ABSTRACT
Objective To investigate the isolation and culture of porcine bone marrow mesenchymal stem cell (BMSC) with α-1, 3-galactosyltransferase (GGTA1) gene knockout (GTKO), GTKO/ human CD46 (hCD46) insertion and cytidine monopho-N-acetylneuraminic acid hydroxylase (CMAH)/GGTA1 gene knockout (Neu5GC/Gal), and the protective effect of co-culture with porcine islets on islet cells. Methods Bone marrow was extracted from different transgenic pigs modified with GTKO, GTKO/hCD46 and Neu5GC/Gal. Porcine BMSC were isolated by the whole bone marrow adherent method and then cultured. The morphology of BMSC was observed and the surface markers of BMSC were identified by flow cytometry. Meantime, the multi-directional differentiation induced by BMSC was observed, and the labeling and tracing of BMSC were realized by green fluorescent protein (GFP) transfection. The porcine BMSC transfected with GFP were co-cultured with porcine islet cells. Morphological changes of porcine islet cells were observed, and compared with those in the porcine islet cell alone culture group. Results BMSC derived from pigs were spindle-shaped in vitro, expressing biomarkers of CD29, CD44, CD73, CD90, CD105 and CD166 rather than CD34 and CD45. These cells were able to differentiate into adipocytes, osteoblasts and chondrocytes. Porcine BMSC with GFP transfection could be labeled and traced, which could be stably expressed in the daughter cells after cell division. Porcine BMSC exerted certain protective effect on islet cells. Conclusions GFP-labeled porcine BMSC modified with GTKO, GTKO/hCD46 and Neu5GC/Gal are successfully established, which exert certain protective effect upon islet cells.
ABSTRACT
Islet transplantation is considered as one of the most effective approach for type 1 diabetes mellitus, although its efficacy is limited by several factors. Anoxia, stress and rejection occurring during the isolation, culturing and transplantation of islets may have impact on the outcome of the islet transplantation. Due to the biological properties such as anti-inflammation, angiogenetic promotion and immune regulation, mesenchymal stem cells (MSCs) are all the way focused by researchers. Additionally, exosome, a derivative of MSC, also plays an import role in regulating anoxia-induced oxidative stress modulation, angiogenetic promotion, and immune regulation. MSC-based islet transplantation may be a useful therapeutic tool in treating type 1 diabetes. Therefore, in this review, the potential effect of MSC prior and posterior to the operation of the islet transplantation, its clinical application as well as its limitations were reviewed, aiming to offer insights into the future application of islet transplantation in treating type 1 diabetes.
ABSTRACT
Islet transplantation has developed rapidly over the last 20 years and is becoming one of the ideal clinical treatment options for type 1 diabetes mellitus (T1DM). There is growing clinical evidence that islet transplantation has significant efficacy in insulin independence or reduction, preventing hypoglycemic episodes and preventing diabetic complications.However, clinical islet transplantation still faces challenges, such as a shortage of donor resources, difficulties in early implantation and survival of islet grafts, and immune rejection.In the future, donor pancreatic donation and its effective utilization should be promoted, and clinical exploration of xenogeneic islet transplantation and stem cell-derived islet transplantation should be encouraged to effectively solve the problem of insufficient islet source.At the same time, through continuous research and development of new materials and technologies, optimize the location of islet transplantation to improve the implantation and survival of islet grafts, and gradually eliminate the need for immunosuppression.In addition, we should actively promote the development and application of post-islet transplantation graft monitoring tools to further ensure the long-term survival of post-islet transplantation grafts, so that more diabetic patients can benefit from it.
