Genetic deletion or TWEAK blocking antibody administration reduce atherosclerosis and enhance plaque stability in mice

Exploring the bidirectional causal associations between pain and circulating inflammatory proteins: A Mendelian randomization study

Multisite chronic pain (MCP) and site-specific chronic pain (SSCP) may be influenced by circulating inflammatory proteins, but the causal relationship remains unknown. To overcome this limitation, two-sample bidirectional Mendelian randomization (MR) analysis was used to analyse data for 91 circulating inflammatory proteins, MCP and SSCP encompassing headache, back pain, shoulder pain, hip pain, knee pain, stomach abdominal pain and facial pain. The primary MR method used was inverse variance weighting, sensitivity analyses included weighted median, MR pleiotropy residual sum and outlier and the Egger intercept method. Heterogeneity was also detected using Cochrane's Q test and leave-one-out analyses. Finally, a causal relationship between 29 circulating inflammatory proteins and chronic pain was identified. Among these proteins, 14 exhibited a protective effect, including MCP (T-cell surface glycoprotein cluster of differentiation 5), headache (4E-binding protein 1 [4EBP1], cluster of differentiation 40, cluster of differentiation 6 and C-X-C motif chemokine [CXCL] 11), back pain (leukaemia inhibitory factor), shoulder pain (fibroblast growth factor [FGF]-5 and interleukin [IL]-18R1), stomach abdominal pain (tumour necrosis factor [TNF]-α), hip pain (CXCL1, IL-20 and signalling lymphocytic activation molecule 1) and knee pain (IL-7 and TNF-β). Additionally, 15 proteins were identified as risk factors for MCP and SSCP: MCP (colony-stimulating factor 1, human glial cell line-derived neurotrophic factor and IL-17C), headache (fms-related tyrosine kinase 3 ligand, IL-20 receptor subunit α [IL-20RA], neurotrophin-3 and tumour necrosis factor receptor superfamily member 9), facial pain (CXCL1), back pain (TNF), shoulder pain (IL-17C and matrix metalloproteinase-10), stomach abdominal pain (IL-20RA), hip pain (C-C motif chemokine 11/eotaxin-1 and tumour necrosis factor ligand superfamily member 12) and knee pain (4EBP1). Importantly, in the opposite direction, MCP and SSCP did not exhibit a significant causal impact on circulating inflammatory proteins. Our study identified potential causal influences of various circulating inflammatory proteins on MCP and SSCP and provided promising treatments for the clinical management of MCP and SSCP.

Systematic Mendelian Randomization Exploring Druggable Genes for Hemorrhagic Strokes

Patients with hemorrhagic stroke have high rates of morbidity and mortality, and drugs for prevention are very limited. Mendelian randomization (MR) analysis can increase the success rate of drug development by providing genetic evidence. Previous MR analyses only analyzed the role of individual drug target genes in hemorrhagic stroke; therefore, we used MR analysis to systematically explore the druggable genes for hemorrhagic stroke. We sequentially performed summary-data-based MR analysis and two-sample MR analysis to assess the associations of all genes within the database with intracranial aneurysm, intracerebral hemorrhage, and their subtypes. Validated genes were further analyzed by colocalization. Only genes that were positive in all three analyses and were druggable were considered desirable genes. We also explored the mediators of genes affecting hemorrhagic stroke incidence. Finally, the associations of druggable genes with other cardiovascular diseases were analyzed to assess potential side effects. We identified 56 genes that significantly affected hemorrhagic stroke incidence. Moreover, TNFSF12, SLC22A4, SPARC, KL, RELT, and ADORA3 were found to be druggable. The inhibition of TNFSF12, SLC22A4, and SPARC can reduce the risk of intracranial aneurysm, subarachnoid hemorrhage, and intracerebral hemorrhage. Gene-induced hypertension may be a potential mechanism by which these genes cause hemorrhagic stroke. We also found that blocking these genes may cause side effects, such as ischemic stroke and its subtypes. Our study revealed that six druggable genes were associated with hemorrhagic stroke, and the inhibition of TNFSF12, SLC22A4, and SPARC had preventive effects against hemorrhagic strokes.

Targeting the TWEAK-Fn14 pathway prevents dysfunction in cardiac calcium handling after acute kidney injury

Heart and kidney have a closely interrelated pathophysiology. Acute kidney injury (AKI) is associated with significantly increased rates of cardiovascular events, a relationship defined as cardiorenal syndrome type 3 (CRS3). The underlying mechanisms that trigger heart disease remain, however, unknown, particularly concerning the clinical impact of AKI on cardiac outcomes and overall mortality. Tumour necrosis factor-like weak inducer of apoptosis (TWEAK) and its receptor fibroblast growth factor-inducible 14 (Fn14) are independently involved in the pathogenesis of both heart and kidney failure, and recent studies have proposed TWEAK as a possible therapeutic target; however, its specific role in cardiac damage associated with CRS3 remains to be clarified. Firstly, we demonstrated in a retrospective longitudinal clinical study that soluble TWEAK plasma levels were a predictive biomarker of mortality in patients with AKI. Furthermore, the exogenous application of TWEAK to native ventricular cardiomyocytes induced relevant calcium (Ca2+ ) handling alterations. Next, we investigated the role of the TWEAK-Fn14 axis in cardiomyocyte function following renal ischaemia-reperfusion (I/R) injury in mice. We observed that TWEAK-Fn14 signalling was activated in the hearts of AKI mice. Mice also showed significantly altered intra-cardiomyocyte Ca2+ handling and arrhythmogenic Ca2+ events through an impairment in sarcoplasmic reticulum Ca2+ -adenosine triphosphatase 2a pump (SERCA2a ) and ryanodine receptor (RyR2 ) function. Administration of anti-TWEAK antibody after reperfusion significantly improved alterations in Ca2+ cycling and arrhythmogenic events and prevented SERCA2a and RyR2 modifications. In conclusion, this study establishes the relevance of the TWEAK-Fn14 pathway in cardiac dysfunction linked to CRS3, both as a predictor of mortality in patients with AKI and as a Ca2+ mishandling inducer in cardiomyocytes, and highlights the cardioprotective benefits of TWEAK targeting in CRS3. © 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Fn14 and TNFR2 as regulators of cytotoxic TNFR1 signaling

