Scutellarin ameliorates ischemia/reperfusion injury‑induced cardiomyocyte apoptosis and cardiac dysfunction via inhibition of the cGAS‑STING pathway

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.

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.

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-STING/PERK-eIF2α: Individual or Potentially Collaborative Signaling Transduction in Cardiovascular Diseases

Over the past several decades, a canonical pathway called the cyclic GMP-AMP (cGAMP) synthase (cGAS)-stimulator of interferon genes (STING) mediating type I interferon (IFN) release via TANK-binding kinase 1(TBK1) / IFN regulatory factor 3 (IRF3) pathway has been widely investigated and characterized. Unexpectedly, recent studies show that the cGAS-STING noncanonically activates the protein kinase RNA-like ER kinase (PERK)-eukaryotic initiation factor 2α (eIF2α), an essential branch of unfolded protein response (UPR), even before the activation of the TBK1/IRF3 signaling. Additionally, we found that the PERK could regulate the STING signaling besides being modulated by upstream cGAS-STING. However, earlier evidence solely focused on the unidirectional regulation of STING and PERK, lacking their functional crosstalk. Hence, we postulate that there is a complex relationship between the cGAS-STING and PERK-eIF2α pathways and that, through convergent downstream signaling, they may collaboratively contribute to the pathophysiology of cardiovascular diseases (CVDs) via the cGAS-STING/PERK-eIF2α signaling axis. This study provides a novel pathway for the development of CVDs and paves the foundation for potential therapeutic targets for CVDs.

Inhibiting the cGAS-STING Pathway in Ulcerative Colitis with Programmable Micelles

Ulcerative colitis is a chronic condition in which a dysregulated immune response contributes to the acute intestinal inflammation of the colon. Current clinical therapies often exhibit limited efficacy and undesirable side effects. Here, programmable nanomicelles were designed for colitis treatment and loaded with RU.521, an inhibitor of the cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING) pathway. STING-inhibiting micelles (SIMs) comprise hyaluronic acid-stearic acid conjugates and include a reactive oxygen species (ROS)-responsive thioketal linker. SIMs were designed to selectively accumulate at the site of inflammation and trigger drug release in the presence of ROS. Our in vitro studies in macrophages and in vivo studies in a murine model of colitis demonstrated that SIMs leverage HA-CD44 binding to target sites of inflammation. Oral delivery of SIMs to mice in both preventive and delayed therapeutic models ameliorated colitis's severity by reducing STING expression, suppressing the secretion of proinflammatory cytokines, enabling bodyweight recovery, protecting mice from colon shortening, and restoring colonic epithelium. In vivo end points combined with metabolomics identified key metabolites with a therapeutic role in reducing intestinal and mucosal inflammation. Our findings highlight the significance of programmable delivery platforms that downregulate inflammatory pathways at the intestinal mucosa for managing inflammatory bowel 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.

Current advances on the therapeutic potential of scutellarin: an updated review

Scutellarin is widely distributed in Scutellaria baicalensis, family Labiatae, and Calendula officinalis, family Asteraceae, and belongs to flavonoids. Scutellarin has a wide range of pharmacological activities, it is widely used in the treatment of cerebral infarction, angina pectoris, cerebral thrombosis, coronary heart disease, and other diseases. It is a natural product with great research and development prospects. In recent years, with in-depth research, researchers have found that wild scutellarin also has good therapeutic effects in anti-tumor, anti-inflammatory, anti-oxidation, anti-virus, treatment of metabolic diseases, and protection of kidney. The cancer treatment involves glioma, breast cancer, lung cancer, renal cancer, colon cancer, and so on. In this paper, the sources, pharmacological effects, in vivo and in vitro models of scutellarin were summarized in recent years, and the current research status and future direction of scutellarin were analyzed.

The combination of Tanshinone IIA and Astragaloside IV attenuates myocardial ischemia-reperfusion injury by inhibiting the STING pathway

BACKGROUND

Astragaloside IV (As-IV) and Tanshinone IIA (Ta-IIA) are the main ingredients of traditional Chinese medicinal Astragalus membranaceus (Fisch.) Bunge and Salvia miltiorrhiza Bunge, respectively, both of which have been employed in the treatment of cardiovascular diseases. Nevertheless, the efficacy of the combination (Co) of Ta-IIA and As-IV for cardiovascular diseases remain unclear and warrant further investigation. This study aimed to investigate the efficacy and the underlying molecular mechanism of Co in treating myocardial ischemia-reperfusion injury (MIRI).

