TREM-1 orchestrates angiotensin II-induced monocyte trafficking and promotes experimental abdominal aortic aneurysm.
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ABSTRACT:
SUBMITTER: Vandestienne M
PROVIDER: S-EPMC7810476 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:Abdominal aortic aneurysm (AAA) is an inflammatory vascular disease characterized by structural deterioration of the aorta caused by inflammation and oxidative stress, leading to aortic dilatation and rupture. Peroxiredoxin 2 (PRDX2), an antioxidant enzyme, has been reported as a potential negative regulator of inflammatory vascular diseases, and it has been identified as a protein that is increased in patients with ruptured AAA compared to patients with nonruptured AAA. In this study, we demonstrated that PRDX2 was a pivotal factor involved in the inhibition of AAA progression. PRDX2 levels were increased in AAA compared with those in normal aortas in both humans and mice. Ultrasound imaging revealed that the loss of PRDX2 accelerated the development of AAA in the early stages and increased AAA incidence in mice infused with angiotensin II (Ang II). Prdx2-/- mice infused with Ang II exhibited increased aortic dilatation and maximal aortic diameter without a change in blood pressure. Structural deterioration of the aortas from Prdx2-/- mice infused with Ang II was associated with increases in the degradation of elastin, oxidative stress, and intramural thrombi caused by microhemorrhages, immature neovessels, and the activation of matrix metalloproteinases compared to that observed in controls. Moreover, an increase in inflammatory responses, including the production of cell adhesion molecules and the accumulation of inflammatory cells and proinflammatory cytokines due to PRDX2 deficiency, accelerated Ang II-induced AAA progression. Our data confirm that PRDX2 plays a role as a negative regulator of the pathological process of AAA and suggest that increasing PRDX2 activity may be a novel strategy for the prevention and treatment of AAA.
| S-EPMC8080566 | biostudies-literature
Project description:RationaleBlood eosinophil count and ECP (eosinophil cationic protein) associate with human cardiovascular diseases. Yet, whether eosinophils play a role in cardiovascular disease remains untested. The current study detected eosinophil accumulation in human and murine abdominal aortic aneurysm (AAA) lesions, suggesting eosinophil participation in this aortic disease.ObjectiveTo test whether and how eosinophils affect AAA growth.Methods and resultsPopulation-based randomized clinically controlled screening trials revealed higher blood eosinophil count in 579 male patients with AAA than in 5063 non-AAA control (0.236±0.182 versus 0.211±0.154, 109/L, P<0.001). Univariate (odds ratio, 1.381, P<0.001) and multivariate (odds ratio, 1.237, P=0.031) logistic regression analyses indicated that increased blood eosinophil count in patients with AAA served as an independent risk factor of human AAA. Immunostaining and immunoblot analyses detected eosinophil accumulation and eosinophil cationic protein expression in human and murine AAA lesions. Results showed that eosinophil deficiency exacerbated AAA growth with increased lesion inflammatory cell contents, matrix-degrading protease activity, angiogenesis, cell proliferation and apoptosis, and smooth muscle cell loss using angiotensin-II perfusion-induced AAA in Apoe-/- and eosinophil-deficient Apoe-/-ΔdblGATA mice. Eosinophil deficiency increased lesion chemokine expression, muted lesion expression of IL (interleukin) 4 and eosinophil-associated-ribonuclease-1 (mEar1 [mouse EOS-associated-ribonuclease-1], human ECP homolog), and slanted M1 macrophage polarization. In cultured macrophages and monocytes, eosinophil-derived IL4 and mEar1 polarized M2 macrophages, suppressed CD11b+Ly6Chi monocytes, and increased CD11b+Ly6Clo monocytes. mEar1 treatment or adoptive transfer of eosinophil from wild-type and Il13-/- mice, but not eosinophil from Il4-/- mice, blocked AAA growth in Apoe-/-ΔdblGATA mice. Immunofluorescent staining and immunoblot analyses demonstrated a role for eosinophil IL4 and mEar1 in blocking NF-κB (nuclear factor-κB) activation in macrophages, smooth muscle cells, and endothelial cells.ConclusionsEosinophils play a protective role in AAA by releasing IL4 and cationic proteins such as mEar1 to regulate macrophage and monocyte polarization and to block NF-κB activation in aortic inflammatory and vascular cells.
