Activation of the alternative complement pathway modulates inflammation in thoracic aortic aneurysm/dissection.

Thoracic aortic aneurysm/dissection (TAAD) is a lethal vascular disease, and several pathological factors participate in aortic medial degeneration. We previously discovered that the complement C3a-C3aR axis in smooth muscle cells promotes the development of thoracic aortic dissection (TAD) through regulation of matrix metalloproteinase 2. However, discerning the specific complement pathway that is activated and elucidating how inflammation of the aortic wall is initiated remain unknown. We ascertained that the plasma levels of C3a and C5a were significantly elevated in patients with TAD and that the levels of C3a, C4a, and C5a were higher in acute TAD than in chronic TAD. We also confirmed the activation of the complement in a TAD mouse model. Subsequently, knocking out Cfb (Cfb) or C4 in mice with TAD revealed that the alternative pathway and Cfb played a significant role in the TAD process. Activation of the alternative pathway led to generation of the anaphylatoxins C3a and C5a, and knocking out their receptors reduced the recruitment of inflammatory cells to the aortic wall. Moreover, we used serum from wild-type mice or recombinant mice Cfb as an exogenous source of Cfb to treat Cfb KO mice and observed that it exacerbated the onset and rupture of TAD. Finally, we knocked out Cfb in the FBN1C1041G/+ Marfan-syndrome mice and showed that the occurrence of TAA was reduced. In summary, the alternative complement pathway promoted the development of TAAD by recruiting infiltrating inflammatory cells. Targeting the alternative pathway may thus constitute a strategy for preventing the development of TAAD.NEW & NOTEWORTHY The alternative complement pathway promoted the development of TAAD by recruiting infiltrating inflammatory cells. Targeting the alternative pathway may thus constitute a strategy for preventing the development of TAAD.

Abnormal circulating steroids refine risk of progression to heart failure in ischemic heart disease.

BACKGROUND: Patients with ischemic heart disease (IHD) experience a high incidence of progression to heart failure (HF) despite current therapies. We speculated that steroid hormone metabolic disorders distinct adverse phenotypes and contribute to HF. METHODS: We measured 18 steroids using liquid chromatography with tandem mass spectrometry in 2023 patients from the Registry Study of Biomarkers in Ischemic Heart Disease (BIOMS-IHD), including 1091 patients with IHD in a retrospective discovery set and 932 patients with IHD in a multicentre validation set. Our outcomes included incident HF after a median follow-up of 4 years. RESULTS: We demonstrated steroid-based signatures of inflammation, coronary microvascular dysfunction and left ventricular hypertrophy that were associated with subsequent HF events in patients with IHD. In both cohorts, patients with a high steroid-heart failure score (SHFS) (>1) exhibited a greater risk of incident HF than patients with a low SHFS (≤1). The SHFS further improved the prognostic accuracy beyond clinical variables (net reclassification improvement of 0.628 in the discovery set and 0.299 in the validation set) and demonstrated the maximal effect of steroid signatures in patients with IHD who had lower B-type natriuretic peptide levels (pinteraction = 0.038). CONCLUSIONS: A steroid-based strategy can simply and effectively identify individuals at higher HF risk who may derive benefit from more intensive follow-ups.

Knowledge map and hotspot analysis in climate resilience infrastructure (CRI) from 1997 to 2022 through scientometric analysis.

The global consensus is to reduce greenhouse gas emissions and actively respond to climate change (CC). Global warming has irreversibly altered the Earth's ecosystems. Unpredictable extreme weather events caused by CC are posing new risks to urban infrastructure. Infrastructure is one of the primary guarantees to maintain the stable operation of the city. Therefore, it is imperative to strengthen the climate resilience of infrastructure to avoid the loss of life and property caused by climate risks. This paper uses CiteSpace to analyze data in the field of climate resilience infrastructure (CRI) over the past 25 years. We find that global CRI research has transitioned through three stages. According to the geographic spatial distribution map drawn by ArcGIS, it can be found that developed countries account for a relatively large number of documents. The research institution is dominated by institutions of higher learning, with limited cooperation between institutions and loose organizational collaboration. CRI is composed of multi-disciplinary collaborative development, from a single discipline of environmental ecology or water resources to a research field integrating engineering, meteorology, sustainability, and energy. Urban resilience and Nature-based solutions are research hotspots. Small Island Developing States are major objects in the future. The research emphasis has shifted from addressing the multiple problems caused by CC to increasing the climate resilience of infrastructure to enhance the resistance of urban systems. Renewable energy and climate models are applied to infrastructure construction. In general, CRI is a effective measure that can help reduce environmental pollution, carbon emissions, and global climate regulation. In addition, we suggest taking cities as pilot projects in the future, increasing CRI projects and providing policy guidance for urban planning and construction.

