MicroRNA-223 triggers inflammation in porcine aorta by activating NLRP3 inflammasome under selenium deficiency.

Selenium (Se) is an essential trace element in organism. Se deficiency can cause many diseases, including vascular disease. Studies have shown that inflammation is the main inducement of vascular disease, microRNA (miRNA) can influence inflammation in various ways, and Se deficiency can affect miRNAs expression. To study the mechanism of aorta damage caused by Se deficiency, we constructed a Se deficiency porcine aorta model and found that Se deficiency can significantly inhibit miR-223, which downregulates the expression of nucleotide-binding oligomerization domain-like receptor family 3 (NLRP3). Subsequently, we found that in Se deficiency group, NLRP3, and its downstream (caspase-1, apoptosis-related spot-like protein [ASC], IL-18, IL-1ß) expression was significantly increased. In vitro, we cultured pig iliac endothelium cell lines, and constructed miR-223 knockdown and overexpression models. NLRP3 messenger RNA and protein levels were significant increased in the knockdown group, and decreased in the overexpression group. The results of this study show that Se deficiency in porcine arteries can induce inflammation through miR-223/NLRP3.

Positive disease-specific autoantibodies have limited clinical significance in diagnosing IgG4-related disease in daily clinical practice.

OBJECTIVES: The 2019 ACR/EULAR classification criteria for IgG4-related disease (IgG4-RD) have exclusion criteria including positive disease-specific autoantibodies, and these have been documented to have a high specificity. This study aimed to further validate these criteria as well as identify characteristics of patients showing false-negative results. METHODS: We retrospectively analysed 162 IgG4-RD patients and 130 mimickers. The sensitivity, specificity and fulfilment rates for each criterion were calculated, and intergroup comparisons were performed to characterize the false-negative cases. RESULTS: Both the IgG4-RD patients and mimickers were aged ≥65 years with male predominance. The final diagnoses of mimickers were mainly malignancy, vasculitis, sarcoidosis and aneurysm. The classification criteria had a sensitivity of 72.8% and specificity of 100%. Of the 44 false-negative cases, one did not fulfil the entry criteria, 20 fulfilled one exclusion criterion and 27 did not achieve sufficient inclusion criteria scores. The false-negative cases had fewer affected organs, lower serum IgG4 levels, and were less likely to have received biopsies than the true-positive cases. Notably, positive disease-specific autoantibodies were the most common exclusion criterion fulfilled in 18 patients, only two of whom were diagnosed with a specific autoimmune disease complicated by IgG4-RD. In addition, compared with the true-positive cases, the 18 had comparable serum IgG4 levels, number of affected organs, and histopathology and immunostaining scores despite higher serum IgG and CRP levels. CONCLUSIONS: The ACR/EULAR classification criteria for IgG4-RD have an excellent diagnostic specificity in daily clinical practice. Positive disease-specific autoantibodies may have limited clinical significance for the diagnosis of IgG4-RD.

Immunoglobulin G4-related thoracic aortitis.

Patients with immunoglobulin G4-related thoracic aortitis often have nonspecific symptoms, but pain in the chest or back is common. The rate of misdiagnosis of immunoglobulin G4-related thoracic aortitis is high, which may lead to mistreatment in extreme cases. A correct diagnosis should be based on comprehensive medical imaging, pathology, and laboratory and immunohistochemical results. Most patients' condition can be significantly improved using conservative or surgical treatment.

Clinical phenotypes of IgG4-related disease: an analysis of two international cross-sectional cohorts.