| S-EPMC7855167 | biostudies-literature
Project description:Abstract: The pathogenesis of AAA involves vascular inflammation and oxidative stress. Astragali Radix contains cycloastragenol (CAG) known to have anti-inflammatory and anti-oxidative properties. We hypothesized that CAG supplement impairs AAA progression. AAA was induced in male rats by intraluminal elastase infusion in the infrarenal aorta and treated daily with CAG (125 mg/kg/day). Aortic expansion was followed weekly by ultrasound, with euthanization at day 28. Changes in AAA wall composition were analyzed at mRNA levels, histology, zymography and explorative proteomic analyses. At day 28, mean AAA diameter was 37% lower in CAG group (p<0.0001). In aneurysm cross sections, elastin content was insignificantly higher in CAG group (10.5% ± 5.9% vs 19.9% ± 16.8%, p=0.20) with more preserved elastin lamellae structures (p=0.0003) and with no microcalcifications. Aneurysmal matrix metalloprotease-2 activity was reduced by CAG treatment (p=0.022), and mRNA levels of inflammatory- and antioxidative markers showed no difference between groups. Explorative proteomic analysis showed no difference in protein levels when adjustment for multiple testing. Amongst unadjusted affected proteins were fibulin-5 (p=0.02), aquaporin-1 (p=0.02) and prostacyclin synthase (p=0.006). CAG impairs experimental AAA progression by reduction of elastin degradation through decreased MMP-2 activity, thus CAG could be considered tested in AAA patients.
2022-05-20 | PXD030441 | Pride
Project description:In the present study, we want to test whether deletion of resistin-like molecule-beta (RELM?) attenuates angiotensin II (Ang II)-induced formation of abdominal aortic aneurysm (AAA). RELM? gene expression was inhibited by siRNA both in vivo and in vitro. Apolipoprotein E-knockout (ApoE-/-) mice were randomly divided into saline, Ang II, siRNA negative control (si-NC) and siRNA RELM? (si-RELM?) groups (n=15 each), and mice in the last three groups underwent Ang II infusion for 4 weeks to induce AAA. RELM? gene deficiency significantly decreased AAA incidence and severity, which was associated with reduced macrophage accumulation and decreased expression of proinflammatory cytokines (monocyte chemoattractant protein 1 and interleukin 6), matrix metalloproteinase 2 (MMP-2) and MMP-9 in the aortic wall. In cultured macrophages, RELM? deficiency blunted the response of macrophages to Ang II and downregulated the levels of proinflammatory cytokines, MMP-2 and MMP-9. Recombinant RELM? promoted the secretion of proinflammatory cytokines, MMP-2 and MMP-9 in macrophages and activated extracellular signal-regulated kinase 1/2 (ERK1/2) and c-Jun N-terminal kinase (JNK) signaling, which was reversed with pretreatment with inhibitors of ERK1/2 and JNK. Deletion of RELM? attenuated Ang II-induced AAA formation in ApoE-/- mice. The inherent mechanism may involve the reduced expression of proinflammatory cytokines, MMP-2 and MMP-9, which was mediated by ERK1/2 and JNK activation. Therefore, inhibiting RELM? secretion may be a novel approach for anti-aneurysm treatment.
| S-EPMC5732796 | biostudies-literature
Project description:Vascular inflammation via T-cell-mediated immune responses has been shown to be critically involved in the pathogenesis of abdominal aortic aneurysm (AAA). T-cell coinhibitory molecule cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4) is known to act as a potent negative regulator of immune responses. However, the role of this molecule in the development of AAA remains completely unknown. We determined the effects of CTLA-4 overexpression on experimental AAA. We continuously infused CTLA-4 transgenic (CTLA-4-Tg)/apolipoprotein E-deficient (Apoe-/-) mice or control Apoe-/- mice fed a high-cholesterol diet with angiotensin II by implanting osmotic mini-pumps and evaluated the development of AAA. Ninety percent of angiotensin II-infused mice developed AAA, with 50% mortality because of aneurysm rupture. Overexpression of CTLA-4 significantly reduced the incidence (66%), mortality (26%), and diameter of AAA. These protective effects were associated with a decreased number of effector CD4+ T cells and the downregulated expression of costimulatory molecules CD80 and CD86, ligands for CTLA-4, on CD11c+ dendritic cells in lymphoid tissues. CTLA-4-Tg/Apoe-/- mice had reduced accumulation of macrophages and CD4+ T cells, leading to attenuated aortic inflammation, preserved vessel integrity, and decreased susceptibility to AAA and aortic rupture. Our findings suggest T-cell coinhibitory molecule CTLA-4 as a novel therapeutic target for AAA.
