OBJECTIVE: To explore the role of 5-hydroxytryptamine (5-HT) in type 2 diabetes mellitus (T2DM)-related hepatic inflammation and fibrosis. METHODS: Male C57BL/6J mice were used to establish T2DM model by high-fat diet feeding combined with intraperitoneal injection of streptozotocin. Then, the mice with hyperglycemia were still fed with high-fat diet for nine weeks, and treated with or without 5-HT_2A receptor (5-HT_2AR) antagonist sarpogrelate hydrochloride (SH) and 5-HT synthesis inhibitor carbidopa (CDP) (alone or in combination). To observe the role of 5-HT in the myofibroblastization of hepa-tic stellate cells (HSCs), human HSCs LX-2 were exposed to high glucose, and were treated with or without SH, CDP or monoamine oxidase A (MAO-A) inhibitor clorgiline (CGL). Hematoxylin & eosin and Masson staining were used to detect the pathological lesions of liver tissue section, immunohistochemistry and Western blot were used to analyze protein expression, biochemical indicators were measured by ELISA or enzyme kits, and levels of intracellular reactive oxygen species (ROS) were detected by fluorescent probe. RESULTS: There were up-regulated expressions of 5-HT_2AR, 5-HT synthases and MAO-A, and elevated levels of 5-HT in the liver of the T2DM mice. In addition to reduction of the hepatic 5-HT levels and MAO-A expression, treatment with SH and CDP could effectively ameliorate liver lesions in the T2DM mice, both of which could ameliorate hepatic injury and steatosis, significantly inhibit the increase of hepatic ROS (H₂O₂) levels to alleviate oxidative stress, and markedly suppress the production of transforming growth factor β1 (TGF-β1) and the development of inflammation and fibrosis in liver. More importantly, there was a synergistic effect between SH and CDP. Studies on LX-2 cells showed that high glucose could induce up-regulation of 5-HT_2AR, 5-HT synthases and MAO-A expression, increase intracellular 5-HT level, increase the production of ROS, and lead to myofibroblastization of LX-2, resulting in the increase of TGF-β1 synthesis and production of inflammatory and fibrosis factors. The effects of high glucose could be significantly inhibited by 5-HT_2AR antagonist SH or be markedly abolished by mitochondrial 5-HT degradation inhibitor CGL. In addition, SH significantly suppressed the up-regulation of 5-HT synthases and MAO-A induced by high glucose in LX-2. CONCLUSION Hyperglycemia-induced myofibroblastization and TGF-β1 production of HSCs, which leads to hepatic inflammation and fibrosis in T2DM mice, is probably due to the up-regulation of 5-HT_2AR expression and increase of 5-HT synthesis and degradation, resulting in the increase of ROS production in mitochondria. Among them, 5-HT_2AR is involved in the regulation of 5-HT synthases and MAO-A expression.
Male ; Mice ; Humans ; Animals ; Hepatic Stellate Cells/pathology* ; Transforming Growth Factor beta1/pharmacology* ; Serotonin/metabolism* ; Reactive Oxygen Species/metabolism* ; Diabetes Mellitus, Type 2/complications* ; Hydrogen Peroxide/metabolism* ; Mice, Inbred C57BL ; Liver Cirrhosis/etiology* ; Hyperglycemia/pathology* ; Monoamine Oxidase/metabolism* ; Inflammation ; Glucose/metabolism* ; Cytidine Diphosphate/pharmacology*

Diabetes Mellitus, Type 2 ; diagnostic imaging ; metabolism ; Fluorodeoxyglucose F18 ; Humans ; Immunoglobulin G ; metabolism ; Lymph Nodes ; diagnostic imaging ; pathology ; Male ; Middle Aged ; Neoplasms, Connective Tissue ; diagnostic imaging ; metabolism ; Positron-Emission Tomography

