Txnip ablation reduces vascular smooth muscle cell inflammation and ameliorates atherosclerosis in apolipoprotein E knockout mice

Prediction of prognosis in patients with ischemic stroke combined with type 2 diabetes mellitus based on serum total bilirubin levels

Serum bilirubin levels may have therapeutic benefits in oxidative stress-related diseases, but their role in stroke remains unclear. This study aimed to investigate the relationship between serum bilirubin levels on admission and clinical outcomes in ischemic stroke patients. We prospectively collected data from consecutive ischemic stroke admissions. Serum total bilirubin (TBIL) and direct bilirubin levels on admission were measured. Stroke severity at admission was assessed using the National Institutes of Health Stroke Scale, and functional status at discharge was evaluated using the modified Rankin scale. Among 180 patients, lower TBIL levels were observed in all 3 groups, with the mild group (7.89 ± 2.12 μmol/L) having lower levels than the moderate group (8.01 ± 2.12 μmol/L) and the severe group (9.12 ± 2.12 μmol/L). Although TBIL levels were initially associated with stroke severity, this relationship did not hold after adjusting for confounding factors. Serum bilirubin levels appear to be related to stroke severity but not independently associated with outcomes in ischemic stroke patients. Further research is needed to understand the underlying mechanisms of this relationship. There is a strong correlation between serum bilirubin levels and the severity and prognosis of ischemic stroke in patients with type 2 diabetes. Therefore, early control of serum TBIL and direct bilirubin is crucial for the treatment and prognosis of ischemic stroke in patients with type 2 diabetes.

Non-coding RNAs and angiogenesis in cardiovascular diseases: a comprehensive review

Non-coding RNAs (ncRNAs) have key roles in the etiology of many illnesses, including heart failure, myocardial infarction, stroke, and in physiological processes like angiogenesis. In transcriptional regulatory circuits that control heart growth, signaling, and stress response, as well as remodeling in cardiac disease, ncRNAs have become important players. Studies on ncRNAs and cardiovascular disease have made great progress recently. Here, we go through the functions of non-coding RNAs (ncRNAs) like circular RNAs (circRNAs), and microRNAs (miRNAs) as well as long non-coding RNAs (lncRNAs) in modulating cardiovascular disorders.

Myocardial Glutathione Synthase and TRXIP Expression Are Significantly Elevated in Hypertension and Diabetes: Influence of Stress on Antioxidant Pathways

Antioxidant protection is one of the key reactions of cardiomyocytes (CMCs) in response to myocardial damage of various origins. The thioredoxin interacting protein (TXNIP) is an inhibitor of thioredoxin (TXN). Over the recent few years, TXNIP has received significant attention due to its wide range of functions in energy metabolism. In the present work, we studied the features of the redox-thiol systems, in particular, the amount of TXNIP and glutathione synthetase (GS) as markers of oxidative damage to CMCs and antioxidant protection, respectively. This study was carried out on 38-week-old Wistar-Kyoto rats with insulin-dependent diabetes mellitus (DM) induced by streptozotocin, on 38- and 57-week-old hypertensive SHR rats and on a model of combined hypertension and DM (38-week-old SHR rats with DM). It was found that the amount of TXNIP increased in 57-week-old SHR rats, in diabetic rats and in SHR rats with DM. In 38-week-old SHR rats, the expression of TXNIP significantly decreased. The expression of GS was significantly higher compared with the controls in 57-week-old SHR rats, in DM rats and in the case of the combination of hypertension and DM. The obtained data show that myocardial damage caused by DM and hypertension are accompanied by the activation of oxidative stress and antioxidant protection.

TXNIP Suppresses the Osteochondrogenic Switch of Vascular Smooth Muscle Cells in Atherosclerosis

BACKGROUND

The osteochondrogenic switch of vascular smooth muscle cells (VSMCs) is a pivotal cellular process in atherosclerotic calcification. However, the exact molecular mechanism of the osteochondrogenic transition of VSMCs remains to be elucidated. Here, we explore the regulatory role of TXNIP (thioredoxin-interacting protein) in the phenotypical transitioning of VSMCs toward osteochondrogenic cells responsible for atherosclerotic calcification.

METHODS

The atherosclerotic phenotypes of Txnip^-/- mice were analyzed in combination with single-cell RNA-sequencing. The atherosclerotic phenotypes of Tagln-Cre; Txnip^flox/flox mice (smooth muscle cell-specific Txnip ablation model), and the mice transplanted with the bone marrow of Txnip^-/- mice were analyzed. Public single-cell RNA-sequencing dataset (GSE159677) was reanalyzed to define the gene expression of TXNIP in human calcified atherosclerotic plaques. The effect of TXNIP suppression on the osteochondrogenic phenotypic changes in primary aortic VSMCs was analyzed.

RESULTS

Atherosclerotic lesions of Txnip^-/- mice presented significantly increased calcification and deposition of collagen content. Subsequent single-cell RNA-sequencing analysis identified the modulated VSMC and osteochondrogenic clusters, which were VSMC-derived populations. The osteochondrogenic cluster was markedly expanded in Txnip^-/- mice. The pathway analysis of the VSMC-derived cells revealed enrichment of bone- and cartilage-formation-related pathways and bone morphogenetic protein signaling in Txnip^-/- mice. Reanalyzing public single-cell RNA-sequencing dataset revealed that TXNIP was downregulated in the modulated VSMC and osteochondrogenic clusters of human calcified atherosclerotic lesions. Tagln-Cre; Txnip^flox/flox mice recapitulated the calcification and collagen-rich atherosclerotic phenotypes of Txnip^-/- mice, whereas the hematopoietic deficiency of TXNIP did not affect the lesion phenotype. Suppression of TXNIP in cultured VSMCs accelerates osteodifferentiation and upregulates bone morphogenetic protein signaling. Treatment with the bone morphogenetic protein signaling inhibitor K02288 abrogated the effect of TXNIP suppression on osteodifferentiation.

CONCLUSIONS

Our results suggest that TXNIP is a novel regulator of atherosclerotic calcification by suppressing bone morphogenetic protein signaling to inhibit the transition of VSMCs toward an osteochondrogenic phenotype.

Bibliometric evaluation of publications on inflammasomes in atherosclerosis from 2002 to 2022

Background

Inflammasomes have emerged as an important and promising area of investigation in atherosclerosis. This field, however, lacks bibliometric studies. To help understand how basic and clinical research on inflammasomes in atherosclerosis will develop in the future, we used bibliometric analysis to visualize hotspots and trends.

Methods

Studies related to inflammasomes in atherosclerosis were collected from the Web of Science Core Collection database. Each study was analyzed bibliometrically and visually. CiteSpace and VOSviewer software were used to generate knowledge maps.

Results

A total of 894 articles were identified. Sixty-two countries and 338 institutions led by China and the United States contributed to these publications. The leading research institutions were Harvard Medical School and Columbia University. Circulation was the most frequently cited journal in this field. Among the 475 authors determined, Eicke Latz authored the most studies, and Peter Duewell has been cocited the most. NLRP3 inflammasome, NF-kappa B, macrophage and oxidative stress are the most commonly used keywords.

Conclusion

There has been a blooming of research on inflammasomes in atherosclerosis during the last two decades. Future studies will likely explore the molecular mechanism of inflammasomes in cell death. More compellingly, researchers may further delve into the potential clinical value of affecting pathological changes in atherosclerosis by modulating the initial transcription immune response and intracellular multiprotein assembly process of the NLRP3 inflammasome. Our research will be helpful to scholars focusing on inflammation-a much-needed breakthrough in the pathophysiological alterations of atherosclerosis-with a novel perspective.

The role of mitochondria-associated membranes mediated ROS on NLRP3 inflammasome in cardiovascular diseases

Reactive oxygen species (ROS) metabolism is essential for the homeostasis of cells. Appropriate production of ROS is an important signaling molecule, but excessive ROS production can damage cells. ROS and ROS-associated proteins can act as damage associated molecular pattern molecules (DAMPs) to activate the NACHT, LRR, and PYD domains-containing protein 3 (NLRP3) inflammasome in cardiovascular diseases. Previous studies have shown that there are connected sites, termed mitochondria-associated membranes (MAMs), between mitochondria and the endoplasmic reticulum. In cardiovascular disease progression, MAMs play multiple roles, the most important of which is the ability to mediate ROS generation, which further activates the NLPR3 inflammasome, exacerbating the progression of disease. In this review, the following topics will be covered: 1. Molecular structures on MAMs that can mediate ROS generation; 2. Specific mechanisms of molecule-mediated ROS generation and the molecules' roles in cardiovascular disease, 3. The effects of MAMs-mediated ROS on the NLRP3 inflammasome in cardiovascular disease. The purpose of this review is to provide a basis for subsequent clinical treatment development.

