Exosome-Derived From Sepsis Patients' Blood Promoted Pyroptosis of Cardiomyocytes by Regulating miR-885-5p/HMBOX1

Roles and Therapeutic Targeting of Exosomes in Sepsis-Induced Cardiomyopathy

Sepsis-induced cardiomyopathy (SICM) is a complex and fatal manifestation of sepsis, characterised by myocardial dysfunction that exacerbates the clinical prognosis in septic patients. While the pathophysiology of SICM remains incompletely understood, emerging evidence highlights the multifaceted functions of exosomes, small membrane-bound extracellular vesicles, in mediating the inflammatory responses and cardiac dysfunction involved in this condition. During sepsis, exosomes are secreted by various cells, such as cardiomyocytes, endothelial cells and macrophages, which serve as critical messengers, transferring proteins, lipids and RNA molecules that influence recipient cells, thus affecting cellular functions and disease progression. This review summarises the pathophysiology of SICM and the basics of exosomes and focuses on exosome-mediated mechanisms in SICM, including their role in inflammation, oxidative stress, mitochondrial dysfunction and myocardial injury, offering novel insights into the exosome-based therapeutic strategies in SICM.

Understanding Propofol's Protective Mechanism in Tubular Epithelial Cells: Mitigating Pyroptosis via the miR-143-3p/ATPase Na + /K + Transporting Subunit Alpha 2 Pathway in Renal Ischemia-Reperfusion

Propofol (Pro), a prevalent intravenous anesthetic, has recently been recognized for its potential in mitigating ischemia-reperfusion (I/R) injuries. Despite a plethora of evidence suggesting the beneficial effects of low-dose Pro in renal I/R injury (RI/R), its role in modulating pyroptosis in renal tubular epithelial cells consequent to RI/R has not been thoroughly elucidated. In our investigation, we explored the therapeutic potential of Pro against pyroptosis in renal tubular epithelial cells under the duress of RI/R, employing both in vivo and in vitro models, while deciphering the intricate molecular pathways involved. Our results demonstrate an elevation in the expression of miR-143-3p, contrasted by a diminution in ATPase Na + /K + Transporting Subunit Alpha 2 (ATP1A2) under RI/R conditions. Pro effectively mitigates apoptosis in renal tubular epithelial cells induced by RI/R, principally characterized by the inhibition of pro-inflammatory cytokines interleukin (IL-)-1β and IL-18, enhancement of cellular viability, reduction in the ratio of pyroptotic cells, and suppression of nucleotide-binding domain and leucine-rich repeat-related family, pyrin domain containing 3 inflammasome activation along with the expression of cleaved caspase-1, and gasdermin D. Both knockdown and overexpression studies of miR-143-3p revealed its pivotal role in modulating RI/R-induced tubular cell pyroptosis. Notably, Pro's capacity to inhibit pyroptosis in renal tubular epithelial cells was found to be reversible following ATP1A2 knockdown. Furthermore, our study unveils miR-143-3p as a targeted regulator of ATP1A2 expression. From a mechanistic standpoint, Pro's therapeutic efficacy is attributed to its regulatory influence on miR-143-3p and ATP1A2 expression levels. In conclusion, our findings pioneer the understanding that Pro can significantly ameliorate pyroptosis in renal tubular epithelial cells in the context of RI/R, predominantly through the modulation of the miR-143-3p/ATP1A2 axis. This novel insight furnishes robust empirical support for the development of targeted therapeutics and clinical strategies in addressing RI/R.

Dual Roles of Plasma miRNAs in Myocardial Injuries After Polytrauma: miR-122-5p and miR-885-5p Reflect Inflammatory Response, While miR-499a-5p and miR-194-5p Contribute to Cardiomyocyte Damage

Cardiac injury after severe trauma is associated with higher mortality in polytrauma patients. Recent evidence suggests that miRNAs play a key role in cardiac pathophysiology and could serve as potential markers of cardiac damage after polytrauma. To explore this hypothesis, plasma miRNA profiles from polytrauma patients (ISS ≥ 16) with and without cardiac injury, stratified by troponin T levels (TnT, > 50 pg/mL vs. < 12 pg/mL), were analysed using NGS and validated via RT-qPCR. Five miRNAs (miR-122-5p, miR-424-5p, miR-885-5p, miR-194-5p, and miR-499a-5p) were found to be significantly upregulated in polytrauma patients with elevated TnT levels. miR-122-5p was associated with markers of right ventricular dysfunction (TAPSE) and left ventricular hypertrophy (IVS/LVPW), while miR-885-5p correlated with left ventricular hypertrophy (IVS/LVPW) and diastolic dysfunction (E/E' ratio). In vitro, miR-194-5p mimic and miR-499a-5p mimic exhibited more active roles in cardiomyocyte injury by increasing caspase-3/7 activity and/or enhancing caspase-1 activity. Notably, the miR-194-5p mimic significantly enhanced the cytotoxic effects of the polytrauma cocktail, while miR-499a-5p boosted effects of LPS/nigericin stimulation in cardiomyocytes. Our findings identify miR-122-5p and miR-885-5p as potential biomarkers reflecting the cardiomyocyte response to polytrauma-induced inflammation, while miR-499a-5p and miR-194-5p appear to play a direct role in myocardial injury after polytrauma.

