Oxidized LDL induces FAK-dependent RSK signaling to drive NF-κB activation and VCAM-1 expression

Fibronectin-dependent integrin signaling drives EphA2 expression in vascular smooth muscle cells

Vascular smooth muscle cells undergo a phenotypic shift to a "synthetic" phenotype during atherosclerosis characterized by downregulation of contractile markers and augmented proliferation, migration, and extracellular matrix deposition. While absent in contractile smooth muscle cells, the receptor tyrosine kinase EphA2 shows enhanced expression in synthetic vascular smooth muscle in vitro and in atherosclerotic plaques in vivo. EphA2 deletion in atheroprone ApoE knockout mice reduces plaque size, fibrous tissue, and smooth muscle content. However, the mechanisms regulating smooth muscle EphA2 expression remain unknown. Although serum strongly induces EphA2 expression, individual growth factors and insulin all failed to stimulate EphA2 expression in smooth muscle cells. In contrast, adhesion to fibronectin stimulated the expression of EphA2, while blunting serum-induced fibronectin deposition attenuated EphA2 expression, suggesting a critical role for fibronectin signaling. Fibronectin binds to a subset of extracellular matrix-binding integrins, and blocking fibronectin-integrin interactions or inhibiting specific fibronectin-binding integrins both attenuated EphA2 expression. Furthermore, pharmacological inhibition of fibronectin-binding integrins significantly reduced EphA2 expression in atherosclerotic plaques. RNA sequencing analysis of fibronectin-associated gene expression pointed to NF-κB as a likely transcription factor mediating fibronectin-responsive genes. Adhesion to fibronectin enhanced NF-κB activation in smooth muscle cells and inhibiting NF-κB blunted EphA2 expression associated with fibronectin. In addition, chromatin immunoprecipitation showed that NF-κB directly interacts with the EphA2 promoter, and mutating this site blunts fibronectin-dependent EphA2 promoter activity. Together these data identify a novel role for fibronectin-dependent integrin signaling in the induction of smooth muscle EphA2 expression.NEW & NOTEWORTHY Here, we demonstrate a novel interplay between cell-cell and cell-matrix adhesions, showing that fibronectin-dependent integrin signaling promotes NF-κB activation and interaction with the EphA2 promoter to drive smooth muscle EphA2 expression, whereas integrin inhibition attenuates EphA2 expression in atherosclerotic plaques in vivo. Although this relationship has clear implications on smooth muscle fibroproliferative remodeling in atherosclerosis, the matrix-specific regulation of EphA2 expression may impact a variety of pathological conditions.

GOLM1 Promotes Atherogenesis by Activating Macrophage EGFR-ERK Signaling Cascade

BACKGROUND

Atherosclerosis is a chronic inflammatory disease. GOLM1 (Golgi membrane protein 1) is an inflammation-responsive protein and a mediator in some inflammation-associated pathological processes. Because we found a positive correlation between GOLM1 expression and atherosclerosis progression by checking the gene expression data set of human atherosclerotic lesions, we explored the potential significance of GOLM1 in atherosclerosis in this study.

METHODS

GOLM1 levels in serums and lesions of patients with atherosclerosis and mice with atherosclerosis were examined by immunostaining and ELISA. Gain-of-function and loss-of-function approaches were used to study the impacts of GOLM1 in inflammation and atherogenesis of Apoe-/- mice on a Western diet. The effects of GOLM1 on macrophage behaviors were determined by OxLDL (oxidized low-density lipoprotein) uptake assay, single-cell sequencing analysis, global phosphoproteomics analysis, and molecular biological techniques. The therapeutic potential of GOLM1 neutralization for atherosclerosis was evaluated in Apoe-/- mice.

RESULTS

GOLM1 was elevated in serums and lesions of patients with atherosclerosis and mice with atherosclerosis. Global deletion of GOLM1 ameliorated mouse inflammation and atherosclerosis, while knock-in of GOLM1 exacerbated these pathological manifestations. Furthermore, hepatic GOLM1 deletion reduced circulating GOLM1 and attenuated atherogenesis. Mechanistically, the expression and secretion of GOLM1 were induced in multiple mouse tissues by atherogenic stimulus, leading to the elevation of extracellular GOLM1. Extracellular GOLM1 then stimulated ERK (extracellular signal-regulated kinase) signaling cascade by binding to its putative receptor EGFR (epidermal growth factor receptor) to promote macrophage uptake of LDL (low-density lipoprotein) and enhance the corresponding macrophage immune response. Moreover, neutralizing GOLM1 by an antibody suppressed mouse inflammation and atherogenesis.

CONCLUSIONS

GOLM1 is an atherogenic mediator and a promising therapeutic target for the intervention of atherosclerotic diseases.

Unravelling the Mechanisms of Oxidised Low-Density Lipoprotein in Cardiovascular Health: Current Evidence from In Vitro and In Vivo Studies

Cardiovascular diseases (CVD) are the number one cause of death worldwide, with atherosclerosis, which is the formation of fatty plaques in the arteries, being the most common underlying cause. The activation of inflammatory events and endothelium dysfunction are crucial for the development and pathophysiology of atherosclerosis. Elevated circulating levels of low-density lipoprotein (LDL) have been associated with severity of atherosclerosis. LDL can undergo oxidative modifications, resulting in oxidised LDL (oxLDL). OxLDL has been found to have antigenic potential and contribute significantly to atherosclerosis-associated inflammation by activating innate and adaptive immunity. Various inflammatory stimuli such as interleukin-6 (IL-6), tumour necrosis factor-alpha (TNF-α) and intercellular adhesion molecule 1 (ICAM-1) play major roles in atherosclerosis. To date, studies have provided valuable insights into the role of oxLDL in the development of atherosclerosis. However, there remains a gap in understanding the specific pathways involved in this process. This review aims to provide and discuss the mechanisms by which oxLDL modulates signalling pathways that cause cardiovascular diseases by providing in vitro and in vivo experimental evidence. Its critical role in triggering and sustaining endothelial dysfunction highlights its potential as a therapeutic target. Advancing the understanding of its atherogenic role and associated signalling pathways could pave the way for novel targeted therapeutic strategies to combat atherosclerosis more effectively.

RSK1 and RSK2 as therapeutic targets: an up-to-date snapshot of emerging data

INTRODUCTION

The four members of the p90 ribosomal S6 kinase (RSK) family are serine/threonine protein kinases, which are phosphorylated and activated by ERK1/2. RSK1/2/3 are further phosphorylated by PDK1. Receiving inputs from two major signaling pathways places RSK as a key signaling node in numerous pathologies. A plethora of RSK1/2 substrates have been identified, and in the majority of cases the causative roles these RSK substrates play in the pathology are unknown.

AREAS COVERED

The majority of studies have focused on RSK1/2 and their functions in a diverse group of cancers. However, RSK1/2 are known to have important functions in cardiovascular disease and neurobiological disorders. Based on the literature, we identified substrates that are common in these pathologies with the goal of identifying fundamental physiological responses to RSK1/2.

EXPERT OPINION

The core group of targets in pathologies driven by RSK1/2 are associated with the immune response. However, there is a paucity of the literature addressing RSK function in inflammation, which is critical to know as the pan RSK inhibitor, PMD-026, is entering phase II clinical trials for metastatic breast cancer. A RSK inhibitor has the potential to be used in numerous diverse diseases and disorders.

p-Coumaric acid modulates cholesterol efflux and lipid accumulation and inflammation in foam cells

BACKGROUND/OBJECTIVES

Atherosclerosis is a primary cause of cardiovascular disease associated with inflammation and lipid metabolism disorders. The accumulation of cholesterol-containing macrophage foam cells characterizes the early stages. The p-coumaric acid (p-CA) contained in vegetables may have various physiological activities. The inhibitory effect of p-CA on foam cell creation in THP-1 macrophages needs clarification. In this study, we explored the impact of p-CA on foam cells by co-treatment with oxidized low-density lipoprotein (ox-LDL) and lipopolysaccharides (LPS), mimicking the development of atherosclerosis in vitro and studied the regulation of its underlying mechanisms.

MATERIALS/METHODS

THP-1 cells differentiated by phorbol 12-myristate 13-acetate (1 μM) for 48 h and treated in the absence or presence of p-CA for 48 h. THP-1 macrophages were treated with combined ox-LDL (20 μg/mL) and LPS (500 ng/mL) for 24 h. The 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide assays detected cell viability. Oil red O staining allowed us to observe lipid accumulation. Western blotting and quantitative polymerase chain reactions quantified corresponding proteins and mRNA.