OBJECTIVE: IgG4-related disease (IgG4-RD) is a heterogeneous, multiorgan condition of unclear aetiology that can cause organ failure. Difficulty recognising IgG4-RD contributes to diagnostic delays. We sought to identify key IgG4-RD phenotypes. METHODS: We used two cross-sectional studies assembled by an international, multispecialty network of IgG4-RD specialists who submitted 765 cases to derive and replicate phenotypic groups. Phenotype groups of disease manifestations and key covariate distributions across the identified groups were measured using latent class analysis. RESULTS: In the derivation cohort (n=493), we identified four groups with distinct manifestations: Group 1 (31%), Pancreato-Hepato-Biliary disease; Group 2 (24%), Retroperitoneal Fibrosis and/or Aortitis; Group 3 (24%), Head and Neck-Limited disease and Group 4 (22%), classic Mikulicz syndrome with systemic involvement. We replicated the identification of four phenotype groups in the replication cohort. Compared with cases in Groups 1, 2 and 4, respectively, cases in Group 3 were more likely to be female (OR 11.60 (95% CI 5.39 to 24.98), 10.35 (95% CI 4.63 to 23.15) and 9.24 (95% CI 3.53 to 24.20)) and Asian (OR 6.68 (95% CI 2.82 to 15.79), 7.43 (95% CI 2.97 to 18.56) and 6.27 (95% CI 2.27 to 17.29)). Cases in Group 4 had a higher median serum IgG4 concentration (1170 mg/dL) compared with groups 1-3 (316, 178 and 445 mg/dL, respectively, p<0.001). CONCLUSION: We identified four distinctive IgG4-RD phenotypes according to organ involvement. Being Asian or female may predispose individuals to head and neck-limited disease. These phenotypes serve as a framework for identifying IgG4-RD and studying its aetiology and optimal treatment.

Aortitis caused by antineutrophil cytoplasmic antibodies (ANCA)-associated vasculitis: a case-based review.

Antineutrophil cytoplasmic antibodies (ANCA)-associated vasculitis (AAV) is a systemic necrotizing small vessel vasculitis primarily affecting elderly patients. Neutrophil apoptosis and release of pro-inflammatory mediators promote small vessel inflammation and hence multi-organ disease. It rarely affects larger vessels with extremely rare aortic involvement. Diagnosis is made based on clinical presentation, tissue biopsy of affected organ, as well as immunofluorescence and ELISA assays for ANCA. Management includes immunosuppression (e.g., glucocorticoids, cyclophosphamide and rituximab) and supportive therapy. We present a rare case of a younger patient with AAV involving the aorta. The patient's diagnosis was supported by clinical presentation, systemic organ involvement, strongly positive c-ANCA, and skin as well as aortic tissue biopsy results. After failing multiple immunosuppressants, he responded well to rituximab with improved symptoms, inflammatory markers, and imaging findings. Based on our literature review, we were only able to find ten cases of ANCA-related vasculitis involving the aorta. This is the first reported case of successful treatment of AAV-related aortitis using rituximab. Our case report and literature review provide insight into treatment of severe cases of AAV with aortic involvement.

Bromodomain-containing protein 7 deficiency augments atherosclerotic lesions in ApoE-/- mice.

Atherosclerotic plaque formation is characterized by the persistence of lipid-laden macrophages on the inner walls of arteries. Chronic inflammation and imbalanced macrophage function are likely to play a critical role. Herein, we investigated whether bromodomain-containing protein 7 (Brd7), a member of the bromodomain-containing protein family, regulates atherosclerosis, and if so, which mechanisms are responsible for the process. We found that Brd7 is expressed in mouse atherosclerotic plaques, and mostly in macrophages. Inhibition of Brd7 accelerates atherosclerotic lesion formation in ApoE-/- mice by promoting NF-κB-mediated inflammation. Furthermore, Brd7 inhibition alters the phenotype of macrophages and promotes plaque instability, at least partly via STAT6 signaling. Our data define a previously undescribed role of Brd7 in the development of atherosclerosis.

Inhibition of Orai1-mediated Ca2+ entry limits endothelial cell inflammation by suppressing calcineurin-NFATc4 signaling pathway.

Orai1-dependent Ca2+ entry plays an essential role in inflammatory response through regulating T cell and macrophage activation and neutrophil infiltration. However, whether Orai1 Ca2+ entry contributes to endothelial activation, one of the early steps of vascular inflammation, remains elusive. In the present study, we observed that knockdown of Orai1 reduced, whereas overexpression of Orai1 potentiated, TNFα-induced expression of adhesion molecules such as ICAM-1 and VCAM-1 in HUVECs, and subsequently blocked adhesion of monocyte to HUVECs. In vivo, Orai1 downregulation attenuated TNFα-induced ICAM-1 and VCAM-1 expression in mouse aorta and the levels of pro-inflammatory cytokines in the serum. In addition, Orai1 knockdown also dramatically decreased the expression of pro-inflammatory cytokines and neutrophil infiltration in the lung after TNFα treatment, and thus protected lung tissue injury. Notably, among all isoforms of nuclear factor of activated T cells (NFATs), TNFα only triggered NFATc4 nuclear accumulation in HUVECs. Knockdown of Orai1 or inhibition of calcineurin prevented TNFα-induced NFATc4 nuclear translocation and reduced ICAM-1 and VCAM-1 expression in HUVECs. Overexpression of NFATc4 further enhanced ICAM-1 and VCAM-1 expression induced by TNFα. Our study demonstrates that Orai1-Ca2+-calcineurin-NFATc4 signaling is an essential inflammatory pathway required for TNFα-induced endothelial cell activation and vascular inflammation. Therefore, Orai1 may be a potential therapeutic target for treatment of inflammatory diseases.

