Interleukin-10 Mitigates Doxorubicin-Induced Endoplasmic Reticulum Stress as Well as Cardiomyopathy

Doxorubicin‑induced cardiomyopathy is mitigated by empagliflozin via the modulation of endoplasmic reticulum stress pathways

Doxorubicin (Dox) exhibits a high efficacy in the treatment of numerous types of cancer. However, the beneficial cytotoxic effects of Dox are often accompanied by an increase in the risk of cardiotoxicity. Oxidative stress (OS) plays a key role in Dox‑induced cardiomyopathy (DIC). OS in cardiomyocytes disrupts endoplasmic reticulum (ER) function, leading to the accumulation of misfolded/unfolded proteins known as ER stress. ER stress acts as an adaptive mechanism; however, prolonged ER stress together with OS may lead to the initiation of cardiomyocyte apoptosis. The present study aimed to explore the potential of an anti‑diabetic drug, empagliflozin (EMPA), in mitigating Dox‑induced ER stress and cardiomyocyte apoptosis. In the present study, the effects of 1 h pretreatment of EMPA on Dox‑treated cardiomyocytes isolated from Sprague‑Dawley rats were investigated. After 24 h, EMPA pre‑treatment promoted cell survival in the EMPA + Dox group compared with the Dox group. Results of the present study also demonstrated that EMPA mitigated overall ER stress, as the increased expression of ER stress markers was reduced in the EMPA + Dox group. Additionally, OS, inflammation and expression of ER stress apoptotic proteins were also significantly reduced following EMPA pre‑treatment in the EMPA + Dox group. Thus, EMPA may exert beneficial effects on Dox‑induced ER stress and may exhibit potential changes that can be utilised to further evaluate the role of EMPA in mitigating DIC.

Sex-related differences in delayed doxorubicin-induced cardiac dysfunction in C57BL/6 mice

Cancer survivors may experience long-term cardiovascular complications due to chemotherapeutic drugs such as doxorubicin (DOX). The exact mechanism of delayed DOX-induced cardiotoxicity has not been fully elucidated. Sex is an important risk factor for DOX-induced cardiotoxicity. In the current study, we identified sex differences in delayed DOX-induced cardiotoxicity and determined the underlying molecular determinants of the observed sexual dimorphism. Five-week-old male and female mice were administered intraperitoneal injections of DOX (4 mg/kg/week) or saline for 6 weeks. Echocardiography was performed 5 weeks after the last dose of DOX to evaluate cardiac function. Thereafter, mice were sacrificed and gene expression of markers of apoptosis, senescence, and inflammation was measured by PCR in hearts and livers. Proteomic profiling of the heart from both sexes was conducted to determine differentially expressed proteins (DEPs). Only DOX-treated male, but not female, mice demonstrated cardiac dysfunction, cardiac atrophy, and upregulated cardiac expression of Nppb and Myh7. No sex-related differences were observed in DOX-induced expression of most apoptotic, senescence, and pro-inflammatory markers. However, the gene expression of Trp53 was significantly reduced in hearts of DOX-treated female mice only. The anti-inflammatory marker Il-10 was significantly reduced in hearts of DOX-treated male mice only, while the pro-inflammatory marker Il-1α was significantly reduced in livers of DOX-treated female mice only. Gene expression of Tnf-α was reduced in hearts of both DOX-treated male and female mice. Proteomic analysis identified several DEPs after DOX treatment in a sex-specific manner, including anti-inflammatory acute phase proteins. This is the first study to assess sex-specific proteomic changes in a mouse model of delayed DOX-induced cardiotoxicity. Our proteomic analysis identified several sexually dimorphic DEPs, many of which are associated with the anti-inflammatory marker Il-10.

Endoplasmic Reticulum Stress and Metabolism in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer, accounting for 85% to 90% of all liver cancer cases. It is a hepatocyte-derived primary tumor, causing 550,000 deaths per year, ranking it as one of the most common cancers worldwide. The liver is a highly metabolic organ with multiple functions, including digestion, detoxification, breakdown of fats, and production of bile and cholesterol, in addition to storage of vitamins, glycogen, and minerals, and synthesizing plasma proteins and clotting factors. Due to these fundamental and diverse functions, the malignant transformation of hepatic cells can have a severe impact on the liver's metabolism. Furthermore, tumorigenesis is often accompanied by activation of the endoplasmic reticulum (ER) stress pathways, which are known to be highly intertwined with several metabolic pathways. Because HCC is characterized by changes in the metabolome and by an aberrant activation of the ER stress pathways, the aim of this review was to summarize the current knowledge that links ER stress and metabolism in HCC, thereby focusing on potential therapeutic targets.

IL-27p28 knockout aggravates Doxorubicin-induced cardiotoxicity by regulating Macrophage polarization

BACKGROUND

Several interleukins (ILs) have been demonstrated to participate in cardiac injury. This study aimed to investigate whether IL-27p28 plays a regulatory role in doxorubicin (DOX)-induced cardiac injury by regulating inflammation and oxidative stress.

METHODS

Dox was used to establish a mouse cardiac injury model, and IL-27p28 was knocked out to observe its role in cardiac injury. In addition, monocytes were adoptively transferred to clarify whether monocyte-macrophages mediate the regulatory role of IL-27p28 in DOX-induced cardiac injury.

RESULTS

IL-27p28 knockout significantly aggravated DOX-induced cardiac injury and cardiac dysfunction. IL-27p28 knockout also upregulated the phosphorylation levels of p65 and STAT1 and promoted M1 macrophage polarization in DOX-treated mice, which increased cardiac inflammation and oxidative stress. Moreover, IL-27p28-knockout mice that were adoptively transferred WT monocytes exhibited worse cardiac injury and cardiac dysfunction and higher cardiac inflammation and oxidative stress.

CONCLUSIONS

IL-27p28 knockdown aggravates DOX-induced cardiac injury by worsening the M1 macrophage/M2 macrophage imbalance and its associated inflammatory response and oxidative stress.

Molecular mechanisms of anthracycline induced cardiotoxicity: Zebrafish come into play

Anthracyclines are among the most potent chemotherapeutics; however, cardiotoxicity significantly restricts their use. Indeed, anthracycline-induced cardiotoxicity (AIC) fares among the worst types of cardiomyopathy, and may only slowly and partially respond to standard heart failure therapies including β-blockers and ACE inhibitors. No therapy specifically designed to treat anthracycline cardiomyopathy at present, and neither is it known if any such strategy could be developed. To address this gap and to elucidate the molecular basis of AIC with a therapeutic goal in mind, zebrafish has been introduced as an in vivo vertebrate model about a decade ago. Here, we first review our current understanding of the basic molecular and biochemical mechanisms of AIC, and then the contribution of zebrafish to the AIC field. We summarize the generation of embryonic zebrafish AIC models (eAIC) and their use for chemical screening and assessment of genetic modifiers, and then the generation of adult zebrafish AIC models (aAIC) and their use for discovering genetic modifiers via forward mutagenesis screening, deciphering spatial-temporal-specific mechanisms of modifier genes, and prioritizing therapeutic compounds via chemical genetic tools. Several therapeutic target genes and related therapies have emerged, including a retinoic acid (RA)-based therapy for the early phase of AIC and an autophagy-based therapy that, for the first time, is able to reverse cardiac dysfunction in the late phase of AIC. We conclude that zebrafish is becoming an important in vivo model that would accelerate both mechanistic studies and therapeutic development of AIC.