LncRNA GAS5 inhibits NLRP3 inflammasome activation-mediated pyroptosis in diabetic cardiomyopathy by targeting miR-34b-3p/AHR

The mechanism and promising therapeutic strategy of diabetic cardiomyopathy dysfunctions: Focus on pyroptosis

Diabetes is a major risk factor for cardiovascular diseases, and myocardial damage caused by hyperglycemia is the main cause of heart failure. However, there is still a lack of systematic understanding of myocardial damage caused by diabetes. At present, we believe that the cellular inflammatory damage caused by hyperglycemia is one of the causes of diabetic cardiomyopathy. Pyroptosis, as a proinflammatory form of cell death, is closely related to the occurrence and development of diabetic cardiomyopathy. Therefore, this paper focuses on the important role of inflammation in the occurrence and development of diabetic cardiomyopathy. From the perspective of pyroptosis, we summarize the pyroptosis of different types of cells in diabetic cardiomyopathy and its related signaling pathways. It also summarizes the treatment of diabetic cardiomyopathy, hoping to provide methods for the prevention and treatment of diabetic cardiomyopathy by inhibiting pyroptosis.

Exploring 2-Sulfonylpyrimidine Warheads as Acrylamide Surrogates for Targeted Covalent Inhibition: A BTK Story

Targeted covalent inhibitors (TCIs) directing cysteine have historically relied on a narrow set of electrophilic "warheads". While Michael acceptors remain at the forefront of TCI design strategies, they show variable stability and selectivity under physiological conditions. Here, we show that the 2-sulfonylpyrimidine motif is an effective replacement for the acrylamide warhead of Ibrutinib, for the inhibition of Bruton's tyrosine kinase. In a few iterations, we discovered new derivatives, which inhibit BTK both in vitro and in cellulo at low nanomolar concentrations, on par with Ibrutinib. Several derivatives also displayed good plasma stability and reduced off-target binding in vitro across 135 tyrosine kinases. This proof-of-concept study on a well-studied kinase/TCI system highlights the 2-sulfonylpyrimidine group as a useful acrylamide replacement. In the future, it will be interesting to investigate its wider potential for developing TCIs with improved pharmacologies and selectivity profiles across structurally related protein families.

Epigenetic regulation of diverse regulated cell death modalities in cardiovascular disease: Insights into necroptosis, pyroptosis, ferroptosis, and cuproptosis

Cell death constitutes a critical component of the pathophysiology of cardiovascular diseases. A growing array of non-apoptotic forms of regulated cell death (RCD)-such as necroptosis, ferroptosis, pyroptosis, and cuproptosis-has been identified and is intimately linked to various cardiovascular conditions. These forms of RCD are governed by genetically programmed mechanisms within the cell, with epigenetic modifications being a common and crucial regulatory method. Such modifications include DNA methylation, RNA methylation, histone methylation, histone acetylation, and non-coding RNAs. This review recaps the roles of DNA methylation, RNA methylation, histone modifications, and non-coding RNAs in cardiovascular diseases, as well as the mechanisms by which epigenetic modifications regulate key proteins involved in cell death. Furthermore, we systematically catalog the existing epigenetic pharmacological agents targeting novel forms of RCD and their mechanisms of action in cardiovascular diseases. This article aims to underscore the pivotal role of epigenetic modifications in precisely regulating specific pathways of novel RCD in cardiovascular diseases, thus offering potential new therapeutic avenues that may prove more effective and safer than traditional treatments.

Molecular Basis of Cardiomyopathies in Type 2 Diabetes

Diabetic cardiomyopathy (DbCM) is a common complication in individuals with type 2 diabetes mellitus (T2DM), and its exact pathogenesis is still debated. It was hypothesized that chronic hyperglycemia and insulin resistance activate critical cellular pathways that are responsible for numerous functional and anatomical perturbations in the heart. Interstitial inflammation, oxidative stress, myocardial apoptosis, mitochondria dysfunction, defective cardiac metabolism, cardiac remodeling, hypertrophy and fibrosis with consequent impaired contractility are the most common mechanisms implicated. Epigenetic changes also have an emerging role in the regulation of these crucial pathways. The aim of this review was to highlight the increasing knowledge on the molecular mechanisms of DbCM and the new therapies targeting specific pathways.

Mesenchymal stem cells ameliorate inflammation and pyroptosis in diabetic cardiomyopathy via the miRNA-223-3p/NLRP3 pathway

BACKGROUND

Diabetic cardiomyopathy (DCM) stands as the primary cause of heart failure and mortality among patients with diabetes. Nevertheless, conventional treatment approaches are limited in their ability to effectively prevent myocardial tissue damage itself. Mesenchymal stem cell (MSC) therapy exhibits immense potential for treating DCM; however, the precise mechanisms involved in regulating inflammatory responses and pyroptosis processes, an emerging form of cellular death, within myocardial cells remain elusive. Hence, it is imperative to further elucidate the precise underlying mechanisms to facilitate the clinical implementation of MSC therapy.

METHODS

In vivo, we established a DCM mouse model by administering streptozotocin and fed the mice a high-glucose and high-fat diet, followed by MSC therapy. Cardiac function and myocardial injury were evaluated through echocardiography and histological analysis. Furthermore, the levels of inflammation and pyroptosis were assessed using ELISA, Western blotting, and qRT-PCR. In vitro experiments involved inducing H9C2 myocardial cell damage with high glucose treatment, followed by coculture with MSCs to investigate their role in modulating inflammation and pyroptosis mechanisms.

RESULTS

MSCs can maintain cardiac function and alleviate myocardial injury in mice with DCM. Moreover, they effectively suppress the activation of NLRP3 and reduce the release of inflammatory factors (such as IL-1β and ROS), thereby further downregulating the expression of pyroptosis-related proteins including NLRP3, Caspase-1, and GSDMD. Additionally, we experimentally validated that MSCs exert their therapeutic effects by promoting the expression of miR-223-3p in cardiac myocytes; however, this effect can be reversed by an miR-223-3p inhibitor.

CONCLUSION

MSCs effectively mitigate the release of inflammatory factors and cell lysis caused by pyroptosis through the regulation of the miR-223-3p/NLRP3 pathway, thereby safeguarding cardiomyocytes against damage in DCM. This mechanism establishes a novel theoretical foundation for the clinical treatment of cardiac conditions utilizing MSCs.

The study of the mechanism of non-coding RNA regulation of programmed cell death in diabetic cardiomyopathy

Diabetic cardiomyopathy (DCM) represents a distinct myocardial disorder elicited by diabetes mellitus, characterized by aberrations in myocardial function and structural integrity. This pathological condition predominantly manifests in individuals with diabetes who do not have concurrent coronary artery disease or hypertension. An escalating body of scientific evidence substantiates the pivotal role of programmed cell death (PCD)-encompassing apoptosis, autophagy, pyroptosis, ferroptosis, and necroptosis-in the pathogenic progression of DCM, thereby emerging as a prospective therapeutic target. Additionally, numerous non-coding RNAs (ncRNAs) have been empirically verified to modulate the biological processes underlying programmed cell death, consequently influencing the evolution of DCM. This review systematically encapsulates prevalent types of PCD manifest in DCM as well as nascent discoveries regarding the regulatory influence of ncRNAs on programmed cell death in the pathogenesis of DCM, with the aim of furnishing novel insights for the furtherance of research in PCD-associated disorders relevant to DCM.

