The cardiovascular safety trials of DPP-4 inhibitors, GLP-1 agonists, and SGLT2 inhibitors.

PubMed

Secrest, Matthew H; Udell, Jacob A; Filion, Kristian B

2017-04-01

In this paper, we review the results of large, double-blind, placebo-controlled randomized trials mandated by the US Food and Drug Administration to examine the cardiovascular safety of newly-approved antihyperglycemic agents in patients with type 2 diabetes. The cardiovascular effects of dipeptidyl peptidase-4 (DPP-4) inhibitors remain controversial: while these drugs did not reduce or increase the risk of primary, pre-specified composite cardiovascular outcomes, one DPP-4 inhibitor (saxagliptin) increased the risk of hospitalization for heart failure in the overall population; another (alogliptin) demonstrated inconsistent effects on heart failure hospitalization across subgroups of patients, and a third (sitagliptin) demonstrated no effect on heart failure. Evidence for cardiovascular benefits of glucagon-like peptide-1 (GLP-1) agonists has been similarly heterogeneous, with liraglutide and semaglutide reducing the risk of composite cardiovascular outcomes, but lixisenatide having no reduction or increase in cardiovascular risk. The effect of GLP-1 agonists on retinopathy remains a potential concern. In the only completed trial to date to assess a sodium-glucose cotransporter-2 (SGLT2) inhibitor, empagliflozin reduced the risk of composite cardiovascular endpoints, predominantly through its impact on cardiovascular mortality and heart failure hospitalization. Copyright © 2017 Elsevier Inc. All rights reserved.

Comparisons of the efficacy of glucose control, lipid profile, and β-cell function between DPP-4 inhibitors and AGI treatment in type 2 diabetes patients: a meta-analysis.

PubMed

Cai, Xiaoling; Yang, Wenjia; Zhou, Lingli; Zhang, Simin; Han, Xueyao; Ji, Linong

2015-12-01

The aim of this study is to compare the efficacy of dipeptidyl peptidase-4 (DPP-4) inhibitor treatment with α-glucosidase inhibitor (AGI) treatment in patients with type 2 diabetes through a meta-analysis. Studies were identified by a literature search of Medline, Embase, and others from the time that recording commenced until December 2014. The meta-analysis was performed by computing the weighted mean difference (WMD) and 95 % confidence interval (CI) for a change from baseline to the study endpoint for DPP-4 inhibitors versus AGIs. Nine randomized controlled trial were judged to be appropriate for inclusion in the meta-analysis. One thousand and forty-six patients were treated with a DPP-4 inhibitor, while 929 patients were treated with AGI treatment; the groups had a comparable baseline body mass index of 25.5 ± 1.3 kg/m(2) and mean baseline HbA1c of 7.83 ± 0.53 %. Treatment with DPP-4 inhibitors led to a significantly greater change from baseline in the HbA1c levels (WMD -0.30 %; 95 % CI -0.47 to -0.13 %, p < 0.001) and fasting plasma glucose levels (WMD -0.50 mmol/L; 95 % CI -0.89 to -0.11 mmol/L, p = 0.01) compared with AGI treatment. Compared with AGIs, treatment with DPP-4 inhibitors was associated with a significantly greater increase in the weight change from baseline (WMD 0.89 kg; 95 % CI 0.53-1.25, p < 0.001). Treatment with DPP-4 inhibitors was associated with a significantly greater increase in the fasting insulin level from baseline (WMD 0.63 µU/mL; 95 % CI 0.35-0.90 µU/mL, p < 0.001). DPP-4 inhibitors significantly improved homeostatic model assessment for β-cell function in type 2 diabetes patients compared with AGI treatment (WMD 5.43; 95 % CI 1.01-9.85, p = 0.02). DPP-4 inhibitors were associated with a significantly greater decrease in the cholesterol (CHO) level (WMD -0.19 mmol/L; 95 % CI -0.19 to -0.19 mmol/L, p < 0.001) and a significantly greater decrease in the low-density lipoprotein cholesterol (LDL-C) level (WMD -0.16 mmol/L; 95

The effects of GLP-1 analogues, DPP-4 inhibitors and SGLT2 inhibitors on the renal system.

PubMed

Schernthaner, Guntram; Mogensen, Carl Erik; Schernthaner, Gerit-Holger

2014-09-01

Diabetic nephropathy (DN) affects an estimated 20%-40% of patients with type 2 diabetes mellitus (T2DM). Key modifiable risk factors for DN are albuminuria, anaemia, dyslipidaemia, hyperglycaemia and hypertension, together with lifestyle factors, such as smoking and obesity. Early detection and treatment of these risk factors can prevent DN or slow its progression, and may even induce remission in some patients. DN is generally preceded by albuminuria, which frequently remains elevated despite treatment in patients with T2DM. Optimal treatment and prevention of DN may require an early, intensive, multifactorial approach, tailored to simultaneously target all modifiable risk factors. Regular monitoring of renal function, including urinary albumin excretion, creatinine clearance and glomerular filtration rate, is critical for following any disease progression and making treatment adjustments. Dipeptidyl peptidase (DPP)-4 inhibitors and sodium-glucose cotransporter 2 (SGLT2) inhibitors lower blood glucose levels without additional risk of hypoglycaemia, and may also reduce albuminuria. Further investigation of the potential renal benefits of DPP-4 and SGLT2 inhibitors is underway. © The Author(s) 2014.

The effects of GLP-1 analogues, DPP-4 inhibitors and SGLT2 inhibitors on the renal system

PubMed Central

Mogensen, Carl Erik; Schernthaner, Gerit-Holger

2014-01-01

Diabetic nephropathy (DN) affects an estimated 20%–40% of patients with type 2 diabetes mellitus (T2DM). Key modifiable risk factors for DN are albuminuria, anaemia, dyslipidaemia, hyperglycaemia and hypertension, together with lifestyle factors, such as smoking and obesity. Early detection and treatment of these risk factors can prevent DN or slow its progression, and may even induce remission in some patients. DN is generally preceded by albuminuria, which frequently remains elevated despite treatment in patients with T2DM. Optimal treatment and prevention of DN may require an early, intensive, multifactorial approach, tailored to simultaneously target all modifiable risk factors. Regular monitoring of renal function, including urinary albumin excretion, creatinine clearance and glomerular filtration rate, is critical for following any disease progression and making treatment adjustments. Dipeptidyl peptidase (DPP)-4 inhibitors and sodium-glucose cotransporter 2 (SGLT2) inhibitors lower blood glucose levels without additional risk of hypoglycaemia, and may also reduce albuminuria. Further investigation of the potential renal benefits of DPP-4 and SGLT2 inhibitors is underway. PMID:25116004

Experience with DPP-4 inhibitors in the management of patients with type 2 diabetes fasting during Ramadan

PubMed Central

Schweizer, Anja; Halimi, Serge; Dejager, Sylvie

2014-01-01

A large proportion of Muslim patients with type 2 diabetes mellitus (T2DM) elect to fast during the holy month of Ramadan. For these patients hypo- and hyperglycemia constitute two major complications associated with the profound changes in food pattern during the Ramadan fast, and efficacious treatment options with a low risk of hypoglycemia are therefore needed to manage their T2DM as effectively and safely as possible. Dipeptidyl peptidase-4 (DPP-4) inhibitors modulate insulin and glucagon secretion in a glucose-dependent manner, and consequently a low propensity of hypoglycemia has consistently been reported across different patient populations with these agents. Promising data with DPP-4 inhibitors have now also started to emerge in patients with T2DM fasting during Ramadan. The objective of this review is to provide a comprehensive overview of the currently available evidence and potential role of DPP-4 inhibitors in the management of patients with T2DM fasting during Ramadan whose diabetes is treated with oral antidiabetic drugs, and to discuss the mechanistic basis for their beneficial effects in this setting. PMID:24391442

Pharmacovigilance Evaluation of the Association Between DPP-4 Inhibitors and Heart Failure: Stimulated Reporting and Moderation by Drug Interactions.

PubMed

Fadini, Gian Paolo; Sarangdhar, Mayur; Avogaro, Angelo

2018-04-01

In the SAVOR-TIMI trial, the risk of heart failure (HF) was increased by 27% in T2D patients randomized to the dipeptidyl peptidase-4 inhibitor (DPP4i) saxagliptin. Other studies have provided inconsistent results regarding this association. Herein, we performed a pharmacovigilance analysis of the rate of HF associated with DPP4is, focusing on stimulated reporting and moderation by drug-drug interactions. We mined the FDA adverse event (AE) reporting system (FAERS) from 2004q1 to 2017q3, including a total of 9906,642 AE reports. Rates (/1000 reports) of HF within the reports for DPP4is and reports for other antidiabetic drugs were calculated for the period up to 2013q3 (date of publication of the SAVOR-TIMI trial results) and from 2013q4 to 2017q3. Analyses were refined by filtering according to therapeutic area, concomitant diseases and drugs, and competing AEs. The rate of HF among the AE reports filed for DPP4is significantly increased after 2013q3, especially for saxagliptin. When compared to non-insulin non-glitazone antidiabetic drugs, the proportional reporting ratio (PRR) of HF for DPP4is was 0.62 (95% CI 0.56-0.68) up to 2013q3 and 2.12 (95% CI 1.96-2.28) from 2013q4 to 2017q3. This stimulated reporting was consistent in subanalyses based on the presence/absence of cardiac disorders and after controlling for competing AEs. The rate of HF among AE reports for DPP4is was modestly moderated by the concomitant use of metformin (- 15%) and strongly moderated by the concomitant use of SGLT2 inhibitors (- 63%), even after excluding competing AEs. Within the FAERS, the association between HF and DPP4is was biased by stimulated reporting, implying that the publication of the SAVOR-TIMI trial and the subsequent regulatory warnings primed clinicians to report HF events in DPP4i users as drug-related AEs. The rate of HF associated with DPP4is was moderated when they were used in combination with SGLT2 inhibitors.

DPP-4 Inhibitor Treatment in Chinese Type 2 Diabetes Patients: A Meta-Analysis.

PubMed

Cai, Xiaoling; Gao, Xueying; Yang, Wenjia; Chen, Yifei; Zhou, Lingli; Zhang, Simin; Han, Xueyao; Ji, Linong

2016-12-01

The aim of this meta-analysis was to assess the comprehensive clinical efficacy of dipeptidyl peptidase-IV (DPP-4) inhibitors in Chinese type 2 diabetes patients and to evaluate whether there is a different response to treatment with different kinds of DPP-4 inhibitors in those patients. Databases were systematically searched, and qualifying clinical studies of Chinese type 2 diabetes patients were included. A total of 30 studies were included. Treatment with saxagliptin resulted in a significantly greater change from baseline in HbA 1c levels (weighted mean difference [WMD], -1.28%; 95% CI, -1.37% to -1.19%); treatment with sitagliptin led to a significantly greater change from baseline (WMD, -1.17%; 95% CI, -1.46% to -0.89%); treatment with vildagliptin was associated with a significantly greater change in HbA 1c levels (WMD, -0.77%; 95% CI, -0.88% to -0.65%); treatment with linagliptin led to a significantly greater change (WMD, -0.84%; 95% CI, -0.92% to -0.75%); and treatment with alogliptin also led to a significantly greater change (WMD, -0.91%; 95% CI, -1.48% to -0.33%). In terms of body weight, treatment with saxagliptin was associated with no significant decreases in Chinese type 2 diabetes mellitus (T2DM) patients (WMD, -0.17 kg, 95% CI, -4.26 to 3.92 kg). Treatment with sitagliptin and linagliptin was also associated with no significant changes in body weight (WMD, 0.16 and 0.11 kg, respectively, P > 0.05). In Chinese type 2 diabetes patients, the efficacy of glucose control in all five kinds of DPP-4 inhibitor treatments was well confirmed, and no significant change in body weight was found.

DPP-4 inhibitors for the treatment of type 2 diabetes: a methodology overview of systematic reviews.

PubMed

Ling, Juan; Ge, Long; Zhang, Ding-Hua; Wang, Yong-Feng; Xie, Zhuo-Lin; Tian, Jin-Hui; Xiao, Xiao-Hui; Yang, Ke-Hu

2018-06-01

To evaluate the methodological quality of systematic reviews (SRs), and summarize evidence of important outcomes from dipeptidyl peptidase-4 inhibitors (DPP4-I) in treating type 2 diabetes mellitus (T2DM). We included SRs of DPP4-I for the treatment of T2DM until January, 2018 by searching the Cochrane Library, PubMed, EMBASE and three Chinese databases. We evaluated the methodological qualities with the AMSTAR (Assessing the Methodological Quality of Systematic Reviews) tool and the GRADE (The Grading of Recommendations Assessment, Development and Evaluation) approach. Sixty-three SRs (a total of 2,603,140 participants) receiving DPP4-I for the treatment of T2DM were included. The results of AMSTAR showed that the lowest quality was "a list of studies (included and excluded) item" with only one (1.6%) study provided, followed by the "providing a priori design" item with only four (6.3%) studies conforming to this item, the next were "the status of publication (gray literature) used as an inclusion criterion item", with only 18 (28.9%) studies conforming to these items. Only seven (11.1%) studies scored more than nine points in AMSTAR, indicating high methodological quality. For GRADE, of the 128 outcomes, high quality evidence was provided in only 28 (21.9%), moderate in 70 (54.7%), low in 27 (21.1%), and very low in three (2.3%). The methodological quality of SRs of DPP4-I for type 2 diabetes mellitus is not high and there are common areas for improvement. Furthermore, the quality of evidence level is moderate and more high quality evidence is needed.

Design, synthesis and biological evaluation of novel pyrazolo-pyrimidinones as DPP-IV inhibitors in diabetes.

PubMed

Sagar, Sneha R; Agarwal, Jessica K; Pandya, Dhaivat H; Dash, Ranjeet Prasad; Nivsarkar, Manish; Vasu, Kamala K

2015-10-15

We report the design, synthesis, biological activity and docking studies of series of novel pyrazolo[3,4-d]pyrimidinones as DPP-IV inhibitors in diabetes. Molecules were synthesized and evaluated for their DPP-IV inhibition activity. Compounds 5e, 5k, 5o and 6a were found to be potent inhibitors of DPP-IV enzyme. Amongst all the synthesized compounds, 6-methyl-5-(4-methylpyridin-2-yl)-1-phenyl-1H-pyrazolo[3,4-d]pyrimidin-4(5H)-one (5k) was found to be the most active based on in vitro DPP-IV studies and also exhibited promising in vivo blood glucose lowering activity in male Wistar rats. Copyright © 2015. Published by Elsevier Ltd.

The effect of DPP-4 inhibitors on asthma control: an administrative database study to evaluate a potential pathophysiological relationship.

PubMed

Colice, Gene; Price, David; Gerhardsson de Verdier, Maria; Rabon-Stith, Karma; Ambrose, Christopher; Cappell, Katherine; Irwin, Debra E; Juneau, Paul; Vlahiotis, Anna

2017-01-01

DPP-4 may regulate immunological pathways implicated in asthma. Assessing whether DPP-4 inhibitor (DPP-4i) use might affect asthma control is clinically important because DPP-4i use in type 2 diabetes mellitus management (T2DM) is increasing. This study evaluated associations between DPP-4i use and asthma control. This was a retrospective, observational, matched cohort study using administrative claims in the MarketScan ® Commercial Claims and Encounters (Commercial) and Medicare Supplemental and Coordination of Benefits (Medicare Supplemental) databases. Adult asthma patients initiating an oral DPP-4i or a non-DPP-4i between November 1, 2006 and March 31, 2014 were included. Patients were followed for asthma-related outcomes for 12 months after initiation of the antidiabetes medication. Outcomes included risk-domain asthma control (RDAC), defined as no asthma hospitalizations, no lower respiratory tract infections, and no oral corticosteroid (OCS) prescriptions; overall asthma control (RDAC criteria plus limited short-acting beta agonist use); treatment stability (RDAC criteria plus no increase of ≥50% in inhaled corticosteroid dose or addition of other asthma therapy); and severe asthma exacerbation rates (asthma-related hospitalizations, emergency room visits, or acute treatments with OCS). Comparisons were made between two matched cohorts (DPP-4i vs. non-DPP-4i initiators) using multivariable logistic regression and generalized linear modeling. Covariates included baseline demographic and clinical characteristics related to asthma and T2DM. The adjusted odds of achieving RDAC (odds ratio [OR]: 1.05; 95% CI: 0.964 to 1.147), overall asthma control (OR: 1.04; 95% CI: 0.956 to 1.135), and treatment stability (OR: 1.04; 95% CI: 0.949 to 1.115) did not differ between the DPP-4i and non-DPP-4i cohorts. A difference was not found between cohorts in severe asthma exacerbation rates during the 12 months following initiation of antidiabetes treatment (mean = 0.32 vs

Early and late effects of the DPP-4 inhibitor vildagliptin in a rat model of post-myocardial infarction heart failure

PubMed Central

2011-01-01

Background Progressive remodeling after myocardial infarction (MI) is a leading cause of morbidity and mortality. Recently, glucagon-like peptide (GLP)-1 was shown to have cardioprotective effects, but treatment with GLP-1 is limited by its short half-life. It is rapidly degraded by the enzyme dipeptidyl peptidase-4 (DPP-4), an enzyme which inhibits GLP-1 activity. We hypothesized that the DPP-4 inhibitor vildagliptin will increase levels of GLP-1 and may exert protective effects on cardiac function after MI. Methods Sprague-Dawley rats were either subjected to coronary ligation to induce MI and left ventricular (LV) remodeling, or sham operation. Parts of the rats with an MI were pre-treated for 2 days with the DPP-4 inhibitor vildagliptin (MI-Vildagliptin immediate, MI-VI, 15 mg/kg/day). The remainder of the rats was, three weeks after coronary artery ligation, subjected to treatment with DPP-4 inhibitor vildagliptin (MI-Vildagliptin Late, MI-VL) or control (MI). At 12 weeks, echocardiography and invasive hemodynamics were measured and molecular analysis and immunohistochemistry were performed. Results Vildagliptin inhibited the DPP-4 enzymatic activity by almost 70% and increased active GLP-1 levels by about 3-fold in plasma in both treated groups (p < 0.05 vs. non-treated groups). Cardiac function (ejection fraction) was decreased in all 3 MI groups compared with Sham group (p < 0.05); treatment with vildagliptin, either early or late, did not reverse cardiac remodeling. ANP (atrial natriuretic peptide) and BNP (brain natriuretic peptide) mRNA levels were significantly increased in all 3 MI groups, but no significant reductions were observed in both vildagliptin groups. Vildagliptin also did not change cardiomyocyte size or capillary density after MI. No effects were detected on glucose level and body weight in the post-MI remodeling model. Conclusion Vildagliptin increases the active GLP-1 level via inhibition of DPP-4, but it has no substantial protective

Quantitative Evaluation of Compliance with Recommendation for Sulfonylurea Dose Co-Administered with DPP-4 Inhibitors in Japan

PubMed Central

Kimura, Tomomi; Shiosakai, Kazuhito; Takeda, Yasuaki; Takahashi, Shinji; Kobayashi, Masahiko; Sakaguchi, Motonobu

2012-01-01

After the launch of dipeptidyl peptidase-4 (DPP-4), a new oral hypoglycemic drug (OHD), in December 2009, severe hypoglycemia cases were reported in Japan. Although the definite cause was unknown, co-administration with sulfonylureas (SU) was suspected as one of the potential risk factors. The Japan Association for Diabetes Education and Care (JADEC) released a recommendation in April 2010 to lower the dose of three major SUs (glimepiride, glibenclamide, and gliclazide) when adding a DPP-4 inhibitor. To evaluate the effectiveness of this risk minimization action along with labeling changes, dispensing records for 114,263 patients prescribed OHDs between December 2008 and December 2010 were identified in the Nihon-Chouzai pharmacy claims database. The adherence to the recommended dosing of SU co-prescribed with DPP-4 inhibitors increased from 46.3% before to 63.8% after the JADEC recommendation (p < 0.01 by time-series analysis), while no change was found in those for SU monotherapy and SU with other OHD co-prescriptions. The adherence was significantly worse for those receiving a glibenclamide prescription. The JADEC recommendation, along with labeling changes, appeared to have a favorable effect on the risk minimization action in Japan. In these instances, a pharmacy claims database can be a useful tool to evaluate risk minimization actions. PMID:24300302

Effects of Inhibiting Dipeptidyl Peptidase-4 (DPP4) in Cows with Subclinical Ketosis

PubMed Central

Schulz, Kirsten; Frahm, Jana; Kersten, Susanne; Meyer, Ulrich; Rehage, Jürgen; Piechotta, Marion; Meyerholz, Maria; Breves, Gerhard; Reiche, Dania; Sauerwein, Helga; Dänicke, Sven

2015-01-01

The inhibition of dipeptidyl peptidase-4 (DPP4) via specific inhibitors is known to result in improved glucose tolerance and insulin sensitivity and decreased accumulation of hepatic fat in type II diabetic human patients. The metabolic situation of dairy cows can easily be compared to the status of human diabetes and non-alcoholic fatty liver. For both, insulin sensitivity is reduced, while hepatic fat accumulation increases, characterized by high levels of non-esterified fatty acids (NEFA) and ketone bodies.Therefore, in the present study, a DPP4 inhibitor was employed (BI 14332) for the first time in cows. In a first investigation BI 14332 treatment (intravenous injection at dosages of up to 3 mg/kg body weight) was well tolerated in healthy lactating pluriparous cows (n = 6) with a significant inhibition of DPP4 in plasma and liver. Further testing included primi- and pluriparous lactating cows suffering from subclinical ketosis (β-hydroxybutyrate concentrations in serum > 1.2 mM; n = 12). The intension was to offer effects of DPP4 inhibition during comprehensive lipomobilisation and hepatosteatosis. The cows of subclinical ketosis were evenly allocated to either the treatment group (daily injections, 0.3 mg BI 14332/kg body weight, 7 days) or the control group. Under condition of subclinical ketosis, the impact of DPP4 inhibition via BI 14332 was less, as in particular β-hydroxybutyrate and the hepatic lipid content remained unaffected, but NEFA and triglyceride concentrations were decreased after treatment. Owing to lower NEFA, the revised quantitative insulin sensitivity check index (surrogate marker for insulin sensitivity) increased. Therefore, a positive influence on energy metabolism might be quite possible. Minor impacts on immune-modulating variables were limited to the lymphocyte CD4+/CD8+ ratio for which a trend to decreased values in treated versus control animals was noted. In sum, the DPP4 inhibition in cows did not affect glycaemic control like

Effects of Inhibiting Dipeptidyl Peptidase-4 (DPP4) in Cows with Subclinical Ketosis.

PubMed

Schulz, Kirsten; Frahm, Jana; Kersten, Susanne; Meyer, Ulrich; Rehage, Jürgen; Piechotta, Marion; Meyerholz, Maria; Breves, Gerhard; Reiche, Dania; Sauerwein, Helga; Dänicke, Sven

2015-01-01

The inhibition of dipeptidyl peptidase-4 (DPP4) via specific inhibitors is known to result in improved glucose tolerance and insulin sensitivity and decreased accumulation of hepatic fat in type II diabetic human patients. The metabolic situation of dairy cows can easily be compared to the status of human diabetes and non-alcoholic fatty liver. For both, insulin sensitivity is reduced, while hepatic fat accumulation increases, characterized by high levels of non-esterified fatty acids (NEFA) and ketone bodies.Therefore, in the present study, a DPP4 inhibitor was employed (BI 14332) for the first time in cows. In a first investigation BI 14332 treatment (intravenous injection at dosages of up to 3 mg/kg body weight) was well tolerated in healthy lactating pluriparous cows (n = 6) with a significant inhibition of DPP4 in plasma and liver. Further testing included primi- and pluriparous lactating cows suffering from subclinical ketosis (β-hydroxybutyrate concentrations in serum > 1.2 mM; n = 12). The intension was to offer effects of DPP4 inhibition during comprehensive lipomobilisation and hepatosteatosis. The cows of subclinical ketosis were evenly allocated to either the treatment group (daily injections, 0.3 mg BI 14332/kg body weight, 7 days) or the control group. Under condition of subclinical ketosis, the impact of DPP4 inhibition via BI 14332 was less, as in particular β-hydroxybutyrate and the hepatic lipid content remained unaffected, but NEFA and triglyceride concentrations were decreased after treatment. Owing to lower NEFA, the revised quantitative insulin sensitivity check index (surrogate marker for insulin sensitivity) increased. Therefore, a positive influence on energy metabolism might be quite possible. Minor impacts on immune-modulating variables were limited to the lymphocyte CD4+/CD8+ ratio for which a trend to decreased values in treated versus control animals was noted. In sum, the DPP4 inhibition in cows did not affect glycaemic control like

Weight neutrality with the DPP-4 inhibitor, vildagliptin: Mechanistic basis and clinical experience

PubMed Central

Foley, James E; Jordan, Jens

2010-01-01

Various factors may confound how diabetes medications affect a patient’s weight. Agents that induce hypoglycemia may promote weight gain through “defensive eating”. Conversely, patients whose hyperglycemia exceeds the renal glucose threshold may overeat to compensate for calories lost in urine and so gain weight when drug therapy ablates glycosuria. Some drugs, such as thiazolidinediones, may promote weight gain via increased lipid storage. Glucagon-like peptide-1 receptor agonists increase satiety, delay gastric emptying, and generally produce weight loss. Dipeptidyl peptidase (DPP)-4 inhibitors are generally weight-neutral, although modest weight loss has been observed with the DPP-4 inhibitor, vildagliptin, in patients with relatively low baseline glycemia. The weight neutrality of vildagliptin likely results in part from its intrinsically low risk for hypoglycemia. Recent studies point to additional potential mechanisms. One study found that drug-naïve patients randomized to vildagliptin exhibited significantly lower chylomicron lipid and apolipoprotein levels than placebo patients, suggesting that vildagliptin may inhibit intestinal fat extraction. Another trial found that patients randomized to vildagliptin versus placebo experienced paradoxical postprandial increases in markers of fatty acid mobilization and oxidation, in conjunction with increased sympathetic stimulation. Elaboration of these and other pathways could further clarify the origins of the favorable weight profile of vildagriptin. PMID:20730070

DPP IV inhibitor treatment attenuates bone loss and improves mechanical bone strength in male diabetic rats.

PubMed

Glorie, Lorenzo; Behets, Geert J; Baerts, Lesley; De Meester, Ingrid; D'Haese, Patrick C; Verhulst, Anja

2014-09-01

Dipeptidyl peptidase IV (DPP IV) modulates protein activity by removing dipeptides. DPP IV inhibitors are currently used to improve glucose tolerance in type 2 diabetes patients. DPP IV substrates not only increase insulin secretion but also affect bone metabolism. In this study, the effect of DPP IV inhibitor sitagliptin on bone was evaluated in normal and streptozotocin-induced diabetic rats. This study included 64 male Wistar rats divided into four groups (n = 16): two diabetic and two control groups. One diabetic and one control group received sitagliptin through drinking water. Tibiae were scanned every 3 wk using an in vivo μCT scanner. After 6 and 12 wk, rats were euthanized for histomorphometric analysis of bone parameters. The mechanical resistance of femora to fracture was assessed using a three-point bending test, and serum levels of bone metabolic markers were measured. Efficient DPP IV inhibition was achieved in sitagliptin-treated groups. Trabecular bone loss, the decrease in trabecular number, and the increase in trabecular spacing was attenuated through sitagliptin treatment in diabetic rats, as shown by in vivo μCT. Bone histomorphometry was in line with these results. μCT analysis furthermore showed that sitagliptin prevented cortical bone growth stagnation in diabetic rats, resulting in stronger femora during three-point bending. Finally, the serum levels of the resorption marker CTX-I were significantly lower in sitagliptin-treated diabetic animals compared with untreated diabetic animals. In conclusion, sitagliptin treatment attenuates bone loss and increases bone strength in diabetic rats probably through the reduction of bone resorption and independent of glycemic management. Copyright © 2014 the American Physiological Society.

SGLT2 inhibitor/DPP-4 inhibitor combination therapy - complementary mechanisms of action for management of type 2 diabetes mellitus.

PubMed

Dey, Jayant

2017-05-01

Type 2 diabetes mellitus is a progressive disease with multiple underlying pathophysiologic defects. Monotherapy alone cannot maintain glycemic control and leads to treatment failure. Ideally, a combination of glucose-lowering agents should have complementary mechanisms of action that address multiple pathophysiologic pathways, can be used at all stages of the disease, and be generally well tolerated with no increased risk of hypoglycemia, cardiovascular events, or weight gain. The combination should also provide conveniences for patients, such as oral dosing, single-pill formulations, and once-daily administration, potentially translating to improved adherence. Two classes of glucose-lowering agents that meet these criteria are the sodium glucose cotransporter-2 (SGLT2) inhibitors and dipeptidyl peptidase-4 (DPP-4) inhibitors. This article reviews the rationale for combination therapy with these agents, and evidence from clinical trials with empagliflozin and linagliptin or dapagliflozin and saxagliptin in the management of type 2 diabetes mellitus. Both combinations have been approved as single-pill formulations.

Reduction of serum FABP4 level by sitagliptin, a DPP-4 inhibitor, in patients with type 2 diabetes mellitus.

PubMed

Furuhashi, Masato; Hiramitsu, Shinya; Mita, Tomohiro; Fuseya, Takahiro; Ishimura, Shutaro; Omori, Akina; Matsumoto, Megumi; Watanabe, Yuki; Hoshina, Kyoko; Tanaka, Marenao; Moniwa, Norihito; Yoshida, Hideaki; Ishii, Junnichi; Miura, Tetsuji

2015-12-01

Fatty acid binding protein 4 (FABP4), also known as adipocyte FABP or aP2, is secreted from adipocytes in association with lipolysis as a novel adipokine, and elevated serum FABP4 level is associated with obesity, insulin resistance, and atherosclerosis. However, little is known about the modulation of serum FABP4 level by therapeutic drugs. Sitagliptin (50 mg/day), a dipeptidyl peptidase 4 (DPP-4) inhibitor that increases glucagon-like peptide 1 (GLP-1), was administered to patients with type 2 diabetes (n = 24) for 12 weeks. Treatment with sitagliptin decreased serum FABP4 concentration by 19.7% (17.8 ± 1.8 vs. 14.3 ± 1.5 ng/ml, P < 0.001) and hemoglobin A1c without significant changes in adiposity or lipid variables. In 3T3-L1 adipocytes, sitagliptin or exendin-4, a GLP-1 receptor agonist, had no effect on short-term (2 h) secretion of FABP4. However, gene expression and long-term (24 h) secretion of FABP4 were significantly reduced by sitagliptin, which was not mimicked by exendin-4. Treatment with recombinant DPP-4 increased gene expression and long-term secretion of FABP4, and the effects were cancelled by sitagliptin. Furthermore, knockdown of DPP-4 in 3T3-L1 adipocytes decreased gene expression and long-term secretion of FABP4. In conclusion, sitagliptin decreases serum FABP4 level, at least in part, via reduction in the expression and consecutive secretion of FABP4 in adipocytes by direct inhibition of DPP-4. Copyright © 2015 by the American Society for Biochemistry and Molecular Biology, Inc.

Reduction of serum FABP4 level by sitagliptin, a DPP-4 inhibitor, in patients with type 2 diabetes mellitus[S

PubMed Central

Furuhashi, Masato; Hiramitsu, Shinya; Mita, Tomohiro; Fuseya, Takahiro; Ishimura, Shutaro; Omori, Akina; Matsumoto, Megumi; Watanabe, Yuki; Hoshina, Kyoko; Tanaka, Marenao; Moniwa, Norihito; Yoshida, Hideaki; Ishii, Junnichi; Miura, Tetsuji

2015-01-01

Fatty acid binding protein 4 (FABP4), also known as adipocyte FABP or aP2, is secreted from adipocytes in association with lipolysis as a novel adipokine, and elevated serum FABP4 level is associated with obesity, insulin resistance, and atherosclerosis. However, little is known about the modulation of serum FABP4 level by therapeutic drugs. Sitagliptin (50 mg/day), a dipeptidyl peptidase 4 (DPP-4) inhibitor that increases glucagon-like peptide 1 (GLP-1), was administered to patients with type 2 diabetes (n = 24) for 12 weeks. Treatment with sitagliptin decreased serum FABP4 concentration by 19.7% (17.8 ± 1.8 vs. 14.3 ± 1.5 ng/ml, P < 0.001) and hemoglobin A1c without significant changes in adiposity or lipid variables. In 3T3-L1 adipocytes, sitagliptin or exendin-4, a GLP-1 receptor agonist, had no effect on short-term (2 h) secretion of FABP4. However, gene expression and long-term (24 h) secretion of FABP4 were significantly reduced by sitagliptin, which was not mimicked by exendin-4. Treatment with recombinant DPP-4 increased gene expression and long-term secretion of FABP4, and the effects were cancelled by sitagliptin. Furthermore, knockdown of DPP-4 in 3T3-L1 adipocytes decreased gene expression and long-term secretion of FABP4. In conclusion, sitagliptin decreases serum FABP4 level, at least in part, via reduction in the expression and consecutive secretion of FABP4 in adipocytes by direct inhibition of DPP-4. PMID:26467280

The DPP-4 inhibitor vildagliptin impacts the gut microbiota and prevents disruption of intestinal homeostasis induced by a Western diet in mice.

PubMed

Olivares, Marta; Neyrinck, Audrey M; Pötgens, Sarah A; Beaumont, Martin; Salazar, Nuria; Cani, Patrice D; Bindels, Laure B; Delzenne, Nathalie M

2018-05-25

Dipeptidyl peptidase 4 (DPP-4) inhibitors are agents designed to increase the half-life of incretins. Although they are administered orally, little is known about their effects on the gut microbiota and functions, despite the fact that some bacteria present in the gut microbiota exhibit DPP-4-like activity. Our objective was to study the impact of the DPP-4 inhibitor vildagliptin on gut functions and the intestinal ecosystem in a murine model of obesity induced by a Western diet (WD). Twenty seven male C57BL/6J mice were randomised to receive a control diet, a WD (45% kJ from fat and 17% kJ from sucrose) or a WD + vildagliptin (0.6 mg/ml in drinking water) for 8 weeks. Vildagliptin significantly reduced DPP-4 activity in the caecal content and faeces. Vildagliptin impacted on the composition of the gut microbiota and its metabolic activity. It mainly decreased Oscillibacter spp. (a direct effect independent of DPP-4 activity was shown on cultured O. valericigenes), increased Lactobacillus spp. and propionate, and reduced the ligands of Toll-like receptors 2 and 4. Vildagliptin protected against the reductions in crypt depth and ileal expression of antimicrobial peptides induced by the WD. In the liver, the expression of immune cell populations (Cd3g and Cd11c [also known as Itgax]) and cytokines was decreased in the WD + vildagliptin-fed mice compared with the WD-fed group. Ex vivo exposure of precision-cut liver slices to vildagliptin showed that this response was not related to a direct effect of the drug on the liver tissue. Our study is the first to consider the DPP-4-like activity of the gut microbiota as a target of DPP-4 inhibition. We propose that vildagliptin exerts beneficial effects at the intestinal level in association with modulation of gut microbiota, with consequences for hepatic immunity. If relevant in humans, this could open new therapeutic uses of DPP-4 inhibition to tackle gut dysfunctions in different pathophysiological contexts. The

Diabetes therapies in hemodialysis patients: Dipeptidase-4 inhibitors

PubMed Central

Nakamura, Yuya; Hasegawa, Hitomi; Tsuji, Mayumi; Udaka, Yuko; Mihara, Masatomo; Shimizu, Tatsuo; Inoue, Michiyasu; Goto, Yoshikazu; Gotoh, Hiromichi; Inagaki, Masahiro; Oguchi, Katsuji

2015-01-01

Although several previous studies have been published on the effects of dipeptidase-4 (DPP-4) inhibitors in diabetic hemodialysis (HD) patients, the findings have yet to be reviewed comprehensively. Eyesight failure caused by diabetic retinopathy and aging-related dementia make multiple daily insulin injections difficult for HD patients. Therefore, we reviewed the effects of DPP-4 inhibitors with a focus on oral antidiabetic drugs as a new treatment strategy in HD patients with diabetes. The following 7 DPP-4 inhibitors are available worldwide: sitagliptin, vildagliptin, alogliptin, linagliptin, teneligliptin, anagliptin, and saxagliptin. All of these are administered once daily with dose adjustments in HD patients. Four types of oral antidiabetic drugs can be administered for combination oral therapy with DPP-4 inhibitors, including sulfonylureas, meglitinide, thiazolidinediones, and alpha-glucosidase inhibitor. Nine studies examined the antidiabetic effects in HD patients. Treatments decreased hemoglobin A1c and glycated albumin levels by 0.3% to 1.3% and 1.7% to 4.9%, respectively. The efficacy of DPP-4 inhibitor treatment is high among HD patients, and no patients exhibited significant severe adverse effects such as hypoglycemia and liver dysfunction. DPP-4 inhibitors are key drugs in new treatment strategies for HD patients with diabetes and with limited choices for diabetes treatment. PMID:26131325

Cardiovascular pleiotropic actions of DPP-4 inhibitors: a step at the cutting edge in understanding their additional therapeutic potentials.

PubMed

Balakumar, Pitchai; Dhanaraj, Sokkalingam A

2013-09-01

Dipeptidyl peptidase 4 (DPP-4) is a serine protease enzyme expressed widely in many tissues, including the cardiovascular system. The incretin hormones such as glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) are released from the small intestine into the vasculature during a meal, and these incretins have a potential to release insulin from pancreatic beta cells of islets of Langerhans, affording a glucose-lowering action. However, both incretins are hurriedly degraded by the DPP-4. Inhibitors of DPP-4, therefore, enhance the bioavailability of GLP-1 and GIP, and thus have been approved for better glycemic management in patients afflicted with type 2 diabetes mellitus (T2DM). Five different DPP-4 inhibitors, often called as 'gliptins', namely sitagliptin, vildagliptin, saxagliptin, linagliptin and alogliptin have been approved hitherto for clinical use. These drugs are used along with diet and exercise to lower blood sugar in diabetic subjects. T2DM is intricately related with an increased risk of cardiovascular disease. Growing body of evidence suggests that gliptins, in addition to their persuasive anti-diabetic action, have a beneficial pleiotropic action on the heart and vessels. In view of the fact of cardiovascular disease susceptibility of patients afflicted with T2DM, gliptins might offer additional therapeutic benefits in treating diabetic cardiovascular complications. Exploring further the cardiovascular pleiotropic potentials of gliptins might open a panorama in impeccably employing these agents for the dual management of T2DM and T2DM-associated perilous cardiovascular complications. This review will shed lights on the newly identified beneficial pleiotropic actions of gliptins on the cardiovascular system. Copyright © 2013 Elsevier Inc. All rights reserved.

The DPP-4 inhibitor anagliptin ameliorates hypercholesterolemia in hypercholesterolemic mice via inhibition of intestinal cholesterol transport.

PubMed

Goto, Moritaka; Furuta, Shinji; Yamashita, Satoko; Hashimoto, Hiroyuki; Yano, Wataru; Inoue, Noriyuki; Kato, Noriaki; Kaku, Kohei

2018-05-13

Recent data showed that DPP-4 inhibitors exert a lipid-lowering effect in diabetic patients. However, the mechanism of action is not yet clearly understood. We investigated the effect of anagliptin on cholesterol metabolism and transport in the small intestine using non-diabetic hyperlipidemic animals, to clarify the mechanisms underlying the cholesterol-lowering action. Male ApoE-deficient mice were orally administered anagliptin in the normal chow. Serum cholesterol levels and lipoprotein profiles were measured, and cholesterol transport was assessed by measuring the radioactivity in the tissues after oral loading of 14 C-labeled cholesterol ( 14 C-Chol). In additional experiments, effects of exendin-4 in mice and of anagliptin in DPP-4-deficient rats were assessed. Effect on target gene expressions in the intestine were analyzed by qPCR in normal mice. The serum total and non-HDL cholesterol concentrations decreased after anagliptin treatment in the ApoE-deficient mice. The cholesterol-lowering effect was predominantly observed in the chylomicron fraction. The plasma 14 C-Chol radioactivity was significantly decreased by 26% at 2 hours after cholesterol loading, and the fecal 14 C-Chol excretion was significantly increased by 38% at 72 hours. The aforementioned effects on cholesterol transport were abrogated in rats lacking DPP-4 activity, and exendin-4 had no effect on the 14 C-Chol transport in ApoE-deficient mice. Furthermore, significant decreases of the intestinal cholesterol transport related MTTP, ACAT2, ApoA2 and ApoC2 mRNA expressions were observed in the mice treated with repeated doses of anagliptin. These findings suggest that anagliptin may exert a cholesterol-lowering action via DPP-4-dependent and GLP-1-independent suppression of intestinal cholesterol transport. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Comparative Effectiveness of DPP-4 Inhibitors Versus Sulfonylurea for the Treatment of Type 2 Diabetes in Routine Clinical Practice: A Retrospective Multicenter Real-World Study.

PubMed

Fadini, Gian Paolo; Bottigliengo, Daniele; D'Angelo, Federica; Cavalot, Franco; Bossi, Antonio Carlo; Zatti, Giancarlo; Baldi, Ileana; Avogaro, Angelo

2018-06-01

DPP-4 inhibitors (DPP4i) and sulfonylureas are popular second-line therapies for type 2 diabetes (T2D), but there is a paucity of real-world studies comparing their effectiveness in routine clinical practice. This was a multicenter retrospective study on diabetes outpatient clinics comparing the effectiveness of DPP4i versus gliclazide extended release. The primary endpoint was change from baseline in HbA1c. Secondary endpoints were changes in fasting plasma glucose, body weight, and systolic blood pressure. Automated software extracted data from the same clinical electronic chart system at all centers. Propensity score matching (PSM) was used to generate comparable cohorts to perform outcome analysis. We included data on 2410 patients starting DPP4i and 1590 patients starting gliclazide (mainly 30-60 mg/day). At baseline, the two groups differed in disease duration, body weight, blood pressure, HbA1c, fasting glucose, HDL cholesterol, triglycerides, liver enzymes, eGFR, prevalence of microangiopathy, and use of metformin. Among DPP4i molecules, no difference in glycemic effectiveness was detected. In matched cohorts (n = 1316/group), patients starting DPP4i, as compared with patients starting gliclazide, experienced greater reductions in HbA1c (- 0.6% versus - 0.4%; p < 0.001), fasting glucose (- 14.1 mg/dl versus - 8.8 mg/dl; p = 0.007), and body weight (- 0.4 kg versus - 0.1 kg; p = 0.006) after an average 6 months follow-up. DPP4i improved glucose control more than gliclazide, especially in patients who had failed with other glucose-lowering medications or were on basal insulin. This large retrospective real-world study shows that, in routine clinical practice, starting a DPP4i allows better glycemic control than starting low-dose gliclazide. The Italian Diabetes Society, with external support from AstraZeneca.