Aerobic exercise alleviates pyroptosis-related diseases by regulating NLRP3 inflammasome

Pyroptosis plays a crucial role in a variety of human diseases, including atherosclerosis, obesity, diabetes, depression, and Alzheimer’s disease, which usually release pyroptosis-related cytokines due to inflammation. Many studies have demonstrated that aerobic exercise is a good option for decreasing the release of pyroptosis-related cytokines. However, the molecular mechanisms of aerobic exercise on pyroptosis-related diseases remain unknown. In this review, the effects of aerobic exercise on pyroptosis in endothelial cells, adipocytes and hippocampal cells, and their potential mechanisms are summarized. In endothelial cells, aerobic exercise could inhibit NOD-like receptor protein 3 (NLRP3) inflammasome-mediated pyroptosis by improving the endothelial function, while reducing vascular inflammation and oxidative stress. In adipocytes, aerobic exercise has been shown to inhibit pyroptosis by ameliorating inflammation and insulin resistance. Moreover, aerobic exercise could restrict pyroptosis by attenuating microglial activation, neuroinflammation, and amyloid-beta deposition in hippocampal cells. In summary, aerobic exercise alleviates the pyroptosis-related diseases by regulating the NLRP3 inflammation si0067naling.

Galectin-3 induces vascular smooth muscle cells calcification via AMPK/TXNIP pathway

Galectin-3 plays an important role in atherosclerosis. Upregulation of VSMCs calcification is involved in the progression and development of vulnerable plaques. Thioredoxin-interacting protein (TXNIP) has been regarded as an important determinant in regulating inflammation and oxidative stress. In this study, we evaluated the role of TXNIP in galectin-3-induced vascular calcification. A primary culture of mouse VSMCs was established by enzymatic digestion of aorta. Small interfering (si) RNA was used to knock down the expression of target gene. VSMCs were treated with 3-methyladenine (3-MA) or compound C respectively. Western blot was performed to detect the protein level in VSMCs, Alkaline phosphatase (ALP) and Alizarin red staining was used to observe calcium deposition. Dihydroethidium (DHE) staining was used to observe the reactive oxygen species (ROS) production. Here we showed that galectin-3 increased aorta and VSMCs calcification, which was associated with AMPK/TXNIP upregulation and autophagy activation. TXNIP inhibition decreased galectin-3-induced aorta and VSMCs calcification and autophagy activation. 3-MA or Atg5 siRNA decreased galectin-3-induced upregulation of Runx2, BMP2 and OPN. AMPK mediated galectin-3-induced VSMCs osteogenic differentiation. These findings illustrated that TXNIP mediated galectin-3-induced vascular calcification, AMPK and autophagy activation were also associated with this process.

Endothelial thioredoxin interacting protein (TXNIP) modulates endothelium-dependent vasorelaxation in hyperglycemia

Endothelial dysfunction, hallmarked by an imbalance between vasoconstriction and vasorelaxation, is associated with diabetes. Thioredoxin Interacting protein (TXNIP), controlled by an exquisitely glucose sensitive gene, is increasingly recognized for its role in diabetes. However, the role of TXNIP in modulating diabetes-related endothelial dysfunction remains unclear. To elucidate the role of TXNIP, we generated two novel mouse strains; endothelial-specific TXNIP knockout (EKO) and a Tet-O inducible, endothelial-specific TXNIP overexpression (EKI). Hyperglycemia was induced by streptozotocin (STZ) treatment in floxed control (fl/fl) and EKO mice. Doxycycline (DOX) was given to EKI mice to induce endothelial TXNIP overexpression. The ablation of endothelial TXNIP improved glucose tolerance in EKO mice. Acetylcholine-induced, endothelium-dependent vasorelaxation was impaired in STZ-treated fl/fl mice while this STZ impaired vasorelaxation was attenuated in EKO mice. Hyperglycemia induction of NLRP3 and reductions in Akt and eNOS phosphorylation were also mitigated in EKO mice. Overexpression of endothelial TXNIP did not impair glucose tolerance in DOX-treated EKI mice, however induction of endothelial TXNIP led to impaired vasorelaxation in EKI mice. This was associated with increased NLRP3 and reduced Akt and eNOS activation. In conclusion, deletion of endothelial TXNIP is protective against and overexpression of endothelial TXNIP induces endothelial dysfunction; thus, endothelial TXNIP plays a critical role in modulating endothelial dysfunction.

Oxidized low-density lipoprotein contributes to injury of endothelial cells via the circ_0090231/miR-9-5p/TXNIP axis

Atherosclerosis (AS) has been reported to induce severe clinical complications. Circular RNA (circRNA) circ_0090231 was found to be aberrantly overexpressed in oxidized low-density lipoprotein (ox-LDL)-induced endothelial cells. This study was designed to explore the role and mechanism of circ_0090231 in ox-LDL-triggered endothelial cell injury in AS. Circ_0090231, microRNA-9-5p (miR-9-5p), and thioredoxin interacting protein (TXNIP) levels were detected by real-time quantitative polymerase chain reaction (RT-qPCR). Cell viability, angiogenesis, and apoptosis were detected by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT), tube formation, and flow cytometry assay. Bcl-2, Bax, and TXNIP protein levels were gauged by western blot assay. Malondialdehyde (MDA), lactate dehydrogenase (LDH), and superoxide dismutase (SOD) activity were determined by special kits. Tumor necrosis factor α (TNF-α), interleukin-1β (IL-1β), and interleukin 6 (IL-6) levels were analyzed using enzyme-linked immunosorbent assay (ELISA) kits. The binding relationship between miR-9-5p and circ_0090231 or TXNIP was predicted by starBase, and then verified by a dual-luciferase reporter and RNA immunoprecipitation (RIP) assays. Circ_0090231 and TXNIP were increased, and miR-9-5p was decreased in ox-LDL-treated HUVECs. Moreover, circ_0090231 knockdown mitigated ox-LDL-induced HUVEC injury by boosting angiogenesis, oxidative stress, and inflammation, and hindering apoptosis. The mechanical analysis revealed that circ_0090231 acted as a sponge of miR-9-5p to regulate TXNIP expression. Circ_0090231 could attenuate ox-LDL-mediated HUVEC damage by the miR-9-5p/TXNIP axis, providing a promising therapeutic strategy for AS treatment.

NLRP3 Inflammasome in Vascular Disease: A Recurrent Villain to Combat Pharmacologically

Despite the great advances in medicine, mortality from cardiovascular diseases keeps on growing. This tendency is not likely to change considering the pandemic proportions of obesity and diabetes. Besides, the global population is more aged as life expectancy increases, and vascular aging plays a key role in the increased risk of vascular disease. In light of recent trials, namely the CANTOS study, showing the enormous potential of anti-inflammatory therapies and in particular those targeted to IL-1β, a change in therapeutical management of cardiovascular diseases is coming about. The NLRP3 inflammasome is a multiprotein complex that assembles to engage the innate immune defense by processing the maturation of pro-inflammatory cytokines IL-1β and IL-18. Substantial evidence has positioned the NLRP3 inflammasome at the center of vascular disease progression, with a particular significance in the context of aging and the low-grade chronic inflammation associated (inflammaging). Therefore, pharmacological blockade of the NLRP3 inflammasome and its end products has arisen as an extremely promising tool to battle vascular disease. In this review, we discuss the mechanisms by which the NLRP3 inflammasome contributes to vascular disease, with particular attention to the consequences of aging, and we enumerate the therapeutic options available to combat this recurrent villain.

