OBJECTIVE: To investigate the effect of administration of rosiglitazone, an artificial ligand of PPARγ, on the expression and secretion of apolipoprotein (apoM) in fat-fed, streptozotocin-treated rats, an animal model for type 2-like diabetes. METHODS: Healthy male SD rats were divided into 4 groups: a control group (n=7), a high-fat chow group (HF group, n=8), a diabetes mellitus group (DM group, n=7), and a diabetes mellitus group with rosiglitazone intervention group (RSG group, n=7). Fasting blood glucose (FBG), fasting insulin (FINS), triglyceride (TG) and total cholesterol (TC) were measured at the beginning of the study. The diabetic rats model was established by feeding high fat chow and intraperitoneal injection of streprozotocin. Then the randomly selected treatment group was given rosiglitazone by daily gavage for 8 weeks. All the rats were killed at the fifteenth week, at which time blood and tissues (liver, kidney, adipose) were collected and prepared. The levels of FBG, FINS, TG and TC were assayed. The level of apoM in serum was measured by enzyme-linked immunosorbent assay (ELISA). Reverse transcription polymerase chain reaction (RT-PCR) was used to determine apoM mRNA expression in liver, kidney, and adipose tissues. RESULTS: Compared with either control group or HF group, serum apoM concentration in the DM group was reduced significantly (P<0.05); compared with the DM group, however, serum apoM concentrations in RSG group were increased (P<0.05). The expression of apoM mRNA in liver was highest, in kidney medium, and in adipose tissue extremely low (P<0.05). ApoM mRNA expression in liver and kidney was decreased in both DM and HF groups compared to control group (P<0.05). But, as with serum apoM concentration, apoM mRNA in the liver, kidney and adipose tissues of the RSG group were all increased markedly (P<0.05). The level of serum apoM in SD rats correlated negatively with TG (r=-0.466, P=0.011), TC (r=-0.568, P= 0.001), FBS (r =-0.371, P<0.001), and FINS(r=-0.768, P= 0.048 ). CONCLUSION These results suggest that apoM may participate in the glucose and lipid metabolism by the regulation of PPARγ.
Animals ; Apolipoproteins ; blood ; genetics ; metabolism ; Apolipoproteins M ; Diabetes Mellitus, Experimental ; drug therapy ; metabolism ; Dietary Fats ; administration & dosage ; Lipocalins ; blood ; genetics ; metabolism ; Male ; PPAR gamma ; agonists ; RNA, Messenger ; genetics ; metabolism ; Rats ; Rats, Sprague-Dawley ; Rosiglitazone ; Thiazolidinediones ; therapeutic use

FGF21 (fibroblast growth factor 21) is a recently described member of the FGF family. It has been previously demonstrated that FGF21 is a potent regulator of glucose homeostasis. To improve stability of FGF21 for better efficacy, a new form of recombinant FGF21 was generated by fusion of a full length FGF21 gene and the Fc fragment of human IgG4 with flexible linker sequence. To examine the glucose regulation activity of FGF21-L-Fc, 3T3-L1 pre-adipocytes were differentiated into adipocytes, and glucose uptake activity of FGF21-L-Fc was examined by glucose oxidase and peroxidase (GOD-POD) assay. The results showed that in comparison with wild type FGF21, FGF21-L-Fc was more potent in stimulation of glucose uptake by 3T3-L1. In vivo studies on the modified protein demonstrated that FGF-L-Fc had a better efficacy in lowering blood glucose of the STZ-induced diabetic animals and controlled glucose level for a longer time. The results provided a sound basis for further studies.
3T3-L1 Cells ; Adipocytes ; metabolism ; Animals ; Blood Glucose ; metabolism ; Diabetes Mellitus, Experimental ; drug therapy ; metabolism ; Escherichia coli ; metabolism ; Fibroblast Growth Factors ; genetics ; pharmacology ; Glucose ; metabolism ; Immunoglobulin G ; genetics ; pharmacology ; Male ; Mice ; Recombinant Proteins ; genetics ; pharmacology