Choosing between GLP-1 Receptor Agonists and DPP-4 Inhibitors: A Pharmacological Perspective

PubMed Central

Brown, Dominique Xavier; Evans, Marc

2012-01-01

In recent years the incretin therapies have provided a new treatment option for patients with type 2 diabetes mellitus (T2DM). The incretin therapies focus on the increasing levels of the two incretin hormones, glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP). This results in increased glucose dependent insulin synthesis and release. GLP-1 receptor agonists such as liraglutide and exenatide exert an intrinsic biological effect on GLP-1 receptors directly stimulating the release of insulin from pancreatic beta cells. DPP-4 inhibitors such as sitagliptin and linagliptin prevent the inactivation of endogenous GLP-1 and GIP through competitive inhibition of the DPP-4 enzyme. Both incretin therapies have good safety and tolerability profiles and interact minimally with a number of medications commonly prescribed in T2DM. This paper focuses on the pharmacological basis by which the incretin therapies function and how this knowledge can inform and benefit clinical decisions. Each individual incretin agent has benefits and pitfalls relating to aspects such as glycaemic and nonglycaemic efficacy, safety and tolerability, ease of administration, and cost. Overall, a personalized medicine approach has been found to be favourable, tailoring the incretin agent to benefit and suit patient's needs such as renal impairment (RI) or hepatic impairment (HI). PMID:23125920

Structural studies of a bifunctional inhibitor of neprilysin and DPP-IV.

PubMed

Oefner, Christian; Pierau, Sabine; Schulz, Henk; Dale, Glenn E

2007-09-01

Neutral endopeptidase (NEP) is the major enzyme involved in the metabolic inactivation of a number of bioactive peptides including the enkephalins, substance P, endothelin, bradykinin and atrial natriuretic factor, as well as the incretin hormone glucagon-like peptide 1 (GLP-1), which is a potent stimulator of insulin secretion. The activity of GLP-1 is also rapidly abolished by the serine protease dipeptidyl peptidase IV (DPP-IV), which led to an elevated interest in inhibitors of this enzyme for the treatment of type II diabetes. A dual NEP/DPP-IV inhibitor concept is proposed, offering an alternative strategy for the treatment of type 2 diabetes. Here, the synthesis and crystal structures of the soluble extracellular domain of human NEP (residues 52-749) complexed with the NEP, competitive and potent dual NEP/DPP-IV inhibitor MCB3937 are described.

Chronic administration of DSP-7238, a novel, potent, specific and substrate-selective DPP IV inhibitor, improves glycaemic control and beta-cell damage in diabetic mice.

PubMed

Furuta, Y; Horiguchi, M; Sugaru, E; Ono-Kishino, M; Otani, M; Sakai, M; Masui, Y; Tsuchida, A; Sato, Y; Takubo, K; Hochigai, H; Kimura, H; Nakahira, H; Nakagawa, T; Taiji, M

2010-05-01

contrast, vildagliptin and saxagliptin showed similar degree of inhibition of degradation for all the substrates tested. Compared to treatment with the vehicle, single oral administration of DSP-7238 dose-dependently decreased plasma DPP IV activity and improved glucose tolerance in DIO mice. In addition, DSP-7238 significantly decreased HbA1c and ameliorated pancreatic damage following 11 weeks of chronic treatment in HFD/STZ mice. We have shown in this study that DSP-7238 is a potent DPP IV inhibitor that has high specificity for DPP IV and substrate selectivity against GLP-1. We have also found that chronic treatment with DSP-7238 improves glycaemic control and ameliorates beta-cell damage in a mouse model with impaired insulin sensitivity and secretion. These findings indicate that DSP-7238 may be a new therapeutic agent for the treatment of type 2 diabetes.

Differential effects of PPAR-{gamma} activation versus chemical or genetic reduction of DPP-4 activity on bone quality in mice.

PubMed

Kyle, Kimberly A; Willett, Thomas L; Baggio, Laurie L; Drucker, Daniel J; Grynpas, Marc D

2011-02-01

Patients with type 2 diabetes mellitus have an increased risk of fracture that can be further exacerbated by thiazolidinediones. A new class of antidiabetic agents control glucose through reduction of dipeptidyl peptidase-4 (DPP-4) activity; however the importance of DPP-4 for the control of bone quality has not been extensively characterized. We compared the effects of the thiazolidinedione pioglitazone and the DPP-4 inhibitor sitagliptin on bone quality in high-fat diet (HFD)-fed wild-type mice. In complementary studies, we examined bone quality in Dpp4(+/+) vs. Dpp4(-/-) mice. Pioglitazone produced yellow bones with greater bone marrow adiposity and significantly reduced vertebral bone mechanics in male, female, and ovariectomized (OVX) HFD fed female mice. Pioglitazone negatively affected vertebral volumetric bone mineral density, trabecular architecture, and mineral apposition rate in male mice. Sitagliptin treatment of HFD-fed wild-type mice significantly improved vertebral volumetric bone mineral density and trabecular architecture in female mice, but these improvements were lost in females after OVX. Genetic inactivation of Dpp4 did not produce a major bone phenotype in male and female Dpp4(-/-) mice; however, OVX Dpp4(-/-) mice exhibited significantly reduced femoral size and mechanics. These findings delineate the skeletal consequences of pharmacological and genetic reduction of DPP-4 activity and reveal significant differences in the effects of pioglitazone vs. sitagliptin vs. genetic Dpp4 inactivation on bone mechanics in mice.

Cost effectiveness of dipeptidyl peptidase-4 inhibitors for type 2 diabetes.

PubMed

Geng, Jinsong; Yu, Hao; Mao, Yiwei; Zhang, Peng; Chen, Yingyao

2015-06-01

Dipeptidyl peptidase-4 (DPP-4) inhibitors are a new class of antidiabetic drugs used for treating type 2 diabetes mellitus. While many studies have reported on the cost-effectiveness of DPP-4 inhibitors for treating type 2 diabetes, a systematic review of economic evaluations of DPP-4 inhibitors is currently lacking. The aim of this systematic review was to assess the cost effectiveness of DPP-4 inhibitors for patients with type 2 diabetes. MEDLINE, EMBASE, National Health Service Economic Evaluation Database (NHS EED), Web of Science, EconLit databases, and the Cochrane Library were searched in November 2013. Studies assessing the cost effectiveness of DPP-4 inhibitors for type 2 diabetes were eligible for analysis. DPP-4 inhibitor monotherapy or combinations with other antidiabetic agents were included in the review. The DPP-4 inhibitors were all marketed drugs. Two reviewers independently reviewed titles, abstracts, and articles sequentially to select studies for data abstraction based on the inclusion and exclusion criteria. Disagreements were resolved by consensus. The quality of included studies was assessed according to the 24-item checklist of the Consolidated Health Economic Evaluation Reporting Standards (CHEERS) statement. The costs reported by the included studies were converted to US dollars via purchasing power parities (PPP) in the year 2013 using the CCEMG-EPPI-Center Cost Converter. A total of 11 published studies were selected for inclusion; all were cost-utility analyses. Nine studies were conducted from a payer perspective and one used a societal perspective; however, the perspective of the other study was unclear. Four studies were of good quality, six were of moderate quality, and one was of low quality. Of the seven studies comparing DPP-4 inhibitors plus metformin with sulfonylureas plus metformin, six concluded that DPP-4 inhibitors were cost effective in patients with type 2 diabetes who were no longer adequately controlled by metformin

Medicinal Chemistry and Applications of Incretins and DPP-4 Inhibitors in the Treatment of Type 2 Diabetes Mellitus

PubMed Central

Lotfy, Mohamed; Singh, Jaipaul; Kalász, Huba; Tekes, Kornelia; Adeghate, Ernest

2011-01-01

Diabetes mellitus (DM) is a major metabolic disorder currently affecting over 200 million people worldwide. Approximately 90% of all diabetic patients suffer from Type 2 diabetes mellitus (T2DM). The world's economy coughs out billions of dollars annually to diagnose, treat and manage patients with diabetes. It has been shown that the naturally occurring gut hormones incretins, glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) can preserve the morphology and function of pancreatic beta cell. In addition, GIP and GLP-1 act on insulin receptors to facilitate insulin-receptor binding, resulting in optimal glucose metabolism. This review examines the medicinal chemistry and roles of incretins, specifically, GLP-1 and drugs which can mimic its actions and prevent its enzymatic degradation. The review discussed GLP-1 agonists such as exenatide, liraglutide, taspoglutide and albiglutide. The paper also identified and reviewed a number of inhibitors, which can block dipeptidyl peptidase 4 (DPP-4), the enzyme responsible for the rapid degradation of GLP-1. These DPP-4 inhibitors include sitagliptin, saxagliptin, vildagliptin and many others which are still in the experimental phase. PMID:21966329

Soluble DPP-4 up-regulates toll-like receptors and augments inflammatory reactions, which are ameliorated by vildagliptin or mannose-6-phosphate.

PubMed

Lee, Dong-Sung; Lee, Eun-Sol; Alam, Md Morshedul; Jang, Jun-Hyeog; Lee, Ho-Sub; Oh, Hyuncheol; Kim, Youn-Chul; Manzoor, Zahid; Koh, Young-Sang; Kang, Dae-Gil; Lee, Dae Ho

2016-02-01

Studies have shown that dipeptidyl peptidase-4 (DPP-4) inhibitors have anti-inflammatory effects. Soluble DPP-4 (sDPP-4) has been considered as an adipokine of which actions need to be further characterized. We investigated the pro-inflammatory actions of sDPP-4 and the anti-inflammatory effects of DPP-4 inhibition, using vildagliptin, as an enzymatic inhibitor, and mannose-6-phosphate (M6P) as a competitive binding inhibitor. In lipopolysaccharide (LPS)-stimulated RAW264.7 cells, vildagliptin suppressed the increased expression of inducible nitric oxide synthase (iNOS) and phosphorylated JNK (pJNK), activation of the NF-κB pathway, and the resultant NO and proinflammatory cytokine production. Although sDPP-4 alone did not affect the protein level of iNOS or pJNK or the production of NO in RAW264.7 cells, it did amplify iNOS expression, NO responses, and proinflammatory cytokine production in LPS-stimulated RAW264 cells. As a probable mechanism, we found that sDPP-4 caused dose-dependent increases in the expression levels of toll-like receptor 4 (TLR4) and TLR2 in RAW264.7 cells, and that these alterations were inhibited by vildagliptin, M6P, or bisindolylmaleimide II, a protein kinase C inhibitor. Either vildagliptin or M6P suppressed iNOS expression and NO and cytokine production in LPS+DPP-4-co-stimulated macrophages, while combined treatment of the co-stimulated cells with both agents had increased anti-inflammatory effects compared with either treatment alone. Intravenous injection of sDPP-4 to C57BL/6J mice increased the expression of both TLRs in kidney and white adipose tissues. Our findings suggest that sDPP-4 enhances inflammatory actions via TLR pathway, while DPP-4 inhibition with either an enzymatic or binding inhibitor has anti-inflammatory effects. Copyright © 2015 Elsevier Inc. All rights reserved.

Cut to the chase: a review of CD26/dipeptidyl peptidase‐4's (DPP4) entanglement in the immune system

PubMed Central

Wagner, L.; Stephan, M.; von Hörsten, S.

2016-01-01

Summary CD26/DPP4 (dipeptidyl peptidase 4/DP4/DPPIV) is a surface T cell activation antigen and has been shown to have DPP4 enzymatic activity, cleaving‐off amino‐terminal dipeptides with either L‐proline or L‐alanine at the penultimate position. It plays a major role in glucose metabolism by N‐terminal truncation and inactivation of the incretins glucagon‐like peptide‐1 (GLP) and gastric inhibitory protein (GIP). In 2006, DPP4 inhibitors have been introduced to clinics and have been demonstrated to efficiently enhance the endogenous insulin secretion via prolongation of the half‐life of GLP‐1 and GIP in patients. However, a large number of studies demonstrate clearly that CD26/DPP4 also plays an integral role in the immune system, particularly in T cell activation. Therefore, inhibition of DPP4 might represent a double‐edged sword. Apart from the metabolic benefit, the associated immunological effects of long term DPP4 inhibition on regulatory processes such as T cell homeostasis, maturation and activation are not understood fully at this stage. The current data point to an important role for CD26/DPP4 in maintaining lymphocyte composition and function, T cell activation and co‐stimulation, memory T cell generation and thymic emigration patterns during immune‐senescence. In rodents, critical immune changes occur at baseline levels as well as after in‐vitro and in‐vivo challenge. In patients receiving DPP4 inhibitors, evidence of immunological side effects also became apparent. The scope of this review is to recapitulate the role of CD26/DPP4 in the immune system regarding its pharmacological inhibition and T cell‐dependent immune regulation. PMID:26919392

A nomogram to estimate the HbA1c response to different DPP-4 inhibitors in type 2 diabetes: a systematic review and meta-analysis of 98 trials with 24 163 patients

PubMed Central

Esposito, Katherine; Chiodini, Paolo; Maiorino, Maria Ida; Capuano, Annalisa; Cozzolino, Domenico; Petrizzo, Michela; Bellastella, Giuseppe; Giugliano, Dario

2015-01-01

Objectives To develop a nomogram for estimating the glycated haemoglobin (HbA1c) response to different dipeptidyl peptidase-4 (DPP-4) inhibitors in type 2 diabetes. Design A systematic review and meta-analysis of randomised controlled trials (RCTs) of DPP-4 inhibitors (vildagliptin, sitagliptin, saxagliptin, linagliptin and alogliptin) on HbA1c were conducted. Electronic searches were carried out up to December 2013. Trials were included if they were carried out on participants with type 2 diabetes, lasted at least 12 weeks, included at least 30 participants and had a final assessment of HbA1c. A random effect model was used to pool data. A nomogram was used to represent results of the metaregression model. Participants Adults with type 2 diabetes. Interventions Any DPP-4 inhibitor (vildagliptin, sitagliptin, saxagliptin, linagliptin or alogliptin). Outcome measures The HbA1c response to each DPP-4 inhibitor within 1 year of therapy. Results We screened 928 citations and reviewed 98 articles reporting 98 RCTs with 100 arms in 24 163 participants. There were 26 arms with vildagliptin, 37 with sitagliptin, 13 with saxagliptin, 13 with linagliptin and 11 with alogliptin. For all 100 arms, the mean baseline HbA1c value was 8.05% (64 mmol/mol); the decrease of HbA1c from baseline was −0.77% (95% CI −0.82 to −0.72%), with high heterogeneity (I2=96%). Multivariable metaregression model that included baseline HbA1c, type of DPP-4 inhibitor and fasting glucose explained 58% of variance between studies, with no significant interaction between them. Other factors, including age, previous diabetes drugs and duration of treatment added low predictive power (<1%). The nomogram estimates the absolute HbA1c reduction from baseline using the type of DPP-4 inhibitor, baseline values of HbA1c and fasting glucose. Conclusions Baseline HbA1c level and fasting glucose explain most of the variance in HbA1c change in response to DPP-4 inhibitors: each increase of 1.0% units

Pyrrolidine-constrained phenethylamines: The design of potent, selective, and pharmacologically efficacious dipeptidyl peptidase IV (DPP4) inhibitors from a lead-like screening hit.

PubMed

Backes, Bradley J; Longenecker, Kenton; Hamilton, Gregory L; Stewart, Kent; Lai, Chunqiu; Kopecka, Hana; von Geldern, Thomas W; Madar, David J; Pei, Zhonghua; Lubben, Thomas H; Zinker, Bradley A; Tian, Zhenping; Ballaron, Stephen J; Stashko, Michael A; Mika, Amanda K; Beno, David W A; Kempf-Grote, Anita J; Black-Schaefer, Candace; Sham, Hing L; Trevillyan, James M

2007-04-01

A novel series of pyrrolidine-constrained phenethylamines were developed as dipeptidyl peptidase IV (DPP4) inhibitors for the treatment of type 2 diabetes. The cyclohexene ring of lead-like screening hit 5 was replaced with a pyrrolidine to enable parallel chemistry, and protein co-crystal structural data guided the optimization of N-substituents. Employing this strategy, a >400x improvement in potency over the initial hit was realized in rapid fashion. Optimized compounds are potent and selective inhibitors with excellent pharmacokinetic profiles. Compound 30 was efficacious in vivo, lowering blood glucose in ZDF rats that were allowed to feed freely on a mixed meal.

[Research progress of dipeptidyl peptidase 4 inhibitors on healing of chronic diabetic foot ulcers].

PubMed

Gao, Yunyi; Liang, Yujie; Ran, Xingwu

2018-05-01

To review the effect of dipeptidyl peptidase 4 (DPP-4) inhibitors on the wound healing and its mechanisms in chronic diabetic foot ulcers. The latest literature concerning DPP-4 inhibitors for chronic diabetic foot ulcers was extensively reviewed, as well as the potential benefit and mechanism of DPP-4 inhibitors on wound healing of diabetic foot ulcers was analyzed thoroughly. DPP-4 inhibitors can accelerated the ulcer healing. The mechanisms probably include inhibiting the expression of the matrix metalloproteinase (MMP) and restoring the balance of the wound MMP and the tissue inhibitors of MMP; promoting recruitment of endothelial progenitor cells and augmenting angiogenesis; optimizing extracellular matrix construction and the immune response to persistent hypoxia in chronic diabetes wounds, and so on. At present, clinical researches show that DPP-4 inhibitors may be considered as an adjuvant treatment for chronic diabetic foot ulcers. DPP-4 inhibitors show promise in the local wound healing of chronic diabetic foot ulcers. However, more strictly designed, adequately powered, long-term follow-up, and high-quality randomized control trials are needed to further verify their efficacy and safety for chronic diabetic foot ulcers.

In vivo dual-delivery of glucagon like peptide-1 (GLP-1) and dipeptidyl peptidase-4 (DPP4) inhibitor through composites prepared by microfluidics for diabetes therapy

NASA Astrophysics Data System (ADS)

Araújo, F.; Shrestha, N.; Gomes, M. J.; Herranz-Blanco, B.; Liu, D.; Hirvonen, J. J.; Granja, P. L.; Santos, H. A.; Sarmento, B.

2016-05-01

Oral delivery of proteins is still a challenge in the pharmaceutical field. Nanoparticles are among the most promising carrier systems for the oral delivery of proteins by increasing their oral bioavailability. However, most of the existent data regarding nanosystems for oral protein delivery is from in vitro studies, lacking in vivo experiments to evaluate the efficacy of these systems. Herein, a multifunctional composite system, tailored by droplet microfluidics, was used for dual delivery of glucagon like peptide-1 (GLP-1) and dipeptidyl peptidase-4 inhibitor (iDPP4) in vivo. Oral delivery of GLP-1 with nano- or micro-systems has been studied before, but the simultaneous nanodelivery of GLP-1 with iDPP4 is a novel strategy presented here. The type 2 diabetes mellitus (T2DM) rat model, induced through the combined administration of streptozotocin and nicotinamide, a non-obese model of T2DM, was used. The combination of both drugs resulted in an increase in the hypoglycemic effects in a sustained, but prolonged manner, where the iDPP4 improved the therapeutic efficacy of GLP-1. Four hours after the oral administration of the system, blood glucose levels were decreased by 44%, and were constant for another 4 h, representing half of the glucose area under the curve when compared to the control. An enhancement of the plasmatic insulin levels was also observed 6 h after the oral administration of the dual-drug composite system and, although no statistically significant differences existed, the amount of pancreatic insulin was also higher. These are promising results for the oral delivery of GLP-1 to be pursued further in a chronic diabetic model study.

Substituted 4-carboxymethylpyroglutamic acid diamides as potent and selective inhibitors of fibroblast activation protein.

PubMed

Tsai, Ting-Yueh; Yeh, Teng-Kuang; Chen, Xin; Hsu, Tsu; Jao, Yu-Chen; Huang, Chih-Hsiang; Song, Jen-Shin; Huang, Yu-Chen; Chien, Chia-Hui; Chiu, Jing-Huai; Yen, Shih-Chieh; Tang, Hung-Kuan; Chao, Yu-Sheng; Jiaang, Weir-Torn

2010-09-23

Fibroblast activation protein (FAP) belongs to the prolyl peptidase family. FAP inhibition is expected to become a new antitumor target. Most known FAP inhibitors often resemble the dipeptide cleavage products, with a boroproline at the P1 site; however, these inhibitors also inhibit DPP-IV, DPP-II, DPP8, and DPP9. Potent and selective FAP inhibitor is needed in evaluating that FAP as a therapeutic target. Therefore, it is important to develop selective FAP inhibitors for the use of target validation. To achieve this, optimization of the nonselective DPP-IV inhibitor 8 led to the discovery of a new class of substituted 4-carboxymethylpyroglutamic acid diamides as FAP inhibitors. SAR studies resulted in a number of FAP inhibitors having IC(50) of <100 nM with excellent selectivity over DPP-IV, DPP-II, DPP8, and DPP9 (IC(50) > 100 μM). Compounds 18a, 18b, and 19 are the only known potent and selective FAP inhibitors, which prompts us to further study the physiological role of FAP.

Postauthorization safety study of the DPP-4 inhibitor saxagliptin: a large-scale multinational family of cohort studies of five outcomes.

PubMed

Lo Re, Vincent; Carbonari, Dena M; Saine, M Elle; Newcomb, Craig W; Roy, Jason A; Liu, Qing; Wu, Qufei; Cardillo, Serena; Haynes, Kevin; Kimmel, Stephen E; Reese, Peter P; Margolis, David J; Apter, Andrea J; Reddy, K Rajender; Hennessy, Sean; Bhullar, Harshvinder; Gallagher, Arlene M; Esposito, Daina B; Strom, Brian L

2017-01-01

To evaluate the risk of serious adverse events among patients with type 2 diabetes mellitus initiating saxagliptin compared with oral antidiabetic drugs (OADs) in classes other than dipeptidyl peptidase-4 (DPP-4) inhibitors. Cohort studies using 2009-2014 data from two UK medical record data sources (Clinical Practice Research Datalink, The Health Improvement Network) and two USA claims-based data sources (HealthCore Integrated Research Database, Medicare). All eligible adult patients newly prescribed saxagliptin (n=110 740) and random samples of up to 10 matched initiators of non-DPP-4 inhibitor OADs within each data source were selected (n=913 384). Outcomes were hospitalized major adverse cardiovascular events (MACE), acute kidney injury (AKI), acute liver failure (ALF), infections, and severe hypersensitivity events, evaluated using diagnostic coding algorithms and medical records. Cox regression was used to determine HRs with 95% CIs for each outcome. Meta-analyses across data sources were performed for each outcome as feasible. There were no increased incidence rates or risk of MACE, AKI, ALF, infection, or severe hypersensitivity reactions among saxagliptin initiators compared with other OAD initiators within any data source. Meta-analyses demonstrated a reduced risk of hospitalization/death from MACE (HR 0.91, 95% CI 0.85 to 0.97) and no increased risk of hospitalization for infection (HR 0.97, 95% CI 0.93 to 1.02) or AKI (HR 0.99, 95% CI 0.88 to 1.11) associated with saxagliptin initiation. ALF and hypersensitivity events were too rare to permit meta-analysis. Saxagliptin initiation was not associated with increased risk of MACE, infection, AKI, ALF, or severe hypersensitivity reactions in clinical practice settings. NCT01086280, NCT01086293, NCT01086319, NCT01086306, and NCT01377935; Results.

Postauthorization safety study of the DPP-4 inhibitor saxagliptin: a large-scale multinational family of cohort studies of five outcomes

PubMed Central

Carbonari, Dena M; Saine, M Elle; Newcomb, Craig W; Roy, Jason A; Liu, Qing; Wu, Qufei; Cardillo, Serena; Haynes, Kevin; Kimmel, Stephen E; Reese, Peter P; Margolis, David J; Apter, Andrea J; Reddy, K Rajender; Hennessy, Sean; Bhullar, Harshvinder; Gallagher, Arlene M; Esposito, Daina B; Strom, Brian L

2017-01-01

Objective To evaluate the risk of serious adverse events among patients with type 2 diabetes mellitus initiating saxagliptin compared with oral antidiabetic drugs (OADs) in classes other than dipeptidyl peptidase-4 (DPP-4) inhibitors. Research design and methods Cohort studies using 2009–2014 data from two UK medical record data sources (Clinical Practice Research Datalink, The Health Improvement Network) and two USA claims-based data sources (HealthCore Integrated Research Database, Medicare). All eligible adult patients newly prescribed saxagliptin (n=110 740) and random samples of up to 10 matched initiators of non-DPP-4 inhibitor OADs within each data source were selected (n=913 384). Outcomes were hospitalized major adverse cardiovascular events (MACE), acute kidney injury (AKI), acute liver failure (ALF), infections, and severe hypersensitivity events, evaluated using diagnostic coding algorithms and medical records. Cox regression was used to determine HRs with 95% CIs for each outcome. Meta-analyses across data sources were performed for each outcome as feasible. Results There were no increased incidence rates or risk of MACE, AKI, ALF, infection, or severe hypersensitivity reactions among saxagliptin initiators compared with other OAD initiators within any data source. Meta-analyses demonstrated a reduced risk of hospitalization/death from MACE (HR 0.91, 95% CI 0.85 to 0.97) and no increased risk of hospitalization for infection (HR 0.97, 95% CI 0.93 to 1.02) or AKI (HR 0.99, 95% CI 0.88 to 1.11) associated with saxagliptin initiation. ALF and hypersensitivity events were too rare to permit meta-analysis. Conclusions Saxagliptin initiation was not associated with increased risk of MACE, infection, AKI, ALF, or severe hypersensitivity reactions in clinical practice settings. Trial registration number NCT01086280, NCT01086293, NCT01086319, NCT01086306, and NCT01377935; Results. PMID:28878934

Low DPP4 expression and activity in multiple sclerosis.

PubMed

Tejera-Alhambra, Marta; Casrouge, Armanda; de Andrés, Clara; Ramos-Medina, Rocío; Alonso, Bárbara; Vega, Janet; Albert, Matthew L; Sánchez-Ramón, Silvia

2014-02-01

Multiple sclerosis (MS) is a prototypic Th1/Th17 chronic autoimmune disease of the central nervous system. Dipeptidyl peptidase 4 (DPP4 or CD26) is a multifunctional molecule involved in autoimmune diseases' pathophysiology. We sought to integrate disparate pieces of data and analyze the plasma levels of sDPP4, DPP activity and DPP4 surface expression on T-cells in 129 MS patients with different clinical forms and 53 healthy controls, across two independent cohorts. Herein, we provide new evidence that sDPP4 concentration and DPP activity are significantly lower in MS patients than controls (p < 0.0001 and p < 0.01, respectively). In contrast, the frequency of circulating CD8(+)DPP4(hi) T-cells (p = 0.02) was increased in MS patients. This is the first study that simultaneously analyzes DPP4 expression and function in a large cohort of MS patients. Our data indicate a putative role for DPP4 in MS pathophysiology and suggest that a deeper understanding of surface versus shed DPP4 biology is warranted. Copyright © 2013 Elsevier Inc. All rights reserved.

Sitagliptin, a dipeptidyl peptidase-4 inhibitor, improves recognition memory, oxidative stress and hippocampal neurogenesis and upregulates key genes involved in cognitive decline.

PubMed

Gault, V A; Lennox, R; Flatt, P R

2015-04-01

To examine whether prolonged dipeptidyl peptidase-4 (DPP-4) inhibition can reverse learning and memory impairment in high-fat-fed mice. High-fat-fed mice received oral sitagliptin (50 mg/kg body weight) once daily or saline vehicle over 21 days. An additional group of mice on standard chow received saline vehicle. Energy intake, body weight, glucose and insulin concentrations were measured at regular intervals. Glucose tolerance, insulin sensitivity, novel object recognition, DPP-4 activity, hormone analysis, hippocampal gene expression and histology were performed. Sitagliptin decreased circulating DPP-4 activity and improved glucose tolerance, glucose-stimulated insulin secretion and insulin sensitivity, and reduced plasma triglycerides and cholesterol levels. DPP-4 inhibition improved recognition memory (1.2-fold increase) without affecting hypermoteric activity or anxiety levels. Improvement in memory and learning was linked to reduced immunostaining for 8-oxoguanine and increased doublecortin staining in the hippocampus, which were indicative of reduced brain oxidative stress and increased hippocampal neurogenesis, respectively. These effects were associated with significant upregulation of hippocampal gene expression of glucagon-like peptide-1 (GLP-1) receptor, glucose-dependent insulinotropic polypeptide receptor, synaptophysin, sirtuin 1, glycogen synthase kinase 3β, superdioxide mutase 2, nuclear factor (erythroid-derived 2)-like 2 and vascular endothelial growth factor. Total plasma and brain GLP-1 concentrations were significantly increased after sitagliptin therapy, whereas DPP-4 activity in brain tissue was not altered. These studies show that sitagliptin can reverse memory impairment in high-fat-fed mice and is also associated with improved insulin sensitivity, enhanced hippocampal neurogenesis and reduced oxidative stress. DPP-4 inhibitors may therefore exhibit dual benefits by improving metabolic control and reducing the decline in cognitive

Changes in Adenosine Deaminase Activity in Patients with Type 2 Diabetes Mellitus and Effect of DPP-4 Inhibitor Treatment on ADA Activity.

PubMed

Lee, Jae-Geun; Kang, Dong Gu; Yu, Jung Re; Kim, Youngree; Kim, Jinsoek; Koh, Gwanpyo; Lee, Daeho

2011-04-01

Dipeptidyl peptidase 4 (DPP-4, also known as CD26) binds with adenosine deaminase (ADA) to activate T lymphocytes. Here, we investigated whether ADA activity is specifically affected by treatment with DPP-4 inhibitor (DPP4I) compared with other anti-diabetic agents. Fasting ADA activity, in addition to various metabolic and biochemical parameters, were measured in 262 type 2 diabetes mellitus (T2DM) patients taking various anti-diabetic agents and in 46 non-diabetic control subjects. ADA activity was increased in T2DM patients compared with that in non-diabetic control subjects (mean±standard error, 23.1±0.6 U/L vs. 18.6±0.8 U/L; P<0.05). ADA activity was correlated with fasting plasma glucose (r=0.258, P<0.05), HbA1c (r=0.208, P<0.05), aspartate aminotransferase (r=0.325, P<0.05), and alanine aminotransferase (r=0.248, P<0.05). Compared with the well-controlled T2DM patients (HbA1c<7%), the poorly controlled group (HbA1c>9%) showed significantly increased ADA activity (21.1±0.8 U/L vs. 25.4±1.6 U/L; P<0.05). The effect of DPP4I on ADA activity in T2DM patients did not differ from those of other oral anti-diabetic agents or insulin. T2DM patients on metformin monotherapy showed a lower ADA activity (20.9±1.0 U/L vs. 28.1±2.8 U/L; P<0.05) compared with that of those on sulfonylurea monotherapy. Our results show that ADA activity is increased in T2DM patients compared to that in non-diabetic patients, is positively correlated with blood glucose level, and that DPP4I has no additional specific effect on ADA activity, except for a glycemic control- or HbA1c-dependent effect.

Changes in Adenosine Deaminase Activity in Patients with Type 2 Diabetes Mellitus and Effect of DPP-4 Inhibitor Treatment on ADA Activity

PubMed Central

Lee, Jae-Geun; Kang, Dong Gu; Yu, Jung Re; Kim, Youngree; Kim, Jinsoek; Koh, Gwanpyo

2011-01-01

Background Dipeptidyl peptidase 4 (DPP-4, also known as CD26) binds with adenosine deaminase (ADA) to activate T lymphocytes. Here, we investigated whether ADA activity is specifically affected by treatment with DPP-4 inhibitor (DPP4I) compared with other anti-diabetic agents. Methods Fasting ADA activity, in addition to various metabolic and biochemical parameters, were measured in 262 type 2 diabetes mellitus (T2DM) patients taking various anti-diabetic agents and in 46 non-diabetic control subjects. Results ADA activity was increased in T2DM patients compared with that in non-diabetic control subjects (mean±standard error, 23.1±0.6 U/L vs. 18.6±0.8 U/L; P<0.05). ADA activity was correlated with fasting plasma glucose (r=0.258, P<0.05), HbA1c (r=0.208, P<0.05), aspartate aminotransferase (r=0.325, P<0.05), and alanine aminotransferase (r=0.248, P<0.05). Compared with the well-controlled T2DM patients (HbA1c<7%), the poorly controlled group (HbA1c>9%) showed significantly increased ADA activity (21.1±0.8 U/L vs. 25.4±1.6 U/L; P<0.05). The effect of DPP4I on ADA activity in T2DM patients did not differ from those of other oral anti-diabetic agents or insulin. T2DM patients on metformin monotherapy showed a lower ADA activity (20.9±1.0 U/L vs. 28.1±2.8 U/L; P<0.05) compared with that of those on sulfonylurea monotherapy. Conclusion Our results show that ADA activity is increased in T2DM patients compared to that in non-diabetic patients, is positively correlated with blood glucose level, and that DPP4I has no additional specific effect on ADA activity, except for a glycemic control- or HbA1c-dependent effect. PMID:21738897

Dipeptidyl Peptidase-4 Inhibitor-Associated Pancreatic Carcinoma: A Review of the FAERS Database.

PubMed

Nagel, Angela K; Ahmed-Sarwar, Nabila; Werner, Paul M; Cipriano, Gabriela C; Van Manen, Robbert P; Brown, Jack E

2016-01-01

To date, there is limited literature regarding the association between dipeptidyl peptidase-4 (DPP-4) inhibitors and pancreatic carcinoma. To describe the comparative incidence of DPP-4 inhibitors and pancreatic carcinoma as reportedly available in the Food and Drug Administration (FDA) Adverse Event Reporting System (FAERS) database. The goal was to provide health care practitioners a general understanding of the drug-disease occurrence. This is a case/noncase study utilizing Empirica Signal software to query FAERS from November 1968 to December 31, 2013. The software was used to calculate a disproportionality statistic--namely, the empirical Bayesian geometric mean (EBGM)--for reports of DPP-4 inhibitors-associated pancreatic carcinoma. The FDA considers an EBGM significant if the fifth percentile of the distribution is at least 2, defined as an EB05 ≥ 2. With use of a disproportionality analysis, DPP-4 inhibitors were compared with all agents listed in FAERS. A total of 156 patients experienced pancreatic carcinoma while receiving DPP-4 inhibitor therapy. An EB05 of 10.3 was determined for sitagliptin, 7.1 for saxagliptin, 4.9 for linagliptin, and 1.4 for alogliptin, compared with all other agents included in FAERS. Although an EB05 > 2 was achieved in 2 other antihyperglycemic agents, the findings were not consistent within their medication classes. There appears to be a statistical association between DPP-4 inhibitor use and pancreatic carcinoma. Causality cannot be inferred from the data provided. Additional clinical studies are needed to further explore this statistical association. © The Author(s) 2015.

Wound healing effects of dipeptidyl peptidase-4 inhibitors: An emerging concept in management of diabetic foot ulcer-A review.

PubMed

Saboo, Apoorva; Rathnayake, Ayeshmanthe; Vangaveti, Venkat N; Malabu, Usman H

2016-01-01

Dipeptidyl peptidase-4 (DPP-4) inhibitors have a well-known effect on glycaemic control in patients with diabetes but little is known on their wound healing role in this group of population. This paper reviews the effects of DPP-4 inhibitors on wound healing of diabetic foot ulcers. Published data on effects and mechanism of DDP-4 inhibitors on wound healing were derived from Medline, PubMed and Google Scholar search of English language literature from 1994 to 2014 using the key words such as "DPP-4 inhibitors", "endothelial healing" "diabetes" and "chronic ulcers". DPP-4 inhibitors show a potential benefit in processes of wound healing in diabetic chronic foot ulcers. The enzyme inhibitors promote recruitment of endothelial progenitor cells and allow the final scaffolding of wounds. Furthermore DPP-4 inhibitors augment angiogenesis and have widespread effects on optimising the immune response to persistent hypoxia in chronic diabetes wounds. DPP-4 inhibitors show promise in the local wound healing of diabetic foot ulcers in addition to its already established glycaemic control. In the light of high rate of amputations due to non-healing ulcers with profound psychological and economical liability, more investigations on the usefulness of DPP-4 inhibitors in the high risk diabetes population are needed. Copyright © 2015 Diabetes India. Published by Elsevier Ltd. All rights reserved.

Recent progress of the development of dipeptidyl peptidase-4 inhibitors for the treatment of type 2 diabetes mellitus.

PubMed

Li, Ning; Wang, Li-Jun; Jiang, Bo; Li, Xiang-Qian; Guo, Chuan-Long; Guo, Shu-Ju; Shi, Da-Yong

2018-05-10

Diabetes is a fast growing chronic metabolic disorder around the world. Dipeptidyl peptidase-4 (DPP-4) is a new promising target during type 2 diabetes glycemic control. Thus, a number of potent DPP-4 inhibitors were developed and play a rapidly evolving role in the management of type 2 diabetes in recent years. This article reviews the development of synthetic and natural DPP-4 inhibitors from 2012 to 2017 and provides their physico-chemical properties, biological activities against DPP-4 and selectivity over dipeptidyl peptidase-8/9. Moreover, the glucose-lowering mechanisms and the active site of DPP-4 are also discussed. We also discuss strategies and structure-activity relationships for identifying potent DPP-4 inhibitors, which will provide useful information for developing potent DPP-4 drugs as type 2 diabtes treatments. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

A Common Susceptibility Gene for Type 2 Diabetes Is Associated with Drug Response to a DPP-4 Inhibitor: Pharmacogenomic Cohort in Okinawa Japan.

PubMed

Osada, Uru Nezu; Sunagawa, Hiroshi; Terauchi, Yasuo; Ueda, Shinichiro

2016-01-01

We investigated the association between common type 2 susceptibility variants of CDK5 regulatory subunit associated protein 1-like 1(CDKAL1) and therapeutic responses to anti-diabetic agents among patients with type 2 diabetes. Two SNPs (rs7754840: C>G, rs7756992: A>G) were genotyped via the Taqman PCR method. A total of 798 type 2 diabetic patients were included. HbA1c reduction after use of DPP-4 inhibitors for 3 months was significantly greater in patients with a risk allele for type 2 diabetes (GG -0.4%, CG -0.5%, CC -0.8%, p = 0.02 for rs7754840 and AA -0.4%, AG -0.5%, GG -0.8%, p = 0.01 for rs7756992). Linear regression analysis showed that per allele reductions of hemoglobin A1c (HbA1c) after 3 months were -0.10% for rs7754840 (p = 0.02) and -0.13% for rs7756992 (p = 0.0008) after adjusting for clinically influential covariates such as age, sex, BMI, duration of diabetes, baseline HbA1c and concomitant anti-diabetic agents. The results suggested that common variants of CDKAL1 are associated with therapeutic response to DPP-4 inhibitors.

Discovery of DPP IV inhibitors by pharmacophore modeling and QSAR analysis followed by in silico screening.

PubMed

Al-Masri, Ihab M; Mohammad, Mohammad K; Taha, Mutasem O

2008-11-01

Dipeptidyl peptidase IV (DPP IV) deactivates the natural hypoglycemic incretin hormones. Inhibition of this enzyme should restore glucose homeostasis in diabetic patients making it an attractive target for the development of new antidiabetic drugs. With this in mind, the pharmacophoric space of DPP IV was explored using a set of 358 known inhibitors. Thereafter, genetic algorithm and multiple linear regression analysis were employed to select an optimal combination of pharmacophoric models and physicochemical descriptors that yield selfconsistent and predictive quantitative structure-activity relationships (QSAR) (r(2) (287)=0.74, F-statistic=44.5, r(2) (BS)=0.74, r(2) (LOO)=0.69, r(2) (PRESS) against 71 external testing inhibitors=0.51). Two orthogonal pharmacophores (of cross-correlation r(2)=0.23) emerged in the QSAR equation suggesting the existence of at least two distinct binding modes accessible to ligands within the DPP IV binding pocket. Docking experiments supported the binding modes suggested by QSAR/pharmacophore analyses. The validity of the QSAR equation and the associated pharmacophore models were established by the identification of new low-micromolar anti-DPP IV leads retrieved by in silico screening. One of our interesting potent anti-DPP IV hits is the fluoroquinolone gemifloxacin (IC(50)=1.12 muM). The fact that gemifloxacin was recently reported to potently inhibit the prodiabetic target glycogen synthase kinase 3beta (GSK-3beta) suggests that gemifloxacin is an excellent lead for the development of novel dual antidiabetic inhibitors against DPP IV and GSK-3beta.

Inadequate Triglyceride Management Worsens the Durability of Dipeptidyl Peptidase-4 Inhibitor in Subjects with Type 2 Diabetes Mellitus.

PubMed

Shimoda, Masashi; Miyoshi-Takai, Maiko; Irie, Shintaro; Tanabe, Akihito; Obata, Atsushi; Okauchi, Seizo; Hirukawa, Hidenori; Kimura, Tomohiko; Kohara, Kenji; Kamei, Shinji; Mune, Tomoatsu; Kaku, Kohei; Kaneto, Hideaki

2017-01-01

Dipeptidyl peptidase-4 (DPP-4) inhibitors are often used all over the world and exert various beneficial effects including glucose-lowering effect in many subjects with type 2 diabetes. It is poorly understood, however, which factors are closely related with the durability of glucose-lowering effect by DPP-4 inhibitor. In this study, we examined retrospectively which factors could mainly influence the durability of DPP-4 inhibitor. We enrolled 212 participants with type 2 diabetes to whom DPP-4 inhibitor was administered for over 1 year without an addition or increase of other hypoglycemic agents. Age and baseline HbA1c level were significantly higher in the effective group than those in the ineffective group. The effective group had a tendency of smaller amounts of weight change, average total cholesterol, and average triglyceride compared with the ineffective group. Multiple logistic regression analysis showed that average triglyceride and baseline HbA1c were independent predictors associated with the durability of DPP-4 inhibitor. Moreover, an average triglyceride level contributed to the durability of DPP-4 inhibitor in the obese group (BMI ≥ 25 kg/m 2 ) but not in the nonobese group (BMI < 25 kg/m 2 ). These results suggest the importance of strict triglyceride management to maintain the durability of glucose-lowering effect by DPP-4 inhibitor, especially in obese subjects with type 2 diabetes.

Visceral fat obesity increases serum DPP-4 levels in men with type 2 diabetes mellitus.

PubMed

Tanaka, Sayuri; Kanazawa, Ippei; Notsu, Masakazu; Sugimoto, Toshitsugu

2016-06-01

The relationship between serum DPP-4 level and visceral fat mass is still unclear in type 2 diabetes mellitus (T2DM). This study thus aimed to examine the association of visceral fat accumulation and metabolic syndrome with serum DPP-4 levels in T2DM. Visceral and subcutaneous fat areas were evaluated by performing computed tomography scan in 135 men with T2DM, who had never taken DPP-4 inhibitors or GLP-1 receptor agonists. We investigated the association between serum DPP-4 levels and visceral fat area as well as the presence of metabolic syndrome. Multiple regression analysis adjusted for age, duration of T2DM, body mass index, serum creatinine, and HbA1c showed that serum DPP-4 levels were positively associated with visceral fat area (β=0.25, p=0.04), but not subcutaneous fat area (β=-0.18, p=0.13). In logistic regression analyses adjusted for the confounding factors described above, serum DPP-4 levels were positively associated with visceral fat obesity and metabolic syndrome [odds ratio (OR)=1.63, 95% confidence interval (CI)=1.00-2.66 per standard deviation (SD) increase, p=0.04; OR=1.77, 95%CI=1.09-2.88 per SD increase, p=0.02, respectively]. The present study showed that serum DPP-4 level was positively and specifically associated with accumulation of visceral fat and the presence of metabolic syndrome in men with T2DM. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Cardiac DPP-4 inhibition by saxagliptin ameliorates isoproterenol-induced myocardial remodeling and cardiac diastolic dysfunction in rats.

