Pyruvate dehydrogenase kinase regulates vascular inflammation in atherosclerosis and increases cardiovascular risk

Dichloroacetate, a pyruvate dehydrogenase activator, alleviates high-fat-induced impairment of myogenic differentiation in skeletal muscles

Obesity-induced impairment of myogenic differentiation leads to muscle loss and sarcopenia. Pyruvate dehydrogenase (PDH) plays a crucial role in glucose metabolism and is associated with muscle differentiation. However, the effect of dichloroacetate (DCA), a PDH activator, on obesity-induced impairment of myogenic differentiation remains unknown. Here, we evaluated the effects of DCA treatment on high-fat intake-induced impairment of myogenic differentiation in C2C12 cells and C57BL/6 mice. In C2C12 cells, DCA treatment improved PDH activity that was reduced by palmitate (PAL) and decreased the lactate concentrations in the media. Additionally, DCA reversed PAL- and high-fat diet (HFD)-induced decrease in the expression of myoblast determination protein 1 (MyoD), myogenin (MyoG) and myosin heavy chain (MyHC) in C2C12 cells and C57BL/6 mice. To explore the possible mechanism, DCA treatment restored the levels of p-Akt, p-FoxO1, p-FoxO3a and p-p38 MAPK levels in PAL-treated C2C12 cells. Moreover, the protective effects of DCA were reversed by treatment with the Akt inhibitor MK2206 in C2C12 cells. In summary, DCA treatment alleviated high-fat intake-induced impairment of myogenic differentiation via Akt signalling, suggesting its potential in treating obesity-associated muscle loss and sarcopenia.

TNF-α/IL-1β/IL-1α/IL-12 inflammatory cytokine axes coupled with TLR1/TLR3/TLR5/MYD88 immune signaling pathway over-activation contribute to simultaneous carotid and coronary artery and occlusion in elderly patients

BACKGROUND

It remains difficult to evaluate the risk factors for concomitant carotid artery as well as coronary artery diseases in elderly patients. The aim of this research was to determine the TNF-α/IL-1β/IL-1α/IL-12 axes-TLR1/TLR3/TLR5/MYD88 immune signaling pathway interactions in coexistent carotid artery occlusion and coronary artery occlusion in elderly patients.

METHODS

Elderly patients, who underwent carotid ultrasonography and coronary computed tomography angiography, were consecutively included in this research. The analyzed groups consisted of those with coexistent carotid artery occlusion and coronary artery occlusion as well as healthy individuals were enrolled as control group. The circulating levels of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-1α (IL-1α), interleukin-12 (IL-12), toll-like receptor 1 (TLR1), toll-like receptor 3 (TLR3), toll-like receptor 5 (TLR5) and myeloid differentiation factor 88 (MYD88) were measured.

RESULTS

The biomarkers (TNF-α, IL-1β, IL-1α, IL-12, TLR1, TLR3, TLR5 and MYD88) were significantly increased in carotid artery occlusion + left circumflex coronary artery occlusion group when compared with control group and carotid artery occlusion + right coronary artery occlusion group, respectively (P < 0.001), and were further elevated in carotid artery occlusion + left anterior descending coronary artery occlusion group when compared to carotid artery occlusion + right coronary artery occlusion group and carotid artery occlusion + left circumflex coronary artery occlusion group, respectively (P < 0.001).

CONCLUSION

This research demonstrated that the TNF-α/IL-1β/IL-1α/IL-12 axes and TLR1/TLR3/TLR5/MYD88 immune signaling pathway implicated in the pathogenesis of carotid artery occlusion with coronary artery occlusion in elderly patients.

Salvianic acid A ameliorates atherosclerosis through metabolic-dependent anti-EndMT pathway and repression of TGF-β/ALK5 signaling

BACKGROUND

Endothelial-to-mesenchymal transition (EndMT) has been identified as a key factor to the initiation and progression of the pathogenesis of atherosclerosis (AS). Salvianic acid A (SAAS) is the primary water-soluble bioactive ingredient found in Salvia miltiorrhiza, is renowned for its therapeutic effects on cardiovascular diseases. However, the efficacy and mechanisms of SAAS in treating EndMT-induced AS remain underexplored.

PURPOSE

This study aimed to investigate the role SAAS in reversing EndMT process to impede AS development.

METHODS

We used a murine model of cholesterol-rich and high-fat diet-induced AS in ApoE-/- mice to evaluate the effect of SAAS on EndMT during AS progression in vivo. The biological effects of SAAS on EndMT-induced HUVEC cells were also detected by transcriptome sequencing (RNA-seq). Mechanistic exploration was carried out using omics data mining and screening, gene knockout experiments, gene expression, protein expression, and localization of key gene expression in animal lesion areas.

