Microchip-based engineering of super-pancreatic islets supported by adipose-derived stem cells

Type 1 diabetes mellitus (T1DM) is a chronic disorder characterized by targeted autoimmune-mediated destruction of the β cells of Langerhans within pancreatic islets. Currently, islet transplantation is the only curative therapy; however, donor shortages and cellular damage during the isolation process critically limit the use of this approach. Here, we describe a method for creating viable and functionally potent islets for successful transplantation by co-culturing single primary islet cells with adipose-derived stem cells (ADSCs) in concave microwells. We observed that the ADSCs segregated from the islet cells, eventually yielding purified islet spheroids in the three-dimensional environment. Thereafter, the ADSC-exposed islet spheroids showed significantly different ultrastructural morphologies, higher viability, and enhanced insulin secretion compared to mono-cultured islet spheroids. This suggests that ADSCs may have a significant potential to protect islet cells from damage during culture, and may be employed to improve islet cell survival and function prior to transplantation. In vivo experiments involving xenotransplantation of microfiber-encapsulated spheroids into a mouse model of diabetes revealed that co-culture-transplanted mice maintained their blood glucose levels longer than mono-culture-transplanted mice, and required less islet mass to reverse diabetes. This method for culturing islet spheroids could potentially help overcome the cell shortages that have limited clinical applications and could possibly be developed into a bioartificial pancreas.     

Microfluidics-generated pancreatic islet microfibers for enhanced immunoprotection

Pancreatic islet transplantation is a promising method for treatment of type 1 diabetes mellitus. However, transplanted islets can be destroyed due to host immune reactions. To immunologically protect transplanted islets, here an immunoprotective microfiber including islets by using a polydimethylsiloxane (PDMS)-based microfluidic device is newly designed. A cylindrical-flow channel in the microfluidic platform is used for producing collagen-alginate composite (CAC) fibers. This enables mass production and uniform diameter distribution (<250 μm) without protruding islets. Collagen, which is the main extracellular matrix component, is added to alginate to mimic the native islet microenvironment. Compared to free islets (control) and alginate-fiber-encapsulated islets, CAC-fiber-encapsulated islets show higher viability and normal insulin secretion. When CAC-fiber-encapsulated islets (1200 islet equivalent) are implanted into the intraperitoneal cavity of streptozotocin-induced diabetic BALB/C mice, the blood glucose levels of all mice return to normoglycemia. Moreover, intraperitoneal glucose tolerance tests demonstrate that islets in the CAC-fiber have similar glucose responsiveness to those of non-diabetic normal mice. These results are attributed to the immunoprotection of the transplanted islets from host immune reactions. On the other hand, all free islets are completely rejected within a week due to severe immune responses. Collectively, fabrication of CAC fibers using microfluidic devices can be used for successful islet transplantation.     

耐受性树突状细胞过继转移建立1型糖尿病小鼠感染性免疫耐受

目的探讨耐受性树突状细胞(DC)过继转移,在T1DM模型小鼠体内建立感染性免疫耐受的方法和机制。方法在链脲佐菌素(STZ)所致1型糖尿病模型(type 1 diabetes mellitus,T1DM)内采用胰岛素与IFA混合乳剂皮下注射的方式诱导免疫耐受。体外分离和纯化耐受性树突状细胞。另取BALB/c小鼠,通过体内腹腔注射STZ,尾静脉注射T1DM发病小鼠脾脏T淋巴细胞(DTL),诱导T1DM。同时将不同来源DC经腹腔注射入模型小鼠体内。每周测定血糖,第4周时处死动物,取胰腺进行病理组织学检查。MTF法测定小鼠脾淋巴细胞增殖反应,采用流式细胞术检测CIM~ CD25~ 调节性T细胞。结果采用2次小剂量STZ加DTL联合注射的方式可在小鼠体内建立以胰腺β细胞炎性破坏为主要病理特征的T1DM。通过过继转移免疫耐受性DC,可明显降低糖尿病高血糖以及小鼠脾淋巴细胞增殖能力,与模型对照组差异有统计学意义(P<0.01);组织病理检查发现胰岛内炎症细胞浸润减少,组织结构完整;FACS显示CD4~ CD25~ T细胞亚群比例显著升高。结论过继转移耐受性DC可以在次一级T1DM模型内诱导感染性免疫耐受并防止T1DM的发生,其机制与促进体内CD4~ CD25~ T细胞亚群产生相关。     