OBJECTIVE: To investigate the intervention of curcumin and its analogue J7 on oxidative stress injury in testis of type 2 diabetic rats. METHODS: Sixty male SD rats, 10 rats were chosen as normal control group (NC), the other 50 rats were assigned to experiment group. Experiment diabetic rats were induced by high-fat food and intraperitoneal injection of steptozotocin (STZ). After the model was established successfully, diabetic rats were divided into four groups randomly: diabetes mellitus group (DM, n=12), curcumin treatment group (CUR, n=10), high dose treatment group of J7 (J+, n=10), low dose treatment group of J7 (J-, n=10). The CUR group were intragastrically administered with curcumin 20 mg/kg daily, in addition, the J+ group and the J- group were intragastrically administered with J7 20 mg/kg and 10 mg/kg daily respectively. After 8 weeks, the fast blood glucose was detected biochemically. The activity of superoxide dismutase (SOD) and the level of malondialdehyde (MDA) were detected by hydroxylamine method and thiobarbituric acid method respectively. The protein expressions of the nuclear factor-erythroid 2-related factor 2 (tNrf2), phosphorylation of Nrf2 (pNrf2), catalase (CAT), NAD(P)H quinine oxidoreductase 1 (NQO1) were measured by Western blot. The mRNA expressions of CAT, NQO1, hemeoxygenase-1 (HO1) were measured by quantitative real-time PCR (qRT-PCR). Morphological structure of testis was observed by hematoxylin-eosin (HE) staining. The expressions of Nrf2 and CAT were also detected by immunohistochemical method. RESULTS: The levels of fast blood glucose and MDA in DM group were increased significantly(P＜0.05), while the body weight, the activity of SOD, the protein expressions of pNrf2/tNrf2, CAT, NQO1 and the mRNA expressions of CAT, NQO1, HO1 were decreased (P＜0.05). Under light microscope, the DM group showed disrupted histological appearance. Immunohistochemistry showed that the protein expressions of Nrf2 around the nucleus and CAT were decreased. With the treatment of curcumin and J7, the MDA levels in the three treatment groups were decreased (P＜0.05). The activity of SOD, the protein expressions of pNrf2/tNrf2, CAT, NQO1 and the mRNA expressions of NQO1, HO1 were increased (P＜0.05). the levels of fast blood glucose were decreased in the J+ and J- group (P＜0.05), and the mRNA expression of CAT was increased in the J+ group (P＜0.05). The ratio of pNrf2/tNrf2 in the J+ group was significantly higher than that in CUR and J- group (P＜0.05). The protein level of CAT in the J+ group was also significantly higher than that in J- group (P＜0.05). There were no significant differences in other indexes among the three treatment groups. Under light microscope, the morphology was obviously improved in the three treatment groups. Immunohistochemistry showed that the protein expressions of Nrf2 around the nucleus and CAT were increased in the three treatment groups. It was suggested that high dose J7 had better antioxidant stress ability in testis of diabetic rats. CONCLUSION Curcumin and J7 could inhibit the oxidative stress damage of testicular tissue in diabetic rats, which might be related with the activation of the Nrf2-ARE signaling pathway.
Animals ; Blood Glucose ; analysis ; Curcumin ; analogs & derivatives ; pharmacology ; Diabetes Mellitus, Experimental ; Diabetes Mellitus, Type 2 ; Male ; Malondialdehyde ; metabolism ; NF-E2-Related Factor 2 ; metabolism ; Oxidative Stress ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Signal Transduction ; Superoxide Dismutase ; metabolism ; Testis ; drug effects ; pathology

