Endoplasmic Reticulum Stress Promotes iNOS/NO and Influences Inflammation in the Development of Doxorubicin-Induced Cardiomyopathy

Mechanisms of doxorubicin-induced cardiac inflammation and fibrosis; therapeutic targets and approaches

Doxorubicin plays a pivotal role in the treatment of various malignancies. Despite its efficacy, the cardiotoxicity associated with doxorubicin limits its clinical utility. The cardiotoxic nature of doxorubicin is attributed to several mechanisms, including its interference with mitochondrial function, the generation of reactive oxygen species (ROS), and the subsequent damage to cardiomyocyte DNA, proteins, and lipids. Furthermore, doxorubicin disrupts the homeostasis of cardiac-specific transcription factors and signaling pathways, exacerbating cardiac dysfunction. Oxidative stress, cell death, and other severe changes, such as mitochondrial dysfunction, activation of pro-oxidant enzymes, the renin-angiotensin system (RAS), endoplasmic reticulum (ER) stress, and infiltration of immune cells in the heart after treatment with doxorubicin, may cause inflammatory and fibrotic responses. Fibrosis and inflammation can lead to a range of disorders in the heart, resulting in potential cardiac dysfunction and disease. Various adjuvants have shown potential in preclinical studies to mitigate these challenges associated with cardiac inflammation and fibrosis. Antioxidants, plant-based products, specific inhibitors, and cardioprotective drugs may be recommended to alleviate cardiotoxicity. This review explores the complex mechanisms of doxorubicin-induced heart inflammation and fibrosis, identifies possible cellular and molecular targets, and investigates potential substances that could help reduce these harmful effects.

Potential role of endoplasmic reticulum stress in doxorubicin-induced cardiotoxicity-an update

As a chemotherapy agent, doxorubicin is used to combat cancer. However, cardiotoxicity has limited its use. The existing strategies fail to eliminate doxorubicin-induced cardiotoxicity, and an in-depth exploration of its pathogenesis is in urgent need to address the issue. Endoplasmic reticulum stress (ERS) occurs when Endoplasmic Reticulum (ER) dysfunction results in the accumulation of unfolded or misfolded proteins. Adaptive ERS helps regulate protein synthesis to maintain cellular homeostasis, while prolonged ERS stimulation may induce cell apoptosis, leading to dysfunction and damage to tissue and organs. Numerous studies on doxorubicin-induced cardiotoxicity strongly link excessive activation of the ERS to mechanisms including oxidative stress, calcium imbalance, autophagy, ubiquitination, and apoptosis. The researchers also found several clinical drugs, chemical compounds, phytochemicals, and miRNAs inhibited doxorubicin-induced cardiotoxicity by targeting ERS. The present review aims to outline the interactions between ERS and other mechanisms in doxorubicin-induced cardiotoxicity and summarize ERS's role in this type of cardiotoxicity. Additionally, the review enumerates several clinical drugs, phytochemicals, chemical compounds, and miRNAs targeting ERS for considering therapeutic regimens that address doxorubicin-induced cardiotoxicity.

Isolation and anti-neuroinflammation activity of sesquiterpenoids from Artemisia argyi: computational simulation and experimental verification

BACKGROUND

Artemisia argyi is a traditional herbal medicine belonging to the genus Artemisia that plays an important role in suppressing inflammation. However, the chemical constituents and underlying mechanisms of its therapeutic potential in neuroinflammation are still incompletely understood, and warrant further investigation.

METHODS

Several column chromatography were employed to isolate and purify chemical constituents from Artemisia argyi, and modern spectroscopy techniques were used to elucidate their chemical structures. The screening of monomeric compounds with nitric oxide inhibition led to the identification of the most effective bioactive compound, which was subsequently confirmed for its anti-inflammatory capability through qRT‒PCR. Predictions of compound-target interactions were made using the PharmMapper webserver and the TargetNet database, and an integrative protein-protein interaction network was constructed by intersecting the predicted targets with neuroinflammation-related targets. Topological analysis was performed to identify core targets, and molecular docking and molecular dynamics simulations were utilized to validate the findings. The result of the molecular simulations was experimentally validated through drug affinity responsive target stability (DARTS) and Western blot experiments.

