OBJECTIVE: To elucidate the effect of Huanglian-Renshen-Decoction (HRD) on ameliorating type 2 diabetes mellitus by maintaining islet β -cell identity through regulating paracrine and endocrine glucagon-like peptide-1 (GLP-1)/GLP-1 receptor (GLP-1R) in both islet and intestine. METHODS: The db/db mice were divided into the model (distilled water), low-dose HRD (LHRD, 3 g/kg), high-dose HRD (HHRD, 6 g/kg), and liraglutide (400 µ g/kg) groups using a random number table, 8 mice in each group. The db/m mice were used as the control group (n=8, distilled water). The entire treatment of mice lasted for 6 weeks. Blood insulin, glucose, and GLP-1 levels were quantified using enzyme-linked immunosorbent assay kits. The proliferation and apoptosis factors of islet cells were determined by immunohistochemistry (IHC) and immunofluorescence (IF) staining. Then, GLP-1, GLP-1R, prohormone convertase 1/3 (PC1/3), PC2, v-maf musculoaponeurotic fibrosarcoma oncogene homologue A (MafA), and pancreatic and duodenal homeobox 1 (PDX1) were detected by Western blot, IHC, IF, and real-time quantitative polymerase chain reaction, respectively. RESULTS: HRD reduced the weight and blood glucose of the db/db mice, and improved insulin sensitivity at the same time (P<0.05 or P<0.01). HRD also promoted mice to secrete more insulin and less glucagon (P<0.05 or P<0.01). Moreover, it also increased the number of islet β cell and decreased islet α cell mass (P<0.01). After HRD treatment, the levels of GLP-1, GLP-1R, PC1/3, PC2, MafA, and PDX1 in the pancreas and intestine significantly increased (P<0.05 or P<0.01). CONCLUSION HRD can maintain the normal function and identity of islet β cell, and the underlying mechanism is related to promoting the paracrine and endocrine activation of GLP-1 in pancreas and intestine.
Animals ; Glucagon-Like Peptide 1/metabolism* ; Diabetes Mellitus, Type 2/metabolism* ; Glucagon-Like Peptide-1 Receptor/metabolism* ; Insulin-Secreting Cells/pathology* ; Drugs, Chinese Herbal/pharmacology* ; Male ; Blood Glucose/metabolism* ; Insulin/blood* ; Mice ; Intestinal Mucosa/pathology* ; Apoptosis/drug effects* ; Cell Proliferation/drug effects* ; Islets of Langerhans/pathology*

As a member of the apolipoprotein C (ApoC) family with a relatively high content, ApoC3 plays a major role in the regulation of triglyceride metabolism, and plays an important role in the occurrence and development of cardiovascular diseases, glucose and lipid metabolism disorders. Nonalcoholic fatty liver disease (NAFLD) refers to the accumulation of a large amount of fat in the liver in the absence of a history of chronic alcohol consumption or other damage to the liver. A large number of previous studies have shown that there is a correlation between the gene polymorphism and high expression of ApoC3 and NAFLD. In the context of hypertriglyceridemia (HTG), this article reviews the relationship between ApoC3 and NAFLD, glucose and lipid metabolism, and islet β cell function, showing that ApoC3 can not only inhibit lipoprotein lipase (LPL) and hepatic lipase (HL) activity, delay the decomposition of triglyceride in plasma to maintain the body's energy metabolism during fasting, but also be significantly increased under insulin resistance, prompting the liver to secrete a large amount of very low-density lipoprotein (VLDL) to induce HTG. Therefore, targeting and inhibiting ApoC3 might become a new approach to treat HTG. Increasing evidence suggests that ApoC3 does not appear to be an independent "contributor" to NAFLD. Similarly, our previous studies have shown that ApoC3 is not an independent factor triggering islet β cell dysfunction in ApoC3 transgenic mice, but in a state of excess nutrition, HTG triggered by ApoC3 high expression may exacerbate the effects of hyperglycemia and insulin resistance on islet β cell function, and the underlying mechanism remains to be further discussed.
Apolipoprotein C-III/genetics* ; Non-alcoholic Fatty Liver Disease/pathology* ; Glucose/metabolism* ; Lipid Metabolism ; Humans ; Animals ; Hypertriglyceridemia/metabolism* ; Islets of Langerhans/metabolism*