MicroRNAs as regulators of cardiac dysfunction in sepsis: pathogenesis and diagnostic potential

Introduction

Sepsis, a life-threatening condition arising from an uncontrolled immune response to infection, can lead to organ dysfunction, with severe inflammation potentially causing multiple organ failures. Sepsis-induced cardiac dysfunction (SIMD) is a common and severe complication of sepsis, significantly increasing patient mortality. Understanding the pathogenesis of SIMD is crucial for improving treatment, and microRNAs (miRNAs) have emerged as important regulators in this process.

Methods

A comprehensive literature search was conducted in PubMed, Science Direct, and Embase databases up to September 2024. The search terms included ["miRNA" or "microRNA"] and ["Cardiac" or "Heart"] and ["Sepsis" or "Septic"], with the language limited to English. After initial filtering by the database search engine, Excel software was used to further screen references. Duplicate articles, those without abstracts or full texts, and review/meta-analyses or non-English articles were excluded. Finally, 106 relevant research articles were included for data extraction and analysis.

Results

The pathogenesis of SIMD is complex and involves mitochondrial dysfunction, oxidative stress, cardiomyocyte apoptosis and pyroptosis, dysregulation of myocardial calcium homeostasis, myocardial inhibitory factors, autonomic nervous regulation disorders, hemodynamic changes, and myocardial structural alterations. miRNAs play diverse roles in SIMD. They are involved in regulating the above-mentioned pathological processes.

Discussion

Although significant progress has been made in understanding the role of miRNAs in SIMD, there are still challenges. Some studies on the pathogenesis of SIMD have limitations such as small sample sizes and failure to account for confounding factors. Research on miRNAs also faces issues like inconsistent measurement techniques and unclear miRNA-target gene relationships. Moreover, the translation of miRNA-based research into clinical applications is hindered by problems related to miRNA stability, delivery mechanisms, off-target effects, and long-term safety. In conclusion, miRNAs play a significant role in the pathogenesis of SIMD and have potential as diagnostic biomarkers. Further research is needed to overcome existing challenges and fully exploit the potential of miRNAs in the diagnosis and treatment of SIMD.

Pathogenic and therapeutic roles of extracellular vesicles in sepsis

Sepsis is a systemic injury resulting in vascular dysfunction, which can lead to multiple organ dysfunction, even shock and death. Extracellular vesicles (EVs) released by mammalian cells and bacteria have been shown to play important roles in intercellular communication and progression of various diseases. In past decades, the functional role of EVs in sepsis and its complications has been well explored. EVs are one of the paracrine components of cells. By delivering bioactive materials, EVs can promote immune responses, particularly the development of inflammation. In addition, EVs can serve as beneficial tools for delivering therapeutic cargos. In this review, we discuss the dual role of EVs in the progression and treatment of sepsis, exploring their intricate involvement in both inflammation and tissue repair processes. Specifically, the remarkable role of engineered strategies based on EVs in the treatment of sepsis is highlighted. The engineering EVs-mediated drug delivery and release strategies offer broad prospects for the effective treatment of sepsis. EVs-based approaches provide a novel avenue for diagnosing sepsis and offer opportunities for more precise intervention.

Exosomes Derived from Apelin-Pretreated Mesenchymal Stem Cells Ameliorate Sepsis-Induced Myocardial Dysfunction by Alleviating Cardiomyocyte Pyroptosis via Delivery of miR-34a-5p

Background

Exosomes sourced from mesenchymal stem cells (MSC-EXOs) have become a promising therapeutic tool for sepsis-induced myocardial dysfunction (SMD). Our previous study demonstrated that Apelin pretreatment enhanced the therapeutic benefit of MSCs in myocardial infarction by improving their paracrine effects. This study aimed to determine whether EXOs sourced from Apelin-pretreated MSCs (Apelin-MSC-EXOs) would have potent cardioprotective effects against SMD and elucidate the underlying mechanisms.