The aim of this study is to investigate the therapeutic effect of RegIII-proinsulin-pBudCE4.1 plasmid on streptozotocin (STZ)-induced type 1 diabetes mellitus and its underlying mechanisms. The model of type 1 diabetes mellitus was established by intraperitoneal injections of STZ (40 mg kg(-1)) to Balb/c mice for five consecutive days. Then, ten type 1 diabetic mice were intramuscularly injected with 100 microg RegIII-proinsulin-pBudCE4.1 plasmid for 4 weeks (one time/week) and the blood glucose levels were monitored every week; whereas another ten diabetic mice served as negative control group were injected with pBudCE4.1 vector at the same dose. Normal control and model control mice were treated with normal saline at identical volume under the same way. Western blotting, MTT assay, ELISA, HE staining and Tunel assay were applied to explore the underlying mechanisms. Results showed that RegIII-proinsulin-pBudCE4.1 plasmid ameliorated the hyperglycemia symptoms in diabetic mouse remarkably. It induced an immunological tolerance state in type 1 diabetic mice by inhibiting the proliferation of splenic lymphocytes and recovering Th1/Th2 balance evidenced by MTT and ELISA analysis. Furthermore, it elevated insulin concentration in the serum of type 1 diabetic mice and promoted the regeneration of beta cells supported by the results of HE staining and Tunel assay. In conclusion, RegIII-proinsulin-pBudCE4.1 plasmid possesses powerful anti-diabetic ability, which may be involved in the inducing of immunological tolerance and enhancing beta cells recovery.
Animals ; Apoptosis ; Blood Glucose ; metabolism ; Cell Proliferation ; Diabetes Mellitus, Experimental ; metabolism ; pathology ; therapy ; Diabetes Mellitus, Type 1 ; chemically induced ; metabolism ; pathology ; therapy ; Genetic Therapy ; Hyperglycemia ; therapy ; Injections, Intramuscular ; Insulin ; blood ; Islets of Langerhans ; cytology ; Male ; Mice ; Mice, Inbred BALB C ; Plasmids ; Proinsulin ; genetics ; metabolism ; therapeutic use ; Proteins ; genetics ; metabolism ; therapeutic use ; Streptozocin ; T-Lymphocytes ; cytology ; Th1-Th2 Balance

OBJECTIVETo observe the effects of Shenqi Compound (SQC) on the mRNA expression of angiotensin II type 1 receptor (AT1R) in the aorta of Goto-Kakizaki (GK) rats.

METHODSTotally 67 GK rats were randomly divided into 5 groups, i.e., the GK group (n =18), the model group (n =16), the atorvastatin group (n =17), and the SQC group (n =16). Another a normal control group was set up (n =18). The diabetic macrovascular disease model was prepared by adding L-NAME (at the daily dose of 0.10 mg/mL) in drinking water for GK rats. GK rats, except those in the normal control group were fed with high fat diet. Atorvastatin (at the daily dose of 1.60 mg/kg) and SQC (at the daily dose of 1.44 g/kg) were respectively administered by gastrogavage, once daily for 35 successive days. The blood glucose was determined by glucose oxidase method once per week. After 5-week medication, the contents of triglyceride (TG) and total cholesterol (TC) were determined by ELISA. The serum concentrations of angiotensin I (Ang II) were determined by RIA. The mRNA expression of AT1R in the aorta was determined by real-time quantitative reverse transcriptase PCR (RT-PCR).