Intraportal transplantation of islets is no longer considered to be an ideal procedure and finding the extrahepatic alternative site is becoming a subject of high priority. Herein, in this study, we would introduce our initial outcomes of using gastric submucosa (GS) and liver as sites of islet autotransplantation in pancreatectomized diabetic Beagles. Total pancreatectomy was performed in Beagles and then their own islets extracted from the excised pancreas were transplanted into GS (GS group, n=8) or intrahepatic via portal vein (PV group, n=5). Forty-eight hours post transplantation, graft containing tissue harvested from the recipients revealed the presence of insulin-positive cells. All recipients in GS group achieved euglycemia within 1 day, but returned to a diabetic state at 6 to 8 days post-transplantation (mean survival time, 7.16±0.69 days). However, all of the animals kept normoglycemic until 85 to 155 days post-transplantation in PV group (mean survival time, 120±28.58 days; P<0.01 vs. GS group). The results of intravenous glucose tolerance test (IVGTT) confirmed that the marked improvement in glycometabolism was obtained in intrahepatic islet autotransplantation. Thus, our findings indicate that the liver is still superior to the GS as the site of islet transplantation, at least in our islet autotransplant model in pancreatectomized diabetic Beagles.
Animals ; Diabetes Mellitus, Experimental ; metabolism ; pathology ; therapy ; Dogs ; Gastric Mucosa ; metabolism ; transplantation ; Glucose ; metabolism ; Glucose Tolerance Test ; Graft Survival ; Humans ; Insulin ; metabolism ; Islets of Langerhans Transplantation ; Liver ; pathology ; Liver Transplantation ; Transplantation, Autologous

The Goto-Kakizaki (GK) rat is a spontaneous type 2 diabetic animal model, which is characterized by a progressive loss of beta islet cells with fibrosis. In the present study, the hypoglycemic effect of asiatic acid (AA) in GK rats was examined. GK rats receiving AA at a daily dose of 25 mg·kg(-1) for four weeks showed a significant reduction in blood glucose levels. Age-matched normal Wistar rats were given 0.5% sodium carboxymethyl cellulose (CMC-Na) solution for the same periods and used as control. Compared to the normal Wistar rats, GK rats treated with AA showed improvement in insulin resistance partially through decreasing glucose level (P < 0.01) and insulin level (P < 0.05). Furthermore, the results of immunohistochemistry indicate that AA treatment reduced islet fibrosis in GK rats. Fibronectin, a key protein related to islet fibrosis, was over-expressed in GK rats, which was reversed significantly by AA treatment (P < 0.05). These findings suggest that AA has a beneficial effect on lowering blood glucose levels in GK rats and improves fibrosis of islets in diabetes, which may play a role in the prevention of islets dysfunction.
Animals ; Blood Glucose ; metabolism ; Centella ; chemistry ; Diabetes Mellitus, Type 2 ; drug therapy ; pathology ; Disease Models, Animal ; Fibronectins ; metabolism ; Fibrosis ; Glucose Tolerance Test ; Hyperglycemia ; drug therapy ; pathology ; Insulin ; blood ; Insulin Resistance ; Islets of Langerhans ; drug effects ; pathology ; Male ; Pancreatic Diseases ; metabolism ; pathology ; prevention & control ; Pentacyclic Triterpenes ; pharmacology ; therapeutic use ; Phytotherapy ; Plant Extracts ; pharmacology ; therapeutic use ; Rats, Inbred Strains

