In this study, insulin (insulin, INS)/Ca₃PO₄ complex and glucose oxidase (glucose oxidase, GOx)/Cu₃(PO₄)₂ complex were prepared by coprecipitation method. The mineralized insulin (mineralized insulin, m-INS) showed irregular crystalline clusters, and the mineralized glucose oxidase (m-GOx) showed flower spherical morphology, with a diameter of about 1-2 μm. In vitro simulated release experiment showed that m-INS released INS as the pH value of the medium decreased. When the pH value was 4.5, the release amount reached 96.68%. The enzyme activity detection experiment showed that the enzyme activity stability of m-GOx was higher than that of free GOx. It still maintained high activity after 10 days at room temperature, while the activity of GOx was less than 60%. The glucose solution was prepared to simulate the state of normal blood glucose (5.6 mmol/L) and hyperglycemia (22.2 mmol/L). When m-INS and m-GOx were added to the glucose solution, the release amount of INS showed a significant glucose concentration dependence. The higher the glucose concentration, the greater the release amount and release rate of INS. Finally, m-INS, m-GOx and hyaluronic acid (HA) solution were mixed to prepare HA microneedle arrays loaded with m-INS and m-GOx. Type 1 diabetes mice were constructed to evaluate the effect of drug-loaded HA microarray on blood glucose control in diabetic rats. The results show that the HA microneedles loaded with m-INS/m-GOx could deliver drugs effectively. The average blood glucose concentration in diabetic rats dropped to about 7 mmol/L within 1 h, normal blood glucose concentration could be maintained for 10 h, and the overall blood glucose concentration was lower than the level before administration for 36 hours. Compared with HA microneedles loaded with INS only, m-ins microneedles showed better glucose tolerance, longer-lasting glucose control effect and less risk of hypoglycemia. Compared with other sustained-release systems, the preparation process of the core components in this study is simple, efficient, safe and effective, and has great commercial potential.
Animals ; Blood Glucose ; Delayed-Action Preparations/therapeutic use* ; Diabetes Mellitus, Experimental/drug therapy* ; Drug Delivery Systems/methods* ; Glucose Oxidase/chemistry* ; Hyaluronic Acid ; I Blood-Group System ; Insulin/therapeutic use* ; Mice ; P Blood-Group System ; Rats

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*

OBJECTIVE: To investigate the mechanism of high glucose affecting the apoptosis of schwann cells through Nox4 NADPH oxidase. METHODS: The schwann cells of newborn Wistar rats were cultured in vitro. The cultured cells were divided into four groups: control group, high-glucose group, NOX4 siRNA group and control siRNA group (n=10). The WST-1 method was used to detect the cell vitality, and the DCFH-DA method was used to detect the contents of intracellular reactive oxygen free radicals (ROS). Nox4 and Caspase3 mRNA expressions were detected by real-time fluorescence quantitative RT-PCR. Nox4 and Caspase3 protein expressions were determined by Western blot. RESULTS: High glucose culture up-regulated Nox4 mRNA and protein expressions of schwann cells, decreased activity of schwann cells, increased intracellular ROS content, and promoted apoptosis by increasing Caspase3 mRNA and protein expressions. NOX4 siRNA blocked the accumulation of ROS in the high glucose cultured schwann cells, and reduced the damage of glucose on cell viability, by inhibiting NOX4 gene expression. NOX4 siRNA also reduced cell apoptosis by down-regulating Caspase3 mRNA and protein expressions. CONCLUSION Nox4 was involved in the hyperglycemic-induced apoptosis of schwann cells through ROS. The regulation of Nox4 expression or function might be a new way to treat diabetic peripheral neuropathy.
Animals ; Apoptosis ; Caspase 3 ; metabolism ; Cells, Cultured ; Culture Media ; Glucose ; NADPH Oxidase 4 ; metabolism ; Rats ; Rats, Wistar ; Reactive Oxygen Species ; metabolism ; Schwann Cells ; cytology ; metabolism

Obesity is currently one of the most serious public health problems and it can lead to numerous metabolic diseases. Leucrose, d-glucopyranosyl-α-(1-5)-d-fructopyranose, is an isoform of sucrose and it is naturally found in pollen and honey. The aim of this study was to investigate the effect of leucrose on metabolic changes induced by a high-fat diet (HFD) that lead to obesity. C57BL/6 mice were fed a 60% HFD or a HFD with 25% (L25) or 50% (L50) of its total sucrose content replaced with leucrose for 12 weeks. Leucrose supplementation improved fasting blood glucose levels and hepatic triglyceride content. In addition, leucrose supplementation reduced mRNA levels of lipogenesis-related genes, including peroxisome proliferator-activated receptor γ, sterol regulatory element binding protein 1C, and fatty acid synthase in HFD mice. Conversely, mRNA levels of β oxidation-related genes, such as carnitine palmitoyltransferase 1A and acyl CoA oxidase, returned to control levels with leucrose supplementation. Taken together, these results demonstrated the therapeutic potential of leucrose to prevent metabolic abnormalities by mediating regulation of plasma glucose level and hepatic triglyceride accumulation.
Acyl-CoA Oxidase ; Animals ; Blood Glucose ; Carnitine O-Palmitoyltransferase ; Diet, High-Fat ; Fasting ; Honey ; Lipogenesis ; Liver ; Metabolic Diseases ; Mice ; Mice, Obese ; Negotiating ; Obesity ; Peroxisomes ; Pollen ; Public Health ; RNA, Messenger ; Sterol Regulatory Element Binding Protein 1 ; Sucrose ; Triglycerides