Abnormal adenosine metabolism of neutrophils inhibits airway inflammation and remodeling in asthma model induced by Aspergillus fumigatus.

BACKGROUND: Neutrophils consume a large amount of energy when performing their functions. Compared with other white blood cells, neutrophils contain few mitochondria and mainly rely on glycolysis and gluconeogenesis to produce ATP. The inflammatory site is hypoxic and nutrient poor. Our aim is to study the role of abnormal adenosine metabolism of neutrophils in the asthmatic airway inflammation microenvironment. METHOD: In this study, an asthma model was established by intratracheal instillation of Aspergillus fumigatus extract in Ecto-5'-Nucleotidase (CD73) gene-knockout and wild-type mice. Multiple analyses from bronchoalveolar lavage fluid (BALF) were used to determine the levels of cytokines and chemokines. Immunohistochemistry was used to detect subcutaneous fibrosis and inflammatory cell infiltration. Finally, adenosine 5'-(α, ß-methylene) diphosphate (APCP), a CD73 inhibitor, was pumped subcutaneously before Aspergillus attack to observe the infiltration of inflammatory cells and subcutaneous fibrosis to clarify its therapeutic effect. RESULT: PAS staining showed that CD73 knockout inhibited pulmonary epithelial cell proliferation and bronchial fibrosis induced by Aspergillus extract. The genetic knockdownof CD73 significantly reduced the production of Th2 cytokines, interleukin (IL)-4, IL-6, IL-13, chemokine (C-C motif) ligand 5 (CCL5), eosinophil chemokine, neutrophil IL-17, and granulocyte colony-stimulating factor (G-CSF). In addition, exogenous adenosine supplementation increased airway inflammation. Finally, the CD73 inhibitor APCP was administered to reduce inflammation and subcutaneous fibrosis. CONCLUSION: Elevated adenosine metabolism plays an inflammatory role in asthma, and CD73 could be a potential therapeutic target for asthma.

[Factors analysis of worsening renal function in patients with acute right ventricular myocardial infarction during hospitalization].

Objective: To analyze the related factors of worsening renal function (WRF) in patients with acute right ventricular myocardial infarction (RVMI) during hospitalization. Methods: A total of 98 patients with acute RVMI admitted to the emergency comprehensive ward of Beijing Anzhen Hospital from August 2011 to January 2020 were enrolled in this cross-sectional study. According to the situation of WRF, the patients were divided into non-WRF group (76 cases) and WRF group (22 cases). WRF was defined as ≥0.3 mg/dL increase in serum creatinine level from baseline on day 6 of hospitalization (if hospital stay<6 days, it was at discharge). Baseline data, intravenous fluid infusion, diuretic and significant positive balance of patients' intake and output volume [any 24 h intakes and outputs ≥1 000 ml or any consecutive 72 h intakes and outputs ≥2 000 ml within 6 d of hospitalization (if hospitalization<6 d, it was from admission to discharge)] were obtained, and the differences of above indicators between the two groups were analyzed. Multiple logistic regression model was used to analyze the related factors of WRF. Results: The ages of patients in WRF group and non-WRF group were 60 (50, 68) and 63 (52, 72) years, and the male proportions were 63.6% (14 cases) and 76.3% (58 cases), respectively, and there was no significant difference (all P>0.05). The proportion of positive balance was 31.8% (7 cases) in WRF group, which was higher than 14.5% (11 cases) in non-WRF group (P=0.034). The rate of loop diuretic use in WRF group was 4.5% (1 case), lower than that in non-WRF group 10.5% (8 cases) (P=0.027). After adjusting for age, sex, baseline estimated glomerular filtration rate (eGFR), preoperative isoproterenol/temporary pacemaker/atropine use, significant positive balance of intake and output volume, and loop diuretic use, it was found that eGFR≥60 ml·min-1·1.73 m-2 and significant positive balance were associated with WRF, the OR (95%CI) were 0.71 (0.62-0.86) and 1.21 (1.02-1.43) (both P<0.05); After eliminating the variable of significant positive balance in the above model, loop diuretic use was found to be a correlation factor for WRF, with an OR (95%CI) of 0.89 (0.72-0.97) (P<0.05). Conclusions: Significant positive balance of intake and output volume during hospitalization in patients with acute RVMI is a risk factor for WRF on day 6 or at discharge. In the presence of a significant positive balance, loop diuretic use is a protective factor for WRF.

