Application progress of mesenchymal stem cells in islet transplantation for type 1 diabetes mellitus / 器官移植

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.

Isolation of bone marrow mesenchymal stem cells in transgenic pigs and co-culture with porcine islets / 器官移植

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.

Presencia de autoanticuerpos anti islotes pancreáticos en diabetes tipo 1 durante la edad pediátrica / Presence of anti-pancreatic islet autoantibodies in type 1 diabetes in children

En la Diabetes tipo 1 (DM1) la pérdida de células ß pancreáticas es consecuencia de un proceso de autoinmunidad que cursa con la presencia de autoanticuerpos anti-islotes pancreáticos (AAPs). Estos AAPs son marcadores útiles para la clasificación de la enfermedad. En un centro pediátrico de tercer nivel se analizó la frecuencia de presentación de GADA, IA-2A, ZnT8A e IAA en un grupo con reciente debut entre enero 2018 y agosto 2021 (n= 90). Además, se investigó la frecuencia de presentación y relación de los AAPs con la edad, sexo y tiempo de evolución en pacientes en seguimiento (n= 240). En el grupo de debut se obtuvo positividad de GADA, IA-2A, ZnT8A y IAA en 77,8; 60; 62 y 47,8% de los pacientes respectivamente, un 4% no presentó AAPs. El 95,6% de los pacientes presentaron al menos un AAPs positivo. La frecuencia de IAA en el grupo en debut fue mayor en menores de 5 años. En el grupo en seguimiento el 75,2% resultaron GADA positivo (85,7% en mujeres y 62,8% en varones) p<0,05. IA-2A y ZnT8A fueron positivos en 45 y 51.7% respectivamente. El 91% presentaron al menos un AAP positivo. En este grupo se evidenció una menor positividad en función del tiempo de evolución. Se pudo determinar la frecuencia de presentación de los AAPs en un grupo en debut y la relación con la edad, sexo y tiempo de evolución en pacientes en seguimiento. La determinación de APPs facilita la correcta clasificación y elección de la terapia adecuada (AU)

In type 1 diabetes (DM1) the loss of pancreatic ß-cells is a consequence of an autoimmune process that results in the presence of pancreatic anti-islet autoantibodies (PAAs). PAAs are useful markers for the classification of the disease. The frequency of presentation of GADA, IA-2A, ZnT8A, and IAA in a group with recent debut seen between January 2018 and August 2021 (n= 90) was analyzed in a tertiary pediatric center. In addition, we investigated the frequency of presentation and association of PAAs with age, sex, and time of evolution in patients in follow-up (n= 240). In the debut group, GADA, IA2A, ZnT8A, and IAA positivity was found in 77.8, 60, 62, and 47.8% of patients, respectively; no PAAs were observed in 4% of the patients. Overall, 95.6% presented at least one positive PAA. The frequency of IAA in the debut group was higher in children younger than 5 years. In the follow-up group, 75.2% were GADA positive (85.7% of females and 62.8% of males) p<0.05. IA-2A and ZnT8A were positive in 45 and 51.7% respectively. Ninety-one percent presented with at least one positive PAA. In this group, a lower positivity was evidenced as a function of the time of evolution. The frequency of presentation of PAAs in a debut group and the relationship with age, sex, and time of evolution in patients in follow-up was demonstrated. The assessment of PAAs facilitates the correct classification and choice of adequate therapy (AU)

Trends in clinical islet transplantation / 中华器官移植杂志

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.