RESULTS

Seventeen sesquiterpenoids, including fifteen known sesquiterpenoids and two newly discovered guaiane-type sesquiterpenoids (argyinolide S and argyinolide T) were isolated from Artemisia argyi. Bioactivity screening revealed that argyinolide S (AS) possessed the most potent anti-inflammatory activity. However, argyinolide T (AT) showed weak anti-inflammatory activity, so AS was the target compound for further study. AS may regulate neuroinflammation through its modulation of eleven core targets: protein kinase B 1 (AKT1), epidermal growth factor receptor (EGFR), proto-oncogene tyrosine-protein Kinase (FYN), Janus Kinase (JAK) 1, mitogen-activated protein (MAP) Kinase 1,8 and 14, matrix metalloproteinase 9 (MMP9), ras-related C3 botulinum toxin substrate 1 (RAC1), nuclear factor kappa-B p65 (RELA), and retinoid X receptor alpha (RXRA). Molecular dynamics simulations and DARTS experiments confirmed the stable binding of AS to JAK1, and Western blot experiments demonstrated the ability of AS to inhibit the phosphorylation of downstream Signal transducer and activator of transcription 3 (STAT3) mediated by JAK1.

CONCLUSIONS

The sesquiterpenoid compounds isolated from Artemisia argyi, exhibit significant inhibitory effects on inflammation in C57BL/6 murine microglia cells (BV-2). Among these compounds, AS, a newly discovered guaiane-type sesquiterpenoid in Artemisia argyi, has been demonstrated to effectively inhibit the occurrence of neuroinflammation by targeting JAK1.

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.

Endoplasmic reticulum stress is upregulated in inflammatory bowel disease and contributed TLR2 pathway-mediated inflammatory response

OBJECTIVE

Endoplasmic reticulum stress (ERS) and Toll-like receptor 2 (TLR2) signaling play an important role in inflammatory bowel disease (IBD); however, the link between TLR2 and ERS in IBD is unclear. This study investigated whether Thapsigargin (TG) -induced ER protein expression levels contributed to TLR2-mediated inflammatory response.

METHODS

The THP-1 cells were treated with TLR2 agonist (Pam3CSK4), ERS inducer Thapsigargin (TG) or inhibitor (TUDCA). The mRNA expressions of TLR1-TLR10 were detected by qPCR. The production and secretion of inflammatory factors were detected by PCR and ELISA. Immunohistochemistry was used to detect the expressions of GRP78 and TLR2 in the intestinal mucosa of patients with Crohn's disease (CD). The IBD mouse model was established by TNBS in the modeling group. ERS inhibitor (TUDCA) was used in the treatment group.

RESULTS

The expression of TLRs was detected via polymerase chain reaction (PCR) in THP-1 cells treated by ERS agonist Thapsigargin (TG). According to the findings, TG could promote TLR2 and TLR5 expression. Subsequently, in TLR2 agonist Pam3CSK4 induced THP-1 cells, TG could lead to increased expression of the inflammatory factors such as TNF-α, IL-1β and IL-8, and ERS inhibitor (TUDCA) could block this effect. However, Pam3CSK4 did not significantly impact the GRP78 and CHOP expression. Based upon the immunohistochemical results, TLR2 and GRP78 expression were significantly increased in the intestinal mucosa of patients with Crohn's disease (CD). For in vivo experiments, TUDCA displayed the ability to inhibit intestinal mucosal inflammation and reduce GRP78 and TLR2 proteins.

CONCLUSIONS

ERS and TLR2 is upregulated in inflammatory bowel disease, ERS may promote TLR2 pathway-mediated inflammatory response. Moreover, ERS and TLR2 signaling could be novel therapeutic targets for IBD.