Epigenetics in diabetic cardiomyopathy

Diabetic cardiomyopathy (DCM) is a critical complication that poses a significant threat to the health of patients with diabetes. The intricate pathological mechanisms of DCM cause diastolic dysfunction, followed by impaired systolic function in the late stages. Accumulating researches have revealed the association between DCM and various epigenetic regulatory mechanisms, including DNA methylation, histone modifications, non-coding RNAs, and other epigenetic molecules. Recently, a profound understanding of epigenetics in the pathophysiology of DCM has been broadened owing to advanced high-throughput technologies, which assist in developing potential therapeutic strategies. In this review, we briefly introduce the epigenetics regulation and update the relevant progress in DCM. We propose the role of epigenetic factors and non-coding RNAs (ncRNAs) as potential biomarkers and drugs in DCM diagnosis and treatment, providing a new perspective and understanding of epigenomics in DCM.

LncRNA GAS5 restrains ISO-induced cardiac fibrosis by modulating mir-217 regulation of SIRT1

Considering the effect of SIRT1 on improving myocardial fibrosis and GAS5 inhibiting occurrence and development of myocardial fibrosis at the cellular level, the aim of the present study was to investigate whether LncRNA GAS5 could attenuate cardiac fibrosis through regulating mir-217/SIRT1, and whether the NLRP3 inflammasome activation was involved in this process. Isoprenaline (ISO) was given subcutaneously to the male C57BL/6 mice to induce myocardial fibrosis and the AAV9 vectors were randomly injected into the left ventricle of each mouse to overexpress GAS5. Primary myocardial fibroblasts (MCFs) derived from neonatal C57BL/6 mice and TGF-β1 were used to induce fibrosis. And the GAS5 overexpressed MCFs were treated with mir-217 mimics and mir-217 inhibitor respectively. Then the assays of expression levels of NLRP3, Caspase-1, IL-1β and SIRT1 were conducted. The findings indicated that the overexpression of GAS5 reduced the expression levels of collagen, NLRP3, Capase-1, IL-1β and SIRT1 in ISO treated mice and TGF-β1 treated MCFs. However, this effect was significantly weakened after mir-217 overexpression, but was further enhanced after knockdown of mir-217. mir-217 down-regulates the expression of SIRT1, leading to increased activation of the NLRP3 inflammasome and subsequent pyroptosis. LncRNA GAS5 alleviates cardiac fibrosis induced via regulating mir-217/SIRT1 pathway.

LncRNA and mRNA expression characteristic and bioinformatic analysis in myocardium of diabetic cardiomyopathy mice

BACKGROUND

Diabetic cardiomyopathy (DCM) is becoming a very well-known clinical entity and leads to increased heart failure in diabetic patients. Long non-coding RNAs (LncRNAs) play an important role in the pathogenesis of DCM. In the present study, the expression profiles of lncRNAs and mRNAs were illuminated in myocardium from DCM mice, with purpose of exploring probable pathological processes of DCM involved by differentially expressed genes in order to provide a new direction for the future researches of DCM.

RESULTS

The results showed that a total of 93 differentially expressed lncRNA transcripts and 881 mRNA transcripts were aberrantly expressed in db/db mice compared with the controls. The top 6 differentially expressed lncRNAs like up-regulated Hmga1b, Gm8909, Gm50252 and down-regulated Msantd4, 4933413J09Rik, Gm41414 have not yet been reported in DCM. The lncRNAs-mRNAs co-expression network analysis showed that LncRNA 2610507I01Rik, 2310015A16Rik, Gm10503, A930015D03Rik and Gm48483 were the most relevant to differentially expressed mRNAs.

CONCLUSION

Our results showed that db/db DCM mice exist differentially expressed lncRNAs and mRNAs in hearts. These differentially expressed lncRNAs may be involved in the pathological process of cardiomyocyte apoptosis and fibrosis in DCM.

The role of ncRNAs-mediated pyroptosis in diabetes and its vascular complications

Over the past decade, the prevalence of diabetes has increased significantly worldwide, leading to an increase in vascular complications of diabetes (VCD), such as diabetic cardiomyopathy (DCM), diabetic nephropathy (DN), and diabetic retinopathy (DR). Noncoding RNAs (ncRNAs), such as microRNAs (miRNAs), long Noncoding RNAs (lncRNAs), and circular RNAs (circRNAs), play a key role in cellular processes, including the pathophysiology of diabetes and VCD via pyroptosis. ncRNAs (e.g., miR-17, lnc-MEG3, and lnc-KCNQ1OT1) can regulate pyroptosis in pancreatic β cells. Some ncRNAs are involved in VCD progression. For example, miR-21, lnc-KCNQ1OT1, lnc-GAS5, and lnc-MALAT1 were reported in DN and DCM, and lnc-MIAT was identified in DCM and DR. Herein, this review aimed to summarize recent research findings related to ncRNAs-mediated pyroptosis at the onset and progression of diabetes and VCD.

Roles of lncRNAs in NF-κB-Mediated Macrophage Inflammation and Their Implications in the Pathogenesis of Human Diseases

Over the past century, molecular biology's focus has transitioned from proteins to DNA, and now to RNA. Once considered merely a genetic information carrier, RNA is now recognized as both a vital element in early cellular life and a regulator in complex organisms. Long noncoding RNAs (lncRNAs), which are over 200 bases long but do not code for proteins, play roles in gene expression regulation and signal transduction by inducing epigenetic changes or interacting with various proteins and RNAs. These interactions exhibit a range of functions in various cell types, including macrophages. Notably, some macrophage lncRNAs influence the activation of NF-κB, a crucial transcription factor governing immune and inflammatory responses. Macrophage NF-κB is instrumental in the progression of various pathological conditions including sepsis, atherosclerosis, cancer, autoimmune disorders, and hypersensitivity. It orchestrates gene expression related to immune responses, inflammation, cell survival, and proliferation. Consequently, its malfunction is a key contributor to the onset and development of these diseases. This review aims to summarize the function of lncRNAs in regulating NF-κB activity in macrophage activation and inflammation, with a particular emphasis on their relevance to human diseases and their potential as therapeutic targets. The insights gained from studies on macrophage lncRNAs, as discussed in this review, could provide valuable knowledge for the development of treatments for various pathological conditions involving macrophages.

LncRNA as a regulator in the development of diabetic complications

Diabetes is a metabolic disease characterized by hyperglycemia, which induces the production of AGEs, ROS, inflammatory cytokines, and growth factors, leading to the formation of vascular dysfunction and target organ damage, promoting the development of diabetic complications. Diabetic nephropathy, retinopathy, and cardiomyopathy are common complications of diabetes, which are major contributors to disability and death in people with diabetes. Long non-coding RNAs affect gene transcription, mRNA stability, and translation efficiency to influence gene expression for a variety of biological functions. Over the past decade, it has been demonstrated that dysregulated long non-coding RNAs are extensively engaged in the pathogenesis of many diseases, including diabetic complications. Thus, this review discusses the regulations of long non-coding RNAs on the primary pathogenesis of diabetic complications (oxidative stress, inflammation, fibrosis, and microvascular dysfunction), and some of these long non-coding RNAs may function as potential biomarkers or therapeutic targets for diabetic complications.

Pyroptosis: Mechanisms and links with diabetic cardiomyopathy

Diabetes mellitus (DM) is a chronic metabolic disease characterized by hyperglycaemia that seriously affects human health. Diabetic cardiomyopathy (DCM) is a major cardiovascular complication and one of the main causes of death in patients with DM. Although DCM attracts great attention, and new therapeutic methods are continuously developed, there is a lack of effective treatment strategies. Therefore, exploring and targeting new signalling pathways related to the evolution of DCM becomes a hotspot and difficulty in the prevention and treatment of DCM. Pyroptosis is a newly discovered regulated cell death that is heavily dependent on the formation of plasma membrane pores by members of the gasdermin protein family and is reported to be involved in the occurrence, development, and pathogenesis of DCM. In this review, we focus on the molecular mechanisms of pyroptosis, its involvement in the relevant signalling pathways of DCM, and potential pyroptosis-targeting therapeutic strategies for the treatment of DCM. Our review provides new insights into the use of pyroptosis as a useful tool for the prevention and treatment of DCM and clarifies future research directions.

