Justin R Kingery

Cardioprotective and Antiapoptotic Effects of Heme Oxygenase-1 in the Failing Heart

Background— Heme oxygenase-1 (HO-1) is an inducible stress-response protein that imparts antioxidant and antiapoptotic effects. However, its pathophysiological role in cardiac remodeling and chronic heart failure (HF) is unknown. We hypothesized that induction of HO-1 in HF alleviates pathological remodeling. Methods and Results— Adult male nontransgenic and myocyte-restricted HO-1 transgenic mice underwent either sham operation or coronary ligation to induce HF. Four weeks after ligation, nontransgenic HF mice exhibited postinfarction left ventricular (LV) remodeling and dysfunction, hypertrophy, fibrosis, oxidative stress, apoptosis, and reduced capillary density, associated with a 2-fold increase in HO-1 expression in noninfarcted myocardium. Compared with nontransgenic mice, HO-1 transgenic HF mice exhibited significantly (P<0.05) improved postinfarction survival (94% versus 57%) and less LV dilatation (end-diastolic volume, 46±8 versus 85±32 &mgr;L), mechanical dysfunction (ejection fraction, 65±9% versus 49±16%), hypertrophy (LV/tibia length 4.4±0.4 versus 5.2±0.6 mg/mm), interstitial fibrosis (11.2±3.1% versus 18.5±3.5%), and oxidative stress (3-fold reduction in tissue malondialdehyde). Moreover, myocyte-specific HO-1 overexpression in HF promoted tissue neovascularization and ameliorated myocardial p53 expression (2-fold reduction) and apoptosis. In isolated mitochondria, mitochondrial permeability transition was inhibited by HO-1 in a carbon monoxide (CO)–dependent manner and was recapitulated by the CO donor tricarbonylchloro(glycinato)ruthenium(II) (CORM-3). HO-1–derived CO also prevented H2O2-induced cardiomyocyte apoptosis and cell death. Finally, in vivo treatment with CORM-3 alleviated postinfarction LV remodeling, p53 expression, and apoptosis. Conclusions— HO-1 induction in the failing heart is an important cardioprotective adaptation that opposes pathological LV remodeling, and this effect is mediated, at least in part, by CO-dependent inhibition of mitochondrial permeability transition and apoptosis. Augmentation of HO-1 or its product, CO, may represent a novel therapeutic strategy for ameliorating HF.

Cardiomyocyte NF-κB p65 promotes adverse remodelling, apoptosis, and endoplasmic reticulum stress in heart failure

AIMS the role of nuclear factor (NF)-κB in heart failure (HF) is not well defined. We sought to determine whether myocyte-localized NF-κB p65 activation in HF exacerbates post-infarction remodelling and promotes maladaptive endoplasmic reticulum (ER) stress. METHODS AND RESULTS non-transgenic (NTg) and transgenic (Tg) mice with myocyte-restricted overexpression of a phosphorylation-resistant inhibitor of κBα (IκBα(S32A,S36A)) underwent coronary ligation (to induce HF) or sham operation. Over 4 weeks, the remote myocardium of ligated hearts exhibited robust NF-κB activation that was almost exclusively p65 beyond 24 h. Compared with sham at 4 weeks, NTg HF hearts were dilated and dysfunctional, and exhibited hypertrophy, fibrosis, up-regulation of inflammatory cytokines, increased apoptosis, down-regulation of ER protein chaperones, and up-regulation of the ER stress-activated pro-apoptotic factor CHOP. Compared with NTg HF, Tg-IκBα(S32A,S36A) HF mice exhibited: (i) improved survival, chamber remodelling, systolic function, and pulmonary congestion, (ii) markedly diminished NF-κB p65 activation, cytokine expression, and fibrosis, and (iii) a three-fold reduction in apoptosis. Moreover, Tg-IκBα(S32A,S36A) HF hearts exhibited maintained expression of ER chaperones and CHOP when compared with sham. In cardiomyocytes, NF-κB activation was required for ER stress-mediated apoptosis, whereas abrogation of myocyte NF-κB shifted the ER stress response to one of adaptation and survival. CONCLUSION persistent myocyte NF-κB p65 activation in HF exacerbates cardiac remodelling by imparting pro-inflammatory, pro-fibrotic, and pro-apoptotic effects. p65 modulation of cell death in HF may occur in part from NF-κB-mediated transformation of the ER stress response from one of adaptation to one of apoptosis.