RESULTS

We found that SAAS treatment significantly alleviated EndMT injury in the AS mice model and also improved aortic root lesions and dyslipidemia. Furthermore, pre-treatment with SAAS effectively inhibited the EndMT in HUVEC cells, as evidenced by maintained endothelial cell morphology and reduced cell migration ability, as well as elevated CD31 and decreased α-SMA. RNA sequencing data indicated that key differentially expressed genes were mainly enriched in metabolism-related and TGF-β receptor signaling pathways. The metabolic regulator PDK4 and profibrotic TGF-β receptor ALK5 were identified specifically. Subsequently, RT-qPCR and western blot results demonstrated that SAAS notably increased metabolic regulator PDK4 and decreased profibrotic TGF-β receptor ALK5 in EndMT-induced HUVEC cells. Moreover, siRNA-directed PDK4 inhibition resulted in EndMT induction and SAAS mediated the suppression of EndMT in a PDK4-dependent manner. Additionally, SAAS partially reduced the TGF-β receptor ALK5 expression. Furthermore, ApoE-/- AS mice with SAAS treatment displayed downregulation of ALK5 and upregulation of PDK4 with reduced EndMT during AS.

CONCLUSION

This investigation demonstrated that SAAS improved AS through metabolic-dependent anti-EndMT pathway and repression of profibrotic TGF-β receptor signaling, thereby providing SAAS as a promising therapeutic candidate for managing AS and EndMT-related disorders.

Regulation of lactate accumulation in bovine mammary epithelial cells by LPS-induced HIF-1α/MCT1 pathway

Lactate has been increasingly recognized for its role in diseases progression, necessitating a deeper understanding of its metabolic processes and regulatory mechanisms. This study aimed to evaluate the impact of lipopolysaccharide (LPS) on lactate accumulation in bovine mammary epithelial cells (BMECs) and to elucidate the underlying regulatory mechanisms. Further optimization of LPS treatment points was achieved by assessing the content of key glycolytic enzymes-hexokinases (HK), pyruvate kinase (PK) and pyruvate dehydrogenase (PDH)-as well as the expression levels of HK2, pyruvate dehydrogenase kinase4 (PDK4) and lactate dehydrogenase (LDHA). Our results indicate that LPS can promote intracellular glycolysis and inhibits pyruvate synthesis, thereby increasing lactate content. BMECs were cultured and divided into a control group (CON) and an LPS-stimulated group (10 μg/mL for 6 h, LPS group). LPS was found to upregulate expression levels of HIF-1α and MCT1, suggesting a role for HIF-1α and MCT1 in cellular glucose metabolism. To explore the effect of HIF-1α on lactate accumulation, BMECs were stimulated with a HIF-1α inducer (COCL2) and HIF-1α inhibitor (DMBPA). COCL2 was observed to promote lactate accumulation, while DMBPA inhibited it. Additionally, modulation of HIF-1α expression influenced the expression of MCT1, which is a crucial transporter for extracellular lactate influx. To investigate the specific impact of MCT1 on intracellular lactate, we utilized overexpression plasmids and small interfering RNA to modulate MCT1 expression. The findings indicate that while MCT1 expression alone does not affect intracellular lactate levels, it does modulate the changes induced by LPS. In conclusion, our study suggests that LPS regulates lactate accumulation in BMECs through the HIF-1α/MCT1 pathway, providing insights into the metabolic dysregulation associated with LPS-induced stress in dairy cattle.

Deciphering Structural Dynamics of Atherosclerosis Proteins: Insights from Crataegus oxyacantha Phytochemicals that Interceded Functional and Structural Changes in Targeted Atherosclerotic Proteins

Atherosclerosis (ASC) is characterized by foam cell-mediated plaque formation, vascular endothelial inflammation, and lipidosis and is the rudimentary cause of cardiovascular diseases. This is the pre-eminent global factor of mortality. This etiological paradigm is significantly influenced by several proteins, where 23 pivotal proteins involved in ASC were meticulously gleaned on the basis of literature studies. The crux of the present study was aimed to probe the drugability of four active phytochemicals from Crataegus oxyacantha (COC): epicatechin, gallate, tyramine, and vitexin against the selected 23 proteins. The molecular docking analysis was judiciously administered via Glide, the binding free energy was calculated in detail utilizing the prime molecular mechanics-generalized Born surface area (MM-GBSA) module, and a deeper comprehensive investigation of protein-ligand dynamic associations was elucidated through Desmond. Drawing from the upper echelons of our docking results, the molecular dynamics simulation outcomes revealed that the macrophage migration inhibitory factor and prethrombin-1 showed persistent binding nature with gallate. The bioactive compound known as gallate sourced from COC shows the best molecular association with pivotal proteins involved in ASC and has a promising therapeutic potential for drug development endeavors.