RESULTSThe blood glucose level was obviously lower in both the atorvastatin group and the SQC group after 4 weeks of medication (P <0.05). Besides, it was significantly lower in the SQC group than in the model group by the end of the 4th week (P <0.05). The concentrations of TG, TC and serum Ang II , and the mRNA expression of AT1R in the aorta were significantly higher in the model group than in the normal control group (P <0.01). After 5-week medication, the concentrations of TG, TC and serum Ang I , and the mRNA expression of AT1 R in the aorta were significantly lower in the atorvastatin group and the SQC group than in the model group (P <0.01, P <0.05). The mRNA expression of AT1R was significantly higher in the SQC group than in the atorvastatin group (P <0.05).

CONCLUSIONSSQC could significantly reduce the levels of blood glucose, TG, TC, down-regulate the mRNA expression of AT1R in the aorta, and decrease the expressions of serum Ang II of GK rats with diabetic macrovascular disease. AT1 R might be one of effective targets of SQC in treating diabetic macrovascular diseases.

Angiotensin II ; blood ; Animals ; Aorta ; drug effects ; metabolism ; Blood Glucose ; analysis ; Cholesterol ; blood ; Diabetes Mellitus, Experimental ; drug therapy ; metabolism ; Diabetes Mellitus, Type 2 ; drug therapy ; metabolism ; Drugs, Chinese Herbal ; pharmacology ; Male ; RNA, Messenger ; genetics ; Rats ; Receptor, Angiotensin, Type 1 ; genetics ; metabolism ; Triglycerides ; blood

Hepatocyte growth factor (HGF) is a potent mitogen and promoter of proliferation of insulin producing beta cells of pancreatic islets. To study the role of HGF, an adenoviral vector carrying the human HGF (Ad.hHGF) gene was transfected into the streptozotocin-induced diabetic mice and evaluated the effect on the blood glucose metabolism and the insulin-secreting beta cells of pancreatic islets. Ad.hHGF gene transfection resulted in amelioration of hyperglycemia and prolongation of survival period in the diabetic mice. Concomitantly adenoviral- mediated hHGF gene therapy slightly increased serum insulin concentration and the expression of insulin in the pancreatic islet. Although the proliferation of beta-cell mass was not noticeable, the beneficial effect of HGF is significant to an almost deteriorated pancreatic islets. Taken together, these data suggest that the Ad.hHGF gene therapy into diabetic mice may prevent the further destruction and present as a beneficial remedy for type 1 diabetic patients.
Adenoviridae/*genetics/physiology ; Animals ; Blood Glucose/analysis ; Body Weight ; Diabetes Mellitus, Experimental/blood/genetics/*metabolism/*therapy ; *Gene Therapy ; Hepatocyte Growth Factor/genetics/*metabolism ; Humans ; Hyperglycemia/blood/complications/genetics/*therapy ; Insulin/blood ; Islets of Langerhans/metabolism/*pathology ; Male ; Mice ; Mice, Inbred BALB C ; Recombinant Proteins/genetics/metabolism ; Survival Rate

The insulin complement with gene therapy has been used as an experimental treatment for insulin dependent diabetes (IDDM). In the present study, we constructed naked plasmid DNA vector encoding recombinant human preproinsulin gene (pCMV-IN), and injected the plasmids (100 microg/mouse) intramuscularly combined with electroporation, to achieve the in vivo transfer of insulin gene in streptozotocin (STZ)-induced diabetic C57 mice. The expression of vector-derived insulin mRNA was detected with RT-PCR in transfected local skeletal muscles. The plasma insulin was elevated significantly in pCMV-IN injected diabetic C57 mice, which was complemented to the level similar to the intact normal control. The protein expression lasted for at least 35 days after the plasmid injection. Gene therapy with pCMV-IN plasmids considerably decreased the blood glucose level in STZ-induced diabetic mice from d 7 to d 35 by about 6 mmol/L. The gene therapy also reduced the mortality of severe diabetic mice significantly from 100% to 37% at the 6th week. Our results indicate that the direct intramuscular injection of naked plasmids encoding human preproinsulin gene achieves the effective expression of insulin. The restoration of insulin decreases blood glucose and increases the survival in severe diabetic mice. The gene therapy might be provided as a practical therapeutic approach to IDDM.
Animals ; Blood Glucose ; metabolism ; Diabetes Mellitus, Experimental ; blood ; therapy ; Diabetes Mellitus, Type 1 ; blood ; therapy ; Electroporation ; Gene Transfer Techniques ; Genetic Therapy ; methods ; Genetic Vectors ; Injections, Intramuscular ; Insulin ; Male ; Mice ; Mice, Inbred C57BL ; Plasmids ; genetics ; Proinsulin ; genetics ; therapeutic use ; Protein Precursors ; genetics ; therapeutic use

