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Aims The main purpose of this study was to evaluate the associations between circulating angiopoietin-like protein 6 (ANGPTL6) levels and various diabetes- and atherosclerosis-related variables in patients with type 2 diabetes. Methods Serum ANGPTL6 levels in patients with type 2 diabetes hospitalized for glycemic control and/or diabetic education were measured using a chemiluminescent immunoassay (CLIA). Results Most patients had elevated HbA1c levels; 85.7% and 71.4% of patients had HbA1c levels of (8% and (9%, respectively. ANGPTL6 levels were significantly higher in patients with type 2 diabetes than in non-diabetic controls. In patients with type 2 diabetes, ANGPTL6 was significantly and positively correlated with the duration of diabetes, systolic blood pressure (SBP), gamma-glutamyl transpeptidase (GGT), C-reactive protein (CRP), and the intimal medial complex thickness of the carotid artery (IMT), and inversely correlated with hemoglobin A1c (HbA1c). In the multiple regression analysis, ANGPTL6 had a significant positive association with triglyceride (TG) in one of the models in which it was included as a variable. Furthermore, ANGPTL6 also showed significant positive associations with CRP and IMT in models in which they were included as variables. Conclusion The current study suggests that circulating levels of ANGPTL6 may be negatively associated with poor glycemic control and positively associated with the degree of atherosclerosis, as reflected by IMT, in patients with type 2 diabetes, most of whom had elevated HbA1c levels.
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AIM: The main purpose of the current study was to investigate the effect of season change and the influence of the COVID-19 pandemic on the ratio of glycoalbumin to hemoglobin A1c (GA/HbA1c) in patients with type 2 diabetes. PATIENTS AND METHODS: A total of 267 patients in whom both HbA1c and GA were measured at baseline were included in this retrospective study. GA/HbA1c was investigated for three years, 2018, 2019, and 2020 (COVID-19 pandemic period). RESULTS: The mean values for GA/HbA1c per year in 2018, 2019, and 2020 were 2.64±0.35, 2.61±0.35, 2.64±0.39, respectively. There were no significant differences in GA/HbA1c during these years. There was a tendency toward seasonal variation in GA/HbA1c (i.e., higher in summer or autumn and lower in spring or winter). CONCLUSION: In patients with type 2 diabetes, GA/HbA1c tended to show seasonal variation, which was not influenced by the COVID-19 pandemic.
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Renal anemia is generally caused by a decrease in the production of erythropoietin in kidney due to renal dysfunction, and this may be associated with the increase in mortality and cardiovascular events in addition to subjective symptoms such as fatigue and wobbliness. We report a case of an 87-year-old man with type 2 diabetes, hypertension, and dyslipidemia who had received roxadustat (a hypoxia-inducible factor (HIF) prolyl hydroxylase (PH) inhibitor) for renal anemia due to diabetic nephropathy and in whom roxadustat was switched to daprodustat (another HIF-PH inhibitor) due to the onset of central hypothyroidism. About three weeks after this change, the patient developed acute asymptomatic cerebral infarction with an elevation of hemoglobin (Hb). It is unclear if the change to daprodustat was involved in the onset of cerebral infarction. However, this case suggests that particular caution should be paid to unexpected acute elevation of Hb after a change from one HIF-PH inhibitor to another, especially in a patient at high risk for cardiovascular events.
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Fibroblast growth factor (FGF) 21, a hormone produced by the liver, improves glucose and lipid metabolism. We recently demonstrated that the FGF21 gene (Fgf21) underwent DNA demethylation in the mouse liver via peroxisome proliferator-activated receptor (PPAR) α during the fetal to lactation periods. Furthermore, we found that the DNA methylation state of Fgf21 was involved in obesity in adult animals. In the present study, we analyzed the DNA methylation state of the FGF21 gene (FGF21) in obese patients using genomic DNA extracted from human monocytes and macrophages and investigated the pathophysiological significance of the FGF21 expression response to pemafibrate (PM), a PPARα ligand. We examined 67 patients with obesity stratified into in- and outpatient cohorts. A positive correlation was observed between serum FGF21 levels and triglyceride (TG) levels before PM administration. However, changes in serum FGF21 levels following PM administration did not correlate with the FGF21 DNA methylation rate, except at one CpG site. The body mass index (BMI) and serum TG levels positively correlated with the FGF21 DNA methylation rate, particularly at different CpG positions. A negative correlation was observed between absolute changes in serum FGF21 levels and the ratio of change in serum TG levels after PM administration. Collectively, these results indicate the potential of FGF21 DNA methylation as a surrogate indicator of BMI and serum TG levels, while absolute changes in serum FGF21 levels after PM administration may offer prognostic insights into the efficacy of reducing serum TG levels through PM administration.