Dexmedetomidine Ameliorates Myocardial Ischemia-Reperfusion Injury by Inhibiting MDH2 Lactylation via Regulating Metabolic Reprogramming

Myocardial ischemia-reperfusion injury (MIRI) significantly worsens the outcomes of patients with cardiovascular diseases. Dexmedetomidine (Dex) is recognized for its cardioprotective properties, but the related mechanisms, especially regarding metabolic reprogramming, have not been fully clarified. A total of 60 patients with heart valve disease are randomly assigned to Dex or control group. Blood samples are collected to analyze cardiac injury biomarkers and metabolomics. In vivo and vitro rat models of MIRI are utilized to assess the effects of Dex on cardiac function, lactate production, and mitochondrial function. It is found that postoperative CK-MB and cTNT levels are significantly lower in the Dex group. Metabolomics reveals that Dex regulates metabolic reprogramming and reduces lactate level. In Dex-treated rats, the myocardial infarction area is reduced, and myocardial contractility is improved. Dex inhibits glycolysis, reduces lactate, and improves mitochondrial function following MIRI. Lactylation proteomics identifies that Dex reduces the lactylation of Malate Dehydrogenase 2（MDH2), thus alleviating myocardial injury. Further studies reveal that MDH2 lactylation induces ferroptosis, leading to MIRI by impairing mitochondrial function. Mechanistic analyses reveal that Dex upregulates Nuclear Receptor Subfamily 3 Group C Member 1（NR3C1) phosphorylation, downregulates Pyruvate Dehydrogenase Kinase 4 (PDK4), and reduces lactate production and MDH2 lactylation. These findings provide new therapeutic targets and mechanisms for the treatment for MIRI.

Transcriptome analysis of jejunal mucosal tissue in breeder hens exposed to acute heat stress

Heat stress (HS) severely compromises intestinal barrier function in poultry, resulting in significant production losses. This study aimed to explore the molecular response of the small intestine to acute HS in breeder hens. Fifty 28-week-old breeder hens were raised individually in a cage and randomly assigned to control and heat-treated groups (25 hens each). Control group hens were maintained at thermoneutral conditions (23°C) and heat-treated group hens were subjected to acute HS (36°C for a 6-h). The heart rate and cloacal temperature were measured in all hens. The jejunal mucosa tissues were collected from 12 randomly selected hens per group for transcriptomic analysis. The acute HS induced significant physiological alterations, with a marked increase in the heart rate and cloacal temperature in hens (P = 0.001). Transcriptome analysis revealed 138 genes with altered expression patterns under acute HS conditions. Of these, 75 genes including heat shock proteins (HSPs) showed upregulated expression, while 63 genes including a key bile acid transport molecule (SLC10A2) exhibited downregulated expression. Functional analysis through gene ontology classification, pathway mapping via the Kyoto encyclopedia of genes and genomes, and protein interaction networks identified several important regulatory genes in thermal response (HSPA8 and HSPA2), energy homeostasis and fat metabolism (PDK4, PPARA, and CD36), glucose transport (SLC2A5), and cholesterol synthesis pathway (SQLE, CYP51A1, and HSD17B7). The findings suggest that acute HS might affect energy utilization, fat metabolism, and glucose transport mechanisms in the jejunal mucosa of breeder hens. The upregulation of HSPs appears to serve as a protective mechanism, potentially preserving intestinal nutrient processing capacity under acute HS. These findings provide foundational knowledge for further investigation into the molecular mechanisms governing HS responses in avian intestinal function and may inform strategies for maintaining gut health in commercial poultry operations exposed to environmental challenges.