AIMTo determine whether adenoviral gene transfer of insulin like growth factor-1 (IGF-1) to the penis of streptozotocin (STZ)-induced diabetic rats could improve erectile capacity.

METHODSTHE STZ diabetic rats were transfected with AdCMV-betagal or AdCMV-IGF-1. These rats underwent cavernous nerve stimulation to assess erectile function and their responses were compared with those of age-matched control rats 1 to 2 days after transfection. In control and transfected STZ diabetic rats, IGF-1 expression were examined by reverse transcription polymerase chain reaction (RT-PCR), Western blot and histology. The penis beta-galactosidase activity and localization of the STZ diabetic rats were also determined.

RESULTSOne to two days after transfection, the beta-galactosidase was found in the smooth muscle cells of the diabetic rat penis transfected with AdCMV-betagal. One to 2 days after administration of AdCMV-IGF-1, the cavernosal pressure, as determined by the ratio of maximal intracavernous pressure-to-mean arterial pressure (ICP/MAP) and total intracavernous pressure (ICP), was increased in response to cavernous nerve stimulation. Transgene expression was confirmed by RT-PCR, Western blot and histology.

CONCLUSIONGene transfer of IGF-1 significantly increased erectile function in the STZ diabetic rats. These results suggest that in vivo gene transfer of IGF-1 might be a new therapeutic intervention for the treatment of erectile dysfunction (ED) in the STZ diabetic rats.

Animals ; Blood Glucose ; metabolism ; Body Weight ; Diabetes Mellitus, Experimental ; physiopathology ; Erectile Dysfunction ; prevention & control ; Genetic Therapy ; Insulin-Like Growth Factor I ; genetics ; Male ; Penile Erection ; physiology ; Penis ; enzymology ; physiopathology ; Rats ; Rats, Sprague-Dawley ; Reference Values ; beta-Galactosidase ; metabolism

BACKGROUNDThe effects of triterpenic acid from Prunella vulgaris L. (TAP) on diabetes and its mechanism are uncertain. The aim of this study was to investigate the effects of TAP on antihyperglycemic, antioxidant, and pancreas-protective in streptozotozin (STZ)-diabetic rats.

METHODSThe diabetic model was produced by injection of 60 mg/kg STZ. Blood was drawn from the tail vein of rats after 72 hours. Rats with blood glucose ≥ 16.7 mmol/L were considered diabetic. Diabetic rats were randomly divided into four groups: (1) Diabetes rat (STZ), (2) Diabetic rats treated with 50 mg/kg of triterpenic acid from Prunella vulgaris L (STZ + TAP50), (3) Diabetic rats treated with 100 mg/kg TAP (STZ + TAP100), and (4) Diabetic rats treated with 200 mg/kg TAP (STZ + TAP200). Normal rats (n = 10) acted as the control group (NC). TAP was administered by the intragastric route once each day for six weeks. Body weight and the concentration of blood glucose (BG) were measured after three and six weeks. Fructosamine (FMN), malondialdehyde (MDA), and nitric oxide (NO), and the activities of nitric oxide synthase (NOS) and superoxide dismutase (SOD) in serum were determined after six weeks using commercially available kits following the manufacturer's instructions. Pathologic changes in pancreatic β-cells were also investigated by microscopic examination after hematoxylin-eosin (HE) staining. The level of SOD mRNA in pancreatic β-cells was measured by polymerase chain reaction (PCR).

