Carvedilol Phenocopies PGC-1α Overexpression to Alleviate Oxidative Stress, Mitochondrial Dysfunction and Prevent Doxorubicin-Induced Toxicity in Human iPSC-Derived Cardiomyocytes.

Doxorubicin (DOX), one of the most effective and widely used anticancer drugs, has the major limitation of cancer treatment-related cardiotoxicity (CTRTOX) in the clinic. Reactive oxygen species (ROS) generation and mitochondrial dysfunction are well-known consequences of DOX-induced injury to cardiomyocytes. This study aimed to explore the mitochondrial functional consequences and associated mechanisms of pretreatment with carvedilol, a ß-blocking agent known to exert protection against DOX toxicity. When disease modeling was performed using cultured rat cardiac muscle cells (H9c2 cells) and human iPSC-derived cardiomyocytes (iPSC-CMs), we found that prophylactic carvedilol mitigated not only the DOX-induced suppression of mitochondrial function but that the mitochondrial functional readout of carvedilol-pretreated cells mimicked the readout of cells overexpressing the major regulator of mitochondrial biogenesis, PGC-1α. Carvedilol pretreatment reduces mitochondrial oxidants, decreases cell death in both H9c2 cells and human iPSC-CM and maintains the cellular 'redox poise' as determined by sustained expression of the redox sensor Keap1 and prevention of DOX-induced Nrf2 nuclear translocation. These results indicate that, in addition to the already known ROS-scavenging effects, carvedilol has a hitherto unrecognized pro-reducing property against the oxidizing conditions induced by DOX treatment, the sequalae of DOX-induced mitochondrial dysfunction and compromised cell viability. The novel findings of our preclinical studies suggest future trial design of carvedilol prophylaxis, such as prescreening for redox state, might be an alternative strategy for preventing oxidative stress writ large in lieu of the current lack of clinical evidence for ROS-scavenging agents.

Collagen-Specific HSP47+ Myofibroblasts and CD163+ Macrophages Identify Profibrotic Phenotypes in Deceased Hearts With SARS-CoV-2 Infections.

Background Cardiac fibrosis complicates SARS-CoV-2 infections and has been linked to arrhythmic complications in survivors. Accordingly, we sought evidence of increased HSP47 (heat shock protein 47), a stress-inducible chaperone protein that regulates biosynthesis and secretion of procollagen in heart tissue, with the goal of elucidating molecular mechanisms underlying cardiac fibrosis in subjects with this viral infection. Methods and Results Using human autopsy tissue, immunofluorescence, and immunohistochemistry, we quantified Hsp47+ cells and collagen α 1(l) in hearts from people with SARS-CoV-2 infections. Because macrophages are also linked to inflammation, we measured CD163+ cells in the same tissues. We observed irregular groups of spindle-shaped HSP47+ and CD163+ cells as well as increased collagen α 1(I) deposition, each proximate to one another in "hot spots" of ≈40% of hearts after SARS-CoV-2 infection (HSP47+ P<0.05 versus nonfibrotics and P<0.001 versus controls). Because HSP47+ cells are consistent with myofibroblasts, subjects with hot spots are termed "profibrotic." The remaining 60% of subjects dying with COVID-19 without hot spots are referred to as "nonfibrotic." No control subject exhibited hot spots. Conclusions Colocalization of myofibroblasts, M2(CD163+) macrophages, and collagen α 1(l) may be the first evidence of a COVID-19-related "profibrotic phenotype" in human hearts in situ. The potential public health and diagnostic implications of these observations require follow-up to further define mechanisms of viral-mediated cardiac fibrosis.

Lurbinectedin versus pegylated liposomal doxorubicin or topotecan in patients with platinum-resistant ovarian cancer: A multicenter, randomized, controlled, open-label phase 3 study (CORAIL).

OBJECTIVE: The randomized phase 3 CORAIL trial evaluated whether lurbinectedin improved progression-free survival (PFS) compared to pegylated liposomal doxorubicin (PLD) or topotecan in patients with platinum-resistant ovarian cancer. METHODS: Patients were randomly assigned (1:1) to lurbinectedin 3.2 mg/m2 1-h i.v. infusion q3wk (experimental arm), versus PLD 50 mg/m2 1-h i.v. infusion q4wk or topotecan 1.50 mg/m2 30-min i.v. infusion Days 1-5 q3wk (control arm). Stratification factors were PS (0 vs. ≥1), prior PFI (1-3 months vs. >3 months), and prior chemotherapy lines (1-2 vs. 3). The primary endpoint was PFS by Independent Review Committee in all randomized patients. This study was registered with ClinicalTrials.gov, NCT02421588. RESULTS: 442 patients were randomized: 221 in lurbinectedin arm and 221 in control arm (127 PLD and 94 topotecan). With a median follow-up of 25.6 months, median PFS was 3.5 months (95% CI, 2.1-3.7) in the lurbinectedin arm and 3.6 months (95% CI, 2.7-3.8) in the control arm (stratified log-rank p = 0.6294; HR = 1.057). Grade ≥ 3 treatment-related adverse events (AEs) were most frequent in the control arm: 64.8% vs. 47.9% (p = 0.0005), mainly due to hematological toxicities. The most common grade ≥ 3 AEs were: fatigue (7.3% of patients) and nausea (5.9%) with lurbinectedin; mucosal inflammation (8.5%) and fatigue (8.0%) in the control arm. CONCLUSIONS: The primary endpoint of improvement in PFS was not met. Lurbinectedin showed similar antitumor efficacy and was better tolerated than current standard of care in patients with platinum-resistant ovarian cancer.