RESULTS

Ox-LDL and LPS for 24 h enhanced the lipid accumulation using Oil red O in treated foam cells. By contrast, p-CA treatment inhibited lipid accumulation. p-CA significantly upregulated cholesterol efflux-related genes such as ATP binding cassette transporter A1, liver-X-receptor α and peroxisome proliferator-activated receptor gamma expression. Moreover, p-CA decreased lipid accumulation-related gene such as lectin-like oxidized low-density lipoprotein receptor-1, cluster of differentiation 36 and scavenger receptor class A1 expression. Combined ox-LDL and LPS increased nuclear factor-κB (NF-κB), cyclooxygenase-2 (COX-2) and pro-inflammatory (tumor necrosis factor-α [TNF-α] and interleukin [IL]-6) activation and expression compared with untreated. p-CA suppressed this increased expression of NF-κB and COX-2, TNF-α and IL-6.

CONCLUSION

p-CA may play a vital role in atherosclerosis inhibition and protective effects by suppressing lipid accumulation and foam cell creation by increasing cholesterol efflux and can be potential agents for preventing atherosclerosis.

FAK Family Kinases: A Potential Therapeutic Target for Atherosclerosis

Atherosclerosis (AS) is a chronic progressive inflammatory disease of the vascular wall and the primary pathological basis of cardiovascular and cerebrovascular disease. Focal adhesion kinase (FAK) and proline-rich tyrosine kinase 2 (Pyk2), two highly homologous members of the FAK family kinases, play critical roles in integrin signaling. They also serve as scaffolding proteins that contribute to the assembly of cellular signaling complexes that regulate cell survival, cell cycle progression, and cell motility. Research indicates that the FAK family kinases is involved in the gene regulation of vascular cells and that aberrant expression of this family is associated with pathological changes in vascular disease. These findings establish the FAK family kinases as a critical signaling mediator in atherosclerotic lesions and inhibition of its activity has the potential to attenuate the pathological progression of AS. This review highlights the indispensable role of the FAK family kinases in abnormal vascular smooth muscle cell proliferation, endothelial cell dysfunction, inflammation, and lipid metabolism associated with AS. We also summarize therapeutic targets against the FAK family kinases, providing valuable insights into therapeutic strategies for AS.

The Multifaceted Nature of Macrophages in Cardiovascular Disease

As the leading cause of mortality worldwide, cardiovascular disease (CVD) represents a variety of heart diseases and vascular disorders, including atherosclerosis, aneurysm, ischemic injury in the heart and brain, arrythmias, and heart failure. Macrophages, a diverse population of immune cells that can promote or suppress inflammation, have been increasingly recognized as a key regulator in various processes in both healthy and disease states. In healthy conditions, these cells promote the proper clearance of cellular debris, dead and dying cells, and provide a strong innate immune barrier to foreign pathogens. However, macrophages can play a detrimental role in the progression of disease as well, particularly those inflammatory in nature. This review will focus on the current knowledge regarding the role of macrophages in cardiovascular diseases.

A novel circRNA, hsa_circ_0069382, regulates gastric cancer progression

Aberrant expression of circRNAs is closely associated with the progression of gastric cancer; however, the specific mechanisms involved remain unclear. Our aim was to identify new gastric cancer biomarkers and explore the molecular mechanisms of gastric cancer progression. Therefore, we analyzed miRNA and circRNA microarrays of paired early-stage gastric cancer samples. Our study identified a new circRNA called hsa_circ_0069382, that had not been reported before and was expressed at low levels in gastric cancer tissues. Our study also included bioinformatics analyses which determined that the high expression of hsa_circ_0069382 regulated the BTG anti-proliferation factor 2 (BTG2)/ focal adhesion kinase (FAK) axis in gastric cancer lines by sponging for miR-15a-5p. Therefore, proliferation, invasion, and migration of gastric cancer is impacted. miR-15a-5p overexpression partially restored the effects of hsa_circ_0069382. This study provides potential new therapeutic options and a future direction to explore for gastric cancer treatment, and biomarkers.

Beneficial Effects of lncRNA-UC.360+ shRNA on Diabetic Cardiac Sympathetic Damage via NLRP3 Inflammasome-Induced Pyroptosis in Stellate Ganglion

Hyperglycemia is one of the common symptoms of diabetes, and it produces excessive reactive oxygen species (ROS). This study investigated whether the long noncoding RNA (lncRNA) UC.360+ is involved in diabetic cardiac autonomic neuropathy (DCAN) mediated by NLRP3 inflammasome-induced pyroptosis in the stellate ganglion (SG). Using a rat type 2 diabetes model, we found that lncRNA UC.360+ short hairpin RNA (shRNA) ameliorated the dyslipidaemia of type 2 diabetic rats and reduced serum adrenaline and ROS production in SG under hyperglycemia. In addition, UC.360+ shRNA also reduced the expression of nuclear factor kappa-B (NF-κB), NLRP3, ASC, caspase-1, interleukin-1β (IL-1β), and IL-18 in the SG of diabetic rats and inhibited the phosphorylation of p38 mitogen-activated protein kinase (p38 MAPK). Therefore, lncRNA-UC.360+ shRNA may modulate the NLRP3 inflammasome/inflammatory pathway in the SG, which in turn alleviates diabetic heart sympathetic nerve damage.

Cyclic-AMP Increases Nuclear Actin Monomer Which Promotes Proteasomal Degradation of RelA/p65 Leading to Anti-Inflammatory Effects

The second messenger, cAMP has potent immunosuppressive and anti-inflammatory actions. These have been attributed, in part, to the ability of cAMP-induced signals to interfere with the function of the proinflammatory transcription factor Nuclear Factor-kappa B (NF-κB). However, the mechanisms underlying the modulation of NF-κB activity by cAMP remain unclear. Here we demonstrate an important role for cAMP-mediated increase in nuclear actin monomer levels in inhibiting NF-κB activity. Elevated cAMP or forced expression of a nuclear localised polymerisation defective actin mutant (NLS-Actin_R62D) inhibited basal and TNFα induced mRNA levels of NF-κB-dependent genes and NF-κB-dependent reporter gene activity. Elevated cAMP or NLS-Actin_R62D did not affect NF-κB nuclear translocation but did reduce total cellular and nuclear RelA/p65 levels. Preventing the cAMP-induced increase in nuclear actin monomer, either by expressing a nuclear localised active mutant of the actin polymerising protein mDIA, silencing components of the nuclear actin import complex IPO9 and CFL1 or overexpressing the nuclear export complex XPO6, rescued RelA/p65 levels and NF-κB reporter gene activity in forskolin-stimulated cells. Elevated cAMP or NLS-Actin_R62D reduced the half-life of RelA/p65, which was reversed by the proteasome inhibitor MG132. Accordingly, forskolin stimulated association of RelA/p65 with ubiquitin affinity beads, indicating increased ubiquitination of RelA/p65 or associated proteins. Taken together, our data demonstrate a novel mechanism underlying the anti-inflammatory effects of cAMP and highlight the important role played by nuclear actin in the regulation of inflammation.

Mechanosensitive molecular interactions in atherogenic regions of the arteries: development of atherosclerosis

A terrible disease of the cardiovascular system, atherosclerosis, develops in the areas of bends and branches of arteries, where the direction and modulus of the blood flow velocity vector change, and consequently so does the mechanical effect on endothelial cells in contact with the blood flow. The review focuses on topical research studies on the development of atherosclerosis – mechanobiochemical events that transform the proatherogenic mechanical stimulus of blood flow – low and low/oscillatory arterial wall shear stress in the chains of biochemical reactions in endothelial cells, leading to the expression of specific proteins that cause the progression of the pathological process. The stages of atherogenesis, systemic risk factors for atherogenesis and its important hemodynamic factor, low and low/oscillatory wall shear stress exerted by blood flow on the endothelial cells lining the arterial walls, have been described. The interactions of cell adhesion molecules responsible for the development of atherosclerosis under low and low/oscillating shear stress conditions have been demonstrated. The activation of the regulator of the expression of cell adhesion molecules, the transcription factor NF-κB, and the factors regulating its activation under these conditions have been described. Mechanosensitive signaling pathways leading to the expression of NF-κB in endothelial cells have been described. Studies of the mechanobiochemical signaling pathways and interactions involved in the progression of atherosclerosis provide valuable information for the development of approaches that delay or block the development of this disease. Key words: atherogenesis; shear stress; transcription factor NF-κB; RelA expression; mechanosensitive receptors; cell adhesion molecules; signaling pathways; mechanotransduction.