Large-vessel vasculitis in human immunodeficiency virus-infected patients.

OBJECTIVE: The objective of this study was to describe large-vessel vasculitis (LVV) in patients with human immunodeficiency virus (HIV) infection. It is a retrospective single-center study conducted between 2000 and 2015 through a university hospital of 11 HIV-infected patients with LVV. METHODS: The characteristics and outcome of 11 HIV-infected patients with LVV (7 patients fulfilled international criteria for Takayasu arteritis, 5 patients had histologic findings of vasculitis, and 5 patients had imaging features of aortitis) were analyzed and compared with those of 82 patients with LVV but without HIV infection. RESULTS: Concerning the HIV-infected patients with LVV (n = 11), the mean age was 40 years (range, 36-56 years), and 55% of patients were female. At diagnosis of LLV, the mean initial CD4 cell count was 455 cells/mm3 (range, 166-837 cells/mm3), and the median HIV viral load was 9241 copies. Vascular lesions were located in the aorta (n = 7), in supra-aortic trunks (n = 7), and in digestive arteries (n = 3). Inflammatory aorta infiltrates showed a strong expression of interferon-γ and interleukin 6. In HIV-negative LVV patients (n = 82), the median age was 42 years, and 88% of the patients were women. Thirty patients had an inflammatory syndrome. Seventy patients had been treated with glucocorticosteroids and 57 with immunosuppressive treatments. Compared with their negative counterparts, HIV-positive patients with LVV were more frequently male (P = .014), had more vascular complications (ie, Ishikawa score; P = .017), and had more frequent revascularization (P = .047). After a mean follow-up of 96 months, four relapses of vasculitis were reported, and one patient died. Regardless of the HIV virologic response, antiretroviral therapy improved LVV in only one case. CONCLUSIONS: LVV in HIV-infected patients is a rare and severe entity.

Systemic Inflammation and Evidence of a Cardio-splenic Axis in Patients with Psoriasis.

The spleen is thought to play a role in atherosclerosis-associated immunity and cardiovascular research has indicated the existence of a cardio-splenic axis. The aim of this study was to assess splenic 18F-fluorodeoxyglucose uptake as a measure of systemic inflammation in patients with untreated psoriasis compared with historical controls assessed by positron emission tomography-computed tomography. Patients with moderate-to-severe psoriasis (n = 12, age 61.4 ± 4.1 years, 83% men, mean Psoriasis Area Severity Index score of 14.5) and controls (n = 23, age 60.4 ± 4.5 years, 87% men) were included in the study. Splenic inflammation was measured using the background-corrected spleen-liver-ratio (SLR) based on mean standardized uptake values. Mean ± SD SLR was increased in patients with psoriasis compared with controls (0.94 ± 0.11 vs. 0.82 ± 0.08; p = 0.001). SLR was significantly associated with aortic inflammation. These results support the existence of systemic inflammation in patients with psoriasis, and provide the rationale for a mechanistic link between psoriasis-driven inflammation and cardiovascular comorbidity through a spleen-atherosclerotic axis.

The many faces of IgG4-related disease: report of a case with inaugural recurrent aortic aneurism ruptures and literature review.

Vascular involvement in IgG4-related disease (IgG4-RD), is a well-recognized feature and large vessel commitment, especially the aorta, can be the only manifestation of the disease. Being a newly recognized disease, its diagnosis and workup still represents a challenge in clinical practice. A 47-year-old-man with two aortic aneurysms ruptures, one at abdominal and the other at thoracic level, was referred to our rheumatology department. The initial analysis of the surgical specimen obtained 3 years earlier revealed a nonspecific aortitis. Re-evaluation of the biopsy with immunohistology now demonstrated the presence of IgG4 deposits. Evidence-based recommendations regarding diagnosis, treatment and follow-up of IgG4-related large-vessel involvement are lacking. In this particular case, histopathology were crucial. The authors review and discuss vascular involvement in IgG4-RD and respective treatment options.