Integrated multi-omics analysis reveals molecular changes associated with chronic lipid accumulation following contusive spinal cord injury

Functional and pathological recovery after spinal cord injury (SCI) is often incomplete due to the limited regenerative capacity of the central nervous system (CNS), which is further impaired by several mechanisms that sustain tissue damage. Among these, the chronic activation of immune cells can cause a persistent state of local CNS inflammation and damage. However, the mechanisms that sustain this persistent maladaptive immune response in SCI have not been fully clarified yet. In this study, we integrated histological analyses with proteomic, lipidomic, transcriptomic, and epitranscriptomic approaches to study the pathological and molecular alterations that develop in a mouse model of cervical spinal cord hemicontusion. We found significant pathological alterations of the lesion rim with myelin damage and axonal loss that persisted throughout the late chronic phase of SCI. This was coupled by a progressive lipid accumulation in myeloid cells, including resident microglia and infiltrating monocyte-derived macrophages. At tissue level, we found significant changes of proteins indicative of glycolytic, tricarboxylic acid cycle (TCA), and fatty acid metabolic pathways with an accumulation of triacylglycerides with C16:0 fatty acyl chains in chronic SCI. Following transcriptomic, proteomic, and epitranscriptomic studies identified an increase of cholesterol and m6A methylation in lipid-droplet-accumulating myeloid cells as a core feature of chronic SCI. By characterizing the multiple metabolic pathways altered in SCI, our work highlights a key role of lipid metabolism in the chronic response of the immune and central nervous system to damage.

A detective story of intermittent fasting effect on immunity

Intermittent fasting (IF) refers to periodic fasting routines, that caloric intake is minimized not by meal portion size reduction but by intermittently eliminating ingestion of one or several consecutive meals. IF can instigate comprehensive and multifaceted alterations in energy metabolism, these metabolic channels may aboundingly function as primordial mechanisms that interface with the immune system, instigating intricate immune transformations. This review delivers a comprehensive understanding of IF, paying particular attention to its influence on the immune system, thus seeking to bridge these two research domains. We explore how IF effects lipid metabolism, hormonal levels, circadian rhythm, autophagy, oxidative stress, gut microbiota, and intestinal barrier integrity, and conjecture about the mechanisms orchestrating the intersect between these factors and the immune system. Moreover, the review includes research findings on the implications of IF on the immune system and patients burdened with autoimmune diseases.

Chitinase‑3 like‑protein‑1: A potential predictor of cardiovascular disease (Review)

Chitinase‑3 like‑protein‑1 (CHI3L1), a glycoprotein belonging to the glycoside hydrolase family 18, binds to chitin; however, this protein lacks chitinase activity. Although CHI3L1 is not an enzyme capable of degrading chitin, it plays significant roles in abnormal glucose and lipid metabolism, indicating its involvement in metabolic disorders. In addition, CHI3L1 is considered a key player in inflammatory diseases, with clinical data suggesting its potential as a predictor of cardiovascular disease. CHI3L1 regulates the inflammatory response of various cell types, including macrophages, vascular smooth muscle cells and fibroblasts. In addition, CHI3L1 participates in vascular remodeling and fibrosis, contributing to the pathogenesis of cardiovascular disease. At present, research is focused on elucidating the role of CHI3L1 in cardiovascular disease. The present systematic review was conducted to comprehensively evaluate the effects of CHI3L1 on cardiovascular cells, and determine the potential implications in the occurrence and progression of cardiovascular disease. The present study may further the understanding of the involvement of CHI3L1 in cardiovascular pathology, demonstrating its potential as a therapeutic target or biomarker in the management of cardiovascular disease.

Post-translational modifications of pyruvate dehydrogenase complex in cardiovascular disease

Pyruvate dehydrogenase complex (PDC) is a crucial enzyme that connects glycolysis and the tricarboxylic acid (TCA) cycle pathway. It plays an essential role in regulating glucose metabolism for energy production by catalyzing the oxidative decarboxylation of pyruvate to acetyl coenzyme A. Importantly, the activity of PDC is regulated through post-translational modifications (PTMs), phosphorylation, acetylation, and O-GlcNAcylation. These PTMs have significant effects on PDC activity under both physiological and pathophysiological conditions, making them potential targets for metabolism-related diseases. This review specifically focuses on the PTMs of PDC in cardiovascular diseases (CVDs) such as myocardial ischemia/reperfusion injury, diabetic cardiomyopathy, obesity-related cardiomyopathy, heart failure (HF), and vascular diseases. The findings from this review offer theoretical references for the diagnosis, treatment, and prognosis of CVD.

Immunometabolism in atherosclerosis: a new understanding of an old disease

Atherosclerosis, a chronic inflammatory condition, remains a leading cause of death globally, necessitating innovative approaches to target pro-atherogenic pathways. Recent advancements in the field of immunometabolism have highlighted the crucial interplay between metabolic pathways and immune cell function in atherogenic milieus. Macrophages and T cells undergo dynamic metabolic reprogramming to meet the demands of activation and differentiation, influencing plaque progression. Furthermore, metabolic intermediates intricately regulate immune cell responses and atherosclerosis development. Understanding the metabolic control of immune responses in atherosclerosis, known as athero-immunometabolism, offers new avenues for preventive and therapeutic interventions. This review elucidates the emerging intricate interplay between metabolism and immunity in atherosclerosis, underscoring the significance of metabolic enzymes and metabolites as key regulators of disease pathogenesis and therapeutic targets.

