OBJECTIVETo study the effect of Mudan Granule (MD) on the glucose metabolism and beta cell function in monosodium glutamate (MSG) induced obese mice with insulin resistance (IR).

METHODSMSG obese mice were induced by subcutaneous injecting MSG (4 g/kg for 7 successive days in neonatal ICR mice). Forty MSG mice with IR features were recruited and divided into four groups according to body weight, fasting blood glucose, triglyceride (TG), total cholesterol (TC), and the percentage of blood glucose decreased within 40 min in the IR test, i.e., the model group (Con), the low dose MD group, the high dose MD group, and the Metformin group (Met). Besides, another 10 ICR mice were recruited as the normal control group (Nor). The water solvent of 2.5 g/kg MD or 5 g/kg MD was respectively administered to mice in the low dose MD group and the high dose MD group. Metformin hydrochloride was given to mice in the Met group at 0.2 g/kg body weight. Equal dose solvent distilled water was administered to mice in the Nor group and the Con group by gastrogavage, once per day. All medication was lasted for 15 weeks. Insulin tolerance test (ITT) and oral glucose tolerance test (OGTT) were performed after 6 weeks of treatment. Beta cell function was assessed by hyperglycemic clamp technique. The morphological changes in the pancreas were evaluated by hematoxylin-eosin (HE) staining. Changes of iNOS, NF-kappaB p65, and p-NF-kappaB p65 in the pancreas were tested.

RESULTSCompared with the Nor group, the blood glucose level, AUC, and fasting blood insulin, ONOO-contents, iNOS activities, and the expression of iNOS, NF-kappaB p65 subunit, pNF-kappaB p65 subunit obviously increased; decreased percentage of blood glucose within 40 min in ITT, glucose infusion rate (GIR), Clamp 1 min insulin, and Max-Insulin obviously decreased in the Con group (P < 0.05, P < 0.01). Compared with the Con group, the aforesaid indices could be improved in the Met group (P < 0.05, P < 0.01). In the low dose MD group, AUC, iNOS activities, and the expression of iNOS and p-NF-kappaB p65 subunit obviously decreased; percentage of blood glucose within 40 min in ITT and GIR obviously increased (P < 0.05, P < 0.01). In the high dose MD group, AUC, ONOO-contents, iNOS activities, and the expression of iNOS, NF-kappaB p65 subunit, and p-NF-KB p65 subunit obviously decreased; percentage of blood glucose within 40 min in ITT, Max-Insulin, and GIR obviously increased (P < 0.05, P < 0.01).

CONCLUSIONMD could significantly improve IR and functional disorder of 3 cells in MSG obese mice, which might be associated with lowering inflammatory reaction in the pancreas.

Animals ; Disease Models, Animal ; Drugs, Chinese Herbal ; pharmacology ; Female ; Insulin Resistance ; Insulin-Secreting Cells ; drug effects ; metabolism ; Male ; Metformin ; pharmacology ; Mice ; Mice, Inbred ICR ; Mice, Obese ; Obesity ; chemically induced ; metabolism ; Pancreas ; cytology ; drug effects ; Sodium Glutamate

In this study, the rat type 2 diabetes mellitus (T2DM) model was established through tail vein injection with low dose of streptozotocin (STZ) and high fat diet for 8 weeks, and then treated with Jiaotai Pill. The oral glucose tolerance test (OGTT), fasting serum insulin (FINS), free fatty acid(FFA) levels and blood lipid were assayed. HOMA-IR was calculated. Pancreatic pathology was performed. And pancreatic triglyceride (TG) content was examined by the lipid extraction method. Pancreatic islet cell apoptosis were detected by terminal dexynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL). According to the results, the model group showed abnormal OGTT, increased FINS, HOMA-IR, FFA, lipid disorder, obvious fat accumulation and significantly increased TG content in pancreatic tissues, and enhanced pancreatic islet cell apoptosis. Compared with the model group, the Jiaotai Pill group displayed improved OGTT, reduced FINS, HOMA-IR, FFA, recovered lipid disorder, decreased fat accumulation and significantly declined TG content in pancreatic tissues, and lowered pancreatic islet cell apoptosis. In summary, Jiaotai pill could effectively treat type 2 diabetes in rats. Its mechanism may be related to the reduction in pancreatic fat accumulation and islet cell apoptosis.
Animals ; Apoptosis ; drug effects ; Diabetes Mellitus, Type 2 ; drug therapy ; metabolism ; physiopathology ; Drugs, Chinese Herbal ; administration & dosage ; Fats ; metabolism ; Glucose Tolerance Test ; Humans ; Islets of Langerhans ; cytology ; drug effects ; Male ; Pancreas ; drug effects ; metabolism ; Rats ; Rats, Wistar

OBJECTIVETo construct a method to culture pancreatic progenitor cells in hanging drop and on floating filter,and to examine if pancreatic progenitor cells can differentiate into mature endocrine cells with this method.