Methods

MSC-EXOs and Apelin-MSC-EXOs were isolated and identified. Mice neonatal cardiomyocytes (NCMs) were treated with MSC-EXOs or Apelin-MSC-EXOs under lipopolysaccharide (LPS) condition in vitro. Cardiomyocyte pyroptosis was determined by TUNEL staining. RNA sequencing was used to identify differentially expressed functional miRNAs between MSC-EXOs and Apelin-MSC-EXOs. MSC-EXOs and Apelin-MSC-EXOs were transplanted into a mouse model of SMD induced by cecal ligation puncture (CLP) via the tail vein. Heart function was evaluated by echocardiography.

Results

Compared with MSC-EXOs, Apelin-MSC-EXO transplantation greatly enhanced cardiac function in SMD mice. Both MSC-EXOs and Apelin-MSC-EXOs suppressed cardiomyocyte pyroptosis in vivo and in vitro, with the latter exhibiting superior protective effects. miR-34a-5p effectively mediated Apelin-MSC-EXOs to exert their cardioprotective effects in SMD with high mobility group box-1 (HMGB1) as the potential target. Mechanistically, Apelin-MSC-EXOs delivered miR-34a-5p into injured cardiomyocytes, thereby ameliorating cardiomyocyte pyroptosis via regulation of the HMGB1/AMPK axis. These cardioprotective effects were partially abrogated by downregulation of miR-34a-5p in Apelin-MSC-EXOs.

Conclusion

Our study revealed miR-34a-5p as a key component of Apelin-MSC-EXOs that protected against SMD via mediation of the HMGB1/AMPK signaling pathway.

Exosomes as novel biomarkers in sepsis and sepsis related organ failure

Sepsis, a severe and life-threatening condition arising from a dysfunctional host response to infection, presents considerable challenges to the health care system and is characterized by high mortality rates and substantial economic costs. Exosomes have garnered attention as potential diagnostic markers because of their capacity to mirror the pathophysiological milieu of sepsis. This discourse reviews the progression of sepsis classification from Sepsis 1.0 to Sepsis 3.0, highlighting the imperative for sensitive and specific biomarkers to facilitate timely diagnosis and optimize patient outcomes. Existing biomarkers, such as procalcitonin (PCT) and C-reactive protein (CRP), exhibit certain limitations, thereby prompting the quest for more dependable diagnostic indicators. Exosomal cargoes, which encompass proteins and miRNAs, present a trove of biomarker candidates, attributable to their stability, pervasive presence, and indicative nature of the disease status. The potential of exosomal biomarkers in the identification of sepsis-induced organ damage, including cardiomyopathy, acute kidney injury, and acute lung injury, is emphasized, as they provide real-time insights into cardiac and renal impairments. Despite promising prospects, hurdles persist in the standardization of exosome extraction and the need for extensive clinical trials to validate their efficacy. The combination of biomarker development and sophisticated exosome detection techniques represents a pioneering strategy in the realm of sepsis diagnosis and management, underscoring the significance of further research and clinical validation.

Pyroptosis in Endothelial Cells and Extracellular Vesicle Release in Atherosclerosis via NF-κB-Caspase-4/5-GSDM-D Pathway

Background: Pyroptosis, an inflammatory cell death, is involved in the progression of atherosclerosis. Pyroptosis in endothelial cells (ECs) and its underlying mechanisms in atherosclerosis are poorly understood. Here, we investigated the role of a caspase-4/5-NF-κB pathway in pyroptosis in palmitic acid (PA)-stimulated ECs and EVs as players in pyroptosis. Methods: Human umbilical vein endothelial cells (HUVECs) were cultured in an endothelial cell medium, treated with Ox-LDL, PA, caspase-4/5 inhibitor, NF-κB inhibitor, and sEV release inhibitor for 24 h, respectively. The cytotoxicity of PA was determined using an MTT assay, cell migration using a scratch-wound-healing assay, cell morphology using bright field microscopy, and lipid deposition using oil red O staining. The mRNA and protein expression of GSDM-D, CASP4, CASP5, NF-κB, NLRP3, IL-1β, and IL-18 were determined with RT-PCR and Western blot. Immunofluorescence was used to determine NLRP3 and ICAM-1 expressions. Extracellular vesicles (EVs) were isolated using an exosome isolation kit and were characterized by Western blot and scanning electron microscopy. Results: PA stimulation significantly changed the morphology of the HUVECs characterized by cell swelling, plasma membrane rupture, and increased LDH release, which are features of pyroptosis. PA significantly increased lipid accumulation and reduced cell migration. PA also triggered inflammation and endothelial dysfunction, as evidenced by NLRP3 activation, upregulation of ICAM-1 (endothelial activation marker), and pyroptotic markers (NLRP3, GSDM-D, IL-1β, IL-18). Inhibition of caspase-4/5 (Ac-FLTD-CMK) and NF-κB (trifluoroacetate salt (TFA)) resulted in a significant reduction in LDH release and expression of caspase-4/5, NF-κB, and gasdermin D (GSDM-D) in PA-treated HUVECs. Furthermore, GW4869, an exosome release inhibitor, markedly reduced LDH release in PA-stimulated HUVECs. EVs derived from PA-treated HUVECs exacerbated pyroptosis, as indicated by significantly increased LDH release and augmented expression of GSDM-D, NF-κB. Conclusions: The present study revealed that inflammatory, non-canonical caspase-4/5-NF-κB signaling may be one of the crucial mechanistic pathways associated with pyroptosis in ECs, and pyroptotic EVs facilitated pyroptosis in normal ECs during atherosclerosis.