Identification and analysis of circulating long non-coding RNAs with high significance in diabetic cardiomyopathy.

Diabetic cardiomyopathy (DCM) lacks diagnostic biomarkers. Circulating long non-coding RNAs (lncRNAs) can serve as valuable diagnostic biomarkers in cardiovascular disease. To seek potential lncRNAs as a diagnostic biomarker for DCM, we investigated the genome-wide expression profiling of circulating lncRNAs and mRNAs in type 2 diabetic db/db mice with and without DCM and performed bioinformatic analyses of the deregulated lncRNA-mRNA co-expression network. Db/db mice had obesity and hyperglycemia with normal cardiac function at 6 weeks of age (diabetes without DCM) but with an impaired cardiac function at 20 weeks of age (DCM) on an isolated Langendorff apparatus. Compared with the age-matched controls, 152 circulating lncRNAs, 127 mRNAs and 3355 lncRNAs, 2580 mRNAs were deregulated in db/db mice without and with DCM, respectively. The lncRNA-mRNA co-expression network analysis showed that five deregulated lncRNAs, XLOC015617, AK035192, Gm10435, TCR-α chain, and MouselincRNA0135, have the maximum connections with differentially expressed mRNAs. Bioinformatic analysis revealed that these five lncRNAs were highly associated with the development and motion of myofilaments, regulation of inflammatory and immune responses, and apoptosis. This finding was validated by the ultrastructural examination of myocardial samples from the db/db mice with DCM using electron microscopy and changes in the expression of myocardial tumor necrosis factor-α and phosphorylated p38 mitogen-activated protein kinase in db/db mice with DCM. These results indicate that XLOC015617, AK035192, Gm10435, TCR-α chain, and MouselincRNA0135 are crucial circulating lncRNAs in the pathogenesis of DCM. These five circulating lncRNAs may have high potential as a diagnostic biomarker for DCM.

Optimización del desempeño del observador al medir la presión arterial en el consultorio: declaración de posición de la Comisión Lancet de Hipertensión / Optimizing observer performance of clinic blood Pressure measurement: a position statement from the Lancet Commission on Hypertension Group / Otimização do desempenho do observador na medição clínica da pressão arterial: posicionamento do Grupo da Lancet Commission on Hypertension

RESUMEN La hipertensión arterial es una causa modificable muy prevalente de enfermedades cardiovasculares, accidentes cerebrovasculares y muerte. Medir con exactitud la presión arterial es fundamental, dado que un error de medición de 5 mmHg puede ser motivo para clasificar incorrectamente como hipertensas a 84 millones de personas en todo el mundo. En la presente declaración de posición se resumen los procedimientos para optimizar el desempeño del observador al medir la presión arterial en el consultorio, con atención especial a los entornos de ingresos bajos o medianos, donde esta medición se ve complicada por limitaciones de recursos y tiempo, sobrecarga de trabajo y falta de suministro eléctrico. Es posible reducir al mínimo muchos errores de medición con una preparación adecuada de los pacientes y el uso de técnicas estandarizadas. Para simplificar la medición y prevenir errores del observador, deben usarse tensiómetros semiautomáticos o automáticos de manguito validados, en lugar del método por auscultación. Pueden ayudar también la distribución de tareas, la creación de un área específica de medición y el uso de aparatos semiautomáticos o de carga solar. Es fundamental garantizar la capacitación inicial y periódica de los integrantes del equipo de salud. Debe considerarse la implementación de programas de certificación de bajo costo y fácilmente accesibles con el objetivo de mejorar la medición de la presión arterial.(AU)