OBJECTIVE: The present study aims at determining the stability of a popular type 2 diabetes rat model induced by a high-fat diet combined with a low-dose streptozotocin injection. METHODS: Wistar rats were fed with a high-fat diet for 8 weeks followed by a one-time injection of 25 or 35 mg/kg streptozotocin to induce type 2 diabetes. Then the diabetic rats were fed with regular diet/high-fat diet for 4 weeks. Changes in biochemical parameters were monitored during the 4 weeks. RESULTS: All the rats developed more severe dyslipidemia and hepatic dysfunction after streptozotocin injection. The features of 35 mg/kg streptozotocin rats more resembled type 1 diabetes with decreased body weight and blood insulin. Rats with 25 mg/kg streptozotocin followed by normal diet feeding showed normalized blood glucose level and pancreatic structure, indicating that normal diet might help recovery from certain symptoms of type 2 diabetes. In comparison, diabetic rats fed with high-fat diet presented decreased but relatively stable blood glucose level, and this was significantly higher than that of the control group (P<0.05). CONCLUSIONS This model easily recovers with normal diet feeding. A high-fat diet is suggested as the background diet in future pharmacological studies using this model.
Animals ; Blood Glucose ; metabolism ; Diabetes Mellitus, Experimental ; blood ; etiology ; physiopathology ; Diabetes Mellitus, Type 2 ; blood ; etiology ; physiopathology ; Diet, High-Fat ; adverse effects ; Insulin ; blood ; Lipids ; blood ; Liver ; drug effects ; pathology ; physiopathology ; Male ; Malondialdehyde ; blood ; Oxidative Stress ; Rats ; Rats, Wistar ; Streptozocin ; administration & dosage ; toxicity ; Superoxide Dismutase ; blood ; Uric Acid ; blood

Biomarkers ; urine ; Cross-Sectional Studies ; Diabetes Mellitus, Type 2 ; pathology ; urine ; Enzyme-Linked Immunosorbent Assay ; Hepatitis A Virus Cellular Receptor 1 ; metabolism ; Humans ; Intracellular Signaling Peptides and Proteins ; urine ; Kidney Diseases ; pathology ; urine ; Lipocalin-2 ; urine ; Membrane Proteins ; urine ; Sialoglycoproteins ; urine ; Tissue Inhibitor of Metalloproteinase-2 ; urine

Xiao Ke Qing (XKQ) granule has been clinically used to treat type 2 diabetes mellitus (T2DM) for 10 years in Chinese traditional medication. However, its mechanisms against hyperglycemia remain poorly understood. This study aims to investigate XKQ mechanisms on diabetes and diabetic liver disease by using the KKAy mice model. Our results indicate that XKQ can significantly reduce food and water intake. XKQ treatment also remarkably decreases both the fasting blood glucose and blood glucose in the oral glucose tolerance test. Additionally, XKQ can significantly decrease the serum alanine aminotransferase level and liver index and can alleviate the fat degeneration in liver tissues. Moreover, XKQ can ameliorate insulin resistance and upregulate the expression of IRS-1, PI3K (p85), p-Akt, and GLUT4 in the skeletal muscle of KKAy mice. XKQ is an effective drug for T2DM by ameliorating insulin resistance and regulating the PI3K/Akt signaling pathway in the skeletal muscle.
Animals ; Blood Glucose ; drug effects ; metabolism ; Diabetes Mellitus, Type 2 ; drug therapy ; metabolism ; Disease Models, Animal ; Drugs, Chinese Herbal ; pharmacology ; Female ; Glucose Tolerance Test ; Glucose Transporter Type 4 ; metabolism ; Hypoglycemic Agents ; pharmacology ; Insulin ; blood ; Insulin Resistance ; Liver ; drug effects ; pathology ; Mice ; Mice, Inbred C57BL ; Phosphatidylinositol 3-Kinases ; metabolism ; Proto-Oncogene Proteins c-akt ; metabolism ; Signal Transduction ; drug effects