Nesidioblastosis is a term used to describe pathologic overgrowth of pancreatic islet cells. It also means maldistribution of islet cells within the ductules of exocrine pancreas. Generally, nesidioblastosis occurs in beta-cell and causes neonatal hyperinsulinemic hypoglycemia or adult noninsulinoma pancreatogenous hypoglycemia syndrome. Alpha-cell nesidioblastosis and hyperplasia is an extremely rare disorder. It often accompanies glucagon-producing marco- and mircoadenoma without typical glucagonoma syndrome. A 35-year-old female was referred to our hospital with recurrent acute pancreatitis. On radiologic studies, 1.5 cm sized mass was noted in pancreas tail. Cytological evaluation with EUS-fine-needle aspiration suggested serous cystadenoma. She received distal pancreatectomy. The histologic examination revealed a 1.7 cm sized neuroendocrine tumor positive for immunohistochemical staining with glucagon antibody. Multiple glucagon-producing micro endocrine cell tumors were scattered next to the main tumor. Additionally, diffuse hyperplasia of pancreatic islets and ectopic proliferation of islet cells in centroacinar area, findings compatible to nesidioblastosis, were seen. These hyperplasia and almost all nesidioblastic cells were positive for glucagon immunochemistry. Even though serum glucagon level still remained higher than the reference value, she has been followed-up without any evidence of recurrence or hormone related symptoms. Herein, we report a case of alpha-cell nesidioblastosis and hyperplasia combined with glucagon-producing neuroendocrine tumor with literature review.
Adult ; Chromogranin A/blood ; Female ; Glucagon/*metabolism ; Glucagon-Secreting Cells/metabolism ; Humans ; Hyperplasia/complications/*diagnosis ; Islets of Langerhans/metabolism/ultrasonography ; Nesidioblastosis/complications/*diagnosis ; Neuroendocrine Tumors/complications/*diagnosis/pathology ; Pancreas/*pathology ; Tomography, X-Ray Computed

OBJECTIVETo study the effect of pretreatment with apoptotic donor spleen cells on spleen lymphocyte function of recipient rats undergoing islet transplantation to explore new approaches to prolong islet graft survival.

METHODSApoptotic spleen cells from donor rats were obtained by exposure to γ-ray irradiation from (60)Co. Diabetic SD rat models were randomly divided into 4 groups to receive tail vein injections with saline (group A), normal cells (group B), apoptotic donor cells (group C), or necrotic donor cells (group D). One week later, orthotopic transplantation of islets under the renal capsule was performed. Before and at 1 and 2 weeks after islet transplantation, the recipient rats were examined for proliferative activity of spleen lymphocytes with CFSE cell staining and for IL-2 and IL-10 expressions in the cells using ELISA.

RESULTSPretreatment with donor apoptotic cells significantly suppressed the proliferative activity of recipient spleen lymphocytes before and at 1 and 2 weeks after islet transplantation as compared with the other three groups (P<0.05). The level of IL-2 was significantly decreased while IL-10 increased in apoptotic donor cell pretreatment group compared with those in the other 3 groups at each time point of observation.

CONCLUSIONThe effect of pretreatment with apoptotic donor cells on recipient spleen lymphocytes suggest an important role of apoptotic donor spleen cells in immune tolerance of grafts.

Animals ; Apoptosis ; immunology ; Cell Proliferation ; Cobalt Radioisotopes ; Diabetes Mellitus, Experimental ; metabolism ; pathology ; surgery ; Gamma Rays ; Graft Survival ; Immune Tolerance ; Interleukin-10 ; metabolism ; Interleukin-2 ; metabolism ; Islets of Langerhans Transplantation ; Lymphocyte Transfusion ; Lymphocytes ; metabolism ; pathology ; radiation effects ; Male ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Rats, Wistar ; Spleen ; cytology ; metabolism ; radiation effects