Machanism of methyleugenoc in protecting islet cells from hypoxia/reoxygenation injury / 中华器官移植杂志

Objective:To explore the protective effect of methyl eugenol (Me) on islet ischemia/reperfusion (I/R) injury and elucidate its underlying mechanism.Methods:The islets were isolated and purified from 6-8 week male BALB/c mice and divided into four groups of normal control (normal culture without any treatment), hypoxia/reoxygenation (H/R treatment), H/R+ dimethyl sulfoxide (DMSO dosing plus H/R treatment) and H/R+ Me (Me dosing plus H/R). Viability of islet cells in each group was detected by acridine orange (AO)/propidium iodide (PI) double stain.Function of islet cells (insulin secretion) was measured by enzyme-linked immunosorbent assay (ELISA). Murine islet β Min6 cells were selected for detecting the effect of Me on the proliferative activity of normal cultured and H/R treated islet cells under different concentration gradients by CCK8.Then Min6 cells were divided into four groups of normal, H/R, H/R+ DMSO and H/R+ Me.The definition of group was the same as that of primary murine islets.Flow cytometry and Hoechst 33342 nuclear stain were utilized for detecting cell apoptotic rate in each group.The protein expressions of p-JNK, p-p38, JNK, p38, Bcl-2 and Bax were detected by Western blot.And the data were processed by one-way ANOVA or t test.Results:The proportion of dead islet cells in H/R group was (29.47±2.65)% and it was significantly lower than that in normal group (7.63±1.53)%.And the inter-group differences were statistically significant ( P<0.001). The proportion of dead islet cells was (20.63±3.07)% in H/R+ Me group.It was higher than that in H/R group (29.47±2.65)% and in H/R+ DMSO group (30.13±1.50)% and inter-group difference was statistically significant ( P<0.05 & P<0.01). Under the stimulation of high glucose, the insulin secretion level of islet in H/R+ Me group was (1.76+ 0.08) mg/L, which was higher than that in H/R group and H/R+ DMSD group(1.24±0.14)mg/L and(1.27±0.05)mg/L, and the difference was statistically significant[(1.76±0.08) vs. (1.24±0.14) mg/L; (1.76±0.08) vs.(1.27±0.05) mg/L, P<0.01]. There was no significant effect on cell viability after Me dosing within a certain concentration range (0-40 μmol/L). After Me dosing (5 μmol/L), cell viability of H/R-treated Min6 cells was significantly higher than that without Me.And the difference was statistically significant[(1.19±0.03) vs.(1.00±0), P<0.01]. As compared with H/R and H/R+ DMSO groups, overall apoptotic rate declined in H/R+ Me group (Hoechst 33342 stain: 14.50%±1.05% vs. 23.30%±1.18%, 14.50%±1.05% vs. 22.77%±1.75%, P<0.001; Flow cytometry: 4.36%±0.54% vs. 21.44%±1.02%, 4.36%±0.54% vs. 21.68%±3.06%, P<0.01). The expressions of p-JNK and p-p38 were down-regulated (p-JNK: 0.77±0.06 vs. 1.03±0.05, 0.77±0.06 vs.0.93±0.04, P<0.001; p-p38: 0.80±0.05 vs. 1.01±0.08; 0.80±0.05 vs. 1.00±0.05, P<0.05) while Bcl-2/Bax ratio rose (1.62±0.13 vs. 0.72±0.10, 1.62±0.13 vs. 0.74±0.13, P<0.01). Conclusions:Me can improve the viability and function of islets and suppress the apoptosis of Min6 cells after H/R.The mechanism is correlated with JNK and p38 MAPK signaling pathways.

Application of the Chinese Expert Consensus on Diabetes Classification in clinical practice / 中华内科杂志