Design and synthesis of novel fluorene derivatives as inhibitors of pyruvate dehydrogenase kinase

Activation of pyruvate dehydrogenase (PDH) by inhibition of pyruvate dehydrogenase kinase (PDHK) has the potential for the treatment of diabetes mellitus and its complications, caused by the malfunction of the glycolytic system and glucose oxidation. In this paper, we describe the identification of novel PDHK inhibitors with a fluorene structure. High-throughput screening using our in-house library provided compound 6 as a weak inhibitor that occupied the allosteric lipoyl group binding site in PDHK2. Structure-based drug design (SBDD) while addressing physicochemical properties succeeded in boosting inhibitory activity approximately 700-fold. Thus obtained compound 32 showed favorable pharmacokinetics profiles supported by high membrane permeability and metabolic stability, and exhibited activation of PDH in rat livers and a glucose lowering effect in Zucker fatty rats.

A potential early-atheroprotective target: Irgm1 mediates lymphangiogenesis through LEC autophagy by Tfeb translocation

Lymphatic dysfunction is a pivotal pathological mechanism underlying the development of early atherosclerotic plaques. Potential targets of lymphatic function must be identified to realize the early prevention and treatment of atherosclerosis (AS). The immunity-related GTPase Irgm1 is involved in orchestrating cellular autophagy and apoptosis. However, the effect of Irgm1 on early AS progression, particularly through alterations in lymphatic function, remains unclear. In this study, we confirmed the protective effect of lymphangiogenesis on early-AS in vivo. Subsequently, an in vivo model of early AS mice with Irgm1 knockdown shows that Irgm1 reduces early atherosclerotic plaque burden by promoting lymphangiogenesis. Given that lymphatic endothelial cell (LEC) autophagy significantly contributes to lymphangiogenesis, Irgm1 may enhance lymphatic circulation by promoting LEC autophagy. Moreover, Irgm1 orchestrates autophagy in LECs by inhibiting mTOR and facilitating nuclear translocation of Tfeb. Collectively, these processes lead to lymphangiogenesis. Thus, this study establishes a link between Irgm1 and early AS, thus revealing a novel mechanism by which Irgm1 exerts an early protective influence on AS within the context of lymphatic circulation. The insights gained from this study have the potential to revolutionize the approach and management of AS onset.

The emerging importance of the α-keto acid dehydrogenase complexes in serving as intracellular and intercellular signaling platforms for the regulation of metabolism

The α-keto acid dehydrogenase complex (KDHc) class of mitochondrial enzymes is composed of four members: pyruvate dehydrogenase (PDHc), α-ketoglutarate dehydrogenase (KGDHc), branched-chain keto acid dehydrogenase (BCKDHc), and 2-oxoadipate dehydrogenase (OADHc). These enzyme complexes occupy critical metabolic intersections that connect monosaccharide, amino acid, and fatty acid metabolism to Krebs cycle flux and oxidative phosphorylation (OxPhos). This feature also imbues KDHc enzymes with the heightened capacity to serve as platforms for propagation of intracellular and intercellular signaling. KDHc enzymes serve as a source and sink for mitochondrial hydrogen peroxide (mtH2O2), a vital second messenger used to trigger oxidative eustress pathways. Notably, deactivation of KDHc enzymes through reversible oxidation by mtH2O2 and other electrophiles modulates the availability of several Krebs cycle intermediates and related metabolites which serve as powerful intracellular and intercellular messengers. The KDHc enzymes also play important roles in the modulation of mitochondrial metabolism and epigenetic programming in the nucleus through the provision of various acyl-CoAs, which are used to acylate proteinaceous lysine residues. Intriguingly, nucleosomal control by acylation is also achieved through PDHc and KGDHc localization to the nuclear lumen. In this review, I discuss emerging concepts in the signaling roles fulfilled by the KDHc complexes. I highlight their vital function in serving as mitochondrial redox sensors and how this function can be used by cells to regulate the availability of critical metabolites required in cell signaling. Coupled with this, I describe in detail how defects in KDHc function can cause disease states through the disruption of cell redox homeodynamics and the deregulation of metabolic signaling. Finally, I propose that the intracellular and intercellular signaling functions of the KDHc enzymes are controlled through the reversible redox modification of the vicinal lipoic acid thiols in the E2 subunit of the complexes.