Characteristics of autoantibodies targeting 14-3-3 proteins and their association with clinical features in newly diagnosed giant cell arteritis.

Objectives: Autoantibodies are useful biomarkers for diagnosing and monitoring treatment in some autoimmune diseases. Antibodies against isoforms of 14-3-3 protein have been proposed as biomarkers for the presence of aortic aneurysm in large-vessel vasculitis (LVV). Here, we aimed to evaluate the diagnostic role and potential immunopathological involvement of anti-14-3-3 antibodies in newly diagnosed LVV patients. Methods: Antibodies against three isoforms of 14-3-3 (γ, ɛ and ζ) were measured in 90 subjects: 48 GCA and 3 Takayasu's arteritis (TA) patients, and 39 controls (non-inflammatory and inflammatory diseases), using a multiplexed bead-based immunoassay and immunoprecipitation studies. The positive cut-off value was defined based on young healthy controls. Anti-14-3-3 IgG antibodies in LVV patients were compared with those in controls in order to assess their diagnostic performance, and the relationship of anti-14-3-3 IgG antibodies to the immunohistopathology of artery explants was assessed. Results: Antibodies against all three 14-3-3 isoforms were detected in LVV patients as well as in age-matched inflammatory and non-inflammatory controls. Among LVV patients, detection of antibodies targeting 14-3-3 ɛ and ζ was associated with more severe disease. Detection of antibodies against 14-3-3 γ was linked to latent Toxoplasma gondii infection, a parasite that secrets a 14-3-3 homologue, suggesting potential cross-reactivity. Conclusion: Detection of antibodies against 14-3-3 proteins at the time of LVV diagnosis is not disease-specific. Their presence at high levels in LVV patients with stroke, aortitis and-in a previous study-aneurysm formation may indicate an association with extensive tissue destruction. The relevance of 14-3-3 antibodies in non-LVV patients needs to be investigated in larger cohorts.

Consequences of lipopolysaccharide and n-3 polyunsaturated fatty acid administration on aortic function of spontaneously hypertensive rats.

The aim of the work was to study the delayed effect of lipopolysaccharide (LPS) administration on endothelial function of the aorta of rats with genetic hypertension. Further, the possibility to ameliorate LPS-induced changes by n-3 polyunsaturated fatty acids (n-3 PUFA) was tested. Rats received a bolus of 1 mg/kg LPS i.p.; n-3 PUFA were administered in the dose of 30 mg/kg daily for 10 days p.o.. Ten days after receiving of LPS, the body weight gain of rats was statistically lower compared to control rats (p < 0.05). n-3 PUFA administration to LPS rats had no effect on this parameter. The TBARS and NAGA concentrations in plasma were significantly increased in the LPS group (p < 0.05) and n-3 PUFA administration returned them to control values. In functional studies, phenylephrine (PE, 1 µmol/l) evoked contraction of aortas which was not statistically different among experimental groups. However, endothelium-dependent relaxation was depressed in the LPS group (p < 0.05) and n-3 PUFA slightly recovered it to control values. In conclusion, oxidative stress seems to be responsible for aortic endothelial dysfunction detected 10 days after administration of LPS to rats. n-3 PUFA slightly improved the function of the endothelium injured by LPS, probably thanks to their antioxidant properties. Prolonged administration of higher doses of n-3 PUFA should defend the vascular endothelium against detrimental effect of bacterial inflammation.

IGG4 Disease And Slerosing Aortitis.