Remodeling of the Mononuclear Phagocyte Network Underlies Chronic Inflammation and Disease Progression in Heart Failure: Critical Importance of the Cardiosplenic Axis

Rationale: The role of mononuclear phagocytes in chronic heart failure (HF) is unknown. Objective: Our aim was to delineate monocyte, macrophage, and dendritic cell trafficking in HF and define the contribution of the spleen to cardiac remodeling. Methods and Results: We evaluated C57Bl/6 mice with chronic HF 8 weeks after coronary ligation. As compared with sham-operated controls, HF mice exhibited: (1) increased proinflammatory CD11b+F4/80+CD206− macrophages and CD11b+F4/80+Gr-1hi monocytes in the heart and peripheral blood, respectively, and reduced CD11b+F4/80+Gr-1hi monocytes in the spleen; (2) significantly increased CD11c+B220− classical dendritic cells and CD11c+/lowB220+ plasmacytoid dendritic cells in both the heart and spleen, and increased classic dendritic cells and plasmacytoid dendritic cells in peripheral blood and bone marrow, respectively; (3) increased CD4+ helper and CD8+ cytotoxic T-cells in the spleen; and (4) profound splenic remodeling with abundant white pulp follicles, markedly increased size of the marginal zone and germinal centers, and increased expression of alarmins. Splenectomy in mice with established HF reversed pathological cardiac remodeling and inflammation. Splenocytes adoptively transferred from mice with HF, but not from sham-operated mice, homed to the heart and induced long-term left ventricular dilatation, dysfunction, and fibrosis in naive recipients. Recipient mice also exhibited monocyte activation and splenic remodeling similar to HF mice. Conclusions: Activation of mononuclear phagocytes is central to the progression of cardiac remodeling in HF, and heightened antigen processing in the spleen plays a critical role in this process. Splenocytes (presumably splenic monocytes and dendritic cells) promote immune-mediated injurious responses in the failing heart and retain this memory on adoptive transfer.

Chronic AMD3100 antagonism of SDF-1α–CXCR4 exacerbates cardiac dysfunction and remodeling after myocardial infarction

The role of the SDF-1alpha-CXCR4 axis in response to myocardial infarction is unknown. We addressed it using the CXCR4 antagonist, AMD3100, to block SDF-1alpha interaction with CXCR4 after chronic coronary artery ligation. Chronic AMD3100 treatment decreased ejection fraction and fractional shortening in mice 20days after myocardial infarction compared with vehicle-treated mice (echocardiography). Morphometric analysis showed hearts of AMD3100-treated infarcted mice to have expanded scar, to be hypertrophic (confirmed by myocyte cross-section area) and dilated, with increased LV end systolic and end diastolic dimensions, and to have decreased scar collagen content; p-AKT levels were attenuated and this was accompanied by increased apoptosis. Despite increased injury, c-kit(pos) cardiac progenitor cells (CPCs) were increased in the risk region of AMD3100-treated infarcted mice; CPCs were CD34(neg)/CD45(neg) with the majority undergoing symmetric cell division. c-kit(pos)/MHC(pos) CPCs also increased in the risk region of the AMD3100-treated infarcted group. In this group, GSK-3beta signaling was attenuated compared to vehicle-treated, possibly accounting for increased proliferation and increased cardiac committed MHC(pos) CPCs. Increased proliferation following AMD3100 treatment was supported by increased levels of cyclin D1, a consequence of increased prolyl isomerase, Pin1, and decreased cyclin D1 phosphorylation. In summary, pharmacologic antagonism of CXCR4 demonstrates that SDF-1alpha-CXCR4 signaling plays an important role during and after myocardial infarction and that it exerts pleiotropic salubrious effects, protecting the myocardium from apoptotic cell death, facilitating scar formation, restricting CPC proliferation, and directing CPCs toward a cardiac fate.

Short-term and long-term cardiovascular risk, metabolic syndrome and HIV in Tanzania

Objective To compare short-term and long-term cardiovascular disease (CVD) risk scores and prevalence of metabolic syndrome in HIV-infected adults receiving and not receiving antiretroviral therapy (ART) to HIV-negative controls. Methods A cross-sectional study including 151 HIV-infected, ART-naive, 150 HIV-infected on ART and 153 HIV-negative adults. Traditional cardiovascular risk factors were determined by standard investigations. The primary outcome was American College of Cardiology/American Heart Association Atherosclerotic CVD (ASCVD) Risk Estimator lifetime CVD risk score. Secondary outcomes were ASCVD 10-year risk, Framingham risk scores, statin indication and metabolic syndrome. Results Compared with HIV-negative controls, more HIV-infected adults on ART were classified as high lifetime CVD risk (34.7% vs 17.0%, p<0.001) although 10-year risk scores were similar, a trend which was similar across multiple CVD risk models. In addition, HIV-infected adults on ART had a higher prevalence of metabolic syndrome versus HIV-negative controls (21.3% vs 7.8%, p=0.008), with two common clusters of risk factors. More than one-quarter (28.7%) of HIV-infected Tanzanian adults on ART meet criteria for statin initiation. Conclusions HIV-infected ART-treated individuals have high lifetime cardiovascular risk, and this risk seems to develop rapidly in the first 3–4 years of ART as does the development of clusters of metabolic syndrome criteria. These data identify a new subgroup of low short-term/high–lifetime risk HIV-infected individuals on ART who do not currently meet criteria for CVD risk factor modification but require further study.

