Protective Effect of Crocin on Immune Checkpoint Inhibitors-Related Myocarditis Through Inhibiting NLRP3 Mediated Pyroptosis in Cardiomyocytes via NF-κB Pathway

Gasdermin-E-mediated pyroptosis drives immune checkpoint inhibitor-associated myocarditis via cGAS-STING activation

Immune checkpoint inhibitor (ICI)-induced myocarditis involves intensive immune/inflammation activation; however, its molecular basis is unclear. Here, we show that gasdermin-E (GSDME), a gasdermin family member, drives ICI-induced myocarditis. Pyroptosis mediated by GSDME, but not the canonical GSDMD, is activated in myocardial tissue of mice and cancer patients with ICI-induced myocarditis. Deficiency of GSDME in male mice alleviates ICI-induced cardiac infiltration of T cells, macrophages, and monocytes, as well as mitochondrial damage and inflammation. Restoration of GSDME expression specifically in cardiomyocytes, rather than myeloid cells, in GSDME-deficient mice reproduces ICI-induced myocarditis. Mechanistically, quantitative proteomics reveal that GSDME-dependent pyroptosis promotes cell death and mitochondrial DNA release, which in turn activates cGAS-STING signaling, triggering a robust interferon response and myocardial immune/inflammation activation. Pharmacological blockade of GSDME attenuates ICI-induced myocarditis and improves long-term survival in mice. Our findings may advance the understanding of ICI-induced myocarditis and suggest that targeting the GSDME-cGAS-STING-interferon axis may help prevent and manage ICI-associated myocarditis.

Cardiovascular toxicity in antitumor therapy: biological and therapeutic insights

The evolution of antitumor therapies has significantly improved cancer prognosis but has concurrently resulted in cardiovascular toxicities. Understanding the biological mechanisms behind these toxicities is crucial for effective management. Immunotherapy-related cardiovascular toxicities are primarily mediated by immune cells and secreted cytokines. Chemotherapy may cause cardiovascular damage through autophagy disruption and mitochondrial dysfunction. Targeted therapies can induce toxicity through endothelin-1 (ET-1) production and cardiac signaling disruption. Radiotherapy may lead to cardiomyopathy and myocardial fibrosis by affecting endothelial cells, triggering inflammatory responses and accelerating atherosclerosis. This review provides insights into these mechanisms and strategies, aiming to enhance the clinical prevention and treatment of cardiovascular toxicities.

Immune-checkpoint inhibitor-mediated myocarditis: CTLA4, PD1 and LAG3 in the heart

Immune-checkpoint inhibitors (ICIs) have revolutionized oncology, with nearly 50% of all patients with cancer eligible for treatment with ICIs. However, patients on ICI therapy are at risk for immune-related toxicities that can affect any organ. Inflammation of the heart muscle, known as myocarditis, resulting from ICI targeting cytotoxic T lymphocyte-associated antigen 4 (CTLA4), programmed cell death protein 1 (PD1) and PD1 ligand 1 (PDL1) is an infrequent but potentially fatal complication. ICI-mediated myocarditis (ICI-myocarditis) is a growing clinical entity given the widespread use of ICIs, its increased clinical recognition and growing use of combination ICI treatment, a well-documented risk factor for ICI-myocarditis. In this Review, we approach ICI-myocarditis from a basic and mechanistic perspective, synthesizing the recent data from both preclinical models and patient samples. We posit that mechanistic understanding of the fundamental biology of immune-checkpoint molecules may yield new insights into disease processes, which will enable improvement in diagnostic and therapeutic approaches. The syndrome of ICI-myocarditis is novel, and our understanding of immune checkpoints in the heart is in its nascency. Yet, investigations into the pathophysiology will inform better patient risk stratification, improved diagnostics and precision-based therapies for patients.