PubMed

Ikeda, Junichi; Kimoto, Naoya; Kitayama, Tetsuya; Kunori, Shunji

2016-09-01

Saxagliptin, a potent and selective DPP-4 inhibitor, is characterized by its slow dissociation from DPP-4 and its long half-life and is expected to have a potent tissue membrane-bound DPP-4-inhibitory effect in various tissues. In the present study, we examined the effects of saxagliptin on in situ cardiac DPP-4 activity. We also examined the effects of saxagliptin on isoproterenol-induced the changes in the early stage such as, myocardial remodeling and cardiac diastolic dysfunction. Male SD rats treated with isoproterenol (1 mg/kg/day via osmotic pump) received vehicle or saxagliptin (17.5 mg/kg via drinking water) for 2 weeks. In situ cardiac DPP-4 activity was measured by a colorimetric assay. Cardiac gene expressions were examined and an echocardiographic analysis was performed. Saxagliptin treatment significantly inhibited in situ cardiac DPP-4 activity and suppressed isoproterenol-induced myocardial remodeling and the expression of related genes without altering the blood glucose levels. Saxagliptin also significantly ameliorated cardiac diastolic dysfunction in isoproterenol-treated rats. In conclusion, the inhibition of DPP-4 activity in cardiac tissue by saxagliptin was associated with suppression of myocardial remodeling and cardiac diastolic dysfunction independently of its glucose-lowering action in isoproterenol-treated rats. Cardiac DPP-4 activity may contribute to myocardial remodeling in the development of heart failure. Copyright © 2016 Kyowa Hakko Kirin Co.,Ltd. Production and hosting by Elsevier B.V. All rights reserved.

Dipeptidyl peptidase-4 inhibitor ameliorates early renal injury through its anti-inflammatory action in a rat model of type 1 diabetes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kodera, Ryo, E-mail: kodera@cc.okayama-u.ac.jp; Shikata, Kenichi; Department of Medicine and Clinical Science, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Kita-ku, Okayama 700-8558

Highlights: •DPP-4 inhibitor decreased urinary albumin excretion in a rat of type 1 diabetes. •DPP-4 inhibitor ameliorated histlogical changes of diabetic nephropathy. •DPP-4 inhibitor has reno-protective effects through anti-inflammatory action. •DPP-4 inhibitor is beneficial on diabetic nephropathy besides lowering blood glucose. -- Abstract: Introduction: Dipeptidyl peptidase-4 (DPP-4) inhibitors are incretin-based drugs in patients with type 2 diabetes. In our previous study, we showed that glucagon-like peptide-1 (GLP-1) receptor agonist has reno-protective effects through anti-inflammatory action. The mechanism of action of DPP-4 inhibitor is different from that of GLP-1 receptor agonists. It is not obvious whether DPP-4 inhibitor prevents the exacerbationmore » of diabetic nephropathy through anti-inflammatory effects besides lowering blood glucose or not. The purpose of this study is to clarify the reno-protective effects of DPP-4 inhibitor through anti-inflammatory actions in the early diabetic nephropathy. Materials and methods: Five-week-old male Sprague–Dawley (SD) rats were divided into three groups; non-diabetes, diabetes and diabetes treated with DPP-4 inhibitor (PKF275-055; 3 mg/kg/day). PKF275-055 was administered orally for 8 weeks. Results: PKF275-055 increased the serum active GLP-1 concentration and the production of urinary cyclic AMP. PKF275-055 decreased urinary albumin excretion and ameliorated histological change of diabetic nephropathy. Macrophage infiltration was inhibited, and inflammatory molecules were down-regulated by PKF275-055 in the glomeruli. In addition, nuclear factor-κB (NF-κB) activity was suppressed in the kidney. Conclusions: These results indicate that DPP-4 inhibitor, PKF275-055, have reno-protective effects through anti-inflammatory action in the early stage of diabetic nephropathy. The endogenous biological active GLP-1 might be beneficial on diabetic nephropathy besides lowering blood glucose.« less

Unravelling the immunological roles of dipeptidyl peptidase 4 (DPP4) activity and/or structure homologue (DASH) proteins

PubMed Central

Klemann, C.; Stephan, M.

2016-01-01

Summary Dipeptidyl peptidase (DPP) 4 (CD26, DPP4) is a multi‐functional protein involved in T cell activation by co‐stimulation via its association with adenosine deaminase (ADA), caveolin‐1, CARMA‐1, CD45, mannose‐6‐phosphate/insulin growth factor‐II receptor (M6P/IGFII‐R) and C‐X‐C motif receptor 4 (CXC‐R4). The proline‐specific dipeptidyl peptidase also modulates the bioactivity of several chemokines. However, a number of enzymes displaying either DPP4‐like activities or representing structural homologues have been discovered in the past two decades and are referred to as DPP4 activity and/or structure homologue (DASH) proteins. Apart from DPP4, DASH proteins include fibroblast activation protein alpha (FAP), DPP8, DPP9, DPP4‐like protein 1 (DPL1, DPP6, DPPX L, DPPX S), DPP4‐like protein 2 (DPL2, DPP10) from the DPP4‐gene family S9b and structurally unrelated enzyme DPP2, displaying DPP4‐like activity. In contrast, DPP6 and DPP10 lack enzymatic DPP4‐like activity. These DASH proteins play important roles in the immune system involving quiescence (DPP2), proliferation (DPP8/DPP9), antigen‐presenting (DPP9), co‐stimulation (DPP4), T cell activation (DPP4), signal transduction (DPP4, DPP8 and DPP9), differentiation (DPP4, DPP8) and tissue remodelling (DPP4, FAP). Thus, they are involved in many pathophysiological processes and have therefore been proposed for potential biomarkers or even drug targets in various cancers (DPP4 and FAP) and inflammatory diseases (DPP4, DPP8/DPP9). However, they also pose the challenge of drug selectivity concerning other DASH members for better efficacy and/or avoidance of unwanted side effects. Therefore, this review unravels the complex roles of DASH proteins in immunology. PMID:26671446

In silico approaches to predict the potential of milk protein-derived peptides as dipeptidyl peptidase IV (DPP-IV) inhibitors.

PubMed

Nongonierma, Alice B; Mooney, Catherine; Shields, Denis C; FitzGerald, Richard J

2014-07-01

Molecular docking of a library of all 8000 possible tripeptides to the active site of DPP-IV was used to determine their binding potential. A number of tripeptides were selected for experimental testing, however, there was no direct correlation between the Vina score and their in vitro DPP-IV inhibitory properties. While Trp-Trp-Trp, the peptide with the best docking score, was a moderate DPP-IV inhibitor (IC50 216μM), Lineweaver and Burk analysis revealed its action to be non-competitive. This suggested that it may not bind to the active site of DPP-IV as assumed in the docking prediction. Furthermore, there was no significant link between DPP-IV inhibition and the physicochemical properties of the peptides (molecular mass, hydrophobicity, hydrophobic moment (μH), isoelectric point (pI) and charge). LIGPLOTs indicated that competitive inhibitory peptides were predicted to have both hydrophobic and hydrogen bond interactions with the active site of DPP-IV. DPP-IV inhibitory peptides generally had a hydrophobic or aromatic amino acid at the N-terminus, preferentially a Trp for non-competitive inhibitors and a broader range of residues for competitive inhibitors (Ile, Leu, Val, Phe, Trp or Tyr). Two of the potent DPP-IV inhibitors, Ile-Pro-Ile and Trp-Pro (IC50 values of 3.5 and 44.2μM, respectively), were predicted to be gastrointestinally/intestinally stable. This work highlights the needs to test the assumptions (i.e. competitive binding) of any integrated strategy of computational and experimental screening, in optimizing screening. Future strategies targeting allosteric mechanisms may need to rely more on structure-activity relationship modeling, rather than on docking, in computationally selecting peptides for screening. Copyright © 2014 Elsevier Inc. All rights reserved.

Design and synthesis of aminocoumarin derivatives as DPP-IV inhibitors and anticancer agents.

PubMed

Soni, Rina; Soman, Shubhangi S

2018-09-01

DPP-IV "a moonlighting protein" has immerged as promising pathway to control Type 2 diabetes as well as found to play key role in earlier stages of cancer. Here we have reported design, synthesis and applications of aminocoumarin derivatives as DPP-IV inhibitors. Compounds have been synthesized and studied for their DPP-IV inhibition activity. Three compounds have shown moderate inhibition at 100 µM concentration. All compounds were also screened for their anticancer activity against A549 (Lung cancer cell line), MCF-7 (Breast cancer cell line) using MTT assay. One of the compounds has shown very good anticancer activity with IC 50 value 24 ± 0.1 nM against A549 cell line. Copyright © 2018 Elsevier Inc. All rights reserved.

Head-to-head comparison of structurally unrelated dipeptidyl peptidase 4 inhibitors in the setting of renal ischemia reperfusion injury.

PubMed

Reichetzeder, Christoph; von Websky, Karoline; Tsuprykov, Oleg; Mohagheghi Samarin, Azadeh; Falke, Luise Gabriele; Dwi Putra, Sulistyo Emantoko; Hasan, Ahmed Abdallah; Antonenko, Viktoriia; Curato, Caterina; Rippmann, Jörg; Klein, Thomas; Hocher, Berthold

2017-07-01

Results regarding protective effects of dipeptidyl peptidase 4 (DPP4) inhibitors in renal ischaemia-reperfusion injury (IRI) are conflicting. Here we have compared structurally unrelated DPP4 inhibitors in a model of renal IRI. IRI was induced in uninephrectomized male rats by renal artery clamping for 30 min. The sham group was uninephrectomized but not subjected to IRI. DPP4 inhibitors or vehicle were given p.o. once daily on three consecutive days prior to IRI: linagliptin (1.5 mg·kg -1 ·day -1 ), vildagliptin (8 mg·kg -1 ·day -1 ) and sitagliptin (30 mg·kg -1 ·day -1 ). An additional group received sitagliptin until study end (before IRI: 30 mg·kg -1 ·day -1 ; after IRI: 15 mg·kg -1 ·day -1 ). Plasma-active glucagon-like peptide type 1 (GLP-1) increased threefold to fourfold in all DPP4 inhibitor groups 24 h after IRI. Plasma cystatin C, a marker of GFR, peaked 48 h after IRI. Compared with the placebo group, DPP4 inhibition did not reduce increased plasma cystatin C levels. DPP4 inhibitors ameliorated histopathologically assessed tubular damage with varying degrees of drug-specific efficacies. Renal osteopontin expression was uniformly reduced by all DPP4 inhibitors. IRI-related increased renal cytokine expression was not decreased by DPP4 inhibition. Renal DPP4 activity at study end was significantly inhibited in the linagliptin group, but only numerically reduced in the prolonged/dose-adjusted sitagliptin group. Active GLP-1 plasma levels at study end were increased only in the prolonged/dose-adjusted sitagliptin treatment group. In rats with renal IRI, DPP4 inhibition did not alter plasma cystatin C, a marker of glomerular function, but may protect against tubular damage. © 2017 The Authors. British Journal of Pharmacology published by John Wiley & Sons Ltd on behalf of British Pharmacological Society.

Design and Elaboration of a Tractable Tricyclic Scaffold To Synthesize Druglike Inhibitors of Dipeptidyl Peptidase-4 (DPP-4), Antagonists of the C-C Chemokine Receptor Type 5 (CCR5), and Highly Potent and Selective Phosphoinositol-3 Kinase δ (PI3Kδ) Inhibitors.

PubMed

Schwehm, Carolin; Kellam, Barrie; Garces, Aimie E; Hill, Stephen J; Kindon, Nicholas D; Bradshaw, Tracey D; Li, Jin; Macdonald, Simon J F; Rowedder, James E; Stoddart, Leigh A; Stocks, Michael J

2017-02-23

A novel molecular scaffold has been synthesized, and its incorporation into new analogues of biologically active molecules across multiple target classes will be discussed. In these studies, we have shown use of the tricyclic scaffold to synthesize potent inhibitors of the serine peptidase DPP-4, antagonists of the CCR5 receptor, and highly potent and selective PI3K δ isoform inhibitors. We also describe the predicted physicochemical properties of the resulting inhibitors and conclude that the tractable molecular scaffold could have potential application in future drug discovery programs.

The dipeptidyl peptidase-4 inhibitor Saxagliptin improves function of circulating pro-angiogenic cells from type 2 diabetic patients

PubMed Central

2014-01-01

Background Type 2 diabetes (T2D) is associated with reduction and dysfunction of circulating pro-angiogenic cells (PACs). DPP-4 inhibitors, a class of oral agents for T2D, might possess pleiotropic vasculoprotective activities. Herein, we tested whether DPP-4 inhibition with Saxagliptin affects the function of circulating PACs from T2D and healthy subjects. Methods PACs were isolated from T2D (n = 20) and healthy (n = 20) subjects. Gene expression, clonogenesis, proliferation, adhesion, migration and tubulisation were assessed in vitro by incubating PACs with or without Saxagliptin and SDF-1α. Stimulation of angiogenesis by circulating cells from T2D patients treated with Saxagliptin or other non-incretinergic drugs was assessed in vivo using animal models. Results Soluble DPP-4 activity was predominant over cellular activity and was successfully inhibited by Saxagliptin. At baseline, T2D compared to healthy PACs contained less acLDL+Lectin+ cells, and showed altered expression of genes related to adhesion and cell cycle regulation. This was reflected by impaired adhesion and clonogenesis/proliferative response of T2D PACs. Saxagliptin + SDF-1α improved adhesion and tube sustaining capacity of PACs from T2D patients. CD14+ PACs were more responsive to Saxagliptin than CD14- PACs. While Saxagliptin modestly reduced angiogenesis by mature endothelial cells, circulating PACs-progeny cells from T2D patients on Saxagliptin treatment displayed higher growth factor-inducible in vivo angiogenetic activity, compared to cells from T2D patients on non-incretinergic regimen. Conclusions Saxagliptin reverses PACs dysfunction associated with T2D in vitro and improves inducible angiogenesis by circulating cells in vivo. These data add knowledge to the potential pleiotropic cardiovascular effects of DPP-4 inhibition. PMID:24886621

The dipeptidyl peptidase-4 inhibitor saxagliptin improves function of circulating pro-angiogenic cells from type 2 diabetic patients.

PubMed

Poncina, Nicol; Albiero, Mattia; Menegazzo, Lisa; Cappellari, Roberta; Avogaro, Angelo; Fadini, Gian Paolo

2014-05-14

Type 2 diabetes (T2D) is associated with reduction and dysfunction of circulating pro-angiogenic cells (PACs). DPP-4 inhibitors, a class of oral agents for T2D, might possess pleiotropic vasculoprotective activities. Herein, we tested whether DPP-4 inhibition with Saxagliptin affects the function of circulating PACs from T2D and healthy subjects. PACs were isolated from T2D (n = 20) and healthy (n = 20) subjects. Gene expression, clonogenesis, proliferation, adhesion, migration and tubulisation were assessed in vitro by incubating PACs with or without Saxagliptin and SDF-1α. Stimulation of angiogenesis by circulating cells from T2D patients treated with Saxagliptin or other non-incretinergic drugs was assessed in vivo using animal models. Soluble DPP-4 activity was predominant over cellular activity and was successfully inhibited by Saxagliptin. At baseline, T2D compared to healthy PACs contained less acLDL(+)Lectin(+) cells, and showed altered expression of genes related to adhesion and cell cycle regulation. This was reflected by impaired adhesion and clonogenesis/proliferative response of T2D PACs. Saxagliptin + SDF-1α improved adhesion and tube sustaining capacity of PACs from T2D patients. CD14+ PACs were more responsive to Saxagliptin than CD14- PACs. While Saxagliptin modestly reduced angiogenesis by mature endothelial cells, circulating PACs-progeny cells from T2D patients on Saxagliptin treatment displayed higher growth factor-inducible in vivo angiogenetic activity, compared to cells from T2D patients on non-incretinergic regimen. Saxagliptin reverses PACs dysfunction associated with T2D in vitro and improves inducible angiogenesis by circulating cells in vivo. These data add knowledge to the potential pleiotropic cardiovascular effects of DPP-4 inhibition.

E3024, 3-but-2-ynyl-5-methyl-2-piperazin-1-yl-3,5-dihydro-4H-imidazo[4,5-d]pyridazin-4-one tosylate, is a novel, selective and competitive dipeptidyl peptidase-IV inhibitor.

PubMed

Yasuda, Nobuyuki; Nagakura, Tadashi; Inoue, Takashi; Yamazaki, Kazuto; Katsutani, Naruo; Takenaka, Osamu; Clark, Richard; Matsuura, Fumiyoshi; Emori, Eita; Yoshikawa, Seiji; Kira, Kazunobu; Ikuta, Hironori; Okada, Toshimi; Saeki, Takao; Asano, Osamu; Tanaka, Isao

2006-10-24

Dipeptidyl peptidase IV (DPP-IV) inhibitors are expected to become a useful new class of anti-diabetic agent. The aim of the present study is to characterize the in vitro and in vivo profile of E3024, 3-but-2-ynyl-5-methyl-2-piperazin-1-yl-3,5-dihydro-4H-imidazo[4,5-d]pyridazin-4-one tosylate, which is a novel imidazopyridazinone-derived DPP-IV inhibitor. E3024 inhibited recombinant human and mouse DPP-IV with IC50 values of approximately 100 nM. E3024 inhibited DPP-IV in human, mouse, rat and canine plasma with IC50 values of 140 to 400 nM. In contrast, E3024 did not inhibit DPP-8 or DPP-9 activity. Kinetic analysis indicated that E3024 is a competitive DPP-IV inhibitor. In Zucker fa/fa rats, E3024 (1 mg/kg) reduced glucose excursion after glucose load, with increases in plasma insulin and active glucagon-like peptide-1 levels. In fasted rats, this compound did not cause hypoglycemia. In a rat 4-week toxicological study, no notable changes were found at doses up to 750 mg/kg. The present preclinical studies indicate that E3024 is a novel selective DPP-IV inhibitor with anti-diabetic effects and a good safety profile.

Hemoglobin glycation index as a useful predictor of therapeutic responses to dipeptidyl peptidase-4 inhibitors in patients with type 2 diabetes

PubMed Central

Chen, Yu-Wei; Wang, Jun-Sing; Sheu, Wayne H-H; Lin, Shih-Yi; Lee, I-Te; Song, Yuh-Min; Fu, Chia-Po; Lee, Chia-Lin

2017-01-01

Introduction A high hemoglobin glycation index (HGI) and glycated hemoglobin (HbA1c) level are associated with greater inflammatory status, and dipeptidyl peptidase-4 (DPP-4) inhibitors can suppress inflammation. We aimed to evaluate the relationship between HGI and the therapeutic effect of DPP-4 inhibitors. Methods This retrospective cohort study followed 468 patients with type 2 diabetes receiving DPP-4 inhibitor treatment for 1 year. Estimated HbA1c was calculated using a linear regression equation derived from another 2969 randomly extracted patients with type 2 diabetes based on fasting plasma glucose (FPG) level. The subjects were divided into two groups based on HGI (HGI = observed HbA1c - estimated HbA1c). Mixed model repeated measures were used to compare the treatment efficacy after 1 year in patients with a low (HGI<0, n = 199) and high HGI (HGI≧0, n = 269). Results There were no significant group differences in mean changes of FPG after 1 year (-12.8 and -13.4 mg/dL in the low and high HGI groups, respectively). However, the patients with a high HGI had a significantly greater reduction in HbA1c from baseline compared to those with a low HGI (-1.9 versus -0.3% [-20.8 versus -3.3 mmol/mol]). Improvements in glycemic control were statistically significantly associated with the tested DPP-4 inhibitors in the high HGI group (-2.4, -1.4, -1.2 and -2.2% [-26.2, -15.3, -13.1 and -24.0 mmol/mol] for vildagliptin, linagliptin, saxagliptin and sitagliptin, respectively) but not in the low HGI group. Conclusions The HGI index derived from FPG and HbA1c may be able to identify who will have a better response to DPP-4 inhibitors. PMID:28182722

Structures of Human DPP7 Reveal the Molecular Basis of Specific Inhibition and the Architectural Diversity of Proline-Specific Peptidases

PubMed Central

Dong, Aiping; Seitova, Almagul; Crombett, Lissete; Shewchuk, Lisa M.; Hassell, Annie M.; Sweitzer, Sharon M.; Sweitzer, Thomas D.; McDevitt, Patrick J.; Johanson, Kyung O.; Kennedy-Wilson, Karen M.; Cossar, Doug; Bochkarev, Alexey; Gruber, Karl; Dhe-Paganon, Sirano

2012-01-01

Proline-specific dipeptidyl peptidases (DPPs) are emerging targets for drug development. DPP4 inhibitors are approved in many countries, and other dipeptidyl peptidases are often referred to as DPP4 activity- and/or structure-homologues (DASH). Members of the DASH family have overlapping substrate specificities, and, even though they share low sequence identity, therapeutic or clinical cross-reactivity is a concern. Here, we report the structure of human DPP7 and its complex with a selective inhibitor Dab-Pip (L-2,4-diaminobutyryl-piperidinamide) and compare it with that of DPP4. Both enzymes share a common catalytic domain (α/β-hydrolase). The catalytic pocket is located in the interior of DPP7, deep inside the cleft between the two domains. Substrates might access the active site via a narrow tunnel. The DPP7 catalytic triad is completely conserved and comprises Ser162, Asp418 and His443 (corresponding to Ser630, Asp708 and His740 in DPP4), while other residues lining the catalytic pockets differ considerably. The “specificity domains” are structurally also completely different exhibiting a β-propeller fold in DPP4 compared to a rare, completely helical fold in DPP7. Comparing the structures of DPP7 and DPP4 allows the design of specific inhibitors and thus the development of less cross-reactive drugs. Furthermore, the reported DPP7 structures shed some light onto the evolutionary relationship of prolyl-specific peptidases through the analysis of the architectural organization of their domains. PMID:22952628

Identifying neuropeptide Y (NPY) as the main stress-related substrate of dipeptidyl peptidase 4 (DPP4) in blood circulation.

PubMed

Wagner, Leona; Kaestner, Florian; Wolf, Raik; Stiller, Harald; Heiser, Ulrich; Manhart, Susanne; Hoffmann, Torsten; Rahfeld, Jens-Ulrich; Demuth, Hans-Ulrich; Rothermundt, Matthias; von Hörsten, Stephan

2016-06-01

Dipeptidyl peptidase 4 (DPP4; EC 3.4.14.5; CD26) is a membrane-bound or shedded serine protease that hydrolyzes dipeptides from the N-terminus of peptides with either proline or alanine at the penultimate position. Substrates of DPP4 include several stress-related neuropeptides implicated in anxiety, depression and schizophrenia. A decline of DPP4-like activity has been reported in sera from depressed patient, but not fully characterized regarding DPP4-like enzymes, therapeutic interventions and protein. Sera from 16 melancholic- and 16 non-melancholic-depressed patients were evaluated for DPP4-like activities and the concentration of soluble DPP4 protein before and after treatment by anti-depressive therapies. Post-translational modification of DPP4-isoforms and degradation of NPY, Peptide YY (PYY), Galanin-like peptide (GALP), Orexin B (OrxB), OrxA, pituitary adenylate cyclase-activating polypeptide (PACAP) and substance P (SP) were studied in serum and in ex vivo human blood. N-terminal truncation of biotinylated NPY by endothelial membrane-bound DPP4 versus soluble DPP4 was determined in rat brain perfusates and spiked sera. Lower DPP4 activities in depressed patients were reversed by anti-depressive treatment. In sera, DPP4 contributed to more than 90% of the overall DPP4-like activity and correlated with its protein concentration. NPY displayed equal degradation in serum and blood, and was equally truncated by serum and endothelial DPP4. In addition, GALP and rat OrxB were identified as novel substrates of DPP4. NPY is the best DPP4-substrate in blood, being truncated by soluble and membrane DPP4, respectively. The decline of soluble DPP4 in acute depression could be reversed upon anti-depressive treatment. Peptidases from three functional compartments regulate the bioactivity of NPY in blood. Copyright © 2016 Elsevier Ltd. All rights reserved.

Sarcoid-like lung granulomas in a hemodialysis patient treated with a dipeptidyl peptidase-4 inhibitor.

PubMed

Sada, Ken-Ei; Wada, Jun; Morinaga, Hiroshi; Tuchimochi, Shigeyuki; Uka, Mayu; Makino, Hirofumi

2014-04-01

It has been reported that the inhibition of dipeptidyl peptidase-4 (DPP-4)/CD26 on T-cells by DPP-4 enzymatic inhibitors suppresses lymphocyte proliferation and reduces the production of various cytokines, including tumor necrosis factor (TNF)-α. A 72-year-old female with diabetic nephropathy on hemodialysis developed multiple lung nodules following the administration of vildagliptin. A biopsy demonstrated the histology of granulomas without caseous necrosis. The discontinuation of vildagliptin resulted in the disappearance of the granulomas within 4 months. As granulomatosis often develops in patients under anti-TNF-α therapy, the accumulation of DPP-4 inhibitors or its metabolites is possibly linked to unrecognized complications, such as sarcoid-like lung granulomas.

Sarcoid-like lung granulomas in a hemodialysis patient treated with a dipeptidyl peptidase-4 inhibitor

PubMed Central

Sada, Ken-ei; Wada, Jun; Morinaga, Hiroshi; Tuchimochi, Shigeyuki; Uka, Mayu; Makino, Hirofumi

2014-01-01

It has been reported that the inhibition of dipeptidyl peptidase-4 (DPP-4)/CD26 on T-cells by DPP-4 enzymatic inhibitors suppresses lymphocyte proliferation and reduces the production of various cytokines, including tumor necrosis factor (TNF)-α. A 72-year-old female with diabetic nephropathy on hemodialysis developed multiple lung nodules following the administration of vildagliptin. A biopsy demonstrated the histology of granulomas without caseous necrosis. The discontinuation of vildagliptin resulted in the disappearance of the granulomas within 4 months. As granulomatosis often develops in patients under anti-TNF-α therapy, the accumulation of DPP-4 inhibitors or its metabolites is possibly linked to unrecognized complications, such as sarcoid-like lung granulomas. PMID:25852868

Drug development from the bench to the pharmacy: with special reference to dipeptidyl peptidase-4 inhibitor development.

PubMed

Carr, R D

2016-06-01

The dipeptidyl peptidase-4 (DPP-4) inhibitor concept is an example of prospective drug design and development based upon a distinct endocrine hypothesis. The design of enzyme inhibitors is a pragmatic approach to drug design; being compatible with the identification and optimization of small molecules that have properties commensurate with oral administration, as well as acceptable drug metabolism, distribution and elimination characteristics. Glucagon-like peptide 1 (GLP-1), a hormone with a spectrum of favourable metabolic actions, including glucose-dependent stimulation of insulin and inhibition of glucagon secretion, provided the endocrine basis from which the idea of using DPP-4 inhibitors as anti-diabetic agents was developed. The origin of the DPP-4 inhibitor concept was inspired by the angiotensin-converting enzyme inhibitor approach, which succeeded in establishing a class of extensively used therapeutic agents for the treatment of cardiovascular disorders. © 2016 Diabetes UK.

Effectiveness and safety of dipeptidyl peptidase 4 inhibitors in the management of type 2 diabetes in older adults: a systematic review and development of recommendations to reduce inappropriate prescribing.

PubMed

Schott, Gisela; Martinez, Yolanda V; Ediriweera de Silva, R Erandie; Renom-Guiteras, Anna; Vögele, Anna; Reeves, David; Kunnamo, Ilkka; Marttila-Vaara, Minna; Sönnichsen, Andreas

2017-10-16

data on clinically relevant benefits of their use. Twenty-two of the included studies were funded by pharmaceutical companies and authored or co-authored by employees of the sponsor. Other than the surrogate endpoint of improved glycaemic control, data on clinically relevant benefits of DPP-4 inhibitors in the treatment of type 2 diabetes mellitus in older adults is scarce. DPP-4 inhibitors might have a lower risk of hypoglycaemia compared to other antidiabetic drugs but data show conflicting findings for long-term benefits. Further studies are needed that evaluate the risks and benefits of DPP-4 inhibitors for the management of type 2 diabetes mellitus in older adults, using clinically relevant outcomes and including representative samples of older adults with information on their frailty status and comorbidities. Studies are also needed that are independent of pharmaceutical company involvement.

Clinical Pharmacokinetics and Pharmacodynamics of Saxagliptin, a Dipeptidyl Peptidase-4 Inhibitor.

PubMed

Boulton, David W

2017-01-01

Saxagliptin is an orally active, highly potent, selective and competitive dipeptidyl peptidase (DPP)-4 inhibitor used in the treatment of type 2 diabetes mellitus at doses of 2.5 or 5 mg once daily. DPP-4 is responsible for degrading the intestinally derived hormones glucagon-like peptide (GLP)-1 and glucose-dependent insulinotropic polypeptide (GIP). Inhibition of DPP-4 increases intact plasma GLP-1 and GIP concentrations, augmenting glucose-dependent insulin secretion. Both saxagliptin and its major active metabolite, 5-hydroxy saxagliptin, demonstrate high degrees of selectivity for DPP-4 compared with other DPP enzymes. Saxagliptin is orally absorbed and can be administered with or without food. The half-life of plasma DPP-4 inhibition with saxagliptin 5 mg is ~27 h, which supports a once-daily dosing regimen. Saxagliptin is metabolized by cytochrome P450 (CYP) 3A4/5 and is eliminated by a combination of renal and hepatic clearance. No clinically meaningful differences in saxagliptin or 5-hydroxy saxagliptin pharmacokinetics have been detected in patients with hepatic impairment. No clinically meaningful differences in saxagliptin or 5-hydroxy saxagliptin pharmacokinetics have been detected in patients with mild renal impairment, whereas dose reduction is recommended in patients with moderate or severe renal impairment because of greater systemic exposure [the area under the plasma concentration-time curve (AUC)] to saxagliptin total active moieties. Clinically relevant drug-drug interactions have not been detected; however, limiting the dose to 2.5 mg once daily is recommended in the USA when saxagliptin is coadministered with strong CYP inhibitors, because of increased saxagliptin exposure. In summary, saxagliptin has a predictable pharmacokinetic and pharmacodynamic profile.

Efficacy of dipeptidyl-peptidase-4 inhibitors and impact on β-cell function in Asian and Caucasian type 2 diabetes mellitus patients: A meta-analysis.

PubMed

Cai, Xiaoling; Han, Xueyao; Luo, Yingying; Ji, Linong

2015-05-01

This work aimed to compare the efficacy of dipeptidyl peptidase-IV (DPP-4) inhibitors and their impact on β-cell function in Asian and Caucasian patients with type 2 diabetes mellitus. Databases were systematically searched and qualifying studies that compared DPP-4 inhibitors with other antidiabetic medications in type 2 diabetes were included. A total of 68 studies were included in the meta-analysis. Comparison of DPP-4 inhibitors with placebo in Asian patients showed a decrease in glycosylated hemoglobin (HbA1c ) favoring DPP-4 inhibitors (weighted mean difference [WMD], -0.81%; 95% confidence interval [CI], -0.95% to -0.68%; P < 0.001). Comparison of HbA1c changes between Asian and Caucasian patients showed a significant between-group difference of -0.18% (95% CI, -0.32% to -0.04%; P = 0.011) when compared with placebo. In Asian patients, the homeostatic model assessment for β-cell function (HOMA-β) was increased with DPP-4 inhibitors compared with placebo (WMD, 7.90; 95% CI, 4.29 to 11.51; P < 0.001), although to a lesser extent in Caucasian patients. Comparisons between Asian and Caucasian patients showed a significant between-group difference of -4.97 (95% CI, -9.86 to -0.09; P = 0.046) compared with placebo. Body weight increase with DPP-4 inhibitors compared with placebo was comparable in Asian and Caucasian studies (WMD, 0.37 kg and 0.45 kg and 95% CI, 0.04-0.69 and 0.27-0.62, respectively). The glucose-lowering efficacy of DPP-4 inhibitors was greater in Asian patients than in Caucasian patients, although the effect on β-cell function was inferior in Asian patients. The effect of DPP-4 inhibitors on insulin resistance and body weight in Asian patients was comparable with that observed in Caucasian patients. © 2014 Ruijin Hospital, Shanghai Jiaotong University School of Medicine and Wiley Publishing Asia Pty Ltd.

Effect of dipeptidyl peptidase-4 inhibitors on circulating tumor necrosis factor-α concentrations: A systematic review and meta-analysis of controlled trials.

PubMed

Atkin, Stephen L; Katsiki, Niki; Banach, Maciej; Mikhailidis, Dimitri P; Pirro, Matteo; Sahebkar, Amirhossein

2017-09-01

Dipeptidyl peptidase-4 (DPP-4) inhibitors improve glycemic control in patients with type 2 diabetes mellitus. There are also reports of an effect of these drugs in reducing inflammation through inhibition of tumor necrosis factor-α (TNF-α) that is an important mediator for several inflammatory processes. The present systematic review and meta-analysis were performed to evaluate the effect of DPP-4 inhibitors on circulating TNF-α levels in T2DM patients. A systematic review and a meta-analysis were undertaken on all controlled trials of DPP-4 inhibitors that included measurement of TNF-α. The search included PubMed-Medline, Scopus, ISI Web of Knowledge and Google Scholar databases. Quantitative data synthesis was performed using a random-effects model, with standardized mean difference (SMD) and 95% confidence interval (CI) as summary statistics. Meta-regression and leave-one-out sensitivity analysis were performed to assess the modifiers of treatment response. Eight eligible articles (6 with sitagliptin and 2 with vildagliptin) comprising 9 treatment arms were selected for this meta-analysis. Meta-analysis suggested a significant reduction of circulating TNF-α concentrations following treatment with DPP-4 inhibitors (SMD: -1.84, 95% CI: -2.88, -0.80, p=0.001). The effect size was robust in the sensitivity analysis and not mainly driven by a single study. A subgroup analysis did not suggest any significant difference between the TNF-α-lowering activity of sitagliptin (SMD: -1.49, 95% CI: -2.89, -0.10) and vildagliptin (SMD: -2.80, 95% CI: -4.98, -0.61) (p=0.326). This meta-analysis of the 8 available controlled trials showed that DPP-4 inhibition in patients with type 2 diabetes mellitus was associated with significant reductions in plasma TNF-α levels with no apparent difference between sitagliptin and vildagliptin. Copyright © 2017 Elsevier Inc. All rights reserved.

Dipeptidyl Peptidase-4 Inhibitor Anagliptin Prevents Intracranial Aneurysm Growth by Suppressing Macrophage Infiltration and Activation.

PubMed

Ikedo, Taichi; Minami, Manabu; Kataoka, Hiroharu; Hayashi, Kosuke; Nagata, Manabu; Fujikawa, Risako; Higuchi, Sei; Yasui, Mika; Aoki, Tomohiro; Fukuda, Miyuki; Yokode, Masayuki; Miyamoto, Susumu

2017-06-19

Chronic inflammation plays a key role in the pathogenesis of intracranial aneurysms (IAs). DPP-4 (dipeptidyl peptidase-4) inhibitors have anti-inflammatory effects, including suppressing macrophage infiltration, in various inflammatory models. We examined whether a DPP-4 inhibitor, anagliptin, could suppress the growth of IAs in a rodent aneurysm model. IAs were surgically induced in 7-week-old male Sprague Dawley rats, followed by oral administration of 300 mg/kg anagliptin. We measured the morphologic parameters of aneurysms over time and their local inflammatory responses. To investigate the molecular mechanisms, we used lipopolysaccharide-treated RAW264.7 macrophages. In the anagliptin-treated group, aneurysms were significantly smaller 2 to 4 weeks after IA induction. Anagliptin inhibited the accumulation of macrophages in IAs, reduced the expression of MCP-1 (monocyte chemotactic protein 1), and suppressed the phosphorylation of p65. In lipopolysaccharide-stimulated RAW264.7 cells, anagliptin treatment significantly reduced the production of tumor necrosis factor α, MCP-1, and IL-6 (interleukin 6) independent of GLP-1 (glucagon-like peptide 1), the key mediator in the antidiabetic effects of DPP-4 inhibitors. Notably, anagliptin activated ERK5 (extracellular signal-regulated kinase 5), which mediates the anti-inflammatory effects of statins, in RAW264.7 macrophages. Preadministration with an ERK5 inhibitor blocked the inhibitory effect of anagliptin on MCP-1 and IL-6 expression. Accordingly, the ERK5 inhibitor also counteracted the suppression of p65 phosphorylation in vitro. A DPP-4 inhibitor, anagliptin, prevents the growth of IAs via its anti-inflammatory effects on macrophages. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley.

Glucose-independent renoprotective mechanisms of the tissue dipeptidyl peptidase-4 inhibitor, saxagliptin, in Dahl salt-sensitive hypertensive rats.

PubMed

Uchii, Masako; Kimoto, Naoya; Sakai, Mariko; Kitayama, Tetsuya; Kunori, Shunji

2016-07-15

Although previous studies have shown an important role of renal dipeptidyl peptidase-4 (DPP-4) inhibition in ameliorating kidney injury in hypertensive rats, the renal distribution of DPP-4 and mechanisms of renoprotective action of DPP-4 inhibition remain unclear. In this study, we examined the effects of the DPP-4 inhibitor saxagliptin on DPP-4 activity in renal cells (using in situ DPP-4 staining) and on renal gene expression related to inflammation and fibrosis in the renal injury in hypertensive Dahl salt-sensitive (Dahl-S) rats. Male rats fed a high-salt (8% NaCl) diet received vehicle (water) or saxagliptin (12.7mg/kg/day) for 4 weeks. Blood pressure (BP), serum glucose and 24-h urinary albumin and sodium excretions were measured, and renal histopathology was performed. High salt-diet increased BP and urinary albumin excretion, consequently resulting in glomerular sclerosis and tubulointerstitial fibrosis. Although saxagliptin did not affect BP and blood glucose levels, it significantly ameliorated urinary albumin excretion. In situ staining showed DPP-4 activity in glomerular and tubular cells. Saxagliptin significantly suppressed DPP-4 activity in renal tissue extracts and in glomerular and tubular cells. Saxagliptin also significantly attenuated the increase in inflammation and fibrosis-related gene expressions in the kidney. Our results demonstrate that saxagliptin inhibited the development of renal injury independent of its glucose-lowering effect. Glomerular and tubular DPP-4 inhibition by saxagliptin was associated with improvements in albuminuria and the suppression of inflammation and fibrosis-related genes. Thus, local glomerular and tubular DPP-4 inhibition by saxagliptin may play an important role in its renoprotective effects in Dahl-S rats. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Association of DPP4 Gene Polymorphisms with Type 2 Diabetes Mellitus in Malaysian Subjects

PubMed Central

Ahmed, Radwan H.; Huri, Hasniza Zaman; Al-Hamodi, Zaid; Salem, Sameer D.; Al-absi, Boshra; Muniandy, Sekaran

2016-01-01

Background Genetic polymorphisms of the Dipeptidyl Peptidase 4 (DPP4) gene may play a role in the etiology of type 2 diabetes mellitus (T2DM). This study aimed to investigate the possible association of single nucleotide polymorphisms (SNPs) of the DPP4 gene in Malaysian subjects with T2DM and evaluated whether they had an effect on the serum levels of soluble dipeptidyl peptidase 4 (sDPP-IV). Method Ten DPP4 SNPs were genotyped by TaqMan genotyping assays in 314 subjects with T2DM and 235 controls. Of these, 71 metabolic syndrome (MetS) subjects were excluded from subsequent analysis. The odds ratios (ORs) and their 95% confidence interval (CIs) were calculated using multiple logistic regression for the association between the SNPs of DPP4 and T2DM. In addition, the serum levels of sDPP-IV were investigated to evaluate the association of the SNPs of DPP4 with the sDPP-IV levels. Results Dominant, recessive, and additive genetic models were employed to test the association of DPP4 polymorphisms with T2DM, after adjusting for age, race, gender and BMI. The rs12617656 was associated with T2DM in Malaysian subjects in the recessive genetic model (OR = 1.98, p = 0.006), dominant model (OR = 1.95, p = 0.008), and additive model (OR = 1.63, p = 0.001). This association was more pronounced among Malaysian Indians, recessive (OR = 3.21, p = 0.019), dominant OR = 3.72, p = 0.003) and additive model (OR = 2.29, p = 0.0009). The additive genetic model showed that DPP4 rs4664443 and rs7633162 polymorphisms were associated with T2DM (OR = 1.53, p = 0.039), and (OR = 1.42, p = 0.020), respectively. In addition, the rs4664443 G>A polymorphism was associated with increased sDPP-IV levels (p = 0.042) in T2DM subjects. Conclusions DPP4 polymorphisms were associated with T2DM in Malaysian subjects, and linked to variations in sDPP-IV levels. In addition, these associations were more pronounced among Malaysian Indian subjects. PMID:27111895

Association of DPP4 Gene Polymorphisms with Type 2 Diabetes Mellitus in Malaysian Subjects.

PubMed

Ahmed, Radwan H; Huri, Hasniza Zaman; Al-Hamodi, Zaid; Salem, Sameer D; Al-Absi, Boshra; Muniandy, Sekaran

2016-01-01

Genetic polymorphisms of the Dipeptidyl Peptidase 4 (DPP4) gene may play a role in the etiology of type 2 diabetes mellitus (T2DM). This study aimed to investigate the possible association of single nucleotide polymorphisms (SNPs) of the DPP4 gene in Malaysian subjects with T2DM and evaluated whether they had an effect on the serum levels of soluble dipeptidyl peptidase 4 (sDPP-IV). Ten DPP4 SNPs were genotyped by TaqMan genotyping assays in 314 subjects with T2DM and 235 controls. Of these, 71 metabolic syndrome (MetS) subjects were excluded from subsequent analysis. The odds ratios (ORs) and their 95% confidence interval (CIs) were calculated using multiple logistic regression for the association between the SNPs of DPP4 and T2DM. In addition, the serum levels of sDPP-IV were investigated to evaluate the association of the SNPs of DPP4 with the sDPP-IV levels. Dominant, recessive, and additive genetic models were employed to test the association of DPP4 polymorphisms with T2DM, after adjusting for age, race, gender and BMI. The rs12617656 was associated with T2DM in Malaysian subjects in the recessive genetic model (OR = 1.98, p = 0.006), dominant model (OR = 1.95, p = 0.008), and additive model (OR = 1.63, p = 0.001). This association was more pronounced among Malaysian Indians, recessive (OR = 3.21, p = 0.019), dominant OR = 3.72, p = 0.003) and additive model (OR = 2.29, p = 0.0009). The additive genetic model showed that DPP4 rs4664443 and rs7633162 polymorphisms were associated with T2DM (OR = 1.53, p = 0.039), and (OR = 1.42, p = 0.020), respectively. In addition, the rs4664443 G>A polymorphism was associated with increased sDPP-IV levels (p = 0.042) in T2DM subjects. DPP4 polymorphisms were associated with T2DM in Malaysian subjects, and linked to variations in sDPP-IV levels. In addition, these associations were more pronounced among Malaysian Indian subjects.

(2S,4S)-4-Fluoro-1-{[(2-hydroxy-1,1-dimethylethyl)amino]acetyl}-pyrrolidine-2-carbonitrile monobenzenesulfonate (TS-021) is a selective and reversible dipeptidyl peptidase IV inhibitor.