Intermittent Hypoxia Alleviates ß-Aminopropionitrile Monofumarate Induced Thoracic Aortic Dissection in C57BL/6 Mice.

OBJECTIVE: Thoracic aortic dissection (TAD) has a high mortality rate. Intermittent hypoxia (IH) triggers both harmful and beneficial effects in numerous physiological systems. The effects of IH on TAD development were explored in a mouse model. METHODS: ß-Aminopropionitrile monofumarate (BAPN) was used to induce TAD in C57BL/6 mice. Three week old male mice were treated with 1 g/kg/day BAPN in drinking water for four weeks and simultaneously subjected to IH (n = 30) (21%-5% O2, 90 s/cycle, 10 h/day, IH + BAPN group) or normoxia (n = 30) (21% O2, 24 h/day, BAPN group). Human VSMCs (HUASMCs) exposed to IH (30 min, 5% O2)/re-oxygenation (30 min, 21% O2) cycles with a maximum of 60 min/cycle to detect the effect of IH on HIF-1α and LOX via HIF-1α-siRNA. RESULTS: It was found that BAPN administration significantly increased the lumen size and wall thickness of aortas compared with the normal group, but was significantly reversed by IH exposure. Additionally, IH exposure significantly increased the survival rate of BAPN induced TAD (70% vs. 40%). Furthermore, IH exposure reduced BAPN induced elastin breaks and apoptosis of vascular smooth muscle cells. IH exposure also reversed BAPN induced upregulation of inflammation and extracellular matrix (ECM) degradation. Real time polymerase chain reaction (RT-PCR) confirmed that IH inhibited inflammation and ECM degradation related genes interleukin (IL)-1ß, IL-6, cathepsin S (Cat S), and matrix metalloproteinase 9 (MMP-9), but upregulated the ECM synthesis related genes lysyl oxidase (LOX) and collagen type I alpha2 (Col1a2) compared with the BAPN group. In vitro results suggest that IH promotes the expression of LOX via HIF-1α. CONCLUSION: The results suggest that IH alleviates BAPN induced TAD in C57BL/6 mice.

The Complement C3a-C3aR Axis Promotes Development of Thoracic Aortic Dissection via Regulation of MMP2 Expression.

Thoracic aortic dissection (TAD), once ruptured, is devastating to patients, and no effective pharmaceutical therapy is available. Anaphylatoxins released by complement activation are involved in a variety of diseases. However, the role of the complement system in TAD is unknown. We found that plasma levels of C3a, C4a, and C5a were significantly increased in patients with TAD. Elevated circulating C3a levels were also detected in the developmental process of mouse TAD, which was induced by ß-aminopropionitrile monofumarate (BAPN) treatment, with enhanced expression of C1q and properdin in mouse dissected aortas. These findings indicated activation of classical and alternative complement pathways. Further, expression of C3aR was obviously increased in smooth muscle cells of human and mouse dissected aortas, and knockout of C3aR notably inhibited BAPN-induced formation and rupture of TAD in mice. C3aR antagonist administered pre- and post-BAPN treatment attenuated the development of TAD. We found that C3aR knockout decreased matrix metalloproteinase 2 (MMP2) expression in BAPN-treated mice. Additionally, recombinant C3a stimulation enhanced MMP2 expression and activation in smooth muscle cells that were subjected to mechanical stretch. Finally, we generated MMP2-knockdown mice by in vivo MMP2 short hairpin RNA delivery using recombinant adeno-associated virus and found that MMP2 deficiency significantly reduced the formation of TAD. Therefore, our study suggests that the C3a-C3aR axis contributes to the development of TAD via regulation of MMP2 expression. Targeting the C3a-C3aR axis may represent a strategy for inhibiting the formation of TAD.