ABSTRACT High blood pressure (BP) is a highly prevalent modifiable cause of cardiovascular disease, stroke, and death. Accurate BP measurement is critical, given that a 5-mmHg measurement error may lead to incorrect hypertension status classification in 84 million individuals worldwide. This position statement summarizes procedures for optimizing observer performance in clinic BP measurement, with special attention given to low-tomiddle- income settings, where resource limitations, heavy workloads, time constraints, and lack of electrical power make measurement more challenging. Many measurement errors can be minimized by appropriate patient preparation and standardized techniques. Validated semi-automated/automated upper arm cuff devices should be used instead of auscultation to simplify measurement and prevent observer error. Task sharing, creating a dedicated measurement workstation, and using semi-automated or solar-charged devices may help. Ensuring observer training, and periodic re-training, is critical. Low-cost, easily accessible certification programs should be considered to facilitate best BP measurement practice.(AU)

RESUMO A hipertensão é uma causa altamente prevalente de doença cardiovascular, acidente vascular cerebral e morte. A medição precisa da pressão arterial (PA) é um aspecto crítico, uma vez que erros de mensuração da ordem de 5 mmHg podem levar a uma classificação incorreta do status de hipertensão em 84 milhões de pessoas em todo o mundo. O presente posicionamento resume os procedimentos para otimizar o desempenho do observador (o indivíduo responsável pela mensuração da PA) na mensuração clínica da PA, com atenção especial para contextos de baixa a média renda, onde recursos limitados, cargas de trabalho pesadas, restrições de tempo e falta de energia elétrica tornam mais desafiadora a tarefa de medir a PA. Muitos erros de mensuração podem ser minimizados pela preparação adequada do paciente e pelo uso de técnicas padronizadas. Para simplificar a mensuração e evitar erros do observador, devem-se utilizar dispositivos semiautomatizados ou automatizados validados, com manguito para braço, ao invés de auscultação. O compartilhamento de tarefas, a criação de uma estação de trabalho dedicada à mensuração e o uso de dispositivos semiautomatizados ou com carga solar podem ajudar. É essencial que seja assegurado o treinamento e retreinamento periódico do observador. Programas de certificação de baixo custo e de fácil acesso devem ser considerados para facilitar a adoção das melhores práticas na mensuração da PA.(AU)

Declaración de posición del Grupo de la Comisión Lancet de Hipertensión con respecto a la mejora mundial de las normas de exactitud para los dispositivos de medición de la presión arterial / Lancet Commission on Hypertension Group position statement on the global improvement of accuracy standards for devices that measure blood pressure / Posicionamento do Grupo da Lancet Commission on Hypertension sobre a melhoria global dos padrões de acurácia para aparelhos que medem a pressão arterial

Objetivos. El boletín de notas de México correspondiente al 2018 evalúa las oportunidades a disposición de la población infantil y joven mexicana para que puedan desarrollar niveles adecuados de actividad física y sueño, y disminuyan el sedentarismo.Métodos. El boletín es un sistema de vigilancia que recopila los datos obtenidos en las encuestas nacionales, censos, documentos gubernamentales, sitios web, literatura gris y estudios publicados con respecto al análisis de 16 indicadores en 4 categorías: comportamientos diarios, estado físico, entornos y fuentes influyentes, y estrategias e inversión. Los datos fueron cotejados con los puntos de referencia establecidos. A cada indicador se le asignó una calificación entre 1 y 10 (< 6 significa reprobado) o fue marcado como "incompleto" si los datos eran nulos o insuficientes. Resultados. Las calificaciones obtenidas para los comportamientos diarios fueron: actividad física en general: 4; participación en actividades deportivas organizadas: 5; juego activo: 3; modalidades de transporte activas: 5; sueño: 7; y sedentarismo: 3. El estado físico obtuvo un 7. Las calificaciones para los entornos y fuentes influyentes fueron: familiares y pares: "incompleto"; escuela: 3; comunidad y entorno: 4. Para las estrategias e inversión: estrategias gubernamentales: 6; entidades no gubernamentales: 2.Conclusiones. Las bajas calificaciones obtenidas en 11 de los 16 indicadores demuestran que las escuelas, las familias, las comunidades y el gobierno tienen que aunar esfuerzos para mejorar las oportunidades que tiene la población infantil y joven en México para desarrollar niveles de actividad física satisfactorios.(AU)

ABSTRACT The Lancet Commission on Hypertension identified that a key action to address the worldwide burden of high blood pressure (BP) was to improve the quality of BP measurements by using BP devices that have been validated for accuracy. Currently, there are over 3 000 commercially available BP devices, but many do not have published data on accuracy testing according to established scientific standards. This problem is enabled through weak or absent regulations that allow clearance of devices for commercial use without formal validation. In addition, new BP technologies have emerged (e.g. cuffless sensors) for which there is no scientific consensus regarding BP measurement accuracy standards. Altogether, these issues contribute to the widespread availability of clinic and home BP devices with limited or uncertain accuracy, leading to inappropriate hypertension diagnosis, management and drug treatment on a global scale. The most significant problems relating to the accuracy of BP devices can be resolved by the regulatory requirement for mandatory independent validation of BP devices according to the universally-accepted International Organization for Standardization Standard. This is a primary recommendation for which there is an urgent international need. Other key recommendations are development of validation standards specifically for new BP technologies and online lists of accurate devices that are accessible to consumers and health professionals. Recommendations are aligned with WHO policies on medical devices and universal healthcare. Adherence to recommendations would increase the global availability of accurate BP devices and result in better diagnosis and treatment of hypertension, thus decreasing the worldwide burden from high BP.(AU)

