HSP60 knockdown exerts differential response in endothelial cells and monocyte derived macrophages during atherogenic transformation

The Role of Alarmins in the Pathogenesis of Atherosclerosis and Myocardial Infarction

Atherosclerosis is a condition that is associated with lipid accumulation in the arterial intima. Consequently, the enlarging lesion, which is also known as an atherosclerotic plaque, may close the blood vessel lumen, thus leading to organ ischaemia. Furthermore, the plaque may rupture and initiate the formation of a thrombus, which can cause acute ischaemia. Atherosclerosis is a background pathological condition that can eventually lead to major cardiovascular diseases such as acute coronary syndrome or ischaemic stroke. The disorder is associated with an altered profile of alarmins, stress response molecules that are secreted due to cell injury or death and that induce inflammatory responses. High-mobility group box 1 (HMGB1), S100 proteins, interleukin-33, and heat shock proteins (HSPs) also affect the behaviour of endothelial cells and vascular smooth muscle cells (VSMCs). Thus, alarmins control the inflammatory responses of endothelial cells and proliferation of VSMCs, two important processes implicated in the pathogenesis of atherosclerosis. In this review, we will discuss the role of alarmins in the pathophysiology of atherosclerosis and myocardial infarction.

Hegemony of inflammation in atherosclerosis and coronary artery disease

Inflammation drives coronary artery disease and atherosclerosis implications. Lipoprotein entry, retention, and oxidative modification cause endothelial damage, triggering innate and adaptive immune responses. Recruited immune cells orchestrate the early atherosclerotic lesions by releasing proinflammatory cytokines, expediting the foam cell formation, intraplaque haemorrhage, secretion of matrix-degrading enzymes, and lesion progression, eventually promoting coronary artery syndrome via various inflammatory cascades. In addition, soluble mediators disrupt the dynamic anti- and prothrombotic balance maintained by endothelial cells and pave the way for coronary artery disease such as angina pectoris. Recent studies have established a relationship between elevated levels of inflammatory markers, including C-reactive protein (CRP), interleukins (IL-6, IL-1β), and tumour necrosis factor-alpha (TNF-α) with the severity of CAD and the possibility of future cardiovascular events. High-sensitivity C-reactive protein (hs-CRP) is a marker for assessing systemic inflammation and predicting the risk of developing CAD based on its peak plasma levels. Hence, understanding cross-talk interactions of inflammation, atherogenesis, and CAD is highly warranted to recalculate the risk factors that activate and propagate arterial lesions and devise therapeutic strategies accordingly. Cholesterol-inflammation lowering agents (statins), monoclonal antibodies targeting IL-1 and IL-6 (canakinumab and tocilizumab), disease-modifying antirheumatic drugs (methotrexate), sodium-glucose transport protein-2 (SGLT2) inhibitors, colchicine and xanthene oxidase inhibitor (allopurinol) have shown promising results in reducing inflammation, regressing atherogenic plaque and modifying the course of CAD. Here, we review the complex interplay between inflammatory, endothelial, smooth muscle and foam cells. Moreover, the putative role of inflammation in atherosclerotic CAD, underlying mechanisms and potential therapeutic implications are also discussed herein.

USP14-mediated NLRC5 upregulation inhibits endothelial cell activation and inflammation in atherosclerosis

Atherosclerosis, a chronic inflammatory condition that leads to a variety of life-threatening cardiovascular diseases, is a worldwide public health concern. Endothelial cells (ECs), which line the inside of blood vessels, play an important role in atherogenic initiation. Endothelial activation and inflammation are indispensable for the early stage of atherosclerosis. Ubiquitin-specific protease 14 (USP14), a deubiquitinating enzyme that regulates the stability and activity of target proteins, has been identified as a potential therapeutic target for many inflammatory diseases. However, the role of USP14 on ECs is undefined. In this study, we found that USP14 is downregulated in either atherosclerosis patient specimens or oxidized low-density lipoprotein (ox-LDL)-stimulated ECs as compared to the control group. Overexpression of USP14 in ECs restrains ox-LDL-stimulated nuclear transcription factor kappa B (NF-κB) activation and subsequent adhesion molecule production. USP14 inhibits endothelium proinflammatory activation by suppressing the degradation of the negative regulator of NF-κB signaling, nod-like receptor family caspase recruitment domain family domain containing 5 (NLRC5). Finally, our in vivo experiments confirmed that USP14 adenovirus injection in apolipoprotein E deficient (ApoE^-/-) mice fed with a western diet reduced the atherosclerotic lesion size, inhibited macrophage accumulation in the intima, and restricted the progression of atherosclerosis. Our results reveal that USP14 may represent a new therapeutic target for atherosclerosis.

