Dinender K. Singla

Doxorubicin (DOX) is a potent chemotherapeutic drug used to treat a variety of cancer types, but its usage is limited due to major cardiovascular side effects. According to World Health Organization reports, by 2050, new cancer cases are projected to increase to >35 million, implying an enhanced risk of DOX-induced cardiomyopathy (DIC). Despite its cardiotoxic side effects, DOX has remained an effective therapeutic choice for cancer treatment. Current evidence suggests that multiple pathophysiological mechanisms are involved in DIC, including oxidative stress, mitochondrial dysfunction, endoplasmic reticulum (ER) stress, calcium dysregulation, and inflammation, all of which lead to cardiac cell death and disease progression. Recently, several oxidative stress and inflammation-mediated signaling pathways, including MAPK, HMGB1/TLR4, NFκB, NLRP3 inflammasome, JAK-STAT, and TNFα, have been identified as contributing factors to cardiac remodeling in DIC. Although significant progress has been made over the past two decades in understanding the pathophysiological mechanisms of DIC, the exact mechanism leading to DIC remains unclear. Hence, in this review, we discuss various types of immune cells, including neutrophils, monocytes, and macrophages, cellular and molecular pathological mechanisms of inflammation, and various types of cell death in DIC. Further we discussed how understanding the significance of inflammatory mechanisms may enhance therapeutic efficacy and inform future perspectives.

Background: Ponatinib (PON), an effective tyrosine kinase inhibitor for leukemias harboring the T315I mutation, is limited by severe cardiotoxicity, including myocardial infarction and heart failure. Here, we investigated the therapeutic potential of Bone Morphogenetic Protein-7 (BMP-7), an anti-inflammatory growth factor, in a murine model of PON-induced cardiotoxicity. Methods: C57BL/6J mice were distributed into experimental groups receiving PON (25 mg/kg cumulative dose) either alone or with BMP-7 (600 μg/kg cumulative dose), along with a corresponding control group. Cardiac analyses included molecular and histological assessments. Results: PON administration induced a marked increase in monocyte infiltration and M1 macrophage polarization. These inflammatory events led to the upregulation of the pyroptotic cascade, leading to activation of the TGF-β1/SMAD2/3 signaling axis. In contrast, BMP-7 significantly attenuated these pathological responses by suppressing inflammation-induced pyroptosis and the TGF-β1/SMAD2/3 signaling axis. Conclusions: These findings identify inflammation-induced pyroptosis as a central driver of the pathological changes in PON-induced cardiotoxicity. Notably, our work highlights BMP-7’s capacity to inhibit these disease-related alterations. Collectively, these results expand on the current knowledge of the mechanistic framework of PON-induced cardiotoxicity, while also emphasizing BMP-7 as a promising therapeutic candidate with potential translational relevance.

Background/Objectives: Ponatinib (PON) is a potent anticancer drug widely used to treat chronic myeloid leukemia (CML). Although many cancer survivors benefit from such therapies, managing drug-induced side effects, especially cardiotoxicity, remains a major challenge. Despite its prevalence, the exact mechanisms underlying PON-induced cardiotoxicity have not been thoroughly investigated. Additionally, the potential of Bone Morphogenetic Protein 7 (BMP-7) to alleviate these cardiotoxic effects has yet to be explored. Methods: To address these essential questions, we conducted a study using C57BL/6 mice. Mice were treated with PON (25 mg/kg cumulative dosage) or a combination of PON and BMP-7 (600 μg/kg), alongside a suitable control group. Heart function was assessed by echocardiography. Different techniques were performed to evaluate the apoptotic pathway. Histological staining was performed to investigate structural changes. Results: PON treatment increased apoptotic cell death (increased expression of BAX and caspase-3) in the heart through the PTEN/Akt signaling pathway. Further, PON treatment led to increased cardiac hypertrophy, adverse remodeling, and reduced cardiac function. Importantly, BMP-7 markedly reduced PON-induced apoptosis (increased Bcl2 expression) and its downstream effects. Conclusions: These results suggest that BMP-7 might inhibit PON-induced cardiotoxicity. Furthermore, our findings pave the way for future translational studies with BMP-7, which can demonstrate the therapeutic potential of BMP-7 in a clinical setting.

