What Powers Trastuzumab's Cardiotoxicity? Decoding Mitochondrial-Related Gene Expression Through Integrative Review and Meta-Analysis in Cardiomyocytes.

Trastuzumab is a monoclonal antibody used in oncotherapy for HER2-positive tumors. However, as an adverse effect, trastuzumab elevates the risk of heart failure, implying the involvement of energy production and mitochondrial processes. Past studies with transcriptome analysis have offered insights on pathways related to trastuzumab safety and toxicity but limited study sizes hinder conclusive findings. Therefore, we meta-analyzed mitochondria-related gene expression data in trastuzumab-treated cardiomyocytes. We searched the transcriptome databases for trastuzumab-treated cardiomyocytes in the ArrayExpress, DDBJ Omics Archive, Gene Expression Omnibus, Google Scholar, PubMed, and Web of Science repositories. A subset of 1270 genes related to mitochondrial functions (biogenesis, organization, mitophagy, and autophagy) was selected from the Kyoto Encyclopedia of Genes and Genomes and Gene Ontology Resource databases to conduct the present meta-analysis using the Metagen package (Study register at PROSPERO: CRD42021270645). Three datasets met the inclusion criteria and 1243 genes were meta-analyzed. We observed 69 upregulated genes after trastuzumab treatment which were related mainly to autophagy (28 genes) and mitochondrial organization (28 genes). We also found 37 downregulated genes which were related mainly to mitochondrial biogenesis (11 genes) and mitochondrial organization (24 genes). The present meta-analysis indicates that trastuzumab therapy causes an unbalance in mitochondrial functions, which could, in part, help explain the development of heart failure and yields a list of potential molecular targets. These findings contribute to our understanding of the molecular mechanisms underlying the cardiotoxic effects of trastuzumab and may have implications for the development of targeted therapies to mitigate such effects.

Cell culture: a promising environment for research on cardiology / Cultivos celulares: un entorno promisorio para la investigación en cardiología

Abstract At present, tissue engineering is transforming the area of cardiovascular regenerative medicine, which combines the principles and methods of materials engineering and biological sciences, interacting with biochemical and physicochemical factors, for the understanding of their structure-function relationship. Thus, the course of diseases is reoriented by implementing methods and procedures involved in the regeneration of organs and tissues by means of the interaction with biocompatible matrices, pre-treated organs or stem cell management, among others, thus recovering the functionality in the system affected by acquired pathologies, alterations or congenital defects. Consequently, these procedures are increasingly becoming one the most promising treatment alternative for patients who suffer from any type of functional deficit. Known that all these possibilities make cell cultures a promising study environment to be used in biomedical applications, especially in tissue engineering and regenerative medicine, this manuscript presents a general reviews of established cell lines or primary tissue lines and how cell cultures serve as a model before experimental work on laboratory animals and human subjects which makes it a valuable tool for broad models of study in the research on cardiology.

Resumen En la actualidad, la ingeniería de tejidos está transformando el área de la medicina regenerativa cardiovascular, combinando los principios y métodos de la ingeniería de materiales y las ciencias biológicas, interactuando entre factores bioquímicos y fisicoquímicos, para la comprensión de su relación estructura-función. Así, el curso de las enfermedades se viene a reorientar mediante la implementación de métodos y procedimientos implicados en la regeneración de órganos y tejidos a través de la interacción con matrices biocompatibles, órganos pretratados o manejo de células madre, entre otros, recuperando así la funcionalidad en el sistema afectado por enfermedades adquiridas y alteraciones o defectos congénitos. En consecuencia, estos procedimientos se están convirtiendo en una de las alternativas de tratamiento cada vez más prometedoras para los pacientes que sufren de algún tipo de alteración funcional. Considerando que todas estas posibilidades hacen de los cultivos celulares un entorno de estudio prometedor para ser utilizado en aplicaciones biomédicas, especialmente en ingeniería de tejidos y medicina regenerativa, este manuscrito presenta una revisión general de las líneas celulares establecidas o líneas de tejido primario y cómo los cultivos celulares sirven como modelo de evaluación antes del trabajo experimental en animales de laboratorio y sujetos humanos, lo cual los convierte en una herramienta valiosa para amplios modelos de estudio en la investigación en cardiología.

Titanium Dioxide (E171) Induces Toxicity in H9c2 Rat Cardiomyoblasts and Ex Vivo Rat Hearts.

Cardiovascular diseases are the leading cause of death worldwide. Food-grade TiO2 (E171) is the most widely used additive in the food industry. Existing evidence shows TiO2 nanoparticles reach systemic circulation through biological barriers, penetrate cell membranes, accumulate in cells of different organs, and cause damage; however, their effects on cardiac cells and the development of heart diseases are still unexplored. Therefore, in this work, we tested E171 toxicity in rat cardiomyoblasts and hearts. E171 internalization and impact on cell viability, proliferation, mitochondria, lysosomes, F-actin distribution, and cell morphology were evaluated in H9c2 cells. Additionally, effects of E171 were measured on cardiac function in ex vivo rat hearts. E171 was uptaken by cells and translocated into the cytoplasm. E171 particles changed cell morphology reducing proliferation and metabolic activity. Higher caspase-3 and caspase-9 expression as well as Tunel-positive cells induced by E171 exposure indicate apoptotic death. Mitochondrial and lysosome alterations resulting from mitophagy were detected after 24 and 48 h exposure, respectively. Additionally, high E171 concentrations caused rearrangements of the F-actin cytoskeleton. Finally, hearts exposed to E171 showed impaired cardiac function. These results support E171 toxicity in cardiac cells in vitro altering cardiac function in an ex vivo model, indicating that consumption of this food additive could be toxic and may lead to the development of cardiovascular disease.

