Small molecule STING inhibition improves myocardial infarction remodeling

Dysfunctional cardiomyocyte signalling and heart disease

Cardiomyocyte signalling pathways are central to maintaining the structural and functional integrity of the heart. Dysregulation of these pathways contributes to the onset and progression of heart diseases, including heart failure, arrhythmias and cardiomyopathies. This review focuses on very recent work on dysfunctional cardiomyocyte signalling and its role in the pathophysiology of heart disease. We discuss key pathways, including immune signalling within cardiomyocytes, signalling associated with microtubule dysfunction, Hippo-yes-associated protein signalling and adenosine monophosphate-activated protein kinase signalling, highlighting how aberrations in their regulation lead to impaired cardiomyocyte functions and pinpointing the potential therapeutic opportunities in these pathways. This review underscores the complexity of cardiomyocyte signalling networks and emphasises the need for further dissecting signalling pathways to prevent cardiomyocyte dysfunction.

Tanshinone IIA alleviates myocarditis in Trex1-D18N lupus-like mice by inhibiting the interaction between STING and SEC24C

The cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING) signaling pathway serves as a crucial component of the innate immune defense, playing a vital role in combating pathogen invasion. However, its dysregulation or abnormal activation can trigger the development of autoimmune diseases. This study demonstrated that Tanshinone IIA, a major lipid-soluble component of Salvia miltiorrhiza Bunge, can effectively inhibit the activation of the cGAS-STING signaling pathway. Mechanistically, Tanshinone IIA inhibits the transport of STING from the ER to the Golgi apparatus by weakening the interaction between STING and SEC24C, thereby preventing the activation of the cGAS-STING signaling pathway. Furthermore, Tanshinone IIA significantly ameliorated myocardial inflammation in WT and Trex1D18N/D18N mice. Our research indicates that Tanshinone IIA shows potential therapeutic value in alleviating autoimmune diseases by effectively inhibiting the abnormal activation of the cGAS-STING pathway.

cGAS-STING targeting offers a novel therapeutic paradigm in cardiovascular diseases

Cyclic GMP/AMP (cGAMP) synthase (cGAS), along with the endoplasmic reticulum (ER)-associated stimulator of interferon genes (STING), are crucial elements of the type 1 interferon response. cGAS senses microbial DNA and self-DNA, labeling cGAS-STING as a crucial mechanism in autoimmunity, sterile inflammatory responses, and cellular senescence. However, chronic and aberrant activation of the cGAS/STING axis results in inflammatory and autoimmune diseases. cGAS-STING has emerged as a vital mechanism driving inflammation-related diseases, including cardiovascular diseases (CVDs). Insights into the biology of the cGAS-STING pathway have enabled the discovery of small-molecule agents which have the potential to inhibit the cGAS-STING axis in many human diseases. In this review, we first outline the principal components of the cGAS-STING signaling cascade. From such we discuss recent research that highlights general mechanisms by which cGAS-STING contributes to CVDs. Then, we summarize a list of bioactive small-molecule compounds which modulate the cGAS-STING axis, reviewing their potential clinical applications. Finally, we discuss key limitations of this new proposed therapeutic approach and provide possible techniques to overcome them.These review highlights a novel groundbreaking therapeutic possibilities through targeting cGAS-STING in CVDs.

STING aggravates ferroptosis-dependent myocardial ischemia-reperfusion injury by targeting GPX4 for autophagic degradation

Despite advancements in interventional coronary reperfusion technologies following myocardial infarction, a notable portion of patients continue to experience elevated mortality rates as a result of myocardial ischemia-reperfusion (MI/R) injury. An in-depth understanding of the mechanisms underlying MI/R injury is crucial for devising strategies to minimize myocardial damage and enhance patient survival. Here, it is discovered that during MI/R, double-stranded DNA (dsDNA)-cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) signal accumulates, accompanied by high rates of myocardial ferroptosis. The specific deletion of cgas or Sting in cardiomyocytes, resulting in the inhibition of oxidative stress, has been shown to mitigate ferroptosis and I/R injury. Conversely, activation of STING exacerbates ferroptosis and I/R injury. Mechanistically, STING directly targets glutathione peroxidase 4 (GPX4) to facilitate its degradation through autophagy, by promoting the fusion of autophagosomes and lysosomes. This STING-GPX4 axis contributes to cardiomyocyte ferroptosis and forms a positive feedback circuit. Blocking the STING-GPX4 interaction through mutations in T267 of STING or N146 of GPX4 stabilizes GPX4. Therapeutically, AAV-mediated GPX4 administration alleviates ferroptosis induced by STING, resulting in enhanced cardiac functional recovery from MI/R injury. Additionally, the inhibition of STING by H-151 stabilizes GPX4 to reverse GPX4-induced ferroptosis and alleviate MI/R injury. Collectively, a novel autophagy-dependent ferroptosis mechanism is identified in this study. Specifically, STING autophagy induced by anoxia or ischemia-reperfusion leads to GPX4 degradation, thereby presenting a promising therapeutic target for heart diseases associated with I/R.

Double-stranded DNA enhances platelet activation, thrombosis, and myocardial injury via cyclic GMP-AMP synthase

AIMS

Elevated dsDNA levels in ST-elevated myocardial infarction (STEMI) patients are associated with increased infarct size and worse clinical outcomes. However, the direct effect of dsDNA on platelet activation remains unclear. This study aims to investigate the direct influence of dsDNA on platelet activation, thrombosis, and the underlying mechanisms.

METHODS AND RESULTS

Analysis of clinical samples revealed elevated plasma dsDNA levels in STEMI patients, which positively correlated with platelet aggregation and markers of neutrophil extracellular traps such as MPO-DNA and CitH3. Platelet assays demonstrated the activation of the cGAS-STING pathway in platelets from STEMI patients. DsDNA directly potentiated platelet activation and thrombus formation. Mechanistic studies using G150 (cGAS inhibitor), H151 (STING inhibitor), and MCC950 (NLRP3 inhibitor), as well as cGAS-/-, STING-/-, and NLRP3-/- mice, showed that dsDNA activated cGAS, a previously unreported DNA sensor in platelets, and induced activation of the STING/NLRP3/caspase-1/IL-1β axis. This cascade enhanced platelet activation and thrombus formation. Platelet cGAS depletion or Palbociclib, a cGAS-STING inhibitor, approved by the FDA for advanced breast cancer, ameliorated myocardial ischaemia-reperfusion injury in ApoE-/- mice fed with a high-fat diet for 12 weeks.