Guarding the heart: How SGLT-2 inhibitors protect against chemotherapy-induced cardiotoxicity: SGLT-2 inhibitors and chemotherapy-induced cardiotoxicity

The introduction of chemotherapy agents has significantly transformed cancer treatment, with anthracyclines being one of the most commonly used drugs. While these agents have proven to be highly effective against various types of cancers, they come with complications, including neurotoxicity, nephrotoxicity, and cardiotoxicity. Among these side effects, cardiotoxicity is the leading cause of morbidity and mortality, with anthracyclines being the primary culprit. Chemotherapy medications have various mechanisms that can lead to cardiac injury. Hence, numerous studies have been conducted to decrease the cardiotoxicity of these treatments. Combination therapy with beta-blockers, Angiotensin-converting enzyme inhibitors, and angiotensin receptor blockers have effectively reduced such outcomes. However, a definitive preventive strategy is yet to be established. Meanwhile, sodium-glucose co-transporter-2 (SGLT-2) inhibitors lower blood glucose levels in type 2 diabetes by reducing its re-absorption in the kidneys. They are thus considered potent drugs for glycemic control and reduction of cardiovascular risks. Recent studies have shown that SGLT-2 inhibitors are crucial in preventing chemotherapy-induced cardiotoxicity. They enhance heart cell viability, prevent degenerative changes, stimulate autophagy, and reduce cell death. This drug class also reduces inflammation by inhibiting reactive oxygen species and inflammatory cytokine production. Moreover, it can not only reverse the harmful effects of anticancer agents on the heart structure but also enhance the effectiveness of chemotherapy by minimizing potential consequences on the heart. In conclusion, SGLT-2 inhibitors hold promise as a therapeutic strategy for protecting cancer patients from chemotherapy-induced heart damage and improving cardiovascular outcomes.

Sesquiterpene from Artemisia argyi seed extracts: A new anti-acute peritonitis agent that suppresses the MAPK pathway and promotes autophagy

To find novel anti-inflammatory drugs, we screened anti-inflammatory compounds from 18 different types of Artemisia argyi seed extracts. The in vitro and in vivo anti-inflammatory activities of the screened compounds and their mechanisms were characterized. We first detected the cytotoxic effect of the compounds on RAW264.7 cells and the inhibitory effect on LPS-induced NO release. It was found that sesquiterpenoids CA-2 and CA-4 had low cytotoxic and strong NO inhibitory activity with an IC50 of 4.22 ± 0.61 μM and 2.98 ± 0.23 μM for NO inhibition, respectively. Therefore, compound CA-4 was studied in depth. We found that compound CA-4 inhibited LPS-induced pro-inflammatory factor production and M1 macrophage differentiation in RAW264.7 cells. Additionally, CA-4 inhibited the expression of p-ERK1/2, p-JNK, iNOS, and COX-2 by blocking the MAPK signaling pathway. CA-4 also promoted the expression of autophagy-related proteins such as LC3 II and Beclin-1 by inhibiting activation of the PI3K/AKT/mTOR signaling pathway, and promoted the generation of autophagosomes. Finally, CA-4 significantly inhibited the degree of inflammation in mice with acute peritonitis, showing good anti-inflammatory activity in vivo. Consequently, compound CA-4 may be a promising drug for the treatment of acute inflammatory diseases and provide new ideas for the synthesis of novel anti-inflammatory compounds.

Turmeric Extract-loaded Selenium Nanoparticles Counter Doxorubicin-induced Hepatotoxicity in Mice via Repressing Oxidative Stress, Inflammatory Cytokines, and Cell Apoptosis

BACKGROUND

Doxorubicin (DOX) is an antitumor anthracycline used to treat a variety of malignancies; however, its clinical use is associated with noticeable hepatotoxicity. Therefore, the current study was designed to delineate if biosynthesized SeNPs with turmeric extract (Tur-SeNPs) could alleviate DOX-induced hepatic adverse effects.

METHODS

Mice were orally post-treated with Tur extract, Tur-SeNPs, or N-acetyl cysteine after the intraperitoneal injection of DOX.

