The gut microbiota in experimental abdominal aortic aneurysm.

Background: Abdominal aortic aneurysm (AAA) is a life-threatening disease and there are no effective treatments to inhibit aneurysm progression and rupture. The gut microbiota has been increasingly recognized, as a new therapeutic target, because of its role in host homeostasis. However, the role of the gut microbiota in AAA has not been clarified. Therefore, we performed 16S rRNA analysis to determine and compare the composition of the gut microbiota between AAA and control groups. Methods: We used the classical angiotensin-II induced AAA mouse model to investigate the role of gut microbiota and abdominal aortic aneurysm. The mice were randomly assigned to 2 groups: the control (n = 7) group received saline (vehicle), while the AAA (n = 13) group received solutions of Ang II. Aortic tissue and fecal samples were harvested 28 days after infusion. Fecal samples were analyzed by 16S rRNA sequencing. Results: The levels of Oscillospira, Coprococcus, Faecalibacterium prausnitzii, Alistipes massiliensis, and Ruminococcus gnavus were increased in the AAA group, while those of Akkermansia muciniphila, Allobaculum, and Barnesiella intestinihominis were increased in the control group. Furthermore, network analysis and ZiPi score assessment highlighted species in the phylum Bacteroidetes as the keystone species. PICRUSt2 analysis revealed that PWY-6629 (a super pathway of L-tryptophan biosynthesis), PWY-7446 (sulfoglycolysis), and PWY-6165 [chorismate biosynthesis II (archaea)] may-be involved in the metabolic pathways that contribute to AAA formation, and E. coli/Shigella may be the key bacteria that influence those three pathways. Conclusion: Alterations in the gut microbiota may be associated with the formation of AAA. Akkermansia and Lactobacillus were significantly decreased in the AAA group, but the keystone species in the phylum Bacteroidetes and the metabolic products of these bacteria should be given more attention in AAA formation research.

Endothelial cell-derived tetrahydrobiopterin prevents aortic valve calcification.

AIMS: Tetrahydrobiopterin (BH4) is a critical determinant of the biological function of endothelial nitric oxide synthase. The present study was to investigate the role of valvular endothelial cell (VEC)-derived BH4 in aortic valve calcification. METHODS AND RESULTS: Plasma and aortic valve BH4 concentrations and the BH4:BH2 ratio were significantly lower in calcific aortic valve disease patients than in controls. There was a significant decrease of the two key enzymes of BH4 biosynthesis, guanosine 5'-triphosphate cyclohydrolase I (GCH1) and dihydrofolate reductase (DHFR), in calcified aortic valves compared with the normal ones. Endothelial cell-specific deficiency of Gch1 in Apoe-/- (Apoe-/-Gch1fl/flTie2Cre) mice showed a marked increase in transvalvular peak jet velocity, calcium deposition, runt-related transcription factor 2 (Runx2), dihydroethidium (DHE), and 3-nitrotyrosine (3-NT) levels in aortic valve leaflets compared with Apoe-/-Gch1fl/fl mice after a 24-week western diet (WD) challenge. Oxidized LDL (ox-LDL) induced osteoblastic differentiation of valvular interstitial cells (VICs) co-cultured with either si-GCH1- or si-DHFR-transfected VECs, while the effects could be abolished by BH4 supplementation. Deficiency of BH4 in VECs caused peroxynitrite formation increase and 3-NT protein increase under ox-LDL stimulation in VICs. SIN-1, the peroxynitrite generator, significantly up-regulated alkaline phosphatase (ALP) and Runx2 expression in VICs via tyrosine nitration of dynamin-related protein 1 (DRP1) at Y628. Finally, folic acid (FA) significantly attenuated aortic valve calcification in WD-fed Apoe-/- mice through increasing DHFR and salvaging BH4 biosynthesis. CONCLUSION: The reduction in endothelial-dependent BH4 levels promoted peroxynitrite formation, which subsequently resulted in DRP1 tyrosine nitration and osteoblastic differentiation of VICs, thereby leading to aortic valve calcification. Supplementation of FA in diet attenuated hypercholesterolaemia-induced aortic valve calcification by salvaging BH4 bioavailability.

Intraoperative blood transfusion volume is an independent risk factor for postoperative acute kidney injury in type A acute aortic dissection.