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We encountered five cases that exhibited false-high Hemoglobin A1c (HbA1c) levels when samples were examined using the enzyme-based NORUDIA N HbA1c kit. HbA1c levels were higher than those obtained using other methods, such as HPLC, immune-based methods, and other enzyme-based kits. This kit produced inaccurate results for HbA1c when residual peroxides were present in samples. The addition of peroxidase solution restored false-high HbA1c levels in the five cases, indicating that reduced catalase activity was responsible for these values because catalase eliminates peroxide. Catalase activity and gene mutations were examined in the five cases and an immunohistological analysis was performed to assess the expression of catalase. Cases #1 and 2 were diagnosed as acatalasemia and cases #3, 4, and 5 as hypocatalasemia based on compound heterozygous SNP and heterozygous splicing mutations in the catalase gene. Therefore, impaired catalase activity was responsible for false-high HbA1c levels measured by the NORUDIA N HbA1c kit.
Subject(s)
Antioxidants , Peroxidase , Glycated Hemoglobin , Catalase/geneticsABSTRACT
Aim: The purpose of the study was to investigate seasonal variations in HbA1c, GA and LDL-C and to examine the effects of the COVID-19 pandemic on these variations and on glycemic and lipid control themselves in patients with type 2 diabetes. Patients and methods: The subjects were outpatients with type 2 diabetes who had received standard treatment for glycemic control for more than 3 years. Data for patients who visited our hospital from January 2021 to March 2021 were retrospectively investigated based on electronic medical records. Results: HbA1c showed seasonal variation (high in winter-spring and low in summer-autumn), and this was similar during the COVID-19 pandemic. However, the mean HbA1c over 1 year was significantly elevated during the COVID-19 pandemic (7.53 ± 1.02% in 2020) compared with the previous 2 years: (7.34 ± 0.91 in 2018, 7.39 ± 0.93 in 2019; 2020 vs. 2018; 0.19%, P < 0.001; 2020 vs. 2019; 0.14%, P = 0.0013) and the difference was larger in winter. GA showed no apparent seasonal variation, but mean GA during the COVID-19 pandemic was elevated compared with earlier years (2020 vs. 2018, P < 0.001; 2020 vs. 2019, P < 0.001). LDL-C did not show apparent seasonal variation and was unaffected by COVID-19 pandemic. Conclusion: The COVID-19 pandemic influenced mean HbA1c and GA levels over 1 year, but did not affect seasonal variations, while LDL-C was not affected by COVID-19. Observation of these levels over a longer period is warranted to determine the longer-term influence of the COVID-19 pandemic.
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Previous studies have shown that dipeptidyl peptidase (DPP)-4, is released from adipocytes in a differentiation-dependent manner and a marker for insulin resistance in obese individuals who have particularly high circulating DPP-4/soluble CD26 (sCD26) concentrations. In this study, we have evaluated the effects of short-term hospitalization with calorie restriction on body composition and circulating DPP-4/sCD26 concentrations in patients with type 2 diabetes. A total of 47 Japanese adults with type 2 diabetes were recruited to the study (age; 56.6 ± 13.0 years, body mass index (BMI); 27.3 ± 5.6 kg/m2). Body composition, circulating DPP-4/sCD26 concentrations and metabolic parameters were assessed upon admission and at discharge from hospital (average of the period: 13.0 ± 2.5 days). Visceral fat area (VFA) was also assessed by dual impedance method. During hospitalization, there was a significant reduction in body weight, BMI, lean body mass, VFA and circulating DPP-4/sCD26 concentrations, but not in body fat mass. Fasting circulating DPP-4/sCD26 concentrations were significantly correlated with fasting insulin, aspartate aminotransferase, γ-glutamyltransferase (γ-GTP) levels, and HOMA-IR (r = 0.477, 0.423, 0.415, 0.548, respectively), but not with VFA (r = - 0.056) by liner regression analyses at base line. It was also observed a positive correlation between changes in circulating DPP-4/sCD26 concentrations and γ-GTP level, HOMA-IR, and a negative correlation between the changes in circulating DPP-4/sCD26 concentrations and VFA significantly (r = 0.300, 0.633, - 0.343, respectively). In conclusion, our observations suggest that liver enzymes as well as VFA might be associated with the response of DPP-4/sCD26 concentrations.