RESULTS

Our findings have unveiled a remarkable liver attenuating effect in DOX-injected mice post-treated with Tur-SeNPs. High serum levels of ALT, AST, ALP, and total bilirubin induced by DOX were significantly decreased by Tur-SeNPs therapy. Furthermore, Tur-SeNPs counteracted DOX-caused hepatic oxidative stress, indicated by decreased MDA and NO levels along with elevated levels of SOD, CAT, GPx, GR, GSH, and mRNA expression levels of Nrf-2. Noteworthily, decreased hepatic IL-1β, TNF-α, and NF-κB p65 levels in addition to downregulated iNOS gene expression in Tur-SeNPs-treated mice have indicated their potent antiinflammatory impact. Post-treatment with Tur-SeNPs also mitigated the hepatic apoptosis evoked by DOX injection. A liver histological examination confirmed the biochemical and molecular findings.

CONCLUSIONS

In brief, the outcomes have demonstrated Tur loaded with nanoselenium to successfully mitigate the liver damage induced by DOX via blocking oxidative stress, and inflammatory and apoptotic signaling.

Hydroxyfasudil regulates immune balance and suppresses inflammatory responses in the treatment of experimental autoimmune encephalomyelitis

Multiple sclerosis (MS) is a central nervous system (CNS) disease with complicated etiology. Multifocal demyelination and invasion of inflammatory cells are its primary pathological features. Fasudil has been confirmed to improve experimental autoimmune encephalomyelitis (EAE), an animal model of MS. However, Fasudil is accompanied by several shortcomings in the clinical practice. Hydroxyfasudil is a metabolite of Fasudil in the body with better pharmaceutical properties. Therefore, we attempted to study the influence of Hydroxyfasudil upon EAE mice. The results demonstrated that Hydroxyfasudil relieved the symptoms of EAE and the associated pathological damage, reduced the adhesion molecules and chemokines, decreased the invasion of peripheral immune cells. Simultaneously, Hydroxyfasudil modified the rebalance of peripheral T cells. Moreover, Hydroxyfasudil shifted the M1 phenotype to M2 polarization, inhibited inflammatory signaling cascades as well as inflammatory factors, and promoted anti-inflammatory factors in the CNS. In the end, mice in the Hydroxyfasudil group expressed more tight junction proteins, indirectly indicating that the blood-brain barrier (BBB) was protected. Our results indicate that Hydroxyfasudil may be a prospective treatment for MS.

MicroRNA in the Diagnosis and Treatment of Doxorubicin-Induced Cardiotoxicity

Doxorubicin (DOX), a broad-spectrum chemotherapy drug, is widely applied to the treatment of cancer; however, DOX-induced cardiotoxicity (DIC) limits its clinical therapeutic utility. However, it is difficult to monitor and detect DIC at an early stage using conventional detection methods. Thus, sensitive, accurate, and specific methods of diagnosis and treatment are important in clinical practice. MicroRNAs (miRNAs) belong to non-coding RNAs (ncRNAs) and are stable and easy to detect. Moreover, miRNAs are expected to become biomarkers and therapeutic targets for DIC; thus, there are currently many studies focusing on the role of miRNAs in DIC. In this review, we list the prominent studies on the diagnosis and treatment of miRNAs in DIC, explore the feasibility and difficulties of using miRNAs as diagnostic biomarkers and therapeutic targets, and provide recommendations for future research.

Role of oxidative stress and inflammation-related signaling pathways in doxorubicin-induced cardiomyopathy

Doxorubicin (DOX) is a powerful and commonly used chemotherapeutic drug, used alone or in combination in a variety of cancers, while it has been found to cause serious cardiac side effects in clinical application. More and more researchers are trying to explore the molecular mechanisms of DOX-induced cardiomyopathy (DIC), in which oxidative stress and inflammation are considered to play a significant role. This review summarizes signaling pathways related to oxidative stress and inflammation in DIC and compounds that exert cardioprotective effects by acting on relevant signaling pathways, including the role of Nrf2/Keap1/ARE, Sirt1/p66Shc, Sirt1/PPAR/PGC-1α signaling pathways and NOS, NOX, Fe²⁺ signaling in oxidative stress, as well as the role of NLRP3/caspase-1/GSDMD, HMGB1/TLR4/MAPKs/NF-κB, mTOR/TFEB/NF-κB pathways in DOX-induced inflammation. Hence, we attempt to explain the mechanisms of DIC in terms of oxidative stress and inflammation, and to provide a theoretical basis or new idea for further drug research on reducing DIC. Video Abstract.

