Circulating transthyretin and retinol binding protein 4 levels among middle-age V122I TTR carriers in the general population.

BACKGROUND: Hereditary transthyretin cardiac amyloidosis (ATTRv-CA) has a long latency phase before clinical onset, creating a need to identify subclinical disease. We hypothesized circulating transthyretin (TTR) and retinol binding protein 4 (RBP4) levels would be associated with TTR carrier status and correlated with possible evidence of subclinical ATTRv-CA. METHODS: TTR and RBP4 were measured in blood samples from V122I TTR carriers and age-, sex- and race-matched non-carrier controls (1:2 matching) among Dallas Heart Study participants (phases 1 (DHS-1) and 2 (DHS-2)). Multivariable linear regression models determined factors associated with TTR and RBP4. RESULTS: There were 40 V122I TTR carriers in DHS-1 and 54 V122I TTR carriers in DHS-2. In DHS-1 and DHS-2, TTR was lower in V122I TTR carriers (p < .001 for both), and RBP4 in DHS-2 was lower in V122I TTR carriers than non-carriers (p = .002). Among V122I TTR carriers, TTR was negatively correlated with markers of kidney function, and limb lead voltage (p < .05 for both) and TTR and RBP4 were correlated with atrial volume in DHS-2 (p < .05). CONCLUSIONS: V122I TTR carrier status is independently associated with lower TTR and RBP4 in comparison with non-carriers. These findings support the hypothesis that TTR and RBP4 may correlate with evidence of subclinical ATTRv-CA.

Urinary total conjugated 3-bromotyrosine, asthma severity, and exacerbation risk.

Asthma is an inflammatory disease of the airways characterized by eosinophil recruitment, eosinophil peroxidase release, and protein oxidation through bromination, which following tissue remodeling results in excretion of 3-bromotyrosine. Predicting exacerbations and reducing their frequency is critical for the treatment of severe asthma. In this study, we aimed to investigate whether urinary total conjugated bromotyrosine can discriminate asthma severity and predict asthma exacerbations. We collected urine from participants with severe (n = 253) and nonsevere (n = 178) asthma, and the number of adjudicated exacerbations in 1-yr longitudinal follow-up was determined among subjects enrolled in the Severe Asthma Research Program, a large-scale National Institutes of Health (NIH)-funded consortium. Urine glucuronidated bromotyrosine and total conjugated forms were quantified by hydrolysis with either glucuronidase or methanesulfonic acid, respectively, followed by liquid chromatography-tandem mass spectrometry analyses of free 3-bromotyrosine. Blood and sputum eosinophils were also counted. The majority of 3-bromotyrosine in urine was found to exist in conjugated forms, with glucuronidated bromotyrosine representing approximately a third, and free bromotyrosine less than 1% of total conjugated bromotyrosine. Total conjugated bromotyrosine was poorly correlated with blood (r2 = 0.038) or sputum eosinophils (r2 = 0.0069). Compared with participants with nonsevere asthma, participants with severe asthma had significantly higher urinary total conjugated bromotyrosine levels. Urinary total conjugated bromotyrosine was independently associated with asthma severity, correlated with the number of asthma exacerbations, and served as a predictor of asthma exacerbation risk over 1-yr of follow-up.

RNA Sequence Analyses throughout the Course of Mouse Cardiac Laminopathy Identify Differentially Expressed Genes for Cell Cycle Control and Mitochondrial Function.

