scholarly journals HDAC Inhibition Reverses Preexisting Diastolic Dysfunction and Blocks Covert Extracellular Matrix Remodeling

Circulation ◽  
2021 ◽  
Author(s):  
Joshua G. Travers ◽  
Sara A. Wennersten ◽  
Brisa Peña ◽  
Rushita A. Bagchi ◽  
Harrison E. Smith ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Blood Pressure ◽  
Extracellular Matrix ◽  
Diastolic Dysfunction ◽  
Hdac Inhibitor ◽  
Cardiac Fibrosis ◽  
Regulatory Elements ◽  
Left Ventricular ◽  
Systemic Hypertension ◽  
Hdac Inhibition

Background: Diastolic dysfunction (DD) is associated with the development of heart failure (HF) and contributes to the pathogenesis of other cardiac maladies, including atrial fibrillation (AF). Inhibition of histone deacetylases (HDACs) has been shown to prevent DD by enhancing myofibril relaxation. Here, we addressed the therapeutic potential of HDAC inhibition in a model of established DD with preserved ejection fraction (EF). Methods: Four weeks following uninephrectomy (UNX) and implantation with deoxycorticosterone acetate (DOCA) pellets, when DD was clearly evident, one cohort of mice was administered the clinical-stage HDAC inhibitor ITF2357/Givinostat. Echocardiography, blood pressure measurements, and endpoint invasive hemodynamic analyses were performed. Myofibril mechanics and intact cardiomyocyte relaxation were assessed ex vivo . Cardiac fibrosis was evaluated by picrosirius red (PSR) staining and second harmonic generation (SHG) microscopy of left ventricular (LV) sections, RNA-sequencing of LV mRNA, mass spectrometry-based evaluation of decellularized LV biopsies, and atomic force microscopy (AFM) determination of LV stiffness. Mechanistic studies were performed with primary rat and human cardiac fibroblasts. Results: HDAC inhibition normalized DD without lowering blood pressure in this model of systemic hypertension. Surprisingly, in contrast to prior models, myofibril relaxation was unimpaired in UNX/DOCA mice. Furthermore, cardiac fibrosis was not evident in any mouse cohorts based on PSR staining or SHG microscopy. However, mass spectrometry revealed induction in the expression of more than one hundred extracellular matrix (ECM) proteins in LVs of UNX/DOCA mice, which correlated with profound tissue stiffening based on AFM. Remarkably, ITF2357/Givinostat treatment blocked ECM expansion and LV stiffening. The HDAC inhibitor was subsequently shown to suppress cardiac fibroblast activation, at least in part, by blunting recruitment of the pro-fibrotic chromatin reader protein, BRD4, to key gene regulatory elements. Conclusions: These findings demonstrate the potential of HDAC inhibition as a therapeutic intervention to reverse existing DD, and establish blockade of ECM remodeling as a second mechanism by which HDAC inhibitors improve ventricular filling. Additionally, our data reveal the existence of pathophysiologically relevant 'covert' or 'hidden' cardiac fibrosis that is below the limit of detection of histochemical stains such as PSR, highlighting the need to evaluate fibrosis of the heart using diverse methodologies.

Abstract 15707: Histone Deacetylase Inhibition Reverses Preexisting Diastolic Dysfunction and Blocks Covert Extracellular Matrix Remodeling

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Joshua G Travers ◽  
Sara A Wennersten ◽  
Brisa Pena ◽  
Rushita A Bagchi ◽  
Harrison E Smith ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Extracellular Matrix ◽  
Ejection Fraction ◽  
Diastolic Dysfunction ◽  
Histone Deacetylase ◽  
Hdac Inhibitor ◽  
Cardiac Fibrosis ◽  
Systemic Hypertension ◽  
Preserved Ejection Fraction ◽  
Hdac Inhibition