Targeting the NLRP3 inflammasome in cardiovascular diseases

The NACHT, leucine-rich repeat (LRR), and pyrin domain (PYD)-containing protein 3 (NLRP3) inflammasome is an intracellular sensing protein complex that plays a major role in innate immunity. Following tissue injury, activation of the NLRP3 inflammasome results in cytokine production, primarily interleukin(IL)-1β and IL-18, and, eventually, inflammatory cell death - pyroptosis. While a balanced inflammatory response favors damage resolution and tissue healing, excessive NLRP3 activation causes detrimental effects. A key involvement of the NLRP3 inflammasome has been reported across a wide range of cardiovascular diseases (CVDs). Several pharmacological agents selectively targeting the NLRP3 inflammasome system have been developed and tested in animals and early phase human studies with overall promising results. While the NLRP3 inhibitors are in clinical development, multiple randomized trials have demonstrated the safety and efficacy of IL-1 blockade in atherothrombosis, heart failure and recurrent pericarditis. Furthermore, the non-selective NLRP3 inhibitor colchicine has been recently shown to significantly reduce cardiovascular events in patients with chronic coronary disease. In this review, we will outline the mechanisms driving NLRP3 assembly and activation, and discuss the pathogenetic role of the NLRP3 inflammasome in CVDs, providing an overview of the current and future therapeutic approaches targeting the NLRP3 inflammasome.

Anti-inflammatory effects of artesunate on atherosclerosis via miR-16-5p and TXNIP regulation of the NLRP3 inflammasome

Background

Atherosclerosis (AS) is chronic inflammatory arterial disorder. Artesunate could exhibit anti-inflammatory activity in AS, but its role in AS is still in its incipient stage. In this study, we explored the anti-inflammatory effect of artesunate in AS and its underlying mechanism.

Methods

We isolated CD14⁺ monocytes from peripheral blood (PB) of 115 coronary heart disease (CHD) patients and 33 non-CHD patients confirmed by coronary angiography. Phorbol myristate acetate (PMA) was used to induce the differentiation of THP-1 monocytes to macrophages. Cells were treated with artesunate at a final concentration of 2.5, 5 or 10 µmol/L. The activation of NLRP3 inflammasome was assessed by immunoblotting of apoptosis-associated speck-like protein containing caspase recruitment domain (ASC). The expression of pro-caspase-1/pro-interleukin (IL)-1β/pro-IL-18 and their mature forms was measured using immunoblotting. A rat model of AS was induced by vitamin D3 (VD3) and a 21-day high-fat diet.

Results

Downregulated miR-16-5p and upregulated thioredoxin-interacting protein (TXNIP) was determined in CD14⁺ monocytes from CHD patients and associated with disease severity. Artesunate abrogated the activation of NLRP3 inflammasome in the presence of inflammasome activators in cultured macrophages. Artesunate reduced TXNIP expression and impaired the interaction between TXNIP and NLRP3, thereby inhibiting release of inflammatory cytokines and ASC production in cultured macrophages. In addition, miR-16-5p negatively regulated the messenger RNA (mRNA) of TXNIP. Artesunate increased the expression of miR-16-5p in a dose-dependent manner, and inhibition of miR-16-5p enhanced the secretion of inflammatory cytokines. Our in vivo experiments also demonstrated that artesunate reduced lipid accumulation, atherosclerotic plaque formation, and antagonized inflammation in a dose-dependent manner by upregulating miR-16-5p.

Conclusions

In summary, the present study unveiled a mechanism underlying the anti-inflammatory role of artesunate in AS.

Dyslipidemia, Diabetes and Atherosclerosis: Role of Inflammation and ROS-Redox-Sensitive Factors

The prevalence of diabetes is growing at an alarming rate with increased disability, morbidity, and often premature mortality because of the various complications of this disorder. Chronic hyperglycemia, dyslipidemia, and other metabolic alterations lead to the development and progression of macro- and microvascular complications of diabetes including cardiovascular, retinal and kidney disease. Despite advances in glucose and lipid lowering treatments, a large number of diabetic individuals develop one or more types of these complications, ultimately leading to end-organ damage over the time. Atherosclerosis is the major macro-vascular complications of diabetes and the primary underlying cause of cardiovascular disease (CVD) posing heavy burden on the health care system. In this review, we discuss the involvement of dyslipidemia in the progression of atherosclerosis by activating the pro-inflammatory cytokines and oxidative stress-related factors. In addition, we also provide information on various pharmacological agents that provides protection against diabetic atherosclerosis by reducing inflammation and oxidative stress.

Molecular Interactions Between Vascular Smooth Muscle Cells and Macrophages in Atherosclerosis

Atherosclerosis is the largest contributor toward life-threatening cardiovascular events. Cellular activity and cholesterol accumulation lead to vascular remodeling and the formation of fatty plaques. Complications arise from blood clots, forming at sites of plaque development, which may detach and result in thrombotic occlusions. Vascular smooth muscle cells and macrophages play dominant roles in atherosclerosis. A firm understanding of how these cells influence and modulate each other is pivotal for a better understanding of the disease and the development of novel therapeutics. Recent studies have investigated molecular interactions between both cell types and their impact on disease progression. Here we aim to review the current knowledge. Intercellular communications through soluble factors, physical contact, and extracellular vesicles are discussed. We also present relevant background on scientific methods used to study the disease, the general pathophysiology and intracellular factors involved in phenotypic modulation of vascular smooth muscle cells. We conclude this review with a discussion of the current state, shortcomings and potential future directions of the field.

Role of Thioredoxin-Interacting Protein in Diabetic Fatty Kidney Induced by Advanced Glycation End-Products

Advanced glycation end-products (AGEs) have been identified as the etiological factors associated with the fatty kidney. Thioredoxin-interacting protein (TXNIP) might be a mediator involved in AGE-induced fatty kidney. This study focused on investigating how TXNIP affected the AGE-mediated renal lipid deposition. In an in vivo experiment, the db/db mice injected with the lentiviral vector encoding shRNA targeting TXNIP were given the AIN-76 basal or the high-AGE diet. TXNIP-targeting siRNA-transfected human renal proximal tubular epithelial (HK-2) cells were exposed to AGE-BSA in a study in vitro. The results showed that the silencing of TXNIP reduced tubular lipid droplets and intracellular cholesterol content, as well as upregulated Insig-1 and downregulated HMGCoAR, LDLr, nSREBP-2, and SCAP in the kidneys of the db/db mice, the high-AGE-diet-fed db/db mice, and AGE-BSA-treated HK-2 cells. Furthermore, AGE-BSA enhanced SCAP-SREBP-2 complex formation while promoting their transportation to the Golgi apparatus. However, these could be inhibited by TXNIP silencing in the HK-2 cells. The above findings indicated that TXNIP knockdown mitigated the accumulation of renal tubular lipids in diabetes through the regulation of SCAP, thereby inhibiting the SCAP-SREBP-2 signaling pathway, resulting in reduced cholesterol uptake and synthesis. Therefore, TXNIP might be a potential therapeutic target to treat a diabetic fatty kidney.

Urantide alleviates the symptoms of atherosclerotic rats in vivo and in vitro models through the JAK2/STAT3 signaling pathway

Atherosclerosis is the leading cause of human death, and its occurrence and development are related to the urotensin II (UII) and UII receptor (UT) system and the biological function of vascular smooth muscle cells (VSMCs). During atherosclerosis, impaired biological function VSMCs may promote atherosclerotic plaque formation. The Janus kinase 2/signal transducer and activator of transcription 3 (JAK2/STAT3) pathway is an important mediator of signal transduction; however, the role of this signaling pathway in atherosclerosis and VSMCs remains unknown. This study aimed to investigate the effects of urantide on the JAK2/STAT3 signaling pathway in atherosclerosis. We examined the effect of urantide on the UII/UT system and the JAK2/STAT3 signaling pathway in a high fat diet induced atherosclerosis rat model and studied the effect and mechanism of urantide on the phenotypic transformation of VSMCs. We found that the UII/UT system and JAK2/STAT3 signaling pathway were highly activated in the thoracic aorta in atherosclerotic rats and in ox-LDL- and UII-induced VSMCs. After urantide treatment, the pathological changes in atherosclerotic rats were effectively improved, and the activities of the UII/UT system and JAK2/STAT3 signaling pathway were inhibited. Moreover, urantide effectively inhibited proliferation and migration and reversed the phenotypic transformation of VSMCs. These results demonstrated that urantide may control the JAK2/STAT3 signaling pathway by antagonizing the UII/UT system, thereby maintaining the biological function of VSMCs and potentially preventing and curing atherosclerosis.

