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Antabi MA, Hagler MA, Zhang H, Zhang B, Roos CM, Miller J. Abstract 413: Targeting Fundamental Mechanisms Of Aging To Attenuate Molecular Drivers Of Vascular Calcification. Arterioscler Thromb Vasc Biol 2022. [DOI: 10.1161/atvb.42.suppl_1.413] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
Abstract
Increases in vascular calcification (VC) and fibrosis are a near ubiquitous finding with aging. Here, we sought to test the hypothesis that Metformin (MET)—an AMPK activator entering large clinical trials that is thought to attenuate multimorbidity associated with aging—attenuates key molecular processes known to drive vascular calcification (VC) and fibrogenic signaling in vascular smooth muscle cells (VSMCs) in vitro. Given recent reports highlighting the importance of mitochondria and sirtuins with aging, we also tested the hypothesis that MET-driven reductions in osteogenic signaling are associated with upregulation of SIRT3. We used exogenous BMP2 (100 ng/ml) and TGFβ1 (10 ng/ml) as osteogenic and fibrogenic stimuli, respectively. Consistent with prior work from our lab, treatment with BMP2 for 24 hours robustly increased expression of the osteogenic genes Msx2 (3.9±1.5 fold-change, FC), Runx2 (3.5±1.2 FC), and osterix (17.2±5.2 FC) in VSMCs. Critically, co-treatment with Metformin dramatically reduced expression of these genes by 68 ± 22%, 58 ±20%, and 63 ± 4%, respectively. Subsequent experiments treating cells with exogenous TGFβ1 resulted in significant induction of the fibrogenic marker/known TGFβ1 target versican (1.7±0.4 FC), an effect that was largely attenuated by co-treatment with MET (58±3%). Treatment with MET did not, however, impact TGFβ1-induced increases in CTGF or fibronectin. Treatment with either BMP2 or TGFβ1 resulted in significant increases in mRNA levels of SIRT3 (2.5 ±0.11 and 1.4 ±0.17 FC, respectively), whereas treatment with MET resulted in modest and less consistent increases in SIRT3 mRNA (1.3 ± 0.2 FC). Interestingly, however, co-treatment with BMP2+MET or TGFβ1+MET resulted in uniform suppression of BMP2/ TGFβ1-induced increases in SIRT3 (54±19% and 25±12%, respectively). Collectively, these data suggest that treatment with MET may be a viable strategy to attenuate age-associated increases in osteogenic and fibrogenic signaling in conduit vessels, and suggest further in vivo investigation into therapeutic efficacy is warranted.
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Greiten LE, Zhang B, Roos CM, Hagler M, Jahns FP, Miller JD. Sirtuin 6 Protects Against Oxidative Stress and Vascular Dysfunction in Mice. Front Physiol 2021; 12:753501. [PMID: 34744793 PMCID: PMC8564013 DOI: 10.3389/fphys.2021.753501] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Accepted: 09/28/2021] [Indexed: 01/05/2023] Open
Abstract
Objective: Sirtuin deacetylases are major regulators of organismal aging, and while depletion of sirtuin 6 (SIRT6) in mice results in a profound progeroid phenotype, the role of SIRT6 in the regulation of vasomotor function is unknown. Thus, our objective was to test the hypothesis that reductions in SIRT6 elicit endothelial dysfunction in young, genetically altered mice. Results and Approach: We used young (3 month old), littermate-matched, SIRT6 wild-type (WT), and SIRT6 heterozygous (HET) mice. SIRT6 expression (qRT-PCR) was reduced by 50% in HET mice. Carotid vessel responses to acetylcholine, sodium nitroprusside, U46619, and serotonin were examined in isolated organ chamber baths. Relaxation in response to acetylcholine (ACH) was impaired in HET mice compared to littermate-matched WT controls (67 ± 3% versus 76 ± 3%, respectively; p < 0.05), while responses to sodium nitroprusside were unchanged. Short-term incubation of carotid rings with the NAD(P)H oxidase inhibitor, apocynin, significantly improved in vessels from HET mice but not their WT littermates. Peak tension generated in response to either U46619 or serotonin was significantly blunted in HET mice compared to their WT littermates. Conclusion: These data suggest that SIRT6 is a key regulator of vasomotor function in conduit vessels. More specifically, we propose that SIRT6 serves as a tonic suppressor of NAD(P)H oxidase expression and activation, as inhibition of NAD(P)H oxidase improved endothelial function in SIRT6 haploinsufficient mice. Collectively, SIRT6 activation and/or histone acetyltransferase inhibition may be useful therapeutic approaches to reduce endothelial dysfunction and combat age-associated cardiovascular disease.
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Affiliation(s)
| | - Bin Zhang
- Department of Surgery, Mayo Clinic, Rochester, MN, United States
| | - Carolyn M Roos
- Department of Surgery, Mayo Clinic, Rochester, MN, United States
| | - Michael Hagler
- Department of Surgery, Mayo Clinic, Rochester, MN, United States
| | | | - Jordan D Miller
- Department of Surgery, Mayo Clinic, Rochester, MN, United States.,Department of Biomedical Engineering and Physiology, Mayo Clinic, Rochester, MN, United States
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Holmes HL, Stiller AA, Moore CJ, Gregory AV, Roos CM, Miller JD, Gessner RC, Czernuszewicz TJ, Kline TL, Romero MF. Use of 3D Robotic Ultrasound for In Vivo Analysis of Mouse Kidneys. J Vis Exp 2021. [PMID: 34459826 DOI: 10.3791/62682] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Common modalities for in vivo imaging of rodents include positron emission tomography (PET), computed tomography (CT), magnetic resonance imaging (MRI), and ultrasound (US). Each method has limitations and advantages, including availability, ease of use, cost, size, and the use of ionizing radiation or magnetic fields. This protocol describes the use of 3D robotic US for in vivo imaging of rodent kidneys and heart, subsequent data analysis, and possible research applications. Practical applications of robotic US are the quantification of total kidney volume (TKV), as well as the measurement of cysts, tumors, and vasculature. Although the resolution is not as high as other modalities, robotic US allows for more practical high throughput data collection. Furthermore, using US M-mode imaging, cardiac function may be quantified. Since the kidneys receive 20%-25% of the cardiac output, assessing cardiac function is critical to the understanding of kidney physiology and pathophysiology.
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Affiliation(s)
| | | | | | | | | | - Jordan D Miller
- Physiology & Biomedical Engineering, Mayo Clinic; Surgery, Mayo Clinic
| | | | | | | | - Michael F Romero
- Physiology & Biomedical Engineering, Mayo Clinic; Nephrology & Hypertension, Mayo Clinic;
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Roos CM, Zhang B, Hagler MA, Verzosa GC, Huang R, Oehler EA, Arghami A, Miller JD. Effects of Altering Mitochondrial Antioxidant Capacity on Molecular and Phenotypic Drivers of Fibrocalcific Aortic Valve Stenosis. Front Cardiovasc Med 2021; 8:694881. [PMID: 34250048 PMCID: PMC8263922 DOI: 10.3389/fcvm.2021.694881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Accepted: 05/17/2021] [Indexed: 11/25/2022] Open
Abstract
Background: While a small number of studies suggest that oxidative stress has an influential role in fibrocalcific aortic valve disease (FCAVD), the roles of specific antioxidant enzymes in progression of this disease remain poorly understood. Here, we focused on selectively altering mitochondrial-derived oxidative stress—which has been shown to alter progression of a myriad of age-associated diseases—on the progression of molecular and phenotypic drivers of FCAVD. Methods: We generated low-density lipoprotein receptor-deficient, Apolipoprotein B100-only mice (LA) that were either haploinsufficient for MnSOD (LA-MnSOD+/−) or genetically overexpressing MnSOD (LA-MnSODTg/0). After 6 months of Western diet feeding, mice underwent echocardiography to assess valvular and cardiac function and tissues were harvested. Quantitative-RT PCR, immunohistochemistry, and histopathology were used to measure changes in molecular pathways related to oxidative stress, calcification, and fibrosis. Results: While reductions in MnSOD increased oxidative stress, there was not an overt phenotypic effect of MnSOD deficiency on valvular and cardiac function in LA-MnSOD+/− mice. While markers of canonical bone morphogenetic protein signaling tended to increase in valve tissue from LA-MnSOD+/− (e.g., p-SMAD1/5/8 and osterix), we did not observe statistically significant increases in osteogenic signaling. We did, however, observe highly significant reductions in expression of osteopontin, which were associated with significant increases in calcium burden in LA-MnSOD+/− mice. Reciprocally, genetically increasing MnSOD did not preserve valve function in LA-MnSODTg/0, but we did observe slight reductions in p-SMAD1/5/8 levels compared to their non-transgenic littermates. Interestingly, overexpression of MnSOD dramatically increased expression of osteopontin in valve tissue from LA-MnSODTg/0 mice, but was not sufficient to attenuate calcium burden when compared to their LA-MnSOD0/0 littermates. Conclusions: Collectively, this study demonstrates that maintenance of mitochondrial antioxidant capacity is important in preventing accelerated disease progression in a mouse model of FCAVD, but that effectively altering mitochondrial antioxidant capacity as a monotherapeutic approach to slow key histopathological and molecular drivers of FCAVD remains biologically and therapeutically challenging.
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Affiliation(s)
- Carolyn M Roos
- Department of Surgery, Mayo Clinic, Rochester, MN, United States
| | - Bin Zhang
- Department of Surgery, Mayo Clinic, Rochester, MN, United States
| | - Michael A Hagler
- Department of Surgery, Mayo Clinic, Rochester, MN, United States
| | - Grace C Verzosa
- Department of Surgery, Mayo Clinic, Rochester, MN, United States
| | - Runqing Huang
- Department of Surgery, Mayo Clinic, Rochester, MN, United States
| | - Elise A Oehler
- Department of Surgery, Mayo Clinic, Rochester, MN, United States
| | - Arman Arghami
- Department of Surgery, Mayo Clinic, Rochester, MN, United States
| | - Jordan D Miller
- Department of Surgery, Mayo Clinic, Rochester, MN, United States.,Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, MN, United States
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Roos CM, Zhang B, Hagler MA, Arghami A, Miller JD. MnSOD protects against vascular calcification independent of changes in vascular function in hypercholesterolemic mice. Atherosclerosis 2021; 331:31-37. [PMID: 34147244 DOI: 10.1016/j.atherosclerosis.2021.06.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 05/05/2021] [Accepted: 06/04/2021] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND AIMS The overall goal of this study was to determine the effects of MnSOD-deficiency on vascular structure and function in hypercholesterolemic mice. Previous work suggested that increases in mitochondrial-derived reactive oxygen species (ROS) can exacerbate vascular dysfunction and atherosclerosis. It remains unknown, however, how MnSOD-deficiency and local compensatory mechanisms impact atherosclerotic plaque composition. METHODS AND RESULTS We used a hypercholesterolemic mouse model (ldlr-/-/ApoB100/100; LA), either wild-type for MnSOD (LA-MnSOD+/+) or MnSOD-haploinsufficient (LA-MnSOD+/-), that was fed a western diet for either 3 or 6 months. Consistent with previous reports, reductions of MnSOD did not significantly worsen hypercholesterolemia-induced endothelial dysfunction in the aorta. Critically, dramatic impairment of vascular function with Nox2 inhibition or catalase pretreatment suggested the presence of a significant NO-independent vasodilatory mechanism in LA-MnSOD+/- mice (e.g. H2O2). Despite remarkably well-preserved overall vascular relaxation, loss of mitochondrial antioxidant capacity in LA-MnSOD+/- mice significantly increased osteogenic signalling and vascular calcification compared to the LA-MnSOD+/+ littermates. CONCLUSIONS Collectively, these data are the first to suggest that loss of mitochondrial antioxidant capacity in hypercholesterolemic mice results in dramatic upregulation of NADPH oxidase-derived H2O2. While this appears to be adaptive in the context of preserving overall endothelium-dependent relaxation and vascular function, these increases in ROS appear to be remarkably maladaptive and deleterious in the context of vascular calcification.
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Affiliation(s)
| | - Bin Zhang
- Departments of Surgery, Mayo Clinic, Rochester, MN, USA
| | | | - Arman Arghami
- Departments of Surgery, Mayo Clinic, Rochester, MN, USA
| | - Jordan D Miller
- Departments of Surgery, Mayo Clinic, Rochester, MN, USA; Physiology & Biomedical Engineering, Mayo Clinic, Rochester, MN, USA.
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Liu B, Zhang B, Roos CM, Zeng W, Zhang H, Guo R. Upregulation of Orai1 and increased calcium entry contribute to angiotensin II-induced human coronary smooth muscle cell proliferation: Running Title: Angiotensin II-induced human coronary smooth muscle cells proliferation. Peptides 2020; 133:170386. [PMID: 32827590 DOI: 10.1016/j.peptides.2020.170386] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 08/18/2020] [Accepted: 08/18/2020] [Indexed: 12/12/2022]
Abstract
Angiotensin II (Ang II) is an oligopeptide of the renin-angiotensin system, and Ang II-induced vascular smooth muscle cell (VSMC) proliferation is an important pathophysiological process involved in atherosclerosis; however, the underlying mechanism remains unclear. Orai1 and Stim1 are the main components of store-operated Ca2+ entry (SOCE), which has an important effect on VSMC proliferation. In the present study, we showed that Ang II-induced human coronary smooth muscle cell (HCSMC) proliferation was associated with increased calcium entry. The expression of Orai1, but not that of Stim1, was significantly upregulated in Ang II-treated HCSMCs. However, knockdown of Orai1 or Stim1 decreased HCSMC proliferation and SOCE activity in Ang II-treated HCSMCs. Orai1 was significantly downregulated in HCSMCs transfected with short interfering RNA (siRNA) against NOX2 or NF-κB. Transfection with siRNA against NOX2 or p65 also decreased Ang II-induced HCSMCs SOCE activation and proliferation. These findings suggested that Ang II upregulated Orai1 via the NF-κB and NOX2 pathways, leading to increased SOCE and HCSMC proliferation. The molecular factors mediating Ang II-induced SOCE upregulation are potential therapeutic targets for the prevention of Ang II-sensitive or Ang II-dependent HCSMC proliferation.