| S-EPMC6542846 | biostudies-literature
Project description:Objective- Abdominal aortic aneurysm is caused by the accumulation of inflammatory cells in the aortic wall. Our recent studies demonstrated that inhibition of Notch signaling attenuates abdominal aortic aneurysm formation by shifting the macrophage balance towards anti-inflammatory (M2) phenotype. Using IL12p40-/- (interleukin 12 p40) mice, we investigated the effects of M2-predominant macrophages on the development of abdominal aortic aneurysm. Approach and Results- Male (8-10 week-old) wild-type and IL12p40-/- mice (n=15) on C57BL/6 background were infused with Ang II (angiotensin II, 1000 ng/kg per minute) by implanting osmotic pumps subcutaneously for 28 days. In the IL12p40-/- mice, Ang II significantly increased the maximal intraluminal diameter (9/15) as determined by transabdominal ultrasound imaging. In addition, IL12p40-deletion significantly increased aortic stiffness in response to Ang II as measured by pulse wave velocity and atomic force microscopy. Histologically, IL12p40-/- mice exhibited increased maximal external diameter of aorta and aortic lesions associated with collagen deposition and increased elastin fragmentation compared with wild-type mice infused with Ang II. Mechanistically, IL12p40 deficiency by siRNA (small interfering RNA) augmented the Tgfβ2-mediated Mmp2 expression in wild-type bone marrow-derived macrophages without affecting the expression of Mmp9. No such effects of IL12p40 deficiency on MMP2/MMP9 was observed in human aortic smooth muscle cells or fibroblasts. Depletion of macrophages in IL12p40-/- mice by clodronate liposomes significantly decreased the maximal external diameter of aorta and aortic stiffness in response to Ang II as determined by imaging and atomic force microscopy. Conclusions- IL12p40 depletion promotes the development of abdominal aortic aneurysm, in part, by facilitating recruitment of M2-like macrophages and potentiating aortic stiffness and fibrosis mediated by Tgfβ2.
| S-EPMC6355331 | biostudies-literature
Project description:Rationale: The progressive disruption of extracellular matrix (ECM) proteins, particularly early elastin fragmentation followed by abnormalities in collagen fibril organization, are key pathological processes that contribute to dissecting abdominal aortic aneurysm (AAA) pathogenesis. Lysyl hydroxylase 1 (LH1) is essential for type I/III collagen intermolecular crosslinking and stabilization. However, its function in dissecting AAA has not been explored. Here, we investigated whether LH1 is significantly implicated in dissecting AAA progression and therapeutic intervention. Methods and Results: Sixteen-week-old male LH1-deficient and wild-type (WT) mice on the C57Bl/6NCrl background were infused with angiotensin II (Ang II, 1000 ng/kg per minute) via subcutaneously implanted osmotic pumps for 4 weeks. Ang II increased LH1 levels in the abdominal aortas of WT mice, whereas mice lacking LH1 developed dissecting AAA. To evaluate the related mechanism, we performed whole-transcriptomic analysis, which demonstrated that LH1 deficiency aggravated gene transcription alterations; in particular, the expression of thrombospondin-1 was markedly upregulated in the aortas of LH1-deficient mice. Furthermore, targeting thrombospondin-1 with TAX2 strongly inhibited the proinflammatory process, matrix metalloproteinase (MMP) activity and vascular smooth muscle cells (VSMCs) apoptosis, ultimately decreasing the incidence of dissecting AAA. Restoration of LH1 protein expression in LH1-deficient mice by intraperitoneal injection of an adeno-associated virus normalized thrombospondin-1 levels, subsequently alleviating dissecting AAA formation and preserving aortic structure and function. Consistently, in human AAA specimens, decreased LH1 expression was associated with increased thrombospondin-1 levels. Conclusions: LH1 deficiency contributes to dissecting AAA pathogenesis, at least in part, by upregulating thrombospondin-1 expression, which subsequently enables proinflammatory processes, MMP activation and VSMCs apoptosis. Our study provides evidence that LH1 is a potential critical therapeutic target for AAA.
