Sinomenine promotes differentiation of induced pluripotent stem cells into immature dendritic cells with high induction of immune tolerance

BACKGROUND Immature dendritic cells(imDCs)play an important role in the induction of donor-specific transplant immunotolerance.However,these cells have limitations,such as rapid maturation and a short lifespan in vivo.In previous studies,induced pluripotent stem cells(iPSCs)differentiated into imDCs,and sinomenine(SN)was used to inhibit the maturation of imDCs.AIM To study the capacity of SN to maintain iPSC-derived imDCs(SN-iPSCs-imDCs)in an immature state and the mechanism by which SN-iPSCs-imDCs induce immunotolerance.METHODS In this study,mouse iPSCs were induced to differentiate into imDCs in culture medium without or with SN(iPSCs-imDCs and SN-iPSCs-imDCs).The imDCrelated surface markers,endocytotic capacity of fluorescein isothiocyanate Dextran and apoptosis were analyzed by flow cytometry.The effects of iPSCs-imDCs and SNiPSCs-imDCs on T-cell stimulatory function,and regulatory T(Treg)cell proliferative function in vitro were analyzed by mixed lymphocyte reaction.Cytokine expression was detected by ELISA.The apoptosis-related proteins of iPSCs-DCs and SN-iPSCs-DCs were analyzed by western blotting.The induced immunotolerance of SN-iPSCs-DCs was evaluated by treating recipient Balb/c skin graft mice.Statistical evaluation of graft survival was performed using Kaplan–Meier curves.RESULTS Both iPSCs-imDCs and SN-iPSCs-imDCs were successfully obtained,and their biological characteristics and ability to induce immunotolerance were compared.SN-iPSCs-imDCs exhibited higher CD11c levels and lower CD80 and CD86 levels compared with iPSCs-imDCs.Reduced major histocompatibility complex II expression,worse T-cell stimulatory function,higher Treg cell proliferative function and stronger endocytotic capacity were observed with SN-iPSCs-imDCs(P<0.05).The levels of interleukin(IL)-2,IL-12,interferon-γin SN-iPSCs-imDCs were lower than those in iPSCs-imDCs,whereas IL-10 and transforming growth factor-βlevels were higher(P<0.05).The apoptosis rate of these cells was significantly higher(P<0.05),and the expression levels of cleaved caspase3,Bax and cleaved poly(ADP-ribose)polymerase were higher after treatment with lipopolysaccharides,but Bcl-2 was reduced.In Balb/c mice recipients immunized with iPSCsimDCs or SN-iPSCs-imDCs 7 d before skin grafting,the SN-iPSCs-imDCs group showed lower ability to inhibit donor-specific CD4+T-cell proliferation(P<0.05)and a higher capacity to induce CD4+CD25+FoxP3+Treg cell proliferation in the spleen(P<0.05).The survival span of C57bl/6 skin grafts was significantly prolonged in immunized Balb/c recipients with a donor-specific pattern.CONCLUSION This study demonstrated that SN-iPSCs-imDCs have potential applications in vitro and in vivo for induction of immunotolerance following organ transplantation.

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.

Comparison of the characteristics of macrophages derived from murine spleen, peritoneal cavity, and bone marrow

Macrophages have a diverse set of functions based upon their activation states. The activation states, including resting（M0） and polarizing（M1 and M2） states, of macrophages derived from the mouse bone marrow, spleen, and peritoneal cavity（BMs, SPMs, and PCMs, respectively） were compared. We evaluated the macrophage yield per mouse and compared the surface markers major histocompatibility complex（MHC） Ⅱ and CD86 by flow cytometry. The relative mRNA levels of tumor necrosis factor-α（TNF-α）, interleukin（IL）-1β, mannose receptor（MR）, and Ym1 in the M0, M1, and M2 states were also compared using real-time polymerase chain reaction（PCR） analysis. Bone marrow yielded the most macrophages with the best homogeneity, but they were polarized toward the M2 phenotype. All three types of macrophages had the capacity to polarize into the M1 and M2 states, but SPMs had a stronger capacity to polarize into M1. The three types of macrophages showed no differences in their capacity to polarize into the M2 state. Therefore, the three types of macrophages have distinct characteristics regardless of their resting or polarizing states. Although bone marrow can get large amounts of homogeneous macrophages, the macrophages cannot replace tissue-derived macrophages.

Polyglycolic Acid Fibrous Scaffold Improving Endothelial Cell Coating and Vascularization of Islet

Background：Improving islet graft revascularization has become a crucial task for prolonging islet graft survival.Endothelial cells （ECs） are the basis of new microvessels in an isolated islet,and EC coating has been demonstrated to improve the vascularization and survival of an islet.However,the traditional method of EC coating of islets has low efficiency in vitro.This study was conducted to evaluate the effect of a polyglycolic acid （PGA） scaffold on the efficiency of islet coating by ECs and the angiogenesis in the coated islet graft.Methods：A PGA fibrous scaffold was used for EC coating of islet culture and was evaluated for its efficiency of EC coating on islets and islet graft angiogenesis.Results：In in vitro experiments,we found that apoptosis index of ECs-coating islet in PGA group （27% ± 8%） was significantly lower than that in control group （83% ± 20%,P 〈 0.05） after 7 days culture.Stimulation index was significantly greater in the PGA group than in the control group at day 7 after ECs-coating （2.07 ± 0.31 vs.1.80 ± 0.23,P 〈 0.05）.vascular endothelial growth factor （VEGF） level in the PGA group was significantly higher than the coating in the control group after 7 days culture （52.10 ± 13.50 ng/ml vs.16.30 ± 8.10 ng/ml,P 〈 0.05）.Because of a tight,circumvallated,adhesive and three-dimensional growth microenvironment,islet cultured in a PGA scaffold had higher coating efficiency showing stronger staining intensity of enzyme than those in the control group after 14 days of culture following ECs-coating.For in vivo study,PGA scaffold significantly prolonged the average survival time of EC-coated islet graft after transplantation compared with control group （15.30 ± 5.60 days vs.8.30 ± 2.45 days,P 〈 0.05）.The angiogenesis and area of survived grafts were more in the PGA group compared with the control group by measuring the mean microvessel density （8.60 ± 1.21/mm2 vs.5.20 ± 0.87/mm2,P 〈 0.05）.In addition,expression of VEGF and tyrosin-protein kinase receptor （Tie-2） gene increased in PGA scaffold group than that in control group by real-time reverse transcription-polymerase chain reaction analysis.Conclusions：These results demonstrate that the efficiency of EC coating of islets was successfully increased by culturing ECs on a PGA scaffold.This method enhances the function,survival,and vascularization of isolated islets in vitro and in vivo.

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.