MiR-181c protects cardiomyocyte injury by preventing cell apoptosis through PI3K/Akt signaling pathway

E3 ubiquitin ligase Smurf1 promotes cardiomyocyte pyroptosis by mediating ubiquitin-dependent degradation of TRIB2 in a rat model of heart failure

OBJECTIVE

Heart failure (HF) causes structural and functional changes in the heart, with the pyroptosis-mediated inflammatory response as the core link in HF pathogenesis. E3 ubiquitin ligases participate in cardiovascular disease progression. Here, we explored the underlying molecular mechanisms of E3 ubiquitin ligase Smurf1 in governing HF.

METHODS

HF rat/H9C2 cell models were established by doxorubicin intraperitoneal injections/hypoxia-reoxygenation (H/R), and treated with Smurf1 siRNA and oe-TRIB2 lentivirus plasmids or the NF-κB pathway inhibitor PDTC/si-smurf1, si-TRIB2, protease inhibitor MG132, or lysosomal inhibitor NH4Cl. The cardiac function/cardiac tissue pathological changes/fibrosis in HF rats were evaluated by echocardiography/H&E and Masson staining. GSDMD-N expression was determined by immunohistochemistry. Cell viability/lactate dehydrogenase (LDH) activity/IL-1β and IL-18 levels were measured by CCK-8/LDH kit/ELISA. The interaction between TRIB2 and Smurf1/TRIB2 ubiquitination levels was assessed by co-immunoprecipitation assay. The expression levels of Smurf1 and TRIB2 messenger RNA (mRNA) were determined by RT-qPCR. Levels of Smurf1/TRIB2/the NF-κB pathway-related factors/pyroptosis-related factors and TRIB2 mRNA were determined by Western blot/RT-qPCR.

RESULTS

Smurf1 was highly expressed in H/R-induced H9C2 cells/HF rats, while its knockdown up-regulated TRIB2 and repressed the NF-κB pathway, reduced cardiomyocyte pyroptosis, and attenuated HF. Mechanistically, Smurf1 promoted TRIB2 degradation through an ubiquitin-dependent manner and activated the NF-κB pathway under H/R conditions. TRIB2 silencing annulled Smurf1 knockdown-regulated NF-κB pathway and cardiomyocyte pyroptosis. TRIB2 overexpression inactivated the NF-κB pathway and reduced cardiomyocyte pyroptosis, thus retarding HF.

CONCLUSION

Smurf1 was highly expressed in HF rats, which promoted TRIB2 ubiquitination degradation and activated the NF-κB pathway, thereby promoting cardiomyocyte pyroptosis in HF rats.

The Effect of Physical Activity/Exercise on miRNA Expression and Function in Non-Communicable Diseases-A Systematic Review

Exercise may differently affect the expression of key molecular markers, including skeletal muscle and circulating miRNAs, involved in cellular and metabolic pathways' regulation in healthy individuals and in patients suffering from non-communicable diseases (NCDs). Epigenetic factors are emerging as potential therapeutic biomarkers in the prognosis and treatment of NCDs and important epigenetic factors, miRNAs, play a crucial role in cellular pathways. This systematic review aims to underline the potential link between changes in miRNA expression after different types of physical activity/exercise in some populations affected by NCDs. In June 2023, we systematically investigated the following databases: PubMed, MEDLINE, Scopus, and Web of Science, on the basis of our previously established research questions and following the PRISMA guidelines. The risk of bias and quality assessment were, respectively, covered by ROB2 and the Newcastle Ottawa scale. Of the 1047 records extracted from the initial search, only 29 studies were found to be eligible. In these studies, the authors discuss the association between exercise-modulated miRNAs and NCDs. The NCDs included in the review are cancer, cardiovascular diseases (CVDs), chronic obstructive pulmonary disease (COPD), and type 2 diabetes mellitus (T2DM). We evidenced that miR-146, miR-181, miR-133, miR-21, and miRNA-1 are the most reported miRNAs that are modulated by exercise. Their expression is associated with an improvement in health markers and they may be a potential target in terms of the development of future therapeutic tools.

