MD2 activation by direct AGE interaction drives inflammatory diabetic cardiomyopathy

Mechanism of ferroptosis in heart failure: The role of the RAGE/TLR4-JNK1/2 pathway in cardiomyocyte ferroptosis and intervention strategies

The ferroptosis of cardiomyocytes has been recognized as the core pathological mechanism of heart failure. During the evolution of cardiovascular diseases, the accumulation of angiotensin II and advanced glycation end products can lead to the excessive activation of the RAGE/TLR4-JNK1/2 pathway, which subsequently triggers ferritinophagy, clockophagy, and enhanced p53 activity, ultimately leading to cardiomyocyte ferroptosis. It is evident that deeply unraveling the specific mechanisms in this field and comprehensively evaluating potential drugs and therapeutic strategies targeting this pathway is crucial for improving the status of cardiomyocyte ferroptosis. However, our current understanding of this pathway's specific molecular biological mechanisms in the process of cardiomyocyte ferroptosis remains limited. In light of this, this paper first comprehensively reviews the historical context of ferroptosis research, compares the similarities and differences between ferroptosis and other standard modes of cell death, elucidates the core mechanisms of ferroptosis and its close connection with heart failure, aiming to establish a basic cognitive framework for readers on ferroptosis and its role in heart failure. Subsequently, the paper delves into the pivotal role of the RAGE/TLR4-JNK1/2 pathway in cardiomyocyte ferroptosis and its intricate molecular biological regulatory network. Furthermore, it systematically integrates various therapeutic approaches aimed at inhibiting RAGE, TLR4, and JNK1/2 activity to alleviate cardiomyocyte ferroptosis, encompassing RNA interference technology, gene knockout techniques, small molecule inhibitors, natural active ingredients, as well as traditional Chinese and Western medicines, with the ultimate goal of forging new avenues and strategies for the prevention and treatment of heart failure.

Chemical Food Safety in Europe Under the Spotlight: Principles, Regulatory Framework and Roadmap for Future Directions

Chemical food safety is a fundamental pillar of public health, regulatory governance, and economic stability, with far-reaching implications for human, animal, and environmental well-being. In the matter of chemicals in the food chain, the European Union (EU) has established one of the most sophisticated and robust regulatory frameworks to ensure food safety and balance consumer protection with scientific advancements and industry needs. This review provides a holistic analysis of the EU chemical food safety scenario, examining its regulatory framework, key risk assessment methodologies, and the roles of critical institutions involved in monitoring, enforcement, and policymaking. The new and evolving challenges of chemical food safety, including transparency, cumulative risk assessment, and emerging contaminants, were discussed. Special attention is given to major classes of chemical substances in food, their regulatory oversight, and the scientific principles guiding their assessment, as well as to the role of key actors, including regulatory agencies, official laboratories, and competent authorities. This work offers an updated and integrated analysis of chemical food safety in the EU, uniquely combining regulatory, scientific, and enforcement perspectives and providing a structured roadmap for future directions.

Discovery of c-Kit as a New Therapeutic Target in LPS-Induced Acute Lung Injury through Novel Phenylamide Derivative D9

Discovering effective anti-inflammatory drugs and targets is a critical research priority. Herein, 28 novel phenylamide derivatives were designed and synthesized. Compound D9 showed favorable anti-inflammatory activities in acute lung injury (ALI) and sepsis mouse models. The target of D9 was predicted and studied, and c-Kit was identified by surface plasmon resonance (SPR) and cellular thermal shift assay (CETSA), which demonstrated high selectivity in kinase activity profiling. It was further verified that c-Kit participated in the LPS-induced inflammatory response in J774A.1, RAW264.7, MPMs, and lung tissue. Additionally, c-Kit is proved to be essential for LPS-induced activation of the NF-κB pathway. Finally, c-Kit was confirmed as a therapeutic target in the LPS-induced ALI with c-Kit gene knockdown and was further verified as the target of D9. Notably, there has been no report of c-Kit's influence on the LPS-induced inflammatory response. Therefore, c-Kit was identified as a new therapeutic target for the LPS-induced ALI.

Ferroptosis: a potential therapeutic target in cardio-cerebrovascular diseases

Cardio-cerebrovascular diseases (CCVDs) are the leading cause of global mortality, yet effective treatment options remain limited. Ferroptosis, a novel form of regulated cell death, has emerged as a critical player in various CCVDs, including atherosclerosis, myocardial infarction, ischemia-reperfusion injury, cardiomyopathy, and ischemic/hemorrhagic strokes. This review highlights the core mechanisms of ferroptosis, its pathological implications in CCVDs, and the therapeutic potential of targeting this process. Additionally, it explores the role of Chinese herbal medicines (CHMs) in mitigating ferroptosis, offering novel therapeutic strategies for CCVDs management. Ferroptosis is regulated by several key pathways. The GPX4-GSH-System Xc- axis is central to ferroptosis execution, involving GPX4 using GSH to neutralize lipid peroxides, with system Xc- being crucial for GSH synthesis. The NAD(P)H/FSP1/CoQ10 axis involves FSP1 regenerating CoQ10 via NAD(P)H, inhibiting lipid peroxidation independently of GPX4. Lipid peroxidation, driven by PUFAs and enzymes like ACSL4 and LPCAT3, and iron metabolism, regulated by proteins like TfR1 and ferritin, are also crucial for ferroptosis. Inhibiting ferroptosis shows promise in managing CCVDs. In atherosclerosis, ferroptosis inhibitors reduce iron accumulation and lipid peroxidation. In myocardial infarction, inhibitors protect cardiomyocytes by preserving GPX4 and SLC7A11 levels. In ischemia-reperfusion injury, targeting ferroptosis reduces myocardial and cerebral damage. In diabetic cardiomyopathy, Nrf2 activators alleviate oxidative stress and iron metabolism irregularities. CHMs offer natural compounds that mitigate ferroptosis. They possess antioxidant properties, chelate iron, and modulate signaling pathways like Nrf2 and AMPK. For example, Salvia miltiorrhiza and Astragalus membranaceus reduce oxidative stress, while some CHMs chelate iron, reducing its availability for ferroptosis. In conclusion, ferroptosis plays a pivotal role in CCVDs, and targeting it offers novel therapeutic avenues. CHMs show promise in reducing ferroptosis and improving patient outcomes. Future research should explore combination therapies and further elucidate the molecular interactions in ferroptosis.

Cystathionine γ-lyase contributes to exacerbation of periodontal destruction in experimental periodontitis under hyperglycemia

BACKGROUND

Diabetes is one of the major inflammatory comorbidities of periodontitis via 2-way interactions. Cystathionine γ-lyase (CTH) is a pivotal endogenous enzyme synthesizing hydrogen sulfide (H2S), and CTH/H2S is crucially implicated in modulating inflammation in various diseases. This study aimed to explore the potential role of CTH in experimental periodontitis under a hyperglycemic condition.

METHODS

CTH-silenced and normal human periodontal ligament cells (hPDLCs) were cultured in a high glucose and Porphyromonas gingivalis lipopolysaccharide (P.g-LPS) condition. The effects of CTH on hPDLCs were assessed by Cell Counting Kit 8 (CCK8), real-time quantitative polymerase chain reaction (RT-qPCR), and enzyme-linked immunosorbent assay (ELISA). The model of experimental periodontitis under hyperglycemia was established on both Cth-/- and wild-type (WT) mice, and the extent of periodontal destruction was assessed by micro-CT, histology, RNA-Seq, Western blot, tartrate-resistant acid phosphatase (TRAP) staining and immunostaining.

RESULTS

CTH mRNA expression increased in hPDLCs in response to increasing concentration of P.g-LPS stimulation in a high glucose medium. With reference to WT mice, Cth-/- mice with experimental periodontitis under hyperglycemia exhibited reduced bone loss, decreased leukocyte infiltration and hindered osteoclast formation, along with reduced expression of proinflammatory cytokines interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α) in periodontal tissue. RNA-seq-enriched altered NF-κB pathway signaling in healthy murine gingiva with experimental periodontitis mice under hyperglycemia. Accordingly, phosphorylation of p65 (P-p65) was alleviated in CTH-silenced hPDLCs, leading to decreased expression of IL6 and TNF. CTH knockdown inhibited activation of nuclear factor kappa-B (NF-κB) pathway and decreased production of proinflammatory cytokines under high glucose and P.g-LPS treatment.

CONCLUSION

The present findings suggest the potential of CTH as a therapeutic target for tackling periodontitis in diabetic patients.

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.

Schisandrin B alleviates angiotensin II-induced cardiac inflammatory remodeling by inhibiting the recruitment of MyD88 to TLRs in mouse cardiomyocytes

Cardiac tissue remodeling is characterized by altered heart tissue architecture and dysfunction, leading to heart failure. Sustained activation of the renin-angiotensin-aldosterone system (RAAS) greatly promotes the development of myocardial remodeling. Angiotensin II (Ang II), which is the major component of RAAS, can directly lead to cardiac remodeling by inducing an inflammatory response. Schisandrin B (Sch B), the active component extracted from the fruit of Schisandra chinensis (Turcz.) Baill has been shown to exhibit anti-inflammatory activity through its ability to target TLR4 and its adaptor protein, MyD88. In this study, we explored whether Sch B alleviates Ang II-induced myocardial inflammation and remodeling via targeting MyD88. Sch B significantly suppressed Ang II-induced inflammation as well as increased the expression of several genes of tissue remodeling (β-Mhc, Tgfb, Anp, α-Ska) both in vivo and in vitro. These protective effects of Sch B were due to the inhibition of recruitment of MyD88 to TLR2 and TLR4, suppressing the Ang II-induced NF-κB activation and reducing the following inflammatory responses. Moreover, the knockdown of Myd88 in cardiomyocytes abrogated the Ang II-induced increases in the production of inflammatory cytokines and expression of remodeling genes. These findings provide new evidence that the mechanism of Sch B protection was attributed to selective inhibition of MyD88 signaling. This finding could pave the way for novel therapeutic strategies for myocardial inflammatory diseases.