Role of pyroptosis in diabetic cardiomyopathy: an updated review

Diabetic cardiomyopathy (DCM), one of the common complications of diabetes, presents as a specific cardiomyopathy with anomalies in the structure and function of the heart. With the increasing prevalence of diabetes, DCM has a high morbidity and mortality worldwide. Recent studies have found that pyroptosis, as a programmed cell death accompanied by an inflammatory response, exacerbates the growth and genesis of DCM. These studies provide a theoretical basis for exploring the potential treatment of DCM. Therefore, this review aims to summarise the possible mechanisms by which pyroptosis promotes the development of DCM as well as the relevant studies targeting pyroptosis for the possible treatment of DCM, focusing on the molecular mechanisms of NLRP3 inflammasome-mediated pyroptosis, different cellular pyroptosis pathways associated with DCM, the effects of pyroptosis occurring in different cells on DCM, and the relevant drugs targeting NLRP3 inflammasome/pyroptosis for the treatment of DCM. This review might provide a fresh perspective and foundation for the development of therapeutic agents for DCM.

The anti-diabetic effects of metformin are mediated by regulating long non-coding RNA

Type 2 diabetes (T2D) is a metabolic disease with complex etiology and mechanisms. Long non-coding ribonucleic acid (LncRNA) is a novel class of functional long RNA molecules that regulate multiple biological functions through various mechanisms. Studies in the past decade have shown that lncRNAs may play an important role in regulating insulin resistance and the progression of T2D. As a widely used biguanide drug, metformin has been used for glucose lowering effects in clinical practice for more than 60 years. For diabetic therapy, metformin reduces glucose absorption from the intestines, lowers hepatic gluconeogenesis, reduces inflammation, and improves insulin sensitivity. However, despite being widely used as the first-line oral antidiabetic drug, its mechanism of action remains largely elusive. Currently, an increasing number of studies have demonstrated that the anti-diabetic effects of metformin were mediated by the regulation of lncRNAs. Metformin-regulated lncRNAs have been shown to participate in the inhibition of gluconeogenesis, regulation of lipid metabolism, and be anti-inflammatory. Thus, this review focuses on the mechanisms of action of metformin in regulating lncRNAs in diabetes, including pathways altered by metformin via targeting lncRNAs, and the potential targets of metformin through modulation of lncRNAs. Knowledge of the mechanisms of lncRNA modulation by metformin in diabetes will aid the development of new therapeutic drugs for T2D in the future.

Dynamic relationship between the aryl hydrocarbon receptor and long noncoding RNA balances cellular and toxicological responses

The aryl hydrocarbon receptor (AhR) is a cytosolic transcription factor activated by endogenous ligands and xenobiotic chemicals. Once the AhR is activated, it translocates to the nucleus, dimerizes with the AhR nuclear translator (ARNT) and binds to xenobiotic response elements (XRE) to promote gene transcription, notably the cytochrome P450 CYP1A1. The AhR not only mediates the toxic effects of environmental chemicals, but also has numerous putative physiological functions. This dichotomy in AhR biology may be related to reciprocal regulation of long non-coding RNA (lncRNA). lncRNA are defined as transcripts more than 200 nucleotides in length that do not encode a protein but are implicated in many physiological processes such as cell differentiation, cell proliferation, and apoptosis. lncRNA are also linked to disease pathogenesis, particularly the development of cancer. Recent studies have revealed that AhR activation by environmental chemicals affects the expression and function of lncRNA. In this article, we provide an overview of AhR signaling pathways activated by diverse ligands and highlight key differences in the putative biological versus toxicological response of AhR activation. We also detail the functions of lncRNA and provide current data on their regulation by the AhR. Finally, we outline how overlap in function between AhR and lncRNA may be one way in which AhR can be both a regulator of endogenous functions but also a mediator of toxicological responses to environmental chemicals. Overall, more research is still needed to fully understand the dynamic interplay between the AhR and lncRNA.

Endoplasmic reticulum stress: molecular mechanism and therapeutic targets

The endoplasmic reticulum (ER) functions as a quality-control organelle for protein homeostasis, or "proteostasis". The protein quality control systems involve ER-associated degradation, protein chaperons, and autophagy. ER stress is activated when proteostasis is broken with an accumulation of misfolded and unfolded proteins in the ER. ER stress activates an adaptive unfolded protein response to restore proteostasis by initiating protein kinase R-like ER kinase, activating transcription factor 6, and inositol requiring enzyme 1. ER stress is multifaceted, and acts on aspects at the epigenetic level, including transcription and protein processing. Accumulated data indicates its key role in protein homeostasis and other diverse functions involved in various ocular diseases, such as glaucoma, diabetic retinopathy, age-related macular degeneration, retinitis pigmentosa, achromatopsia, cataracts, ocular tumors, ocular surface diseases, and myopia. This review summarizes the molecular mechanisms underlying the aforementioned ocular diseases from an ER stress perspective. Drugs (chemicals, neurotrophic factors, and nanoparticles), gene therapy, and stem cell therapy are used to treat ocular diseases by alleviating ER stress. We delineate the advancement of therapy targeting ER stress to provide new treatment strategies for ocular diseases.

Effects of non-coding RNAs and RNA-binding proteins on mitochondrial dysfunction in diabetic cardiomyopathy

Vascular complications are the main cause of diabetes mellitus-associated morbidity and mortality. Oxidative stress and metabolic dysfunction underly injury to the vascular endothelium and myocardium, resulting in diabetic angiopathy and cardiomyopathy. Mitochondrial dysfunction has been shown to play an important role in cardiomyopathic disruptions of key cellular functions, including energy metabolism and oxidative balance. Both non-coding RNAs and RNA-binding proteins are implicated in diabetic cardiomyopathy, however, their impact on mitochondrial dysfunction in the context of this disease is largely unknown. Elucidating the effects of non-coding RNAs and RNA-binding proteins on mitochondrial pathways in diabetic cardiomyopathy would allow further insights into the pathophysiological mechanisms underlying diabetic vascular complications and could facilitate the development of new therapeutic strategies. Stem cell-based models can facilitate the study of non-coding RNAs and RNA-binding proteins and their unique characteristics make them a promising tool to improve our understanding of mitochondrial dysfunction and vascular complications in diabetes.

MALAT1/miR-185-5p mediated high glucose-induced oxidative stress, mitochondrial injury and cardiomyocyte apoptosis via the RhoA/ROCK pathway

To explore the underlying mechanism of lncRNA MALAT1 in the pathogenesis of diabetic cardiomyopathy (DCM). DCM models were confirmed in db/db mice. MiRNAs in myocardium were detected by miRNA sequencing. The interactions of miR-185-5p with MALAT1 and RhoA were validated by dual-luciferase reporter assays. Primary neonatal cardiomyocytes were cultured with 5.5 or 30 mmol/L D-glucose (HG) in the presence or absence of MALAT1-shRNA and fasudil, a ROCK inhibitor. MALAT1 and miR-185-5p expression were determined by real-time quantitative PCR. The apoptotic cardiomyocytes were evaluated using flow cytometry and TUNEL staining. SOD activity and MDA contents were measured. The ROCK activity, phosphorylation of Drp1S616 , mitofusin 2 and apoptosis-related proteins were analysed by Western blotting. Mitochondrial membrane potential was examined by JC-1. MALAT1 was significantly up-regulated while miR-185-5p was down-regulated in myocardium of db/db mice and HG-induced cardiomyocytes. MALAT1 regulated RhoA/ROCK pathway via sponging miR-185-5p in cardiomyocytes in HG. Knockdown of MALAT1 and fasudil all inhibited HG-induced oxidative stress, and alleviated imbalance of mitochondrial dynamics and mitochondrial dysfunction, accompanied by reduced cardiomyocyte apoptosis. MALAT1 activated the RhoA/ROCK pathway via sponging miR-185-5p and mediated HG-induced oxidative stress, mitochondrial damage and apoptosis of cardiomyocytes in mice.