Transplantation of islet cells into diabetic patients is a promising therapy, provided that the islet cells are able to evade host immune rejection. With improved islet viability, this strategy may effectively reverse diabetes. We applied 2% calcium alginate to generate small and large capsules to encapsulate porcine neonatal pancreatic cell clusters (NPCCs) using an air-driven encapsulator. After encapsulation, the viability was assessed at 1, 4, 7, 14 and 28 days and secretion of functional insulin in response to glucose stimulation were tested at days 14 and 28. Selective permeability of the small alginate capsules was confirmed using various sizes of isothiocyanate-labeled dextran (FITC-dextran). Encapsulation of NPCCs was performed without islet protrusion in the small and large capsules. The viability of NPCCs in all experimental groups was greater than 90% at day 1 and then gradually decreased after day 7. The NPCCs encapsulated in large capsules showed significantly lower viability (79.50 +/- 2.88%) than that of naive NPCCs and NPCCs in small capsule (86.83 +/- 2.32%, 87.67 +/- 2.07%, respectively) at day 7. The viability of naive NPCCs decreased rapidly at day 14 (75.67 +/- 1.75%), whereas the NPCCs encapsulated in small capsules maintained (82.0 +/- 2.19%). After 14 and 28 days NPCCs' function in small capsules (2.67 +/- 0.09 and 2.13 +/- 0.09) was conserved better compared to that of naive NPCCs (2.04 +/- 0.25 and 1.53 +/- 0.32, respectively) and NPCCs in large capsules (2.04 +/- 0.34 and 1.13 +/- 0.10, respectively), as assessed by a stimulation index. The small capsules also demonstrated selective permeability. With this encapsulation technique, small capsules improved the viability and insulin secretion of NPCCs without islet protrusion.
Alginates/chemistry/metabolism ; Animals ; Animals, Newborn ; Capsules/chemistry ; Cell Survival ; Diabetes Mellitus/pathology/*therapy ; Disease Models, Animal ; Glucuronic Acid/chemistry/metabolism ; Graft Rejection/etiology/*prevention & control ; Hexuronic Acids/chemistry/metabolism ; Humans ; Insulin/secretion ; Islets of Langerhans/*metabolism/pathology ; Islets of Langerhans Transplantation/*methods ; Postoperative Complications/etiology/*prevention & control ; *Swine

This study is to observe anti-lipotoxic effect of sesamin on renovascular hypertensive rats fed with a high-fat, high-sucrose diet. Thirty-four complex model rats were induced by two-kidney, one-clip method and on high-fat and refined-carbohydrate diet for thirteen weeks. From the fifth week, intragastric administration of sesamin (120, 60 and 30 mg x kg(-1) x d(-1)) lasted for eight weeks. Blood pressure (BP), blood fat (BF), blood glucose (BG), free fatty acids (FFA), insulin (Ins), tumor necrosis factor (TNF)-alpha and interleukin (IL)-6 were determined. Pathological changes of pancreas, perirenal fat and liver were semiquantitatively analyzed. In sesamin (120 and 60 mg x kg(-1) x d(-1)) group, it was found that there were decrease of levels of BP, BF, BG, TNF-alpha, IL-6 and FFA, improvement of insulin resistance and glucose tolerance, alleviation of body weight, humid weight of fat, liver and pancreas and their organ index, and reduction of islet cell hyperplasia and amount of lipid droplet vacuoles in lipocyte and hepatocyte. It is implied that sesamin had anti-lipotoxic effect and its mechanism may be closely associated with the amelioration of insulin resistance via reducing lipidoses in hepatocyte and inflammatory adipokines such as TNF-alpha and IL-6.
Adipocytes ; drug effects ; Animals ; Anticholesteremic Agents ; administration & dosage ; pharmacology ; Antihypertensive Agents ; administration & dosage ; pharmacology ; Blood Glucose ; metabolism ; Blood Pressure ; drug effects ; Body Weight ; drug effects ; Cholesterol ; blood ; Diet, High-Fat ; Dioxoles ; administration & dosage ; pharmacology ; Dose-Response Relationship, Drug ; Fatty Acids, Nonesterified ; blood ; Glucose Tolerance Test ; Hypertension, Renovascular ; blood ; pathology ; Insulin ; blood ; Insulin Resistance ; Interleukin-6 ; blood ; Islets of Langerhans ; pathology ; Lignans ; administration & dosage ; pharmacology ; Liver ; pathology ; Male ; Pancreas ; pathology ; Rats ; Rats, Sprague-Dawley ; Sucrose ; Triglycerides ; blood ; Tumor Necrosis Factor-alpha ; blood