TAK-242 alleviates diabetic cardiomyopathy via inhibiting pyroptosis and TLR4/CaMKII/NLRP3 pathway

Diabetic cardiomyopathy (DCM) is identified as a progressive disease that may lead to irreparable heart failure. Toll-like receptor (TLR) signaling is believed to be implicated in the pathogenesis of DCM. This study intended to explore the potential impact of Toll-like receptor 4 (TLR4) on DCM in vitro and in vivo. Streptozotocin and HG medium were utilized to induce diabetes in animal and cell models, respectively. Selective TLR4 inhibitor TAK-242 and calcium/calmodulin-dependent protein kinase-II (CaMKII) inhibitor KN-93 were employed to explore the involvement of TLR4/CaMKII in DCM. TLR4 expression was increased in DCM hearts, while inhibition of TLR4 activation by TAK-242 improved cardiac function, attenuated heart hypertrophy, and fibrosis, as well as reduced oxidative stress and proinflammatory cytokine levels in rats, which were confirmed by Doppler echocardiography, hematoxylin and eosin staining, and Masson Trichome staining and specific enzyme-linked immunosorbent assay kits. Besides, the expression of hypertrophy-related molecules and oxidative stress damage were also inhibited by TAK-242. Furthermore, TAK-242 treatment reduced CaMKII phosphorylation accompanied by decreased expression of NOD-like pyrin domain-containing protein 3, gasdermin D (GSDMD), The N-terminal domain of Gasdermin D (GSDMD-N), apoptosis-associated speck-like protein containing a caspase-recruitment domain (ASC) and Caspase-1 both in vivo and in vitro. Similar positive impacts on HG-induced pyroptosis were also observed with KN-93 treatment, and this was achieved without affecting TLR4 expression. Collectively, our work suggested that TAK-242 demonstrated substantial benefits against DCM both in vivo and in vitro, potentially attributed to the suppression of the TLR4-mediated CaMKII/NLRP3 pathway activity.

The cellular and molecular targets of natural products against metabolic disorders: a translational approach to reach the bedside

Metabolic disorders, including obesity, dyslipidemia, diabetes, nonalcoholic fatty liver disease, and metabolic syndrome, are characterized by insulin resistance, abnormalities in circulating cholesterol and lipid profiles, and hypertension. The most common pathophysiologies of metabolic disorders are glucose/lipid metabolism dysregulation, insulin resistance, inflammatory response, and oxidative stress. Although several agents have been approved for the treatment of metabolic disorders, there is still a strong demand for more efficacious drugs with less side effects. Natural products have been critical sources of drug research and discovery for decades. However, the usefulness of bioactive natural products is often limited by incomplete understanding of their direct cellular targets. In this review, we highlight the current understanding of the established and emerging molecular mechanisms of metabolic disorders. We further summarize the therapeutic effects and underlying mechanisms of natural products on metabolic disorders, with highlights on their direct cellular targets, which are mainly implicated in the regulation of glucose/lipid metabolism, insulin resistance, metabolic inflammation, and oxidative stress. Finally, this review also covers the clinical studies of natural products in metabolic disorders. These progresses are expected to facilitate the application of these natural products and their derivatives in the development of novel drugs against metabolic disorders.

Effect of NLRP3 gene knockdown on pyroptosis and ferroptosis in diabetic cardiomyopathy injury

Diabetic cardiomyopathy (DCM) is a chronic disease caused by diabetes mellitus, which is recognized as a worldwide challenging disease. This study aimed to investigate the role and the potential mechanism of knocking down the NACHT-, LRR- and PYD domains-containing protein 3 (NLRP3), an inflammasome associated with onset and progression of various diseases, on high glucose or diabetes -induced cardiac cells pyroptosis and ferroptosis, two regulated non-necrosis cell death modalities discovered recent years. In the present study, both in vivo and in vitro studies were conducted simultaneously. Diabetic rats were induced by 55 mg/kg intraperitoneal injection of streptozotocin (STZ). Following the intraperitoneal injection of MCC950 (10 mg/kg), On the other hand, the DCM model in H9C2 cardiac cells was simulated with 35 mmol/L glucose and a short hairpin RNA vector of NLRP3 were transfected to cells. The results showed that in vivo study, myocardial fibers were loosely arranged and showed inflammatory cell infiltration, mitochondrial cristae were broken and the GSDMD-NT expression was found notably increased in the DM group, while the protein expressions of xCT and GPX4 was significantly decreased, both of which were reversed by MCC950. High glucose reduced the cell viability and ATP level in vitro, accompanied by an increase in LDH release. All of the above indicators were reversed after NLRP3 knockdown compared with the HG treated alone. Moreover, the protein expressions of pyroptosis- and ferroptosis-related fators were significantly decreased or increased, consistent with the results shown by immunofluorescence. Furthermore, the protective effects of NLRP3 knockdown against HG were reversed following the mtROS agonist rotenone (ROT) treatment. In conclusion, inhibition of NLRP3 suppressed DM-induced myocardial injury. Promotion of mitochondrial ROS abolished the protective effect of knockdown NLRP3, and induced the happening of pyroptosis and ferroptosis. These findings may present a novel therapeutic underlying mechanism for clinical diabetes-induced myocardial injury treatment.

Design, synthesis and bioactivity evaluation of 4-hydroxycoumarin derivatives as potential anti-inflammatory agents against acute lung injury and colitis

Acute lung injury (ALI) and inflammatory bowel disease (IBD) are common inflammatory illnesses that seriously affect people's health. Herein, a series of 4-hydroxylcoumarin (4-HC) derivatives were designed and synthesized. The inhibitory effects of these compounds on LPS-induced interleukin-6 (IL-6) release from J774A.1 cells were then screened via ELISA assay, compound B8 showed 3 times more active than the lead compound 4-HC. The most active compound B8 had the IC50 values of 4.57 μM and 6.51 μM for IL-6 release on mouse cells J774A.1 and human cells THP-1, respectively. Furthermore, we also found that B8 could act on the MAPK pathway. Based on the target prediction results of computer virtual docking, kinase inhibitory assay was carried out, and it revealed that targeting IRAK1 was a key mechanism for B8 to exert anti-inflammatory activity. Moreover, B8 exerted a good therapeutic effect on the dextran sulfate sodium (DSS)-induced colitis model and liposaccharide (LPS)-induced ALI mouse models. The acute toxicity experiments indicated that high-dose B8 caused no adverse reactions in mice, confirming its safety in vivo. Additionally, the preliminary pharmacokinetic (PK) parameters of B8 in SD rats were also examined, revealing a bioavailability (F) of 28.72 %. In conclusion, B8 is a potential candidate of drug for the treatment of ALI and colitis.

Metabolite-derived damage-associated molecular patterns in immunological diseases

Damage-associated molecular patterns (DAMPs) are typically derived from the endogenous elements of necrosis cells and can trigger inflammatory responses by activating DAMPs-sensing receptors on immune cells. Failure to clear DAMPs may lead to persistent inflammation, thereby contributing to the pathogenesis of immunological diseases. This review focuses on a newly recognized class of DAMPs derived from lipid, glucose, nucleotide, and amino acid metabolic pathways, which are then termed as metabolite-derived DAMPs. This review summarizes the reported molecular mechanisms of these metabolite-derived DAMPs in exacerbating inflammation responses, which may attribute to the pathology of certain types of immunological diseases. Additionally, this review also highlights both direct and indirect clinical interventions that have been explored to mitigate the pathological effects of these DAMPs. By summarizing our current understanding of metabolite-derived DAMPs, this review aims to inspire future thoughts and endeavors on targeted medicinal interventions and the development of therapies for immunological diseases.

Mitochondrial energy metabolism in diabetic cardiomyopathy: Physiological adaption, pathogenesis, and therapeutic targets

Diabetic cardiomyopathy is defined as abnormal structure and function of the heart in the setting of diabetes, which could eventually develop heart failure and leads to the death of the patients. Although blood glucose control and medications to heart failure show beneficial effects on this disease, there is currently no specific treatment for diabetic cardiomyopathy. Over the past few decades, the pathophysiology of diabetic cardiomyopathy has been extensively studied, and an increasing number of studies pinpoint that impaired mitochondrial energy metabolism is a key mediator as well as a therapeutic target. In this review, we summarize the latest research in the field of diabetic cardiomyopathy, focusing on mitochondrial damage and adaptation, altered energy substrates, and potential therapeutic targets. A better understanding of the mitochondrial energy metabolism in diabetic cardiomyopathy may help to gain more mechanistic insights and generate more precise mitochondria-oriented therapies to treat this disease.