PD-1 Inhibitor Aggravate Irradiation-Induced Myocardial Fibrosis by Regulating TGF-β1/Smads Signaling Pathway via GSDMD-Mediated Pyroptosis

Cancer therapy has entered a new era with the use of programmed cell death protein 1 (PD-1) immune checkpoint inhibitors. When combined with thoracic radiotherapy, it demonstrates synergistic anti-tumor effects and potentially worsens radiation-induced myocardial fibrosis (RIMF). RIMF is the final stage of radiation-induced heart disease (RIHD) and a potentially fatal clinical complication of chest radiotherapy. It is characterized by decreased ventricular elasticity and distensibility, which can result in decreased ejection fraction, heart failure, and even sudden cardiac death. Pyroptosis, a type of programmed cell death, is mediated by members of the gasdermin (GSDM) family and has been associated with numerous cardiac disorders. The effect of pyroptosis on myocardial fibrosis caused by a combination of radiotherapy and PD-1 inhibitors remains uncertain. In this study, a 6MV X-ray of 20 Gy for local heart irradiation was used in the RIHD mouse model. We noticed that PD-1 inhibitors aggravated radiation-induced cardiac dysfunction and RIMF, concurrently enhancing the presence of CD8+ T lymphocytes in the cardiac tissue. Additionally, our findings indicated that the combination of PD-1 inhibitor and thoracic radiation can stimulate caspase-1 to cleave GSDMD, thereby regulating pyroptosis and liberating interleukin-8 (IL-18). In the myocardium of mice, the manifestation of pyroptosis mediated by GSDMD is accompanied by the buildup of proteins associated with fibrosis, such as collagen I, transforming growth factor β1 (TGF-β1), interleukin-6 (IL-6), vascular endothelial growth factor (VEGF), and tumor necrosis factor α (TNF-α). Moreover, it was discovered that TFG-β1 induced the phosphorylation of Smad2/Smad3 when the cardiac underwent PD-1 inhibitor in conjunction with thoracic irradiation (IR). The findings of this research indicate that PD-1 inhibitor worsen RIMF in mice by triggering GSDMD-induced pyroptosis and influencing the TGF-β1/Smads pathway. While using the caspase-1 inhibitor Z-YVAD-FMK, RIMF can be alleviated. Blocking GSDMD may be a viable strategy for managing myocardial fibrosis caused by the combination of PD-1 inhibitors and radiotherapy.

Atrazine exposure promotes cardiomyocyte pyroptosis to exacerbate cardiotoxicity by activating NF-κB pathway

Atrazine is a ubiquitous herbicide with persistent environmental presence and accumulation in the food chain, posing potential health hazards to organisms. Increasing evidence suggests that atrazine may have detrimental effects on various organ systems, including the nervous, digestive, and immune systems. However, the specific toxicity and underlying mechanism of atrazine-induced cardiac injury remain obscure. In this study, 4-week-old male C57BL/6 mice were administered atrazine via intragastric administration at doses of 50 and 200 mg/kg for 4 and 8 weeks, respectively. Our findings showed that atrazine exposure led to cardiac fibrosis, as evidenced by elevated heart index and histopathological scores, extensive myofiber damage, and interstitial collagen deposition. Moreover, atrazine induced cardiomyocyte apoptosis, macrophage infiltration, and excessive production of inflammatory factors. Importantly, atrazine upregulated the expressions of crucial pyroptosis proteins, including NLRP3, ASC, CASPASE1, and GSDMD, via the activation of NF-κB pathway, thus promoting cardiomyocyte pyroptosis. Collectively, our findings provide novel evidence demonstrating that atrazine may exacerbate myocardial fibrosis by inducing cardiomyocyte pyroptosis, highlighting its potential role in the development of cardiac fibrosis.

Interplay between inflammasomes and PD-1/PD-L1 and their implications in cancer immunotherapy

The inflammasomes play crucial roles in inflammation and cancer development, while the PD-1/PD-L1 pathway is critical for immune suppression in the tumor microenvironment (TME). Recent research indicates a reciprocal regulatory relationship between inflammasomes and PD-1/PD-L1 signaling in cancer development and PD-1 blockade treatment. By activating in diverse cells in tumor tissues, inflammasome upregulates PD-L1 level in the TME. Moreover, the regulation of PD-1/PD-L1 activity by inflammasome activation involves natural killer cells, tumor-associated macrophages and myeloid-derived suppressor cells. Conversely, PD-1 blockade can activate the inflammasome, potentially influencing treatment outcomes. The interplay between inflammasomes and PD-1/PD-L1 has profound and intricate effects on cancer development and treatment. In this review, we discuss the crosstalk between inflammasomes and PD-1/PD-L1 in cancers, exploring their implications for tumorigenesis, metastasis and immune checkpoint inhibitor (ICI) resistance. The combined therapeutic strategies targeting both inflammasomes and checkpoint molecules hold promising potential as treatments for cancer.