Introduction: Diastolic dysfunction is associated with the development of heart failure with preserved ejection fraction and other cardiac maladies, including atrial fibrillation. Inhibition of histone deacetylase (HDAC) activity has previously been shown to prevent diastolic dysfunction by enhancing myofibril relaxation. Here, we further addressed the therapeutic potential of HDAC inhibition in a model of established diastolic dysfunction with preserved ejection fraction. Methods: Four weeks following uninephrectomy (UNX) and implantation with deoxycorticosterone acetate (DOCA) pellets, when diastolic dysfunction was clearly evident, one cohort of mice was administered the clinical-stage HDAC inhibitor ITF2357/Givinostat. Serial echocardiography, blood pressure measurements, and endpoint invasive hemodynamic analyses were performed, along with the evaluation of pathological cardiac fibrosis and remodeling. Results: HDAC inhibition completely normalized diastolic function without lowering blood pressure in this model of systemic hypertension. Cardiac fibrosis was not evident in any mouse cohorts based on picrosirius red staining or second harmonic generation microscopy. However, mass spectrometry revealed induction in the expression of more than one hundred extracellular matrix (ECM) proteins in LVs of UNX/DOCA mice, which correlated with profound tissue stiffening based on atomic force microscopy. Remarkably, ITF2357/Givinostat treatment entirely blocked ECM expansions and LV stiffening. The HDAC inhibitor was subsequently shown to suppress cardiac fibroblast activation, at least in part, by blunting recruitment of the pro-fibrotic chromatin reader protein, BRD4, to key gene regulatory elements. Conclusions: These findings demonstrate the potential of HDAC inhibition as a therapeutic intervention to reverse existing diastolic dysfunction, and establish blockade of ECM remodeling as a second mechanism by which HDAC inhibitors improve ventricular filling. Additionally, our data reveal the existence of pathophysiologically relevant ‘covert’ cardiac fibrosis that is below the limit of detection of histochemical stains, highlighting the need to evaluate fibrosis of the heart using diverse methodologies.

scholarly journals Moderate Loss of the Extracellular Matrix Proteoglycan Lumican Attenuates Cardiac Fibrosis in Mice Subjected to Pressure Overload

Cardiology ◽  
2020 ◽  
Vol 145 (3) ◽  
pp. 187-198 ◽  
Author(s):  
Naiyereh Mohammadzadeh ◽  
Arne Olav Melleby ◽  
Sheryl Palmero ◽  
Ivar Sjaastad ◽  
Shukti Chakravarti ◽  
...  
Keyword(s):  
Heart Failure ◽  
Extracellular Matrix ◽  
Diastolic Dysfunction ◽  
Cardiac Fibrosis ◽  
Pressure Overload ◽  
Left Ventricular ◽  
Cross Linking ◽  
Myocardial Remodeling ◽  
Functional Changes ◽  
Collagen Cross Linking

Introduction: The heart undergoes myocardial remodeling during progression to heart failure following pressure overload. Myocardial remodeling is associated with structural and functional changes in cardiac myocytes, fibroblasts, and the extracellular matrix (ECM) and is accompanied by inflammation. Cardiac fibrosis, the accumulation of ECM molecules including collagens and collagen cross-linking, contributes both to impaired systolic and diastolic function. Insufficient mechanistic insight into what regulates cardiac fibrosis during pathological conditions has hampered therapeutic so­lutions. Lumican (LUM) is an ECM-secreted proteoglycan known to regulate collagen fibrillogenesis. Its expression in the heart is increased in clinical and experimental heart failure. Furthermore, LUM is important for survival and cardiac remodeling following pressure overload. We have recently reported that total lack of LUM increased mortality and left ventricular dilatation, and reduced collagen expression and cross-linking in LUM knockout mice after aortic banding (AB). Here, we examined the effect of LUM on myocardial remodeling and function following pressure overload in a less extreme mouse model, where cardiac LUM level was reduced to 50% (i.e., moderate loss of LUM). Methods and Results: mRNA and protein levels of LUM were reduced to 50% in heterozygous LUM (LUM+/–) hearts compared to wild-type (WT) controls. LUM+/– mice were subjected to AB. There was no difference in survival between LUM+/– and WT mice post-AB. Echocardiography revealed no striking differences in cardiac geometry between LUM+/– and WT mice 2, 4, and 6 weeks post-AB, although markers of diastolic dysfunction indicated better function in LUM+/– mice. LUM+/– hearts revealed reduced cardiac fibrosis assessed by histology. In accordance, the expression of collagen I and III, the main fibrillar collagens in the heart, and other ECM molecules central to fibrosis, i.e. including periostin and fibronectin, was reduced in the hearts of LUM+/– compared to WT 6 weeks post-AB. We found no differences in collagen cross-linking between LUM+/– and WT mice post-AB, as assessed by histology and qPCR. Conclusions: Moderate lack of LUM attenuated cardiac fibrosis and improved diastolic dysfunction following pressure overload in mice, adding to the growing body of evidence suggesting that LUM is a central profibrotic molecule in the heart that could serve as a potential therapeutic target.

