HMOX1 silencing prevents doxorubicin-induced cardiomyocyte injury, mitochondrial dysfunction, and ferroptosis by downregulating CTGF

The role of lncRNA H19/Hmox1 axis regulating ferroptosis in anthracycline-induced cardiotoxicity

This study investigates the molecular mechanisms underlying anthracyclines (ANT)-induced cardiotoxicity, with a specific focus on ferroptosis regulated by the long non-coding RNA (lncRNA) H19/heme oxygenase-1 (Hmox1) signaling axis. A retrospective analysis was performed on 50 breast cancer patients who developed ANT-associated cardiac dysfunction. Clinical assessments included measurements of left ventricular ejection fraction (LVEF) and serum markers, such as cardiac troponin I (cTnI), creatine kinase-MB (CK-MB), N-terminal pro-B-type natriuretic peptide (NT-proBNP), and serum iron levels. Serum analysis revealed a marked downregulation of lncRNA H19 and upregulation of Hmox1, both significantly correlated with impaired cardiac function and disrupted iron homeostasis. To further elucidate the mechanism, an Epirubicin (EPI)-induced injury model in HL-1 cardiomyocytes was established. EPI exposure led to suppression of lncRNA H19, upregulation of Hmox1, and induction of apoptosis and ferroptotic cell death. RNA-seq analysis identified potential downstream targets linking lncRNA H19 to iron metabolism via Hmox1 modulation. Functional assays demonstrated that overexpression of lncRNA H19 mitigated EPI-induced ferroptosis, while enforced expression of Hmox1 reversed these protective effects. Collectively, these findings identify the lncRNA H19/Hmox1 axis as a critical regulator of ferroptosis in ANT-induced cardiotoxicity and suggest it as a potential therapeutic target for mitigating cardiac injury in breast cancer patients undergoing anthracycline chemotherapy.

TLR2 activates AP-1 to facilitate CTGF transcription and stimulate doxorubicin-induced myocardial injury

BACKGROUND AND PURPOSE

Our study aimed to explore the mechanistic network of toll-like receptor 2 (TLR2)/activator protein-1 (AP-1) combined with SOX10 activation of the mitogen-activated protein kinase (MAPK) pathway via connective tissue growth factor (CTGF) in doxorubicin (Dox)-induced myocardial injury.

EXPERIMENTAL APPROACH

Rats with Dox-induced myocardial injury were treated with a TLR2 inhibitor or CTGF silencing lentiviral vector. H9c2 cells were treated with genetic vectors or MAPK pathway activators. Cardiac function was tested using echocardiography and serum markers. H&E, Sirius red and TUNEL staining were used to detect myocardial pathological changes, collagen accumulation and apoptosis. Western blot was used to detect proteins related to cardiac hypertrophy, fibrosis, apoptosis and the MAPK pathway. H9c2 cell injury was assessed by testing cell viability, lactate dehydrogenase (LDH) release and mitochondrial membrane potential.

KEY RESULTS

TLR2 and CTGF were highly expressed in patients with heart failure, and Dox treatment further increased their expression. Inhibiting TLR2 or silencing CTGF improved cardiac function and reduced myocardial fibrosis and apoptosis in Dox-treated rats. Silencing of TLR2 alleviated Dox-induced H9c2 cell injury, which was nullified by CTGF overexpression. TLR2 activated AP-1, which cooperated with SOX10 to promote CTGF transcription. MAPK activation aggravated H9c2 cells against Dox-induced injury.

CONCLUSIONS AND IMPLICATIONS

TLR2 activates AP-1 which cooperates with SOX10 to promote CTGF transcription and subsequently activate the MAPK pathway, thereby stimulating Dox-induced myocardial injury.

Paeonol alleviates ox-LDL-induced endothelial cell injury by targeting the heme oxygenase-1/phosphoinositide 3-kinase/protein kinase B pathway

Atherosclerosis is a leading cause of vascular disease worldwide. Paeonol has been reported to have therapeutical potential in atherosclerosis. The aim of this study is to explore the effect of paeonol on oxidized low-density lipoprotein (ox-LDL)-induced endothelial cells injury and the underlying mechanism. Human umbilical vein endothelial cells (HUVECs) were treated with ox-LDL (100 μg/ml) to mimic atherosclerosis in vitro. The cell viability, proliferation, and apoptosis were assessed by cell counting kit-8 (CCK8), 5-ethynyl-2'-deoxyuridine (EdU), and flow cytometry, respectively. The angiogenesis was detected by tube formation assay. The levels of inflammatory factor were measured by enzyme-linked immunosorbent assay (ELISA). In addition, the levels of Fe2+, reactive oxygen species (ROS), and glutathione (GSH) were detected to assess ferroptosis. The western blot was used to detect the protein expression. Ox-LDL inhibited cell viability, proliferation, and angiogenesis, but induced apoptosis and inflammation in HUVECs, and paeonol (75 μM) relieves ox-LDL-induced HUVEC injury. Also, paeonol inhibited ox-LDL-induced ferroptosis of HUVECs. Interestingly, heme oxygenase-1 (HMOX1) knockdown alleviated ox-LDL-induced HUVECs injury and ferroptosis. Paeonol affected ox-LDL-induced HUVECs via regulating HMOX1. In addition, paeonol regulated PI3K/AKT pathway via HMOX1, and the inhibitor of phosphoinositide 3-kinase/protein kinase B (PI3K/AKT) pathway reversed the effects of HMOX1 knockdown on ox-LDL-induced HUVECs. Paeonol alleviated ox-LDL-induced HUVEC injury by regulating the PI3K/AKT pathway via targeting HMOX1.