Lactate and lactylation in macrophage metabolic reprogramming: current progress and outstanding issues

It is commonly known that different macrophage phenotypes play specific roles in different pathophysiological processes. In recent years, many studies have linked the phenotypes of macrophages to their characteristics in different metabolic pathways, suggesting that macrophages can perform different functions through metabolic reprogramming. It is now gradually recognized that lactate, previously overlooked as a byproduct of glycolytic metabolism, acts as a signaling molecule in regulating multiple biological processes, including immunological responses and metabolism. Recently, lactate has been found to mediate epigenetic changes in macrophages through a newfound lactylation modification, thereby regulating their phenotypic transformation. This novel finding highlights the significant role of lactate metabolism in macrophage function. In this review, we summarize the features of relevant metabolic reprogramming in macrophages and the role of lactate metabolism therein. We also review the progress of research on the regulation of macrophage metabolic reprogramming by lactylation through epigenetic mechanisms.

Dysregulated cellular metabolism in atherosclerosis: mediators and therapeutic opportunities

Accumulating evidence over the past decades has revealed an intricate relationship between dysregulation of cellular metabolism and the progression of atherosclerotic cardiovascular disease. However, an integrated understanding of dysregulated cellular metabolism in atherosclerotic cardiovascular disease and its potential value as a therapeutic target is missing. In this Review, we (1) summarize recent advances concerning the role of metabolic dysregulation during atherosclerosis progression in lesional cells, including endothelial cells, vascular smooth muscle cells, macrophages and T cells; (2) explore the complexity of metabolic cross-talk between these lesional cells; (3) highlight emerging technologies that promise to illuminate unknown aspects of metabolism in atherosclerosis; and (4) suggest strategies for targeting these underexplored metabolic alterations to mitigate atherosclerosis progression and stabilize rupture-prone atheromas with a potential new generation of cardiovascular therapeutics.

Construction and analysis of a network of exercise-induced mitochondria-related non-coding RNA in the regulation of diabetic cardiomyopathy

Diabetic cardiomyopathy (DCM) is a major factor in the development of heart failure. Mitochondria play a crucial role in regulating insulin resistance, oxidative stress, and inflammation, which affect the progression of DCM. Regular exercise can induce altered non-coding RNA (ncRNA) expression, which subsequently affects gene expression and protein function. The mechanism of exercise-induced mitochondrial-related non-coding RNA network in the regulation of DCM remains unclear. This study seeks to construct an innovative exercise-induced mitochondrial-related ncRNA network. Bioinformatic analysis of RNA sequencing data from an exercise rat model identified 144 differentially expressed long non-coding RNA (lncRNA) with cutoff criteria of p< 0.05 and fold change ≥1.0. GSE6880 and GSE4745 were the differentially expressed mRNAs from the left ventricle of DCM rat that downloaded from the GEO database. Combined with the differentially expressed mRNA and MitoCarta 3.0 dataset, the mitochondrial located gene Pdk4 was identified as a target gene. The miRNA prediction analysis using miRanda and TargetScan confirmed that 5 miRNAs have potential to interact with the 144 lncRNA. The novel lncRNA-miRNA-Pdk4 network was constructed for the first time. According to the functional protein association network, the newly created exercise-induced ncRNA network may serve as a promising diagnostic marker and therapeutic target, providing a fresh perspective to understand the molecular mechanism of different exercise types for the prevention and treatment of diabetic cardiomyopathy.

Genetic Ablation of Pyruvate Dehydrogenase Kinase Isoform 4 Gene Enhances Recovery from Hyperoxic Lung Injury: Insights into Antioxidant and Inflammatory Mechanisms

BACKGROUND

Pyruvate dehydrogenase kinase isoform 4 (PDK4) plays a pivotal role in the regulation of cellular proliferation and apoptosis. The objective of this study was to examine whether the genetic depletion of the PDK4 gene attenuates hyperoxia-induced lung injury in neonatal mice.

METHODS

Neonatal PDK4-/- mice and wild-type (WT) mice were exposed to oxygen concentrations of 21% (normoxia) and 95% (hyperoxia) for the first 4 days of life. Pulmonary histological assessments were performed, and the mRNA levels of lung PDK4, monocyte chemoattractant protein (MCP)-1 and interleukin (IL)-6 were assessed. The levels of inflammatory cytokines in lung tissue were quantified.