Reflecting on the cardiac toxicity in non-small cell lung cancer in the era of immune checkpoint inhibitors therapy combined with thoracic radiotherapy

In recent years, immune checkpoint inhibitors (ICIs) have become a widely used treatment for non-small cell lung cancer (NSCLC), and the combination with traditional radiotherapy (RT) has shown significant potential in prolonging patient survival. However, both thoracic RT and ICIs can lead to cardiac toxicity, including radiation-induced heart damage (RIHD) and immunotherapy-related heart damage (IRHD). It still remains uncertain whether the combination of thoracic RT and immunotherapy will exacerbate acute or late cardiovascular (CV) toxicity and incidence. In this review, we summarize safety data from relevant clinical studies regarding CV toxicity for the combination therapy in NSCLC patients, explore the underlying synergetic mechanisms and common risk factors, and proposed treatment and management strategies. We hope to increase emphasis on the long-term assessment of CV toxicity risks associated with the combination therapy, and reduce the incidence of CV deaths resulting from such regimens.

Platelet factor 4 (PF4) induces cluster of differentiation 40 (CD40) expression in human aortic endothelial cells (HAECs) through the SIRT1/NF-κB/p65 signaling pathway

PF4 is a pro-atherosclerotic molecule. Endothelial CD40, upon binding to its ligand CD40L, induces endothelial cell (EC) activation, which is a vital pathophysiological process in the initiation and progression of atherosclerosis. However, the relationship between PF4 and endothelial CD40 remains elusive. This study aims to investigate whether and how PF4 affects endothelial CD40 expression using primary HAECs. PF4 treatment down-regulated sirtuin 1 (SIRT1) expression but upregulated the expression of acetylated NF-κB p65 (Ac-p65) and CD40 in HAECs in a concentration- and time-dependent manner. Pretreatment with SIRT1 agonist (SRT1720 or RSV) or SIRT1-overexpressing lentivirus attenuated PF4-induced Ac-p65 and CD40 expression in HAECs, whereas preincubation with SIRT1 antagonist (NAM or EX527) or SIRT1 shRNA had the opposite effect. To investigate whether NF-κB/p65 signaling pathway modulates CD40 expression in PF4-treated HAECs, PDTC, a NF-κB inhibitor, and p65-shRNA were introduced. PDTC or p65-shRNA treatment down-regulated Ac-p65 expression in HAECs. PDTC or p65-shRNA preincubation suppressed CD40 expression in HAECs after PF4 treatment. To better determine whether SIRT1 regulates CD40 expression in PF4-treated HAECs via the NF-κB/p65 signaling pathway, p65-knockdown HAECs were preincubated with SIRT1 agonists before PF4 treatment. SIRT1 agonist preincubation further decreased CD40 expression in p65-knockdown HAECs treated with PF4. Moreover, PF4 treatment promoted p65 nuclear translocation in HAECs. The results of dual luciferase assay demonstrated that four NF-κB binding sites in the promoter of human CD40 gene were activated in PF4-treated HAECs. In conclusion, our findings suggest that PF4 treatment facilitates CD40 expression in HAECs through the SIRT1/NF-κB/p65 pathway.