Targeting MAPK-ERK/JNK pathway: A potential intervention mechanism of myocardial fibrosis in heart failure

Myocardial fibrosis is a significant pathological basis of heart failure. Overactivation of the ERK1/2 and JNK1/2 signaling pathways of MAPK family members synergistically promotes the proliferation of myocardial fibroblasts and accelerates the development of myocardial fibrosis. In addition to some small molecule inhibitors and Western drugs, many Chinese medicines can also inhibit the activity of ERK1/2 and JNK1/2, thus slowing down the development of myocardial fibrosis, and are generally safe and effective. However, the specific biological mechanisms of ERK1/2 and JNK1/2 signaling pathways in myocardial fibrosis still need to be fully understood, and there is no systematic review of existing drugs and methods to inhibit them from improving myocardial fibrosis. This study aims to summarize the roles and cross-linking mechanisms of ERK1/2 and JNK1/2 signaling pathways in myocardial fibrosis and to systematically sort out the small-molecule inhibitors, Western drugs, traditional Chinese medicines, and non-pharmacological therapies that inhibit ERK1/2 and JNK1/2 to alleviate myocardial fibrosis. In the future, we hope to conduct more in-depth research from the perspective of precision-targeted therapy, using this as a basis for developing new drugs that provide new perspectives on the prevention and treatment of heart failure.

Understanding One Half of the Sex Difference Equation: The Modulatory Effects of Testosterone on Diabetic Cardiomyopathy

Diabetes is a prevalent disease, primarily characterized by high blood sugar (hyperglycemia). Significantly higher rates of myocardial dysfunction have been noted in individuals with diabetes, even in those without coronary artery disease or high blood pressure (hypertension). Numerous molecular mechanisms have been identified through which diabetes contributes to the pathology of diabetic cardiomyopathy, which presents as cardiac hypertrophy and fibrosis. At the cellular level, oxidative stress and inflammation in cardiomyocytes are triggered by hyperglycemia. Although males are generally more likely to develop cardiovascular disease than females, diabetic males are less likely to develop diabetic cardiomyopathy than are diabetic females. One reason for these differences may be the higher levels of serum testosterone in males compared with females. Although testosterone appears to protect against cardiomyocyte oxidative stress and exacerbate hypertrophy, its role in inflammation and fibrosis is much less clear. Additional preclinical and clinical studies will be required to delineate testosterone's effect on the diabetic heart.

Regulation of immunomodulatory networks by Nrf2-activation in immune cells: Redox control and therapeutic potential in inflammatory diseases

Inflammatory diseases present a serious health challenge due to their widespread prevalence and the severe impact on patients' lives. In the quest to alleviate the burden of these diseases, nuclear factor erythroid 2-related factor 2 (Nrf2) has emerged as a pivotal player. As a transcription factor intimately involved in cellular defense against metabolic and oxidative stress, Nrf2's role in modulating the inflammatory responses of immune cells has garnered significant attention. Recent findings suggest that Nrf2's ability to alter the redox status of cells underlies its regulatory effects on immune responses. Our review delves into preclinical and clinical evidence that underscores the complex influence of Nrf2 activators on immune cell phenotypes, particularly in the inflammatory milieu. By offering a detailed analysis of Nrf2's role in different immune cell populations, we cast light on the potential of Nrf2 activators in shaping the immune response towards a more regulated state, mitigating the adverse effects of inflammation through modeling redox status of immune cells. Furthermore, we explore the innovative use of nanoencapsulation techniques that enhance the delivery and efficacy of Nrf2 activators, potentially advancing the treatment strategies for inflammatory ailments. We hope this review will stimulate the development and expansion of Nrf2-targeted treatments that could substantially improve outcomes for patients suffering from a broad range of inflammatory diseases.

Hyperglycemia activates FGFR1 via TLR4/c-Src pathway to induce inflammatory cardiomyopathy in diabetes

Protein tyrosine kinases (RTKs) modulate a wide range of pathophysiological events in several non-malignant disorders, including diabetic complications. To find new targets driving the development of diabetic cardiomyopathy (DCM), we profiled an RTKs phosphorylation array in diabetic mouse hearts and identified increased phosphorylated fibroblast growth factor receptor 1 (p-FGFR1) levels in cardiomyocytes, indicating that FGFR1 may contribute to the pathogenesis of DCM. Using primary cardiomyocytes and H9C2 cell lines, we discovered that high-concentration glucose (HG) transactivates FGFR1 kinase domain through toll-like receptor 4 (TLR4) and c-Src, independent of FGF ligands. Knocking down the levels of either TLR4 or c-Src prevents HG-activated FGFR1 in cardiomyocytes. RNA-sequencing analysis indicates that the elevated FGFR1 activity induces pro-inflammatory responses via MAPKs-NFκB signaling pathway in HG-challenged cardiomyocytes, which further results in fibrosis and hypertrophy. We then generated cardiomyocyte-specific FGFR1 knockout mice and showed that a lack of FGFR1 in cardiomyocytes prevents diabetes-induced cardiac inflammation and preserves cardiac function in mice. Pharmacological inhibition of FGFR1 by a selective inhibitor, AZD4547, also prevents cardiac inflammation, fibrosis, and dysfunction in both type 1 and type 2 diabetic mice. These studies have identified FGFR1 as a new player in driving DCM and support further testing of FGFR1 inhibitors for possible cardioprotective benefits.

Molecular mechanisms of metabolic dysregulation in diabetic cardiomyopathy

Diabetic cardiomyopathy (DCM), one of the most serious complications of diabetes mellitus, has become recognized as a cardiometabolic disease. In normoxic conditions, the majority of the ATP production (>95%) required for heart beating comes from mitochondrial oxidative phosphorylation of fatty acids (FAs) and glucose, with the remaining portion coming from a variety of sources, including fructose, lactate, ketone bodies (KB) and branched chain amino acids (BCAA). Increased FA intake and decreased utilization of glucose and lactic acid were observed in the diabetic hearts of animal models and diabetic patients. Moreover, the polyol pathway is activated, and fructose metabolism is enhanced. The use of ketones as energy sources in human diabetic hearts also increases significantly. Furthermore, elevated BCAA levels and impaired BCAA metabolism were observed in the hearts of diabetic mice and patients. The shift in energy substrate preference in diabetic hearts results in increased oxygen consumption and impaired oxidative phosphorylation, leading to diabetic cardiomyopathy. However, the precise mechanisms by which impaired myocardial metabolic alterations result in diabetes mellitus cardiac disease are not fully understood. Therefore, this review focuses on the molecular mechanisms involved in alterations of myocardial energy metabolism. It not only adds more molecular targets for the diagnosis and treatment, but also provides an experimental foundation for screening novel therapeutic agents for diabetic cardiomyopathy.

A Narrative Review of Diabetic Macroangiopathy: From Molecular Mechanism to Therapeutic Approaches

Diabetic macroangiopathy, a prevalent and severe complication of diabetes mellitus, significantly contributes to the increased morbidity and mortality rates among affected individuals. This complex disorder involves multifaceted molecular mechanisms that lead to the dysfunction and damage of large blood vessels, including atherosclerosis (AS) and peripheral arterial disease. Understanding the intricate pathways underlying the development and progression of diabetic macroangiopathy is crucial for the development of effective therapeutic interventions. This review aims to shed light on the molecular mechanism implicated in the pathogenesis of diabetic macroangiopathy. We delve into the intricate interplay of chronic inflammation, oxidative stress, endothelial dysfunction, and dysregulated angiogenesis, all of which contribute to the vascular complications observed in this disorder. By exploring the molecular mechanism involved in the disease we provide insight into potential therapeutic targets and strategies. Moreover, we discuss the current therapeutic approaches used for treating diabetic macroangiopathy, including glycemic control, lipid-lowering agents, and vascular interventions.

The anti-inflammatory effect of metformin: The molecular targets

Metformin is an anti-diabetic drug. Metformin mainly inhibits gluconeogenesis in the liver and reduces blood sugar. In addition to the anti-diabetic effects, many studies have revealed that metformin has anti-inflammatory effects. Various molecules were suggested to be the target of the metformin's anti-inflammatory effects. However, the conclusion is not clear. Metformin is related to a number of molecules and the identification of the main target in anti-inflammatory effects leads to the understanding of inflammation and metformin. In this article, I discuss each suggested molecule, involved mechanisms, and their relationship with various diseases.

D-pinitol alleviates diabetic cardiomyopathy by inhibiting the optineurin-mediated endoplasmic reticulum stress and glycophagy signaling pathway

Diabetic cardiomyopathy (DCM) is an important complication resulting in heart failure and death of diabetic patients. However, there is no effective drug for treatments. This study investigated the effect of D-pinitol (DP) on cardiac injury using diabetic mice and glycosylation injury of cardiomyocytes and its molecular mechanisms. We established the streptozotocin-induced SAMR1 and SAMP8 mice and DP (150 mg/kg/day) intragastrically and advanced glycation end-products (AGEs)-induced H9C2 cells. H9C2 cells were transfected with optineurin (OPTN) siRNA and overexpression plasmids. The metabolic disorder indices, cardiac dysfunction, histopathology, immunofluorescence, western blot, and immunoprecipitation were investigated. Our results showed that DP reduced the blood glucose and AGEs, and increased the expression of heart OPTN in diabetic mice and H9C2 cells, thereby inhibiting the endoplasmic reticulum stress (GRP78, CHOP) and glycophagy (STBD1, GABARAPL1), and alleviating the myocardial apoptosis and fibrosis of DCM. The expression of filamin A as an interaction protein of OPTN downregulated by AGEs decreased OPTN abundance. Moreover, OPTN siRNA increased the expression of GRP78, CHOP, STBD1, and GABARAPL1 and inhibited the expression of GAA via GSK3β phosphorylation and FoxO1. DP may be helpful to treat the onset of DCM. Targeting OPTN with DP could be translated into clinical application in the fighting against DCM.