CONCLUSIONS

These results suggested that dsDNA is a novel driver of platelet activation and thrombus formation in STEMI patients.

Mitochondrial dysfunction in AMI: mechanisms and therapeutic perspectives

Acute myocardial infarction (AMI) and the myocardial ischemia-reperfusion injury (MI/RI) that typically ensues represent a significant global health burden, accounting for a considerable number of deaths and disabilities. In the context of AMI, percutaneous coronary intervention (PCI) is the preferred treatment option for reducing acute ischemic damage to the heart. Despite the modernity of PCI therapy, pathological damage to cardiomyocytes due to MI/RI remains an important target for intervention that affects the long-term prognosis of patients. In recent years, mitochondrial dysfunction during AMI has been increasingly recognized as a critical factor in cardiomyocyte death. Damaged mitochondria play an active role in the formation of an inflammatory environment by triggering key signaling pathways, including those mediated by cyclic GMP-AMP synthase, NOD-like receptors and Toll-like receptors. This review emphasizes the dual role of mitochondria as both contributors to and regulators of inflammation. The aim is to explore the complex mechanisms of mitochondrial dysfunction in AMI and its profound impact on immune dysregulation. Specific interventions including mitochondrial-targeted antioxidants, membrane-stabilizing peptides, and mitochondrial transplantation therapies have demonstrated efficacy in preclinical AMI models.

The CGAS-STING1 Pathway as a Mediator of Innate Immune Response in Cardiovascular Disease

The innate immune response, a rapid and cell-autonomous response of the cell to the pathogens, recognizes the external as well as the internal pathogens, such as self-DNA, released from the damaged cells. The response activates a set of molecules that induce the expression of proinflammatory cytokines and chemokines and leads to inflammation, fibrosis, and cell death. The innate immune response comprised of DNA-sensing protein cyclic guanosine monophosphate-adenosine monophosphate synthase (CGAS) and its downstream molecules, the stimulator of interferon genes 1 (STING1), TANK-binding kinase 1 (TBK1), interferon regulatory factor 3 (IRF3), and nuclear factor kappa B (NFκB), are activated in several cardiovascular diseases, including hereditary cardiomyopathies, myocardial infarction, hypertension, atherosclerosis, and aortic aneurysm. The genetic deletion of key molecules in this pathway, such as CGAS, STING1, and interferon regulatory factor 3, affords salubrious effects, including improving survival and cardiac dysfunction, rendering the CGAS-STING1 pathway an attractive therapeutic target in cardiovascular disease.

Causes and consequences of DNA double-stranded breaks in cardiovascular disease

The genome, whose stability is essential for survival, is incessantly exposed to internal and external stressors, which introduce an estimated 104 to 105 lesions, such as oxidation, in the nuclear genome of each mammalian cell each day. A delicate homeostatic balance between the generation and repair of DNA lesions maintains genomic stability. To initiate transcription, DNA strands unwind to form a transcription bubble and provide a template for the RNA polymerase II (RNAPII) complex to synthesize nascent RNA. The process generates DNA supercoils and introduces torsional stress. To enable RNAPII processing, the supercoils are released by topoisomerases by introducing strand breaks, including double-stranded breaks (DSBs). Thus, DSBs are intrinsic genomic features of gene expression. The breaks are quickly repaired upon processing of the transcription. DNA lesions and damaged proteins involved in transcription could impede the integrity and efficiency of RNAPII processing. The impediment, which is referred to as transcription stress, not only could lead to the generation of aberrant RNA species but also the accumulation of DSBs. The latter is particularly the case when topoisomerase processing and/or the repair mechanisms are compromised. The DSBs activate the DNA damage response (DDR) pathways to repair the damaged DNA and/or impose cell cycle arrest and cell death. In addition, the release of DSBs into the cytosol activates the cytosolic DNA-sensing proteins (CDSPs), which along with the nuclear DDR pathways induce the expression of senescence-associated secretory phenotype (SASP), cell cycle arrest, senescence, cell death, inflammation, and aging. The primary stimulus in hereditary cardiomyopathies is a mutation(s) in genes encoding the protein constituents of cardiac myocytes; however, the phenotype is the consequence of intertwined complex interactions among numerous stressors and the causal mutation(s). Increased internal DNA stressors, such as oxidation, alkylation, and cross-linking, are expected to be common in pathological conditions, including in hereditary cardiomyopathies. In addition, dysregulation of gene expression also imposes transcriptional stress and collectively with other stressors provokes the generation of DSBs. In addition, the depletion of nicotinamide adenine dinucleotide (NAD), which occurs in pathological conditions, impairs the repair mechanism and further facilitates the accumulation of DSBs. Because DSBs activate the DDR pathways, they are expected to contribute to the pathogenesis of cardiomyopathies. Thus, interventions to reduce the generation of DSBs, enhance their repair, and block the deleterious DDR pathways would be expected to impart salubrious effects not only in pathological states, as in hereditary cardiomyopathies but also aging.

Cytosolic nucleic acid sensing as driver of critical illness: mechanisms and advances in therapy

Nucleic acids from both self- and non-self-sources act as vital danger signals that trigger immune responses. Critical illnesses such as acute respiratory distress syndrome, sepsis, trauma and ischemia lead to the aberrant cytosolic accumulation and massive release of nucleic acids that are detected by antiviral innate immune receptors in the endosome or cytosol. Activation of receptors for deoxyribonucleic acids and ribonucleic acids triggers inflammation, a major contributor to morbidity and mortality in critically ill patients. In the past decade, there has been growing recognition of the therapeutic potential of targeting nucleic acid sensing in critical care. This review summarizes current knowledge of nucleic acid sensing in acute respiratory distress syndrome, sepsis, trauma and ischemia. Given the extensive research on nucleic acid sensing in common pathological conditions like cancer, autoimmune disorders, metabolic disorders and aging, we provide a comprehensive summary of nucleic acid sensing beyond critical illness to offer insights that may inform its role in critical conditions. Additionally, we discuss potential therapeutic strategies that specifically target nucleic acid sensing. By examining nucleic acid sources, sensor activation and function, as well as the impact of regulating these pathways across various acute diseases, we highlight the driving role of nucleic acid sensing in critical illness.