PubMed

Tajima, Atsushi; Yamamoto, Koji; Kozakai, Akinori; Okumura-Kitajima, Lisa; Mita, Yasuo; Kitano, Kiyokazu; Jingu, Shigeji; Nakaike, Shiro

2011-03-25

The incretin hormone glucagon-like peptide-1 (GLP-1) has significant roles in the regulation of postprandial glucose metabolism, and the active form of GLP-1 is rapidly degraded by dipeptidyl peptidase (DPP)-IV. Therefore, DPP-IV inhibition is a promising approach for the treatment of type 2 diabetes. In the present study, we investigated the character of a DPP-IV inhibitor, TS-021, (2S, 4S)-4-fluoro-1-{[(2-hydroxy-1,1-dimethylethyl)amino]acetyl}-pyrrolidine-2-carbonitrile monobenzenesulfonate both in vitro and in vivo. TS-021 inhibits DPP-IV activity in human plasma with an IC(50) value of 5.34nM. In kinetics experiments, TS-021 had a relatively higher dissociation rate constant, with a k(off) value of 1.09×10(-3)s, despite exhibiting a potent human plasma DPP-IV inhibition activity with a K(i) value of 4.96nM. TS-021 exhibited significant inhibition selectivity against DPP-8 (>600 fold), DPP-9 (>1200 fold) and other peptidases examined (>15,000 fold). In normal rats, dogs and monkeys, a single oral dose of TS-021 exhibited favorable pharmacokinetic profiles. In Zucker fatty (fa/fa) rats, a rat model of obesity and impaired glucose tolerance, the oral administration of TS-021 resulted in the suppression of plasma DPP-IV activity and an increase in the active form of GLP-1. Furthermore, TS-021 exhibited a significant improvement in glucose tolerance by increasing the plasma insulin level during oral glucose tolerance tests at doses of 0.02-0.5mg/kg. These results suggest that TS-021 is a selective and reversible dipeptidyl peptidase IV inhibitor and has excellent characteristics as an oral anti-diabetic agent for postprandial hyperglycemia in patients with impaired glucose tolerance or type 2 diabetes. Copyright © 2011 Elsevier B.V. All rights reserved.

Dipeptidyl Peptidase-4 Inhibitor Development and Post-authorisation Programme for Vildagliptin - Clinical Evidence for Optimised Management of Chronic Diseases Beyond Type 2 Diabetes.

PubMed

Strain, William David; Paldánius, Päivi M

2017-08-01

The last decade has witnessed the role of dipeptidyl peptidase-4 (DPP-4) inhibitors in producing a conceptual change in early management of type 2 diabetes mellitus (T2DM) by shifting emphasis from a gluco-centric approach to holistically treating underlying pathophysiological processes. DPP-4 inhibitors highlighted the importance of acknowledging hypoglycaemia and weight gain as barriers to optimised care in T2DM. These complications were an integral part of diabetes management before the introduction of DPP-4 inhibitors. During the development of DPP-4 inhibitors, regulatory requirements for introducing new agents underwent substantial changes, with increased emphasis on safety. This led to the systematic collection of adjudicated cardiovascular (CV) safety data, and, where 95% confidence of a lack of harm could not be demonstrated, the standardised CV safety studies. Furthermore, the growing awareness of the worldwide extent of T2DM demanded a more diverse approach to recruitment and participation in clinical trials. Finally, the global financial crisis placed a new awareness on the health economics of diabetes, which rapidly became the most expensive disease in the world. This review encompasses unique developments in the global landscape, and the role DPP-4 inhibitors, specifically vildagliptin, have played in research advancement and optimisation of diabetes care in a diverse population with T2DM worldwide.

Involvement of DPP-IV catalytic residues in enzyme–saxagliptin complex formation

PubMed Central

Metzler, William J.; Yanchunas, Joseph; Weigelt, Carolyn; Kish, Kevin; Klei, Herbert E.; Xie, Dianlin; Zhang, Yaqun; Corbett, Martin; Tamura, James K.; He, Bin; Hamann, Lawrence G.; Kirby, Mark S.; Marcinkeviciene, Jovita

2008-01-01

The inhibition of DPP-IV by saxagliptin has been proposed to occur through formation of a covalent but reversible complex. To evaluate further the mechanism of inhibition, we determined the X-ray crystal structure of the DPP-IV:saxagliptin complex. This structure reveals covalent attachment between S630 and the inhibitor nitrile carbon (C–O distance <1.3 Å). To investigate whether this serine addition is assisted by the catalytic His-Asp dyad, we generated two mutants of DPP-IV, S630A and H740Q, and assayed them for ability to bind inhibitor. DPP-IVH740Q bound saxagliptin with an ∼1000-fold reduction in affinity relative to DPP-IVWT, while DPP-IVS630A showed no evidence for binding inhibitor. An analog of saxagliptin lacking the nitrile group showed unchanged binding properties to the both mutant proteins, highlighting the essential role S630 and H740 play in covalent bond formation between S630 and saxagliptin. Further supporting mechanism-based inhibition by saxagliptin, NMR spectra of enzyme–saxagliptin complexes revealed the presence of three downfield resonances with low fractionation factors characteristic of short and strong hydrogen bonds (SSHB). Comparison of the NMR spectra of various wild-type and mutant DPP-IV:ligand complexes enabled assignment of a resonance at ∼14 ppm to H740. Two additional DPP-IV mutants, Y547F and Y547Q, generated to probe potential stabilization of the enzyme–inhibitor complex by this residue, did not show any differences in inhibitor binding either by ITC or NMR. Together with the previously published enzymatic data, the structural and binding data presented here strongly support a histidine-assisted covalent bond formation between S630 hydroxyl oxygen and the nitrile group of saxagliptin. PMID:18227430

Involvement of DPP-IV Catalytic Residues in Enzyme-Saxagliptin Complex Formation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Metzler,W.; Yanchunas, J.; Weigelt, C.

The inhibition of DPP-IV by saxagliptin has been proposed to occur through formation of a covalent but reversible complex. To evaluate further the mechanism of inhibition, we determined the X-ray crystal structure of the DPP-IV:saxagliptin complex. This structure reveals covalent attachment between S630 and the inhibitor nitrile carbon (C-O distance <1.3 Angstroms). To investigate whether this serine addition is assisted by the catalytic His-Asp dyad, we generated two mutants of DPP-IV, S630A and H740Q, and assayed them for ability to bind inhibitor. DPP-IVH740Q bound saxagliptin with an {approx}1000-fold reduction in affinity relative to DPP-IVWT, while DPP-IVS630A showed no evidence formore » binding inhibitor. An analog of saxagliptin lacking the nitrile group showed unchanged binding properties to the both mutant proteins, highlighting the essential role S630 and H740 play in covalent bond formation between S630 and saxagliptin. Further supporting mechanism-based inhibition by saxagliptin, NMR spectra of enzyme-saxagliptin complexes revealed the presence of three downfield resonances with low fractionation factors characteristic of short and strong hydrogen bonds (SSHB). Comparison of the NMR spectra of various wild-type and mutant DPP-IV:ligand complexes enabled assignment of a resonance at {approx}14 ppm to H740. Two additional DPP-IV mutants, Y547F and Y547Q, generated to probe potential stabilization of the enzyme-inhibitor complex by this residue, did not show any differences in inhibitor binding either by ITC or NMR. Together with the previously published enzymatic data, the structural and binding data presented here strongly support a histidine-assisted covalent bond formation between S630 hydroxyl oxygen and the nitrile group of saxagliptin.« less

Dipeptidyl Peptidase-4 Inhibitors and Heart Failure Exacerbation in the Veteran Population: An Observational Study.

PubMed

Cobretti, Michael R; Bowman, Benjamin; Grabarczyk, Ted; Potter, Emily

2018-03-01

The dipeptidyl peptidase-4 inhibitors (DPP-4 inhibitors) are effective modulators of fasting and postprandial hyperglycemia in patients with type 2 diabetes mellitus (T2DM). In 2013 the Saxagliptin Assessment of Vascular Outcomes Recorded in Patients with Diabetes Mellitus-Thrombolysis in Myocardial Infarction 53 (SAVOR-TIMI 53) clinical trial found an increased risk of heart failure exacerbation, as a secondary outcome, among patients treated with saxagliptin. This study examines the safety of DPP-4 inhibitors as a class in T2DM in relation to risk of heart failure exacerbations. Retrospective cohort study of two groups of patients using data from the national Department of Veteran's Affairs (VA) Health Care System: patients initially prescribed DPP-4 inhibitors with or without second-generation sulfonylureas and/or metformin (exposed group) compared with patients initially prescribed only second-generation sulfonylureas and/or metformin (unexposed group) between August 1, 2013, and August 30, 2016. The primary aim of this study was to determine the difference in 1-year heart failure exacerbation rate in patients with T2DM between the exposed and unexposed groups. Data were analyzed using the χ 2 Student t test and Kaplan-Meier analysis. Significance was set at p<0.05. The study evaluated 672,265 patients: 33,614 patients in the exposed group and 638,651 patients in the unexposed group. Overall, 130 (0.38%) heart failure exacerbations were documented in the exposed group, and 2222 (0.34%) heart failure exacerbations were documented in the unexposed group; the difference in exacerbation rate was nonsignificant between groups (p=0.24). In a subgroup analysis of patients with a baseline diagnosis of heart failure, the difference in rate of heart failure exacerbations remained nonsignificant (p=0.334). Patients in the veteran population with T2DM treated with DPP-4 inhibitors did not demonstrate a significant increase in risk for heart failure exacerbation

Dipeptidyl Peptidase-4 Inhibitor Development and Post-authorisation Programme for Vildagliptin — Clinical Evidence for Optimised Management of Chronic Diseases Beyond Type 2 Diabetes

PubMed Central

Paldánius, Päivi M

2017-01-01

Abstract The last decade has witnessed the role of dipeptidyl peptidase-4 (DPP-4) inhibitors in producing a conceptual change in early management of type 2 diabetes mellitus (T2DM) by shifting emphasis from a gluco-centric approach to holistically treating underlying pathophysiological processes. DPP-4 inhibitors highlighted the importance of acknowledging hypoglycaemia and weight gain as barriers to optimised care in T2DM. These complications were an integral part of diabetes management before the introduction of DPP-4 inhibitors. During the development of DPP-4 inhibitors, regulatory requirements for introducing new agents underwent substantial changes, with increased emphasis on safety. This led to the systematic collection of adjudicated cardiovascular (CV) safety data, and, where 95% confidence of a lack of harm could not be demonstrated, the standardised CV safety studies. Furthermore, the growing awareness of the worldwide extent of T2DM demanded a more diverse approach to recruitment and participation in clinical trials. Finally, the global financial crisis placed a new awareness on the health economics of diabetes, which rapidly became the most expensive disease in the world. This review encompasses unique developments in the global landscape, and the role DPP-4 inhibitors, specifically vildagliptin, have played in research advancement and optimisation of diabetes care in a diverse population with T2DM worldwide. PMID:29632609

Comparison of efficacies of a dipeptidyl peptidase IV inhibitor and alpha-glucosidase inhibitors in oral carbohydrate and meal tolerance tests and the effects of their combination in mice.

PubMed

Yamazaki, Kazuto; Inoue, Takashi; Yasuda, Nobuyuki; Sato, Yoshiaki; Nagakura, Tadashi; Takenaka, Osamu; Clark, Richard; Saeki, Takao; Tanaka, Isao

2007-05-01

E3024 (3-but-2-ynyl-5-methyl-2-piperazin-1-yl-3,5-dihydro-4H-imidazo[4,5-d]pyridazin-4-one tosylate) is a dipeptidyl peptidase IV (DPP-IV) inhibitor. Since the target of both DPP-IV inhibitors and alpha-glucosidase inhibitors is the lowering of postprandial hyperglycemia, we compared antihyperglycemic effects for E3024 and alpha-glucosidase inhibitors in various oral carbohydrate and meal tolerance tests using normal mice. In addition, we investigated the combination effects of E3024 and voglibose on blood glucose levels in a meal tolerance test using mice fed a high-fat diet. ER-235516-15 (the trifluoroacetate salt form of E3024, 1 mg/kg) lowered glucose excursions consistently, regardless of the kind of carbohydrate loaded. However, the efficacy of acarbose (10 mg/kg) and of voglibose (0.1 mg/kg) varied with the type of carbohydrate administered. The combination of E3024 (3 mg/kg) and voglibose (0.3 mg/kg) improved glucose tolerance additively, with the highest plasma active glucagon-like peptide-1 levels. This study shows that compared to alpha-glucosidase inhibitors, DPP-IV inhibitors may have more consistent efficacy to reduce postprandial hyperglycemia, independent of the types of carbohydrate contained in a meal, and that the combination of a DPP-IV inhibitor and an alpha-glucosidase inhibitor is expected to be a promising option for lowering postprandial hyperglycemia.

Dipeptidyl-peptidase IV (DPP-IV) inhibitor delays tolerance to anxiolytic effect of ethanol and withdrawal-induced anxiety in rats.

PubMed

Sharma, Ajaykumar N; Pise, Ashish; Sharma, Jay N; Shukla, Praveen

2015-06-01

Dipeptidyl-peptidase IV (DPP-IV) is an enzyme responsible for the metabolism of endogenous gut-derived hormone, glucagon-like peptide-1 (GLP-1). DPP-IV is known for its role in energy homeostasis and pharmacological blockade of this enzyme is a recently approved clinical strategy for the management of type II diabetes. Accumulating evidences suggest that enzyme DPP-IV can affect spectrum of central nervous system (CNS) functions. However, little is known about the role of this enzyme in ethanol-mediated neurobehavioral complications. The objective of the present study was to examine the impact of DPP-IV inhibitor, sitagliptin on the development of tolerance to anxiolytic effect of ethanol and anxiety associated with ethanol withdrawal in rats. A dose-response study revealed that sitaglitpin (20 mg/kg, p.o.) per se exhibit anxiolytic effect in the elevated plus maze (EPM) test in rats. Tolerance to anxiolytic effect of ethanol (2 g/kg, i.p.; 8 % w/v) was observed from 7(th) day of ethanol-diet (6 % v/v) consumption. In contrast, tolerance to anxiolytic effect of ethanol was delayed in rats that were treated daily with sitagliptin (20 mg/kg, p.o.) as tolerance was observed from 13(th)day since commencement of ethanol-diet consumption. Discontinuation of rats from ethanol-diet after 15-days of ethanol consumption resulted in withdrawal anxiety between 8 h and 12 h post-abstinence. However, rats on 15-day ethanol-diet with concomitant sitagliptin (20 mg/kg, p.o.) treatment exhibited delay in appearance (24 h post-withdrawal) of withdrawal anxiety. In summary, DPP-IV inhibitors may prove as an attractive research strategy against ethanol tolerance and dependence.

Cost-effectiveness of dipeptidyl peptidase-4 inhibitor monotherapy versus sulfonylurea monotherapy for people with type 2 diabetes and chronic kidney disease in Thailand.

PubMed

Permsuwan, Unchalee; Dilokthornsakul, Piyameth; Thavorn, Kednapa; Saokaew, Surasak; Chaiyakunapruk, Nathorn

2017-02-01

With a high prevalence of chronic kidney disease (CKD) in type 2 diabetes (T2DM) in Thailand, the appropriate treatment for the patients has become a major concern. This study aimed to evaluate long-term cost-effective of dipeptidyl peptidase-4 (DPP-4) inhibitor monothearpy vs sulfonylurea (SFU) monotherapy in people with T2DM and CKD. A validated IMS CORE Diabetes Model was used to estimate the long-term costs and outcomes. The efficacy parameters were identified and synthesized using a systematic review and meta-analysis. Baseline characteristics and cost parameters were obtained from published studies and hospital databases in Thailand. Costs were expressed in 2014 US Dollars. Outcomes were presented as an incremental cost-effectiveness ratio (ICER). One-way and probabilistic sensitivity analyses were performed to estimate parameter uncertainty. From a societal perspective, treatment with DPP-4 inhibitors yielded more quality-adjusted life years (QALYs) (0.024) at a higher cost (>66,000 Thai baht (THB) or >1,829.27 USD) per person than SFU, resulting in the ICER of >2.7 million THB/QALY (>74,833.70 USD/QALY). The cost-effectiveness results were mainly driven by differences in HbA1c reduction, hypoglycemic events, and drug acquisition cost of DPP-4 inhibitors. At the ceiling ratio of 160,000 THB/QALY (4,434.59 USD/QALY), the probability that DPP-4 inhibitors are cost-effective compared to SFU was less than 10%. Compared to SFU, DPP-4 inhibitor monotherapy is not a cost-effective treatment for people with T2DM and CKD in Thailand.

Short-term and long-term effects of dipeptidyl peptidase-4 inhibitors in type 2 diabetes mellitus patients with renal impairment: a meta-analysis of randomized controlled trials.

PubMed

Li, Ruifei; Wang, Rui; Li, Haixia; Sun, Sihao; Zou, Meijuan; Cheng, Gang

2016-09-01

To assess the short-term and long-term effects of dipeptidyl peptidase-4 (DPP-4) inhibitors in type 2 diabetes mellitus patients with renal impairment, a meta-analysis of randomized clinical trials of DPP-4 inhibitor interventions in type 2 diabetes mellitus patients with renal impairment was performed. PubMed, Embase, Cochrane Library and ClinicalTrials.gov were searched through the end of March 2015. Randomized clinical trials were selected if (1) DPP-4 inhibitors were compared with a placebo or other active-comparators, (2) the treatment duration was ≥12 weeks and (3) data regarding changes in haemoglobin A1c (HbA1c ), changes in fasting plasma glucose or hypoglycaemia and other adverse events were reported. Of 790 studies, ten studies on eight randomized clinical trials were included. Compared with the control group, DPP-4 inhibitors were associated with a greater HbA1c reduction in both the short-term [mean differences (MD) = -0.45, 95% confidence intervals (-0.57, -0.33), p < 0.0001] and long-term [MD = -0.33, 95% confidence intervals (-0.63, -0.03), p = 0.03] treatments. However, the long-term greater reduction in HbA1c with DPP-4 inhibitor treatment was only significant when the control treatment comprised placebo plus stable background treatment, but not glipizide plus stable background treatment. DPP-4 inhibitors were associated with a greater fasting plasma glucose reduction [MD = -12.59, 95% confidence intervals (-22.01, -3.17), p = 0.009] over the short-term; however, this effect was not present over the long-term. Regarding the hypoglycaemia adverse events assessment, the long-term treatment data indicated there was no increased risk of hypoglycaemia compared with placebo or active-controlled anti-diabetic drugs. The present meta-analysis confirms that DPP-4 inhibitors are effective and equivalent to other agents in type 2 diabetes mellitus patients with renal impairment. Copyright © 2015 John Wiley & Sons, Ltd. Copyright �

Localized expression of a dpp/BMP2/4 ortholog in a coral embryo

PubMed Central

Hayward, David C.; Samuel, Gabrielle; Pontynen, Patricia C.; Catmull, Julian; Saint, Robert; Miller, David J.; Ball, Eldon E.

2002-01-01

As the closest outgroup to the Bilateria, the Phylum Cnidaria is likely to be critical to understanding the origins and evolution of body axes. Proteins of the decapentaplegic (DPP)/bone morphogenetic protein (BMP) 2/4 subfamily are central to the specification of the dorsoventral (D/V) axis in bilateral animals, albeit with an axis inversion between arthropods and chordates. We show that a dpp/BMP2/4 ortholog (bmp2/4-Am) is present in the reef-building scleractinian coral, Acropora millepora (Class Anthozoa) and that it is capable of causing phenotypic effects in Drosophila that mimic those of the endogenous dpp gene. We also show that, during coral embryonic development, bmp2/4-Am expression is localized in an ectodermal region adjacent to the blastopore. Thus, a representative of the DPP/BMP2/4 subfamily of ligands was present in the common ancestor of diploblastic and triploblastic animals where it was probably expressed in a localized fashion during development. A localized source of DPP/BMP2/4 may have already been used in axis formation in this ancestor, or it may have provided a means by which an axis could evolve in triploblastic animals. PMID:12048233

The Dipeptidyl Peptidase-4 Inhibitor Teneligliptin Attenuates Hepatic Lipogenesis via AMPK Activation in Non-Alcoholic Fatty Liver Disease Model Mice.

PubMed

Ideta, Takayasu; Shirakami, Yohei; Miyazaki, Tsuneyuki; Kochi, Takahiro; Sakai, Hiroyasu; Moriwaki, Hisataka; Shimizu, Masahito

2015-12-08

Non-alcoholic fatty liver disease (NAFLD), which is strongly associated with metabolic syndrome, is increasingly a major cause of hepatic disorder. Dipeptidyl peptidase (DPP)-4 inhibitors, anti-diabetic agents, are expected to be effective for the treatment of NAFLD. In the present study, we established a novel NAFLD model mouse using monosodium glutamate (MSG) and a high-fat diet (HFD) and investigated the effects of a DPP-4 inhibitor, teneligliptin, on the progression of NAFLD. Male MSG/HFD-treated mice were divided into two groups, one of which received teneligliptin in drinking water. Administration of MSG and HFD caused mice to develop severe fatty changes in the liver, but teneligliptin treatment improved hepatic steatosis and inflammation, as evaluated by the NAFLD activity score. Serum alanine aminotransferase and intrahepatic triglyceride levels were significantly decreased in teneligliptin-treated mice (p < 0.05). Hepatic mRNA levels of the genes involved in de novo lipogenesis were significantly downregulated by teneligliptin (p < 0.05). Moreover, teneligliptin increased hepatic expression levels of phosphorylated AMP-activated protein kinase (AMPK) protein. These findings suggest that teneligliptin attenuates lipogenesis in the liver by activating AMPK and downregulating the expression of genes involved in lipogenesis. DPP-4 inhibitors may be effective for the treatment of NAFLD and may be able to prevent its progression to non-alcoholic steatohepatitis.

Aminopiperidine-Fused Imidazoles as Dipeptidyl Peptidase-IV Inhibitors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Edmondson, S.; Mastracchio, A; Cox, J

2009-01-01

A new series of DPP-4 inhibitors derived from piperidine-fused benzimidazoles and imidazopyridines is described. Optimization of this class of DPP-4 inhibitors led to the discovery of imidazopyridine 34. The potency, selectivity, cross-species DMPK profiles, and in vivo efficacy of 34 is reported.

Left ventricular diastolic function in patients with type 2 diabetes treated with a dipeptidyl peptidase-4 inhibitor- a pilot study.

PubMed

Nogueira, Katia Camarano; Furtado, Meive; Fukui, Rosa Tsuneshiro; Correia, Marcia Regina Silva; Dos Santos, Rosa Ferreira; Andrade, José Lázaro; Rossi da Silva, Maria Elizabeth

2014-01-01

Blood glucose control is fundamental albeit not enough to prevent diabetic macrovascular complications. Dipeptidyl peptidase-4 (DPP-4) inhibitors are effective in improving metabolic parameters in patients with type 2 diabetes mellitus (T2DM) but little is known about its cardiovascular effects. We compared the DPP-4 inhibitor sitagliptin with bedtime NPH insulin (NPH) as add-on therapy in patients with T2DM, aiming to ascertain which drug would have additional cardioprotective effects. Thirty-five T2DM patients inadequately controlled with metformin plus glyburide were randomized to receive sitagliptin (n = 18) or NPH (n = 17) for 24 weeks. Fasting plasma glucose, HbA1c, lipid profile, C-reactive protein, active glucagon-like peptide (aGLP-1) levels, 24-hour ambulatory blood pressure measurement and comprehensive 2-dimensional echocardiogram were determined before and after treatments. Both sitagliptin and NPH therapies decreased HbA1c levels after 24 weeks. Fasting plasma glucose and triglyceride levels decreased in the NPH group whereas only sitagliptin increased aGLP-1 levels. Left ventricular diastolic dysfunction (LVDD) was detected in 58.6% of twenty-nine patients evaluated. Beneficial effects in LVDD were observed in 75% and 11% of patients treated with sitagliptin and NPH, respectively (p = 0.015). Neither therapy changed C-reactive protein or blood pressure. Sitagliptin and bedtime NPH were similarly effective on glucose control. Improvement in LVDD in T2DM patients treated with sitagliptin was suggested, probably related to the increase of aGLP-1 levels. Therefore, DPP-4 inhibitor seems to have cardioprotective effects independent of glucose control and may have a role in the prevention of diabetic cardiomyopathy.

Structure activity relationship modelling of milk protein-derived peptides with dipeptidyl peptidase IV (DPP-IV) inhibitory activity.

PubMed

Nongonierma, Alice B; FitzGerald, Richard J

2016-05-01

Quantitative structure activity type models were developed in an attempt to predict the key features of peptide sequences having dipeptidyl peptidase IV (DPP-IV) inhibitory activity. The models were then employed to help predict the potential of peptides, which are currently reported in the literature to be present in the intestinal tract of humans following milk/dairy product ingestion, to act as inhibitors of DPP-IV. Two models (z- and v-scale) for short (2-5 amino acid residues) bovine milk peptides, behaving as competitive inhibitors of DPP-IV, were developed. The z- and the v-scale models (p<0.05, R(2) of 0.829 and 0.815, respectively) were then applied to 56 milk protein-derived peptides previously reported in the literature to be found in the intestinal tract of humans which possessed a structural feature of DPP-IV inhibitory peptides (P at the N2 position). Ten of these peptides were synthetized and tested for their in vitro DPP-IV inhibitory properties. There was no agreement between the predicted and experimentally determined DPP-IV half maximal inhibitory concentrations (IC50) for the competitive peptide inhibitors. However, the ranking for DPP-IV inhibitory potency of the competitive peptide inhibitors was conserved. Furthermore, potent in vitro DPP-IV inhibitory activity was observed with two peptides, LPVPQ (IC50=43.8±8.8μM) and IPM (IC50=69.5±8.7μM). Peptides present within the gastrointestinal tract of human may have promise for the development of natural DPP-IV inhibitors for the management of serum glucose. Copyright © 2016 Elsevier Inc. All rights reserved.

Incorporation of DPP6a and DPP6K variants in ternary Kv4 channel complex reconstitutes properties of A-type K current in rat cerebellar granule cells.

PubMed

Jerng, Henry H; Pfaffinger, Paul J

2012-01-01

Dipeptidyl peptidase-like protein 6 (DPP6) proteins co-assemble with Kv4 channel α-subunits and Kv channel-interacting proteins (KChIPs) to form channel protein complexes underlying neuronal somatodendritic A-type potassium current (I(SA)). DPP6 proteins are expressed as N-terminal variants (DPP6a, DPP6K, DPP6S, DPP6L) that result from alternative mRNA initiation and exhibit overlapping expression patterns. Here, we study the role DPP6 variants play in shaping the functional properties of I(SA) found in cerebellar granule (CG) cells using quantitative RT-PCR and voltage-clamp recordings of whole-cell currents from reconstituted channel complexes and native I(SA) channels. Differential expression of DPP6 variants was detected in rat CG cells, with DPP6K (41 ± 3%)>DPP6a (33 ± 3%)>DPP6S (18 ± 2%)>DPP6L (8 ± 3%). To better understand how DPP6 variants shape native neuronal I(SA), we focused on studying interactions between the two dominant variants, DPP6K and DPP6a. Although previous studies did not identify unique functional effects of DPP6K, we find that the unique N-terminus of DPP6K modulates the effects of KChIP proteins, slowing recovery and producing a negative shift in the steady-state inactivation curve. By contrast, DPP6a uses its distinct N-terminus to directly confer rapid N-type inactivation independently of KChIP3a. When DPP6a and DPP6K are co-expressed in ratios similar to those found in CG cells, their distinct effects compete in modulating channel function. The more rapid inactivation from DPP6a dominates during strong depolarization; however, DPP6K produces a negative shift in the steady-state inactivation curve and introduces a slow phase of recovery from inactivation. A direct comparison to the native CG cell I(SA) shows that these mixed effects are present in the native channels. Our results support the hypothesis that the precise expression and co-assembly of different auxiliary subunit variants are important factors in shaping the I

Dipeptidyl peptidase-IV inhibitor use associated with increased risk of ACE inhibitor-associated angioedema.

PubMed

Brown, Nancy J; Byiers, Stuart; Carr, David; Maldonado, Mario; Warner, Barbara Ann

2009-09-01

Dipeptidyl peptidase-IV (DPP-IV) inhibitors decrease degradation of the incretins. DPP-IV inhibitors also decrease degradation of peptides, such as substance P, that may be involved in the pathogenesis of angiotensin-converting enzyme (ACE) inhibitor-associated angioedema. This study tested the hypothesis that DPP-IV inhibition affects risk of clinical angioedema, by comparing the incidence of angioedema in patients treated with the DPP-IV inhibitor vildagliptin versus those treated with comparator in Phase III randomized clinical trials. Prospectively defined angioedema-related events were adjudicated in a blinded fashion by an internal medicine adjudication committee and expert reviewer. Concurrent ACE inhibitor or angiotensin receptor blocker exposure was ascertained from case report forms. Study drug exposure was ascertained from unblinded data from phase III studies. Odds ratios and 95% confidence intervals comparing angioedema risk in vildagliptin-treated and comparator-treated patients were calculated for the overall population and for patients taking ACE inhibitors or angiotensin receptor blockers, using both an analysis of pooled data and a meta-analysis (Peto method). Overall, there was no association between vildagliptin use and angioedema. Among individuals taking an ACE inhibitor, however, vildagliptin use was associated with an increased risk of angioedema (14 confirmed cases among 2754 vildagliptin users versus 1 case among 1819 comparator users: odds ratio 4.57 [95% confidence interval 1.57 to 13.28]) in the meta-analysis. Vildagliptin use may be associated with increased risk of angioedema among patients taking ACE inhibitors, although absolute risk is small. Physicians confronted with angioedema in a patient taking an ACE inhibitor and DPP-IV inhibitor should consider this possible drug-drug interaction.

(2R)-4-Oxo-4[3-(Trifluoromethyl)-5,6-diihydro:1,2,4}triazolo[4,3-a}pyrazin-7(8H)-y1]-1-(2,4,5-trifluorophenyl)butan-2-amine: A Potent, Orally Active Dipeptidyl Peptidase IV Inhibitor for the Treatment of Type 2 Diabetes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, D.; Wang, L.; Beconi, M.

2010-11-10

A novel series of {beta}-amino amides incorporating fused heterocycles, i.e., triazolopiperazines, were synthesized and evaluated as inhibitors of dipeptidyl peptidase IV (DPP-IV) for the treatment of type 2 diabetes. (2R)-4-Oxo-4-[3-(trifluoromethyl)-5,6-dihydro[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl]-1-(2,4,5-trifluorophenyl)butan-2-amine (1) is a potent, orally active DPP-IV inhibitor (IC{sub 50} = 18 nM) with excellent selectivity over other proline-selective peptidases, oral bioavailability in preclinical species, and in vivo efficacy in animal models. MK-0431, the phosphate salt of compound 1, was selected for development as a potential new treatment for type 2 diabetes.

SGLT2-inhibitor and DPP-4 inhibitor improve brain function via attenuating mitochondrial dysfunction, insulin resistance, inflammation, and apoptosis in HFD-induced obese rats.

PubMed

Sa-Nguanmoo, Piangkwan; Tanajak, Pongpan; Kerdphoo, Sasiwan; Jaiwongkam, Thidarat; Pratchayasakul, Wasana; Chattipakorn, Nipon; Chattipakorn, Siriporn C

2017-10-15

Dipeptidyl peptidase-4 inhibitor (vildagliptin) has been shown to exert beneficial effects on insulin sensitivity and neuroprotection in obese-insulin resistance. Recent studies demonstrated the neuroprotection of the sodium-glucose co-transporter 2 inhibitor (dapagliflozin) in diabetes. However, the comparative effects of both drugs and a combination of two drugs on metabolic dysfunction and brain dysfunction impaired by the obese-insulin resistance have never been investigated. Forty male Wistar rats were divided into two groups, and received either a normal-diet (ND, n=8) or a high-fat diet (HFD, n=32) for 16weeks. At week 13, the HFD-fed rats were divided into four subgroups (n=8/subgroup) to receive either a vehicle, vildagliptin (3mg/kg/day) dapagliflozin (1mg/kg/day) or combined drugs for four weeks. ND rats were given a vehicle for four weeks. Metabolic parameters and brain function were investigated. The results demonstrated that HFD rats developed obese-insulin resistance and cognitive decline. Dapagliflozin had greater efficacy on improved peripheral insulin sensitivity and reduced weight gain than vildagliptin. Single therapy resulted in equally improved brain mitochondrial function, insulin signaling, apoptosis and prevented cognitive decline. However, only dapagliflozin improved hippocampal synaptic plasticity. A combination of the drugs had greater efficacy in improving brain insulin sensitivity and reducing brain oxidative stress than the single drug therapy. These findings suggested that dapagliflozin and vildagliptin equally prevented cognitive decline in the obese-insulin resistance, possibly through some similar mechanisms. Dapagliflozin had greater efficacy than vildagliptin for preserving synaptic plasticity, thus combined drugs could be the best therapeutic approach for neuroprotection in the obese-insulin resistance. Copyright © 2017 Elsevier Inc. All rights reserved.

Dipeptidyl peptidase 4 inhibitor attenuates obesity-induced myocardial fibrosis by inhibiting transforming growth factor-βl and Smad2/3 pathways in high-fat diet-induced obesity rat model.

PubMed

Hong, Seul-Ki; Choo, Eun-Ho; Ihm, Sang-Hyun; Chang, Kiyuk; Seung, Ki-Bae

2017-11-01

Obesity-induced myocardial fibrosis may lead to diastolic dysfunction and ultimately heart failure. Activation of the transforming growth factor (TGF)-βl and its downstream Smad2/3 pathways may play a pivotal role in the pathogenesis of obesity-induced myocardial fibrosis, and the antidiabetic dipeptidyl peptidase 4 inhibitors (DPP4i) might affect these pathways. We investigated whether DPP4i reduces myocardial fibrosis by inhibiting the TGF-β1 and Smad2/3 pathways in the myocardium of a diet-induced obesity (DIO) rat model. Eight-week-old male spontaneously hypertensive rats (SHRs) were fed either a normal fat diet (chow) or a high-fat diet (HFD) and then the HFD-fed SHRs were randomized to either the DPP4i (MK-0626) or control (distilled water) groups for 12weeks. At 20weeks old, all the rats underwent hemodynamic and metabolic studies and Doppler echocardiography. Compared with the normal fat diet (chow)-fed SHRs, the HFD-fed SHRs developed a more intense degree of hyperglycemia and dyslipidemia and showed a constellation of left ventricular (LV) diastolic dysfunction, and exacerbated myocardial fibrosis, as well as activation of the TGF-β1 and Smad2/3 pathways. DPP4i significantly improved the metabolic and hemodynamic parameters. The echocardiogram showed that DPP4i improved the LV diastolic dysfunction (early to late ventricular filling velocity [E/A] ratio, 1.49±0.21 vs. 1.77±0.09, p<0.05). Furthermore, DPP4i significantly reduced myocardial fibrosis and collagen production by the myocardium and suppressed TGF-β1 and phosphorylation of Smad2/3 in the heart. In addition, DPP4i decreased TGF-β1-induced collagen production and TGF-β1-mediated phosphorylation and nuclear translocation of Smad2/3 in rat cardiac fibroblasts. In conclusion, DPP4 inhibition attenuated myocardial fibrosis and improved LV diastolic dysfunction in a DIO rat model by modulating the TGF-β1 and Smad2/3 pathways. Copyright © 2017 Elsevier Inc. All rights reserved.

Discovery of ((4R,5S)-5-amino-4-(2,4,5- trifluorophenyl)cyclohex-1-enyl)-(3- (trifluoromethyl)-5,6-dihydro- [1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl)methanone (ABT-341), a highly potent, selective, orally efficacious, and safe dipeptidyl peptidase IV inhibitor for the treatment of type 2 diabetes.

PubMed

Pei, Zhonghua; Li, Xiaofeng; von Geldern, Thomas W; Madar, David J; Longenecker, Kenton; Yong, Hong; Lubben, Thomas H; Stewart, Kent D; Zinker, Bradley A; Backes, Bradley J; Judd, Andrew S; Mulhern, Mathew; Ballaron, Stephen J; Stashko, Michael A; Mika, Amanda K; Beno, David W A; Reinhart, Glenn A; Fryer, Ryan M; Preusser, Lee C; Kempf-Grote, Anita J; Sham, Hing L; Trevillyan, James M

2006-11-02

Dipeptidyl peptidase IV (DPP4) deactivates glucose-regulating hormones such as GLP-1 and GIP, thus, DPP4 inhibition has become a useful therapy for type 2 diabetes. Optimization of the high-throughput screening lead 6 led to the discovery of 25 (ABT-341), a highly potent, selective, and orally bioavailable DPP4 inhibitor. When dosed orally, 25 dose-dependently reduced glucose excursion in ZDF rats. Amide 25 is safe in a battery of in vitro and in vivo tests and may represent a new therapeutic agent for the treatment of type 2 diabetes.

Dipeptidyl peptidase-4 inhibitors-associated bullous pemphigoid: a retrospective study of 168 pemphigoid and 9,304 diabetes mellitus cases.

PubMed

Kawaguchi, Yohei; Shimauchi, Risa; Nishibori, Nobuhiro; Kawashima, Kiyohito; Oshitani, So; Fujiya, Atsushi; Shibata, Taiga; Ohashi, Norimi; Izumi, Kentaro; Nishie, Wataru; Shimizu, Hiroshi; Arima, Hiroshi; Sobajima, Hiroshi

2018-06-19

Bullous pemphigoid (BP) may be drug-induced. This study evaluated the relation between BP and dipeptidyl peptidase-4 inhibitors (DPP4Is). We recruited patients diagnosed with BP at Ogaki Municipal Hospital from December 1, 2009 through December 31, 2017. We retrospectively collected data from medical records and divided patients into two groups based on whether they received DPP4Is. Additionally, we determined the incidence of BP in patients who were first prescribed DPP4Is at our hospital during the study period. Of 168 patients diagnosed with BP, 133 (79.1%) were positive for anti-BP180NC16a antibody. Thirty-two (19.0%) patients had been prescribed a DPP4I, 21 of whom (65.6%) were positive for anti-BP180NC16a antibody; this rate was lower than that in patients not receiving a DPP4I (82.3%) (p = 0.0360). Sixteen patients with type 2 diabetes mellitus (T2DM) had not been prescribed a DPP4I; only one (6.3%) was positive for anti-BP180NC16a antibody (p = 0.0339). During the study period, 9304 patients were prescribed DPP4Is, eight of whom developed BP; six (75.0%) had non-inflammatory BP, and five of the six (83.3%) were negative for anti-BP180NC16a antibody. The positive rate of anti-BP180NC16a antibody was lower in BP patients with DPP4I than without DPP4I, regardless of T2DM. The antibody titer was low in both the overall and T2DM populations. The prevalence of BP in 9304 patients receiving DPP4Is was 0.0859%, which is higher than that in the general population. Since DPP4Is are common diabetes treatments, we must be aware of the risk of BP. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Sarcopenia in Elderly Diabetic Patients: Role of Dipeptidyl Peptidase 4 Inhibitors.

PubMed

Rizzo, Maria Rosaria; Barbieri, Michelangela; Fava, Ilaria; Desiderio, Manuela; Coppola, Carla; Marfella, Raffaele; Paolisso, Giuseppe

2016-10-01

Our study aimed to investigate the effect of dipeptidyl peptidase 4 inhibitors (DPP4-I) on sarcopenic parameters in elderly type 2 diabetic patients. All elderly diabetic patients were invited to present themselves at our outpatient Geriatric Centre to undergo to evaluation of glycemic, inflammatory, and sarcopenic parameters and to perform a meal test for glucagon-like peptide-1 analogue (GLP-1) activity evaluation. According to European Working Group on Sarcopenia in Older People (EWGSOP) criteria, sarcopenic parameters were assessed by bioelectrical impedance analysis (BIA) and Kern dynamometer and 4-m gait speed tests. All patients received standardized meals for the assessment of postprandial levels of GLP-1 activity. Data of 80 elderly diabetic patients treated with oral glucose-lowering drugs (DPP4-I or Sulfonylureas Group) for at least 24 months before enrollment were analyzed. The DPP4-I Group showed appropriate glycemic control, lower levels of inflammatory parameters, a significant and greater increase, during interprandial periods, of GLP-1 activity, and better sarcopenic parameters (fat-free mass, skeletal muscle mass, and related indices, muscle strength, and gait speed) compared with the Sulfonylureas Group. Univariate analysis showed that sarcopenic parameters correlated with glycemic control and with GLP-1 area under the curve values. Multivariate analysis confirms these relationships. The results are consistent with the hypothesis that DPP4-I use might have a positive effect on the loss of muscle mass and its function. Copyright © 2016 AMDA – The Society for Post-Acute and Long-Term Care Medicine. Published by Elsevier Inc. All rights reserved.

Multiprotein assembly of Kv4.2, KChIP3 and DPP10 produces ternary channel complexes with ISA-like properties.

PubMed

Jerng, Henry H; Kunjilwar, Kumud; Pfaffinger, Paul J

2005-11-01

Kv4 pore-forming subunits are the principal constituents of the voltage-gated K+ channel underlying somatodendritic subthreshold A-type currents (I(SA)) in neurones. Two structurally distinct types of Kv4 channel modulators, Kv channel-interacting proteins (KChIPs) and dipeptidyl-peptidase-like proteins (DPLs: DPP6 or DPPX, DPP10 or DPPY), enhance surface expression and modify functional properties. Since KChIP and DPL distributions overlap in the brain, we investigated the potential coassembly of Kv4.2, KChIP3 and DPL proteins, and the contribution of DPLs to ternary complex properties. Immunoprecipitation results show that KChIP3 and DPP10 associate simultaneously with Kv4.2 proteins in rat brain as well as heterologously expressing Xenopus oocytes, indicating Kv4.2 + KChIP3 + DPP10 multiprotein complexes. Consistent with ternary complex formation, coexpression of Kv4.2, KChIP3 and DPP10 in oocytes and CHO cells results in current waveforms distinct from the arithmetic sum of Kv4.2 + KChIP3 and Kv4.2 + DPP10 currents. Furthermore, the Kv4.2 + KChIP3 + DPP10 channels recover from inactivation very rapidly (tau(rec) approximately 18-26 ms), closely matching that of native I(SA) and significantly faster than the recovery of Kv4.2 + KChIP3 or Kv4.2 + DPP10 channels. For comparison, identical triple coexpression experiments were performed using DPP6 variants. While most results are similar, the Kv4.2 + KChIP3 + DPP6 channels exhibit inactivation that slows with increasing membrane potential, resulting in inactivation slower than that of Kv4.2 + KChIP3 + DPP10 channels at positive voltages. In conclusion, the native neuronal subthreshold A-type channel is probably a macromolecular complex formed from Kv4 and a combination of both KChIP and DPL proteins, with the precise composition of channel alpha and auxiliary subunits underlying tissue and regional variability in I(SA) properties.

Macrocarpal C isolated from Eucalyptus globulus inhibits dipeptidyl peptidase 4 in an aggregated form.

PubMed

Kato, Eisuke; Kawakami, Kazuhiro; Kawabata, Jun

2018-12-01

Dipeptidyl peptidase 4 (DPP-4) inhibitors are used for the treatment of type-2 diabetes mellitus. Various synthetic inhibitors have been developed to date, and plants containing natural DPP-4 inhibitors have also been identified. Here, 13 plant samples were tested for their DPP-4 inhibitory activity. Macrocarpals A-C were isolated from Eucalyptus globulus through activity-guided fractionation and shown to be DPP-4 inhibitors. Of these, macrocarpal C showed the highest inhibitory activity, demonstrating an inhibition curve characterised by a pronounced increase in activity within a narrow concentration range. Evaluation of macrocarpal C solution by turbidity, nuclear magnetic resonance spectroscopy and mass spectrometry indicated its aggregation, which may explain the characteristics of the inhibition curve. These findings will be valuable for further study of potential small molecule DPP-4 inhibitors.