METHODSMurine embryos at day 12.5 were isolated and digested into single cells,which were then cultured in hanging drop for 24h and formed spheres.Spheres were cultured on the filter for 6 days,which floated in the dish containing medium.During culture,the expressions of pancreas duodenum homeobox-1(PDX-1)and neurogenin3(Ngn3)were determined.The expressions of endocrine and exocrine markers,insulin,glucagon,and carboxypeptidase(CPA)were determined on day 7 by immunohistochemistry.Insulin secretion of spheres stimulated by glucose was detected by ELISA.The changes of pancreatic marker expressions during culture were monitored by real-time polymerase chain reaction(PCR).

RESULTSOne day after the culture,there were still a large amount of PDX-1 positive cells in pancreatic spheres,and these cells proliferated.On day 3,high expression of Ngn3 was detected,and the Ngn3-positive cells did not proliferate.On day 7,The expressions of endocrine and exocrine markers in the differentiated pancreatic progenitor cells were detected,which were consistent with that in vivo.Insulin was secreted by spheres upon the stimulation of glucose.

CONCLUSIONIn hanging drop and on floating filter,pancreatic progenitor cells can differentiate into mature endocrine cells.

Animals ; Cell Culture Techniques ; Cell Differentiation ; Cells, Cultured ; Endocrine Cells ; cytology ; Homeodomain Proteins ; metabolism ; Insulin ; metabolism ; Mice ; Pancreas ; cytology ; Stem Cells ; cytology ; Trans-Activators ; metabolism

OBJECTIVETo establish a new culture method to induce the differentiation of embryonic pancreatic cells into mature endocrine cells.

METHODSMouse embryos at day 12.5 were used and embryonic pancreata were isolated. The isolated embryonic pancreata were cultured on the filter for 7 days, which floated in the dish containing medium. During culture, the expression of pancreas duodenum homeobox-1 (PDX-1), a pancreatic stem cell marker, was examined at day 1. The expression of neurogenin 3 (Ngn3), a pancreatic progenitor cell marker, was examined at day 3. The expressions of endocrine and exocrine markers, insulin, glucagon, and carboxypeptidase (CPA) were examined at day 7 by immunohistochemistry. The kinetics of pancreatic marker expression during culture was assayed by real-time PCR.

RESULTSMany pancreatic stem cells still existed in embryonic pancreata cultured for 1 day; meanwhile, these pancreatic stem cells proliferated in high rate. A large amount of pancreatic progenitor cells were found in embryonic pancreata cultured for 3 days.Pancreatic stem/progenitor cells differentiated into mature endocrine and exocrine cells in embryonic pancreata after having been cultured for 7 days. Furthermore, the expression pattern of pancreatic marker is consistent with that in vivo.

CONCLUSIONWe successfully established a new culture method, with which embryonic pancreatic cells can efficiently differentiate into mature endocrine cell.

Animals ; Basic Helix-Loop-Helix Transcription Factors ; metabolism ; Cell Culture Techniques ; Cell Differentiation ; Cells, Cultured ; Embryo, Mammalian ; Endocrine Cells ; cytology ; Female ; Homeodomain Proteins ; metabolism ; Male ; Mice ; Nerve Tissue Proteins ; metabolism ; Pancreas ; cytology ; Trans-Activators ; metabolism

