Chunrong Bao

USP22 promotes NSCLC tumorigenesis via MDMX up-regulation and subsequent p53 inhibition.

Increasing evidence suggests that ubiquitin-specific protease 22 (USP22) has great clinicopathologic significance in oncology. In this study, we investigated the role of USP22 in human NSCLC tumorigenesis along with the underlying mechanisms of action. First, we determined the expression of USP22 in human NSCLC, as well as normal tissues and cell lines. We then studied the effects of USP22 silencing by shRNA on NSCLC cell growth in vitro and tumorigenesis in vivo, along with the effect on the p53 pathway. We found that USP22 is overexpressed in human NSCLC tissues and cell lines. USP22 silencing by shRNA inhibits proliferation, induces apoptosis and arrests cells at the G0/G1 phases in NSCLC cells and curbs human NSCLC tumor growth in a mouse xenograft model. Additionally, USP22 silencing downregulates MDMX protein expression and activates the p53 pathway. Our co-immunoprecipitation analysis shows that USP22 interacts with MDMX in NSCLC cells. Furthermore, MDMX silencing leads to growth arrest and apoptosis in NSCLC cells, and over-expression of MDMX reverses the USP22 silencing-induced effects. Taken together, our results suggest that USP22 promotes NSCLC tumorigenesis in vitro and in vivo through MDMX upregulation and subsequent p53 inhibition. USP22 may represent a novel target for NSCLC treatment.

Cardiopulmonary bypass increases pulmonary microvascular permeability through the Src kinase pathway: Involvement of caveolin-1 and vascular endothelial cadherin

Changes in pulmonary microvascular permeability following cardiopulmonary bypass (CPB) and the underlying mechanisms have not yet been established. Therefore, the aim of the present study was to elucidate the alterations in pulmonary microvascular permeability following CPB and the underlying mechanism. The pulmonary microvascular permeability was measured using Evans Blue dye (EBD) exclusion, and the neutrophil infiltration and proinflammatory cytokine secretion was investigated. In addition, the activation of Src kinase and the phosphorylation of caveolin-1 and vascular endothelial cadherin (VE-cadherin) was examined. The results revealed that CPB increased pulmonary microvascular leakage, neutrophil count and proinflammatory cytokines in the bronchoalveolar lavage fluid, and activated Src kinase. The administration of PP2, an inhibitor of Src kinase, decreased the activation of Src kinase and attenuated the increase in pulmonary microvascular permeability observed following CPB. Two important proteins associated with vascular permeability, caveolin-1 and VE-cadherin, were significantly activated at 24 h in the lung tissues following CPB, which correlated with the alterations in pulmonary microvascular permeability and Src kinase. PP2 administration inhibited their activation, suggesting that they are downstream factors of Src kinase activation. The data indicated that the Src kinase pathway increased pulmonary microvascular permeability following CPB, and the activation of caveolin-1 and VE-cadherin may be involved. Inhibition of this pathway may provide a potential therapy for acute lung injury following cardiac surgery.

Analysis of the Synergistic Effects of Fasting Plasma Glucose and Hypertension on Cardiovascular Autonomic Neuropathy

Background: The purpose of this study was to evaluate the associations of fasting plasma glucose (FPG) and hypertension (HTN) with cardiovascular autonomic neuropathy (CAN) and to estimate the extent to which the synergistic effects of FPG and HTN affect outcomes in a Chinese population. Method: We conducted a large-scale, population-based study to analyze the association and interaction of the two factors with CAN in a sample of 2,092 Chinese people. Univariate and multiple linear regression (MLR) analyses were employed to detect these relationships. Interaction on an additive scale can be calculated by using the relative excess risk due to interaction, the proportion attributable to interaction (AP), and the synergy index (S). Result: After adjusting for confounding factors, MLR showed that FPG and HTN were independently associated with CAN (p < 0.001 for both). A significant synergistic effect of FPG and HTN on CAN was detected (p = 0.046, RETI = 0.733, 95% CI 0.059-1.450; AP = 0.167, 95% CI -0.033 to 0.367; S = 1.275, 95% CI 0.140-2.410). Conclusion: Our findings suggest that FPG and HTN are independently associated with CAN, and they offer evidence to support the hypothesis that FPG and HTN have synergistic effects that influence the progression of CAN.