Tumor necrosis factor (TNF) receptor 1 (TNFR1), TNFR2 and fibroblast growth factor-inducible 14 (Fn14) belong to the TNF receptor superfamily (TNFRSF). From a structural point of view, TNFR1 is a prototypic death domain (DD)-containing receptor. In contrast to other prominent death receptors, such as CD95/Fas and the two TRAIL death receptors DR4 and DR5, however, liganded TNFR1 does not instruct the formation of a plasma membrane-associated death inducing signaling complex converting procaspase-8 into highly active mature heterotetrameric caspase-8 molecules. Instead, liganded TNFR1 recruits the DD-containing cytoplasmic signaling proteins TRADD and RIPK1 and empowers these proteins to trigger cell death signaling by cytosolic complexes after their release from the TNFR1 signaling complex. The activity and quality (apoptosis versus necroptosis) of TNF-induced cell death signaling is controlled by caspase-8, the caspase-8 regulatory FLIP proteins, TRAF2, RIPK1 and the RIPK1-ubiquitinating E3 ligases cIAP1 and cIAP2. TNFR2 and Fn14 efficiently recruit TRAF2 along with the TRAF2 binding partners cIAP1 and cIAP2 and can thereby limit the availability of these molecules for other TRAF2/cIAP1/2-utilizing proteins including TNFR1. Accordingly, at the cellular level engagement of TNFR2 or Fn14 inhibits TNFR1-induced RIPK1-mediated effects reaching from activation of the classical NFκB pathway to induction of apoptosis and necroptosis. In this review, we summarize the effects of TNFR2- and Fn14-mediated depletion of TRAF2 and the cIAP1/2 on TNFR1 signaling at the molecular level and discuss the consequences this has in vivo.

Validating human and mouse tissues commonly used in atherosclerosis research with coronary and aortic reference tissue: similarities but profound differences in disease initiation and plaque stability

Objective

Characterization of the atherosclerotic process fully relies on histological evaluation and staging through a consensus grading system. So far, a head-to-head comparison of atherosclerotic process in experimental models and tissue resources commonly applied in atherosclerosis research with the actual human atherosclerotic process is missing.

Material and Methods

Aspects of the atherosclerotic process present in established murine atherosclerosis models and human carotid endarterectomy specimen were systematically graded using the modified American Heart Association histological classification (Virmani classification). Aspects were aligned with the atherosclerotic process observed in human coronary artery and aortic atherosclerosis reference tissues that were available through biobanks based on human tissue/organ donor material.

Results

Apart from absent intraplaque hemorrhages in aortic lesions, the histological characteristics of the different stages of human coronary and aortic atherosclerosis are similar. Carotid endarterectomy samples all represent end-stage "fibrous calcified plaque" lesions, although secondary, progressive, and vulnerable lesions with gross morphologies similar to coronary/aortic lesions occasionally present along the primary lesions. For the murine lesions, clear histological parallels were observed for the intermediate lesion types ("pathological intimal thickening," and "early fibroatheroma"). However, none of the murine lesions studied progressed to an equivalent of late fibroatheroma or beyond. Notable contrasts were observed for disease initiation: whereas disease initiation in humans is characterized by a mesenchymal cell influx in the intima, the earliest murine lesions are exclusively intimal, with subendothelial accumulation foam cells. A mesenchymal (and medial) response are absent. In fact, it is concluded that the stage of "adaptive intimal thickening" is absent in all mouse models included in this study.

Conclusions

The Virmani classification for coronary atherosclerosis can be applied for systematically grading experimental and clinical atherosclerosis. Application of this histological grading tool shows clear parallels for intermediate human and murine atherosclerotic lesions. However, clear contrasts are observed for disease initiation, and late stage atherosclerotic lesions. Carotid endarterectomy all represent end-stage fibrous calcified plaque lesions, although secondary earlier lesions may present in a subset of samples.

Can plasma TWEAK levels predict coronary slow flow in patients with chronic kidney disease?

BACKGROUND

The tumor necrosis factor-like weak inducer of apoptosis (TWEAK) is one of the inflammatory mediators contributing to the atherosclerotic process. TWEAK has been studied in patients with chronic kidney disease (CKD), and it has demonstrated that its level declines as estimated glomerular filtration rate (eGFR) decreases. Most studies have found that the decreased TWEAK levels were seen in atherosclerosis and associated with plaque calcification. The objective of this prospective study was to clarify any relationship between coronary slow-flow (CSF) and TWEAK levels in patients with CKD under conservative treatment.

METHODS

This prospective study included 93 consecutive patients with CKD (mean creatinine level was 1.8±0.4 mg/dL) undergoing invasive coronary angiography (ICA) for any reason except for acute coronary syndromes from May 2019 to March 2020. A total of 93 patients were divided into two groups concerning having CSF (n=35) or no-CSF (n=58).

RESULTS

Patients with CSF had higher TWEAK levels than those without CSF (695.2± 225.2 vs. 465.8±157.6, p<0.001). As the number of coronary arteries with slow flow increased, TWEAK levels increased statistically significantly (r:0.635/ p<0.001). Receiver operating characteristic (ROC) analysis showed that TWEAK levels of 516 pg/mL could predict CSF in patients with CKD.

CONCLUSIONS

Our study has shown that plasma TWEAK levels were an independent predictor for CSF in patients with CKD. In addition, our study has found that elevated TWEAK levels may not reflect the healthy arteries as it was hypothesized in the past.

A potential fate decision landscape of the TWEAK/Fn14 axis on stem and progenitor cells: a systematic review

Stem and progenitor cells (SPCs) possess self-remodeling ability and differentiation potential and are responsible for the regeneration and development of organs and tissue systems. However, the precise mechanisms underlying the regulation of SPC biology remain unclear. Tumor necrosis factor-like weak inducer of apoptosis (TWEAK) acts on miscellaneous cells via binding to fibroblast growth factor-inducible 14 (Fn14) and exerts pleiotropic functions in the regulation of divergent stem cell fates. TWEAK/Fn14 signaling can regulate the proliferation, differentiation, and migration of multiple SPCs as well as tumorigenesis in certain contexts. Although TWEAK’s roles in modulating multiple SPCs are sparsely reported, the systemic effector functions of this multifaceted protein have not been fully elucidated. In this review, we summarized the fate decisions of TWEAK/Fn14 signaling on multiple stem cells and characterized its potential in stem cell therapy.

