Tissue factor pathway inhibitor in atherosclerosis

Mechanisms regulating heterogeneity of hemostatic gene expression in endothelial cells

The hemostatic system involves an array of circulating coagulation factors that work in concert with platelets and the vascular endothelium to promote clotting in a space- and time-defined manner. Despite equal systemic exposure to circulating factors, bleeding and thrombotic diseases tend to prefer specific sites, suggesting an important role for local factors. This may be provided by endothelial heterogeneity. Endothelial cells differ not only between arteries, veins, and capillaries but also between microvascular beds from different organs, which present unique organotypic morphology and functional and molecular profiles. Accordingly, regulators of hemostasis are not uniformly distributed in the vasculature. The establishment and maintenance of endothelial diversity are orchestrated at the transcriptional level. Recent transcriptomic and epigenomic studies have provided a global picture of endothelial cell heterogeneity. In this review, we discuss the organotypic differences in the hemostatic profile of endothelial cells; we focus on 2 major endothelial regulators of hemostasis, namely von Willebrand factor and thrombomodulin, to provide examples of transcriptional mechanisms that control heterogeneity; finally, we consider some of the methodological challenges and opportunities for future studies.

High-throughput transcriptome sequencing reveals the protective role of adenosine receptor-related genes in paraquat-exposed Caenorhabditis elegans

This study sought to identify the genes associated with adenosine's protective action against paraquat (PQ)-induced oxidative stress via the adenosine receptor (ADOR-1) in Caenorhabditis elegans (C. elegans). The C. elegans was divided into 3 groups-2 groups exposed to PQ, one in presence, and one in absence of adenosine-and a control group that was not treated. Each group's total RNA was extracted and sequenced. When the transcriptomes of these groups were analyzed, several genes were found to be differently expressed. These differentially expressed genes were significantly enriched in adenosine-response biological processes and pathways, including gene ontology terms related to neuropeptide and kyoto encyclopedia of genes and genomes pathways associated to cAMP pathway regulator activity. Quantitative reverse-transcription PCR confirmed that G-protein-coupled receptors signaling pathway involving dop-1, egl-30, unc-13, kin-1, and goa-1 genes may play crucial roles in modulating adenosine's protective action. Interestingly, there are no significant variations in the expression of the ador-1 gene across the 3 treatments, thereby indicating that adenosine receptor exerts a consistent and stable influence on its related pathways irrespective of the presence or absence of PQ. Furthermore, the wild-type group with ador-1 gene has higher survival rate than that of the ador-1-/RNA interference group while treated with PQ in the presence of adenosine. Conclusively, our study uncovered a number of novel PQ-response genes and adenosine receptor-related genes in C. elegans, which may function as major regulators of PQ-induced oxidative stress and indicate the possible protective effects of adenosine.

rTFPI Protects Cardiomyocytes from Hypoxia/Reoxygenation Injury through Inhibiting Autophagy and the Class III PI3K/Beclin-1 Pathway

Autophagy plays various roles at different stages of ischemia reperfusion (I/R) injury in cardiomyocytes. It has been reported that tissue factor pathway inhibitor (TFPI) has a protective effect on I/R injury. This study aimed to determine the roles of TFPI in autophagy during the I/R injury process in cardiomyocytes and the possible mechanisms. An isolated hypoxia/reoxygenation (H/R) pattern of cardiomyocytes was established by the MIC101 system. The cell viability and oxidative stress of cardiomyocytes were detected by an MTT assay and ROS assay, respectively. The autophagy level was measured by Ad-mCherry-GFP-LC3B and MDC. We detected the expression levels of autophagy-related proteins by western blotting. After 2 h of hypoxia and 12 h of reoxygenation, the cardiomyocyte viability in the H/R group was significantly lower than that in the control group (p < 0.05) than in the H/R group. According to intracellular ROS production, the fluorescence intensity in the H/R group was enhanced compared with that in the negative control group, and it was weaker in the H/R + rTFPI group compared with the H/R group. The level of autophagy and the expression levels of autophagy-related proteins (LC3-II/LC3-I, Beclin-1 and PI3K) were markedly increased in the H/R group compared to the control group (p < 0.05) whereas the levels were markedly decreased in the H/R + rTFPI group compared to the H/R group (p < 0.05). TFPI could relieve cardiomyocyte injury by inhibiting the Class III PI3K/Beclin-1 pathway and oxidative stress; thus, TFPI decreased autophagy and protected cardiomyocytes induced by H/R injury. In conclusion, TFPI may be a new direction for the prevention of myocardial I/R injury.