RESULTS

Following convalescence from neonatal hyperoxia, PDK4-/- mice exhibited improved lung alveolarization. Notably, PDK4-/- mice displayed significantly elevated MCP-1 protein levels in pulmonary tissues following 4 days of hyperoxic exposure, whereas WT mice showed increased IL-6 protein levels under similar conditions. Furthermore, neonatal PDK4-/- mice subjected to hyperoxia demonstrated markedly higher MCP-1 mRNA expression at 4 days of age compared to WT mice, while IL-6 mRNA expression remained unaffected in PDK4-/- mice.

CONCLUSIONS

Newborn PDK4-/- mice exhibited notable recovery from hyperoxia-induced lung injury, suggesting the potential protective role of PDK4 depletion in mitigating lung damage.

Type 2 diabetes and succinate: unmasking an age-old molecule

Beyond their conventional roles in intracellular energy production, some traditional metabolites also function as extracellular messengers that activate cell-surface G-protein-coupled receptors (GPCRs) akin to hormones and neurotransmitters. These signalling metabolites, often derived from nutrients, the gut microbiota or the host's intermediary metabolism, are now acknowledged as key regulators of various metabolic and immune responses. This review delves into the multi-dimensional aspects of succinate, a dual metabolite with roots in both the mitochondria and microbiome. It also connects the dots between succinate's role in the Krebs cycle, mitochondrial respiration, and its double-edge function as a signalling transmitter within and outside the cell. We aim to provide an overview of the role of the succinate-succinate receptor 1 (SUCNR1) axis in diabetes, discussing the potential use of succinate as a biomarker and the novel prospect of targeting SUCNR1 to manage complications associated with diabetes. We further propose strategies to manipulate the succinate-SUCNR1 axis for better diabetes management; this includes pharmacological modulation of SUCNR1 and innovative approaches to manage succinate concentrations, such as succinate administration and indirect strategies, like microbiota modulation. The dual nature of succinate, both in terms of origins and roles, offers a rich landscape for understanding the intricate connections within metabolic diseases, like diabetes, and indicates promising pathways for developing new therapeutic strategies.

Management of ulcerative colitis by dichloroacetate: Impact on NFATC1/NLRP3/IL1B signaling based on bioinformatics analysis combined with in vivo experimental verification

The inflammatory response in ulcerative colitis (UC) could be relieved by the conventional immunomodulatory agents; 5-aminosalicylic acid, corticosteroids, or azathioprine. However, the low remission rates and the intolerance to these agents necessitate investigation of gene expression signature in UC that could influence the therapeutic efficacy of drugs, as well as the interference with persistence genes by novel therapeutic option. Three microarray datasets (GSE66407, GSE38713 and GSE14580) from the NCBI-GEO database were utilized. Differentially expressed genes between samples of patients with UC and healthy ones were analyzed using R software. In addition, in vivo study using oxazolone-induced UC in BALB/c mice was carried out to investigate the proposed therapeutic efficacy of dichloroacetate (DCA). The bioinformatics analysis revealed the persistence of NLRP3, NFATC1, and IL1B in UC despite treatment with common therapeutic agents. DCA administration to oxazolone-treated mice showed remarkable interference with those persistence genes. Western blotting analysis for NLRP3, NFATC1, nuclear/total NF-κB, and cleaved caspase-1 revealed the ability of DCA to reduce the expression levels of these proteins in oxazolone-treated mice. Additionally, the inflammatory cytokines IL-1β and IL-13 were reduced in colonic tissue by DCA treatment. The therapeutic efficacy of DCA was further confirmed by the apparent reduction in histopathological scoring, disease activity index, and the normalization of colon length. Therefore, DCA could be suggested as a novel and promising therapeutic option in UC based on its ability to interfere with the persistence of NFATC1/NLRP3/IL1B signaling. That merits further safety/toxicological pre-clinical assessment and update of bioavailability/metabolism data prior to clinical investigation.

Metabolic targeting of platelets to combat thrombosis: dawn of a new paradigm?