A Associação de TWEAK com Calcificação da Artéria Coronária em Pacientes com Doença Renal Crônica

Fundamento

O receptor fraco indutor de apoptose semelhante a fator de necrose tumoral solúvel (sTWEAK) é um membro da superfamília de TNF que tem um papel crítico na proliferação e inflamação na circulação arterial.

Objetivos

Este estudo prospectivo tem o objetivo de mostrar a relação entre os níveis de sTWEAK e calcificação da artéria coronária (CAC) em pacientes com doença renal crônica (DRC).

Métodos

Este estudo prospectivo incluiu 139 pacientes consecutivos que passaram por angiografia coronariana por tomografia computadorizada, por qualquer motivo, para síndromes coronarianas agudas, de agosto de 2020 a fevereiro de 2021. Um total de 12 pacientes foi excluído do estudo devido aos critérios de exclusão. Os pacientes foram divididos em dois grupos com base em terem um escore CAC menor que 400 (n=84) ou um escore de 400 ou mais (n=43). A significância foi presumida em p-valor bilateral <0,05.

Resultados

À medida que o escore CAC aumentou, os níveis de sTWEAK diminuíram de forma estatisticamente significativa e detectou-se uma relação forte entre níveis de sTWEAK e escore CAC (r: -0,779, p<0,001). A análise ROC revelou que o nível de corte ideal de sTWEAK para prever o escore CAC de 400 era 761 pg/mL com uma sensibilidade de 71% e especificidade de 73% (AUC: 0,78; IC 95%: 0,70-0,85; p <0,001).

Conclusões

Embora os estudos em larga escala tenham demonstrado uma correlação positiva entre os níveis de TFGe e sTWEAK, alguns estudos detectaram que o aumento nos níveis de sTWEAK estão associados a mortalidade e gravidade do sistema da artéria coronária em pacientes com DRC. Nossos resultados comprovam nossa hipótese de que os níveis de sTWEAK mostram calcificação coronária em vez de outros tipos de placas ateroscleróticas.

Analysis of inflammatory cytokines and estimated glomerular filtration rate decline in Japanese patients with diabetic kidney disease: a pilot study

Background: It is important to identify additional prognostic factors for diabetic kidney disease. Materials & methods: Baseline levels of ten cytokines (APRIL/TNFSF13, BAFF/TNFSF13B, chitinase 3-like 1, LIGHT/TNFSF14, TWEAK/TNFSF12, gp130/sIL-6Rβ, sCD163, sIL-6Rα, sTNF-R1, sTNF-R2) were measured in two cohorts of diabetic patients. In one cohort (n = 777), 156 individuals were randomly sampled after stratification and their plasma samples were analyzed; in the other cohort (n = 69), serum samples were analyzed in all the individuals. The levels of cytokines between rapid (estimated glomerular filtration rate decline >5 ml/min/1.73 m²/year) and non-rapid decliners were compared. Results: Multivariate analysis demonstrated significantly high levels of LIGHT/TNFSF14, TWEAK/TNFSF12 and sTNF-R2 in rapid decliners. Conclusion: These three cytokines can be potential biomarkers for the progression of diabetic kidney disease.

Anti-TWEAK Antibody Alleviates Renal Interstitial Fibrosis by Increasing PGC-1α Expression in Lupus Nephritis

Purpose

Current studies on the mechanism of tumor necrosis factor-like weak inducer of apoptosis (TWEAK) in lupus nephritis (LN) mainly focus on the inflammatory pathway. Herein, we aimed to determine whether TWEAK could promote the progression of renal interstitial fibrosis by regulating peroxisome proliferator-activated receptor-gamma coactivator-1α (PGC-1α) expression and intervening in lipid metabolism in LN.

Materials and Methods

MRL/lpr mice, an animal model of lupus, were treated with the anti-TWEAK antibody or co-treated with adeno-associated virus-mediated PGC-1α short hairpin RNA (shRNA). In addition, human proximal tubular epithelial cells (HK2 cells) were treated with recombinant human TWEAK (rhTWEAK) or ammonium pyrrolidine dithiocarbamate (PDTC) in vitro.

Results

The renal contents of free fatty acids and triglycerides were higher in MRL/lpr mice than in MRL/MpJ mice; however, these contents were decreased by treatment with the anti-TWEAK antibody. Based on immunofluorescence staining, the expression of PGC-1α was markedly more in the renal tubules of MRL/MpJ mice than in the glomeruli. However, treatment with anti-TWEAK antibody increased the levels of PGC-1α and its downstream target genes, which were remarkably lower in MRL/lpr mice than in MRL/MpJ mice. Anti-TWEAK antibody effectively eased renal interstitial fibrosis, which manifested as a decrease in the deposition of collagen fibers and the inhibition of type I collagen and fibronectin expression. However, the therapeutic effects of the anti-TWEAK antibody were abolished by PGC-1α shRNA. Treatment with rhTWEAK decreased PGC-1α expression in both dose- and time-dependent manners in HK2 cells in vitro. PDTC, an inhibitor of IκBα phosphorylation, suppressed the decrease in the PGC-1α protein level induced by rhTWEAK treatment.

Conclusion

Our results suggest that TWEAK prevents renal tubular PGC-1α expression by promoting NF-κB activation, resulting in a deficiency in lipid metabolism and the progress of renal interstitial fibrosis. The upregulation of renal tubular PGC-1α expression to improve lipid metabolism is one of the mechanisms employed by the anti-TWEAK antibody to treat renal interstitial fibrosis.