[Accepted Manuscript] Short-term and long-term cardiovascular risk, metabolic syndrome and HIV in Tanzania.

Objective To compare short-term and long-term cardiovascular disease (CVD) risk scores and prevalence of metabolic syndrome in HIV-infected adults receiving and not receiving antiretroviral therapy (ART) to HIV-negative controls. Methods A cross-sectional study including 151 HIV-infected, ART-naive, 150 HIV-infected on ART and 153 HIV-negative adults. Traditional cardiovascular risk factors were determined by standard investigations. The primary outcome was American College of Cardiology/American Heart Association Atherosclerotic CVD (ASCVD) Risk Estimator lifetime CVD risk score. Secondary outcomes were ASCVD 10-year risk, Framingham risk scores, statin indication and metabolic syndrome. Results Compared with HIV-negative controls, more HIV-infected adults on ART were classified as high lifetime CVD risk (34.7% vs 17.0%, p<0.001) although 10-year risk scores were similar, a trend which was similar across multiple CVD risk models. In addition, HIV-infected adults on ART had a higher prevalence of metabolic syndrome versus HIV-negative controls (21.3% vs 7.8%, p=0.008), with two common clusters of risk factors. More than one-quarter (28.7%) of HIV-infected Tanzanian adults on ART meet criteria for statin initiation. Conclusions HIV-infected ART-treated individuals have high lifetime cardiovascular risk, and this risk seems to develop rapidly in the first 3–4 years of ART as does the development of clusters of metabolic syndrome criteria. These data identify a new subgroup of low short-term/high–lifetime risk HIV-infected individuals on ART who do not currently meet criteria for CVD risk factor modification but require further study.

Heart failure, post-hospital mortality and renal function in Tanzania: A prospective cohort study

OBJECTIVE To determine one-year, post-hospital mortality and the predictors of mortality in Tanzanian adults with heart failure (HF) compared to other admitted adults. METHODS In this prospective cohort study we consecutively enrolled medical inpatients admitted during a 3-month period, screened for HF and followed until 12 months after hospital discharge. Standardized history, physical examination, echocardiography and laboratory investigations were obtained during hospital presentation. The primary outcome was one-year post-discharge mortality. The secondary outcome was in-hospital mortality. Cox regression adjusted for age and sex was used. RESULTS During the study period, we enrolled 558 adults; 145 had HF and 107 of these survived until discharge. Patients with HF had a higher one-year post-hospital discharge mortality than all other diagnoses (62/107 (57.9%) vs 150/343 (43.7%), respectively, HR=1.57[1.13-2.18]). In-hospital mortality was similar. Markers of renal disease were more common in adults with HF (40/107 (37.4%) and were the strongest independent predictors of post-hospital mortality: low eGFR (HR=2.94[1.62-5.31]) and proteinuria (HR=2.03, [95%CI 1.13-3.66]). No patients discharged with the combination of low eGFR/proteinuria survived to the one-year endpoint. Of note, 79/145 (54.5%) of adults admitted with HF were newly diagnosed during hospital admission. CONCLUSIONS Over half of adults discharged with HF died within 12months after discharge. Adults with HF had higher post-hospital mortality compared to other medical inpatients. Markers of renal disease were the strongest predictor of this mortality. Innovative interventions are needed to reduce post-hospital mortality in adults with HF and should focus on those with renal disease.

Remodeling of the Mononuclear Phagocyte Network Underlies Chronic Inflammation and Disease Progression in Heart Failure

Rationale: The role of mononuclear phagocytes in chronic heart failure (HF) is unknown. Objective: Our aim was to delineate monocyte, macrophage, and dendritic cell trafficking in HF and define the contribution of the spleen to cardiac remodeling. Methods and Results: We evaluated C57Bl/6 mice with chronic HF 8 weeks after coronary ligation. As compared with sham-operated controls, HF mice exhibited: (1) increased proinflammatory CD11b+F4/80+CD206− macrophages and CD11b+F4/80+Gr-1hi monocytes in the heart and peripheral blood, respectively, and reduced CD11b+F4/80+Gr-1hi monocytes in the spleen; (2) significantly increased CD11c+B220− classical dendritic cells and CD11c+/lowB220+ plasmacytoid dendritic cells in both the heart and spleen, and increased classic dendritic cells and plasmacytoid dendritic cells in peripheral blood and bone marrow, respectively; (3) increased CD4+ helper and CD8+ cytotoxic T-cells in the spleen; and (4) profound splenic remodeling with abundant white pulp follicles, markedly increased size of the marginal zone and germinal centers, and increased expression of alarmins. Splenectomy in mice with established HF reversed pathological cardiac remodeling and inflammation. Splenocytes adoptively transferred from mice with HF, but not from sham-operated mice, homed to the heart and induced long-term left ventricular dilatation, dysfunction, and fibrosis in naive recipients. Recipient mice also exhibited monocyte activation and splenic remodeling similar to HF mice. Conclusions: Activation of mononuclear phagocytes is central to the progression of cardiac remodeling in HF, and heightened antigen processing in the spleen plays a critical role in this process. Splenocytes (presumably splenic monocytes and dendritic cells) promote immune-mediated injurious responses in the failing heart and retain this memory on adoptive transfer.