Molecular mechanisms underlying hypertensive effect of fructose and the preventive properties of inulin - Global transcriptomic analysis in rat aorta

BACKGROUND AND AIMS

Excessive intake of fructose is a significant contributor in the development of hypertension and pathogenesis of cardiometabolic diseases. We previously showed that dietary inulin can prevent fructose-induced hypertension in rats. Nevertheless, molecular mechanisms of both fructose and inulin in aorta remain unknown. The aim of this study was to identify global transcriptomic changes in aorta in rats on fructose-based diet or partial substitution of dietary fructose with inulin.

METHODS AND RESULTS

At the end of study periods, aortas were isolated, RNA extracted, and transcriptomics performed using microarrays followed by in-dept bioinformatic analyses. We observed that fructose-based diet affected the expression of over 1700 genes involved in the regulation of vascular functions, cell signaling, and cellular metabolism. Partial substitution of dietary fructose with inulin affected the expression of over 1300 genes regulating endothelial and vascular functions, including relaxin signaling pathway, immune/inflammatory response, or cellular metabolism. Bioinformatic analyses revealed transcription factors, such as Junb or Nr4a2, and miRNAs, such as miR-206, miR-137 or miR-375, as potential transcriptional and post-transcriptional regulators of identified differentially expressed genes. Genes identified following both diets are associated with development of cardiovascular diseases, hypertension, immune system diseases and metabolic diseases. Moreover, a negative correlation between the expression profiles obtained by fructose-based diet and that by partial substitution of dietary fructose with inulin was observed.

CONCLUSION

Our study showed that fructose can significantly impact global transcriptomic profile in aorta, changes that can be counteracted by inulin and which present relevant molecular mechanisms underlying its anti-hypertensive property.

Anti-Inflammatory Activity of CIGB-258 against Acute Toxicity of Carboxymethyllysine in Paralyzed Zebrafish via Enhancement of High-Density Lipoproteins Stability and Functionality

Background: Hyperinflammation is frequently associated with the chronic pain of autoimmune disease and the acute death of coronavirus disease (COVID-19) via a severe cytokine cascade. CIGB-258 (Jusvinza®), an altered peptide ligand with 3 kDa from heat shock protein 60 (HSP60), inhibits the systemic inflammation and cytokine storm, but the precise mechanism is still unknown. Objective: The protective effect of CIGB-258 against inflammatory stress of N-ε-carboxymethyllysine (CML) was tested to provide mechanistic insight. Methods: CIGB-258 was treated to high-density lipoproteins (HDL) and injected into zebrafish and its embryo to test a putative anti-inflammatory activity under presence of CML. Results: Treatment of CML (final 200 μM) caused remarkable glycation of HDL with severe aggregation of HDL particles to produce dysfunctional HDL, which is associated with a decrease in apolipoprotein A-I stability and lowered paraoxonase activity. Degradation of HDL3 by ferrous ions was attenuated by a co-treatment with CIGB-258 with a red-shift of the Trp fluorescence in HDL. A microinjection of CML (500 ng) into zebrafish embryos resulted in the highest embryo death rate, only 18% of survivability with developmental defects. However, co-injection of CIGB-258 (final 1 ng) caused the remarkable elevation of survivability around 58%, as well as normal developmental speed. An intraperitoneal injection of CML (final 250 μg) into adult zebrafish resulted acute paralysis, sudden death, and laying down on the bottom of the cage with no swimming ability via neurotoxicity and inflammation. However, a co-injection of CIGB-258 (1 μg) resulted in faster recovery of the swimming ability and higher survivability than CML alone injection. The CML alone group showed 49% survivability, while the CIGB-258 group showed 97% survivability (p < 0.001) with a remarkable decrease in hepatic inflammation up to 50%. A comparison of efficacy with CIGB-258, Infliximab (Remsima®), and Tocilizumab (Actemra®) showed that the CIGB-258 group exhibited faster recovery and swimming ability with higher survivability than those of the Infliximab group. The CIGB-258 group and Tocilizumab group showed the highest survivability, the lowest plasma total cholesterol and triglyceride level, and the infiltration of inflammatory cells, such as neutrophils in hepatic tissue. Conclusion: CIGB-258 ameliorated the acute neurotoxicity, paralysis, hyperinflammation, and death induced by CML, resulting in higher survivability in zebrafish and its embryos by enhancing the HDL structure and functionality.