TWEAK-Fn14 as a common pathway in the heart and the kidneys in cardiorenal syndrome

There is a complex relationship between cardiac and renal disease, often referred to as the cardiorenal syndrome. Heart failure adversely affects kidney function, and both acute and chronic kidney disease are associated with structural and functional changes to the myocardium. The pathological mechanisms and contributing interactions that surround this relationship remain poorly understood, limiting the opportunities for therapeutic intervention. The cytokine tumor necrosis factor-like weak inducer of apoptosis (TWEAK) and its receptor, fibroblast growth factor-inducible 14 (Fn14), are abundantly expressed in injured kidneys and heart. The TWEAK-Fn14 axis promotes responses that drive tissue injury such as inflammation, proliferation, fibrosis, and apoptosis, while restraining the expression of tissue protective factors such as the anti-aging factor Klotho and the master regulator of mitochondrial biogenesis peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α). High levels of TWEAK induce cardiac remodeling, and promote inflammation, tubular and podocyte injury and death, fibroblast proliferation, and, ultimately, renal fibrosis. Accordingly, targeting the TWEAK-Fn14 axis is protective in experimental kidney and heart disease. TWEAK has also emerged as a biomarker of kidney damage and cardiovascular outcomes and has been successfully targeted in clinical trials. In this review, we update our current knowledge of the roles of the TWEAK-Fn14 axis in cardiovascular and kidney disease and its potential contribution to the cardiorenal syndrome. © 2021 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

CD163 deficiency increases foam cell formation and plaque progression in atherosclerotic mice

Atherosclerosis is an inflammatory disease characterized by the accumulation of macrophages in the vessel wall. Macrophages depend on their polarization to exert either pro-inflammatory or anti-inflammatory effects. Macrophages of the anti-inflammatory phenotype express high levels of CD163, a scavenger receptor for the hemoglobin-haptoglobin complex. CD163 can also bind to the pro-inflammatory cytokine TWEAK. Using ApoE-deficient or ApoE/CD163 double-deficient mice we aim to investigate the involvement of CD163 in atherosclerosis development and its capacity to neutralize the TWEAK actions. ApoE/CD163 double-deficient mice displayed a more unstable plaque phenotype characterized by an increased lipid and macrophage content, plaque size, and pro-inflammatory cytokine expression. In vitro experiments demonstrated that the absence of CD163 in M2-type macrophages-induced foam cell formation through upregulation of CD36 expression. Moreover, exogenous TWEAK administration increased atherosclerotic lesion size, lipids, and macrophages content in ApoE^-/- /CD163^-/- compared with ApoE^-/- /CD163^+/+ mice. Treatment with recombinant CD163 was able to neutralize the proatherogenic effects of TWEAK in ApoE/CD163 double-deficient mice. Recombinant CD163 abolished the pro-inflammatory actions of TWEAK on vascular smooth muscle cells, decreasing NF-kB activation, cytokines and metalloproteinases expression, and macrophages migration. In conclusion, CD163-expressing macrophages serve as a protective mechanism to prevent the deleterious effects of TWEAK on atherosclerotic plaque development and progression.

Effects of influenza vaccination on the risk of cardiovascular and respiratory diseases and all-cause mortality

BACKGROUND

Influenza vaccination is a simple strategy recommended for the prevention of influenza infection and its complications. This meta-analysis aimed to provide current supportive evidence for the breadth and validity of the observed protective effects of influenza vaccination on cardiovascular and respiratory adverse outcomes and all-cause mortality in older adults and in general adult population.

METHODS

We searched PubMed, Embase, Web of Science, and the Cochrane Library to identify all published studies comparing influenza vaccination with placebo from the database inception to November 11, 2018. These included studies reporting the associations of influenza vaccination with the risk of aforementioned adverse outcomes.

RESULTS

The pooled adjusted relative risks among influenza-vaccinated people relative to unvaccinated people for the outcomes of interest were 0.74 (95 % confidence interval [CI] = 0.70-0.78) for cardiovascular diseases (63 studies), 0.82 (95 % CI = 0.75-0.91) for respiratory diseases (29 studies), and 0.57 (95 % CI = 0.51-0.63) for all-cause mortality (43 studies). We performed subgroup analysis of age, sex, and region/country and found that these protective effects were evident in the general adult population and particularly robust in older adults and in those with pre-existing specific diseases.

CONCLUSION

Influenza vaccine is associated with a significant risk reduction of cardiovascular and respiratory adverse outcomes as well as all-cause mortality. Such a preventative measure can benefit the general population as well as those in old age and with pre-existing specific diseases.

TWEAK/Fn14 axis in respiratory diseases

Tumor necrosis factor-like weak inducer of apoptosis (TWEAK) is a well known multifunctional cytokine extensively distributed in cell types and tissues. Accumulating evidence has shown that TWEAK binding to the receptor factor-inducible 14 (Fn14) participates in diverse pathologic processes including cell proliferation and death, angiogenesis, carcinogenesis and inflammation. Interestingly, alterations of intracellular signaling cascades are correlated to the development of respiratory disease. Recently, a several lines of evidence suggests that TWEAK in lung tissues are closely associated with these signaling pathways. In this review, we explore if TWEAK could provide a novel therapeutic strategy for managing respiratory disease in general and pulmonary arterial hypertension (PAH), obstructive sleep apnea syndrome (OSAS), asthma, idiopathic pulmonary fibrosis (IPF), chronic obstructive pulmonary disease (COPD) and non-small cell lung cancer (NSCLC), specifically.

Changes in Soluble TWEAK Concentrations, but Not Those in Amyloid-β(1-40), Are Associated with a Decrease in Carotid Intima-Media Thickness after Bariatric Surgery in Obese Women

BACKGROUND/AIM

Soluble tumor necrosis factor-like weak inducer of apoptosis (sTWEAK) and amyloid-β(1-40) (Aβ40) emerged as markers of cardiovascular risk because of their actions in the endothelium and their role in atherosclerotic progression. The aim of this study was to analyze the association of these two factors with the decrease in carotid intima-media thickness (cIMT) after bariatric surgery in obese women.

METHODS

We studied 60 severely obese women, of whom 20 were submitted to laparoscopic Roux-en-Y gastric bypass (RYGB), 20 to sleeve gastrectomy (SG), and 20 to lifestyle modification therapy. Circulating sTWEAK, Aβ40, high-sensitivity C-reactive protein, plasminogen activator inhibitor type 1, insulin resistance (HOMA-IR), and cIMT were measured at baseline and after 1 year of follow-up.

RESULTS

sTWEAK increased similarly after both surgical procedures, whereas the increase observed after lifestyle intervention did not reach statistical significance. Aβ40 showed no differences between groups of women, nor did it change during follow-up. The decrease in cIMT at 12 months correlated with the decrease in body mass index (BMI) (r = 0.45; p < 0.001) and fasting insulin (r = 0.30; p = 0.038), and also with the increase in sTWEAK (r = -0.43; p = 0.002). Multivariate linear regression showed that only the changes in BMI (β = 0.389; p = 0.005) and sTWEAK (β = -0.358; p = 0.009) were associated with the decrease in cIMT (R2 = 0.313; F = 9.348; p < 0.001).