Myocardial structural protein expression in umbilical cord blood mesenchymal stem cells after myogenic induction.

To assess the effects of three methods of inducing myogenic cells differentiation, umbilical blood mesenchymal stem cells (UCMSCs) from nearly full‐term pregnancy mongrel dogs were purified and cultured. Fourth‐passage UCMSCs were used to detect surface antigens, including CD11a, CD11b, CD29, CD34 and CD71. The cells were induced by 5‐azacytidine (5‐aza), myocardial lysates and myocardial induced fluid. Positive expression of Nkx2.5, α‐actin, desmin, β‐MHC and troponin‐I (TN I) were detected after 3 weeks. The immunohistochemical results were CD11a (−), CD11b (−), CD34 (−), CD29 (+) and CD71 (+). Nkx2.5 was detected in 5‐aza group, myocardial lysates group and myocardial induced fluid group. Semi‐quantitative analysis showed Nkx2.5 expression significantly higher in myocardial lysates group than in the 5‐aza group or myocardial‐induced fluid group (P < 0.05), but there was no significant difference between the 5‐aza and myocardial‐induced fluid groups for Nkx2.5 expression (P > 0.05). MSCs did not express myocardial structural proteins before differentiation, but α‐actin, desmin, β‐MHC and troponin‐I were present after differentiation. The positive expression of four proteins differed with the differentiation conditions. The UCMSCs can be differentiated into myogenic cells by three methods, but the degrees of differentiation are inconsistent. Our results show that the effects of 5‐aza and myocardial lysates are better than that of myocardial induced fluid.

Suppression of cardiac allograft vasculopathy in mice by inhibition of CC-motif chemokine receptor 5

Cardiac allograft vasculopathy (CAV) is the leading cause of late morbidity and mortality in heart-transplant patients. Increasing evidences support the important role of chemokines and their receptors in transplant immunology. Chemokine-chemokine receptor interaction and subsequent recruitment of T-lymphocytes to the graft are early events in the development of chronic rejection of transplanted hearts. In this study, we first inhibited CC-motif chemokine receptor 5 (CCR5) expression by using lentiviral-mediated gene transfer of an anti-CCR5 siRNA, which introduced through CD34(+) hematopoietic stem/progenitor cell transplantation. Stably marked lymphocytes expressing siRNA and consistent downregulation of CCR5 expression were detected. Our results showed that survival was significantly prolonged in CCR5 knock-down mice and donor hearts from siRNA-treated mice developed markedly less CAV. Infiltration of CD4(+) and CD8(+) T-lymphocytes into transplanted hearts was also markedly decreased. These findings suggest that CCR5 plays an important role in CAV development and inhibition of this chemokine could improve long-term survival after cardiac transplantation.

A Modified Epicardial Radiofrequency Ablation for Preoperative Atrial Fibrillation Combined With Isolated Aortic Valve Disease

Isolated aortic valve diseases can lead to atrial fibrillation (AF) by causing left atrium pressure overload and enlargement. At present, most patients with preoperative AF and isolated aortic valve disease have undergone a Cox-maze IV procedure through a left atriotomy under cardiopulmonary bypass with aortic cross-clamping. Here, we describe a novel modified epicardial radiofrequency ablation procedure performed on a beating heart without aortic cross-clamping or opening the left atrium. This technique has proved to be safe and feasible, with good clinical outcomes. It may be useful in selecting the best ablation approaches for patients with AF and aortic valve disease.