Stem cell therapies in cardiac diseases: Current status and future possibilities.

Cardiovascular diseases represent the world's leading cause of death. In this heterogeneous group of diseases, ischemic cardiomyopathies are the most devastating and prevalent, estimated to cause 17.9 million deaths per year. Despite all biomedical efforts, there are no effective treatments that can replace the myocytes lost during an ischemic event or progression of the disease to heart failure. In this context, cell therapy is an emerging therapeutic alternative to treat cardiovascular diseases by cell administration, aimed at cardiac regeneration and repair. In this review, we will cover more than 30 years of cell therapy in cardiology, presenting the main milestones and drawbacks in the field and signaling future challenges and perspectives. The outcomes of cardiac cell therapies are discussed in three distinct aspects: The search for remuscularization by replacement of lost cells by exogenous adult cells, the endogenous stem cell era, which pursued the isolation of a progenitor with the ability to induce heart repair, and the utilization of pluripotent stem cells as a rich and reliable source of cardiomyocytes. Acellular therapies using cell derivatives, such as microvesicles and exosomes, are presented as a promising cell-free therapeutic alternative.

Hyperglycemia and hyperlipidemia can induce morphophysiological changes in rat cardiac cell line.

H9c2 cardiac cells were incubated under the control condition and at different hyperglycemic and hyperlipidemic media, and the following parameters were determined and quantified: a) cell death, b) type of cell death, and c) changes in cell length, width and height. Of all the proven media, the one that showed the greatest differences compared to the control was the medium glucose (G) 33 mM + 500 µM palmitic acid. This condition was called the hyperglycemic and hyperlipidemic condition (HHC). Incubation of H9c2 cells in HHC promoted 5.2 times greater total cell death when compared to the control. Of the total death ofthe HHC cells, 38.6% was late apoptotic and 8.3% early apoptotic. HHC also changes cell morphology. The reordering of the actin cytoskeleton and cell stiffness was also studied in control and HHC cells. The actin cytoskeleton was quantified and the number and distance of actin bundles were not the same in the control as under HHC. Young's modulus images show a map of cell stiffness. Cells incubated in HHC with the reordered actin cytoskeleton were stiffer than those incubated in control. The region of greatest stiffness was the peripheral zone of HHC cells (where the number of actin bundles was higher and the distance between them smaller). Our results suggest a correlation between the reordering of the actin cytoskeleton and cell stiffness. Thus, our study showed that HHC can promote morphophysiological changes in rat cardiac cells confirming that gluco-and lipotoxicity may play a central role in the development of diabetic cardiomyopathy.

Dantrolene hinders dengue virus-induced upregulation and translocation of calmodulin to cardiac cell nuclei.

Dengue virus (DENV) infection elevates intracellular Ca2+ concentration ([Ca2+]i), but it is unknown whether Ca2+ and calmodulin (CaM) are involved in DENV infection. We conducted immunofluorescence and western blot experiments and measured [Ca2+]i examining the effects of DENV infection and drugs that alter Ca2+/CaM functions on CaM translocation, DENV2 infection, protein expression, virus-inducible STAT2 protein abundance, and CREB phosphorylation in H9c2 cells. DENV infection increased CaM expression, its nuclear translocation and NS3 and E viral proteins expression and colocalization in a manner that could be blocked by the ryanodine receptor antagonist dantrolene. DENV infection also increased CREB phosphorylation, an effect inhibited by either dantrolene or the CaM inhibitor W7. Dantrolene substantially hindered infection as assessed by focus assays in Vero cells. These results suggest that Ca2+ and CaM play an important role in DENV infection of cardiac cells and that dantrolene may protect against severe DENV cardiac morbidity.

Role of cyclooxygenase-2 in Trypanosoma cruzi survival in the early stages of parasite host-cell interaction

Chagas disease, caused by the intracellular protozoan Trypanosoma cruzi, is a serious health problem in Latin America. During this parasitic infection, the heart is one of the major organs affected. The pathogenesis of tissue remodelling, particularly regarding cardiomyocyte behaviour after parasite infection and the molecular mechanisms that occur immediately following parasite entry into host cells are not yet completely understood. When cells are infected with T. cruzi, they develop an inflammatory response, in which cyclooxygenase-2 (COX-2) catalyses rate-limiting steps in the arachidonic acid pathway. However, how the parasite interaction modulates COX-2 activity is poorly understood. In this study, the H9c2 cell line was used as our model and we investigated cellular and biochemical aspects during the initial 48 h of parasitic infection. Oscillatory activity of COX-2 was observed, which correlated with the control of the pro-inflammatory environment in infected cells. Interestingly, subcellular trafficking was also verified, correlated with the control of Cox-2 mRNA or the activated COX-2 protein in cells, which is directly connected with the assemble of stress granules structures. Our collective findings suggest that in the very early stage of the T. cruzi-host cell interaction, the parasite is able to modulate the cellular metabolism in order to survives.