Focal Adhesion Kinase Activity and Localization is Critical for TNF-α-Induced Nuclear Factor-κB Activation

While sustained nuclear factor-κB (NF-κB) activation is critical for proinflammatory molecule expression, regulators of NF-κB activity during chronic inflammation are not known. We investigated the role of focal adhesion kinase (FAK) on sustained NF-κB activation in tumor necrosis factor-α (TNF-α)-stimulated endothelial cells (ECs) both in vitro and in vivo. We found that FAK inhibition abolished TNF-α-mediated sustained NF-κB activity in ECs by disrupting formation of TNF-α receptor complex-I (TNFRC-I). Additionally, FAK inhibition diminished recruitment of receptor-interacting serine/threonine-protein kinase 1 (RIPK1) and the inhibitor of NF-κB (IκB) kinase (IKK) complex to TNFRC-I, resulting in elevated stability of IκBα protein. In mice given TNF-α, pharmacological and genetic FAK inhibition blocked TNF-α-induced IKK-NF-κB activation in aortic ECs. Mechanistically, TNF-α activated and redistributed FAK from the nucleus to the cytoplasm, causing elevated IKK-NF-κB activation. On the other hand, FAK inhibition trapped FAK in the nucleus of ECs even upon TNF-α stimulation, leading to reduced IKK-NF-κB activity. Together, these findings support a potential use for FAK inhibitors in treating chronic inflammatory diseases.

Metabolic Consequences of Efferocytosis and its Impact on Atherosclerosis

Billions of cells undergo apoptosis daily and are swiftly removed by macrophages through an evolutionarily conserved program termed "efferocytosis". Consequently, macromolecules within an apoptotic cell significantly burden a phagocyte with nutrients, such as lipids, oligonucleotides, and amino acids. In response to this nutrient overload, metabolic reprogramming must occur for the process of efferocytosis to remain non-phlogistic and to execute successive rounds of efferocytosis. The inability to undergo metabolic reprogramming after efferocytosis drives inflammation and impairs its resolution, often promoting many chronic inflammatory diseases. This is particularly evident for atherosclerosis, as metabolic reprogramming alters macrophage function in every stage of atherosclerosis, from the early formation of benign lesions to the progression of clinically relevant atheromas and during atherosclerosis regression upon aggressive lipid-lowering. This Review focuses on the metabolic pathways utilized upon apoptotic cell ingestion, the consequences of these metabolic pathways in macrophage function thereafter, and the role of metabolic reprogramming during atherosclerosis. Due to the growing interest in this new field, I introduce a new term, "efferotabolism", as a means to define the process by which macrophages break down, metabolize, and respond to AC-derived macromolecules. Understanding these aspects of efferotabolism will shed light on novel strategies to combat atherosclerosis and compromised inflammation resolution.

Phoenixin-20 Prevents ox-LDL-Induced Attachment of Monocytes to Human Aortic Endothelial Cells (HAECs): A Protective Implication in Atherosclerosis

The exact cause of atherosclerosis is not known, and therefore, the current treatment options are limited. The activation of endothelial cells by oxidized low-density lipoprotein (ox-LDL) plays a key role in the initiation and progression of atherosclerosis. Phoenixin-20 is one of the newly identified neuropeptides with pleiotropic effects in the regulation of reproduction and other biological functions. G-protein receptor-coupled 173 (GPR173) is the putative receptor of Phoenixin-20. In the present study, we show that endothelial GPR173 is repressed upon ox-LDL stimulation in human aortic endothelial cells (HAECs). We further elaborate on the hypothesis that GPR173 could be involved in the pathogenesis of atherosclerosis through a series of experiments. Our results indicate that ox-LDL remarkably triggers the increase of ROS, NOX-4, pro-inflammatory cytokines IL-1β, IL-8, and MCP-1 expression, as well as adhesion molecules ICAM-1 and VCAM-1 release. However, the agonism of GPR173 using Phoenixin-20 significantly ameliorates all of these harmful effects from ox-LDL by suppressing the NF-κB pathway. Furthermore, we show that agonism of GPR173 by Phoenixin-20 prevents the attachment of monocytes THP-1 to endothelial cells, which is an important therapeutic approach to preventing atherogenesis. In conclusion, our study demonstrates that GPR173 agonism by Phoenixin-20 plays a protective role against ox-LDL-induced endothelial dysfunction, implying that Phoenixin-20 may have therapeutic implications in atherosclerosis.

Effects of lipoproteins on endothelial cells and macrophages function and its possible implications on fetal adverse outcomes associated to maternal hypercholesterolemia during pregnancy

Hypercholesterolemia is one of the main risk factors associated with atherosclerosis and cardiovascular disease, the leading cause of death worldwide. During pregnancy, maternal hypercholesterolemia develops, and it can occur in a physiological (MPH) or supraphysiological (MSPH) manner, where MSPH is associated with endothelial dysfunction and early atherosclerotic lesions in the fetoplacental vasculature. In the pathogenesis of atherosclerosis, endothelial activation and endothelial dysfunction, characterized by an imbalance in the bioavailability of nitric oxide, contribute to the early stages of this disease. Macrophages conversion to foam cells, cholesterol efflux from these cells and its differentiation into a pro- or anti-inflammatory phenotype are also important processes that contribute to atherosclerosis. In adults it has been reported that native and modified HDL and LDL play an important role in endothelial and macrophage function. In this review it is proposed that fetal lipoproteins could be also relevant factors involved in the detrimental vascular effects described in MSPH. Changes in the composition and function of neonatal lipoproteins compared to adults has been reported and, although in MSPH pregnancies the fetal lipid profile does not differ from MPH, differences in the lipidomic profiles of umbilical venous blood have been reported, which could have implications in the vascular function. In this review we summarize the available information regarding the effects of lipoproteins on endothelial and macrophage function, emphasizing its possible implications on fetal adverse outcomes associated to maternal hypercholesterolemia during pregnancy.

Oxidatively Modified LDL Suppresses Lymphangiogenesis via CD36 Signaling

Arterial accumulation of plasma-derived LDL and its subsequent oxidation contributes to atherosclerosis. Lymphatic vessel (LV)-mediated removal of arterial cholesterol has been shown to reduce atherosclerotic lesion formation. However, the precise mechanisms that regulate LV density and function in atherosclerotic vessels remain to be identified. The aim of this study was to investigate the role of native LDL (nLDL) and oxidized LDL (oxLDL) in modulating lymphangiogenesis and underlying molecular mechanisms. Western blotting and immunostaining experiments demonstrated increased oxLDL expression in human atherosclerotic arteries. Furthermore, elevated oxLDL levels were detected in the adventitial layer, where LV are primarily present. Treatment of human lymphatic endothelial cells (LEC) with oxLDL inhibited in vitro tube formation, while nLDL stimulated it. Similar results were observed with Matrigel plug assay in vivo. CD36 deletion in mice and its siRNA-mediated knockdown in LEC prevented oxLDL-induced inhibition of lymphangiogenesis. In addition, oxLDL via CD36 receptor suppressed cell cycle, downregulated AKT and eNOS expression, and increased levels of p27 in LEC. Collectively, these results indicate that oxLDL inhibits lymphangiogenesis via CD36-mediated regulation of AKT/eNOS pathway and cell cycle. These findings suggest that therapeutic blockade of LEC CD36 may promote arterial lymphangiogenesis, leading to increased cholesterol removal from the arterial wall and reduced atherosclerosis.

