver College of Medicine
| | - Kamal Rahmouni
- From the Department of Pharmacology (J.J.R., D.-F.G., D.A.M., K.R.), University of Iowa Carver College of Medicine.,Department of Internal Medicine (K.R.), University of Iowa Carver College of Medicine.,Obesity Education and Research Initiative (K.R.), University of Iowa Carver College of Medicine.,Fraternal Order of Eagles Diabetes Research Center (K.R.), University of Iowa Carver College of Medicine.,Veterans Affairs Health Care System, Iowa City, IA (K.R.)
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11
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Zhuo X, Wu Y, Yang Y, Gao L, Qiao X, Chen T. LncRNA AK094457 promotes AngII-mediated hypertension and endothelial dysfunction through suppressing of activation of PPARγ. Life Sci 2019; 233:116745. [PMID: 31404524 DOI: 10.1016/j.lfs.2019.116745] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Revised: 08/01/2019] [Accepted: 08/08/2019] [Indexed: 02/06/2023]
Abstract
Hypertension is one of the major risk factors for cardiovascular disease worldwide and is striking more young people, which is characterized by impaired vascular endothelial function. To find the functional lncRNAs associated with hypertension, high throughput lncRNA microarray were used to analyze expression profile of the lncRNAs in the aortic vascular endothelial cells (VECs) of spontaneously hypertensive rats (SHRs). The tail vein injection of siRNA was used to study the influence of lncRNA AK094457 inhibition on endothelial function in vivo. In vitro, endothelial function was studied in endothelial cells transfected with lncRNA AK094457-overexpressed vectors and siRNAs. pPPARγ and iNOS protein levels were detected with Western blot. Elisa assay was used to analyze the secretion of AngII, ET-1, ROS and LDH level. The nitrite/nitrate (NO2-/NO3-) concentration was measured using a colorimetric assay. LncRNA AK094457 was a most upregulated lncRNA in SHRs. It is showed that downregulation of AK094457 significantly reduced rat arterial pressure, increased activation of endothelial PPARγ, and suppressed serum contents of AngII and NO in vivo. Furthermore, results from gain-and-loss of function in primary aortic endothelial cells indicated that AK094457 negatively regulated activation of PPARγ and promoted AngII-mediated endothelial dysfunction, manifested by decreased capacities of cell proliferation and migration, and increased levels of ROS production and LDH release. In conclusion, lncRNA AK094457 is identified as a key regulator in blood pressure and endothelial function, which can increase AngII-induced hypertension and endothelial dysfunction via suppression of PPARγ.
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Affiliation(s)
- Xiaozhen Zhuo
- Department of Cardiovascular Medicine, the First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710061, China
| | - Yan Wu
- Department of Cardiovascular Medicine, the First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710061, China
| | - Yanjie Yang
- Department of Cardiovascular Medicine, the First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710061, China
| | - Li Gao
- Department of Cardiovascular Medicine, the First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710061, China
| | - Xiangrui Qiao
- Department of Cardiovascular Medicine, the First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710061, China
| | - Tao Chen
- Department of Cardiovascular Medicine, the First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710061, China.
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12
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Nair AR, Agbor LN, Mukohda M, Liu X, Hu C, Wu J, Sigmund CD. Interference With Endothelial PPAR (Peroxisome Proliferator-Activated Receptor)-γ Causes Accelerated Cerebral Vascular Dysfunction in Response to Endogenous Renin-Angiotensin System Activation. Hypertension 2019; 72:1227-1235. [PMID: 30354810 DOI: 10.1161/hypertensionaha.118.11857] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Low-salt diet is beneficial in salt-sensitive hypertension but may provoke cardiovascular risk in patients with heart failure, diabetes mellitus, or other cardiovascular abnormalities because of endogenous renin-angiotensin system activation. PPAR (peroxisome proliferator-activated receptor)-γ is a transcription factor which promotes an antioxidant pathway in the endothelium. We studied transgenic mice expressing a dominant-negative mutation in PPAR-γ selectively in the endothelium (E-V290M) to test the hypothesis that endothelial PPAR-γ plays a protective role in response to low salt-mediated renin-angiotensin system activation. Plasma renin and Ang II (angiotensin II) were significantly and equally increased in all mice fed low salt for 6 weeks. Vasorelaxation to acetylcholine was not affected in basilar artery from E-V290M at baseline but was significantly and selectively impaired in E-V290M after low salt. Unlike basilar artery, low salt was not sufficient to induce vascular dysfunction in carotid artery or aorta. Endothelial dysfunction in the basilar artery from E-V290M mice fed low salt was attenuated by scavengers of superoxide, inhibitors of NADPH oxidase, or blockade of the Ang II AT1 (angiotensin type-1) receptor. Simultaneous AT1 and AT2 receptor blockade revealed that the restoration of endothelial function after AT1 receptor blockade was not a consequence of AT2 receptor activation. We conclude that interference with PPAR-γ in the endothelium produces endothelial dysfunction in the cerebral circulation in response to low salt-mediated activation of the endogenous renin-angiotensin system, mediated at least in part, through AT1 receptor activation and perturbed redox homeostasis. Moreover, our data suggest that the cerebral circulation may be particularly sensitive to inhibition of PPAR-γ activity and renin-angiotensin system activation.