Mouse-adapted MERS coronavirus causes lethal lung disease in human DPP4 knockin mice.

PubMed

Li, Kun; Wohlford-Lenane, Christine L; Channappanavar, Rudragouda; Park, Jung-Eun; Earnest, James T; Bair, Thomas B; Bates, Amber M; Brogden, Kim A; Flaherty, Heather A; Gallagher, Tom; Meyerholz, David K; Perlman, Stanley; McCray, Paul B

2017-04-11

The Middle East respiratory syndrome (MERS) emerged in Saudi Arabia in 2012, caused by a zoonotically transmitted coronavirus (CoV). Over 1,900 cases have been reported to date, with ∼36% fatality rate. Lack of autopsies from MERS cases has hindered understanding of MERS-CoV pathogenesis. A small animal model that develops progressive pulmonary manifestations when infected with MERS-CoV would advance the field. As mice are restricted to infection at the level of DPP4, the MERS-CoV receptor, we generated mice with humanized exons 10-12 of the mouse Dpp4 locus. Upon inoculation with MERS-CoV, human DPP4 knockin (KI) mice supported virus replication in the lungs, but developed no illness. After 30 serial passages through the lungs of KI mice, a mouse-adapted virus emerged (MERS MA ) that grew in lungs to over 100 times higher titers than the starting virus. A plaque-purified MERS MA clone caused weight loss and fatal infection. Virus antigen was observed in airway epithelia, pneumocytes, and macrophages. Pathologic findings included diffuse alveolar damage with pulmonary edema and hyaline membrane formation associated with accumulation of activated inflammatory monocyte-macrophages and neutrophils in the lungs. Relative to the parental MERS-CoV, MERS MA viruses contained 13-22 mutations, including several within the spike (S) glycoprotein gene. S-protein mutations sensitized viruses to entry-activating serine proteases and conferred more rapid entry kinetics. Recombinant MERS MA bearing mutant S proteins were more virulent than the parental virus in hDPP4 KI mice. The hDPP4 KI mouse and the MERS MA provide tools to investigate disease causes and develop new therapies.

Identification of Dipeptidyl-Peptidase (DPP)5 and DPP7 in Porphyromonas endodontalis, Distinct from Those in Porphyromonas gingivalis.

PubMed

Nishimata, Haruka; Ohara-Nemoto, Yuko; Baba, Tomomi T; Hoshino, Tomonori; Fujiwara, Taku; Shimoyama, Yu; Kimura, Shigenobu; Nemoto, Takayuki K

2014-01-01

Dipeptidyl peptidases (DPPs) that liberate dipeptides from the N-terminal end of oligopeptides are crucial for the growth of Porphyromonas species, anaerobic asaccharolytic gram negative rods that utilize amino acids as energy sources. Porphyromonas endodontalis is a causative agent of periapical lesions with acute symptoms and Asp/Glu-specific DPP11 has been solely characterized in this organism. In this study, we identified and characterized two P. endodontalis DPPs, DPP5 and DPP7. Cell-associated DPP activity toward Lys-Ala-4-methylcoumaryl-7-amide (MCA) was prominent in P. endodontalis ATCC 35406 as compared with the Porphyromonas gingivalis strains ATCC 33277, 16-1, HW24D1, ATCC 49417, W83, W50, and HNA99. The level of hydrolysis of Leu-Asp-MCA by DPP11, Gly-Pro-MCA by DPP4, and Met-Leu-MCA was also higher than in the P. gingivalis strains. MER236725 and MER278904 are P. endodontalis proteins belong to the S9- and S46-family peptidases, respectively. Recombinant MER236725 exhibited enzymatic properties including substrate specificity, and salt- and pH-dependence similar to P. gingivalis DPP5 belonging to the S9 family. However, the kcat/Km figure (194 µM-1·sec-1) for the most potent substrate (Lys-Ala-MCA) was 18.4-fold higher as compared to the P. gingivalis entity (10.5 µM-1·sec-1). In addition, P. endodontalis DPP5 mRNA and protein contents were increased several fold as compared with those in P. gingivalis. Recombinant MER278904 preferentially hydrolyzed Met-Leu-MCA and exhibited a substrate specificity similar to P. gingivalis DPP7 belonging to the S46 family. In accord with the deduced molecular mass of 818 amino acids, a 105-kDa band was immunologically detected, indicating that P. endodontalis DPP7 is an exceptionally large molecule in the DPP7/DPP11/S46 peptidase family. The enhancement of four DPP activities was conclusively demonstrated in P. endodontalis, and remarkable Lys-Ala-MCA-hydrolysis was achieved by qualitative and quantitative

Identification of Dipeptidyl-Peptidase (DPP)5 and DPP7 in Porphyromonas endodontalis, Distinct from Those in Porphyromonas gingivalis

PubMed Central

Nishimata, Haruka; Ohara-Nemoto, Yuko; Baba, Tomomi T.; Hoshino, Tomonori; Fujiwara, Taku; Shimoyama, Yu; Kimura, Shigenobu; Nemoto, Takayuki K.

2014-01-01

Dipeptidyl peptidases (DPPs) that liberate dipeptides from the N-terminal end of oligopeptides are crucial for the growth of Porphyromonas species, anaerobic asaccharolytic gram negative rods that utilize amino acids as energy sources. Porphyromonas endodontalis is a causative agent of periapical lesions with acute symptoms and Asp/Glu-specific DPP11 has been solely characterized in this organism. In this study, we identified and characterized two P. endodontalis DPPs, DPP5 and DPP7. Cell-associated DPP activity toward Lys-Ala-4-methylcoumaryl-7-amide (MCA) was prominent in P. endodontalis ATCC 35406 as compared with the Porphyromonas gingivalis strains ATCC 33277, 16-1, HW24D1, ATCC 49417, W83, W50, and HNA99. The level of hydrolysis of Leu-Asp-MCA by DPP11, Gly-Pro-MCA by DPP4, and Met-Leu-MCA was also higher than in the P. gingivalis strains. MER236725 and MER278904 are P. endodontalis proteins belong to the S9- and S46-family peptidases, respectively. Recombinant MER236725 exhibited enzymatic properties including substrate specificity, and salt- and pH-dependence similar to P. gingivalis DPP5 belonging to the S9 family. However, the k cat/K m figure (194 µM−1·sec−1) for the most potent substrate (Lys-Ala-MCA) was 18.4-fold higher as compared to the P. gingivalis entity (10.5 µM−1·sec−1). In addition, P. endodontalis DPP5 mRNA and protein contents were increased several fold as compared with those in P. gingivalis. Recombinant MER278904 preferentially hydrolyzed Met-Leu-MCA and exhibited a substrate specificity similar to P. gingivalis DPP7 belonging to the S46 family. In accord with the deduced molecular mass of 818 amino acids, a 105-kDa band was immunologically detected, indicating that P. endodontalis DPP7 is an exceptionally large molecule in the DPP7/DPP11/S46 peptidase family. The enhancement of four DPP activities was conclusively demonstrated in P. endodontalis, and remarkable Lys-Ala-MCA-hydrolysis was achieved by qualitative and

Diabetes and cardiovascular risk: are dipeptidyl peptidase-4 inhibitors beneficial?

PubMed

Howard, Patricia A

2014-09-01

Cardiovascular (CV) disease is a major cause of morbidity and mortality in patients with diabetes. Whereas the link between glycemic control and reducing microvascular disease is firmly established, the evidence for macrovascular risk reduction remains unclear. Despite a host of available drugs for lowering serum glucose, none to date have been shown to substantially reduce CV risk and some have been associated with adverse effects. Recent trials have examined the CV effects of the dipeptidyl peptidase 4 (DPP-4) inhibitors or "gliptins."

Discovery of 2-[4-{{2-(2S,5R)-2-cyano-5-ethynyl-1-pyrrolidinyl]-2-oxoethyl]amino]- 4-methyl-1-piperidinyl]-4-pyridinecarboxylic acid (ABT-279): a very potent, selective, effective, and well-tolerated inhibitor of dipeptidyl peptidase-IV, useful for the treatment of diabetes.

PubMed

Madar, David J; Kopecka, Hana; Pireh, Daisy; Yong, Hong; Pei, Zhonghua; Li, Xiaofeng; Wiedeman, Paul E; Djuric, Stevan W; Von Geldern, Thomas W; Fickes, Michael G; Bhagavatula, Lakshmi; McDermott, Todd; Wittenberger, Steven; Richards, Steven J; Longenecker, Kenton L; Stewart, Kent D; Lubben, Thomas H; Ballaron, Stephen J; Stashko, Michael A; Long, Michelle A; Wells, Heidi; Zinker, Bradley A; Mika, Amanda K; Beno, David W A; Kempf-Grote, Anita J; Polakowski, James; Segreti, Jason; Reinhart, Glenn A; Fryer, Ryan M; Sham, Hing L; Trevillyan, James M

2006-10-19

Dipeptidyl peptidase-IV (DPP-IV) inhibitors are poised to be the next major drug class for the treatment of type 2 diabetes. Structure-activity studies of substitutions at the C5 position of the 2-cyanopyrrolidide warhead led to the discovery of potent inhibitors of DPP-IV that lack activity against DPP8 and DPP9. Further modification led to an extremely potent (Ki(DPP)(-)(IV) = 1.0 nM) and selective (Ki(DPP8) > 30 microM; Ki(DPP9) > 30 microM) clinical candidate, ABT-279, that is orally available, efficacious, and remarkably safe in preclinical safety studies.

Immunohistochemical localization of DPP10 in rat brain supports the existence of a Kv4/KChIP/DPPL ternary complex in neurons.

PubMed

Wang, Wan-Chen; Cheng, Chau-Fu; Tsaur, Meei-Ling

2015-03-01

Subthreshold A-type K(+) currents (ISA s) have been recorded from the cell bodies of hippocampal and neocortical interneurons as well as neocortical pyramidal neurons. Kv4 channels are responsible for the somatodendritic ISA s. It has been proposed that neuronal Kv4 channels are ternary complexes including pore-forming Kv4 subunits, K(+) channel-interacting proteins (KChIPs), and dipeptidyl peptidase-like proteins (DPPLs). However, colocalization evidence was still lacking. The distribution of DPP10 mRNA in rodent brain has been reported but its protein localization remains unknown. In this study, we generated a DPP10 antibody to label DPP10 protein in adult rat brain by immunohistochemistry. Absent from glia, DPP10 proteins appear mainly in the cell bodies of DPP10(+) neurons, not only at the plasma membrane but also in the cytoplasm. At least 6.4% of inhibitory interneurons in the hippocampus coexpressed Kv4.3, KChIP1, and DPP10, with the highest density in the CA1 strata alveus/oriens/pyramidale and the dentate hilus. Colocalization of Kv4.3/KChIP1/DPP10 was also detected in at least 6.9% of inhibitory interneurons scattered throughout the neocortex. Both hippocampal and neocortical Kv4.3/KChIP1/DPP10(+) inhibitory interneurons expressed parvalbumin or somatostatin, but not calbindin or calretinin. Furthermore, we found colocalization of Kv4.2/Kv4.3/KChIP3/DPP10 in neocortical layer 5 pyramidal neurons and olfactory bulb mitral cells. Together, although DPP10 is also expressed in some brain neurons lacking Kv4 (such as parvalbumin- and somatostatin-positive Golgi cells in the cerebellum), colocalization of DPP10 with Kv4 and KChIP at the plasma membrane of ISA -expressing neuron somata supports the existence of Kv4/KChIP/DPPL ternary complex in vivo. © 2014 Wiley Periodicals, Inc.

Dipeptidyl peptidase 4 - An important digestive peptidase in Tenebrio molitor larvae.

PubMed

Tereshchenkova, Valeriia F; Goptar, Irina A; Kulemzina, Irina A; Zhuzhikov, Dmitry P; Serebryakova, Marina V; Belozersky, Mikhail A; Dunaevsky, Yakov E; Oppert, Brenda; Filippova, Irina Yu; Elpidina, Elena N

2016-09-01

Dipeptidyl peptidase 4 (DPP 4) is a proline specific serine peptidase that plays an important role in different regulatory processes in mammals. In this report, we isolated and characterized a unique secreted digestive DPP 4 from the anterior midgut of a stored product pest, Tenebrio molitor larvae (TmDPP 4), with a biological function different than that of the well-studied mammalian DPP 4. The sequence of the purified enzyme was confirmed by mass-spectrometry, and was identical to the translated RNA sequence found in a gut EST database. The purified peptidase was characterized according to its localization in the midgut, and substrate specificity and inhibitor sensitivity were compared with those of human recombinant DPP 4 (rhDPP 4). The T. molitor enzyme was localized mainly in the anterior midgut of the larvae, and 81% of the activity was found in the fraction of soluble gut contents, while human DPP 4 is a membrane enzyme. TmDPP 4 was stable in the pH range 5.0-9.0, with an optimum activity at pH 7.9, similar to human DPP 4. Only specific inhibitors of serine peptidases, diisopropyl fluorophosphate and phenylmethylsulfonyl fluoride, suppressed TmDPP 4 activity, and the specific dipeptidyl peptidase inhibitor vildagliptin was most potent. The highest rate of TmDPP 4 hydrolysis was found for the synthetic substrate Arg-Pro-pNA, while Ala-Pro-pNA was a better substrate for rhDPP 4. Related to its function in the insect midgut, TmDPP 4 efficiently hydrolyzed the wheat storage proteins gliadins, which are major dietary proteins of T. molitor. Published by Elsevier Ltd.

Dipeptidyl peptidase-4 inhibitors and risk of heart failure in type 2 diabetes: systematic review and meta-analysis of randomised and observational studies.

PubMed

Li, Ling; Li, Sheyu; Deng, Ke; Liu, Jiali; Vandvik, Per Olav; Zhao, Pujing; Zhang, Longhao; Shen, Jiantong; Bala, Malgorzata M; Sohani, Zahra N; Wong, Evelyn; Busse, Jason W; Ebrahim, Shanil; Malaga, German; Rios, Lorena P; Wang, Yingqiang; Chen, Qunfei; Guyatt, Gordon H; Sun, Xin

2016-02-17

To examine the association between dipeptidyl peptidase-4 (DPP-4) inhibitors and the risk of heart failure or hospital admission for heart failure in patients with type 2 diabetes. Systematic review and meta-analysis of randomised and observational studies. Medline, Embase, Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov searched up to 25 June 2015, and communication with experts. Randomised controlled trials, non-randomised controlled trials, cohort studies, and case-control studies that compared DPP-4 inhibitors against placebo, lifestyle modification, or active antidiabetic drugs in adults with type 2 diabetes, and explicitly reported the outcome of heart failure or hospital admission for heart failure. Teams of paired reviewers independently screened for eligible studies, assessed risk of bias, and extracted data using standardised, pilot tested forms. Data from trials and observational studies were pooled separately; quality of evidence was assessed by the GRADE approach. Eligible studies included 43 trials (n=68,775) and 12 observational studies (nine cohort studies, three nested case-control studies; n=1,777,358). Pooling of 38 trials reporting heart failure provided low quality evidence for a possible similar risk of heart failure between DPP-4 inhibitor use versus control (42/15,701 v 33/12,591; odds ratio 0.97 (95% confidence interval 0.61 to 1.56); risk difference 2 fewer (19 fewer to 28 more) events per 1000 patients with type 2 diabetes over five years). The observational studies provided effect estimates generally consistent with trial findings, but with very low quality evidence. Pooling of the five trials reporting admission for heart failure provided moderate quality evidence for an increased risk in patients treated with DPP-4 inhibitors versus control (622/18,554 v 552/18,474; 1.13 (1.00 to 1.26); 8 more (0 more to 16 more)). The pooling of adjusted estimates from observational studies similarly suggested (with very low

Direct reductive amination of aldehyde bisulfite adducts induced by 2-picoline borane: application to the synthesis of a DPP-IV inhibitor.

PubMed

Faul, Margaret; Larsen, Rob; Levinson, Adam; Tedrow, Jason; Vounatsos, Filisaty

2013-02-15

Aldehyde-bisulfite adducts dervied from unstable parent aldehydes were reductively alkylated in a direct fashion with a variety of amines. This approach features the use of 2-picoline borane as the reducing agent and a protic solvent for the reaction media and has been successfully applied to the synthesis of a DPP-IV inhibitor and a variety of other amines.

Cost-effectiveness of dapagliflozin versus DPP-4 inhibitors as an add-on to Metformin in the Treatment of Type 2 Diabetes Mellitus from a UK Healthcare System Perspective.

PubMed

Charokopou, M; McEwan, P; Lister, S; Callan, L; Bergenheim, K; Tolley, K; Postema, R; Townsend, R; Roudaut, M

2015-11-05

Type 2 diabetes mellitus (T2DM) is a chronic, progressive condition where the primary treatment goal is to maintain control of glycated haemoglobin (HbA1c). In order for healthcare decision makers to ensure patients receive the highest standard of care within the available budget, the clinical benefits of each treatment option must be balanced against the economic consequences. The aim of this study was to assess the cost-effectiveness of dapagliflozin, the first-in-class sodium-glucose co-transporter 2 (SGLT2) inhibitor, compared with a dipeptidyl peptidase-4 inhibitor (DPP-4i), when added to metformin for the treatment of patients with T2DM inadequately controlled on metformin alone. The previously published and validated Cardiff diabetes model was used as the basis for this economic evaluation, with treatment effect parameters sourced from a systematic review and network meta-analysis. Costs, derived from a UK healthcare system perspective, and quality-adjusted life years (QALYs), were used to present the final outcome as an incremental cost-effectiveness ratio (ICER) over a lifetime horizon. Univariate and probabilistic sensitivity analyses (PSA) were carried out to assess uncertainty in the model results. Compared with DPP-4i, dapagliflozin was associated with a mean incremental benefit of 0.032 QALYs (95% confidence interval [CI]: -0.022, 0.140) and with an incremental cost of £216 (95% CI: £-258, £795). This resulted in an ICER point estimate of £6,761 per QALY gained. Sensitivity analysis determined incremental costs to be insensitive to variation in most parameters, with only the treatment effect on weight having a notable impact on the incremental QALYs; however, there were no scenarios which raised the ICER above £15,000 per QALY. The PSA estimated that dapagliflozin had an 85% probability of being cost-effective at a willingness-to-pay threshold of £20,000 per QALY gained. Dapagliflozin in combination with metformin was shown to be a cost

The Dipeptidyl Peptidases 4, 8, and 9 in Mouse Monocytes and Macrophages: DPP8/9 Inhibition Attenuates M1 Macrophage Activation in Mice.

PubMed

Waumans, Yannick; Vliegen, Gwendolyn; Maes, Lynn; Rombouts, Miche; Declerck, Ken; Van Der Veken, Pieter; Vanden Berghe, Wim; De Meyer, Guido R Y; Schrijvers, Dorien; De Meester, Ingrid

2016-02-01

Atherosclerosis remains the leading cause of death in Western countries. Dipeptidyl peptidase (DPP) 4 has emerged as a novel target for the prevention and treatment of atherosclerosis. Family members DPP8 and 9 are abundantly present in macrophage-rich regions of atherosclerotic plaques, and DPP9 inhibition attenuates activation of human M1 macrophages in vitro. Studying this family in a mouse model for atherosclerosis would greatly advance our knowledge regarding their potential as therapeutic targets. We found that DPP4 is downregulated during mouse monocyte-to-macrophage differentiation. DPP8 and 9 expression seems relatively low in mouse monocytes and macrophages. Viability of primary mouse macrophages is unaffected by DPP4 or DPP8/9 inhibition. Importantly, DPP8/9 inhibition attenuates macrophage activation as IL-6 secretion is significantly decreased. Mouse macrophages respond similarly to DPP inhibition, compared to human macrophages. This shows that the mouse could become a valid model species for the study of DPPs as therapeutic targets in atherosclerosis.

[Combination therapy of metformin vs dipeptidulpeptidase inhibitors and sulfonylureas in type 2 diabetes: clinical and economic impact].

PubMed

Sicras-Mainar, Antoni; Navarro-Artieda, Ruth

2014-01-01

Determine the clinical repurcussions of adherence, metabolic control, hypoglycemia and cardiovascular events (CVE) and economics (resources and costs) in the combination therapy of metformin vs DPP-4 (dipeptidyl peptidase-4) inhibitors and sulfonylureas in patients with type 2 diabetes. Materials and methods. Observational-multicenter and retrospective design. We evaluated patients ≥ 30 years of age in treatment with metformin and who started a second oral antidiabetic treatment during 2008-2009. 2 study groups were established: a) metformin + DPP-4 inhibitors, and b) metformin + sulfonylurea. comorbidity, metabolic control (HbA1c <7%), compliance and complications (hypoglycemia, CVE). Follow up was conducted over two years. The cost model differentiated between direct healthcare costs (primary/ specialty care), and indirect costs (labor productivity). logistic regression and ANCOVA models. Results. 1,405 patients were recruited (average age 67.1 years old; 56.2% male). 37.0% started a second treatment with DPP-4 inhibitors, and 63.0% with sulfonylureas. After two years of follow up, patients treated with DPP-4 inhibitors showed greater treatment adherence (70.3% vs. 60.6%; p <0.001); better metabolic control (64.3% vs. 60.6%; p<0.001), and a lower proportion of hypoglycemia (13.9% vs. 40.4%; p <0.001, respectively). The average/unit of adjusted total costs was € 2,341 vs. € 2,512; p = 0.038. CVE and renal failure rates were 3.7% vs. 6.4%; p = 0.027. Vildagliptin was the most used drug among DPP-4 inhibitors. Conclusions. Sulfonylureas were the most used drug for diabetes treatment. Patients treated with DPP-4 inhibitors had higher adherence and control of diabetes, with lower rates of hypoglycemia and CVE, resulting in lower healthcare costs.

Dipeptidyl-peptidase (DPP)-4 inhibitors and glucagon-like peptide (GLP)-1 analogues for prevention or delay of type 2 diabetes mellitus and its associated complications in people at increased risk for the development of type 2 diabetes mellitus.

PubMed

Hemmingsen, Bianca; Sonne, David P; Metzendorf, Maria-Inti; Richter, Bernd

2017-05-10

The projected rise in the incidence of type 2 diabetes mellitus (T2DM) could develop into a substantial health problem worldwide. Whether dipeptidyl-peptidase (DPP)-4 inhibitors or glucagon-like peptide (GLP)-1 analogues are able to prevent or delay T2DM and its associated complications in people at risk for the development of T2DM is unknown. To assess the effects of DPP-4 inhibitors and GLP-1 analogues on the prevention or delay of T2DM and its associated complications in people with impaired glucose tolerance, impaired fasting blood glucose, moderately elevated glycosylated haemoglobin A1c (HbA1c) or any combination of these. We searched the Cochrane Central Register of Controlled Trials; MEDLINE; PubMed; Embase; ClinicalTrials.gov; the World Health Organization (WHO) International Clinical Trials Registry Platform; and the reference lists of systematic reviews, articles and health technology assessment reports. We asked investigators of the included trials for information about additional trials. The date of the last search of all databases was January 2017. We included randomised controlled trials (RCTs) with a duration of 12 weeks or more comparing DPP-4 inhibitors and GLP-1 analogues with any pharmacological glucose-lowering intervention, behaviour-changing intervention, placebo or no intervention in people with impaired fasting glucose, impaired glucose tolerance, moderately elevated HbA1c or combinations of these. Two review authors read all abstracts and full-text articles and records, assessed quality and extracted outcome data independently. One review author extracted data which were checked by a second review author. We resolved discrepancies by consensus or the involvement of a third review author. For meta-analyses, we planned to use a random-effects model with investigation of risk ratios (RRs) for dichotomous outcomes and mean differences (MDs) for continuous outcomes, using 95% confidence intervals (CIs) for effect estimates. We assessed the

Neuroprotective effect of selective DPP-4 inhibitor in experimental vascular dementia.

PubMed

Jain, Swati; Sharma, Bhupesh

2015-12-01

Vascular risk factors are associated with a higher incidence of dementia. Diabetes mellitus is considered as a main risk factor for Alzheimer's disease and vascular dementia. Both forms of dementia are posing greater risk to the world population and are increasing at a faster rate. In the past we have reported the induction of vascular dementia by experimental diabetes. This study investigates the role of vildagliptin, a dipeptidyl peptidase-4 inhibitor in the pharmacological interdiction of pancreatectomy diabetes induced vascular endothelial dysfunction and subsequent vascular dementia in rats. Attentional set shifting and Morris water-maze test were used for assessment of learning and memory. Vascular endothelial function, blood brain barrier permeability, serum glucose, serum nitrite/nitrate, oxidative stress (viz. aortic superoxide anion, brain thiobarbituric acid reactive species and brain glutathione), brain calcium and inflammation (myeloperoxidase) were also estimated. Pancreatectomy diabetes rats have shown impairment of endothelial function, blood brain barrier permeability, learning and memory along with increase in brain inflammation, oxidative stress and calcium. Administration of vildagliptin has significantly attenuated pancreatectomy induced impairment of learning, memory, endothelial function, blood brain barrier permeability and biochemical parameters. It may be concluded that vildagliptin, a dipeptidyl peptidase-4 inhibitor may be considered as potential pharmacological agents for the management of pancreatectomy induced endothelial dysfunction and subsequent vascular dementia. The selective modulators of dipeptidyl peptidase-4 may further be explored for their possible benefits in vascular dementia. Copyright © 2015 Elsevier Inc. All rights reserved.

DPP10 splice variants are localized in distinct neuronal populations and act to differentially regulate the inactivation properties of Kv4-based ion channels.

PubMed

Jerng, Henry H; Lauver, Aaron D; Pfaffinger, Paul J

2007-08-01

Dipeptidyl peptidase-like proteins (DPLs) and Kv-channel-interacting proteins (KChIPs) join Kv4 pore-forming subunits to form multi-protein complexes that underlie subthreshold A-type currents (I(SA)) in neuronal somatodendritic compartments. Here, we characterize the functional effects and brain distributions of N-terminal variants belonging to the DPL dipeptidyl peptidase 10 (DPP10). In the Kv4.2+KChIP3+DPP10 channel complex, all DPP10 variants accelerate channel gating kinetics; however, the splice variant DPP10a produces uniquely fast inactivation kinetics that accelerates with increasing depolarization. This DPP10a-specific inactivation dominates in co-expression studies with KChIP4a and other DPP10 isoforms. Real-time qRT-PCR and in situ hybridization analyses reveal differential expression of DPP10 variants in rat brain. DPP10a transcripts are prominently expressed in the cortex, whereas DPP10c and DPP10d mRNAs exhibit more diffuse distributions. Our results suggest that DPP10a underlies rapid inactivation of cortical I(SA), and the regulation of isoform expression may contribute to the variable inactivation properties of I(SA) across different brain regions.

The Place of Dipeptidyl Peptidase-4 Inhibitors in Type 2 Diabetes Therapeutics: A “Me Too” or “the Special One” Antidiabetic Class?

PubMed Central

Godinho, Ricardo; Carvalho, Eugénia; Teixeira, Frederico

2015-01-01

Incretin-based therapies, the most recent therapeutic options for type 2 diabetes mellitus (T2DM) management, can modify various elements of the disease, including hypersecretion of glucagon, abnormal gastric emptying, postprandial hyperglycaemia, and, possibly, pancreatic β cell dysfunction. Dipeptidyl peptidase-4 (DPP-4) inhibitors (gliptins) increase glucagon-like peptide-1 (GLP-1) availability and correct the “incretin defect” seen in T2DM patients. Clinical studies have shown good glycaemic control with minimal risk of hypoglycaemia or any other adverse effects, despite the reports of pancreatitis, whose association remains to be proved. Recent studies have been focusing on the putative ability of DPP-4 inhibitors to preserve pancreas function, in particular due to the inhibition of apoptotic pathways and stimulation of β cell proliferation. In addition, other cytoprotective effects on other organs/tissues that are involved in serious T2DM complications, including the heart, kidney, and retina, have been increasingly reported. This review outlines the therapeutic potential of DPP-4 inhibitors for the treatment of T2DM, focusing on their main features, clinical applications, and risks, and discusses the major challenges for the future, in particular the possibility of becoming the preferred therapy for T2DM due to their ability to modify the natural history of the disease and ameliorate nephropathy, retinopathy, and cardiovascular complications. PMID:26075286

Dipeptidyl Peptidase-4 Inhibitor Use is Associated with Decreased Risk of Fracture in Patients with Type 2 Diabetes: A Population-Based Cohort Study.

PubMed

Hou, Wen-Hsuan; Chang, Kai-Cheng; Li, Chung-Yi; Ou, Huang-Tz

2018-05-16

To investigate the putative link between dipeptidyl peptidase-4 inhibitor (DPP-4i) use and the risk of fracture in patients with type 2 diabetes. This propensity-score-matched population-based cohort study was performed between 2009 and 2013 on patients with type 2 diabetes who were stable metformin users. A total of 3,996 patients with type 2 diabetes used DPP-4i as a second-line antidiabetic drug. The same number of matched non-DPP-4i users were followed up until fracture occurrence, health insurance policy termination, or the end of 2013. The incidence rates of overall and cause-specific fractures were estimated based on the Poisson assumption. A multiple Cox proportional hazard model was used to estimate the covariate-adjusted hazard ratio (HR) and 95% confidence interval (CI) to determine the association between DPP-4i use and overall and cause-specific fractures stratified by age and sex. Over a maximum follow-up period of 5 years, 340 DPP-4i users and 419 non-DPP-4i users were newly diagnosed with fractures, yielding incidence rates of 28.03 and 32.04 per 1,000 people per year, respectively. The Cox proportional hazard model revealed that DPP-4i use significantly reduced the risk of all-cause fractures and upper extremity fractures, with adjusted HRs of 0.86 (95% CI: 0.74-0.99) and 0.75 (95% CI: 0.59-0.95), respectively. The aforementioned associations of DDP-4i use with fracture were sustained across sex and age stratifications. The results of this study supported the premise that DPP-4i usage is associated with a reduced risk of all-cause fractures and upper extremity fractures in patients with type 2 diabetes. This article is protected by copyright. All rights reserved.

Inhibition of CD26/DPP IV attenuates ischemia/reperfusion injury in orthotopic mouse lung transplants: the pivotal role of vasoactive intestinal peptide.

PubMed

Jungraithmayr, Wolfgang; De Meester, Ingrid; Matheeussen, Veerle; Inci, Ilhan; Augustyns, Koen; Scharpé, Simon; Weder, Walter; Korom, Stephan

2010-04-01

The T cell activation Ag CD26/dipeptidylpeptidase IV (DPP IV) combines co-stimulatory and enzymatic properties. Catalytically, it functions as an exopeptidase, modulating biological activity of key chemokines and peptides. Here we investigated the effect of organ-specific inhibition of DPP IV catalytic activity on ischemia/reperfusion injury after extended ischemia in the mouse model of orthotopic single lung transplantation. C57BL/6 mice were syngeneically, transplanted, grafts were perfused and stored in Perfadex with (treated) or without (control) a DPP IV enzymatic activity inhibitor (AB192). Transplantation was performed after 18h cold ischemia time; following 2-h reperfusion, grafts were analyzed for oxygenation, thiobarbituric acid-reactive substances, histomorphology, and immunohistochemistry was performed for leukocyte Ag 6, myeloperoxidase, hemoxygenase 1, vasoactive intestinal protein (VIP), and real-time PCR for VIP. Treatment with the DPP IV inhibitor AB192 resulted in significant improvement of gas exchange, less lipid oxidation, preservation of parenchymal ultrastructure, reduced neutrophil infiltration, reduced myeloperoxidase expression, increased hemoxygenase 1 expression, pronounced expression of VIP in alveolar macrophages and increased mRNA expression of VIP. Inhibition of intragraft DPP IV catalytic activity with AB192 strikingly ameliorates ischemia/reperfusion injury after extended ischemia. Furthermore, preservation of endogenous intragraft VIP levels correlate with maintaining lung function and structural integrity. Copyright (c) 2009 Elsevier Inc. All rights reserved.

Mechanism-based population pharmacokinetic modelling in diabetes: vildagliptin as a tight binding inhibitor and substrate of dipeptidyl peptidase IV

PubMed Central

Landersdorfer, Cornelia B; He, Yan-Ling; Jusko, William J

2012-01-01

AIMS To assess the pharmacokinetics of vildagliptin at different doses and build a mechanism-based population model that simultaneously describes vildagliptin pharmacokinetics and its effects on DPP-4 activity based on underlying physiology and biology. METHODS Vildagliptin concentrations and DPP-4 activity vs. time from 13 type 2 diabetic patients after oral vildagliptin 10, 25 or 100 mg and placebo twice daily for 28 days were co-modelled. NONMEM VI and S-ADAPT were utilized for population modelling. RESULTS A target-mediated drug disposition (TMDD) model accounting for capacity-limited high affinity binding of vildagliptin to DPP-4 in plasma and tissues had good predictive performance. Modelling the full time course of the vildagliptin-DPP-4 interaction suggested parallel vildagliptin dissociation from DPP-4 by a slow first-order process and hydrolysis by DPP-4 to an inactive metabolite as a disposition mechanism. Due to limited amounts of DPP-4, vildagliptin concentrations increased slightly more than dose proportionally. This newly proposed model and the parameter estimates are supported by published in vitro studies. Mean parameter estimates (inter-individual coefficient of variation) were: non-saturable clearance 36 l h−1 (25%), central volume of distribution 22 l (37%), half-life of dissociation from DPP-4 1.1 h (94%) and half-life of hydrolysis 6.3 h (81%). CONCLUSIONS Vildagliptin is both an inhibitor and substrate for DPP-4. By utilizing the TMDD approach, slow dissociation of vildagliptin from DPP-4 was found in patients and the half-life of hydrolysis by DPP-4 estimated. This model can be used to predict DPP-4 inhibition effects of other dosage regimens and be modified for other DPP-4 inhibitors to differentiate their properties. PMID:22442826

Adherence to dipeptidyl peptidase-4 inhibitor therapy among type 2 diabetes patients with employer-sponsored health insurance in Japan.

PubMed

Kurtyka, Karen; Nishikino, Rie; Ito, Chie; Brodovicz, Kim; Chen, Yong; Tunceli, Kaan

2016-09-01

Dipeptidyl peptidase-4 inhibitors (DPP-4i) are a common first-line treatment for type 2 diabetes in Japan. However, little is known about patients' medication adherence, persistence and discontinuation in this setting. This was a retrospective cohort study of new DPP-4i users in a Japanese claims database. Adult patients (age 18-65 years) with type 2 diabetes diagnosis and no diagnosis of other diabetes or pregnancy during the study period were included if they were prescribed a DPP-4i as monotherapy or combination oral therapy. Adherence to therapy was measured using the proportion of days covered method over a fixed period of 1 year. The proportion of days covered of ≥80% was considered adherent. Persistence was defined as continuing index DPP-4i treatment with <90-day gap between refills. Patient baseline characteristics were explored as potential predictors of DPP-4i discontinuation and adherence in multivariable models. The final sample contained 2,874 monotherapy and 3,016 dual therapy patients. The mean age was approximately 51 years, and 75% were men. The mean proportion of days covered was 76.6% among monotherapy patients and 82.5% among dual therapy patients, with 67.2% of monotherapy and 74.4% of dual therapy patients classified as adherent. At 12 months, 72.2% of monotherapy and 79.2% of dual therapy patients were persistent. In adjusted models, younger age and having fewer concomitant medications were significantly associated with lower adherence and higher discontinuation, in both treatment groups. Those under the age of 45 years, and those with fewer concomitant medications were less likely to be adherent and persistent, and more likely to discontinue DPP-4i therapy. © 2016 Merck Sharp & Dohme Corp. Journal of Diabetes Investigation published by Asian Association of the Study of Diabetes (AASD) and John Wiley & Sons Australia, Ltd.

Effect of vildagliptin, a dipeptidyl peptidase 4 inhibitor, on cardiac hypertrophy induced by chronic beta-adrenergic stimulation in rats

PubMed Central

2014-01-01

Background Heart failure with left ventricular (LV) hypertrophy is often associated with insulin resistance and inflammation. Recent studies have shown that dipeptidyl peptidase 4 (DPP4) inhibitors improve glucose metabolism and inflammatory status. We therefore evaluated whether vildagliptin, a DPP4 inhibitor, prevents LV hypertrophy and improves diastolic function in isoproterenol-treated rats. Methods Male Wistar rats received vehicle (n = 20), subcutaneous isoproterenol (2.4 mg/kg/day, n = 20) (ISO), subcutaneous isoproterenol (2.4 mg/kg/day + oral vildagliptin (30 mg/kg/day, n = 20) (ISO-VL), or vehicle + oral vildagliptin (30 mg/kg/day, n = 20) (vehicle-VL) for 7 days. Results Blood pressure was similar among the four groups, whereas LV hypertrophy was significantly decreased in the ISO-VL group compared with the ISO group (heart weight/body weight, vehicle: 3.2 ± 0.40, ISO: 4.43 ± 0.39, ISO-VL: 4.14 ± 0.29, vehicle-VL: 3.16 ± 0.16, p < 0.05). Cardiac catheterization revealed that vildagliptin lowered the elevated LV end-diastolic pressure observed in the ISO group, but other parameters regarding LV diastolic function such as the decreased minimum dp/dt were not ameliorated in the ISO-VL group. Histological analysis showed that vildagliptin attenuated the increased cardiomyocyte hypertrophy and perivascular fibrosis, but it did not affect angiogenesis in cardiac tissue. In the ISO-VL group, quantitative PCR showed attenuation of increased mRNA expression of tumor necrosis factor-α, interleukin-6, insulin-like growth factor-l, and restoration of decreased mRNA expression of glucose transporter type 4. Conclusions Vildagliptin may prevent LV hypertrophy caused by continuous exposure to isoproterenol in rats. PMID:24521405

Does the treatment of type 2 diabetes mellitus with the DPP-4 inhibitor vildagliptin reduce HbA1c to a greater extent in Japanese patients than in Caucasian patients?

PubMed

Foley, James E; Bhosekar, Vaishali; Kawamori, Ryuzo

2016-01-01

Previous work suggests that Japanese patients with type 2 diabetes mellitus (T2DM) may respond more favorably to a DPP-4 (dipeptidyl peptidase-4) inhibitor than Caucasians. We aimed to compare the efficacy of the DPP-4 inhibitor vildagliptin (50 mg twice daily [bid]) between Japanese and Caucasian populations. This analysis pooled data from 19 studies of drug-naïve patients with T2DM who were treated for 12 weeks with vildagliptin 50 mg bid as monotherapy. The pool comprised Japanese patients (n=338) who had been treated in Japan and Caucasian patients (n=1,275) who were treated elsewhere. Change from baseline (Δ) in glycated hemoglobin (HbA1c) at 12 weeks (in millimoles per mole) versus baseline HbA1c (both in percentage National Glycohemoglobin Standardization Program units [NGSP%] and millimoles per mole) for each population was reported. Universal HbA1c in millimoles per mole was calculated from either the Japanese Diabetes Society or the NGSP% HbA1c standards. At baseline, mean values for Japanese and Caucasian patients, respectively, were as follows: age, 59 years and 56 years; % male, 69% and 57%. The average HbA1c was reduced from 7.90% to 6.96% (Japanese Diabetes Society) and from 8.57% to 7.50% (United States National Glycohemoglobin Standardization Program), while HbA1c was reduced from 63 mmol/mol to 53 mmol/mol and from 70 mmol/mol to 58 mmol/mol in Japanese and Caucasians, respectively. ΔHbA1c increased with increasing baseline in both populations. The slopes were the same (0.41, r (2)=0.36; and 0.41, r (2)=0.15), and the intercepts were 15.4 mmol/mol and 17.2 mmol/mol, respectively. In Japanese patients, mean ΔHbA1c was greater by 1.7 mmol/mol (0.2% NGSP HbA1c) at any given baseline HbA1c than in Caucasians (P=0.01). The present pooled analysis suggests that Japanese patients respond better to vildagliptin treatment compared with Caucasians. However, when glycemic control was corrected by using the same glycemic standard, the difference in HbA1c

A novel DPP6 isoform (DPP6-E) can account for differences between neuronal and reconstituted A-type K(+) channels.

PubMed

Maffie, Jonathon; Blenkinsop, Timothy; Rudy, Bernardo

2009-01-16

The channels mediating most of the somatodendritic A-type K(+) current in neurons are thought to be ternary complexes of Kv4 pore-forming subunits and two types of auxiliary subunits, the K(+) channel interacting proteins (KChIPs) and dipeptidyl-peptidase-like (DPPL) proteins. The channels expressed in heterologous expression systems by mixtures of Kv4.2, KChIP1 and DPP6-S resemble in many properties the A-type current in hippocampal CA1 pyramidal neurons and cerebellar granule cells, neurons with prominent A-type K(+) currents. However, the native currents have faster kinetics. Moreover, the A-type currents in neurons in intermediary layers of the superior colliculus have even faster inactivating rates. We have characterized a new DPP6 spliced isoform, DPP6-E, that produces in heterologous cells ternary Kv4 channels with very fast kinetics. DPP6-E is selectively expressed in a few neuronal populations in brain including cerebellar granule neurons, hippocampal pyramidal cells and neurons in intermediary layers of the superior colliculus. The effects of DPP6-E explain past discrepancies between reconstituted and native Kv4 channels in some neurons, and contributes to the diversity of A-type K(+) currents in neurons.

Identification and characterization of a dipeptidyl peptidase IV inhibitor from aronia juice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kozuka, Miyuki; Yamane, Takuya, E-mail: t-yamane@pharm.hokudai.ac.jp; Nakano, Yoshihisa

Aronia berries have many potential effects on health, including an antioxidant effect, effect for antimutagenesis, hepatoprotection and cardioprotection, an antidiabetic effect and inhibition of cancer cell proliferation. Previous human studies have shown that aronia juice may be useful for treatment of obesity disorders. In this study, we found that aronia juice has an inhibitory effect against dipeptidyl peptidase IV (DPP IV) (EC 3.4.14.5). DPP IV is a peptidase that cleaves the N-terminal region of incretins such as glucagon-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1). Inactivation of incretins by DPP IV induces reduction of insulin secretion. Furthermore, we identified thatmore » cyanidin 3, 5-diglucoside as the DPP IV inhibitor in aronia juice. DPP IV was inhibited more strongly by cyanidin 3, 5-diglucoside than by cyanidin and cyanidin 3-glucoside. The results suggest that DPP IV is inhibited by cyanidin 3, 5-diglucoside present in aronia juice. The antidiabetic effect of aronia juice may be mediated through DPP IV inhibition by cyanidin 3, 5-diglucoside. - Highlights: • DPP IV activity is inhibited by aronia juice. • DPP IV inhibitor is cyanidin 3, 5-diglucoside in aronia juice. • DPP IV is inhibited by cyanidin 3, 5-diglucoside more than cyanidin and cyanidin 3-glucoside.« less

Implication of LRRC4C and DPP6 in neurodevelopmental disorders

PubMed Central

Maussion, Gilles; Cruceanu, Cristiana; Rosenfeld, Jill A.; Bell, Scott C.; Jollant, Fabrice; Szatkiewicz, Jin; Collins, Ryan L.; Hanscom, Carrie; Kolobova, Ilaria; de Champfleur, Nicolas Menjot; Blumenthal, Ian; Chiang, Colby; Ota, Vanessa; Hultman, Christina; O’Dushlaine, Colm; McCarroll, Steve; Alda, Martin; Jacquemont, Sebastien; Ordulu, Zehra; Marshall, Christian R.; Carter, Melissa T.; Shaffer, Lisa G.; Sklar, Pamela; Girirajan, Santhosh; Morton, Cynthia C.; Gusella, James F.; Turecki, Gustavo; Stavropoulos, D. J.; Sullivan, Patrick F.; Scherer, Stephen W.; Talkowski, Michael E.; Ernst, Carl

2018-01-01

We performed whole-genome sequencing on an individual from a family with variable psychiatric phenotypes that had a sensory processing disorder, apraxia, and autism. The proband harbored a maternally inherited balanced translocation (46,XY,t(11;14)(p12;p12)mat) that disrupted LRRC4C, a member of the highly specialized netrin G family of axon guidance molecules. The proband also inherited a paternally derived chromosomal inversion that disrupted DPP6, a potassium channel interacting protein. Copy Number (CN) analysis in 14,077 cases with neurodevelopmental disorders and 8,960 control subjects revealed that 60% of cases with exonic deletions in LRRC4C had a second clinically recognizable syndrome associated with variable clinical phenotypes, including 16p11.2, 1q44, and 2q33.1 CN syndromes, suggesting LRRC4C deletion variants may be modifiers of neurodevelopmental disorders. In vitro, functional assessments modeling patient deletions in LRRC4C suggest a negative regulatory role of these exons found in the untranslated region of LRRC4C, which has a single, terminal coding exon. These data suggest that the proband’s autism may be due to the inheritance of disruptions in both DPP6 and LRRC4C, and may highlight the importance of the netrin G family and potassium channel interacting molecules in neurodevelopmental disorders. PMID:27759917

Uncoupling protein-2 mediates DPP-4 inhibitor-induced restoration of endothelial function in hypertension through reducing oxidative stress.