RESULTSThe levels of BG, FMN, NO, and MDA and the activities of NOS in serum in the four diabetes groups were significantly increased compared with the control group (P < 0.01). The activity of SOD in serum and the body weight was significantly decreased compared with the control group (P < 0.01). After administration of TAP to diabetic rats for six weeks, the body weight and the levels of BG, FMN, MDA, NO and the activity of NOS in serum decreased significantly compared with the STZ group in a dose-dependent manner. The activity of SOD in serum and body weight increased significantly compared with the STZ group in a dose-dependent manner. In addition, diabetic rats showed a significant decrease in SOD mRNA expression in pancreatic β cells. However, these changes were reversed by TAP. Histopathological examination also showed the protective effect of TAP on pancreatic β cells.

CONCLUSIONSTriterpenic acid from Prunella vulgaris L. has an anti-diabetic effect, by controlling blood glucose and antioxidants, and has a protective effect on the pancreas.

Animals ; Blood Glucose ; analysis ; Diabetes Mellitus, Experimental ; drug therapy ; metabolism ; Insulin-Secreting Cells ; drug effects ; pathology ; Male ; Prunella ; chemistry ; RNA, Messenger ; analysis ; Rats ; Rats, Sprague-Dawley ; Streptozocin ; Superoxide Dismutase ; genetics ; Triterpenes ; therapeutic use

OBJECTIVETo study the effect of Dangua Recipe (DGR) on glycolipid metabolism, vascular cell adhesion molecule-1 (VCAM-1) and its mRNA expression level of transgenic Apo E(-/-) mouse with spontaneous atherosclerosis, thus revealing its partial mechanism for curing diabetes mellitus (DM) with angiopathy.

METHODSDiabetic model was prepared by peritoneally injecting streptozotocin (STZ) to Apo E(-/-) mouse. Totally 32 modeled mice were stratified by body weight, and then divided into 4 groups referring to blood glucose levels from low to high by random digit table, i.e., the model group (MOD, fed with sterile water, at the daily dose of 15 mL/kg), the DGR group (fed with DGR at the daily dose of 15 mL/kg), the combination group (COM, fed with DGR at the daily dose of 15 mL/kg and pioglitazone at the daily dose of 4.3 mg/kg), and the pioglitazone group (PIO, at the daily dose of 4.3 mg/kg), 8 in each group. Another 8 normal glucose C57 mouse of the same age and strain were recruited as the control group. All interventions lasted for 12 weeks by gastrogavage. The fasting blood glucose (FBG), body weight, food intake, water intake, skin temperature, the length of tail, and the degree of fatty liver were monitored. The hemoglobin A1c (HbA1c), total cholesterol (TC), and LDL-C were determined. Endothelin-1 (ET-1) was determined by radioimmunoassay. Nitrogen monoxidum (NO) was determined by nitrate reductase. The kidney tissue VCAM-1 level was analyzed with ELISA. The expression of VCAM-1 mRNA in the kidney tissue was detected with real time quantitative PCR.

RESULTSCompared with the control group, the body weight and food intake decreased, water intake increased in all the other model groups (P < 0.05). Besides, the curve of blood glucose was higher in all the other model groups than in the control group (P < 0.01). Compared with the model group, the body weight increased; levels of HbAlc, TC, LDL-C, ET-1, and VCAM-1 were significantly lower; and skin temperature was higher in the DGR group (P < 0.05, P < 0.01). Compared with the PIO group, body weight, the increment of body weight, FBG, TC, and LDL-C were lower (P < 0.05, P < 0.01); food intake and water intake increased more and the tail length was longer in the DRG group (P < 0.01). There was no statistical difference in the level of NO among groups. The degree of fatty liver in the model group was significantly severer than that in the control group (P < 0.05). It was obviously alleviated in the DGR group (P < 0.05) when compared with the model group and the PIO group (P < 0.05, P < 0.01). But it was severer in the PIO group than in the model group (P < 0.01). The degree of fatty liver in the combination group ranged between that of the DGR group and the PIO group (P < 0.05). The level of VCAM-1 mRNA expression was significantly lower in the DGR group than in the model group, the PIO group, and the combination group (P < 0.05).