circACTA2 inhibits NLRP3 inflammasome-mediated inflammation via interacting with NF-κB in vascular smooth muscle cells

circACTA2 derived from the smooth muscle α-actin gene plays an important role in the regulation of vascular smooth muscle cell (VSMC) phenotype. The activation of NLRP3 inflammasome is involved in VSMC phenotypic switching. However, the mechanistic relationship between circACTA2 and NLRP3 inflammasome during vascular remodeling remains poorly understood. Here, we showed that circACTA2 was down-regulated in human intimal hyperplasia. circACTA2 overexpression in circACTA2 transgenic mice significantly decreased the neointimal hyperplasia induced by vascular injury, which is concomitant with a decrease in IL-18, IL-1β, TNF-α, and IL-6 levels. Gain- and loss-of-function studies revealed that circACTA2 alleviated VSMC inflammation by suppressing the activation of NLRP3 inflammasome. Mechanistically, circACTA2 inhibited the expression of NF-κB p65 and p50 subunits and interacted with p50, which impedes the formation of the p50/p65 heterodimer and nuclear translocation induced by TNF-α, thus resulting in the suppression of NLRP3 gene transcription and inflammasome activation. Furthermore, circACTA2 overexpression mitigated inflammation via repressing NLRP3 inflammasome-mediated VSMC pyroptosis. Importantly, employing a decoy oligonucleotide to compete with circACTA2 for binding to p50 could attenuate the expression of NLRP3, ASC, and caspase-1. These findings provide a novel insight into the functional roles of circACTA2 in VSMCs, and targeting the circACTA2-NF-κB-NLRP3 axis represents a promising therapeutic strategy for vascular remodeling.

The role of lncRNA-mediated pyroptosis in cardiovascular diseases

Cardiovascular disease (CVD) is the leading cause of death worldwide. Pyroptosis is a unique kind of programmed cell death that varies from apoptosis and necrosis morphologically, mechanistically, and pathophysiologically. Long non-coding RNAs (LncRNAs) are thought to be promising biomarkers and therapeutic targets for the diagnosis and treatment of a variety of diseases, including cardiovascular disease. Recent research has demonstrated that lncRNA-mediated pyroptosis has significance in CVD and that pyroptosis-related lncRNAs may be potential targets for the prevention and treatment of specific CVDs such as diabetic cardiomyopathy (DCM), atherosclerosis (AS), and myocardial infarction (MI). In this paper, we collected previous research on lncRNA-mediated pyroptosis and investigated its pathophysiological significance in several cardiovascular illnesses. Interestingly, certain cardiovascular disease models and therapeutic medications are also under the control of lncRNa-mediated pyroptosis regulation, which may aid in the identification of new diagnostic and therapy targets. The discovery of pyroptosis-related lncRNAs is critical for understanding the etiology of CVD and may lead to novel targets and strategies for prevention and therapy.

MALAT1 knockdown alleviates the pyroptosis of microglias in diabetic cerebral ischemia via regulating STAT1 mediated NLRP3 transcription

BACKGROUND

Dysregulated long non-coding RNAs participate in the development of diabetic cerebral ischemia. This study aimed to investigate the underlying mechanism of lncRNA MALAT1 in diabetic cerebral ischemia.

METHOD

Middle cerebral artery occlusion (MCAO) was performed to establish diabetic cerebral I/R in vivo. TTC and neurological deficits assessment were performed to assess cerebral ischemic injury. LDH was conducted to detect cytotoxicity. RT-qPCR and western blotting assays were applied to determine mRNA and protein expression. Flow cytometry was performed to detect the pyroptosis of BV2 cells. Immunofluorescence and FISH were conducted for subcellular localization of MALAT1 and STAT1. ELISA was performed to determine cytokine release. Dual luciferase reporter, RIP, and ChIP assays were used to validate the interaction between STAT1 and MALAT1/NLRP3. Diabetes aggravated cerebral injury in vivo and in vitro. Diabetic cerebral ischemia induced inflammatory response and inflammation-induced cell pyroptosis.

RESULT

MALAT1 was overexpressed in diabetic cerebral ischemia models in vivo and in vitro. However, knockdown of MALAT1 suppressed inflammatory response and the pyroptosis of BV2 cells. Moreover, MALAT1 interacted with STAT1 to transcriptionally activate NLRP3. Knockdown of STAT1 significantly reversed the effects of MALAT1. Furthermore, STAT1 promotes the MALAT1 transcription. MALAT1 interacts with STAT1 to promote the pyroptosis of microglias induced by diabetic cerebral ischemia through activating NLRP3 transcription.

CONCLUSION

Thus, knockdown of MALAT1 may be a potential promising therapy target for diabetic cerebral ischemia.

Targeting epigenetics in diabetic cardiomyopathy: Therapeutic potential of flavonoids

The pathophysiological mechanisms of diabetic cardiomyopathy have been extensively studied, but there is still a lack of effective prevention and treatment methods. The ability of flavonoids to protect the heart from diabetic cardiomyopathy has been extensively described. In recent years, epigenetics has received increasing attention from scholars in exploring the etiology and treatment of diabetes and its complications. DNA methylation, histone modifications and non-coding RNAs play key functions in the development, maintenance and progression of diabetic cardiomyopathy. Hence, prevention or reversal of the epigenetic alterations that have occurred during the development of diabetic cardiomyopathy may alleviate the personal and social burden of the disease. Flavonoids can be used as natural epigenetic modulators in alternative therapies for diabetic cardiomyopathy. In this review, we discuss the epigenetic effects of different flavonoid subtypes in diabetic cardiomyopathy and summarize the evidence from preclinical and clinical studies that already exist. However, limited research is available on the potential beneficial effects of flavonoids on the epigenetics of diabetic cardiomyopathy. In the future, clinical trials in which different flavonoids exert their antidiabetic and cardioprotective effects through various epigenetic mechanisms should be further explored.

Transcriptomic profiling of miR-203a inhibitor and miR-34b-injected zebrafish (Danio rerio) validates oil-induced neurological, cardiovascular and eye toxicity response pathways

The global sequencing of microRNA (miRNA; miR) and integration to downstream mRNA expression profiles in early life stages (ELS) of fish following exposure to crude oil determined consistently dysregulated miRNAs regardless of the oil source or fish species. The overlay of differentially expressed miRNAs and mRNAs into in silico software determined that the key roles of these miRNAs were predicted to be involved in cardiovascular, neurological and visually-mediated pathways. Of these, altered expression of miRNAs, miR-203a and miR-34b were predicted to be primary targets of crude oil. To better characterize the effect of these miRNAs to downstream transcript changes, zebrafish embryos were microinjected at 1 h post fertilization (hpf) with either a miR-203a inhibitor or miR-34b. Since both miRs have been shown to be associated with aryl hydrocarbon receptor (AhR) function, benzo(a)pyrene (BaP), a potent AhR agonist, was used as a potential positive control. Transcriptomic profiling was conducted on injected and exposed larvae at 7 and 72 hpf, and eye morphology assessed following exposure at 72 hpf. The top predicted physiological system disease and functions between differentially expressed genes (DEGs) shared with miR-203a inhibitor-injected and miR-34b-injected embryos were involved in brain formation, and the development of the central nervous system and neurons. When DEGs of miR-203a inhibitor-injected embryos were compared with BaP-exposed DEGs, alterations in nervous system development and function, and abnormal morphology of the neurosensory retina, eye and nervous tissue were predicted, consistent with both AhR and non-AhR pathways. When assessed morphologically, the eye area of miR-203a inhibitor and miR-34b-injected and BaP-exposed embryos were significantly reduced. These results suggest that miR-203a inhibition and miR-34b overexpression contribute to neurological, cardiovascular and eye toxicity responses that are caused by oil and PAH exposure in ELS fish, and are likely mediated through both AhR and non-AhR pathways.