To enhance the production of glucose oxidase by recombinant Pichia pastoris, two strategies were developed, which were namely co-feeding of methanol and sorbitol and co-expressing of the protein disulfide isomerase (PDI) and Vitreoscialla hemoglobin (VHb). The volumetric activity reached 456 U/mL by using the strain X33/pPIC9k-GOD, in 5 liter fermentator, with the co-feeding of methanol and sorbitol, it was 0.2 fold higher than that only feeding by methanol. The improved strain was obtained by co-expressing PDI-VHb with GOD. While fermented in a 5 liter fermentator by feeding methanol and sorbitol, the activity of the improved strain reached 716 U/mL with a yield of 7 400 mg/L total soluble protein concentration. These results indicated that heterologous protein expression level can be enhanced by optimizing fermentation condition and co-expression molecular chaperon in Pichia pastoris.
Bioreactors ; Fermentation ; Glucose Oxidase ; biosynthesis ; Methanol ; Pichia ; metabolism ; Recombinant Proteins ; biosynthesis ; Sorbitol

We studied the effect of calcium ion on particle size and pore structure of cross-linked enzyme aggregates (CLEAs) of glucose oxidase, with activity and stability of the enzyme as evaluation criteria. With calcium ion to prepare CLEA significantly decreased particle sizes of CLEAs whilst the pore structures of CLEAs gradually disappeared with the increase of calcium concentration. When glucose oxidase was precipitated at 0.1 mmol/L Ca²⁺, glucose oxidase in CLEA showed the definitive pore structure. Moreover, glucose oxidase activity in CLEA with Ca²⁺ was 1.69 times higher than that without Ca²⁺. Even at Ca²⁺ as high as 1.0 mmol/L, glucose oxidase activity in CLEA was 42% higher than that of CLEA without Ca²⁺. Furthermore, CLEA prepared with 0.1 mmol/L Ca²⁺ not only exhibited higher substrate conversion and operational stability, but also increased the maximum reaction speed. Therefore, calcium ion improved the performance of glucose oxidase in CLEAs.
Calcium ; chemistry ; Cross-Linking Reagents ; Enzyme Stability ; Enzymes, Immobilized ; Glucose Oxidase ; chemistry ; Oxidation-Reduction ; Particle Size

Obesity resulting from the delivery of an excess amount of energy to adipose tissue from glucose or free fatty acids is associated with insulin resistance and adipose tissue inflammation. Reactive oxygen species (ROS) have been implicated as contributors to both the onset and the progression of insulin resistance. ROS can be generated by overloading the mitochondrial oxidative phosphorylation system, and also by nicotinamide adenine dinucleotide phosphate oxidases (NOX) produced by either adipocytes, which only produce NOX4, or by macrophages, which produce mainly NOX2. The source of the ROS might differ in the early, intermediate and late stages of obesity, switching from NOX4-dependence in the early phases to NOX2-dependence, in the intermediate phase, and transiting to mitochondria-dependence later in the time course of obesity. Thus, depending on the stage of obesity, ROS can be generated by three distinct mechanisms: i.e., NOX4, NOX2, and mitochondria. In this review, we will discuss whether NOX4-, NOX2-, and/or mitochondria-derived ROS is/are causal in the onset of adipocyte insulin resistance as obesity progresses. Moreover, we will review the pathophysiological roles of NOX4, NOX2, and mitochondria-derived ROS on adipose tissue inflammation.
Adipocytes ; Adipose Tissue* ; Fatty Acids, Nonesterified ; Glucose ; Inflammation ; Insulin Resistance* ; Insulin* ; Macrophages ; Mitochondria ; NADP ; NADPH Oxidase ; Obesity ; Oxidative Phosphorylation ; Oxidoreductases ; Reactive Oxygen Species*