ABSTRACT
Objective:To explore the selection criteria of the donor for islet transplantation of Chinese people by analyzing the correlation between pancreas characteristics and success rate of islets isolation.Methods:Data from 113 cases of human islet isolation were collected. According to the result of islet isolation, the donors were divided into two groups, the success group(IEQ≥250 000, purification≥30%, and viability≥80%), and the failure group(IEQ<250 000, or purification<30%, or viability<80%). The modified Ricordi method was used to digest pancreas tissue, and the continuous density gradient method was performed to purify islets. The islets were identified by staining with the Dithizone(DTZ), the islets were analyzed for cell viability and purity.Results:The donor age in success group was significantly younger than failure group in the range of age eligible for this study( t=2.479, P=0.015). Pearson correlation showed that donor age was positively corelated with islet yield( r=-0.214, P=0.047). There was more fat on the pancreas surface in the successful islet isolation group( z=-2.007, P=0.045). The digestibility( t=2.133, P=0.035) and recovery rate( t=5.912, P=0.001) were elevated in success group. Conclusion:The pancreases from younger donors could obtain the higher-yielding islet, the pancreas with more surface fat or with higher weight was associated with islet isolation success in the scope covered by the inclusion criteria of this study.
ABSTRACT
Objective To identify the key genes and targeted protection methods affecting the survival of human islets. Methods Using bioinformatics method, the gene expression profile (GSE53454) was selected through screening and comparison from Gene Expression Omnibus(GEO) database. GEO2R tool was employed to screen the differentially expressed gene(DEG) between the human islets exposed (exposure group) and non-exposed (non-exposure group) to interleukin (IL)-1β and interferon (IFN)-γ for 24, 48 and 72 h, respectively. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were performed by DAVID. Protein-protein interaction (PPI) network was constructed by STRING and Cytoscape apps. Results A total of 69 up-regulated DEGs and 2 down-regulated DEGs were identified. GO analysis showed that during the biological process, DEGs were enriched in the aspects of virus defense and inflammatory response. In cellular components, DEGs were significantly enriched in extracellular space, outside plasma membrane and extracellular regions. Regarding molecular functions, DEGs were significantly enriched in chemokine activity and cytokine activity. KEGG analysis revealed that DEGs were mainly enriched in multiple signaling pathways, such as cytokine-cytokine receptor interaction, virus protein-cytokine and cytokine-receptor interaction, etc. Ten key genes (STAT1, CXCL10, IRF1, IL6, CXCL9, CCL5, CXCL11, ISG15, CD274, IFIT3) with high connectivity were selected by STRING analysis, all of which were significantly up-regulated in human islets exposed to IL-1β and IFN-γ. Six genes (STAT1, CXCL10, CXCL9, CXCL11, CCL5, IL6) were screened by KEGG enrichment analysis, mainly in Toll-like receptor signaling pathway. Conclusions STAT1, CXCL10, CXCL9, CXCL11, CCL5 and IL6 are the key genes affecting the survival of human islets, which are mainly enriched in Toll-like receptor signaling pathway and act as important targets for islet protection.
ABSTRACT
Islet transplantation is a promising treatment of diabetes mellitus and its complications. Nevertheless, dysfunction post-transplantation, rejection and shortage of donors are the bottleneck issues in the field of islet transplantation. Optimizing the preservation method of pancreas plays a positive role in obtaining a sufficient quantity of effective islets and maintaining their functions. During the culture stage, anti-rejection and anti-apoptosis treatment of islets, including mesenchymal stem cell (MSC), MSC-derived exosomes, anti-apoptosis drugs and gene modification, may become major approaches for islet protection and functional maintenance in clinical islet transplantation. Use of anti-instant blood-mediated inflammatory reaction (IBMIR) drugs after islet transplantation also plays a critical role in protecting islet function. In this article, the whole process from islet preparation to islet transplantation was illustrated, and relevant strategies of islet protection and functional maintenance were reviewed, aiming to provide reference for improving the quality of donors to compensate for the shortage of absolute quantity of donors and elevating the efficiency of islet transplantation.