BACKGROUND: Type A acute aortic dissection is a life-threatening disease associated with adverse clinical outcomes. Acute kidney injury (AKI) is common after surgery. However, the relationship between intraoperative blood transfusion and postoperative AKI remains unclear. METHODS: The records of 130 patients who underwent type A acute aortic dissection surgery from January 2015 to December 2018 were retrospectively analyzed. According to the Kidney Disease Improving Global Outcomes criteria, postoperative AKI was defined based on serum creatinine concentration. Multivariable logistic regression analysis was applied to estimate the independent association between intraoperative blood transfusion volume and the risk of postoperative AKI. RESULTS: Postoperative AKI was observed in 82 patients (63.08%). The in-hospital mortality was 16.15% (n = 21). Multivariate logistic regression showed that the amount of intraoperative blood transfusion was independently associated with the risk of postoperative AKI in a dose-dependent manner. Every 200 ml increment of blood transfusion volume was associated with a 31% increase in AKI risk (odds ratio 1.31 and 95% confidence interval 1.01-1.71). CONCLUSIONS: Intraoperative transfusion volume may increase the incidence of postoperative AKI. The mechanism and influence of transfusion thresholds on AKI need to be explored in the future.

Downregulation of miR­142­5p inhibits human aortic smooth muscle cell proliferation and migration by targeting MKL2.

The increased proliferation and migration of vascular smooth muscle cells (VSMCs) are critical in the progression of atherosclerosis (AS). Platelet­derived growth factor type BB (PDGF­BB) may induce VSMC proliferation and migration. miR­142­5p plays a critical role in various biological processes, including tumorigenesis, angiogenesis and inflammation. However, whether miR­142­5p is involved in regulating the pathological process of arteriosclerosis remains to be elucidated. Therefore, in this study, the role of miR­142­5p in PDGF­BB­induced human aortic smooth muscle cell (HSAMC) proliferation and migration was investigated. The results revealed that the expression level of miR­142­5p was enhanced in the serum of patients with AS, while that of its target gene, myocardin­like protein 2 (MKL2) was decreased, compared with that in healthy volunteers. Moreover, there was a negative correlation between miR­142­5p and MKL2 expression in the serum of patients with AS. Furthermore, the downregulation of miR­142­5p inhibited PDGF­BB­induced HASMC proliferation and migration; however, the inhibition of HASMC proliferation and migration was reversed by co­transfection with small interfering RNA (siRNA) against MKL2 (siRNA­MKL2). In addition, transfection with miR­142­5p inhibitor significantly increased the expression levels of MKL2, and decreased those of matrix metalloproteinase (MMP)2 and 9, and these effects were reversed by transfection with siRNA­MKL2. Finally, MKL2 was proven to be a target of miR­142­5p. On the whole, the findings of the present study demonstrate that the downregulation of miR­142­5p inhibits human aortic smooth muscle cell (HSAMC) proliferation and migration possibly by targeting MKL2. Hence, miR­142­5p may prove to be a novel therapeutic target in the treatment of AS.

Experimental abdominal aortic aneurysm growth is inhibited by blocking the JAK2/STAT3 pathway.