Isoproterenol induces MD2 activation by β-AR-cAMP-PKA-ROS signalling axis in cardiomyocytes and macrophages drives inflammatory heart failure

Cardiac inflammation contributes to heart failure (HF) induced by isoproterenol (ISO) through activating β-adrenergic receptors (β-AR). Recent evidence shows that myeloid differentiation factor 2 (MD2), a key protein in endotoxin-induced inflammation, mediates inflammatory heart diseases. In this study, we investigated the role of MD2 in ISO-β-AR-induced heart injuries and HF. Mice were infused with ISO (30 mg·kg-1·d-1) via osmotic mini-pumps for 2 weeks. We showed that MD2 in cardiomyocytes and cardiac macrophages was significantly increased and activated in the heart tissues of ISO-challenged mice. Either MD2 knockout or administration of MD2 inhibitor L6H21 (10 mg/kg every 2 days, i.g.) could prevent mouse hearts from ISO-induced inflammation, remodelling and dysfunction. Bone marrow transplantation study revealed that both cardiomyocyte MD2 and bone marrow-derived macrophage MD2 contributed to ISO-induced cardiac inflammation and injuries. In ISO-treated H9c2 cardiomyocyte-like cells, neonatal rat primary cardiomyocytes and primary mouse peritoneal macrophages, MD2 knockout or pre-treatment with L6H21 (10 μM) alleviated ISO-induced inflammatory responses, and the conditioned medium from ISO-challenged macrophages promoted the hypertrophy and fibrosis in cardiomyocytes and fibroblasts. We demonstrated that ISO induced MD2 activation in cardiomyocytes via β1-AR-cAMP-PKA-ROS signalling axis, and induced inflammatory responses in macrophages via β2-AR-cAMP-PKA-ROS axis. This study identifies MD2 as a key inflammatory mediator and a promising therapeutic target for ISO-induced heart failure.

Glycolysis-Mediated Activation of v-ATPase by Nicotinamide Mononucleotide Ameliorates Lipid-Induced Cardiomyopathy by Repressing the CD36-TLR4 Axis

BACKGROUND

Chronic overconsumption of lipids followed by their excessive accumulation in the heart leads to cardiomyopathy. The cause of lipid-induced cardiomyopathy involves a pivotal role for the proton-pump vacuolar-type H+-ATPase (v-ATPase), which acidifies endosomes, and for lipid-transporter CD36, which is stored in acidified endosomes. During lipid overexposure, an increased influx of lipids into cardiomyocytes is sensed by v-ATPase, which then disassembles, causing endosomal de-acidification and expulsion of stored CD36 from the endosomes toward the sarcolemma. Once at the sarcolemma, CD36 not only increases lipid uptake but also interacts with inflammatory receptor TLR4 (Toll-like receptor 4), together resulting in lipid-induced insulin resistance, inflammation, fibrosis, and cardiac dysfunction. Strategies inducing v-ATPase reassembly, that is, to achieve CD36 reinternalization, may correct these maladaptive alterations. For this, we used NAD+ (nicotinamide adenine dinucleotide)-precursor nicotinamide mononucleotide (NMN), inducing v-ATPase reassembly by stimulating glycolytic enzymes to bind to v-ATPase.

METHODS

Rats/mice on cardiomyopathy-inducing high-fat diets were supplemented with NMN and for comparison with a cocktail of lysine/leucine/arginine (mTORC1 [mechanistic target of rapamycin complex 1]-mediated v-ATPase reassembly). We used the following methods: RNA sequencing, mRNA/protein expression analysis, immunofluorescence microscopy, (co)immunoprecipitation/proximity ligation assay (v-ATPase assembly), myocellular uptake of [3H]chloroquine (endosomal pH), and [14C]palmitate, targeted lipidomics, and echocardiography. To confirm the involvement of v-ATPase in the beneficial effects of both supplementations, mTORC1/v-ATPase inhibitors (rapamycin/bafilomycin A1) were administered. Additionally, 2 heart-specific v-ATPase-knockout mouse models (subunits V1G1/V0d2) were subjected to these measurements. Mechanisms were confirmed in pharmacologically/genetically manipulated cardiomyocyte models of lipid overload.

RESULTS

NMN successfully preserved endosomal acidification during myocardial lipid overload by maintaining v-ATPase activity and subsequently prevented CD36-mediated lipid accumulation, CD36-TLR4 interaction toward inflammation, fibrosis, cardiac dysfunction, and whole-body insulin resistance. Lipidomics revealed C18:1-enriched diacylglycerols as lipid class prominently increased by high-fat diet and subsequently reversed/preserved by lysine/leucine/arginine/NMN treatment. Studies with mTORC1/v-ATPase inhibitors and heart-specific v-ATPase-knockout mice further confirmed the pivotal roles of v-ATPase in these beneficial actions.

CONCLUSION

NMN preserves heart function during lipid overload by preventing v-ATPase disassembly.

Identification of a 10-mer peptide from the death domain of MyD88 which attenuates inflammation and insulin resistance and improves glucose metabolism

Insulin resistance (IR) is the key pathophysiological cause of type 2 diabetes, and inflammation has been implicated in it. The death domain (DD) of the adaptor protein, MyD88 plays a crucial role in the transduction of TLR4-associated inflammatory signal. Herein, we have identified a 10-residue peptide (M10), from the DD of MyD88 which seems to be involved in Myddosome formation. We hypothesized that M10 could inhibit MyD88-dependent TLR4-signaling and might have effects on inflammation-associated IR. Intriguingly, 10-mer M10 showed oligomeric nature and reversible self-assembly property indicating the peptide's ability to recognize its own amino acid sequence. M10 inhibited LPS-induced nuclear translocation of NF-κB in L6 myotubes and also reduced LPS-induced IL-6 and TNF-α production in peritoneal macrophages of BALB/c mice. Remarkably, M10 inhibited IL-6 and TNF-α secretion in diabetic, db/db mice. Notably, M10 abrogated IR in insulin-resistant L6 myotubes, which was associated with an increase in glucose uptake and a decrease in Ser307-phosphorylation of IRS1, TNF-α-induced JNK activation and nuclear translocation of NF-κB in these cells. Alternate day dosing with M10 (10 and 20 mg/kg) for 30 days in db/db mice significantly lowered blood glucose and improved glucose intolerance after loading, 3.0 g/kg glucose orally. Furthermore, M10 increased insulin and adiponectin secretion in db/db mice. M10-induced glucose uptake in L6 myotubes involved the activation of PI3K/AKT/GLUT4 pathways. A scrambled M10-analog was mostly inactive. Overall, the results show the identification of a 10-mer peptide from the DD of MyD88 with anti-inflammatory and anti-diabetic properties, suggesting that targeting of TLR4-inflammatory pathway, could lead to the discovery of molecules against IR and diabetes.

Optimized new Shengmai powder ameliorates myocardial fibrosis in rats with heart failure by inhibition of the MAPK signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Optimized New Shengmai Powder (ONSMP) is a traditional Chinese medicine (TCM) formula for heart failure treatment. MAPK signaling pathway is the key driver of myocardial fibrosis in heart failure. However, the mechanism of ONSMP on myocardial fibrosis and MAPK signaling pathway remains unclear.

AIM OF THE STUDY

To evaluate the effect of ONSMP against myocardial fibrosis in heart failure and the underlying mechanisms.

MATERIALS AND METHODS

Firstly, UHPLC-Q-Exactive-MS/MS was used to identify the active components in ONSMP. Secondly, a rat model of heart failure was established by ligating the left anterior descending branch of the coronary artery. After four weeks of intragastric administration of ONSMP, we used various classic tests, including echocardiography, exhaustive swimming, cardiopulmonary coefficient, heart failure markers, and cardiac pathological section, to assess the prescription's anti-myocardial fibrosis in heart failure properties. AGEs, Ang Ⅱ, VEGF, CTGF, and TGFβ levels in rat serum were quantified using ELISA. The positive expression of p-ERK1/2 and p-JNK1/2 of rat myocardium was determined immunohistochemical. The protein and mRNA levels of genes involved in the MAPK signaling pathway and myocardial fibrosis were measured using western blotting or real-time PCR.

RESULTS

The main components of ONSMP that regulate the MAPK signaling pathway are isorhamnetin, kaempferol, quercetin, and tanshinone ⅡA. ONSMP ameliorated cardiac function and exercise tolerance and reduced cardiopulmonary coefficient, heart failure marker levels, and myocardial fibrosis in the heart failure rats. In addition, ONSMP diminished the serum MAPK pathway activator levels, positive expression level of p-ERK1/2 and p-JNK1/2, protein and mRNA levels of components of the MAPK signaling pathway in the myocardial tissue of heart failure rat, indicating that it inhibits MAPK signaling pathway.

CONCLUSIONS

ONSMP delayed heart failure by inhibiting myocardial fibrosis via the MAPK signaling pathway.

What is the impact of ferroptosis on diabetic cardiomyopathy: a systematic review

Iron overload increases the production of harmful reactive oxygen species in the Fenton reaction, which causes oxidative stress in the body and lipid peroxidation in the cell membrane, and eventually leads to ferroptosis. Diabetes is associated with increased intracellular oxidative stress, inflammation, autophagy, microRNA alterations, and advanced glycation end products (AGEs), which cause cardiac remodeling and cardiac diastolic contractile dysfunction, leading to the development of diabetic cardiomyopathy (DCM). While these factors are also closely associated with ferroptosis, more and more studies have shown that iron-mediated ferroptosis is an important causative factor in DCM. In order to gain fresh insights into the functions of ferroptosis in DCM, this review methodically summarizes the traits and mechanisms connected with ferroptosis and DCM.