Objective:To evaluate the diagnostic for classification of newly diagnosed diabetes patients and assess the application of the screening tests recommended by the 2022 Chinese Expert Consensus on Diabetes Classification.Methods:Retrospective case series study. The data from the electronic medical record system of patients with new-onset diabetes mellitus (within 1 year of disease onset) who attending the Diabetes Specialist Outpatient Clinic at the Second Xiangya Hospital of Central South University from January 1, 2018 to December 31, 2021 were collected for the analysis. Based on the consensus, patients were categorized according their age of onset, body mass index (BMI), and suspicion of type 1 diabetes mellitus (T1DM). The chi-square statistic was used to compare key classifier indicators, including C-peptide, islet autoantibodies, and genetic markers, in the subgroups. The diagnosis in suspected T1DM patients was also evaluated. The screening strategy recommended in the consensus was further assessed using a logistic regression model and the area under the receiver-operating curve (AUC).Results:A total of 3 384 patients with new-onset diabetes were included. The average age of disease onset was (46.3±13.9) years, and 61.0% (2 065/3 384) of the patients were male. The proportions of patients who completed C-peptide and glutamic acid decarboxylase antibody (GADA) tests were 36.6% (1 238/3 384) and 37.5% (1 269/3 384), respectively. There were no significant differences in C-peptide test results among the subgroups (all P>0.05). In contrast, the GADA detection rate was higher in patients with young age of onset (<30 years old), in those who were non-obese (BMI<24 kg/m 2), and in those clinically suspected of T1DM (all P<0.05). According to the diagnostic pathway proposed by the consensus, only 57.4% (1 941/3 384) of patients could be subtyped. For a definitive diagnosis, the remaining patients needed completion of C-peptide, islet autoantibody, genetic testing, or follow-up. Furthermore, among patients with clinical features of suspected T1DM, the antibody positivity rate was higher than in non-suspected T1DM patients [24.5% (154/628) vs. 7.1% (46/646), P<0.001]. When the clinical features of suspected T1DM defined in the consensus were taken as independent variables and antibody positivity was considered the outcome variable in the logistic regression model, young onset, non-obese onset, and ketosis onset could enter the model. Based on AUC analysis, the accuracy of the diagnostic model was 0.77 (95% CI 0.73-0.81), suggesting that the clinical features of suspected T1DM in the consensus have good clinical diagnostic value for this patient subgroup. Conclusions:There was a significant discrepancy between the clinical practice of diabetes classification and the process recommended by the consensus, which was specifically reflected in the low proportions of both subtyping indicator testing and definitively subtyped diabetes patients. Attention should be pay to the classification diagnosis process proposed in the consensus and the clinical detection rate of key diabetes subtyping indicators such as C-peptide and islet autoantibodies for diabetes classification should be improved. Noteworthy, the screening strategy for T1DM proposed by the consensus showed good clinical application value.

The impact of human umbilical cord-derived mesenchymal stem cells on the pancreatic function of type 2 diabetic mice and their regulatory role on NLRP3 inflammasomes / 中华内科杂志

Objective:To investigate the effect and regulation of umbilical cord-derived mesenchymal stem cells (UC-MSCs) on islets function and NOD-like receptor family, pyrin domain containing 3 (NLRP3) and autophagy in type 2 diabetic mellitus (T2DM) mice.Methods:Experimental study. Twenty, 8-week-old, male C57BL/6J mice were selected and divided into a normal control group ( n=5) and a high-fat feeding modeling group ( n=15). The model of T2DM was established by high-fat feeding combined with intraperitoneal injection of low-dose streptozotocin. After successful modeling, those mice were divided into a diabetes group ( n=7) and a UC-MSCs treatment group ( n=7). The UC-MSCs treatment group was given UC-MSCs (1×10 6/0.2 ml phosphate buffer solution) by tail vein infusion once a week for a total of 4 weeks; the diabetes group was injected with the same amount of normal saline, and the normal control group was not treated. One week after the treatment, mice underwent intraperitoneal glucose tolerance tests and intraperitoneal insulin tolerance tests, and then the mice were sacrificed to obtain pancreatic tissue to detect the expressions of interleukin-1β (IL-1β) and pancreatic and duodenal homeobox 1 (PDX-1) by immunofluorescence. The bone marrow-derived macrophages were stimulated with lipopolysaccharide and adenosine triphosphate (experimental group) in vitro, then co-cultured with UC-MSCs for 24 h (treatment group). After the culture, enzyme-linked immunosorbent assay was used to detect the secretion level of IL-1β in the supernatant, and immunofluorescence staining was used to detect the expression of NLRP3 inflammasome, and related autophagy proteins. Statistical analysis was performed using unpaired one-way analysis of variance, repeated measure analysis of variance. Results:In vivo experiments showed that compared with the diabetes group, the UC-MSCs treatment group partially repaired islet structure, improved glucose tolerance and insulin sensitivity (all P<0.05), and the expression of PDX-1 increased and IL-1β decreased in islets under confocal microscopy. In vitro experiments showed that compared with the experimental group, the level of IL-1β secreted by macrophages in the treatment group was decreased [(85.9±74.6) pg/ml vs. (883.4±446.2) pg/ml, P=0.001], the expression of NLRP3 inflammasome and autophagy-related protein P62 was decreased, and the expressions of microtubule-associated protein 1 light chain 3β (LC3) and autophagy effector Beclin-1 were increased under confocal microscopy. Conclusions:UC-MSCs can reduce the level of pancreatic inflammation in T2DM mice, preserving pancreatic function. This might be associated with the ability of UC-MSCs to inhibit the activity of NLRP3 inflammasomes in macrophages and enhance autophagy levels.