RESUMO A Comissão Lancet sobre Hipertensão Arterial identificou que uma iniciativa central para enfrentar a carga mundial da hipertensão arterial seria a melhoria na qualidade da mensuração da pressão arterial pelo uso aparelhos de pressão arterial validados quanto à acurácia. Atualmente, existem mais de 3 000 aparelhos de pressão arterial disponíveis comercialmente; entretanto, muitos não têm dados publicados sobre testes de acurácia realizados de acordo com padrões científicos estabelecidos. Este problema resulta de regulamentação fraca ou inexistente, o que permite a aprovação para uso comercial de dispositivos sem validação formal. Além disso, surgiram novas tecnologias de mensuração da pressão arterial (por exemplo, sensores sem algemas) sem consenso científico quanto aos padrões de acurácia. No conjunto, essas questões contribuem para a oferta generalizada de dispositivos de pressão arterial clínica e domiciliar com acurácia limitada ou incerta, levando a diagnóstico, gerenciamento e tratamento inadequados da hipertensão em escala global. Os problemas mais significativos relacionados com a acurácia dos dispositivos de pressão arterial podem ser resolvidos por regulamentação que imponha a obrigatoriedade de validação independente dos aparelhos de pressão arterial, de acordo com a norma universalmente aceita pela Organização Internacional de Normalização. Esta é uma recomendação fundamental para a qual existe uma necessidade internacional urgente. Outras recomendações essenciais incluem o desenvolvimento de padrões de validação especificamente para novas tecnologias de mensuração da pressão arterial e listas on-line de aparelhos com acurácia adequada que sejam acessíveis aos consumidores e profissionais de saúde. As recomendações estão alinhadas com as políticas da Organização Mundial da Saúde (OMS) sobre dispositivos médicos e atenção universal à saúde. A adesão às recomendações aumentaria a oferta global de dispositivos de pressão arterial com acurácia adequada e resultaria em melhor diagnóstico e tratamento da hipertensão arterial, diminuindo assim a carga mundial dessa doença.(AU)

Investigation of a dilated cardiomyopathy-associated variant in BAG3 using genome-edited iPSC-derived cardiomyocytes.

Mutations in B cell lymphoma 2-associated athanogene 3 (BAG3) are recurrently associated with dilated cardiomyopathy (DCM) and muscular dystrophy. Using isogenic genome-edited human induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs), we examined how a DCM-causing BAG3 mutation (R477H), as well as complete loss of BAG3 (KO), impacts myofibrillar organization and chaperone networks. Although unchanged at baseline, fiber length and alignment declined markedly in R477H and KO iPSC-CMs following proteasome inhibition. RNA sequencing revealed extensive baseline changes in chaperone- and stress response protein-encoding genes, and protein levels of key BAG3 binding partners were perturbed. Molecular dynamics simulations of the BAG3-HSC70 complex predicted a partial disengagement by the R477H mutation. In line with this, BAG3-R477H bound less HSC70 than BAG3-WT in coimmunoprecipitation assays. Finally, myofibrillar disarray triggered by proteasome inhibition in R477H cells was mitigated by overexpression of the stress response protein heat shock factor 1 (HSF1). These studies reveal the importance of BAG3 in coordinating protein quality control subsystem usage within the cardiomyocyte and suggest that augmenting HSF1 activity might be beneficial as a means to mitigate proteostatic stress in the context of BAG3-associated DCM.

Transcription Factor EB Activation Rescues Advanced αB-Crystallin Mutation-Induced Cardiomyopathy by Normalizing Desmin Localization.