Blockage of DCLK1 in cardiomyocytes suppresses myocardial inflammation and alleviates diabetic cardiomyopathy in streptozotocin-induced diabetic mice

Diabetic cardiomyopathy (DCM) is a pathophysiological condition triggered by diabetes mellitus and can lead to heart failure. Doublecortin-like kinase protein 1 (DCLK1) is a multifunctional protein kinase involved in the regulation of cell proliferation, differentiation, survival, and migration. Current studies on DCLK1 mainly focus on cancer development; however, its role in non-tumor diseases such as DCM is yet to be deciphered. Our analysis revealed that DCLK1 was upregulated in cardiomyocytes of streptozotocin (STZ)-induced type 1 diabetic mouse, suggesting a correlation between DCLK1 and DCM progression. It was further demonstrated that either cardiomyocyte-specific DCLK1 knockout or pharmacological DCLK1 inhibitor DCLK1-IN-1 significantly alleviated cardiac hypertrophy and fibrosis in STZ-induced diabetic mice. RNA-seq analysis of heart tissues revealed that DCLK1 regulated the nuclear factor kappa B (NF-κB)-mediated inflammatory response in DCM. In vitro, DCLK1 activated NF-κB and the inflammatory response by inducing the IKKβ phosphorylation in high-concentration glucose (HG)-challenged cardiomyocytes. DCLK1-IN-1 also prevented HG-induced IKKβ/NF-κB activation and inflammatory injuries in cardiomyocytes. In conclusion, this study highlights the novel role of cardiomyocyte DCLK1 in regulating IKKβ/NF-κB, which aggravates inflammation to promote the pathogenesis of DCM. DCLK1 may serve as a new target for DCM treatment.

Ferroptosis: potential targets and emerging roles in pancreatic diseases

Ferroptosis is a newly discovered form of regulatory cell death characterized by excessive iron-dependent lipid peroxidation. In the past decade, significant breakthroughs have been made in comprehending the features and regulatory mechanisms of ferroptosis, and it has been confirmed that ferroptosis plays a pivotal role in the pathophysiological processes of various diseases, including tumors, inflammation, neurodegenerative diseases, and infectious diseases. The pancreas, which is the second largest digestive gland in the human body and has both endocrine and exocrine functions, is a vital organ for controlling digestion and metabolism. In recent years, numerous studies have confirmed that ferroptosis is closely related to pancreatic diseases, which is attributed to abnormal iron accumulation, as an essential biochemical feature of ferroptosis, is often present in the pathological processes of various pancreatic exocrine and endocrine diseases and the vulnerability of the pancreas to oxidative stress stimulation and damage. Therefore, comprehending the regulatory mechanism of ferroptosis in pancreatic diseases may provide valuable new insights into treatment strategies. In this review, we first summarize the hallmark features of ferroptosis and then analyze the exact mechanisms by which ferroptosis is precisely regulated at multiple levels and links, including iron metabolism, lipid metabolism, the GPX4-mediated ferroptosis defense system, the GPX4-independent ferroptosis defense system, and the regulation of autophagy on ferroptosis. Finally, we discuss the role of ferroptosis in the occurrence and development of pancreatic diseases and summarize the feasibility and limitations of ferroptosis as a therapeutic target for pancreatic diseases.

The effect of hyperglycemia on the activation of peritoneal macrophages of albino rats

Hyperglycemia is one of the main damaging factors of diabetes mellitus (DM). The severity of this disease is most clearly manifested under conditions of the inflammatory process. In this work, we have studied the activation features of rat peritoneal macrophages (MPs) under conditions of high glucose concentration in vitro. Comparison of the independent and combined effects of streptozotocin-induced DM and hyperglycemia on proliferation and accumulation of nitrites in the MPs culture medium revealed similarity of their effects. Elevated glucose levels and, to a lesser extent, DM decreased basal proliferation and NO production by MPs in vitro. The use of the protein kinase C (PKC) activator, phorbol ester (PMA), abolished the proinflammatory effect of thrombin on PMs. This suggests the involvement of PKC in the effects of the protease. At the same time, the effect of thrombin on the level of nitrites in the culture medium demonstrates a pronounced dose-dependence, which was not recognized during evaluation of proliferation. Proinflammatory activation of MPs is potentiated by hyperglycemia, one of the main pathological factors of diabetes. Despite the fact that high concentrations of glucose have a significant effect on proliferation and NO production, no statistically significant differences were found between the responses of MPs obtained from healthy animals and from animals with streptozotocin-induced DM. This ratio was observed for all parameters studied in the work, during analysis of cell proliferation and measurement of nitrites in the culture medium. Thus, the results obtained indicate the leading role of elevated glucose levels in the regulation of MPs activation, which is comparable to the effect of DM and even "masks" it.

Inhibition of MD2 by natural product-drived JM-9 attenuates renal inflammation and diabetic nephropathy in mice

Diabetic kidney disease (DKD) is one of the severe complications of diabetes mellitus-related microvascular lesions, which remains the leading cause of end-stage kidney disease. The genesis and development of DKD is closely related to inflammation. Myeloid differentiation 2 (MD2) mediates hyperlyciemia-induced renal inflammation and DKD development and is considered as a potential therapeutic target of DKD. Here, we identified a new small-molecule MD2 inhibitor, JM-9. In vitro, JM-9 suppressed high glucose (HG) and palmitic acid (PA)-induced inflammation in MPMs, accompanied by inhibition of MD2 activation and the downstream TLR4/MyD88-MAPKs/NFκB pro-inflammatory signaling pathway. Macrophage-derived factors increased the fibrotic and inflammatory responses in renal tubular epithelial cells, which were inhibited by treating macrophages with JM-9. Then, we investigated the therapeutic effects against DKD in streptozotocin-induced type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM) mouse models. Treatment with JM-9 prevented renal inflammation, fibrosis, and dysfunction by targeting MD2 in both T1DM and T2DM models. Our results show that JM-9, a new small-molecule MD2 inhibitor, protects against DKD by targeting MD2 and inhibiting MD2-mediated inflammation. In summary, JM-9 is a potential therapeutic agent for DKD.

The essential role of glutamine metabolism in diabetic cardiomyopathy: A review

Diabetic cardiomyopathy (DCM) is a pathophysiological condition caused by diabetes mellitus and is the leading cause of diabetes mellitus-related mortality. The pathophysiology of DCM involves various processes, such as oxidative stress, inflammation, ferroptosis, and abnormal protein modification. New evidence indicates that dysfunction of glutamine (Gln) metabolism contributes to the pathogenesis of DCM by regulating these pathophysiological mechanisms. Gln is a conditionally essential amino acid in the human body, playing a vital role in maintaining cell function. Although the precise molecular mechanisms of Gln in DCM have yet to be fully elucidated, recent studies have shown that supplementing with Gln improves cardiac function in diabetic hearts. However, excessive Gln may worsen myocardial injury in DCM by generating a large amount of glutamates or increasing O-GlcNacylation. To highlight the potential therapeutic method targeting Gln metabolism and its downstream pathophysiological mechanisms, this article aims to review the regulatory function of Gln in the pathophysiological mechanisms of DCM.

Qi Fu Yin ameliorates neuroinflammation through inhibiting RAGE and TLR4/NF-κB pathway in AD model rats

The purpose of this study is to investigate the therapeutic effect of Qi Fu Yin (QFY) on Alzheimer's disease (AD) both computationally and experimentally. Network pharmacology analysis and molecular docking were conducted to identify potential targets and signaling pathways involved in QFY treating AD. Streptozotocin-induced AD rat model was used to verify important targets and predicted pathways. The components of QFY were identified using liquid chromatography-tandem mass spectrometry. The results indicate that the potential targets of QFY are highly enriched for anti-inflammatory pathways. Molecular docking analysis revealed stable structures formed between QFY's active compounds, including stigmasterol, β-sitosterol, and isorhamnetin, and the identified targets. In vivo, QFY improved cognitive memory in AD rats and reduced the mRNA expression levels of toll-like receptor 4 (TLR4), the receptor for advanced glycation end products (AGER), and the inflammatory factors interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) in the brains of AD rats. Furthermore, QFY effectively reduced nuclear translocation of nuclear factor-kappa B (NF-κB) and inhibited NF-κB and microglia activation. In conclusion, QFY can ameliorate neuroinflammation in AD model rats, partly via the inhibition of TLR4 and RAGE/NF-κB pathway and microglia activation, thereby enhancing learning and memory in AD model rats.

Compound c17 alleviates inflammatory cardiomyopathy in streptozotocin-induced diabetic mice by targeting MyD88

BACKGROUND

Diabetic cardiomyopathy (DCM) is a common complication of diabetes mellitus and is associated with increased morbidity and mortality due to cardiac dysfunction. Chronic inflammation plays a significant role in the development of DCM, making it a promising target for novel pharmacological strategies. Our previous study has synthesized a novel compound, c17, which exhibited strong anti-inflammatory activity by specifically targeting to myeloid differentiation primary response 88 (MyD88). In this study, we evaluated the therapeutic effect of c17 in DCM.

METHODS

The small molecular selective MyD88 inhibitor, c17, was used to evaluate the effect of MyD88 on DCM in both high concentration of glucose- and palmitic acid-stimulated macrophages and streptozotocin (STZ)-induced type 1 diabetes mellitus (T1DM) mice.