CONCLUSIONSDGR had effect in lowering blood glucose and blood lipids, and fighting against fatty liver of transgenic Apo E(-/-) mouse with spontaneous atherosclerosis. DGR played an effective role in preventing and treating DM with angiopathy by comprehensively regulating glycolipid metabolism and promoting the vascular function.

Animals ; Apolipoproteins E ; genetics ; Blood Glucose ; metabolism ; Diabetes Mellitus, Experimental ; blood ; drug therapy ; Diabetic Angiopathies ; drug therapy ; Drugs, Chinese Herbal ; pharmacology ; Lipids ; blood ; Male ; Mice ; Mice, Knockout ; RNA, Messenger ; genetics ; Random Allocation ; Thiazolidinediones ; pharmacology ; Vascular Cell Adhesion Molecule-1 ; genetics ; metabolism

OBJECTIVETo investigate the effect of Dan-gua Fang on adenosine 5'-monophosphate (AMP) activated protein kinase (AMPK) α expression in liver and subsequent improvement of glucose and lipid metabolism.

METHODSForty 13-week-old diabetic Goto-Kakizaki (GK) rats were randomly divided into model, Dan-gua Fang, metformin and simvastatin groups (n=10 for each), and fed high-fat diet ad libitum. Ten Wistar rats were used as normal group and fed normal diet. After 24 weeks, liver expression of AMPKα mRNA was assessed by real-time PCR. AMPKα and phospho-AMPKα protein expression in liver was evaluated by Western blot. Liver histomorphology was carried out after hematoxylin-eosin staining, and blood glucose (BG), glycosylated hemoglobin A1c (HbA1c), food intake and body weight recorded.

RESULTSSimilar AMPKα mRNA levels were found in the Dan-gua Fang group and normal group, slightly higher than the values obtained for the remaining groups (P<0.05). AMPKα protein expression in the Dan-gua Fang group animals was similar to other diabetic rats, whereas phospho-AMPKα (Thr-172) protein levels were markedly higher than in the metformin group and simvastatin group (P<0.05), respectively. However, phosphor-AMPKα/AMPKα ratios were similar in all groups. Dan-gua Fang reduced fasting blood glucose with similar strength to metformin, and was superior in reducing cholesterol, triglycerides, high-density lipoprotein cholesterol as well as improving low-density lipoprotein cholesterol in comparison with simvastatin and metformin. Dan-gua Fang decreases plasma alanine aminotransferase (ALT) significantly.

CONCLUSIONDan-gua Fang, while treating phlegm-stasis, could decrease BG and lipid in type 2 diabetic GK rats fed with high-fat diet, and effectively protect liver histomorphology and function. This may be partly explained by increased AMPK expression in liver. Therefore, Dan-gua Fang might be an ideal drug for comprehensive intervention for glucose and lipid metabolism disorders in type 2 diabetes mellitus.

AMP-Activated Protein Kinases ; genetics ; metabolism ; Animals ; Blood Glucose ; metabolism ; Body Weight ; Diabetes Mellitus, Experimental ; blood ; drug therapy ; enzymology ; metabolism ; Drugs, Chinese Herbal ; therapeutic use ; Feeding Behavior ; Glycolipids ; metabolism ; Liver ; enzymology ; pathology ; Male ; Phosphorylation ; RNA, Messenger ; genetics ; metabolism ; Rats, Wistar ; Real-Time Polymerase Chain Reaction ; Time Factors