INTRODUCTION: IgG4-related disease (IgG4-RD) is an immune- -mediated fibro-inflammatory condition with unknown etiology that can affect various organs. Although its prevalence is still unknown, it appears to be more frequent in adult males. Cardiovascular manifestations are rare and can include idiopathic retroperitoneal periaortic fibrosis, inflammatory aortic aneurism, inflammatory periarteritis and inflammatory pericarditis. Vascular involvement is a well-recognized feature and large vessel commitment, especially the aorta, can be the only manifestation of the disease. The gold standard diagnosis is histological. METHODS: A 47-year-old man presented rupture of two aortic aneurysms: one thoracic and one abdominal, and underwent surgical correction. A segment of the aorta artery wall measuring 3x2x0.5cm, exhibited smooth intimate and white vinous adventitia, medium tunic was white, through firm tissue with loss of elasticity. RESULTS: In addition to heterogenous collagenation with destruction of the elastic network of the aortic mediae tunica, there was fibrin deposition and neutrophil overlap. Lymphoid follicles with reactive germinate centers were along the tunica media and adventitia, without phenotype of endothelitis and absence of either macrophages and Langerhans cells (CD1a). Plasmocytes showed immunopositivity to IgG4, with heterogeneous and well defined localization, supporting the diagnosis of igG4 Disease. Serological studies showed negativity for vasculitis, hereditary connective tissue diseases were not component of the clinical set and normal serum IgG4 concentration was determined. CONCLUSION: Few cases of involvement of large vessels by IgG4- -RD have been reported in literature. Serum IgG4 concentration may be normal in one third of patients. In this case, IgG4 immunostaining was crucial for the diagnosis of IgG4-RD aortitis, together with the hyaline destruction of the tunica media (ESP 2015 / Aagaimy 2013). There is still no clinical knowledge for the treatment and monitoring of the involvement of large vessels by IgG4-RD.

Nanoformulated copper/zinc superoxide dismutase attenuates vascular cell activation and aortic inflammation in obesity.

OBJECTIVE: Endothelial cell (EC) oxidative stress can lead to vascular dysfunction which is an underlying event in the development of cardiovascular disease (CVD). The lack of a potent and bioavailable anti-oxidant enzyme is a major challenge in studies on antioxidant therapy. The objective of this study is to determine whether copper/zinc superoxide dismutase (CuZnSOD or SOD1) after nanoformulation (nanoSOD) can effectively reduce EC oxidative stress and/or vascular inflammation in obesity. METHODS: Human aortic endothelial cells (HAECs) were treated with native- or nanoSOD for 6 h followed by treatment with linoleic acid (LA), a free fatty acid, for 6-24 h. To determine the in vivo relevance, the effectiveness of nanoSOD in reducing vascular cell activation was studied in a mouse model of diet-induced obesity. RESULTS: We noted that nanoSOD was more effectively taken up by ECs than native SOD. Western blot analysis further confirmed that the intracellular accumulation of SOD1 protein was greatly increased upon nanoSOD treatment. Importantly, nanoSOD pretreatment led to a significant decrease in LA-induced oxidative stress in ECs which was associated with a marked increase in SOD enzyme activity in ECs. In vivo studies showed a significant decrease in markers of EC/vascular cell activation and/or inflammation in visceral adipose tissue (VAT), thoracic aorta, and heart collected from nanoSOD-treated mice compared to obese control mice. Interestingly, the expression of metallothionein 2, an antioxidant gene was significantly increased in nanoSOD-treated mice. CONCLUSION: Our data show that nanoSOD is very effective in delivering active SOD to ECs and in reducing EC oxidative stress. Our data also demonstrate that nanoSOD will be a useful tool to reduce vascular cell activation in VAT and aorta in obesity which, in turn, can protect against obesity-associated CVD, in particular, hypertension.

Differential effects of NOX4 and NOX1 on immune cell-mediated inflammation in the aortic sinus of diabetic ApoE-/- mice.

Oxidative stress and inflammation are central mediators of atherosclerosis particularly in the context of diabetes. The potential interactions between the major producers of vascular reactive oxygen species (ROS), NADPH oxidase (NOX) enzymes and immune-inflammatory processes remain to be fully elucidated. In the present study we investigated the roles of the NADPH oxidase subunit isoforms, NOX4 and NOX1, in immune cell activation and recruitment to the aortic sinus atherosclerotic plaque in diabetic ApoE(-/-) mice. Plaque area analysis showed that NOX4- and NOX1-derived ROS contribute to atherosclerosis in the aortic sinus following 10 weeks of diabetes. Immunohistochemical staining of the plaques revealed that NOX4-derived ROS regulate T-cell recruitment. In addition, NOX4-deficient mice showed a reduction in activated CD4(+) T-cells in the draining lymph nodes of the aortic sinus coupled with reduced pro-inflammatory gene expression in the aortic sinus. Conversely, NOX1-derived ROS appeared to play a more important role in macrophage accumulation. These findings demonstrate distinct roles for NOX4 and NOX1 in immune-inflammatory responses that drive atherosclerosis in the aortic sinus of diabetic mice.