Pathogenesis and Therapy of Coagulation Disorders in Severe Acute Pancreatitis

Ischemia superimposed upon pancreatic edema leads to acute necrotizing pancreatitis. One possible mechanism contributing to ischemia is intravascular thrombogenesis since fibrin deposits have been detected in pancreatic capillaries by electron microscope. Current experimental and clinical data provided compelling evidence that the disorders in the blood coagulation system play a critical role in the pathogenesis of severe acute pancreatitis (SAP). This leads to microcirculatory failure of intra- and extrapancreatic organs and multiple organ failure and increases the case fatality rate. However, the mechanism of coagulopathy underlying SAP is not yet clear, although some anticoagulant drugs have entered clinical practice showing improvement in prognosis. Thus, enhanced understanding of the process might improve the treatment strategies with safety and high efficacy. Herein, the pathogenesis of the coagulation system of SAP was reviewed with a focus on the coagulation pathway, intercellular interactions, and complement system, thereby illustrating some anticoagulant therapies and potential therapeutic targets.

Magnesium Supplementation Affects the Expression of Sirtuin1, Tumor Protein P53 and Endothelial Nitric Oxide Synthase Genes in Patients with Atherosclerosis: A Double-Blind, Randomized, Placebo-Controlled Trial

Magnesium seems to play a role in improving cardiovascular function, but its exact mechanism is unknown. In this study, we hypothesized that magnesium could modulate the expression of genes involved in atherosclerosis. The aim of the present investigation was to evaluate the effect of magnesium sulfate on the expression of sirtuin1 (SIRT1), tumor protein p53 (TP53), and endothelial nitric oxide synthase (eNOS) genes in patients with atherosclerosis. This study was a placebo-controlled double-blind randomized clinical trial on 56 patients with angiographically proven atherosclerosis. Participants were randomly divided into two groups receiving 300 mg/day magnesium sulfate (n = 29) and placebo (n = 27) for three months (following up every month). Fasting blood samples were taken before and after the intervention and total RNA was extracted and used to evaluate the expression level of SIRT1, TP53, and eNOS genes by Real-Time PCR. The expression of eNOS gene was significantly increased (P < 0.0001) and the expression of TP53 gene was decreased (P = 0.02) in the magnesium sulfate group compared to the placebo group. But SIRT1 gene expression was not significantly different between the two groups. Our findings demonstrate that magnesium sulfate supplementation may have a protective role against the progression of atherosclerosis through upregulation of eNOS and downregulation of TP53 gene. Trial registration: This present clinical trial has been registered in the Iranian Registry of Clinical Trials (IRCT) with the registration code of "IRCT20151028024756N3", https://www.irct.ir/trial/29097?revision=114102. Registered on 16 December 2019.

Immune system and atherosclerosis: Hostile or friendly relationship

Coronary artery disease has remained a major health challenge despite enormous progress in prevention, diagnosis, and treatment strategies. Formation of atherosclerotic plaque is a chronic process that is developmentally influenced by intrinsic and extrinsic determinants. Inflammation triggers atherosclerosis, and the fundamental element of inflammation is the immune system. The immune system involves in the atherosclerosis process by a variety of immune cells and a cocktail of mediators. It is believed that almost all main components of this system possess a profound contribution to the atherosclerosis. However, they play contradictory roles, either protective or progressive, in different stages of atherosclerosis progression. It is evident that monocytes are the first immune cells appeared in the atherosclerotic lesion. With the plaque growth, other types of the immune cells such as mast cells, and T lymphocytes are gradually involved. Each cell releases several cytokines which cause the recruitment of other immune cells to the lesion site. This is followed by affecting the expression of other cytokines as well as altering certain signaling pathways. All in all, a mix of intertwined interactions determine the final outcome in terms of mild or severe manifestations, either clinical or subclinical. Therefore, it is of utmost importance to precisely understand the kind and degree of contribution which is made by each immune component in order to stop the growing burden of cardiovascular morbidity and mortality. In this review, we present a comprehensive appraisal on the role of immune cells in the atherosclerosis initiation and development.