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OBJECTIVES: The main purpose of the study was to study the association between circulating soluble lectin-like oxidized low-density lipoprotein receptor-1 levels and various markers, including inflammatory markers such as high-sensitivity C-reactive protein and fibrinogen, serum lipids, and renal function, in patients with poorly controlled type 2 diabetes. METHODS: The subjects were 70 patients (men 45, women 25) who were hospitalized for treatment of poor glycemic control. Plasma soluble lectin-like oxidized low-density lipoprotein receptor-1 levels were assayed using a sandwich chemiluminescence enzyme immunoassay. RESULTS: Circulating soluble lectin-like oxidized low-density lipoprotein receptor-1 was significantly positively correlated with lectin-like oxidized low-density lipoprotein-1 ligands containing apolipoprotein B, reflecting modified low-density lipoprotein, and with inflammatory markers such as high-sensitivity C-reactive protein and fibrinogen. In addition, there was a significant positive correlation between soluble lectin-like oxidized low-density lipoprotein receptor-1 and urinary albumin excretion. CONCLUSIONS: Soluble lectin-like oxidized low-density lipoprotein receptor-1 may serve as a marker reflecting the degrees of inflammation and albuminuria in patients with poorly controlled type 2 diabetes.
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OBJECTIVES: To investigate the effect of androgens and estrogens on surtuin 1 (SIRT1) expression in human aortic endothelial cells (HAECs). METHODS: Real-time polymerase chain reaction analysis of SIRT-1 expression over 48 hours (h) was performed in HAECs treated with various concentrations of dehydroepiandrostendione (DHEA), androstenedione and testosterone (androgens), estrone (E1), estradiol (E2), and estriol (E3) (estrogens) to investigate the dose-dependency of time courses. The influence of high glucose on SIRT1 expression induced by the androgens and estrogens was also examined. RESULTS: Dehydroepiandrostendione, androstenedione, and testosterone remarkedly produced a dose-dependent increase in SIRT1 expression in the range of 10 to 20 µg/ml. High glucose (40mM) medium had significantly inhibitory effects on 10 µg/ml DHEA-induced SIRT1 expression (p=0.024). Estrone and E2, but not E3, caused a marked dose-dependent increase in SIRT1 expression from 10 to 20 µg/ml. Treatment with 20 mM or 40 mM glucose medium did not significantly inhibit E1- and E3-induced SIRT1 expression in control medium; however, both high glucose mediums significantly emphasized E2-induced SIRT1 expression in control medium (p=0.007, p=0.005). CONCLUSION: These results suggest that DHEA, androstenedione, testosterone, E1, and E2 definitely activate SIRT1 expression in HAECs. A high glucose medium is potent to inhibit the basal gene expression; however, it could not reduce powerful androgen- and estrogen-induced SIRT1 expression in HAECs.