PubMed

Liu, Limei; Liu, Jian; Tian, Xiao Yu; Wong, Wing Tak; Lau, Chi Wai; Xu, Aimin; Xu, Gang; Ng, Chi Fai; Yao, Xiaoqiang; Gao, Yuansheng; Huang, Yu

2014-10-10

Although uncoupling protein 2 (UCP2) negatively regulates intracellular reactive oxygen species (ROS) production and protects vascular function, its participation in vascular benefits of drugs used to treat cardiometabolic diseases is largely unknown. This study investigated whether UCP2 and associated oxidative stress reduction contribute to the improvement of endothelial function by a dipeptidyl peptidase-4 inhibitor, sitagliptin, in hypertension. Pharmacological inhibition of cyclooxygenase-2 (COX-2) but not COX-1 prevented endothelial dysfunction, and ROS scavengers reduced COX-2 mRNA and protein expression in spontaneously hypertensive rats (SHR) renal arteries. Angiotensin II (Ang II) evoked endothelium-dependent contractions (EDCs) in C57BL/6 and UCP2 knockout (UCP2KO) mouse aortae. Chronic sitagliptin administration attenuated EDCs in SHR arteries and Ang II-infused C57BL/6 mouse aortae and eliminated ROS overproduction in SHR arteries, which were reversed by glucagon-like peptide 1 receptor (GLP-1R) antagonist exendin 9-39, AMP-activated protein kinase (AMPK)α inhibitor compound C, and UCP2 inhibitor genipin. By contrast, sitagliptin unaffected EDCs in Ang II-infused UCP2KO mice. Sitagliptin increased AMPKα phosphorylation, upregulated UCP2, and downregulated COX-2 expression in arteries from SHR and Ang II-infused C57BL/6 mice. Importantly, exendin 9-39, compound C, and genipin reversed the inhibitory effect of GLP-1R agonist exendin-4 on Ang II-stimulated mitochondrial ROS rises in SHR endothelial cells. Moreover, exendin-4 improved the endothelial function of renal arteries from SHR and hypertensive patients. We elucidate for the first time that UCP2 serves as an important signal molecule in endothelial protection conferred by GLP-1-related agents. UCP2 could be a useful target in treating hypertension-related vascular events. UCP2 inhibits oxidative stress and downregulates COX-2 expression through GLP-1/GLP-1R/AMPKα cascade.

DPP and DSP are Necessary for Maintaining TGF-β1 Activity in Dentin

PubMed Central

Yamakoshi, Y.; Kinoshita, S.; Izuhara, L.; Karakida, T.; Fukae, M.; Oida, S.

2014-01-01

Porcine dentin sialophosphoprotein (DSPP) is the most abundant non-collagenous protein in dentin. It is processed by proteases into 3 independent proteins: dentin sialoprotein (DSP), dentin glycoprotein (DGP), and dentin phosphoprotein (DPP). We fractionated DPP and DSP along with TGF-β activity by ion exchange (IE) chromatography from developing pig molars and measured their alkaline phosphatase (ALP)-stimulating activity in human periodontal (HPDL) cells with or without TGF-β receptor inhibitor. We then purified TGF-β-unbound or -bound DPP and DSP by reverse-phase high-performance liquid chromatography (RP-HPLC) using the ALP-HPDL system. The TGF-β isoform bound to DPP and DSP was identified as being TGF-β1 by both ELISA and LC-MS/MS analysis. We incubated carrier-free human recombinant TGF-β1 (CF-hTGF-β1) with TGF-β-unbound DPP or DSP and characterized the binding on IE-HPLC using the ALP-HPDL system. When only CF-hTGF-β1 was incubated, approximately 3.6% of the ALP-stimulating activity remained. DPP and DSP rescued the loss of TGF-β1 activity. Approximately 19% and 10% of the ALP stimulating activities were retained by the binding of TGF-β to DPP and DSP, respectively. The type I collagen infrequently bound to CF-hTGF-β1. We conclude that both DPP and DSP help retain TGF-β1 activity in porcine dentin. PMID:24799420

Gestational glucocorticoid exposure disrupts glucose homeostasis that is accompanied by increased endoglin and DPP-4 activity instead of GSK-3 in rats.

PubMed

Badmus, Olufunto O; Michael, Olugbenga S; Rabiu, Saheed; Olatunji, Lawrence A

2018-04-13

Gestational glucocorticoid (GC) treatment has been associated with cardiometabolic disorder (CMD) in offspring's in later life. Elevated dipeptidyl peptidase-4 (DPP-4) activity, endoglin and glycogen synthase kinase-3 (GSK-3) has also been implicated in the development of insulin resistance (IR) and/or vascular inflammation. We aimed to investigate the impact of GC exposure on glucose metabolism and the circulating levels of inflammatory biomarkers, DPP-4 activity and GSK-3 in pregnant rats. Pregnant Wistar rats received either vehicle or dexamethasone (DEX; 0.2 mg/kg; po) between gestational days 14 and 19. Gestational GC exposure resulted in impaired glucose homeostasis that is accompanied with elevated circulating levels of inflammatory biomarkers (endoglin, uric acid, and platelet/lymphocyte ratio), oxidative stress (malondialdehyde), blood viscosity, reduced NO level and increased DPP-4 activity. However, these effects were associated with atherogenic dyslipidemia and reduced GSK-3.We conclude that plasma endoglin, a marker of vascular inflammation, and plasma DPP-4 activity are increased in pregnant rats treated with GC during late gestation. Therefore, glucose deregulation associated with gestational GC exposure is through endoglin-/DPP-4-dependent but GSK-3-independent pathway. Copyright © 2018 Elsevier B.V. All rights reserved.

Efficacy and safety of once-weekly oral trelagliptin switched from once-daily dipeptidyl peptidase-4 inhibitor in patients with type 2 diabetes mellitus: An open-label, phase 3 exploratory study.

PubMed

Inagaki, Nobuya; Sano, Hiroki; Seki, Yoshifumi; Kuroda, Shingo; Kaku, Kohei

2018-03-01

Trelagliptin, a novel once-weekly oral dipeptidyl peptidase-4 (DPP-4) inhibitor, has shown favorable efficacy and safety in type 2 diabetes mellitus patients. Trelagliptin was launched in Japan, and is expected to be initially used for switchover from a daily DPP-4 inhibitor in the clinical setting. Thus, the present study was carried out to explore the efficacy and safety of trelagliptin after a daily DPP-4 inhibitor was switched to it. This was an open-label, phase 3 exploratory study to evaluate the efficacy and safety of trelagliptin in Japanese type 2 diabetes mellitus patients who had stable glycemic control on once-daily sitagliptin therapy. Eligible patients received trelagliptin 100 mg orally before breakfast once a week for 12 weeks. The primary end-point was blood glucose by the meal tolerance test, and additional end-points were glycemic control (efficacy) and safety. Altogether, 14 patients received the study drug. The blood glucose did not markedly change from baseline at major assessment points in the meal tolerance test, and a decrease in blood glucose was observed at several other assessment points. Adverse events were reported in 42.9% (6/14) of patients, but all adverse events were mild or moderate in severity, and most were not related to the study drug. No cases of death, serious adverse events or hypoglycemia were reported. It is considered possible to switch a once-daily DPP-4 inhibitor to trelagliptin in type 2 diabetes mellitus patients with stable glycemic control in combination with diet and exercise therapy without any major influences on glycemic control or safety. © 2017 The Authors. Journal of Diabetes Investigation published by Asian Association for the Study of Diabetes (AASD) and John Wiley & Sons Australia, Ltd.

DPP8 and DPP9 inhibition induces pro-caspase-1-dependent monocyte and macrophage pyroptosis.

PubMed

Okondo, Marian C; Johnson, Darren C; Sridharan, Ramya; Go, Eun Bin; Chui, Ashley J; Wang, Mitchell S; Poplawski, Sarah E; Wu, Wengen; Liu, Yuxin; Lai, Jack H; Sanford, David G; Arciprete, Michael O; Golub, Todd R; Bachovchin, William W; Bachovchin, Daniel A

2017-01-01

Val-boroPro (Talabostat, PT-100), a nonselective inhibitor of post-proline cleaving serine proteases, stimulates mammalian immune systems through an unknown mechanism of action. Despite this lack of mechanistic understanding, Val-boroPro has attracted substantial interest as a potential anticancer agent, reaching phase 3 trials in humans. Here we show that Val-boroPro stimulates the immune system by triggering a proinflammatory form of cell death in monocytes and macrophages known as pyroptosis. We demonstrate that the inhibition of two serine proteases, DPP8 and DPP9, activates the pro-protein form of caspase-1 independent of the inflammasome adaptor ASC. Activated pro-caspase-1 does not efficiently process itself or IL-1β but does cleave and activate gasdermin D to induce pyroptosis. Mice lacking caspase-1 do not show immune stimulation after treatment with Val-boroPro. Our data identify what is to our knowledge the first small molecule that induces pyroptosis and reveals a new checkpoint that controls the activation of the innate immune system.

Association of dipeptidyl peptidase 4 inhibitors with risk of metastases in patients with type 2 diabetes and breast, prostate or digestive system cancer.

PubMed

Rathmann, Wolfgang; Kostev, Karel

2017-04-01

Experimental and animal studies have supported the hypothesis that dipeptidyl peptidase-4 inhibitors (DPP-4i) may accelerate tumor metastasis. The aim was to analyze the relationships between DPP-4i therapy with risk of metastases in type 2 diabetes patients with breast, prostate and digestive organ cancers. Type 2 diabetes patients with first diagnoses of breast, prostate or digestive organ cancer were selected in general and internal medicine practices (Disease Analyzer Germany: 01/2008-12/2014). Propensity score matching between DPP-4i users and non-users was carried out for age, sex, diabetes duration, and metformin use. Time-dependent Cox regression models were used to estimate hazard ratios (HR) for metastases further adjusting for HbA1c, body mass index, comorbidity and co-therapy with glucose-lowering drugs (3-4years follow-up). 668 patients with newly diagnosed breast cancer, 906 with prostate cancer and 908 with digestive organ cancer were analyzed. In Cox regression, use of DPP-4i was not associated with an increased risk of metastases in patients with breast (adjusted HR, 95%CI: 1.00, 0.49-2.02), prostate (0.98, 0.54-1.77) or digestive organ cancers (0.97, 0.57-1.66). This first observational study in patients with type 2 diabetes and breast, prostate or digestive organ cancer found no increased risk of metastases in DPP-4i users. Copyright © 2017 Elsevier Inc. All rights reserved.

Dipeptidyl peptidase-4 inhibitors or sodium glucose co-transporter-2 inhibitors as an add-on to insulin therapy: A comparative review

PubMed Central

Singh, Awadhesh Kumar; Singh, Ritu

2016-01-01

The gradual decline in β-cell function is inevitable in type 2 diabetes mellitus and therefore, substantial proportions of patients require insulin subsequently, in order to achieve optimal glucose control. While weight gain, hypoglycemia, and fluid retention especially during dose intensification is a known limitation to insulin therapy, these adverse effects also reduce patient satisfaction and treatment adherence. It is also possible that the benefits of intensive control achieved by insulin therapy, perhaps get nullified by the weight gain and hypoglycemia. In addition, improvement in plasma glucose or glycated hemoglobin (HbA1c) itself is associated with weight gain. Notably, studies have already suggested that reduction in body weight by ~3–5%, may allow a significantly better glycemic control. Thus, a class of drugs, which can reduce HbA1c effectively, yet are weight neutral or preferably reduce body weight, could be the most sought out strategy as an add-on therapy to insulin. While sulfonylureas (SUs) are associated with weight gain and hypoglycemia, pioglitazone increases body weight and fluid retention. Moreover, SUs are not recommended once premix or prandial insulin is commenced. The addition of newer agents, such as glucagon-like peptide-1 receptor agonist to insulin certainly appears to be an effective tool in reducing both HbA1c and body weight as is evident across the studies; however, this approach incurs an additional injection as well as cost. Dipeptidyl peptidase-4 inhibitors (DPP-4I) and sodium-glucose co-transporter-2 inhibitors (SGLT-2I) are other exciting options, as an add-on to insulin therapy primarily because these are oral drugs and do not possess any intrinsic potential of hypoglycemia. Furthermore, these are either weight neutral or induce significant weight loss. This review article aims to comparatively analyze the safety and efficacy of DPP-4I and SGLT-2I, as an add-on therapy to insulin. PMID:26904466

Increased plasma DPP4 activities predict new-onset atherosclerosis in association with its proinflammatory effects in Chinese over a four year period: A prospective study.

PubMed

Zheng, T P; Yang, F; Gao, Y; Baskota, A; Chen, T; Tian, H M; Ran, X W

2014-08-01

DPP4, a novel proinflammatory cytokine, is involved in the inflammatory process through its interaction with IGF-II/M6P receptor. We aimed to investigate whether it could predict new-onset atherosclerosis in Chinese. A prospective study was conducted of 590 adults (213 men and 377 women) aged 18-70 years without atherosclerosis examined in 2007(baseline) and 2011(follow-up). Circulating DPP4 activity, inflammatory markers, IGF-II/M6P receptor and common carotid artery Intima-Media Thickness (C-IMT) were measured at baseline and four years later. At baseline, individuals in the highest quartile of DPP4 activity had higher age, WHR, BMI, SBP, fasting insulin, 2h-PG, TG, LDL-C, IL-6, hs-CRP, IGF-II/M6P-R, C-IMT and lower HDL-C compared with individuals in the lowest quartile. After a 4-year follow-up, 71 individuals developed atherosclerosis. In multiple linear regression analysis, baseline DPP4 activity was an independent predictor of an increase in inflammatory markers, IGF-II/M6P receptor, and C-IMT over a 4-year period (all P < 0.01). In multivariable-adjusted models, the odds ratio (OR) for incident atherosclerosis comparing the highest with the lowest quartiles of DPP4 activity was 3.17 (95%CI 1.33-7.58) after adjustment for confounding risk factors (P = 0.009). The incidence of atherosclerosis owing to DPP4 activity increased by 12.41%. DPP4 activity is an important predictor of the onset of inflammation and atherosclerosis in apparently healthy Chinese. This finding may have important implications for understanding the proinflammatory role of DPP-4 in the pathogenesis of atherosclerosis. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Effect of dipeptidyl peptidase-4 inhibition on circadian blood pressure during the development of salt-dependent hypertension in rats

PubMed Central

Sufiun, Abu; Rafiq, Kazi; Fujisawa, Yoshihide; Rahman, Asadur; Mori, Hirohito; Nakano, Daisuke; Kobori, Hiroyuki; Ohmori, Koji; Masaki, Tsutomu; Kohno, Masakazu; Nishiyama, Akira

2015-01-01

A growing body of evidence has indicated that dipeptidyl peptidase-4 (DPP-4) inhibitors have antihypertensive effects. Here, we aim to examine the effect of vildagliptin, a DPP-4-specific inhibitor, on blood pressure and its circadian-dipping pattern during the development of salt-dependent hypertension in Dahl salt-sensitive (DSS) rats. DSS rats were treated with a high-salt diet (8% NaCl) plus vehicle or vildagliptin (3 or 10 mg kg−1 twice daily by oral gavage) for 7 days. Blood pressure was measured by the telemetry system. High-salt diet for 7 days significantly increased the mean arterial pressure (MAP), systolic blood pressure (SBP) and were also associated with an extreme dipping pattern of blood pressure in DSS rats. Treatment with vildagliptin dose-dependently decreased plasma DPP-4 activity, increased plasma glucagon-like peptide 1 (GLP-1) levels and attenuated the development of salt-induced hypertension. Furthermore, vildagliptin significantly increased urine sodium excretion and normalized the dipping pattern of blood pressure. In contrast, intracerebroventricular infusion of vildagliptin (50, 500 or 2500 μg) did not alter MAP and heart rate in DSS rats. These data suggest that salt-dependent hypertension initially develops with an extreme blood pressure dipping pattern. The DPP-4 inhibitor, vildagliptin, may elicit beneficial antihypertensive effects, including the improvement of abnormal circadian blood pressure pattern, by enhancing urinary sodium excretion. PMID:25588850

Concordance with prescribing information dosage recommendations for dipeptidyl-peptidase-4 inhibitors among type 2 diabetes mellitus patients with moderate to severe chronic kidney disease.

PubMed

Huang, Huan; Shetty, Sharash; Bauer, Elise; Lang, Kathleen

2018-06-01

To estimate the proportion of patients with moderate to severe chronic kidney disease (CKD) whose initial dipeptidyl-peptidase-4 inhibitor (DPP4-i) dosage was concordant with prescribing information (label) recommendations in the United States. Adult patients with type 2 diabetes mellitus (T2DM) who initiated a DPP4-i (linagliptin, sitagliptin, saxagliptin) between 1 January 2011 and 30 June 2014 were identified using electronic medical records and administrative claims, with index date being the date of first observed DPP4-i treatment. Patients were required to have chronic kidney disease (CKD) stage 3b, 4 or 5 (estimated Glomerular Filtration Rate [eGFR] value <45 ml/min/1.73 m 2 ) during the 12 month pre-index period. Patients were classified as concordant or not concordant based on whether the first prescribed dose was consistent with label recommendations. Demographics, clinical characteristics, resource use and costs during pre-index were evaluated by DPP4-i concordance status. Of the 492 patients (323 sitagliptin, 57 saxagliptin, 112 linagliptin), 36.2% were prescribed doses that were not concordant with label recommendations (44.9% for sitagliptin, 57.9% for saxagliptin and 0% for linagliptin [which does not require dosage adjustment]). Concordant patients were slightly older (mean age 71 years vs. 68, p = .01) but had similar gender distribution (55% vs. 60% female, p = .31) compared to those who were not concordant. They had lower general health status (Charlson Comorbidity Score 2.6 vs. 2.2, p = .03), and had similar pre-index all-cause total costs ($25,245 vs. $21,972, p = .68) and lower pre-index T2DM-related costs ($1618 vs. $1922, p = .05). More than a third of DPP4-i patients with CKD stage 3b or higher were prescribed doses not concordant with DPP4-i label dosage recommendations.

Phenotyping of congenic dipeptidyl peptidase 4 (DP4) deficient Dark Agouti (DA) rats suggests involvement of DP4 in neuro-, endocrine, and immune functions.

PubMed

Frerker, Nadine; Raber, Kerstin; Bode, Felix; Skripuletz, Thomas; Nave, Heike; Klemann, Christian; Pabst, Reinhard; Stephan, Michael; Schade, Jutta; Brabant, Georg; Wedekind, Dirk; Jacobs, Roland; Jörns, Anne; Forssmann, Ulf; Straub, Rainer H; Johannes, Sigrid; Hoffmann, Torsten; Wagner, Leona; Demuth, Hans-Ulrich; von Hörsten, Stephan

2009-01-01

Treatment of diabetes type 2 using chronic pharmacological inhibition of dipeptidyl peptidase 4 (DP4) still requires an in-depth analysis of models for chronic DP4 deficiency, because adverse reactions induced by some DP4 inhibitors have been described. In the present study, a novel congenic rat model of DP4 deficiency on a "DP4-high" DA rat genetic background was generated (DA.F344-Dpp4(m)/ SvH rats) and comprehensively phenotyped. Similar to chronic pharmacological inhibition of DP4, DP4 deficient rats exhibited a phenotype involving reduced diet-induced body weight gain and improved glucose tolerance associated with increased levels of glucagon-like peptide-1 (GLP-1) and bound leptin as well as decreased aminotransferases and triglycerides. Additionally, DA.F344-Dpp4(m)/SvH rats showed anxiolytic-like and reduced stress-like responses, a phenomenon presently not targeted by DP4 inhibitors. However, several immune alterations, such as differential leukocyte subset composition at baseline, blunted natural killer cell and T-cell functions, and altered cytokine levels were observed. While this animal model confirms a critical role of DP4 in GLP-1-dependent glucose regulation, genetically induced chronic DP4 deficiency apparently also affects stress-regulatory and immuneregulatory systems, indicating that the use of chronic DP4 inhibitors might have the potential to interfere with central nervous system and immune functions in vivo.

Risk of hospitalization for heart failure in patients with type 2 diabetes newly treated with DPP-4 inhibitors or other oral glucose-lowering medications: a retrospective registry study on 127,555 patients from the Nationwide OsMed Health-DB Database.

PubMed

Fadini, Gian Paolo; Avogaro, Angelo; Degli Esposti, Luca; Russo, Pierluigi; Saragoni, Stefania; Buda, Stefano; Rosano, Giuseppe; Pecorelli, Sergio; Pani, Luca

2015-09-21

Oral glucose-lowering medications are associated with excess risk of heart failure (HF). Given the absence of comparative data among drug classes, we performed a retrospective study in 32 Health Services of 16 Italian regions accounting for a population of 18 million individuals, to assess the association between HF risk and use of sulphonylureas, DPP-4i, and glitazones. We extracted data on patients with type 2 diabetes who initiated treatment with DPP-4i, thiazolidinediones, or sulphonylureas alone or in combination with metformin during an accrual time of 2 years. The endpoint was hospitalization for HF (HHF) occurring after the first 6 months of therapy, and the observation was extended for up to 4 years. A total of 127 555 patients were included, of whom 14.3% were on DPP-4i, 72.5% on sulphonylurea, 13.2% on thiazolidinediones, with average 70.7% being on metformin as combination therapy. Patients in the three groups differed significantly for baseline characteristics: age, sex, Charlson index, concurrent medications, and previous cardiovascular events. During an average 2.6-year follow-up, after adjusting for measured confounders, use of DPP-4i was associated with a reduced risk of HHF compared with sulphonylureas [hazard ratio (HR) 0.78; 95% confidence interval (CI) 0.62-0.97; P = 0.026]. After propensity matching, the analysis was restricted to 39 465 patients, and the use of DPP-4i was still associated with a lower risk of HHF (HR 0.70; 95% CI 0.52-0.94; P = 0.018). In a very large observational study, the use of DPP-4i was associated with a reduced risk of HHF when compared with sulphonylureas. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2015. For permissions please email: journals.permissions@oup.com.

Use of SGLT2 inhibitors for diabetes and risk of infection: Analysis using general practice records from the NPS MedicineWise MedicineInsight program.

PubMed

Gadzhanova, Svetla; Pratt, Nicole; Roughead, Elizabet

2017-08-01

To explore the feasibility of MedicineInsight data to support risk management plan evaluation, focusing on sodium glucose co-transporter 2 (SGLT2) inhibitors for type 2 diabetes. A retrospective study using de-identified electronic general practitioner records. Patients who initiated SGLT2 inhibitor between 1 Jan 2012 to 1 Sep 2015 were compared to patients who initiated dipeptidyl peptidase 4 (DPP-4) inhibitors. The two cohorts were followed-up for six months. Risk of urinary-tract (UT) and genital infections was evaluated. The indication for use of SGLT2 inhibitors, recommended prior diabetes therapies and recommended monitoring were investigates. There were 1977 people in the SGLT2 cohort (with 93% initiated on dapagliflozin) and 1964 people in the DPP-4 cohort. Of the SGLT2 initiators, 54% had a documented indication for use as type 2 diabetes; 86% had used metformin and/or a sulfonylurea in the prior 12months. Renal function monitoring was documented for only 25% in the 6months initiation. The frequency of UTI in the 6months post SGLT2 initiation was not significantly increased compared to the DPP-4 cohort (3.6%vs 4.9%; aHR=0.90, 95% CI 0.66-1.24). Genital infection were more frequent in the SGLT2 than in the DPP-4 cohort (2.9% vs 0.9%, aHR=3.50, 95% CI 1.95-5.89). Similar to existing evidence, we found a higher risk of genital infection associated with SGLT2 inhibitors (primarily dapagliflozin) but no increased risk of UTIs compared to DPP-4 use. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Anagliptin, A Dipeptidyl Peptidase-4 Inhibitor Ameliorates Arterial Stiffness in Association with Reduction of Remnant-Like Particle Cholesterol and Alanine Transaminase Levels in Type 2 Diabetic Patients.

PubMed

Tahara, Nobuhiro; Yamagishi, Sho-Ichi; Bekki, Munehisa; Kodama, Norihiro; Nakamura, Tomohisa; Sugiyama, Yoichi; Oshige, Tamami; Kumashiro, Yuki; Honda, Akihiro; Tahara, Atsuko; Igata, Sachiyo; Fukumoto, Yoshihiro

2016-01-01

Inhibition of dipeptidyl peptidase-4 (DPP-4) has been proposed as a therapeutic target for type 2 diabetes (T2DM). Arterial stiffness, a predictor of future cardiovascular events and all-cause mortality, is augmented in these patients. However, effects of DPP-4 inhibitors on arterial stiffness remain unknown. In this study, we compared effects of anagliptin, an inhibitor of DPP-4 on arterial stiffness evaluated by cardio-ankle vascular index (CAVI) with those of an equipotent glucose-lowering agent, glimepiride in patients with T2DM. The study involved 50 consecutive outpatients (33 males and 17 females; mean age of 72.5±9.5 years) who visited our hospitals for a risk-screening test or treatment for T2DM. They underwent complete history and physical examination, and determination of blood chemistry and anthropometric variables, and then were randomized to receive either anagliptin (n=26) or glimepiride (n=24) for 6 months. After 6-months treatment, fasting plasma glucose and HbA1c values were comparably reduced in both groups. Anagliptin, but not glimepiride treatment significantly decreased low-density lipoprotein cholesterol, malondialdehyde-modified LDL, remnant-like particle (RLP) cholesterol, CAVI, alanine transaminase (ALT), γ-glutamyl transferase and visceral fat volume. In multiple regression analysis, absolute changes from baseline of RLP cholesterol and ALT after anagliptin treatment for 6 months (ΔRLP cholesterol and ΔALT) were independently correlated with ΔCAVI (R2=0.445). The present study suggests that anagliptin may exert a beneficial effect on arterial stiffness in patients with T2DM, which is independent of its blood glucose-lowering property. Anagliptin may ameliorate arterial stiffness partly via reduction of RLP cholesterol and improvement of liver function.

The DPP-IV inhibitor linagliptin and GLP-1 induce synergistic effects on body weight loss and appetite suppression in the diet-induced obese rat.

PubMed

Hansen, Henrik H; Hansen, Gitte; Paulsen, Sarah; Vrang, Niels; Mark, Michael; Jelsing, Jacob; Klein, Thomas

2014-10-15

Linagliptin is a dipeptidyl peptidase (DPP)-IV inhibitor approved for the treatment of type 2 diabetes. DPP-IV inhibitors are considered weight neutral, suggesting that elevation of endogenous incretin levels is not sufficient to promote weight loss per se. Here we evaluated the effect of linagliptin in combination with subcutaneous treatment of GLP-1(7-36) on body weight regulation in diet-induced obese (DIO) rats. Linagliptin administered perorally (1.5mg/kg, b.i.d.), but not subcutaneously (0.5mg/kg, b.i.d.), evoked a very modest body weight loss (2.2%) after 28 days of treatment. GLP-1 (0.5mg/kg, s.c.) treatment alone induced a body weight loss of 4.1%. In contrast, combined linagliptin (1.5mg/kg, p.o., or 0.5mg/kg, s.c.) and GLP-1 (0.5mg/kg) treatment evoked a marked anorectic response with both routes of linagliptin administration being equally effective on final body weight loss (7.5-8.0%). In comparison, liraglutide monotherapy (0.2mg/kg, s.c., b.i.d.) reduced body weight by 10.1%. Interestingly, the weight lowering effect of combined linagliptin and GLP-1 treatment was associated with a marked increase in chow preference, being more pronounced as compared to liraglutide treatment. In addition, linagliptin and GLP-1 co-treatment, but not liraglutide, specifically increased prepro-dynorphin mRNA levels in the caudate-putamen, an effect not obtained with administration of the compounds individually. In conclusion, co-treatment with linagliptin and GLP-1 synergistically reduces body weight in obese rats. The anti-obesity effect was caused by appetite suppression with a concomitant change in diet preference, which may potentially be associated with increased dynorphin activity in forebrain regions involved in reward anticipation and habit learning. Copyright © 2014 Elsevier B.V. All rights reserved.

Dipeptidyl peptidase-4: A key player in chronic liver disease

PubMed Central

Itou, Minoru; Kawaguchi, Takumi; Taniguchi, Eitaro; Sata, Michio

2013-01-01

Dipeptidyl peptidase-4 (DPP-4) is a membrane-associated peptidase, also known as CD26. DPP-4 has widespread organ distribution throughout the body and exerts pleiotropic effects via its peptidase activity. A representative target peptide is glucagon-like peptide-1, and inactivation of glucagon-like peptide-1 results in the development of glucose intolerance/diabetes mellitus and hepatic steatosis. In addition to its peptidase activity, DPP-4 is known to be associated with immune stimulation, binding to and degradation of extracellular matrix, resistance to anti-cancer agents, and lipid accumulation. The liver expresses DPP-4 to a high degree, and recent accumulating data suggest that DPP-4 is involved in the development of various chronic liver diseases such as hepatitis C virus infection, non-alcoholic fatty liver disease, and hepatocellular carcinoma. Furthermore, DPP-4 occurs in hepatic stem cells and plays a crucial role in hepatic regeneration. In this review, we described the tissue distribution and various biological effects of DPP-4. Then, we discussed the impact of DPP-4 in chronic liver disease and the possible therapeutic effects of a DPP-4 inhibitor. PMID:23613622

Hepatic Dipeptidyl Peptidase-4 Controls Pharmacokinetics of Vildagliptin In Vivo.

PubMed

Asakura, Mitsutoshi; Fukami, Tatsuki; Nakajima, Miki; Fujii, Hideaki; Atsuda, Koichiro; Itoh, Tomoo; Fujiwara, Ryoichi

2017-02-01

The main route of elimination of vildagliptin, which is an inhibitor of dipeptidyl peptidase-4 (DPP-4), in humans is cyano group hydrolysis to produce a carboxylic acid metabolite M20.7. Our in vitro study previously demonstrated that DPP-4 itself greatly contributed to the hydrolysis of vildagliptin in mouse, rat, and human livers. To investigate whether hepatic DPP-4 contributes to the hydrolysis of vildagliptin in vivo, in the present study, we conducted in vivo pharmacokinetics studies of vildagliptin in mice coadministered with vildagliptin and sitagliptin, which is another DPP-4 inhibitor, and also in streptozotocin (STZ)-induced diabetic mice. The area under the plasma concentration-time curve (AUC) value of M20.7 in mice coadministered with vildagliptin and sitagliptin was significantly lower than that in mice administered vildagliptin alone (P < 0.01). Although plasma DPP-4 expression level was increased 1.9-fold, hepatic DPP-4 activity was decreased in STZ-induced diabetic mice. The AUC values of M20.7 in STZ-induced diabetic mice were lower than those in control mice (P < 0.01). Additionally, the AUC values of M20.7 significantly positively correlated with hepatic DPP-4 activities in the individual mice (Rs = 0.943, P < 0.05). These findings indicated that DPP-4 greatly contributed to the hydrolysis of vildagliptin in vivo and that not plasma, but hepatic DPP-4 controlled pharmacokinetics of vildagliptin. Furthermore, enzyme assays of 23 individual human liver samples showed that there was a 3.6-fold interindividual variability in vildagliptin-hydrolyzing activities. Predetermination of the interindividual variability of hepatic vildagliptin-hydrolyzing activity might be useful for the prediction of blood vildagliptin concentrations in vivo. Copyright © 2017 by The American Society for Pharmacology and Experimental Therapeutics.

Diabetes Prevention Program (DPP)

MedlinePlus

... mass index of 35 or higher. DPP Study Design The DPP was a randomized, controlled clinical trial ... by several earlier small-scale studies. DPPOS Study Design The DPPOS follow-up study started in 2002. ...

Identification of Novel Human Dipeptidyl Peptidase-IV Inhibitors of Natural Origin (Part II): In Silico Prediction in Antidiabetic Extracts

PubMed Central

Guasch, Laura; Sala, Esther; Ojeda, María José; Valls, Cristina; Bladé, Cinta; Mulero, Miquel; Blay, Mayte; Ardévol, Anna; Garcia-Vallvé, Santiago; Pujadas, Gerard

2012-01-01

Background Natural extracts play an important role in traditional medicines for the treatment of diabetes mellitus and are also an essential resource for new drug discovery. Dipeptidyl peptidase IV (DPP-IV) inhibitors are potential candidates for the treatment of type 2 diabetes mellitus, and the effectiveness of certain antidiabetic extracts of natural origin could be, at least partially, explained by the inhibition of DPP-IV. Methodology/Principal Findings Using an initial set of 29,779 natural products that are annotated with their natural source and an experimentally validated virtual screening procedure previously developed in our lab (Guasch et al.; 2012) [1], we have predicted 12 potential DPP-IV inhibitors from 12 different plant extracts that are known to have antidiabetic activity. Seven of these molecules are identical or similar to molecules with described antidiabetic activity (although their role as DPP-IV inhibitors has not been suggested as an explanation for their bioactivity). Therefore, it is plausible that these 12 molecules could be responsible, at least in part, for the antidiabetic activity of these extracts through their inhibitory effect on DPP-IV. In addition, we also identified as potential DPP-IV inhibitors 6 molecules from 6 different plants with no described antidiabetic activity but that share the same genus as plants with known antidiabetic properties. Moreover, none of the 18 molecules that we predicted as DPP-IV inhibitors exhibits chemical similarity with a group of 2,342 known DPP-IV inhibitors. Conclusions/Significance Our study identified 18 potential DPP-IV inhibitors in 18 different plant extracts (12 of these plants have known antidiabetic properties, whereas, for the remaining 6, antidiabetic activity has been reported for other plant species from the same genus). Moreover, none of the 18 molecules exhibits chemical similarity with a large group of known DPP-IV inhibitors. PMID:23028712

Comparative Analysis of Binding Kinetics and Thermodynamics of Dipeptidyl Peptidase-4 Inhibitors and Their Relationship to Structure.

PubMed

Schnapp, Gisela; Klein, Thomas; Hoevels, Yvette; Bakker, Remko A; Nar, Herbert

2016-08-25

The binding kinetics and thermodynamics of dipeptidyl peptidase (DPP)-4 inhibitors (gliptins) were investigated using surface plasmon resonance and isothermal titration calorimetry. Binding of gliptins to DPP-4 is a rapid electrostatically driven process. Off-rates were generally slow partly because of reversible covalent bond formation by some gliptins, and partly because of strong and extensive interactions. Binding of all gliptins is enthalpy-dominated due to strong ionic interactions and strong solvent-shielded hydrogen bonds. Using a congeneric series of molecules which represented the intermediates in the lead optimization program of linagliptin, the onset of slow binding kinetics and development of the thermodynamic repertoire were analyzed in the context of incremental changes of the chemical structures. All compounds rapidly associated, and therefore the optimization of affinity and residence time is highly correlated. The major contributor to the increasing free energy of binding was a strong increase of binding enthalpy, whereas entropic contributions remained low and constant despite significant addition of lipophilicity.

Discovery and structure-activity relationships of piperidinone- and piperidine-constrained phenethylamines as novel, potent, and selective dipeptidyl peptidase IV inhibitors.

PubMed

Pei, Zhonghua; Li, Xiaofeng; von Geldern, Thomas W; Longenecker, Kenton; Pireh, Daisy; Stewart, Kent D; Backes, Bradley J; Lai, Chunqiu; Lubben, Thomas H; Ballaron, Stephen J; Beno, David W A; Kempf-Grote, Anita J; Sham, Hing L; Trevillyan, James M

2007-04-19

Dipeptidyl peptidase IV (DPP4) inhibitors are emerging as a new class of therapeutic agents for the treatment of type 2 diabetes. They exert their beneficial effects by increasing the levels of active glucagon-like peptide-1 and glucose-dependent insulinotropic peptide, which are two important incretins for glucose homeostasis. Starting from a high-throughput screening hit, we were able to identify a series of piperidinone- and piperidine-constrained phenethylamines as novel DPP4 inhibitors. Optimized compounds are potent, selective, and have good pharmacokinetic profiles.

Hypoglycemia hospitalization frequency in patients with type 2 diabetes mellitus: a comparison of dipeptidyl peptidase 4 inhibitors and insulin secretagogues using the French health insurance database.

PubMed

Detournay, Bruno; Halimi, Serge; Robert, Julien; Deschaseaux, Céline; Dejager, Sylvie

2015-01-01

We aimed to compare the frequency of severe hypoglycemia leading to hospitalization (HH) and emergency visits (EV) for any cause in patients with type 2 diabetes mellitus exposed to dipeptidyl peptidase 4 (DPP4) inhibitors (DPP4-i) versus those exposed to insulin secretagogues (IS; sulfonylureas or glinides). Data were extracted from the EGB (Echantillon Généraliste des Bénéficiaires) database, comprising a representative sample of ~1% of patients registered in the French National Health Insurance System (~600,000 patients). Type 2 diabetes mellitus patients exposed to regimens containing either a DPP4-i (excluding treatment with IS, insulin, or glucagon-like peptide 1 analog) or IS (excluding treatment with insulin and any incretin therapy) between 2009 and 2012 were selected. HH and EV during the exposure periods were identified in both cohorts. A similar analysis was conducted considering vildagliptin alone versus IS. Comparative analyses adjusting for covariates within the model (subjects matched for key characteristics) and using multinomial regression models were performed. Overall, 7,152 patients exposed to any DPP4-i and 1,440 patients exposed to vildagliptin were compared to 10,019 patients exposed to IS. Eight patients (0.11%) from the DPP4-i cohort and none from the vildagliptin cohort (0.0%) were hospitalized for hypoglycemia versus 130 patients (1.30%) from the IS cohort (138 hospitalizations) (P=0.02 and P<0.0001, respectively). Crude rates of HH/1,000 patient-years were 1.4 (95% CI: 0.7; 2.4) in the DPP4-i cohort, 0.0 in the vildagliptin cohort (95% CI: 0.0; 4.0), versus 5.6 (95% CI, 4.7; 6.6) in the IS cohort (P<0.0001). After adjustments, rates per 1,000 patient-years of HH were 1.4 (95% CI: 0.7; 2.4) with DPP4-i versus 7.5 (95% CI: 6.0; 9.2) with IS (P<0.0001), and 0.0 (95% CI: 0.0; 4.0) with vildagliptin versus 13.6 (95% CI: 10.4; 17.5) with IS (P<0.0001). Adjusted EV rates were also significantly lower with all DPP4-i or with vildagliptin

Hypoglycemia hospitalization frequency in patients with type 2 diabetes mellitus: a comparison of dipeptidyl peptidase 4 inhibitors and insulin secretagogues using the French health insurance database

PubMed Central

Detournay, Bruno; Halimi, Serge; Robert, Julien; Deschaseaux, Céline; Dejager, Sylvie

2015-01-01

Aim We aimed to compare the frequency of severe hypoglycemia leading to hospitalization (HH) and emergency visits (EV) for any cause in patients with type 2 diabetes mellitus exposed to dipeptidyl peptidase 4 (DPP4) inhibitors (DPP4-i) versus those exposed to insulin secretagogues (IS; sulfonylureas or glinides). Methods Data were extracted from the EGB (Echantillon Généraliste des Bénéficiaires) database, comprising a representative sample of ~1% of patients registered in the French National Health Insurance System (~600,000 patients). Type 2 diabetes mellitus patients exposed to regimens containing either a DPP4-i (excluding treatment with IS, insulin, or glucagon-like peptide 1 analog) or IS (excluding treatment with insulin and any incretin therapy) between 2009 and 2012 were selected. HH and EV during the exposure periods were identified in both cohorts. A similar analysis was conducted considering vildagliptin alone versus IS. Comparative analyses adjusting for covariates within the model (subjects matched for key characteristics) and using multinomial regression models were performed. Results Overall, 7,152 patients exposed to any DPP4-i and 1,440 patients exposed to vildagliptin were compared to 10,019 patients exposed to IS. Eight patients (0.11%) from the DPP4-i cohort and none from the vildagliptin cohort (0.0%) were hospitalized for hypoglycemia versus 130 patients (1.30%) from the IS cohort (138 hospitalizations) (P=0.02 and P<0.0001, respectively). Crude rates of HH/1,000 patient-years were 1.4 (95% CI: 0.7; 2.4) in the DPP4-i cohort, 0.0 in the vildagliptin cohort (95% CI: 0.0; 4.0), versus 5.6 (95% CI, 4.7; 6.6) in the IS cohort (P<0.0001). After adjustments, rates per 1,000 patient-years of HH were 1.4 (95% CI: 0.7; 2.4) with DPP4-i versus 7.5 (95% CI: 6.0; 9.2) with IS (P<0.0001), and 0.0 (95% CI: 0.0; 4.0) with vildagliptin versus 13.6 (95% CI: 10.4; 17.5) with IS (P<0.0001). Adjusted EV rates were also significantly lower with all DPP4-i or

Safety evaluation of trelagliptin in the treatment of Japanese type 2 diabetes mellitus patients.

PubMed

Kaku, Kohei

2017-11-01

Trelagliptin is a novel, long-acting dipeptidyl peptidase-4 (DPP-4) inhibitor approved for the treatment of type 2 diabetes mellitus (T2DM) in japan. The safety and efficacy of trelagliptin has been evaluated in three published clinical trials to date: one phase II and two phase III studies. As trelagliptin only requires dosing once per week, this new agent has the potential to improve compliance and subsequently, glycaemic control, in patients with T2DM. Areas covered: This article reviews the available safety data for trelagliptin from published clinical trials, and evaluates the published safety profile relative to competitor once-daily and once-weekly DPP-4 inhibitors. Expert opinion: Clinical trial data to date suggest that trelagliptin is a safe and efficacious medication with a similar safety profile to once-daily DPP-4 inhibitors, and to the once-weekly DPP-4 inhibitor, omarigliptin. Trelagliptin is well tolerated when given alone, and in combination with other anti-diabetic medications. An advantage of trelagliptin over existing once-daily DPP-4 inhibitors is the decrease of dosing frequency, rather than once-daily. No specific, serious adverse events have been reported for trelagliptin in published clinical trials, making it an attractive alternative to other DPP-4 inhibitors.

