Doxorubicin-induced cardiovascular toxicity: a longitudinal evaluation of functional and molecular markers

Atrial fibrillation in cancer patients: Epidemiology, identification and management

Cancer and cardiovascular disease (CVD) are among the leading causes of death globally, and the rate of coexistence of the two diseases has been increasing in recent years, with the elevation of the susceptible population base in aging societies and the improvement of therapeutic approaches. Atrial fibrillation (AF), as a common type of cancer-related cardiovascular toxicity (CTR-CVT) in oncology patients, is a serious threat to patients' health and may lead to other cardiovascular complications. Therefore, early detection, timely recognition, and effective intervention of AF are essential to maintain long-term survival of tumor survivors. However, the causal mechanisms regarding its association are still inconclusive, and there is no consensus in the clinic on the optimal treatment. In this review, we will integrate existing guidelines and studies to summarize the current state of research on atrial fibrillation in oncology patients in terms of epidemiology, pathophysiological mechanisms, predictive diagnostics, and therapeutic measures, and propose some research directions to be improved. We hope to provide a more comprehensive review and provide assistance in clinical response.

Asiatic acid and its derivatives: Pharmacological insights and applications

Centella asiatica (L.) Urban has been utilized in wound healing remedies for nearly 3000 years. Asiatic acid (AA), a pentacyclic triterpenoid characterized by ursane-type skeleton, serves as principal bioactive constituent of Centella asiatica, exhibits remarkable therapeutic potential across a spectrum of health conditions. Pharmacological investigations have revealed that AA exerts direct regulatory effects on a multitude of enzymes, receptors, inflammatory mediators, and transcription factors. This article systematically examines the therapeutic applications of AA and its derivatives in the management of neurodegenerative diseases, cancer, cardiovascular disorders, and infections. Additionally, recent advancements in the structural modification of AA are summarized, offering new insights for the development of low-toxicity, effective AA-based therapeutics and diagnostic agents. However, several challenges remain, including the paucity of clinical trials, uncertainties in dosage and treatment regimens, limited data on long-term safety and side effects, and poor bioavailability. Addressing these limitations is crucial for advancing AA-based therapies and ensuring their clinical applicability.

Sequential drug release nanocomposites for synergistic therapy in disease treatment

Time-sequenced drug release, or sequential drug release, represents a pivotal strategy in the synergistic treatment of diseases using nanocomposites. Achieving this requires the rational integration of multiple therapeutic agents within a single nanocomposite, coupled with precise time-controlled release mechanisms. These nanocomposites offer many advantages, including enhanced therapeutic synergy, reduced side effects, attenuated adverse interactions, improved stability and optimized drug utilization. Consequently, research in the field of drug delivery and synergistic therapy has become increasingly important. Currently, sequential drug release research is still in the data collection and basic research stages, and its potential has not yet been fully explored. Although prior studies have explored the sequential drug release strategy in various contexts, a comprehensive review of the underlying mechanisms and their applications in nanocomposites remains scarce. This review categorizes different types of sequential drug release strategies and summarizes diverse nanocomposites, focusing on both physical approaches driven by structural variations and chemical methods based on stimulus-responsive mechanisms. Furthermore, we highlight the major applications of sequential drug release strategies in the treatment of various diseases and detail their therapeutic efficacy. Finally, emerging trends and challenges in advancing sequential drug release strategies based on nanocomposites for disease treatment are also discussed.

MICRORNA-146B TARGETS HIF-1Α AND ATTENUATES CARDIOMYOCYTE APOPTOSIS AND FIBROSIS IN DOXORUBICIN-INDUCED HEART FAILURE

ABSTRACT

The global prevalence of heart failure is still growing, which imposes a heavy economic burden. The role of microRNA-146b (miR-146b) in HF remains largely unknown. This study aims to explore the role and mechanism of miR-146b in HF. Method: We applied reverse transcription-polymerase chain reaction to search for differential microRNAs between myocardial tissues of heart failure patients and controls. We also used reverse transcription-polymerase chain reaction to detect the miR-146b expression in primary neonatal mouse cardiomyocytes and mice models of doxorubicin-induced HF. In vivo experiments, echocardiography was performed at baseline and weeks 6. After that we harvested mice's heart and evaluated the cardiomyocyte with hematoxylin and eosin (HE), Masson trichrome staining, and TUNEL staining. Through bioinformatics analysis, we found HIF-1α might be the target gene of miR-146b, which validated by luciferase reporter gene assay. Subsequently, mRNA and protein expression levels of HIF-1α were detected by overexpression or inhibition of miR-146b in primary neonatal mouse cardiomyocytes. Results: We found that miR-146b expression was decreased in myocardial tissues of HF patients compared with controls ( P < 0.01). MiR-146b levels were notably downregulated in HF models. MiR-146b knockout mice showed a more pronounced decrease in cardiac function and more severe myocardial fibrosis and apoptosis than wild type. Meanwhile, over expression or repression of miR-146b in primary neonatal mouse cardiomyocytes could inhibit or upregulate HIF-1α mRNA and protein expression. Conclusion : Our study shows that miR-146b may be a protective factor for cardiomyocytes by modulating HIF-1α.