Inhibition of the cGAS‑STING Pathway Reduces Cisplatin-Induced Inner Ear Hair Cell Damage

Although cisplatin is a widely used chemotherapeutic agent, it is severely toxic and causes irreversible hearing loss, restricting its application in clinical settings. This study aimed to determine the molecular mechanism underlying cisplatin-induced ototoxicity. Here, we established in vitro and in vivo ototoxicity models of cisplatin-induced hair cell loss, and our results showed that reducing STING levels decreased inflammatory factor expression and hair cell death. In addition, we found that cisplatin-induced mitochondrial dysfunction was accompanied by cytosolic DNA, which may act as a critical linker between the cyclic GMP-AMP synthesis-stimulator of interferon genes (cGAS-STING) pathway and the pathogenesis of cisplatin-induced hearing loss. H-151, a specific inhibitor of STING, reduced hair cell damage and ameliorated the hearing loss caused by cisplatin in vivo. This study underscores the role of cGAS-STING in cisplatin ototoxicity and presents H-151 as a promising therapeutic for hearing loss.

Mitochondrial Amount Determines Doxorubicin-Induced Cardiotoxicity in Cardiomyocytes

Doxorubicin, an anthracycline commonly used for treating cancer patients, is known for its cardiotoxic side-effects. Although dose-dependent, but susceptibility remains variable among patients, and childhood-exposure-adult-onset remains challenging. Besides topoisomerase toxicity, Doxorubicin is also toxic to the mitochondria yet the underlying late onset mechanism remains elusive. Here, it is observed that the mitochondrial copy number in PBMCs of patients treated with anthracycline chemotherapy is negatively correlated with the change in plasma BNP levels after treatment. Isogenic hiPSC-CMs are generated with high, norm, and low mitochondrial copy numbers using mitochondrial transplantation and the YFP-Parkin system. Remarkably, lower mitochondria copy number translates to lower IC50, suggesting increased susceptibility. Mitochondria supplementation by intramyocardial injection prevents doxorubicin induced heart failure. Mechanistically, doxorubicin treatment leads to mPTP opening and mitochondrial DNA (mtDNA) leakage. This mtDNA leakage event activates the cGAS-STING pathway and drives inflammation and myocardial senescence. Cardiomyocyte-specific knockout of Sting (Myh6-Cre/Stingflox/flox; StingCKO) and over expression of mitochondrial tagged DNase1 in mice partially rescue doxorubicin-induced cardiac dysfunction. In conclusion, the work establishes a negative correlation between cardiomyocyte mitochondrial copy number and doxorubicin toxicity. Molecularly, it is demonstrated that mtDNA leakage activates cGAS-STING pathway and accelerates myocardial dysfunction. These insights offer new co-administration strategies for cancer patients.

The application of mass defect percentage in the evaluation of acute coronary syndrome

OBJECTIVES

White blood cells, neutrophils, lymphocytes, and neutrophil-to-lymphocyte ratio (NLR) distribution patterns in patients with anatomic coronary disease have previously been associated with cardiac events such as myocardial infarct size, complications, and prognosis. However, it remains unknown whether myocardial perfusion mass defect percentage (MDP) obtained from gated myocardial perfusion imaging (G-MPI) correlates with these hematological parameters. Therefore, our research aimed to investigate the application of MDP in the evaluation of acute coronary syndrome (ACS).

METHODS

Thirty-six patients with ACS underwent single-photon emission computed tomography/computed tomography using retrospective electrocardiography gating during the resting state. The primary outcome was the percentage of left ventricular mass with abnormal myocardial perfusion (i.e. MDP) in G-MPI. Furthermore, the correlation between myocardial perfusion MDP and lymphocyte count, neutrophil count, white blood cell count, and NLR was calculated. In addition, we explored the relationship of myocardial perfusion MDP with other cardiac function parameters obtained from G-MPI, such as summed rest score, left ventricular ejection fraction, end-systolic volume, and end-diastolic volume.

RESULTS

Myocardial perfusion MDP significantly correlated with white blood cell count, neutrophil count, and NLR ( P  < 0.01). Furthermore, these hematological parameters were significantly different between low and high MDP groups. Additionally, myocardial perfusion MDP negatively correlated with end-systolic volume ( r  = -0.615) and left ventricular ejection fraction ( r  = -0.657).

CONCLUSION

Myocardial perfusion MDP has a high correlation with inflammatory cell counts and cardiac function parameters obtained from G-MPI in ACS; this may be of help in the evaluation and treatment of these patients.

M2 Macrophage Exosomes Reverse Cardiac Functional Decline in Mice with Diet-Induced Myocardial Infarction by Suppressing Type 1 Interferon Signaling in Myeloid Cells

Effective treatment strategies to alleviate heart failure that develops as a consequence of myocardial infarction (MI) remain an unmet need in cardiovascular medicine. In this study, we uncovered that exosomes produced by human THP-1 macrophages cultured with the cytokine IL-4 (THP1-IL4-exo), reverse cardiac functional decline in mice that develop MI as a consequence of diet-induced occlusive coronary atherosclerosis. Therapeutic benefits of THP1-IL4-exo stem from their ability to reprogram circulating Ly-6Chi monocytes into an M2-like phenotype and suppress Type 1 Interferon signaling in myeloid cells within the bone marrow, the circulation, and cardiac tissue. Collectively, these benefits suppress myelopoiesis, myeloid cell recruitment to cardiac tissue, and preserve populations of resident cardiac macrophages that together mitigate cardiac inflammation, adverse ventricular remodeling, and heart failure. Our findings introduce THP1-IL4-exo, one form of M2-macrophage exosomes, as novel therapeutics to preserve cardiac function subsequent to MI.

The Cardioprotective Role of Neutrophil-Specific STING in Myocardial Ischemia/Reperfusion Injury

Background

Neutrophils are the most rapid and abundant immune cells to infiltrate the myocardium following myocardial ischemia/reperfusion injury (MI/R). Neutrophil heterogeneity has not been well characterized in MI/R, and studies have shown conflicting results regarding the impact of neutrophil depletion on cardiac injury. We thus aim to study the impact of neutrophils with enriched type I interferon signature and the role of STING (stimulator of interferon genes) signaling in neutrophils on cardiac reperfusion injury.

Methods

We utilized single-cell RNA sequencing to study neutrophil heterogeneity in response to MI/R. We generated a neutrophil-specific STING knockout mouse to assess the role of neutrophil STING in a model of MI/R. We examined cardiac function following injury via echocardiography and assessed the immune cell trajectory following injury utilizing flow cytometry.

Results

We identified a population of neutrophils with enriched type I interferon signaling and response to type I interferon following MI/R. We found that genetic deletion of neutrophil-specific STING led to worsened cardiac function following MI/R. Further investigation of the immune response by flow cytometry revealed decreased neutrophil infiltration into the myocardium and a shift in macrophage polarization.

