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.

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

Clinical complications associated with atherosclerotic plaques arise from luminal obstruction due to plaque growth or destabilization leading to rupture. Tumour necrosis factor ligand superfamily member 12 (TNFSF12) also known as TNF-related weak inducer of apoptosis (TWEAK) is a proinflammatory cytokine that participates in atherosclerotic plaque development, but its role in plaque stability remains unclear. Using two different approaches, genetic deletion of TNFSF12 and treatment with a TWEAK blocking mAb in atherosclerosis-prone mice, we have analysed the effect of TWEAK inhibition on atherosclerotic plaques progression and stability. Mice lacking both TNFSF12 and Apolipoprotein E (TNFSF12(-/-) ApoE(-/-) ) exhibited a diminished atherosclerotic burden and lesion size in their aorta. Advanced atherosclerotic plaques of TNFSF12(-/-) ApoE(-/-) or anti-TWEAK treated mice exhibited an increase collagen/lipid and vascular smooth muscle cell/macrophage ratios compared with TNFSF12(+/+) ApoE(-/-) control mice, reflecting a more stable plaque phenotype. These changes are related with two different mechanisms, reduction of the inflammatory response (chemokines expression and secretion and nuclear factor kappa B activation) and decrease of metalloproteinase activity in atherosclerotic plaques of TNFSF12(-/-) ApoE(-/-) . A similar phenotype was observed with anti-TWEAK mAb treatment in TNFSF12(+/+) ApoE(-/-) mice. Brachiocephalic arteries were also examined since they exhibit additional features akin to human atherosclerotic plaques associated with instability and rupture. Features of greater plaque stability including augmented collagen/lipid ratio, reduced macrophage content, and less presence of lateral xanthomas, buried caps, medial erosion, intraplaque haemorrhage and calcium content were present in TNFSF12(-/-) ApoE(-/-) or anti-TWEAK treatment in TNFSF12(+/+) ApoE(-/-) mice. Overall, our data indicate that anti-TWEAK treatment has the capacity to diminish proinflamatory response associated with atherosclerotic plaque progression and to alter plaque morphology towards a stable phenotype.

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.

Soluble TWEAK and atheromatosis progression in patients with chronic kidney disease.

BACKGROUND AND AIMS: Circulating soluble TNF-like weak inducer of apoptosis (sTWEAK) concentrations are related to the presence of chronic kidney disease (CKD) and cardiovascular disease (CVD). However, there are no data regarding the potential association between sTWEAK and atheromatosis progression in patients free of cardiovascular events. METHODS: Soluble TWEAK serum concentration was measured in 702 CKD patients without any previous CV event from The National Observatory of Atherosclerosis in Nephrology (NEFRONA) Study. B-mode ultrasound was performed to detect the presence of carotid and/or femoral atherosclerotic plaques. The association between sTWEAK levels, atherosclerotic burden (number of plaques) and atheromatosis progression (increase in the number of plaques) after 24 months of follow-up was analyzed. RESULTS: A continuous decrease in sTWEAK concentrations, with an increase in the number of atherosclerotic plaques after 24 months of follow-up, was observed in the studied population. Multivariable linear regression analysis showed that age, blood pressure, HDL-c, and sTWEAK concentrations were independent predictors of atherosclerotic burden after 24 months of follow-up. In addition, sTWEAK concentrations diminished in CKD patients in whom progressive silent atherosclerosis was observed. Multivariable linear regression analysis showed that age, sex, smoking status and sTWEAK levels were independent predictors of atheromatosis progression after 24 months of follow-up. CONCLUSIONS: Lower sTWEAK concentrations are associated with atherosclerotic burden and atheromatosis progression in CKD patients free of clinical CVD. These data suggest that sTWEAK could serve as a biomarker to predict CV risk before clinical manifestations.

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.

[Atorvastatin inhibits the atherosclerotic lesion induced by tumor necrosis factor-like weak inducer of apoptosis in apolipoprotein E deficient mice]. / La atorvastatina inhibe la progresión de la lesión aterosclerótica inducida por el factor inductor débil de apoptosis similar al factor de necrosis tumoral en ratones deficientes en apolipoproteína E.

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 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.

Soluble TWEAK levels predict the presence of carotid atherosclerotic plaques in subjects free from clinical cardiovascular diseases.