Lamin A/C (LMNA) gene mutations are a known cause of familial dilated cardiomyopathy, but the precise mechanisms triggering disease progression remain unknown. We hypothesize that analysis of differentially expressed genes (DEGs) throughout the course of Lmna knockout (Lmna-/-)-induced cardiomyopathy may reveal novel Lmna-mediated alterations of signaling pathways leading to dilated cardiomyopathy. Although Lmna was the only DEG down-regulated at 1 week of age, we identified 730 and 1004 DEGs in Lmna-/- mice at 2 weeks and 1 month of age, respectively. At 2 weeks, Lmna-/- mice demonstrated both down- and up-regulation of the key genes involving cell cycle control, mitochondrial dysfunction, and oxidative phosphorylation, as well as down-regulated genes governing DNA damage repair and up-regulated genes involved in oxidative stress response, cell survival, and cardiac hypertrophy. At 1 month, the down-regulated genes included those involved in oxidative phosphorylation, mitochondrial dysfunction, nutrient metabolism, cardiac ß-adrenergic signaling, action potential generation, and cell survival. We also found 96 overlapping DEGs at both ages involved in oxidative phosphorylation, mitochondrial function, and calcium signaling. Impaired oxidative phosphorylation was observed at early disease stage, even before the appearance of disease phenotypes, and worsened with disease progression, suggesting its importance in the pathogenesis and progression of LMNA cardiomyopathy. Reduction of oxidative stress might therefore prevent or delay the development from Lmna mutation to LMNA cardiomyopathy.

Soluble angiotensin converting enzyme 2 levels in chronic heart failure is associated with decreased exercise capacity and increased oxidative stress-mediated endothelial dysfunction.

The aim of this study was to explore the relationship between serum soluble angiotensin converting enzyme 2 (sACE2), parameters of cardiopulmonary exercise testing and plasma asymmetric dimethylarginine (ADMA), a marker of oxidative stress-induced endothelial dysfunction. This has not been previously evaluated. We assessed 50 consecutive ambulatory patients with chronic systolic heart failure and left ventricular ejection fraction (LVEF) ≤45%. Their blood samples were collected for sACE2 and ADMA tests before they underwent symptom-limited cardiopulmonary exercise testing and transthoracic echocardiography. The majority of our study subjects had New York Heart Association functional class II (74%) and III (18%) presentation, and 42% of patients had ischemic etiology. Median sACE2 activity was 10.36 (7.00-14.47) ng/mL and mean ADMA was 0.90 ± 0.22. sACE2 activity was inversely correlated with pVO2 (r = -0.42, P = 0.00283), exercise time (r = -0.35, P = 0.0138) and LVEF (r = -0.548, P < 0.001), and positively correlated with VE/VCO2 slope (r = 0.294, P = 0.0405), ΔDBP (r = 0.315, P = 0.0278), mitral E/Ea ratio (r = 0.442, P = 0.00158) and ADMA levels (r = 0.351, P = 0.0134). Meanwhile, we observed a negative correlation between ADMA and pVO2 (r = -0.424, P = 0.00227) and positive correlations between ADMA and VE/VCO2 slope (r = 0.515, P < 0.001), ΔDBP (r = 0.391, P = 0.00568), mitral E/Ea ratio (r = 0.426, P = 0.00219). In multivariate logistic regression analysis, sACE2 was independently associated with peak oxygen uptake (% predicted) after adjusting for body mass index (BMI) and mitral E/Ea ratio (odds ratio [OR] 0.81 (0.58-0.94), P = 0.041) and associated with oxygen pulse (VO2/HR) (%) after adjusting for age, gender, BMI and mitral E/Ea ratio (OR 0.83 [0.68-0.95], P = 0.025). Therefore in stable chronic systolic heart failure patients, higher sACE2 activity is independently associated with diminished exercise capacity and correlates with elevated systemic oxidative stress-mediated endothelial dysfunction.

Paraoxonase 2 prevents the development of heart failure.