Influence of donor and pancreatic characteristics on the success rate of islet isolation / 中华内分泌代谢杂志

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.

Application of single cell RNA sequencing in the treatment of diabetes / 中华内分泌代谢杂志

Single-cell RNA sequencing (scRNA-seq) is used for transcriptome profiling at the individual cell level, which is capable of screening in differentially gene expression that results from genetic mutation. Islet-based developmental atlas and heterogeneity characterization are currently the main applications of scRNA-seq in diabetes. scRNA-seq also can be used to mark and purify the functional β cells from resident adult stem cells in the pancreatic islets, which is expected to improve the outcome of islet β cells transplantation in type 1 diabetic patients. In addition, the technique can aid in learning diabetic β cell dedifferentiation and immunomodulatory functions. Although the study of scRNA-seq in diabetic retinopathy, nephropathy, atherosclerosis, and peripheral neuropathy is still at a nascent stage, scRNA-seq has great potential in a wide range of biomedical and clinical applications.

Medicated effect of CDKN1B on promoting proliferation of islet β cells in diabetes mellitus / 中国综合临床

The serious decrease in the number of functional β cells is one of the main features in the pathogenesis of diabetes mellitus. CDKN1B is a new kind of regulatory protein, which can bind and inactivate cyclin and cyclin-dependent kinase complex to control the process of cell cycle. It was suggested that down-regulation or deletion of CDKN1B in islet β cells could accelerate the proliferation of islet β cells, thus increasing the number of islet β cells, which is of great significance for treatments of diabetes.

Research progress of total pancreatectomy with islet autotransplantation for chronic pancrea-titis or recurrent acute pancreatitis / 中华消化外科杂志

Total pancreatectomy with islet autotransplantation, (TPIAT) is a complex surgical procedure for recurrent acute pancreatitis (RAP) and chronic pancreatitis, which can eliminate the risk of pancreatitis for pancreatic cancer and reduce the threat of severe diabetes mellitus. An increa-sing number of centers, here in the United States and internationally, are performing TPIAT and studies emerging from multiple centers highlight the benefits and persistent challenges of TPIAT for RAP and chronic pancreatitis. However, clear guidance on indications, contraindications, evaluation, timing of treatment and follow-up is lacking. The author reviews the history of TPIAT, and discusses the current state of TPIAT including indications of treatment, preoperative evaluations, surgical method, islet isolation and portal vein infusion, and postoperative management and a single center′s experience in TPIAT. A multiple center study with large numbers of patients will be critical to optimizing the successful application of this procedure.

Effect of modified Xiaoke Prescription on the patients with Yin deficiency and heat excessive type 2 diabetes mellitus / 国际中医中药杂志