Ccn2 Deletion Reduces Cardiac Dysfunction, Oxidative Markers, and Fibrosis Induced by Doxorubicin Administration in Mice

Cellular Communication Network Factor 2 (CCN2) is a matricellular protein implicated in cell communication and microenvironmental signaling. Overexpression of CCN2 has been documented in various cardiovascular pathologies, wherein it may exert either deleterious or protective effects depending on the pathological context, thereby suggesting that its role in the cardiovascular system is not yet fully elucidated. In this study, we aimed to investigate the effects of Ccn2 gene deletion on the progression of acute cardiac injury induced by doxorubicin (DOX), a widely utilized chemotherapeutic agent. To this end, we employed conditional knockout (KO) mice for the Ccn2 gene (CCN2-KO), which were administered DOX and compared to DOX-treated wild-type (WT) control mice. Our findings demonstrated that the ablation of CCN2 ameliorated DOX-induced cardiac dysfunction, as evidenced by improvements in ejection fraction (EF) and fractional shortening (FS) of the left ventricle. Furthermore, DOX-treated CCN2-KO mice exhibited a significant reduction in the gene expression and activation of oxidative stress markers (Hmox1 and Nfe2l2/NRF2) relative to DOX-treated WT controls. Additionally, the deletion of Ccn2 markedly attenuated DOX-induced cardiac fibrosis. Collectively, these results suggest that CCN2 plays a pivotal role in the pathogenesis of DOX-mediated cardiotoxicity by modulating oxidative stress and fibrotic pathways. These findings provide a novel avenue for future investigations to explore the therapeutic potential of targeting CCN2 in the prevention of DOX-induced cardiac dysfunction.

HMOX1 Participates in Pre-Eclampsia by Regulating the Proliferation, Apoptosis, and Angiogenesis Modulation Potential of Mesenchymal Stem Cells via VEGF

Mesenchymal stem cells (MSCs) are involved in the pathogenesis of pre-eclampsia (PE). Heme oxygenase (HMOX) protects against placental cytotoxic injuries associated with PE. Here, we aimed to clarify the roles of HMOX1 in MSC proliferation and apoptosis, trophoblast cell migration, and regulation of angiogenesis, and assess its involvement in the pathogenesis of PE. HMOX1 and vascular endothelial growth factor (VEGF) expression levels in decidual tissues and decidua-derived MSCs (dMSCs) of healthy pregnant women and patients with PE were evaluated via quantitative reverse transcription-polymerase chain reaction and western blotting. Moreover, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, flow cytometry, and transwell assays were used to analyze the cell viability, apoptosis, and migration, respectively. The tube formation ability of human umbilical vein endothelial cells (HUVECs) was also evaluated. Compared to the healthy pregnant women, HMOX1 expression was upregulated in the decidual tissue and downregulated in the dMSCs of patients with PE. HMOX1 overexpression significantly increased dMSC proliferation, decreased cell apoptosis, and increased VEGF expression. Moreover, HMOX1-plasmid transfected dMSC culture supernatant promoted the migration of HTR-8/SVneo cells and improved angiogenesis by HUVECs. The opposite effects were observed in HMOX1-small interfering RNA-treated dMSCs cells. However, VEGF-siRNA reversed the effects of HMOX1-plasmid. HMOX1 is involved in the pathogenesis of PE by regulating the proliferation, apoptosis, and angiogenesis modulation potential of MSCs via VEGF, acting as a potential therapeutic target for PE.