CONCLUSIONS

One year after bariatric surgery, RYGB and SG induced a similar increase in circulating sTWEAK that occurred in parallel to the decrease observed in cIMT.

Periodontitis and vascular inflammatory biomarkers: an experimental in vivo study in rats

The objective of this preclinical in vivo study was to determine changes in vascular inflammatory biomarkers in systemic circulation after injection of lipopolysaccharide (LPS) from Porphyromonas gingivalis (Pg) in rats. Experimental periodontitis was induced by injections of Pg-LPS. Gingival soft and hard tissues changes were analysed by means of magnetic resonance imaging and micro computed tomography. Serum levels of interleukin (IL)-6, IL-10, pentraxin (PTX) 3, and soluble fragment of tumor necrosis factor-like weak inducer of apoptosis (sTWEAK) were determined at baseline and 24 h, 7, 14, and 21 days after periodontal induction. Significant periodontal inflammation and alveolar bone loss were evident at the end of periodontal induction. Experimental periodontitis posed an acute systemic inflammatory response with increased serum levels of IL-6 and PTX3 at 24 h post-induction, followed by a significant overexpression of sTWEAK at 7 days. This inflammatory state was maintained until the end of the experiment (21 days). As expected, IL-10 serum levels were significantly lower during the follow-up compared to baseline concentrations. In the present animal model, experimental periodontitis is associated with increased systemic inflammation. Further studies are needed to confirm whether PTX3 and sTWEAK could be useful biomarkers to investigate potential mechanisms underlying the relationship between periodontitis and atherosclerotic vascular diseases.

Tumor Necrosis Factor-Like Weak Inducer of Apoptosis (TWEAK)/Fibroblast Growth Factor-Inducible 14 (Fn14) Axis in Cardiovascular Diseases: Progress and Challenges

Cardiovascular diseases (CVD) are the leading cause of mortality in Western countries. CVD include several pathologies, such as coronary artery disease, stroke, peripheral artery disease, and aortic aneurysm, among others. All of them are characterized by a pathological vascular remodeling in which inflammation plays a key role. Interaction between different members of the tumor necrosis factor superfamily and their cognate receptors induce several biological actions that may participate in CVD. The cytokine tumor necrosis factor-like weak inducer of apoptosis (TWEAK) and its functional receptor, fibroblast growth factor-inducible 14 (Fn14), are abundantly expressed during pathological cardiovascular remodeling. The TWEAK/Fn14 axis controls a variety of cellular functions, such as proliferation, differentiation, and apoptosis, and has several biological functions, such as inflammation and fibrosis that are linked to CVD. It has been demonstrated that persistent TWEAK/Fn14 activation is involved in both vessel and heart remodeling associated with acute and chronic CVD. In this review, we summarized the role of the TWEAK/Fn14 axis during pathological cardiovascular remodeling, highlighting the cellular components and the signaling pathways that are involved in these processes.

A major role of TWEAK/Fn14 axis as a therapeutic target for post-angioplasty restenosis

Background

Tumor necrosis factor-like weak inducer of apoptosis (Tnfsf12; TWEAK) and its receptor Fibroblast growth factor-inducible 14 (Tnfrsf12a; Fn14) participate in the inflammatory response associated with vascular remodeling. However, the functional effect of TWEAK on vascular smooth muscle cells (VSMCs) is not completely elucidated.

Methods

Next generation sequencing-based methods were performed to identify genes and pathways regulated by TWEAK in VSMCs. Flow-citometry, wound-healing scratch experiments and transwell migration assays were used to analyze VSMCs proliferation and migration. Mouse wire injury model was done to evaluate the role of TWEAK/Fn14 during neointimal hyperplasia.

Findings

TWEAK up-regulated 1611 and down-regulated 1091 genes in VSMCs. Using a gene-set enrichment method, we found a functional module involved in cell proliferation defined as the minimal network connecting top TWEAK up-regulated genes. In vitro experiments in wild-type or Tnfrsf12a deficient VSMCs demonstrated that TWEAK increased cell proliferation, VSMCs motility and migration. Mechanistically, TWEAK increased cyclins (cyclinD1), cyclin-dependent kinases (CDK4, CDK6) and decreased cyclin-dependent kinase inhibitors (p15^lNK4B) mRNA and protein expression. Downregulation of p15^INK4B induced by TWEAK was mediated by mitogen-activated protein kinase ERK and Akt activation.

Tnfrsf12a or Tnfsf12 genetic depletion and pharmacological intervention with TWEAK blocking antibody reduced neointimal formation, decreasing cell proliferation, cyclin D1 and CDK4/6 expression, and increasing p15^INK4B expression compared with wild type or IgG-treated mice in wire-injured femoral arteries. Finally, immunohistochemistry in human coronary arteries with stenosis or in-stent restenosis revealed high levels of Fn14, TWEAK and PCNA in VSMCs enriched areas of the neointima as compared with healthy coronary arteries.

Interpretation

Our data define a major role of TWEAK/Fn14 in the control of VSMCs proliferation and migration during neointimal hyperplasia after wire injury in mice, and identify TWEAK/Fn14 as a potential target for treating in-stent restenosis.

Fund

ISCiii-FEDER, CIBERCV and CIBERDEM.

Effect of influenza vaccine on tumor necrosis factor-like weak inducer of apoptosis (TWEAK) in older adults

Influenza immunization is recommended for older adults annually, and has been reported to have cardiovascular protective effects. TNF-related weak inducer of apoptosis (TWEAK), an inflammatory mediator implicated in the development of cardiovascular diseases, could be a mechanism for such effect. The objective of this study was to evaluate the effect of influenza vaccine on TWEAK levels. Older persons over 70 years of age were recruited during 2007-2008 influenza season and immunized with the standard dose trivalent inactivated influenza vaccine. Frailty was evaluated using a validated set of criteria. Sera were collected immediately before and during the 4th week after vaccination. Pre- and post-vaccination levels of TWEAK, soluble CD163 (sCD163) and strain-specific influenza antibody titers were measured in 69 participants. Multiple regression analyses were employed to examine the effect of influenza vaccine on TWEAK and sCD163, adjusting for age, sex, and hypertension. Post-vaccination TWEAK [mean ± standard deviation (SD) = 591.7 ± 290.1 pg/ml] was significantly lower than pre-vaccination level (690.6 ± 330.0 pg/ml) (p = .003). No significant difference was observed between pre and post-vaccination sCD163 levels (p = .71). Post-vaccination TWEAK levels were significantly higher in men (p = .01) and in participants with college or higher level of education (p = .044). There was no significant difference in post-vaccination TWEAK according to other demographics or pre-existing medical conditions. A 2-fold or greater antibody titer against H1N1 vaccine strain was associated with a more pronounced reduction in TWEAK at the p < .10 level (p = .091). A time by frailty interaction term (p = .091) indicated that the vaccination-induced reduction of TWEAK was greatest among frail individuals. These results of this observational study indicate that the impact of Influenza vaccine on TWEAK, including the role of specific antibody responses of specific vaccine strains and frailty status, warrants further investigation. Such investigation may elucidate whether this effect plays a role in mediating cardiovascular protection of influenza vaccination.