Cardiovascular complications, particularly diabetic cardiomyopathy (DCM), are the primary causes of morbidity and mortality among individuals with diabetes. Hyperglycemia associated with diabetes leads to cardiomyocyte hypertrophy, apoptosis, and myocardial fibrosis, culminating in heart failure (HF). Patients with diabetes face a 2–4 times greater risk of developing HF compared with those without diabetes. Consequently, there is a growing interest in exploring the molecular mechanisms that contribute to the development of DCM. MicroRNAs (miRNAs) are short, single-stranded, noncoding RNA molecules that participate in the maintenance of physiological homeostasis through the regulation of essential processes such as metabolism, cell proliferation, and apoptosis. At the posttranscriptional level, miRNAs modulate gene expression by binding directly to genes’ mRNAs. Multiple cardiac-enriched miRNAs were reported to be dysregulated under diabetic conditions. Different studies revealed the role of specific miRNAs in the pathogenesis of diabetes and related cardiovascular complications, including cardiomyocyte hypertrophy and fibrosis, mitochondrial dysfunction, metabolic impairment, inflammatory response, or cardiomyocyte death. Circulating miRNAs have been shown to represent the potential biomarkers for early detection of diabetic heart injury. A deeper understanding of miRNAs and their role in diabetes-related pathophysiological processes could lead to new therapeutic strategies for addressing cardiac complications associated with diabetes.

Introduction: Diabetes is a debilitating disease that leads to complications like cardiac dysfunction and heart failure. In this study, we investigated the pathophysiology of diabetes-induced cardiac dysfunction in mice with dyslipidemia. We hypothesize diabetes in ApoE knockout (ApoE-/-) mice induces cardiac dysfunction by increasing inflammation and necroptosis.Methods: ApoE-/- mice were divided into experimental groups: Control, Streptozotocin (STZ), STZ + MSC-Exo (mesenchymal stem cell-derived exosomes), and STZ+MEF-Exo (Mouse embryonic fibroblast derived exosomes). At Day 42, we assessed cardiac function, collected blood and heart tissues. Heart tissue samples were analyzed for inflammation, necroptosis, signaling mechanism, hypertrophy and adverse structural remodeling using histology, immunohistochemistry, western blotting, RT-PCR, cytokine array and TF array. Results and Discussion: STZ treated ApoE-/- mice developed diabetes, with significantly (p<0.05) increased blood glucose and body weight loss. These mice developed cardiac dysfunction with significantly (p<0.05) increased left ventricular internal diameter end diastole and end systole, and decreased ejection fraction, and fractional shortening. We found significant (p<0.05) increased expression of inflammatory cytokines TNF- a, IL-6, IL-1a, IL-33 and decreased IL-10 expression. Diabetic mice also exhibited significantly (p<0.05) increased necroptosis marker expression and infiltration of inflammatory monocytes and macrophages. MSC-Exos treated mice showed recovery of diabetes associated pathologies with significantly reduced blood glucose, recovered body weight, increased IL-10 secretion and M2 polarized macrophages in the heart. These mice showed reduced TAK1-pJNK-NFKB inflammation associated expression and improved cardiac function with significantly reduced cardiac hypertrophy and fibrosis compared to diabetic mice. Treatment with MEF-Exos did not play a significant role in attenuating diabetes-induced cardiomyopathy as these treatment mice presented with cardiac dysfunction and underlying pathologies observed in STZ mice. Conclusion: Thus, we conclude that cardiac dysfunction develops in diabetic ApoE-/- mice, arising from inflammation, necroptosis, and adverse tissue remodeling, which is ameliorated by MSC-Exos, a potential therapeutic for diabetes-induced cardiomyopathy.

Doxorubicin (DOX) is an incessantly used chemotherapeutic drug that can cause detrimental dose-dependent effects such as cardiotoxicity and congestive heart failure. Hence, there is a need to discover innovative therapeutic approaches to counteract DOX-induced cardiotoxicity (DIC). MSC-Exos have shown to reduce apoptosis and cardiac fibrosis and promote cardiomyocyte proliferation in myocardial infracted mice. However, the effect of MSC-Exos on ameliorating DOX-induced pyroptosis has not been investigated. In this current study, H9c2 were first exposed to DOX to stimulate pyroptosis, followed by subsequent treatment with MSC-Exos, with further analysis performed through immunocytochemistry, western blotting, and RT-PCR. Our data depicted that post-treatment with MSC-Exos significantly (p < 0.05) reduced the HMGB1/TLR4 axis, inflammasome formation (NLRP3), pyroptotic markers (caspase-1, IL-1β, and IL-18), and the pyroptotic executioner (GSDMD) in DOX-treated H9c2 cells. In conclusion, our data show that MSC-Exos attenuates inflammation-induced pyroptosis in our in vitro DIC model. Our findings indicate that MSC-Exos may serve as a promising therapeutic intervention for mitigating DIC, as they maintain the therapeutic capabilities of MSCs while circumventing the drawbacks associated with traditional stem cell therapy.