Endothelial extracellular vesicles induce acute lung injury via follistatin-like protein 1.

Cardiopulmonary bypass has been speculated to elicit systemic inflammation to initiate acute lung injury (ALI), including acute respiratory distress syndrome (ARDS), in patients after cardiac surgery. We previously found that post-operative patients showed an increase in endothelial cell-derived extracellular vesicles (eEVs) with components of coagulation and acute inflammatory responses. However, the mechanism underlying the onset of ALI owing to the release of eEVs after cardiopulmonary bypass, remains unclear. Plasma plasminogen-activated inhibitor-1 (PAI-1) and eEV levels were measured in patients with cardiopulmonary bypass. Endothelial cells and mice (C57BL/6, Toll-like receptor 4 knockout (TLR4-/-) and inducible nitric oxide synthase knockout (iNOS-/-)) were challenged with eEVs isolated from PAI-1-stimulated endothelial cells. Plasma PAI-1 and eEVs were remarkably enhanced after cardiopulmonary bypass. Plasma PAI-1 elevation was positively correlated with the increase in eEVs. The increase in plasma PAI-1 and eEV levels was associated with post-operative ARDS. The eEVs derived from PAI-1-stimulated endothelial cells could recognize TLR4 to stimulate a downstream signaling cascade identified as the Janus kinase 2/3 (JAK2/3)-signal transducer and activator of transcription 3 (STAT3)-interferon regulatory factor 1 (IRF-1) pathway, along with iNOS induction, and cytokine/chemokine production in vascular endothelial cells and C57BL/6 mice, ultimately contributing to ALI. ALI could be attenuated by JAK2/3 or STAT3 inhibitors (AG490 or S3I-201, respectively), and was relieved in TLR4-/- and iNOS-/- mice. eEVs activate the TLR4/JAK3/STAT3/IRF-1 signaling pathway to induce ALI/ARDS by delivering follistatin-like protein 1 (FSTL1), and FSTL1 knockdown in eEVs alleviates eEV-induced ALI/ARDS. Our data thus demonstrate that cardiopulmonary bypass may increase plasma PAI-1 levels to induce FSTL1-enriched eEVs, which target the TLR4-mediated JAK2/3/STAT3/IRF-1 signaling cascade and form a positive feedback loop, leading to ALI/ARDS after cardiac surgery. Our findings provide new insight into the molecular mechanisms and therapeutic targets for ALI/ARDS after cardiac surgery.

Outcomes of Selective Strategies for Distal Entry Tears After Thoracic Endovascular Aortic Repair in Type B Aortic Dissection.

BACKGROUND: Distal entry tears have undesirable influence in type B aortic dissection (TBAD) after thoracic endovascular aortic repair (TEVAR), including inhibition of aortic remolding and increase of late aortic events. Therefore, distal entry tears should be managed. Nowadays, main strategies for managing distal entry tears included total and selective strategies. However, which strategy is better still remains controversial. The objective of the study is to investigate the outcomes of selective strategy for distal entry tears after TEVAR in TBAD. METHODS: A total of 43 consecutive patients with TBAD with distal entry tears after TEVAR were administered with selective strategy for distal entry tears, including occlusion of the tear in the thoracic aortic segment, thrombosis of the reverse blood flow channel in the false lumen, and selective occlusion of distal entry tears. Mortality, complications, and aortic remolding in early follow-up (12 months after operation) were analyzed. RESULTS: All 43 patients survived during the follow-up period. Operation was performed again for femoral artery reconstruction in 1 patient who had occlusion of the approach vessel during the follow-up period, and the remaining 42 patients had no uncomfortable symptoms and operation-related complications. The maximum diameter of the aorta was 32.03 ± 6.35 mm and 27.36 ± 4.92 mm, respectively, for before and after reintervention, and the difference was significant (t = 5.899, P < 0.001). The unthrombotic range of the false lumen after reintervention was significantly shrunken in all patients, compared with the range before reintervention. CONCLUSIONS: Selective strategy was safe and effective, at least in early follow-up. Its effectiveness should be further verified by more clinical observation results and long-term follow-up results.