Objective:The purpose of this study was to explore the therapeutic effect of modified Xiaoke prescription on patients with Yin deficiency and heat excessive type 2 diabetes mellitus (T2DM), and its influence on TCM syndrome scores, pancreatic islet function and oxidative stress.Methods:Randomized controlled trial. Eighty patients with Yin deficiency and heat excessive T2DM treated in the hospital between January and July 2021 were selected, and divided into observation group (41 cases) and control group (39 cases) by random number table method. Patients in the control group were treated with conventional western medicine, and patients in the observation group were treated with modified Xiaoke Prescription on the basis of the control group. Both groups were treated for 1 month. TCM syndrome scores were performed before and after treatment. Fasting plasma glucose (FPG) and 2 hPG were measured by glucose oxidase method. Serum HbA1c, malondialdehyde (MDA), 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels and SOD activity were measured by ELISA. The levels of low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C) and total cholesterol (TC) were detected by colorimetry.Results:The total effective rate of the observation group was 92.68% (38/41), and that of the control group was 76.92% (30/39). The difference between the two groups was statistically significant ( χ2=3.89, P=0.048). After treatment, the scores of tiredness and fatigue, thirst and appetite, overeating and hunger, redness of tongue and lack of saliva and total scores in the observation group were significantly lower than those in the control group ( t=4.46, 16.89, 13.37, 8.58, 8.38, P<0.01). After treatment, the levels of serum FPG [(7.31±0.90) mmol/L vs. (8.72±1.50) mmol/L, t=5.13], 2 hPG [(9.64±2.05) mmol/L vs. (12.85±1.20) mmol/L, t=8.49], HbA1c [(7.64±0.58)% vs. (8.11±1.35)%, t=2.04] in the observation group were significantly lower than those in the control group ( P<0.05); MDA [(3.96±1.00) mmol/L vs. (5.04±0.73) mmol/L, t=5.49], 8-OHdG [(203.41±30.70) ng/L vs. (234.50±59.00) ng/L, t=2.98] levels were significantly lower than those in the control group ( P<0.05); The activity of serum SOD [(48.64±5.05) mU/L vs. (41.75±3.58) mU/L, t=7.01] was significantly higher than that of the control group ( P<0.01); The serum LDL-C [(2.01±0.11) mmol/L vs. (2.56±0.25) mmol/L, t=12.84], TC [(4.75±0.20) mmol/L vs. (5.12±0.07) mmol/L, t=10.93] levels were significantly lower than those in the control group ( P<0.01); The serum HDL-C [(1.62±0.18) mmol/L vs. (1.24±0.42) mmol/L, t=5.31] level was significantly higher than that of the control group ( P<0.01). Conclusion:The modified Xiaoke Prescription can improve clinical symptoms, curative effect and pancreatic function, and relieve oxidative stress on the patients with T2DM.

Oral nano-formulation improves pancreatic islets dysfunction via lymphatic transport for antidiabetic treatment

Type 2 diabetes mellitus (T2DM) therapy is facing the challenges of long-term medication and gradual destruction of pancreatic islet β-cells. Therefore, it is timely to develop oral prolonged action formulations to improve compliance, while restoring β-cells survival and function. Herein, we designed a simple nanoparticle with enhanced oral absorption and pancreas accumulation property, which combined apical sodium-dependent bile acid transporter-mediated intestinal uptake and lymphatic transportation. In this system, taurocholic acid (TCA) modified poly(lactic-co-glycolic acid) (PLGA) was employed to achieve pancreas location, hydroxychloroquine (HCQ) was loaded to execute therapeutic efficacy, and 1,2-dilauroyl-sn-glycero-3-phosphocholine (DLPC) was introduced as stabilizer together with synergist (PLGA-TCA/DLPC/HCQ). In vitro and in vivo results have proven that PLGA-TCA/DLPC/HCQ reversed the pancreatic islets damage and dysfunction, thus impeding hyperglycemia progression and restoring systemic glucose homeostasis via only once administration every day. In terms of mechanism PLGA-TCA/DLPC/HCQ ameliorated oxidative stress, remodeled the inflammatory pancreas microenvironment, and activated PI3K/AKT signaling pathway without obvious toxicity. This strategy not only provides an oral delivery platform for increasing absorption and pancreas targetability but also opens a new avenue for thorough T2DM treatment.

Therapeutic strategy for instant blood-mediated inflammatory reaction after islet transplantation / 器官移植

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.

Analysis of key genes and targeted protection methods affecting the survival of human islets / 器官移植

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.

Research progress on islet protection and functional maintenance / 器官移植

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.