Circular RNA Circ-BANP Regulates Oxidized Low-density Lipoprotein-induced Endothelial Cell Injury Through Targeting the miR-370/Thioredoxin-interacting Protein Axis

ABSTRACT

Dysfunction of endothelial cells is now recognized as an important contributor to the pathogenesis of atherosclerosis (AS). Circular RNAs (circRNAs) have been demonstrated to be involved in AS pathogenesis. The purpose of this study was to explore the biological action of circRNA BTG3-associated nuclear protein (circ-BANP, hsa_circ_0040824) on the dysfunction of human umbilical vein endothelial cells (HUVECs) induced by oxidized low-density lipoprotein (ox-LDL). The levels of circ-BANP, miR-370, and thioredoxin-interacting protein (TXNIP) were gauged by quantitative real-time polymerase chain reaction or Western blot. The subcellular fractionation assay was used to determine the localization of circ-BANP, and the ribonuclease R assay was performed to evaluate the stability of circ-BANP. Cell viability, apoptosis, migration, invasion, and tube formation abilities were assessed by the Cell Counting Kit-8, flow cytometry, transwell, and tube formation assays. The levels of interleukin-6, tumor necrosis factor-α, and interleukin-1β were detected by enzyme-linked immunosorbent assay. Targeted relationships among circ-BANP, miR-370, and TXNIP were confirmed by a dual-luciferase reporter assay. Our data showed that circ-BANP expression was upregulated in AS blood and ox-LDL-induced HUVECs. The inhibition of circ-BANP promoted cell viability, migration, invasion, tube formation, and repressed cell inflammation and apoptosis in ox-LDL-induced HUVECs, demonstrating that circ-BANP silencing alleviated ox-LDL-induced HUVEC injury. Mechanistically, circ-BANP directly targeted miR-370. Moreover, miR-370 mediated the regulation of circ-BANP in ox-LDL-induced cell injury in HUVECs. TXNIP was a target of miR-370, and miR-370 overexpression relieved ox-LDL-induced HUVEC injury by downregulating TXNIP. Furthermore, circ-BANP modulated TXNIP expression by targeting miR-370. Our findings demonstrated that circ-BANP regulated ox-LDL-induced cell injury in HUVECs at least in part through targeting the miR-370/TXNIP axis, illuminating circ-BANP as a potential target for AS detection and treatment.

Long Non-coding RNA GAS5 Worsens Coronary Atherosclerosis Through MicroRNA-194-3p/TXNIP Axis

It is formerly conducted that long non-coding RNA growth arrest-specific 5 (GAS5) is involved in the process of coronary atherosclerosis (AS). The regulatory effects of GAS5 on the microRNA (miR)-194-3p/thioredoxin-interacting protein (TXNIP) axis in AS have been insufficiently explored yet. Thereafter, this work is started from GAS5/miR-194-3p/TXNIP axis in AS. AS rats were modeled to obtain their coronary vascular tissues and endothelial cells (ECs), in which GAS5, miR-194-3p, and TXNIP expression were tested. ECs were identified by immunohistochemistry. The mechanism among GAS5, miR-194-3p, and TXNIP was determined. ECs were transfected with inhibited GAS5 or overexpressed miR-194-3p to decipher their functions in proliferation and apoptosis of ECs in AS. Raised GAS5 and TXNIP and degraded miR-194-3p expression levels exhibited in AS. GAS5 bound to miR-194-3p while miR-194-3p targeted TXNIP. Depleting GAS5 or restoring miR-194-3p enhanced proliferation and depressed apoptosis of ECs in AS. This work clearly manifests that inhibited GAS5 facilitates the growth of ECs through miR-194-3p-targeted TXNIP in AS, consolidating the basal reference to the curing for AS.

Circ_0004872 promotes platelet-derived growth factor-BB-induced proliferation, migration and dedifferentiation in HA-VSMCs via miR-513a-5p/TXNIP axis

The proliferation, migration and dedifferentiation of vascular smooth muscle cells (VSMCs) exert crucial roles in atherosclerosis (AS) progression. The aim of our study was to explore the influences of circular RNA 0004872 (circ_0004872) in platelet-derived growth factor-BB (PDGF-BB)-induced AS cell model and investigate the underlying mechanisms. Real-time quantitative polymerase chain reaction (RT-qPCR) was implemented for the expression detection of circ_0004872, mitogen-activated protein kinase 1 (MAPK1) messenger RNA (mRNA), microRNA-513a-5p (miR-513a-5p) and thioredoxin interacting protein (TXNIP). Cell proliferation was analyzed via Cell Counting Kit 8 (CCK8) assay. Cell migration was assessed via wound healing assay and transwell migration assay. Western blot assay was used to measure the expression of alpha smooth muscle actin (α-SMA), osteopontin (OPN), calponin and TXNIP. Dual-luciferase reporter assay and RNA-pull down assay were used for confirmation of interaction between miR-513a-5p and circ_0004872 or TXNIP. Circ_0004872 expression was elevated in PDGF-BB-induced human aortic vascular smooth muscle cells (HA-VSMCs) and carotid plaque tissues. Circ_0004872 silencing alleviated PDGF-BB-induced proliferation, migration and dedifferentiation in HA-VSMCs. MiR-513a-5p bound to circ_0004872, and circ_0004872 knockdown-induced effects in PDGF-BB-treated HA-VSMCs were largely attenuated by the silencing of miR-513a-5p. MiR-513a-5p bound to the 3' untranslated region (3'UTR) of TXNIP, and miR-513a-5p overexpression-mediated effects were counteracted by the transfection of pcDNA-TXNIP in PDGF-BB-induced HA-VSMCs. TXNIP was modulated by circ_0004872/miR-513a-5p signaling cascade in HA-VSMCs. Circ_0004872 accelerated PDGF-BB-induced proliferation, migration and dedifferentiation in HA-VSMCs through enhancing TXNIP level via sponging miR-513a-5p.

The Emerging Role of TXNIP in Ischemic and Cardiovascular Diseases; A Novel Marker and Therapeutic Target

Thioredoxin interacting protein (TXNIP) is a metabolism- oxidative- and inflammation-related marker induced in cardiovascular diseases and is believed to represent a possible link between metabolism and cellular redox status. TXNIP is a potential biomarker in cardiovascular and ischemic diseases but also a novel identified target for preventive and curative medicine. The goal of this review is to focus on the novelties concerning TXNIP. After an overview in TXNIP involvement in oxidative stress, inflammation and metabolism, the remainder of this review presents the clues used to define TXNIP as a new marker at the genetic, blood, or ischemic site level in the context of cardiovascular and ischemic diseases.

Pyroptosis is a critical immune-inflammatory response involved in atherosclerosis

Pyroptosis is a form of programmed cell death activated by various stimuli and is characterized by inflammasome assembly, membrane pore formation, and the secretion of inflammatory cytokines (IL-1β and IL-18). Atherosclerosis-related risk factors, including oxidized low-density lipoprotein (ox-LDL) and cholesterol crystals, have been shown to promote pyroptosis through several mechanisms that involve ion flux, ROS, endoplasmic reticulum stress, mitochondrial dysfunction, lysosomal rupture, Golgi function, autophagy, noncoding RNAs, post-translational modifications, and the expression of related molecules. Pyroptosis of endothelial cells, macrophages, and smooth muscle cells in the vascular wall can induce plaque instability and accelerate atherosclerosis progression. In this review, we focus on the pathogenesis, influence, and therapy of pyroptosis in atherosclerosis and provide novel ideas for suppressing pyroptosis and the progression of atherosclerosis.

Diabetes and Cardiovascular Complications: The Epidemics Continue

PURPOSE OF REVIEW

The cardiovascular complications of type 1 and 2 diabetes are major causes of morbidity and mortality. Extensive efforts have been made to maximize glycemic control; this strategy reduces certain manifestations of cardiovascular complications. There are drawbacks, however, as intensive glycemic control does not impart perennial protective benefits, and these efforts are not without potential adverse sequelae, such as hypoglycemic events.

RECENT FINDINGS

Here, the authors have focused on updates into key areas under study for mechanisms driving these cardiovascular disorders in diabetes, including roles for epigenetics and gene expression, interferon networks, and mitochondrial dysfunction. Updates on the cardioprotective roles of the new classes of hyperglycemia-targeting therapies, the sodium glucose transport protein 2 inhibitors and the agonists of the glucagon-like peptide 1 receptor system, are reviewed. In summary, insights from ongoing research and the cardioprotective benefits of the newer type 2 diabetes therapies are providing novel areas for therapeutic opportunities in diabetes and CVD.