BACKGROUND: Mitochondrial oxidation is a major source of reactive oxygen species (ROS) and mitochondrial dysfunction plays a central role in development of heart failure (HF). Paraoxonase 2 deficient (PON2-def) mitochondria are impaired in function. In this study, we tested whether PON2-def aggravates HF progression. METHODS AND RESULTS: Using qPCR, immunoblotting and lactonase activity assay, we demonstrate that PON2 activity was significantly decreased in failing hearts despite increased PON2 expression. To determine the cardiac-specific function of PON2, we performed heart transplantations in which PON2-def and wild type (WT) donor hearts were implanted into WT recipient mice. Beating scores of the donor hearts, assessed at 4 weeks post-transplantation, were significantly decreased in PON2-def hearts when compared to WT donor hearts. By using a transverse aortic constriction (TAC) model, we found PON2 deficiency significantly exacerbated left ventricular remodeling and cardiac fibrosis post-TAC. We further demonstrated PON2 deficiency significantly enhanced ROS generation in heart tissues post-TAC. ROS generation was measured through dihydroethidium (DHE) using high-pressure liquid chromatography (HPLC) with a fluorescent detector. By using neonatal cardiomyocytes treated with CoCl2 to mimic hypoxia, we found PON2 deficiency dramatically increased ROS generation in the cardiomyocytes upon CoCl2 treatment. In response to a short CoCl2 exposure, cell viability and succinate dehydrogenase (SDH) activity assessed by MTT assay were significantly diminished in PON2-def cardiomyocytes compared to those in WT cardiomyocytes. PON2-def cardiomyocytes also had lower baseline SDH activity. By using adult mouse cardiomyocytes and mitochondrial ToxGlo assay, we found impaired cellular ATP generation in PON2-def cells compared to that in WT cells, suggesting that PON2 is necessary for proper mitochondrial function. CONCLUSION: Our study suggests a cardioprotective role for PON2 in both experimental and human heart failure, which may be associated with the ability of PON2 to improve mitochondrial function and diminish ROS generation.

Update on viral hepatitis in pregnancy.

Pregnant women with acute viral hepatitis are at higher risk of morbidity and death than pregnant women with chronic viral hepatitis. The risk of death is highest with acute viral hepatitis E, and the rate of transmission to the baby may be highest with hepatitis B virus (HBV) infection. Managing viral hepatitis in pregnancy requires assessing the risk of transmission to the baby, determining the gestational age at the time of infection and the mother's risk of decompensation, and understanding the side effects of antiviral drugs.

Racial and Ethnic Disparity in Major Depressive Disorder.

Major depressive disorder (MDD) is one of the most common and disabling psychiatric disorders in the USA. Early diagnosis and appropriate treatment are extremely important to prevent disability and improve quality of life. Recent studies have demonstrated racial and ethnic disparities in the diagnosis and treatment of MDD. African Americans (AA), Hispanics, and Asian Americans were significantly less likely to receive a depression diagnosis from a health-care provider than were non-Hispanic whites. The underdiagnosis of MDD in minority groups may be due to differences in socioeconomic status (SES), care affordability, cultural beliefs about depression, help-seeking patterns, access to culturally and linguistically appropriate care, patient-physician relationship, clinical presentation of depression, etc. Meanwhile, the likelihood of both having access to and receiving adequate care for depression was significantly low for AA, Hispanics, and Asian Americans, in contrast to whites. Similar disparities also exist in treatment outcomes. Besides the reasons for MDD underdiagnosis, additional contributing factors include access barriers to preferred mode of treatment, cultural concerns about antidepressants and different metabolism of antidepressants, etc. There are many ways to address these disparities and improve MDD care in minority populations, including universal depression screening, public financial incentives to ensure access to care in low-income and minority neighborhoods, quality improvement programs, cultural competency of mental health professionals, collaborative care management, community engagement and planning, and enhanced participation of minorities in clinical research.

Usefulness of elevated urine neopterin levels in assessing cardiac dysfunction and exercise ventilation inefficiency in patients with chronic systolic heart failure.