Cross talk between the extracellular matrix and the immune system in the context of endocrine pancreatic islet transplantation. A review article

This review aims to highlight the importance of the bidirectional influence of the extracellular matrix (ECM) and immune cells in the context of type 1 diabetes mellitus (T1DM) and endocrine pancreatic islet transplantation. We introduced the main classes of molecules and proteins constituting the ECM as well as cells and cytokines of the immune system with the aim to further examine their roles in T1DM and islet transplantation. Integrins expressed by immune cells and their functions are detailed. Finally, this article reviews the roles of the ECM and the immune system in islet transplantation as well as ECM-related cytokines and their influence on the ECM and immune cells.     

分泌型PD-L1真核表达载体的构建、表达及其体外效应的初步研究

目的 构建分泌型PD-L1真核表达载体，并对其生物学活性进行初步研究。方法以RT-PCR方法从孕鼠胎盘中获得程序性死亡因子-1（programmed death-1，PD-1）配体PD-L1的胞外段基因片段，定向连接于pcDNA3．1上构建真核表达载体pcDNA-PDL1；用脂质体将重组子导入NTT细胞，转染后的NTT命名为NITp。以Western blot鉴定重组蛋白的表达。MTT比色法检测NITp细胞培养上清对同种混合淋巴细胞培养反应的影响；用ELISA试剂盒检测NITp细胞培养上清对反应性T细胞分泌的细胞因子的影响。结果 RT-PCR得到约730bp目的基因片段，测序结果显示该目的基因与Gen-Bank上的序列相符；Western blot分析提示NTTp分泌性表达目的蛋白；NTTp培养上清可抑制混合淋巴细胞增殖，其效应呈剂量依赖性；反应性T细胞分泌的细胞因子检测结果显示，培养上清中IL-4、IFN-γ、IL-2水平降低，与正常对照组差异有统计学意义。结论 成功构建PD-L1基因真核表达载体pcDNA-PDL1，PD-L1蛋白对同种细胞刺激的增殖反应有抑制作用，并可在一定程度上抑制特异性T细胞的活化。     

Analysis of children with type 1 diabetes in Korea: high prevalence of specific anti-islet autoantibodies, immunogenetic similarities to Western populations with "unique" haplotypes, and lack of discrimination by aspartic acid at position 57 of DQB

This study analyzed the expression of anti-islet autoantibodies and HLA-DR and -DQ genotypes in Korean children with type 1 diabetes mellitus (T1DM). The positivity of the anti-ICA512, anti-GAD65, and anti-insulin autoantibodies in the newly onset T1DM patients (n = 15) was 66.7%, 86.7%, and 46.7%, respectively, and all of them had one or more of the autoantibodies. HLA analysis showed higher frequencies of HLA-DRB1*0301, *0405, *09012 and -DQB1*0201, *0401, *03032 alleles in T1DM patients compared to controls (P(c) < 0.05). Because HLA-DQB1*0401, *03032 alleles carry aspartic acid at position 57 of DQB, susceptibility to T1DM in Korean children was not related to the presence of aspartic acid at position 57 of DQB1 locus. We suggest this unique HLA-DR, -DQ allele distribution might be an important factor for the low incidence of T1DM in Korea, and the combined anti-islet autoantibody assays could be valuable screening markers for the early detection of T1DM in Korea.     