Conclusions

Our findings suggest that neutrophil-specific STING is cardioprotective in MI/R, partly due to its effects on downstream immune cells. These results demonstrate that early alterations or therapeutic interventions can influence key events in the resolution of inflammation following MI/R.

The cGAS-STING Pathway: A New Therapeutic Target for Ischemia-Reperfusion Injury in Acute Myocardial Infarction?

The innate immune system is the body's natural defense system, which recognizes a wide range of microbial molecules (such as bacterial DNA and RNA) and abnormal molecules within cells (such as misplaced DNA, self-antigens) to play its role. DNA released into the cytoplasm activates the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) signaling pathway to initiate an immune response. Ischemia-reperfusion injury (IRI) after acute myocardial infarction refers to the phenomenon where myocardial tissue suffers further damage upon the restoration of blood flow. This issue is a significant clinical problem in the treatment of myocardial infarction, as it can diminish the effectiveness of reperfusion therapy and lead to further deterioration of cardiac function. Studies have found that the cGAS-STING signaling pathway is closely related to this phenomenon. Therefore, this review aims to describe the role of the cGAS-STING signaling pathway in ischemia-reperfusion injury after myocardial infarction and summarize the current development status of cGAS-STING pathway inhibitors and the application of nanomaterials to further elucidate the potential of this pathway as a therapeutic target.

Mechanisms of myocardial reverse remodelling and its clinical significance: A scientific statement of the ESC Working Group on Myocardial Function

Cardiovascular disease (CVD) is the leading cause of morbimortality in Europe and worldwide. CVD imposes a heterogeneous spectrum of cardiac remodelling, depending on the insult nature, that is, pressure or volume overload, ischaemia, arrhythmias, infection, pathogenic gene variant, or cardiotoxicity. Moreover, the progression of CVD-induced remodelling is influenced by sex, age, genetic background and comorbidities, impacting patients' outcomes and prognosis. Cardiac reverse remodelling (RR) is defined as any normative improvement in cardiac geometry and function, driven by therapeutic interventions and rarely occurring spontaneously. While RR is the outcome desired for most CVD treatments, they often only slow/halt its progression or modify risk factors, calling for novel and more timely RR approaches. Interventions triggering RR depend on the myocardial insult and include drugs (renin-angiotensin-aldosterone system inhibitors, beta-blockers, diuretics and sodium-glucose cotransporter 2 inhibitors), devices (cardiac resynchronization therapy, ventricular assist devices), surgeries (valve replacement, coronary artery bypass graft), or physiological responses (deconditioning, postpartum). Subsequently, cardiac RR is inferred from the degree of normalization of left ventricular mass, ejection fraction and end-diastolic/end-systolic volumes, whose extent often correlates with patients' prognosis. However, strategies aimed at achieving sustained cardiac improvement, predictive models assessing the extent of RR, or even clinical endpoints that allow for distinguishing complete from incomplete RR or adverse remodelling objectively, remain limited and controversial. This scientific statement aims to define RR, clarify its underlying (patho)physiologic mechanisms and address (non)pharmacological options and promising strategies to promote RR, focusing on the left heart. We highlight the predictors of the extent of RR and review the prognostic significance/impact of incomplete RR/adverse remodelling. Lastly, we present an overview of RR animal models and potential future strategies under pre-clinical evaluation.

Repair of the Infarcted Heart: Cellular Effectors, Molecular Mechanisms and Therapeutic Opportunities

The adult mammalian heart has limited endogenous regenerative capacity and heals through the activation of inflammatory and fibrogenic cascades that ultimately result in the formation of a scar. After infarction, massive cardiomyocyte death releases a broad range of damage-associated molecular patterns that initiate both myocardial and systemic inflammatory responses. TLRs (toll-like receptors) and NLRs (NOD-like receptors) recognize damage-associated molecular patterns (DAMPs) and transduce downstream proinflammatory signals, leading to upregulation of cytokines (such as interleukin-1, TNF-α [tumor necrosis factor-α], and interleukin-6) and chemokines (such as CCL2 [CC chemokine ligand 2]) and recruitment of neutrophils, monocytes, and lymphocytes. Expansion and diversification of cardiac macrophages in the infarcted heart play a major role in the clearance of the infarct from dead cells and the subsequent stimulation of reparative pathways. Efferocytosis triggers the induction and release of anti-inflammatory mediators that restrain the inflammatory reaction and set the stage for the activation of reparative fibroblasts and vascular cells. Growth factor-mediated pathways, neurohumoral cascades, and matricellular proteins deposited in the provisional matrix stimulate fibroblast activation and proliferation and myofibroblast conversion. Deposition of a well-organized collagen-based extracellular matrix network protects the heart from catastrophic rupture and attenuates ventricular dilation. Scar maturation requires stimulation of endogenous signals that inhibit fibroblast activity and prevent excessive fibrosis. Moreover, in the mature scar, infarct neovessels acquire a mural cell coat that contributes to the stabilization of the microvascular network. Excessive, prolonged, or dysregulated inflammatory or fibrogenic cascades accentuate adverse remodeling and dysfunction. Moreover, inflammatory leukocytes and fibroblasts can contribute to arrhythmogenesis. Inflammatory and fibrogenic pathways may be promising therapeutic targets to attenuate heart failure progression and inhibit arrhythmia generation in patients surviving myocardial infarction.

Pharmacological potential of cyclic nucleotide signaling in immunity

Cyclic nucleotides are important signaling molecules that play many critical physiological roles including controlling cell fate and development, regulation of metabolic processes, and responding to changes in the environment. Cyclic nucleotides are also pivotal regulators in immune signaling, orchestrating intricate processes that maintain homeostasis and defend against pathogenic threats. This review provides a comprehensive examination of the pharmacological potential of cyclic nucleotide signaling pathways within the realm of immunity. Beginning with an overview of the fundamental roles of cAMP and cGMP as ubiquitous second messengers, this review delves into the complexities of their involvement in immune responses. Special attention is given to the challenges associated with modulating these signaling pathways for therapeutic purposes, emphasizing the necessity for achieving cell-type specificity to avert unintended consequences. A major focus of the review is on the recent paradigm-shifting discoveries regarding specialized cyclic nucleotide signals in the innate immune system, notably the cGAS-STING pathway. The significance of cyclic dinucleotides, exemplified by 2'3'-cGAMP, in controlling immune responses against pathogens and cancer, is explored. The evolutionarily conserved nature of cyclic dinucleotides as antiviral agents, spanning across diverse organisms, underscores their potential as targets for innovative immunotherapies. Findings from the last several years have revealed a striking diversity of novel bacterial cyclic nucleotide second messengers which are involved in antiviral responses. Knowledge of the existence and precise identity of these molecules coupled with accurate descriptions of their associated immune defense pathways will be essential to the future development of novel antibacterial therapeutic strategies. The insights presented herein may help researchers navigate the evolving landscape of immunopharmacology as it pertains to cyclic nucleotides and point toward new avenues or lines of thinking about development of therapeutics against the pathways they regulate.