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Affiliation(s)
- Bei Liu
- Department of Cardiology, 920th Hospital of the PLA Joint Logistics Support Force, Kunming, Yunnan, 650032, China
| | - Bin Zhang
- Division of Cardiovascular Surgery, Mayo Clinic, 200 First St. SW, Rochester, MN 55905, USA
| | - Carolyn M Roos
- Division of Cardiovascular Surgery, Mayo Clinic, 200 First St. SW, Rochester, MN 55905, USA
| | - Wenjun Zeng
- Department of Cardiology, 920th Hospital of the PLA Joint Logistics Support Force, Kunming, Yunnan, 650032, China
| | - Haiping Zhang
- Department of Cardiology, 920th Hospital of the PLA Joint Logistics Support Force, Kunming, Yunnan, 650032, China
| | - Ruiwei Guo
- Department of Cardiology, 920th Hospital of the PLA Joint Logistics Support Force, Kunming, Yunnan, 650032, China.
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Anderson R, Lagnado A, Maggiorani D, Walaszczyk A, Dookun E, Chapman J, Birch J, Salmonowicz H, Ogrodnik M, Jurk D, Proctor C, Correia-Melo C, Victorelli S, Fielder E, Berlinguer-Palmini R, Owens A, Greaves LC, Kolsky KL, Parini A, Douin-Echinard V, LeBrasseur NK, Arthur HM, Tual-Chalot S, Schafer MJ, Roos CM, Miller JD, Robertson N, Mann J, Adams PD, Tchkonia T, Kirkland JL, Mialet-Perez J, Richardson GD, Passos JF. Length-independent telomere damage drives post-mitotic cardiomyocyte senescence. EMBO J 2019; 38:embj.2018100492. [PMID: 30737259 PMCID: PMC6396144 DOI: 10.15252/embj.2018100492] [Citation(s) in RCA: 265] [Impact Index Per Article: 53.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Revised: 12/18/2018] [Accepted: 01/02/2019] [Indexed: 01/08/2023] Open
Abstract
Ageing is the biggest risk factor for cardiovascular disease. Cellular senescence, a process driven in part by telomere shortening, has been implicated in age‐related tissue dysfunction. Here, we address the question of how senescence is induced in rarely dividing/post‐mitotic cardiomyocytes and investigate whether clearance of senescent cells attenuates age‐related cardiac dysfunction. During ageing, human and murine cardiomyocytes acquire a senescent‐like phenotype characterised by persistent DNA damage at telomere regions that can be driven by mitochondrial dysfunction and crucially can occur independently of cell division and telomere length. Length‐independent telomere damage in cardiomyocytes activates the classical senescence‐inducing pathways, p21CIP and p16INK4a, and results in a non‐canonical senescence‐associated secretory phenotype, which is pro‐fibrotic and pro‐hypertrophic. Pharmacological or genetic clearance of senescent cells in mice alleviates detrimental features of cardiac ageing, including myocardial hypertrophy and fibrosis. Our data describe a mechanism by which senescence can occur and contribute to age‐related myocardial dysfunction and in the wider setting to ageing in post‐mitotic tissues.
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Affiliation(s)
- Rhys Anderson
- Ageing Research Laboratories, Institute for Ageing, Newcastle University, Newcastle upon Tyne, UK.,Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, UK
| | - Anthony Lagnado
- Ageing Research Laboratories, Institute for Ageing, Newcastle University, Newcastle upon Tyne, UK.,Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, UK
| | - Damien Maggiorani
- INSERM Institute of metabolic and cardiovascular diseases, University of Toulouse, Toulouse, France
| | - Anna Walaszczyk
- Cardiovascular Research Centre, Institute for Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK
| | - Emily Dookun
- Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, UK.,Cardiovascular Research Centre, Institute for Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK
| | - James Chapman
- Ageing Research Laboratories, Institute for Ageing, Newcastle University, Newcastle upon Tyne, UK.,Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, UK
| | - Jodie Birch
- Ageing Research Laboratories, Institute for Ageing, Newcastle University, Newcastle upon Tyne, UK.,Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, UK
| | - Hanna Salmonowicz
- Ageing Research Laboratories, Institute for Ageing, Newcastle University, Newcastle upon Tyne, UK.,Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, UK
| | - Mikolaj Ogrodnik
- Ageing Research Laboratories, Institute for Ageing, Newcastle University, Newcastle upon Tyne, UK.,Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, UK
| | - Diana Jurk
- Ageing Research Laboratories, Institute for Ageing, Newcastle University, Newcastle upon Tyne, UK.,Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, UK.,Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, MN, USA
| | - Carole Proctor
- Ageing Research Laboratories, Institute for Ageing, Newcastle University, Newcastle upon Tyne, UK.,Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, UK
| | - Clara Correia-Melo
- Ageing Research Laboratories, Institute for Ageing, Newcastle University, Newcastle upon Tyne, UK.,Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, UK
| | - Stella Victorelli
- Ageing Research Laboratories, Institute for Ageing, Newcastle University, Newcastle upon Tyne, UK.,Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, UK
| | - Edward Fielder
- Ageing Research Laboratories, Institute for Ageing, Newcastle University, Newcastle upon Tyne, UK.,Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, UK
| | | | - Andrew Owens
- Cardiovascular Research Centre, Institute for Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK
| | - Laura C Greaves
- Wellcome Trust Centre for Mitochondrial Research, Centre for Ageing and Vitality, Newcastle University, Newcastle upon Tyne, UK
| | - Kathy L Kolsky
- Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, MN, USA
| | - Angelo Parini
- INSERM Institute of metabolic and cardiovascular diseases, University of Toulouse, Toulouse, France
| | - Victorine Douin-Echinard
- INSERM Institute of metabolic and cardiovascular diseases, University of Toulouse, Toulouse, France
| | | | - Helen M Arthur
- Cardiovascular Research Centre, Institute for Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK
| | - Simon Tual-Chalot
- Cardiovascular Research Centre, Institute for Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK
| | - Marissa J Schafer
- Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, MN, USA
| | - Carolyn M Roos
- Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, MN, USA
| | - Jordan D Miller
- Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, MN, USA
| | - Neil Robertson
- Institute of Cancer Sciences, CR-UK Beatson Institute, University of Glasgow, Glasgow, UK
| | - Jelena Mann
- Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, UK
| | - Peter D Adams
- Institute of Cancer Sciences, CR-UK Beatson Institute, University of Glasgow, Glasgow, UK.,Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA
| | - Tamara Tchkonia
- Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, MN, USA
| | - James L Kirkland
- Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, MN, USA
| | - Jeanne Mialet-Perez
- INSERM Institute of metabolic and cardiovascular diseases, University of Toulouse, Toulouse, France
| | - Gavin D Richardson
- Cardiovascular Research Centre, Institute for Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK
| | - João F Passos
- Ageing Research Laboratories, Institute for Ageing, Newcastle University, Newcastle upon Tyne, UK .,Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, UK.,Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, MN, USA
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Roos CM, Hagler MA, Zhang B, Fujimoto H, Miller JD. Organismal Sex is a Major Determinant of Phenotypic and Molecular Changes Caused by Genetic Inactivation of the Mitochondria‐specific Deacetylase SIRT3. FASEB J 2018. [DOI: 10.1096/fasebj.2018.32.1_supplement.618.17] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | | | | | | | - Jordan D. Miller
- SurgeryMayo ClinicRochesterMN
- Physiology & Biomedical EngineeringMayo ClinicRochesterMN
- Kogod Center on AgingMayo ClinicRochesterMN
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Roos BB, Roos CM, Hagler MA, Zhang B, Miller JD. Paradoxical Effects of Overexpressing Human Catalase on Vascular Function and Atherosclerotic Plaque Composition in Hypercholesterolemic Mice. FASEB J 2018. [DOI: 10.1096/fasebj.2018.32.1_supplement.lb303] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | | | | | | | - Jordan D Miller
- SurgeryMayo ClinicRochesterMN
- Physiology & Biomedical EngineeringMayo ClinicRochesterMN
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Brown AK, Mazula DL, Zhang B, Roos CM, White TA, Miller RA, Miller JD, LeBrasseur NK. Physical Resilience as a Determinant of Healthy Aging. FASEB J 2018. [DOI: 10.1096/fasebj.2018.32.1_supplement.674.7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Liu B, Zhang B, Huang S, Yang L, Roos CM, Thompson MA, Prakash YS, Zang J, Miller JD, Guo R. Ca 2+ Entry Through Reverse Mode Na +/Ca 2+ Exchanger Contributes to Store Operated Channel-Mediated Neointima Formation After Arterial Injury. Can J Cardiol 2018; 34:791-799. [PMID: 29705161 DOI: 10.1016/j.cjca.2018.01.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Revised: 01/16/2018] [Accepted: 01/16/2018] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND Na+/Ca2+ exchange (NCX) reversal-mediated Ca2+ entry is a critical pathway for stimulating proliferation in many cell lines. However, the role of reverse-mode NCX1 in neointima formation and atherosclerosis remains unclear. The aims of the present study were to investigate the functional role of NCX1 in the pathogenesis of atherosclerosis and vascular smooth muscle cell (VSMC) proliferation, and to determine the interaction between NCX1 and store depletion in VSMCs. METHODS A rat balloon injury model was established to examine the effect of the knockdown of NCX1 on neointima formation after injury. VSMCs were cultured to verify that NCX1 knockdown suppressed serum-induced VSMC proliferation. RESULTS The results showed that balloon injury induced neointima formation and upregulated NCX1 expression at 7 and 14 days after injury in rat carotid arteries (1.18- and 1.45-fold, respectively). A lentivirus vector expressing short hairpin (sh)RNA against rat NCX1 dramatically downregulated NCX1, proliferating cell nuclear antigen (PCNA) and Ki-67 expression, and suppressed neointima formation in vivo (62% at 7 days and 70% at 14 days). KB-R7943 (an inhibitor of reverse-mode NCX1) and NCX1 knockdown significantly inhibited serum-induced VSMC proliferation (65% at 72 hours and 41% at 72 hours, respectively), determined according to PCNA and Ki-67 expression and cell counting in vitro, and markedly suppressed store depletion-mediated Ca2+ entry and peripheral cytosolic Na+ transients in VSMCs. CONCLUSIONS Reverse-mode NCX1 is activated by store depletion and is required for proliferative VSMC proliferation and neointima formation after arterial injury.
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Affiliation(s)
- Bei Liu
- Department of Obstetrics and Gynecology, Kunming General Hospital, Kunming, Yunnan, China
| | - Bin Zhang
- Division of Cardiovascular Surgery, and Department of Physiology, Mayo Clinic, Rochester, Minnesota, USA
| | - Shiliang Huang
- Department of Cardiology, Kunming General Hospital, Kunming, Yunnan, China
| | - Lixia Yang
- Department of Cardiology, Kunming General Hospital, Kunming, Yunnan, China
| | - Carolyn M Roos
- Division of Cardiovascular Surgery, and Department of Physiology, Mayo Clinic, Rochester, Minnesota, USA
| | | | - Y S Prakash
- Department of Anesthesiology, Mayo Clinic, Rochester, Minnesota, USA
| | - Jie Zang
- Musculoskeletal Tumor Center, Peking University People's Hospital, Peking, China
| | - Jordan D Miller
- Division of Cardiovascular Surgery, and Department of Physiology, Mayo Clinic, Rochester, Minnesota, USA.
| | - Ruiwei Guo
- Department of Cardiology, Kunming General Hospital, Kunming, Yunnan, China.
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Zhang B, Liu B, Roos CM, Thompson MA, Prakash YS, Miller JD, Guo RW. TRPC6 and TRPC4 Heteromultimerization Mediates Store Depletion-Activated NCX1 Reversal in Proliferative Vascular Smooth Muscle Cells. Channels (Austin) 2018; 12:119-125. [PMID: 29560783 PMCID: PMC5972809 DOI: 10.1080/19336950.2018.1451696] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Store depletion has been shown to induce Ca2+ entry by Na+/Ca+ exchange (NCX) 1 reversal in proliferative vascular smooth muscle cells (VSMCs). The study objective was to investigate the role of transient receptor potential canonical (TRPC) channels in store depletion and NCX1 reversal in proliferative VSMCs. In cultured VSMCs, expressing TRPC1, TRPC4, and TRPC6, the removal of extracellular Na+ was followed by a significant increase of cytosolic Ca2+ concentration that was inhibited by KBR, a selective NCX1 inhibitor. TRPC1 knockdown significantly suppressed store-operated, channel-mediated Ca2+ entry, but TRPC4 knockdown and TRPC6 knockdown had no effect. Separate knockdown of TRPC1, TRPC4, or TRPC6 did not have a significant effect on thapsigargin-initiated Na+ increase in the peripheral regions with KBR treatment, but knockdown of both TRPC4 and TRPC6 did. Stromal interaction molecule (STIM)1 knockdown significantly reduced TRPC4 and TRPC6 binding. The results demonstrated that TRPC4–TRPC6 heteromultimerization linked Ca2+ store depletion and STIM1 accumulation with NCX reversal in proliferative VSMCs.