艾塞那肽对血糖控制不佳的肥胖糖尿病患者疗效分析

目的：观察血糖控制不佳的肥胖2型糖尿病(type 2 diabetes mellitus,T2DM)患者加用艾塞那肽后的疗效。方法：选取研究对象60例(退出3例,实际完成57例),根据不同体重指数(BMI)分为A组(25 kg/m2≤BMI<30 kg/m2)23例,B组(30 kg/m2≤BMI<35 kg/m2)27例,C组(35 kg/m2≤BMI<40 kg/m2)7例,连续给予艾塞那肽治疗12周,比较治疗前后3组患者的临床疗效及血清指标变化。结果：随访结束后,所有患者平均空腹血糖(fasting blood glucose,FBG)水平、HbA1c、体重和BMI、血脂(TC、TG、LDL)等较基线有明显下降(P<0.05);所有患者平均空腹胰岛素(fasting serum insulin,FINS)水平较治疗前有所升高(P>0.05),所有患者HOMA-IR较治疗前明显降低(P均<0.05),HOMA-β较治疗前无显著变化(P>0.05)。3组间比较显示,各组FBG下降幅度C组>B组>A组(P>0.05);HbA1c下降幅度水平C组>A组(P<0.05);体重减轻幅度和BMI的下降幅度依次为C组>B组>A组(P均<0.05)。结论：艾塞那肽可以有效控制血糖控制不佳的肥胖T2DM患者的FBG、HbA1c,改善血脂水平和胰岛功能,减轻体重和BMI。其中,艾塞那肽对FBG、HbA1c、体重、BMI的疗效,在BMI较高组中疗效更显著。     

Hypoglycemia anticipation,awareness and treatment training (HAATT) reduces occurrence of severe hypoglycemia among adults with type 1 diabetes mellitus

Severe hypoglycemia (SH) can be a significant problem for patients around the world with Type 1 Diabetes Mellitus (T1DM). To avoid SH, patients need to better manage, and reduce the occurrence of, preceding mild hypoglycemia. Hypoglycemia Anticipation, Awareness and Treatment Training (HAATT), developed in the United States specifically to address such issues, was evaluated at short- and long-term follow-up in a medically, economically and culturally different setting; Bulgaria. Sixty adults with T1DM and a history of recurrent SH (20 each from Sofia, Russe, and Varna, Bulgaria) were randomized to Self-Monitoring of Blood Glucose (SMBG) or SMBG+ HAATT. For 6 months before and 1 to 6 and 13 to 18 months after intervention, participants recorded occurrence of moderate, severe, and nocturnal hypoglycemia. For 1-month pre- and post-intervention, participants completed daily diaries concerning their diabetes management. Relative to SMBG, HAATT produced significant improvement in occurrence of low BG, moderate, severe, and nocturnal hypoglycemia, and detection and treatment of low BG (p values < .05 to < .001), with no compromise in metabolic control. At long-term follow-up, HAATT participants continued to have significantly fewer episodes of moderate and severe hypoglycemia. These findings suggest that a structured, specialized psycho-educational treatment program (HAATT) can be highly effective in managing hypoglycemia.     

Tr1 cell immunotherapy promotes transplant tolerance via de novo Tr1 cell induction in mice and is safe and effective during acute viral infection

Tr1 cell therapy is considered an emerging approach to improve transplant tolerance and enhance allogeneic graft survival. However, it remains unclear how Tr1 cells promote transplant tolerance and whether they will be safe and stable in the face of an acute viral infection. By employing a mouse model of pancreatic islet transplantation, we report that Tr1 cell therapy promoted transplant tolerance via de novo induction of Tr1 cells in the recipients. Acute viral infection with lymphocytic choriomeningitis virus (LCMV) had no impact on Tr1 cell number and function, neither on the Tr1 cells infused nor on the ones induced, and that was reflected in the robust maintenance of the graft. Moreover, Tr1 cell immunotherapy had no detrimental effect on CD8 and CD4 anti‐LCMV effector T‐cell responses and viral control. Together, these data suggest that Tr1 cells did not convert to effector cells during acute infection with LCMV, maintained transplant tolerance and did not inhibit antiviral immunity.     