In an oxygen-depleted environment, endothelial cells initiate an adaptive pattern of synthesis, which may enable them to survive hypoxic crises. Using high-resolution two-dimensional gel electrophoresis in conjunction with mass spectroscopy, we obtained a 24 differential display of proteins in the pancreatic endothelial cell line, MS-1, at four time points following induction of hypoxia. The induction of Wee1 under hypoxia was confirmed both at the mRNA and protein levels. The phosphorylation of cell division cycle 2, which is downstream of Wee1, was also increased after hypoxic exposure. In addition, pre-exposure to hypoxia attenuated a decrease in hydrogen peroxide-induced cell number. The induction of bax (a pro-apoptotic protein) and reduction of bcl (an anti-apoptotic protein) after hypoxia stimulus were also attenuated by hypoxic pre-exposure. Moreover, hydrogen peroxide-induced morphologic damage did not appear in the wild-type Wee1-expressing cells. Taken together, our results suggest that Wee1 may have important role in hypoxia-induced pathophysiological situations in endothelial cells.
Animals ; CDC2 Protein Kinase/metabolism ; Cell Cycle Proteins/*genetics/metabolism ; Cell Hypoxia ; Cell Line ; Cell Survival ; Endothelial Cells/cytology/*metabolism ; *Gene Expression Regulation ; Hydrogen Peroxide/*metabolism ; Mice ; Nuclear Proteins/*genetics/metabolism ; Pancreas/cytology ; Phosphorylation ; Protein-Tyrosine Kinases/*genetics/metabolism

To study the expression of X-linked inhibitor of apoptosis protein (XIAP) and cell apoptosis in vitro model of acute pancreatitis (AP), we carried out experiments to stimulate AR42J cell line with caerulein (10(-8) mol/L) for 12 hours, then collected cells at various time points (0 h, 4 h, 8 h, 12 h, and 24 h, respectively). We then observed the morphologic changes of AR42J cells with the stimulation of caerulein with electronic microscope. The gene expression of XIAP, caspase-3 and caspase-9 was detected using real-time fluorescence quantitative polymerase chain reaction (FQ-PCR), and the protein expression of XIAP was assessed by western blot. The activation of nuclear factor-kappa B (NF-kappaB) was measured by flow cytometry (FCM). With the stimulation of caerulein, the expression of XIAP and the NF-kappaB activation could first decrease and then increase, but the change of caspase-3 and caspase-9 expressions were opposite. XIAP may inhibit the cell apoptosis in rat pancreatic acinus AR42J cell lines at first with the stimulation of caerulein, then NF-kappaB can upgrade the expression of XIAP and increase the cell apoptosis.
Acinar Cells ; cytology ; metabolism ; Animals ; Apoptosis ; physiology ; Cell Line ; Ceruletide ; pharmacology ; NF-kappa B ; metabolism ; Pancreas ; cytology ; metabolism ; Pancreatitis ; metabolism ; Rats ; X-Linked Inhibitor of Apoptosis Protein ; genetics ; metabolism

In order to construct the recombinant retrovirus vector of human ngn3 gene and its packaging cell line, we successfully amplified the open reading frame (ORF) of ngn3 gene from human fetal pancreatic tissue by RT-PCR. The PCR products of human ngn3 gene was subcloned into pMD18-T vectors and sequenced. Results showed that its sequence was fully consistent with the ngn3 gene published in GenBank(GenBank Accession No. BC126468). The correct fragment was digested by EcoR I and Hpa I from recombinant pMD18-T vector and inserted into the same restriction enzyme sites of retroviral vector pMSCV-neo. We got recombinant retrovirus vector pMSCV-ngn3, which was identified by double restriction enzyme digestion and then transfected into PT67 cells by lipofectamine 2000. We established the PT67-ngn3 packaging cell line by G418 selection, which was detected by RT-PCR and immunohistochemistry staining. The detection results showed that the Ngn3 expressed at the mRNA and protein level in the packaging cell line. RT-PCR detection and electronic microscope analysis showed that the recombinant retroviral vector pMSCV-ngn3 was packaged into infectious virus particles and released into the supernatant of the cells. These results demonstrated that a PT67-ngn3 packaging cell line was successfully established, and this could facilitate the study of differentiation of the human fetal pancreatic progenitor cells into insulin-producing cells by using the ngn3 gene.
Basic Helix-Loop-Helix Transcription Factors ; biosynthesis ; genetics ; Cell Differentiation ; drug effects ; Cell Line ; Cloning, Molecular ; Fetus ; Genetic Vectors ; genetics ; Humans ; Insulin-Secreting Cells ; cytology ; Molecular Sequence Data ; Nerve Tissue Proteins ; biosynthesis ; genetics ; Open Reading Frames ; genetics ; Pancreas ; cytology ; RNA, Messenger ; biosynthesis ; genetics ; Recombinant Proteins ; biosynthesis ; genetics ; pharmacology ; Retroviridae ; genetics ; metabolism ; Stem Cells ; cytology ; Transfection