cGAS-STING signaling in cardiovascular diseases

Sterile inflammation, characterized by a persistent chronic inflammatory state, significantly contributes to the progression of various diseases such as autoimmune, metabolic, neurodegenerative, and cardiovascular disorders. Recent evidence has increasingly highlighted the intricate connection between inflammatory responses and cardiovascular diseases, underscoring the pivotal role of the Stimulator of Interferon Genes (STING). STING is crucial for the secretion of type I interferon (IFN) and proinflammatory cytokines in response to cytosolic nucleic acids, playing a vital role in the innate immune system. Specifically, research has underscored the STING pathway involvement in unregulated inflammations, where its aberrant activation leads to a surge in inflammatory events, enhanced IFN I responses, and cell death. The primary pathway triggering STING activation is the cyclic GMP-AMP synthase (cGAS) pathway. This review delves into recent findings on STING and the cGAS-STING pathways, focusing on their regulatory mechanisms and impact on cardiovascular diseases. It also discusses the latest advancements in identifying antagonists targeting cGAS and STING, and concludes by assessing the potential of cGAS or STING inhibitors as treatments for cardiovascular diseases.

The cGAS-STING pathway in cardiovascular diseases: from basic research to clinical perspectives

The cyclic guanosine monophosphate (GMP)-adenosine monophosphate (AMP) synthase-stimulator of interferon genes (cGAS-STING) signaling pathway, an important component of the innate immune system, is involved in the development of several diseases. Ectopic DNA-induced inflammatory responses are involved in several pathological processes. Repeated damage to tissues and metabolic organelles releases a large number of damage-associated molecular patterns (mitochondrial DNA, nuclear DNA, and exogenous DNA). The DNA fragments released into the cytoplasm are sensed by the sensor cGAS to initiate immune responses through the bridging protein STING. Many recent studies have revealed a regulatory role of the cGAS-STING signaling pathway in cardiovascular diseases (CVDs) such as myocardial infarction, heart failure, atherosclerosis, and aortic dissection/aneurysm. Furthermore, increasing evidence suggests that inhibiting the cGAS-STING signaling pathway can significantly inhibit myocardial hypertrophy and inflammatory cell infiltration. Therefore, this review is intended to identify risk factors for activating the cGAS-STING pathway to reduce risks and to simultaneously further elucidate the biological function of this pathway in the cardiovascular field, as well as its potential as a therapeutic target.

Interferons and interferon-related pathways in heart disease

Interferons (IFNs) and IFN-related pathways play key roles in the defence against microbial infection. However, these processes may also be activated during the pathogenesis of non-infectious diseases, where they may contribute to organ injury, or function in a compensatory manner. In this review, we explore the roles of IFNs and IFN-related pathways in heart disease. We consider the cardiac effects of type I IFNs and IFN-stimulated genes (ISGs); the emerging role of the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway; the seemingly paradoxical effects of the type II IFN, IFN-γ; and the varied actions of the interferon regulatory factor (IRF) family of transcription factors. Recombinant IFNs and small molecule inhibitors of mediators of IFN receptor signaling are already employed in the clinic for the treatment of some autoimmune diseases, infections, and cancers. There has also been renewed interest in IFNs and IFN-related pathways because of their involvement in SARS-CoV-2 infection, and because of the relatively recent emergence of cGAS-STING as a pattern recognition receptor-activated pathway. Whether these advances will ultimately result in improvements in the care of those experiencing heart disease remains to be determined.

Cardiac injury activates STING signaling via upregulating SIRT6 in macrophages after myocardial infarction

AIMS

This work sought to investigate the mechanism underlying the STING signaling pathway during myocardial infarction (MI), and explore the involvement and the role of SIRT6 in the process.

MAIN METHODS

Mice underwent the surgery of permanent left anterior descending (LAD) artery constriction. Primary cardiomyocytes (CMs) and fibroblasts were subjected to hypoxia to mimic MI in vitro. STING expression was assessed in the infarct heart, and the effect of STING inhibition on cardiac fibrosis was explored. This study also evaluated the regulatory effect of STING by SIRT6 in macrophages.

KEY FINDINGS

STING protein was increased in the infarct heart tissue, highlighting its involvement in the post-MI inflammatory response. Hypoxia-induced death of CMs and fibroblasts contributed to the upregulation of STING in macrophages, establishing the involvement of STING in the intercellular signaling during MI. Inhibition of STING resulted in a significant reduction of cardiac fibrosis at day 14 after MI. Additionally, this study identified SIRT6 as a key regulator of STING via influencing its acetylation and ubiquitination in macrophages, providing novel insights into the posttranscriptional modification and expression of STING at the acute phase after myocardial infarction.

SIGNIFICANCE

This work shows the key role of SIRT6/STING signaling in the pathogenesis of cardiac injury after MI, suggesting that targeting this regulatory pathway could be a promising strategy to attenuate cardiac fibrosis after MI.

Cardiovascular diseases crossroads: cGAS-STING signaling and disease progression

It is now widely accepted that inflammation is critical in cardiovascular diseases (CVD). Here, studies are being conducted on how cyclic GMP-AMP synthase (cGAS), a component of innate immunity's DNA-sensing machinery, communicates with the STING receptor, which is involved in activating the immune system's antiviral response. Significantly, a growing body of research in recent years highlights the strong activation of the cGAS-STING signalling pathways in several cardiovascular diseases, such as myocardial infarction, heart failure, and myocarditis. This developing collection of research emphasises these pathways' crucial role in initiating and advancing cardiovascular disease. In this extensive narrative, we explore the role of the cGAS-STING pathway in the development of CVD. We elaborate on the basic mechanisms involved in the onset and progression of CVD. This review explores the most recent developments in the recognition and characterization of cGAS-STING pathway. Additionally, it considers the field's future prospects while examining how cGAS-STING pathway might be altered and its clinical applications for cardiovascular diseases.