Subject(s)
Androgens/pharmacology , Aorta/cytology , Endothelial Cells/metabolism , Estrogens/pharmacology , Gene Expression/drug effects , Sirtuin 1/genetics , Sirtuin 1/metabolism , Androstenedione/pharmacology , Cells, Cultured , Dehydroepiandrosterone/pharmacology , Dose-Response Relationship, Drug , Estradiol/pharmacology , Estriol/pharmacology , Estrone/pharmacology , Glucose/pharmacology , Humans , Real-Time Polymerase Chain Reaction , Testosterone/pharmacologyABSTRACT
Non-islet cell tumor hypoglycemia (NICTH) is a rare paraneoplastic syndrome, and NICTH associated with gastrointestinal stromal tumor (GIST) is even more rare. Herein, we describe a patient with severe NICTH due to GIST who had developed liver cirrhosis as a consequence of chronic hepatitis B. Although circulating insulin, C-peptide, and insulin-like growth factor-1 (IGF-1) levels were significantly decreased, in contrast to our expectations, the growth hormone (GH) level was slightly elevated. Steroid therapy with prednisolone appeared to be effective for the prevention of severe and continuous hypoglycemia.
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We herein report a 50-year-old Chinese woman with Hb Phnom Penh (α117Phe-Ile-α118Thr) showing high or reasonable HbA1c values depending on the type of high-performance liquid chromatography (HPLC) system. A high HbA1c value of 7.5% (HPLC assay: G9) and a reasonable HbA1c value of 5.2% (assay unknown) were observed. Therefore, the patient was refereed to our hospital; the oral glucose tolerance test showed normal glucose tolerance. The HbA1c values measured by an enzymatic assay, immunoassay, and affinity assay, as well as most HPLC assays were within the reference range, whereas those measured by the Tosoh HPLC systems were high.
Subject(s)
Chromatography, High Pressure Liquid/instrumentation , Glycated Hemoglobin/analysis , Hemoglobins, Abnormal/analysis , Female , Glucose Tolerance Test , Humans , Immunoassay , Middle Aged , Sensitivity and SpecificityABSTRACT
Objective This study was performed to evaluate the association of the serum level of angiopoietin-like protein 2 (ANGPTL2) with circulating inflammatory markers and oxidized and modified low-density lipoprotein (LDL) cholesterol as evaluated by lectin-like oxidized LDL receptor 1 ligand containing apolipoprotein B (LAB) in patients with type 2 diabetes. Methods The study included 70 patients with type 2 diabetes hospitalized for glycemic control and 9 control subjects. Results The serum level of ANGPTL2 was significantly higher in the patients with type 2 diabetes than in the healthy controls. There was a significant positive correlation between ANGPTL2 and the high-sensitivity C-reactive protein, fibrinogen, and LAB levels and a significant negative correlation between ANGPTL2 and the estimated glomerular filtration rate (eGFR). Conclusions These results suggest that the serum ANGPTL2 level has a close positive association with inflammatory markers, especially fibrinogen and oxidized and modified LDL as evaluated by LAB. The data also suggest that the serum ANGPTL2 level is influenced by renal function as reflected by the eGFR.
Subject(s)
Angiopoietin-like Proteins/blood , Apolipoproteins B/blood , Diabetes Mellitus, Type 2/blood , Scavenger Receptors, Class E/blood , Aged , Angiopoietin-Like Protein 2 , Biomarkers/blood , C-Reactive Protein/analysis , Diabetes Mellitus, Type 2/physiopathology , Female , Fibrinogen/analysis , Glomerular Filtration Rate , Humans , Ligands , Male , Middle AgedABSTRACT
We describe a 58-year-old man with a malignant melanoma metastasis to the liver. After initiation of nivolumab therapy, he developed destructive thyroiditis and subsequently simultaneous isolated adrenocorticotropic hormone (ACTH) deficiency and severe hypercalcemia. Although isolated ACTH deficiency and hypercalcemia due to nivolumab therapy are both rare occurrences, these conditions can often cause a severe clinical course accompanied by a disturbance of consciousness. Therefore, clinicians should pay attention to these possible side effects of nivolumab if the patients have clinical symptoms, such as fatigue and a disturbance of consciousness.