BACKGROUND: The JAK/STAT pathway is a vital transcription signaling pathway that regulates gene expression and cellular activity. Our recently published study highlighted the role of IL-17A in abdominal aortic aneurysm (AAA) formation and rupture. IL-17A has been proven to upregulate vascular endothelial growth factor (VEGF) expression in some diseases. However, no study has demonstrated the relationships among JAK2/STAT3, IL-17A and VEGF. Therefore, we hypothesized that IL-17A may up-regulate VEGF expression via the JAK2/STAT3 signaling pathway to amplify the inflammatory response, exacerbate neovascularization, and accelerate AAA progression. METHODS: To fully verify our hypothesis, two separate studies were performed: i) a study investigating the influence of JAK2/STAT3 on AAA formation and progression. ii) a study evaluating the relationship among IL-17A, JAK2/STAT3 and VEGF. Human tissues were collected from 7 AAA patients who underwent open surgery and 7 liver transplantation donors. All human aortic tissues were examined by histological and immunohistochemical staining, and Western blotting. Furthermore, mouse aortic tissues were also examined by histological and immunohistochemical staining and Western blotting, and the mouse aortic diameters were assessed by high-resolution Vevo 2100 microimaging system. RESULTS: Among human aortic tissues, JAK2/STAT3, IL-17A and VEGF expression levels were higher in AAA tissues than in control tissues. Group treated with WP1066 (a selective JAK2/STAT3 pathway inhibitor), IL-17A, and VEGF groups had AAA incidences of 25%, 40%, and 65%, respectively, while the control group had an incidence of 75%. Histopathological analysis revealed that the IL-17A- and VEGF-related inflammatory responses were attenuated by WP1066. Thus, blocking the JAK2/STAT3 pathway with WP1066 attenuated experimental AAA progression. In addition, in study ii, we found that IL-17A siRNA seemed to attenuate the expression of IL-17A and VEGF in vivo study; treatment with VEGF siRNA decreased the expression of VEGF, while IL-17A expression remained high. In an in vitro study, rhIL-17A treatment increased JAK2/STAT3 and VEGF expression in macrophages in a dose-dependent manner. CONCLUSION: Blocking the JAK2/STAT3 pathway with WP1066 (a JAK2/STAT3 specific inhibitor) attenuates experimental AAA progression. During AAA progression, IL-17A may influence the expression of VEGF via the JAK2/STAT3 signaling pathway. This potential mechanism may suggest a novel strategy for nonsurgical AAA treatment.

MicroRNA-16-5p Aggravates Myocardial Infarction Injury by Targeting the Expression of Insulin Receptor Substrates 1 and Mediating Myocardial Apoptosis and Angiogenesis.

PURPOSE: Myocardial infarction is a common cardiovascular disease. MicroRNA-16-5p (miR-16-5p) was upregulated in heart and kidney hypoxia/reoxygenation (H/R) injury. However, the role of miR-16-5p in myocardial infarction injury is still unclear. METHODS: Human adult ventricular cardiomyocytes (AC16) were treated with ischemia/reperfusion (H/R). The miR-16-5p level was evaluated through real-time PCR. The activity of lactate dehydrogenase (LDH) and creatine kinase-MB (CK-MB) was detected via LDH and CK-MB monitoring kits. Cell viability was examined with 3-(4,5-dimethylthiazol-2-yl)-2,5diphenyltetra-zolium bromide (MTT) assay. Western blotting was used to analyze the protein levels. The luci-ferase report assay confirmed the relative luciferase activity. RESULTS: miR-16-5p was elevated in H/R-treated AC16 cells. miR-16-5p overexpression and knockdown were carried out. miR-16-5p knockdown repressed cell apoptosis, attenuated LDH and CK-MB activities, and enhanced cell viability in H/R-treated AC16 cells. Moreover, miR-16-5p knockdown promoted angiogenesis in human microvascular endothelial cells (HMVEC), causing elevation of vascular endothelial growth factor (VEGF), insulin receptor substrates 1 (IRS1), minichromosome maintenance complex component 2 (MCM2) and proliferating cell nuclear antigen (PCNA) protein levels. Moreover, miR-16-5p was testified to target IRS1. IRS1 silencing alleviated miR-16-5p knockdown-mediated inhibition of apoptosis in AC16 cells. CONCLUSION: miR-16-5p knockdown increased cell viability and angiogenesis, as well as inhibited cell apoptosis by increasing IRS1. These findings indicated that miR-16-5p knockdown may be a new therapeutic target for myocardial infarction.

TROVE2 strengthens the anti-inflammatory effect via macrophage polarization by estrogen induction in abdominal aortic aneurysm.

Abdominal Aortic Aneurysm (AAA) is a severe cardiovascular disease, with high mortality rate after acute rupture of blood vessels. However, the underlying pathogenesis of different morbidity between men and women remains unclear. In the present study, we first selected four datasets including 68 AAA and 32 control samples from published data on GEO database, and analyzed them by data mining. The integrative analysis found a total of 368 differentially expressed genes in E2-related AAA. Next, regulatory mechanism networks among these target genes were predicted, and four genes were identified as key nodes in the network, which play a major role in the immune system. We focused on the role of monocytes/macrophages in the development of cardiovascular diseases to further explore the role of estrogen in the polarization of monocytes/macrophage, the mRNA level of the four genes was validated by RT-PCR in RAW264.7 cells treated with ß-estradiol (E2), diarylpropionitrile (DPN), 1,3,5-Tris(4-hydroxyphenyl)-4-propyl-1H-pyrazole (PPT), fulvestrant or vehicle. The results showed that the mRNA level and protein level of TROVE2 was significantly increased in estrogen or estrogen receptor agonist-treated groups. Moreover, estrogen affected the transformation of macrophages to M2 phenotype by detecting M1- and M2-related indicator genes at the mRNA level. Flow cytometry demonstrated that the TROVE2 deficiency led to a notable decrease in the level of M2 phenotype marker protein CD206. In conclusion, our results suggest that E2 can promote the expression of TROVE2, which is closely related to the M2-phenotype transformation of macrophages.