Unveiling the Vital Role of Long Non-Coding RNAs in Cardiac Oxidative Stress, Cell Death, and Fibrosis in Diabetic Cardiomyopathy

Diabetes mellitus is a burdensome public health problem. Diabetic cardiomyopathy (DCM) is a major cause of mortality and morbidity in diabetes patients. The pathogenesis of DCM is multifactorial and involves metabolic abnormalities, the accumulation of advanced glycation end products, myocardial cell death, oxidative stress, inflammation, microangiopathy, and cardiac fibrosis. Evidence suggests that various types of cardiomyocyte death act simultaneously as terminal pathways in DCM. Long non-coding RNAs (lncRNAs) are a class of RNA transcripts with lengths greater than 200 nucleotides and no apparent coding potential. Emerging studies have shown the critical role of lncRNAs in the pathogenesis of DCM, along with the development of molecular biology technologies. Therefore, we summarize specific lncRNAs that mainly regulate multiple modes of cardiomyopathy death, oxidative stress, and cardiac fibrosis and provide valuable insights into diagnostic and therapeutic biomarkers and strategies for DCM.

Targeting Pyroptosis: New Insights into the Treatment of Diabetic Microvascular Complications

Pyroptosis is an inflammatory form of programmed cell death that is dependent on inflammatory caspases, leading to the cleavage of gasdermin D (GSDMD) and increased secretion of interleukin (IL)-1β and IL-18. Recent studies have reported that hyperglycemia-induced cellular stress stimulates pyroptosis, and different signaling pathways have been shown to play crucial roles in regulating pyroptosis. This review summarized and discussed the molecular mechanisms, regulation, and cellular effects of pyroptosis in diabetic microvascular complications, such as diabetic nephropathy, diabetic retinopathy, and diabetic cardiomyopathy. In addition, this review aimed to provide new insights into identifying better treatments for diabetic microvascular complications.

The Role of NLRP3 Inflammasome in Diabetic Cardiomyopathy and Its Therapeutic Implications

Diabetic cardiomyopathy (DCM) is a serious complication of diabetes mellitus (DM). However, the precise molecular mechanisms remain largely unclear, and it is still a challenging disease to diagnose and treat. The nucleotide-binding oligomerization domain and leucine-rich repeat pyrin 3 domain (NLRP3) inflammasome is a critical part of the innate immune system in the host to defend against endogenous danger and pathogenic microbial infections. Dysregulated NLRP3 inflammasome activation results in the overproduction of cytokines, primarily IL-1β and IL-18, and eventually, inflammatory cell death-pyroptosis. A series of studies have indicated that NLRP3 inflammasome activation participates in the development of DCM, and that corresponding interventions could mitigate disease progression. Accordingly, this narrative review is aimed at briefly summarizing the cell-specific role of the NLRP3 inflammasome in DCM and provides novel insights into developing DCM therapeutic strategies targeting the NLRP3 inflammasome.

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

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

Non-coding RNAs to regulate cardiomyocyte proliferation: A new trend in therapeutic cardiac regeneration

Cardiovascular diseases remain the leading cause of death worldwide, particularly ischemic heart disease (IHD). It is also classified as incurable given the irreversible damage it causes to cardiomyocytes. Thus, myocardial tissue rejuvenation following ischemia is one of the global primary research concerns for scientists. Interestingly, the mammalian heart thrives after an injury during the embryonic or neonatal period; however, this ability disappears with increasing age. Previous studies have found that specific non-coding (nc) RNAs play a pivotal role in this process. Hence, the review herein summarizes the research on cardiomyocyte regenerative medicine in recent years and sets forth the biological functions and mechanisms of the micro (mi)RNA, long non-coding (lnc)RNA, and circular (circ)RNA in the posttranscriptional regulation of cardiomyocytes. In addition, this review summarizes the roles of ncRNAs in specific species while enumerating potential therapeutic strategies for myocardial infarction.

Potential diabetic cardiomyopathy therapies targeting pyroptosis: A mini review

Pyroptosis is primarily considered a pro-inflammatory class of caspase-1- and gasdermin D (GSDMD)-dependent programmed cell death. Inflammasome activation promotes the maturation and release of interleukin (IL)-1β and IL-18, cleavage of GSDMD, and development of pyroptosis. Recent studies have reported that NLRP3 inflammasome activation-mediated pyroptosis aggravates the formation and development of diabetes cardiomyopathy (DCM). These studies provide theoretical mechanisms for exploring a novel approach to treat DCM-associated cardiac dysfunction. Accordingly, this review aims to summarize studies that investigated possible DCM therapies targeting pyroptosis and elucidate the molecular mechanisms underlying NLRP3 inflammasome-mediated pyroptosis, and its potential association with the pathogenesis of DCM. This review may serve as a basis for the development of potential pharmacological agents as novel and effective treatments for managing and treating DCM.

Perspectives for Forkhead box transcription factors in diabetic cardiomyopathy: Their therapeutic potential and possible effects of salvianolic acids

Diabetic cardiomyopathy (DCM) is the primary cause of morbidity and mortality in diabetic cardiovascular complications, which initially manifests as cardiac hypertrophy, myocardial fibrosis, dysfunctional remodeling, and diastolic dysfunction, followed by systolic dysfunction, and eventually end with acute heart failure. Molecular mechanisms underlying these pathological changes in diabetic hearts are complicated and multifactorial, including but not limited to insulin resistance, oxidative stress, lipotoxicity, cardiomyocytes apoptosis or autophagy, inflammatory response, and myocardial metabolic dysfunction. With the development of molecular biology technology, accumulating evidence illustrates that members of the class O of Forkhead box (FoxO) transcription factors are vital for maintaining cardiomyocyte metabolism and cell survival, and the functions of the FoxO family proteins can be modulated by a wide variety of post-translational modifications including phosphorylation, acetylation, ubiquitination, arginine methylation, and O-glycosylation. In this review, we highlight and summarize the most recent advances in two members of the FoxO family (predominately FoxO1 and FoxO3a) that are abundantly expressed in cardiac tissue and whose levels of gene and protein expressions change as DCM progresses, with the goal of providing valuable insights into the pathogenesis of diabetic cardiovascular complications and discussing their therapeutic potential and possible effects of salvianolic acids, a natural product.

Non-coding RNAs in necroptosis, pyroptosis, and ferroptosis in cardiovascular diseases

Accumulating evidence has proved that non-coding RNAs (ncRNAs) play a critical role in the genetic programming and gene regulation of cardiovascular diseases (CVDs). Cardiovascular disease morbidity and mortality are rising and have become a primary public health issue that requires immediate resolution through effective intervention. Numerous studies have revealed that new types of cell death, such as pyroptosis, necroptosis, and ferroptosis, play critical cellular roles in CVD progression. It is worth noting that ncRNAs are critical novel regulators of cardiovascular risk factors and cell functions by mediating pyroptosis, necroptosis, and ferroptosis. Thus, ncRNAs can be regarded as promising therapeutic targets for treating and diagnosing cardiovascular diseases. Recently, there has been a surge of interest in the mediation of ncRNAs on three types of cell death in regulating tissue homeostasis and pathophysiological conditions in CVDs. Although our understanding of ncRNAs remains in its infancy, the studies reviewed here may provide important new insights into how ncRNAs interact with CVDs. This review summarizes what is known about the functions of ncRNAs in modulating cell death-associated CVDs and their role in CVDs, as well as their current limitations and future prospects.