OBJECTIVE: Reduced soluble tumor necrosis factor-like weak inducer of apoptosis (sTWEAK) levels have been related with cardiovascular disease. However, there are no data on the relationship between sTWEAK and atherosclerotic burden in subjects with or without cardiovascular risk factors but free from clinical disease. We have analyzed the association between circulating sTWEAK levels and the presence of carotid and/or femoral atherosclerotic plaques in subjects without known vascular disease. METHODS: A multicenter, cross-sectional study was conducted in 448 subjects free from clinical CVD. B-mode ultrasound was performed to detect the presence of carotid and/or femoral atherosclerotic plaques. sTWEAK concentrations were measured by enzyme-linked immunosorbent assay. RESULTS: sTWEAK serum levels were reduced in parallel with an increment in cardiovascular risk factors. sTWEAK concentrations were independently and negatively associated with carotid intima/media thickness. Subjects with atherosclerotic plaques showed a reduction in sTWEAK levels [808 (645-963) vs 993 (830-1278); p < 0.001]. A gradual decrease in sTWEAK levels was observed as the number of atherosclerotic plaques increased in our studied population. When we analyzed sTWEAK levels according to the vascular territory affected, we observed that sTWEAK concentrations were only diminished in subjects with carotid atherosclerotic plaques but not in those with femoral plaques. Following adjustment for various confounders, the OR for presenting carotid atherosclerotic plaque in subjects in lower vs higher tertile of sTWEAK levels was 8.09 [4.30-15.23; median (IQR); p < 0.001]. CONCLUSIONS: Diminished sTWEAK concentrations were significantly and independently associated with the presence of carotid atherosclerotic plaques in asymptomatic subjects.

Tumor necrosis factor-like weak inducer of apoptosis or Fn14 deficiency reduce elastase perfusion-induced aortic abdominal aneurysm in mice.

BACKGROUND: Abdominal aortic aneurysm (AAA) involves leukocyte recruitment, inflammatory cytokine production, vascular cell apoptosis, neovascularization, and vascular remodeling, all of which contribute to aortic dilatation. Tumor necrosis factor-like weak inducer of apoptosis (TWEAK) is a cytokine implicated in proinflammatory responses, angiogenesis, and matrix degradation but its role in AAA formation is currently unknown. METHODS AND RESULTS: Experimental AAA with aortic elastase perfusion in mice was induced in wild-type (WT), TWEAK deficient (TWEAK KO), or Fn14-deficient (Fn14 KO) mice. TWEAK or Fn14 KO deficiency reduced aortic expansion, lesion macrophages, CD3(+) T cells, neutrophils, CD31(+) microvessels, CCL2 and CCL5 chemokines expression, and MMP activity after 14 days postperfusion. TWEAK and Fn14 KO mice also showed a reduced loss of medial vascular smooth muscle cells (VSMC) that was related to a reduced number of apoptotic cells in these animals compared with WT mice. Aortas from WT animals present a higher disruption of the elastic layer and MMP activity than those from TWEAK or Fn14 KO mice, indicating a diminished vascular remodeling in KO animals. In vitro experiments unveiled that TWEAK induces CCL5 secretion and MMP-9 activation in both VSMC and bone marrow-derived macrophages, and decrease VSMC viability, effects dependent on Fn14. CONCLUSIONS: TWEAK/Fn14 axis participates in AAA formation by promoting lesion inflammatory cell accumulation, angiogenesis, matrix-degrading protease expression, and vascular remodeling. Blocking TWEAK/Fn14 interaction could be a new target for the treatment of AAA.

La atorvastatina inhibe la progresión de la lesión aterosclerótica inducida por el factor inductor débil de apoptosis similar al factor de necrosis tumoral en ratones deficientes en apolipoproteína E / Atorvastatin inhibits the atherosclerotic lesion induced by tumor necrosis factor-like weak inducer of apoptosis in apolipoprotein E deficient mice

Objetivos: La interacción del factor inductor débil de apoptosis similar al factor de necrosis tumoral (TWEAK) con su receptor Fn14 acelera el desarrollo de la lesión aterosclerótica en ratones deficientes en ApoE (ApoE KO). En este trabajo hemos analizado el efecto de un inhibidor de la HMG-CoA reductasa, la atorvastatina, sobre el desarrollo de la lesión aterosclerótica acelerada por TWEAK en ratones ApoE KO. Materiales y métodos: Se alimentaron ratones ApoE KO de 8 semanas de edad durante 4 semanas con una dieta hiperlipidémica y se aleatorizaron en 3 grupos: ratones tratados i.p. con salino (control), tratados con TWEAK recombinante (10 μg/kg/2 veces a la semana) o tratados con TWEAK recombinante más atorvastatina (1 mg/kg/día) durante 4 semanas más. Se analizó el tamaño, la composición celular, la respuesta inflamatoria y la expresión de Fn14 en las lesiones ateroscleróticas presentes en la raíz aórtica de los ratones. Resultados: La inyección sistémica de TWEAK aumentó el tamaño de la lesión y el cociente colágeno/lípidos así como la respuesta inflamatoria asociada a un aumento en la actividad de NF-κB, expresión de MCP-1 y RANTES y a una mayor presencia de macrófagos en las placas ateroscleróticas de ratones ApoE KO. El tratamiento con atorvastatina fue capaz de prevenir los cambios inducidos por TWEAK en las lesiones ateroscleróticas. Finalmente, el tratamiento con atorvastatina disminuyó la expresión de Fn14 en las lesiones ateroscleróticas de ratones ApoE KO. Conclusiones: La atorvastatina previene los efectos proaterogénicos inducidos por TWEAK en el ratón ApoE KO, efecto relacionado con la inhibición de la expresión de Fn14. Estos resultados aportan nueva información sobre los efectos beneficiosos de las estatinas en el tratamiento de las enfermedades cardiovasculares

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 atorvastat in (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