Regulation of ferroptosis in osteoarthritis and osteoarthritic chondrocytes by typical MicroRNAs in chondrocytes

Osteoarthritis (OA) is a progressive degenerative disorder impacting bones and joints, worsened by chronic inflammation, immune dysregulation, mechanical stress, metabolic disturbances, and various other contributing factors. The complex interplay of cartilage damage, loss, and impaired repair mechanisms remains a critical and formidable aspect of OA pathogenesis. At the genetic level, multiple genes have been implicated in the modulation of chondrocyte metabolism, displaying both promotive and inhibitory roles. Recent research has increasingly focused on the influence of non-coding RNAs in the regulation of distinct cell types within bone tissue in OA. In particular, an expanding body of evidence highlights the regulatory roles of microRNAs in OA chondrocytes. This review aims to consolidate the most relevant microRNAs associated with OA chondrocytes, as identified in recent studies, and to elucidate their involvement in chondrocyte metabolic processes and ferroptosis. Furthermore, this study explores the complex regulatory interactions between long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs) in OA, with an emphasis on microRNA-mediated mechanisms. Finally, critical gaps in the current research are identified, offering strategic insights to advance the understanding of OA pathophysiology and guide therapeutic developments in this field.

Overview of pyroptosis mechanism and in-depth analysis of cardiomyocyte pyroptosis mediated by NF-κB pathway in heart failure

The pyroptosis of cardiomyocytes has become an essential topic in heart failure research. The abnormal accumulation of these biological factors, including angiotensin II, advanced glycation end products, and various growth factors (such as connective tissue growth factor, vascular endothelial growth factor, transforming growth factor beta, among others), activates the nuclear factor-κB (NF-κB) signaling pathway in cardiovascular diseases, ultimately leading to pyroptosis of cardiomyocytes. Therefore, exploring the underlying molecular biological mechanisms is essential for developing novel drugs and therapeutic strategies. However, our current understanding of the precise regulatory mechanism of this complex signaling pathway in cardiomyocyte pyroptosis is still limited. Given this, this study reviews the milestone discoveries in the field of pyroptosis research since 1986, analyzes in detail the similarities, differences, and interactions between pyroptosis and other cell death modes (such as apoptosis, necroptosis, autophagy, and ferroptosis), and explores the deep connection between pyroptosis and heart failure. At the same time, it depicts in detail the complete pathway of the activation, transmission, and eventual cardiomyocyte pyroptosis of the NF-κB signaling pathway in the process of heart failure. In addition, the study also systematically summarizes various therapeutic approaches that can inhibit NF-κB to reduce cardiomyocyte pyroptosis, including drugs, natural compounds, small molecule inhibitors, gene editing, and other cutting-edge technologies, aiming to provide solid scientific support and new research perspectives for the prevention and treatment of heart failure.

Contribution of PKS+ Escherichia coli to colon carcinogenesis through the inhibition of exosomal miR-885-5p

Objectives

About 90 % of all colorectal cancer (CRC) fatalities are caused by the metastatic spread of primary tumors, which is closely correlated with patient survival and spreads by circulating tumor cells (CTCs). The epithelial-mesenchymal transition (EMT) that characterizes CTCs is associated with a poor prognosis. Organotropic metastasis is dictated by the transmission of miRNAs by cancer-derived exosomes. The purpose of this research is to examine PKS + E's function. Coli in CRC metastases and exosomal miR-885-5p suppression.

Methods

A cohort of 100 patients (50 CRC, 50 healthy) underwent colonoscopy screenings from February 2018 to August 2021. Exosomes were isolated using ultracentrifugation, and exosomal miRNA was analyzed using sequencing and qPCR.