Severity of Psoriasis Associates With Aortic Vascular Inflammation Detected by FDG PET/CT and Neutrophil Activation in a Prospective Observational Study.

OBJECTIVE: To understand whether directly measured psoriasis severity is associated with vascular inflammation assessed by (18)F-fluorodeoxyglucose positron emission tomography computed tomography. APPROACH: In-depth cardiovascular and metabolic phenotyping was performed in adult psoriasis patients (n=60) and controls (n=20). Psoriasis severity was measured using psoriasis area severity index. Vascular inflammation was measured using average aortic target-to-background ratio using (18)F-fluorodeoxyglucose positron emission tomography computed tomography. RESULTS: Both the psoriasis patients (28 men and 32 women, mean age 47 years) and controls (13 men and 7 women, mean age 41 years) were young with low cardiovascular risk. Psoriasis area severity index scores (median 5.4; interquartile range 2.8-8.3) were consistent with mild-to-moderate skin disease severity. Increasing psoriasis area severity index score was associated with an increase in aortic target-to-background ratio (ß=0.41, P=0.001), an association that changed little after adjustment for age, sex, and Framingham risk score. We observed evidence of increased neutrophil frequency (mean psoriasis, 3.7±1.2 versus 2.9±1.2; P=0.02) and activation by lower neutrophil surface CD16 and CD62L in blood. Serum levels of S100A8/A9 (745.1±53.3 versus 195.4±157.8 ng/mL; P<0.01) and neutrophil elastase-1 (43.0±2.4 versus 30.8±6.7 ng/mL; P<0.001) were elevated in psoriasis. Finally, S100A8/A9 protein was related to both psoriasis skin disease severity (ß=0.53; P=0.02) and vascular inflammation (ß=0.48; P=0.02). CONCLUSIONS: Psoriasis severity is associated with vascular inflammation beyond cardiovascular risk factors. Psoriasis increased neutrophil activation and neutrophil markers, and S100A8/A9 was related to both skin disease severity and vascular inflammation.

Membrane-Bound Thrombomodulin Regulates Macrophage Inflammation in Abdominal Aortic Aneurysm.

OBJECTIVE: Thrombomodulin (TM), a glycoprotein constitutively expressed in the endothelium, is well known for its anticoagulant and anti-inflammatory properties. Paradoxically, we recently found that monocytic membrane-bound TM (ie, endogenous TM expression in monocytes) triggers lipopolysaccharide- and gram-negative bacteria-induced inflammatory responses. However, the significance of membrane-bound TM in chronic sterile vascular inflammation and the development of abdominal aortic aneurysm (AAA) remains undetermined. APPROACH AND RESULTS: Implicating a potential role for membrane-bound TM in AAA, we found that TM signals were predominantly localized to macrophages and vascular smooth muscle cells in human aneurysm specimens. Characterization of the CaCl2-induced AAA in mice revealed that during aneurysm development, TM expression was mainly localized in infiltrating macrophages and vascular smooth muscle cells. To investigate the function of membrane-bound TM in vivo, transgenic mice with myeloid- (LysMcre/TM(flox/flox)) and vascular smooth muscle cell-specific (SM22-cre(tg)/TM(flox/flox)) TM ablation and their respective wild-type controls (TM(flox/flox) and SM22-cre(tg)/TM(+/+)) were generated. In the mouse CaCl2-induced AAA model, deficiency of myeloid TM, but not vascular smooth muscle cell TM, inhibited macrophage accumulation, attenuated proinflammatory cytokine and matrix metalloproteinase-9 production, and finally mitigated elastin destruction and aortic dilatation. In vitro TM-deficient monocytes/macrophages, versus TM wild-type counterparts, exhibited attenuation of proinflammatory mediator expression, adhesion to endothelial cells, and generation of reactive oxygen species. Consistently, myeloid TM-deficient hyperlipidemic mice (ApoE(-/-)/LysMcre/TM(flox/flox)) were resistant to AAA formation induced by angiotensin II infusion, along with reduced macrophage infiltration, suppressed matrix metalloproteinase activities, and diminished oxidative stress. CONCLUSIONS: Membrane-bound TM in macrophages plays an essential role in the development of AAA by enhancing proinflammatory mediator elaboration, macrophage recruitment, and oxidative stress.