Fluvastatin alleviates doxorubicin-induced cardiac and renal toxicity in rats via regulation of oxidative stress, inflammation, and apoptosis associated genes expressions

Doxorubicin (DOXO) is a cytostatic agent used in the chemotherapy protocol of several cancers for more than 40 years, but usage of this drug in cancer treatment has been limited due to severe renal and cardiac tissue toxicities that may result in death in patients. Fluvastatin (FV) is a fully synthetic hydroxymethyl glutaryl coenzyme A (HMG-CoA) reductase inhibitor used as a cholesterol-lowering agent in patients with hypercholesterolemia. Previous studies revealed that FV also exhibits antioxidant, anti-inflammatory, and antitumor activity. Additionally, our previous study indicated that FV exerts a prophylactic effect on DOXO-induced testicular toxicity by preventing lipid peroxidation, supporting the antioxidant system, and regulating the blood-testis barrier-associated genes expression. Herein, we purposed to evaluate the possible therapeutic and the protective effects of FV on the DOXO-induced cardiac and renal toxicitiy model by histochemical, immunohistochemical, biochemical, and real-time polymerase chain reaction (real-time PCR) analyses. Results point out protective use of FV exerts a beneficial effect by repressing lipid peroxidation and by regulating the inducible nitric oxide synthase (iNOS), nitric oxide synthase endothelial (eNOS), nuclear factor kappa-B (NF-κB), and Caspase-3 (Casp3) protein and mRNA expressions, which play an important role in mediating DOXO-induced renal and cardiac toxicity mechanisms. In conclusion, FV may be a candidate agent for the prevention of renal and cardiac toxicities in cancer patients receiving DOXO chemotherapy.

Neprilysin Inhibition in the Prevention of Anthracycline-Induced Cardiotoxicity

Anthracycline-induced cardiotoxicity (AIC) poses a clinical challenge in the management of cancer patients. AIC is characterized by myocardial systolic dysfunction and remodeling, caused by cardiomyocyte DNA damage, oxidative stress, mitochondrial dysfunction, or renin-angiotensin-aldosterone system (RAAS) dysregulation. In the past decade, after positive results of a PARADIGM-HF trial, a new class of drugs, namely angiotensin receptor/neprilysin inhibitors (ARNi), was incorporated into the management of patients with heart failure with reduced ejection fraction. As demonstrated in a variety of preclinical studies of cardiovascular diseases, the cardioprotective effects of ARNi administration are associated with decreased oxidative stress levels, the inhibition of myocardial inflammatory response, protection against mitochondrial damage and endothelial dysfunction, and improvement in the RAAS imbalance. However, data on ARNi's effectiveness in the prevention of AIC remains limited. Several reports of ARNi administration in animal models of AIC have shown promising results, as ARNi prevented ventricular systolic dysfunction and electrocardiographic changes and ameliorated oxidative stress, mitochondrial dysfunction, endoplasmic reticulum stress, and the inflammatory response associated with anthracyclines. There is currently an ongoing PRADAII trial aimed to assess the efficacy of ARNi in patients receiving breast cancer treatment, which is expected to be completed by late 2025.

Cardiac Remodelling Following Cancer Therapy: A Review

Cardiac remodelling is characterized by abnormal changes in the function and morphological properties such as diameter, mass, normal diameter of cavities, heart shape, fibrosis, thickening of vessels and heart layers, cardiomyopathy, infiltration of inflammatory cells, and some others. These damages are associated with damage to systolic and diastolic abnormalities, damage to ventricular function, and vascular remodelling, which may lead to heart failure and death. Exposure of the heart to radiation or anti-cancer drugs including chemotherapy drugs such as doxorubicin, receptor tyrosine kinase inhibitors (RTKIs) such as imatinib, and immune checkpoint inhibitors (ICIs) can induce several abnormal changes in the heart structure and function through the induction of inflammation and fibrosis, vascular remodelling, hypertrophy, and some others. This review aims to explain the basic mechanisms behind cardiac remodelling following cancer therapy by different anti-cancer modalities.