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Affiliation(s)
- Anand R Nair
- From the Department of Pharmacology, UIHC Center for Hypertension Research, Roy J. and Lucille A. Carver College of Medicine, University of Iowa
| | - Larry N Agbor
- From the Department of Pharmacology, UIHC Center for Hypertension Research, Roy J. and Lucille A. Carver College of Medicine, University of Iowa
| | - Masashi Mukohda
- From the Department of Pharmacology, UIHC Center for Hypertension Research, Roy J. and Lucille A. Carver College of Medicine, University of Iowa
| | - Xuebo Liu
- From the Department of Pharmacology, UIHC Center for Hypertension Research, Roy J. and Lucille A. Carver College of Medicine, University of Iowa
| | - Chunyan Hu
- From the Department of Pharmacology, UIHC Center for Hypertension Research, Roy J. and Lucille A. Carver College of Medicine, University of Iowa
| | - Jing Wu
- From the Department of Pharmacology, UIHC Center for Hypertension Research, Roy J. and Lucille A. Carver College of Medicine, University of Iowa
| | - Curt D Sigmund
- From the Department of Pharmacology, UIHC Center for Hypertension Research, Roy J. and Lucille A. Carver College of Medicine, University of Iowa
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13
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Sun L, Bian K. The Nuclear Export and Ubiquitin-Proteasome-Dependent Degradation of PPARγ Induced By Angiotensin II. Int J Biol Sci 2019; 15:1215-1224. [PMID: 31223281 PMCID: PMC6567814 DOI: 10.7150/ijbs.29741] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Accepted: 03/12/2019] [Indexed: 12/24/2022] Open
Abstract
Evidence has documented local angiotensin II (Ang II) as a pro-oxidant and pro-inflammatory molecule contributes to progressive deterioration of organ function in diseases. Peroxisome proliferator-activated receptor γ (PPARγ), a ligand-activated transcription factor, plays crucial roles in protection against oxidative stress and inflammation. Ang II stimulation decreases PPARγ protein in multiple types of cells, while the regulatory role of Ang II on PPARγ is not clear. Here we show that Ang II down-regulated PPARγ in ECV304 cells through 2 actions, inducing nuclear export and loss of protein. The nuclear export of PPARγ occurred transiently in the early phase, while the reduction in PPARγ protein happened in the later phase and was more persistent. Both alterations in PPARγ were accompanied by the decrease in PPARγ-DNA binding activity. Reduction of PPARγ protein levels was also coupled with the inhibition of PPARγ target genes. In addition, activation of PPARγ by its ligand troglitazone could completely counteract both 2 actions of Ang II on PPARγ. Further studies demonstrated that the decline of PPARγ protein was in association with ubiquitin-proteasome-dependent degradation, which was supported by the increase in polyubiquitin-PPARγ conjugates and the inhibitory effect of lactacystin, a specific proteasome inhibitor, on the loss of PPARγ. Taken together, this study uncovers a novel means by which Ang II down-regulates PPARγ. This down-regulation disrupts nuclear PPARγ function, which may lead to the loss of beneficial effects of PPARγ in response to Ang II stress.