Neopterin is synthesized by macrophages upon stimulation with gamma-interferon, and high neopterin production is associated with cellular immune activation and increased production of reactive oxygen species (oxidant stress), but the clinical utility of urine neopterin levels in patients with heart failure (HF) has not been explored. Fifty-three ambulatory patients with chronic systolic HF (left ventricular [LV] ejection fraction ≤40%) underwent comprehensive echocardiographic evaluation and cardiopulmonary exercise testing. Urine neopterin levels were quantified by liquid chromatography with tandem mass spectrometric analyses and corrected to urine creatinine (Cr) levels. In our study cohort, median urine neopterin level was 60 µmol/mol Cr (interquartile range 40 to 86). There were modest correlations between urine neopterin levels and abnormalities in cardiac structure and function by echocardiography: LV ejection fraction (r = -0.33, p = 0.017), indexed LV end-diastolic volume (r = 0.31, p = 0.029), indexed LV end-systolic volume (r = 0.32, p = 0.024), and E/septal Ea (r = 0.28, p = 0.041). Although there was no significant correlation between urine neopterin and maximal oxygen uptake (peak VO2: r = -0.25, p = 0.07), there was a modest correlation between urine neopterin and maximal ventilation/carbon dioxide production ratio (VE/VCO2 max: r = 0.38, p = 0.005). In conclusion, increase in urine neopterin levels tracks with disease severity in patients with chronic systolic HF.

[Relationship between the level of sialic acid during perinatal period and early intelligence development of full term infants].

OBJECTIVE: To investigate the correlation between the status of sialic acid (SA) during perinatal period and early intelligence development of healthy full term infant, and to explore the effect of SA on the early intelligence development. METHOD: A total of 127 pairs of healthy mothers-neonates in the Affiliated Hospital of Nantong University were recruited randomly in this prospective cohort study. The levels of SA from body fluids of mothers-neonates were measured by enzyme-linked immunosorbent assay, such as the full-term maternal and cord blood and the colostrum. The questionnaire surveys were carried out in mothers and mental development evaluation according to Children's Development Center of China (CDCC) were carried out in infants 3 to 4 months of age to obtain the mental development index (MDI) and psycho-motor development index (PDI). RESULT: A total of 120 pairs of maternal-neonatal subjects with complete data were included into statistical analysis. The levels of SA of maternal and cord blood and colostrum were (2.25 ± 0.02), (1.21 ± 0.01), and (5.01 ± 0.06) mmol/L respectively. MDI and PDI of infants 3 to 4 months of age were (99.40 ± 1.87) and (98.53 ± 1.96). The analysis using multiple linear regression indicated that MDI was associated with SA levels of cord blood and colostrum (ß = 0.636, 0.175, P < 0.05), and PDI was also associated with them (ß = 0.502, 0.262, P < 0.05). The levels of SA of cord blood and colostrums were individually divided into high-level group and low-level one according to the median level. MDI and PDI in high-level group of cord blood were both significantly higher than that in low-level group (111.85 ± 2.79) vs. (108.88 ± 2.0) , (101.08 ± 4.44) vs. (98.88 ± 2.0) P < 0.01. So were MDI and PDI in high-level group of colostrum compared with those in low-level group (111.71 ± 3.07) vs. (108.81 ± 1.56), P < 0.01; (101.29 ± 4.23) vs.(98.56 ± 1.79), P < 0.05. The analysis on correlation between the levels of maternal-neonatal body fluids showed that the level of SA of colostrum was positively correlated with that of cord blood (r = 0.507, P = 0.004). However, no correlation was found either between the level of SA of maternal and cord blood or between the level of SA of maternal blood and colostrums. Further division into high-level and low-level groups was done according to the median level of maternal blood. The levels of SA of colostrum and cord blood in high-level group were markedly higher than those in low-level one (5.12 ± 0.35) vs. (4.87 ± 0.22) and (1.21 ± 0.02) vs. (1.17 ± 0.01), P < 0.05. CONCLUSION: High levels of SA of cord blood and colostrums might be beneficial to the early intelligence development of full term infant. Abundant intake of SA during perinatal period and good function of placenta may play important role in early intelligence development.

Angiotensin-converting enzyme 2 as a therapeutic target for heart failure.