Targeting the class IA PI3K isoforms p110α/δ attenuates heart allograft rejection in mice by suppressing the CD4+ T lymphocyte response.

Acute rejection is the most important factor causing allograft loss, which remains a challenge for patients undergoing organ transplantation. There is considerable evidence indicating that the activity of PI3K and its downstream positive and negative regulators plays a major role in regulating the activation of different subsets of effector CD4+ T cells. Thus, we investigated whether class A PI3Ks are involved in the development of acute allograft rejection, we found that p110α protein expression levels in the allograft group were significantly up-regulated on day 7 post-transplantation, while p110ß and p110δ expression was significantly increased on days 5 and 7 post-transplantation. Treatment with PIK and IC but not TGX significantly prolonged allograft survival and altered pathological grades. The percentages of Th1 and Th2, Th17 and Tfh cells/monocytes in the spleens from the IC treatment group were all down-regulated. In contrast, the percentage of Treg cells in the spleens from IC treatment group was remarkably increased. IL-17A and IL-21 and IFN-γ expression levels were significantly decreased in the IC group. Moreover, IC significantly reduced P70 S6 Kinase ß and 4E-BP1 protein expression. In conclusion, small-molecule inhibitors of p110δ and p110α suppress acute heart allograft rejection in mice. These inhibitors may play a role in anti-rejection by impacting the phosphorylation and expression of proteins in the AKT/mTOR pathway to modulate CD4+ T cell subsets levels in recipients, reduce proinflammatory factor expression and increase anti-inflammatory cytokine expression. These findings indicate that some small-molecule inhibitors of p110 can serve as novel targets in acute allograft rejection treatment.

Incidence of atrial fibrillation after off-pump versus on-pump coronary artery bypass grafting: A meta-analysis of randomized clinical trials and propensity score matching trials.

The association between atrial fibrillation (AF) after coronary artery bypass grafting (CABG) and the surgical techniques selected has been extensively reported. However, no consistent results were obtained. In the present study, a meta-analysis was conducted by searching the electronic databases PubMed, Embase, Web of Science, and Cochrane to identify the association of post-CABG AF with on-pump (conventional CABG, cCABG) or off-pump CABG (OPCABG). Outcomes from randomized clinical trials (RCTs) and propensity score matching (PSM) trials were pooled by using the fixed-effect or the random-effect modeling method, and verified by the quality-effect modeling method. There were 35 studies with 36 independent reports that met the inclusion criteria and were eventually included in our meta-analysis. The total odds ratio (OR) of the incidence of post-CABG AF between OPCABG and cCABG was 0.80 (95% CI 0.71-0.91). The 25 randomized clinical trials (RCTs) had an OR of 0.69 (95% CI 0.56-0.86), while the OR of the 11 PSM trials was 0.88 (95% CI 0.77-1.00). Twenty-six studies involving the patients at a mean age no more than 65 years showed an OR of 0.76 (95% CI 0.64-0.90), whereas 10 studies with patients greater than 65 years old showed an OR of 0.90 (95% CI 0.78-1.05). The results of this meta-analysis suggest that OPCAB surgery may reduce the incidence of post-CABG AF when compared to cCABG and that younger patients may benefit more from OPCAB and have a lower incidence of post-CABG AF.

MicroRNA-193-5p modulates angiogenesis through IGF2 in type 2 diabetic cardiomyopathy.