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Affiliation(s)
- Li Sun
- Tianjin Medical University General Hospital; Tianjin Neurological Institute; Key Laboratory of Post-trauma Neuro-repair and Regeneration in Central Nervous System, Ministry of Education and Tianjin City, Tianjin, 300052, PR China.,Murad Research Institute for Modernized Chinese Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, PR China
| | - Ka Bian
- Department of Biochemistry and Molecular Medicine, The George Washington University, Ross Hall 2300 Eye Street, NW, Washington, DC 20037, USA
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14
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De Silva TM, Li Y, Kinzenbaw DA, Sigmund CD, Faraci FM. Endothelial PPARγ (Peroxisome Proliferator-Activated Receptor-γ) Is Essential for Preventing Endothelial Dysfunction With Aging. Hypertension 2018; 72:227-234. [PMID: 29735632 DOI: 10.1161/hypertensionaha.117.10799] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2017] [Revised: 01/12/2018] [Accepted: 04/02/2018] [Indexed: 12/15/2022]
Abstract
Little is known about mechanisms that control vascular aging, particularly at the cell-specific level. PPARγ (peroxisome proliferator-activated receptor-γ) exerts protective effects in the vasculature when activated pharmacologically. To gain insight into the cell-specific impact of PPARγ, we examined the hypothesis that genetic interference with endothelial PPARγ would augment age-induced vascular dysfunction. We studied carotid arteries from adult (11.6±0.3 months) and old (24.7±0.6 months) mice with endothelial-specific expression of a human dominant negative mutation in PPARγ driven by the vascular cadherin promoter (E-V290M), along with age-matched, nontransgenic littermates. Acetylcholine (an endothelium-dependent agonist) produced similar relaxation in arteries from adult nontransgenic and E-V290M mice and old nontransgenic mice. In contrast, responses to acetylcholine were reduced by >50% in old male and female E-V290M mice (P<0.01). Endothelial function in old E-V290M mice was not altered by an inhibitor of COX (cyclooxygenase) but was restored to normal by a superoxide scavenger, an inhibitor of NADPH oxidase, or inhibition of ROCK (Rho kinase). Relaxation of arteries to nitroprusside, which acts directly on vascular muscle, was similar in all groups. Vascular expression of IL (interleukin)-6, Nox-2, and CDKN2A (a marker of senescence) was significantly increased in old E-V290M mice compared with controls (P<0.05). These findings provide the first evidence that age-related vascular dysfunction, inflammation, and senescence is accelerated after interference with endothelial PPARγ via mechanisms involving oxidative stress and ROCK. The finding of an essential protective role for endothelial PPARγ has implications for vascular disease and therapy for vascular aging.
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Affiliation(s)
- T Michael De Silva
- From the Departments of Internal Medicine (T.M.D.S., D.A.K., C.D.S., F.M.F.).,Department of Physiology, Anatomy and Microbiology (T.M.D.S.), La Trobe University, Bundoora, VIC, Australia
| | - Ying Li
- Pharmacology (Y.L., C.D.S., F.M.F.), Center for Hypertension Research, Carver College of Medicine, University of Iowa, Iowa City
| | - Dale A Kinzenbaw
- From the Departments of Internal Medicine (T.M.D.S., D.A.K., C.D.S., F.M.F.)
| | - Curt D Sigmund
- From the Departments of Internal Medicine (T.M.D.S., D.A.K., C.D.S., F.M.F.).,Pharmacology (Y.L., C.D.S., F.M.F.), Center for Hypertension Research, Carver College of Medicine, University of Iowa, Iowa City
| | - Frank M Faraci
- From the Departments of Internal Medicine (T.M.D.S., D.A.K., C.D.S., F.M.F.) .,Pharmacology (Y.L., C.D.S., F.M.F.), Center for Hypertension Research, Carver College of Medicine, University of Iowa, Iowa City.,Iowa City Veterans Affairs Healthcare System, IA (F.M.F.)
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15
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Woll AW, Quelle FW, Sigmund CD. PPARγ and retinol binding protein 7 form a regulatory hub promoting antioxidant properties of the endothelium. Physiol Genomics 2017; 49:653-658. [PMID: 28916634 DOI: 10.1152/physiolgenomics.00055.2017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Peroxisome proliferator-activated receptors (PPARs) are a family of conserved ligand-activated nuclear receptor transcription factors heterogeneously expressed in mammalian tissues. PPARγ is recognized as a master regulator of adipogenesis, fatty acid metabolism, and glucose homeostasis, but genetic evidence also supports the concept that PPARγ regulates the cardiovascular system, particularly vascular function and blood pressure. There is now compelling evidence that the beneficial blood pressure-lowering effects of PPARγ activation are due to its activity in vascular smooth muscle and endothelium, through its modulation of nitric oxide-dependent vasomotor function. Endothelial PPARγ regulates the production and bioavailability of nitric oxide, while PPARγ in the smooth muscle regulates the vasomotor response to nitric oxide. We recently identified retinol binding protein 7 (RBP7) as a PPARγ target gene that is specifically and selectively expressed in the endothelium. In this review, we will discuss the evidence that RBP7 is required to mediate the antioxidant effects of PPARγ and mediate PPARγ target gene selectivity in the endothelium.
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Affiliation(s)
- Addison W Woll
- Department of Pharmacology, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa.,Interdisciplinary Program in Molecular Medicine, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa
| | - Frederick W Quelle
- Department of Pharmacology, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa
| | - Curt D Sigmund
- Department of Pharmacology, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa; .,UIHC Center for Hypertension Research, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa; and
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