Remodeling of the Mononuclear Phagocyte Network Underlies Chronic Inflammation and Disease Progression in Heart FailureNovelty and Significance

Rationale: The role of mononuclear phagocytes in chronic heart failure (HF) is unknown. Objective: Our aim was to delineate monocyte, macrophage, and dendritic cell trafficking in HF and define the contribution of the spleen to cardiac remodeling. Methods and Results: We evaluated C57Bl/6 mice with chronic HF 8 weeks after coronary ligation. As compared with sham-operated controls, HF mice exhibited: (1) increased proinflammatory CD11b+F4/80+CD206− macrophages and CD11b+F4/80+Gr-1hi monocytes in the heart and peripheral blood, respectively, and reduced CD11b+F4/80+Gr-1hi monocytes in the spleen; (2) significantly increased CD11c+B220− classical dendritic cells and CD11c+/lowB220+ plasmacytoid dendritic cells in both the heart and spleen, and increased classic dendritic cells and plasmacytoid dendritic cells in peripheral blood and bone marrow, respectively; (3) increased CD4+ helper and CD8+ cytotoxic T-cells in the spleen; and (4) profound splenic remodeling with abundant white pulp follicles, markedly increased size of the marginal zone and germinal centers, and increased expression of alarmins. Splenectomy in mice with established HF reversed pathological cardiac remodeling and inflammation. Splenocytes adoptively transferred from mice with HF, but not from sham-operated mice, homed to the heart and induced long-term left ventricular dilatation, dysfunction, and fibrosis in naive recipients. Recipient mice also exhibited monocyte activation and splenic remodeling similar to HF mice. Conclusions: Activation of mononuclear phagocytes is central to the progression of cardiac remodeling in HF, and heightened antigen processing in the spleen plays a critical role in this process. Splenocytes (presumably splenic monocytes and dendritic cells) promote immune-mediated injurious responses in the failing heart and retain this memory on adoptive transfer.

Remodeling of the Mononuclear Phagocyte Network Underlies Chronic Inflammation and Disease Progression in Heart FailureNovelty and Significance: Critical Importance of the Cardiosplenic Axis

Rationale: The role of mononuclear phagocytes in chronic heart failure (HF) is unknown. Objective: Our aim was to delineate monocyte, macrophage, and dendritic cell trafficking in HF and define the contribution of the spleen to cardiac remodeling. Methods and Results: We evaluated C57Bl/6 mice with chronic HF 8 weeks after coronary ligation. As compared with sham-operated controls, HF mice exhibited: (1) increased proinflammatory CD11b+F4/80+CD206− macrophages and CD11b+F4/80+Gr-1hi monocytes in the heart and peripheral blood, respectively, and reduced CD11b+F4/80+Gr-1hi monocytes in the spleen; (2) significantly increased CD11c+B220− classical dendritic cells and CD11c+/lowB220+ plasmacytoid dendritic cells in both the heart and spleen, and increased classic dendritic cells and plasmacytoid dendritic cells in peripheral blood and bone marrow, respectively; (3) increased CD4+ helper and CD8+ cytotoxic T-cells in the spleen; and (4) profound splenic remodeling with abundant white pulp follicles, markedly increased size of the marginal zone and germinal centers, and increased expression of alarmins. Splenectomy in mice with established HF reversed pathological cardiac remodeling and inflammation. Splenocytes adoptively transferred from mice with HF, but not from sham-operated mice, homed to the heart and induced long-term left ventricular dilatation, dysfunction, and fibrosis in naive recipients. Recipient mice also exhibited monocyte activation and splenic remodeling similar to HF mice. Conclusions: Activation of mononuclear phagocytes is central to the progression of cardiac remodeling in HF, and heightened antigen processing in the spleen plays a critical role in this process. Splenocytes (presumably splenic monocytes and dendritic cells) promote immune-mediated injurious responses in the failing heart and retain this memory on adoptive transfer.