BACKGROUND: Patients with diabetic cardiomyopathy are often associated with increasing risk of heart failure. In this work, we used animal model to characterize the angiogenic effect of microRNA-193-5p, miR-193-5p in type 2 diabetic Goto-Kakizaki (GK) rats' myocardial microvascular endothelial cells, MMEC(GK). METHODS: MiR-193-5p in MMEC(GK) was compared to its expression in Wistar rat MMEC. In MMEC(GK), miR-193-5p was downregulated through viral infection. Its angiogenic effects on MMEC(GK) migration and proliferation were assessed by transwell and MTT assays, respectively. Downstream target of miR-193-5p, insulin growth factor 2 (IGF2), was assessed by dual-luciferase activity, qRT-PCR and western blot assays, respectively. In miR-193-5p-downregulated MMEC(GK), IGF2 was further de-regulated to assess its mechanism in miR-193-5p-downreuglation induced angiogenic regulation. RESULTS: MiR-193-5p is overexpressed in MMEC(GK). Its downregulation has significantly angiogenic effect by inducing migration and proliferation in MMEC(GK). IGF2 was demonstrated to be directly regulated by miR-193-5p in MMEC(GK). In addition, IGF2 inhibition in miR-193-5p-downregulated MMEC(GK)'s severely hindered cell migration and proliferation. CONCLUSION: MiR-193-5p is an active angiogenic factor in diabetic cardiomyopathy, possibly through inverse regulation on its downstream IGF2 gene.

Incidence of Atrial Fibrillation after Off-pump versus On-pump Coronary Artery Bypass Grafting: A Meta-analysis of Randomized Clinical Trials and Propensity Score Matching Trials / 华中科技大学学报（医学）（英德文版）

The association between atrial fibrillation (AF) after coronary artery bypass grafting (CABG) and the surgical techniques selected has been extensively reported.However,no consistent results were obtained.In the present study,a meta-analysis was conducted by searching the electronic databases PubMed,Embase,Web of Science,and Cochrane to identify the association of post-CABG AF with on-pump (conventional CABG,cCABG) or off-pump CABG (OPCABG).Outcomes from randomized clinical trials (RCTs) and propensity score matching (PSM) trials were pooled by using the fixed-effect or the random-effect modeling method,and verified by the quality-effect modeling method.There were 35 studies with 36 independent reports that met the inclusion criteria and were eventually included in our meta-analysis.The total odds ratio (OR) of the incidence of post-CABG AF between OPCABG and cCABG was 0.80 (95％ CI 0.71-0.91).The 25 randomized clinical trials (RCTs) had an OR of 0.69 (95％ CI 0.56-0.86),while the OR of the 11 PSM trials was 0.88 (95％ CI 0.77-1.00).Twenty-six studies involving the patients at a mean age no more than 65 years showed an OR of 0.76 (95％ CI 0.64-0.90),whereas 10 studies with patients greater than 65 years old showed an OR of 0.90 (95％ CI 0.78-1.05).The results of this meta-analysis suggest that OPCAB surgery may reduce the incidence of post-CABG AF when compared to cCABG and that younger patients may benefit more from OPCAB and have a lower incidence ofpost-CABG AF.

[Relative factors of recent discovered atrial fibrillation following isolated coronary artery bypass grafting].

OBJECTIVE: To identify the relative factors of recent discovered atrial fibrillation (AF) following isolated coronary artery bypass grafting (CABG). METHODS: Classified the 649 cases undergoing isolated CABG from January 2005 to December 2006 to two groups according to whether AF appeared after operation. Collected the peri-operative data and operative strategy, then analyzed with single-factor analysis and Logistic regression. RESULTS: The incidence of AF was 8.0% (52 cases), and 84.6% (44 cases) recovered sinus-rhythm leaving hospital. Age, standard European system for cardiac operative risk evaluation (EuroSCORE), ratio of high-operative-risk, left atrium diameter and ratio of left coronary artery dominance were higher in AF group than in non-AF group. Age, eject fraction, left atrium diameter, operative risk evaluation, left coronary artery dominance and anastomosis on right coronary artery were the relative factors of recent discovered AF following isolated CABG. But off-pump operation, prescription of adrenergic beta-antagonists pre-operatively and degree of coronary artery stenosis had no influence to AF. CONCLUSIONS: AF following CABG is a result of common influence by many factors. EuroSCORE might forecast partially the incidence of AF following CABG. Improve the myocardial protection and reduce the surgical damage during operative progress maybe the mostly approach to decrease the incidence of AF following CABG.