吡格列酮对DM2大鼠肝脏及MCP-1表达的影响

目的:观察吡格列酮对2型糖尿病(Type 2 diabetes mellitus,DM2)大鼠血、尿单核细胞趋化蛋白-1(monocyte chemoattractant protein-1,MCP-1)表达及肝脏组织结构和功能的影响。方法:正常对照组(NC组)以普通饲料喂养;DM2 SD大鼠模型采用高糖高脂饲料喂养联合小剂量链脲佐菌素(streptozotocin,STZ)注射的方法建立。将模型组大鼠随机分为糖尿病组(DM组)和吡格列酮组(PIO组),后者采用吡格列酮对PIO组大鼠进行干预治疗。8周后检测血糖、糖化血红蛋白(HbA1c)水平、生化指标及肝脏组织病理的改变情况,同时检血、尿MCP-1水平、尿白蛋白/尿肌酐(urinary albumin/creatinine ratio,ACR)、尿视黄醇结合蛋白(urinaryretinol binding protein,URBP)的变化。结果:与NC组比较,DM组和PIO组第8周空腹血糖及HbAlc水平均明显升高,但DM组及PIO组间差异无统计学意义(P>0.05);第8周DM组与PIO组的尿ACR、URBP、血及尿MCP-1和肝脏纤维化程度均高于NC组(P<0.05),而PIO组4项指标较DM组明显降低,且UMCP-1与ACR呈正相关;病理显示,PIO组大鼠肝脏病变程度均较DM组明显减轻,肝组织MCP-1表达减少。结论:吡格列酮对DM2大鼠肝脏有明显的保护作用,其保护作用是独立于降糖作用之外的。其机制可能与其抑制肝组织MCP-1表达及其合成有关。     

金芪降糖片联合西药治疗糖尿病对患者血浆ET-1和sICAM-1水平的影响

目的：探讨金芪降糖片对糖尿病患者血浆ET-1和sICAM-1水平的影响及临床应用价值。方法：金芪降糖片和降糖类西药同时服用治疗糖尿病，并与只服西药治疗组进行比较。采用酶联免疫法检测两组患者治疗前后血浆中血管内皮细胞活性因子ET-1和sICAM-1水平，同时观察血糖和血脂、HbA1c等各项指标的变化。结果：金芪组治疗后血糖和血脂、HbA1c均有显著变化（P〈0．05），对照组仅血糖有明显变化（P〈0．05）；金芪组治疗后ET-1和sICAM-1均显著降低，分别为P〈0．05和P〈0．01，对照组两者水平皆无明显变化（P〉0．05）。结论：金芪降糖片通过降低糖尿病患者血浆中ET-1和s／CAM-1水平，从而保护患者的血管内皮细胞，在西药常规治疗糖尿病的基础上，再加以中药辨证施治，可以提高临床对糖尿病的疗效。     

Collective effects of common single nucleotide polymorphisms and genetic risk prediction in type 1 diabetes

Type 1 diabetes (T1D) is a common autoimmune disease and may be related to multiple genetic and environmental risk factors. Previous genetic studies have focused on looking for individual polymorphic risk variants. Here, we studied the overall levels of genetic diversity in T1D patients by making use of a previously published study including 1865 cases and 2828 reference samples with genotyping data for 500 K common single nucleotide polymorphisms (SNPs). We determined the minor allele (MA) status of each SNP in the reference samples and calculated the total number of MAs or minor allele contents (MAC) of each individual. We found the average MAC of cases to be greater than that of the reference samples. By focusing on MAs with strong linkage to cases, we further identified a set of 112 SNPs that could predict 19.19% of cases. These results suggest that overall genetic variation over a threshold level may be a risk factor in T1D and provide a new genetic method for predicting the disorder.     

Epitopes recognized by CBV4 responding T cells: effect of type 1 diabetes and associated HLA-DR-DQ haplotypes

The present study aimed at characterizing the epitopes recognized by coxsackievirus B4 (CBV4)-specific T-cell lines established from 23 children with type 1 diabetes (T1D) and 29 healthy children with T1D risk-associated HLA genotypes. Responsiveness to VP1 region was dependent on the specific infection history as 55% of the T-cell lines from donors with neutralizing antibodies to CBV serotypes responded to VP1 peptides compared to none of the T-cell lines from other donors (P = 0.01). The pattern of recognized peptides was dependent of the HLA genotype. Forty-two percent of the T-cell lines from donors carrying the HLA-(DR4)-DQB1*0302 haplotype responded to VP1 peptides 71-80 compared to none of the T-cell lines from donors without this haplotype (P = 0.02). No evidence for the existence of diabetes-specific epitopes was found. Only few epitopes were exclusive recognized by T cells from diabetic children, and in each case only one or two T-cell lines were responding.     