PURPOSE: In non-excitable cells, which include parotid and pancreatic acinar cells, Ca(2+) entry is triggered via a mechanism known as capacitative Ca(2+) entry, or store-operated Ca(2+) entry. This process is initiated by the perception of the filling state of endoplasmic reticulum (ER) and the depletion of internal Ca(2+) stores, which acts as an important factor triggering Ca(2+) entry. However, both the mechanism of store-mediated Ca(2+) entry and the molecular identity of store-operated Ca(2+) channel (SOCC) remain uncertain. MATERIALS AND METHODS: In the present study we investigated the Ca(2+) entry initiation site evoked by depletion of ER to identify the localization of SOCC in mouse parotid and pancreatic acinar cells with microfluorometeric imaging system. RESULTS: Treatment with thapsigargin (Tg), an inhibitor of sarco/endoplasmic reticulum Ca(2+)-ATPase, in an extracellular Ca(2+) free state, and subsequent exposure to a high external calcium state evoked Ca(2+) entry, while treatment with lanthanum, a non-specific blocker of plasma Ca(2+) channel, completely blocked Tg-induced Ca(2+) entry. Microfluorometric imaging showed that Tg-induced Ca(2+) entry started at a basal membrane, not a apical membrane. CONCLUSION: These results suggest that Ca2+ entry by depletion of the ER initiates at the basal pole in polarized exocrine cells and may help to characterize the nature of SOCC.
Animals ; Calcium/*metabolism ; Calcium Channels/drug effects/metabolism ; Cells, Cultured ; Endoplasmic Reticulum/drug effects/*metabolism ; Mice ; Mice, Inbred ICR ; Microscopy, Fluorescence ; Pancreas/cytology/drug effects/*metabolism ; Parotid Gland/cytology/drug effects/*metabolism ; Thapsigargin/pharmacology

OBJECTIVETo explore the mechanisms of differentiation and development of pancreatic endocrine cells as well as pancreatic regeneration.

METHODSHuman embryonic pancreatic tissue at 7-14 weeks of gestation was collected. Diabetes mellitus rat model was induced with 65 mg/kg of streptozotocin. Insulin, glucagon, somatostatin, nestin, and cytokeratin 19 (CK19) of pancreatic tissues were observed by immunohistochemistry.

RESULTSAt 9 weeks of gestation, pancreatic epithelial cells began to co-express insulin, glucagon, somatostatin, and CK19 before migration. Islet cells gradually congregated along with the increase of aging, and at 14 weeks of gestation histological examination showed islet formation. At 12 weeks of gestation, nestin-positive cells could be seen in the pancreatic mesenchyme. During early embryogenesis, islet cells of pancreatic ducts co-expressed insulin, glucagon, and somatostatin. During pancreatic regeneration after damage, nestin expression of islet cells increased.

CONCLUSIONIn the early stage of embryogenesis, islet cells of primary pancreatic ducts can be differentiated to multipotential endocrine cells before migration. During tissue regeneration, pancreatic stem cells may differentiate and proliferate to form pancreatic islet.

Animals ; Cell Differentiation ; Diabetes Mellitus, Experimental ; chemically induced ; metabolism ; pathology ; Embryonic Development ; physiology ; Epithelial Cells ; cytology ; physiology ; Humans ; Insulin-Secreting Cells ; cytology ; physiology ; Islets of Langerhans ; cytology ; physiology ; Male ; Pancreas ; cytology ; embryology ; physiology ; Pancreatic Ducts ; cytology ; embryology ; physiology ; Rats ; Rats, Sprague-Dawley ; Regeneration ; physiology ; Stem Cells ; cytology ; metabolism ; physiology

OBJECTIVETo verify the hypothesis that selected nestin positive cells derived from human fetal pancreas (according as medical ethnics) have surface markers similar to bone marrow mesenchymal stem cells (MSCs), and that these cells have multilineage potential.

METHODThe cell surface markers were determined by flow cytometry, and then the potential that these cells might be differentiated into adipocytes and osteoplasts were explored.

RESULTThese cells have similar surface markers as MSCs of bone marrow origin. These cells was induced to differentiate into adipocytes and osteoplasts.

CONCLUSIONSelected nestin positive cells derived from human fetal pancreas have certain characteristics of MSCs.

Adipocytes ; cytology ; Bone Marrow Cells ; cytology ; Cell Differentiation ; Cell Separation ; methods ; Cells, Cultured ; Fetal Stem Cells ; chemistry ; cytology ; metabolism ; Flow Cytometry ; Humans ; Intermediate Filament Proteins ; Mesenchymal Stromal Cells ; metabolism ; Nerve Tissue Proteins ; Nestin ; Pancreas ; cytology ; embryology