Background Mutations in αB-crystallin result in proteotoxic cardiomyopathy with desmin mislocalization to protein aggregates. Intermittent fasting ( IF ) is a novel approach to activate transcription factor EB (TFEB), a master regulator of the autophagy-lysosomal pathway, in the myocardium. We tested whether TFEB activation can be harnessed to treat advanced proteotoxic cardiomyopathy. Methods and Results Mice overexpressing the R120G mutant of αB-crystallin in cardiomyocytes ( Myh6-Cry ABR 120G) were subjected to IF or ad-lib feeding, or transduced with adeno-associated virus- TFEB or adeno-associated virus-green fluorescent protein after development of advanced proteotoxic cardiomyopathy. Adeno-associated virus-short hairpin RNA-mediated knockdown of TFEB and HSPB 8 was performed simultaneously with IF . Myh6-Cry ABR 120G mice demonstrated impaired autophagic flux, reduced lysosome abundance, and mammalian target of rapamycin activation in the myocardium. IF resulted in mammalian target of rapamycin inhibition and nuclear translocation of TFEB with restored lysosome abundance and autophagic flux; and reduced aggregates with normalized desmin localization. IF also attenuated left ventricular dilation and myocardial hypertrophy, increased percentage fractional shortening, and increased survival. Adeno-associated virus- TFEB transduction was sufficient to rescue cardiomyopathic manifestations, and resulted in reduced aggregates and normalized desmin localization in Myh6-Cry ABR 120G mice. Cry ABR 120G-expressing hearts demonstrated increased interaction of desmin with αB-crystallin and reduced interaction with chaperone protein, HSPB 8, compared with wild type, which was reversed by both IF and TFEB transduction. TFEB stimulated autophagic flux to remove protein aggregates and transcriptionally upregulated HSPB 8, to restore normal desmin localization in Cry ABR 120G-expressing cardiomyocytes. Short hairpin RNA-mediated knockdown of TFEB and HSPB 8 abrogated IF effects, in vivo. Conclusions IF and TFEB activation are clinically relevant therapeutic strategies to rescue advanced R120G αB-crystallin mutant-induced cardiomyopathy by normalizing desmin localization via autophagy-dependent and autophagy-independent mechanisms.

Cooperative interaction among BMAL1, HSF1, and p53 protects mammalian cells from UV stress.

The circadian clock allows physiological systems to adapt to their changing environment by synchronizing their timings in response to external stimuli. Previously, we reported clock-controlled adaptive responses to heat-shock and oxidative stress and showed how the circadian clock interacts with BMAL1 and HSF1. Here, we present a similar clock-controlled adaptation to UV damage. In response to UV irradiation, HSF1 and tumor suppressor p53 regulate the expression of the clock gene Per2 in a time-dependent manner. UV irradiation first activates the HSF1 pathway, which subsequently activates the p53 pathway. Importantly, BMAL1 regulates both HSF1 and p53 through the BMAL1-HSF1 interaction to synchronize the cellular clock. Based on these findings and transcriptome analysis, we propose that the circadian clock protects cells against the UV stress through sequential and hierarchical interactions between the circadian clock, the heat shock response, and a tumor suppressive mechanism.

The growing world of small heat shock proteins: from structure to functions.

Small heat shock proteins (sHSPs) are present in all kingdoms of life and play fundamental roles in cell biology. sHSPs are key components of the cellular protein quality control system, acting as the first line of defense against conditions that affect protein homeostasis and proteome stability, from bacteria to plants to humans. sHSPs have the ability to bind to a large subset of substrates and to maintain them in a state competent for refolding or clearance with the assistance of the HSP70 machinery. sHSPs participate in a number of biological processes, from the cell cycle, to cell differentiation, from adaptation to stressful conditions, to apoptosis, and, even, to the transformation of a cell into a malignant state. As a consequence, sHSP malfunction has been implicated in abnormal placental development and preterm deliveries, in the prognosis of several types of cancer, and in the development of neurological diseases. Moreover, mutations in the genes encoding several mammalian sHSPs result in neurological, muscular, or cardiac age-related diseases in humans. Loss of protein homeostasis due to protein aggregation is typical of many age-related neurodegenerative and neuromuscular diseases. In light of the role of sHSPs in the clearance of un/misfolded aggregation-prone substrates, pharmacological modulation of sHSP expression or function and rescue of defective sHSPs represent possible routes to alleviate or cure protein conformation diseases. Here, we report the latest news and views on sHSPs discussed by many of the world's experts in the sHSP field during a dedicated workshop organized in Italy (Bertinoro, CEUB, October 12-15, 2016).

Characterization of the Cardiac Overexpression of HSPB2 Reveals Mitochondrial and Myogenic Roles Supported by a Cardiac HspB2 Interactome.