Safety, effectiveness, and cost of dipeptidyl peptidase-4 inhibitors versus intermediate acting insulin for type 2 diabetes: protocol for a systematic review and network meta-analysis.

PubMed

Tricco, Andrea C; Antony, Jesmin; Soobiah, Charlene; Hemmelgarn, Brenda; Moher, David; Hutton, Brian; Yu, Catherine H; Majumdar, Sumit R; Straus, Sharon E

2013-06-28

Type 2 diabetes mellitus (T2DM) results from insulin resistance and relative insulin deficiency. T2DM treatment is a step-wise approach beginning with lifestyle modifications (for example, diet, exercise), followed by the addition of oral hypoglycemic agents (for example, metformin). Patients who do not respond to first-line therapy are offered second-line therapy (for example, sulfonylureas). Third-line therapy may include insulin and/or dipeptidyl peptidase-4 (DPP-4) inhibitors.It is unclear whether DPP-4 inhibitors are safer and more effective than intermediate acting insulin for third-line management of T2DM. As such, our objective is to evaluate the comparative effectiveness, safety and cost-effectiveness of DPP-4 inhibitors versus intermediate acting insulin for T2DM patients who have failed both first- and second-line diabetes treatments. Electronic searches of MEDLINE, Cochrane Central Register of Controlled Trials, EMBASE, and grey literature (for example, trial registries, public health websites) will be conducted to identify studies examining DPP-4 inhibitors compared with each other, intermediate acting insulin, no treatment, or placebo for adults with T2DM. The outcomes of interest include glycosylated hemoglobin (A1C) (primary outcome), as well as emergency department visits, physician visits, hospital admissions, weight gain, quality of life, microvascular complications, macrovascular complications, all-cause mortality, and cost (secondary outcomes). Randomized clinical trials (RCTs), quasi-RCTs, non-RCTs, controlled before-after, interrupted time series, cohort studies, and cost studies reporting data on these outcomes will be included. Eligibility will not be restricted by publication status, language of dissemination, duration of study follow-up, or time period of study conduct.Two reviewers will screen the titles and abstracts resulting from the literature search, as well as potentially relevant full-text articles, in duplicate. Data will be

Discovery of Potent and Selective Dipeptidyl Peptidase IV Inhibitors Derived from [beta]-Aminoamides Bearing Subsituted Triazolopiperazines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Dooseop; Kowalchick, Jennifer E.; Brockunier, Linda L.

2008-06-30

A series of {beta}-aminoamides bearing triazolopiperazines have been discovered as potent, selective, and orally active dipeptidyl peptidase IV (DPP-4) inhibitors by extensive structure-activity relationship (SAR) studies around the triazolopiperazine moiety. Among these, compound 34b with excellent in vitro potency (IC{sub 50} = 4.3 nM) against DPP-4, high selectivity over other enzymes, and good pharmacokinetic profiles exhibited pronounced in vivo efficacy in an oral glucose tolerance test (OGTT) in lean mice. On the basis of these properties, compound 34b has been profiled in detail. Further refinement of the triazolopiperazines resulted in the discovery of a series of extremely potent compounds withmore » subnanomolar activity against DPP-4 (42b-49b), that is, 4-fluorobenzyl-substituted compound 46b, which is notable for its superior potency (IC{sub 50} = 0.18 nM). X-ray crystal structure determination of compounds 34b and 46b in complex with DPP-4 enzyme revealed that (R)-stereochemistry at the 8-position of triazolopiperazines is strongly preferred over (S) with respect to DPP-4 inhibition.« less

[Ru(dpp)(3)][(4-Clph)(4)B](2) nanoislands directly assembled on an ITO electrode surface and its electrogenerated chemiluminescence.

PubMed

Chen, Ying; Mao, Jianfei; Liu, Chunhua; Yuan, Hongyan; Xiao, Dan; Choi, Martin M F

2009-01-20

In this work, solid-state tris(4,7-diphenyl-1,10-phenanthroline) ruthenium(II) ditetrakis(4-chlorophenyl)borate ([Ru(dpp)(3)][(4-Clph)(4)B](2)) nanoislands are assembled spontaneously and simultaneously on an indium-doped tin oxide (ITO) glass electrode surface via a facile dewetting procedure. The fabrication process is very simple and also amenable to mass production. The as-prepared ruthenium complex nanoislands exhibit useful properties. The electrode is more electrochemically active and can produce strong, stable, reproducible solid-state electrochemiluminescence (ECL) signals using oxalate as the coreactant. The self-assembled nanoislands exhibit semiconductor-like broad, red-shift ECL spectrum. More importantly, they extend the application of the ruthenium complex ECL system from the usual alkaline to acidic conditions. The pH turn-off behavior of the ECL is observed for the first time and can serve as an ultrasensitive pH sensor around physiological pH 7.0. The solid-state [Ru(dpp)(3)][(4-Clph)(4)B](2) ECL signal is efficiently inhibited by phenol even at a very low concentration (i.e., 20 nM), thus providing the potential for the determination of phenolic compounds in practical applications.

Effects of linagliptin on human immortalized podocytes: a cellular system to study dipeptidyl‐peptidase 4 inhibition

PubMed Central

Miglio, Gianluca; Vitarelli, Giovanna; Klein, Thomas

2017-01-01

Background and Purpose Dipeptidyl‐peptidase 4 (DPP4) is expressed by resident renal cells, including glomerular cells. DPP4 inhibitors (gliptins) exert albuminuria lowering effects, but the role of renal DPP4 as a pharmacological target has not been elucidated. To better understand the actions of gliptins, the effects of linagliptin on the behaviour of immortalized human podocytes and mesangial cells were evaluated. Experimental Approach The expression of DPP4 was measured at both the mRNA and protein levels. The effects of linagliptin on DPP4 activity, cell growth and cell cycle progression were determined. The contribution of the stromal cell‐derived factor‐1‐ CXCR4/CXCR7 signalling pathways was evaluated by studying the effects of AMD3100 (a CXCR4 antagonist and CXCR7 agonist) alone and in combination with linagliptin. The contribution of ERK1/2 activation was analysed by studying the effects of the MAPK kinase 1/2 inhibitor AZD6244. Key Results DPP4 was highly expressed in podocytes. The activity of DPP4 and podocyte growth were reduced by linagliptin. The effects of sitagliptin on podocyte growth were similar to those of linagliptin, were associated with inhibition of cell proliferation and mimicked by AMD3100. Moreover, linagliptin and AMD3100 were found to have a synergistic interaction, whereas no interaction was seen between linagliptin and AZD6244. Conclusions and Implications Our cultures of human glomerular cells represent a reliable system for investigating the actions of gliptins. Moreover, DPP4 contributes to the regulation of podocyte behaviour. Inhibition of DPP4 in podocytes could underlie the effects of linagliptin on glomerular cells. PMID:28177527

Formation of the long range Dpp morphogen gradient.

PubMed

Schwank, Gerald; Dalessi, Sascha; Yang, Schu-Fee; Yagi, Ryohei; de Lachapelle, Aitana Morton; Affolter, Markus; Bergmann, Sven; Basler, Konrad

2011-07-01

The TGF-β homolog Decapentaplegic (Dpp) acts as a secreted morphogen in the Drosophila wing disc, and spreads through the target tissue in order to form a long range concentration gradient. Despite extensive studies, the mechanism by which the Dpp gradient is formed remains controversial. Two opposing mechanisms have been proposed: receptor-mediated transcytosis (RMT) and restricted extracellular diffusion (RED). In these scenarios the receptor for Dpp plays different roles. In the RMT model it is essential for endocytosis, re-secretion, and thus transport of Dpp, whereas in the RED model it merely modulates Dpp distribution by binding it at the cell surface for internalization and subsequent degradation. Here we analyzed the effect of receptor mutant clones on the Dpp profile in quantitative mathematical models representing transport by either RMT or RED. We then, using novel genetic tools, experimentally monitored the actual Dpp gradient in wing discs containing receptor gain-of-function and loss-of-function clones. Gain-of-function clones reveal that Dpp binds in vivo strongly to the type I receptor Thick veins, but not to the type II receptor Punt. Importantly, results with the loss-of-function clones then refute the RMT model for Dpp gradient formation, while supporting the RED model in which the majority of Dpp is not bound to Thick veins. Together our results show that receptor-mediated transcytosis cannot account for Dpp gradient formation, and support restricted extracellular diffusion as the main mechanism for Dpp dispersal. The properties of this mechanism, in which only a minority of Dpp is receptor-bound, may facilitate long-range distribution.

Relationship between deterioration of glycated hemoglobin-lowering effects in dipeptidyl peptidase-4 inhibitor monotherapy and dietary habits: Retrospective analysis of Japanese individuals with type 2 diabetes.

PubMed

Kuwata, Hitoshi; Okamoto, Saki; Seino, Yusuke; Murotani, Kenta; Tatsuoka, Hisato; Usui, Ryota; Hamamoto, Yoshiyuki; Kurose, Takeshi; Seino, Yutaka; Yabe, Daisuke

2017-11-24

The present study was designed to assess possible relationships between deterioration of the glycated hemoglobin (HbA1c)-lowering effects in dipeptidyl peptidase-4 inhibitor (DPP4i) monotherapy and macronutrient intake among individuals with type 2 diabetes. Type 2 diabetes patients who began and continued DPP4i monotherapy without any prescription change for 1 year were retrospectively stratified into two groups: (i) patients who maintained their HbA1c levels during the 0.5- to 1-year period after DPP4i initiation (group A, ΔHbA1c [1-0.5 year] <0.4%, n = 53); and (ii) those whose HbA1c levels increased [group B, ΔHbA1c (1-0.5 year] ≥0.4%, n = 10). Group B had significantly higher ΔHbA1c (1-0.5 year), Δbodyweight (1-0.5 year) and fat intake, especially of saturated and monounsaturated fats; the carbohydrate and protein intake were similar between groups. Multiple regression analyses showed that fat intake, especially saturated fat intake, was significantly correlated with ΔHbA1c (1-0.5 year). Thus, dietary habits, especially saturated fat intake, might well contribute to deterioration of the HbA1c-lowering effects in DPP4i monotherapy. © 2017 The Authors. Journal of Diabetes Investigation published by Asian Association for the Study of Diabetes (AASD) and John Wiley & Sons Australia, Ltd.

Boundary Dpp promotes growth of medial and lateral regions of the Drosophila wing.

PubMed

Barrio, Lara; Milán, Marco

2017-07-04

The gradient of Decapentaplegic (Dpp) in the Drosophila wing has served as a paradigm to characterize the role of morphogens in regulating patterning. However, the role of this gradient in regulating tissue size is a topic of intense debate as proliferative growth is homogenous. Here, we combined the Gal4/UAS system and a temperature-sensitive Gal80 molecule to induce RNAi-mediated depletion of dpp and characterise the spatial and temporal requirement of Dpp in promoting growth. We show that Dpp emanating from the AP compartment boundary is required throughout development to promote growth by regulating cell proliferation and tissue size. Dpp regulates growth and proliferation rates equally in central and lateral regions of the developing wing appendage and reduced levels of Dpp affects similarly the width and length of the resulting wing. We also present evidence supporting the proposal that graded activity of Dpp is not an absolute requirement for wing growth.

Boundary Dpp promotes growth of medial and lateral regions of the Drosophila wing

PubMed Central

Barrio, Lara; Milán, Marco

2017-01-01

The gradient of Decapentaplegic (Dpp) in the Drosophila wing has served as a paradigm to characterize the role of morphogens in regulating patterning. However, the role of this gradient in regulating tissue size is a topic of intense debate as proliferative growth is homogenous. Here, we combined the Gal4/UAS system and a temperature-sensitive Gal80 molecule to induce RNAi-mediated depletion of dpp and characterise the spatial and temporal requirement of Dpp in promoting growth. We show that Dpp emanating from the AP compartment boundary is required throughout development to promote growth by regulating cell proliferation and tissue size. Dpp regulates growth and proliferation rates equally in central and lateral regions of the developing wing appendage and reduced levels of Dpp affects similarly the width and length of the resulting wing. We also present evidence supporting the proposal that graded activity of Dpp is not an absolute requirement for wing growth. DOI: http://dx.doi.org/10.7554/eLife.22013.001 PMID:28675372

Synthesis, QSAR, and Molecular Dynamics Simulation of Amidino-substituted Benzimidazoles as Dipeptidyl Peptidase III Inhibitors.

PubMed

Rastija, Vesna; Agić, Dejan; Tomiš, Sanja; Nikolič, Sonja; Hranjec, Marijana; Grace, Karminski-Zamola; Abramić, Marija

2015-01-01

A molecular modeling study is performed on series of benzimidazol-based inhibitors of human dipeptidyl peptidase III (DPP III). An eight novel compounds were synthesized in excellent yields using green chemistry approach. This study is aimed to elucidate the structural features of benzimidazole derivatives required for antagonism of human DPP III activity using Quantitative Structure-Activity Relationship (QSAR) analysis, and to understand the mechanism of one of the most potent inhibitor binding into the active site of this enzyme, by molecular dynamics (MD) simulations. The best model obtained includes S3K and RDF045m descriptors which have explained 89.4 % of inhibitory activity. Depicted moiety for strong inhibition activity matches to the structure of most potent compound. MD simulation has revealed importance of imidazolinyl and phenyl groups in the mechanism of binding into the active site of human DPP III.

Pharmacokinetics of the dipeptidyl peptidase 4 inhibitor saxagliptin in rats, dogs, and monkeys and clinical projections.

PubMed

Fura, Aberra; Khanna, Ashish; Vyas, Viral; Koplowitz, Barry; Chang, Shu-Ying; Caporuscio, Christian; Boulton, David W; Christopher, Lisa J; Chadwick, Kristina D; Hamann, Lawrence G; Humphreys, W Griffith; Kirby, Mark

2009-06-01

Saxagliptin is a potent, selective, reversible dipeptidyl peptidase 4 (DPP4) inhibitor specifically designed for extended inhibition of the DPP4 enzyme and is currently under development for the treatment of type-2 diabetes. The pharmacokinetics of saxagliptin were evaluated in rats, dogs, and monkeys and used to predict its human pharmacokinetics. Saxagliptin was rapidly absorbed and had good bioavailability (50-75%) in the species tested. The plasma clearance of saxagliptin was higher in rats (115 ml/min/kg) than in dogs (9.3 ml/min/kg) and monkeys (14.5 ml/min/kg) and was predicted to be low to moderate in humans. The plasma elimination half-life was between 2.1 and 4.4 h in rats, dogs, and monkeys, and both metabolism and renal excretion contributed to the overall elimination. The primary metabolic clearance pathway involved the formation of a significant circulating, pharmacologically active hydroxylated metabolite, M2. The volume of distribution values observed in rats, dogs, and monkeys (1.3-5.2 l/kg) and predicted for humans (2.7 l/kg) were greater than those for total body water, indicating extravascular distribution. The in vitro serum protein binding was low (< or =30%) in rats, dogs, monkeys, and humans. After intra-arterial administration of saxagliptin to Sprague-Dawley and Zucker diabetic fatty rats, higher levels of saxagliptin and M2 were observed in the intestine (a proposed major site of drug action) relative to that in plasma. Saxagliptin has prolonged pharmacodynamic properties relative to its plasma pharmacokinetic profile, presumably due to additional contributions from M2, distribution of saxagliptin and M2 to the intestinal tissue, and prolonged dissociation of both saxagliptin and M2 from DPP4.

Phosphodiesterase 4 inhibitors.

PubMed

Zebda, Rema; Paller, Amy S

2018-03-01

Historically, drugs available for treating atopic dermatitis (AD) have been limited to topical corticosteroids and topical calcineurin inhibitors, with systemic immunosuppressants and phototherapy reserved for severe AD. Despite their efficacy and infrequent adverse events, phobia about the use of topical steroids and calcineurin inhibitors has limited their use. More targeted options with fewer systemic and cutaneous side effects are needed for treating AD. Phosphodiesterase 4 (PDE4) is involved in the regulation of proinflammatory cytokines via the degradation of cyclic adenosine monophosphate. PDE4 activity is increased in the inflammatory cells of patients with AD, leading to increased production of proinflammatory cytokines and chemokines. Targeting PDE4 reduces the production of these proinflammatory mediators in AD. Both topical and oral PDE4 inhibitors have a favorable safety profile. Crisaborole 2% ointment, a topical PDE4, is now US Food and Drug Administration-approved for children older than 2 years and adults in the treatment of AD. Crisaborole 2% ointment shows early and sustained improvement in disease severity and pruritus and other AD symptoms, with burning and/or stinging upon application as the only related adverse event. Other PDE4 inhibitors are currently in trials with promising efficacy and safety. Copyright © 2017. Published by Elsevier Inc.

The Effects of Aerobic Exercises and 25(OH) D Supplementation on GLP1 and DPP4 Level in Type II Diabetic Patients.

PubMed

Rahimi, Naser; Samavati Sharif, Mohammad Ali; Goharian, Amir Reza; Pour, Ali Heidarian

2017-01-01

The purpose of this study was to investigate the effects of an 8-week aerobic exercise and supplementation of 25(OH)D3 on GLP1 and DDP4 levels in men with type II diabetes. In this semiexperimental research, among 40-60-year-old men with type II diabetes who were referred to the diabetic center of Isabn-E Maryam hospital in Isfahan; of whom, 48 patients were voluntarily accepted and then were randomly divided into 4 groups: aerobic exercise group, aerobic exercise with 25(OH) D supplement group, 25(OH) D supplement group, and the control group. An aerobic exercise program was conducted for 8 weeks (3 sessions/week, each session 60 to75 min with 60-80% HRmax). The supplement user group received 50,000 units of oral Vitamin D once weekly for 8 weeks. The GLP1, DPP4, and 25(OH) D levels were measured before and after the intervention. At last, the data were statistically analyzed using the ANCOVA and post hoc test of least significant difference. The results of ANCOVA showed a significant difference between the GLP1 and DPP4 levels in aerobic exercise with control group while these changes were not statistically significant between the 25(OH) D supplement group with control group ( P < 0.05). Aerobic exercises have resulted an increase in GLP1 level and a decrease in DPP4 level. However, consumption of Vitamin D supplement alone did not cause any changes in GLP1and DPP4 levels but led to an increase in 25-hydroxy Vitamin D level.

Synthesis, Biological Evaluation, and Molecular Docking of (R)-2-((8-(3-aminopiperidin-1-yl)-3-methyl-7-(3-methylbut-2-en-1-yl)-2,6-dioxo-2,3,6,7-tetrahydro-1H-purin-1-yl)methyl)benzonitrile as Dipeptidyl Peptidase IV Inhibitors.

PubMed

Ran, Yan; Pei, Heying; Shao, Mingfeng; Chen, Lijuan

2016-02-01

Type 2 diabetes (T2D) is classified as a major metabolic disorder, which has affected approximately 194 million people worldwide. DPP-IV inhibitors as a new therapy have shown several advantages over traditional antidiabetic drugs. Based on the similar binding modes of Alogliptin and Linagliptin, molecular operation was conducted via combining pharmacophore hybridization with structural optimization between the two market drugs and racemic compounds 40 and 43 were reported as DPP-IV inhibitors in our previous studies. But the majority of DPP-IV inhibitors have developed into a small molecule with certain conformation; in this study, we described the synthesis, biological evaluation, and molecular docking of corresponding enantiomers of compounds 40 and 43. The most potent inhibitor is (R)-40 (IC50  = 23.5 nm, F = 74.67%, T1/2  = 4 h), which exhibited moderate antihyperglycemic activity as compared to the standard antidiabetic drug Linagliptin in OGTT. In addition, compound (R)-40 effectively improved the pathological state of DIO mice. Molecular docking studies clarified the favorable binding affinity between compound (R)-40 and DPP-IV active site. Thus, compound (R)-40 would be entitled to further development as a drug candidate on the basis of the suitable pharmacokinetic (PK) and desirable pharmacodynamic (PD) profiles. © 2015 John Wiley & Sons A/S.

EFFECTS OF SOG ON DPP-RECEPTOR BINDING*

PubMed Central

LOU, YUAN; NIE, QING; WAN, FREDERIC Y. M.

2007-01-01

Concentration gradients of morphogens are known to be instrumental in cell signaling and tissue patterning. Of interest here is how the presence of a competitor of BMP ligands affects cell signaling. The effects of Sog on the binding of Dpp with cell receptors are analyzed for dorsal-ventral morphogen gradient formation in vertebrate and Drosophila embryos. This prototype system includes diffusing ligands, degradation of morphogens, and cleavage of Dpp-Sog complexes by Tolloid to free up Dpp. Simple and biologically meaningful necessary and sufficient conditions for the existence of a steady state gradient configuration are established, and existence theorems are proved. For high Sog production rates (relative to the Dpp production rate), it is found that the steady state configuration exhibits a more intense Dpp-receptor concentration near the dorsal midline. Numerical simulations of the evolution of the system show that, beyond some threshold Sog production rate, the transient Dpp-receptor concentration at the dorsal midline would become more intense than that of the steady state, before subsiding and approaching a nonuniform steady state of lower magnitude. The magnitude of the transient concentration has been found to increase by several fold with increasing Sog production rate. The highly intense Dpp activity at and around the dorsal midline is consistent with available experimental observations and other analytical studies. PMID:17377624

Critical role of renal dipeptidyl peptidase-4 in ameliorating kidney injury induced by saxagliptin in Dahl salt-sensitive hypertensive rats.

PubMed

Sakai, Mariko; Uchii, Masako; Myojo, Kensuke; Kitayama, Tetsuya; Kunori, Shunji

2015-08-15

Saxagliptin, a potent dipeptidyl peptidase-4 (DPP-4) inhibitor, is currently used to treat type 2 diabetes mellitus, and it has been reported to exhibit a slower rate of dissociation from DPP-4 compared with another DPP-4 inhibitor, sitagliptin. In this study, we compared the effects of saxagliptin and sitagliptin on hypertension-related renal injury and the plasma and renal DPP-4 activity levels in Dahl salt-sensitive hypertensive (Dahl-S) rats. The high-salt diet (8% NaCl) significantly increased the blood pressure and quantity of urinary albumin excretion and induced renal glomerular injury in the Dahl-S rats. Treatment with saxagliptin (14mg/kg/day via drinking water) for 4 weeks significantly suppressed the increase in urinary albumin excretion and tended to ameliorate glomerular injury without altering the blood glucose levels and systolic blood pressure. On the other hand, the administration of sitagliptin (140mg/kg/day via drinking water) did not affect urinary albumin excretion and glomerular injury in the Dahl-S rats. Meanwhile, the high-salt diet increased the renal DPP-4 activity but did not affect the plasma DPP-4 activity in the Dahl-S rats. Both saxagliptin and sitagliptin suppressed the plasma DPP-4 activity by 95% or more. Although the renal DPP-4 activity was also inhibited by both drugs, the inhibitory effect of saxagliptin was more potent than that of sitagliptin. These results indicate that saxagliptin has a potent renoprotective effect in the Dahl-S rats, independent of its glucose-lowering actions. The inhibition of the renal DPP-4 activity induced by saxagliptin may contribute to ameliorating renal injury in hypertension-related renal injury. Copyright © 2015 Elsevier B.V. All rights reserved.

Comparative risk for cardiovascular diseases of dipeptidyl peptidase-4 inhibitors vs. sulfonylureas in combination with metformin: Results of a two-phase study.

PubMed

Enders, Dirk; Kollhorst, Bianca; Engel, Susanne; Linder, Roland; Verheyen, Frank; Pigeot, Iris

2016-01-01

The aim was to assess whether the use of additional data from the Disease Management Program (DMP) diabetes mellitus type 2 to minimize the potential for residual confounding will alter the estimated risk of either myocardial infarction, ischemic stroke or heart failure in patients with type 2 diabetes using sulfonylureas compared to dipeptidyl peptidase-4 (DPP-4) inhibitors in addition to metformin based on routine health care data. We conducted a nested two-phase case-control study using claims data of one German health insurance from 2004 to 2013 (phase 1) and data of the DMP from 2010 to 2013 (phase 2). Adjusted odds ratios (ORs) for the combined cardiovascular event myocardial infarction, ischemic stroke or heart failure were calculated using a two-phase logistic regression. Phase 1 comprised 3179 patients (289 cases; 2890 controls) and phase 2 comprised 1968 patients (168 cases; 1800 controls). We observed an adjusted OR of 0.83 for the combined cardiovascular event (95% CI: 0.61-1.13). We observed a non-significantly reduced risk for cardiovascular diseases in patients using DPP-4 inhibitors compared to sulfonylureas in addition to metformin. This finding was not altered by the inclusion of additional information of the DMP in the analysis. However, due to the low power of this study, further studies are needed to reproduce our findings. Copyright © 2016 Elsevier Inc. All rights reserved.

Dipeptidyl peptidase IV (DPP-IV) inhibition prevents fibrosis in adipose tissue of obese mice.

PubMed

Marques, Ana Patrícia; Cunha-Santos, Janete; Leal, Helena; Sousa-Ferreira, Lígia; Pereira de Almeida, Luís; Cavadas, Cláudia; Rosmaninho-Salgado, Joana

2018-03-01

During the development of obesity the expansion of white adipose tissue (WAT) leads to a dysregulation and an excessive remodeling of extracellular matrix (ECM), leading to fibrosis formation. These ECM changes have high impact on WAT physiology and may change obesity progression. Blocking WAT fibrosis may have beneficial effects on the efficacy of diet regimen or therapeutical approaches in obesity. Since dipeptidyl peptidase IV (DPP-IV) inhibitors prevent fibrosis in tissues, such as heart, liver and kidney, the objective of this study was to assess whether vildagliptin, a DPP-IV inhibitor, prevents fibrosis in WAT in a mouse model of obesity, and to investigate the mechanisms underlying this effect. We evaluated the inhibitory effect of vildagliptin on fibrosis markers on WAT of high-fat diet (HFD)-induced obese mice and on 3T3-L1 cell line of mouse adipocytes treated with a fibrosis inducer, transforming growth factor beta 1 (TGFβ1). Vildagliptin prevents the increase of fibrosis markers in WAT of HFD-fed mice and reduces blood glucose, serum triglycerides, total cholesterol and leptin levels. In the in vitro study, the inhibition of DPP-IV with vildagliptin, neuropeptide Y (NPY) treatment and NPY Y 1 receptor activation prevents ECM deposition and fibrosis markers increase induced by TGFβ1 treatment. Vildagliptin prevents fibrosis formation in adipose tissue in obese mice, at least partially through NPY and NPY Y 1 receptor activation. This study highlights the importance of vildagliptin in the treatment of fibrosis that occur in obesity. Copyright © 2017 Elsevier B.V. All rights reserved.

Regulation of Dpp activity by tissue-specific cleavage of an upstream site within the prodomain

PubMed Central

Sopory, Shailaja; Kwon, Sunjong; Wehrli, Marcel; Christian, Jan L.

2010-01-01

BMP4 is synthesized as an inactive precursor that is cleaved at two sites during maturation: initially at a site (S1) adjacent to the ligand domain, and then at an upstream site (S2) within the prodomain. Cleavage at the second site regulates the stability of mature BMP4 and this in turn influences its signaling intensity and range of action. The Drosophila ortholog of BMP4, Dpp, functions as a long- or short-range signaling molecule in the wing disc or embryonic midgut, respectively but mechanisms that differentially regulate its bioactivity in these tissues have not been explored. In the current studies we demonstrate, by dpp mutant rescue, that cleavage at the S2 site of proDpp is required for development of the wing and leg imaginal discs, whereas cleavage at the S1 site is sufficient to rescue Dpp function in the midgut. Both the S1 and S2 site of proDpp are cleaved in the wing disc, and S2-cleavage is essential to generate sufficient ligand to exceed the threshold for pMAD activation at both short- and long-range in most cells. By contrast, proDpp is cleaved at the S1 site alone in the embryonic mesoderm and this generates sufficient ligand to activate physiological target genes in neighboring cells. These studies provide the first biochemical and genetic evidence that that selective cleavage of the S2 site of proDPP provides a tissue-specific mechanism for regulating Dpp activity, and that differential cleavage can contribute to, but is not an absolute determinant of signaling range. PMID:20659445

Di-peptidyl peptidase-4 inhibitor sitagliptin protects vascular function in metabolic syndrome: possible role of epigenetic regulation.

PubMed

Cicek, Figen Amber; Amber, Cicek Figen; Tokcaer-Keskin, Zeynep; Zeynep, Tokcaer-Keskin; Ozcinar, Evren; Evren, Ozcinar; Bozkus, Yosuf; Yusuf, Bozkus; Akcali, Kamil Can; Can, Akcali Kamil; Turan, Belma; Belma, Turan

2014-08-01

Metabolic syndrome (MetS) is a complex medical disorder characterized by insulin resistance, hypertension, and high risk of coronary disease and stroke. Microvascular rarefaction and endothelial dysfunction have also been linked with MetS, and recent evidence from clinical studies supports the efficacy of incretin-based antidiabetic therapies for vascular protection in diabetes. Previous studies pointed out the importance of dipeptidyl peptidase-4 (DPP-4) inhibition in endothelial cells due to getting protection against metabolic pathologies. We therefore aimed to investigate the acute effects of a DPP-4 inhibitor, sitagliptin, on vascular function in rats with high-sucrose diet-induced MetS. In order to elucidate the mechanisms implicated in the effects of DPP-4 inhibition, we tested the involvement of NO pathway and epigenetic regulation in the MetS. Acute use of sitagliptin protects the vascular function in the rats with MetS in part due to NO pathway via restoring the depressed aortic relaxation responses mediated by receptors. Application of sitagliptin enhanced the depressed phosphorylation levels of both the endothelial NO synthase and the apoptotic status of protein kinase B, known as Akt, in endothelium-intact thoracic aorta from rats with MetS. One-hour application of sitagliptin on aortic rings from rats with MetS also induced remarkable histon posttranslational modifications such as increased expression of H3K27Me3, but not of H3K27Me2, resulting in an accumulation of the H3K27Me3. Our findings suggest that, in addition to its well-known hypoglycemic action, sitagliptin may also have beneficial effects on hyperglycemia-induced vascular changes in an endotheium-dependent manner. These present results with sitagliptin aside from the glycaemic control, may demonstrate its important role in the treatment of patients with MetS.

Substrate Binding Protein DppA1 of ABC Transporter DppBCDF Increases Biofilm Formation in Pseudomonas aeruginosa by Inhibiting Pf5 Prophage Lysis

PubMed Central

Lee, Yunho; Song, Sooyeon; Sheng, Lili; Zhu, Lei; Kim, Jun-Seob; Wood, Thomas K.

2018-01-01

Filamentous phage impact biofilm development, stress tolerance, virulence, biofilm dispersal, and colony variants. Previously, we identified 137 Pseudomonas aeruginosa PA14 mutants with more than threefold enhanced and 88 mutants with more than 10-fold reduced biofilm formation by screening 5850 transposon mutants (PLoS Pathogens 5: e1000483, 2009). Here, we characterized the function of one of these 225 mutations, dppA1 (PA14_58350), in regard to biofilm formation. DppA1 is a substrate-binding protein (SBP) involved in peptide utilization via the DppBCDF ABC transporter system. We show that compared to the wild-type strain, inactivating dppA1 led to 68-fold less biofilm formation in a static model and abolished biofilm formation in flow cells. Moreover, the dppA1 mutant had a delay in swarming and produced 20-fold less small-colony variants, and both biofilm formation and swarming were complemented by producing DppA1. A whole-transcriptome analysis showed that only 10 bacteriophage Pf5 genes were significantly induced in the biofilm cells of the dppA1 mutant compared to the wild-type strain, and inactivation of dppA1 resulted in a 600-fold increase in Pf5 excision and a million-fold increase in phage production. As expected, inactivating Pf5 genes PA0720 and PA0723 increased biofilm formation substantially. Inactivation of DppA1 also reduced growth (due to cell lysis). Hence, DppA1 increases biofilm formation by repressing Pf5 prophage. PMID:29416528

Effects of Incretin-Based Therapies and SGLT2 Inhibitors on Skeletal Health.

PubMed

Egger, Andrea; Kraenzlin, Marius E; Meier, Christian

2016-12-01

Anti-diabetic drugs are widely used and are essential for adequate glycemic control in patients with type 2 diabetes. Recently, marketed anti-diabetic drugs include incretin-based therapies (GLP-1 receptor agonists and DPP-4 inhibitors) and sodium-glucose co-transporter 2 (SGLT2) inhibitors. In contrast to well-known detrimental effects of thiazolidinediones on bone metabolism and fracture risk, clinical data on the safety of incretin-based therapies is limited. Based on meta-analyses of trials investigating the glycemic-lowering effect of GLP-1 receptor agonists and DPP4 inhibitors, it seems that incretin-based therapies are not associated with an increase in fracture risk. Sodium-glucose co-transporter 2 inhibitors may alter calcium and phosphate homeostasis as a result of secondary hyperparathyroidism induced by increased phosphate reabsorption. Although these changes may suggest detrimental effects of SGLT-2 inhibitors on skeletal integrity, treatment-related direct effects on bone metabolism seem unlikely. Observed changes in BMD, however, seem to result from increased bone turnover in the early phase of drug-induced weight loss. Fracture risk, which is observed in older patients with impaired renal function and elevated cardiovascular disease risk treated with SGLT2 inhibitors, seems to be independent of direct effects on bone but more likely to be associated with falls and changes in hydration status secondary to osmotic diuresis.

Gemigliptin, a novel dipeptidyl peptidase 4 inhibitor: first new anti-diabetic drug in the history of Korean pharmaceutical industry.

PubMed

Kim, Sung-Ho; Lee, Sung-Hack; Yim, Hyeon-Joo

2013-10-01

Gemigliptin, a potent, selective and long-acting DPP 4 inhibitor was developed by LG Life Sciences and approved for use in patients with type 2 diabetes mellitus by the Korean Food and Drug Administration in June 2012 under the trade name Zemiglo(®). Clinical pharmacokinetic and pharmacodynamic data suggest the efficacy and once daily dosing of gemigliptin. In clinical phase III studies, gemigliptin was efficacious as either monotherapy or combination therapy (add-on to metformin) and well tolerated in patients with type 2 diabetes. Further development of combination therapy is on-going.

Changes in Gene Expression Profiles in Adult Rat Brain Structures after Neonatal Action of Dipeptidyl Peptidase-IV Inhibitors.

PubMed

Zubkov, Eugene A; Zorkina, Yana A; Orshanskaya, Elena V; Khlebnikova, Nadezhda N; Krupina, Natalia A; Chekhonin, Vladimir P

2017-01-01

Previous studies have shown the development of emotional and motivational disorders, such as anxiety-depression-like disorders with increased aggression in adolescent and adult Wistar rats, occurs after neonatal exposure to the dipeptidyl peptidase-IV (DPP-IV, EC 3.4.14.5) inhibitors diprotin A and sitagliptin (postnatal days 5-18). In this study, using real-time PCR, we evaluated changes in the gene expression of serine protease DPP-IV and prolyl endopeptidase (PREP, EC 3.4.21.26; dpp4 and prep genes), monoamine oxidase А (maoA) and B (maoB), and serotonin transporter (SERT; sert) in the brain structures from 3-month-old rats after postnatal action of DPP-IV inhibitors diprotin A and sitagliptin. Dpp4, sert, and maoB gene expression increased and maoA gene expression changed with a tendency to increase in the striatum of rats with neonatal sitagliptin action. The increase of maoA gene expression was also shown in the amygdala. An increase in prep gene expression was found in the striatum of rats with the neonatal action of diprotin A, and a decrease in maoB gene expression was observed in the amygdala. We detected a significant downward trend in sert gene expression in the frontal cortex and amygdala, as well as a tendency to increase in maoA gene expression in the hypothalamus. These findings suggest that changes in the expression of the abovementioned genes are associated with the development of anxiety and depression, with increased aggression caused by the neonatal action of diprotin A and sitagliptin. © 2018 S. Karger AG, Basel.

The persistent inhibitory properties of saxagliptin on renal dipeptidyl peptidase-4: Studies with HK-2 cells in vitro and normal rats in vivo.

PubMed

Uchii, Masako; Sakai, Mariko; Hotta, Yuhei; Saeki, Satoshi; Kimoto, Naoya; Hamaguchi, Akinori; Kitayama, Tetsuya; Kunori, Shunji

2017-11-01

Saxagliptin, a potent and selective DPP-4 inhibitor, exhibits a slow dissociation from DPP-4. We investigated the sustained effects of saxagliptin on renal DPP-4 activity in a washout study using renal tubular (HK-2) cells, and in a pharmacodynamic study using normal rats. In HK-2 cells, the inhibitory potency of saxagliptin on DPP-4 activity persisted after washout, while that of sitagliptin was clearly reduced. In normal rats, a single treatment of saxagliptin or sitagliptin inhibited the plasma DPP-4 activity to similar levels. The inhibitory action of saxagliptin on the renal DPP-4 activity was retained, even when its inhibitory effect on the plasma DPP-4 activity disappeared. However, the inhibitory action of sitagliptin on the renal DPP-4 activity was abolished in correlation with the inhibition of the plasma DPP-4 activity. In situ staining showed that saxagliptin suppressed the DPP-4 activity in both glomerular and tubular cells and its inhibitory effects were significantly higher than those of sitagliptin. Saxagliptin exerted a sustained inhibitory effect on the renal DPP-4 activity in vitro and in vivo. The long binding action of saxagliptin in renal tubular cells might involve the sustained inhibition of renal DPP-4. Copyright © 2017 The Authors. Production and hosting by Elsevier B.V. All rights reserved.

Inhibition of dipeptidyl peptidase 4 regulates microvascular endothelial growth induced by inflammatory cytokines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Takasawa, Wataru; Ohnuma, Kei; Hatano, Ryo

2010-10-08

Research highlights: {yields} TNF-{alpha} or IL-1{beta} induces EC proliferation with reduction of CD26 expression. {yields} CD26 siRNA or DPP-4 inhibition enhances TNF-{alpha} or IL-1{beta}-induced EC proliferation. {yields} Loss of CD26/DPP-4 enhances aortic sprouting induced by TNF-{alpha} or IL-1{beta}. {yields} Capillary formation induced by TNF-{alpha} or IL-1{beta} is enahced in the CD26{sup -/-} mice. -- Abstract: CD26/DPP-4 is abundantly expressed on capillary of inflamed lesion as well as effector T cells. Recently, CD26/dipeptidyl peptidase 4 (DPP-4) inhibition has been used as a novel oral therapeutic approach for patients with type 2 diabetes. While accumulating data indicate that vascular inflammation is amore » key feature of both micro- and macro-vascular complications in diabetes, the direct role of CD26/DPP-4 in endothelial biology is to be elucidated. We herein showed that proinflammatory cytokines such as tumor necrosis factor or interleukin-1 reduce expression of CD26 on microvascular endothelial cells, and that genetical or pharmacological inhibition of CD26/DPP-4 enhances endothelial growth both in vitro and in vivo. With DPP-4 inhibitors being used widely in the treatment of type 2 diabetes, our data strongly suggest that DPP-4 inhibition plays a pivotal role in endothelial growth and may have a potential role in the recovery of local circulation following diabetic vascular complications.« less

Sitagliptin but not alpha glucosidase inhibitor reduced the serum soluble CD163, a marker for activated macrophage, in individuals with type 2 diabetes mellitus.

PubMed

Hattori, Akiko; Takemoto, Minoru; Tokuyama, Hirotake; Koshizaka, Masaya; Yokote, Koutaro

2017-04-01

Dipeptidyl peptidase-4 inhibitor (DPP-4i) is commonly used worldwide for the treatment of type 2 diabetes mellitus. In addition to its hypoglycemic activity, DPP-4i might have anti-inflammatory effects. In this study we examined the effects of DPP-4i on the serum levels of soluble CD163 (sCD163), a marker for activated macrophages, in individuals with type 2 diabetes mellitus. We compared these anti-inflammatory effects with those of α glucosidase inhibitor (αGI). Japanese patients with type 2 diabetes mellitus who were stably maintained on ≤2mg/day glimepiride alone were recruited and randomly assigned to receive additional sitagliptin (n=37) or αGI (n=37). Levels of sCD163 were measured before the addition and after a 24-week treatment period. Addition of sitagliptin significantly reduced the serum sCD163 (632 vs. 575ng/mL, p<0.05), while αGI did not display this effect (624 vs. 607ng/mL). The changes in levels of sCD163 were not related to changes in either HbA1c or body mass index (BMI). Our results suggested that DPP-4i might exert anti-inflammatory effects in individuals with type 2 diabetes mellitus, which are independent of its effects on glycemia and BMI. Copyright © 2017 Elsevier B.V. All rights reserved.

Hibiscus sabdariffa polyphenols prevent palmitate-induced renal epithelial mesenchymal transition by alleviating dipeptidyl peptidase-4-mediated insulin resistance.

PubMed

Huang, Chien-Ning; Wang, Chau-Jong; Yang, Yi-Sun; Lin, Chih-Li; Peng, Chiung-Huei

2016-01-01

Diabetic nephropathy has a significant socioeconomic impact, but its mechanism is unclear and needs to be examined. Hibiscus sabdariffa polyphenols (HPE) inhibited high glucose-induced angiotensin II receptor-1 (AT-1), thus attenuating renal epithelial mesenchymal transition (EMT). Recently, we reported HPE inhibited dipeptidyl-peptidase-4 (DPP-4, the enzyme degrades type 1 glucagon-like peptide (GLP-1)), which mediated insulin resistance signals leading to EMT. Since free fatty acids can realistically bring about insulin resistance, using the palmitate-stimulated cell model in contrast with type 2 diabetic rats, in this study we examined if insulin resistance causes renal EMT, and the preventive effect of HPE. Our findings reveal that palmitate hindered 30% of glucose uptake. Treatment with 1 mg mL(-1) of HPE and the DPP-4 inhibitor linagliptin completely recovered insulin sensitivity and palmitate-induced signal cascades. HPE inhibited DPP-4 activity without altering the levels of DPP-4 and the GLP-1 receptor (GLP-1R). HPE decreased palmitate-induced phosphorylation of Ser307 of insulin receptor substrate-1 (pIRS-1 (S307)), AT-1 and vimentin, while increasing phosphorylation of phosphatidylinositol 3-kinase (pPI3K). IRS-1 knockdown revealed its essential role in mediating downstream AT-1 and EMT. In type 2 diabetic rats, it suggests that HPE concomitantly decreased the protein levels of DPP-4, AT-1, vimentin, and fibronectin, but reversed the in vivo compensation of GLP-1R. In conclusion, HPE improves insulin sensitivity by attenuating DPP-4 and the downstream signals, thus decreasing AT-1-mediated tubular-interstitial EMT. HPE could be an adjuvant to prevent diabetic nephropathy.

Design of a comparative effectiveness randomized controlled trial testing a faith-based Diabetes Prevention Program (WORD DPP) vs. a Pacific culturally adapted Diabetes Prevention Program (PILI DPP) for Marshallese in the United States.