Pathogenesis of extra efferent vessel development in diabetic glomeruli

The development of extra efferent vessels (EEV) is a little-known feature of diabetic glomerulopathy. The only previous large study [Min W, Yamanaka N. Three-dimensional analysis of increased vasculature around the glomerular vascular pole in diabetic nephropathy. Virchows Archiv A Pathol Anat 1993; 423:201-7] known to us found that up to 5 EEV per glomerulus (glom) each drained a separate lobule. Most EEV connected to the second- and third-order branches of the afferent arteriole (AA), and drained into peritubular capillaries. Although not so stated, the illustrations suggested that some EEV could be shunts, and thus detrimental to glom function, and possibly glom health. There was no correlation between the unquantitated presence of increased EEV at the vascular pole (VP) and the severity of the major diabetic glomerular (glom) lesions. The authors opined that efferent arteriole (EA) stenosis by insudative lesions (IL) stimulated the formation of EEV. To confirm and extend these findings, we have repeated the study in 18 diabetic cases with mild to severe, but not end-stage, diffuse and nodular lesions (DL and NL), 8 controls, and the 2 normal traumatic nephrectomy cases. Up to 18 EEV per glom were found in diabetic cases along with occasional EEV in controls. EEV contained muscle and were almost identical to the EA in structure. Nearly all EEV connected with efferent glom capillaries at the VP, where they exited the glom through apparently preexisting gaps in the Bowman's capsule and/or glomerular capillary basement membranes (BCBM/GCBM). The EA exited through a similar gap, so the exit of EEV was accomplished without altering the anatomical relationships between the exiting vessels and the components of the VP thought to be important in the control of glom outflow. The largest number of EEV occurred in long-standing T2DM cases with mild to moderate DL and NL. Complete photographic glom reconstructions revealed numerous anastomoses among efferent glom capillaries in normal and diabetic gloms with mild to moderate DL and NL. No disproportionately dilated EEV were seen. The findings just cited confirm that EEV are common and surprisingly numerous in diabetic gloms. They suggest that EEV formation served to preserve glom function, and that EEV could neither shunt nor restrict glom outflow locally. In our opinion, the formation of EEV represents a significant, possibly hemodynamically induced, remodeling of the glom that should be added to the list of changes that occur in diabetes. It is hypothesized that EEV develop because of increased glom inflow, and that the latter may be attributable to AA muscle damage that impairs its contractile ability.     

MAP3738c and MptD are specific tags of Mycobacterium avium subsp. paratuberculosis infection in type I diabetes mellitus

Mycobacterium avium subsp. paratuberculosis (Map) is the causative agent of Johne's disease, a chronic inflammation of ruminants' intestine. Recent studies have linked Map to type I Diabetes mellitus (T1DM). We searched the presence of antibodies against two specific proteins of Map (MptD and MAP3738c) in sera of patients affected by T1DM and type II Diabetes mellitus (T2DM). MptD protein (MAP3733c) has been recognized as a Map virulent factor whereas MAP3738c has not yet been studied. Both proteins are encoded by genes belonging to a Map specific pathogenicity island. Forty three T1DM patients' sera, 56 T2DM patients' sera and 48 healthy subjects' sera were screened by ELISA to evaluate the immunoresponse against MptD or MAP3738c recombinant proteins. Results showed a positive response to both proteins in T1DM patients whereas no difference with controls was found for T2DM patients. Results suggest a potential relation between T1DM and the bacterial infection.     

Effects of combination therapy with dipeptidyl peptidase‐IV and histone deacetylase inhibitors in the non‐obese diabetic mouse model of type 1 diabetes

Type 1 diabetes (T1D) results from T helper type 1 (Th1)‐mediated autoimmune destruction of insulin‐producing β cells. Novel experimental therapies for T1D target immunomodulation, β cell survival and inflammation. We examined combination therapy with the dipeptidyl peptidase‐IV inhibitor MK‐626 and the histone deacetylase inhibitor vorinostat in the non‐obese diabetic (NOD) mouse model of T1D. We hypothesized that combination therapy would ameliorate T1D by providing protection from β cell inflammatory destruction while simultaneously shifting the immune response towards immune‐tolerizing regulatory T cells (T_regs). Although neither mono‐ nor combination therapies with MK‐626 and vorinostat caused disease remission in diabetic NOD mice, the combination of MK‐626 and vorinostat increased β cell area and reduced the mean insulitis score compared to diabetic control mice. In prediabetic NOD mice, MK‐626 monotherapy resulted in improved glucose tolerance, a reduction in mean insulitis score and an increase in pancreatic lymph node T_reg percentage, and combination therapy with MK‐626 and vorinostat increased pancreatic lymph node T_reg percentage. We conclude that neither single nor combination therapies using MK‐626 and vorinostat induce diabetes remission in NOD mice, but combination therapy appears to have beneficial effects on β cell area, insulitis and T_reg populations. Combinations of vorinostat and MK‐626 may serve as beneficial adjunctive therapy in clinical trials for T1D prevention or remission.     

