Toll-Like Receptor 3 in Cardiovascular Diseases

Exploring therapeutic targets in Toll-like receptor pathways: Implications for cardiovascular management in polycystic ovary syndrome

Inflammation plays a crucial role in the development of Polycystic Ovary Syndrome (PCOS) via modulation in Toll-like receptor (TLR) signaling pathways and over the recent couple of years, there has been an increase in the cardiovascular events associated with PCOS. To overcome this condition, the development of targeted drugs to modulate the TLR signaling pathway, a major trigger in the development of cardiovascular complications with PCOS patients is required. This review aims to explore the therapeutic targets with TLR pathways and their implications for cardiovascular management in PCOS. The chronic activation of TLRs contributes significantly to inflammation and endothelial dysfunction, which are critical factors in the development of cardiovascular diseases in patients with PCOS. Various novel therapeutic approaches are taken into consideration, such as TLR antagonists, naturally occurring TLR inhibitors like curcumin, Cryptotanshinone (CRY), quercetin, berberine, omega-3 fatty acids, and some novel targeted therapies like exosome and gene therapy. The literature findings indicated that targeting specific TLR pathways, TLR2 and TLR4 presents a promising avenue for mitigating cardiovascular complications associated with PCOS which play a major role in disease pathogenesis. The findings underscore the importance of understanding TLR-mediated mechanisms to develop effective interventions tailored to this population. This exploration not only enhances our understanding of immune responses, specific TLRs such as TLR2 and TLR4 in relation to cardiovascular health but also lays the groundwork for innovative therapeutic strategies.

Intratracheal instillation of graphene oxide with different diameters suppressed toll-like receptor 3-mediated lipid droplet biogenesis in lungs and livers of mice

Recent advances have established lipid droplets as dynamic innate immune hubs coordinating cellular metabolism and defense mechanisms. While previous studies primarily focused on nanomaterials (NMs) altering lipid metabolism to influence lipid droplet dynamics, this study pioneers the investigation of NM-induced immune modulation via Toll-like receptor (TLR) pathways as a novel regulatory axis for lipid droplets. Building on our prior findings that graphene oxide (GO) impaired TLR3-mediated lipid signaling, we systematically explored the role of GO's diameter in modulating this process. Mice were subjected to daily intratracheal instillation of three GO variants (50-200 nm, <500 nm or > 500 nm) at 1 mg/kg for 7 days. Although no significant change in body weight or organ coefficient was observed, all GO exposure suppressed lipid staining in mouse lungs and livers, correlating with altered co-localization of TLR3 and perilipin 2 (PLIN2), critical regulators of lipid droplet biogenesis. Down-regulation of TLR3 signaling components, namely interferon induced protein with tetratricopeptide repeats 1 (IFIT1), radical S-adenosyl methionine domain containing 2 (RSAD2), and PLIN2, occurred in a diameter-dependent manner, with GO 50-200 nm showing the most pronounced effects, likely attributable to the smallest hydrodynamic size and polydispersity index in suspension. This work provides evidence that NM geometry governs TLR-mediated lipid droplet regulation, bridging the knowledge gap between nanotoxicology and immunometabolic cross-talking, a paradigm distinct from conventional lipid metabolism-focused nanotoxicological studies.

Sinigrin Selectively Mitigates the Acute-Cardiac Inflammatory Response Through an AMPK-Dependent Mechanism

Inflammatory cardiomyopathy is an inflammatory condition characterised by infiltrating inflammatory cells into the heart, which causes impaired myocardial function. Sinigrin (SNG) has been reported to possess antioxidant and anti-inflammatory properties. This study aimed to investigate the therapeutic benefit of SNG against endotoxin/Poly(I:C)-induced acute-cardiac inflammation using in vitro and in vivo models. Experimental procedure: THP-1, HCF and H9C2 cells were employed as an in vitro model, while lipopolysaccharide (LPS)/Poly(I:C)-induced cardiac inflammation model served as an in vivo to examine the anti-inflammatory potential of SNG using molecular biology techniques, cardiac function and histological assessments. The network pharmacological approach revealed that SNG could target the myocarditis-responsible genes. mRNA/protein expression studies showed that SNG treatment significantly mitigated the LPS + Poly(I:C)-induced expression of pro-inflammatory and myocarditis-responsive genes. Further analysis revealed that SNG treatment significantly reduced the LPS + Poly(I:C)-induced elevation of neutrophil, lymphocyte count, AST, ALT, LDH and CK-MB levels; infiltration of inflammatory cells, cardiomyocyte degeneration, cardiac troponin and macrophage markers, on the other hand, improved the platelet levels. Cardiac functional parameters by Langendorff indicated that SNG potentially ameliorated the LPS + Poly(I:C)-induced elevation of LVP and other parameters and improved cardiac functions. Molecular docking studies demonstrated that sinigrin forms a H-bond with Asn-111 (significant interaction) and binds to the activator site of AMPK with a docking score of -8.88 kcal/mol. The current study reveals that sinigrin exerts potent anti-inflammatory and antioxidant activities by modulating AMPK signalling. These findings support sinigrin's potential as a promising option for treating acute myocardial inflammation and open avenues for translational research.