| S-EPMC8490513 | biostudies-literature
Project description:BackgroundOur previous study showed that interleukin-22 (IL-22) levels were increased in patients with aortic dissection (AD). This study evaluated the effects of IL-22 on AD/abdominal aortic aneurysm (AAA) formation in angiotensin II (Ang II)-infused ApoE-/- mice.MethodsApoE-/- mice were treated with Ang II for 28 days, and IL-22 expression was examined. In addition, the effects of IL22 deficiency on AAA/AD formation induced by Ang II infusion in ApoE-/- mice were investigated. ApoE-/-IL-22-/- mice were transplanted with bone marrow cells isolated from ApoE-/- mice or ApoE-/-IL-22-/- mice, and AAA/AD formation was observed.ResultsIL-22 expression was increased in both the aortas and serum of ApoE-/- mice after Ang II infusion and was mainly derived from aortic CD4+ T lymphocytes (CD4+ TCs). IL-22 deficiency significantly reduced the AAA/AD formation as well as the maximal aortic diameter in Ang II-infused ApoE-/- mice. Decreased elastin fragmentation and reduced fibrosis were observed in the aortas of ApoE-/-IL-22-/- mice compared with ApoE-/- mice. The deletion of IL-22 also decreased aortic M1 macrophage differentiation, alleviated M1 macrophage-induced oxidative stress, and reduced aortic smooth muscle cell loss. Furthermore, M1 macrophage-induced oxidative stress was worsened and AAA/AD formation was promoted in ApoE-/-IL-22-/- mice that received transplanted bone marrow cells from ApoE-/- mice compared with those that were transplanted with bone marrow cells isolated from ApoE-/-IL-22-/- mice.ConclusionsIL-22 deficiency inhibits AAA/AD formation by inhibiting M1 macrophage-induced oxidative stress. IL-22 potentially represents a promising new target for preventing the progression of AAA/AD.
| S-EPMC8956387 | biostudies-literature
Project description:Obesity is recognized as an independent risk factor for abdominal aortic aneurysm (AAA). While mutations in the melanocortin-4 receptor (MC4R) gene is the most common cause of obesity caused by mutations in a single gene, the link between MC4R function and vascular disease has still remained unclear. Here, by using melanocortin-4 receptor (MC4R) deficient mice, we confirmed MC4R deficiency promotes AAA and atherosclerosis. We demonstrated the contribution of two novel factors towards vascular vulnerability in this model: leptin signaling in vascular smooth muscle cells (VSMCs) and loss of MC4R signaling in macrophages. Leptin was shown to promote vascular vulnerability via PI3K-dependent upregulation of Spp1 expression in VSMC. Additionally, Ang II-induced AAA incidence was significantly reduced when MC4R gene expression was myeloid cell-specifically rescued in MC4R deficient (MC4RTB/TB) mice. Ex vivo analysis showed a suppression in NF-κB activity in bone marrow-derived macrophages from LysM(+);MC4RTB/TB mice compared to LysM(-);MC4RTB/TB mice, which exaggerates with endogenous MC4R ligand treatment; α-MSH. These results suggest that MC4R signaling in macrophages attenuates AAA by inhibiting NF-κB activity and subsequent vascular inflammation.
| S-EPMC10643430 | biostudies-literature
Project description:We sought to characterize temporal gene expression changes in the murine angiotensin II (ANG II)-ApoE-/- model of abdominal aortic aneurysm (AAA). Aortic ultrasound measurements were obtained over the 28-day time-course. Harvested suprarenal aortic segments were evaluated with whole genome expression profiling at 7, 14, and 28 days using the Agilent Whole Mouse Genome microarray platform and Statistical Analysis of Microarrays at a false discovery rate of <1%. A group of angiotensin-treated mice experienced contained rupture (CR) within 7 days and were analyzed separately. Progressive aortic dilatation occurred throughout the treatment period. However, the numerous early expression differences between ANG II-treated and control were not sustained over time. Ontologic analysis revealed widespread upregulation of inflammatory, immune, and matrix remodeling genes with ANG II treatment, among other pathways such as apoptosis, cell cycling, angiogenesis, and p53 signaling. CR aneurysms displayed significant decreases in TGF-β/BMP-pathway signaling, MAPK signaling, and ErbB signaling genes vs. non-CR/ANG II-treated samples. We also performed literature-based network analysis, extracting numerous highly interconnected genes associated with aneurysm development such as Spp1, Myd88, Adam17 and Lox. 1) ANG II treatment induces extensive early differential expression changes involving abundant signaling pathways in the suprarenal abdominal aorta, particularly wide-ranging increases in inflammatory genes with aneurysm development. 2) These gene expression changes appear to dissipate with time despite continued growth, suggesting that early changes in gene expression influence disease progression in this AAA model, and that the aortic tissue adapts to prolonged ANG II infusion. 3) Network analysis identified nexus genes that may constitute aneurysm biomarkers or therapeutic targets.
| S-EPMC3180735 | biostudies-literature