BACKGROUND: With the advent of sodium glucose co-transporter 2 inhibitors to control glucose and treat diabetes, laboratory data aided by either timed or spot glucose levels in the urine could be used as an alternative marker of drug response. The aim of this study was to assess the agreement between overnight urinary glucose excretion (UGE) and morning spot urinary glucose-to-creatinine ratio (UGCR). METHODS: In this prospective cross-sectional study, we enrolled a total of 215 participants with either normal glucose tolerance (NGT), pre-diabetes, or type 2 diabetes mellitus (T2DM). To exclude external factors such as food intake and physical activity, urine samples collected overnight at an 8-hr interval and the first-voided morning spot urine were collected and compared. RESULTS: The median values of overnight 8-hr UGE in participants with NGT (N=14), pre-diabetes (N=41), and T2DM (N=160) were 35.0 mg, 35.6 mg, and 653.4 mg, respectively. In participants with T2DM, the median values of overnight 8-hr UGCR and first-voided morning spot UGCR (M-UGCR) were 1.37 mg/mg and 0.16 mg/mg, respectively. Quantitative analyses using an intraclass correlation coefficient (ICC) demonstrated a good reliability of measurement of the overnight 8-hr UGCR and M-UGCR (ICC=0.943, P<0.001). The M-UGCR was also significantly related to the overnight 8-hr UGE (r=0.828, P<0.001). CONCLUSIONS: M-UGCR and overnight 8-hr UGCR showed good agreement, suggesting that M-UGCR be used as a simple index for estimating overnight amounts of UGE in patients with T2DM.
Adult ; Aged ; Blood Glucose/analysis ; Creatinine/*urine ; Cross-Sectional Studies ; Diabetes Mellitus, Type 2/*pathology ; Female ; Glucose/*analysis/metabolism ; Humans ; Linear Models ; Male ; Middle Aged ; Prospective Studies ; Urinalysis

PURPOSE: Diabetic nephropathy is a serious complication of type 2 diabetes mellitus, and delaying the development of diabetic nephropathy in patients with diabetes mellitus is very important. In this study, we investigated inflammation, oxidative stress, and lipid metabolism to assess whether curcumin ameliorates diabetic nephropathy. MATERIALS AND METHODS: Animals were divided into three groups: Long-Evans-Tokushima-Otsuka rats for normal controls, Otsuka-Long-Evans-Tokushima Fatty (OLETF) rats for the diabetic group, and curcumin-treated (100 mg/kg/day) OLETF rats. We measured body and epididymal fat weights, and examined plasma glucose, adiponectin, and lipid profiles at 45 weeks. To confirm renal damage, we measured albumin-creatinine ratio, superoxide dismutase (SOD), and malondialdehyde (MDA) in urine samples. Glomerular basement membrane thickness and slit pore density were evaluated in the renal cortex tissue of rats. Furthermore, we conducted adenosine monophosphate-activated protein kinase (AMPK) signaling and oxidative stress-related nuclear factor (erythroid-derived 2)-like 2 (Nrf2) signaling to investigate mechanisms of lipotoxicity in kidneys. RESULTS: Curcumin ameliorated albuminuria, pathophysiologic changes on the glomerulus, urinary MDA, and urinary SOD related with elevated Nrf2 signaling, as well as serum lipid-related index and ectopic lipid accumulation through activation of AMPK signaling. CONCLUSION: Collectively, these findings indicate that curcumin exerts renoprotective effects by inhibiting renal lipid accumulation and oxidative stress through AMPK and Nrf2 signaling pathway.
Albuminuria ; Animals ; Anti-Inflammatory Agents, Non-Steroidal/*therapeutic use ; Curcumin/*pharmacology ; Diabetes Mellitus, Type 2/*metabolism/urine ; Diabetic Nephropathies/complications/*drug therapy/metabolism/pathology ; Gene Expression/drug effects ; Inflammation ; Kidney/drug effects/metabolism/physiopathology ; Kidney Glomerulus/metabolism/physiopathology ; Lipid Metabolism/*drug effects ; Male ; Malondialdehyde/metabolism/urine ; Oxidative Stress/*drug effects ; Rats ; Rats, Inbred OLETF ; Rats, Long-Evans ; Superoxide Dismutase/metabolism