To investigate the semi-quantitative method for evaluating the lipid accumulation in pancreas, the KKAy mice, a classical type 2 diabetes mellitus model mice, were used and treated with rosiglitazone (Rosi); and the age-matched C57BL/6J mice were used as normal control. Pancreas was fixed quickly for histological examination with HE staining. For the estimation of the lipid accumulation in pancreas, semi-quantitative method was designed: the number and the size of islet, lipid accumulation in islet and in exocrine gland were observed and the integrative score calculated under the microscope, separately. In KKAy mice, the characteristics of the increased amount of islet, the enlarged area of islet, an abundance of large vacuolations, lipid droplets, and fat proliferation were exposed frequently, and the integrative score increased 2.1 folds compared with that in C57BL/6J mice. Meanwhile, the levels of serum glucose, insulin, and triglyceride (TG) were 1.7, 18.0, and 9.0 times as those in C57BL/6J mice, respectively. With the rosiglitazone (10 mg x kg(-1)) treatment, compared with that in KKAy mice, the pancreatic pathological changes were ameliorated significantly, and the integrative score in KKAy + Rosi mice decreased by 28.9%; and the levels of serum glucose, insulin, and triglyceride decreased by 48.3%, 81.3% and 64.1%, respectively. It showed there is a correlation between the pancreatic pathological semi-quantitative score and the values of serum parameters. In conclusion, this semi-quantitative scoring method is simple and objective for the evaluation of lipid accumulation in pancreas of mice.
Animals ; Blood Glucose ; metabolism ; Diabetes Mellitus, Type 2 ; blood ; metabolism ; pathology ; Female ; Hypoglycemic Agents ; pharmacology ; Insulin ; blood ; Islets of Langerhans ; metabolism ; pathology ; Lipid Metabolism ; drug effects ; Mice ; Mice, Inbred C57BL ; Pancreas ; metabolism ; pathology ; Random Allocation ; Thiazolidinediones ; pharmacology ; Triglycerides ; blood

Nonspecific inflammatory response is the major cause for failure of islet grafts at the early phase of intraportal islet transplantation (IPIT). Bilirubin, a natural product of heme catabolism, has displayed anti-oxidative and anti-inflammatory activities. The present study has demonstrated that bilirubin protected islet grafts by inhibiting nonspecific inflammatory response in a syngeneic rat model of IPIT. The inflammation-induced cell injury was mimicked by exposing cultured rat insulinoma INS-1 cells to cytokines (IL-1beta, TNF-alpha and IFN-gamma) in in vitro assays. At appropriate lower concentrations, bilirubin significantly attenuated the reduced cell viability and enhanced cell apoptosis induced by cytokines, and protected the insulin secretory function of INS-1 cells. Diabetic inbred male Lewis rats induced by streptozotocin underwent IPIT at different islet equivalents (IEQs) (optimal dose of 1000, and suboptimal doses of 750 or 500), and bilirubin was administered to the recipients every 12 h, starting from one day before transplantation until 5 days after transplantation. Administration of bilirubin improved glucose control and enhanced glucose tolerance in diabetic recipients, and reduced the serum levels of inflammatory mediators including IL-1beta, TNF-alpha, soluble intercellular adhesion molecule 1, monocyte chemoattractant protein-1 and NO, and inhibited the infiltration of Kupffer cells into the islet grafts, and restored insulin-producing ability of transplanted islets.
Animals ; Apoptosis/drug effects/immunology ; Bilirubin/*administration & dosage/pharmacology ; Cell Line, Tumor ; Cytokines/immunology/metabolism ; Diabetes Mellitus, Experimental/*drug therapy/*immunology ; Inflammation ; Inflammation Mediators/immunology/metabolism ; Islets of Langerhans/drug effects/*immunology/injuries/pathology ; *Islets of Langerhans Transplantation ; Male ; Oxidative Stress/drug effects/immunology ; Rats ; Rats, Inbred Lew ; Transplantation, I