Results

Among the patients, 40 tested positive for E. coli (12 CRC, 23 healthy). Serotyping revealed that 68.57 % harbored the PKS gene. Exosomal miR-885-5p levels were significantly altered in CRC patients with PKS + E. coli. Intriguingly, our findings indicate that exosomes derived from EMT-CRC cells did not affect miR-885-5p synthesis in HUVECs. Moreover, we observed that the levels of miR-885-5p in both exosomes and the total CRC-conditioned medium were comparable upon isolation of exosomes from CRC cells. What's more, an increased expression of miR-558-5p within the tumors, and the group that received exosome treatment, as well as the EMT-HCT116 group, exhibited a higher occurrence of distant metastasis.

Conclusion

PKS + E. By inhibiting exosomal miR-885-5p, coli is linked to CRC metastases, offering a possible target for therapeutic intervention.

The role of extracellular vesicles in pyroptosis-mediated infectious and non-infectious diseases

Pyroptosis, a lytic and pro-inflammatory cell death, is important in various pathophysiological processes. Host- and bacteria-derived extracellular vesicles (EVs), as natural nanocarriers messengers, are versatile mediators of intercellular communication between different types of cells. Recently, emerging research has suggested that EVs exhibit multifaceted roles in disease progression by manipulating pyroptosis. This review focuses on new findings concerning how EVs shape disease progression in infectious and non-infectious diseases by regulating pyroptosis. Understanding the characteristics and activity of EVs-mediated pyroptotic death may conducive to the discovery of novel mechanisms and more efficient therapeutic targets in infectious and non-infectious diseases.

The Protective Effects of Ruscogenin Against Lipopolysaccharide-Induced Myocardial Injury in Septic Mice

ABSTRACT

Sepsis-induced myocardial dysfunction commonly occurs in individuals with sepsis and is a severe complication with high morbidity and mortality rates. This study aimed to investigate the effects and potential mechanisms of the natural steroidal sapogenin ruscogenin (RUS) against lipopolysaccharide (LPS)-induced myocardial injury in septic mice. We found that RUS effectively alleviated myocardial pathological damage, normalized cardiac function, and increased survival in septic mice. RNA sequencing demonstrated that RUS administration significantly inhibited the activation of the NOD-like receptor signaling pathway in the myocardial tissues of septic mice. Subsequent experiments further confirmed that RUS suppressed myocardial inflammation and pyroptosis during sepsis. In addition, cultured HL-1 cardiomyocytes were challenged with LPS, and we observed that RUS could protect these cells against LPS-induced cytotoxicity by suppressing inflammation and pyroptosis. Notably, both the in vivo and in vitro findings indicated that RUS inhibited NOD-like receptor protein-3 (NLRP3) upregulation in cardiomyocytes stimulated with LPS. As expected, knockdown of NLRP3 blocked the LPS-induced activation of inflammation and pyroptosis in HL-1 cells. Furthermore, the cardioprotective effects of RUS on HL-1 cells under LPS stimulation were abolished by the novel NLRP3 agonist BMS-986299. Taken together, our results suggest that RUS can alleviate myocardial injury during sepsis, at least in part by suppressing NLRP3-mediated inflammation and pyroptosis, highlighting the potential of this molecule as a promising candidate for sepsis-induced myocardial dysfunction therapy.

Exosome-Derived microRNA: Potential Target for Diagnosis and Treatment of Sepsis

Exosome-derived microRNAs (miRNAs) are emerging as pivotal players in the pathophysiology of sepsis, representing a new frontier in both the diagnosis and treatment of this complex condition. Sepsis, a severe systemic response to infection, involves intricate immune and nonimmune mechanisms, where exosome-mediated communication can significantly influence disease progression and outcomes. During the progress of sepsis, the miRNA profile of exosomes undergoes notable alterations, is reflecting, and may affect the progression of the disease. This review comprehensively explores the biology of exosome-derived miRNAs, which originate from both immune cells (such as macrophages and dendritic cells) and nonimmune cells (such as endothelial and epithelial cells) and play a dynamic role in modulating pathways that affect the course of sepsis, including those related to inflammation, immune response, cell survival, and apoptosis. Taking into account these dynamic changes, we further discuss the potential of exosome-derived miRNAs as biomarkers for the early detection and prognosis of sepsis and advantages over traditional biomarkers due to their stability and specificity. Furthermore, this review evaluates exosome-based therapeutic miRNA delivery systems in sepsis, which may pave the way for targeted modulation of the septic response and personalized treatment options.