Prior exposure to doxorubicin exacerbates atherosclerotic plaque formation in apolipoprotein-E-deficient mice on a high-fat diet

BACKGROUND AND AIMS

Epidemiological data suggest that anthracyclines, such as doxorubicin (DOX), promote atherosclerosis in cancer survivors. However, this has not been established experimentally so far. Here, we investigated whether DOX pre-exposure exacerbates atherosclerotic plaque formation (Study 1) as well as the impact of DOX on plaque progression (Study 2). Further, we evaluated the role of alpha-1-antichymotrypsin (Serpina3n) and thrombospondin-1 (Thbs1) in these plaques as we previously identified these proteins to be associated with DOX-induced cardiovascular disease.

METHODS

In Study 1, DOX (4 mg/kg body weight/week) was administered for three weeks to apolipoprotein-E-deficient mice followed by a high-fat plaque-promoting diet for 8 weeks. In Study 2, mice were fed a high-fat diet for 17 weeks with DOX administered concomitantly from the third week of diet for three weeks. Plaque size and composition were assessed in the thoracic aorta, brachiocephalic artery and proximal ascending aorta.

RESULTS

Prior DOX exposure increased plaque size along the aortic tree, regardless of sex. This was accompanied by enhanced cell death (increased TUNEL positivity) as well as elevated Serpina3n and Thbs1 in plaques of DOX-treated mice. DOX did not change total cholesterol, HDL and LDL plasma concentrations. Conversely, concomitant DOX exposure did not enhance plaque size nor affect overall plaque composition along the aortic tree, highlighting the importance of experimental design.

CONCLUSIONS

Early DOX exposure exacerbated plaque development in mice, providing first experimental evidence for anthracycline chemotherapy as a possible risk factor for atherosclerosis in cancer patients.

Dynamics of SERPINA3 in response to anthracycline treatment and cardiovascular dysfunction

BACKGROUND

SERPINA3 recently emerged as potential prognostic biomarker in heart failure. In a population of cancer survivors with cancer therapy-related cardiac dysfunction (CTRCD) circulating SERPINA3 was elevated compared to age-matched controls. We aimed to assess the longitudinal dynamics of circulating SERPINA3 levels in patients with cancer treated with anthracycline chemotherapy (AnC) and its relation to CTRCD.

METHODS

In this single centre cohort study, 55 patients with cancer scheduled for AnC were prospectively enrolled. Cardiac evaluation (echocardiography, high-sensitive cardiac troponin I and NT-proBNP) was performed and SERPINA3 levels in plasma were assessed at 4 timepoints: before chemotherapy, directly after the end of chemotherapy, three months and twelve months after the end of chemotherapy.

RESULTS

Forty-two out of 55 patients (76.4%) developed CTRCD within 1 year after end of treatment. CTRCD was mild in 32 and moderate in 10 patients, defined as a change in cardiac biomarkers or GLS and LVEF decline < 50% respectively. Overall, median SERPINA3 levels decreased from baseline to three months after AnC (215.7 [62.0-984.0] to 176.9 [94.7-678.0] µg/ml, p = 0.031). This decrease was most prominent in patients without CTRCD (30.8% decrease, p = 0.007), followed by mild CTRCD (9.0% decrease, p = 0.022), while patients with moderate CTRCD did not show a reduction in SERPINA3 (5.1% increase, p = 0.987). SERPINA3 values at three months after AnC were positively correlated with NT-proBNP (r = 0.47, p = 0.002). Several malignancy, treatment and patient characteristics were associated with higher SERPINA3 values.

CONCLUSION

Circulating SERPINA3 levels show dynamic changes in a population of patients with cancer, with an overall decrease following AnC. However, in patients that developed moderate CTRCD, SERPINA3 levels remained elevated. The potential of SERPINA3 dynamics as a biomarker for CTRCD, deserves validation in larger cohorts.

