Effect and mechanism of high glucose on apoptosis and cell cycle arrest of islet β cells via p27 pathway

Objective:To study the effect of mechanism of high glucose on apoptosis and cell cycle arrest of isletβcells via p27 pathway.Methods:Islet INS-1 cells were cultured and divided into groups.The control group was treated with ordinary medium,the high glucose group was treated with high glucose medium containing 25mmol/L glucose,the high glucose+si-NC group was treated with high glucose medium and transfected with NC siRNA,and the high glucose+si-P27 group was treated with high glucose medium and transfected with p27 siRNA.After 24 hours treatment,MTS assay was used to detect the cell viability A490,TUNEL assay was used to detect apoptosis rate,flow cytometry was used to detect the cell cycle distribution and western blot was used to detect the expression levels of P27,caspase-8 and cyclinD1.Results:Compared with those in the control group,the A490,the ratio of S phase and G2/M phase as well as the expression level of CyclinD1 decreased,while the apoptosis rate,the ratio of G0/G1 phase as well as the expression levels of P27 and caspase-8 increased in the high glucose group(P<0.05);compared with those in the high glucose group,the A490,cell cycle as well as the expression levels of P27,caspase-8 and cyclinD1 were not different from those in the high glucose+si-NC group(P>0.05);compared with those in the high glucose group and high glucose+si-NC group,the A490,the ratio of S phase and G2/M phase as well as the expression levels of cyclinD1 increased,while the apoptosis rate,the ratio of G0/G1 phase as well as the expression levels of p27 and caspase-8 decreased in the high glucose+si-P27 group(P<0.05).Conclusion:The apoptosis and cell cycle arrest induced by high glucose are related to P27 pathway activation.

Beneficial Effect of Moderately Increasing Hypothermic Machine Perfusion Pressure on Donor after Cardiac Death Renal Transplantation

Background:Vascular resistance and flow rate during hypotherrnic machine perfusion (HMP)of kidneys is correlated with graft function. We aimed to determine the effects of increasing HMP pressure versus maintaining the initial pressure on kidney transplantation outcomes. Methods:We retrospectively reviewed the data of 76 primary transplantation patients who received HMP-preserved kidneys from 48 donors after cardiac death between September 1,2013,and August 31,2015.HMP pressure was increased from 30 to 40mmHg (1mmHg =0.133kPa)in kidneys with poor flow and/or vascular resistance (increased pressure [IP]group;36 patients);otherwise,the initial pressure was maintained (constant pressure group;40 patients).Finally,the clinical characteristics and transplantation outcomes in both groups were assessed. Results:Delayed graft function (DGF)incidence,1-year allograft,patient survival,kidney function recovery time,and serum creatinine level on day 30 were similar in both groups,with improved flow and resistance in the IP group.Among patients with DGF,kidney function recovery time and DGF duration were ameliorated in the IP group.Multivariate logistic regression analysis revealed that donor hypertension (odds ratio [OR]:1.43,95%confidence interval [CI]:1.02-2.06,P =0.035),donor terminal serum creatinine (OR:1.27,95%C7:1.06-1.62,P =0.023),warm ischemic time (OR:3.45,95%CI:1.97-6.37,P =0.002),and terminal resistance (OR:3.12,95%CI:1.76-6.09,P =0.012)were independent predictors of DGF.Cox proportional hazards analysis showed that terminal resistance (hazard ratio:2.06,95%C1:1.32-5.16,P =0.032)significantly affected graft survival. Conclusion:Increased HMP pressure improves graft perfusion but does not affect DGF incidence or 1-year graft survival.

Predictive Score Model for Delayed Graft Function Based on Hypothermic Machine Perfusion Variables in Kidney Transplantation

Background: Hypothermic machine perfusion(HMP) is being used more often in cardiac death kidney transplantation; however, the significance of assessing organ quality and predicting delayed graft function(DGF) by HMP parameters is still controversial. Therefore,we used a readily available HMP variable to design a scoring model that can identify the highest risk of DGF and provide the guidance and advice for organ allocation and DCD kidney assessment.Methods: From September 1, 2012 to August 31, 2016, 366 qualified kidneys were randomly assigned to the development and validation cohorts in a 2:1 distribution. The HMP variables of the development cohort served as candidate univariate predictors for DGF. The independent predictors of DGF were identified by multivariate logistic regression analysis with a P < 0.05. According to the odds ratios(ORs) value, each HMP variable was assigned a weighted integer, and the sum of the integers indicated the total risk score for each kidney. The validation cohort was used to verify the accuracy and reliability of the scoring model.Results: HMP duration(OR = 1.165, 95% confidence interval [CI ]: 1.008–1.360, P = 0.043), resistance(OR = 2.190, 95%CI: 1.032–10.20, P < 0.001), and flow rate(OR = 0.931, 95% CI: 0.894–0.967, P = 0.011) were the independent predictors of identified DGF. The HMP predictive score ranged from 0 to 14, and there was a clear increase in the incidence of DGF, from the low predictive score group to the very high predictive score group. We formed four increasingly serious risk categories(scores 0–3, 4–7, 8–11, and 12–14)according to the frequency associated with the different risk scores of DGF. The HMP predictive score indicates good discriminative power with a c?statistic of 0.706 in the validation cohort, and it had significantly better prediction value for DGF compared to both terminal flow(P = 0.012) and resistance(P = 0.006).Conclusion: The HMP predictive score is a good noninvasive tool for assessing the quality of DCD kidneys, and it is potentially useful for physicians in making optimal decisions about the organs donated.