Association of C1q/TNF-Related Protein-9 (CTRP9) Level with Obstructive Sleep Apnea in Patients with Coronary Artery Disease.

BACKGROUND: Obstructive sleep apnea (OSA) is closely related to the incidence and progression of coronary artery disease (CAD), and the mechanisms linking OSA and CAD are multifactorial. C1q/TNF-related protein-9 (CTRP9) is a novel adipokine that protects the heart against ischemic injury and ameliorates cardiac remodeling. We aimed to ascertain the clinical relevance of CTRP9 with OSA prevalence in patients with CAD. METHODS: From August 2016 to March 2019, consecutive eligible patients with CAD (n = 154; angina pectoris, n = 88; acute myocardial infarction [AMI], n = 66) underwent cardiorespiratory polygraphy. OSA was defined as an apnea-hypopnea index (AHI) ≥15 events·h-1. Plasma CTRP9 concentrations were measured by ELISA method. RESULTS: Moderate/severe OSA was present in 89 patients (57.8%). CTRP9 levels were significantly decreased in the moderate/severe OSA group than in the no/mild OSA group (4.7 [4.1-5.2] ng/mL vs. 4.9 [4.4-6.0] ng/mL, P = 0.003). The difference between groups was only observed in patients with AMI (3.0 [2.3-4.9] vs. 4.5 [3.2-7.9], P = 0.009). Correlation analysis showed that CTRP9 levels were negatively correlated with AHI (r = -0.238, P = 0.003) and oxygen desaturation index (r = -0.234, P = 0.004) and positively correlated with left ventricular ejection fraction (r = 0.251, P = 0.004) in all subjects. Multivariate analysis showed that male gender (OR 3.099, 95% CI 1.029-9.330, P = 0.044), BMI (OR 1.148, 95% CI 1.040-1.268, P = 0.006), and CTRP9 levels (OR 0.726, 95% CI 0.592-0.890, P = 0.002) were independently associated with the prevalence of moderate/severe OSA. CONCLUSIONS: Plasma CTRP9 levels were independently related to the prevalence of moderate/severe OSA in patients with CAD, suggesting that CTRP9 might play a role in the pathogenesis of CAD exacerbated by OSA.

Magnitude of Soluble ST2 as a Novel Biomarker for Acute Aortic Dissection.

BACKGROUND: Misdiagnosis of acute aortic dissection (AAD) can lead to significant morbidity and death. Soluble ST2 (sST2) is a cardiovascular injury-related biomarker. The extent to which sST2 is elevated in AAD and whether sST2 can discriminate AAD from other causes of sudden-onset severe chest pain are unknown. METHODS: We measured plasma concentrations of sST2 (R&D Systems assay) in 1360 patients, including 1027 participants in the retrospective discovery set and 333 patients with initial suspicion of AAD enrolled in the prospective validation cohort. Measures of discrimination for differentiating AAD from other causes of chest pain were calculated. RESULTS: In the acute phase, sST2 levels were higher in patients with AAD than those with either acute myocardial infarction in the first case-control discovery set within 24 hours of symptom onset or with patients with pulmonary embolism in the second discovery set (medians of 129.2 ng/mL versus 14.7 with P<0.001 for AAD versus acute myocardial infarction and 88.6 versus 9.3 with P<0.001 for AAD versus pulmonary embolism). In the prospective validation set, sST2 was most elevated in patients with AAD (median [25th, 75th percentile]: 76.4 [49.6, 130.3]) and modestly elevated in acute myocardial infarction (25.0 [15.5, 37.2]), pulmonary embolism (14.9 [10.2, 30.1]), and angina patients (21.5 [13.1, 27.6], all P<0.001 versus AAD). The area under receiver operating characteristic curve for patients with AAD versus all control patients within 24 hours of presenting at the emergency department was 0.97 (0.95, 0.98) for sST2, 0.91 (0.88, 0.94) for D-dimer, and 0.50 (0.44, 0.56) for cardiac troponin I, respectively. At a cutoff level of 34.6 ng/mL, sST2 had a sensitivity of 99.1%, specificity of 84.9%, positive predictive value of 68.7%, negative predictive value of 99.7%, positive likelihood ratio of 6.6, and negative likelihood ratio of 0.01. CONCLUSIONS: Among patients with suspected aortic dissection in the emergency department, sST2 showed superior overall diagnostic performance to D-dimer or cardiac troponin I. Additional study is needed to determine whether sST2 might be a useful rule-out marker for AAD in the emergency room.