Effects of scutellarin on the mechanism of cardiovascular diseases: a review

Cardiovascular diseases represent a significant worldwide problem, jeopardizing individuals' physical and mental wellbeing as well as their quality of life as a result of their widespread incidence and fatality. With the aging society, the occurrence of Cardiovascular diseases is progressively rising each year. However, although drugs developed for treating Cardiovascular diseases have clear targets and proven efficacy, they still carry certain toxic and side effect risks. Therefore, finding safe, effective, and practical treatment options is crucial. Scutellarin is the primary constituent of Erigeron breviscapus (Vant.) Hand-Mazz. This article aims to establish a theoretical foundation for the creation and use of secure, productive, and logical medications for Scutellarin in curing heart-related illnesses. Additionally, the examination and analysis of the signal pathway and its associated mechanisms with regard to the employment of SCU in treating heart diseases will impart innovative resolving concepts for the treatment and prevention of Cardiovascular diseases.

Microtubule-destabilizing agents enhance STING-mediated innate immune response via biased mechanism in human monocyte cells

The stimulator of the interferon gene (STING) signaling pathway acts as a primary defense system against DNA pathogens. Because of the crucial role of STING in type I interferon (IFN) response and innate immunity, extensive research has been conducted to elucidate the roles of various effector molecules involved in STING-mediated signal transduction. However, despite the substantial contribution of microtubules to the immune system, the association between the STING signaling pathway and microtubules remains unclear. In this study, we revealed that the modulation of STING via microtubule-destabilizing agents (MDAs) specifically induced type I IFN responses rather than inflammatory responses in human monocytes. Co-treatment of MDAs with STING agonists induced the elevation of phospho-TANK-binding kinase 1 (TBK1), amplifying the innate immune response. However, during the deficiency of TBK1, the non-canonical signaling pathway through nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) contributed to MDA-induced STING activation in type I IFN response which suggested the versatile regulation of MDA in STING-mediated immunity.

Mitochondrial DNA-triggered innate immune response: mechanisms and diseases

Various cellular stress conditions trigger mitochondrial DNA (mtDNA) release from mitochondria into the cytosol. The released mtDNA is sensed by the cGAS-MITA/STING pathway, resulting in the induced expression of type I interferon and other effector genes. These processes contribute to the innate immune response to viral infection and other stress factors. The deregulation of these processes causes autoimmune diseases, inflammatory metabolic disorders and cancer. Therefore, the cGAS-MITA/STING pathway is a potential target for intervention in infectious, inflammatory and autoimmune diseases as well as cancer. In this review, we focus on the mechanisms underlying the mtDNA-triggered activation of the cGAS-MITA/STING pathway, the effects of the pathway under various physiological and pathological conditions, and advances in the development of drugs that target cGAS and MITA/STING.

Hallmarks of cardiovascular ageing

Normal circulatory function is a key determinant of disease-free life expectancy (healthspan). Indeed, pathologies affecting the cardiovascular system, which are growing in prevalence, are the leading cause of global morbidity, disability and mortality, whereas the maintenance of cardiovascular health is necessary to promote both organismal healthspan and lifespan. Therefore, cardiovascular ageing might precede or even underlie body-wide, age-related health deterioration. In this Review, we posit that eight molecular hallmarks are common denominators in cardiovascular ageing, namely disabled macroautophagy, loss of proteostasis, genomic instability (in particular, clonal haematopoiesis of indeterminate potential), epigenetic alterations, mitochondrial dysfunction, cell senescence, dysregulated neurohormonal signalling and inflammation. We also propose a hierarchical order that distinguishes primary (upstream) from antagonistic and integrative (downstream) hallmarks of cardiovascular ageing. Finally, we discuss how targeting each of the eight hallmarks might be therapeutically exploited to attenuate residual cardiovascular risk in older individuals.

Stimulator of interferon genes (STING): Key therapeutic targets in ischemia/reperfusion injury

The Stimulator of Interferon Genes (STING) is predominantly expressed in immune cells, including macrophages, natural killer cells, dendritic cells, and T cells, functioning as a pattern recognition receptor. STING activation upon detecting cytosolic DNA released from damaged cells initiates downstream pathways, leading to the production of inflammatory cytokines such as IFNs, IL-6, and TNF-α. Dysregulated STING activation has been implicated in inflammatory and metabolic diseases. Ischemia/reperfusion injury (I/RI) is common in stroke, acute myocardial infarction, organ transplantation, and surgeries for certain end-stage diseases. Recent studies suggest that STING could be a novel therapeutic target for I/RI treatment. In this review, we provide a concise overview of the cGAS-STING signaling pathway's general functions and summarize STING's role in I/RI across various organs, including the heart, liver, kidney, and lung. Moreover, we explore potential therapeutic approaches for I/RI by targeting STING.

The battle between the innate immune cGAS-STING signaling pathway and human herpesvirus infection

The incidence of human herpesvirus (HHVs) is gradually increasing and has affected a wide range of population. HHVs can result in serious consequences such as tumors, neonatal malformations, sexually transmitted diseases, as well as pose an immense threat to the human health. The cGAS-STING pathway is one of the innate immune pattern-recognition receptors discovered recently. This article discusses the role of the cGAS-STING pathway in human diseases, especially in human herpesvirus infections, as well as highlights how these viruses act on this pathway to evade the host immunity. Moreover, the author provides a comprehensive overview of modulators of the cGAS-STING pathway. By focusing on the small molecule compounds based on the cGAS-STING pathway, novel targets and concepts have been proposed for the development of antiviral drugs and vaccines, while also providing a reference for the investigation of disease models related to the cGAS-STING pathway. HHV is a double-stranded DNA virus that can trigger the activation of intracellular DNA sensor cGAS, after which the host cells initiate a cascade of reactions that culminate in the secretion of type I interferon to restrict the viral replication. Meanwhile, the viral protein can interact with various molecules in the cGAS-STING pathway. Viruses can evade immune surveillance and maintain their replication by inhibiting the enzyme activity of cGAS and reducing the phosphorylation levels of STING, TBK1 and IRF3 and suppressing the interferon gene activation. Activators and inhibitors of the cGAS-STING pathway have yielded numerous promising research findings in vitro and in vivo pertaining to cGAS/STING-related disease models. However, there remains a dearth of small molecule modulators that have been successfully translated into clinical applications, which serves as a hurdle to be overcome in the future.

Risk prediction model construction for post myocardial infarction heart failure by blood immune B cells

Background

Myocardial infarction (MI) is a common cardiac condition with a high incidence of morbidity and mortality. Despite extensive medical treatment for MI, the development and outcomes of post-MI heart failure (HF) continue to be major factors contributing to poor post-MI prognosis. Currently, there are few predictors of post-MI heart failure.