scholarly journals CMR-Verified Myocardial Fibrosis Is Associated With Subclinical Diastolic Dysfunction in Primary Aldosteronism Patients

2021 ◽  
Vol 12 ◽  
Author(s):  
Fangli Zhou ◽  
Tao Wu ◽  
Wei Wang ◽  
Wei Cheng ◽  
Shuang Wan ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Essential Hypertension ◽  
Diastolic Dysfunction ◽  
Myocardial Fibrosis ◽  
Primary Aldosteronism ◽  
Cardiac Fibrosis ◽  
Left Ventricular ◽  
Diffuse Myocardial Fibrosis ◽  
Clinical Trial Registration ◽  
Plasma Aldosterone Concentration

ObjectivesThe main cardiac features of primary aldosteronism (PA) are impaired left ventricular (LV) diastolic function, and some articles also reported more cardiac fibrosis in PA patients. However, the correlation between LV dysfunction and diffuse myocardial fibrosis in PA remains unknown.MethodsWe enrolled 84 PA patients and 28 essential hypertension (EH) patients in West China Hospital. Cardiac magnetic resonance imaging (CMR) contrast enhancement was arranged for all subjects. Postcontrast T1 time and left ventricular myocardial strains and strain rates were measured.Results76 PA patients and 27 essential hypertension (EH) patients were included in the final analysis. Blood pressure, LV mass indexes, and LV ejection fractions were comparable in both groups, while the global circumferential peak diastolic strain rate (PDSR) was lower (0.9 ± 0.3 vs. 1.1 ± 0.4, p <0.01) and the postcontrast T1 time was shorter (520 ± 38 vs. 538 ± 27, p = 0.01) in PA patients than those in EH patients. Postcontrast T1 time (p = 0.01) was independently related to global circumferential PDSR after adjusting for age and duration of hypertension in PA patients. Furthermore, plasma aldosterone concentration was negatively associated with postcontrast T1 time (R = −0.253, p = 0.028) in PA patients.ConclusionsThe global circumferential PDSR derived by CMR is decreased, and the diffuse myocardial fibrosis is increased in PA patients compared to those in blood pressure matched EH patients. The severity of cardiac diastolic dysfunction independently relates to the degree of diffuse myocardial fibrosis in PA patients, and the diffuse myocardial fibrosis may be caused by high PAC level.Clinical Trial Registrationhttp://www.chictr.org.cn/listbycreater.asp, identifier ChiCTR2000031792.

scholarly journals CMR-Verified Myocardial Fibrosis is Associated With Subclinical Diastolic Dysfunction in Primary Aldosteronism Patients