An elevated IgG4 response in chronic infectious aortitis is associated with aortic atherosclerosis.

Recently, it was shown that infectious bacterial aortitis can stimulate an elevated IgG4⁺ plasma cell response in the vessel wall, which could mimic IgG4 aortitis/periaortitis. However, the factors that are associated with an elevated IgG4⁺ plasma cell response in infectious aortitis are unclear. To ascertain these factors, 17 cases of infectious aortitis and 6 cases of non-infectious severe abdominal aortic atherosclerosis were assessed for the magnitude of IgG4⁺ plasma cell response. The degree of IgG4⁺ plasma cell infiltration was determined by immunohistochemistry. Infectious cases were subcharacterized as chronic (>3 weeks duration) or acute (<3 weeks duration) based on the duration of symptoms, and as involving either the ascending aorta or the distal aorta, ie, the descending thoracic and/or abdominal aorta. There was a 5-16-fold greater degree of IgG4⁺ plasma cell infiltration in the chronic distal infectious aortitis group compared with the other three infectious aortitis groups (P ≤ 0.0007), and compared with non-infectious severe abdominal aortic atherosclerosis (P<0.0008). This resulted in a greater IgG4/IgG ratio in the chronic distal infectious aortitis group compared with the acute ascending and acute distal infectious aortitis groups (P<0.03). The degree of IgG4⁺ plasma cell infiltration in chronic distal infectious aortitis overlaps with that seen in the aortitis and periaortitis of IgG4-related disease. In the chronic infectious aortitis cases, the degree of IgG4⁺ plasma cell infiltration was more intense in patients with moderate to severe aortic atherosclerosis compared with those patients with less aortic atherosclerosis (P=0.007). These findings indicate that an elevated IgG4⁺ plasma cell response occurs in the descending thoracic and abdominal aorta in the setting of chronic bacterial infectious aortitis and pre-existing atherosclerosis. This inflammatory response to chronic infection in atherosclerosis-laden aortas may have implications for the development of IgG4-rich inflammatory atherosclerotic aortic aneurysms.

Increased atherosclerotic lesion formation and vascular leukocyte accumulation in renal impairment are mediated by interleukin-17A.

RATIONALE: Atherosclerosis is a major cause of death in patients with chronic kidney disease. Chronic inflammation of the arterial wall including invasion, proliferation, and differentiation of leukocytes is important in atherosclerotic lesion development. How atherosclerotic inflammation is altered in renal impairment is incompletely understood. OBJECTIVE: This study analyzed leukocytes of the atherosclerotic aorta in mice with impaired and normal renal function and studied a mechanism for the alteration in aortic myeloid leukocytes. METHODS AND RESULTS: Unilateral nephrectomy significantly decreased glomerular filtration rate and increased atherosclerotic lesion size and aortic leukocyte numbers in 2 murine atherosclerosis models, apolipoprotein E (Apoe(-/-)) and low-density lipoprotein (LDL) receptor-deficient (LDLr(-/-)) mice. The number of aortic myeloid cells increased significantly. They took-up less oxidized LDL, whereas CD11c expression, interaction with T cells, and aortic T cell proliferation were significantly enhanced in renal impairment. In human peripheral blood mononuclear cell cultures, chronic kidney disease serum decreased lipid uptake and increased human leukocyte antigen II (HLA II) expression. Supplementation with interleukin-17A similarly increased HLA II and CD11c expression and impaired oxidized LDL uptake. Interleukin-17A expression was increased in atherosclerotic mice with renal impairment. Ablation of interleukin-17A in LDLr(-/-) mice by lethal irradiation and reconstitution with Il17a(-/-) bone marrow abolished the effect of renal impairment on aortic CD11b(+) myeloid cell accumulation, CD11c expression, and cell proliferation. Atherosclerotic lesion size was decreased to levels observed in normal kidney function. CONCLUSIONS: Kidney function modifies arterial myeloid cell accumulation and phenotype in atherosclerosis. Our results suggest a central role for interleukin-17A in aggravation of vascular inflammation and atherosclerosis in renal impairment.