Atherosclerosis Pathways are Activated in Pericoronary Adipose Tissue of Patients with Coronary Artery Disease

PURPOSE

Perivascular release of inflammatory mediators may accelerate coronary lesion formation and contribute to plaque instability. Accordingly, we compared gene expression in pericoronary adipose tissue (PCAT) in patients with advanced coronary artery disease (CAD) and non-CAD controls.

PATIENTS AND METHODS

PCAT samples were collected during coronary bypass grafting from CAD patients (n = 21) and controls undergoing valve replacement surgery, with CAD excluded by coronary angiography (n = 19). Gene expression was measured by GeneChip™ Human Transcriptome Array 2.0. Obtained list of 1348 transcripts (2.0%) that passed the filter criteria was further analyzed by Ingenuity Pathway Analysis software, identifying 735 unique differentially expressed genes (DEGs).

RESULTS

Among the CAD patients, 416 (30.9%) transcripts were upregulated, and 932 (69.1%) were downregulated, compared to controls. The top upregulated genes were involved in inflammation and atherosclerosis (chemokines, interleukin-6, selectin E and low-density lipoprotein cholesterol (LDL-C) receptor), whereas the downregulated genes were involved in cardiac ischaemia and remodelling, platelet function and mitochondrial function (miR-3671, miR-4524a, multimerin, biglycan, tissue factor pathway inhibitor (TFPI), glucuronidases, miR-548, collagen type I, III, IV). Among the top upstream regulators, we identified molecules that have proinflammatory and atherosclerotic features (High Mobility Group Box 2 (HMGB2), platelet-derived growth platelet (PDGF) and evolutionarily conserved signaling intermediate in Toll pathways (ESCIT)). The activated pathway related to DEGs consisted of molecules with well-established role in the pathogenesis of atherosclerosis (TFPI, plasminogen activator, plasminogen activator, urokinase receptor (PLAUR), thrombomodulin). Moreover, we showed that 22 of the altered genes form a pro-atherogenic network.

CONCLUSION

Altered gene expression in PCAT of CAD patients, with genes upregulation and activation of pathway involved in inflammation and atherosclerosis, may be involved in CAD development and progression.

Non-alcoholic fatty liver disease: a metabolic burden promoting atherosclerosis

Non-alcoholic fatty liver disease (NAFLD) has become the fastest growing chronic liver disease, with a prevalence of up to 25% worldwide. Individuals with NAFLD have a high risk of disease progression to cirrhosis, hepatocellular carcinoma (HCC), and liver failure. With the exception of intrahepatic burden, cardiovascular disease (CVD) and especially atherosclerosis (AS) are common complications of NAFLD. Furthermore, CVD is a major cause of death in NAFLD patients. Additionally, AS is a metabolic disorder highly associated with NAFLD, and individual NAFLD pathologies can greatly increase the risk of AS. It is increasingly clear that AS-associated endothelial cell damage, inflammatory cell activation, and smooth muscle cell proliferation are extensively impacted by NAFLD-induced systematic dyslipidemia, inflammation, oxidative stress, the production of hepatokines, and coagulations. In clinical trials, drug candidates for NAFLD management have displayed promising effects for the treatment of AS. In this review, we summarize the key molecular events and cellular factors contributing to the metabolic burden induced by NAFLD on AS, and discuss therapeutic strategies for the improvement of AS in individuals with NAFLD.

The Secretive Liaison of Particulate Matter and SARS-CoV-2. A Hypothesis and Theory Investigation

As the novel coronavirus disease sweeps across the world, there is growing speculation on the role that atmospheric factors may have played on the different distribution of SARS-CoV-2, and on the epidemiological characteristics of COVID-19. Knowing the role that environmental factors play in influenza virus outbreaks, environmental pollution and, in particular, atmospheric airborne (particulate matter, PM) has been considered as a potential key factor in the spread and mortality of COVID-19. A possible role of the PM as the virus carrier has also been debated. The role of PM in exacerbating respiratory and cardiovascular disease has been well recognized. Accumulating evidence support the hypothesis that PM can trigger inflammatory response at molecular, cellular and organ levels. On this basis, we developed the hypothesis that PM may play a role as a booster of COVID-19 rather than as a carrier of SARS-CoV-2. To support our hypothesis, we analyzed the molecular signatures detected in cells exposed to PM samples collected in one of the most affected areas by the COVID-19 outbreak, in Italy. T47D human breast adenocarcinoma cells were chosen to explore the global gene expression changes induced by the treatment with organic extracts of PM 2.5. The analysis of the KEGG's pathways showed modulation of several gene networks related to the leucocyte transendothelial migration, cytoskeleton and adhesion system. Three major biological process were identified, including coagulation, growth control and immune response. The analysis of the modulated genes gave evidence for the involvement of PM in the endothelial disease, coagulation disorders, diabetes and reproductive toxicity, supporting the hypothesis that PM, directly or through molecular interplay, affects the same molecular targets as so far known for SARS-COV-2, contributing to the cytokines storm and to the aggravation of the symptoms triggered by COVID-19. We provide evidence for a plausible cooperation of receptors and transmembrane proteins, targeted by PM and involved in COVID-19, together with new insights into the molecular interplay of chemicals and pathogens that could be of importance for sustaining public health policies and developing new therapeutic approaches.