Methods

In this study, we re-examined single-cell RNA sequencing and bulk RNA sequencing datasets derived from the peripheral blood samples of patients with myocardial infarction, including patients who developed heart failure and those who did not develop heart failure after myocardial infarction. Using marker genes of the relevant cell subtypes, a signature was generated and validated using relevant bulk datasets and human blood samples.

Results

We identified a subtype of immune-activated B cells that distinguished post-MI HF patients from non-HF patients. Polymerase chain reaction was used to confirm these findings in independent cohorts. By combining the specific marker genes of B cell subtypes, we developed a prediction model of 13 markers that can predict the risk of HF in patients after myocardial infarction, providing new ideas and tools for clinical diagnosis and treatment.

Conclusion

Sub-cluster B cells may play a significant role in post-MI HF. We found that the STING1, HSPB1, CCL5, ACTN1, and ITGB2 genes in patients with post-MI HF showed the same trend of increase as those without post-MI HF.

Drug repurposing for cardiovascular diseases: New targets and indications for probenecid

The available pharmacological options in the management of cardiovascular diseases such as ischaemic heart disease and subsequent heart failure are effective in slowing the progression of this condition. However, the long-term prognosis is still poor, raising the demand for new therapeutic strategies. Drug repurposing is a time- and cost-effective drug development strategy that offers approved and abandoned drugs a new chance for new indications. Recently, drugs used for the management of gout-related inflammation such as canakinumab or colchicine have been considered for drug repurposing in cardiovascular indications. The old uricosuric drug, probenecid, has been identified as a novel therapeutic option in the management of specific cardiac diseases as well. Probenecid can modulate myocardial contractility and vascular tone and exerts anti-inflammatory properties. The mechanisms behind these beneficial effects might be related inhibition of inflammasomes, and to modulation purinergic-pannexin-1 signalling and TRPV2 channels, which are recently identified molecular targets of probenecid. In this review, we provide an overview on repurposing probenecid for ischaemic heart disease and subsequent heart failure by summarizing the related experimental and clinical data and propose its potential repurposing to treat cardiovascular diseases.

Targeting immunoregulation for cardiac regeneration

Inducing endogenous cardiomyocyte proliferation and heart regeneration is a promising strategy to treat ischemic heart failure. The immune response has recently been considered critical in cardiac regeneration. Thus, targeting the immune response is a potent strategy to improve cardiac regeneration and repair after myocardial infarction. Here we reviewed the characteristics of the relationship between the postinjury immune response and heart regenerative capacity and summarized the latest studies focusing on inflammation and heart regeneration to identify potent targets of the immune response and strategies in the immune response to promote cardiac regeneration.

The Role of cGAS-STING in Age-Related Diseases from Mechanisms to Therapies

With aging, the incidence of age-related diseases increases. Hence, age-related diseases are inevitable. However, the mechanisms by which aging leads to the onset and progression of age-related diseases remain unclear. It has been reported that inflammation is closely associated with age-related diseases and that the cGAS-STING signaling pathway, which can sense the aberrant presence of cytosolic DNA during aging and induce an inflammatory response, is an important mediator of inflammation in age-related diseases. With a better understanding of the structure and molecular biology of the cGAS-STING signaling axis, numerous selective inhibitors and agonists targeting the cGAS-STING pathway in human age-related diseases have been developed to modulate inflammatory responses. Here, we provide a narrative review of the activity of the cGAS- STING pathway in age-related diseases and discuss its general mechanisms in the onset and progression of age-related diseases. In addition, we outline treatments targeting the cGAS-STING pathway, which may constitute a potential therapeutic alternative for age-related diseases.

Inhibition of Stimulator of Interferon Genes Protects Against Myocardial Ischemia-Reperfusion Injury in Diabetic Mice

Background: Although the past decade has witnessed substantial scientific progress with the advent of cardioprotective pharmacological agents, most have failed to protect against myocardial ischemia/reperfusion (I/R) injury in diabetic hearts. This study was aimed at investigating the role of stimulator of interferon genes (STING) in I/R injury in diabetic mice and further exploring the underlying mechanisms.

Methods: Type 2 diabetic mice were subjected to I/R or sham operation to investigate the role of STING. STING knockout mice were subjected to 30 minutes of ischemia followed by reperfusion for 24 hours. Finally, myocardial injury, cardiac function, and inflammation levels were assessed.

Results: STING pathway activation was observed in diabetic I/R hearts, as evidenced by increased p-TBK and p-IRF3 expression. STING knockout significantly decreased the ischemic area and improved cardiac function after I/R in diabetic mice. STING knockout also elicited cardio-protective effects by decreasing serum cardiac troponin T and lactate dehydrogenase levels, thus diminishing the inflammatory response in the heart after I/R in diabetic mice. In vitro, STING inhibition decreased the expression of hypoxia-re-oxygenation-induced inflammatory cytokines.

Conclusions: Targeting STING inhibits inflammation and prevents I/R injury in diabetic mice. Thus, STING may be a potential novel therapeutic target against myocardial I/R injury in diabetes.

Multifaceted functions of STING in human health and disease: from molecular mechanism to targeted strategy

Since the discovery of Stimulator of Interferon Genes (STING) as an important pivot for cytosolic DNA sensation and interferon (IFN) induction, intensive efforts have been endeavored to clarify the molecular mechanism of its activation, its physiological function as a ubiquitously expressed protein, and to explore its potential as a therapeutic target in a wide range of immune-related diseases. With its orthodox ligand 2'3'-cyclic GMP-AMP (2'3'-cGAMP) and the upstream sensor 2'3'-cGAMP synthase (cGAS) to be found, STING acquires its central functionality in the best-studied signaling cascade, namely the cGAS-STING-IFN pathway. However, recently updated research through structural research, genetic screening, and biochemical assay greatly extends the current knowledge of STING biology. A second ligand pocket was recently discovered in the transmembrane domain for a synthetic agonist. On its downstream outputs, accumulating studies sketch primordial and multifaceted roles of STING beyond its cytokine-inducing function, such as autophagy, cell death, metabolic modulation, endoplasmic reticulum (ER) stress, and RNA virus restriction. Furthermore, with the expansion of the STING interactome, the details of STING trafficking also get clearer. After retrospecting the brief history of viral interference and the milestone events since the discovery of STING, we present a vivid panorama of STING biology taking into account the details of the biochemical assay and structural information, especially its versatile outputs and functions beyond IFN induction. We also summarize the roles of STING in the pathogenesis of various diseases and highlight the development of small-molecular compounds targeting STING for disease treatment in combination with the latest research. Finally, we discuss the open questions imperative to answer.