MiR-449b-5p Ameliorates Hypoxia-induced Cardiomyocyte Injury through Activating PI3K/AKT Pathway by Targeting BCL2L13

Recent reports show miR-449b-5p reduces liver and renal ischemia/reperfusion (I/R) injury, but its effects on hypoxia-induced cardiomyocyte injury in ischemic heart disease are still unknown. In this study, AC16 human cardiomyocytes underwent hypoxic conditions for durations of 24, 48, and 72 h. We observed that miR-449b-5p expression was significantly downregulated in hypoxic AC16 cardiomyocytes. Elevating the levels of miR-449b-5p in these cells resulted in enhanced cell survival, diminished release of LDH, and a reduction in cell apoptosis and oxidative stress using CCK-8, LDH assays, flow cytometry, TUNEL staining, and various commercial kits. Conversely, reducing miR-449b-5p levels resulted in the opposite effects. Through bioinformatics analysis and luciferase reporter assays, BCL2-like 13 (BCL2L13) was determined to be a direct target of miR-449b-5p. Inhibiting BCL2L13 greatly inhibited hypoxia-induced cell viability loss, LDH release, cell apoptosis, and excessive production of oxidative stress, whereas increasing BCL2L13 negated miR-449b-5p's protective impact in hypoxic AC16 cardiomyocytes. Additionally, miR-449b-5p elevated the levels of the proteins p-PI3K, p-AKT, and Bcl-2, while decreasing Bax expression in hypoxic AC16 cardiomyocytes by targeting BCL2L13. In summary, the research indicates that the protective effects of miR-449b-5p are facilitated through the activation of the PI3K/AKT pathway, which promotes cell survival, and by targeting BCL2L13, which inhibits apoptosis, offering a potential therapeutic strategy for ischemic heart disease by mitigating hypoxia-induced cardiomyocyte injury.

Early and Accurate Detection of Radiation-induced Heart Damage by Cardiodynamicsgram

Cardiodynamicsgram (CDG) has emerged recently as a noninvasive spatiotemporal electrocardiographic method for subtle cardiac dynamics information analysis within electrocardiogram (ECG). This study explored the feasibility of CDG for detecting radiation-induced heart damage (RIHD) in a rat model. A single radiation dose of 40 Gy was delivered to the cardiac apex of female Wistar rats. First, CDG was generated through dynamic modeling of ECG signals using the deterministic learning algorithm. Furthermore, CDG indexes were calculated using the wavelet transform and entropy. In this model, CDG entropy indexes decreased significantly after radiotherapy. The shape of CDG changed significantly after radiotherapy (irregular shape) compared with controls (regular shape). Macrophage and fibrosis in myocardium of rats increased significantly after radiotherapy. CDG changes after radiotherapy were significantly correlated with histopathological changes and occurred significantly earlier than histopathological changes. This study provides an experimental basis for the clinical application of CDG for the early detection of RIHD.

A bibliometric and visual analysis of research trends and hotspots of myocardial apoptosis: A review

BACKGROUND

Recent studies have found that cardiomyocyte apoptosis is closely associated with the pathophysiological development of various cardiovascular diseases, for example chronic heart failure and myocardial infarction. At present, there are many researches in this field, such as pharmacological research, traditional Chinese medicine intervention research and pathway research. However, the relevant research is fragmented, with few comprehensive analysis and systematic combing.

METHODS

The relevant literature on cardiomyocyte apoptosis was downloaded from the Web of Science Core Collection (WoSCC) and PubMed databases. Citespace 6.1.R2 software Microsoft Excel 2019 and VOSviewer1.6.18.0 were used for bibliometric and visual analysis of publication volume, countries, institutions, journals, authors, keywords.

RESULTS

Since 1996, there are 1881 research articles and reviews related to cardiomyocyte apoptosis published by 10,313 researchers from 1648 institutions in 58 countries or regions were included. The number of annual publications showed an upward trend, especially in recent years. Countries participating in this research area include China, the United States, and Japan. Capital Medical University, Harbin Medical University are the key research institution, and other institutions also have substantial contribution on the project as to cardiomyocyte apoptosis. The journal EUR REV MED PHARMACO has a large number of publications, whereas CIRCULATION has the highest number of co-citations. Keywords analysis showed that apoptosis, expression and oxidative stress had higher frequencies, leading to 8 clusters.