RESULTS

The treatment of c17 in T1DM mice resulted in improved heart function and reduced cardiac hypertrophy, inflammation and fibrogenesis. RNA sequencing analysis of the heart tissues revealed that c17 effectively suppressed the inflammatory response by regulating the MyD88-dependent pathway. Co-immunoprecipitation experiments further confirmed that c17 disrupted the interaction between MyD88 and Toll-like receptor 4 (TLR4), consequently inhibiting downstream NF-κB activation. In vitro studies demonstrated that c17 exhibited similar anti-inflammatory activity by targeting MyD88 in macrophages, which are the primary regulators of cardiac inflammation. Furthermore, conditioned medium derived from c17-treated macrophages showed reduced capacity to induce hypertrophy, pro-fibrotic reactions, and secondary inflammation in cardiomyocytes.

CONCLUSIONS

In conclusion, the small-molecule MyD88 inhibitor, c17, effectively combated the inflammatory DCM, therefore could be a potential candidate for the treatment of this disease.

The role of sRAGE in cardiovascular diseases

Advanced glycation end products (AGEs), by-products of glucose metabolism, have been linked to the emergence of cardiovascular disorders (CVD). AGEs can cause tissue damage in four different ways: (1) by altering protein function, (2) by crosslinking proteins, which makes tissue stiffer, (3) by causing the generation of free radicals, and (4) by activating an inflammatory response after binding particular AGE receptors, such as the receptor for advanced glycation end products (RAGE). It is suggested that the soluble form of RAGE (sRAGE) blocks ligand-mediated pro-inflammatory and oxidant activities by serving as a decoy. Therefore, several studies have investigated the possible anti-inflammatory and anti-oxidant characteristics of sRAGE, which may help lower the risk of CVD. According to the results of various studies, the relationship between circulating sRAGE, cRAGE, and esRAGE and CVD is inconsistent. To establish the potential function of sRAGE as a therapeutic target in the treatment of cardiovascular illnesses, additional studies are required to better understand the relationship between sRAGE and CVD. In this review, we explored the potential function of sRAGE in different CVD, highlighting unanswered concerns and outlining the possibilities for further investigation.

Rhein alleviates advanced glycation end products (AGEs)-induced inflammatory injury of diabetic cardiomyopathy in vitro and in vivo models

In diabetic patients, diabetic cardiomyopathy (DCM) is one of the most common causes of death. The inflammatory response is essential in the pathogenesis of DCM. Rhein, an anthraquinone compound, is extracted from the herb rhubarb, demonstrating various biological activities. However, it is unclear whether rhein has an anti-inflammatory effect in treating DCM. In our research, we investigated the anti-inflammatory properties as well as its possible mechanism. According to the findings in vitro, rhein could to exert an anti-inflammatory effect by reducing the production of NO, TNF-α, PGE2, iNOS, and COX-2 in RAW264.7 cells that had been stimulated with advanced glycosylation end products (AGEs). In addition, rhein alleviated H9C2 cells inflammation injury stimulated by AGEs/macrophage conditioned medium (CM). In vivo have depicted that continuous gavage of rhein could improve cardiac function and pathological changes. Moreover, it could inhibit the accumulation of AGEs and infiltration of inflammatory factors inside the heart of rats having DCM. Mechanism study showed rhein could suppress IKKβ and IκB phosphorylation via down-regulating TRAF6 expression to inhibit NF-κB pathway in AGEs/CM-induced H9C2 cells. Moreover, the anti-inflammation effect of rhein was realized through down-regulation phosphorylation of JNK MAPK. Furthermore, we found JNK MAPK could crosstalk with NF-κB pathway by regulating IκB phosphorylation without affecting IKKβ activity. And hence, the protective mechanism of rhein may involve the inhibiting of the TRAF6-NF/κB pathway, the JNK MAPK pathway, and the crosstalk between the two pathways. These results suggested that rhein may be a promising drug candidate in anti-inflammation and inflammation-related DCM therapy.

Macrophage DCLK1 promotes obesity-induced cardiomyopathy via activating RIP2/TAK1 signaling pathway

Obesity increases the risk for cardiovascular diseases and induces cardiomyopathy. Chronic inflammation plays a significant role in obesity-induced cardiomyopathy and may provide new therapeutic targets for this disease. Doublecortin-like kinase 1 (DCLK1) is an important target for cancer therapy and the role of DCLK1 in obesity and cardiovascular diseases is unclear. Herein, we showed that DCLK1 was overexpressed in the cardiac tissue of obese mice and investigated the role of DCLK1 in obesity-induced cardiomyopathy. We generated DCLK1-deleted mice and showed that macrophage-specific DCLK1 knockout, rather than cardiomyocyte-specific DCLK1 knockout, prevented high-fat diet (HFD)-induced heart dysfunction, cardiac hypertrophy, and fibrosis. RNA sequencing analysis showed that DCLK1 deficiency exerted cardioprotective effects by suppressing RIP2/TAK1 activation and inflammatory responses in macrophages. Upon HFD/palmitate (PA) challenge, macrophage DCLK1 mediates RIP2/TAK1 phosphorylation and subsequent inflammatory cytokine release, which further promotes hypertrophy in cardiomyocytes and fibrogenesis in fibroblasts. Finally, a pharmacological inhibitor of DCLK1 significantly protects hearts in HFD-fed mice. Our study demonstrates a novel role and a pro-inflammatory mechanism of macrophage DCLK1 in obesity-induced cardiomyopathy and identifies DCLK1 as a new therapeutic target for the treatment of this disease. Upon HFD/PA challenge, DCLK1 induces RIP2/TAK1-mediated inflammatory response in macrophages, which subsequently promotes cardiac hypertrophy and fibrosis. Macrophage-specific DCLK1 deletion or pharmacological inhibition of DCLK1 protects hearts in HFD-fed mice.

TRPA1 deficiency attenuates cardiac fibrosis via regulating GRK5/NFAT signaling in diabetic rats

BACKGROUND

Transient receptor potential ankyrin 1 (TRPA1) has been linked to the development of various cardiovascular diseases, but its role in diabetic cardiomyopathy is not well understood. This study aimed to investigate the protective effects of TRPA1 deficiency on diabetic cardiomyopathy in rats with streptozotocin-induced diabetes and in neonatal rat cardiac fibroblasts (CFs) exposed to high glucose (HG).

METHODS

Cardiac TRPA1 expression levels were measured in diabetic rats. Cardiac function, remodeling, and fibrosis were analyzed in Sprague-Dawley (SD) rats and TRPA1-deficient rats with diabetic cardiomyopathy. In vitro, fibrosis was measured in CFs exposed to HG. Additionally, 1,8-cineole, a natural inhibitor of TRPA1, was used to treat SD rats with diabetic cardiomyopathy.

RESULTS

TRPA1 expression was increased in the heart tissue of diabetic rats and in CFs treated with HG. TRPA1 deficiency significantly improved cardiac function in diabetic rats, as evidenced by improved echocardiography and reduced cardiac hypertrophy and fibrosis. In vitro, TRPA1 deficiency suppressed the transformation of HG-induced CFs into myofibroblasts. The cardioprotective effect of TRPA1 deficiency was found to inhibit cardiac fibrosis by regulating GRK5/NFAT signaling. Furthermore, inhibition of GRK5/NFAT signaling abolished the promotion of CF transformation into myofibroblasts by TRPA1 activation. Inhibition of TRPA1 activation by 1,8-cineole reduced cardiac dysfunction and remodeling in diabetic rats by regulating GRK5/NFAT signaling.

CONCLUSIONS

TRPA1 deficiency reduced cardiac fibrosis in diabetic rats and inhibited HG-induced CF activation in vitro by regulating GRK5/NFAT signaling. The TRPA1 inhibitor 1,8-cineole may serve as a novel therapeutic agent for the treatment of diabetic cardiomyopathy.

Pathophysiology and Clinical Impacts of Chronic Kidney Disease on Coronary Artery Calcification

The global prevalence of chronic kidney disease (CKD) has increased in recent years. Adverse cardiovascular events have become the main cause of life-threatening events in patients with CKD, and vascular calcification is a risk factor for cardiovascular disease. Vascular calcification, especially coronary artery calcification, is more prevalent, severe, rapidly progressive, and harmful in patients with CKD. Some features and risk factors are unique to vascular calcification in patients with CKD; the formation of vascular calcification is not only influenced by the phenotypic transformation of vascular smooth muscle cells, but also by electrolyte and endocrine dysfunction, uremic toxin accumulation, and other novel factors. The study on the mechanism of vascular calcification in patients with renal insufficiency can provide a basis and new target for the prevention and treatment of this disease. This review aims to illustrate the impact of CKD on vascular calcification and to discuss the recent research data on the pathogenesis and factors involved in vascular calcification, mainly focusing on coronary artery calcification, in patients with CKD.