ABSTRACT
Objective To evaluate the effect of mesenchymal stem cell (MSC) coated-islets on instant blood-mediated inflammatory reaction (IBMIR) after islet transplantation. Methods MSC labeled with tracer and human islets were placed into an ultra-low adsorption cell culture dish, shaken and mixed twice at an interval of 0.5 h, and then incubated at 37 ℃ and 5% CO2 for 24 h to obtain MSC-coated islets. The coating effect of MSC and in vitro function of the islets were assessed. A blood circulation tube-shaped model was established in vitro. In the blank control group, 0.2 mL of islet culture solution was added. In the islet group, 800 islet equivalent quantity (IEQ) of uncoated islets were supplemented. In the MSC-coated islets group, 800 IEQ of MSC-coated islets were added, and circulated for 60 min at 37 ℃. A portion of 0.5 mL blood sample was taken for routine blood test at 0, 30 and 60 min, respectively. After 60 min circulation, the blood sample was filtered with a 70 μm filter to collect plasma, blood clots and islets. Blood clots and islets were subject to hematoxylin-eosin (HE) staining and immunohistochemical staining. Morphological changes and the aggregation of CD11b-positive cells surrounding the islets were observed. The contents of plasma thrombin-antithrombin complex (TAT), tissue factor (TF), C3a, C5b-9, interleukin (IL)-1β, IL-6, tumor necrosis factor (TNF)-α, monocyte chemoattractant protein (MCP)-1 and IL-8 were determined by enzyme-linked immune absorbent assay. Results After 24 h co-incubation, the islets were coated by MSC, with a coating degree of approximately 80%. In the islet and MSC-coated islet group, a large quantity of neutrophils and monocytes were observed surrounding the blood clots and islets, and the quantity of CD11b-positive cells in the MSC-coated islet group was less compared with that in the islet group. After co-incubation with the whole blood for 0, 30 and 60 min, the quantity of platelets, neutrophils and monocytes was declined in the MSC-coated and islet groups, and gradually decreased over time. Compared with the blank control group, the quantity of platelets, monocytes and neutrophils was lower, whereas the TF content was higher in the MSC-coated islet group. Compared with the islet group, the quantity of platelets, monocytes and neutrophils was higher, whereas the TAT and TF contents were less in the MSC-coated islet group, the differences were statistically significant (all P < 0.05). Compared with the blank control group, the expression levels of C3a, C5b-9, IL-6, TNF-α and IL-8 were up-regulated in the MSC-coated islet group. Compared with the islet group, the expression levels of C3a, C5b-9, IL-1β, IL-6, TNF-α, IL-8 and MCP-1 were down-regulated in the MSC-coated islet group, and the differences were statistically significant (all P < 0.05). Conclusions MSC-coated islets may reduce the exposure of islet TF in the blood and prevent the incidence of IBMIR during the coagulation response stage, thereby mitigating the injury and loss of islet allograft in the early stage of islet transplantation.
ABSTRACT
As an effective procedure for type 1 diabetes mellitus and end-stage type 2 diabetes mellitus, islet transplantation could enable those patients to obtain proper control of blood glucose levels. Instant blood-mediated inflammatory reaction (IBMIR) is a nonspecific inflammation during early stage after islet transplantation. After IBMIR occurs, coagulation cascade, complement system activation and inflammatory cell aggregation may be immediately provoked, leading to loss of a large quantity of transplant islets, which severely affects clinical efficacy of islet transplantation. How to alleviate the islet damage caused by IBMIR is a hot topic in islet transplantation. Heparin and etanercept, an inhibitor of tumor necrosis factor-α, are recommended as drugs for treating IBMIR following islet transplantation. Recent studies have demonstrated that multiple approaches and drugs may be adopted to mitigate the damage caused by IBMIR to the islets. In this article, the findings in clinical and preclinical researches were reviewed, aiming to provide reference for the management of IBMIR after islet transplantation.