The renin-angiotensin system (RAS) plays a major role in the pathophysiology of cardiovascular disorders. Angiotensin II (Ang-II), the final product of this pathway, is known for its vasoconstrictive and proliferative effects. Angiotensin-converting enzyme 2 (ACE2), a newly discovered homolog of ACE, plays a key role as the central negative regulator of the RAS. It diverts the generation of vasoactive Ang-II into the vasodilatory and growth inhibiting peptide angiotensin(1-7) [Ang(1-7)], thereby providing counter-regulatory responses to neurohormonal activation. There is substantial experimental evidence evaluating the role of ACE2/Ang(1-7) in hypertension, heart failure, and atherosclerosis. In this review, we aim to focus on the conceptual facts of the ACE2-Ang(1-7) axis with regards to clinical implications and therapeutic targets in cardiovascular disorders, with emphasis on the potential therapeutic role in cardiovascular diseases.

Increasing serum soluble angiotensin-converting enzyme 2 activity after intensive medical therapy is associated with better prognosis in acute decompensated heart failure.

BACKGROUND: Angiotensin-converting enzyme 2 (ACE2) is an endogenous counterregulator of the renin-angiotensin system that has been recently identified in circulating form. We aimed to investigate the relationship among changes in soluble ACE2 (sACE2) activity, myocardial performance, and long-term clinical outcomes in patients with acute decompensated heart failure (ADHF). We hypothesized that increasing sACE2 activity levels during intensive medical treatment are associated with improved myocardial performance and long-term clinical outcomes. METHODS AND RESULTS: In 70 patients admitted to the intensive care unit with ADHF, serum sACE2 activity levels, echocardiographic data, and hemodynamic variables were collected within 12 hours of admission (n = 70) and 48-72 hours after intensive medical treatment (n = 57). The median [interquartile range] baseline and 48-72-hour serum sACE2 activity levels were 32 [23-43] ng/mL and 40 [28-60] ng/mL, respectively. Baseline serum sACE2 activity levels correlated with surrogate measures of right ventricular diastolic dysfunction, including right atrial volume index (RAVi; r = 0.31; P = .010), tricuspid E/A ratio (r = 0.39; P = .007), and B-type natriuretic peptide (r = 0.32; P = .008). However, there were no correlations between serum sACE2 and left ventricular systolic or diastolic dysfunction. After intensive medical therapy, a 50% increase in baseline serum sACE2 levels predicted a significant reduction in risk of death, cardiac transplantation, or ADHF rehospitalization, including after adjustment for baseline age, RAVi, and BNP levels (hazard ratio 0.35, 95% confidence interval 0.12-0.84; P = .018). CONCLUSIONS: In patients admitted with ADHF, increasing serum sACE2 activity levels during intensive medical therapy predict improved outcomes independently from underlying cardiac indices.

Novel urinary biomarkers in detecting acute kidney injury, persistent renal impairment, and all-cause mortality following decongestive therapy in acute decompensated heart failure.

BACKGROUND: New urinary biomarkers, such as neutrophil gelatinase-associated lipocalin (NGAL), kidney injury molecule-1 (KIM-1), and interleukin-18 (IL-18), are proposed to allow a more reliable early diagnosis and prognosis of acute kidney injury (AKI) in acute decompensated heart failure (ADHF). Our aim was to compare the predictive value of urinary NGAL, KIM-1, and IL-18 for the occurrence of AKI, persistent renal impairment, and mortality in ADHF. METHODS AND RESULTS: Eighty-three patients admitted for ADHF were analyzed. Urinary creatinine (Cr), NGAL, KIM-1, and IL-18 were measured at baseline. Serum Cr was measured daily during the next 4 days and again at outpatient follow-up after 6 months. Mortality data were prospectively collected. Urinary NGAL, KIM-1, and IL-18 were modestly correlated with each other (Spearman ρ ≤0.61) and poorly correlated with estimated glomerular filtration rate (eGFR; Spearman ρ ≤0.28). None predicted AKI, defined as a 25% decrease in eGFR, during the index hospitalization, but urinary IL-18/Cr was the strongest predictor of persistently elevated serum Cr ≥0.3 mg/dL after 6 months compared with baseline (area under the receiver operating characteristic curve 0.674; P = .013). Urinary IL-18 was also significantly associated with all-cause mortality (hazard ratio 1.48, 95% confidence interval 1.16-1.87; P = .001). CONCLUSIONS: Like urinary NGAL, urinary KIM-1 and IL-18 are relatively modest predictors of AKI in ADHF. Among these novel renal biomarkers examined, further investigations regarding the prognostic value of urinary IL-18 are warranted.