Mitochondrial DAMPs and altered mitochondrial dynamics in OxLDL burden in atherosclerosis

Atherosclerosis results in life-threatening cardiovascular pathologies, including ischemic heart disease, stroke, myocardial infarction, and peripheral arterial disease. The role of increased serum low-density lipoprotein (LDL) and resultant accumulation of oxidized-LDL (oxLDL) in atheroma formation is well established. Recent findings elucidate the significance of mitochondrial damage-associated molecular patterns (mtDAMPs) in triggering sterile inflammation in concert with oxLDL. The mtDAMPs including mitochondrial DNA (mtDNA), cytochrome C, cardiolipin, heat shock protein 60 (HSP60), mitochondrial transcription factor A (TFAM), and N-formyl peptides, are expected to possess proatherogenic roles. However, limited data are available in the literature. The mtDAMPs initiate sterile inflammation in atherosclerotic lesions via numerous signaling pathways, most of which converge to the NOD-, LRR- and pyrin domain-containing protein 3 (NLRP3) inflammasome. Priming the activation of the NLRP3 inflammasome, mtDAMPs promote secretion of proinflammatory cytokines, including interleukin-1β (IL-1β), implicated in atherosclerotic lesions through vascular smooth muscle and fibroblast proliferation, arterial wall thickening, and plaque formation. In this article we critically reviewed and discussed the central role of the NLRP3 inflammasome in mtDAMP-induced sterile inflammation in atherosclerosis with specific components including caspase-1, pregnane X receptor (PXR), adenosine monophosphate activated protein kinase (AMPK), protein phosphatase 2A (PP2A), thioredoxin-interacting protein (TXNIP), and downstream cytokines including IL-1β and IL-18 as potential mediators of atherosclerosis. Better understanding of the proinflammatory effects of mtDAMPs and its pathological association with oxLDL possess immense translational significance for novel therapeutic intervention.

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

Ectopic expression of HSP60 in vascular cells is known to activate auto-immune response that is critical to atherogenic initiation. However, the pathogenic relevance of the aberrant HSP60 upregulation in intracellular signaling pathways associated with atherogenic consequences in vascular cells remains unclear. The aim of the present study was to determine the role of endogenous HSP60 in atherogenic transformation of endothelial cells and macrophages. After generating primary evidence of oxidized low density lipoprotein (OxLDL) induced HSP60 upregulation in human umbilical vein endothelial cells (HUVEC), its physiological relevance in high fat high fructose (HFHF) induced early atherogenic remodelling was investigated in C57BL/6J mice. Prominent HSP60 expression was recorded in tunica intima and media of thoracic aorta that showed hypertrophy, lumen dilation, elastin fragmentation and collagen deposition. Further, HSP60 overexpression was found to be prerequisite for its surface localization and secretion in HUVEC. eNOS downregulation and MCP-1, VCAM-1 and ICAM-1 upregulation with subsequent macrophage accumulation provided compelling evidences on HFHF induced endothelial dysfunction and activation that were also observed in OxLDL treated- and HSP60 overexpressing-HUVEC. OxLDL induced concomitant reduction in NO production and monocyte adhesion were prevented by HSP60 knockdown, implying towards HSP60 mediated possible regulation of the said genes. OxLDL induced HSP60 upregulation and secretion was also recorded in THP-1 derived macrophages (TDMs). HSP60 knockdown in TDMs accounted for higher OxLDL accumulation that correlated with altered scavenger receptors (SR-A1, CD36 and SR-B1) expression further culminating in M1 polarization. Collectively, the results highlight HSP60 upregulation as a critical vascular alteration that exerts differential regulatory role in atherogenic transformation of endothelial cells and macrophages.

Bazedoxifene Plays a Protective Role against Inflammatory Injury of Endothelial Cells by Targeting CD40

The inflammatory response and oxidative stress play key roles in the formation and development of atherosclerosis. Bazedoxifene is a new IL6/GP130 inhibitor recommended by the FDA for clinical use as a selective estrogen receptor modulator. However, its role in cardiovascular diseases has been poorly studied. In our study, we explored the mechanism of bazedoxifene's protective effect against inflammatory injury of vascular endothelial cells (VECs) stimulated by TNF-α. Various methods were used to verify the effect of bazedoxifene on VECs, including a cell viability assay, a wound healing assay, immunofluorescence staining, and western blotting. Our results showed that TNF-α could induce inflammatory damage to VECs, which manifested as upregulated expression of CD40, increased production of ROS, enhanced adhesion of THP-1 cells to VECs, and impaired viability and migration of VECs, while bazedoxifene could significantly reduce the endothelial damage caused by TNF-α. In addition, we found that an siRNA targeting CD40 dramatically alleviated the VEC damage induced by TNF-α. Therefore, we explored the potential relationship between bazedoxifene and CD40. Our data suggest that bazedoxifene has a protective effect against VEC damage induced by TNF-α and that its underlying mechanism may be related to the regulation of CD40.

NOD2 induces VCAM-1 and ET-1 gene expression via NF-κB in human umbilical vein endothelial cells with muramyl dipeptide stimulation

OBJECTIVES

Endothelial dysfunction is involved in various aspects of vascular biology and different stages of cardiovascular diseases (CVDs). Nucleotide-binding oligomerization domain-containing protein (NOD) 2, a pivotal innate immune receptor for muramyl dipeptide (MDP), has been reported to be a central regulator in CVDs. Previously, we reported that NOD2 played a leading role in MDP-triggered oxidative stress in endothelial cells (ECs). However, whether NOD2 participates in the regulatory mechanism of vascular cell adhesion molecule‑1 (VCAM-1) and endothelin‑1 (ET-1) expression was not elucidated.

METHODS

Human umbilical vein endothelial cells (HUVECs) were stimulated with MDP for 12 h. mRNA expression of VCAM‑1 and ET‑1 was detected using real time polymerase chain reaction (PCR). Scrambled control small interfering RNA (siRNA) and NOD2 siRNA were transfected into HUVECs using Lipofectamine 2000 reagent (Invitrogen, Waltham, MA, USA). Furthermore, pyrrolidine dithiocarbamate was adopted to investigate the effect of nuclear factor κB (NF-κB) on NOD2-mediated VCAM‑1 and ET‑1 gene expression in MDP-treated HUVECs.

RESULTS

Data showed that MDP significantly increased VCAM‑1 and ET‑1 mRNA expression, which was dependent on NOD2. In addition, NF-κB inhibition suppressed NOD2-mediated gene expression of VCAM‑1 and ET‑1.

CONCLUSION

Collectively, we confirmed NOD2 aggravated VCAM‑1 and ET‑1 gene expression through NF-κB in HUVECs treated with MDP.

Differential Roles of Endothelial Cell-Derived and Smooth Muscle Cell-Derived Fibronectin Containing Extra Domain A in Early and Late Atherosclerosis

OBJECTIVE

The extracellular matrix of atherosclerotic arteries contains abundant deposits of cellular Fn-EDA (fibronectin containing extra domain A), suggesting a functional role in the pathophysiology of atherosclerosis. Fn-EDA is synthesized by several cell types, including endothelial cells (ECs) and smooth muscle cells (SMCs), which are known to contribute to different stages of atherosclerosis. Although previous studies using global Fn-EDA-deficient mice have demonstrated that Fn-EDA is proatherogenic, the cell-specific role of EC versus SMC-derived-Fn-EDA in atherosclerosis has not been investigated yet. Approach and Results: To determine the relative contribution of different pools of Fn-EDA in atherosclerosis, we generated mutant strains lacking Fn-EDA in the ECs (Fn-EDAEC-KO) or smooth muscle cells (Fn-EDASMC-KO) on apolipoprotein E-deficient (Apoe-/-) background. The extent of atherosclerotic lesion progression was evaluated in whole aortae, and cross-sections of the aortic sinus in male and female mice fed a high-fat Western diet for either 4 weeks (early atherosclerosis) or 14 weeks (late atherosclerosis). Irrespective of sex, Fn-EDAEC-KO, but not Fn-EDASMC-KO mice, exhibited significantly reduced early atherogenesis concomitant with decrease in inflammatory cells (neutrophil and macrophage) and VCAM-1 (vascular cell adhesion molecule-1) expression levels within the plaques. In late atherosclerosis model, irrespective of sex, Fn-EDASMC-KO mice exhibited significantly reduced atherogenesis, but not Fn-EDAEC-KO mice, that was concomitant with decreased macrophage content within plaques. Lesional SMCs, collagen content, and plasma inflammatory cytokines (TNF-α [tumor necrosis factor-α] and IL-1β [interleukin-1β]), total cholesterol, and triglyceride levels were comparable among groups.

CONCLUSIONS

EC-derived Fn-EDA contributes to early atherosclerosis, whereas SMC-derived Fn-EDA contributes to late atherosclerosis.

