[Early efficacy of islet transplantation in the treatment of adult advanced diabetes].

Objective: To evaluate the safety and efficacy of islet transplantation for patients with advanced diabetes. Methods: Five cases of islet allotransplantation were performed on 4 adult recipients. The same blood type adult brain-dead pancreas donors were selected and the islets were prepared in GMP laboratory. The prepared islet suspension was slowly injected into the liver of the recipients within 30-60 minutes. The immunosuppressive regimen was a combination of basiliximab, tacrolimus and mycophenolate mofetil and TNF-alpha monoclonal antibody was used to reduce the post-transplant inflammatory response. Insulin was temporarily applied to control blood glucose after surgery, and the dosage of insulin was adjusted to decrease according to the blood glucose level until it was discontinued. Results: A total of 5 islet transplants were performed in 4 patients, including 1 patient who received the second islet transplantations. All operations were succeed and the blood glucose and portal pressure were stable during the operation. Exogenous insulin was continued to keep blood glucose level stable (4-12 mmol/L) after surgery. Four cases (including the one who received two islet transplantation) started to stop using insulin at the third to fourth week, and the insulin dosage of the other case was 74% lower than that before the operation, and no hypoglycemic reaction occurred in all patients after islet transplantation. The C-peptide level in 3 patients reached the normal range, and the level in one patient with type I diabetes (without insulin release) remained at 0.45-0.6 µg/L (0.15-0.2 nmol/L). In addition, one patient showed a rise in blood glucose again and continued to use insulin half a year after insulin discontinuation. Then, he was performed the second islet transplantation which showed good effect and stopped taking insulin in 10 days after surgery. There were 3 cases of liver puncture bleeding after opeation, of which 2 cases were treated with ultrasound radiofrequency ablation to stop bleeding, 1 case stopped spontaneously, and no other complications were found. Conclusions: Islet transplantation is effective in the treatment of advanced diabetes patients with small trauma and high safety, which is worthy of more promotion. Long-term efficacy and maintenance therapy still need further investigation.

[Effect of Wnt/ß-catenin signal regulating EMT level on the differentiation of mouse ESC to liver tissue].

Objective: To study embryonic stem cell (ESC) differentiation into liver tissue structure from the perspective of epithelial mesenchymal transition (EMT). Methods: ESC of Balb/c mice was selected to induced into hepatic cell using hepatocyte growth factor (HGF), fibroblast growth factor (FGF) in vitro, and at the time points of metaphase (13 d) and maturity (17 d) of differentiation, dynamic inhibition of Wnt/ß-catenin signal was made to reduce the level of EMT. Finally, three-dimensional organization structure growth of the differentiation cells was observed in the differentiation system.Expressions of the liver cells vascular markers[albumin (Alb) and vascular endothelial growth factor (VEGFR)]were detected. Results: During the differentiation of ESC, the level of early EMT in the experimental group and the control group was not significantly different. The level of mid-late EMT in the experiment group was significantly lower than the control group. On the day 18 and 20 of differentiation, the relative mRNA expression level of E-cadherin was 0.61±0.15 and 0.47±0.05 in the experimental group, and 0.07±0.05 and 0 in the control group, respectively.The expression level of ALB/AFP/CK8/CK19 in the experimental group was generally higher than that of the control group in the same period, while CD31/VEGFR1 markers in the experimental group decreased more slowly in the late period of differentiation compared with the control group. In the supernatant of ESC culture, the Alb of the experimental group could be detected onday 7, and the concentration was (0.32±0.02) mg/L, while Alb in the control group was (0.19±0.05) mg/L. Urea in the experimental group could be detected on the day 13, and the concentration was (8.7 ±1.0) µmol/L, and the urea concentration of the control group was (3.1±1.2) µmol/L. The concentration of Alb and urea in the culture supernatant of ESC differentiation system increased significantly with the prolongation of the differentiation time, and the Alb and urea concentrations in the experimental group were significantly higher than those in the control group at the same time period. In addition, the differentiated cells in the experimental group could maintain the growth of three-dimensional tissue, while the differentiated cells in the control group eventually showed a single cell state. The expression of hepatic and vascular cell markers could be detected in the experimental group. Immunofluorescence results showed that the hepatocytes and vascular structures were tightly arranged. HE staining showed the formation of hepatic lobular structure, while the control group had no vascular component markers. Conclusion: The differentiation of ESC into liver tissue can be effectively promoted by decreasing the level of EMT at the mid-late stage of ESC differentiation.

[The effect of semimature dendritic cell and the levels of Treg on transplantation tolerance of hepatocytes differentiated from mouse embryonic stem cell].

Objective: To investigate the inducing effect and mechanism of semimature dendritic cell (smDCs) on transplantation tolerance of hepatocytes differentiated from mouse embryonic stem cells (ESCs), and to study the connections between smDCs and regulatory dendritic cells (regDCs). Methods: ESCs of 129 mouse labelled green fluorescent protein (GFP) were induced to hepatocytes by using previous methods. Meanwhile, bone marrow mononuclear cells of 129 mouse were induced to smDCs and regDCs. Moreover, the hepatocytes differentiated from 129 mouse ESCs were transplanted into liver of BALB/c mouse 3 days after infusing smDCs and regDCs suspension of 129 mouse into BALB/c mouse by tail vein respectively. After that, the growth status and survival time of transplanted cells in the recipient and infiltration of lymphocytes in transplant sites were observed. Furthermore, Foxp3 expression of peripheral blood CD4+ T cells was also tested. Results: In the control group, the transplanted cells in liver of BALB/c mouse survived only about 1 week. In contrast, the transplanted cells of smDC groups and regDCs groups survived about 4 weeks and the transplant sites of smDC groups also had less CD3(+) T cells. The morphology of smDCs were similar with regDCs. The expression of MHC-Ⅱ, CD40, CD80 and CD86 on smDCs and regDCs were moderate. Moreover, the Foxp3 expression of peripheral blood CD4+ T cells in smDC groups was higher than that in the control groups, from 1.11% up to 5.38%. The Foxp3 expression in regDC groups rose to 3.87%. Conclusion: The smDCs could induce transplantation tolerance of hepatocytes differentiated from 129 mouse ESCs in the recipient. The mechanism was associated with high level of Foxp3(+) Tregs, which could be increased by means of smDCs appropriate expression of MHC-Ⅱ, CD40, CD80 and CD86. The smDCs and regDCs were the same type of tolerance dendritic cells.