Exosomes based strategies for cardiovascular diseases: Opportunities and challenges

Exosomes, as nanoscale extracellular vesicles (EVs), are secreted by all types of cells to facilitate intercellular communication in living organisms. After being taken up by neighboring or distant cells, exosomes can alter the expression levels of target genes in recipient cells and thereby affect their pathophysiological outcomes depending on payloads encapsulated therein. The functions and mechanisms of exosomes in cardiovascular diseases have attracted much attention in recent years and are thought to have cardioprotective and regenerative potential. This review summarizes the biogenesis and molecular contents of exosomes and details the roles played by exosomes released from various cells in the progression and recovery of cardiovascular disease. The review also discusses the current status of traditional exosomes in cardiovascular tissue engineering and regenerative medicine, pointing out several limitations in their application. It emphasizes that some of the existing emerging industrial or bioengineering technologies are promising to compensate for these shortcomings, and the combined application of exosomes and biomaterials provides an opportunity for mutual enhancement of their performance. The integration of exosome-based cell-free diagnostic and therapeutic options will contribute to the further development of cardiovascular regenerative medicine.

Overexpression of Homeobox A1 Relieves Ovalbumin-Induced Asthma in Mice and Is Associated with Blocking of the NF-κB Signaling Pathway

Homeobox A1 (HOXA1) is a protein coding gene involved in regulating immunity signaling. This study aims to explore the function and mechanism of HOXA1 in asthma. An asthma mouse model was established via ovalbumin (OVA) induction. Airway hyperresponsiveness was evaluated by the value of pause enhancement (Penh). Inflammatory cells in bronchoalveolar lavage fluid (BALF) were detected by Trypan blue and Wright staining. The pathological morphology of lung tissues was assessed by H&E staining. The IgE and inflammatory biomarkers (IL-1β, IL-6, IL-17, and TNF-α) in BALF and lung tissues were measured by ELISA. Western blot was performed to detect the expression of NF-κB pathway-related proteins. HOXA1 was down-regulated in OVA-induced asthmatic mice. Overexpression of HOXA1 decreased Penh and relieved pathological injury of lung tissues in OVA-induced mice. Overexpression of HOXA1 also reduced the numbers of total cells, leukocytes, eosinophils, neutrophils, macrophages, and lymphocytes, as well as the levels of IgE, IL-1β, IL-6, IL-17, and TNF-α in BALF of OVA-induced mice. The inflammatory biomarkers were also decreased in lung tissues by HOXA1 overexpression. In addition, HOXA1 overexpression blocked the NF-κB signaling pathway in OVA-induced mice. Overexpression of HOXA1 relieved OVA-induced asthma in female mice, which is associated with the blocking of the NF-κB signaling pathway.

Role of toll-like receptor-mediated pyroptosis in sepsis-induced cardiomyopathy

Sepsis, a life-threatening dysregulated status of the host response to infection, can cause multiorgan dysfunction and mortality. Sepsis places a heavy burden on the cardiovascular system due to the pathological imbalance of hyperinflammation and immune suppression. Myocardial injury and cardiac dysfunction caused by the aberrant host responses to pathogens can lead to cardiomyopathy, one of the most critical complications of sepsis. However, many questions about the specific mechanisms and characteristics of this complication remain to be answered. The causes of sepsis-induced cardiac dysfunction include abnormal cardiac perfusion, myocardial inhibitory substances, autonomic dysfunction, mitochondrial dysfunction, and calcium homeostasis dysregulation. The fight between the host and pathogens acts as the trigger for sepsis-induced cardiomyopathy. Pyroptosis, a form of programmed cell death, plays a critical role in the progress of sepsis. Toll-like receptors (TLRs) act as pattern recognition receptors and participate in innate immune pathways that recognize damage-associated molecular patterns as well as pathogen-associated molecular patterns to mediate pyroptosis. Notably, pyroptosis is tightly associated with cardiac dysfunction in sepsis and septic shock. In line with these observations, induction of TLR-mediated pyroptosis may be a promising therapeutic approach to treat sepsis-induced cardiomyopathy. This review focuses on the potential roles of TLR-mediated pyroptosis in sepsis-induced cardiomyopathy, to shed light on this promising therapeutic approach, thus helping to prevent and control septic shock caused by cardiovascular disorders and improve the prognosis of sepsis patients.

NLRP3 inflammasome involves in the pathophysiology of sepsis-induced myocardial dysfunction by multiple mechanisms

Sepsis-induced myocardial dysfunction (SIMD) is one of the serious health-affecting problems worldwide. At present, the mechanisms of SIMD are still not clearly elucidated. The NOD-like receptor protein 3 (NLRP3) inflammasome has been assumed to be involved in the pathophysiology of SIMD by regulating multiple biological processes. NLRP3 inflammasome and its related signaling pathways might affect the regulation of inflammation, autophagy, apoptosis, and pyroptosis in SIMD. A few molecular specific inhibitors of NLRP3 inflammasome (e.g., Melatonin, Ulinastatin, Irisin, Nifuroxazide, and Ginsenoside Rg1, etc.) have been developed, which showed a promising anti-inflammatory effect in a cellular or animal model of SIMD. These experimental findings indicated that NLRP3 inflammasome could be a promising therapeutic target for SIMD treatment. However, the clinical translation of NLRP3 inhibitors for treating SIMD still requires robust in vivo and preclinical trials.