Dectin-1 deficiency alleviates diabetic cardiomyopathy by attenuating macrophage-mediated inflammatory response

Cardiovascular diseases are the primary cause of mortality in patients with diabetes and obesity. Hyperglycemia and hyperlipidemia in diabetes alters cardiac function, which is associated with broader cellular processes such as aberrant inflammatory signaling. Recent studies have shown that a pattern recognition receptor called Dectin-1, expressed on macrophages, mediates pro-inflammatory responses in innate immunity. In the present study, we examined the role of Dectin-1 in the pathogenesis of diabetic cardiomyopathy. We observed increased Dectin-1 expression in heart tissues of diabetic mice and localized the source to macrophages. We then investigated the cardiac function in Dectin-1-deficient mice with STZ-induced type 1 diabetes and high-fat-diet-induced type 2 diabetes. Our results show that Dectin-1 deficient mice are protected against diabetes-induced cardiac dysfunction, cardiomyocyte hypertrophy, tissue fibrosis, and inflammation. Mechanistically, our studies show that Dectin-1 is important for cell activation and induction of inflammatory cytokines in high-concentration glucose and palmitate acid (HG + PA)-challenged macrophages. Deficiency of Dectin-1 generate fewer paracrine inflammatory factors capable of causing cardiomyocyte hypertrophy and fibrotic responses in cardiac fibroblasts. In conclusion, this study provides evidence that Dectin-1 mediates diabetes-induced cardiomyopathy through regulating inflammation. Dectin-1 may be a potential target to combat diabetic cardiomyopathy.

Lipid-Sensing Receptor FFAR4 Modulates Pulmonary Epithelial Homeostasis following Immunogenic Exposures Independently of the FFAR4 Ligand Docosahexaenoic Acid (DHA)

The role of pulmonary free fatty acid receptor 4 (FFAR4) is not fully elucidated and we aimed to clarify the impact of FFAR4 on the pulmonary immune response and return to homeostasis. We employed a known high-risk human pulmonary immunogenic exposure to extracts of dust from swine confinement facilities (DE). WT and Ffar4-null mice were repetitively exposed to DE via intranasal instillation and supplemented with docosahexaenoic acid (DHA) by oral gavage. We sought to understand if previous findings of DHA-mediated attenuation of the DE-induced inflammatory response are FFAR4-dependent. We identified that DHA mediates anti-inflammatory effects independent of FFAR4 expression, and that DE-exposed mice lacking FFAR4 had reduced immune cells in the airways, epithelial dysplasia, and impaired pulmonary barrier integrity. Analysis of transcripts using an immunology gene expression panel revealed a role for FFAR4 in lungs related to innate immune initiation of inflammation, cytoprotection, and immune cell migration. Ultimately, the presence of FFAR4 in the lung may regulate cell survival and repair following immune injury, suggestive of potential therapeutic directions for pulmonary disease.

Diabetic vascular diseases: molecular mechanisms and therapeutic strategies

Vascular complications of diabetes pose a severe threat to human health. Prevention and treatment protocols based on a single vascular complication are no longer suitable for the long-term management of patients with diabetes. Diabetic panvascular disease (DPD) is a clinical syndrome in which vessels of various sizes, including macrovessels and microvessels in the cardiac, cerebral, renal, ophthalmic, and peripheral systems of patients with diabetes, develop atherosclerosis as a common pathology. Pathological manifestations of DPDs usually manifest macrovascular atherosclerosis, as well as microvascular endothelial function impairment, basement membrane thickening, and microthrombosis. Cardiac, cerebral, and peripheral microangiopathy coexist with microangiopathy, while renal and retinal are predominantly microangiopathic. The following associations exist between DPDs: numerous similar molecular mechanisms, and risk-predictive relationships between diseases. Aggressive glycemic control combined with early comprehensive vascular intervention is the key to prevention and treatment. In addition to the widely recommended metformin, glucagon-like peptide-1 agonist, and sodium-glucose cotransporter-2 inhibitors, for the latest molecular mechanisms, aldose reductase inhibitors, peroxisome proliferator-activated receptor-γ agonizts, glucokinases agonizts, mitochondrial energy modulators, etc. are under active development. DPDs are proposed for patients to obtain more systematic clinical care requires a comprehensive diabetes care center focusing on panvascular diseases. This would leverage the advantages of a cross-disciplinary approach to achieve better integration of the pathogenesis and therapeutic evidence. Such a strategy would confer more clinical benefits to patients and promote the comprehensive development of DPD as a discipline.

Licochalcone A protects against LPS-induced inflammation and acute lung injury by directly binding with myeloid differentiation factor 2 (MD2)

BACKGROUND AND PURPOSE

Acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) is a challenging clinical syndrome that leads to various respiratory sequelae and even high mortality in patients with severe disease. The novel pharmacological strategies and therapeutic drugs are urgently needed. Natural products have played a fundamental role and provided an abundant pool in drug discovery.

EXPERIMENTAL APPROACH

A compound library containing 160 natural products was used to screen potential anti-inflammatory compounds. Mice with LPS-induced ALI was then used to verify the preventive and therapeutic effects of the selected compounds.

KEY RESULTS

Licochalcone A was discovered from the anti-inflammatory screening of natural products in macrophages. A qPCR array validated the inflammation-regulatory effects of licochalcone A and indicated that the potential targets of licochalcone A may be the upstream proteins in LPS pro-inflammatory signalling. Further studies showed that licochalcone A directly binds to myeloid differentiation factor 2 (MD2), an assistant protein of toll-like receptor 4 (TLR4), to block both LPS-induced TRIF- and MYD88-dependent pathways. LEU61 and PHE151 in MD2 protein are the two key residues that contribute to the binding of MD2 to licochalcone A. In vivo, licochalcone A treatment alleviated ALI in LPS-challenged mice through significantly reducing immunocyte infiltration, suppressing activation of TLR4 pathway and inflammatory cytokine induction.

CONCLUSION AND IMPLICATIONS

In summary, our study identified MD2 as a direct target of licochalcone A for its anti-inflammatory activity and suggested that licochalcone A might serve as a novel MD2 inhibitor and a potential drug for developing ALI/ARDS therapy.

New Insights into the Role of Ferroptosis in Cardiovascular Diseases

Cardiovascular diseases (CVDs) are the principal cause of disease burden and death worldwide. Ferroptosis is a new form of regulated cell death mainly characterized by altered iron metabolism, increased polyunsaturated fatty acid peroxidation by reactive oxygen species, depletion of glutathione and inactivation of glutathione peroxidase 4. Recently, a series of studies have indicated that ferroptosis is involved in the death of cardiac and vascular cells and has a key impact on the mechanisms leading to CVDs such as ischemic heart disease, ischemia/reperfusion injury, cardiomyopathies, and heart failure. In this article, we reviewed the molecular mechanism of ferroptosis and the current understanding of the pathophysiological role of ferroptosis in ischemic heart disease and in some cardiomyopathies. Moreover, the comprehension of the machinery governing ferroptosis in vascular cells and cardiomyocytes may provide new insights into preventive and therapeutic strategies in CVDs.

Tabersonine alleviates obesity-induced cardiomyopathy by binding to Transforming growth factor activated kinase 1 (TAK1) and inhibiting TAK1-mediated inflammation

Obesity-induced cardiomyopathy (OIC) is an increasingly serious global disease caused by obesity. Chronic inflammation greatly contributes to the pathogenesis of OIC. This study aimed to explore the role and mechanism of tabersonine (Tab), a natural alkaloid with antiinflammatory activity, in the treatment of OIC. High fat diet (HFD)-induced obese mice were administered with Tab. The results showed that Tab significantly inhibit inflammation, myocardial fibrosis, and hypertrophy to prevent heart dysfunction, without the alteration of body weight and hyperlipidemia, in HFD-induced obese mice. H9c2 cells and primary cardiomyocytes stimulated by palmitic acid (PA) were used to explore the molecular mechanism and target of Tab. We examined the effect of Tab on key proteins involved in HFD/PA-induced inflammatory signaling pathway and found that Tab significantly inhibits TAK1 phosphorylation in cardiomyocytes. We further detected the direct interaction between Tab and TAK1 at the cellular, animal, and molecular levels. We found that Tab directly binds to TAK1 to inhibit TAK1 phosphorylation, which then blocks TAK1-TAB2 interaction and then NF-κB pro-inflammatory pathway in cultured cardiomyocytes. Our results indicate that Tab is a potential agent for the treatment of OIC, and TAK1 is an effective therapeutic target for this disease.

LncRNA TUG1 Exacerbates Myocardial Fibrosis in Diabetic Cardiomyopathy by Modulating the microRNA-145a-5p/Cfl2 Axis

ABSTRACT

Nowadays, there is limited prevention and treatment for myocardial fibrosis in diabetic cardiomyopathy (DCM). Our study aimed to depict the mechanism of the lncRNA TUG1/miR-145a-5p/Cfl2 axis in DCM and to provide a molecular basis for the study of this disease. Male C57BL/6J mice were intraperitoneally injected with streptozotocin to establish DCM mouse models. The expression levels of lncRNA TUG1, miR-145a-5p, and Cfl2 in myocardial tissues of mice were tested by RT-qPCR or Western blot. Cardiac function was assessed by echocardiography. The contents of Ang-II, TNF-α, and IL-1β were measured using ELISA. The histopathological observation was performed by HE staining and Masson staining. The expression levels of myocardial fibrosis-related genes COL1A1, MMP2, and FN1 were determined by RT-qPCR. In addition, bioinformatics website, RIP assay, pull-down assay, and luciferase activity assay were conducted to verify the relationships of lncRNA TUG1, miR-145a-5p, and Cfl2. In the DCM mouse model, lncRNA TUG1 and Cfl2 expression levels were upregulated and miR-145a-5p expression was downregulated. Downregulation of lncRNA TUG1 improved cardiac function and myocardial fibrosis; decreased COL1A1, MMP2, and FN1 expression levels; as well as TNF-α, IL-1β, and Ang-II contents in myocardial tissues of DCM mice. Upregulation of miR-145a-5p showed the same trend as downregulation of lncRNA TUG1. In addition, upregulating miR-145a-5p reversed the promotion roles of lncRNA TUG1 on myocardial fibrosis in DCM mice, and upregulating Cfl2 compromised the improvement effect of downregulated lncRNA TUG1 on myocardial fibrosis in DCM mice. Mechanistically, there was a binding site between lncRNA TUG1 and miR-145a-5p, and miR-145a-5p had a targeting relationship with Cfl2. This study highlights that lncRNA TUG1 sponges miR-145a-5p to aggravate myocardial fibrosis in DCM mice by promoting Cfl2.