Current antithrombotic therapies used in clinical settings target either the coagulation pathways or platelet activation receptors (P2Y12 or GPIIb/IIIa), as well as the cyclooxygenase (COX) enzyme through aspirin. However, they are associated with bleeding risk and are not suitable for long-term use. Thus, novel strategies which provide broad protection against platelet activation with minimal bleeding risks are required. Regardless of the nature of agonist stimulation, platelet activation is an energy-intensive and ATP-driven process characterized by metabolic switching toward a high rate of aerobic glycolysis, relative to oxidative phosphorylation (OXPHOS). Consequently, there has been considerable interest in recent years in investigating whether targeting metabolic pathways in platelets, especially aerobic glycolysis and OXPHOS, can modulate their activation, thereby preventing thrombosis. This review briefly discusses the choices of metabolic substrates available to platelets that drive their metabolic flexibility. We have comprehensively elucidated the relevance of aerobic glycolysis in facilitating platelet activation and the underlying molecular mechanisms that trigger this switch from OXPHOS. We have provided a detailed account of the antiplatelet effects of targeting vital metabolic checkpoints such as pyruvate dehydrogenase kinases (PDKs) and pyruvate kinase M2 (PKM2) that preferentially drive the pyruvate flux to aerobic glycolysis. Furthermore, we discuss the role of fatty acids and glutamine oxidation in mitochondria and their subsequent role in driving OXPHOS and platelet activation. While the approach of targeting metabolic regulatory mechanisms in platelets to prevent their activation is still in a nascent stage, accumulating evidence highlights its beneficial effects as a potentially novel antithrombotic strategy.

G-Protein-Coupled Receptor 91-Dependent Signalling Does Not Influence Vascular Inflammation and Atherosclerosis in Hyperlipidaemic Mice

The TCA cycle intermediate metabolite 'succinate' has been proposed as an inflammatory mediator, influencing autoimmunity and allergic reactions, through ligation to its sensing receptor SUCNR1/GPR91. Whether GPR91-mediated signalling influences the chronic inflammatory process of atherosclerosis has never been investigated. The examination of publicly available datasets revealed that the SUCNR1 gene is expressed in human atherosclerotic plaques, especially in vascular smooth muscle cells. Using GPR91 knockout (Gpr91-/-) and wildtype (WT) littermates, made hyperlipidaemic with the overexpression of the gain-of-function mutated Pcsk9 and Western diet feeding, we showed that the full ablation of GPR91 did not accelerate atherosclerosis-lesions in the aortic arch 2.18 ± 0.48% vs. 1.64 ± 0.31%, and in the aortic roots 10.06 ± 0.91% vs. 10.67 ± 1.53% for Gpr91-/- and WT mice, respectively. In line with this, no differences between groups were observed for macrophage and T-cell infiltration in the plaque, as well as the polarization towards M1- or M2-like macrophages in the aorta, spleen and liver of Gpr91-/- and WT control mice. In conclusion, our study indicates that the global ablation of GPR91 signalling does not influence vascular inflammation or atherogenesis.

Heat stress exposure cause alterations in intestinal microbiota, transcriptome, and metabolome of broilers

Introduction

Heat stress can affect the production of poultry through complex interactions between genes, metabolites and microorganisms. At present, it is unclear how heat stress affects genetic, metabolic and microbial changes in poultry, as well as the complex interactions between them.

Methods

Thus, at 28  days of age a total of 200 Arbor Acres broilers with similar body weights were randomly divided into the control (CON) and heat stress treatment (HS). There were 5 replicates in CON and HS, respectively, 20 per replication. From the 28-42  days, the HS was kept at 31 ± 1°C (9:00-17:00, 8 h) and other time was maintained at 21 ± 1°C as in the CON. At the 42nd day experiment, we calculated the growth performance (n = 8) of broilers and collected 3 and 6 cecal tissues for transcriptomic and metabolomic investigation and 4 cecal contents for metagenomic investigation of each treatment.

Results and discussion

The results indicate that heat stress significantly reduced the average daily gain and body weight of broilers (value of p < 0.05). Transcriptome KEGG enrichment showed that the differential genes were mainly enriched in the NF-kB signaling pathway. Metabolomics results showed that KEGG enrichment showed that the differential metabolites were mainly enriched in the mTOR signaling pathway. 16S rDNA amplicon sequencing results indicated that heat stress increased the relative abundance of Proteobacteria decreased the relative abundance of Firmicutes. Multi-omics analysis showed that the co-participating pathway of differential genes, metabolites and microorganisms KEGG enrichment was purine metabolism. Pearson correlation analysis found that ornithine was positively correlated with SULT1C3, GSTT1L and g_Lactobacillus, and negatively correlated with CALB1. PE was negatively correlated with CALB1 and CHAC1, and positively with g_Alistipes. In conclusion, heat stress can generate large amounts of reactive oxygen and increase the types of harmful bacteria, reduce intestinal nutrient absorption and antioxidant capacity, and thereby damage intestinal health and immune function, and reduce growth performance indicators. This biological process is manifested in the complex regulation, providing a foundational theoretical basis for solving the problem of heat stress.