ABSTRACT
Islet transplantation is one of the effective therapies for diabetes mellitus. Nevertheless, multiple issues still exist, such as shortage of donors and adverse reactions caused by long-term use of immunosuppressants, which limit the islet survival post-transplantation. Microencapsulated islet transplantation may overcome these difficulties to certain extent, whereas many factors, such as the destruction of immune isolation microenvironment within the microcapsules and insufficient supply of oxygen and nutrients, constrain the application of microencapsulated islet transplantation in clinical practice. In recent years, how to enhance the effect of microencapsulated islet transplantation has been gradually studied. The application of stem cells in microencapsulated islet transplantation has steadily become a research hot spot. Therefore, the optimizing strategies for microencapsulated islet transplantation and the application of stem cells in microencapsulated islet transplantation were reviewed, and the potential improvement techniques of microencapsulated islet transplantation were investigated in this article, aiming to provide reference for further clinical application of microencapsulated islet transplantation.
ABSTRACT
Objective:To Eveluate the safty and clinical efficacy of combined laparoscopic spleen-preserving distal pancreatectomy and autologous islet transplantation in the treatment of solid pseudopapillary neoplasm.Methods:A 22 years old solid pseudopapillary neoplasm female patient who underwent distal pancreatectomy and an autologous islet transplantation at Tianjin First Central Hospital, clinical date for 6 months follow up was collected and analyzed.Results:The patient was well recovered after surgery, and during the post-operative follow up, the fasting blood glucose was 5.72 mmol/L, HbA1c was 6.1%, remained insulin independent, the liver function was kept well.Conclusions:Combined Laparoscopic spleen-preserving distal pancreatectomy and autologous islet transplantation can effectively prevent diabetes after distal pancreatectomy.
ABSTRACT
Objective:To explore the application value of whole-process ultrasound-guided percutaneous portal vein puncture islet transplantation.Methods:From October 2018 to May 2021, 16 diabetics underwent whole-process ultrasound-guided percutaneous portal vein puncture islet transplantation at First Affiliated Hospital of Sun Yat-sen University.The whole process was guided by ultrasound for completing percutaneous portal vein puncture catheterization, islet infusion monitoring, bleeding prevention and ablation hemostasis after bleeding.Results:Ten patients [8 males and 2 females with a mean age of(45.9±21.1)years]underwent 16 islet transplants, including one islet(5 cases), two islets(4 cases)and three islets(1 case). A single puncture was successfully performed without damage to other extrahepatic organs, persistent portal hypertension, portal vein embolism or infection.Bleeding at liver puncture site occurred in 3 cases and ultrasound radiofrequency ablation was performed for immediate hemostasis.Among them, postoperative blood glucose stabilized at 4~12 mmol/l post-operation.And 5 cases(31.3%)achieved insulin independence for>2 months and 10 cases(62.5%)lowered insulin dosage by>50% as compared with preoperative level.The level of fasting C-peptide recovered or was higher than normal in 10 cases(62.5%)and became obviously elevated in the remainders.In 11 cases(68.8%)of them, liver transaminase was briefly and mildly elevated post-operation, and no other complications were observed.Conclusions:The whole-process ultrasound-guided percutaneous portal vein islet transplantation is both safe and feseasible.It avoids the injury of transplanted kidney caused by contrast agent and radiological radiation to operator and patient.It is a method of islet transplantation worth a wider popularization.