Histone demethylase KDM3C regulates the lncRNA GAS5-miR-495-3p-PHF8 axis in cardiac hypertrophy

Cardiac hypertrophy (CH) is a pathological phenotype of cardiomyopathy. Epigenetic modification is a mechanism associated with CH. Our study here investigated the histone demethylase KDM3C in relation to epigenetic regulation in CH. We found that KDM3C mRNA silencing alleviated CH, as evidenced by reduced ANP, BNP, and β-MHC mRNAs, increased α-MHC mRNA, decreased cell surface area, and reduced cellular protein/DNA ratios. Specifically, KDM3C upregulated miR-200c-3p expression through demethylation of H3K9me2, leading to enhanced binding of miR-200c-3p to GAS5 and suppression of GAS5 expression; these effects then led to reduced binding of GAS5 to miR-495-3p, increased miR-495-3p expression, and repression of PHF8 transcription. Through these mechanisms, our data indicate that KDM3C-dependent epigenetic modification promotes CH.

Effect of berberine on global modulation of lncRNAs and mRNAs expression profiles in patients with stable coronary heart disease

BACKGROUND

Berberine (BBR) is an isoquinoline alkaloid found in the Berberis species. It was found to have protected effects in cardiovascular diseases. Here, we investigated the effect the regulatory function of long noncoding RNAs (lncRNAs) during the treatment of stable coronary heart disease (CHD) using BBR. We performed microarray analyses to identify differentially expressed (DE) lncRNAs and mRNAs between whole blood samples from 5 patients with stable CHD taking BBR and 5 no BBR volunteers. DE lncRNAs and mRNAs were validated by quantitative real-time PCR.

RESULTS

A total of 1703 DE lncRNAs and 912 DE mRNAs were identified. Kyoto Encyclopedia of Genes and Genomes pathway analysis indicated DE mRNAs might be associated with mammalian target of rapamycin and mitogen-activated protein kinase pathway. These pathways may be involved in the healing process after CHD. To study the relationship between mRNAs encoding transcription factors (DNA damage inducible transcript 3, sal-like protein 4 and estrogen receptor alpha gene) and CHD related de mRNAs, we performed protein and protein interaction analysis on their corresponding proteins. AKT and apoptosis pathway were significant enriched in protein and protein interaction network. BBR may affect downstream apoptosis pathways through DNA damage inducible transcript 3, sal-like protein 4 and estrogen receptor alpha gene. Growth arrest-specific transcript 5 might regulate CHD-related mRNAs through competing endogenous RNA mechanism and may be the downstream target gene regulated by BBR. Verified by the quantitative real-time PCR, we identified 8 DE lncRNAs that may relate to CHD. We performed coding and non-coding co-expression and competing endogenous RNA mechanism analysis of these 8 DE lncRNAs and CHD-related DE mRNA, and predicted their subcellular localization and N6-methyladenosine modification sites.

CONCLUSION

Our research found that BBR may affect mammalian target of rapamycin, mitogen-activated protein kinase, apoptosis pathway and growth arrest-specific transcript 5 in the process of CHD. These pathways may be involved in the healing process after CHD. Our research might provide novel insights for functional research of BBR.

Targeting NLRP3 Inflammasome With Nrf2 Inducers in Central Nervous System Disorders

The NLRP3 inflammasome is an intracellular multiprotein complex that plays an essential role in the innate immune system by identifying and eliminating a plethora of endogenous and exogenous threats to the host. Upon activation of the NLRP3 complex, pro-inflammatory cytokines are processed and released. Furthermore, activation of the NLRP3 inflammasome complex can induce pyroptotic cell death, thereby propagating the inflammatory response. The aberrant activity and detrimental effects of NLRP3 inflammasome activation have been associated with cardiovascular, neurodegenerative, metabolic, and inflammatory diseases. Therefore, clinical strategies targeting the inhibition of the self-propelled NLRP3 inflammasome activation are required. The transcription factor Nrf2 regulates cellular stress response, controlling the redox equilibrium, metabolic programming, and inflammation. The Nrf2 pathway participates in anti-oxidative, cytoprotective, and anti-inflammatory activities. This prominent regulator, through pharmacologic activation, could provide a therapeutic strategy for the diseases to the etiology and pathogenesis of which NLRP3 inflammasome contributes. In this review, current knowledge on NLRP3 inflammasome activation and Nrf2 pathways is presented; the relationship between NLRP3 inflammasome signaling and Nrf2 pathway, as well as the pre/clinical use of Nrf2 activators against NLRP3 inflammasome activation in disorders of the central nervous system, are thoroughly described. Cumulative evidence points out therapeutic use of Nrf2 activators against NLRP3 inflammasome activation or diseases that NLRP3 inflammasome contributes to would be advantageous to prevent inflammatory conditions; however, the side effects of these molecules should be kept in mind before applying them to clinical practice.

Pyroptosis-Induced Inflammation and Tissue Damage

Programmed cell deaths are pathways involving cells playing an active role in their own destruction. Depending on the signaling system of the process, programmed cell death can be divided into two categories, pro-inflammatory and non-inflammatory. Pyroptosis is a pro-inflammatory form of programmed cell death. Upon cell death, a plethora of cytokines are released and trigger a cascade of responses from the neighboring cells. The pyroptosis process is a double-edged sword, could be both beneficial and detrimental in various inflammatory disorders and disease conditions. A physiological outcome of these responses is tissue damage, and sometimes death of the host. In this review, we focus on the inflammatory response triggered by pyroptosis, and resulting tissue damage in selected organs.

CD74 ablation rescues type 2 diabetes mellitus-induced cardiac remodeling and contractile dysfunction through pyroptosis-evoked regulation of ferroptosis

Type 2 diabetes mellitus (T2D) contributes to sustained inflammation and myopathic changes in the heart although the precise interplay between the two remains largely unknown. This study evaluated the impact of deficiency in CD74, the cognate receptor for the regulatory cytokine macrophage migration inhibitory factor (MIF), in T2D-induced cardiac remodeling and functional responses, and cell death domains involved. WT and CD74-/- mice were fed a high fat diet (60% calorie from fat) for 8 weeks prior to injection of streptozotocin (STZ, 35 mg/kg, i.p., 3 consecutive days) and were maintained for another 8 weeks. KEGG analysis for differentially expressed genes (DEGs) reported gene ontology term related to ferroptosis in T2D mouse hearts. T2D patients displayed elevated plasma MIF levels. Murine T2D exerted overt global metabolic derangements, cardiac remodeling, contractile dysfunction, apoptosis, pyroptosis, ferroptosis and mitochondrial dysfunction, ablation of CD74 attenuated T2D-induced cardiac remodeling, contractile dysfunction, various forms of cell death and mitochondrial defects without affecting global metabolic defects. CD74 ablation rescued T2D-evoked NLRP3-Caspase1 activation and oxidative stress but not dampened autophagy. In vitro evidence depicted that high glucose/high fat (HGHF) compromised cardiomyocyte function and promoted lipid peroxidation, the effects were ablated by inhibitors of NLRP3, pyroptosis, and ferroptosis but not by the mitochondrial targeted antioxidant mitoQ. Recombinant MIF mimicked HGHF-induced lipid peroxidation, GSH depletion and ferroptosis, the effects of which were reversed by inhibitors of MIF, NLRP3 and pyroptosis. Taken together, these data suggest that CD74 ablation protects against T2D-induced cardiac remodeling and contractile dysfunction through NLRP3/pyroptosis-mediated regulation of ferroptosis.