Small Heat Shock Proteins (sHSPs) are molecular chaperones that transiently interact with other proteins, thereby assisting with quality control of proper protein folding and/or degradation. They are also recruited to protect cells from a variety of stresses in response to extreme heat, heavy metals, and oxidative-reductive stress. Although ten human sHSPs have been identified, their likely diverse biological functions remain an enigma in health and disease, and much less is known about non-redundant roles in selective cells and tissues. Herein, we set out to comprehensively characterize the cardiac-restricted Heat Shock Protein B-2 (HspB2), which exhibited ischemic cardioprotection in transgenic overexpressing mice including reduced infarct size and maintenance of ATP levels. Global yeast two-hybrid analysis using HspB2 (bait) and a human cardiac library (prey) coupled with co-immunoprecipitation studies for mitochondrial target validation revealed the first HspB2 "cardiac interactome" to contain many myofibril and mitochondrial-binding partners consistent with the overexpression phenotype. This interactome has been submitted to the Biological General Repository for Interaction Datasets (BioGRID). A related sHSP chaperone HspB5 had only partially overlapping binding partners, supporting specificity of the interactome as well as non-redundant roles reported for these sHSPs. Evidence that the cardiac yeast two-hybrid HspB2 interactome targets resident mitochondrial client proteins is consistent with the role of HspB2 in maintaining ATP levels and suggests new chaperone-dependent functions for metabolic homeostasis. One of the HspB2 targets, glyceraldehyde 3-phosphate dehydrogenase (GAPDH), has reported roles in HspB2 associated phenotypes including cardiac ATP production, mitochondrial function, and apoptosis, and was validated as a potential client protein of HspB2 through chaperone assays. From the clientele and phenotypes identified herein, it is tempting to speculate that small molecule activators of HspB2 might be deployed to mitigate mitochondrial related diseases such as cardiomyopathy and neurodegenerative disease.

In vitro chemoresponse in metachronous pairs of ovarian cancers.

BACKGROUND/AIM: An in vitro chemoresponse assay may aid effective therapy selection in epithelial ovarian cancer (EOC). This study explores changes in chemoresponse between paired primary and recurrent EOC tumors. PATIENTS AND METHODS: RESULTS from metachronous tumors were examined in 242 patients. Changes in in vitro chemoresponse, measured by the area under the dose response curve (AUC) between paired tumors were assessed. RESULTS: A significant increase in AUC was identified in most first-line therapies over time. No significant difference was observed in most recurrent therapies. When the elapsed time between occurrences was <17 months, no difference was observed for any recurrent therapies, and half of first-line therapies exhibited significant increases in AUC. When ≥17 months, all 7 therapies showed significant increases. CONCLUSION: These results suggest an increase in chemoresistance over time, which is more pronounced for first-line therapies. This is consistent with clinical observations and suggests the biologic concordance between assay results and response to chemotherapy.

Molecular stress-inducing compounds increase osteoclast formation in a heat shock factor 1 protein-dependent manner.

Many anticancer therapeutic agents cause bone loss, which increases the risk of fractures that severely reduce quality of life. Thus, in drug development, it is critical to identify and understand such effects. Anticancer therapeutic and HSP90 inhibitor 17-(allylamino)-17-demethoxygeldanamycin (17-AAG) causes bone loss by increasing osteoclast formation, but the mechanism underlying this is not understood. 17-AAG activates heat shock factor 1 (Hsf1), the master transcriptional regulator of heat shock/cell stress responses, which may be involved in this negative action of 17-AAG upon bone. Using mouse bone marrow and RAW264.7 osteoclast differentiation models we found that HSP90 inhibitors that induced a heat shock response also enhanced osteoclast formation, whereas HSP90 inhibitors that did not (including coumermycin A1 and novobiocin) did not affect osteoclast formation. Pharmacological inhibition or shRNAmir knockdown of Hsf1 in RAW264.7 cells as well as the use of Hsf1 null mouse bone marrow cells demonstrated that 17-AAG-enhanced osteoclast formation was Hsf1-dependent. Moreover, ectopic overexpression of Hsf1 enhanced 17-AAG effects upon osteoclast formation. Consistent with these findings, protein levels of the essential osteoclast transcription factor microphthalmia-associated transcription factor were increased by 17-AAG in an Hsf1-dependent manner. In addition to HSP90 inhibitors, we also identified that other agents that induced cellular stress, such as ethanol, doxorubicin, and methotrexate, also directly increased osteoclast formation, potentially in an Hsf1-dependent manner. These results, therefore, indicate that cellular stress can enhance osteoclast differentiation via Hsf1-dependent mechanisms and may significantly contribute to pathological and therapeutic related bone loss.

Chaperones and cardiac misfolding protein diseases.