Endothelial microparticles are increased in congenital heart diseases and contribute to endothelial dysfunction.

BACKGROUND: We previously demonstrated that endothelial microparticles (EMPs) are increased in mitral valve diseases and impair valvular endothelial cell function. Perioperative systemic inflammation is an important risk factor and complication of cardiac surgery. In this study, we investigate whether EMPs increase in congenital heart diseases to promote inflammation and endothelial dysfunction. METHODS: The level of plasma EMPs in 20 patients with atrial septal defect (ASD), 23 patients with ventricular septal defect (VSD), and 30 healthy subjects were analyzed by flow cytometry. EMPs generated from human umbilical vascular endothelial cells (HUVECs) were injected into C57BL6 mice, or cultured with HUVECs without or with siRNAs targeting P38 MAPK. The expression and/or phosphorylation of endothelial nitric oxide synthase (eNOS), P38 MAPK, and caveolin-1 in mouse heart and/or in cultured HUVECs were determined. We evaluated generation of nitric oxide (NO) in mouse hearts, and levels of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in cultured HUVECs and in mice. RESULTS: EMPs were significantly elevated in patients with ASD and VSD, especially in those with pulmonary hypertension when compared with controls. EMPs increased caveolin-1 expression and P38 MAPK phosphorylation and decreased eNOS phosphorylation and NO production in mouse hearts. EMPs stimulated P38 MAPK expression, TNF-α and IL-6 production, which were all inhibited by siRNAs targeting P38 MAPK in cultured HUVECs. CONCLUSIONS: EMPs were increased in adult patients with congenital heart diseases and may contribute to increased inflammation leading to endothelial dysfunction via P38 MAPK-dependent pathways. This novel data provides a potential therapeutic target to address important complications of surgery of congenial heart disease.

Association between prothrombin gene polymorphisms and hereditary thrombophilia in Xinjiang Kazakhs population.

To assess the association between polymorphisms of prothrombin gene and hereditary thrombophilia in Xinjiang Kazakhs population. Through cross-sectional investigation, permanent Kazakh population of Ili Kazakh Autonomous Prefecture was selected as the study object to measure their antithrombin III (AT-III), protein C, protein S activity and activated C protein resistance value, thus defining the situation of the crowd's hereditary thrombophilia. Sequenom Massarray detection technology was used to conduct a genotype test of the six sites selected by the case and control groups. Haploview software was used to perform linkage disequilibrium analysis of the six sites, and the impact of the interaction between genetic variations and environment on hereditary thrombophilia was researched by the use of sum model. A total of 1005 Kazakh volunteers participated in the test (332 men and 673 women), average age (41.13 ±â€Š11.50) years; the prevalence of hereditary thrombophilia in Xinjiang Kazakh population was 31.0%, and the prevalence of AT-III deficiency, protein C deficiency, protein S deficiency and activated protein C resistance was 16.4, 14.9, 20.6 and 7.8%, respectively. The difference in allele frequency of the hereditary thrombophilia patient group at rs3136447 and rs5896 sites was statistically significant (P = 0.0483 and P = 0.0302, respectively). rs5896 and rs2070852 had high linkage disequilibrium (r = 0.99), and constituted a single-domain block 1. The rs3136447 and the rs5896 polymorphisms located in the region of the prothrombin gene may be associated with hereditary thrombophilia in the Xinjiang Kazakhs population. There is additive interactive effect of rs5896 polymorphism (CT + TT) and smoke on hereditary thrombophilia.

A simple modification results in greater success in the model of coronary artery ligation and myocardial ischemia in mice.