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BACKGROUND: Resveratrol, a kind of polyphenol, has the potential to activate the longevity gene in several cells, in the same manner as calorie restriction. We investigated the effect of resveratrol and ω-3-line polyunsaturated fatty acid on surtuin 1 (SIRT1) gene expression in human monocytes (THP1) cells. MATERIALS AND METHODS: We examined the gene expression of THP1 cells using real-time polymerase chain reaction and Western blotting analysis. Resveratol, eicosapentaenoic acid (EPA) and docosahexaeanoic acid (DHA) as n-3 polyunsaturated fatty acid were added on THP1 cells. We observed the changes in the SIRT1 gene expression in those cells, under various doses of agents and in time courses. Then, we examined the interaction of glucose and mannitol on those agents׳ effect of the gene expression. The concentration range of glucose and mannitol was from 5-20mM, respectively. RESULTS: The SIRT1 gene expression could be defined in 24 and 48 hours both in real-time polymerase chain reaction analysis and in Western blotting. Resveratrol showed SIRT1 gene expression in a dose-dependent manner in the range of 0-20µM in both analyses. Although EPA at 10µM showed marked increase in SIRT1 gene expression compared to control condition in Western blotting, this phenomenon was not in dose-dependent manner. DHA did not exhibit any augmentation of SIRT1 gene expression in a dose-dependent manner in the range of 0-20µM in both analyses. We refined the dose-dependent inhibition of the SIRT1 gene expression within 20mM glucose medium. Although 20mM did not exhibit any inhibition, 10µM resveratrol induced the gene expression compared to control medium. Both 5 and 15mM mannitol medium did not significantly alter basic gene expression and 10µM resveratrol-induced gene expression. CONCLUSIONS: The present results suggest that resveratrol and EPA, but not DHA, markedly activated the SIRT1 gene expression in THP1 cells, and that high glucose medium could inhibit the basic gene expression, but not powerful resveratrol-induced gene expression, in those cells.
Subject(s)
Docosahexaenoic Acids/pharmacology , Eicosapentaenoic Acid/pharmacology , Gene Expression Regulation, Enzymologic/drug effects , Monocytes/enzymology , Sirtuin 1/biosynthesis , Stilbenes/pharmacology , Cell Line, Tumor , Dose-Response Relationship, Drug , Glucose/pharmacology , Humans , Mannitol/pharmacology , Monocytes/cytology , ResveratrolABSTRACT
Canagliflozin has a robust inhibitory effect on sodium glucose transporter (SGLT)-2 and a mild inhibitory effect on SGLT1. The main purpose of this study was to investigate the effect of canagliflozin on circulating active glucagon-like peptide 1 (GLP-1) levels in patients with type 2 diabetes. Patients were randomly divided into a control group (n =15) and a canagliflozin-treated group (n =15). After hospitalization, the canagliflozin-treated group took 100 mg/day canagliflozin for the entire study, and after 3 days both groups took 20 mg/day teneligliptin for an additional 3 days. In a meal test, canagliflozin significantly decreased the area under curve (AUC) (0-120 min) for plasma glucose (PG) after 3 days when compared with that at baseline, and addition of teneligliptin to the canagliflozin-treated group further decreased it. A significant decrease in the AUC (0-120 min) for serum insulin by canagliflozin was obtained, but the addition of teneligliptin elevated the AUC, and thus abolished the significant difference from baseline. A significant increase in the AUC (0-120 min) of plasma active GLP-1 by canagliflozin-treatment compared with that at baseline was observed, and the addition of teneligliptin resulted in a further increase. However, canagliflozin-treatment did not change the AUC (0-120 min) of plasma active glucose-dependent insulinotropic peptide (GIP). In conclusions, canagliflozin-administration before meals decreased PG and serum insulin, and increased plasma active GLP-1 levels in patients with type 2 diabetes. Canagliflozin did not greatly influence plasma active GIP levels.