Combination of biomarkers of vascular calcification and sTWEAK to predict cardiovascular events in chronic kidney disease

BACKGROUND AND AIMS

Vascular calcification (VC) and atherosclerosis are associated with an increased cardiovascular morbimortality in chronic kidney disease (CKD). Osteoprotegerin (OPG) and osteopontin (OPN) are involved in both VC and CKD. Soluble tumor necrosis factor-like weak inducer of apoptosis (sTWEAK) has been related to cardiovascular disease. We hypothesized that OPG, OPN and sTWEAK levels may be associated with a higher prevalence of cardiovascular outcomes in patients with CKD.

METHODS

The presence of calcified or non-calcified atherosclerotic plaques was assessed in 1043 stage 3 to 5D CKD patients from The NEFRONA Study. Biochemical measurements and OPG, OPN and sTWEAK serum levels were analyzed. Patients were followed for cardiovascular outcomes (41 ± 16 months).

RESULTS

At recruitment, 26% of CKD patients had VC. The adjusted odds ratios for having VC were 2.22 (1.32-3.75); p=.003 for OPG, and 0.45 (0.24-0.84); p=.01 for sTWEAK concentrations. After follow-up, 95 CV events occurred. In a Cox model, patients with OPG or OPN above and sTWEAK below their optimal cut-off points had an adjusted higher risk of cardiovascular events [HR: 2.10 (1.49-3.90); p=.02; 1.65 (1.02-2.65); p=.04; 2.05 (1.28-3.29), p=.003; respectively]. When CKD patients were grouped according to the number of biomarkers above (OPG and OPN) or below (sTWEAK) their cut-off points, the combination of these biomarkers showed the highest risk for cardiovascular events [HR: 9.46 (3.80-23.5) p < .001]. A composite score of these three biomarkers increased the C-statistic and net reclassification index beyond conventional risk factors and VC.

CONCLUSIONS

The combination of OPG, OPN and sTWEAK increased the predictability of cardiovascular outcomes.

TWEAK/Fn14 promotes oxidative stress through AMPK/PGC‑1α/MnSOD signaling pathway in endothelial cells

Tumor necrosis factor-like weak inducer of apoptosis (TWEAK) contributes to dysfunction of endothelial cells via its receptor, Fn14. However, its role in the production of reactive oxygen species (ROS), particularly mitochondrial ROS (mtROS) and the subsequent decrease in nitric oxide (NO) in endothelial cells remains unclear. In this study, the effect of TWEAK/Fn14 on generation of ROS, mtROS and NO in endothelial cells and its potential mechanism was investigated. Human umbilical vein endothelial cells (HUVECs) were treated with TWEAK with Fn14 small interfering (si)RNA or negative control RNA. It was demonstrated that TWEAK induced the production of ROS and mtROS in HUVECs, which were detected by fluorescent microscope, and flow cytometry. In addition, TWEAK decreased the generation of NO as indicated using the Nitric Oxide Assay kit. Furthermore, TWEAK aggravated mtDNA damage as measured by quantitative polymerase chain reaction analysis. Inhibition of Fn14 by Fn14 siRNA decreased TWEAK‑induced ROS and mtROS production, as well as mtDNA damage, while it increased the production of NO in endothelial cells. In addition, TWEAK inhibited the expression of active AMP‑activated protein kinase (AMPK) and its downstream protein peroxisome proliferator‑activated receptor‑γ coactivator-1α (PGC‑1α) and manganese superoxide dismutase (MnSOD). Notably, Fn14 siRNA enhanced the expression of the aforementioned proteins. Taken together, TWEAK/Fn14 contributes to endothelial dysfunction through modulation of ROS and mtROS. In addition, the underlying mechanism is implicated in the AMPK/PGC‑1α/MnSOD signaling pathway.

The role of tumor necrosis factor-like weak inducer of apoptosis in atherosclerosis via its two different receptors

At present, it is commonly accepted that atherosclerosis is a chronic inflammatory disease characterized by disorder of the arterial wall. As one of the inflammatory cytokines of the tumor necrosis factor superfamily, tumor necrosis factor-like weak inducer of apoptosis (TWEAK) participates in the formation and progression of atherosclerosis. TWEAK, when binding to its initial receptor, fibroblast growth factor inducible molecule 14 (Fn14), exerts adverse biological functions in atherosclerosis, including dysfunction of endothelial cells, phenotypic change of smooth muscle cells and inflammatory responses of monocytes/macrophages. However, accumulating data supports that, besides Fn14, TWEAK also binds to cluster of differentiation (CD)163, an anti-inflammatory cytokine and a scavenger receptor exclusively expressed by monocytes and macrophages. Furthermore, it has been demonstrated that CD163 is able to internalize TWEAK and likely elicits protective effects in atherosclerosis by terminating inflammation induced by TWEAK. In the present study, the role of TWEAK in atherosclerosis was reviewed, with a predominant focus on CD163 and Fn14 receptors.