Predictive Score Model for Delayed Graft Function Based on Easily Available Variables before Kidney Donation after Cardiac Death

Background： How to evaluate the quality of donation after cardiac transplantation in China. Hence, the aim of this study was to develop kidneys before DCD. death （DCD） kidneys has become a critical problem in kidney a simple donor risk score model to evaluate the quality of DCD Methods： A total of 543 qualified kidneys were randomized in a 2：1 manner to create the development and validation cohorts. The donor variables in the development cohort were considered as candidate univariate predictors of delayed graft function （DGF）. Multivariate logistic regression was then used to identify independent predictors of DGF with P 〈 0.05. Date from validation cohort were used to validate the donor scoring model. Results： Based on the odds ratios, eight identified variables were assigned a weighted integer; the sum of the integer was the total risk score for each kidney. The donor risk score, ranging from 0 to 28, demonstrated good discriminative power with a C-statistic of 0.790. Similar results were obtained from validation cohort with C-statistic of 0.783. Based on the obtained frequencies of DGF in relation to different risk scores, we formed tour risk categories of increasing severity （scores 04, 5 9, 10-14, and 15 28）. Conclusions： The scoring model might be a good noninvasive tool for assessing the quality of DCD kidneys before donation and potentially useful for physicians to make optimal decisions about donor organ offers.

Early Immunosuppressive Exposure of Enteric-Coated-Mycophenolate Sodium Plus Tacrolimus Associated with Acute Rejection in Expanded Criteria Donor Kidney Transplantation

Background： lmmunosuppressive agents are still inefficient in preventing biopsy-proven acute rejection （BPAR） alter expanded criteria donor （ECD） kidney transplantation. The aim of this study was to investigate the relationships between early imrnunosuppressive exposure and the development of BPAR. Methods： We performed a retrospective study of 58 recipients of ECD kidney transplantation treated with enteric-coated-mycophenolate sodium, tacrolirnus （Tac）, and prednisone. The levels of mycophenolic acid-area under the curve （MPA-AUC）0-12h and Tac C0 were measured at the 1st week and the 1st month posttransplant, respectively. The correlation was assessed by multivariate logistic regression. Results： The occurrence rates of BPAR and antibody-mediated rejection were 24.1% and 10.3%, respectively. A low level of MPA-AUC0-12h at the 1st week posttransplant was found in BPAR recipients （38.42 ± 8.37 vs. 50.64 ± 13.22, P 〈 0.01）. In addition, the incidence of BPAR was significantly high （P 〈 0.05） when the MPA-AUC0-12h level was 〈30 mg·h-1·L-1 at the 1st week （ 15.0% vs. 44.4%） or the Tac C0 was 〈4 ng/ml at the 1 st month posttransplant （33.3% vs. 21.6%）. Multivariable logistic regression analysis showed that the MPA-AUC 0-12 h at the 1st week （OR： 0.842, 95% CI： 0.784-0.903） and the Tac C0 at the 1st month （OR： 0.904, 95% C7： 0.822-0.986） had significant inverse correlation with BPA R （ P 〈 0.05 ）. Conclusions： Low-level exposure of MPA and Tac C0 in the early weeks posttransplant reflects an increased acute rejection risk, which suggested that MPA-AUC0-12h 〈30 mg·h-1·L -1 and Tac C0 〈4 ng/ml should be avoided in the first few weeks alter transplantation.

Allograft rejection-related gene expression in the endothelial cells of renal transplantation recipients after cytomegalovirus infection

Objective： To explore the effects of cytomegalovirus （CMV） infection on rejection-related gene expression in the endothelial cells of renal transplantation recipients. Methods： Endothelial cells （ECs） were cultured and stimulated by a variety of factors： A, normal control group; B, inactivated human cytomegalovirus （HCMV） infection group; C, HCMV infection group; D, HCMV supematant infection group; and E, ganciclovir HCMV group. Expression of intercellular adhesion molecule-1 （ICAM-1） and major histocompability complex （MHC） class I and class II antigens was detected by flow cytometry （FCM） and immuno- histochemistry. Results： We found characteristic CMV-infected ECs in this study. There were no significant differences among groups A, B and D （P〉0.05）. Although the expression levels of ICAM-1 were not significantly different between groups C and E （P〉0.05）, the ICAM-1 expression in these two groups was significantly higher than that in group A （P〈0.05）. ICAM-1 expression was detected in groups C and E, while there was no expression in groups A, B and D. Furthermore, there was no significant difference of ICAM-1 mRNA expression between groups C and E （P〉0.05）. Human leucocyte antigen （HLA）-ABC expression was detected in all the groups, while HLA-DR expression was only detected in groups C and E. There were no significant dif- ferences of HLA-ABC and HLA-DR expression among groups A, B and D （P〉0.05）. However, the HLA-ABC and HLA-DR expression levels in groups C and D were higher than those of the remaining groups previously reported （P〈0.05）. Meanwhile, the HLA-ABC and HLA-DR expression levels in group E were lower than those of group C （P〈0.05）. Conclusion： CMV could up-regulate the expression levels of ICAM-1 and MHC antigens, which was closely related to allograft rejection.