Relation of systemic and urinary neutrophil gelatinase-associated lipocalin levels to different aspects of impaired renal function in patients with acute decompensated heart failure.

Both urine and serum neutrophil gelatinase-associated lipocalin (NGAL) reflect active chronic kidney disease and predict acute kidney injury. However, a direct comparison of these markers in acute decompensated heart failure has not been performed. We prospectively evaluated 93 patients admitted with acute decompensated heart failure and treated with intravenous furosemide and measured both systemic (serum) and urine NGAL levels and their corresponding markers of estimated glomerular filtration rate, natriuresis (urine sodium), and diuretic response (net output, urine sodium/furosemide ratio). In our study cohort, the median urine and serum NGAL level was 34 ng/ml (interquartile range 24 to 86) and 252 ng/ml (interquartile range 175 to 350), respectively. The urine and serum NGAL levels correlated modestly (r = 0.37, p <0.001). Higher urine (but not systemic) NGAL correlated with the markers of impaired natriuresis and reduced diuresis (p <0.005 for all). In contrast, higher serum NGAL demonstrated a stronger relation with reduced glomerular filtration function (p <0.0001). Both markers predicted acute kidney injury (urine NGAL, odds ratio 1.7, p = 0.035; serum NGAL, odds ratio 1.9, p = 0.009). In conclusion, in patients with acute decompensated heart failure, urine NGAL levels reflect renal distal tubular injury with impaired natriuresis and diuresis, and systemic NGAL levels demonstrate a stronger association with glomerular filtration function. Both systemic and urine NGAL predict worsening renal function.

Pulmonary hypertension associated with advanced systolic heart failure: dysregulated arginine metabolism and importance of compensatory dimethylarginine dimethylaminohydrolase-1.

OBJECTIVES: This study sought to examine the hemodynamic determinants of dysregulated arginine metabolism in patients with acute decompensated heart failure and to explore possible mechanisms of arginine dysregulation in human heart failure. BACKGROUND: Accumulating methylated arginine metabolites and impaired arginine bioavailability have been associated with heart failure, but the underlying pathophysiology remains unclear. METHODS: This study prospectively determined plasma levels of asymmetric dimethylarginine (ADMA), an endogenous nitric oxide synthase inhibitor, and global arginine bioavailability ratio [GABR = arginine/(ornithine + citrulline)] by tandem mass spectrometry in subjects with advanced decompensated heart failure in the intensive care unit (n = 68) and with stable chronic heart failure (n = 57). RESULTS: Compared with chronic heart failure subjects, plasma ADMA was significantly higher (median [interquartile range]: 1.29 [1.04 to 1.77] µmol/l vs. 0.87 [0.72 to 1.05] µmol/l, p < 0.0001), and global arginine bioavailability ratio significantly lower (median [interquartile range]: 0.90 [0.69 to 1.22] vs. 1.13 [0.92 to 1.37], p = 0.002) in advanced decompensated heart failure subjects. Elevated ADMA and diminished global arginine bioavailability ratio were associated with higher systolic pulmonary artery pressure (sPAP) and higher central venous pressure, but not with other clinical or hemodynamic indices. We further observed myocardial levels of dimethylarginine dimethylaminohydrolase-1 were increased in chronic heart failure without elevated sPAP (<50 mm Hg), but diminished with elevated sPAP (≥50 mm Hg, difference with sPAP <50 mm Hg, p = 0.02). CONCLUSIONS: Dysregulated arginine metabolism was observed in advanced decompensated heart failure, particularly with pulmonary hypertension and elevated intracardiac filling pressures. Compared with hearts of control subjects, we observed higher amounts of ADMA-degradation enzyme dimethylarginine dimethylaminohydrolase-1 (but similar amounts of ADMA-producing enzyme, protein methyltransferase-1) in the human failing myocardium.