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Affiliation(s)
- Bin Zhang
- a Division of Cardiovascular Surgery, Mayo Clinic, Rochester, MN, USA; and Department of Physiology , Mayo Clinic , Rochester , MN , USA
| | - Bei Liu
- b Department of Obstetrics and Gynecology , Kunming General Hospital of Chengdu Military Command , Kunming , Yunnan , China
| | - Carolyn M Roos
- a Division of Cardiovascular Surgery, Mayo Clinic, Rochester, MN, USA; and Department of Physiology , Mayo Clinic , Rochester , MN , USA
| | - Michael A Thompson
- c Department of Anesthesiology , Mayo Clinic , Rochester , Minnesota , USA
| | - Y S Prakash
- c Department of Anesthesiology , Mayo Clinic , Rochester , Minnesota , USA
| | - Jordan D Miller
- a Division of Cardiovascular Surgery, Mayo Clinic, Rochester, MN, USA; and Department of Physiology , Mayo Clinic , Rochester , MN , USA
| | - Rui-Wei Guo
- d Department of Cardiology , Kunming General Hospital of Chengdu Military Command , Kunming , Yunnan , China
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13
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Roos CM, Hagler MA, Verzosa GC, Zhang B, Fujimoto H, Miller JD. Abstract 427: Histopathological and Molecular Effects of SIRT3 Deletion in Advanced Calcific Aortic Valve Disease. Arterioscler Thromb Vasc Biol 2017. [DOI: 10.1161/atvb.37.suppl_1.427] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Increasing age is the greatest risk factor for development and progression of calcific aortic valve disease (CAVD), and mitochondrial dysfunction has been implicated in the pathogenesis of cardiovascular calcification. Previous findings by our group suggested a significant reduction in expression of multiple sirtuin (SIRT) isoforms in normocholesterolemic aged mouse aortic valves, however, it is unclear if losses in SIRT3—a major mitochondrial SIRT isoform—modulates progression of aortic valve calcification. Therefore, we hypothesized that loss of SIRT3 in a hypercholesterolemic mouse model of CAVD will result in augmented calcium burden in aortic valve, increased osteogenic signaling, and impaired aortic valve function. To test this we used mice that were Ldlr
-/-
/ApoB
100/100
mice that were either wild-type (LA-SIRT3
+/+
) or null for SIRT3 (LA-SIRT3
-/-
) and fed a western diet (TD88137) for 12 months. Alizarin red was used to quantitate calcium burden, qRT-PCR was used to measure changes in mRNA levels, and high-resolution echocardiography was used to assess aortic valve function (cusp separation distance). In line with our hypothesis, we observed a substantial increase in calcium burden in LA-SIRT3
-/-
mice compared to their LA-SIRT3
+/+
littermates(11.7±4.0, 4.8±1.8; respectively). Interestingly, expression of Runx2 and osterix—classic markers of osteogenic differentiation—were decreased in LA-SIRT3
-/-
mice compared to their LA-SIRT3
+/+
littermates. Expression of Msx2, were markedly increased in aortic valve tissue from LA-SIRT3-deficient mice. Despite these histological and molecular changes, SIRT3 deletion did not alter cusp separation distance (LA-SIRT3
+/+
= 0.81±0.04; LA-SIRT3
-/-
= 0.81±0.02). Collectively, this data suggest losses in SIRT3 can contribute to accelerated valve calcification through unclear molecular mechanisms, but these changes are not sufficient to drive reductions in cusp separation distance. Additional experiments delineating the histopathological and molecular sequelae of SIRT3 deletion will be critical to understanding its role in the pathogenesis of CAVD.
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14
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Black RL, Roos CM, Hagler MA, Thalji NM, Zhang B, Verzosa GC, Miller JD. Abstract 249: Potential Tissue-specific Interactions Between Inflammation and Canonical Tgfβ Signaling in Marfan Syndrome. Arterioscler Thromb Vasc Biol 2017. [DOI: 10.1161/atvb.37.suppl_1.249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Marfan syndrome is a connective tissue disorder frequently driven by mutations in the fibrillin-1 gene (Fbn1). This results in multiple aberrant cardiovascular phenotypes, including aortic aneurysm and mitral valve prolapse. While the molecular changes underlying aortic aneurysm formation have been extensively studied, the molecular underpinnings of mitral valve prolapse in this syndrome remain poorly understood. Therefore, we hypothesized that smad2/3 phosphorylation would be significantly increased in both aorta and mitral valve from Fbn1
+/1037G
mice with Marfan syndrome and associated with impaired anti-inflammatory signaling in both tissues. We used young (3 months) mice that were wild-type (Fbn1
+/+
) or fibrillin-1 mutant (Fbn1
+/1037G
) and fed a normal chow diet. qRT-PCR was used to measure mRNA levels in aortic arch and mitral valve tissue, and fluorescent immunohistochemistry to evaluate changes in canonical TGFβ signaling. Consistent with previous reports, TGF-β1 mRNA levels were increased in Fbn1
+/1037G
compared to wild-type mice in both aorta and mitral valve. Interestingly, while p-SMAD2/3 protein levels were increased in aorta from Fbn1
+/1037G
mice, we were surprised to find that p-SMAD2/3 protein levels were decreased in mitral valve from Fbn1
+/1037G
mice compared their wild-type littermates. Given the emerging role of inflammatory signaling in accelerated development of Marfan phenotypes, we sought to determine whether there were compensatory or maladaptive changes in IL10 (a known inhibitor of p-SMAD2/3). In aorta, IL10 mRNA levels were decreased in Fbn1
+/1037G
compared to Fbn1
+/+
mice, suggesting a maladaptive response. In contrast, IL10 levels in mitral valve tissue were significantly increased in Fbn1
+/1037G
mice compared to their wild-type littermates, suggesting a compensatory/protective response. Collectively, these data suggest that tissue-specific changes in IL10 levels may modulate p-SMAD2/3 signaling in aorta and mitral valve, which may be a key permissive step in the onset of Marfan-related phenotypes. Future work to experimentally determine the role of IL10 in the regulation of canonical and non-canonical TGFβ signaling and the penetrance of Marfan-associated phenotypes is warranted.
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15
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Jbeli AH, Zhang B, Roos CM, Miller JD. Abstract 634: Partial Genetic Disruption of mTOR Signaling Does Not Improve Vascular Endothelial Function in Hypercholesterolemic Mice. Arterioscler Thromb Vasc Biol 2017. [DOI: 10.1161/atvb.37.suppl_1.634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Endothelial cell senescence promotes inflammation and impairs endothelium-dependent vasodilation. While aging, hypercholesterolemia, and caloric excess are known to drive cellular senescence in part through activation of mTOR, it is unknown whether reducing mTOR signaling can improve vasomotor function in aging mice. Here, we used hypercholesterolemic mice (Ldlr
-/-
/apoB
100/100
, or LA) carrying intact copies of mTOR (LA-mTOR
+/+
) or were deficient in one copy of mTOR (LA- mTOR
+/-
). Mice were fed Western Diet for 6 or 12 months, and vasomotor function in aorta was evaluated using isolated organ chamber baths. Maximum relaxation to acetylcholine (MR
ACH
) was progressively impaired from 6 months to 12 months in LA-mTOR
+/+
mice (55±4% and 30±4%, respectively). In contrast to our hypothesis, however, MR
ACH
was not significantly improved in LA-mTOR
+/-
mice at either time point (62±3% and 35±5%, respectively). Interestingly, a subgroup analysis showed significant improvement in MR
ACH
in male mice at the 6-month point (male LA-mTOR
+/+
mice = 30 ± 9% vs male LA-mTOR
+/-
mice = 55±4%; p < 0.01), whereas vasomotor function in female mice was nearly identical across groups. There was no significant difference at the 12-month point (male LA-mTOR
+/+
mice = 19 ± 3% vs male LA-mTOR
+/-
mice = 22 ± 5%). Relaxation to acetylcholine was attenuated by L-NAME at 6 months and 12 months (but identical between genotypes) and relaxation to nitroprusside was identical between strains at each time point, suggesting that changes in endothelial function were not masked by compensatory mechanisms (e.g., endothelium-derived hyperpolarizing factors). Furthermore, reduction of mTOR did not elicit changes in maximal tension generated in response to Prostaglandin F
2
α
at either time point. Collectively, despite compelling evidence from in vitro model systems, genetic reduction of mTOR signaling
in vivo
does not appear to be sufficient to improve vasomotor function in our model of aging hypercholesterolemic mice. Our data do, however, shed light on a potential role of sex in dictating phenotypic changes in early to moderate stages of disease, which warrants further investigation.
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Affiliation(s)
- Aiham H Jbeli
- Sanford Sch of Medicine - Univ of South Dakota, Sioux Falls, SD
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16
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Roos CM, Zhang B, Palmer AK, Ogrodnik MB, Pirtskhalava T, Thalji NM, Hagler M, Jurk D, Smith LA, Casaclang‐Verzosa G, Zhu Y, Schafer MJ, Tchkonia T, Kirkland JL, Miller JD. Chronic senolytic treatment alleviates established vasomotor dysfunction in aged or atherosclerotic mice. Aging Cell 2016; 15:973-7. [PMID: 26864908 PMCID: PMC5013022 DOI: 10.1111/acel.12458] [Citation(s) in RCA: 468] [Impact Index Per Article: 58.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/03/2016] [Indexed: 12/19/2022] Open
Abstract
While reports suggest a single dose of senolytics may improve vasomotor function, the structural and functional impact of long‐term senolytic treatment is unknown. To determine whether long‐term senolytic treatment improves vasomotor function, vascular stiffness, and intimal plaque size and composition in aged or hypercholesterolemic mice with established disease. Senolytic treatment (intermittent treatment with Dasatinib + Quercetin via oral gavage) resulted in significant reductions in senescent cell markers (TAF+ cells) in the medial layer of aorta from aged and hypercholesterolemic mice, but not in intimal atherosclerotic plaques. While senolytic treatment significantly improved vasomotor function (isolated organ chamber baths) in both groups of mice, this was due to increases in nitric oxide bioavailability in aged mice and increases in sensitivity to NO donors in hypercholesterolemic mice. Genetic clearance of senescent cells in aged normocholesterolemic INK‐ATTAC mice phenocopied changes elicited by D+Q. Senolytics tended to reduce aortic calcification (alizarin red) and osteogenic signaling (qRT–PCR, immunohistochemistry) in aged mice, but both were significantly reduced by senolytic treatment in hypercholesterolemic mice. Intimal plaque fibrosis (picrosirius red) was not changed appreciably by chronic senolytic treatment. This is the first study to demonstrate that chronic clearance of senescent cells improves established vascular phenotypes associated with aging and chronic hypercholesterolemia, and may be a viable therapeutic intervention to reduce morbidity and mortality from cardiovascular diseases.
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Affiliation(s)
| | - Bin Zhang
- Department of Surgery Mayo Clinic Rochester MN USA
| | | | - Mikolaj B. Ogrodnik
- Kogod Center on Aging Mayo Clinic Rochester MN USA
- Newcastle University Institute for Aging Newcastle University Newcastle Upon Tyne UK
| | | | | | | | - Diana Jurk
- Newcastle University Institute for Aging Newcastle University Newcastle Upon Tyne UK
| | | | | | - Yi Zhu
- Kogod Center on Aging Mayo Clinic Rochester MN USA
| | | | | | - James L. Kirkland
- Kogod Center on Aging Mayo Clinic Rochester MN USA
- Department of Physiology & Biomedical Engineering Mayo Clinic Rochester MN USA
| | - Jordan D. Miller
- Department of Surgery Mayo Clinic Rochester MN USA
- Kogod Center on Aging Mayo Clinic Rochester MN USA
- Department of Physiology & Biomedical Engineering Mayo Clinic Rochester MN USA
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17
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Roos CM, Smith LA, Zhang B, Ribeiro MS, Miller JD. Abstract 259: Genetic Inactivation of Sirt3 Does Not Alter Endothelial Function or Vascular Compliance in Hypercholesterolemic Mice. Arterioscler Thromb Vasc Biol 2016. [DOI: 10.1161/atvb.36.suppl_1.259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Endothelial dysfunction and arterial stiffening major risk factors associated with progression of atherosclerosis and increased risk of acute coronary events. Recent data suggest sirtuins may play a role in protecting against a variety age-related diseases, and we recently reported that sirtuins are reduced in the aging vasculature. The roles of SIRT3 (a deacetylase that is largely restricted to the mitochondria) in the regulation of vasomotor function and arterial stiffness, however, remains poorly understood. Therefore, we hypothesized that genetic inactivation of SIRT3 in hypercholesterolemic mice will impair endothelial function and reduce vascular compliance compared to hypercholesterolemic mice with normal levels of SIRT3. We used Ldlr
-/-
/ApoB
100/100
(LA) mice that were either wild-type for SIRT3 (LA-SIRT3
+/+
) or null for SIRT3 (LA-SIRT3
-/-
) and fed a western diet for 12 months. At time of sacrifice, aorta was removed for isolated organ chamber baths to measure changes in endothelium-dependent relaxation to acetylcholine (ACH), and carotid arteries were harvested to assess changes in vascular compliance using a pressurized cannulation system. Surprisingly, losses of SIRT3 did not impair relaxation to ACH in aorta compared to LA-SIRT3
+/+
mice (38.2±4.4%, 37.0±4.4%, respectively). Furthermore, reductions in SIRT3 did not impact vascular compliance or distensibility in carotid arteries from the same animals. In conclusion, in contrast to our hypothesis, inactivation of SIRT3 does not impact vasomotor function or conduit vessel compliance in advanced atherosclerosis. Importantly, this and may be explained by a “floor-effect”, and future work examining the effect of SIRT3 overexpression on vascular function and pathology will be instrumental in determining its biological role and ultimate therapeutic utility.