Determination of CYP450 activities in diabetes mellitus rats by a UHPLC-MS/MS method

In this study, we investigated the effect of type 1 diabetes mellitus on the modulation of the activities of CYP450s in dynamics by a UHPLC-MS/MS method. The diabetic rat model was constructed by an intraperitoneal single injection of streptozotocin. Fasting blood glucose levels > 16.7 mmol/L were considered as diabetic. The rats were given a cocktail of four probe drugs (10 mg/kg phenacetin, 1 mg/kg tolbutamide, 10 mg/kg metoprolol, and 10 mg/kg midazolam) by oral administration for the pharmacokinetic study. Thereafter, the metabolic ratio (MR) of the metabolites to probe substrates were determined. The results indicated that two weeks after diabetes was induced, diabetes increased the MRs of acetaminophen/phenacetin (CYP1A2) and 4-hydroxyl tolbutamide/tolbutamide (CYP2C9); however, it decreased the MRs of α-hydroxy metoprolol/metoprolol (CYP2D6) and 1-hydroxy midazolam/midazolam (CYP3A4). Two months after diabetes was induced, diabetes increased the MRs of acetaminophen/phenacetin and 4-hydroxyl tolbutamide/tolbutamide. The MR of α-hydroxy metoprolol/metoprolol was decreased and the MR of 1-hydroxy midazolam/midazolam was increased but the difference was not significant. According to the results, CYP1A2 and CYP2C9 activities were enhanced in the diabetic rats. and CYP2D6 activity was inhibited in a short period of diabetes; however, the decrease in CYP2D6 activity was not significant in the long period. CYP3A4 activity was decreased in a short period of diabetes and increased in a long period of diabetes but was not significant in the two periods. This study suggests the activity change rule of the CYP450 enzyme system in diabetes mellitus, which can provide a reference for precise clinical medication.

Dihydromyricetin Attenuates Diabetic Cardiomyopathy by Inhibiting Oxidative Stress, Inflammation and Necroptosis via Sirtuin 3 Activation

Dihydromyricetin (DHY), the main flavonoid component in Ampelopsis grossedentata, has important benefits for health. The present study aimed to investigate the exact effects and possible mechanisms of DHY on diabetic cardiomyopathy (DCM). Male C57BL/6 mice and sirtuin 3 (SIRT3) knockout (SIRT3-KO) mice were injected with streptozotocin (STZ) to induce a diabetic model. Two weeks later, DHY (250 mg/kg) or carboxymethylcellulose (CMC) were administrated once daily by gavage for twelve weeks. We found that DHY alleviated fasting blood glucose (FBG) and triglyceride (TG) as well as glycosylated hemoglobin (HbA1c) levels; increased fasting insulin (FINS); improved cardiac dysfunction; ameliorated myocardial hypertrophy, fibrosis and injury; suppressed oxidative stress, inflammasome and necroptosis; but improved SIRT3 expression in STZ-induced mice. Neonatal rat cardiomyocytes were pre-treated with DHY (80 μM) with or without high glucose (HG) stimulation. The results showed that DHY attenuated cell damage but improved SIRT3 expression and inhibited oxidative stress, inflammasome and necroptosis in cardiomyocytes with high glucose stimulation. Moreover, the above protective effects of DHY on DCM were unavailable in SIRT3-KO mice, implying a promising medical potential of DHY for DCM treatment. In sum, DHY improved cardiac dysfunction; ameliorated myocardial hypertrophy, fibrosis and injury; and suppressed oxidative stress, inflammation and necroptosis via SIRT3 activation in STZ-induced diabetic mice, suggesting DHY may serve as a candidate for an agent to attenuate diabetic cardiomyopathy.

MD2 Inhibits Choroidal Neovascularization via Antagonizing TLR4/MD2 Mediated Signaling Pathway

PURPOSE

To explore the pathological mechanism of Toll-like receptor 4 (TLR4) mediating neovascular age-related macular degeneration (nAMD) and the potential role of the TLR4 coreceptor myeloid differentiation protein 2 (MD2).

METHODS

In the study, we inhibited MD2 with the chalcone derivative L2H17 and we utilized a laser-induced choroidal neovascularization (CNV) mouse model and Tert-butyl hydroperoxide (TBHP)-challenged rhesus choroid-retinal endothelial (RF/6A) cells to assess the effect of MD2 blockade on CNV.

RESULTS

Inhibiting MD2 with L2H17 reduced angiogenesis in CNV mice, and significantly protected against retinal dysfunction. In retina and choroid/retinal pigment epithelium (RPE) tissues, L2H17 reduced phospho-ERK, phospho-P65 but not phospho-P38, phospho-JNK, and reduced the transcriptional levels of IL-6, TNF-α, ICAM-1 but not VCAM-1. L2H17 could protect RF/6A against TBHP-induced inflammation, oxidative stress, and apoptosis, via inhibiting the TLR4/MD2 signaling pathway and the following downstream mitogen-activated protein kinase (MAPK) and nuclear transcription factor-κB (NF-κB) activation.

CONCLUSIONS

Inhibiting MD2 with L2H17 significantly reduced CNV, suppressed inflammation, and oxidative stress by antagonizing TLR4/MD2 pathway in an MD2-dependent manner. MD2 may be a potential therapeutic target and L2H17 may offer an alternative treatment strategy for nAMD.

Demethyleneberberine alleviated the inflammatory response by targeting MD-2 to inhibit the TLR4 signaling

Introduction

The colitis induced by trinitrobenzenesulfonic acid (TNBS) is a chronic and systemic inflammatory disease that leads to intestinal barrier dysfunction and autoimmunedisorders. However, the existing treatments of colitis are associated with poor outcomes, and the current strategies remain deep and long-time remission and the prevention of complications. Recently, demethyleneberberine (DMB) has been reported to be a potential candidate for the treatment of inflammatory response that relied on multiple pharmacological activities, including anti-oxidation and antiinflammation. However, the target and potential mechanism of DMB in inflammatory response have not been fully elucidated.

Methods

This study employed a TNBS-induced colitis model and acute sepsis mice to screen and identify the potential targets and molecular mechanisms of DMB in vitro and in vivo. The purity and structure of DMB were quantitatively analyzed by high-performance liquid chromatography (HPLC), mass spectrometry (MS), Hydrogen nuclear magnetic resonance spectroscopy (¹H-NMR), and infrared spectroscopy (IR), respectively. The rats were induced by a rubber hose inserted approximately 8 cm through their anus to be injected with TNBS. Acute sepsis was induced by injection with LPS via the tail vein for 60 h. These animals with inflammation were orally administrated with DMB, berberine (BBR), or curcumin (Curc), respectively. The eukaryotic and prokaryotic expression system of myeloid differentiation protein-2 (MD-2) and its mutants were used to evaluate the target of DMB in inflammatory response.

Resluts

DMB had two free phenolic hydroxyl groups, and the purity exceeded 99% in HPLC. DMB alleviated colitis and suppressed the activation of TLR4 signaling in TNBS-induced colitis rats and LPS-induced RAW264.7 cells. DMB significantly blocked TLR4 signaling in both an MyD88-dependent and an MyD88-independent manner by embedding into the hydrophobic pocket of the MD-2 protein with non-covalent bonding to phenylalanine at position 76 in a pi-pi T-shaped interaction. DMB rescued mice from sepsis shock induced by LPS through targeting the TLR4-MD-2 complex.

Conclusion

Taken together, DMB is a promising inhibitor of the MD-2 protein to suppress the hyperactivated TLR4 signaling in inflammatory response.

The impact of oxidative stress-induced mitochondrial dysfunction on diabetic microvascular complications

Diabetes mellitus (DM) is a metabolic disease characterized by chronic hyperglycaemia, with absolute insulin deficiency or insulin resistance as the main cause, and causes damage to various target organs including the heart, kidney and neurovascular. In terms of the pathological and physiological mechanisms of DM, oxidative stress is one of the main mechanisms leading to DM and is an important link between DM and its complications. Oxidative stress is a pathological phenomenon resulting from an imbalance between the production of free radicals and the scavenging of antioxidant systems. The main site of reactive oxygen species (ROS) production is the mitochondria, which are also the main organelles damaged. In a chronic high glucose environment, impaired electron transport chain within the mitochondria leads to the production of ROS, prompts increased proton leakage and altered mitochondrial membrane potential (MMP), which in turn releases cytochrome c (cyt-c), leading to apoptosis. This subsequently leads to a vicious cycle of impaired clearance by the body's antioxidant system, impaired transcription and protein synthesis of mitochondrial DNA (mtDNA), which is responsible for encoding mitochondrial proteins, and impaired DNA repair systems, contributing to mitochondrial dysfunction. This paper reviews the dysfunction of mitochondria in the environment of high glucose induced oxidative stress in the DM model, and looks forward to providing a new treatment plan for oxidative stress based on mitochondrial dysfunction.