Complement 5a stimulates macrophage polarization and contributes to tumor metastases of colon cancer.

Inflammatory cells such as macrophages can play a pro-tumorigenic role in the tumor stroma. Tumor-associated macrophages (TAMs) generally display an M2 phenotype with tumor-promoting activity; however, the mechanisms regulating the TAM phenotype remain unclear. Complement 5a (C5a) is a cytokine-like polypeptide that is generated during complement system activation and is known to promote tumor growth. Herein, we investigated the role of C5a on macrophage polarization in colon cancer metastasis in mice. We found that deficiency of the C5a receptor (C5aR) severely impairs the metastatic ability of implanted colon cancer cells. C5aR was expressed on TAMs, which exhibited an M2-like functional profile in colon cancer liver metastatic lesions. Furthermore, C5a mediated macrophage polarization and this process relied substantially on activation of the nuclear factor-kappa B (NF-κB) pathway. Finally, analysis of human colon carcinoma indicated that C5aR expression is negatively associated with tumor differentiation grade. Our results demonstrate that C5aR has a central role in regulating the M2 phenotype of TAMs, which in turn, contributes to hepatic metastasis of colon cancer through NF-κB signaling. C5a is a potential novel marker for cancer prognosis and drugs targeting complement system activation, specifically the C5aR pathway, may offer new therapeutic opportunities for colon cancer management.

Interleukin-3 stimulates matrix metalloproteinase 12 production from macrophages promoting thoracic aortic aneurysm/dissection.

Thoracic aortic aneurysm and dissection (TAAD) is due to degeneration of the aorta and causes a high mortality rate, while molecular mechanisms for the development of TAAD are still not completely understood. In the present study, 3-aminopropionitrile (BAPN) treatment was used to induce TAAD mouse model. Through transcriptome analysis, we found the expression levels of genes associated with interleukin-3 (IL-3) signaling pathway were up-regulated during TAAD development in mouse, which were validated by real-time PCR. IL-3 positive cells were increased in TAAD mouse aortas, especially for smooth muscle cells (SMCs). IL-3 deficiency reduced BAPN-induced TAAD formation. We then examined the matrix metalloproteinases (MMPs) expression during TAAD formation in both wild-type and IL-3 deficient mice, showing that MMP12 were significantly down-regulated in IL-3 deficient aortas. Mechanistically, we found recombinant IL-3 could increase MMP12 production and activity from macrophages in vitro Silencing of IL-3 receptor ß, which was mainly expressed in macrophages but not SMCs, diminished the activation of c-Jun N terminal kinase (JNK)/extracellular-regulated protein kinases 1/2 (ERK1/2)/AP-1 signals, and decreased MMP12 expression in IL-3 stimulated macrophages. Moreover, both circulating and aortic inflammation were decreased in IL-3 deficient aortas. Taken together, our results demonstrated that IL-3 stimulated the production of MMP12 from macrophages by a JNK- and ERK1/2-dependent AP-1 pathway, contributing to TAAD formation. Thus, the IL-3/IL-3Rß/MMP12 signals activation may be an important pathological mechanism for progression of TAAD.

Endothelial Cell-Derived Microparticles from Patients with Obstructive Sleep Apnea Hypoxia Syndrome and Coronary Artery Disease Increase Aortic Endothelial Cell Dysfunction.