Cardiomyocytes are best known for their spontaneous beating activity, large cell size, and low regenerative capacity during adulthood. The mechanical activity of cardiomyocytes depends on a sophisticated contractile apparatus comprised of sarcomeres whose rhythmic contraction relies on Ca(2+) transients with a high level of energy consumption. Hence the proper folding and assembly of the sarcomeric and other accessory proteins involved in those diverse functions (i.e., structural, mechanical, energy exchange and production) is critical for muscle mechanics. Chaperone proteins assist other polypeptides to reach their proper conformation, activity and/or location. Consequently, chaperone-like functions are important for the healthy heart but assume greater relevance during cardiac diseases when such chaperone proteins are recruited: 1) to protect cardiac cells against adverse effects during the pathological transition, and 2) to mitigate certain pathogenic mechanisms per se. Protein misfolding is observed as a consequence of inappropriate intracellular environment with acquired conditions (e.g., ischemia/reperfusion and redox imbalance) or because of mutations, which can modify primary to quaternary protein structures. In this review, we discuss the importance of cardiac chaperones while emphasizing the genetic origin (modification of gene/protein sequence) of cardiac protein misfolding and their consequences on the cardiomyocytes leading to organ dysfunction and failure.

Aggregate-prone R120GCRYAB triggers multifaceted modifications of the thioredoxin system.

AIMS: The human mutation R120G in the αB-crystallin (CRYAB) causes a multisystemic disease that is characterized by hypertrophic cardiomyopathy and cytoplasmic protein aggregates. In transgenic mice, human R120GCRYAB (hR120GTg) expression in heart sequentially modifies the REDOX status, in part by the activation of the nuclear factor, erythroid derived 2, like 2 (Nrf2). Thioredoxin system (TS) components are NRF2 target genes, so it could be hypothesized that TS was affected in hR120GTg mice. RESULTS: Transgenic hearts overexpressed thioredoxin 1 (Trx1), which was identified by isotope coded affinity tag-mass spectrometry, among hundreds of peptides displaying an increased reduced/oxidized ratio. Coupled to this higher level of reduced cysteines, the activity of thioredoxin reductase 1 (TrxR1) was augmented by 2.5-fold. Combining mutiple experimental approaches, the enzymatic regulation of TrxR1 by a histone deacetylase 3 (HDAC3)-dependent level of acetylation was confirmed. In vitro and in vivo functional tests established that TrxR1 activity is required to mitigate aggregate development, and this could be mediated by Bcl-2-associated athanogene 3 (BAG3) as a potential TS substrate. INNOVATION AND CONCLUSIONS: This study uncovers the compartmentalized changes and the involvement of TS in the cardiac stress response elicited by misfolded proteins such as R120GCRYAB. Our work suggests that R120GCRYAB triggers a defensive pathway acting through the newly identified interacting partners HDAC3, TrxR1, and BAG3 to counter aggregate growth. Therefore, those interactors may function as modifier genes contributing to the variable onset and expressivity of such human diseases. Furthermore, our work underscores the potential organismal effects of pharmacological interventions targeting TS and HDAC.

Reductive stress linked to small HSPs, G6PD, and Nrf2 pathways in heart disease.

SIGNIFICANCE: Aerobic organisms must exist between the dueling biological metabolic processes for energy and respiration and the obligatory generation of reactive oxygen species (ROS) whose deleterious consequences can reduce survival. Wide fluctuations in harmful ROS generation are circumvented by endogenous countermeasures (i.e., enzymatic and nonenzymatic antioxidants systems) whose capacity decline with aging and are enhanced by disease states. RECENT ADVANCES: Substantial efforts on the cellular and molecular underpinnings of oxidative stress has been complemented recently by the discovery that reductive stress similarly predisposes to inheritable cardiomyopathy, firmly establishing that the biological extremes of the redox spectrum play essential roles in disease pathogenesis. CRITICAL ISSUES: Because antioxidants by nutritional or pharmacological supplement to prevent or mitigate disease states have been largely disappointing, we hypothesize that lack of efficacy of antioxidants might be related to adverse outcomes in responders at the reductive end of the redox spectrum. As emerging concepts, such as reductive, as opposed, oxidative stress are further explored, there is an urgent and critical gap for biochemical phenotyping to guide the targeted clinical applications of therapeutic interventions. FUTURE DIRECTIONS: New approaches are vitally needed for characterizing redox states with the long-term goal to noninvasively assess distinct clinical states (e.g., presymptomatic, end-stage) with the diagnostic accuracy to guide personalized medicine.

Antiangiogenic agents as a maintenance strategy for advanced epithelial ovarian cancer.

Bevacizumab is the first antiangiogenic agent to have demonstrated benefit as first-line and maintenance therapy in epithelial ovarian cancer (EOC), with the Gynecologic Oncology Group 218 and ICON 7 phase III trials revealing significantly prolonged progression-free survival (PFS) for carboplatin/paclitaxel plus bevacizumab followed by bevacizumab maintenance versus carboplatin/paclitaxel alone. Results are forthcoming from several phase III maintenance trials of investigational antiangiogenic agents, each evaluating PFS as the primary endpoint: AGO-OVAR12/LUME-Ovar1 (nintedanib [BIBF 1120]), AGO-OVAR16 (pazopanib), and TRINOVA-1, -2, and -3 (AMG 386). Here we review available data and ongoing clinical trials of investigational antiangiogenic agents as maintenance therapy for EOC. Current controversies, including uncertainties regarding the (1) most appropriate clinical trial endpoints, (2) optimal dosing, duration, and timing of therapy (e.g., with first-line chemotherapy and/or as maintenance monotherapy), and (3) feasibility, tolerability, and cost of adding these agents to platinum/taxane regimens are also highlighted.