PURPOSE: The severity of non-alcoholic fatty liver disease (NAFLD) in type 2 diabetes mellitus (T2DM) population compared with that in normal glucose tolerance (NGT) individuals has not yet been quantitatively assessed. We investigated the prevalence and the severity of NAFLD in a T2DM population using controlled attenuation parameter (CAP). MATERIALS AND METHODS: Subjects who underwent testing for biomarkers related to T2DM and CAP using Fibroscan® during a regular health check-up were enrolled. CAP values of 250 dB/m and 300 dB/m were selected as the cutoffs for the presence of NAFLD and for moderate to severe NAFLD, respectively. Biomarkers related to T2DM included fasting glucose/insulin, fasting C-peptide, hemoglobin A1c (HbA1c), glycoalbumin, and homeostasis model assessment of insulin resistance of insulin resistance (HOMA-IR). RESULTS: Among 340 study participants (T2DM, n=66; pre-diabetes, n=202; NGT, n=72), the proportion of subjects with NAFLD increased according to the glucose tolerance status (31.9% in NGT; 47.0% in pre-diabetes; 57.6% in T2DM). The median CAP value was significantly higher in subjects with T2DM (265 dB/m) than in those with pre-diabetes (245 dB/m) or NGT (231 dB/m) (all p<0.05). Logistic regression analysis showed that subjects with moderate to severe NAFLD had a 2.8-fold (odds ratio) higher risk of having T2DM than those without NAFLD (p=0.02; 95% confidence interval, 1.21-6.64), and positive correlations between the CAP value and HOMA-IR (ρ=0.407) or fasting C-peptide (ρ=0.402) were demonstrated. CONCLUSION: Subjects with T2DM had a higher prevalence of severe NAFLD than those with NGT. Increased hepatic steatosis was significantly associated with the presence of T2DM, and insulin resistance induced by hepatic fat may be an important mechanistic connection.
Adult ; Aged ; Biomarkers/metabolism ; C-Peptide/metabolism ; Case-Control Studies ; Diabetes Mellitus, Type 2/*complications/metabolism ; Female ; Hemoglobin A, Glycosylated/metabolism ; Humans ; Insulin Resistance ; Male ; Middle Aged ; Non-alcoholic Fatty Liver Disease/*epidemiology/metabolism/pathology ; Odds Ratio ; Prevalence

The prevalence of diabetes mellitus (DM) and associated diseases such as cancers are substantially increasing worldwide. About 80% of the patients with pancreatic cancer have glucose metabolism alterations. This suggests an association between type 2 DM and pancreatic cancer risk and progression. There are hypotheses that show metabolic links between the diseases, due to insulin resistance, hyperglycemia, hyperinsulinemia, low grade chronic inflammation, and alteration in the insulin-insulin-like growth factor axis. The use of diabetes medications can influence the extent of carcinogenesis of the pancreas. This study briefly reviews recent literature on investigation of metabolic link of type 2 DM, risk of carcinogenesis of the pancreas and their association, as well as the current understanding of metabolic pathways implicated in metabolism and cellular growth. The main finding of this review, although there are discrepancies, is that according to most research long-term DM does not raise the risk of pancreatic cancer. The longest duration of DM may reflect hypoinsulinemia due to treatment for hyperglycemia, but recent onset diabetes was associated with increased risk for pancreatic cancer due to hyperinsulinemia and hyperglycemia. In conclusion, the review demonstrates that type 2 DM and the duration of diabetes pose a risk for pancreatic carcinogenesis, and that there is biological link between the diseases.
Diabetes Mellitus, Type 2/complications/epidemiology/metabolism/*pathology ; Humans ; Hyperglycemia/pathology ; Insulin/metabolism ; Insulin Resistance ; Insulin-Like Growth Factor I/metabolism ; Pancreatic Neoplasms/epidemiology/*etiology ; Risk Factors