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Affiliation(s)
| | | | | | | | - Jordan D Miller
- Surgery and Biomedical Engineering & Physiology, Mayo Clinic, Rochester, MN
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18
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Fermoyle CC, Roos CM, Casaclang-Verzosa G, Zhang B, Miller JD. Abstract 582: Overexpression of Catalase Impairs Aortic Valve Function and Accelerates Valvular Calification in Mice. Arterioscler Thromb Vasc Biol 2016. [DOI: 10.1161/atvb.36.suppl_1.582] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Previous studies have reported increases in oxidative stress due to reductions in antioxidant enzymes in calcified regions of stenotic human aortic valves. Whether reductions in antioxidant enzymes are adaptive, maladaptive, or an epiphenomenon in calcifying aortic valves remains unclear. Thus, the purpose of this study was to test whether overexpression of catalase reduces valvular calcification and slows progression of aortic valve stenosis in mice. Wild type (WT) mice with calcific aortic valve disease (ldlr-deficient, apoB100-only) were crossed with transgenic mice that overexpress human catalase (TG). All mice were fed a western diet (TD88137; Harlan Teklad). Functional echocardiogram data was collected and analyzed at early (3 months) and advanced (12 months) stages of valve disease, and valves were OCT embedded, sectioned, and stained for calcium levels (Alizarin Red). The transgenic valves show a slight increase in calcification compared to wild type counterparts. While there were no differences in valve function between genotypes at the early time point, cusp separation was decreased in the transgenic mice (0.74 ± 0.02 mm) compared to their wild-type littermates (0.84 ± 0.03 mm) at the 12 month time point (p < 0.05). In a subset of animals, valve calcification also tended to increase in transgenic mice at both time points compared to their wild-type littermates. In conclusion, overexpression of catalase resulted in a surprising finding of accelerated valvular calcification and stenosis. Interestingly, this finding aligns with the findings from several negative clinical trials testing antioxidant therapies in humans with atherosclerosis, suggests that the net impact of changing redox balance on disease progression are highly context dependent, and that increasing antioxidant capacity may not be a viable strategy to slow progression of calcific aortic valve disease in humans.
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Affiliation(s)
| | | | | | - Bin Zhang
- Dept of Surgery, Mayo Clinic, Rochester, MN
| | - Jordan D Miller
- Dept of Physiology & Biomedical Engineering, Dept of Surgery, Mayo Clinic, Rochester, MN
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19
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Zhu Y, Tchkonia T, Pirtskhalava T, Gower AC, Ding H, Giorgadze N, Palmer AK, Ikeno Y, Hubbard GB, Lenburg M, O'Hara SP, LaRusso NF, Miller JD, Roos CM, Verzosa GC, LeBrasseur NK, Wren JD, Farr JN, Khosla S, Stout MB, McGowan SJ, Fuhrmann‐Stroissnigg H, Gurkar AU, Zhao J, Colangelo D, Dorronsoro A, Ling YY, Barghouthy AS, Navarro DC, Sano T, Robbins PD, Niedernhofer LJ, Kirkland JL. The Achilles' heel of senescent cells: from transcriptome to senolytic drugs. Aging Cell 2015; 14:644-58. [PMID: 25754370 PMCID: PMC4531078 DOI: 10.1111/acel.12344] [Citation(s) in RCA: 1386] [Impact Index Per Article: 154.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The healthspan of mice is enhanced by killing senescent cells using a transgenic suicide gene. Achieving the same using small molecules would have a tremendous impact on quality of life and the burden of age-related chronic diseases. Here, we describe the rationale for identification and validation of a new class of drugs termed senolytics, which selectively kill senescent cells. By transcript analysis, we discovered increased expression of pro-survival networks in senescent cells, consistent with their established resistance to apoptosis. Using siRNA to silence expression of key nodes of this network, including ephrins (EFNB1 or 3), PI3Kδ, p21, BCL-xL, or plasminogen-activated inhibitor-2, killed senescent cells, but not proliferating or quiescent, differentiated cells. Drugs targeting these same factors selectively killed senescent cells. Dasatinib eliminated senescent human fat cell progenitors, while quercetin was more effective against senescent human endothelial cells and mouse BM-MSCs. The combination of dasatinib and quercetin was effective in eliminating senescent MEFs. In vivo, this combination reduced senescent cell burden in chronologically aged, radiation-exposed, and progeroid Ercc1−/Δ mice. In old mice, cardiac function and carotid vascular reactivity were improved 5 days after a single dose. Following irradiation of one limb in mice, a single dose led to improved exercise capacity for at least 7 months following drug treatment. Periodic drug administration extended healthspan in Ercc1−/Δ mice, delaying age-related symptoms and pathology, osteoporosis, and loss of intervertebral disk proteoglycans. These results demonstrate the feasibility of selectively ablating senescent cells and the efficacy of senolytics for alleviating symptoms of frailty and extending healthspan.
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Affiliation(s)
- Yi Zhu
- Robert and Arlene Kogod Center on Aging Mayo Clinic Rochester MN USA
| | - Tamara Tchkonia
- Robert and Arlene Kogod Center on Aging Mayo Clinic Rochester MN USA
| | | | - Adam C. Gower
- Section of Computational Biomedicine Boston University School of Medicine Boston MA USA
| | - Husheng Ding
- Robert and Arlene Kogod Center on Aging Mayo Clinic Rochester MN USA
| | - Nino Giorgadze
- Robert and Arlene Kogod Center on Aging Mayo Clinic Rochester MN USA
| | - Allyson K. Palmer
- Robert and Arlene Kogod Center on Aging Mayo Clinic Rochester MN USA
| | - Yuji Ikeno
- Departments of Pathology Barshop Institute for Longevity and Aging Studies The University of Texas Health Science Center San Antonio TX USA
- Research Service Geriatric Research and Education Clinical Center Audie L. Murphy VA Hospital South Texas Veterans Health Care System San Antonio TX USA
| | - Gene B. Hubbard
- Departments of Pathology Barshop Institute for Longevity and Aging Studies The University of Texas Health Science Center San Antonio TX USA
- Research Service Geriatric Research and Education Clinical Center Audie L. Murphy VA Hospital South Texas Veterans Health Care System San Antonio TX USA
| | - Marc Lenburg
- Section of Computational Biomedicine Boston University School of Medicine Boston MA USA
| | - Steven P. O'Hara
- Robert and Arlene Kogod Center on Aging Mayo Clinic Rochester MN USA
| | | | - Jordan D. Miller
- Robert and Arlene Kogod Center on Aging Mayo Clinic Rochester MN USA
| | - Carolyn M. Roos
- Robert and Arlene Kogod Center on Aging Mayo Clinic Rochester MN USA
| | - Grace C. Verzosa
- Robert and Arlene Kogod Center on Aging Mayo Clinic Rochester MN USA
| | | | - Jonathan D. Wren
- Department of Biochemistry and Molecular Biology Oklahoma Medical Research Foundation Oklahoma City OK USA
| | - Joshua N. Farr
- Robert and Arlene Kogod Center on Aging Mayo Clinic Rochester MN USA
| | - Sundeep Khosla
- Robert and Arlene Kogod Center on Aging Mayo Clinic Rochester MN USA
| | - Michael B. Stout
- Robert and Arlene Kogod Center on Aging Mayo Clinic Rochester MN USA
| | - Sara J. McGowan
- Department of Metabolism and Aging The Scripps Research Institute Jupiter FL USA
| | | | - Aditi U. Gurkar
- Department of Metabolism and Aging The Scripps Research Institute Jupiter FL USA
| | - Jing Zhao
- Department of Metabolism and Aging The Scripps Research Institute Jupiter FL USA
| | - Debora Colangelo
- Department of Metabolism and Aging The Scripps Research Institute Jupiter FL USA
| | - Akaitz Dorronsoro
- Department of Metabolism and Aging The Scripps Research Institute Jupiter FL USA
| | - Yuan Yuan Ling
- Department of Metabolism and Aging The Scripps Research Institute Jupiter FL USA
| | - Amira S. Barghouthy
- Department of Metabolism and Aging The Scripps Research Institute Jupiter FL USA
| | - Diana C. Navarro
- Department of Metabolism and Aging The Scripps Research Institute Jupiter FL USA
| | - Tokio Sano
- Department of Metabolism and Aging The Scripps Research Institute Jupiter FL USA
| | - Paul D. Robbins
- Department of Metabolism and Aging The Scripps Research Institute Jupiter FL USA
| | | | - James L. Kirkland
- Robert and Arlene Kogod Center on Aging Mayo Clinic Rochester MN USA
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20
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Roos CM, Hagler MA, Versoza GC, Z B, Thalji NM, Richardson AG, Miller JD. Abstract 582: Overexpression of Mnsod Reduces Aortic Valve Calcification Through Repression of Pro-osteogenic Signaling. Arterioscler Thromb Vasc Biol 2015. [DOI: 10.1161/atvb.35.suppl_1.582] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Increased BMP signaling and markers of osteogenic differentiation are strongly associated with regions of valvular calcification in aortic valves from humans with end-stage calcific aortic valve stenosis. While oxidative stress is also markedly elevated in these regions, it is unknown whether increasing antioxidant capacity can reduce pro-osteogenic signaling and valvular calcification. Therefore, we hypothesized that overexpression of manganese superoxide dismutase (MnSOD) can reduce pro-osteogenic signaling in the aortic valves from hypercholesterolemic mice, ultimately resulting in reduced valvular calcification and improved valvular function. We used Ldlr
-/-
/ApoB
100/100
(LA) mice that were wild-type for MnSOD (LA-MnSOD
0/0
) or overexpressing MnSOD (LA-MnSOD
Tg/0
) and fed a western diet (TD88137) for six months. We first measured mRNA levels of the BMP ligands BMP2 and BMP4 (qRT-PCR), both of which were unchanged between LA-MnSOD
0/0
and LA-MNSOD
Tg/0
mice. While there was a small but significant increase in Runx2 mRNA levels in LA-MnSOD
Tg/0
mice compared to wild-type littermates (1.22±0.09, 1.0±0.09, qRT-PCR, p < 0.05.) gene expression levels of late stage osteoblast marker Sp7 were reduced by approximately 50% in LA-MnSOD
Tg/0
compared to wild-type littermates (0.53±0.15, 1.0±0.24, qRT-PCR, p < 0.05). Sp7 protein levels (immunohistochemistry) were also significantly reduced in LA-MnSOD
Tg/0
compared to wild-type littermates (164.5±12.3 RFU vs 259.6±10.4 RFU, p < 0.05). Critically, aortic valve calcification (Alizarin Red) was also significantly reduced in LA-MnSOD
Tg/0
mice compared to their LA-MnSOD
0/0
littermates. Functionally, aortic valve cusp separation distance (high resolution echocardiography) was slightly improved in LA-MnSOD
Tg/0
mice compared to LA-MnSOD
0/0
mice (0.98±0.04 mm vs 0.91±0.03 mm, p = n.s.). Collectively, these data suggest that increasing mitochondrial antioxidant capacity can reduce pro-osteogenic signaling and attenuate aortic valve calcification, and may be a potential therapeutic target to slow the progression of valvular calcification and dysfunction in patients with calcific aortic valve stenosis.
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Affiliation(s)
| | | | | | - Bin Z
- Surgery, Mayo Clinic, Rochester, MN
| | | | - Arlan G Richardson
- Cellular and Structural Biology, Univ of Texas Health Science Cntr, San Antonio, TX
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21
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Ribeiro M, Smith LA, Thalji NM, Roos CM, Miller JD. Abstract 237: Role of Runx2 in Vascular Responses to Angiotensin II-Induced Hypertension. Arterioscler Thromb Vasc Biol 2015. [DOI: 10.1161/atvb.35.suppl_1.237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Increases in local angiotensin II (ANGII) signaling have been implicated in a number of diseases, including atherosclerosis, hypertension, and aneurysm. Endothelial dysfunction is strongly associated with increased ANGII signaling and the pathogenesis of these diseases. While increases in Runx2 have been implicated in cardiovascular calcification and vascular stiffening in diabetes, little is known regarding the role of Runx2 in the regulation of endothelial function. In the present study, we hypothesized that Runx2 is a key mediator of impaired vascular function and increased vascular wall stiffness provoked by ANGII. Wild-type mice (WT) and littermates that were deficient in one copy of Runx2 (HET) were implanted with osmotic minipumps containing saline or a pressor dose of ANGII (1000 ng/kg/min). Blood pressure was measured non-invasively using tail-cuff methods (CODA) and mice were sacrificed following 14 days of treatment. Changes in endothelium-dependent relaxation (relaxation to acetylcholine, R
ACH
) and passive pressure-diameter relationships were measured in vitro (Living Systems arteriograph). In WT mice, treatment with ANGII for 14 days resulted in profound impairment in R
ACH
(85 ± 4% vs 47 ± 14% p<0.05) and slight reductions in vascular diameter at high distending pressures (~10% reduction in maximal diameter). While Runx2 deficiency did not alter R
ACH
or vascular distensibility/compliance in saline-treated mice, loss of one copy of Runx2 in ANGII-treated mice dramatically improved R
ACH
compared to their wild-type, ANGII-treated littermates. Interestingly, impairments in the pressure-diameter relationship with ANGII infusion were not affected by loss of one copy of Runx2. Critically, reductions in Runx2 did not significantly alter the pressor response to ANGII. In conclusion, our data suggest that Runx2 may play an integral role in the pathogenesis of ANGII-induced endothelial dysfunction, with these changes occurring independently of alterations in extracellular matrix remodeling and vascular stiffness. These data suggest that Runx2 may play a key, context-dependent role mediating vascular responses to ANGII.