Up-regulation of thioredoxin system by puerarin inhibits lipid uptake in macrophages

Cellular oxidative stress promotes lipid accumulation in macrophages during atherogenesis. Puerarin is a natural isoflavone with beneficial effects against oxidation and atherosclerosis. In this study, we investigated the effects of puerarin on lipid uptake and explored the underlying molecular regulation. We found puerarin up-regulated thioredoxin-1 (Trx1) and Trx reductase-1 (TrxR1) expression; it increased TrxR1 activity, cellular thiols contents and decreased oxidized form of Trx1, thus inhibiting cellular ROS generation. Confocal microscope and flow cytometry analysis showed fluorescence labeled Dil-oxLDL uptake was dramatically inhibited by puerarin in RAW264.7 cells as well as in primary bone marrow derived macrophages and peritoneal macrophages. The effects were reversed when Trx1 was inhibited by treatment with Trx1 inhibitor PX-12 or Trx1 siRNA. We also found scavenger receptors such as SR-A and Lox-1, but not CD36 were involved in the Trx1-mediated lipid uptake inhibition. Moreover, measurements of foam cell accumulation and ROS production in sections of aortic roots showed those were reduced by puerarin but raised when additional treatment with PX-12 or Trx1 siRNA in apoE-/- mice, which demonstrates the lipid uptake reduction by puerarin requires Trx1 inhibition in vivo. In addition, we analyzed the upstream regulation and found puerarin induced Nrf2 activity; cooperation between Nrf2 and ATF4 facilitated the puerarin effects. PERK phosphorylation was detected to be increased by puerarin, while PERK inhibition reduced cellular Trx1, TrxR1, nuclear Nrf2 and ATF4. Altogether, puerarin modulates PERK/Nrf2 that coordinates with ATF4 to active Trx1, which causes SR-A and Lox-1 reduction and lipid uptake inhibition in macrophages. This suggests Trx1 could be an effective target by puerarin in the prevention of atherosclerosis.

TXNIP contributes to bone loss via promoting the mitochondrial oxidative phosphorylation during glucocorticoid-induced osteoporosis

Oxidative stress is a promoting factor in the pathologic process of glucocorticoid - induced osteoporosis (GIO), while the mechanism is still unclear. Thioredoxin-interacting protein (TXNIP) is a vital protein responsible for regulation of cellular reactive oxygen species (ROS) generation elicited by mitochondrial oxidative stress, and which may activate oxidative phosphorylation under the pathogenic status. In this research, the results showed that signaling pathway associated with the mitochondrial oxidative phosphorylation (MOP) down-regulated under conditions of TXNIP siRNA in MG63 cells. Furthermore, the evidence revealed that the expression level of TXNIP in serum and bone was elevated in a rat of GIO. Moreover, the differential proteins (Ndufs3, SDHD, Cyt B, COX IV, and ATP B) related to MOP pathway were identified to down-regulate in the proteomics of bone tissues by using isobaric Tags for Relative and Absolute Quantification (iTRAQ) method in TXNIP knockout mice treated with glucocorticoid, and the proteins were also verified by simple western blot. Taken together, the present findings highlights that TXNIP involves in triggering the process of bone loss via up-regulation of the MOP pathway, resulting to GIO, while TXNIP knockout can prevent the pathogenesis of GIO to some extent.

MiR-128-3p inhibits vascular smooth muscle cell proliferation and migration by repressing FOXO4/MMP9 signaling pathway

Background

MicroRNAs (miRNAs) have been identified as important participants in the development of atherosclerosis (AS). The present study explored the role of miR-128-3p in the dysfunction of vascular smooth muscle cells (VSMCs) and the underlying mechanism.

Methods

Human VSMCs and ApoE knockout (ApoE^−/−) C57BL/6J mice were used to establish AS cell and animal models, respectively. Expression levels of miR-128-3p, forkhead box O4 (FOXO4) and matrix metallopeptidase 9 (MMP9) were detected using qRT-PCR and Western blot, respectively. CCK-8, BrdU, and Transwell assays as well as flow cytometry analysis were performed to detect the proliferation, migration and apoptosis of VSMCs. Levels of inflammatory cytokines and lipids in human VSMCs, mice serum and mice VSMCs were also determined. The binding site between miR-128-3p and 3′UTR of FOXO4 was confirmed using luciferase reporter gene assay.

Results

MiR-128-3p was found to be decreased in AS patient serum, ox-LDL-treated VSMCs, AS mice serum and VSMCs of AS mice. Transfection of miR-128-3p mimics suppressed the proliferation and migration of VSMCs, accompanied by the promoted apoptosis and the decreased levels of inflammatory cytokines. Further experiments confirmed the interaction between miR-128-3p and FOXO4. Augmentation of FOXO4 or MMP9 reversed the effects of miR-128-3p. Besides, miR-128-3p inhibited triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) but increased high-density lipoprotein cholesterol (HDL-C) in the serum of AS mice.

Conclusion

MiR-128-3p repressed the proliferation and migration of VSMCs through inhibiting the expressions of FOXO4 and MMP9.

Role of Kruppel-like factor 4 in atherosclerosis

Atherosclerosis is one of the chronic progressive diseases, which is caused by vascular injury and promoted by the interaction of various inflammatory factors and inflammatory cells. In recent years, kruppel-like factor 4 (KLF4), a significant transcription factor that participated in cell growth, differentiation and proliferation, has been proved to cause substantial impacts on regulating cardiovascular disease. This paper will give a comprehensive summary to highlight KLF4 as a crucial regulator of foam cell formation, vascular smooth muscle cells (VSMCs) phenotypic transformation, macrophage polarization, endothelial cells inflammation, lymphocyte differentiation and cell proliferation in the process of atherosclerosis. Recent studies show that KLF4 may be an important "molecular switch" in the process of improving vascular injury and inflammation under harmful stimulation, suggesting that KLF4 is a latent disease biomarker for the therapeutic target of atherosclerosis and vascular disease.

Elevated microRNA-20b-3p and reduced thioredoxin-interacting protein ameliorate diabetic retinopathy progression by suppressing the NLRP3 inflammasomes

Over the years, microRNA-20b-3p (miR-20b-3p) has been found to play an essential role in human diseases; we aimed to investigate the effect of miR-20b-3p on the progression of diabetic retinopathy (DR). The DR rat models were established by streptozotocin injection and treated with miR-20b-3p mimics, silenced, or overexpressed thioredoxin-interacting protein (TXNIP). Afterward, the expression of miR-20b-3p and TXNIP, visual function, inflammatory factors, microvascular injury, vascular permeability, cell apoptosis, and angiogenesis in rats' retinal tissues were assessed. The target relation between miR-20b-3p and TXNIP was confirmed by dual luciferase reporter gene assay. MiR-20b-3p was poorly expressed while TXNIP was highly expressed in DR rats' retinal tissues. Elevated miR-20b-3p and inhibited TXNIP promoted the visual function, and restricted the inflammatory reaction, microvascular injury, vascular permeability, cell apoptosis, and angiogenesis in DR rats, thereby decelerating the development of DR. Furthermore, TXNIP was targeted by miR-20b-3p. We have found in this study that elevated miR-20b-3p could repress the levels of inflammatory factors by inhibiting TXNIP, thus attenuating the pathology of retina in DR rats, which provided new candidates for DR treatment.

LongShengZhi Capsule Reduces Established Atherosclerotic Lesions in apoE-Deficient Mice by Ameliorating Hepatic Lipid Metabolism and Inhibiting Inflammation

Disorders of lipid metabolism and inflammation play an important role in atherosclerosis. LongShengZhi (LSZ) capsule, a Chinese herbal medicine, has been used for treatment of patients with vascular diseases for many years. In this article, we determined the effect of LSZ on the progression of established atherosclerotic lesions in apoE-deficient (apoE) mice. ApoE mice were prefed high-fat diet (HFD) for 8 weeks to induce atherosclerosis, then started with LSZ treatment contained in HFD for 10 weeks. Although LSZ had little effect on HFD-induced hypercholesterolemia, it substantially reduced en face and sinus aortic lesions. The reduction of lesions was associated with reduced macrophage/foam cell accumulation by activating ABCA1/ABCG1 expression. LSZ maintained the integrity of arterial wall by increasing collagen or smooth muscle cell content and inhibiting cell apoptosis. LSZ also attenuated HFD-induced fatty liver by down-regulating expression of lipogenic and cholesterol synthetic genes while activating expression of triglyceride catabolism genes. Moreover, LSZ demonstrated potent anti-inflammatory effects. In vivo, LSZ reduced serum TNF-α levels, infiltration of neutrophils, Kupffer cells, and expression of inflammatory cytokines in the liver. In vitro, it inhibited lipopolysaccharide or palmitate-induced expression of inflammatory cytokines in macrophages. Therefore, LSZ reduces atherosclerosis by ameliorating hepatic lipid metabolism and inhibiting inflammation.