BACKGROUND/AIMS: Obstructive sleep apnea hypoxia syndrome (OSAHS) is an independent risk factor for coronary artery disease (CAD). Treatment of OSAHS improves clinical outcome in some CAD patients, but the relationship between OSAHS and CAD is complex. Microparticles (MPs) are shed by the plasma membrane by either physiologic or pathologic stimulation. In the current study, we investigated the role of MPs in the context of OSAHS. METHODS AND RESULTS: 54 patients with both suspected coronary artery stenosis and OSAHS were recruited and underwent both coronary arteriography and polysomnography. Circulating MPs were isolated and analyzed by flow cytometry. CAD+OSAHS patients exhibited greater levels of total MPs (Annexin V+), erythrocyte-derived MPs (CD235+ Annexin V+), platelet-derived MPs (CD41+ Annexin V+), and leukocyte-derived MPs (CD45+ Annexin V+) compared to CAD alone patients or control. CAD+OSAHS patients expressed the greatest level of endothelial-derived MPs of all cellular origin types (CD144+ Annexin V +). Treatment of human aortic endothelial cells (HAECs) with MPs isolated from CAD+OSAHS patients markedly increased HAEC permeability (as detected by FITC-dextran), and significantly upregulated mRNA levels of ICAM-1, VCAM-1, and MCP-1. CONCLUSION: OSAHS+CAD patients harbor increased levels of MPs, particularly the endothelial cell-derived subtype. When administered to HAECs, OSAHS+CAD patients MPs increase endothelial cell permeability and dysfunction.

ER stress dependent microparticles derived from smooth muscle cells promote endothelial dysfunction during thoracic aortic aneurysm and dissection.

The degeneration of vascular smooth muscle cell(s) (SMC) is one of the key features of thoracic aortic aneurysm and dissection (TAAD). We and others have shown that elevated endoplasmic reticulum (ER) stress causes SMC loss and TAAD formation, however, the mechanism of how SMC dysfunction contributes to intimal damage, leading to TAAD, remains to be explored. In the present study, in vitro assay demonstrated that elevated mechanical stretch (18% elongation, 3600 cycles/h) stimulated the ER stress response and microparticle(s) (MP) production from both SMC and endothelial cell(s) (EC) in a time-dependent manner. Treatment of EC with isolated MP led to anoikis, which was determined by measuring the fluorescence of the ethidium homodimer (EthD-1) and Calcein AM cultured in hydrogel-coated plates and control plates. MP stimulation of EC also up-regulated the mRNA levels of inflammatory molecules (i.e. Vascular cellular adhesion molecular-1 (VCAM-1)), intercellular adhesion molecular-1 (ICAM-1), interleukin-1ß (IL-1ß), and interleukin-6 (IL-6)). Use of an ER stress inhibitor or knockout of CHOP decreased mechanical stretch-induced MP production in SMC. In vivo, administration of an ER stress inhibitor or knockout of CHOP suppressed both apoptosis of EC and the infiltration of inflammatory cells. Moreover, TAAD formation was also suppressed by the administration of an ER stress inhibitor. In conclusion, our study demonstrates that elevated mechanical stretch induces MP formation in SMC leading to endothelial dysfunction, which is ER stress dependent. The inhibition of ER stress suppressed EC apoptosis, inflammation in the aorta, and TAAD development.

Intermedin1-53 Attenuates Abdominal Aortic Aneurysm by Inhibiting Oxidative Stress.

OBJECTIVE: Oxidative stress plays a critical role in the development of abdominal aortic aneurysm (AAA). Intermedin (IMD) is a regulator of oxidative stress. Here, we investigated whether IMD reduces AAA by inhibiting oxidative stress. APPROACH AND RESULTS: In angiotensin II-induced ApoE-/- mouse and CaCl2-induced C57BL/6J mouse model of AAA, IMD1-53 significantly reduced the incidence of AAA and maximal aortic diameter. Ultrasonography, hematoxylin, and eosin staining and Verhoeff-van Gieson staining showed that IMD1-53 significantly decreased the enlarged aortas and elastic lamina degradation induced by angiotensin II or CaCl2. Mechanistically, IMD1-53 attenuated oxidative stress, inflammation, vascular smooth muscle cell apoptosis, and matrix metalloproteinase activation. IMD1-53 inhibited the activation of redox-sensitive signaling pathways, decreased the mRNA and protein expression of nicotinamide adenine dinucleotide phosphate oxidase subunits, and reduced the activity of nicotinamide adenine dinucleotide phosphate oxidase in AAA mice. Expression of Nox4 was upregulated in human AAA segments and in angiotensin II-treated mouse aortas and was markedly decreased by IMD1-53. In vitro, vascular smooth muscle cells with small-interfering RNA knockdown of IMD showed significantly increased angiotensin II-induced reactive oxygen species, and small-interfering RNA knockdown of Nox4 markedly inhibited the reactive oxygen species. IMD knockdown further increased the apoptosis of vascular smooth muscle cells and inflammation, which was reversed by Nox4 knockdown. Preincubation with IMD17-47 and protein kinase A inhibitor H89 inhibited the effect of IMD1-53, reducing Nox4 protein levels. CONCLUSIONS: IMD1-53 could have a protective effect on AAA by inhibiting oxidative stress.