CONCLUSIONS

Cardiomyocyte apoptosis is a hot research field in recent years. Through visualization and bibliometric analysis, it is found that this field focus on hotspots like clinical manifestations including heart failure or myocardial infarction, and microscopic mechanisms such as oxidative stress and inflammation.

Apoptosis and heart failure: The role of non-coding RNAs and exosomal non-coding RNAs

Heart failure is a condition that affects the cardio vascular system and occurs if the heart cannot adequately pump the oxygen and blood to the body. Myocardial infarction, reperfusion injury, and this disease is the only a few examples of the numerous cardiovascular illnesses that are impacted by the closely controlled cell deletion process known as apoptosis. Attention has been paid to the creation of alternative diagnostic and treatment modalities for the condition. Recent evidences have shown that some non-coding RNAs (ncRNAs) influence the stability of proteins, control of transcription factors, and HF apoptosis through a variety of methods. Exosomes make a significant paracrine contribution to the regulation of illnesses as well as to the communication between nearby and distant organs. However, it has not yet been determined whether exosomes regulate the cardiomyocyte-tumor cell interaction in ischemia HF to limit the vulnerability of malignancy to ferroptosis. Here, we list the numerous ncRNAs in HF that are connected to apoptosis. In addition, we emphasize the significance of exosomal ncRNAs in the HF.

miR-181c targets Parkin and SMAD7 in human cardiac fibroblasts: Validation of differential microRNA expression in patients with diabetes and heart failure with preserved ejection fraction

BACKGROUND

Cardiac fibrosis represents a key feature in the pathophysiology of heart failure with preserved ejection fraction (HFpEF), a condition highly prevalent amongst geriatric patients, especially if diabetic. The microRNA miR-181c has been shown to be associated with the response to exercise training in HFpEF patients and has been also linked to diabetic cardiovascular complications. However, the underlying mechanisms have not been fully elucidated.

OBJECTIVE

To measure circulating miR-181c in elderly patients with HFpEF and DM and identify gene targets pathophysiologically relevant in HFpEF.

METHODS

We quantified circulating miR-181c in frail older adults with a confirmed diagnosis of HFpEF and diabetes, and, as control, we enrolled age-matched subjects without HFpEF and without diabetes. We validated in human cardiac fibroblasts the molecular mechanisms linking miR-181c to a pro-fibrotic response.

RESULTS

51 frail patients were included (34 patients with diabetes and HFpEF and 17 age-matched controls. We observed that miR-181c was significantly upregulated (p<0.0001) in HFpEF patients vs controls. We confirmed in vitro that miR-181c is targeting PRKN and SMAD7.

CONCLUSIONS

We demonstrate that miR-181c levels are significantly increased in frail elderly adults with diabetes and HFpEF and that miR-181c targets PRKN and SMAD7 in human cardiac fibroblasts.

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.

Investigating the Mechanism of Action of Schisandra chinensis Combined with Coenzyme Q10 in the Treatment of Heart Failure Based on PI3K-AKT Pathway

Purpose

To study the active components, drug targets and mechanism of Schisandra chinensis (S.chinensis) combined with coenzyme Q10 (CQ10) in the treatment of heart failure (HF).

Methods

Network pharmacology combined with the gene expression omnibus chip method to analyze the main pathways by which S.chinensis combined with CQ10 functioned to treat heart failure. Subsequently, the biological activities of the major pathway key proteins and their corresponding compounds were verified by molecular docking techniques. Finally, the molecular mechanism of S. chinensis combined with CQ10 for the treatment of heart failure was verified using a rat heart failure model induced by isoproterenol hydrochloride and using hematoxylin-eosin staining, TUNEL, immunohistochemistry and Western blot.