Mismatch on Glutathione S-Transferase T1 Increases the Risk of Graft-versus-Host Disease and Mortality after Allogeneic Stem Cell Transplantation

Several drug-metabolizing enzymes, preferentially expressed in the liver, have the potential to act as minor histocompatibility antigens. In the present study, we analyzed the impact of glutathione S-transferase T1 (GSTT1), glutathione S-transferase M1, glutathione S-transferase P1, and UDP glucuronosyl transferase 2B17 (UGT2B17) disparities on the outcome of 125 patients undergoing allogeneic hematopoietic stem cell transplantation. Grades 2 to 4 acute graft-versus-host disease (aGVHD) developed in 56.2% versus 73.3% of GSTT1-matched versus mismatched patients (P = .048). Remarkably, 8.6% GSTT1-matched patients developed grades 2 to 4 liver aGVHD, compared with 36.8% among GSTT1-mismatched recipients (P < .001). Regarding chronic graft-versus-host disease (cGVHD), 34.8% versus 70.7% matched versus mismatched patients developed overall cGVHD (P = .038) and 16.3% versus 48% developed hepatic cGVHD (P = .006). We also found a strong association between the UGT2B17 mismatch and the risk of severe aGVHD (P = .001), especially with gut involvement (P < .001). Most striking was the influence of the GSTT1 mismatch on nonrelapse mortality (26.8% versus 52.6%, P = .031) and overall survival (62% versus 36.9%, P = .045). In summary, UGT2B17 and GSTT1 mismatch are risk factors for the development of GVHD and the latter also influences on mortality and survival after allogeneic transplantation from HLA-identical donors.     

Receptor-interacting protein 2 (RIP2) gene polymorphisms are associated with increased risk of subclinical atherosclerosis and clinical and metabolic parameters. The Genetics of Atherosclerotic Disease (GEA) Mexican study

The receptor-interacting protein 2 (Rip2) is a serine/threonine kinase involved in multiple nuclear factor-κB (NFκB) activation pathways and is a key regulator of cellular lipid metabolism and cardiovascular disease. The aim of the present study was to evaluate the role of RIP2 gene polymorphisms as susceptibility markers for subclinical atherosclerosis (SA). Using an informatics analysis, four RIP2 gene polymorphisms with predicted functional effects (rs2293808, rs43133, rs431264, and rs16900627) were selected. The polymorphisms were genotyped in 405 individuals with SA (calcium score > 0 assessed by computed tomography) and 1099 controls (calcium score = 0). Clinical, anthropometric, tomographic and biochemical traits were measured. The association between the RIP2 polymorphisms and SA was evaluated using logistic regression analyses. Pair wise linkage disequilibrium (LD, D′) estimations between polymorphisms and haplotype reconstruction were performed with Haploview version 4:1. Under different models adjusted by age, gender, body mass index, hypertension, diabetes mellitus, smoking habit, total cholesterol, HDL-cholesterol, LDL-cholesterol and triglyceride levels, rs43133 (OR = 1.43, 95% CI: 1.05–1.94, P = 0.022), and rs16900627 (OR = 1.59, 95% CI: 1.00–2.54, P_dom = 0.048 and OR = 1.60, 95% CI: 1.05–2.54, P_add = 0.028) were associated with increased risk of developing SA. Moreover, rs2293808, and rs431264 were associated with clinical or metabolic parameters in SA individuals and in healthy controls. The four polymorphisms were in high linkage disequilibrium and the GAAG haplotype was associated with increased risk of developing SA (OR = 1.47, P = 0.027). This study shows for the first time, that RIP2 polymorphisms are associated with increased risk of SA and with some clinical and metabolic parameters.