HSPB2 is dispensable for the cardiac hypertrophic response but reduces mitochondrial energetics following pressure overload in mice.

BACKGROUND: CryAB (HspB5) and HspB2, two small heat shock genes located adjacently in the vertebrate genome, are hypothesized to play distinct roles. Mice lacking both cryab and hspb2 (DKO) are viable and exhibit adult-onset degeneration of skeletal muscle but confounding results from independent groups were reported for cardiac responses to different stressful conditions (i.e., ischemia/reperfusion or pressure overload). To determine the specific requirements of HSPB2 in heart, we generated cardiac-specific HSPB2 deficient (HSPB2cKO) mice and examined their cardiac function under basal conditions and following cardiac pressure overload. METHODOLOGY/PRINCIPAL FINDINGS: Transverse aortic constriction (TAC) or sham surgery was performed in HSPB2cKO mice and their littermates (HSPB2wt mice). Eight weeks after TAC, we found that expression of several small HSPs (HSPB2, 5, 6) was not markedly modified in HSPB2wt mice. Both cardiac function and the hypertrophic response remained similar in HSPB2cKO and HSPB2wt hearts. In addition, mitochondrial respiration and ATP production assays demonstrated that the absence of HSPB2 did not change mitochondrial metabolism in basal conditions. However, fatty acid supported state 3 respiration rate (ADP stimulated) in TAC operated HSPB2cKO hearts was significantly reduced in compared with TAC operated HSPB2wt mice (10.5±2.2 vs. 12.8±2.5 nmol O(2)/min/mg dry fiber weight, P<0.05), and ATP production in HSPB2cKO hearts was significantly reduced in TAC compared with sham operated mice (29.8±0.2 vs. 21.1±1.8 nmol ATP/min/mg dry fiber weight, P<0.05). Although HSPB2 was not associated with mitochondria under cardiac stress, absence of HSPB2 led to changes in transcript levels of several metabolic and mitochondrial regulator genes. CONCLUSIONS/SIGNIFICANCE: The present study indicates that HSPB2 can be replaced by other members of the multigene small HSP family under basal conditions while HSPB2 is implicated in the regulation of metabolic/mitochondrial function under cardiac stress such pressure overload.

Trabectedin as a new chemotherapy option in the treatment of relapsed platinum sensitive ovarian cancer.

Trabectedin (ET-743, Yondelis®) is a novel marine antineoplastic alkaloid with a unique mechanism of action. The active substance trabectedin, a tetrahydroisoquinoline alkaloid, is a natural product originally isolated from the Caribbean sea squirt, Ecteinascidia turbinata and is currently manufactured by total synthesis. Trabectedin is licensed by the Spanish pharmaceutical drug company, PharmaMar and co-developed by Johnson & Johnson Pharmaceutical Research and Development, L.L.C., pursuant to a licensing agreement with PharmaMar. Trabectedin is the first anticancer marine-derived drug to be approved by the European Union. In 2007, trabectedin obtained marketing authorization from the European Commission and in many other countries worldwide for the treatment of patients with advanced soft tissue sarcoma (STS) after failure of anthracyclines and ifosfamide, or for those patients who are unsuitable to receive these agents. Based on the recently reported results of a large phase III study (OVA-301) comparing pegylated liposomal doxorubicin (PLD) alone with a combination of PLD and trabectedin in patients with recurrent ovarian cancer, in 2009 the European Commission granted marketing authorization for trabectedin combined with PLD for the treatment of patients with relapsed platinum-sensitive ovarian cancer. The results from OVA-301 showed that the combination of trabectedin and PLD improves progression-free survival and overall response rate over PLD alone with acceptable tolerance in the second-line treatment of recurrent ovarian cancer. In addition, an enhanced activity of trabectedin combined with PLD was observed in platinum sensitive patients, especially in those with a platinum-free interval ranging from 6 to 12 months. Overall, trabectedin-induced toxicities are mainly hematological and hepatic, with grade 3/4 neutropenia and thrombocytopenia observed in approximately 50% and 13% of patients, respectively, and grade 3/4 elevation of liver aminotransferases observed in 40-50% of patients treated with trabectedin. Current efforts are focused on the evaluation of the role of trabectedin in prolonging the platinum-free interval and the identification of predictive factors for patients treated with trabectedin as well as in the development of new trabectedin-based combinations.