ER Stress Activates the NLRP3 Inflammasome: A Novel Mechanism of Atherosclerosis

The endoplasmic reticulum (ER) is an important organelle that regulates several fundamental cellular processes, and ER dysfunction has implications for many intracellular events. The nucleotide-binding oligomerization domain-like receptor family, pyrin domain-containing 3 (NLRP3) inflammasome is an intracellularly produced macromolecular complex that can trigger pyroptosis and inflammation, and its activation is induced by a variety of signals. ER stress has been found to affect NLRP3 inflammasome activation through multiple effects including the unfolded protein response (UPR), calcium or lipid metabolism, and reactive oxygen species (ROS) generation. Intriguingly, the role of ER stress in inflammasome activation has not attracted a great deal of attention. In addition, increasing evidence highlights that both ER stress and NLRP3 inflammasome activation contribute to atherosclerosis (AS). AS is a common cardiovascular disease with complex pathogenesis, and the precise mechanisms behind its pathogenesis remain to be determined. Both ER stress and the NLRP3 inflammasome have emerged as critical individual contributors of AS, and owing to the multiple associations between these two events, we speculate that they contribute to the mechanisms of pathogenesis in AS. In this review, we aim to summarize the molecular mechanisms of ER stress, NLRP3 inflammasome activation, and the cross talk between these two pathways in AS in the hopes of providing new pharmacological targets for AS treatment.

Metformin inhibited Nod-like receptor protein 3 inflammasomes activation and suppressed diabetes-accelerated atherosclerosis in apoE-/- mice

AIMS

The present study aimed to investigate the effect of metformin on diabetes-accelerated atherosclerosis and whether Nod-like receptor protein 3 (NLRP3) inflammasome is a target for metformin.

MATERIALS AND METHODS

ApoE^-/- male mice were divided randomly into control, streptozocin-induced diabetes mellitus and metformin groups. Metabolic parameters, atherosclerotic lesion, activation of NLRP3 inflammasomes and related signaling pathways were detected. THP-1-differentiated macrophages were used in in vitro experiments.

RESULTS

Compared with control mice, increased plasma lipids and proinflammatory interleukin-1β, aggravated macrophage infiltration into the atherosclerotic lesion, and accelerated development of atherosclerosis were observed in diabetic mice, which were associated with the activation of NLRP3 inflammasomes and dysregulation of thioredoxin-1 and thioredoxin-interacting protein. Treatment with metformin alleviated diabetes-induced metabolic disorders and atherosclerosis, as well as NLRP3 inflammasomes activation and dysregulation of thioredoxin-1/thioredoxin-interacting protein. In vitro experiments showed that high glucose induced the accumulation of reactive oxygen species and activated NLRP3 inflammasomes, which was significantly suppressed by treatment with metformin or antioxidant N-acetyl-L-cysteine. Moreover, Compound C, an inhibitor of adenosine 5'-monophosphate-activated protein kinase (AMPK), blocked the anti-inflammatory effect of metformin, indicating that metformin inhibited high glucose-induced NLRP3 inflammasomes activation through AMPK activation. Moreover, high glucose decreased thioredoxin-1 expression and increased thioredoxin-interacting protein expression, which was also reversed by metformin.

CONCLUSIONS

Metformin inhibited NLRP3 inflammasomes activation and suppressed diabetes-accelerated atherosclerosis in apoE^-/- mice, which at least partially through activation of AMPK and regulation of thioredoxin-1/thioredoxin-interacting protein.

miR-125a-5p inhibits the expression of NLRP3 by targeting CCL4 in human vascular smooth muscle cells treated with ox-LDL

Recent findings have revealed that aberrant miR-125a-5p expression is involved in the development of atherosclerosis. The present study aimed to investigate the precise mechanism of microRNA (miR)-125a-5p in atherosclerosis. Human vascular smooth muscle cells (HVSMCs) were treated with 20 µg/ml oxidized low-density lipoprotein (ox-LDL) for 24 h and were employed as in vitro models of atherosclerosis. Reverse transcription quantitative (RT-qPCR) assays were used to detect miR-125a-5p levels. Immunofluorescence analysis was conducted to assess α-smooth muscle actin (α-SMA) expression. Western blotting and RT-qPCR assays were performed to measure the expression levels of NACHT, LRR and PYD domains-containing protein 3 (NLRP3), apoptosis associated speck-like protein (ASC), caspase-1, active interleukin (IL)-1β and C-C motif chemokine 4-like (CCL4). Furthermore, the association between miR-125a-5p and CCL4 was assessed using a double luciferase analysis. In addition, VSMCs were transfected with miR-125a-5p mimics (30 nM), miR-125a-5p inhibitor (100 nM) or small interfering RNA against CCL4 (si-CCL4, 50 pM), respectively to further investigate the function of miR-125a-5p in ox-LDL-treated HVSMCs. The present study found that the expression levels of miR-125a-5p were significantly downregulated in HVSMCs, whereas the expression levels of α-SMA, NLRP3, ASC, caspase-1, IL-1β and CCL4 were markedly upregulated following ox-LDL treatment. Overexpression of miR-125a-5p in the absence of ox-LDL treatment decreased NLRP3, IL-1β and CCL4 expression, whereas inhibition of miR-125a-5p exhibited the opposite effects. The results of double luciferase analysis confirmed that CCL4 was a direct target of miR-125a-5p. Moreover, transfection of si-CCL4 into HVSMCs significantly decreased the ox-LDL-induced expression of NLRP3, ASC, caspase-1 and IL-1β proteins. Taken collectively, the results of the present study suggested that miR-125a-5p could negatively regulate the NLRP3 inflammasome by targeting CCL4 in ox-LDL-treated HVSMCs. The data provide new insight to the inhibition of atherosclerosis progression.

Blocking the REDD1/TXNIP axis ameliorates LPS-induced vascular endothelial cell injury through repressing oxidative stress and apoptosis

The aim of the present study was to investigate the potential role of regulated in development and DNA damage response 1 (REDD1) in LPS-induced vascular endothelial injury by using human umbilical vein endothelial cells (HUVECs). We observed that REDD1 expression was apparently elevated in HUVECs after exposure to LPS. Additionally, elimination of REDD1 strikingly attenuated the secretion of the proinflammatory cytokines TNF-α, IL-6, IL-1β, and monocyte chemotactic protein-1 and the endothelial cell adhesion markers ICAM-1 and VCAM-1 that was induced by LPS stimulation. Subsequently, knockdown of REDD1 augmented cell viability but ameliorated lactate dehydrogenase release in HUVECs stimulated with LPS. Meanwhile, depletion of REDD1 effectively restricted LPS-induced HUVEC apoptosis, as exemplified by reduced DNA fragmentation, and it also elevated antiapoptotic Bcl-2 protein, concomitant with reduced levels of proapoptotic proteins Bax and cleaved caspase-3. Furthermore, repression of REDD1 remarkably alleviated LPS-triggered intracellular reactive oxygen species generation accompanied by decreased malondialdehyde content and increased the activity of the endogenous antioxidant enzymes superoxide dismutase, catalase, and glutathione peroxidase. Most important, depletion of REDD1 protected HUVECs against inflammation-mediated apoptosis and oxidative damage partly through thioredoxin-interacting protein (TXNIP). Collectively, these findings indicate that blocking the REDD1/TXNIP axis repressed the inflammation-mediated vascular injury process, which may be closely related to oxidative stress and apoptosis in HUVECs, implying that the REDD1/TXNIP axis may be a new target for preventing the endothelial cell injury process.