Distinct Impact of Doxorubicin on Skeletal Muscle and Fat Metabolism in Mice: Without Dexrazoxane Effect

The chemotherapeutic agent doxorubicin (DOX) leads to the loss of skeletal muscle and adipose tissue mass, contributing to cancer cachexia. Experimental research on the molecular mechanisms of long-term DOX treatment is modest, and its effect on both skeletal muscle and adipose tissue has not been studied in an integrative manner. Dexrazoxane (DEXRA) is used to prevent DOX-induced cancer-therapy-related cardiovascular dysfunction (CTRCD), but its impact on skeletal muscle and adipose tissue remains elusive. Therefore, this study aimed to investigate the long-term effects of DOX on adipose tissue and skeletal muscle metabolism, and evaluate whether DEXRA can mitigate these effects. To this end, 10-week-old male C57BL6/J mice (n = 32) were divided into four groups: (1) DOX, (2) DOX-DEXRA combined, (3) DEXRA and (4) control. DOX (4 mg/kg weekly) and DEXRA (40 mg/kg weekly) were administered intraperitoneally over 6 weeks. Indirect calorimetry was used to assess metabolic parameters, followed by a molecular analysis and histological evaluation of skeletal muscle and adipose tissue. DOX treatment led to significant white adipose tissue (WAT) loss (74%) and moderate skeletal muscle loss (Gastrocnemius (GAS): 10%), along with decreased basal activity (53%) and energy expenditure (27%). A trend toward a reduced type IIa fiber cross-sectional area and a fast-to-slow fiber type switch in the Soleus muscle was observed. The WAT of DOX-treated mice displayed reduced Pparg (p < 0.0001), Cd36 (p < 0.0001) and Glut4 (p < 0.05) mRNA expression-markers of fat and glucose metabolism-compared to controls. In contrast, the GAS of DOX-treated mice showed increased Cd36 (p < 0.05) and Glut4 (p < 0.01), together with elevated Pdk4 (p < 0.001) mRNA expression-suggesting reduced carbohydrate oxidation-compared to controls. Additionally, DOX increased Murf1 (p < 0.05) and Atrogin1 (p < 0.05) mRNA expression-markers of protein degradation-compared to controls. In both the WAT and GAS of DOX-treated mice, Ppard mRNA expression remained unchanged. Overall, DEXRA failed to prevent these DOX-induced changes. Collectively, our results suggest that DOX induced varying degrees of wasting in adipose tissue and skeletal muscle, driven by distinct mechanisms. While DEXRA protected against DOX-induced CTRCD, it did not counteract its adverse effects on skeletal muscle and adipose tissue.

Intravenous Thrombolysis for Pediatric Ischemic Stroke Secondary to Cancer Therapy-related Cardiac Dysfunction

An 11-year-old boy developed cardioembolic stroke (CES) and cancer therapy-related cardiac dysfunction (CTRCD). He originally developed Ewing sarcoma and was treated with high-dose chemotherapy including doxorubicin. On admission, he had severe aphasia, and magnetic resonance imaging showed occlusion of the left middle cerebral artery M3 segment. Transthoracic echocardiography revealed severe left ventricular dysfunction and a mobile thrombus at the left ventricular apex. Intravenous thrombolysis was administered, and effective recanalization was achieved. The patient did not exhibit any neurological deficits during discharge. Reperfusion therapy for pediatric patients has not yet been established; however, it may be effective for CES secondary to CTRCD.

Enhancing Chemotherapy Efficacy via an Autologous Erythrocyte-Anchoring Strategy with a Closed-System Drug-Transfer Device

Chemotherapeutic drugs often fail to localize efficiently to tumors when administered intravenously, causing off-target effects. This study proposes an autologous erythrocyte (ER)-anchoring strategy to improve chemotherapy efficacy and reduce side effects. Utilizing a modified hemodialysis instrument, a closed-system drug-transfer device was developed for autologous ER procurement and immunogenicity mitigation. Doxorubicin (DOX) and indocyanine green (ICG) were encapsulated in autologous ERs and then modified with DSPE-PEG-FA. The final product, DOX-ICG@ER-D, was reintroduced into circulation to enhance chemotherapy. These obtained DOX-ICG@ER-D showed good stability, minimal cardiotoxicity, and extended circulation time. Compared to free DOX, DOX-ICG@ER-D had a higher accumulation of DOX in hepatocellular carcinoma and the release of DOX could be controlled by laser irradiation. Tumor-bearing rats treated by these DOX-ICG@ER-D demonstrated improved antitumor efficacy and reduced cardiotoxicity. Thus, this autologous ER-anchoring strategy offers a promising alternative to intravenous chemotherapy in the clinic.