Subject(s)
Canagliflozin/therapeutic use , Diabetes Mellitus, Type 2/drug therapy , Glucagon-Like Peptide 1/blood , Hypoglycemic Agents/therapeutic use , Aged , Blood Glucose , Diabetes Mellitus, Type 2/blood , Female , Gastric Inhibitory Polypeptide/blood , Glucagon/blood , Humans , Insulin/blood , Male , Middle Aged , Treatment OutcomeABSTRACT
BACKGROUND: Betatrophin is a hormone mainly secreted by the liver that influences lipid metabolisms. The main purposes of this study were to investigate the effect of canagliflozin (a sodium glucose transporter 2 inhibitor) on circulating betatrophin levels, and to investigate the correlation of various markers associated with glucose and lipid metabolisms with betatrophin in patients with poorly controlled type 2 diabetes. METHODS: Patients were randomly divided into a control group (n = 15) and a canagliflozin-treated group (n = 15). After hospitalization, the canagliflozin-treated group took 100 mg/day of canagliflozin for 3 days. Blood tests were performed at baseline and after 3 days of treatment. RESULTS: Canagliflozin treatment for 3 days did not significantly change fasting and postprandial serum betatrophin levels. On the other hand, betatrophin levels had a significant positive correlation with hemoglobin A1c, fasting plasma glucose, and high-density lipoprotein cholesterol levels at baseline. CONCLUSIONS: The current study suggests that short-term treatment by canagliflozin does not influence circulating betatrophin levels, and that betatrophin is positively associated with markers of glycemic control and high-density lipoprotein cholesterol in patients with poorly controlled type 2 diabetes.
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BACKGROUND: The goal of the current study was to investigate the long-term effects (after 3 years or more) of alogliptin on glycemic control in Japanese patients with type 2 diabetes. METHODS: We retrospectively studied the effect of alogliptin on glycemic control in the patients with type 2 diabetes who had participated in our previous 3-month study and who continued to take alogliptin for at least 36 months. RESULTS: The mean duration of alogliptin treatment was 42.8 ± 2.2 months. In all 39 patients, a significant reduction in hemoglobin A1c (HbA1c) levels was noted between the baseline and final visit: 7.8±0.6% to 7.2±1.0% (P = 0.0001). A significant reduction in HbA1c levels was found in a subgroup of patients who did not change their anti-diabetic drugs or did decrease the dose of their sulfonylureas (SUs) or did change to a lower strength repaglinide (n = 32): 7.7±0.6% to 7.2±1.0% (P = 0.0005). A significant decrease in low-density lipoprotein cholesterol (LDL-C) levels was observed in all of the patients that had LDL-C levels determined (P = 0.0406) (n = 37), and in a subgroup of patients who had not taken either statins, fibrates, or pioglitazone, or who had taken one or more of these drugs but the doses were not changed during the observation period (P = 0.0250) (n = 27). CONCLUSION: The current study found that alogliptin performed well for glycemic control when evaluated by HbA1c levels in a long-term observation period exceeding 3 years in Japanese patients with type 2 diabetes. Alogliptin may also decrease circulating LDL-C levels with long-term use.
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OBJECTIVE: The main purpose of this study was to investigate the association of serum SerpinB1 levels and various parameters in patients with type 2 diabetes. The effect of canagliflozin (a sodium glucose cotransporter 2 (SGLT2) inhibitor), which can decrease circulating insulin levels, on serum SerpinB1 levels was also investigated. A recent study suggests that the serum levels of SerpinB1, also known as monocyte neutrophil elastase inhibitor, increase with insulin resistance, may have a protective effect for pancreatic ß cells, and may decrease insulin resistance. RESEARCH DESIGN AND METHODS: The study included 30 patients with type 2 diabetes hospitalized for glycemic control and 10 control subjects. RESULTS: SerpinB1 levels were significantly higher in patients with type 2 diabetes, compared with that in heathy control subjects (10.01±3.59 vs 5.69±1.64â ng/mL, p<0.0001). Serum SerpinB1 levels had a significant negative correlation with low-density lipoprotein cholesterol (LDL-C) (p=0.0123). Serum SerpinB1 levels had a significant positive association or trend toward a positive association with age and with hemoglobin A1c (HbA1c), and significant negative association with LDL-C levels in some multiple regression analysis models. Patients treated with statins had a tendency toward higher serum SerpinB1 levels, compared with those patients not treated with statins. During a 3-day observation period both with and without canagliflozin treatment, the serum SerpinB1 levels did not change. CONCLUSIONS: Serum SerpinB1 levels are elevated in patients with type 2 diabetes compared with that in healthy subjects and are negatively correlated with serum LDL-C.