TXNIP knockdown alleviates hepatocyte ischemia reperfusion injury through preventing p38/JNK pathway activation

Hepatic ischemia and reperfusion (I/R) injury is a major cause of liver damage during liver transplantation, resection surgery, shock, and trauma. It has been reported that TXNIP expression was upregulated in a rat model of hepatic I/R injury. However, the role of TXNIP in the hepatic I/R injury is little known. In our study, we investigated the biological role of TXNIP and its potential molecular mechanism in the human hepatic cell line (HL7702 cells). Using oxygen-glucose deprivation and reoxygenation (OGD/R) to create a cell model of hepatic I/R injury, we found that the mRNA and protein expression levels of TXNIP were upregulated in HL7702 cells exposed to OGD/R. TXNIP overexpression remarkably promoted OGD/R-induced cell apoptosis and lactate dehydrogenase (LDH) release, both of which were significantly decreased by TXNIP knockdown. The production of malondialdehyde (MDA) was also increased by TXNIP overexpression, but was reduced by TXNIP knockdown. Moreover, TXNIP overexpression significantly upregulated the phosphorylation of p38 and JNK, which was remarkably inhibited by TXNIP knockdown. Additionally, p38-specific inhibitor SB203580 abrogated the effect of TXNIP overexpression on OGD/R-induced cell injury. Taken together, these results indicated that TXNIP knockdown alleviated hepatocyte I/R injury through preventing p38/JNK pathway activation. Thus, TXNIP might offer a novel potential therapeutic target for the treatment of hepatic I/R injury.

Research Progress of Angiogenesis in Atherosclerotic Plaque in Chinese Medicine and Western Medicine

Angiogenesis in atherosclerotic plaque plays a critical role in the mechanism of atherosclerotic physiopathology. Present consensus shows that angiogenesis in atherosclerotic plaque is mainly resulted in hypoxia, inflammation and some pro-angiogenic factors. The homeostasis in plaque, which is hypoxic and infiltrated by inflammatory cells, may lead to angiogenesis, increase the plaque instability and the incidence rate of vascular events. This article reviews the progression of pathogenetic mechanism, physiopathological significance, relevant detecting technique and corresponding therapeutic methods of Chinese and Western medicine of angiogenesis in atherosclerotic plaque, so as to provide more theoretical basis for atherosclerotic clinical treatment.

The role of the thioredoxin/thioredoxin reductase system in the metabolic syndrome: towards a possible prognostic marker?

Mammalian thioredoxin reductase (TrxR) is a selenoprotein with three existing isoenzymes (TrxR1, TrxR2, and TrxR3), which is found primarily intracellularly but also in extracellular fluids. The main substrate thioredoxin (Trx) is similarly found (as Trx1 and Trx2) in various intracellular compartments, in blood plasma, and is the cell's major disulfide reductase. Thioredoxin reductase is necessary as a NADPH-dependent reducing agent in biochemical reactions involving Trx. Genetic and environmental factors like selenium status influence the activity of TrxR. Research shows that the Trx/TrxR system plays a significant role in the physiology of the adipose tissue, in carbohydrate metabolism, insulin production and sensitivity, blood pressure regulation, inflammation, chemotactic activity of macrophages, and atherogenesis. Based on recent research, it has been reported that the modulation of the Trx/TrxR system may be considered as a new target in the management of the metabolic syndrome, insulin resistance, and type 2 diabetes, as well as in the treatment of hypertension and atherosclerosis. In this review evidence about a possible role of this system as a marker of the metabolic syndrome is reported.

Diabetes pathogenic mechanisms and potential new therapies based upon a novel target called TXNIP

PURPOSE OF REVIEW

Thioredoxin-interacting protein has emerged as a major factor regulating pancreatic β-cell dysfunction and death, key processes in the pathogenesis of type 1 and type 2 diabetes. Accumulating evidence based on basic, preclinical, and retrospective epidemiological research suggests that TXNIP represents a promising therapeutic target for diabetes. The present review is aimed at providing an update regarding these developments.

RECENT FINDINGS

TXNIP has been shown to be induced by glucose and increased in diabetes and to promote β-cell apoptosis, whereas TXNIP deletion protected against diabetes. More recently, TXNIP inhibition has also been found to promote insulin production and glucagon-like peptide 1 signaling via regulation of a microRNA. β-Cell TXNIP expression itself was found to be regulated by hypoglycemic agents, carbohydrate-response-element-binding protein, and cytosolic calcium or the calcium channel blocker, verapamil. Retrospective studies now further suggest that verapamil use might be associated with a lower incidence of type 2 diabetes in humans.

SUMMARY

TXNIP has emerged as a key factor in the regulation of functional β-cell mass and TXNIP inhibition has shown beneficial effects in a variety of studies. Thus, the inhibition of TXNIP may provide a novel approach to the treatment of diabetes.

Single-Cell RNA-Seq Reveals the Transcriptional Landscape and Heterogeneity of Aortic Macrophages in Murine Atherosclerosis

RATIONALE

It is assumed that atherosclerotic arteries contain several macrophage subsets endowed with specific functions. The precise identity of these subsets is poorly characterized as they have been defined by the expression of a restricted number of markers.

OBJECTIVE

We have applied single-cell RNA sequencing as an unbiased profiling strategy to interrogate and classify aortic macrophage heterogeneity at the single-cell level in atherosclerosis.

METHOD AND RESULTS

We performed single-cell RNA sequencing of total aortic CD45⁺ cells extracted from the nondiseased (chow fed) and atherosclerotic (11 weeks of high-fat diet) aorta of low-density lipoprotein receptor-deficient (Ldlr^-/-) mice. Unsupervised clustering singled out 13 distinct aortic cell clusters. Among the myeloid cell populations, resident-like macrophages with a gene expression profile similar to aortic resident macrophages were found in healthy and diseased aortas, whereas monocytes, monocyte-derived dendritic cells, and 2 populations of macrophages were almost exclusively detectable in atherosclerotic aortas, comprising inflammatory macrophages showing enrichment in Il1b and previously undescribed TREM2^hi (triggered receptor expressed on myeloid cells 2) macrophages showing enrichment in Trem2. Differential gene expression and gene ontology enrichment analyses revealed specific gene expression patterns distinguishing these 3 macrophage subsets and monocyte-derived dendritic cells and uncovered putative functions of each cell type. Notably, TREM2^hi macrophages seemed to be endowed with specialized functions in lipid metabolism and catabolism and presented a gene expression signature reminiscent of osteoclasts, suggesting a role in lesion calcification. TREM2 expression was moreover detected in human lesional macrophages. Importantly, these macrophage populations were present also in advanced atherosclerosis and in Apoe^-/- aortas, indicating relevance of our findings in different stages of atherosclerosis and mouse models.

CONCLUSIONS

These data unprecedentedly uncovered the transcriptional landscape and phenotypic heterogeneity of aortic macrophages and monocyte-derived dendritic cells in atherosclerotic and identified previously unrecognized macrophage populations and their gene expression signature, suggesting specialized functions. Our findings will open up novel opportunities to explore distinct myeloid cell populations and their functions in atherosclerosis.

Quercetin and Ascorbic Acid Suppress Fructose-Induced NLRP3 Inflammasome Activation by Blocking Intracellular Shuttling of TXNIP in Human Macrophage Cell Lines

The aim of this study was to identify the role of thioredoxin-interacting protein (TXNIP) and its interaction with antioxidants in the activation of the fructose-induced NOD-like receptor protein 3 (NLRP3) inflammasome in human macrophages. The study was performed with U937 and THP-1 macrophage cell lines. Total reactive oxygen species (ROS) were measured by flow cytometry. Interleukin-1β (IL-1β), IL-18, NLRP3, TXNIP, and caspase-1 protein expression was detected using western blotting. Quantitative real-time polymerase chain reaction was used to detect IL-1β, IL-18, and caspase-1 gene expression. Intracellular shuttling of TXNIP was assessed by immunofluorescent staining with MitoTracker Red. Increased production of ROS and expression of IL-1β, IL-18, and caspase-1 genes and proteins were observed in U937 and THP-1 cells incubated with fructose and were effectively inhibited by quercetin and ascorbic acid. Intracellular shuttling of TXNIP from the nucleus into the mitochondria was detected under stimulation with fructose, which was also attenuated by antioxidants quercetin and ascorbic acid but not butylated hydroxyanisole. Treatment of macrophages with fructose promoted the association between TXNIP and NLRP3 in the cytosol, sequentially resulting in the activation of the NLRP3 inflammasome. This study revealed that intracellular TXNIP protein is a critical regulator of activation of the fructose-induced NLRP3 inflammasome, which can be effectively blocked by the antioxidants quercetin and ascorbic acid.