Mediators and mechanisms of immune checkpoint inhibitor-associated myocarditis: Insights from mouse and human

The broad application of immune checkpoint inhibitors (ICIs) has led to significant gains in cancer outcomes. By abrogating inhibitory signals, ICIs promote T cell targeting of cancer cells but can frequently trigger autoimmune manifestations, termed immune-related adverse events (irAEs), affecting essentially any organ system. Among cardiovascular irAEs, immune-related myocarditis (irMyocarditis) is the most described and carries the highest morbidity. The currently recommended treatment for irMyocarditis is potent immunosuppression with corticosteroids and other agents, but this has limited evidence basis. The cellular pathophysiology of irMyocarditis remains poorly understood, though mouse models and human data have both implicated effector CD8+ T cells, some of which are specific for the cardiomyocyte protein α-myosin. While the driving molecular signals and transcriptional programs are not well defined, the involvement of chemokine receptors such as CCR5 and CXCR3 has been proposed. Fundamental questions regarding why only approximately 1% of ICI recipients develop irMyocarditis and why irMyocarditis carries a much worse prognosis than other forms of lymphocytic myocarditis remain unanswered. Further work in both murine systems and with human samples are needed to identify better tools for diagnosis, risk-stratification, and treatment.

Advances on the anti-tumor mechanisms of the carotenoid Crocin

Saffron is located in the upper part of the crocus stigma of iridaceae, which has a long history of medicinal use. Crocin (molecular formula C44H64O24) is a natural floral glycoside ester compound extracted from saffron, which is a type carotenoid. Modern pharmacological studies have shown that crocin has multiple therapeutic effects including anti-inflammatory, anti-oxidant, anti-hyperlipidemic and anti-stone effects. In recent years, crocin has been widely noticed due to its considerable anti-tumor effects manifested by the induction of tumor cell apoptosis, inhibition of tumor cell proliferation, inhibition of tumor cell invasion and metastasis, enhancement of chemotherapy sensitivity and improvement of immune status. The anti-tumor effects have been shown in various malignant tumors such as gastric cancer, liver cancer, cervical cancer, breast cancer and colorectal cancer. In this review, we compiled recent studies on the anti-tumor effects of crocin and summarized its anti-tumor mechanism for developing ideas of treating malignancies and exploring anti-tumor drugs.

Drug therapy for myocarditis induced by immune checkpoint inhibitors

Immune checkpoint inhibitors (ICIs), including cytotoxic T-lymphocyte antigen 4 (CTLA-4), programmed cell death 1 (PD-1), and its ligand 1 (PD-L1), have improved the survival in multiple types of cancers; however, ICIs may cause cardiovascular toxicity. Although rare, ICI-mediated cardiotoxicity is an extremely serious complication with a relatively high mortality. In this review, we discuss the underlying mechanism and clinical manifestations of cardiovascular toxicity induced by ICIs. According to previous studies, multiple signaling pathways are involved in myocarditis induced by ICIs. Further, we summarize the clinical trials of drugs for the treatment of ICI-associated myocarditis. Although these drugs have shown the beneficial effects of alleviating cardiac function and reducing mortality rates, their efficacy is not optimal. Finally, we discuss the therapeutic potential of some novel compounds as well as the underlying mechanisms of their action.

The role of autophagy in cardiovascular disease: Cross-interference of signaling pathways and underlying therapeutic targets

Autophagy is a conserved lysosomal pathway for the degradation of cytoplasmic proteins and organelles, which realizes the metabolic needs of cells and the renewal of organelles. Autophagy-related genes (ATGs) are the main molecular mechanisms controlling autophagy, and their functions can coordinate the whole autophagic process. Autophagy can also play a role in cardiovascular disease through several key signaling pathways, including PI3K/Akt/mTOR, IGF/EGF, AMPK/mTOR, MAPKs, p53, Nrf2/p62, Wnt/β-catenin and NF-κB pathways. In this paper, we reviewed the signaling pathway of cross-interference between autophagy and cardiovascular diseases, and analyzed the development status of novel cardiovascular disease treatment by targeting the core molecular mechanism of autophagy as well as the critical signaling pathway. Induction or inhibition of autophagy through molecular mechanisms and signaling pathways can provide therapeutic benefits for patients. Meanwhile, we hope to provide a unique insight into cardiovascular treatment strategies by understanding the molecular mechanism and signaling pathway of crosstalk between autophagy and cardiovascular diseases.