BACKGROUND: We evaluated the analytical performance of Barozen H (i-SENS Inc., Korea), a new glucometer equipped with networking function for medical institutions, according to the ISO 15197:2003 and ISO/DIS 15197:2011 guidelines. METHODS: We measured the precision of 10 Barozen H glucometers, in terms of repeatability and intermediate precision, and determined their accuracy relative to that of automatic chemistry analyzer AU5421 (Beckman Coulter, USA). Three other glucometers-Precision PCx (Abbott, USA), Glucocard Sigma (Arkray, Japan), and SureStep Flexx (Johnson & Johnson, USA) were also evaluated, and their accuracies and hematocrit interferences were compared. RESULTS: The standard deviation and coefficient of variation of Barozen H for repeatability and intermediate precision were 0.11-0.15 mmol/L and 2.3-3.6%, respectively. With respect to accuracy, in accordance with ISO 15197:2003 criteria, Barozen H yielded 98.0% of results within +/-0.83 mmol/L or +/-20%. Further, per the ISO/DIS 15197:2011 criteria, 95.2% of results were within +/-0.83 mmol/L or +/-15%; Barozen H was the only glucometer satisfying the more stringent ISO/DIS 15197:2011 criteria. Error grid analysis showed that all results from Barozen H were in zone A, indicating its excellent clinical accuracy. Hematocrit, ranging from 20% to 60% did not cause any significant interference. CONCLUSIONS: Barozen H showed excellent analytical performance, and it was the most clinically accurate glucometer tested. It can be expected to provide reliable results satisfying ISO/DIS 15197:2011 as well as ISO 15197:2003 criteria.
Blood Glucose Self-Monitoring ; Blood Glucose* ; Chemistry ; Diabetes Mellitus ; Glucose Oxidase ; Hematocrit ; Point-of-Care Systems

BACKGROUND: We evaluated the analytical performance of Barozen H (i-SENS Inc., Korea), a new glucometer equipped with networking function for medical institutions, according to the ISO 15197:2003 and ISO/DIS 15197:2011 guidelines. METHODS: We measured the precision of 10 Barozen H glucometers, in terms of repeatability and intermediate precision, and determined their accuracy relative to that of automatic chemistry analyzer AU5421 (Beckman Coulter, USA). Three other glucometers-Precision PCx (Abbott, USA), Glucocard Sigma (Arkray, Japan), and SureStep Flexx (Johnson & Johnson, USA) were also evaluated, and their accuracies and hematocrit interferences were compared. RESULTS: The standard deviation and coefficient of variation of Barozen H for repeatability and intermediate precision were 0.11-0.15 mmol/L and 2.3-3.6%, respectively. With respect to accuracy, in accordance with ISO 15197:2003 criteria, Barozen H yielded 98.0% of results within +/-0.83 mmol/L or +/-20%. Further, per the ISO/DIS 15197:2011 criteria, 95.2% of results were within +/-0.83 mmol/L or +/-15%; Barozen H was the only glucometer satisfying the more stringent ISO/DIS 15197:2011 criteria. Error grid analysis showed that all results from Barozen H were in zone A, indicating its excellent clinical accuracy. Hematocrit, ranging from 20% to 60% did not cause any significant interference. CONCLUSIONS: Barozen H showed excellent analytical performance, and it was the most clinically accurate glucometer tested. It can be expected to provide reliable results satisfying ISO/DIS 15197:2011 as well as ISO 15197:2003 criteria.
Blood Glucose Self-Monitoring ; Blood Glucose* ; Chemistry ; Diabetes Mellitus ; Glucose Oxidase ; Hematocrit ; Point-of-Care Systems

BACKGROUND/OBJECTIVES: Mulberry leaves contain quercetin derivatives, which have the effects of reducing obesity and improving lipid and glucose metabolism in mice with obesity. It is not clear whether or not mulberry leaves can directly affect metabolic disorders, in the presence of obesity, because of the interaction between obesity and metabolic disorders. The aim of the current study was to assess the direct action of quercetin derivatives on metabolic disorders in non-obese conditions in short-term high-fat diet fed mice. MATERIALS/METHODS: C57BL/6N mice were fed a high-fat diet, supplemented with either 0% (control), 1%, or 3% mulberry leaf powder (Mul) or 1% catechin powder for five days. Anthropometric parameters and blood biochemistry were determined, and hepatic gene expression associated with lipid and glucose metabolism was analyzed. RESULTS: Body and white fat weights did not differ among the four groups. Plasma triglycerides, total cholesterol, and free fatty acids in the 1%, 3% Mul and catechin groups did not differ significantly from those of the controls, however, plasma glucose and 8-isoprostane levels were significantly reduced. Liver gene expression of gp91phox, a main component of NADPH oxidase, was significantly down-regulated, and PPAR-alpha, related to beta-oxidation, was significantly up-regulated. FAS and GPAT, involved in lipid metabolism, were significantly down-regulated, and Ehhadh was significantly up-regulated. Glucose-metabolism related genes, L-PK and G6Pase, were significantly down-regulated, while GK was significantly up-regulated in the two Mul groups compared to the control group. CONCLUSIONS: Our results suggest that the Mul quercetin derivatives can directly improve lipid and glucose metabolism by reducing oxidative stress and enhancing beta-oxidation. The 1% Mul and 1% catechin groups had similar levels of polyphenol compound intake (0.4 x 10(-5) vs 0.4 x 10(-5) mole/5 days) and exhibited similar effects, but neither showed dose-dependent effects on lipid and glucose metabolism or oxidative stress.
Adipose Tissue, White ; Animals ; Biochemistry ; Blood Glucose ; Catechin ; Cholesterol ; Diet, High-Fat ; Fatty Acids, Nonesterified ; Gene Expression* ; Glucose* ; Lipid Metabolism ; Liver ; Metabolism* ; Mice* ; Morus* ; NADPH Oxidase ; Obesity ; Oxidative Stress ; Plasma ; Quercetin* ; Triglycerides ; Weights and Measures