Results

Network pharmacology combined with experimental validation suggests that the mechanism of action of S.chinensis combined with CQ10 in the treatment of heart failure may involve CQ10, Citral, Schisandrone, Schisanhenol B, Gomisin O, Schisandrin C and other components, which may synergistically inhibit the PI3K-AKT signaling pathway and affect the expression of AKT1, PIK3CG and other targets on this pathway. In addition, S. chinensis combined with CQ10 could effectively improve the cardiac coefficients of rats with heart failure, reduce the area of myocardial fibrosis and lowered the serum levels of IL-1β and TNF-α in heart failure rats, as well as reduced cardiac myocyte apoptosis, increased Bcl-2 expression and decreased p-PI3K/PI3K, p-AKT/AKT, P65 and Bax expression in cardiac tissue. Comparison of the results showed that the combination of S.chinensis and CQ10 was more effective compared with CQ10 alone, ie, the ability of S.chinensis combined with CQ10 in improving cardiac function, inhibiting cardiomyocyte apoptosis and reducing inflammatory response lies in the synergistic effect of PI3K/AKT signaling pathway.

Conclusion

The therapeutic effect of S.chinensis combined with CQ10 on heart failure, which may occur through the inhibition of PI3K/AKT signaling pathway.

Analysis of Function Role and Long Noncoding RNA Expression in Chronic Heart Failure Rats Treated with Hui Yang Jiu Ji Decoction

Hui Yang Jiu Ji (HYJJ) decoction has been applied as a prescription of traditional Chinese medicine for the treatment of chronic heart failure (CHF). However, its comprehensive molecular mechanism remains unclear now. Our study aimed to explore the possible function and lncRNA-miRNA regulation networks of HYJJ on CHF induced by doxorubicin (DOX) in rats. Our study showed that HYJJ could recover cardiac function and alleviate myocardial injury of DOX-induced CHF. Besides, HYJJ had an effect on restraining myocardial apoptosis in CHF rats. Moreover, RNA-sequencing and bioinformatics analysis indicated that among a total of 548 significantly up- and down-regulated differentially expressed (DE) long noncoding RNA (lncRNA), 511 up- and down-regulated DE miRNAs were identified. Cushing's syndrome and Adrenergic signaling in cardiomyocytes were common pathways between DE-lncRNAs-enriched pathways and DE-miRNAs-enriched pathways. Finally, we observed a new pathway-MSTRG.598.1/Lilrb2 pathway with the HYJJ treatment; however, it needs further studies. In conclusion, this study provided evidence that HYJJ may be a suitable medicine for treating CHF. Moreover, several pivotal miRNAs may serve important roles in these processes by regulating some key miRNAs or pathways in CHF.

A novel peptide HSP-17 ameliorates oxidative stress injury and apoptosis in H9c2 cardiomyocytes by activating the PI3K/Akt pathway

Background

Oxidative stress and cell apoptosis play pivotal roles in the pathogenesis of doxorubicin (DOX)-induced myocardial injury. Heat shock protein-derived peptide (HSP-17) is a peptide which is low-expressed in DOX treated mouse heart tissue. It has high bioactivity and interspecies sequence consistency, and is predicted to have myocardial protective effect.

Methods

Firstly, we added 1 µM DOX to H9c2 cell culture medium for 24 hours to construct the myocardial cytotoxicity model. Then we detected the effect of HSP-17 on DOX induced H9c2 cardiomyocyte injury by measuring cell viability and lactate dehydrogenase (LDH) level. In addition, reactive oxygen species (ROS) and tetraethylbenzimidazolylcarbocyanine iodide kits are used to evaluate the effect of the HSP-17 peptide on DOX-induced oxidative stress injury to cardiomyocytes, and the detection of apoptosis related proteins and flow cytometry were applied to detect the level of apoptosis. Furthermore, the protein expression levels [phosphorylated Akt (p-Akt) and phosphorylated PI3K (p-PI3K)] of the PI3K/Akt pathway were also detected by western blotting.

Results

We found that the HSP-17 peptide can increase cell viability, protect mitochondrial potential, reduce LDH levels, and reduce ROS and cardiomyocyte apoptosis. In addition, we also observed that HSP-17 upregulated the expression level of p-Akt, and LY294002, a typical inhibitor of PI3K/Akt, was found to eliminate the protective roles of HSP-17.