Crocin Attenuates NLRP3 Inflammasome Activation by Inhibiting Mitochondrial Reactive Oxygen Species and Ameliorates Monosodium Urate-Induced Mouse Peritonitis

Crocin is a hydrophilic carotenoid pigment found in the stigma of Crocus sativus or the fruit of Gardenia jasminoides. In this study, we investigated the effects of Crocin on the activation of the nucleotide-binding oligomerization domain, leucine-rich repeat, and pyrin domain containing 3 (NLRP3) inflammasome in J774A.1 murine macrophage cells and monosodium urate (MSU)-induced peritonitis. Crocin significantly inhibited Nigericin-, adenosine triphosphate (ATP)-, MSU-induced interleukin (IL)-1β secretion, and caspase-1 cleavage without affecting pro-IL-1β and pro-caspase-1. Crocin also suppressed gasdermin-D cleavage and lactate dehydrogenase release and enhanced cell viability, indicating that Crocin reduces pyroptosis. Similar effects were observed in primary mouse macrophages. However, Crocin did not affect poly(dA:dT)-induced absent in melanoma 2 (AIM2) and muramyl dipeptide-induced NLRP1 inflammasomes. Crocin decreased Nigericin-induced oligimerization and the speck formation of apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC). Crocin also dramatically alleviated the ATP-induced production of mitochondrial reactive oxygen species (mtROS). Finally, Crocin ameliorated the MSU-induced production of IL-1β and IL-18 and the recruitment of neutrophils during peritoneal inflammation. These results suggest that Crocin suppresses NLRP3 inflammasome activation by blocking mtROS production and ameliorates MSU-induced mouse peritonitis. Thus, Crocin may have therapeutic potential in various NLRP3 inflammasome-related inflammatory diseases.

NLRP3-mediated inflammation in cardio-oncology: sterile yet harmful

Despite significant advances and the continuous development of novel, effective therapies to treat a variety of malignancies, cancer therapy-induced cardiotoxicity has been identified as a prominent cause of morbidity and mortality, closely competing with secondary malignancies. This unfortunate limitation has prompted the inception of the field of cardio-oncology with its purpose to provide the necessary knowledge and key information on mechanisms that support the use of the most efficacious cancer therapy with minimal or no interruption while paying close attention to preventing cardiovascular related morbidity and mortality. Several mechanisms that contribute to cancer therapy-induced cardiotoxicity have been proposed and studied. These mainly involve mitochondrial dysfunction and reactive oxygen species-induced oxidative stress, lysosomal damage, impaired autophagy, cell senescence, DNA damage, and sterile inflammation with the formation and activation of the NLRP3 inflammasome. In this review, we focus on describing the principal mechanisms for different classes of cancer therapies that lead to cardiotoxicity involving the NLRP3 inflammasome. We also summarize current evidence of cardio-protection with inflammasome inhibitors in the context of heart disease in general, and further highlight the potential application of this evidence for clinical translation in at risk patients for the purpose of preventing cancer therapy associated cardiovascular morbidity and mortality.

Immunopathogenesis of Immune Checkpoint Inhibitor Induced Myocarditis: Insights from Experimental Models and Treatment Implications

Despite the extraordinary success of immune checkpoint inhibitors (ICIs) in cancer treatment, their use is associated with a high incidence of immune-related adverse events (IRAEs), resulting from therapy-related autoimmunity against various target organs. ICI-induced myocarditis is one of the most severe forms of IRAE, which is associated with risk of hemodynamic compromise and mortality. Despite increasing recognition and prompt treatment by clinicians, there remain significant gaps in knowledge regarding the pathophysiology, diagnosis and treatment of ICI-induced myocarditis. As the newly emerged disease entity is relatively rare, it is challenging for researchers to perform studies involving patients at scale. Alternatively, mouse models have been developed to facilitate research understanding of the pathogenesis of ICI-induced myocarditis and drug discovery. Transgenic mice with immune checkpoint genes knocked out allow induction of myocarditis in a highly reproducible manner. On the other hand, it has not been possible to induce ICI-induced myocarditis in wild type mice by injecting ICIs monotherapy alone. Additional interventions such as combinational ICI, tumor inoculation, cardiac sarcomere immunization, or cardiac irradiation are necessary to mimic the underlying pathophysiology in human cancer patients and to induce ICI-induced myocarditis successfully. This review focuses on the immunopathogenesis of ICI-induced myocarditis, drawing insights from human studies and animal models, and discusses the potential implications for treatment.