METHODS

In order to assess the efficacy of Co, an in vivo MIRI mouse model was created by temporarily blocking the coronary arteries for 30 min and then releasing the blockage. Parameters such as blood myocardial enzymes, infarct size, and ventricular function were measured. Additionally, in vitro experiments were conducted using HL1 cells in both hypoxia-reoxygenation model and oxidative stress models. The apoptosis rate, expression levels of apoptosis-related proteins, oxidative stress indexes, and release of inflammatory factors were detected. Furthermore, molecular docking was applied to examine the binding properties of Ta-IIA and As-IV to STING, and western blotting was performed to analyze protein expression of the STING pathway. Additionally, the protective effect of Ta-IIA, As-IV and Co via inhibiting STING was further confirmed in models of knockdown STING by siRNA and adding STING agonist.

RESULTS

Both in vitro and in vivo data demonstrated that, compared to Ta-IIA or As-IV alone, the Co exhibited superior efficacy in reducing the area of myocardial infarction, lowering myocardial enzyme levels, and promoting the recovery of myocardial contractility. Furthermore, the Co showed more potent anti-apoptosis, antioxidant, and anti-inflammation effects. Additionally, the Co enhanced the inhibitory effects of Ta-IIA and As-IV on STING phosphorylation and the activation of STING signaling pathway. However, the administration of a STING agonist attenuated the protective effects of the Co, Ta-IIA, and As-IV by compromising their anti-apoptotic, antioxidant, and anti-inflammatory effects in MIRI.

CONCLUSION

Compared to the individual administration of Ta-IIA or As-IV, the combined treatment demonstrated more potent ability in inhibiting apoptosis, oxidative stress, inflammation, and the STING signaling pathway in the context of MIRI, indicating a more powerful protective effect against MIRI.

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.

PLGA nanoparticles enhanced cardio-protection of scutellarin and paeoniflorin against isoproterenol-induced myocardial ischemia in rats

This study aims to examine the impact of the microfluidic preparation process on the quality of poly (lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) co-delivered with scutellarin (SCU) and paeoniflorin (PAE) in comparison to a conventional emulsification method and to evaluatethe potential cardio-protective effect of SCU-PAE PLGA NPs produced through emulsification method. As compared with microfluidics, the nanoparticles prepared by emulsification method exhibited a smaller size, higher encapsulation efficiency, higher drug loading and lower viscosity for injection. Subsequently, a rat myocardial ischemia (MI) was established using male Sprague-Dawley (SD) rats (250 ± 20 g) subcutaneously injected with 85 mg/kg isoproterenol (ISO) for two consecutive days. The pharmacokinetic findings demonstrated that our SCU-PAE PLGA NPs exhibited prolonged blood circulation time in MI rats, leading to increased levels of SCU and PAE in the heart. This resulted in significant improvements in electrocardiogram and cardiac index, as well as reduced serum levels of CK, LDH, AST. Histopathological analysis using H&E and TUNEL staining provided further evidence of improved cardiac function and decreased apoptosis. Additionally, experiments measuring SOD, MDA, GSH, NO, TNF-α and IL-6 levels indicated that SCU-PAE PLGA NPs may effectively treat MI through oxidative stress and inflammatory pathways, thereby establishing it as a promising therapeutic intervention.

cGAS-STING pathway in ischemia-reperfusion injury: a potential target to improve transplantation outcomes

Transplantation is an important life-saving therapeutic choice for patients with organ or tissue failure once all other treatment options are exhausted. However, most allografts become damaged over an extended period, and post-transplantation survival is limited. Ischemia reperfusion injury (IRI) tends to be associated with a poor prognosis; resultant severe primary graft dysfunction is the main cause of transplant failure. Targeting the cGAS-STING pathway has recently been shown to be an effective approach for improving transplantation outcomes, when activated or inhibited cGAS-STING pathway, IRI can be alleviated by regulating inflammatory response and programmed cell death. Thus, continuing efforts to develop selective agonists and antagonists may bring great hopes to post-transplant patient. In this mini-review, we reviewed the role of the cGAS-STING pathway in transplantation, and summarized the crosstalk between this pathway and inflammatory response and programmed cell death during IRI, aiming to provide novel insights into the development of therapies to improve patient outcome after transplantation.