The role and mechanism of tetramethylpyrazine for atherosclerosis in animal models: A systematic review and meta-analysis

Background

Atherosclerosis(AS) is widely recognized as a risk factor for incident cardiovascular and cerebrovascular diseases. Tetramethylpyrazine (TMP) is the active ingredient of Ligusticum wallichii that possesses a variety of biological activities against atherosclerosis.

Objective

This systematic review and meta-analysis sought to study the impact of and mechanism of tetramethylpyrazine for atherosclerosis in animal models.

Methods

A systematic search was conducted of PubMed, Embase, Cochrane Library, Web of Science database, Chinese Biomedical (CBM) database, China National Knowledge Infrastructure (CNKI), WanFang data, and Vip Journal Integration Platform, covering the period from the respective start date of each database to December 2021. We used SYRCLE’s 10-item checklist and Rev-Man 5.3 software to analyze the data and the risk of bias.

Results

Twelve studies, including 258 animals, met the inclusion criteria. Compared with the control group, TMP significantly reduced aortic atherosclerotic lesion area, and induced significant decreases in levels of TC (SMD = ‐2.67, 95% CI -3.68 to -1.67, P < 0.00001), TG (SMD = ‐2.43, 95% CI -3.39 to -1.47, P < 0.00001), and LDL-C (SMD = ‐2.87, 95% CI -4.16 to -1.58, P < 0.00001), as well as increasing HDL-C (SMD = 2.04, 95% CI 1.05 to 3.03, P = 0.001). TMP also significantly modulated plasma inflammatory responses and biological signals associated with atherosclerosis. In subgroup analysis, the groups of high-dose TMP (≥50 mg/kg) showed better results than those of the control group. No difference between various durations of treatment groups or various assessing location groups.

Conclusion

TMP exerts anti-atherosclerosis functions in an animal model of AS mediated by anti-inflammatory action, antioxidant action, ameliorating lipid metabolism disorder, protection of endothelial function, antiplatelet activity, reducing the proliferation and migration of smooth muscle cells, inhibition of angiogenesis, antiplatelet aggregation. Due to the limitations of the quantity and quality of current studies, the above conclusions need to be verified by more high-quality studies.

Trial registration number

PROSPERO registration no.CRD42021288874.

Systemic deficiency of vitronectin is associated with aortic inflammation and plaque progression in ApoE-Knockout mice