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22
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Roos CM, Zhang B, Verzosa G, Oehler EA, Hagler MA, Zhang H, Miller JD. Abstract 27: Role of Sirtuin 6 in the Initiation and Progression of Calcific Aortic Valve Disease. Arterioscler Thromb Vasc Biol 2014. [DOI: 10.1161/atvb.34.suppl_1.27] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Increasing age is a major risk factor for calcific aortic valve disease (CAVD). Interestingly, SIRT6 knockout mice have a marked progeroid phenotype, and we recently reported that sirtuin enzyme expression is dramatically reduced with aging and that SIRT6 expression is reduced further in valves from patients with end-stage CAVD. It is unknown, however, whether experimentally reducing SIRT6 promotes osteogenic signaling in the valve and ultimately accelerates progression of CAVD. Thus, we used cultured mouse aortic valve interstitial cells and ldlr-deficient, apolipoprotein B100-only mice (LA) that were SIRT6 wild-type (LA-SIRT6
+/+
) or heterozygous (LA-SIRT6
+/-
) and fed a Western diet for 3 or 12 months to determine the role of SIRT6 in valve calcification.
In vitro
, reduction of SIRT6 increased histone acetylation and significantly increased mRNA and protein levels of the osteogenic genes Runx2 and Sp7 in response to bone morphogenetic protein 2 (100ng/ml BMP2 for 18 hours), and siRNA knockdown of SIRT6 increased mRNA levels of Sp7 even in the absence of exogenous bone morphogens. Using high-resolution ultrasound to evaluate aortic valve function
in vivo,
we found that 3 month old LA-SIRT6
+/-
mice did not have significant impairments in valve function compared to LA-SIRT6
+/+
mice. In contrast, 12 month old LA-SIRT6
+/-
had dramatically worsened aortic valve dysfunction and stenosis compared to LA-SIRT6
+/+
mice, which was also associated with reductions in left ventricular ejection fraction. Collectively, our data strongly suggest SIRT6 plays a critical role in the tonic repression of osteogenic signaling in the aortic valve, and that age-related reductions in SIRT6 are likely to increase susceptibility to valve calcification in response to risk factors for CAVD such as hypercholesterolemia. Collectively, increasing activity of SIRT6 or reducing acetylation of its targets may serve as viable therapeutic strategies to slow progression of age-related valvular calcification and stenosis.
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Affiliation(s)
| | - Bin Zhang
- Dept of Surgery, Mayo Clinic, Rochester, MN
| | | | | | | | - Heyu Zhang
- Dept of Surgery, Mayo Clinic, Rochester, MN
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23
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Hagler MA, Jbeli AH, Kunkala M, Roos CM, Sundt TM, Miller JD. Abstract 291: Upregulation of Multiple DNA Methyltransferase Isoforms is Associated With Tissue Inflammation in Human Thoracic Aortic Aneurysm. Arterioscler Thromb Vasc Biol 2014. [DOI: 10.1161/atvb.34.suppl_1.291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Thoracic aortic aneurysm (TAA) is a degenerative condition of the aorta characterized by aortic dilatation secondary to tissue inflammation and matrix remodeling, which ultimately progresses to aortic dissection and rupture. While recent work suggests that in vitro exposure to pro-inflammatory stimuli promotes DNMT3b-dependent DNA methylation in skeletal muscle, epigenetic mechanisms regulating gene expression in TAA remain largely uncharacterized. We therefore tested the hypothesis that expression of tumor necrosis factor α (TNF-α) is increased in human TAA tissue and that such increases are associated with upregulation of DNA methyltransferase (DNMT) levels. Normal aortic samples (n=13) were acquired from non-aneurysmal hearts/aorta not suitable for cardiac transplant, whereas TAA samples from patients with tricuspid aortic valves (n=29) were acquired from patients undergoing elective surgery for aortic aneurysm. We measured relative expression of TNF-α, DNMT1, DNMT3a and DNMT3b mRNA levels in normal and TAA tissue by qRT-PCR, and DNMT3b protein levels by western blot. Marked increases in expression of the inflammatory marker TNF-α were noted in TAA tissue (12.3± 2.34), and were associated with significantly increased DNMT1 (1.4±0.13), DNMT3a (1.44±0.09) and DNMT3b (1.94±0.27) mRNA levels (p<0.05 for all). DNMT3b protein levels were also dramatically increased in human TAA samples (2.99±0.58-fold, n = 10/group, p<0.05) when compared to normal aortic tissue. Collectively, these data suggest a novel potential role for DNA methyltransferases as major regulators of altered gene expression in TAA, and support our working hypothesis that inflammation-induced increases in DNMT3b levels may be critical repressors of protective gene expression in TAA.
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24
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Roos CM, Hagler MA, Zhang B, Arghami A, Miller JD. Abstract 270: Reduction of Mitochondrial Antioxidant Levels Augments Osteogenic Signaling Independent of Changes in Vasomotor Function in Aorta from Hypercholesterolemic Mice. Arterioscler Thromb Vasc Biol 2014. [DOI: 10.1161/atvb.34.suppl_1.270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Mitochondrial antioxidant genes are major regulators of oxidative stress in the vasculature. Previous data has shown that reducing antioxidant capacity accelerates atherosclerotic plaque size, however, it is unclear whether reducing mitochondrial antioxidant capacity alters plaque composition. Therefore, we tested the hypothesis that reductions of mitochondrial antioxidant capacity will increase osteogenic markers and intimal plaque calcification in aorta from hypercholesterolemic mice. We used
Ldlr
-/-
ApoB
100/100
(LA) mice that were either wild-type (LA-MnSOD
+/+
) or heterozygous (LA-MnSOD
+/-
) for manganese superoxide dismutase that were fed a Western Diet (TD88137) for 3 or 6 months. Changes in changes gene expression were assessed in aortic arch using qRT-PCR, plaque calcium levels were examined using histological evaluation from aortic cryosections, and endothelial function was measured using isolated organ bath chambers (
ex vivo
). While expression of SP7 (an osteogenic transcription factor) was unchanged between LA-MnSOD
+/+
(1.0±0.6) and LA-MnSOD
+/-
(0.95±0.3) at 3 months, SP7 levels were dramatically increased in LA-MnSOD
+/+
(8.0±2.8) at 6 months and increased further in LA-MnSOD
+/+
mice (17.5±5.9; p<0.05). Alizarin Red staining for calcium showed increased calcium burden in plaques of 6 month LA-MnSOD
+/-
compared to LA-MnSOD
+/+
(3636±669 pixels versus 649±206 pixels; p<0.05). Vasomotor function in aorta was unchanged between LA-MnSOD
+/+
and LA-MnSOD
+/-
mice, suggesting that the transcriptional and functional changes related to calcification in LA-MnSOD
+/-
mice occur independently of nitric oxide signaling. In conclusion, our data strongly support our working hypothesis that reductions in mitochondrial antioxidant capacity significantly accelerate osteogenic calcification in aorta from hypercholesterolemic mice, and suggest that targeting mitochondrial oxidative stress may be a viable therapeutic strategy to slow vascular calcification.
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Affiliation(s)
| | | | - Bin Zhang
- Cardiovascular Surgery, Mayo Clinic, Rochester, MN
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25
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Roos CM, Hagler M, Zhang B, Oehler EA, Arghami A, Miller JD. Transcriptional and phenotypic changes in aorta and aortic valve with aging and MnSOD deficiency in mice. Am J Physiol Heart Circ Physiol 2013; 305:H1428-39. [PMID: 23997094 DOI: 10.1152/ajpheart.00735.2012] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The purpose of this study was to characterize changes in antioxidant and age-related gene expression in aorta and aortic valve with aging, and test the hypothesis that increased mitochondrial oxidative stress accelerates age-related endothelial and aortic valve dysfunction. Wild-type (MnSOD(+/+)) and manganese SOD heterozygous haploinsufficient (MnSOD(+/-)) mice were studied at 3 and 18 mo of age. In aorta from wild-type mice, antioxidant expression was preserved, although there were age-associated increases in Nox2 expression. Haploinsufficiency of MnSOD did not alter antioxidant expression in aorta, but increased expression of Nox2. When compared with that of aorta, age-associated reductions in antioxidant expression were larger in aortic valves from wild-type and MnSOD haploinsufficient mice, although Nox2 expression was unchanged. Similarly, sirtuin expression was relatively well-preserved in aorta from both genotypes, whereas expression of SIRT1, SIRT2, SIRT3, SIRT4, and SIRT6 were significantly reduced in the aortic valve. Expression of p16(ink4a), a marker of cellular senescence, was profoundly increased in both aorta and aortic valve from MnSOD(+/+) and MnSOD(+/-) mice. Functionally, we observed comparable age-associated reductions in endothelial function in aorta from both MnSOD(+/+) and MnSOD(+/-) mice. Interestingly, inhibition of NAD(P)H oxidase with apocynin or gp91ds-tat improved endothelial function in MnSOD(+/+) mice but significantly impaired endothelial function in MnSOD(+/-) mice at both ages. Aortic valve function was not impaired by aging or MnSOD haploinsufficiency. Changes in antioxidant and sirtuin gene expression with aging differ dramatically between aorta and aortic valve. Furthermore, although MnSOD does not result in overt cardiovascular dysfunction with aging, compensatory transcriptional responses to MnSOD deficiency appear to be tissue specific.
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Affiliation(s)
- Carolyn M Roos
- Department of Surgery, Mayo Clinic, Rochester, Minnesota
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26
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Roos CM, Fujimoto H, Zhang B, Miller JD. Abstract 184: Sirt3 is a Critical Mediator of Diet-induced Vasomotor Dysfunction. Arterioscler Thromb Vasc Biol 2013. [DOI: 10.1161/atvb.33.suppl_1.a184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Increases in mitochondrial reactive oxygen species (ROS) can contribute to endothelial dysfunction in conduit arteries by reducing nitric oxide bioavailability. SIRT3 is a protein deacetylase localized to mitochondria and regulates activity of numerous electron transport chain enzymes, and can be inactivated by increases in mitochondrial ROS. Whether reductions in SIRT3 are an independent contributor to endothelial dysfunction, however, are unknown. Therefore, we hypothesized that SIRT3 null mice (SIRT3
-/-
) will have impaired relaxation to acetylcholine (MR
Ach
) compared to wild-type littermates (SIRT3
+/+
), and that this difference will be exacerbated by Western diet feeding for 3 months (TD88137, 42% of kcal from fat, 0.2% cholesterol). Endothelial function was measured using isolated organ bath chambers, and endothelium-dependent (MR
Ach
) and endothelium-independent (sodium nitroprusside, MR
SNP
) relaxation were measured. In contrast to our hypothesis, MR
ACH
was virtually identical between SIRT3
+/+
and SIRT3
-/-
fed a standard chow diet (MR
ACH
= 68±2% and 69±3%; respectively), and MR
SNP
also remained unchanged between the two genotypes. In groups fed a Western diet, however, endothelium-dependent relaxation was significantly impaired in SIRT3
-/-
mice compared to SIRT3
+/+
littermates (MR
ACH
= 49±4% and 58±3%, respectively; p<0.05). MR
SNP
was not altered by either Western diet feeding or SIRT3 deficiency. Interestingly, impairments in MR
Ach
in SIRT3
-/-
mice fed a Western diet were not rescued with acute incubation of apocynin (an NAD(P)H oxidase inhibitor) or mito-tempol (a mitochondria-targeted antioxidant), suggesting that chronic antioxidant and/or acetyltransferase inhibition may be required to improve vasomotor function in this model. Collectively, our data suggest that SIRT3 plays a major role in regulating endothelial function with dietary stress, and may be a useful therapeutic target to reduce cardiovascular risk.
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Affiliation(s)
| | | | - Bin Zhang
- Cardiovascular Surgery, Mayo Clinic, Rochester, MN
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27
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Kafa R, Roos CM, Oehler E, Zhang B, Hagler MA, Miller JD. Abstract 193: Chronic Inhibition of Tumor Necrosis Factor-alpha Slows Progression of Aortic Valve Stenosis in Mice. Arterioscler Thromb Vasc Biol 2013. [DOI: 10.1161/atvb.33.suppl_1.a193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Introduction
While progression of calcific aortic valve stenosis (CAVS) is known to be strongly associated with activation of pro-inflammatory and pro-osteogenic pathways, effective treatments for CAVS have remained elusive. TNF-α is a pleiotropic inflammatory cytokine and is upregulated in patients with CAVS. Hence, we hypothesized that TNF-α inhibition, using the neutralizing antibody infliximab, can slow the progression of CAVS
in vivo
.
Methods
We used
Ldlr
-/-
Apob
100/100
mice, which develop robust CAVS in an age-dependent manner, as a model. Mice were fed a Western-type diet for 6 months, then randomized into one of two groups: 1) twice-weekly infliximab injections (10 mg/kg intraperitoneally; n=10), and 2) saline injections (n=9). Aortic valve function was evaluated using echocardiography, and gene expression in aortic valves was measured using quantitative real-time PCR. Data are presented as mean ± SEM.