Usefulness of plasma galectin-3 levels in systolic heart failure to predict renal insufficiency and survival.

Galectin-3 plays an important role in fibroblast activation and fibrosis in animal models. Increased galectin-3 levels are associated with poor long-term survival in heart failure (HF). We examined the relation between plasma galectin-3 levels and myocardial indexes of systolic HF. We measured plasma galectin-3 in 133 subjects with chronic HF and 45 with advanced decompensated HF using echocardiographic and hemodynamic evaluations. In the chronic HF cohort, median plasma galectin-3 level was 13.9 ng/ml (interquartile range 12.1 to 16.9). Higher galectin-3 was associated with more advanced age (r = 0.22, p = 0.010), poor renal function (estimated glomerular filtration rate, r = -0.24, p = 0.007; cystatin C, r = 0.38, p <0.0001) and predicted all-cause mortality (hazard ratio 1.86, 95% confidence interval 1.36 to 2.54, p <0.001). In multivariate analysis, galectin-3 remained an independent predictor of all-cause mortality after adjusting for age, estimated glomerular filtration rate, left ventricular (LV) ejection fraction, and mitral early diastolic myocardial relaxation velocity at septal mitral annulus (hazard ratio 1.94, 95% confidence interval 1.30 to 2.91, p = 0.001). However, galectin-3 did not predict the combined end point of all-cause mortality, cardiac transplantation, or HF hospitalization (p >0.05). Furthermore, there were no relations between galectin-3 and LV end-diastolic volume index (r = -0.05, p = 0.61), LV ejection fraction (r = 0.10, p = 0.25), or LV diastolic function (mitral early diastolic myocardial relaxation velocity at septal mitral annulus, r = 0.06, p = 0.52; left atrial volume index, r = 0.08, p = 0.41). In the advanced decompensated HF cohort, we did not observe any relation between galectin-3 and echocardiographic or hemodynamic indexes. In conclusion, high plasma galectin-3 levels were associated with renal insufficiency and poorer survival in patients with chronic systolic HF. However, we did not observe a relation between galectin-3 and echocardiographic or hemodynamic indexes.

Serine 58 of 14-3-3zeta is a molecular switch regulating ASK1 and oxidant stress-induced cell death.

Oxidant stress is a ubiquitous stressor with negative impacts on multiple cell types. ASK1 is a central mediator of oxidant injury, but while mechanisms of its inhibition, such as sequestration by 14-3-3 proteins and thioredoxin, have been identified, mechanisms of activation have remained obscure and the signaling pathways regulating this are not clear. Here, we report that phosphorylation of 14-3-3zeta at serine 58 (S58) is dynamically regulated in the cell and that the phosphorylation status of S58 is a critical factor regulating oxidant stress-induced cell death. Phosphorylation of S58 releases ASK1 from 14-3-3zeta, and ASK1 then activates stress-activated protein kinases, leading to cell death. While several members of the mammalian sterile 20 (Mst) family of kinases can phosphorylate S58 when overexpressed, we identify Ste20/oxidant stress response kinase 1 (SOK-1), an Mst family member known to be activated by oxidant stress, as a central endogenous regulator of S58 phosphorylation and thereby of ASK1-mediated cell death. Our findings identify a novel pathway that regulates ASK1 activation and oxidant stress-induced cell death.

c-Jun N-terminal kinases mediate reactivation of Akt and cardiomyocyte survival after hypoxic injury in vitro and in vivo.