Interleukin-12p40 deficiency attenuates myocardial ferroptosis in doxorubicin-induced chronic cardiomyopathy by inhibiting Th17 differentiation and interleukin-17A production

AIMS

Interleukin (IL)-12p40 is a common subunit of the bioactive cytokines IL-12 and IL-23, and it also has its own intrinsic functional activity. However, its role in doxorubicin-induced chronic cardiomyopathy (DICCM) as well as the underlying mechanisms are still unknown.

METHODS AND RESULTS

In this study, we used IL-12p40-knockout mice, IL-23p19-knockout mice, Rag1-knockout mice, a ferroptosis inhibitor, recombinant IL-12 (rIL-12), rIL-23, rIL-12p40, rIL-12p80, and anti-IL17A to investigate the effects of IL-12p40 on DICCM and elucidate the underlying mechanisms. We found that myocardial ferroptosis were increased in DICCM and that the inhibition of ferroptosis protected against DICCM. The expression of IL-12p40 was upregulated, and IL-12p40 was predominantly expressed by CD4+ T cells in the hearts of mice with DICCM. IL-12p40 knockout attenuated cardiac dysfunction, fibrosis and ferroptosis in DICCM, and similar results were observed in the context of CD4+ T cell IL-12p40 deficiency in Rag1-/- mice. Treatment with rIL-23, but not rIL-12, rIL-12p40 monomer or rIL-12p80, abolished the protective effects of IL-12p40 knockout. Moreover, rIL-23 treatment and IL-23p19 knockout exacerbated and ameliorated DICCM, respectively. IL-12p40 knockout might protect against DICCM by inhibiting Th17 differentiation and IL-17A production but not Th1, Th2 and Treg differentiation. Neutralizing IL-17A with an antibody also attenuated cardiac dysfunction, fibrosis, and ferroptosis. The IL-12p40/Th17/IL-17A axis might promote cardiomyocyte ferroptosis by activating TNF receptor-associated factor 6 (TRAF6)/mitogen-activated protein kinase (MAPK)/P53 signalling in DICCM.

CONCLUSION

Interleukin-12p40 deficiency protects against DICCM by inhibiting Th17 differentiation and the production of IL-17A, which plays critical roles in cardiomyocyte ferroptosis in DICCM via activating TRAF6/MAPK/P53 signalling. Our study may provide novel insights for the identification of therapeutic targets for treating DICCM in the clinic.

Cardioprotective effect of Saussurea involucrata injection against Doxorubicin-induced cardiotoxicity by network pharmacology analysis and experimental verification

Doxorubicin (Dox) is widely utilized in the clinical treatment of various cancers. Despite its efficacy, Dox induces numerous adverse effects in humans with significant cardiotoxicity, posing a major limitation to its use. Saussurea involucrata injection (SII), derived from Saussurea involucrata, exhibits notable anti-inflammatory and anti-oxidative stress properties. However, its potential protective effects against Dox-induced cardiotoxicity (DIC) remain unexplored. In this study, we investigate the ability of SII to mitigate DIC and elucidate the underlying mechanisms through experimental research and network pharmacology analysis. Results from both in vitro and in vivo experiments reveal that SII treatment significantly improves Dox-induced cardiac dysfunction, reducing pathological alterations and fibrosis in cardiomyocytes. Moreover, SII has cardioprotective effects by diminishing the inflammation, oxidative stress, and apoptosis triggered by Dox. Network pharmacological analysis further shows that SII downregulates P53 protein expression by activating the AKT/MDM2 signaling pathway, thus attenuating DIC. In conclusion, this study confirms that SII mitigates DIC through downregulation of the AKT/MDM2/P53 signaling pathway, suggesting a promising therapeutic strategy for alleviating DIC.