ABSTRACT
Introduction: The success of islet transplantation for patients with unstable type 1 diabetes mellitus depends, in part, on the number of isolated islets and their quality, which is assessed by functional and viability tests. The test currently employed to evaluate islet viability, used by the Collaborative Islet Transplant Registry to release products for transplantation, is fluorescein diacetate/propidium iodide (FDA/PI) staining. However, the efficacy of this method relies on researcher experience; in this context, a quantitative method may be useful. The aim of this study was to compare islet viability as assessed by flow cytometry and the FDA/PI assay. Methods: Viability was analyzed in islets isolated from 10 male Wistar rats. Upon FDA/PI staining, 50 islets from each animal were analyzed under fluorescence microscopy by two well-trained researchers. For flow cytometry, islets were dispersed and 100 000 single cells were incubated with the 7-amino-actinomycin D (7AAD) fluorophore (dyes necrotic and late apoptotic cells) and the Annexin V-APC antibody (marks early apoptotic cells). Results: A moderate correlation was found between techniques (r = 0.6; p = 0.047). The mean islet viability measured by flow cytometry was higher than that estimated using FDA/PI staining (95.5 ± 1.4% vs 89.5 ± 5.0%; p = 0.002). Conclusions: Although flow cytometry is more expensive and time-consuming than FDA/PI staining, it is a quantitative technique with greater reproducibility that is less subject to inter-observer variability than FDA/PI. Therefore, flow cytometry appears to be the technique of choice when aiming for a more precise determination of islet viability. (AU)
Subject(s)
Animals , Male , Rats , Propidium , Islets of Langerhans Transplantation , Fluorescein , Flow Cytometry , Diabetes Mellitus, Type 1ABSTRACT
Objective To explore the feasibility and potential application value of establishing the neonatal pig models of islet transplantation under the renal capsule. Methods Nine wild-type neonatal Duroc pigs were selected, including 1 animal as the control (p6307), 6 as islet transplant donors and 2 as islet transplant recipients (p6210, p6207). After islet isolation and differentiation in vitro, islet transplantation under the renal capsule of the pig was performed. Immunosuppressive therapy of tacrolimus (Tac) combined with sirolimus was given after operation. Postoperative body weight, blood glucose and serum creatinine levels of the recipients were monitored. The p6210 recipient neonatal pig was sacrificed at postoperative 4 weeks, while the p6207 recipient and the control neonatal pig were sacrificed at postoperative 8 weeks. The islet grafts under the renal capsule were collected for pathological staining and insulin immunofluorescent staining. Results After islet transplantation under the renal capsule of the pigs, the growth rate of body weight of the recipients was significantly slower than that of the control neonatal pig, accompanied with intermittent symptoms, such as anorexia and diarrhea, etc. However, the blood glucose and serum creatinine levels of the recipients did not significantly differ from preoperative levels and those of the control neonatal pig. Evident islet mass was observed under the renal capsule of the p6210 recipient. Pathological staining and insulin immunofluorescent staining confirmed that the islet mass had the function of secreting insulin, whereas no obvious islet mass could be seen under the renal capsule of the p6207 recipient. Pathological staining detected no evident islet mass, suggesting the possibility of islet transplantation failure caused by rejection in the p6207 recipient. Conclusions The establishment of neonatal pig models of islet transplantation under the renal capsule is a feasible technique, which provides preliminary evidence for the establishment of composite islet-kidney donor graft in pig models for xenotransplantation in the treatment of end-stage diabetic nephropathy.
ABSTRACT
Objective To investigate the improvement and effect of the method of islet extraction in mice. Methods According to different islet extraction methods, all mice were randomly divided into the common bile duct puncture group (n=100) and common bile duct puncture combined with in situ pancreatic injection group (combined injection group, n=100). Common bile duct puncture combined with in situ pancreatic injection was utilized as the modified method. The islets were selected and purified under stereomicroscope. The morphology and purification of islets were identified. The islet yield and success rate of islet extraction were statistically compared between two groups. The survival of islets after 1 week culture in vitro was analyzed, and the insulin secretion function of islets after 24 h and 4 d culture in vitro was evaluated. Results Compared with the common bile duct puncture group, the islet yield in the combined injection group was significantly increased (P < 0.001). The success rate of islet extraction in both groups was 83% with no statistical significance (P > 0.05). The islets extracted by common bile duct puncture combined with in situ pancreatic injection had intact morphology, high purity and high activity. The survival rate of newly isolated islets was nearly 100% after 24 h culture in vitro. After 1~5 d culture in vitro, the islet cells survived well. After 6 d culture in vitro, the islets showed central death. After culture in vitro for 24 h and 4 d, the islet function of the mice was normal after high glucose stimulation. Conclusions Common bile duct puncture combined with in situ pancreatic injection can increase the islet yield, and the obtained islet cells have high activity and proper function.