Sustained activation of ADP/P2ry12 signaling induces SMC senescence contributing to thoracic aortic aneurysm/dissection.

Thoracic aortic aneurysm/dissection (TAAD) is characterized by excessive smooth muscle cell (SMC) loss, extracellular matrix (ECM) degradation and inflammation. However, the mechanism whereby signaling leads to SMC loss is unclear. We used senescence-associated (SA)-ß-gal staining and analysis of expression of senescence-related proteins (p53, p21, p19) to show that excessive mechanical stretch (20% elongation, 3600cycles/h, 48h) induced SMC senescence. SMC senescence was also detected in TAAD specimens from both mice and humans. High-performance liquid chromatography and luciferin-luciferase-based assay revealed that excessive mechanical stretch increased adenosine diphosphate (ADP) release from SMCs both in vivo and in vitro. Elevated ADP induced SMC senescence while genetic knockout of the ADP receptor, P2Y G protein-coupled receptor 12 (P2ry12), in mice protected against SMC senescence and inflammation. Both TAAD formation and rupture were significantly reduced in P2ry12-/- mice. SMCs from P2ry12-/- mice were resistant to senescence induced by excessive mechanical stretch or ADP treatment. Mechanistically, ADP treatment sustained Ras activation, whereas pharmacological inhibition of Ras protected against SMC senescence and reduced TAAD formation. Taken together, excessive mechanical stress may induce a sustained release of ADP and promote SMC senescence via P2ry12-dependent sustained Ras activation, thereby contributing to excessive inflammation and degeneration, which provides insights into TAAD formation and progression.

Complement 5a Enhances Hepatic Metastases of Colon Cancer via Monocyte Chemoattractant Protein-1-mediated Inflammatory Cell Infiltration.

Complement 5a (C5a), a potent immune mediator generated by complement activation, promotes tumor growth; however, its role in tumor metastasis remains unclear. We demonstrate that C5a contributes to tumor metastases by modulating tumor inflammation in hepatic metastases of colon cancer. Colon cancer cell lines generate C5a under serum-free conditions, and C5a levels increase over time in a murine syngeneic colon cancer hepatic metastasis model. Furthermore, in the absence of C5a receptor or upon pharmacological inhibition of C5a production with an anti-C5 monoclonal antibody, tumor metastasis is severely impaired. A lack of C5a receptor in colon cancer metastatic foci reduces the infiltration of macrophages, neutrophils, and dendritic cells, and the role for C5a receptor on these cells were further verified by bone marrow transplantation experiments. Moreover, C5a signaling increases the expression of the chemokine monocyte chemoattractant protein-1 and the anti-inflammatory molecules arginase-1, interleukin 10, and transforming growth factor ß, but is inversely correlated with the expression of pro-inflammatory molecules, which suggests a mechanism for the role of C5a in the inflammatory microenvironment required for tumor metastasis. Our results indicate a new and potentially promising therapeutic application of complement C5a inhibitor for the treatment of malignant tumors.

Whole Transcriptome Analysis of Hypertension Induced Cardiac Injury Using Deep Sequencing.