Short-Term Proteasome Inhibition: Assessment of the Effects of Carfilzomib and Bortezomib on Cardiac Function, Arterial Stiffness, and Vascular Reactivity

Proteasome inhibitors such as bortezomib and carfilzomib induce apoptosis and are a cornerstone in the treatment of relapsed or refractory multiple myeloma. However, concerns have emerged concerning their link to cancer therapy-related cardiovascular dysfunction (CTRCD). Bortezomib, a reversible first-generation inhibitor, and carfilzomib, a second-generation irreversible inhibitor, are associated with hypertension, heart failure, and cardiac arrhythmias. The current study investigated the effects of bortezomib and carfilzomib on cardiac (left ventricular ejection fraction, LVEF) and vascular (arterial stiffness, vascular reactivity) function. Cardiac function assessment aimed to build upon existing evidence of proteasome inhibitors CTRCD, while arterial stiffness served as an early indicator of potential vascular remodeling. Groups of 12-week-old C57BL/6J male mice (n = 8 per group) were randomly assigned to receive vehicle, carfilzomib (8 mg/kg I.P.), or bortezomib (0.5 mg/kg I.P.). Additionally, proteasome inhibition was assessed in mice treated with L-NAME (0.5 mg/kg) to induce hypertension. Cardiac and vascular parameters were evaluated via echocardiography on days 0 and 3. On day 6, mice were sacrificed for ex vivo analysis of arterial stiffness and vascular reactivity. Overall, no changes in arterial stiffness were detected either in vivo or ex vivo at basal pressures. However, a steeper pressure-stiffness curve was observed for carfilzomib in normotensive (p < 0.01) and hypertensive (p < 0.0001) mice ex vivo. Additionally, in hypertensive mice, carfilzomib decreased LVEF (p = 0.06), with bortezomib exhibiting similar trends. Vascular reactivity remained largely unchanged, but proteasome inhibition tended to enhance endothelial-independent relaxations in both control and hypertensive mice. In conclusion, short-term treatment with carfilzomib and bortezomib is considered relatively safe for the protocols assessed in the study.

Dexrazoxane prevents vascular toxicity in doxorubicin-treated mice

BACKGROUND

Doxorubicin (DOX) is used for breast cancer and lymphoma, but can cause cardiotoxicity, arterial stiffness, and endothelial dysfunction. We recently reported SERPINA3N as biomarker of cardiovascular toxicity in patients and mice. Dexrazoxane (DEXRA) is an FDA-approved drug that prevents DOX-induced cardiac toxicity in high-risk patients. However, the effect of DEXRA on vascular dysfunction during DOX treatment has not been documented. Therefore, here we investigated whether DEXRA protects against DOX-induced arterial stiffness, endothelial dysfunction, and SERPINA3N upregulation in tissue and plasma from mice.

METHODS

Male C57BL6/J mice were treated with DOX (4 mg/kg), DEXRA (40 mg/kg), a combination (DEXRA + DOX), or VEHICLE (0.9% NaCl) weekly i.p. for 6 weeks (n = 8 per group). Cardiovascular function was measured in vivo by ultrasound imaging at baseline, weeks 2 and 6. Vascular reactivity was analyzed ex vivo in the thoracic aorta at week 6 and molecular analysis was performed.

RESULTS

DEXRA prevented left ventricular ejection fraction decline by DOX (DEXRA + DOX: 62 ± 2% vs DOX: 51 ± 2%). Moreover, DEXRA prevented the increase in pulse wave velocity by DOX (DEXRA + DOX: 2.1 ± 0.2 m/s vs DOX: 4.5 ± 0.3 m/s) and preserved endothelium-dependent relaxation (DEXRA + DOX: 82 ± 3% vs DOX: 62 ± 3%). In contrast to DOX-treated mice, SERPINA3N did not increase in the DEXRA + DOX group.

CONCLUSION

Our results not only confirm the cardioprotective effects of DEXRA against DOX-induced cardiotoxicity but also add preservation of vascular endothelial cell function as an important mechanism. Moreover, the study demonstrates the potential of SERPINA3N as a biomarker for monitoring cardiovascular complications of DOX in high-risk patients.

4-Deoxy-ε-Pyrromycinone: A Promising Drug/Lead Compound to Treat Tumors

Background

Anthraquinone drugs are widely used in the treatment of tumors. However, multidrug resistance and severe cardiac toxicity limit its use, which have led to the discovery of new analogues. In this paper, 4-Deoxy-ε-pyrromycinone (4-Deo), belonging to anthraquinone compounds, was first been studied with the anti-tumor effects and the safety in vitro and in vivo as a new anti-tumor drug or lead compound.