Mouse models of myocardial ischemic preconditioning (IPC) and ischemic postconditioning (IPD) have proven to be very useful models of cardiovascular diseases. In 2010, Gao described a novel procedure without the aid of mechanical ventilation. However, the technique of heart externalization could not be applied to mouse models of IPC or IPD due to the limited time frame of the technique. We proposed a modified simple and safe method using lung recruitment and short-term ventilation to perform the procedure in mice with IPC or IPD. The mice were randomly divided into 4 groups: the modified groups, M-IPC and M-IPD, and the conventional groups, C-IPC and C-IPD. In the 2 modified groups, the mice were removed from the ventilator and allowed to resume breathing spontaneously upon completion of the lung recruitment and the rapid closure of the thorax. Our study demonstrated that the postoperative recovery time was significantly reduced for the modified groups compared with the 2 conventional groups. Moreover, the inflammatory damages were attenuated by the modified method compared with the conventional method. In addition, the modified method significantly increased the survival rates of mice with IPC or IPD. The modified method improved the survival rates of mouse models of myocardial ischemia.

Endothelial microparticles increase in mitral valve disease and impair mitral valve endothelial function.

Mitral valve endothelial cells are important for maintaining lifelong mitral valve integrity and function. Plasma endothelial microparticles (EMPs) increased in various pathological conditions related to activation of endothelial cells. However, whether EMPs will increase in mitral valve disease and their relationship remains unclear. Here, 81 patients with mitral valve disease and 45 healthy subjects were analyzed for the generation of EMPs by flow cytometry. Human mitral valve endothelial cells (HMVECs) were treated with EMPs. The phosphorylation of Akt and endothelial nitric oxide synthase (eNOS), the association of eNOS and heat shock protein 90 (HSP90), and the generation of nitric oxide (NO) and superoxide anion (O(2)(∙-)) were measured. EMPs were increased significantly in patients with mitral valve disease compared with those in healthy subjects. EMPs were negatively correlated with mitral valve area in patients with isolated mitral stenosis. EMPs were significantly higher in the group with severe mitral regurgitation than those in the group with mild and moderate mitral regurgitation. Furthermore, EMPs were decreased dramatically in both Akt and eNOS phosphorylation and the association of HSP90 with eNOS in HMVECs. EMPs decreased NO production but increased O(2)(∙-) generation in HMVECs. Our data demonstrated that EMPs were significantly increased in patients with mitral valve disease. The increase of EMPs can in turn impair HMVEC function by inhibiting the Akt/eNOS-HSP90 signaling pathway. These findings suggest that EMPs may be a therapeutic target for mitral valve disease.

Simvastatin reduces myocardial injury undergoing noncoronary artery cardiac surgery: a randomized controlled trial.

OBJECTIVE: Myocardial injury during cardiac surgery is a major cause of perioperative morbidity and mortality. We determined whether perioperative statin therapy is cardioprotective in patients undergoing noncoronary artery cardiac surgery and the potential mechanisms. METHODS AND RESULTS: One hundred fifty-one patients undergoing noncoronary artery cardiac surgery were randomly assigned to either a statin group (n=77) or a control group (n=74). Simvastatin (20 mg) was administered preoperatively and postoperatively. Plasma were analyzed for troponin T, isoenzyme of creatine kinase, C-reaction protein, interleukin-6, interleukin-8, creatinine, and blood urea nitrogen. Cardiac echocardiography was performed. Endothelial nitric oxide synthase (eNOS), Akt, p38, heat shock protein 90, caveolin-1, and nitric oxide (NO) in the heart were detected. Simvastatin significantly reduced plasma troponin T, isoenzyme of creatine kinase, C-reaction protein, blood urea nitrogen , creatinine, interleukin-6, interleukin-8, and the requirement of inotropic postoperatively. Simvastatin increased NO production, the expression of eNOS and phosphorylation at serine1177, phosphorylation of Akt, expression of heat shock protein 90, heat shock protein 90 association with eNOS and decreased eNOS phosphorylation at threonine 495, phosphorylation of p38, and expression of caveolin-1. Simvastatin also improved cardiac function postoperatively. CONCLUSIONS: Perioperative statin therapy can improve cardiac function and renal function by reducing myocardial injury and inflammatory response through activating Akt-eNOS and attenuating p38 signaling pathways in patients undergoing noncoronary artery cardiac surgery. Clinical Trial Registration- URL: http://www.clinicaltrials.gov. Unique identifier: NCT01178710.