Metabolic effect of low fluoride levels in the islets of NOD mice: integrative morphological, immunohistochemical, and proteomic analyses

Abstract Fluoride (F) has been widely used to control dental caries, and studies suggest beneficial effects against diabetes when a low dose of F is added to the drinking water (10 mgF/L). Objectives This study evaluated metabolic changes in pancreatic islets of NOD mice exposed to low doses of F and the main pathways altered by the treatment. Methodology In total, 42 female NOD mice were randomly divided into two groups, considering the concentration of F administered in the drinking water for 14 weeks: 0 or 10 mgF/L. After the experimental period, the pancreas was collected for morphological and immunohistochemical analysis, and the islets for proteomic analysis. Results In the morphological and immunohistochemical analysis, no significant differences were found in the percentage of cells labelled for insulin, glucagon, and acetylated histone H3, although the treated group had higher percentages than the control group. Moreover, no significant differences were found for the mean percentages of pancreatic areas occupied by islets and for the pancreatic inflammatory infiltrate between the control and treated groups. Proteomic analysis showed large increases in histones H3 and, to a lesser extent, in histone acetyltransferases, concomitant with a decrease in enzymes involved in the formation of acetyl-CoA, besides many changes in proteins involved in several metabolic pathways, especially energy metabolism. The conjunction analysis of these data showed an attempt by the organism to maintain protein synthesis in the islets, even with the dramatic changes in energy metabolism. Conclusion Our data suggests epigenetic alterations in the islets of NOD mice exposed to F levels comparable to those found in public supply water consumed by humans.

Effect of Zuoguiwan on Pancreatic Islet Function in Offspring of Maternal Rats with GDM / 中国实验方剂学杂志

ObjectiveTo investigate the effect of Zuoguiwan on pancreatic islet function in offspring of gestational diabetes mellitus （GDM） maternal rat model and explore the mechanisms of Zuoguiwan in improving pancreatic islet function based on postpartum pancreatic regeneration. MethodHealthy female SD rats with normal blood glucose levels were paired with male rats in a 2∶1 ratio and housed together. Pregnancy was confirmed based on vaginal plugs or vaginal smears. The pregnant rats were divided into the following groups： normal group， model group， insulin group （insulin Detemir， 20 U·kg-1）， low-dose Zuoguiwan group （1.89 g·kg-1）， and high-dose Zuoguiwan group （3.78 g·kg-1）. The GDM rat model was induced using streptozotocin in rats except for those in the normal group. The model was confirmed by blood glucose testing in the maternal rats. Except for the normal and model groups， the other groups received daily administration of corresponding treatments. At 21 days after birth， fasting blood glucose （FBG） and fasting serum insulin （FINS） levels were measured in 6 offspring from each group. The homeostasis model assessment of insulin resistance （HOMA-IR） was calculated， and an oral glucose tolerance test （OGTT） was performed on additional 12 offspring from each group. Blood samples were taken from the abdominal aorta of the offspring at postnatal day 22， and enzyme-linked immunosorbent assay （ELISA） was used to measure insulin， glucagon （GC）， pancreatic polypeptide （PPY）， and somatostatin （SS） levels in the serum. Hematoxylin-eosin （HE） staining was performed to observe pathological changes in the pancreatic tissue of the offspring. Immunofluorescence （IF） was used to observe the area and structure of the pancreatic islets. Western blot was used to detect the expression of key proteins involved in the development and functional expression of pancreatic β-cells， namely pancreatic and duodenal homeobox factor 1 （Pdx1）， Nkx6.1， and Glucose transporter 2 （Glut2）. ResultCompared with the normal group， the model group showed significant increases in FBG and FINS levels， and HOMA-IR （P<0.01）. Compared with the model group， the insulin group showed significant decreases in FBG levels and HOMA-IR （P<0.01）， the low-dose Zuoguiwan group showed a significant decrease in FBG levels （P<0.05）， and the high-dose Zuoguiwan group showed significant decreases in FBG and FINS levels， and HOMA-IR （P<0.01）. Compared with the normal group， the model group showed significant increases in OGTT 60-min blood glucose levels and AUC index （P<0.05， P<0.01）. Compared with the model group， the high-dose Zuoguiwan group showed significant decreases in OGTT60-min blood glucose levels and area under the curve（AUC） index （P<0.05， P<0.01）. HE staining of pancreatic tissue showed that compared with the normal group， the model group had a reduced number of islets and a loose arrangement of acinar cells. Compared with the model group， the groups with drug treatment showed increased number of islets and a compact arrangement of acinar cells. Compared with the normal group， the model group had significantly increased levels of insulin， GC， PPY， and SS in the serum （P<0.01）. Compared with the model group， the low-dose and high-dose Zuoguiwan groups and the insulin group showed significantly decreased serum levels of insulin， GC， PPY， and SS （P<0.05， P<0.01）. IF results showed that compared with the normal group， the model group had a significantly lower positive rate of insulin （P<0.05）. Compared with the model group， the low-dose and high-dose Zuoguiwan groups showed a significant increase in the positive rate of insulin （P<0.05）. There was no significant difference in the positive rate of GC among the groups. In terms of the proportion of insulin and GC in individual islets， compared with the normal group， the model group showed a significant decrease in the proportion of insulin （P<0.01） and a significant increase in the proportion of GC （P<0.01）. Compared with the model group， the low-dose and high-dose Zuoguiwan groups showed significantly increased proportion of insulin （P<0.01） and significantly decreased proportion of GC （P<0.01）. Compared with the normal group， the model group showed significantly decreased expression levels of Pdx1， Nkx6.1， and Glut2 proteins in the pancreatic tissue of GDM offspring （P<0.05）. Compared with the model group， the insulin group and the low-dose Zuoguiwan group showed significant increases in the expression levels of Pdx1 and Nkx6.1 proteins in the pancreatic tissue of GDM offspring （P<0.05）， and the low-dose and high-dose Zuoguiwan groups showed significant increases in the expression levels of Glut2 protein （P<0.05）. ConclusionZuoguiwan can promote pancreatic islet development in offspring of GDM maternal rat model， improve pancreatic islet morphology and function， and alleviate insulin resistance. Its mechanism of action may be related to the regulation of Pdx1， Nkx6.1， and Glut2 protein expression in the pancreatic tissue of offspring.