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

The use of doxorubicin (Dox) in cancer patients carries the risk of cardiotoxicity via an increase in oxidative stress, mitochondrial dysfunction, and disturbed endoplasmic reticulum (ER) homeostasis in cardiomyocytes. The present study explores which of the ER transmembrane sensors is involved in Dox-induced apoptosis and whether interleukin-10 (IL-10) has any mitigating effect. There was a time-related increase in apoptosis in cardiomyocytes exposed to 5.43 µg/mL Dox for 0 to 48 h. Dox treatment for 24 h significantly upregulated glucose-regulated proteins 78 and 94, protein disulfide isomerase, cleavage of activating transcription factor 6α, and X-box binding protein 1. These Dox-induced changes in ER stress proteins as well as apoptosis were blunted by IL-10 (10 ng/mL). In Dox-exposed cardiomyocytes, IL-10 also promoted expression of protein kinase-like endoplasmic reticulum kinase and inositol-requiring kinase 1α, which helped in maintaining ER homeostasis. Additionally, under Dox-treatment, IL-10 downregulated caspase-12 activation as well as phosphorylation of c-JUN NH2-terminal kinase, thereby promoting cardiomyocyte survival. IL-10 was able to reduce the overexpression of mitochondrial apoptotic proteins caspase-3 as well as Bax, which were upregulated upon Dox treatment. Thus, a reduction in Dox-induced ER stress as well as apoptosis through IL-10 may provide a significant benefit in improving cardiac function.

MicroRNA-194-5p Attenuates Doxorubicin-Induced Cardiomyocyte Apoptosis and Endoplasmic Reticulum Stress by Targeting P21-Activated Kinase 2

Objective

Many studies have reported that microRNAs (miRs) are involved in the regulation of doxorubicin (DOX)-induced cardiotoxicity. MiR-194-5p has been reported significantly upregulated in patients with myocardial infarction; however, its role in myocardial diseases is still unclear. Various stimuluses can trigger the endoplasmic reticulum (ER) stress and it may activate the apoptosis signals eventually. This study aims to explore the regulatory role of miR-194-5p in DOX-induced ER stress and cardiomyocyte apoptosis.

Methods

H9c2 was treated with 2 μM DOX to induce apoptosis, which is to stimulate the DOX-induced cardiotoxicity model. The expression of miR-194-5p was detected by quantitative real-time PCR (qRT-PCR); the interaction between miR-194-5p and P21-activated kinase 2 (PAK2) was tested by dual luciferase reporter assay; terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) assay and caspase-3/7 activity were used to assess apoptosis; trypan blue staining was applied to measure cell death; Western blotting was performed to detect protein expressions; and ER-related factors splicing X-box binding protein 1 (XBP1s) was detected by polyacrylamide gel electrophoresis and immunofluorescence to verify the activation of ER stress.

Results

MiR-194-5p was upregulated in cardiomyocytes and mouse heart tissue with DOX treatment, while the protein level of PAK2 was downregulated. PAK2 was predicted as the target of miR-194-5p; hence, dual luciferase reporter assay indicated that miR-194-5p directly interacted with PAK2 and inhibited its expression. TUNEL assay, caspase-3/7 activity test, and trypan blue stain results showed that either inhibition of miR-194-5p or overexpression of PAK2 reduced DOX-induced cardiomyocyte apoptosis. Silencing of miR-194-5p also improved DOX-induced cardiac dysfunction. In addition, DOX could induce ER stress in H9c2, which led to XBP1 and caspase-12 activation. The expression level of XBP1s with DOX treatment increased first then decreased. Overexpression of XBP1s suppressed DOX-induced caspase-3/7 activity elevation as well as the expression of cleaved caspase-12, which protected cardiomyocyte from apoptosis. Additionally, the activation of XBP1s was regulated by miR-194-5p and PAK2.

Conclusion

Our findings revealed that silencing miR-194-5p could alleviate DOX-induced cardiotoxicity via PAK2 and XBP1s in vitro and in vivo. Thus, the novel miR-194-5p/PAK2/XBP1s axis might be the potential prevention/treatment targets for cancer patients receiving DOX treatment.