Results
During the 3 months preceding treatment initiation, aortic valve cusp separation distance decreased progressively in both groups (reduction by 0.082±0.011 mm in control group, 0.095±0.016 mm in infliximab group;
p
=0.27). Three months after initiation of treatment, cusp separation continued to decrease in control mice (by 0.108±0.021 mm), while progression of valve dysfunction was slower by 42% in the infliximab group (reduction of 0.063±0.009 mm;
p
=0.03 vs control). Expression of the pro-inflammatory genes
Vcam1
and
Nos2
was significantly reduced in valves of the infliximab group (by 37% and 60%, respectively). Moreover, endothelium-dependent vasodilation was improved by infliximab (improvement in maximum relaxation to acetylcholine in infliximab group 18±6% compared to control).
Conclusions
This study is the first to report that
in vivo
inhibition of TNF-α slows progression of CAVS in mice with established valve disease. This beneficial effect was accompanied by reduction in pro-inflammatory gene expression and improvement of systemic endothelial function, suggesting infliximab may exert its effects in part by increasing nitric oxide bioavailability. The findings warrant further investigation into the role of TNF-α in initiation and progression of CAVS, as well as its potential as a therapeutic target in human CAVS.
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28
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Hagler MA, Hadley TM, Zhang H, Mehra K, Roos CM, Schaff HV, Suri RM, Miller JD. TGF-β signalling and reactive oxygen species drive fibrosis and matrix remodelling in myxomatous mitral valves. Cardiovasc Res 2013; 99:175-84. [PMID: 23554457 DOI: 10.1093/cvr/cvt083] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
AIMS Myxomatous mitral valve disease (MMVD) is associated with leaflet thickening, fibrosis, matrix remodelling, and leaflet prolapse. Molecular mechanisms contributing to MMVD, however, remain poorly understood. We tested the hypothesis that increased transforming growth factor-β (TGF-β) signalling and reactive oxygen species (ROS) are major contributors to pro-fibrotic gene expression in human and mouse mitral valves. METHODS AND RESULTS Using qRT-PCR, we found that increased expression of TGF-β1 in mitral valves from humans with MMVD (n = 24) was associated with increased expression of connective tissue growth factor (CTGF) and matrix metalloproteinase 2 (MMP2). Increased levels of phospho-SMAD2/3 (western blotting) and expression of SMAD-specific E3 ubiquitin-protein ligases (SMURF) 1 and 2 (qRT-PCR) suggested that TGF-β1 signalling occurred through canonical signalling cascades. Oxidative stress (dihydroethidium staining) was increased in human MMVD tissue and associated with increases in NAD(P)H oxidase catalytic subunits (Nox) 2 and 4, occurring despite increases in superoxide dismutase 1 (SOD1). In mitral valves from SOD1-deficient mice, expression of CTGF, MMP2, Nox2, and Nox4 was significantly increased, suggesting that ROS can independently activate pro-fibrotic and matrix remodelling gene expression patterns. Furthermore, treatment of mouse mitral valve interstitial cells with cell permeable antioxidants attenuated TGF-β1-induced pro-fibrotic and matrix remodelling gene expression in vitro. CONCLUSION Activation of canonical TGF-β signalling is a major contributor to fibrosis and matrix remodelling in MMVD, and is amplified by increases in oxidative stress. Treatments aimed at reducing TGF-β activation and oxidative stress in early MMVD may slow progression of MMVD.
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Affiliation(s)
- Michael A Hagler
- Division of Cardiovascular Surgery, Mayo Clinic, 200 First St. SW, Rochester, MN 55905, USA
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29
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Roos CM, Hagler MA, Kafa R, Zhang B, Miller JD. Neutralization of TNFα improves endothelial function and reduces vascular calcification in advanced atherosclerosis. FASEB J 2013. [DOI: 10.1096/fasebj.27.1_supplement.1194.15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | | | - Rami Kafa
- Cardiovascular SurgeryMayo ClinicRochesterMN
| | - Bin Zhang
- Cardiovascular SurgeryMayo ClinicRochesterMN
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30
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Zhang B, Oehler EA, Roos CM, Arghami A, Miller JD. Over Expression of Dimethylarginine Dimethylaminohydrolase‐1 (DDAH1) Slows Progression Fibrocalcific Aortic Valve Stenosis in Hypercholesterolemic Mice. FASEB J 2012. [DOI: 10.1096/fasebj.26.1_supplement.137.11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Bin Zhang
- Division of Cardiovascular SurgeryMayo ClinicRochesterMN
| | | | | | - Arman Arghami
- Division of Cardiovascular SurgeryMayo ClinicRochesterMN
| | - Jordan D. Miller
- Division of Cardiovascular SurgeryMayo ClinicRochesterMN
- Department of PhysiologyMayo ClinicRochesterMN
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31
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Roos CM, Zhang B, Miller JD. Functional consequences of ROS‐induced ROS release in vascular endothelium. FASEB J 2012. [DOI: 10.1096/fasebj.26.1_supplement.1129.11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | - Bin Zhang
- Division of Cardiovascular SurgeryMayo ClinicRochesterMN
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32
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Hagler MA, Roos CM, Hadley TA, Schaff HV, Suri RM, Miller JD. IL‐10 suppresses pro‐fibrotic and matrix remodeling genes in normal and myxomatous mitral valves. FASEB J 2011. [DOI: 10.1096/fasebj.25.1_supplement.1000.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | | | | | | | | | - Jordan D Miller
- Department of Surgery
- Department of PhysiologyMayo ClinicRochesterMN
| |
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33
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Roos CM, Hagler MA, Arghami A, Miller JD. Vascular effects of Nox2‐derived radicals are dependent upon mitochondrial antioxidant capacity in old mice. FASEB J 2011. [DOI: 10.1096/fasebj.25.1_supplement.1093.7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | | | | | - Jordan D Miller
- Department of Surgery
- Department of PhysiologyMayo ClinicRochesterMN
| |
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34
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Immink RV, Secher NH, Roos CM, Pott F, Madsen PL, van Lieshout JJ. The postural reduction in middle cerebral artery blood velocity is not explained by PaCO2. Eur J Appl Physiol 2006; 96:609-14. [PMID: 16470413 DOI: 10.1007/s00421-006-0136-6] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/02/2006] [Indexed: 11/28/2022]
Abstract
In the normocapnic range, middle cerebral artery mean velocity (MCA Vmean) changes approximately 3.5% per mmHg carbon-dioxide tension in arterial blood (PaCO2) and a decrease in PaCO2 will reduce the cerebral blood flow by vasoconstriction (the CO2 reactivity of the brain). When standing up MCA Vmean and the end-tidal carbon-dioxide tension (PETCO2) decrease, suggesting that PaCO2 contributes to the reduction in MCA Vmean. In a fixed body position, PETCO2 tracks changes in the PaCO2 but when assuming the upright position, cardiac output (Q) decreases and its distribution over the lung changes, while ventilation (VE) increases suggesting that PETCO2 decreases more than PaCO2. This study evaluated whether the postural reduction in PaCO2 accounts for the postural decline in MCA Vmean). From the supine to the upright position, VE, Q, PETCO2, PaCO2, MCA Vmean, and the near-infrared spectrophotometry determined cerebral tissue oxygenation (CO2Hb) were followed in seven subjects. When standing up, MCA Vmean (from 65.3+/-3.8 to 54.6+/-3.3 cm s(-1) ; mean +/- SEM; P<0.05) and cO2Hb (-7.2+/-2.2 micromol l(-1) ; P<0.05) decreased. At the same time, the VE/Q ratio increased 49+/-14% (P<0.05) with the postural reduction in PETCO2 overestimating the decline in PaCO2 (-4.8+/-0.9 mmHg vs. -3.0+/-1.1 mmHg; P<0.05). When assuming the upright position, the postural decrease in MCA Vmean seems to be explained by the reduction in PETCO2 but the small decrease in PaCO2 makes it unlikely that the postural decrease in MCA Vmean can be accounted for by the cerebral CO2 reactivity alone.
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Affiliation(s)
- R V Immink
- Department of Anesthesiology, Academic Medical Center, University of Amsterdam, 22700, 1100, DE, Amsterdam, The Netherlands
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35
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Jonkers RE, Lettinga KD, Pels Rijcken TH, Prins JM, Roos CM, van Delden OM, Verbon A, Bresser P, Jansen HM. Abnormal radiological findings and a decreased carbon monoxide transfer factor can persist long after the acute phase of Legionella pneumophila pneumonia. Clin Infect Dis 2004; 38:605-11. [PMID: 14986242 DOI: 10.1086/381199] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2003] [Accepted: 10/07/2003] [Indexed: 11/03/2022] Open
Abstract
Pulmonary abnormalities may persist long after the acute phase of legionnaires disease (LD). In a cohort of 122 survivors of an outbreak of LD, 57% were still experiencing an increased number of symptoms associated with dyspnea at a mean of 16 months after recovery from acute-phase LD. For 86 of these patients, additional evaluation involving high-resolution computed tomography (HRCT) of the lung revealed pulmonary abnormalities in 21 (24%); abnormal HRCT findings generally presented as discrete and multiple radiodensities. Residual pulmonary abnormalities were associated with a mean reduction of 20% in the gas transport capacity of the lung. This latter sign could not be used to explain the increased symptoms of dyspnea reported by patients. Receipt of mechanical ventilation during the acute phase of LD, delayed initiation of adequate antibiotic therapy, and chronic obstructive pulmonary disease were identified as risk factors for the persistence of lung abnormalities.
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Affiliation(s)
- R E Jonkers
- Department of Pulmonology, Division of Infectious Diseases, Tropical Medicine, and AIDS, Amsterdam, The Netherlands.
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36
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Boudoulas KD, Cooke GE, Roos CM, Bray PF, Goldschmidt-Clermont PJ. The PlA polymorphism of glycoprotein IIIa functions as a modifier for the effect of estrogen on platelet aggregation. Arch Pathol Lab Med 2001; 125:112-5. [PMID: 11151063 DOI: 10.5858/2001-125-0112-tpapog] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND Although estrogen has been shown to contribute to retardation of the development of coronary heart disease in premenopausal women, the efficacy of hormone replacement therapy for coronary heart disease prevention in women with established coronary heart disease remains controversial. Hence, additional research is needed to clarify the effects of hormone replacement therapy on the cardiovascular and clotting systems. We investigated the effect of estrogen on platelet aggregation induced by standard agonists (epinephrine and adenosine diphosphate), with and without the platelet antagonist aspirin. Furthermore, we analyzed our data according to the presence or absence of a prevalent polymorphism of the glycoprotein (GP) IIIa subunit of the platelet fibrinogen receptor GPIIb-IIIa, PlA2. METHODS AND RESULTS The effect of estrogen on aggregation of platelets was studied in healthy men (n = 20, 10 PlA1/A1 and 10 PlA1/A2) and premenopausal healthy women (n = 10, 5 PlA1/A1 and 5 PlA1/A2). The PlA1/A1 and PlA1/A2 individuals were matched for age and race. Platelet response to agonists was investigated in the presence of (1) estrogen (10(-11) to 10(-8) mol/L), (2) aspirin (0.056 to 56 micromol/L), (3) estrogen plus aspirin, and (4) estrogen plus ICI 182 780 (ICI, 10(-9) mol/L, an inhibitor of the estrogen receptor). We found that physiologic concentrations of estrogen strongly and significantly inhibited the aggregation of PlA1/A2 platelets (P<.005 for epinephrine and P<.05 for adenosine diphosphate, induced aggregation, respectively) in both men and women. Concentrations of estrogen that were 1000-fold greater were required to observe the same level of inhibition with PlA1/A1 platelets. In the presence of aspirin, estrogen failed to provide additional inhibitory effect on aggregation of both PlA1/A1 and PlA1/A2 platelets. The estrogen-specific inhibitor ICI blocked the effect of estrogen on aggregation, suggesting that this effect is mediated by the estrogen receptor. CONCLUSIONS Estrogen inhibits the aggregation of platelets, but such inhibition is highly dependent on the presence or absence of the PlA2 polymorphism of GPIIIa. However, in the presence of aspirin, the inhibitory effect of estrogen on aggregation was no longer detectable.
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Affiliation(s)
- K D Boudoulas
- Heart and Lung Institute and Division of Cardiology, Department of Internal Medicine, The Ohio State University, Columbus, Ohio, USA
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37
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Douma WR, Kerstjens HA, Roos CM, Koëter GH, Postma DS. Changes in peak expiratory flow indices as a proxy for changes in bronchial hyperresponsiveness. Dutch Chronic Non-Specific Lung Disease study group. Eur Respir J 2000; 16:220-5. [PMID: 10968495 DOI: 10.1034/j.1399-3003.2000.16b07.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Guidelines for asthma management advocate home peak expiratory flow (PEF) monitoring. It is commonly stated that PEF variability is a good proxy of bronchial hyperresponsiveness (BHR), a hallmark of asthma. However, this has hardly been tested longitudinally, as required to monitor asthma. This study assesses which PEF index correlates best with BHR longitudinally and whether the correlation improves when correcting PEF values for the known nonlinearity of mini-Wright PEF meters. Every 6 months, for a period of 2 yrs, PEF diary cards were filled in and BHR to histamine was tested in 104 patients with BHR and reversible airways obstruction, who started treatment with bronchodilators with (n=33) or without (n=71) inhaled corticosteroids. Within each subject, PEF indices and BHR were correlated longitudinally. The highest median correlation coefficients were obtained in the group of patients using inhaled corticosteroids. The PEF indices providing the best correlation with BHR were: mean PEF bronchodilator response (rho=-0.50) and within-day variation (% mean or % maximum) (with postbronchodilator values, rho=-0.50; without postbronchodilator values, rho=-0.40). Using PEF data corrected for the nonlinearity of the PEF meters did not result in higher correlation coefficients. Since current guidelines on asthma management recommend only bronchodilators on demand, the most useful peak expiratory flow index for reflecting bronchial hyperresponsiveness longitudinally is mean within-day peak expiratory flow variation (% mean or % maximum) (without postbronchodilator values). Since the correlation coefficients are not very strong, the authors suggest that peak expiratory flow measurements are not used as a proxy for bronchial hyperresponsiveness longitudinally but as a measurement in its own right. The use of corrections of peak expiratory flows for the nonlinearity of mini-Wright peak expiratory flow meters does not improve the correlation between peak expiratory flow and bronchial hyperresponsiveness.