Unraveling the Intricate Roles of Exosomes in Cardiovascular Diseases: A Comprehensive Review of Physiological Significance and Pathological Implications

Exosomes, as potent intercellular communication tools, have garnered significant attention due to their unique cargo-carrying capabilities, which enable them to influence diverse physiological and pathological functions. Extensive research has illuminated the biogenesis, secretion, and functions of exosomes. These vesicles are secreted by cells in different states, exerting either protective or harmful biological functions. Emerging evidence highlights their role in cardiovascular disease (CVD) by mediating comprehensive interactions among diverse cell types. This review delves into the significant impacts of exosomes on CVD under stress and disease conditions, including coronary artery disease (CAD), myocardial infarction, heart failure, and other cardiomyopathies. Focusing on the cellular signaling and mechanisms, we explore how exosomes mediate multifaceted interactions, particularly contributing to endothelial dysfunction, oxidative stress, and apoptosis in CVD pathogenesis. Additionally, exosomes show great promise as biomarkers, reflecting differential expressions of NcRNAs (miRNAs, lncRNAs, and circRNAs), and as therapeutic carriers for targeted CVD treatment. However, the specific regulatory mechanisms governing exosomes in CVD remain incomplete, necessitating further exploration of their characteristics and roles in various CVD-related contexts. This comprehensive review aims to provide novel insights into the biological implications of exosomes in CVD and offer innovative perspectives on the diagnosis and treatment of CVD.

Therapeutic Potential of EVs: Targeting Cardiovascular Diseases

Due to their different biological functions, extracellular vesicles (EVs) have great potential from a therapeutic point of view. They are released by all cell types, carrying and delivering different kinds of biologically functional cargo. Under pathological events, cells can increase their secretion of EVs and can release different amounts of cargo, thus making EVs great biomarkers as indicators of pathological progression. Moreover, EVs are also known to be able to transport and deliver cargo to different recipient cells, having an important role in cellular communication. Interestingly, EVs have recently been explored as biological alternatives for the delivery of therapeutics, being considered natural drug delivery carriers. Because cardiovascular disorders (CVDs) are the leading cause of death worldwide, in this review, we will discuss the up-to-date knowledge regarding the biophysical properties and biological components of EVs, focusing on myocardial infarction, diabetic cardiomyopathy, and sepsis-induced cardiomyopathy, three very different types of CVDs.

VX-765 inhibits pyroptosis and reduces inflammation to prevent acute liver failure by upregulating PPARα expression

INTRODUCTION AND OBJECTIVES

As a fatal clinical syndrome, acute liver failure (ALF) is characterized by overwhelming liver inflammation and hepatic cell death. Finding new therapeutic methods has been a challenge in ALF research. VX-765 is a known pyroptosis inhibitor and has been reported to prevent damage in a variety of diseases by reducing inflammation. However, the role of VX-765 in ALF is still unclear.

MATERIALS AND METHODS

ALF model mice were treated with D-galactosamine (D-GalN) and lipopolysaccharide (LPS). LO2 cells were stimulated with LPS. Thirty subjects were enrolled in clinical experiments. The levels of inflammatory cytokines, pyroptosis-associated proteins and peroxisome proliferator-activated receptor α (PPARα) were detected using quantitative reverse transcription-polymerase chain reaction (qRT‒PCR), western blotting and immunohistochemistry. An automatic biochemical analyzer was used to determine the serum aminotransferase enzyme levels. Hematoxylin and eosin (HE) staining was used to observe the pathological features of the liver.

RESULTS

With the progression of ALF, the expression levels of interleukin (IL) -1β, IL-18, caspase-1, and serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were increased. VX-765 could reduce the mortality rate of ALF mice, relieve liver pathological damage, and reduce inflammatory responses to protect against ALF. Further experiments showed that VX-765 could protect against ALF through PPARα, and this protective effect against ALF was reduced in the context of PPARα inhibition.

CONCLUSIONS

As ALF progresses, inflammatory responses and pyroptosis deteriorate gradually. VX-765 can inhibit pyroptosis and reduce inflammatory responses to protect against ALF by upregulating PPARα expression, thus providing a possible therapeutic strategy for ALF.

Recombinant human angiotensin-converting enzyme 2 plays a protective role in mice with sepsis-induced cardiac dysfunction through multiple signaling pathways dependent on converting angiotensin II to angiotensin 1-7

Background

Sepsis-induced cardiac dysfunction (SICD) is a common complication of sepsis and contributes to mortality and the complexity of management in patients with sepsis. Recombinant human angiotensin-converting enzyme 2 (rhACE2) has been reported to protect the heart from injury and dysfunction in conditions which involve increased angiotensin II (Ang II). In this study, we aimed to detect the effects of rhACE2 on SICD.