The effect of the cyclic GMP-AMP synthase-stimulator of interferon genes signaling pathway on organ inflammatory injury and fibrosis

The cyclic GMP-AMP synthase-stimulator of interferon genes signal transduction pathway is critical in innate immunity, infection, and inflammation. In response to pathogenic microbial infections and other conditions, cyclic GMP-AMP synthase (cGAS) recognizes abnormal DNA and initiates a downstream type I interferon response. This paper reviews the pathogenic mechanisms of stimulator of interferon genes (STING) in different organs, including changes in fibrosis-related biomarkers, intending to systematically investigate the effect of the cyclic GMP-AMP synthase-stimulator of interferon genes signal transduction in inflammation and fibrosis processes. The effects of stimulator of interferon genes in related auto-inflammatory and neurodegenerative diseases are described in this article, in addition to the application of stimulator of interferon genes-related drugs in treating fibrosis.

Genetic Ablation of the DNA Damage Response Pathway Attenuates Lamin-Associated Dilated Cardiomyopathy in Mice

Hereditary dilated cardiomyopathy (DCM) is a primary disease of cardiac myocytes caused by mutations in genes encoding proteins with a diverse array of functions. Mutations in the LMNA gene, encoding the nuclear envelope protein lamin A/C, are the second most common causes of DCM. The phenotype is characterized by progressive cardiac dysfunction, leading to refractory heart failure, myocardial fibrosis, cardiac arrhythmias, and sudden cardiac death. The molecular pathogenesis of DCM caused by the LMNA mutations is not well known. The LMNA protein is involved in nuclear membrane stability. It is also a guardian of the genome involved in the processing of the topoisomerases at the transcriptionally active domain and the repair of double-stranded DNA breaks (DSBs). Deletion of the mouse Lmna gene in cardiac myocytes leads to premature death, DCM, myocardial fibrosis, and apoptosis. The phenotype is associated with increased expression of the cytosolic DNA sensor cyclic GMP-AMP synthase (CGAS) and activation of the DNA damage response (DDR) pathway. Genetic blockade of the DDR pathway, upon knockout of the Mb21d1 gene encoding CGAS, prolonged survival, improved cardiac function, partially restored levels of molecular markers of heart failure, and attenuated myocardial apoptosis and fibrosis in the LMNA-deficient mice. The findings indicate that targeting the CGAS/DDR pathway might be beneficial in the treatment of DCM caused by mutations in the LMNA gene.

Link between sterile inflammation and cardiovascular diseases: Focus on cGAS-STING pathway in the pathogenesis and therapeutic prospect

Sterile inflammation characterized by unresolved chronic inflammation is well established to promote the progression of multiple autoimmune diseases, metabolic disorders, neurodegenerative diseases, and cardiovascular diseases, collectively termed as sterile inflammatory diseases. In recent years, substantial evidence has revealed that the inflammatory response is closely related to cardiovascular diseases. Cyclic guanosine monophosphate–adenosine monophosphate synthase (cGAS)-stimulator of interferon genes (STING) pathway which is activated by cytoplasmic DNA promotes the activation of interferon regulatory factor 3 (IRF3) or nuclear factor-κB (NF-κB), thus leading to upregulation of the levels of inflammatory factors and interferons (IFNs). Therefore, studying the role of inflammation caused by cGAS-STING pathway in cardiovascular diseases could provide a new therapeutic target for cardiovascular diseases. This review focuses on that cGAS-STING-mediated inflammatory response in the progression of cardiovascular diseases and the prospects of cGAS or STING inhibitors for treatment of cardiovascular diseases.

Can the cGAS-STING Pathway Play a Role in the Dry Eye?

Dry eye is one of the most common ocular surface diseases in the world and seriously affects the quality of life of patients. As an immune-related disease, the mechanism of dry eye has still not been fully elucidated. The cGAS-STING pathway is a recently discovered pathway that plays an important role in autoimmune and inflammatory diseases by recognizing dsDNA. As an important signal to initiate inflammation, the release of dsDNA is associated with dry eye. Herein, we focused on the pathophysiology of the immune-inflammatory response in the pathogenesis of dry eye, attempted to gain insight into the involvement of dsDNA in the dry eye immune response, and investigated the mechanism of the cGAS-STING pathway involved in the immune-inflammatory response. We further proposed that the cGAS-STING pathway may participate in dry eye as a new mechanism linking dry eye and the immune-inflammatory response, thus providing a new direction for the mechanistic exploration of dry eye.

cAMP сoncentrations in cardiac mitochondria and serum in the С57ВL/6 mice under independent melanoma В16/F10 growth versus melanoma В16/F10 growth linked to chronic neurogenic pain

The aim of this research work is to study the cAMP level in the cardiac mitochondria and serum in the С57ВL/6 strain mice of both genders under the independent melanoma В16/F10 growth versus the melanoma В16/F10 growth linked to chronic neurogenic pain (CNP). Materials and methods. Mice of strain С57ВL/6 (n=336) have been grouped as follows: the intact group of the mice (♂n=21; ♀n=21), the reference group (♂n=21; ♀n=21) with the reproduced CNP model, the comparison group (♂n=63; ♀n=63) to include the mice with melanoma В16/F10, and the main test group (♂n=63; ♀n=63) to cover the mice with the melanoma growth against the CNP background. Upon expiration of 1 week, 2 and 3 weeks of the melanoma growth, in the animals of the above experimental groups the cardiac mitochondria have been isolated with the centrifugation using high-performance refrigerated centrifuge Avanti J-E, BECMAN COULTER, USA. With ELISA Kit (RayBio USA) we have determined cAMP concentrations in serum and in the cardiac mitochondria. Results. CNP has induced a decrease in the cAMP level in the cardiac mitochondria by a factor of 3,6 in the female mice only. In the animals of the comparison group the cAMP level in the heart has been increasing beginning with week 2 of the tumor growth on average by a factor of 4, while in the main test group starting from week 1 of the tumor growth it has been recorded 2-4 times higher and was depleted by the end of the experiment. As to the cAMP concentration in serum, the dynamics thereof has not been found to be in correlation with the cardiac mitochondrial data, and its concentration decrease has been recorded both in the females and the males. Conclusion. So, the changes in the cAMP concentration in the cardiac mitochondria demonstrate their gender-specific feature; the female mice as against the males have responded to an independent impact produced by CNP. As to the main test group, CNP has stimulated an increase in the cAMP level in the cardiac mitochondria 1 week earlier than it is the case with the comparison group, and it has resulted in the full cAMP depletion by the 3rd week of the experiment.