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Affiliation(s)
- W R Douma
- Dept of Pulmonology, University Hospital Groningen, The Netherlands
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Ying AK, Hassanain HH, Roos CM, Smiraglia DJ, Issa JJ, Michler RE, Caligiuri M, Plass C, Goldschmidt-Clermont PJ. Methylation of the estrogen receptor-alpha gene promoter is selectively increased in proliferating human aortic smooth muscle cells. Cardiovasc Res 2000; 46:172-9. [PMID: 10727665 DOI: 10.1016/s0008-6363(00)00004-3] [Citation(s) in RCA: 98] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
OBJECTIVE Atherosclerosis is a multigenic process leading to the progressive occlusion of arteries of mid to large caliber. A key step of the atherogenic process is the proliferation and migration of vascular smooth muscle cells into the intimal layer of the arterial conduit. The phenotype of smooth muscle cells, once within the intima, is known to switch from contractile to de-differentiated, yet the regulation of this switch at the genomic level is unknown. Estrogen has been shown to regulate cell proliferation both for cancer cells and for vascular cells. However, methylation of the estrogen receptor-alpha gene (ERalpha) promoter blocks the expression of ERalpha, and thereby can antagonize the regulatory effect of estrogen on cell proliferation. We sought to determine whether methylation of the ERalpha is differentially and selectively regulated in contractile versus de-differentiated arterial smooth muscle cells. METHODS We used Southern blot assay, combined bisulfite restriction analysis (Cobra) and restriction landmark genome scanning (RLGS-M) to determine the methylation status of ERalpha in human aortic smooth muscle cells, either in situ (normal aortic tissue, contractile phenotype), or the same cells explanted from the aorta and cultured in vitro (de-differentiated phenotype). RESULTS We provide evidence that methylation of the ERalpha in smooth muscle cells that display a proliferative phenotype is altered relative to the same cells studied within the media of non-atherosclerotic aortas. Thus, the ERalpha promoter does not appear to be methylated in situ (normal aorta), but becomes methylated in proliferating aortic smooth muscle cells. Using a screening technique, RLGS-M, we show that alteration in methylation associated with the smooth muscle cell phenotypic switch does not seem to require heightened activity of the methyltransferase enzyme, and appears to be selective for the ERalpha and a limited pool of genes whose CpG island becomes either demethylated or de novo methylated. CONCLUSIONS Our data support the concept that the genome of aortic smooth muscle cells is responsive to environmental conditions, and that DNA methylation, in particular methylation of the ERalpha, could contribute to the switch in phenotype observed in these cells.
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Affiliation(s)
- A K Ying
- Heart and Lung Institute, 514 Medical Research Facility, 420 W. 12th Street, Columbus, OH 43210, USA
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Affiliation(s)
- P J Goldschmidt-Clermont
- Heart and Lung Institute, and Division of Cardiology, College of Medicine and Public Health, The Ohio State University, Columbus, Ohio, USA.
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Schoonbrood DF, Out TA, Hart AA, Habets FJ, Roos CM, Jansen HM. Nedocromil sodium in obstructive airways disease: effect on symptoms and plasma protein leakage in sputum. Eur Respir J 1997; 10:1500-6. [PMID: 9230237 DOI: 10.1183/09031936.97.10071500] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
In patients with asthma or chronic obstructive pulmonary disease, there is chronic airway inflammation with increased leakage of plasma proteins into the airway lumen, which can be reduced by inhaled glucocorticosteroids. Nedocromil sodium is an anti-inflammatory drug, and we questioned whether it also affects the leakage of plasma proteins. In a double-blind placebo-controlled study we investigated the effect of 12 weeks of treatment with nedocromil on forced expiratory volume in one second (FEV1), provocative concentration of histamine causing a 20% fall in FEV1 (PC20), peak flow, symptom scores, and plasma protein leakage in sputum, in 31 patients with obstructive airways disease and sputum production (mean (range) FEV1 61% of predicted (42-87%); geometric mean (range) PC20 0.39 (0.04-2.9) mg x mL(-1)). As a measure for plasma protein leakage we calculated the relative coefficients of excretion (RCE) of proteins from serum to the soluble phase of sputum. There was a small increase in morning and evening peak flow (p<0.05) and a decrease in night-time bronchodilator use (p<0.02) in favour of nedocromil. The RCE of alpha2-macroglobulin to albumin significantly decreased after treatment with nedocromil (p=0.03). The results show limited clinical efficacy of nedocromil in our study group. They further suggest that the anti-inflammatory properties of nedocromil extend to inhibition of plasma protein leakage into the airways.
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Affiliation(s)
- D F Schoonbrood
- Dept of Pulmonology, Academic Medical Center, University of Amsterdam, The Netherlands
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Uncles DR, Daugherty MO, Frank DU, Roos CM, Rich GF. Nitric oxide modulation of pulmonary vascular resistance is red blood cell dependent in isolated rat lungs. Anesth Analg 1996; 83:1212-7. [PMID: 8942588 DOI: 10.1097/00000539-199612000-00014] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Nitric oxide (NO) or endothelium-derived relaxing factor may play an important role in modulating pulmonary vascular resistance (PVR), although previous studies have produced conflicting results. Endogenous NO inhibition causes an increase in PVR in intact animals but not in saline-perfused isolated lungs. We hypothesized that blood is essential for NO to serve as a modulator of PVR. Therefore, the effects of endogenous NO inhibition (N omega-nitro-L-arginine methyl ester [L-NAME]) were determined in isolated rat lungs as related to the presence of different blood components under normoxic conditions and after 1 wk of hypoxia (fraction of inspired oxygen [FIO2] = 10%). Exogenously administered inhaled NO was evaluated in isolated lungs from normoxic and hypoxic rats. In normoxic rats, L-NAME (10-100 microM) caused a dose-dependent increase in PVR in whole (hematocrit [Hct] 40%) and diluted (Hct 12%) blood-perfused lungs. L-NAME (10-800 microM) had no effect in isolated lungs perfused with a modified salt solution of equal viscosity to blood either alone, or containing plasma (50%) or free oxyhemoglobin (10 microM). In whole blood perfused lungs, L-NAME (100 microM) increased PVR more in hypoxic versus normoxic isolated lungs (141% vs 100%). Inhaled NO decreased PVR in isolated lungs from hypoxic rats and partially reversed the effects of L-NAME, but had no effect in normoxic lungs. In conclusion, endogenous and inhaled NO modulate PVR in isolated rat lungs and this role is increased by prolonged hypoxia. The response to inhibition of endogenous NO is dependent on the presence of red blood cells and is independent of the changes in viscosity or the presence of oxyhemoglobin or plasma.
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Affiliation(s)
- D R Uncles
- Department of Anesthesiology, University of Virginia, Charlottesville, USA
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42
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Abstract
Hypoxic pulmonary vasoconstriction (HPV) is an important mechanism for maintaining oxygenation, which may be altered by endotoxin. We determined that acute endotoxemia alters the HPV response secondary to changes in endothelium-derived vasoactive products. Rats were treated with Salmonella typhimurium lipopolysaccharide (LPS; 15 mg/kg i.p.) either 1 to 6 h before lung isolation and compared with control rats (no LPS). Additional 6-h LPS-treated and control rats were pretreated with either indomethacin (15 mg/kg i.p.), a cyclooxygenase inhibitor, or bosentan (10 mg/kg po), a nonselective endothelin-receptor antagonist. The rats lungs were isolated and challenged with 3% O2 for 10 min to elicit HPV responses before and after nitric oxide (NO) synthase inhibition with N omega-nitro-L-arginine methyl ester (L-NAME; 100 microM). LPS (6 h) significantly increased the peak HPV responses by 108%. L-NAME had no significant effect in LPS-treated lungs but increased the peak HPV response in control lungs to levels equal to LPS-treated lungs. Bosentan increased the peak HPV response in all lungs, and indomethacin increased the peak HPV in LPS-treated lungs. The HPV response was sustained in control lungs at 10 min and in additional 20-min studies. In contrast, in LPS-treated lungs the HPV response faded after 10 min to levels equal to control, and in 20-min studies it faded by 82% to levels significantly less than in control lungs. The 10-min fade in LPS-treated lungs was attenuated by indomethacin (51%) and bosentan (80%) but not by L-NAME. In conclusion, acute endotoxemia with LPS increased the peak HPV response, but this effect was not sustained and by 20 min was nearly abolished. Inhibition of endogenous NO by LPS may explain the increased peak HPV response, but NO is not involved in the fade. The fade is at least partially due to increased vasodilating cyclooxygenase products and endothelins.
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Affiliation(s)
- D U Frank
- Department of Anesthesiology, University of Virginia Health Sciences Center, Charlottesville 22908, USA
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Roos CM, Frank DU, Xue C, Johns RA, Rich GF. Chronic inhaled nitric oxide: effects on pulmonary vascular endothelial function and pathology in rats. J Appl Physiol (1985) 1996; 80:252-60. [PMID: 8847312 DOI: 10.1152/jappl.1996.80.1.252] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Nitric oxide (NO) is a potent endogenous vasodilator produced in endothelial cells. Inhaled NO selectively vasodilates the pulmonary circulation. We determined the effects of chronic inhaled NO on hypoxic pulmonary vascular remodeling and endothelium NO-dependent and -independent vasodilation during normoxic and hypoxic conditions in rats. Rats were exposed to 3 wk of normoxia (N), normoxia + 20 ppm inhaled NO (N+NO), chronic hypoxia with 10% normobaric oxygen (CH), or CH and 20 ppm inhaled NO (CH+NO). Inhaled NO decreased the number of muscular pulmonary arteries, the medial smooth muscle thickness, and the right ventricular hypertrophy associated with chronic hypoxia but had no effect on these parameters in normoxic rats. All groups were evaluated with isolated perfused lungs. The pulmonary artery pressure increased by the same amount in the CH and CH+NO rats compared with N rats. Inhibition of NO synthase with N omega-nitro-L-arginine methyl ester (L-NAME) caused greater pulmonary vasoconstriction in CH (19.2 +/- 3.7 mmHg) vs. N (7.8 +/- 3.0 mmHg) and less in CH+NO (9.1 +/- 0.8 mmHg) vs. CH rats. Bradykinin (3 micrograms) caused greater vasodilation in CH (76 +/- 12%) vs. N (29 +/- 5%) but significantly less in CH+NO (41 +/- 11%) vs. CH rats. Vasodilation with acute inhaled NO (40 ppm) was no different in CH vs. N rats but was lower in CH+NO (19 +/- 5%) vs. CH (34 +/- 6%) rats. This study demonstrates that chronic inhaled NO attenuates hypoxic pulmonary vascular remodeling. Furthermore, these results suggest that chronic inhaled NO decreases endothelium NO-dependent and -independent vasodilation.
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Affiliation(s)
- C M Roos
- Department of Anesthesiology, University of Virginia Health Sciences Center, Charlottesville 22908, USA
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44
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Bogaard JM, Overbeek SE, Verbraak AF, Vons C, Folgering HT, van der Mark TW, Roos CM, Sterk PJ. Pressure-volume analysis of the lung with an exponential and linear-exponential model in asthma and COPD. Dutch CNSLD Study Group. Eur Respir J 1995. [DOI: 10.1183/09031936.95.08091525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The prevalence of abnormalities in lung elasticity in patients with asthma or chronic obstructive pulmonary disease (COPD) is still unclear. This might be due to uncertainties concerning the method of analysis of quasistatic deflation lung pressure-volume curves. Pressure-volume curves were obtained in 99 patients with moderately severe asthma or COPD. These patients were a subgroup from a Dutch multicentre trial; the entire group was selected on the basis of a moderately lowered % predicted forced expiratory volume in one second (FEV1), and a provocative concentration of histamine producing a 20% decrease in FEV1 (PC20) < 8 mg.mL-1 obtained with the 2 min tidal breathing technique. The curves were fitted with an exponential (E) model and an exponential model which took the linear appearance in the mid vital capacity range into account (linear-exponential (LE)). The linear-exponential model showed a markedly better fit ability, yielding additional parameters, such as the compliance at functional residual capacity (FRC) level as slope of the linear part (b), and the volume at which the linear part changed into the exponential part of the curve (transition volume (Vtr)). Vtr (mean value Vtr/total lung capacity (TLC) = 0.79 (SD 0.07)) showed a close positive linear correlation with obstruction and hyperinflation variables, which might be due to airway closure, already starting at elevated lung volumes. The exponential shape factor K was closely correlated with b and mean values (K = 1.32 (SD 0.05) kPa-1; b = 2.96 (SD 1.16) L,kPa-1) and the relationship with age was comparable with data reported in healthy individuals. The shape factor of the linear-exponential fit showed no correlation with any elasticity related variable. Neither the elastic recoil at 90% TLC, as obtained from the linear-exponential fit, nor its relationship with age were significantly different from healthy individuals. We conclude that, for a more accurate description of the lung pressure-volume curve, a linear-exponential fit is preferable to an exponential model. However, the physiological relevance of the shape parameter (KLE) is still unclear. These results indicate that patients with moderately severe asthma or COPD had, on average, no appreciable loss of elastic lung recoil as compared with healthy individuals.