Optimal cell spreading and interplay of vascular smooth muscle cells (VSMC), inflammatory cells, and cell adhesion molecules (CAM) are critical for progressive atherosclerosis and cardiovascular complications. The role of vitronectin (VTN), a major cell attachment glycoprotein, in the pathogenesis of atherosclerosis remains elusive. In this study, we attempt to examine the pathological role of VTN in arterial plaque progression and inflammation. We found that, relative expression analysis of VTN from the liver of Apolipoprotein E (ApoE) Knockout mice revealed that atherosclerotic progression induced by feeding mice with high cholesterol diet (HCD) causes a significant downregulation of VTN mRNA as well as protein after 60 days. Promoter assay confirmed that cholesterol modulates the expression of VTN by influencing its promoter. Mimicking VTN reduction with siRNA in HCD fed ApoE Knockout mice, accelerated athero-inflammation with an increase in NF-kB, ICAM-1, and VCAM-1 at the site of the plaque along with upregulation of inflammatory proteins like MCP-1 and IL-1β in the plasma. Also, matrix metalloprotease (MMP)-9 and MMP-12 expression were increased and collagen content was decreased in the plaque, in VTN deficient condition. This might pose a challenge to plaque integrity. Human subjects with acute coronary syndrome or having risk factors of atherosclerosis have lower levels of VTN compared to healthy controls suggesting a clinical significance of plasma VTN in the pathophysiology of coronary artery disease. We establish that, VTN plays a pivotal role in cholesterol-driven atherosclerosis and aortic inflammation and might be a useful indicator for atherosclerotic plaque burden and stability.

Melatonin-primed ADMSCs elicit an efficacious therapeutic response in improving high-fat diet induced non-alcoholic fatty liver disease in C57BL/6J mice

Background

Stem cells are widely used for therapy including treatment of liver damage. Adipose-derived mesenchymal stem cells (ADMSCs) administered to treat fatty liver are known to improve liver function but their use is restricted due to a poor success rate. This study investigates efficacy of melatonin-primed ADMSCs (Mel. MSCs) in experimentally induced non-alcoholic fatty liver disease (NAFLD).

Results

MSCs treated with LPS showed prominent DCFDA fluorescence as compared to the untreated cells. Also, the JC-1 staining had accounted for higher intensity of green monomer and a weak fluorescence of red dimer indicating weaker mitochondrial membrane potential. But melatonin co-treatment could make necessary corrective changes as evidenced by reverse set of results. The overall cell survival was also found to be improved following melatonin treatment as evidenced by the MTT assay. Also, the antioxidant (Nrf2 and Ho-1) and anti-inflammatory genes (Il-4 and Il-10) showed a decrement in their mRNA levels following LPS treatment whereas the pro-inflammatory genes (Tnf-α, Il-6, Tlr-4, and Lbp) showed a reciprocal increment in the said group. Melatonin co-treatment accounted for an improved status of antioxidant and anti-inflammatory genes as evidenced by their mRNA levels. High-fat high-fructose diet (HFFD) fed C57BL/6J mice recorded higher serum AST and ALT levels and fatty manifestation in histology of liver along with lowered mRNA levels of antioxidant (Nrf2, Catalase, and Gss) genes and Hgf. These set of parameters showed a significant improvement in HFFD + Mel.MSC group.

Conclusion

A significant improvement in viability of MSCs was recorded due to lowered intracellular oxidative stress and improves mitochondrial membrane potential. Further, melatonin-primed MSCs accounted for a significant decrement in fatty manifestations in liver and an improved physiological status of NAFLD in HFFD fed C57BL/6J mice. Taken together, it is hypothesized that melatonin priming to MSCs prior to its use can significantly augment the success of stem cell therapy.

Recognition of Oxidized Lipids by Macrophages and Its Role in Atherosclerosis Development

Atherosclerosis is a multifactorial chronic disease that has a prominent inflammatory component. Currently, atherosclerosis is regarded as an active autoimmune process that involves both innate and adaptive immune pathways. One of the drivers of this process is the presence of modified low-density lipoprotein (LDL). For instance, lipoprotein oxidation leads to the formation of oxidation-specific epitopes (OSE) that can be recognized by the immune cells. Macrophage response to OSEs is recognized as a key trigger for initiation and a stimulator of progression of the inflammatory process in the arteries. At the same time, the role of oxidized LDL components is not limited to pro-inflammatory stimulation, but includes immunoregulatory effects that can have protective functions. It is, therefore, important to better understand the complexity of oxidized LDL effects in atherosclerosis in order to develop new therapeutic approaches to correct the inflammatory and metabolic imbalance associated with this disorder. In this review, we discuss the process of oxidized LDL formation, mechanisms of OSE recognition by macrophages and the role of these processes in atherosclerosis.