Methods

The quantitative analysis of 4-Deo was established by UV methodology. The anti-cancer effect of 4-Deo in vitro was evaluated by cytotoxicity experiments of H22, HepG2 and Caco2, and the anti-cancer mechanism was explored by cell apoptosis and cycle. The tumor-bearing mouse model was established by subcutaneous inoculation of H22 cells to evaluate the anti-tumor effect of 4-Deo in vivo. The safety of 4-Deo was verified by the in vitro safety experiments of healthy cells and the in vivo safety experiments of H22 tumor-bearing mice. Tumor tissue sections were labeled with CRT, HMGB1, IL-6 and CD115 to explore the preliminary anti-cancer mechanism by immunohistochemistry.

Results

In vitro experiments demonstrated that 4-Deo could inhibit the growth of H22 by inducing cell necrosis and blocking cells in S phase, and 4-Deo has less damage to healthy cells. In vivo experiments showed that 4-Deo increased the positive area of CRT and HMGB1, which may inhibit tumor growth by triggering immunogenic cell death (ICD). In addition, 4-Deo reduced the positive area of CSF1R, and the anti-tumor effect may be achieved by blocking the transformation of tumor-associated macrophages (TAMs) to M2 phenotype.

Conclusion

In summary, this paper demonstrated the promise of 4-Deo for cancer treatment in vitro and in vivo. This paper lays the foundation for the study of 4-Deo, which is beneficial for the further development anti-tumor drugs based on the lead compound of 4-Deo.

Thoracic aorta injury detected by 4D flow MRI predicts subsequent main adverse cardiovascular events in breast cancer patients receiving anthracyclines: A longitudinal study

PURPOSE

To investigate longitudinal thoracic aorta injury using 3-dimensional phase-contrast magnetic resonance imaging (4D flow MRI) parameters and to evaluate their value for predicting the subsequent main adverse cardiovascular events (MACEs) in breast cancer patients receiving anthracyclines.

METHODS

Between July 2020 and July 2021, eighty-eight female participants with breast cancer scheduled to receive anthracyclines with or without trastuzumab prospectively enrolled. Each subjects underwent 4D flow MRI at baseline, 3 and 6 months in relation to baseline. The diameter, peak velocity (Vpeak), wall shear stress (WSS), pulse wave velocity (PWV), energy loss (EL) and pressure gradient (PG) of thoracic aorta were measured. The association between these parameters and subsequent MACEs was performed by Cox proportional hazard models.

RESULTS

Ten participants had subsequently MACEs. The Vpeak and PG gradually decreased and the WSS, PWV and EL progressively increased at 3 and 6 months compared with baseline. Adjusted multivariable analysis showed that the WSS of the proximal, mid- and distal ascending aorta [HR, 1.314 (95% confidence interval (CI): 1.003, 1.898)], [HR, 1.320 (95% CI: 1.002, 1.801)] and [HR, 1.322 (95% CI: 1.001, 1.805)] and PWV of ascending aorta [HR, 2.223 (95% CI: 1.010, 4.653)] at 3 months were associated with subsequent MACEs. Combined WSS and PWV of ascending aorta at 3 months yielded the highest AUC (0.912) for predicting subsequent MACEs.

CONCLUSION

Combined WSS and PWV of ascending aorta at 3 months is helpful for predicting the subsequent MACEs in breast cancer patients treated by anthracyclines.

Irisin links Claudin-5 preservation and Mfn2-mediated mitochondrial dynamics to resist doxorubicin-induced cardiac endothelial damage

Irisin is protective in the cardiac microenvironment and can resist doxorubicin-induced cardiotoxicity. The purpose of this study was to investigate the connection between Irisin, endothelial cell integrity, and mitochondrial dynamics. Primary cardiac microvascular endothelial cells (CMECs) were used to explore the regulatory effects of Irisin on tight junction proteins, mitochondrial dynamics, β-catenin expression, and transcriptional activity. Results showed that Irisin can suppress doxorubicin-induced upregulation of MMP2 and MMP9, thereby reducing the degradation of tight junction proteins (ZO-1 and Claudin-5) and VE-cadherin. The preservation of Claudin-5 contributes to maintaining Mfn2 expression, which in turn supports mitochondrial fusion. Although Irisin restores doxorubicin-induced downregulation of β-catenin, it concurrently limits β-catenin transcriptional activity via Mfn2-mediated sulfenylation. Therefore, this study revealed a novel mechanism linking the protective effects of Irisin on the tight junction proteins and mitochondrial dynamics upon doxorubicin exposure.