Akt is a central regulator of cardiomyocyte survival after ischemic injury in vitro and in vivo, but the mechanisms regulating Akt activity in the postischemic cardiomyocyte are not known. Furthermore, although much is known about the detrimental role that the c-Jun N-terminal kinases (JNKs) play in promoting death of cells exposed to various stresses, little is known of the molecular mechanisms by which JNK activation can be protective. We report that JNKs are necessary for the reactivation of Akt after ischemic injury. We identified Thr450 of Akt as a residue that is phosphorylated by JNKs, and the phosphorylation status of Thr450 regulates reactivation of Akt after hypoxia, apparently by priming Akt for subsequent phosphorylation by 3-phosphoinositide-dependent protein kinase. The reduction in Akt activity that is induced by JNK inhibition may have significant biological consequences, as we find that JNKs, acting via Akt, are critical determinants of survival in posthypoxic cardiomyocytes in culture. Furthermore, in contrast to selective p38-mitogen-activated protein kinase inhibition, which was cardioprotective in vivo, concurrent inhibition of both JNKs and p38-mitogen-activated protein kinases increased ischemia/reperfusion injury in the heart of the intact rat. These studies demonstrate that reactivation of Akt after resolution of hypoxia and ischemia is regulated by JNKs and suggest that this is likely a central mechanism of the myocyte protective effect of JNKs.

Glycogen synthase kinase-3beta regulates growth, calcium homeostasis, and diastolic function in the heart.

Glycogen synthase kinase (GSK) 3beta is a negative regulator of stress-induced cardiomyocyte hypertrophy. It is not clear, however, if GSK-3beta plays any role in regulating normal cardiac growth and cardiac function. Herein we report that a transgenic mouse expressing wild type GSK-3beta in the heart has a dramatic impairment of normal post-natal cardiomyocyte growth as well as markedly abnormal cardiac contractile function. The most striking phenotype, however, is grossly impaired diastolic relaxation, which leads to increased filling pressures of the left ventricle and massive atrial enlargement. This is due to profoundly abnormal calcium handling, leading to an inability to normalize cytosolic [Ca2+] in diastole. The alterations in calcium handling are due at least in part to direct down-regulation of the sarcoplasmic reticulum calcium ATPase (SERCA2a) by GSK-3beta, acting at the level of the SERCA2 promoter. These studies identify GSK-3beta as a regulator of normal growth of the heart and are the first of which we are aware, to demonstrate regulation of expression of SERCA2a, a critical determinant of diastolic function, by a cytosolic signaling pathway, the activity of which is dynamically modulated. De-regulation of GSK-3beta leads to severe systolic and diastolic dysfunction and progressive heart failure. Because down-regulation of SERCA2a plays a central role in the diastolic and systolic dysfunction of patients with heart failure, these findings have potential implications for the therapy of this disorder.

A death-associated protein kinase (DAPK)-interacting protein, DIP-1, is an E3 ubiquitin ligase that promotes tumor necrosis factor-induced apoptosis and regulates the cellular levels of DAPK.

Death-associated protein kinase (DAPK) is a multi-domain Ser/Thr protein kinase with an important role in apoptosis regulation. In these studies we have identified a DAPK-interacting protein called DIP-1, which is a novel multi-RING finger protein. The RING finger motifs of DIP-1 have E3 ligase activity that can auto-ubiquitinate DIP-1 in vitro. In vivo, DIP-1 is detected as a polyubiquitinated protein, suggesting that the intracellular levels of DIP-1 are regulated by the ubiquitin-proteasome system. Transient expression of DIP-1 in HeLa cells antagonizes the anti-apoptotic function of DAPK to promote a caspase-dependent apoptosis. These studies also demonstrate that DAPK is an in vitro and in vivo target for ubiquitination by DIP-1, thereby providing a mechanism by which DAPK activities can be regulated through proteasomal degradation.