Thioredoxin-Interacting Protein (TXNIP) in Cerebrovascular and Neurodegenerative Diseases: Regulation and Implication

Neurological diseases, including acute attacks (e.g., ischemic stroke) and chronic neurodegenerative diseases (e.g., Alzheimer's disease), have always been one of the leading cause of morbidity and mortality worldwide. These debilitating diseases represent an enormous disease burden, not only in terms of health suffering but also in economic costs. Although the clinical presentations differ for these diseases, a growing body of evidence suggests that oxidative stress and inflammatory responses in brain tissue significantly contribute to their pathology. However, therapies attempting to prevent oxidative damage or inhibiting inflammation have shown little success. Identification and targeting endogenous "upstream" mediators that normalize such processes will lead to improve therapeutic strategy of these diseases. Thioredoxin-interacting protein (TXNIP) is an endogenous inhibitor of the thioredoxin (TRX) system, a major cellular thiol-reducing and antioxidant system. TXNIP regulating redox/glucose-induced stress and inflammation, now is known to get upregulated in stroke and other brain diseases, and represents a promising therapeutic target. In particular, there is growing evidence that glucose strongly induces TXNIP in multiple cell types, suggesting possible physiological roles of TXNIP in glucose metabolism. Recently, a significant body of literature has supported an essential role of TXNIP in the activation of the NOD-like receptor protein (NLRP3)-inflammasome, a well-established multi-molecular protein complex and a pivotal mediator of sterile inflammation. Accordingly, TXNIP has been postulated to reside centrally in detecting cellular damage and mediating inflammatory responses to tissue injury. The majority of recent studies have shown that pharmacological inhibition or genetic deletion of TXNIP is neuroprotective and able to reduce detrimental aspects of pathology following cerebrovascular and neurodegenerative diseases. Conspicuously, the mainstream of the emerging evidences is highlighting TXNIP link to damaging signals in endothelial cells. Thereby, here, we keep the trend to present the accumulative data on CNS diseases dealing with vascular integrity. This review aims to summarize evidence supporting the significant contribution of regulatory mechanisms of TXNIP with the development of brain diseases, explore pharmacological strategies of targeting TXNIP, and outline obstacles to be considered for efficient clinical translation.

Paeoniflorin inhibits VSMCs proliferation and migration by arresting cell cycle and activating HO-1 through MAPKs and NF-κB pathway

The proliferation, migration and inflammation of vascular smooth muscle cells (VSMCs) contributes to the pathogenesis and progression of atherosclerosis. Paeoniflorin (PF) as active compound in the Rhizoma Atractylodes macrocephala has been used for various diseases like cancer, splenic asthenia, anaphylaxis and anorexia. This study aimed to explore whether and how PF regulated the inflammation, proliferation and migration of VSMCs under ox-LDL stimulation. Here, we found that PF dose-dependently inhibited ox-LDL-induced VSMCs proliferation and migration, and decreased inflammatory cytokines and chemokine overexpression. Mechanistically, PF prevented p38, ERK1/2 and NF-κB phosphorylation, and arrested cell cycle in S phase. Meanwhile, PF regulated the HO-1 and PCNA expression. Furthermore, PF blocked the foam cell formation in macrophages induced by ox-LDL. These results indicate that PF antagonizes the ox-LDL-induced VSMCs proliferation, migration and inflammation through activation of HO-1, cell cycle arrest and then suppression of p38, ERK1/2/MAPK and NF-κB signaling pathways.

Nuclear Factor (Erythroid-Derived 2)-Like 2 and Thioredoxin-1 in Atherosclerosis and Ischemia/Reperfusion Injury in the Heart

SIGNIFICANCE

Redox signaling is one of the key elements involved in cardiovascular diseases. Two important molecules are the transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2) and the oxidoreductase thioredoxin-1 (Trx-1). Recent Advances: During the previous years, a lot of studies investigated Nrf2 and Trx-1 as protective proteins in cardiovascular disorders. Moreover, post-translational modifications of those molecules were identified that play an important role in the cardiovascular system. This review will summarize changes in the vasculature in atherosclerosis and ischemia reperfusion injury of the heart and the newest findings achieved with Nrf2 and Trx-1 therein. Interestingly, Nrf2 and Trx-1 can act together as well as independently of each other in protection against atherosclerosis and ischemia and reperfusion injury.

CRITICAL ISSUES

In principle, pharmacological activation of a transcription factor-like Nrf2 can be dangerous, since a transcription regulator has multiple targets and the pleiotropic effects of such activation should not be ignored. Moreover, overactivation of Nrf2 as well as long-term treatment with Trx-1 could be deleterious for the cardiovascular system.

FUTURE DIRECTIONS

Therefore, the length of treatment with Nrf2 activators and/or Trx-1 has first to be studied in more detail in cardiovascular disorders. Moreover, a combination of Nrf2 activators and Trx-1 should be investigated and taken into consideration. Antioxid. Redox Signal. 26, 630-644.

Antipsychotic inductors of brain hypothermia and torpor-like states: perspectives of application

Hypothermia and hypometabolism (hypometabothermia) normally observed during natural hibernation and torpor, allow animals to protect their body and brain against the damaging effects of adverse environment. A similar state of hypothermia can be achieved under artificial conditions through physical cooling or pharmacological effects directed at suppression of metabolism and the processes of thermoregulation. In these conditions called torpor-like states, the mammalian ability to recover from stroke, heart attack, and traumatic injuries greatly increases. Therefore, the development of therapeutic methods for different pathologies is a matter of great concern. With the discovery of the antipsychotic drug chlorpromazine in the 1950s of the last century, the first attempts to create a pharmacologically induced state of hibernation for therapeutic purposes were made. That was the beginning of numerous studies in animals and the broad use of therapeutic hypothermia in medicine. Over the last years, many new agents have been discovered which were capable of lowering the body temperature and inhibiting the metabolism. The psychotropic agents occupy a significant place among them, which, in our opinion, is not sufficiently recognized in the contemporary literature. In this review, we summarized the latest achievements related to the ability of modern antipsychotics to target specific receptors in the brain, responsible for the initiation of hypometabothermia.

Investigation of enhanced hemocompatibility and tissue compatibility associated with multi-functional coating based on hyaluronic acid and Type IV collagen

The biocompatibility of cardiovascular devices has always been considered crucial for their clinical efficacy. Therefore, a biofunctional coating composed of Type IV collagen (CoIV) and hyaluronan (HA) was previously fabricated onto the titanium (Ti) substrate for the application of promoting vascular smooth muscle cell contractile phenotype and improving surface endothelialization. However, the anti-inflammation property, blood compatibility and in vivo tissue compatibility of the HA/CoIV coating, as paramount consideration of cardiovascular materials surface coating, have not been investigated. Thus, in this study, the three crucial properties of the HA/CoIV coating were tested. The platelet adhesion/activation test and the dynamic whole blood experiment implied that the HA/CoIV coating had better blood compatibility compared with Ti substrate and pure CoIV coating. The macrophage adhesion/activation and inflammatory cytokine release (tumor necrosis factor-alpha and interleukin-1) results indicated that the HA/CoIV coating could significantly improve the anti-inflammation property of the Ti substrate. The in vivo implantation of SD rats for 3 weeks' results demonstrated that the HA/CoIV coating caused milder tissue response. All these results suggested that the multi-functional HA/CoIV coating possessed good biocompatibility. This research is anticipated to be potentially applied for the surface modification of cardiovascular stents.

Associations of polymorphisms in TXNIP and gene-environment interactions with the risk of coronary artery disease in a Chinese Han population

Single nucleotide polymorphisms (SNPs) in thioredoxin-interacting protein (TXNIP) gene may modulate TXNIP expression, then increase the risk of coronary artery disease (CAD). In a two-stage case-control study with a total of 1818 CAD patients and 1963 controls, we genotyped three SNPs in TXNIP and found that the variant genotypes of SNPs rs7212 [odds ratio (OR) = 1.26, P = 0.001] and rs7211 (OR = 1.23, P = 0.005) were significantly associated with increased CAD risk under a dominant model. In haplotype analyses, compared with the reference haplotype, haplotype 'G-T' had a 1.22-fold increased risk of CAD (P = 0.003). We also observed the cumulative effects of SNPs rs7212 and rs7211 on CAD risk and the severity of coronary atherosclerosis. Moreover, the gene-environment interactions among the variant genotypes of SNP rs7212, smoking habit, alcohol drinking habit and history of type 2 diabetes were associated with a 3.70-fold increased risk of CAD (P < 0.001). Subsequent genotype-phenotype correlation analyses further observed the significant effects of SNP rs7212 on TXNIP mRNA expression, plasma TXNIP and malondialdehyde levels. Taken together, our data suggest that TXNIP SNPs may individually and cumulatively affect CAD risk through a possible mechanism for regulating TXNIP expression and gene-environment interactions.