2021 ◽  
Author(s):  
Fangli Zhou ◽  
Tao Wu ◽  
Wei Wang ◽  
Wei Cheng ◽  
Shuang Wan ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Essential Hypertension ◽  
Diastolic Dysfunction ◽  
Myocardial Fibrosis ◽  
Primary Aldosteronism ◽  
Cardiac Fibrosis ◽  
Final Analysis ◽  
Left Ventricular ◽  
Diffuse Myocardial Fibrosis ◽  
Plasma Aldosterone Concentration

Abstract The main cardiac features of primary aldosteronism (PA) are impaired left ventricular (LV) diastolic function, and some articles also reported more cardiac fibrosis in PA patients. However, the correlation between LV dysfunction and diffuse myocardial fibrosis in PA remains unknown. We enrolled 84 PA patients and 28 essential hypertension (EH) patients in West China Hospital. Cardiac magnetic resonance imaging (CMR) contrast enhancement was arranged for all subjects. Postcontrast T1 time and left ventricular myocardial strains and strain rates were measured. 76 PA patients and 27 essential hypertension (EH) patients were included in the final analysis. Blood pressure, LV mass indexes, and LV ejection fractions were comparable in both groups, while the global circumferential peak diastolic strain rate (PDSR) was lower (53 ± 20 vs. 68 ± 25, p<0.01) and the postcontrast T1 time was shorter (520 ± 38 vs. 538 ± 27, p=0.01) in PA patients than those in EH patients. Postcontrast T1 time (p=0.01) was independently related to global circumferential PDSR after adjusting for age and duration of hypertension in PA patients. Furthermore, plasma aldosterone concentration was negatively associated with myocardial T1 time (R=-0.261, p=0.023) in PA patients. The global circumferential PDSR derived by CMR is decreased, and the diffuse myocardial fibrosis is increased in PA patients compared to those in blood pressure matched EH patients. The severity of cardiac diastolic dysfunction independently relates to the degree of diffuse myocardial fibrosis in PA patients, and the diffuse myocardial fibrosis may be caused by high PAC level. Trial registration number: ChiCTR2000031792.

Myocardial work analysis in screening of familial dilated cardiomyopathy

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
M Triantafyllou ◽  
R Monteiro ◽  
A Protonotarios ◽  
T Gossios ◽  
P Elliott ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Dilated Cardiomyopathy ◽  
Global Longitudinal Strain ◽  
Left Ventricular ◽  
Systemic Hypertension ◽  
Work Efficiency ◽  
Work Analysis ◽  
Significant Difference ◽  
Global Work

Abstract Introduction Early detection of affected family relatives of patients with dilated cardiomyopathy (DCM) is essential in order to guide follow up, outcomes and initiate early treatment. Myocardial work analysis is a novel method which integrated strain imaging and blood pressure and has the potential to identify patients with subclinical disease. Purpose We analysed myocardial work in family relatives of DCM patients with positive genotype but negative phenotype in order to identify whether myocardial work can identify early changes. Methods Seventy-four family relatives of DCM patients attending for screening were examined. All individuals were asymptomatic with either positive (45/74, G+) or negative (29/74, G-) genotype and no echocardiographic evidence of left ventricular dilatation or systolic impairment. Non-invasive myocardial work analysis using two-dimensional (2D) speckle tracking echocardiography was analysed. Global longitudinal strain (GLS) was measured by the same vendor specific software used for myocardial work analysis. Left ventricular (LV) ejection fraction (EF) was measured with the Simpson's biplane method. The peak systolic arm cuff blood pressure (BP) measurement at the time of echocardiography was used for the myocardial work study. Results In total we included 74 individuals (37±15 years old, 50.7% women) with mean systolic and diastolic BP of 121.3±14 and 73.2±10 mmHg respectively, mean EF was 58±5% and mean GLS at 18.4±2.5%. G+ individuals had pathogenic and very likely pathogenic mutations in 8 different genes (TTN, BAG3, DSP, FLNC, LMNA, DMD, RBM20, TPM1). There was no difference in age, systemic hypertension, diabetes or medical treatment between the 2 groups. No significant difference was found among G+ and G- individuals in mean systolic and diastolic BP (121.2±14.7 vs 121.2±15.2 mmHg), mean EF (57.3±5 vs 59.1±4%), GLS (−18.2±1.5 vs −18.6±2.9%), mean global work index (1818±403 vs 1928±295 mmHg%) and global constructive work (2192±464 vs 2260±318 mmHg%). However, we found significant reduction of the global work efficiency (GWE) with a GWE of 94.4±2.7% in the G+ versus 95.9±1.6% in the G- individuals (p 0.02). Moreover, the global wasted work (GWW) was increased in the G+ with a GWW of 111±58 mmHg% versus 82±41 mmHg% in the G- individuals (p 0.03). Conclusion DCM gene carriers show, early on, decreased myocardial work efficiency and increased wasted work compared to unaffected family members, which appears to be earlier than other parameters such as EF and GLS. Myocardial work analysis could potentially recognize individuals showing early cardiac involvement and guide closer follow up and early initiation of treatment. Funding Acknowledgement Type of funding source: None