TWEAK blockade decreases atherosclerotic lesion size and progression through suppression of STAT1 signaling in diabetic mice

Tumor necrosis factor-like weak inducer of apoptosis (TWEAK/Tnfsf12) is a cytokine implicated in different steps associated with vascular remodeling. However, the role of TWEAK under hyperglycemic conditions is currently unknown. Using two different approaches, genetic deletion of Tnfsf12 and treatment with a TWEAK blocking mAb, we have analyzed the effect of TWEAK inhibition on atherosclerotic plaque progression and stability in streptozotocin-induced diabetic ApoE deficient mice. Genetic inactivation of Tnfsf12 reduced atherosclerosis extension and severity in diabetic ApoE deficient mice. Tnfsf12 deficient mice display a more stable plaque phenotype characterized by lower lipid and macrophage content within atherosclerotic plaques. A similar phenotype was observed in diabetic mice treated with anti-TWEAK mAb. The proatherosclerotic effects of TWEAK were mediated, at least in part, by STAT1 activation and expression of proinflammatory target genes (CCL5, CXCL10 and ICAM-1), both in plaques of ApoE mice and in cultured vascular smooth muscle cells (VSMCs) under hyperglycemic conditions. Loss-of-function experiments demonstrated that TWEAK induces proinflammatory genes mRNA expression through its receptor Fn14 and STAT1 activation in cultured VSMCs. Overall, TWEAK blockade delay plaque progression and alter plaque composition in diabetic atherosclerotic mice. Therapies aimed to inhibit TWEAK expression and/or function could protect from diabetic vascular complications.

TWEAK favors phosphate-induced calcification of vascular smooth muscle cells through canonical and non-canonical activation of NFκB

Vascular calcification (VC) is associated with increased cardiovascular mortality in aging, chronic kidney disease (CKD), type 2 diabetes mellitus (T2DM) and atherosclerosis. TNF-like weak inducer of apoptosis (TWEAK) recently emerged as a new biomarker for the diagnosis and prognosis of cardiovascular diseases. TWEAK binding to its functional receptor Fn14 was reported to promote several steps of atherosclerotic plaque progression. However, no information is currently available on the role of TWEAK/Fn14 on the development of medial calcification, which is highly prevalent in aging, CKD and T2DM. This study explored the involvement of TWEAK in human vascular smooth muscle cells (h-VSMCs) calcification in vitro. We report that TWEAK binding to Fn14 promotes inorganic phosphate-induced h-VSMCs calcification, favors h-VSMCs osteogenic transition, decreasing acta2 and myh11 and increasing bmp2 mRNA and tissue non-specific alkaline phosphatase (TNAP), and increases MMP9 activity. Blockade of the canonical NFκB pathway reduced by 80% TWEAK pro-calcific properties and decreased osteogenic transition, TNAP and MMP9 activity. Blockade of non-canonical NFκB signaling by a siRNA targeting RelB reduced by 20% TWEAK pro-calcific effects and decreased TWEAK-induced loss of h-VSMCs contractile phenotype and MMP9 activity, without modulating bmp2 mRNA or TNAP activity. Inhibition of ERK1/2 activation by a MAPK kinase inhibitor did not influence TWEAK pro-calcific properties. Our results suggest that TWEAK/Fn14 directly favors inorganic phosphate-induced h-VSMCs calcification by activation of both canonical and non-canonical NFκB pathways. Given the availability of neutralizing anti-TWEAK strategies, our study sheds light on the TWEAK/Fn14 axis as a novel therapeutic target in the prevention of VC.

Cytokines: roles in atherosclerosis disease progression and potential therapeutic targets

Atherosclerosis, the primary cause of cardiovascular disease (CVD), is a chronic inflammatory disorder in the walls of medium and large arteries. CVD is currently responsible for about one in three global deaths and this is expected to rise in the future due to an increase in the prevalence of obesity and diabetes. Current therapies for atherosclerosis mainly modulate lipid homeostasis and while successful at reducing the risk of a CVD-related death, they are associated with considerable residual risk and various side effects. There is, therefore, a need for alternative therapies aimed at regulating inflammation in order to reduce atherogenesis. This review will highlight the key role cytokines play during disease progression as well as potential therapeutic strategies to target them.

Soluble TWEAK and Major Adverse Cardiovascular Events in Patients with CKD

BACKGROUND AND OBJECTIVES

Soluble TNF-like weak inducer of apoptosis (sTWEAK) is a proinflammatory cytokine belonging to the TNF superfamily. sTWEAK concentrations have been associated with the presence of CKD and cardiovascular disease (CVD). We hypothesized that sTWEAK levels may relate to a higher prevalence of atherosclerotic plaques, vascular calcification, and cardiovascular outcomes observed in patients with CKD.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

A 4-year prospective, multicenter, longitudinal study was conducted in 1058 patients with CKD stages 3-5D (mean age =58±13 years old; 665 men) but without any history of CVD from the NEFRONA Study (a study design on the prevalence of surrogate markers of CVD). Ankle-brachial index and B-mode ultrasound were performed to detect the presence of carotid and/or femoral atherosclerotic plaques together with biochemical measurements and sTWEAK assessment. Patients were followed for cardiovascular outcomes (follow-up of 3.13±1.15 years).

RESULTS

Patients with more advanced CKD had lower sTWEAK levels. sTWEAK concentrations were independently and negatively associated with carotid intima-media thickness. sTWEAK levels were lower in patients with carotid atherosclerotic plaques but not in those with femoral plaques. After adjustment by confounders, the odds ratio (OR) for presenting carotid atherosclerotic plaques in patients in the lowest versus highest tertile of sTWEAK was 4.18 (95% confidence interval [95% CI], 2.89 to 6.08; P<0.001). Furthermore, sTWEAK levels were lower in patients with calcified carotid atherosclerotic plaques. The OR for presenting calcified carotid plaques was 1.77 (95% CI, 1.06 to 2.93; P=0.02) after multivariable adjustment. After the follow-up, 41 fatal and 68 nonfatal cardiovascular events occurred. In a Cox model, after controlling for potential confounding factors, patients in the lowest tertile of sTWEAK concentrations had a higher risk of fatal and nonfatal cardiovascular events (hazard ratio [HR], 2.40; 95% CI, 1.33 to 4.33; P=0.004) and cardiovascular mortality (HR, 2.67; 95% CI, 1.05 to 6.76; P=0.04).

CONCLUSIONS

Low sTWEAK levels were associated with the presence of carotid atherosclerotic plaques in patients with CKD. Additionally, lower sTWEAK levels were associated with a higher risk of cardiovascular morbidity and mortality.