Endosomal Toll-Like Receptors intermediate negative impacts of viral diseases, autoimmune diseases, and inflammatory immune responses on the cardiovascular system

INTRODUCTION

Cardiovascular disease (CVD) is the leading cause of morbidity globally, with chronic inflammation as a key modifiable risk factor. Toll-like receptors (TLRs), pivotal components of the innate immune system, including TLR-3, -7, -8, and -9 within endosomes, trigger intracellular cascades, leading to inflammatory cytokine production by various cell types, contributing to systemic inflammation and atherosclerosis. Recent research highlights the role of endosomal TLRs in recognizing self-derived nucleic acids during sterile inflammation, implicated in autoimmune conditions like myocarditis.

AREAS COVERED

This review explores the impact of endosomal TLRs on viral infections, autoimmunity, and inflammatory responses, shedding light on their intricate involvement in cardiovascular health and disease by examining literature on TLR-mediated mechanisms and their roles in CVD pathophysiology.

EXPERT OPINION

Removal of endosomal TLRs mitigates myocardial damage and immune reactions, applicable in myocardial injury. Targeting TLRs with agonists enhances innate immunity against fatal viruses, lowering viral loads and mortality. Prophylactic TLR agonist administration upregulates TLRs, protecting against fatal viruses and improving survival. TLRs play a complex role in CVDs like atherosclerosis and myocarditis, with therapeutic potential in modulating TLR reactions for cardiovascular health.

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.

Impact of genetic variations of gene involved in regulation of metabolism, inflammation and coagulation on pathogenesis of cardiac injuries associated with COVID-19

BACKGROUND

SARS-CoV-2 infection can result in long-term chronic cardiovascular (CV) damage after the acute phase of the illness. COVID-19 frequently causes active myocarditis, SARS-CoV-2 can directly infect and kill cardiac cells, causing severe pathology and dysfunction across the organs and cells. Till now, the pathogenesis of COVID-19-associated cardiac injuries has not been understood, but there are several factors that contribute to the progression of cardiac injuries, such as genetic, dietary, and environmental. Among them ranges of host genetic factor including metabolizing, inflammation, and coagulation related genes have a role to contribute the cardiac injuries induced by COVID-19. Hereditary DNA sequence variations contribute to the risk of illness in almost all of these diseases. Hence, we comprehended the occurrence of genetic variations of metabolizing, inflammation and coagulation-related genes in the general population, their expression in various diseases, and their impact on cardiac injuries induced by COVID-19.

METHOD

We utilized multiple databases, including PubMed (Medline), EMBASE, and Google Scholar, for literature searches.

DESCRIPTION

The genes involved in metabolism (APOE, MTHFR), coagulation (PAI-1, ACE2), and immune factors (CRP, ESR, and troponin I) may have a role in the progression of COVID-19-associated cardiac injuries. The risk factors for CVD are significantly varied between and within different regions. In healthy individuals, the ACE I allele is responsible for the predisposition to CAD, but the ACE D haplotype is responsible for susceptibility and severity, which ultimately leads to heart failure. Patients who carry the T allele of rs12329760 in the TMPRSS2 gene are at risk for developing the severe form of COVID-19. IL-6 (rs1800796/rs1800795) polymorphism is associated with an increased mortality rate and susceptibility to severe COVID-19 disease. While the putative role of IL-6 associated with chronic, inflammatory diseases like cardiac and cerebrovascular disease is well known.

CONCLUSION

The occurrence of genetic variations in the ACE-2, AGT, DPP-IV, TMPRSS2, FUIRN, IL-4, IL-6, IFN-γ, and CYP2D6 genes is varied among different populations. Examining the correlation between these variations and their protein levels and cardiac injuries induced by COVID-19 may provide valuable insights into the pathogenesis of cardiac injuries induced by COVID-19.

Screening and identification of key biomarkers associated with endometriosis using bioinformatics and next-generation sequencing data analysis

Background

Endometriosis is a common cause of endometrial-type mucosa outside the uterine cavity with symptoms such as painful periods, chronic pelvic pain, pain with intercourse and infertility. However, the early diagnosis of endometriosis is still restricted. The purpose of this investigation is to identify and validate the key biomarkers of endometriosis.

Methods

Next-generation sequencing dataset GSE243039 was obtained from the Gene Expression Omnibus database, and differentially expressed genes (DEGs) between endometriosis and normal control samples were identified. After screening of DEGs, gene ontology (GO) and REACTOME pathway enrichment analyses were performed. Furthermore, a protein–protein interaction (PPI) network was constructed and modules were analyzed using the Human Integrated Protein–Protein Interaction rEference database and Cytoscape software, and hub genes were identified. Subsequently, a network between miRNAs and hub genes, and network between TFs and hub genes were constructed using the miRNet and NetworkAnalyst tool, and possible key miRNAs and TFs were predicted. Finally, receiver operating characteristic curve analysis was used to validate the hub genes.