scholarly journals Inhibition of class I histone deacetylase activity represses matrix metalloproteinase-2 and -9 expression and preserves LV function postmyocardial infarction

2015 ◽  
Vol 308 (11) ◽  
pp. H1391-H1401 ◽  
Author(s):  
Santhosh K. Mani ◽  
Christine B. Kern ◽  
Denise Kimbrough ◽  
Benjamin Addy ◽  
Harinath Kasiganesan ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Hdac Inhibitor ◽  
Histone Deacetylases ◽  
Left Ventricular ◽  
Class I ◽  
Matrix Metalloproteinase 2 ◽  
Lv Function ◽  
Extracellular Matrix Remodeling ◽  
Matrix Remodeling ◽  
Lv Remodeling

Left ventricular (LV) remodeling, after myocardial infarction (MI), can result in LV dilation and LV pump dysfunction. Post-MI induction of matrix metalloproteinases (MMPs), particularly MMP-2 and MMP-9, have been implicated as causing deleterious effects on LV and extracellular matrix remodeling in the MI region and within the initially unaffected remote zone. Histone deacetylases (HDACs) are a class of enzymes that affect the transcriptional regulation of genes during pathological conditions. We assessed the efficacy of both class I/IIb- and class I-selective HDAC inhibitors on MMP-2 and MMP-9 abundance and determined if treatment resulted in the attenuation of adverse LV and extracellular matrix remodeling and improved LV pump function post-MI. MI was surgically induced in MMP-9 promoter reporter mice and randomized for treatment with a class I/IIb HDAC inhibitor for 7 days post-MI. After MI, LV dilation, LV pump dysfunction, and activation of the MMP-9 gene promoter were significantly attenuated in mice treated with either the class I/IIb HDAC inhibitor tichostatin A or suberanilohydroxamic acid (voronistat) compared with MI-only mice. Immunohistological staining and zymographic levels of MMP-2 and MMP-9 were reduced with either tichostatin A or suberanilohydroxamic acid treatment. Class I HDAC activity was dramatically increased post-MI. Treatment with the selective class I HDAC inhibitor PD-106 reduced post-MI levels of both MMP-2 and MMP-9 and attenuated LV dilation and LV pump dysfunction post-MI, similar to class I/IIb HDAC inhibition. Taken together, these unique findings demonstrate that selective inhibition of class I HDACs may provide a novel therapeutic means to attenuate adverse LV remodeling post-MI.