Circular RNA circ_0003645 silencing alleviates inflammation and apoptosis via the NF-κB pathway in endothelial cells induced by oxLDL

Atherosclerosis (AS) is a serious threat to the cardiovascular system. Circular RNA circ_0003645 was found to be differentially expressed in the process of AS. Our study tried to unravel the effect and underlying mechanism of circ_0003645 in endothelial cells treated with oxidized low-density lipoprotein (oxLDL). Si-RNAs and over-circ0003645 were transfected into human umbilical vein endothelial cells (HUVECs), and the expression levels of circ_0003645 and NF-κB mRNA were measured. The protein level of NF-κB, lactate dehydrogenase leakage (LDH leakage), cell viability, and apoptosis were detected. Further, the expression of interleukin (IL)-6, tumor necrosis factor (TNF)-α, ICAM-1, and VCAM-1 were measured. Circ_0003645 was found up-regulated in AS patients and in HUVECs treated with oxLDL. The LDH leakage, cell apoptosis, and expression levels of IL-6, TNF-α, ICAM-1, VCAM-1, NF-κB mRNA, NF-κB protein were all inhibited by circ_0003645 silencing, while cell viability was promoted, and the opposite effects were observed by the overexpression of circ_0003645. In conclusion, circ_0003645 silencing alleviated inflammation and apoptosis, while promoted the viability in oxLDL-induced endothelial cells by the NF-κB pathway.

Oxidized LDL induces vimentin secretion by macrophages and contributes to atherosclerotic inflammation

Activated macrophages show increased expression of vimentin, an intermediate filament protein. Macrophages secrete vimentin into extracellular space; however, the functions of extracellular vimentin and the process of vimentin secretion are not clearly defined. We found that oxidized low-density lipoproteins (oxLDL) via CD36 induced vimentin secretion in macrophages. We also revealed that extracellular vimentin induced macrophages to release inflammatory cytokines and augmented oxLDL-induced release of TNF-α and IL-6. Extracellular vimentin activated NF-κB signaling via phosphorylation of focal adhesion kinase (p-FAK) and IκB kinase (p-IκK). Extracellular vimentin also amplified the oxLDL-induced p-IκK increase and IκB decrease. Vimentin-induced TNF-α release was not dependent on Dectin-1, which is known to bind vimentin. We measured serum vimentin concentrations and found that patients with atherosclerotic coronary artery disease had higher levels of serum vimentin than normal subjects. Circulating oxLDL and vimentin concentrations showed a high degree of correlation. In mouse experiments, vimentin concentration was higher in the sera of apoE null mice with western diet-induced atherosclerosis than in the sera of chow diet-fed apoE null mice without atherosclerosis. We concluded that vimentin is secreted by oxLDL/CD36 interaction in macrophages and extracellular vimentin promotes macrophage release of pro-inflammatory cytokines. This may contribute to atherosclerotic inflammation and based on our analysis of serum vimentin, we suggest serum vimentin as a predictive marker for atherosclerosis. KEY MESSAGES: OxLDL via CD36 induces secretion of vimentin, a cytoskeletal protein in macrophages. Extracellular vimentin induces macrophages to release proinflammatory cytokines such as tumor necrotizing factor-alpha (TNF-α) and this process is mediated by activation of focal adhesion kinase (FAK) and NF-ƙB signaling. Serum concentrations of vimentin in coronary artery disease patients are higher than that in control group. Vimentin concentration is strongly correlated with oxLDL concentration in serum.

FAK Family Kinases in Vascular Diseases

In various vascular diseases, extracellular matrix (ECM) and integrin expression are frequently altered, leading to focal adhesion kinase (FAK) or proline-rich tyrosine kinase 2 (Pyk2) activation. In addition to the major roles of FAK and Pyk2 in regulating adhesion dynamics via integrins, recent studies have shown a new role for nuclear FAK in gene regulation in various vascular cells. In particular, FAK primarily localizes within the nuclei of vascular smooth muscle cells (VSMCs) of healthy arteries. However, vessel injury increased FAK localization back to adhesions and elevated FAK activity, leading to VSMC hyperplasia. The study suggested that abnormal FAK or Pyk2 activation in vascular cells may cause pathology in vascular diseases. Here we will review several studies of FAK and Pyk2 associated with integrin signaling in vascular diseases including restenosis, atherosclerosis, heart failure, pulmonary arterial hypertension, aneurysm, and thrombosis. Despite the importance of FAK family kinases in vascular diseases, comprehensive reviews are scarce. Therefore, we summarized animal models involving FAK family kinases in vascular diseases.

Ginsenoside Rg3 Alleviates ox-LDL Induced Endothelial Dysfunction and Prevents Atherosclerosis in ApoE-/- Mice by Regulating PPARγ/FAK Signaling Pathway

The initiation of atherosclerosis (AS) induced by dyslipidemia is accompanied by endothelial dysfunction, including decreased healing ability and increased recruitment of monocytes. Studies showed ginsenoside Rg3 has potential to treat diseases associated with endothelial dysfunction which can protects against antineoplastic drugs induced cardiotoxicity by repairing endothelial function, while the effect and mechanism of Rg3 on dyslipidemia induced endothelial dysfunction and AS are not clear. Therefore, we investigated the effects of Rg3 on oxidized low-density lipoprotein (ox-LDL) induced human umbilical vein endothelial cells (HUVECs) dysfunction and high-fat diets (HFD) induced atherosclerosis in ApoE^−/− mice, as well as the mechanism. For in vitro assay, Rg3 enhanced healing of HUVECs and inhibited human monocytes (THP-1) adhesion to HUVECs disturbed by ox-LDL, down-regulated focal adhesion kinase (FAK)-mediated expression of vascular cell adhesion molecule 1 (VCAM-1) and intercellular adhesion molecule 1 (ICAM-1); restrained the FAK-mediated non-adherent dependent pathway containing matrix metalloproteinase (MMP)-2/9 expression, activation of nuclear factor-kappa B (NF-κB), high mRNA levels of monocyte chemotactic protein 1 (MCP-1) and interleukin 6 (IL-6), besides Rg3 up-regulated peroxisome proliferators-activated receptor γ (PPARγ) in ox-LDL-stimulated HUVECs. GW9662, the PPARγ-specific inhibitor, can repressed the effects of Rg3 on ox-LDL-stimulated HUVECs. For in vivo assay, Rg3 significantly reduced atherosclerotic pathological changes in ApoE^−/− mice fed with HFD, up-regulated PPARγ, and inhibited activation FAK in aorta, thus inhibited expression of VCAM-1, ICAM-1 in intima. We conclude that Rg3 may protect endothelial cells and inhibit atherosclerosis by up-regulating PPARγ via repressing FAK-mediated pathways, indicating that Rg3 have good potential in preventing dyslipidemia induced atherosclerosis.

How Neutrophils Meet Their End

Neutrophil death can transpire via diverse pathways and is regulated by interactions with commensal and pathogenic microorganisms, environmental exposures, and cell age. At steady state, neutrophil turnover and replenishment are continually maintained via a delicate balance between host-mediated responses and microbial forces. Disruptions in this equilibrium directly impact neutrophil numbers in circulation, cell trafficking, antimicrobial defenses, and host well-being. How neutrophils meet their end is physiologically important and can result in different immunologic consequences. Whereas nonlytic forms of neutrophil death typically elicit anti-inflammatory responses and promote healing, pathways ending with cell membrane rupture may incite deleterious proinflammatory responses, which can exacerbate local tissue injury, lead to chronic inflammation, or precipitate autoimmunity. This review seeks to provide a contemporary analysis of mechanisms of neutrophil death.