Ferroptosis, a Regulated Form of Cell Death, as a Target for the Development of Novel Drugs Preventing Ischemia/Reperfusion of Cardiac Injury, Cardiomyopathy and Stress-Induced Cardiac Injury

The hospital mortality in patients with ST-segment elevation myocardial infarction (STEMI) is about 6% and has not decreased in recent years. The leading cause of death of these patients is ischemia/reperfusion (I/R) cardiac injury. It is quite obvious that there is an urgent need to create new drugs for the treatment of STEMI based on knowledge about the pathogenesis of I/R cardiac injury, in particular, based on knowledge about the molecular mechanism of ferroptosis. In this study, it was demonstrated that ferroptosis is involved in the development of I/R cardiac injury, antitumor drug-induced cardiomyopathy, diabetic cardiomyopathy, septic cardiomyopathy, and inflammation. There is indirect evidence that ferroptosis participates in stress-induced cardiac injury. The activation of AMPK, PKC, ERK1/2, PI3K, and Akt prevents myocardial ferroptosis. The inhibition of HO-1 alleviates myocardial ferroptosis. The roles of GSK-3β and NOS in the regulation of ferroptosis require further study. The stimulation of Nrf2, STAT3 prevents ferroptosis. The activation of TLR4 and NF-κB promotes ferroptosis of cardiomyocytes. MiR-450b-5p and miR-210-3p can increase the tolerance of cardiomyocytes to hypoxia/reoxygenation through the inhibition of ferroptosis. Circ_0091761 RNA, miR-214-3p, miR-199a-5p, miR-208a/b, miR-375-3p, miR-26b-5p and miR-15a-5p can aggravate myocardial ferroptosis.

Ferroptosis-induced Cardiotoxicity and Antitumor Drugs

The induction of regulated cell death ferroptosis in tumors is emerging as an intriguing strategy for cancer treatment. Numerous antitumor drugs (e.g., doxorubicin, etoposide, tyrosine kinase inhibitors, trastuzumab, arsenic trioxide, 5-fluorouracil) induce ferroptosis. Although this mechanism of action is interesting for fighting tumors, the clinical use of drugs that induce ferroptosis is hampered by cardiotoxicity. Besides in cancer cells, ferroptosis induced by chemotherapeutics can occur in cardiomyocytes, and this feature represents an important drawback of antitumor therapy. This inconvenience has been tackled by developing less or no cardiotoxic antitumor drugs or by discovering cardioprotective agents (e.g., berberine, propofol, fisetin, salidroside, melatonin, epigallocatechin- 3gallate, resveratrol) to use in combination with conventional chemotherapeutics. This review briefly summarizes the molecular mechanisms of ferroptosis and describes the ferroptosis dependent mechanisms responsible for cardiac toxicity developed by cancer- suffering patients following the administration of some chemotherapeutics. Additionally, the pharmacological strategies very recently proposed for potentially preventing this inconvenience are considered.

Sheng-Mai-Yin inhibits doxorubicin-induced ferroptosis and cardiotoxicity through regulation of Hmox1

Doxorubicin (DOX) is a potent chemotherapeutic drug used for treating various cancers. However, its clinical use is limited due to its severe cardiotoxicity, which often results in high mortality rates. Sheng-Mai-Yin (SMY), a Traditional Chinese medicine (TCM) prescription, has been reported to exert a cardioprotective effect in various cardiovascular diseases, including DOX-induced cardiotoxicity (DIC). This study aimed to provide novel insights into the underlying cardioprotective mechanism of SMY. SMY, composed of Codonopsis pilosula (Franch.), Ophiopogon japonicus (Thunb.), and Schisandra chinensis (Turcz.) at a ratio of 3:2:1, was intragastrically administered to male C57BL/6 mice for five days prior to the intraperitoneal injection of mitoTEMPO. One day later, DOX was intraperitoneally injected. Hematoxylin-eosin staining and Sirius red staining were carried out to estimate the pharmacological effect of SMY on cardiotoxicity. Mitochondrial function and ferroptosis biomarkers were also examined. AAV was utilized to overexpress Hmox1 to confirm whether Hmox1-mediated ferroptosis is associated with the cardioprotective effect of SMY on DOX-induced cardiotoxicity. The findings revealed that SMY therapy reduced the number of damaged cardiomyocytes. SMY therapy also reversed the inductions of cardiac MDA, serum MDA, LDH, and CK-MB contents, which dramatically decreased nonheme iron levels. In the meantime, SMY corrected the changes to ferroptosis indices brought on by DOX stimulation. Additionally, Hmox1 overexpression prevented SMY's ability to reverse cardiotoxicity. Our results showed that SMY effectively restrained lipid oxidation, reduced iron overload, and inhibited DOX-induced ferroptosis and cardiotoxicity, possibly via the mediation of Hmox1.

The dual role of ferroptosis in anthracycline-based chemotherapy includes reducing resistance and increasing toxicity

In conjunction with previous studies, we have noted that ferroptosis, as an emerging mode of regulated cell death (RCD), is intimately related to anthracycline pharmacotherapy. Not only does ferroptosis significantly modulate tumour resistance and drug toxicity, which are core links of the relevant chemotherapeutic process, but it also appears to play a conflicting role that has yet to be appreciated. By targeting the dual role of ferroptosis in anthracycline-based chemotherapy, this review aims to focus on the latest findings at this stage, identify the potential associations and provide novel perspectives for subsequent research directions and therapeutic strategies.