Ellagic acid inhibits mitochondrial fission protein Drp-1 and cell proliferation in cancer.

Anthracyclines such as doxorubicin (Dox) are widely used to treat a variety of adult and childhood cancers, however, a major limitation to many of these compounds is their propensity for inducing heart failure. A naturally occurring polyphenolic compound such as Ellagic acid (EA) has been shown by our laboratory to mitigate the cardiotoxic effects of Dox, however, the effects of EA on cancer cell viability have not been established. In this study, we explored the effects of EA alone and in combination with Dox on cancer cell viability and tumorigenesis. Herein, we show that EA induces cell cycle exit and reduces proliferation in colorectal cancer (HCT116) and breast adenocarcinoma cells (MCF7). We show that EA promotes cell cycle exit by a mechanism that inhibits mitochondrial dynamics protein Drp-1. EA treatment of HCT116 and MCF7 cells resulted in a hyperfused mitochondrial morphology that coincided with mitochondrial perturbations including loss of mitochondrial membrane potential, impaired respiratory capacity. Moreover, impaired mitochondrial function was accompanied by a reduction in cell cycle and proliferation markers, CDK1, Ki67, and Cyclin B. This resulted in a reduction in proliferation and widespread death of cancer cells. Furthermore, while Dox treatment alone promoted cell death in both HCT116 and MCF7 cancer cell lines, EA treatment lowered the effective dose of Dox to promote cell death. Hence, the findings of the present study reveal a previously unreported anti-tumor property of EA that impinges on mitochondrial dynamics protein, Drp-1 which is crucial for cell division and tumorigenesis. The ability of EA to lower the therapeutic threshold of Dox for inhibiting cancer cell growth may prove beneficial in reducing cardiotoxicity in cancer patients undergoing anthracycline therapy.

Epidemiology of heart failure with preserved ejection fraction.

The prevalence of heart failure (HF) and its subtype, HF with preserved ejection fraction (HFpEF), is on the rise due to aging of the population. HFpEF is convergence of several pathophysiological processes, which are not yet clearly identified. HFpEF is usually seen in association with systemic diseases, such as diabetes, hypertension, atrial fibrillation, sleep apnea, renal and pulmonary disease. The proportion of HF patients with HFpEF varies by patient demographics, study settings (cohort vs. clinical trial, outpatient clinics vs. hospitalised patients) and cut points used to define preserved function. There is an expanding body of literature about prevalence and prognostic significance of both cardiovascular and non-cardiovascular comorbidities in HFpEF patients. Current therapeutic approaches are targeted towards alleviating the symptoms, treating the associated comorbid conditions, and reducing recurrent hospital admissions. There is lack of evidence-based therapies that show a reduction in the mortality amongst HFpEF patients; however, an improvement in exercise tolerance and quality of life is seen with few interventions. In this review, we highlight the epidemiology and current treatment options for HFpEF.

Ellagic acid antagonizes Bnip3-mediated mitochondrial injury and necrotic cell death of cardiac myocytes.

The Bcl-2 protein Bnip3 is crucial for provoking oxidative injury to mitochondria following anthracycline treatment or ischemia-reperfusion injury. Herein, we investigate the effects of the polyphenolic compound ellagic acid (EA) on Bnip3 mediated mitochondrial injury and necrotic cell death in cardiac myocytes. In contrast to vehicle treated cardiomyocytes, Bnip3 was highly enriched in mitochondrial fractions of cardiac myocytes treated with the anthracycline doxorubicin or in cells subjected to hypoxia (HPX). Mitochondrial associated Bnip3 was accompanied by mPTP opening and loss of ∆Ψm. The dynamin related fission protein Drp-1 was phosphorylated (Drp1616) and coincided with excessive mitochondrial fragmentation, mitophagy and necrosis in cardiac myocytes treated with doxorubicin or subjected to hypoxia. Moreover, knock-down of Bnip3 was sufficient to prevent mitochondrial fission and doxorubicin-induced cell death supporting the involvement of Bnip3 in doxorubicin cardiotoxity. Interestingly, mitochondrial associated Bnip3 in cells treated with doxorubicin was markedly reduced by EA. This resulted in significantly less mitochondrial fission and cell death. Notably, EA similarly suppressed mitochondrial injury and cell death induced by hypoxia or Bnip3 over-expression. Herein, we identify a novel signaling axis that operationally links EA and Bnip3 for suppression of cardiac cell death. We provide compelling new evidence that EA suppresses mitochondrial injury and necrotic cell death of cardiac myocytes by functionally abrogating Bnip3 activity. Hence, by suppressing mitochondrial injury induced by Bnip3, EA may provide a therapeutic advantage in reducing oxidative injury and cardiac dysfunction in cancer patients undergoing anthracycline treatment or individuals with ischemic cardiac stress.

Role of coronary artery calcium score in identifying occult coronary artery disease in patients evaluated for deceased-donor liver transplant - a preliminary report.

Coronary artery disease may affect cirrhotic patients regardless of age and etiology of the underlying liver disease. Early identification of coronary artery disease is important to be able to achieve the best posttransplant outcomes and survival. The coronary artery calcium score can be used as a screening tool to supplement the results of cardiac stress tests to identify a subgroup of patients who may benefit from further investigation with coronary arteriogram. Arteriogram is an invasive test and may cause renal compromise and risk of bleeding associated with coagulopathy. The present retrospective study showed that coronary artery calcium score > 250 Agatston units may help select the subgroup of patients who will benefit from further investigation with cardiac catheterization, and determining this score may limit the risks of catheterization.

Recent advances in the treatment of hepatitis C.

Hepatitis C virus (HCV) therapeutics is amidst a revolution. With the recent approval of sofosbuvir (Sovaldi) and simeprevir (Olysio), clinicians and patients started to recognize that for the first time in the history, hepatitis C can be cured in a majority of patients without interferon. These new regimens are safe, and have excellent efficacy and minimal adverse events. Sofosbuvir, a nucleotide analogue (NS5B polymerase inhibitor), is a potent drug with excellent tolerability and pan-genotypic activity with a high barrier to resistance. Simeprevir, a second-generation protease inhibitor which inhibits the initial cleavage of the HCV poly-protein by the NS3/4A protease. Simeprevir has been evaluated in clinical trials in combination with interferon and ribavirin based therapy and also in the COSMO trial in combination with sofosbuvir. More directly acting antiviral therapy drugs are in the pipeline with several drugs being expected to be approved by the FDA in late 2014. Although these drugs have excellent efficacy, they are more costly. The price of these drugs limits treatments of many patients in the world especially in countries with limited economic resources. However, with the availability of a variety of excellent directly acting antivirals (DAAs) in the near future, hopefully many patients would be able to afford the treatment. The future in HCV therapy will focus on special groups of patients who were excluded from initial HCV clinical trials such as post-liver transplant HCV recurrence, patients with HCV/HIV co-infection, and patients with advanced cirrhosis.