Concomitant Maze IV Ablation Procedure Performed Entirely by Bipolar Clamp Through Right Lateral Minithoracotomy

Atrial fibrillation ablation with bipolar clamp has proved to be effective for patients with valvular atrial fibrillation. However, left pulmonary vein ablation with bipolar clamp through right minithoracotomy was considered difficult or impossible. In this report, we described a novel technique of performing concomitant Maze IV ablation procedure entirely by bipolar clamp through right minithoracotomy. Left pulmonary vein ablation with bipolar clamp was performed through an established channel and a natural space. This technique has proved to be safe and feasible and to have good clinical outcomes that may deserve further use for patients with atrial fibrillation and mitral valve disease.

Comparison of the Outcomes of Modified Artificial Chordae Technique for Mitral Regurgitation through Right Minithoracotomy or Median Sternotomy

Background:Right minithoracotomy (RM) has been proven to be a safe and effective approach for mitral valve surgery, but the differences of artificial chordae technique between RM and median sternotomy (MS) were seldom reported. Here, we compared the outcomes of modified artificial chordae technique for mitral regurgitation (MR) through RM or MS approaches. Methods:One hundred and eighteen consecutive adult patients who received mitral valve repair with artificial chordae and annuloplasty for MR through RM (n = 58) or MS (n = 60) from January 2006 to January 2015 were analyzed. Results:All of the selected patients underwent mitral valve repair successfully without any complication during the surgery. There was no significant difference between RM group and MS group in cardiopulmonary bypass time, aortic cross-clamp time, and early postoperative complications. However, compared with the MS group, the RM group had shorter hospital stay and faster surgical recovery. At a mean follow-up of 44.8 ± 25.0 months, the freedom from more than moderate MR was 93.9% ± 3.5% in RM group and 94.8% ± 2.9% in MS group at 3 years postoperatively. Log-rank test showed that there was no significant difference in the freedom from recurrent significant MR between the two groups (&khgr;2 = 0.247, P = 0.619). Multivariate analysis revealed that the presence of mild MR at discharge was the independent risk factor for the recurrent significant MR. Conclusion:Right minithoracotomy can achieve the similar therapeutic effects with MS for the patients who received modified artificial chordae technique for treating MR.

The Role of Aquaporin 1 Activated by cGMP in Myocardial Edema Caused by Cardiopulmonary Bypass in Sheep

Background/Aims: Most cardiac procedures involve the use of cardiopulmonary bypass (CPB), which pumps oxygenated blood to the body while the heart and lungs are isolated. CPB can cause profound alterations V in the homeostasis of physiological fluids, which often results in myocardial edema. In our study, we used sheep CPB model of in vivo and in vitro to assess the relationship between cGMP and AQP1 during CPB. Methods: ODQ, a specific inhibitor of soluble guanylate cyclase (sGC), was used to treat the CPB animals or cardiomyocytes. Left ventricular function of each group was determined by pressure-volume system. Water content of myocardial tissue was assessed by dry-wet weight, and cardiomyocytes water permeability was also calculated. The concentration of cGMP was determined by Radioimmunoassay (RIA). mRNA and protein expression of AQP1 were detected by real-time PCR and western blot, respectively. Results: The relative expression level of AQP1 mRNA and protein at each time point (0, 6, 12, 24 or 48 h) after CPB was significantly increased (1.18-fold at 12 h, 1.77-fold at 24 h and 2.18-fold at 48h) compared with each sham group, the protein expression of AQP1 also showed a rising trend after CPB. The degree of myocardial edema (75.1% at 12 h, 79.3% at 24 h and 81.0% at 48h) increased following the CPB surgery. The mRNA expression level of AQP1 was significantly decreased by 39.7% (p<0.01) upon treatment with ODQ compared with the CPB-only group, and inhibition of cGMP pathway also can significantly decrease the degree of myocardial edema (84.7% in control group, while 75.2% in ODQ group) and improve cardiac function in sheep after CPB. Results of in vitro experiments showed the same changing trends as in vivo. Conclusion: cGMP pathway controls water channels and then affects water intake during CPB through an AQP1-mediated pathway.