Results

A total of 958 DEGs, including 479 upregulated genes and 479 downregulated genes, were screened between endometriosis and normal control samples. GO and REACTOME pathway enrichment analyses of the 958 DEGs showed that they were mainly involved in multicellular organismal process, developmental process, signaling by GPCR and muscle contraction. Further analysis of the PPI network and modules identified 10 hub genes, including vcam1, snca, prkcb, adrb2, foxq1, mdfi, actbl2, prkd1, dapk1 and actc1. Possible target miRNAs, including hsa-mir-3143 and hsa-mir-2110, and target TFs, including tcf3 (transcription factor 3) and clock (clock circadian regulator), were predicted by constructing a miRNA-hub gene regulatory network and TF-hub gene regulatory network.

Conclusions

This investigation used bioinformatics techniques to explore the potential and novel biomarkers. These biomarkers might provide new ideas and methods for the early diagnosis, treatment and monitoring of endometriosis.

Toll-like receptor 3 involvement in vascular function

Maintaining endothelial cell (EC) and vascular smooth muscle cell (VSMC) integrity is an important component of human health and disease because both EC and VSMC regulate various functions, including vascular tone control, cellular adhesion, homeostasis and thrombosis regulation, proliferation, and vascular inflammation. Diverse stressors affect functions in both ECs and VSMCs and abnormalities of functions in these cells play a crucial role in cardiovascular disease initiation and progression. Toll-like receptors (TLRs) are important detectors of pathogen-associated molecular patterns derived from various microbes and viruses as well as damage-associated molecular patterns derived from damaged cells and perform innate immune responses. Among TLRs, several studies reveal that TLR3 plays a key role in initiation, development and/or protection of diseases, and an emerging body of evidence indicates that TLR3 presents components of the vasculature, including ECs and VSMCs, and plays a functional role. An agonist of TLR3, polyinosinic-polycytidylic acid [poly (I:C)], affects ECs, including cell death, inflammation, chemoattractant, adhesion, permeability, and hemostasis. Poly (I:C) also affects VSMCs including inflammation, proliferation, and modulation of vascular tone. Moreover, alterations of vascular function induced by certain molecules and/or interventions are exerted through TLR3 signaling. Hence, we present the association between TLR3 and vascular function according to the latest studies.

Is There a Role for Immunoregulatory and Antiviral Oligonucleotides Acting in the Extracellular Space? A Review and Hypothesis

Here, we link approved and emerging nucleic acid-based therapies with the expanding universe of small non-coding RNAs (sncRNAs) and the innate immune responses that sense oligonucleotides taken up into endosomes. The Toll-like receptors (TLRs) 3, 7, 8, and 9 are located in endosomes and can detect nucleic acids taken up through endocytic routes. These receptors are key triggers in the defense against viruses and/or bacterial infections, yet they also constitute an Achilles heel towards the discrimination between self- and pathogenic nucleic acids. The compartmentalization of nucleic acids and the activity of nucleases are key components in avoiding autoimmune reactions against nucleic acids, but we still lack knowledge on the plethora of nucleic acids that might be released into the extracellular space upon infections, inflammation, and other stress responses involving increased cell death. We review recent findings that a set of single-stranded oligonucleotides (length of 25-40 nucleotides (nt)) can temporarily block ligands destined for endosomes expressing TLRs in human monocyte-derived dendritic cells. We discuss knowledge gaps and highlight the existence of a pool of RNA with an approximate length of 30-40 nt that may still have unappreciated regulatory functions in physiology and in the defense against viruses as gatekeepers of endosomal uptake through certain routes.

Promising directions in the treatment of chronic heart failure: improving old or developing new ones?

Unprecedented advances of recent decades in clinical pharmacology, cardiac surgery, arrhythmology, and cardiac pacing have significantly improved the prognosis in patients with chronic heart failure (CHF). However, unfortunately, heart failure continues to be associated with high mortality. The solution to this problem consists in simultaneous comprehensive use in clinical practice of all relevant capabilities of continuously improving methods of heart failure treatment proven to be effective in randomized controlled trials (especially when confirmed by the results of studies in real clinical practice), on the one hand, and in development and implementation of innovative approaches to CHF treatment, on the other hand. This is especially relevant for CHF patients with mildly reduced and preserved left ventricular ejection fraction, as poor evidence base for the possibility of improving the prognosis in such patients cannot justify inaction and leaving them without hope of a clinical improvement in their condition. The lecture consistently covers the general principles of CHF treatment and a set of measures aimed at inotropic stimulation and unloading (neurohormonal, volumetric, hemodynamic, and immune) of the heart and outlines some promising areas of disease-modifying therapy.