Protective effect of sonic hedgehog against oxidized low‑density lipoprotein‑induced endothelial apoptosis: Involvement of NF‑κB and Bcl‑2 signaling

Sonic hedgehog (Shh) is pivotally important in embryonic and adult blood vessel development and homeostasis. However, whether Shh is involved in atherosclerosis and plays a role in endothelial apoptosis induced by oxidized low‑density lipoprotein (ox‑LDL) has not been reported. The present study used recombinant Shh‑N protein (rShh‑N) and a plasmid encoding the human Shh gene (phShh) to investigate the role of Shh in ox‑LDL‑mediated human umbilical vein endothelial cell (HUVEC) apoptosis. The present study found that ox‑LDL was able to induce apoptosis in HUVECs and that Shh protein expression was downregulated. Furthermore, pretreatment with rShh‑N or transfection with phShh increased anti‑apoptosis protein Bcl‑2 expression and decreased cell apoptosis. These protective effects of rShh‑N could be abolished by cyclopamine, which is a hedgehog signaling inhibitor. Furthermore, a co‑immunoprecipitation assay was performed to demonstrate that Shh interacted with NF‑κB p65 in HUVECs. Additionally, ox‑LDL upregulated the phosphorylation of NF‑κB p65 and inhibitor of NF‑κB‑α (IκBα), and these effects decreased notably following rShh‑N and phShh treatment. Together, the present findings suggested that Shh serves an important protective role in alleviating ox‑LDL‑mediated endothelial apoptosis by inhibiting the NF‑κB signaling pathway phosphorylation and Bcl‑2 mediated mitochondrial signaling.

Caspr1 Facilitates sAPPα Production by Regulating α-Secretase ADAM9 in Brain Endothelial Cells

The expression of contactin-associated protein 1 (Caspr1) in brain microvascular endothelial cells (BMECs), one of the major cellular components of the neurovascular unit (NVU), has been revealed recently. However, the physiological role of Caspr1 in BMECs remains unclear. We previously reported the nonamyloidogenic processing of amyloid protein precursor (APP) pathway in the human BMECs (HBMECs). In this study, we found Caspr1 depletion reduced the levels of soluble amyloid protein precursor α (sAPPα) in the supernatant of HBMECs, which could be rescued by expression of full-length Caspr1. Our further results showed that ADAM9, the α-secretase essential for processing of APP to generate sAPPα, was decreased in Caspr1-depleted HBMECs. The reduced sAPPα secretion in Caspr1-depleted HBMECs was recovered by expression of exogenous ADAM9. Then, we identified that Caspr1 specifically regulates the expression of ADAM9, but not ADAM10 and ADAM17, at transcriptional level by nuclear factor-κB (NF-κB) signaling pathway. Caspr1 knockout attenuated the activation of NF-κB and prevented the nuclear translocation of p65 in brain endothelial cells, which was reversed by expression of full-length Caspr1. The reduced sAPPα production and ADAM9 expression upon Caspr1 depletion were effectively recovered by NF-κB agonist. The results of luciferase assays indicated that the NF-κB binding sites are located at −859 bp to −571 bp of ADAM9 promoter. Taken together, our results demonstrated that Caspr1 facilitates sAPPα production by transcriptional regulation of α-secretase ADAM9 in brain endothelial cells.

Type I collagen promotes the migration and myogenic differentiation of C2C12 myoblastsviathe release of interleukin-6 mediated by FAK/NF-κB p65 activation

Type I collagen has the potential to promote the migration and differentiation of C₂C₁₂myoblastviaIL-6 release that was mediated by FAK/NF-κB pathway.

Colchicine's effects on lipoprotein particle concentrations in adults with metabolic syndrome: A secondary analysis of a randomized controlled trial

BACKGROUND

Colchicine has received renewed interest for its potential beneficial effects in secondary prevention of cardiovascular disease. This was presumed to be primarily because of its anti-inflammatory effects; however, limited data exist regarding colchicine's impact on other cardiovascular risk factors.

OBJECTIVE

The aim of this study was to examine if colchicine's anti-inflammatory actions would lead to reduced circulating concentrations of oxidized low-density lipoprotein (oxLDL) in metabolically unhealthy individuals. We also examined if colchicine would improve concentrations of other atherogenic lipoprotein subfractions.

METHODS

This is a secondary analysis of a double-blind, randomized, placebo-controlled pilot study in which 40 adults with metabolic syndrome were randomized to colchicine 0.6 mg or placebo twice daily for 3 months. Blood samples were collected in the fasted state. OxLDL was measured using enzyme-linked immunosorbent assay. Nuclear magnetic resonance spectroscopy was used to measure other lipoprotein particle subfraction concentrations.

RESULTS

Compared with placebo, colchicine reduced markers of inflammation, including C-reactive protein, erythrocyte sedimentation rate, and GlycA (P < .01). Concentrations of oxLDL (P = .019) and small LDL (P = .022) appeared significantly increased in the colchicine arm. Colchicine had no significant effect on other lipoprotein subfractions or lipoprotein particle sizes (all P > .05).

CONCLUSION

Although colchicine may have benefit in secondary prevention of cardiovascular disease in at-risk individuals, we found no evidence that these effects are because of improvements in circulating atherogenic lipoprotein particle concentrations. Further studies are needed to confirm whether colchicine increases circulating oxLDL and small LDL levels in adults with metabolic syndrome. If true, additional research is warranted to elucidate the mechanisms underlying these associations.

Glucagon-like peptide-1 receptor agonist dulaglutide prevents ox-LDL-induced adhesion of monocytes to human endothelial cells: An implication in the treatment of atherosclerosis

Atherosclerosis is a common comorbidity of type II diabetes and a leading cause of death worldwide. The presence of oxidized low-density lipoprotein (ox-LDL) drives atherogenesis by inducing oxidative stress, mitochondrial dysfunction, expression of proinflammatory cytokines and chemokines including interleukin (IL)-1β, IL-6, and monocyte chemoattractant protein 1 (MCP-1), adhesion molecules including vascular cellular adhesion molecule 1 (VCAM-1) and E-selectin, and downregulating expression of the Krüppel-like factor 2 (KLF2) transcription factor. Importantly, ox-LDL induced the attachment of THP-1 monocytes to endothelial cells. In the present study, we demonstrate for the first time that the specific glucagon-like peptide 1 receptor (GLP-1R) agonist dulaglutide may prevent these atherosclerotic effects of ox-LDL by preventing suppression of KLF2 by p53 protein in human aortic endothelial cells. KLF2 has been shown to play a major role in protecting vascular endothelial cells from damage induced by ox-LDL and oscillatory shear, and therefore, therapies capable of mediating KLF2 signaling may be an attractive treatment option for preventing the development and progression of atherosclerosis.

CD13 deficiency leads to increased oxidative stress and larger atherosclerotic lesions

BACKGROUND AND AIMS

Atherosclerosis is an inflammatory cardiovascular disorder characterized by accumulation of lipid-loaded macrophages in the intima. Prolonged accumulation leads to apoptosis of macrophages and eventually to progression of lesion development. Prevention of macrophage accumulation within the intima has been shown to reduce lesion formation. Since CD13 mediates trafficking of macrophages to sites of injury and repair, we tested the role of CD13 in atherosclerosis.

METHODS

CD13+/+Ldlr-/- and CD13-/-Ldlr-/- (low density lipoprotein receptor) mice were fed basal or high fat diet (HFD) for 9, 12 and 15 weeks. Mice were euthanized and aortic roots along with innominate arteries were analyzed for atherosclerotic lesions. Cellular mechanisms were determined in vitro using CD13+/+ and CD13-/- bone marrow derived macrophages (BMDMs) incubated with highly oxidized low-density lipoprotein (oxLDL).

RESULTS

At the 9 and 12 week time points, no differences were observed in the average lesion size, but at the 15 week time point, CD13-/-Ldlr-/- mice had larger lesions with exaggerated necrotic areas. CD13+/+ and CD13-/- macrophages endocytosed similar amounts of oxLDL, but CD13-/- macrophages generated higher amounts of oxidative stressors in comparison to CD13+/+ macrophages. This increased oxidative stress was due to increased nitric oxide production in oxLDL treated CD13-/- macrophages. Accumulated oxidative stress subsequently led to accelerated apoptosis and enhanced necrosis of oxLDL treated CD13-/- macrophages.

CONCLUSIONS

Contrary to our prediction, CD13 deficiency led to larger atherosclerotic lesions with increased areas of necrosis. Mechanistically, CD13 deficiency led to increased nitric oxide production and consequently, greater oxidative stress.