Emerging Role of LncRNA Regulation for NLRP3 Inflammasome in Diabetes Complications

Diabetes is a widespread metabolic disease with various complications, including diabetic nephropathy, retinopathy, cardiomyopathy, and other cardiovascular or cerebrovascular diseases. As the prevalence of diabetes increases in all age groups worldwide, diabetes and its complications cause an emerging public health burden. NLRP3 inflammasome is a complex of several proteins that play a critical role in inflammatory response and various diseases, including diabetes and its complications. Accumulating evidences indicate that NLRP3 inflammasome contributes to the development of diabetes and diabetic complications and that NLRP3 inflammation inactivation is beneficial in treating these illnesses. Emerging evidences suggest the critical role of long non-coding RNAs (lncRNAs) in regulating NLRP3 inflammasome activity in various diseases. LncRNAs are non-coding RNAs exceeding 200 nucleotides in length. Its dysregulation has been linked to the development of diseases, including diabetes. Recently, growing evidences hint that regulating lncRNAs on NLRP3 inflammasome is critical in developing and progressing diabetes and diabetic complications. Here, we discuss the role of lncRNAs in regulating NLRP3 inflammasome as well as its participation in diabetes and diabetic complications, providing novel insights into developing future therapeutic approaches for diabetes.

Pyroptosis and Its Regulation in Diabetic Cardiomyopathy

Diabetic cardiomyopathy (DbCM) is a prevalent disease, characterized by contractile dysfunction and left ventricular hypertrophy. Patients with DbCM have high morbidity and mortality worldwide. Recent studies have identified that pyroptosis, a kind of cell death, could be induced by hyperglycemia involved in the formation of DbCM. This review summarizes the regulatory mechanisms of pyroptosis in DbCM, including NOD-like receptor3, AIM2 inflammasome, long non-coding RNAs, microRNAs, circular RNA, autophagy, and some drugs.

Novel Insights Into the Pathogenesis of Diabetic Cardiomyopathy and Pharmacological Strategies

Diabetic cardiomyopathy (DCM) is a severe complication of diabetes developed mainly in poorly controlled patients. In DCM, several clinical manifestations as well as cellular and molecular mechanisms contribute to its phenotype. The production of reactive oxygen species (ROS), chronic low-grade inflammation, mitochondrial dysfunction, autophagic flux inhibition, altered metabolism, dysfunctional insulin signaling, cardiomyocyte hypertrophy, cardiac fibrosis, and increased myocardial cell death are described as the cardinal features involved in the genesis and development of DCM. However, many of these features can be associated with broader cellular processes such as inflammatory signaling, mitochondrial alterations, and autophagic flux inhibition. In this review, these mechanisms are critically discussed, highlighting the latest evidence and their contribution to the pathogenesis of DCM and their potential as pharmacological targets.

The advanced glycation end-products (AGEs)/ROS/NLRP3 inflammasome axis contributes to delayed diabetic corneal wound healing and nerve regeneration

Diabetic keratopathy (DK) is an important diabetic complication at the ocular surface. Chronic low-grade inflammation mediated by the NLRP3 inflammasome promotes pathogenesis of diabetes and its complications. However, the effect of the NLRP3 inflammasome on DK pathogenesis remains elusive. Wild-type (WT) and Nlrp3 knockout (KO) C57 mice were used to establish a type I diabetes model by intraperitoneal injection of streptozotocin. The effect of the NLRP3 inflammasome on diabetic corneal wound healing and never regeneration was examined by a corneal epithelial abrasion model. Western blot, immunofluorescence staining, enzyme-linked immunosorbent assay (ELISA) and pharmacological treatment were performed to investigate the regulatory mechanism of advanced glycation end products (AGEs) on NLRP3 inflammasome activation and corneal wound healing in vivo. The cultured mouse corneal epithelial cells (TKE2) were used to evaluate the effect and mechanism of AGEs on NLRP3 inflammasome activation in vitro. We revealed that NLRP3 inflammasome-mediated inflammation and pyroptosis contributed to DK pathogenesis. Under physiological conditions, the NLRP3 inflammasome was required for corneal wound healing and nerve regeneration. However, under a diabetic scenario, sustained activation of the NLRP3 inflammasome resulted in postponed corneal wound healing and impaired nerve regeneration. Mechanistically, the accumulated AGEs promoted hyperactivation of the NLRP3 inflammasome through ROS production. Moreover, genetically and pharmacologically blocking the AGEs/ROS/NLRP3 inflammasome axis significantly expedited diabetic corneal epithelial wound closure and nerve regeneration. Our results revealed that AGEs-induced hyperactivation of the NLRP3 inflammasome resulted in delayed diabetic corneal wound healing and impaired nerve regeneration, which further highlighted the NLRP3 inflammasome as a promising target for DK treatment.

METTL14 suppresses pyroptosis and diabetic cardiomyopathy by downregulating TINCR lncRNA

N6-methyladenosine (m6A) is one of the most important epigenetic regulation of RNAs, such as lncRNAs. However, the underlying regulatory mechanism of m6A in diabetic cardiomyopathy (DCM) is very limited. In this study, we sought to define the role of METTL14-mediated m6A modification in pyroptosis and DCM progression. DCM rat model was established and qRT-PCR, western blot, and immunohistochemistry (IHC) were used to detect the expression of METTL14 and TINCR. Gain-and-loss functional experiments were performed to define the role of METTL14-TINCR-NLRP3 axis in pyroptosis and DCM. RNA pulldown and RNA immunoprecipitation (RIP) assays were carried out to verify the underlying interaction. Our results showed that pyroptosis was tightly involved in DCM progression. METTL14 was downregulated in cardiomyocytes and hear tissues of DCM rat tissues. Functionally, METTL14 suppressed pyroptosis and DCM via downregulating lncRNA TINCR, which further decreased the expression of key pyroptosis-related protein, NLRP3. Mechanistically, METTL14 increased m6A methylation level of TINCR gene, resulting in its downregulation. Moreover, the m6A reader protein YTHDF2 was essential for m6A methylation and mediated the degradation of TINCR. Finally, TINCR positively regulated NLRP3 by increasing its mRNA stability. To conclude, our work revealed the novel role of METTL14-mediated m6A methylation and lncRNA regulation in pyroptosis and DCM, which could help extend our understanding the epigenetic regulation of pyroptosis in DCM progression.

Non-coding RNA-based regulation of inflammation

Inflammation is a multifactorial process and various biological mechanisms and pathways participate in its development. The presence of inflammation is involved in pathogenesis of different diseases such as diabetes mellitus, cardiovascular diseases and even, cancer. Non-coding RNAs (ncRNAs) comprise large part of transcribed genome and their critical function in physiological and pathological conditions has been confirmed. The present review focuses on miRNAs, lncRNAs and circRNAs as ncRNAs and their potential functions in inflammation regulation and resolution. Pro-inflammatory and anti-inflammatory factors are regulated by miRNAs via binding to 3'-UTR or indirectly via affecting other pathways such as SIRT1 and NF-κB. LncRNAs display a similar function and they can also affect miRNAs via sponging in regulating levels of cytokines. CircRNAs mainly affect miRNAs and reduce their expression in regulating cytokine levels. Notably, exosomal ncRNAs have shown capacity in inflammation resolution. In addition to pre-clinical studies, clinical trials have examined role of ncRNAs in inflammation-mediated disease pathogenesis and cytokine regulation. The therapeutic targeting of ncRNAs using drugs and nucleic acids have been analyzed to reduce inflammation in disease therapy. Therefore, ncRNAs can serve as diagnostic, prognostic and therapeutic targets in inflammation-related diseases in pre-clinical and clinical backgrounds.