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The main purpose of the current study was to investigate the effect of a combination of alogliptin [a dipeptydil peptidase (DPP)-4 inhibitor] and lansoprazole [a proton pump inhibitor (PPI)] compared with alogliptin mono-therapy on glycemic control in patients with type 2 diabetes. This study was a multicenter randomized open-label study. One hundred type 2 diabetic patients were randomly assigned to either the alogliptin with lansoprazole group or the alogliptin mono-therapy group. After 3 months of treatment, the changes in hemoglobin (Hb)A1c, fasting plasma glucose (FPG), serum gastrin, homeostasis model assessment (HOMA)-ß, and HOMA-insulin resistance (IR) were evaluated. A significant decrease in HbA1c and FPG, and a significant increase in HOMA-ß were observed in both groups (all with P <0.0001). However, there were no significant differences in changes in HbA1c, FPG, or HOMA-ß before and after therapy between the combination and alogliptin mono-therapy group (P =0.2945, P =0.1901, P =0.3042, respectively). There was a significant elevation of serum gastrin in the combination group compared with the alogliptin mono-therapy group (P =0.0004). This study showed that, although combination therapy with alogliptin and lansoprazole more effectively elevated serum gastrin levels compared with alogliptin mono-therapy, the effect of the combination therapy on glycemic control was equal to that of alogliptin mono-therapy during a 3-month study period.
Subject(s)
Blood Glucose/analysis , Diabetes Mellitus, Type 2/drug therapy , Dipeptidyl-Peptidase IV Inhibitors/therapeutic use , Hypoglycemic Agents/therapeutic use , Lansoprazole/therapeutic use , Piperidines/therapeutic use , Uracil/analogs & derivatives , Aged , Diabetes Mellitus, Type 2/blood , Dipeptidyl-Peptidase IV Inhibitors/administration & dosage , Drug Therapy, Combination , Female , Humans , Hypoglycemic Agents/administration & dosage , Insulin Resistance , Lansoprazole/administration & dosage , Male , Middle Aged , Piperidines/administration & dosage , Treatment Outcome , Uracil/administration & dosage , Uracil/therapeutic useABSTRACT
Using yeast two-hybrid screen, we previously isolated HELZ2 (helicase with zinc finger 2, transcriptional coactivator) that functions as a coregulator of peroxisome proliferator-activated receptorγ (PPARγ). To further delineate its molecular function, we here identified thyroid hormone receptor-associated protein3 (THRAP3), a putative component of the Mediator complex, as a protein stably associating with HELZ2 using immunoprecipitation coupled with mass spectrometry analyses. In immunoprecipitation assays, Thrap3 could associate with endogenous Helz2 as well as Pparg in differentiated 3T3-L1 cells. HELZ2 interacts with the serine/arginine-rich domain and Bcl2 associated transcription factor1-homologous region in THRAP3, whereas THRAP3 directly binds 2 helicase motifs in HELZ2. HELZ2 and THRAP3 synergistically augment transcriptional activation mediated by PPARγ, whereas knockdown of endogenous THRAP3 abolished the enhancement by HELZ2 in reporter assays. Thrap3, similar to Helz2, is evenly expressed in the process of adipogenic differentiation in 3T3-L1 cells. Knockdown of Thrap3 in 3T3-L1 preadipocytes using short-interfering RNA did not influence the expression of Krox20, Klf5, Cebpb, or Cebpd during early stages of adipocyte differentiation, but significantly attenuated the expression of Pparg, Cebpa, and Fabp4/aP2 and accumulation of lipid droplets. Pharmacologic activation of Pparg by troglitazone could not fully restore the differentiation of Thrap3-knockdown adipocytes. In chromatin immunoprecipitation assays, endogenous Helz2 and Thrap3 could be co-recruited, in a ligand-dependent manner, to the PPARγ-response elements in Fabp4/aP2 and Adipoq gene enhancers in differentiated 3T3-L1 cells. These findings collectively suggest that Thrap3 could play indispensable roles in terminal differentiation of adipocytes by enhancing PPARγ-mediated gene activation cooperatively with Helz2.