Un-JAMming atherosclerotic arteries: JAM-L as a target to attenuate plaque development

Atherosclerosis is a chronic inflammatory disease and a major driver of heart attack and stroke. Atherosclerosis development is driven by the infiltration of leukocytes, including monocytes and neutrophils, among other inflammatory cells into the artery wall, monocyte differentiation to macrophages and uptake of oxidized low density lipoprotein. Macrophage activation and inflammatory cytokine production are major factors which drive ongoing inflammation and plaque development. Identification of novel pathways driving this on-going inflammatory process may provide new opportunities for therapeutic intervention. In their article published in Clinical Science (2019) (vol 133, 1215-1228), Sun and colleagues demonstrate a novel role for the junction adhesion molecule-like (JAML) protein in driving on-going atherosclerotic plaque inflammation and plaque development. They report that JAML is expressed in macrophages and other cells in atherosclerotic plaques in both humans and mice, and that silencing JAML expression attenuates atherosclerotic plaque progression in mouse models of early and late stage plaque development. They demonstrate that JAML is required for oxidized-low density lipoprotein (OxLDL)-induced up-regulation of inflammatory cytokine production by macrophages, pointing to it as a potential therapeutic target for reducing ongoing plaque inflammation.

The roles of nuclear focal adhesion kinase (FAK) on Cancer: a focused review

FAK is a tyrosine kinase overexpressed in cancer cells and plays an important role in the progression of tumors to a malignant phenotype. Except for its typical role as a cytoplasmic kinase downstream of integrin and growth factor receptor signaling, related studies have shown new aspects of the roles of FAK in the nucleus. FAK can promote p53 degradation through ubiquitination, leading to cancer cell growth and proliferation. FAK can also regulate GATA4 and IL-33 expression, resulting in reduced inflammatory responses and immune escape. These findings establish a new model of FAK from the cytoplasm to the nucleus. Activated FAK binds to transcription factors and regulates gene expression. Inactive FAK synergizes with different E3 ligases to promote the turnover of transcription factors by enhancing ubiquitination. In the tumor microenvironment, nuclear FAK can regulate the formation of new blood vessels, affecting the tumor blood supply. This article reviews the roles of nuclear FAK in regulating gene expression. In addition, the use of FAK inhibitors to target nuclear FAK functions will also be emphasized.

FAK and Pyk2 activity promote TNF-α and IL-1β-mediated pro-inflammatory gene expression and vascular inflammation

Protein tyrosine kinase (PTK) activity has been implicated in pro-inflammatory gene expression following tumor necrosis factor-α (TNF-α) or interkeukin-1β (IL-1β) stimulation. However, the identity of responsible PTK(s) in cytokine signaling have not been elucidated. To evaluate which PTK is critical to promote the cytokine-induced inflammatory cell adhesion molecule (CAM) expression including VCAM-1, ICAM-1, and E-selectin in human aortic endothelial cells (HAoECs), we have tested pharmacological inhibitors of major PTKs: Src and the focal adhesion kinase (FAK) family kinases - FAK and proline-rich tyrosine kinase (Pyk2). We found that a dual inhibitor of FAK/Pyk2 (PF-271) most effectively reduced all three CAMs upon TNF-α or IL-1β stimulation compared to FAK or Src specific inhibitors (PF-228 or Dasatinib), which inhibited only VCAM-1 expression. In vitro inflammation assays showed PF-271 reduced monocyte attachment and transmigration on HAoECs. Furthermore, FAK/Pyk2 activity was not limited to CAM expression but was also required for expression of various pro-inflammatory molecules including MCP-1 and IP-10. Both TNF-α and IL-1β signaling requires FAK/Pyk2 activity to activate ERK and JNK MAPKs leading to inflammatory gene expression. Knockdown of either FAK or Pyk2 reduced TNF-α-stimulated ERK and JNK activation and CAM expression, suggesting that activation of ERK or JNK is specific through FAK and Pyk2. Finally, FAK/Pyk2 activity is required for VCAM-1 expression and macrophage recruitment to the vessel wall in a carotid ligation model in ApoE-/- mice. Our findings define critical roles of FAK/Pyk2 in mediating inflammatory cytokine signaling and implicate FAK/Pyk2 inhibitors as potential therapeutic agents to treat vascular inflammatory disease such as atherosclerosis.

Evaluation of therapeutic effects of FAK inhibition in murine models of atherosclerosis

Objective

Therapeutic effects of focal adhesion kinase (FAK) inhibition using a small molecule inhibitor was evaluated in apolipoprotein E (apoE) knockout (KO) and low-density lipoprotein receptor (LDLr) KO mouse atherosclerosis models.

Results

The prevention trial consisted of an 8-week treatment with an FAK inhibitor concurrent treatment with a high fat (HF)/high cholesterol (HC) diet. The intervention trial consisted of 6- and 8-week treatment after 6- and 8-week pre-loading, respectively, of a HF/HC diet in apoE KO and LDLr KO mice, respectively. The inhibitor was admixed with a HF/HC diet and mice were given free access to the admixture. The FAK inhibitor exhibited marked inhibition against the development of the atherosclerosis in both of prevention and intervention trials at a dose of 0.03% without showing any remarkable toxic properties in biochemical examinations. These results indicated that FAK inhibition might be a possible candidate for novel therapeutic targets against atherosclerosis.

Electronic supplementary material

The online version of this article (10.1186/s13104-019-4220-5) contains supplementary material, which is available to authorized users.

MiR-652-3p inhibition enhances endothelial repair and reduces atherosclerosis by promoting Cyclin D2 expression

BACKGROUND

Atherosclerosis is a hyperlipidemia-induced condition affecting the arterial wall that damages healthy endothelial cell (EC) function, leading to enhanced risk of atherothrombotic events. Certain microRNAs regulate EC dysfunction in response to hyperlipidemia and may be suitable therapeutic targets to combat atherosclerosis.

METHODS

miRNA expression in human ECs was analyzed under various conditions to identify key microRNAs. High-cholesterol diet (HCD)-fed Mir652-/-Apoe-/- (Mir652-/-) mice and matching Mir652+/+Apoe-/- (Mir652+/+) mice were subjected to carotid injury to analyze the effects of miR-652 knockdown on endothelial repair. In silico analysis followed by in vitro and in vivo experiments were applied to identify miR-652's target gene Ccnd2 and investigate the pair's effects on ECs. miR-652-5p and miR-652-3p antagomir therapies were tested in Mir652+/+ mice under normal and HCD diet to assess their effect on endothelial repair.

FINDINGS

miR-652-3p, which is upregulated in human and murine atherosclerotic plaques, suppresses expression of the endothelial repair gene Ccnd2, thereby enhancing atherosclerotic lesion formation. Post-denudation recovery of ECs was promoted in Mir652-/- mice due to enhanced EC proliferation attributable to de-repression of miR-652-3p's (but not miR-652-5p's) regulation of Ccnd2 expression. Under hyperlipidemic conditions at non-predilection sites, miR-652-3p produces anti-proliferative effects in ECs, such that Mir652-/- mice display reduced atherosclerotic progression. In contrast, neither miR-652-3p nor Ccnd2 displayed significant effects on the endothelium at predilection sites or under disturbed flow conditions. Administration of a miR-652-3p antagomir rescued the proliferation of ECs in vivo, thereby limiting atherosclerotic development.

INTERPRETATION

miR-652-3p blockade may be a potential therapeutic strategy against atherosclerosis.

miR-126/VCAM-1 regulation by naringin suppresses cell growth of human non-small cell lung cancer

Certain studies have indicated that naringin possesses various pharmacological activities including anti-aging, anti-oxidation, anticancer, cardiovascular and cerebrovascular disease prevention, in addition to anti-hepatic effects. The present study explores the anticancer effect of naringin on human small cell lung cancer H69AR cells. Cell growth and apoptosis rates of H69AR cells were measured by MTT or flow cytometry, which demonstrated naringin suppressed cell growth and induced apoptosis of H69AR cells. MicroRNA (miR)-126 expression and levels of phosphorylated protein kinase B (AKT), mechanistic target of rapamycin (mTOR), nuclear factor (NF)-κB and vascular cell adhesion molecule 1 (VCAM-1) proteins were detected by quantitative polymerase chain reaction and western blotting. It was identified that naringin increased miR-126 expression and suppressed the phosphorylation of AKT, mTOR, NF-κB and VCAM-1 proteins in H69AR cells. Suppression of miR-126 expression reduced the anticancer effects of naringin on H69AR cells, reversed the naringin-induced reduction of phosphoinositide 3-kinase/AKT/mTOR, and suppressed VCAM-1 protein levels. However, close of miR-126 expression did not affect the levels of NF-κB protein in H69AR cells. In summary, naringin exhibits its anti-cancer effect by suppressing cell growth of small cell lung cancer cells through miR-126/VCAM-1 signaling pathway.

