Integrative Effect of Carvedilol and Aerobic Exercise Training Therapies on Improving Cardiac Contractility and Remodeling in Heart Failure Mice

The use of b-blockers is mandatory for counteracting heart failure (HF)-induced chronic sympathetic hyperactivity, cardiac dysfunction and remodeling. Importantly, aerobic exercise training, an efficient nonpharmacological therapy to HF, also counteracts sympathetic hyperactivity in HF and improves exercise tolerance and cardiac contractility; the latter associated with changes in cardiac Ca2+ handling. This study was undertaken to test whether combined b-blocker and aerobic exercise training would integrate the beneficial effects of isolated therapies on cardiac structure, contractility and cardiomyocyte Ca2+ handling in a genetic model of sympathetic hyperactivity-induced HF (alpha(2A)/alpha 2C(-)adrenergic receptor knockout mice, KO). We used a cohort of 5-7 mo male wild-type (WT) and congenic mice (KO) with C57Bl6/J genetic background randomly assigned into 5 groups: control (WT), saline-treated KO (KOS), exercise trained KO (KOT), carvedilol-treated KO (KOC) and, combined carvedilol-treated and exercise-trained KO (KOCT). Isolated and combined therapies reduced mortality compared with KOS mice. Both KOT and KOCT groups had increased exercise tolerance, while groups receiving carvedilol had increased left ventricular fractional shortening and reduced cardiac collagen volume fraction compared with KOS group. Cellular data confirmed that cardiomyocytes from KOS mice displayed abnormal Ca2+ handling. KOT group had increased intracellular peak of Ca2+ transient and reduced diastolic Ca2+ decay compared with KOS group, while KOC had increased Ca2+ decay compared with KOS group. Notably, combined therapies re-established cardiomyocyte Ca2+ transient paralleled by increased SERCA2 expression and SERCA2: PLN ratio toward WT levels. Aerobic exercise trained increased the phosphorylation of PLN at Ser16 and Thr17 residues in both KOT and KOCT groups, but carvedilol treatment reduced lipid peroxidation in KOC and KOCT groups compared with KOS group. the present findings provide evidence that the combination of carvedilol and aerobic exercise training therapies lead to a better integrative outcome than carvedilol or exercise training used in isolation.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG)Conselho Nacional de Pesquisa e DesenvolvimentoConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Univ São Paulo, Sch Phys Educ & Sport, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Biosci, Santos, BrazilDept Circulat & Med Imaging, Trondheim, NorwayKG Jebsen Ctr Exercise Med, Trondheim, NorwayUniv Fed Minas Gerais, Dept Physiol & Biophys, Belo Horizonte, MG, BrazilUniv São Paulo, Heart Inst InCor, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Biosci, Santos, BrazilFAPESP: FAPESP:2010/50048-1FAPESP: 06/56123-0CNPq: 302201/2011-4Web of Scienc

A cyclopalladated complex interacts with mitochondrial membrane thiol-groups and induces the apoptotic intrinsic pathway in murine and cisplatin-resistant human tumor cells

<p>Abstract</p> <p>Background</p> <p>Systemic therapy for cancer metastatic lesions is difficult and generally renders a poor clinical response. Structural analogs of cisplatin, the most widely used synthetic metal complexes, show toxic side-effects and tumor cell resistance. Recently, palladium complexes with increased stability are being investigated to circumvent these limitations, and a biphosphinic cyclopalladated complex {Pd₂[<it>S_(-)</it>C², N-dmpa]₂(μ-dppe)Cl₂} named C7a efficiently controls the subcutaneous development of B16F10-Nex2 murine melanoma in syngeneic mice. Presently, we investigated the melanoma cell killing mechanism induced by C7a, and extended preclinical studies.</p> <p>Methods</p> <p>B16F10-Nex2 cells were treated <it>in vitro </it>with C7a in the presence/absence of DTT, and several parameters related to apoptosis induction were evaluated. Preclinical studies were performed, and mice were endovenously inoculated with B16F10-Nex2 cells, intraperitoneally treated with C7a, and lung metastatic nodules were counted. The cytotoxic effects and the respiratory metabolism were also determined in human tumor cell lines treated <it>in vitro </it>with C7a.</p> <p>Results</p> <p>Cyclopalladated complex interacts with thiol groups on the mitochondrial membrane proteins, causes dissipation of the mitochondrial membrane potential, and induces Bax translocation from the cytosol to mitochondria, colocalizing with a mitochondrial tracker. C7a also induced an increase in cytosolic calcium concentration, mainly from intracellular compartments, and a significant decrease in the ATP levels. Activation of effector caspases, chromatin condensation and DNA degradation, suggested that C7a activates the apoptotic intrinsic pathway in murine melanoma cells. In the preclinical studies, the C7a complex protected against murine metastatic melanoma and induced death in several human tumor cell lineages <it>in vitro</it>, including cisplatin-resistant ones. The mitochondria-dependent cell death was also induced by C7a in human tumor cells.</p> <p>Conclusions</p> <p>The cyclopalladated C7a complex is an effective chemotherapeutic anticancer compound against primary and metastatic murine and human tumors, including cisplatin-resistant cells, inducing apoptotic cell death via the intrinsic pathway.</p

Mitochondrial Quality Control in Cardiac Diseases

Disruption of mitochondrial homeostasis is a hallmark of cardiac diseases. Therefore, maintenance of mitochondrial integrity through different surveillance mechanisms is critical for cardiomyocyte survival. In this review, we discuss the most recent findings on the central role of mitochondrial quality control processes including regulation of mitochondrial redox balance, aldehyde metabolism, proteostasis, dynamics and clearance in cardiac diseases, highlighting their potential as therapeutic targets

Skeletal muscle Cathepsin L.

<p>Soleus (<b>A</b>) and plantaris (<b>B</b>) Cathepsin L activity in Sham and MI groups. Correlations between <i>CTSL1</i> mRNA levels and skeletal muscle fiber cross-sectional area (CSA) in soleus (<b>C</b>, Sham n = 7, MI n = 5) and plantaris (<b>D</b>, Sham n = 6, MI n = 6) muscles. Data presented as mean ± SEM. *indicates p≤0.05 vs. Sham. The number of animals in each analysis is shown within the bars.</p

Mitophagy and mitochondrial fission in plantaris muscle.

<p>Plantaris Bnip3 (<b>A</b>), DRP1 (<b>B</b>) and Fis1 (<b>C</b>) protein levels, and representative immunoblots (<b>D</b>) in Sham and MI groups. Correlation between plantaris <i>BNIP3</i> mRNA levels and distance run in a graded treadmill exercise test (<b>E</b>, Sham n = 8, MI n = 10). Data presented as mean ± SEM. *indicates p≤0.05 vs. Sham. The number of animals in each analysis is shown within the bars.</p

Autophagic marker in plantaris muscle.

<p>Plantaris LC3-I (<b>A</b>) and LC3-II (<b>B</b>) protein levels, LC3-II/LC3-I ratio (<b>C</b>) and representative imunnoblots (<b>D</b>) in Sham and MI groups. Correlation between plantaris LC3-II protein expression and distance run in a graded treadmill exercise test (<b>E</b>, Sham n = 9, MI n = 10). Data presented as mean ± SEM. AU, arbitrary unit. The number of animals in each analysis is shown within the bars.</p