Conclusions

In conclusion, this study demonstrated that the HSP-17 peptide protected H9c2 cells against oxidative stress and apoptosis via PI3K/Akt pathway activation, which provides a new idea for the treatment of DOX-induced myocardial injury.

Cardioprotective Mechanism and Active Compounds of Folium Ginkgo on Adriamycin-Induced Cardiotoxicity: A Network Pharmacology Study

Objective

To investigate the mechanism of Folium Ginkgo (FG) against adriamycin-induced cardiotoxicity (AIC) through a network pharmacology approach.

Methods

Active ingredients of FG were screened by TCMSP, and the targets of active ingredient were collected by Genclip3 and HERB databases. AIC-related target genes were predicted by Genecards, OMIM, and CTD databases. Protein-protein interaction (PPI) network was constructed by STRING platform and imported into Cytoscape software to construct the FG-active ingredients-targets-AIC network, and CytoNCA plug-in was used to analyze and identify the core target genes. The Metascape platform was used for transcription factor, GO and signaling pathway enrichment analysis.

Results

27 active ingredients of FG and 1846 potential targets were obtained and 358 AIC target genes were retrieved. The intersection of FG and AIC targets resulted in 218 target genes involved in FG action. The top 5 active ingredients with most targets were quercetin, luteolin, kaempferol, isorhamnetin, and sesamin. After constructing the FG-active ingredients-targets-AIC network, CytoNCA analysis yielded 51 core targets, of which the top ranked target was STAT3. Ninety important transcription factors were enriched by transcription factor enrichment analysis, including RELA, TP53, NFKB1, SP1, JUN, STAT3, etc. The results of GO enrichment analysis showed that the effective active ingredient targets of FG were involved in apoptotic signaling, response to growth factor, cellular response to chemical stress, reactive oxygen species metabolic process, etc. The signaling pathway enrichment analysis showed that there were many signaling pathways involved in AIC, mainly including pathways in cancer, FOXO signaling pathway, AGE-RAGE signaling pathway in diabetic complications, signaling by interleukins, and PI3K-AKT signaling pathway,.

Conclusions

The study based on a network pharmacology approach demonstrates that the possible mechanisms of FG against AIC are the involvement of multicomponents, multitargets, and multipathways, and STAT3 may be a key target. Further experiments are needed to verify the results.

Research Progress on the Mechanism of Reducing Toxicity and Increasing the Efficacy of Sini Decoction Compatibility

Sini Decoction (SND) is the main prescription for treating Shaoyin disease in Zhang Zhongjing's Treatise on Typhoid Diseases in Han Dynasty. It is composed of Aconitum carmichaeli Debeaux, Glycyrrhiza uralensis Fisch ex DC and Zingiber officinale Roscoe. It has the effects of warming middle-jiao to dispel cold and revive the yang for resuscitation. Nowadays, it is mainly used in diseases in cardiovascular system, nervous system, digestive system and so on. In this paper, the effect and mechanism of the compatibility of Aconitum carmichaelii, Glycyrrhiza uralensis Fisch ex DC and Zingiber officinale Roscoe in SND were described. The results showed that SND performed remarkbly on strengthening heart, promoting blood circulation as well as inhibiting cardiomyocyte apoptosis, anti-inflammatory and anti-hypothyroidism. The toxic effect of Aconitum carmichaelii was relieved by the combination of Glycyrrhiza uralensis Fisch ex DC and Zingiber officinale Roscoe. The mechanism of increasing efficiency and reducing toxicity after the compatibility of medicines in SND was discussed from the perspective of changes in biological effects and chemical compositions. In terms of biological effects, the mechanism of SND in treating heart failure, myocardial ischemia, myocardial hypertrophy and hypothyroidism and protecting cell injury were discussed. As to chemical composition changes, most studies have compared the changes of main components in Aconitum carmichaelii, Glycyrrhiza uralensis Fisch ex DC and Zingiber officinale Roscoe with the whole prescription, drug pair and single Decoction, which further confirmed the effect of Glycyrrhiza uralensis Fisch ex DC on the detoxification of Aconitum carmichaelii and the significance of compatibility efficiency of SND. For the application of differently processed varieties of Aconitum carmichaelii in SND, the treatment of different diseases has siginificant tendencies and differences in the selections of Aconitum carmichaelii processed varieties. This paper will lay a foundation on clarifying the mechanism of drug compatibility of SND and in the future, provide a reference for the proper selection of differently processed products of Aconitum carmichaelii in SND in order to exert better effects in clinical pratices.