Preliminary evidence for the presence of multiple forms of cell death in diabetes cardiomyopathy

Diabetic mellitus (DM) is a common degenerative chronic metabolic disease often accompanied by severe cardiovascular complications (DCCs) as major causes of death in diabetic patients with diabetic cardiomyopathy (DCM) as the most common DCC. The metabolic disturbance in DCM generates the conditions/substrates and inducers/triggers and activates the signaling molecules and death executioners leading to cardiomyocyte death which accelerates the development of DCM and the degeneration of DCM to heart failure. Various forms of programmed active cell death including apoptosis, pyroptosis, autophagic cell death, autosis, necroptosis, ferroptosis and entosis have been identified and characterized in many types of cardiac disease. Evidence has also been obtained for the presence of multiple forms of cell death in DCM. Most importantly, published animal experiments have demonstrated that suppression of cardiomyocyte death of any forms yields tremendous protective effects on DCM. Herein, we provide the most updated data on the subject of cell death in DCM, critical analysis of published results focusing on the pathophysiological roles of cell death, and pertinent perspectives of future studies.

A bibliometric analysis of RNA methylation in diabetes mellitus and its complications from 2002 to 2022

BACKGROUND

RNA methylation has emerged as an active research field in diabetes mellitus (DM) and its complications, while few bibliometric analyses have been performed. We aimed to visualize the hotspots and trends using bibliometric analysis to provide a comprehensive and objective overview of the current search state in this field.

METHODS

The articles and reviews regarding RNA methylation in DM and its complications were from the Web of Science Core Collection. A retrospective bibliometric analysis and science mapping was performed using the CiteSpace software to plot the knowledge maps and predict the hotspots and trends.

RESULTS

Three hundred seventy-five qualified records were retrieved. The annual publications gradually increased over the past 20 years. These publications mainly came from 66 countries led by Canada and 423 institutions. Leiter and Sievenpiper were the most productive authors, and Jenkins ranked first in the cited authors. Diabetes Care was the most co-cited journal. The most common keywords were "Type 2 diabetes", "cardiovascular disease", "diabetes mellitus", and "n 6 methyladenosine". The extracted keywords mainly clustered in "beta-cell function", "type 2 diabetes", "diabetic nephropathy", "aging", and "n6-methyladenosine". N6-methyladenosine (m⁶A) in DM and its complications were the developing areas of study.

CONCLUSION

Studies on RNA methylation, especially m⁶A modification, are the current hotspots and the future trends in type 2 diabetes (T2D) and diabetic nephropathy (DN), as well as a frontier field for other complications of DM. Strengthening future cooperation and exchange between countries and institutions is strongly advisable to promote research developments in this field.

Oxytocin Protects Against Isoproterenol-Induced Cardiac Hypertrophy by Inhibiting PI3K/AKT Pathway via a lncRNA GAS5/miR-375-3p/KLF4-Dependent Mechanism

Cardiac hypertrophy is caused by cardiac volume or pressure overload conditions and ultimately leads to contractile dysfunction and heart failure. Oxytocin (OT), an endocrine nonapeptide, has been identified as a cardiovascular homeostatic hormone with anti-hypertrophic effects. However, the underlying mechanism remains elusive. In this study, we aimed to investigate the role and mechanism of OT in cardiac hypertrophy. The rats with cardiac hypertrophy induced by isoproterenol (ISO) were treated with or without oxytocin. Cardiac functional parameters were analyzed by echocardiography. The changes in cell surface area were observed using wheat germ agglutinin (WGA) or immunofluorescence staining. The expressions of cardiac hypertrophy markers (B-Natriuretic Peptide, BNP and β-myosin heavy chain, β-MHC), long non-coding RNA Growth (LcRNA) Arrest-Specific transcript 5 (lncRNA GAS5), miR-375-3p, and Kruppel-like factor 4 (Klf4) were detected by qRT-PCR. KLF4 protein and PI3K/AKT pathway related proteins were detected by Western blot. The interactions among lncRNA GAS5, miR-375-3p, and Klf4 were verified by dual-luciferase reporter assays. The findings showed that OT significantly attenuated cardiac hypertrophy, increased expressions of lncRNA GAS5 and KLF4, and decreased miR-375-3p expression. In vitro studies demonstrated that either knock-down of lncRNA GAS5 or Klf4, or over-expression of miR-375-3p blunted the anti-hypertrophic effects of OT. Moreover, down-regulation of lncRNA GAS5 promoted the expression of miR-375-3p and inhibited KLF4 expression. Similarly, over-expression of miR-375-3p decreased the expression of KLF4. Dual-luciferase reporter assays validated that lncRNA GAS5 could sponge miR-375-3p and Klf4 was a direct target gene of miR-375-3p. In addition, OT could inactivate PI3K/AKT pathway. The functional rescue experiments further identified OT regulated PI3K/AKT pathway through lncRNA GAS5/miR-375-3p/KLF4 axis. In summary, our study demonstrates that OT ameliorates cardiac hypertrophy by inhibiting PI3K/AKT pathway via lncRNA GAS5/miR-375-3p/KLF4 axis.

Silencing lncRNA GAS5 alleviates apoptosis and fibrosis in diabetic cardiomyopathy by targeting miR-26a/b-5p

BACKGROUND

LncRNA GAS5 is associated with high glucose-induced cardiomyocyte injury, but its role in diabetic cardiomyopathy (DCM) remains unclear.

METHODS

Mice were administered with streptozotocin to construct the diabetic model (DM). Primary mouse cardiomyocytes were isolated and treated with 30 mmol/L high glucose to mimic the diabetic condition in vitro. GAS5 expression was detected by quantitative reverse transcription polymerase chain reaction. The relationship between GAS5 and miR-26a/b-5p was determined by bioinformatic prediction, luciferase reporter assay and RNA immunoprecipitation assay. The cardiac function of diabetic mice was evaluated by two-dimensional echocardiography.

RESULTS

GAS5 was significantly upregulated in diabetic cardiomyopathy both in vitro and in vivo. GAS5 knockdown and miR-26a/b-5p overexpression not only effectively attenuated myocardial fibrosis of diabetic mice in vivo but also inhibited high glucose-induced cardiomyocyte injury in vitro. miR-26a/b-5p was identified as a target of GAS5. GAS5 knockdown efficiently attenuated myocardial fibrosis and high glucose-induced cardiomyocyte injury through negatively regulating miR-26a/b-p.

CONCLUSION

Our study showed that GAS5 promotes DCM progression by regulating miR-26a/b-5p, suggesting that GAS5 might be a potential therapeutic target for DCM.

Non-coding RNAs: The key regulators in NLRP3 inflammasome-mediated inflammatory diseases

Inflammasomes are multiprotein complexes responding to various microbes and endogenous danger signals, contributing to initiating the innate protective response of inflammatory diseases. NLRP3 inflammasome is a crucial regulator of pro-inflammatory cytokines (IL-1β and IL-18) production through activating caspase-1. Non-coding RNAs (ncRNAs) are a class of RNA transcripts lacking the ability to encode peptides or proteins. Its dysregulation leads to the development and progression of inflammation in diseases. Recently, accumulating evidence has indicated that NLRP3 inflammasome activation could be modulated by ncRNAs (lncRNAs, miRNAs, and circRNAs) in a variety of inflammatory diseases. This review focuses on the substantial role and function of ncRNAs in the NLRP3 inflammasome activation, providing novel insight for the future therapeutic approach of inflammatory diseases.