TFPIα alleviated vascular endothelial cell injury by inhibiting autophagy and the class III PI3K/Beclin-1 pathway

Endothelium (EC) dysfunction plays an important role in vascular diseases, such as arteriosclerosis and hypoxia/reoxygenation (H/R) injury. Tissue factor pathway inhibitor (TFPI) is the only physiological inhibitor of the TF/FVIIa complex in vivo. This experiment aimed to determine the effect of TFPIα on H/R-induced EC injury and the possible mechanisms. The MIC101 hypoxia system was used to establish an EC H/R injury model in vitro. Our results showed that 6 h after reoxygenation, the EC injury in H/R group was higher than that in the control group, whereas after adding TFPIα, the EC injury was alleviate than that in H/R group. The level of ROS was higher in the H/R group than in the control group, while it was apparently lower in the H/R+TFPIα group than in the H/R group. After H/R, the number of autophagosomes and the autophagic flux were significantly increased, whereas TFPIα could decrease the autophagy level after H/R. The expressions of LC3-II/LC3-I, Beclin-1 and PI3K were obviously higher after H/R and lower after adding TFPIα. In conclusion, autophagy contributes to EC injury during the H/R period. TFPIα could decrease autophagy in ECs, and the mechanism might be class III PI3K/Beclin-1 pathway regulation.

LncRNA TNK2-AS1 regulated ox-LDL-stimulated HASMC proliferation and migration via modulating VEGFA and FGF1 expression by sponging miR-150-5p

Long non‐coding RNAs (lncRNAs) have been indicated for the regulatory roles in cardiovascular diseases. This study determined the expression of lncRNA TNK2 antisense RNA 1 (TNK2‐AS1) in oxidized low‐density lipoprotein (ox‐LDL)‐stimulated human aortic smooth muscle cells (HASMCs) and examined the mechanistic role of TNK2‐AS1 in the proliferation and migration of HASMCs. Our results demonstrated that ox‐LDL promoted HASMC proliferation and migration, and the enhanced proliferation and migration in ox‐LDL‐treated HASMCs were accompanied by the up‐regulation of TNK2‐AS1. In vitro functional studies showed that TNK2‐AS1 knockdown suppressed cell proliferation and migration of ox‐LDL‐stimulated HASMCs, while TNK2‐AS1 overexpression enhanced HASMC proliferation and migration. Additionally, TNK2‐AS1 inversely regulated miR‐150‐5p expression via acting as a competing endogenous RNA (ceRNA), and the enhanced effects of TNK2‐AS1 overexpression on HASMC proliferation and migration were attenuated by miR‐150‐5p overexpression. Moreover, miR‐150‐5p could target the 3’ untranslated regions of vascular endothelial growth factor A (VEGFA) and fibroblast growth factor 1 (FGF1) to regulate FGF1 and VEGFA expression in HASMCs, and the inhibitory effects of miR‐150‐5p overexpression in ox‐LDL‐stimulated HASMCs were attenuated by enforced expression of VEGFA and FGF1. Enforced expression of VEGFA and FGF1 also partially restored the suppressed cell proliferation and migration induced by TNK2‐AS1 knockdown in ox‐LDL‐stimulated HASMCs, while the enhanced effects of TNK2‐AS1 overexpression on HASMC proliferation and migration were attenuated by the knockdown of VEGFA and FGF1. Collectively, our findings showed that TNK2‐AS1 exerted its action in ox‐LDL‐stimulated HASMCs via regulating VEGFA and FGF1 expression by acting as a ceRNA for miR‐150‐5p.