Interplay between PI3K/AKT pathway and heart disorders

The PI3K/AKT signaling has crucial role in the regulation of numerous physiological functions through activation of downstream effectors and modulation of cell cycle transition, growth and proliferation. This pathway participates in the pathogenesis of several human disorders such as heart diseases through regulation of size and survival of cardiomyocytes, angiogenic processes as well as inflammatory responses. Moreover, PI3K/AKT pathway participates in the process of myocardial injury induced by a number of substances such as H₂O₂, Mercury, lipopolysaccharides, adriamycin, doxorubicin and epirubicin. In this review, we describe the contribution of this pathway in the pathoetiology of myocardial ischemia/reperfusion injury and myocardial infarction, heart failure, cardiac hypertrophy, cardiomyopathy and toxins-induced cardiac injury.

The Role of miR-181c in Mechanisms of Diabetes-Impaired Angiogenesis: An Emerging Therapeutic Target for Diabetic Vascular Complications

Diabetes mellitus is estimated to affect up to 700 million people by the year 2045, contributing to an immense health and economic burden. People living with diabetes have a higher risk of developing numerous debilitating vascular complications, leading to an increased need for medical care, a reduced quality of life and increased risk of early death. Current treatments are not satisfactory for many patients who suffer from impaired angiogenesis in response to ischaemia, increasing their risk of ischaemic cardiovascular conditions. These vascular pathologies are characterised by endothelial dysfunction and abnormal angiogenesis, amongst a host of impaired signaling pathways. Therapeutic stimulation of angiogenesis holds promise for the treatment of diabetic vascular complications that stem from impaired ischaemic responses. However, despite significant effort and research, there are no established therapies that directly stimulate angiogenesis to improve ischaemic complications such as ischaemic heart disease and peripheral artery disease, highlighting the immense unmet need. However, despite significant effort and research, there are no established therapies that directly stimulate angiogenesis in a clinical setting, highlighting the immense unmet need. MicroRNAs (miRNAs) are emerging as powerful targets for multifaceted diseases including diabetes and cardiovascular disease. This review highlights the potential role of microRNAs as therapeutic targets for rescuing diabetes-impaired angiogenesis, with a specific focus on miR-181c, which we have previously identified as an important angiogenic regulator. Here we summarise the pathways currently known to be regulated by miR-181c, which include the classical angiogenesis pathways that are dysregulated in diabetes, mitochondrial function and axonal guidance, and describe how these relate both directly and indirectly to angiogenesis. The pleiotropic actions of miR-181c across multiple key angiogenic signaling pathways and critical cellular processes highlight its therapeutic potential as a novel target for treating diabetic vascular complications.

Recent Advances in Gene Therapy for Cardiac Tissue Regeneration

Cardiovascular diseases (CVDs) are responsible for enormous socio-economic impact and the highest mortality globally. The standard of care for CVDs, which includes medications and surgical interventions, in most cases, can delay but not prevent the progression of disease. Gene therapy has been considered as a potential therapy to improve the outcomes of CVDs as it targets the molecular mechanisms implicated in heart failure. Cardiac reprogramming, therapeutic angiogenesis using growth factors, antioxidant, and anti-apoptotic therapies are the modalities of cardiac gene therapy that have led to promising results in preclinical studies. Despite the benefits observed in animal studies, the attempts to translate them to humans have been inconsistent so far. Low concentration of the gene product at the target site, incomplete understanding of the molecular pathways of the disease, selected gene delivery method, difference between animal models and humans among others are probable causes of the inconsistent results in clinics. In this review, we discuss the most recent applications of the aforementioned gene therapy strategies to improve cardiac tissue regeneration in preclinical and clinical studies as well as the challenges associated with them. In addition, we consider ongoing gene therapy clinical trials focused on cardiac regeneration in CVDs.