ABSTRACT
BACKGROUND: Currently, it was confirmed that encapsulating islets with natural or synthetic biomaterials to form a barrier with the function of immune isolation can not only reduce the systematic use of immunosuppressive agents to a certain extent, but also make heterogenous islet transplantation possible. OBJECTIVE: To introduce the research progress of the biomaterials for islet transplantation, describe several models for encapsulating islet, and eventually discuss current research focus and prospects of islets encapsulating models. METHODS: The authors searched PubMed and Web of Science databases with the search terms “islet encapsulation, islet transplantation biomaterials, islet transplantation hydrogel” for relevant papers published. Initially, a total of 447 papers were retrieved, and 89 of them were included in the final analysis. RESULTS AND CONCLUSION: There are two main deficiencies in islet encapsulation for transplantation: one is the attack of immune rejection by the recipient; the other is the shortage of supply of oxygen and nutrient. Encapsulation of islet with a single material, synthetic or natural biomaterial, cannot address the two issues mentioned above. Herein, the biomaterial used for islet encapsulation must be modified. Current islet hydrogel models tend to combine synthetic biomaterials with natural biomaterials to take full advantage of the two kinds of biomaterials. In addition, immune-regulating drugs, angiogenic factors, or factors promoting the survival or function of islets can also be incorporated into the biomaterial. Besides, other cells can be involved to co-transplant with islets in the hydrogel. How to incorporate various strategies for addressing the above issues properly is the key of future research.
ABSTRACT
Objective To explore the effects of Qa-1 and PD-L1 loaded artificial liposomal treatment in allograft rejection and its outcomes .Methods The extracellular domains of Qa-1 and PD-L1 were loaded on liposome surface by streptavidin-biotin system . Mixed lymphocyte reaction (MLR) was performed for measuring Qa-1/PD-L1 liposome biological function .Then liposome was co-transplanted with allo-islets via portal vein .The levels of blood glucose and C-peptide were detected daily after transplantation .Also hepatic lymphocytes after transplantation were isolated for determining the proportion of activated cells and signaling pathway changes .Results Artificial liposome could be easily loaded with biotinylated peptide and its diameter was between 50 to 500 nm . Qa-1/PD-L1 liposome could significantly suppress lymphocyte proliferation , activation and secretion of IFN-γ in MLR by an activation of SHP1/2 and an inhibition of Syk pathway .Qa-1/ PD-L1 liposomes could suppress the activation of hepatic lymphocytes in vivo by activating SHP1/2 ,protecting islet allografts and maintaining a normal level of blood glucose in recipients .Conclusions Qa-1/PD-L1 loaded liposome can effectively suppress allograft rejection and improve the outcomes of islet transplantation .
ABSTRACT
Objective@#To further observe the efficacy of combined transplantation of islet and bone marrow mesenchymal stem cells (BMSC) in diabetic rats, PET-CT was used to trace cells in vivo to determine the homing and distribution of cells in vivo.@*Methods@#Streptozotocin (STZ)was used to construct a rat model of diabetes mellitus. BMSC could be isolated and cultured by full adherence method; islets were isolated by collagenase; Islets and BMSC were labeled with 18F-FDG in vitro. Diabetic rats were randomly divided into 4 groups, 15 rats in each group: A, Control group; B, Stem cell transplantation group; C, Islet Transplantation group; D, Combined transplantation group, a total of four groups, all transplanted through portal vein, PET-CT tracing the distribution of cells transplanted into the body.7 days after transplantation, the livers of each group were taken, and the homing and distribution of transplanted cells were detected by immunofluorescent staining.The SUV was calculated by the analysis of variance of random block, and the difference between groups was compared by t-test.@*Results@#PET-CT results showed that BMSC were mainly distributed uniformly in the right liver, and the islets of the pancreas were mainly clustered in terminal branches of hepatic portal vein, and BMSC were around the islets of pancreas, but there was no obvious development in the liver of the control group.@*Conclusions@#PET-CT can directly reveal the distribution of islets and BMSC in liver after transplantation through portal vein.