Canagliflozin interrupts mTOR-mediated inflammatory signaling and attenuates DMBA-induced mammary cell carcinoma in rats

BACKGROUND

Breast cancer prevalence has been globally increasing, therefore, introducing novel interventions in cancer treatment is of a significant importance. The present study was designed to investigate the anti-cancer effect of Canagliflozin (CNG) in an experimental model of DMBA-induced mammary carcinoma in female rats.

METHODS

18 female rats were divided into three experimental groups: Normal control, DMBA control, DMBA+ CNG treated group. DMBA (7.5 mg/kg) was injected subcutaneously in the mammary cells twice weekly for 4 weeks and CNG (10 mg/kg) was orally administered daily for an additional 3 weeks while DMBA control rats only received the vehicle for 3 weeks. Tumors' weight and volume were measured, BRCA-1 and TAC were quantified in serum samples, mTOR, caspase-1, NFκB, IL-1β, NLRP3, GSDMD and MDA were quantified in tumors' homogenates.

RESULTS

CNG treatment increased the BRCA-1 expression, suppressed mTOR inflammatory pathway, attenuated tumor inflammatory mediators; NLRP3, GSDMD, NFκB, IL-1β, suppressed the oxidative stress and inhibited tumor expression of the proliferation biomarker; Ki67.

CONCLUSION

CNG modulated mTOR-mediated signaling pathway and attenuated pyroptotic, inflammatory pathways, suppressed oxidative stress and eventually inhibited DMBA-induced mammary carcinoma proliferation.

Therapeutic Implications of Targeting Pyroptosis in Cardiac-related Etiology of Heart Failure

Heart failure remains a considerable clinical and public health problem, it is the dominant cause of death from cardiovascular diseases, besides, cardiovascular diseases are one of the leading causes of death worldwide. The survival of patients with heart failure continues to be low with 45-60% reported deaths within five years. Apoptosis, necrosis, autophagy, and pyroptosis mediate cardiac cell death. Acute cell death is the hallmark pathogenesis of heart failure and other cardiac pathologies. Inhibition of pyroptosis, autophagy, apoptosis, or necrosis reduces cardiac damage and improves cardiac function in cardiovascular diseases. Pyroptosis is a form of inflammatory deliberate cell death that is characterized by the activation of inflammasomes such as NOD-like receptors (NLR), absent in melanoma 2 (AIM2), interferon-inducible protein 16 (IFI-16), and their downstream effector cytokines: Interleukin IL-1β and IL-18 leading to cell death. Recent studies have shown that pyroptosis is also the dominant cell death process in cardiomyocytes, cardiac fibroblasts, endothelial cells, and immune cells. It plays a crucial role in the pathogenesis of cardiac diseases that contribute to heart failure. This review intends to summarize the therapeutic implications targeting pyroptosis in the main cardiac pathologies preceding heart failure.

SGLT2 inhibitor, canagliflozin, ameliorates cardiac inflammation in experimental autoimmune myocarditis

Myocarditis is an inflammatory cardiovascular disease which contributes to dilated cardiomyopathy (DCM) and heart failure. Canagliflozin (CANA) exerts anti-inflammatory and cardioprotective effects in heart failure besides its hypoglycemic effect. However, the role of CANA in myocarditis has not been elucidated. In this work, CANA treatment markedly alleviated cardiac inflammation and improved cardiac function in experimental autoimmune myocarditis (EAM) mice induced by α-myosin-heavy chain peptides. The expressions of NLRP3 inflammasome complexes (NLRP3, ASC, and Caspase-1) and their downstream molecules (IL-1β, IL-18) were significantly downregulated by CANA, accompanied with reduced Th17 cell infiltration in hearts. Furthermore, Bax/Bcl-2 ratio, Cleaved Caspase-3 protein level and the percentage of TUNEL-positive myocardial cells, which usually indicated apoptosis, were reduced by CANA treatment. These findings suggest CANA could be a valuable medication for myocarditis treatment.