Transition from identity to bioactivity-guided proteomics for biomarker discovery with focus on the PF2D platform

Proteomic strategies provide a valuable tool kit to identify proteins involved in diseases. With recent progress in MS technology, high throughput proteomics has accelerated protein identification for potential biomarkers. Numerous biomarker candidates have been identified in several diseases, and many are common among pathologies. An overall strategy that could complement and strengthen the search for biomarkers is combining protein identity with biological outcomes. This review describes an emerging framework of bridging bioactivity to protein identity, exploring the possibility that some biomarkers will have a mechanistic role in the disease process. A review of pulmonary, cardiovascular, and CNS biomarkers will be discussed to demonstrate the utility of combining bioactivity with identification as a means to not only find meaningful biomarkers, but also to uncover functional mediators of disease.

TWEAK/Fn14 interaction promotes oxidative stress through NADPH oxidase activation in macrophages

AIM

The interaction between TNF-like weak inducer of apoptosis (TWEAK, Tnfsf12) and the receptor, fibroblast growth factor-inducible 14 (Fn14), regulates vascular damage through different mechanisms, including inflammation. Oxidative stress plays a major role in inflammation and the development of atherosclerosis, but the relationship between TWEAK and oxidative stress is, however, poorly understood.

METHODS AND RESULTS

In this study, we found that TWEAK and Fn14 are co-localized with the NADPH subunits, p22phox and Nox2, in human advanced atherosclerotic plaques. Using primary human macrophages and a murine macrophage cell line, we demonstrate that TWEAK promotes ROS production and enhances NADPH oxidase activity. Hence, we show a direct involvement of the TWEAK-Fn14 axis in oxidative stress, as genetic silencing of Fn14 or Nox2 abrogates the TWEAK-induced ROS production. Furthermore, our results point at Rac1 as an upstream mediator of TWEAK during oxidative stress. Finally, using an in vivo murine model we confirmed the major role of TWEAK in oxidative stress, as genetic silencing of Tnfsf12 in an ApoE(-/-) background reduces the number of DHE and 8-hydroxydeoxyguanosine-positive macrophages by 50%.

CONCLUSIONS

Our results suggest that TWEAK regulates vascular damage by stimulating ROS production in an Nox2-dependent manner. These new insights into the TWEAK/Fn14 axis underline their potential use as therapeutic targets in atherosclerosis.

Cytokines in atherosclerosis: Key players in all stages of disease and promising therapeutic targets

Atherosclerosis, a chronic inflammatory disorder of the arteries, is responsible for most deaths in westernized societies with numbers increasing at a marked rate in developing countries. The disease is initiated by the activation of the endothelium by various risk factors leading to chemokine-mediated recruitment of immune cells. The uptake of modified lipoproteins by macrophages along with defective cholesterol efflux gives rise to foam cells associated with the fatty streak in the early phase of the disease. As the disease progresses, complex fibrotic plaques are produced as a result of lysis of foam cells, migration and proliferation of vascular smooth muscle cells and continued inflammatory response. Such plaques are stabilized by the extracellular matrix produced by smooth muscle cells and destabilized by matrix metalloproteinase from macrophages. Rupture of unstable plaques and subsequent thrombosis leads to clinical complications such as myocardial infarction. Cytokines are involved in all stages of atherosclerosis and have a profound influence on the pathogenesis of this disease. This review will describe our current understanding of the roles of different cytokines in atherosclerosis together with therapeutic approaches aimed at manipulating their actions.

[Atorvastatin inhibits the atherosclerotic lesion induced by tumor necrosis factor-like weak inducer of apoptosis in apolipoprotein E deficient mice]

AIM

Interaction of tumor necrosis factor-like weak inducer of apoptosis (TWEAK) with its receptor Fn14 accelerates atherosclerotic plaque development in ApoE deficient mice (ApoE KO). In this work, an analysis has been made on the effect of an HMG-CoA reductase inhibitor, atorvastatin, on atherosclerotic plaque development accelerated by TWEAK in ApoE KO mice.

MATERIALS AND METHODS

Eight week-old ApoE KO mice were fed with a high cholesterol diet for 4 weeks. The animals were then randomized into 3 groups: mice injected i.p. with saline, recombinant TWEAK (10 μg/kg/twice a week), or recombinant TWEAK plus atorvastatin (1 mg/kg/day) for 4 weeks. The lesion size, cellular composition, lipid and collagen content were analyzed, as well as inflammatory response in atherosclerotic plaques present in aortic root of mice.

RESULTS

TWEAK treated mice showed an increase in atherosclerotic plaque size, as well as in collagen/lipid ratio compared with control mice. In addition, macrophage content, MCP-1 and RANTES expression, and NF-κB activation were augmented in atherosclerotic plaques present in aortic root of TWEAK treated mice compared with control mice. Treatment with atorvastatin prevented all these changes induced by TWEAK in atherosclerotic lesions. Atorvastatin treatment also decreased Fn14 expression in the atherosclerotic plaques of ApoE KO mice.

CONCLUSIONS

Atorvastatin prevents the pro-atherogenic effects induced by TWEAK in ApoE KO mice, which could be related to the inhibition of Fn14 expression. The results of this study provide new information on the beneficial effects of statin treatment in cardiovascular diseases.

TWEAK/Fn14 Axis: A Promising Target for the Treatment of Cardiovascular Diseases

Cardiovascular diseases (CVD) are the first cause of mortality in Western countries. CVD include several pathologies such as coronary heart disease, stroke or cerebrovascular accident, congestive heart failure, peripheral arterial disease, and aortic aneurysm, among others. Interaction between members of the tumor necrosis factor (TNF) superfamily and their receptors elicits several biological actions that could participate in CVD. TNF-like weak inducer of apoptosis (TWEAK) and its functional receptor and fibroblast growth factor-inducible molecule 14 (Fn14) are two proteins belonging to the TNF superfamily that activate NF-κB by both canonical and non-canonical pathways and regulate several cell functions such as proliferation, migration, differentiation, cell death, inflammation, and angiogenesis. TWEAK/Fn14 axis plays a beneficial role in tissue repair after acute injury. However, persistent TWEAK/Fn14 activation mediated by blocking experiments or overexpression experiments in animal models has shown an important role of this axis in the pathological remodeling underlying CVD. In this review, we summarize the role of TWEAK/Fn14 pathway in the development of CVD, focusing on atherosclerosis and stroke and the molecular mechanisms by which TWEAK/Fn14 interaction participates in these pathologies. We also review the role of the soluble form of TWEAK as a biomarker for the diagnosis and prognosis of CVD. Finally, we highlight the results obtained with other members of the TNF superfamily that also activate canonical and non-canonical NF-κB pathway.