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Bogaard JM, Overbeek SE, Verbraak AF, Vons C, Folgering HT, van der Mark TW, Roos CM, Sterk PJ. Pressure-volume analysis of the lung with an exponential and linear-exponential model in asthma and COPD. Dutch CNSLD Study Group. Eur Respir J 1995; 8:1525-31. [PMID: 8575579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The prevalence of abnormalities in lung elasticity in patients with asthma or chronic obstructive pulmonary disease (COPD) is still unclear. This might be due to uncertainties concerning the method of analysis of quasistatic deflation lung pressure-volume curves. Pressure-volume curves were obtained in 99 patients with moderately severe asthma or COPD. These patients were a subgroup from a Dutch multicentre trial; the entire group was selected on the basis of a moderately lowered % predicted forced expiratory volume in one second (FEV1), and a provocative concentration of histamine producing a 20% decrease in FEV1 (PC20) < 8 mg.mL-1 obtained with the 2 min tidal breathing technique. The curves were fitted with an exponential (E) model and an exponential model which took the linear appearance in the mid vital capacity range into account (linear-exponential (LE)). The linear-exponential model showed a markedly better fit ability, yielding additional parameters, such as the compliance at functional residual capacity (FRC) level as slope of the linear part (b), and the volume at which the linear part changed into the exponential part of the curve (transition volume (Vtr)). Vtr (mean value Vtr/total lung capacity (TLC) = 0.79 (SD 0.07)) showed a close positive linear correlation with obstruction and hyperinflation variables, which might be due to airway closure, already starting at elevated lung volumes. The exponential shape factor K was closely correlated with b and mean values (K = 1.32 (SD 0.05) kPa-1; b = 2.96 (SD 1.16) L,kPa-1) and the relationship with age was comparable with data reported in healthy individuals. The shape factor of the linear-exponential fit showed no correlation with any elasticity related variable. Neither the elastic recoil at 90% TLC, as obtained from the linear-exponential fit, nor its relationship with age were significantly different from healthy individuals. We conclude that, for a more accurate description of the lung pressure-volume curve, a linear-exponential fit is preferable to an exponential model. However, the physiological relevance of the shape parameter (KLE) is still unclear. These results indicate that patients with moderately severe asthma or COPD had, on average, no appreciable loss of elastic lung recoil as compared with healthy individuals.
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Affiliation(s)
- J M Bogaard
- Dept of Pulmonary Diseases, University Hospital Rotterdam-Dijkzigt, The Netherlands
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46
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Schoonbrood DF, Lutter R, Habets FJ, Roos CM, Jansen HM, Out TA. Analysis of plasma-protein leakage and local secretion in sputum from patients with asthma and chronic obstructive pulmonary disease. Am J Respir Crit Care Med 1994; 150:1519-27. [PMID: 7952610 DOI: 10.1164/ajrccm.150.6.7952610] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
In order to assess the usefulness of sputum analysis in studying plasma-protein exudation and local secretion of proteins in the airways, we measured specific proteins in the sputum sol phase (SSP) and sputum gel phase (SGP) from patients with stable asthma or chronic obstructive pulmonary disease (COPD). Protein levels in SSP showed relatively small variations between two subsequent visits of each patient (n = 22), as also reflected by intraclass correlation coefficients above 0.79. Protein levels differed between SSP and SGP, but inclusion of the SGP data did not affect the variation of protein levels in sputum. The degree of plasma-protein leakage was estimated from the relative coefficients of excretion (RCE) of alpha 2-macroglobulin and albumin (QA2M/QALB), and of alpha 2-macroglobulin and ceruloplasmin (QA2M/QCP), which do not depend on variable dilution of sputum. Despite the heterogeneity of the study group of 26 patients with asthma (atopic [13] smokers [13], including five patients using inhaled steroids), QA2M/QALB and QA2M/QCP correlated both with bronchial hyperreactivity (Spearman rank: r = -0.45 and r = -0.36, p < 0.05) and with blood eosinophil counts (r = 0.37 and 0.56, p < 0.05). We conclude that protein levels in SSP are relatively constant in patients with stable asthma or COPD; in patients with asthma, the plasma-protein leakage, as measured with the RCE in SSP, appears to correlate with indirect indices of airway inflammation.
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Affiliation(s)
- D F Schoonbrood
- Department of Pulmonology, Academic Medical Center, Amsterdam, The Netherlands
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47
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Boersma LJ, Damen EM, de Boer RW, Muller SH, Roos CM, Valdés Olmos RA, van Zandwijk N, Lebesque JV. Dose-effect relations for local functional and structural changes of the lung after irradiation for malignant lymphoma. Radiother Oncol 1994; 32:201-9. [PMID: 7816939 DOI: 10.1016/0167-8140(94)90019-1] [Citation(s) in RCA: 76] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
PURPOSE To estimate the dose-effect relations for local functional (ventilation and perfusion) and structural (density) changes of the lung, 3-4 months after irradiation. METHODS Twenty-five patients with malignant lymphoma were irradiated with a (modified) mantle field to an average dose of 38 Gy, given in 21 fractions. Single photon emission computed tomography (SPECT) ventilation (V) and perfusion (Q) scans, and CT scans were performed before and 3-4 months after radiation treatment. The three-dimensional dose distribution was calculated using the CT data. After correlation of SPECT and CT data sets, the average post-treatment value of V, Q and lung density per voxel was calculated relative to the pre-treatment value, per dose interval of 4 Gy. Subsequently, the dose-effect relations in each patient were normalized to the average value per voxel in the dose interval of 0-12 Gy. In addition, in each dose interval of 4 Gy the fraction of patients with changes larger than 20% was calculated for all three parameters. The dose-effect relations for perfusion and ventilation normalized to the low-dose regions, and the dose-incidence curves for the fraction of patients with changes larger than 20% were fitted for all three parameters, using a logistic model. RESULTS Marked changes in the distribution of V and Q were found after irradiation. Prior to normalization to the low-dose regions, a change in V and Q was found in most patients in the dose interval of 0-12 Gy, varying from an increase of 37% to a decrease of 10%, which was followed by a decreasing trend at higher doses. The increase in the low-dose regions indicated a redistribution phenomenon, the magnitude of which was dependent of the irradiated volume. The logistic fit of the dose-effect relations for Q and V, normalized to the low-dose regions, resulted in values for D50 of 51 Gy and 54 Gy (given in 21 fractions on average), respectively, and for the steepness parameter k of 4.2 and 4.0, respectively. The logistic fit for the dose-incidence curves for Q, V and lung density resulted in values for D50 and k of 38 Gy, 37 Gy, 44 Gy and 10.3, 7.8 and 9.4, respectively. CONCLUSIONS With the combined use of SPECT and CT scans, we have obtained dose-effect relations for local functional and structural damage in the lung, 3-4 months after irradiation.
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Affiliation(s)
- L J Boersma
- Department of Radiotherapy, The Netherlands Cancer Institute, Antoni van Leeuwenhøek Huis, Amsterdam
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Roos CM, Rich GF, Uncles DR, Daugherty MO, Frank DU. Sites of vasodilation by inhaled nitric oxide vs. sodium nitroprusside in endothelin-constricted isolated rat lungs. J Appl Physiol (1985) 1994; 77:51-7. [PMID: 7961274 DOI: 10.1152/jappl.1994.77.1.51] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
We localized the sites of vasodilation of inhaled nitric oxide (NO), a selective pulmonary vasodilator, and sodium nitroprusside (SNP) in isolated rat lungs. The sites were determined by analyzing the arterial, venous, and double-occlusion data with a two-resistor (small arteries and veins) three-capacitor (large arteries, large veins, and capillaries) model of the pulmonary vascular bed. Inhaled NO (170 and 670 ppm) and SNP (22.5 and 45.0 micrograms) decreased the small-artery resistance by 7.4 +/- 1.6, 17.2 +/- 2.2, 14.2 +/- 2.8, and 21.4 +/- 3.4% and the small-vein resistance by 13.5 +/- 3.2, 20.3 +/- 3.4 (SNP of 22.5 micrograms not significant), and 9.3 +/- 3.3%, respectively, in blood-perfused lungs (n = 12). Similar results were observed in Krebs-perfused lungs (n = 12). Capillary compliance was unaffected by inhaled NO and SNP. SNP increased the large-artery capacitance by 40.0 +/- 8.6 and 69.3 +/- 9.7%, whereas inhaled NO had no effect. SNP increased the large-vein capacitance by 31.0 +/- 8.7 and 48.0 +/- 10.7%, whereas inhaled NO had no effect in blood-perfused lungs. However, in Krebs-perfused lungs inhaled NO and SNP (45.0 micrograms only) increased the large-vein capacitance by 43.3 +/- 11.9, 41.4 +/- 14.2, and 44.2 +/- 11.0%. In conclusion, in blood-perfused isolated rat lungs inhaled NO and SNP dilate small-resistance arteries and veins, whereas SNP but not inhaled NO dilates larger capacitance arteries and veins. Furthermore, blood appears to prevent the downstream vasodilation by inhaled NO on larger capacitance pulmonary veins.
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Affiliation(s)
- C M Roos
- Department of Anesthesiology, University of Virginia, Charlottesville 22908
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Rich GF, Roos CM, Anderson SM, Daugherty MO, Uncles DR. Direct effects of intravenous anesthetics on pulmonary vascular resistance in the isolated rat lung. Anesth Analg 1994; 78:961-6. [PMID: 8160998 DOI: 10.1213/00000539-199405000-00022] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
We determined the direct effects of thiopental, ketamine, midazolam, etomidate, and propofol on pulmonary vascular resistance (PVR), the relationship of the direct effects to the baseline PVR, and the possible interaction with functional endothelium. The intravenous anesthetics were injected randomly into 1) endothelium-intact isolated rat lungs which were either unconstricted or constricted with angiotensin II (n = 10), and 2) lungs with endothelial injury produced by electrolysis (n = 10). In endothelium-intact lungs thiopental (0.5 and 5.0 mg/kg) and etomidate (3.0 mg/kg) significantly (P < 0.05) increased PVR by 3% +/- 1%, 30% +/- 7%, and 29% +/- 5%, respectively. Ketamine (3.0 and 100 mg/kg) and propofol (20 mg/kg) significantly (P < 0.05) decreased the PVR by 6% +/- 1%, 15% +/- 1%, and 8% +/- 1%, respectively. Midazolam (0.3 and 3.0 mg/kg) and smaller doses of etomidate (0.3 mg/kg) and propofol (2.0 mg/kg) did not affect PVR. These responses did not vary with the baseline PVR over a twofold range. The effects of thiopental, ketamine, etomidate, and midazolam were not altered by endothelial injury. In contrast to the vasodilation produced by propofol in normal lungs, propofol (20 mg/kg) significantly (P < 0.05) increased the PVR by 8% +/- 2% after endothelial injury. In conclusion, this study demonstrates that thiopental and etomidate are direct pulmonary vasoconstrictors, ketamine and propofol are direct pulmonary vasodilators, and midazolam has no direct effects in the isolated rat lung. Further, these effects on pulmonary vasculature do not vary with baseline PVR, and only propofol appears to have endothelium-dependent effects.
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Affiliation(s)
- G F Rich
- Department of Anesthesiology, University of Virginia Health Sciences Center, Charlottesville 22908
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50
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Boersma LJ, Damen EM, de Boer RW, Muller SH, Valdés Olmos RA, Hoefnagel CA, Roos CM, van Zandwijk N, Lebesque JV. A new method to determine dose-effect relations for local lung-function changes using correlated SPECT and CT data. Radiother Oncol 1993; 29:110-6. [PMID: 8310136 DOI: 10.1016/0167-8140(93)90235-z] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
PURPOSE To determine dose-effect relations for regional lung-function changes after radiotherapy. METHODS Single Photon Emission Computed Tomography (SPECT) was performed to quantify regional ventilation and perfusion. CT scans were used to calculate the three-dimensional (3-D) dose distribution. Both SPECT and CT scans were performed prior to radiotherapy and 5 months after the start of the treatment. To obtain combined 3-D information on ventilation, perfusion and dose, the SPECT data were correlated with the corresponding CT data. The relative changes in ventilation and perfusion were calculated in each SPECT voxel (voxel size about 6 x 6 x 6 mm) and related to the dose in that voxel. The average relative changes were determined per dose interval of 4 Gy. This procedure was evaluated using the data from five patients treated for Hodgkin's disease with mantle field irradiation with a prescribed total dose of 40-42 Gy. RESULTS Dose-effect relations for perfusion were observed in all patients, while in four of the five patients, a dose-effect relation was found for ventilation. The maximal uncertainty of the calculated radiation dose was 11%: a difference between the position of the patient during treatment and during CT scanning caused a maximal dose uncertainty of 6%, while the accuracy of the dose calculation algorithm itself was estimated to be within 5%. CONCLUSION The results indicate that the combined use of SPECT and CT information is an effective method for determining dose-effect relations for regional lung function parameters in each individual patient.
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Affiliation(s)
- L J Boersma
- Department of Radiotherapy, The Netherlands Cancer Institute (Antoni van Leeuwenhoek Huis), Amsterdam
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