Abstract 608: Uric Acid Potentially Interacts With Parathyroid Hormone To Promote Left Ventricular Diastolic Dysfunction In Mice Fed A Western Diet

Hypertension ◽  
2014 ◽  
Vol 64 (suppl_1) ◽  
Author(s):  
Guanghong Jia ◽  
Brian P Bostick ◽  
Javad Habibi ◽  
Annayya R. Aroor ◽  
Vincent G. DeMarco ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Body Weight ◽  
Uric Acid ◽  
Parathyroid Hormone ◽  
Diastolic Dysfunction ◽  
Cardiac Mri ◽  
Left Ventricular ◽  
Western Diet ◽  
P Value ◽  
Lv Diastolic Dysfunction

Hyperuricemia is frequently observed in obese people and rising obesity rates parallel increased consumption of a high-fat/high-fructose western diet (WD). Epidemiologic and clinical data suggest that serum uric acid (UA) is positively associated with serum parathyroid hormone (PTH) and may be linked with left ventricular (LV) hypertrophy and LV diastolic dysfunction. Accordingly, we hypothesized that allopurinol, a potent xanthine oxidase (XO) inhibitor, would prevent development of LV diastolic dysfunction, independent of blood pressure, by reducing the levels of UA and PTH. Four week-old C57BL6/J male mice were fed a WD and water with 125mg/L allopurinol. After 16 weeks, we assessed levels of UA, XO activity, PTH, as well as diastolic function by cardiac MRI and cardiac ultrastructure by transmission electron microscopy (TEM). Body weight and fat composition were obtained along with HOMA -IR testing for insulin resistance. Allopurinol has been show to exert no effect on blood pressure. High resolution cardiac MRI revealed diastolic dysfunction with WD feeding that was prevented by allopurinol (LV diastolic relaxation time 35.3 ms for WD, 25.4 ms for CD and 27.7 ms for WD+ allopurinol, p value <0.01; Initial filling rate 0. 28 μl/ms for WD, 0.43 μl/ms for CD and 0.42 μl/ms for WD+ allopurinol, p value <0.05). Body weight, fat mass, and HOMA-IR were increased by WD feeding but not significantly improved by allopurinol. However, allopurinol markedly decreased the WD-induced increase in heart weight associated with activation of translational S6 kinase. TEM examination of myocardial ultrastructure revealed that WD induced remodeling changes with large mitochondria with disordered cristae and increased lysosomes. The ultrastructural changes were improved with treatment by allopurinol. Furthermore, allopurinol significantly inhibited both of plasma and urine UA levels and cardiac XO activity caused by WD. Interestingly , WD increased PTH levels which were decreased in parallel with reductions in uric acid with allopurinol. These findings support the notion that increased plasma levels of UA, in concert with elevated PTH, may play a key role in LV hypertrophy and associated LV diastolic dysfunction that result from consuming a WD high in fructose and fat.

Abstract 2280: Urine Albumin/creatinine Ratio, Cardiac Structure And Diastolic Function In Patients With Hypertension And Diastolic Dysfunction: The Validd Study

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Anil Verma ◽  
Rajesh Janardhanan ◽  
William L Daley ◽  
Susan Ritter ◽  
William A Kaye ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Diastolic Dysfunction ◽  
Diastolic Function ◽  
Organ Damage ◽  
Left Ventricular ◽  
Creatinine Ratio ◽  
Albumin Creatinine Ratio ◽  
End Organ Damage ◽  
Urine Albumin ◽  
Urine Albumin Creatinine Ratio

Background: Increasing urine albumin/creatinine ratio (ACR) is associated with systemic microvascular damage and increased cardiovascular morbidity and mortality. However, the relationship between albuminuria and left ventricular (LV) diastolic function, an early measure of myocardial end-organ damage in hypertension, has not been well defined. Methods: Urine ACR and echocardiographic measures of LV structure and function were assessed in 384 patients enrolled in the VALsartan In Diastolic Dysfunction (VALIDD) trial with mild hypertension and no heart failure and evidence of diastolic dysfunction based on Doppler assessment of myocardial relaxation velocities. Results: Urine ACR was undetected in 151 (39.3%) subjects, between 1 to 30 mg/g in 194 (50.5%), and > 30mg/g in 39 (10.2%). The mean blood pressure in the cohort was 143.8 ± 16.1/86.2 ± 10.3 mmHg and LV hypertrophy was present in < 4% of enrolled patients. Higher urine ACR was associated with lower annular relaxation velocity (E′), higher E/E′ (Figure ), higher prevalence of concentric LV remodeling and higher NT-ProBNP even after adjusting for age, diabetes, systolic BP, eGFR and LV mass index (LVMi) (p < 0.02 for all associations). Conclusion: Albuminuria is associated with worsening diastolic function in patients with hypertension, and both measures may represent important and modifiable markers of early end-organ damage even in patients with mild blood pressure elevation. E′ stratified by urine albumin creatinine ratio E/E′ stratified by urine albumin creatinine ratio