BACKGROUND/AIMS: Hypertension plays a critical role in the cardiac inflammation and injury. However, the mechanism of how hypertension causes the cardiac injury at a molecular level remains to be elucidated. METHODS: RNA-Seq has been demonstrated to be an effective approach for transcriptome analysis, which is essential to reveal the molecular constituents of cells and tissues. In this study, we investigated the global molecular events associated with the mechanism of hypertension induced cardiac injury using RNA-Seq analysis. RESULTS: Our results showed that totally 1,801 genes with different expression variations were identified after Ang II infusion at 1, 3 and 7 days. Go analysis showed that the top 5 high enrichment Go terms were response to stress, response to wounding, cellular component organization, cell activation and defense response. KEGG pathway analysis revealed the top 5 significantly overrepresented pathways were associated with ECM-receptor interaction, focal adhesion, protein digestion and absorption, phagosome and asthma. Moreover, protein-protein interaction network analysis indicated that ubiquitin C may play a key role in the processes of hypertension-induced cardiac injury. CONCLUSION: Our study provides a comprehensive understanding of the transcriptome events in hypertension-induced cardiac pathology.

Identification of multiple ACVRL1 mutations in patients with pulmonary arterial hypertension by targeted exome capture.

Pulmonary artery hypertension (PAH) is characterized as sustained elevation of pressure in the pulmonary vascular system that is attributable to a variety of causes. More than a dozen genes have previously been proposed as being associated with PAH. To examine potential mutations of these genes in patients with PAH, we developed a targeted exome kit containing 22 PAH-associated genes for genetic screens of 80 unrelated patients with PAH. As a result, we identified 16 different mutations in the BMPR2 gene and four different mutations in ACVRL1, the gene for activin receptor-like kinase-1 (ACVRL1). However, no deleterious mutations were found in the remaining 20 genes. In the present study, we provided detailed characterization of the ACVRL1 mutations in four pedigrees, including two novel missense mutations (c.676G>A, p.V226M; c.955G>C, p.G319R) and two recurrent mutations (c.1231C>T, p.R411W; c.1450C>T, p.R484W). Furthermore, we showed that markedly reduced Smad1/5 phosphorylation levels and reduced activities of luciferase reporters in each of the four ACVRL1 mutant-transfected NIH-3T3 cells. Therefore, our findings demonstrated that missense mutations of ACVRL1 identified in the present study significantly affected the bone morphogenetic protein 9 (BMP-9) pathway, implicating PAH pathogenesis. Detailed genotype-phenotype correlation analysis revealed initial symptoms of hereditary haemorrhagic telangiectasia (HHT) in some of the patients, suggesting the importance of sequencing molecular markers for early identification and intervention of individuals at risk for PAH and potential HHT. We developed a customized exome sequencing system to identify mutations in these PAH-associated genes, and found two novel missense mutations and two recurrent mutations in the ACVRL1 gene in four unrelated Chinese families; we also determined hypomorphic alleles using functional studies.

Mechanical stretch-induced endoplasmic reticulum stress, apoptosis and inflammation contribute to thoracic aortic aneurysm and dissection.

Thoracic aortic aneurysm/dissection (TAAD) is characterized by excessive smooth muscle cell (SMC) loss, extracellular matrix (ECM) degradation and inflammation. In response to certain stimuli, endoplasmic reticulum (ER) stress is activated and regulates apoptosis and inflammation. Excessive apoptosis promotes aortic inflammation and degeneration, leading to TAAD. Therefore, we studied the role of ER stress in TAAD formation. A lysyl oxidase inhibitor, 3-aminopropionitrile fumarate (BAPN), was administrated to induce TAAD formation in mice, which showed significant SMC loss (α-SMA level). Excessive apoptosis (TUNEL staining) and ER stress (ATF4 and CHOP), along with inflammation, were present in TAAD samples from both mouse and human. Transcriptional profiling of SMCs after mechanical stress demonstrated the expression of genes for ER stress and inflammation. To explore the causal role of ER stress in initiating degenerative signalling events and TAAD, we treated wild-type (CHOP(+/+)) or CHOP(-/-) mice with BAPN and found that CHOP deficiency protected against TAAD formation and rupture, as well as reduction in α-SMA level. Both SMC apoptosis and inflammation were significantly reduced in CHOP(-/-) mice. Moreover, SMCs isolated from CHOP(-/-) mice were resistant to mechanical stress-induced apoptosis. Taken together, our results demonstrated that mechanical stress-induced ER stress promotes SMCs apoptosis, inflammation and degeneration, providing insight into TAAD formation and progression.