Methods

A SICD model was developed in male C57/B6 mice by lipopolysaccharide (LPS) intraperitoneal injection. When cardiac dysfunction was confirmed by echocardiography 3 hours after LPS administration, mice were treated with either saline, rhACE2, or rhACE2 + A779. All mice received echocardiographic examination at 6 hours after LPS injection and then were sacrificed for serum and myocardial tissues collection. Angiotensin, cardiac troponin I (cTnI), and inflammatory markers in serum were measured. Histopathology features were examined by hematoxylin and eosin (HE) and terminal deoxynucleotidyl transferase (TdT) dUTP nick-end labeling (TUNEL) staining to evaluate structure injury and cell pyroptosis rate in heart tissue respectively. Pyroptosis-related proteins and signaling pathways involved in nucleotide binding and oligomerization domain-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome activation in heart tissue were investigated by western blot (WB).

Results

RhACE2 relieved myocardial injury and improved cardiac function in mice with SICD accompanied by decrease of Ang II and increase of angiotensin 1-7 (Ang 1-7) in serum. RhACE2 diminished activation of NLRP3 inflammasome, inflammatory response, and cell pyroptosis induced by LPS. In addition, rhACE2 partly inhibited activation of nuclear factor κB (NF-κB), the p38 mitogen-activated protein kinase (MAPK) pathway, and promoted activation of the AMP-activated protein kinase-α1 (AMPK-α1) pathway in heart tissue. Administration of A779 offset the inhibitive effects of rhACE2 on NLRP3 expression and protective role on cardiac injury and dysfunction in mice with SICD.

Conclusions

RhACE2 plays a protective role in SICD, ameliorating cardiac injury and dysfunction through NF-κB, p38 MAPK, and the AMPK-α1/NLRP3 inflammasome pathway dependent on converting Ang II to Ang 1-7.

Inhibition of Schwann Cell Pyroptosis Promotes Nerve Regeneration in Peripheral Nerve Injury in Rats

Background

Peripheral nerve injury (PNI) is one of the most debilitating injuries, but therapies for PNI are still far from satisfactory. Pyroptosis, a recently identified form of cell death, has been demonstrated to participate in different diseases. However, the role of pyroptosis of Schwann cells in PNI remains unclear.

Methods

We established a rat PNI model, and western blotting, transmission electron microscopy, and immunofluorescence staining were used to confirm pyroptosis of Schwann cells in PNI in vivo. In vitro, pyroptosis of Schwann cells was induced by lipopolysaccharides (LPS)+adenosine triphosphate disodium (ATP). An irreversible inhibitor of pyroptosis, acetyl (Ac)-Tyr-Val-Ala-Asp-chloromethyl ketone (Ac-YVAD-cmk), was used to attenuate Schwann cell pyroptosis. Moreover, the influence of pyroptotic Schwann cells on the function of dorsal root ganglion neurons (DRGns) was analyzed by a coculture system. Finally, the rat PNI model was intraperitoneally treated with Ac-YVAD-cmk to observe the effect of pyroptosis on nerve regeneration and motor function.

Results

Schwann cell pyroptosis was notably observed in the injured sciatic nerve. LPS+ATP treatment effectively induced Schwann cell pyroptosis, which was largely attenuated by Ac-YVAD-cmk. Additionally, pyroptotic Schwann cells inhibited the function of DRGns by secreting inflammatory factors. A decrease in pyroptosis in Schwann cells promoted regeneration of the sciatic nerve and recovery of motor function in rats.

Conclusion

Given the role of Schwann cell pyroptosis in PNI progression, inhibition of Schwann cell pyroptosis might be a potential therapeutic strategy for PNI in the future.

Research Progress on the Mechanism of Sepsis Induced Myocardial Injury

Sepsis is an abnormal condition with multiple organ dysfunctions caused by the uncontrolled infection response and one of the major diseases that seriously hang over global human health. Besides, sepsis is characterized by high morbidity and mortality, especially in intensive care unit (ICU). Among the numerous subsequent organ injuries of sepsis, myocardial injury is one of the most common complications and the main cause of death in septic patients. To better manage septic inpatients, it is necessary to understand the specific mechanisms of sepsis induced myocardial injury (SIMI). Therefore, this review will elucidate the pathophysiology of SIMI from the following certain mechanisms: apoptosis, mitochondrial damage, autophagy, excessive inflammatory response, oxidative stress and pyroptosis, and outline current therapeutic strategies and potential approaches in SIMI.