Nuclear Transcription Factor Kappa B (NF-кB) and Molecular Damage Mechanisms in Acute Cardiovascular Diseases. A Review

Worldwide, cardiovascular diseases (CVDs) represent one of the main causes of morbidity and mortality, and acute coronary syndromes are responsible for a large number of sudden cardiac deaths. One of the main challenges that still exist in this area is represented by the early detection and targeted monitoring of the pathophysiology involved in CVDs. During the last couple of years, researchers have highlighted the importance of molecular and epigenetic mechanisms involved in the initiation and augmentation of CVDs, culminating in their most severe form represented by acute myocardial infarction. One of the most studied molecular factors involved in this type of pathology is represented by nuclear transcription factor kappa B (NF-κB), as well as the involvement of microRNAs (miRNAs). It has been suggested that miRNAs can also be involved in the complex process of atheromatous plaque vulnerabilization that leads to an acute cardiac event. In this review paper, we describe the most important molecular mechanisms involved in the pathogenesis of CVDs and atheromatous plaque progression and vulnerabilization, which include molecular mechanisms dependent on NF-κB. For this paper, we used international databases (PubMed and Scopus). The keywords used for the search were “miRNAs biomarkers”, “miRNAs in cardiovascular disease”, “NF-κB in cardiovascular disease”, “molecular mechanism in cardiovascular disease”, and “myocardial NF-κB mechanisms”. Numerous molecular reactions that have NF-κB as a trigger are involved in the pathogenesis of CVDs. Moreover, miRNAs play an important role in initiating and aggravating certain segments of CVDs. Therefore, miRNAs can be used as biomarkers for early evaluation of CVDs. Furthermore, in the future, miRNAs could be used as a targeted molecular therapy in order to block certain mechanisms responsible for inducing CVDs and leading to acute cardiovascular events.

Polyphenols from Ilex latifolia Thunb. (a Chinese bitter tea) exert anti-atherosclerotic activity through suppressing NF-κB activation and phosphorylation of ERK1/2 in macrophages

Ilex latifolia Thunb is a kind of herbal tea and widely consumed as a functional tea beverage in Asian countries. In this study, polyphenols were extracted from I. latifolia and the major compounds were identified by liquid chromatography-mass spectrometry (LC-MS), then the effect on oxidized low-density lipoprotein (ox-LDL)-induced macrophage foam cell formation was investigated. Results showed that the polyphenols could significantly inhibit ox-LDL-induced macrophage foam cell formation and suppress lipid droplet accumulation and cholesterol uptake in RAW 264.7 cells. Additionally, the secretion of pro-inflammatory cytokines, such as tumor necrosis factor (TNF-α), interleukin (IL)-1β, IL-6 and inducible nitric oxide synthase (iNOS), was significantly inhibited. Moreover, the polyphenols could suppress the expression of lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) and clusters of differentiation 36 (CD 36), which were receptors for ox-LDL. Mechanistically, I. latifolia polyphenols could inhibit macrophage foam cell formation by suppressing NF-κB activation and phosphorylation of ERK1/2.

Mechanisms and Consequences of Defective Efferocytosis in Atherosclerosis

Efficient clearance of apoptotic cells, termed efferocytosis, critically regulates normal homeostasis whereas defective uptake of apoptotic cells results in chronic and non-resolving inflammatory diseases, such as advanced atherosclerosis. Monocyte-derived macrophages recruited into developing atherosclerotic lesions initially display efficient efferocytosis and temper inflammatory responses, processes that restrict plaque progression. However, during the course of plaque development, macrophages undergo cellular reprogramming that reduces efferocytic capacity, which results in post-apoptotic necrosis of apoptotic cells and inflammation. Furthermore, defective efferocytosis in advanced atherosclerosis is a major driver of necrotic core formation, which can trigger plaque rupture and acute thrombotic cardiovascular events. In this review, we discuss the molecular and cellular mechanisms that regulate efferocytosis, how efferocytosis promotes the resolution of inflammation, and how defective efferocytosis leads to the formation of clinically dangerous atherosclerotic plaques.

Mechanisms and Consequences of Defective Efferocytosis in Atherosclerosis

Efficient clearance of apoptotic cells, termed efferocytosis, critically regulates normal homeostasis whereas defective uptake of apoptotic cells results in chronic and non-resolving inflammatory diseases, such as advanced atherosclerosis. Monocyte-derived macrophages recruited into developing atherosclerotic lesions initially display efficient efferocytosis and temper inflammatory responses, processes that restrict plaque progression. However, during the course of plaque development, macrophages undergo cellular reprogramming that reduces efferocytic capacity, which results in post-apoptotic necrosis of apoptotic cells and inflammation. Furthermore, defective efferocytosis in advanced atherosclerosis is a major driver of necrotic core formation, which can trigger plaque rupture and acute thrombotic cardiovascular events. In this review, we discuss the molecular and cellular mechanisms that regulate efferocytosis, how efferocytosis promotes the resolution of inflammation, and how defective efferocytosis leads to the formation of clinically dangerous atherosclerotic plaques.

Capn4 induces human renal cancer cell proliferation by activating NF-κB signaling pathway through FAK phosphorylation

Previous study found that higher Capn4 mRNA level is observed in patients with more advanced pathological stage of ccRCC and is also associated with decreased overall survival of patients with ccRCC. However, the mechanism by which Capn4 promotes progression of RCC is not understood. In the present study, we found that over-expression of Capn4 in RCC cells enhances tumor cell growth and down-regulation of Capn4 in RCC cells decreases tumor cell growth in vitro. Interestingly, Capn4 was found to increase phosphorylation of specific tyrosine residues of FAK and subsequent activate NF-κB p65 phosphorylation. Furthermore, Capn4-mediated cell proliferation of RCC cells required up-regulation of NF-κB p65 phosphorylation through activation of FAK signaling pathway. Taken together, our data showed that Capn4 can contribute to RCC growth via activation of the FAK and the downstream signaling pathways leading to the activation of NF-κB.

Overexpression of stathmin plays a pivotal role in the metastasis of esophageal squamous cell carcinoma

Purpose

Esophageal squamous cell carcinoma (ESCC) is a serious malignant tumor that affects human health. We analyzed the correlation between serum stathmin level and ESCC and elucidated the molecular mechanisms of stathmin's promotion of ESCC cell invasion and metastasis.

Methods

Stathmin level in ESCC and healthy control serum were detected by enzyme-linked immunosorbent assay (ELISA), and the clinical parameters were analyzed. We established ESCC cells with stathmin overexpression or knockdown and then evaluated the effects of stathmin on invasion and metastasis in ESCC. Differentially expressed genes were analyzed by Human Transcriptome Array and confirmed by RT-PCR. The expression levels of the integrin family, focal adhesion kinase (FAK) and extracellular signal-regulated kinase (ERK) were detected by immunoblotting.

Results

Serum levels of stathmin were significantly higher in ESCC than in control serum and associated with lymph node metastasis, tumor stage and size. Furthermore, we found that stathmin promoted migration and invasion of ESCC cells in vitro and in vivo. In addition, we confirmed that the activation of the integrinα5β1/FAK/ERK pathway is increased in stathmin-overexpression cells and accelerates cell motility by enhancing cell adhesion ability.

Conclusion

Stathmin may predict a potential metastasis biomarker for ESCC.

Integrin signaling in atherosclerosis

Atherosclerosis, a chronic lipid-driven inflammatory disease affecting large arteries, represents the primary cause of cardiovascular disease in the world. The local remodeling of the vessel intima during atherosclerosis involves the modulation of vascular cell phenotype, alteration of cell migration and proliferation, and propagation of local extracellular matrix remodeling. All of these responses represent targets of the integrin family of cell adhesion receptors. As such, alterations in integrin signaling affect multiple aspects of atherosclerosis, from the earliest induction of inflammation to the development of advanced fibrotic plaques. Integrin signaling has been shown to regulate endothelial phenotype, facilitate leukocyte homing, affect leukocyte function, and drive smooth muscle fibroproliferative remodeling. In addition, integrin signaling in platelets contributes to the thrombotic complications that typically drive the clinical manifestation of cardiovascular disease. In this review, we examine the current literature on integrin regulation of atherosclerotic plaque development and the suitability of integrins as potential therapeutic targets to limit cardiovascular disease and its complications.