In vitro research of mesenchymal stem cell-coated human islets to alleviate instant blood-mediated inflammatory reaction / 器官移植

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.

Insulinoma / Insulinoma

RESUMEN El insulinoma es un tumor poco frecuente de las células de los islotes pancreáticos, caracterizado por la proliferación de las células betas. Son tumores neuroendocrinos pancreáticos, generalmente benignos y de pequeño tamaño, caracterizados por el síndrome de hipersecreción de insulina con el desarrollo de hipoglucemia. La mayoría de estos tumores son esporádicos, solo alrededor de 15-30 % es hereditario; está asociado a enfermedades como la neoplasia endocrina múltiple tipo 1, o el síndrome de Von Hippel-Lindau. La incidencia de dicho tumor es de 3-10 casos por cada millón de habitantes. La edad media de aparición es entre 40-50 años de edad y es más frecuente en mujeres. El reconocimiento temprano y el diagnóstico adecuado de este tumor pancreático raro, son aspectos importantes pues es potencialmente curable con un tratamiento quirúrgico oportuno.

ABSTRACT Insulinoma is a rare pancreatic islet cell tumor characterized by proliferation of beta cells. They are pancreatic neuroendocrine tumors, generally benign and small in size, characterized by insulin hypersecretion syndrome with the development of hypoglycemia. Most of these tumors are sporadic, only about 15-30% are hereditary; it is associated with diseases such as multiple endocrine neoplasia type 1, or Von Hippel-Lindau syndrome. The incidence of this tumor is 3-10 cases per million inhabitants. The average age of onset is between 40-50 years of age and it is more frequent in women. Early recognition and proper diagnosis of this rare pancreatic tumor are important aspects, as it is potentially curable with timely surgical treatment.