MicroRNA miR-215-5p regulates doxorubicin-induced cardiomyocyte injury by targeting ZEB2

ABSTRACT

Doxorubicin (DOX) is a chemotherapeutic drug for treating various cancers. However, the DOX-induced cardiotoxicity greatly limits its clinical application. MicroRNAs (miRNAs) are emerged as critical mediators of cardiomyocyte injury. This work explored the function of miR-215-5p in the regulation of DOX-induced mouse HL-1 cardiomyocyte injury. An in vitro model of DOX-treated cardiotoxicity was established in HL-1 cells. Gene expression was measured by RT-qPCR. Cell viability was detected using CCK-8. Cell death and apoptosis were tested using TUNEL, flow cytometry, and caspase 3/7 activity assays. Luciferase reporter assay was used to examine the target of miR-215-5p. We found that DOX induced cardiomyocyte injury and upregulated miR-215-5p in HL-1 cells. Inhibition of miR-215-5p attenuated DOX-induced cardiomyocyte death and apoptosis in vitro. Mechanistical experiments indicated that ZEB2 was targeted by miR-215-5p. Additionally, ZEB2 expression was reduced in DOX-treated HL-1 cells. Rescue assays indicated that ZEB2 knockdown reversed the effects of miR-215-5p inhibition. In conclusion, miR-215-5p inhibition protects HL-1 cells against DOX-induced injury by upregulating ZEB2 expression.

Doxorubicin-induced cardiotoxicity: An update on the molecular mechanism and novel therapeutic strategies for effective management

Doxorubicin (Dox) is a secondary metabolite of the mutated strain of Streptomyces peucetius var. Caesius and belongs to the anthracyclines family. The anti-cancer activity of Dox is mainly exerted through the DNA intercalation and inhibiting topoisomerase II enzyme in fast-proliferating tumors. However, Dox causes cumulative and dose-dependent cardiotoxicity, which results in increased risks of mortality among cancer patients and thus limiting its wide clinical applications. There are several mechanisms has been proposed for doxorubicin-induced cardiotoxicity and oxidative stress, free radical generation and apoptosis are most widely reported. Apart from this, other mechanisms are also involved in Dox-induced cardiotoxicity such as impaired mitochondrial function, a perturbation in iron regulatory protein, disruption of Ca²⁺ homeostasis, autophagy, the release of nitric oxide and inflammatory mediators and altered gene and protein expression that involved apoptosis. Dox also causes downregulation of DNA methyltransferase 1 (DNMT1) enzyme activity which leads to a reduction in the DNA methylation process. This hypomethylation causes dysregulation in the mitochondrial genes like peroxisome proliferator-activated receptor-gamma coactivator (PGC)-1-alpha (PGC-1α), nuclear respiratory factor 1 (NRF-1) and mitochondrial transcription factor A (TFAM) unit in the heart. Apart from DNA methylation, Dox treatment also alters the micro RNAs levels and histone deacetylase (HDAC) activity. Therefore, in the current review, we have provided a detailed update on the current understanding of the pathological mechanisms behind the well-known Dox-induced cardiotoxicity. Further, we have provided some of the most plausible pharmacological strategies which have been tested against Dox-induced cardiotoxicity.

Non-coding RNAs in Cardiac Regeneration

The adult heart has a limited capacity to replace or regenerate damaged cardiac tissue following severe myocardial injury. Thus, therapies facilitating the induction of cardiac regeneration holds great promise for the treatment of end-stage heart failure, and for pathologies invoking severe cardiac dysfunction as a result of cardiomyocyte death. Recently, a number of studies have demonstrated that cardiac regeneration can be achieved through modulation and/or reprogramming of cardiomyocyte proliferation, differentiation, and survival signaling. Non-coding RNAs (ncRNAs), including microRNAs (miRNAs), long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs), are reported to play critical roles in regulating key aspects of cardiomyocyte physiologic and pathologic signaling, including the regulation of cardiac regeneration both in vitro and in vivo. In this review, we will explore and detail the current understanding of ncRNA function in cardiac regeneration, and highlight established and novel strategies for the treatment of heart failure through modulation of ncRNAs-driven cardiac regeneration.