scholarly journals A Polyphenol Rich Muscadine Grape Extract Reduces Macrophage Infiltration in Hypertensive Rat Hearts Associated with a Reduction in Macrophage Migration

2020 ◽  
Vol 4 (Supplement_2) ◽  
pp. 52-52
Author(s):  
Ana Clara Melo ◽  
Pooja Patil ◽  
Patricia Gallagher ◽  
Elisabeth Tallant
Keyword(s):  
Blood Pressure ◽  
Inflammatory Response ◽  
Diastolic Dysfunction ◽  
Cardiac Fibrosis ◽  
Total Phenolics ◽  
Ang Ii ◽  
Water Control ◽  
Grape Extract ◽  
Collagen Iii ◽  
Muscadine Grape

Abstract Objectives Hypertension affects over a billion people world-wide and is a major risk factor for cardiovascular disease. Macrophages, the most abundant innate immune cells, home to the heart and secrete cytokines, inducing a heightened inflammatory response which results in fibrosis and cardiac damage. Muscadine grapes are rich in polyphenols, compounds with anti-proliferative, anti-fibrotic, and anti-inflammatory properties. Our aim was to determine whether a muscadine grape extract (MGE) rich in polyphenols prevents the macrophage inflammatory response induced by hypertension. Methods A proprietary extract was prepared from muscadine grape seeds and skins. Male Sprague-Dawley rats (8 weeks old) received drinking water (control), MGE at 0.2 mg total phenolics/mL, 24 μg/kg/h of angiotensin II (Ang II) via osmotic minipump to induce hypertension, or both Ang II and MGE (Ang II/MGE) for 4 weeks. Rats were pre-treated with MGE for 1 week prior to Ang II treatment. Blood pressure was measured weekly by tail cuff plethysmography. Tissues were collected and fixed for immunohistochemistry. Proliferation and migration of macrophage-like RAW264.7 cells were quantified in real-time. Results MGE had no effect on blood pressure in normotensive or hypertensive rats. MGE ameliorated Ang II-induced diastolic dysfunction (E/E’ ratio: 19.9 ± 0.8 control, 28.1 ± 1.1 Ang II, 22.3 ± 2.0 Ang II/MGE rats; n = 8; P &lt; 0.05), interstitial cardiac fibrosis (P &lt; 0.05) and collagen III deposition (0.9 ± 0.2% Control, 6.8 ± 1.0% Ang II, 2.8 ± 0.4% Ang II/MGE; P &lt; 0.01). Thus, MGE may improve diastolic dysfunction in part through a reduction in pathological fibrosis. Ang II caused a significant increase in CD68-positive macrophages in cardiac tissue, which was blocked by MGE (% positive cells/field: control 6.1 ± 0.4, Ang II 12.5 ± 2.0, Ang II/MGE 5.4 ± 0.5, P &lt; 0.01). Treatment of RAW264.6 cells with MGE (20 μg/mL total phenolics) for 18 h attenuated stimulated cell migration by 2-fold with no effect on proliferation (n = 3, P &lt; 0.5), indicating that MGE may reduce the Ang II-mediated increase in cardiac macrophages by blocking migration. Conclusions MGE may serve as medical food to protect the heart from hypertension-induced inflammation thereby reducing cardiac fibrosis to improve diastolic dysfunction. Funding Sources Chronic Disease Research Fund.

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