ABSTRACT
Objective@#Engineer a scaffold with mesenchymal stem cells and small intestinal submucosal to evaluate the effect of islet transplantation in diabetic rats.@*Methods@#MSC and pancreatic islets were isolated from Sprague-Dawley rats, and SIS was isolated from Bamei pigs. MSC were seeded on the SIS to construct MSC-SIS scaffold. The STZ-induced diabetic rats were divided into three groups: islets, SIS, and MSC-SIS. The expressions of insulin and CD31 were detected by immunofluorescence on the 14th day after transplantation, and serum cytokines were detected by protein microarray.One-way ANOVA was used to compare the transplantation effect of each group.@*Results@#In MSC-SIS group, the expressions of insulin and CD31 were significantly higher than those in the other two groups. Cytokines of VEGFA were increased while TNF-α, IFN-γ and IL-6 decreased, showing a significant difference (P<0.05). These results suggest that MSC-SIS scaffold significantly improve graft function and promote the expression of insulin and CD31, which may be related to the angiogenesis and anti-inflammatory effects of MSC.@*Conclusions@#Mesenchymal stem cells combined with intestinal submucosal scaffold can improve the effect of islet transplantation and provide a new method for the treatment of diabetes.
ABSTRACT
Objective@#To investigate the effect factors of liver enzymes elevation by monitoring the liver function changes before and after intraportal islet transplantation.@*Methods@#16 diabetic patients who received intraportal islet transplantation in our hospital were analyzed. The levels of aspartic aminotransferase (AST), alanine aminotransferase (ALT)and total bilirubin (TBil)were monitored after islet transplantation.@*Results@#Among those 16 diabetic patients who received intraportal islet transplantation, 11 patients showed an increased AST and 8 patients showed an increased ALT, among which a 2.5-fold increase in AST was observed in 4 patients and over 1.5-fold elevation of ALT was observed in 3 patients. The level of TBil were in the normal range before and after transplantation in all patients. Transplanted tissue volume of islet was the main factor for significantly increased AST (P<0.05) in this study. It is also shown that the change in portal pressure is related to the AST elevation after islet transplantation.@*Conclusions@#The amount of transplanted islet tissue volume is related to the liver enzymes elevation after intraportal islet transplantation. Therefore, the improvement of the purity of islet to reduce the amount of transplanted tissue could be benefit to prevent the liver injury after islet transplantation. Meanwhile, the purified islets should be injected as slowly as possible to maintain a stable portal pressure.
ABSTRACT
Objective To further observe the efficacy of combined transplantation of islet and bone marrow mesenchymal stem cells (BMSC) in diabetic rats ,PET-CT was used to trace cells in vivo to determine the homing and distribution of cells in vivo .Methods Streptozotocin (STZ)was used to construct a rat model of diabetes mellitus .BMSC could be isolated and cultured by full adherence method;islets were isolated by collagenase ;Islets and BMSC were labeled with 18F-FDG in vitro . Diabetic rats were randomly divided into 4 groups ,15 rats in each group :A ,Control group;B ,Stem cell transplantation group ;C ,Islet Transplantation group ;D ,Combined transplantation group ,a total of four groups ,all transplanted through portal vein ,PET-CT tracing the distribution of cells transplanted into the body .7 days after transplantation ,the livers of each group were taken ,and the homing and distribution of transplanted cells were detected by immunofluorescent staining .The SUV was calculated by the analysis of variance of random block , and the difference between groups was compared by t-test .Results PET-CT results showed that BMSC were mainly distributed uniformly in the right liver ,and the islets of the pancreas were mainly clustered in terminal branches of hepatic portal vein ,and BMSC were around the islets of pancreas ,but there was no obvious development in the liver of the control group .Conclusions PET-CT can directly reveal the distribution of islets and BMSC in liver after transplantation through portal vein .