PubMed

McElfish, Pearl Anna; Long, Christopher R; Kaholokula, Joseph Keawe'aimoku; Aitaoto, Nia; Bursac, Zoran; Capelle, Lucy; Laelan, Melisa; Bing, Williamina Ioanna; Riklon, Sheldon; Rowland, Brett; Ayers, Britni L; Wilmoth, Ralph O; Langston, Krista N; Schootman, Mario; Selig, James P; Yeary, Karen Hye-Cheon Kim

2018-05-01

Pacific Islander populations, including Marshallese, face a disproportionately high burden of health disparities relative to the general population. A community-based participatory research (CBPR) approach was utilized to engage Marshallese participants in a comparative effectiveness trial testing 2 Diabetes Prevention Program (DPP) interventions designed to reduce participant's weight, lower HbA1c, encourage healthy eating, and increase physical activity. To compare the effectiveness of the faith-based (WORD) DPP to the culturally adapted (Pacific Culturally Adapted Diabetes Prevention Program [PILI]) DPP, a clustered randomized controlled trial (RCT) with 384 Marshallese participants will be implemented in 32 churches located in Arkansas, Kansas, Missouri, and Oklahoma. Churches will be randomly assigned to WORD DPP arm or to PILI DPP arm. WORD DPP focuses on connecting faith and health to attain a healthy weight, eat healthy, and be more physically active. In contrast, PILI DPP is a family and community focused DPP curriculum specifically adapted for implementation in Pacific Islander communities. PILI focuses on engaging social support networks to maintain a healthy weight, eat healthy, and be more physically active. All participants are assessed at baseline, immediate post intervention, and 12 months post intervention. Both interventions aim to cause weight loss through improving physical activity and healthy eating, with the goal of preventing the development of T2D. The clustered RCT will determine which intervention is most effective with the Marshallese population. The utilization of a CBPR approach that involves local stakeholders and engages faith-based institutions in Marshallese communities will increase the potential for success and sustainability. This study is registered at clinicaltrials.gov (NCT03270436).

Design of a comparative effectiveness randomized controlled trial testing a faith-based Diabetes Prevention Program (WORD DPP) vs. a Pacific culturally adapted Diabetes Prevention Program (PILI DPP) for Marshallese in the United States

PubMed Central

McElfish, Pearl Anna; Long, Christopher R.; Kaholokula, Joseph Keawe‘aimoku; Aitaoto, Nia; Bursac, Zoran; Capelle, Lucy; Laelan, Melisa; Bing, Williamina Ioanna; Riklon, Sheldon; Rowland, Brett; Ayers, Britni L.; Wilmoth, Ralph O.; Langston, Krista N.; Schootman, Mario; Selig, James P.; Yeary, Karen Hye-cheon Kim

2018-01-01

Abstract Background: Pacific Islander populations, including Marshallese, face a disproportionately high burden of health disparities relative to the general population. Objectives: A community-based participatory research (CBPR) approach was utilized to engage Marshallese participants in a comparative effectiveness trial testing 2 Diabetes Prevention Program (DPP) interventions designed to reduce participant's weight, lower HbA1c, encourage healthy eating, and increase physical activity. Design: To compare the effectiveness of the faith-based (WORD) DPP to the culturally adapted (Pacific Culturally Adapted Diabetes Prevention Program [PILI]) DPP, a clustered randomized controlled trial (RCT) with 384 Marshallese participants will be implemented in 32 churches located in Arkansas, Kansas, Missouri, and Oklahoma. Churches will be randomly assigned to WORD DPP arm or to PILI DPP arm. Methods: WORD DPP focuses on connecting faith and health to attain a healthy weight, eat healthy, and be more physically active. In contrast, PILI DPP is a family and community focused DPP curriculum specifically adapted for implementation in Pacific Islander communities. PILI focuses on engaging social support networks to maintain a healthy weight, eat healthy, and be more physically active. All participants are assessed at baseline, immediate post intervention, and 12 months post intervention. Summary: Both interventions aim to cause weight loss through improving physical activity and healthy eating, with the goal of preventing the development of T2D. The clustered RCT will determine which intervention is most effective with the Marshallese population. The utilization of a CBPR approach that involves local stakeholders and engages faith-based institutions in Marshallese communities will increase the potential for success and sustainability. This study is registered at clinicaltrials.gov (NCT03270436). PMID:29742712

DPP8/9 inhibition induces pro-caspase-1-dependent monocyte and macrophage pyroptosis

PubMed Central

Okondo, Marian C.; Johnson, Darren C.; Sridharan, Ramya; Go, Eun Bin; Chui, Ashley J.; Wang, Mitchell S.; Poplawski, Sarah E.; Wu, Wengen; Liu, Yuxin; Lai, Jack H.; Sanford, David G.; Arciprete, Michael O.; Golub, Todd R.; Bachovchin, William W.; Bachovchin, Daniel A.

2017-01-01

Val-boroPro (talabostat, PT-100), a nonselective inhibitor of post-proline cleaving serine proteases, stimulates mammalian immune systems through an unknown mechanism of action. Despite this lack of mechanistic understanding, Val-boroPro has attracted significant interest as a potential anticancer agent, reaching Phase III trials in humans. Here we show that Val-boroPro stimulates the immune system by triggering a proinflammatory form of cell death in monocytes and macrophages known as pyroptosis. We demonstrate that the inhibition of two serine proteases, DPP8 and DPP9, activates the proprotein form of caspase-1 independent of the inflammasome adaptor ASC. Activated pro-caspase-1 does not efficiently process itself or IL-1β, but does cleave and activate gasdermin D to induce pyroptosis. Mice lacking caspase-1 do not show immune stimulation after treatment with Val-boroPro. Our data identifies the first small molecule that induces pyroptosis and reveals a new checkpoint that controls the activation of the innate immune system. PMID:27820798

Active phytochemicals of Pueraria tuberosa for DPP-IV inhibition: in silico and experimental approach.

PubMed

Srivastava, Shivani; Shree, Priya; Tripathi, Yamini Bhusan

2017-01-01

We had earlier reported that the extract of Pueraria tuberosa significantly inhibits DPP-IV enzyme, resulting in glucose tolerance response in rats. In this study, we have explored the active phytochemicals responsible for this potential. The results have been validated in both fasting and postprandial states in the plasma of normal rats and also in fasting blood and intestinal homogenates of diabetic models. Pueraria tuberosa water extract (PTWE) was administered to normal Charles Foster rats for 35 days and to diabetic model (65 mg/kg bw) for 10 days. After treatments, oral glucose tolerance test (OGTT) and insulin was done for 90 min, and the changes in the levels of GLP-1, GIP, and DPP-IV activities were monitored in fasting and postprandial states. In the case of the diabetic model, DPP-IV activity was measured in intestinal homogenate and basal insulin in plasma. The components of PTWE were analyzed via HPLC-MS based on their chemical formula, molecular mass, and retention time. Using the molecular docking study, we have selected the top five components having strong binding energy with DPP-IV. The increase in secretion of GLP-1 and GIP was significantly higher in the postprandial state when compared to fasting condition. GLP-1 plasma concentration increased by 5.8 and 2.9 folds and GIP increased by 8.7 and 2.4 folds in PTWE and control rats, respectively. In contrast, the postprandial decrease in DPP-IV specific activities was recorded at 2.3 and 1.4 folds. The response in OGTT and insulin was also consistent with these changes. In comparison to diabetic controls, PTWE-administered rats showed decreased DPP-IV activity in the intestine, leading to enhanced basal insulin concentration. Through molecular docking, we found Puerarone and Robinin to be the most potential phytochemicals of PTWE for DPP-IV inhibition. Binding energy (kcal/mol) and dissociation constant (pM) of Robinin with DPP-IV protein were found to be 7.543 and 2,957,383.75, respectively

Dipeptidyl peptidase-4 greatly contributes to the hydrolysis of vildagliptin in human liver.

PubMed

Asakura, Mitsutoshi; Fujii, Hideaki; Atsuda, Koichiro; Itoh, Tomoo; Fujiwara, Ryoichi

2015-04-01

The major metabolic pathway of vildagliptin in mice, rats, dogs, and humans is hydrolysis at the cyano group to produce a carboxylic acid metabolite M20.7 (LAY151), whereas the major metabolic enzyme of vildagliptin has not been identified. In the present study, we determined the contribution rate of dipeptidyl peptidase-4 (DPP-4) to the hydrolysis of vildagliptin in the liver. We performed hydrolysis assay of the cyano group of vildagliptin using mouse, rat, and human liver samples. Additionally, DPP-4 activities in each liver sample were assessed by DPP-4 activity assay using the synthetic substrate H-glycyl-prolyl-7-amino-4-methylcoumarin (Gly-Pro-AMC). M20.7 formation rates in liver microsomes were higher than those in liver cytosol. M20.7 formation rate was significantly positively correlated with the DPP-4 activity using Gly-Pro-AMC in liver samples (r = 0.917, P < 0.01). The formation of M20.7 in mouse, rat, and human liver S9 fraction was inhibited by sitagliptin, a selective DPP-4 inhibitor. These findings indicate that DPP-4 is greatly involved in vildagliptin hydrolysis in the liver. Additionally, we established stable single expression systems of human DPP-4 and its R623Q mutant, which is the nonsynonymous single-nucleotide polymorphism of human DPP-4, in human embryonic kidney 293 (HEK293) cells to investigate the effect of R623Q mutant on vildagliptin-hydrolyzing activity. M20.7 formation rate in HEK293 cells expressing human DPP-4 was significantly higher than that in control HEK293 cells. Interestingly, R623Q mutation resulted in a decrease of the vildagliptin-hydrolyzing activity. Our findings might be useful for the prediction of interindividual variability in vildagliptin pharmacokinetics. Copyright © 2015 by The American Society for Pharmacology and Experimental Therapeutics.

Hibiscus sabdariffa polyphenols alleviate insulin resistance and renal epithelial to mesenchymal transition: a novel action mechanism mediated by type 4 dipeptidyl peptidase.

PubMed

Peng, Chiung-Huei; Yang, Yi-Sun; Chan, Kuei-Chuan; Wang, Chau-Jong; Chen, Mu-Lin; Huang, Chien-Ning

2014-10-08

The epithelial to mesenchymal transition (EMT) is important in renal fibrosis. Ser307 phosphorylation of insulin receptor substrate-1 (IRS-1 (S307)) is a hallmark of insulin resistance. We report that polyphenol extracts of Hibiscus sabdariffa (HPE) ameliorate diabetic nephropathy and EMT. Recently it has been observed that type 4 dipeptidyl peptidase (DPP-4) inhibitor linagliptin is effective for treating type 2 diabetes and albuminuria. We investigated if DPP-4 and insulin resistance are involved in renal EMT and explored the role of HPE. In high glucose-stimulated tubular cells, HPE, like linagliptin, inhibited DPP-4 activation, thereby regulating vimentin (EMT marker) and IRS-1 (S307). IRS-1 knockdown revealed its essential role in mediating downstream EMT. In type 2 diabetic rats, pIRS-1 (S307) abundantly surrounds the tubular region, with increased vimentin in kidney. Both the expressions were reduced by HPE. In conclusion, HPE exerts effects similar to those of linagliptin, which improves insulin resistance and EMT, and could be an adjuvant to prevent diabetic nephropathy.

Incretin therapies: highlighting common features and differences in the modes of action of glucagon-like peptide-1 receptor agonists and dipeptidyl peptidase-4 inhibitors.

PubMed

Nauck, M

2016-03-01

Over the last few years, incretin-based therapies have emerged as important agents in the treatment of type 2 diabetes (T2D). These agents exert their effect via the incretin system, specifically targeting the receptor for the incretin hormone glucagon-like peptide 1 (GLP-1), which is partly responsible for augmenting glucose-dependent insulin secretion in response to nutrient intake (the 'incretin effect'). In patients with T2D, pharmacological doses/concentrations of GLP-1 can compensate for the inability of diabetic β cells to respond to the main incretin hormone glucose-dependent insulinotropic polypeptide, and this is therefore a suitable parent compound for incretin-based glucose-lowering medications. Two classes of incretin-based therapies are available: GLP-1 receptor agonists (GLP-1RAs) and dipeptidyl peptidase-4 (DPP-4) inhibitors. GLP-1RAs promote GLP-1 receptor (GLP-1R) signalling by providing GLP-1R stimulation through 'incretin mimetics' circulating at pharmacological concentrations, whereas DPP-4 inhibitors prevent the degradation of endogenously released GLP-1. Both agents produce reductions in plasma glucose and, as a result of their glucose-dependent mode of action, this is associated with low rates of hypoglycaemia; however, there are distinct modes of action resulting in differing efficacy and tolerability profiles. Furthermore, as their actions are not restricted to stimulating insulin secretion, these agents have also been associated with additional non-glycaemic benefits such as weight loss, improvements in β-cell function and cardiovascular risk markers. These attributes have made incretin therapies attractive treatments for the management of T2D and have presented physicians with an opportunity to tailor treatment plans. This review endeavours to outline the commonalities and differences among incretin-based therapies and to provide guidance regarding agents most suitable for treating T2D in individual patients. © 2015 The Authors

Chromogenic Detection of Dipeptidyl Peptidase IV (DPP-IV) Activity using Peptide-Functionalized Gold Nanoparticles

NASA Astrophysics Data System (ADS)

Abul-Huda, Yasin Mohammad

Metal nanoparticles offer a useful platform for a wide range of biological applications especially for biosensing, bioimaging and drug delivery. This thesis presents a body of original research describing the synthesis, characterisation and development of a novel and convenient biosensing assay for detection of dipeptidyl peptidase IV (DPP-IV) enzyme activity using peptide functionalized gold nanoparticles. The distinctive optical and physical properties of gold nanoparticles (Au NP) were harnessed for the development of a colorimetric assay for rapid sensing of DPP-IV activities and screening DPP-IV inhbitors. The citrate reduction method for Au NPs synthesis was optimised and several potential peptide substrates (GPDC, VP-EN-DC, C/G dipeptide, GPG-EN-PEG4-LA, GPDCALNNC) were designed to provide substrates that mimic the DPP-IV natural substrates. The performances of the substrate functionalized Au NPs were assessed for their appropriateness for the detection of the enzyme activity. Addition of DPP-IV to the solutions containing the functionalized Au NPs resulted in cleavage of the substrate and thus causing the aggregation of the Au NPs which in turn led to a shift of the surface plasmon peak toward longer wavelengths, and a change of the colour of the colloidal suspension from red to blue. Overall, real-time detection of DPP-IV activity over a broader range (0-40 U/L) with high selectivity and stability was obtained, thus providing a method that can be used to determine the levels of DPP-IV/CD26 in biological fluids such as serum and plasma. Further assay developments were conducted to overcome limitations encountered with the original Au NP assay, especially the narrow dynamic linear range and stability in high ionic strength solutions. Validation and comparison of the Au NP assay developed has revealed that this method is highly correlated to the gold standard chromogenic Gly-Pro-pNA method for detection of enzyme activity in biological samples. Very good

Combined treatment with dipeptidyl peptidase-4 inhibitor (sitagliptin) and angiotensin-II type 1 receptor blocker (losartan) suppresses progression in a non-diabetic rat model of steatohepatitis.

PubMed

Okura, Yasushi; Namisaki, Tadashi; Moriya, Kei; Kitade, Mitsuteru; Takeda, Kosuke; Kaji, Kosuke; Noguchi, Ryuichi; Nishimura, Norihisa; Seki, Kenichiro; Kawaratani, Hideto; Takaya, Hiroaki; Sato, Shinya; Sawada, Yasuhiko; Shimozato, Naotaka; Furukawa, Masanori; Nakanishi, Keisuke; Saikawa, Soichiro; Kubo, Takuya; Asada, Kiyoshi; Yoshiji, Hitoshi

2017-11-01

Dipeptidyl peptidase-4 (DPP4) inhibitors (DPP4-I) are oral glucose-lowering drugs for type 2 diabetes mellitus. Previously, we reported that DPP4-I (sitagliptin) exerted suppressive effects on experimental liver fibrosis in rats. Blockade of the renin-angiotensin system by angiotensin-II type 1 receptor blocker (losartan), commonly used in the management of hypertension, has been shown to significantly alleviate hepatic fibrogenesis and carcinogenesis. We aimed to elucidate the effects and possible mechanisms of a sitagliptin + losartan combination on the progression of non-diabetic non-alcoholic steatohepatitis (NASH) in a rat model. To induce NASH, Fischer 344 rats were fed a choline-deficient L-amino acid-defined diet for 12 weeks. We elucidated the chemopreventive effects of sitagliptin + losartan, especially in conjunction with hepatic stellate cell (HSC) activation, angiogenesis, and oxidative stress, all known to play important roles in the progression of NASH. Sitagliptin + losartan suppressed choline-deficient L-amino acid-defined diet-induced hepatic fibrogenesis and carcinogenesis. The combination treatment exerted a greater inhibitory effect than monotherapy. These inhibitory effects occurred almost concurrently with the suppression of HSC activation, neovascularization, and oxidative stress. In vitro studies showed that sitagliptin + losartan inhibited angiotensin II-induced proliferation and expression of transforming growth factor-β1 and α1 (I)-procollagen mRNA of activated HSC and in vitro angiogenesis, in parallel with the suppression observed in in vivo studies. The widely and safely used sitagliptin + losartan combination treatment in clinical practice could be an effective strategy against NASH. © 2016 The Japan Society of Hepatology.

Suppression of Food Intake by Glucagon-Like Peptide-1 Receptor Agonists: Relative Potencies and Role of Dipeptidyl Peptidase-4

PubMed Central

Jessen, Lene; Aulinger, Benedikt A.; Hassel, Jonathan L.; Roy, Kyle J.; Smith, Eric P.; Greer, Todd M.; Woods, Stephen C.; Seeley, Randy J.

2012-01-01

Administration of the glucagon-like peptide-1 (GLP-1) receptor agonists GLP-1 and exendin-4 (Ex-4) directly into the central nervous system decreases food intake. But although Ex-4 potently suppresses food intake after peripheral administration, the effects of parenteral GLP-1 are variable and not as strong. A plausible explanation for these effects is the rapid inactivation of circulating GLP-1 by dipeptidyl peptidase-4 (DPP-4), an enzyme that does not alter Ex-4 activity. To test this hypothesis, we assessed the relative potency of Ex-4 and GLP-1 under conditions in which DPP-4 activity was reduced. Outbred rats, wild-type mice, and mice with a targeted deletion of DPP-4 (Dpp4−/−) were treated with GLP-1 alone or in combination with the DPP-4 inhibitor vildagliptin, Ex-4, or saline, and food intake was measured. GLP-1 alone, even at high doses, did not affect feeding in wild-type mice or rats but did reduce food intake when combined with vildagliptin or given to Dpp4−/− mice. Despite plasma clearance similar to DPP-4-protected GLP-1, equimolar Ex-4 caused greater anorexia than vildagliptin plus GLP-1. To determine whether supraphysiological levels of endogenous GLP-1 would suppress food intake if protected from DPP-4, rats with Roux-en-Y gastric bypass and significantly elevated postprandial plasma GLP-1 received vildagliptin or saline. Despite 5-fold greater postprandial GLP-1 in these animals, vildagliptin did not affect food intake in Roux-en-Y gastric bypass rats. Thus, in both mice and rats, peripheral GLP-1 reduces food intake significantly less than Ex-4, even when protected from DPP-4. These findings suggest distinct potencies of GLP-1 receptor agonists on food intake that cannot be explained by plasma pharmacokinetics. PMID:23033273

Charge Mobility Enhancement for Conjugated DPP-Selenophene Polymer by Simply Replacing One Bulky Branching Alkyl Chain with Linear One at Each DPP Unit

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Zhijie; Liu, Zitong; Ning, Lu

Here, we demonstrate a simple, but efficient, approach for improving the semiconducting performances of DPP-based conjugated D-A polymers. This approach involves the replacement of one bulky branching alkyl chain with the linear one at each DPP unit in regular polymer PDPPSe-10 and PDPPSe-12. The UV–vis absorption, Raman spectra, PDS data, and theoretical calculations support that the replacement of bulky branching chains with linear ones can weaken the steric hindrance, and accordingly conjugated backbones become more planar and rigid. GIWAXS data show that the incorporation of linear alkyl chains as in PDPPSe-10 and PDPPSe-12 is beneficial for side-chain interdigitation and interchainmore » dense packing, leading to improvement of interchain packing order and thin film crystallinity by comparing with PDPPSe, which contains branching alkyl chains. On the basis of field-effect transistor (FET) studies, charge mobilities of PDPPSe-10 and PDPPSe-12 are remarkably enhanced. Hole mobilities of PDPPSe-10 and PDPPSe-12 in air are boosted to 8.1 and 9.4 cm 2 V –1 s –1, which are about 6 and 7 times, respectively, than that of PDPPSe (1.35 cm 2 V –1 s –1). Furthermore, both PDPPSe-10 and PDPPSe-12 behave as ambipolar semiconductors under a nitrogen atmosphere with increased hole/electron mobilities up to 6.5/0.48 cm 2 V –1 s –1 and 7.9/0.79 cm 2 V –1 s –1, respectively.« less

Charge Mobility Enhancement for Conjugated DPP-Selenophene Polymer by Simply Replacing One Bulky Branching Alkyl Chain with Linear One at Each DPP Unit

DOE PAGES

Wang, Zhijie; Liu, Zitong; Ning, Lu; ...

2018-04-17

Here, we demonstrate a simple, but efficient, approach for improving the semiconducting performances of DPP-based conjugated D-A polymers. This approach involves the replacement of one bulky branching alkyl chain with the linear one at each DPP unit in regular polymer PDPPSe-10 and PDPPSe-12. The UV–vis absorption, Raman spectra, PDS data, and theoretical calculations support that the replacement of bulky branching chains with linear ones can weaken the steric hindrance, and accordingly conjugated backbones become more planar and rigid. GIWAXS data show that the incorporation of linear alkyl chains as in PDPPSe-10 and PDPPSe-12 is beneficial for side-chain interdigitation and interchainmore » dense packing, leading to improvement of interchain packing order and thin film crystallinity by comparing with PDPPSe, which contains branching alkyl chains. On the basis of field-effect transistor (FET) studies, charge mobilities of PDPPSe-10 and PDPPSe-12 are remarkably enhanced. Hole mobilities of PDPPSe-10 and PDPPSe-12 in air are boosted to 8.1 and 9.4 cm 2 V –1 s –1, which are about 6 and 7 times, respectively, than that of PDPPSe (1.35 cm 2 V –1 s –1). Furthermore, both PDPPSe-10 and PDPPSe-12 behave as ambipolar semiconductors under a nitrogen atmosphere with increased hole/electron mobilities up to 6.5/0.48 cm 2 V –1 s –1 and 7.9/0.79 cm 2 V –1 s –1, respectively.« less

Treating cancer with selective CDK4/6 inhibitors.

PubMed

O'Leary, Ben; Finn, Richard S; Turner, Nicholas C

2016-07-01

Uncontrolled cellular proliferation, mediated by dysregulation of the cell-cycle machinery and activation of cyclin-dependent kinases (CDKs) to promote cell-cycle progression, lies at the heart of cancer as a pathological process. Clinical implementation of first-generation, nonselective CDK inhibitors, designed to inhibit this proliferation, was originally hampered by the high risk of toxicity and lack of efficacy noted with these agents. The emergence of a new generation of selective CDK4/6 inhibitors, including ribociclib, abemaciclib and palbociclib, has enabled tumour types in which CDK4/6 has a pivotal role in the G1-to-S-phase cell-cycle transition to be targeted with improved effectiveness, and fewer adverse effects. Results of pivotal phase III trials investigating palbociclib in patients with advanced-stage oestrogen receptor (ER)-positive breast cancer have demonstrated a substantial improvement in progression-free survival, with a well-tolerated toxicity profile. Mechanisms of acquired resistance to CDK4/6 inhibitors are beginning to emerge that, although unwelcome, might enable rational post-CDK4/6 inhibitor therapeutic strategies to be identified. Extending the use of CDK4/6 inhibitors beyond ER-positive breast cancer is challenging, and will likely require biomarkers that are predictive of a response, and the use of combination therapies in order to optimize CDK4/6 targeting.

Vildagliptin , a DPP-4 inhibitor for the twice-daily treatment of type 2 diabetes mellitus with or without metformin.

PubMed

Forst, Thomas; Bramlage, Peter

2014-06-01

Dipeptidyl peptidase-4 inhibitors increase circulating levels of glucagon-like peptide 1 (GLP-1) and glucose dependent insulinotropic polypeptide regulating glucose-dependent insulin secretion. In addition, GLP-1 suppresses glucagon secretion, delays gastric emptying and increases satiety. The combination of vildagliptin with the biguanide metformin is of particular interest because of its complementary mode of action, addressing insulin resistance, alpha- and beta cell function in the islet of the pancreas. Because of the abundance of data supporting the use of vildagliptin alone and in combination with metformin, the present paper aims at giving an overview on the current evidence for its use in patients with type 2 diabetes mellitus. The data suggest that vildagliptin offers similar glycemic control compared to sulfonylureas and thiazolidinediones, while having the benefit of being associated with fewer cases of hypoglycemia and less body weight gain. There is increasing evidence that compared with sulfonylureas, vildagliptin has favorable effects on pancreatic alpha- and beta-cell function. Vildagliptin in combination with metformin, improve glycemic control with a favorable safety and tolerability profile, making it an attractive therapeutic option in patients where metformin monotherapy alone is not sufficient.

The Vildagliptin Experience - 25 Years Since the Initiation of the Novartis Glucagon-like Peptide-1 Based Therapy Programme and 10 Years Since the First Vildagliptin Registration.

PubMed

Foley, James E; Ahrén, Bo

2017-08-01

The discovery of the incretin hormone glucagon like peptide-1 (GLP-1), and its usefulness in the treatment of type 2 diabetes mellitus (T2DM) followed by the finding that dipeptidyl peptidase-4 (DPP-4) inhibition prevents GLP-1 inactivation, led to the discovery of DPP-728. In 1999, studies with DPP-728 established the first proof-of-concept that DPP-4 inhibition improves glycaemic control in patients with T2DM. Further efforts to improve the binding kinetics of DPP-728 resulted in the discovery of vildagliptin (LAF237). In the last 20 years, a plethora of studies conducted by Novartis in collaboration with external investigators has demonstrated the mechanism of action of vildagliptin and its efficacy as monotherapy and as an add-on therapy for patients with T2DM. The studies establish that vildagliptin is a selective DPP-4 inhibitor that blocks GLP-1 and glucose-dependent insulinotropic polypeptide (GIP) inactivation, thereby prolonging their action, resulting in improved glycaemic control. This review aims to discuss the discovery and development of vildagliptin, with an emphasis on mechanism of action and clinical efficacy.

Inwardly rectifying potassium channels influence Drosophila wing morphogenesis by regulating Dpp release.

PubMed

Dahal, Giri Raj; Pradhan, Sarala Joshi; Bates, Emily Anne

2017-08-01

Loss of embryonic ion channel function leads to morphological defects, but the underlying reason for these defects remains elusive. Here, we show that inwardly rectifying potassium (Irk) channels regulate release of the Drosophila bone morphogenetic protein Dpp in the developing fly wing and that this is necessary for developmental signaling. Inhibition of Irk channels decreases the incidence of distinct Dpp-GFP release events above baseline fluorescence while leading to a broader distribution of Dpp-GFP. Work by others in different cell types has shown that Irk channels regulate peptide release by modulating membrane potential and calcium levels. We found calcium transients in the developing wing, and inhibition of Irk channels reduces the duration and amplitude of calcium transients. Depolarization with high extracellular potassium evokes Dpp release. Taken together, our data implicate Irk channels as a requirement for regulated release of Dpp, highlighting the importance of the temporal pattern of Dpp presentation for morphogenesis of the wing. © 2017. Published by The Company of Biologists Ltd.

Purification, identification and molecular mechanism of two dipeptidyl peptidase IV (DPP-IV) inhibitory peptides from Antarctic krill (Euphausia superba) protein hydrolysate.

PubMed

Ji, Wei; Zhang, Chaohua; Ji, Hongwu

2017-10-01

Dipeptidyl peptidase IV (DPP-IV) played an important role in blood glucose regulation. Inhibition of DPP-IV may improve glycemic control in diabetics by preventing the rapid breakdown of incretin hormones and prolonging their physiological action. In this study, Antarctic krill (Euphausia superba) protein was hydrolyzed using animal proteolytic enzymes. The hydrolysate was purified sequentially by ultrafiltration, gel filtration chromatography and reversed phase high-performance liquid chromatography (RP-HPLC). DPP-IV inhibitory activity of the fractions achieved from Antarctic krill protein was determined by DPP-IV screening reagent kit. Two purified peptides were identified by Xevo G2-XS QTof mass spectrometer (QTOF-MS). One peptide purified was Ala-Pro (AP) with IC 50 values of 0.0530mg/mL, the other Ile-Pro-Ala (IPA) with IC 50 values of 0.0370mg/mL. They both exhibited strong DPP-IV inhibitory activity. The molecular docking analysis revealed that DPP-IV inhibition by AP and IPA was mainly due to formation of a strong interaction surface force with the 91-96 and 101-105 amino acids of the DPP-IV. Our results suggested that the protein hydrolysate from Antarctic krill can be considered as a promising natural source of DPP-IV inhibitory peptides in the management of diabetes. Copyright © 2017 Elsevier B.V. All rights reserved.

[A novel dipeptidyl peptidase IV inhibitors developed through scaffold hopping and drug splicing strategy].

PubMed

Wang, Shan-Chun; Zeng, Li-Li; Ding, Yu-Yang; Zeng, Shao-Gao; Song, Hong-Rui; Hu, Wen-Hui; Xie, Hui

2014-01-01

Though all the marketed drugs of dipeptidyl peptidase IV inhibitors are structurally different, their inherent correlation is worthy of further investigation. Herein we rapidly discovered a novel DPP-IV inhibitor 8g (IC50 = 4.9 nmol.L-1) which exhibits as good activity and selectivity as the market drugs through scaffold hopping and drug splicing strategies based on alogliptin and linagliptin. This study demonstrated that the employment of classic medicinal chemistry strategy to the marketed drugs with specific target is an efficient approach to discover novel bioactive molecules.

Pharmacokinetic and Pharmacodynamic Effects of Multiple-dose Administration of Omarigliptin, a Once-weekly Dipeptidyl Peptidase-4 Inhibitor, in Obese Participants With and Without Type 2 Diabetes Mellitus.

PubMed

Addy, Carol; Tatosian, Daniel; Glasgow, Xiaoli S; Gendrano, Isaias N; Kauh, Eunkyung; Martucci, Ashley; Johnson-Levonas, Amy O; Selverian, Diana; Matthews, Catherine Z; Gutierrez, Marie; Wagner, John A; Aubrey Stoch, S

2016-03-01

Omarigliptin (MK-3102) is a potent, oral, long-acting dipeptidyl peptidase (DPP)-4 inhibitor approved in Japan and in global development as a once-weekly treatment for type 2 diabetes mellitus (T2DM). The aim of this study was to investigate the pharmacokinetic (PK) and pharmacodynamic (PD) effects of omarigliptin in obese participants with and without T2DM. This was a Phase I, randomized, double-blind, placebo-controlled, multiple-dose study of 50-mg omarigliptin administered once weekly for 4 weeks. Participants included 24 obese but otherwise healthy subjects (panel A; omarigliptin, n = 18; placebo, n = 6) and 8 obese patients with T2DM (treatment naive, hemoglobin A1c ≥ 6.5% and ≤ 10.0% [panel B]; omarigliptin, n = 6; placebo, n = 2). Participants were 45 to 65 years of age with a body mass index of ≥ 30 and ≤ 40 kg/m(2). Blood sampling occurred at select time points, depending on the study panel, to evaluate the PK properties of omarigliptin, DPP-4 activity, active glucagon-like peptide 1 levels, and plasma glucose concentrations. Body weight was an exploratory end point. Due to sparse sampling in panel A, a thorough PK analysis was performed in obese patients with T2DM (panel B) only. PD analyses were performed in the overall study population (pooled panels A and B). PK profiles in obese participants with and without T2DM were similar to those observed in nonobese reference subjects (historical data). Steady state was achieved after 1 or 2 weekly doses in obese participants with and without T2DM. In obese patients with T2DM, omarigliptin was rapidly absorbed, with a median Tmax of 1 to 2.5 hours (days 1 and 22). Compared with those in reference subjects, the geometric mean ratios (95% CI) (Obese T2DM/reference) for steady-state plasma AUC0-168h, Cmax, and C168h were 0.80 (0.65-0.98), 0.86 (0.53-1.41), and 1.08 (0.88-1.33), respectively. Trough DPP-4 activity was inhibited by ~90%; postprandial (PP) 4-hour weighted mean active GLP-1 concentrations were

Assessment of the pharmacokinetic interaction between the novel DPP-4 inhibitor linagliptin and a sulfonylurea, glyburide, in healthy subjects.

PubMed

Graefe-Mody, Ulrike; Rose, Peter; Ring, Arne; Zander, Kerstin; Iovino, Mario; Woerle, Hans-Juergen

2011-01-01

The aim of this study was to investigate the effect of the dipeptidyl peptidase-4 inhibitor linagliptin on the pharmacokinetics of glyburide (a CYP2C9 and CYP3A4 substrate) and vice versa. This randomized, open-label, three-period, two-way crossover study examined the effects of co-administration of multiple oral doses of linagliptin (5 mg/day × 6 days) and single doses of glyburide (1.75 mg/day × 1 day) on the relative bioavailability of either compound in healthy subjects (n = 20, age 18-55 years). Coadministration of glyburide did not alter the steady-state pharmacokinetics of linagliptin. Geometric mean ratios (GMRs) [90% CI] for (linagliptin + glyburide)/linagliptin AUC(τ,ss) and C(max,ss) were 101.7% [97.7-105.8%] and 100.8% [89.0-114.3%], respectively. For glyburide, there was a slight reduction in exposure of ∼14% when coadministered with linagliptin (GMRs [90% CI] for (glyburide + linagliptin)/glyburide AUC(0-∞) and C(max) were 85.7% [79.8-92.1%] and 86.2% [79.6-93.3%], respectively). However, this was not seen as clinically relevant due to the absence of a reliable dose-response relationship and the known large pharmacokinetic interindividual variability of glyburide. These results further support the assumption that linagliptin is not a clinically relevant inhibitor of CYP2C9 or CYP3A4 in vivo. Coadministration of linagliptin and glyburide had no clinically relevant effect on the pharmacokinetics of linagliptin or glyburide. Both agents were well tolerated and can be administered together without the need for dosage adjustments.

Acylated Gly-(2-cyano)pyrrolidines as inhibitors of fibroblast activation protein (FAP) and the issue of FAP/prolyl oligopeptidase (PREP)-selectivity.

PubMed

Ryabtsova, Oxana; Jansen, Koen; Van Goethem, Sebastiaan; Joossens, Jurgen; Cheng, Jonathan D; Lambeir, Anne-Marie; De Meester, Ingrid; Augustyns, Koen; Van der Veken, Pieter

2012-05-15

A series of N-acylated glycyl-(2-cyano)pyrrolidines were synthesized with the aim of generating structure-activity relationship (SAR) data for this class of compounds as inhibitors of fibroblast activation protein (FAP). Specifically, the influence of (1) the choice of the N-acyl group and (2) structural modification of the 2-cyanopyrrolidine residue were investigated. The inhibitors displayed inhibitory potency in the micromolar to nanomolar range and showed good to excellent selectivity with respect to the proline selective dipeptidyl peptidases (DPPs) DPP IV, DPP9 and DPP II. Additionally, selectivity for FAP with respect to prolyl oligopeptidase (PREP) is reported. Not unexpectedly, the latter data suggest significant overlap in the pharmacophoric features that define FAP or PREP-inhibitory activity and underscore the importance of systematically evaluating the FAP/PREP-selectivity index for inhibitors of either of these two enzymes. Finally, this study forwards several compounds that can serve as leads or prototypic structures for future FAP-selective-inhibitor discovery. Copyright © 2012 Elsevier Ltd. All rights reserved.

Bi-diketopyrrolopyrrole (Bi-DPP) as a novel electron accepting compound in low band gap π-conjugated donor–acceptor copolymers/oligomers

PubMed Central

Ahner, Johannes; Nowotny, Jürgen; Schubert, Ulrich S.; Hager, Martin D.

2017-01-01

Abstract The synthesis and characterization of a novel 2,5-diketopyrrolo[3,4-c]pyrrole(DPP)-based accepting building block with the scheme DPP-neutral small linker-DPP (Bi-DPP) is presented, which was utilized as electron accepting moiety for low band gap π-conjugated donor–acceptor copolymers as well as for a donor–acceptor small molecule. The electron accepting moiety Bi-DPP was prepared via a novel synthetic pathway by building up two DPP moieties step by step simultaneously starting from a neutral phenyl core unit. Characterization of the synthesized oligomeric and polymeric materials via cyclic voltammetry afford LUMO energy levels from −3.49 to −3.59 eV as well as HOMO energy levels from −5.07 to −5.34 eV resulting in low energy band gaps from 1.52 to 1.81 eV. Spin coating of the prepared donor–acceptor oligomers/polymers resulted in well-defined films. Moreover, UV–vis measurements of the investigated donor–acceptor systems showed a broad absorption over the whole visible region. It is demonstrated that Bi-DPP as an electron accepting moiety in donor–acceptor systems offer potential properties for organic solar cell devices. PMID:29491794

Asymmetric synthesis of a potent, aminopiperidine-fused imidazopyridine dipeptidyl peptidase IV inhibitor.

PubMed

Xu, Feng; Corley, Edward; Zacuto, Michael; Conlon, David A; Pipik, Brenda; Humphrey, Guy; Murry, Jerry; Tschaen, David

2010-03-05

A practical asymmetric synthesis of a novel aminopiperidine-fused imidazopyridine dipeptidyl peptidase IV (DPP-4) inhibitor 1 has been developed. Application of a unique three-component cascade coupling with chiral nitro diester 7, which is easily accessed via a highly enantioselective Michael addition of dimethyl malonate to a nitrostyrene, allows for the assembly of the functionalized piperidinone skeleton in one pot. Through a base-catalyzed, dynamic crystallization-driven process, the cis-piperidionone 16a is epimerized to the desired trans isomer 16b, which is directly crystallized from the crude reaction stream in high yield and purity. Isomerization of the allylamide 16b in the presence of RhCl(3) is achieved without any epimerization of the acid/base labile stereogenic center adjacent to the nitro group on the piperidinone ring, while the undesired enamine intermediate is consumed to <0.5% by utilizing a trace amount of HCl generated from RhCl(3). The amino lactam 4, obtained through hydrogenation and hydrolysis, is isolated as its crystalline pTSA salt from the reaction solution directly, as such intramolecular transamidation has been dramatically suppressed via kinetic control. Finally, a Cu(I) catalyzed coupling-cyclization allows for the formation of the tricyclic structure of the potent DPP-4 inhibitor 1. The synthesis, which is suitable for large scale preparation, is accomplished in 23% overall yield.

Effects of the combination of a dipeptidyl peptidase IV inhibitor and an insulin secretagogue on glucose and insulin levels in mice and rats.

PubMed

Yamazaki, Kazuto; Yasuda, Nobuyuki; Inoue, Takashi; Yamamoto, Eiichi; Sugaya, Yukiko; Nagakura, Tadashi; Shinoda, Masanobu; Clark, Richard; Saeki, Takao; Tanaka, Isao

2007-02-01

Several combination therapies have been tried for treating of type 2 diabetes to control more effectively fasting hyperglycemia and postprandial hyperglycemia. In this study, we have examined the effects of combining a novel, selective, and competitive dipeptidyl peptidase IV (DPP-IV) inhibitor, 3-but-2-ynyl-5-methyl-2-piperazin-1-yl-3,5-dihydro-4H-imidazo[4,5-d]pyridazin-4-one tosylate (E3024), with a representative of one of two types of insulin secretagogues, i.e., either glybenclamide (a sulfonylurea) or nateglinide (a rapid-onset/short-duration insulin secretagogue), on glucose and insulin levels in an oral glucose tolerance test (OGTT) using mice fed a high-fat diet. In addition, we have investigated the effects of these combinations on blood glucose levels in fasting rats. Two-way analysis of variance showed that the combination of E3024 and glybenclamide improved glucose tolerance additively and also caused a synergistic increase in insulin levels in the OGTT in mice fed a high-fat diet. In a similar way, the combination of E3024 and nateglinide ameliorated glucose tolerance additively and raised insulin levels additively. In fasting rats, coadministration of E3024 with glybenclamide or nateglinide treatment did not affect the glucose-lowering effects of the insulin secretagogues. Therefore, a DPP-IV inhibitor in combination with glybenclamide or nateglinide may be a promising option for the treatment of type 2 diabetes, and particularly, for controlling postprandial hyperglycemia in the clinic.

Dipeptidyl Peptidase 10 (DPP10789): A Voltage Gated Potassium Channel Associated Protein Is Abnormally Expressed in Alzheimer's and Other Neurodegenerative Diseases

PubMed Central

Gai, Wei-Ping; Abbott, Catherine A.

2014-01-01

The neuropathological features associated with Alzheimer's disease (AD) include the presence of extracellular amyloid-β peptide-containing plaques and intracellular tau positive neurofibrillary tangles and the loss of synapses and neurons in defined regions of the brain. Dipeptidyl peptidase 10 (DPP10) is a protein that facilitates Kv4 channel surface expression and neuronal excitability. This study aims to explore DPP10789 protein distribution in human brains and its contribution to the neurofibrillary pathology of AD and other tauopathies. Immunohistochemical analysis revealed predominant neuronal staining of DPP10789 in control brains, and the CA1 region of the hippocampus contained strong reactivity in the distal dendrites of the pyramidal cells. In AD brains, robust DPP10789 reactivity was detected in neurofibrillary tangles and plaque-associated dystrophic neurites, most of which colocalized with the doubly phosphorylated Ser-202/Thr-205 tau epitope. DPP10789 positive neurofibrillary tangles and plaque-associated dystrophic neurites also appeared in other neurodegenerative diseases such as frontotemporal lobar degeneration, diffuse Lewy body disease, and progressive supranuclear palsy. Occasional DPP10789 positive neurofibrillary tangles and neurites were seen in some aged control brains. Western blot analysis showed both full length and truncated DPP10789 fragments with the later increasing significantly in AD brains compared to control brains. Our results suggest that DPP10789 is involved in the pathology of AD and other neurodegenerative diseases. PMID:25025038

Effects of Incretin-Based Therapies on Neuro-Cardiovascular Dynamic Changes Induced by High Fat Diet in Rats.

PubMed

Marques-Neto, Silvio Rodrigues; Castiglione, Raquel Carvalho; Pontes, Aiza; Oliveira, Dahienne Ferreira; Ferraz, Emanuelle Baptista; Nascimento, José Hamilton Matheus; Bouskela, Eliete

2016-01-01

Obesity promotes cardiac and cerebral microcirculatory dysfunction that could be improved by incretin-based therapies. However, the effects of this class of compounds on neuro-cardiovascular system damage induced by high fat diet remain unclear. The aim of this study was to investigate the effects of incretin-based therapies on neuro-cardiovascular dysfunction induced by high fat diet in Wistar rats. We have evaluated fasting glucose levels and insulin resistance, heart rate variability quantified on time and frequency domains, cerebral microcirculation by intravital microscopy, mean arterial blood pressure, ventricular function and mitochondrial swelling. High fat diet worsened biometric and metabolic parameters and promoted deleterious effects on autonomic, myocardial and haemodynamic parameters, decreased capillary diameters and increased functional capillary density in the brain. Biometric and metabolic parameters were better improved by glucagon like peptide-1 (GLP-1) compared with dipeptdyl peptidase-4 (DPP-4) inhibitor. On the other hand, both GLP-1 agonist and DPP-4 inhibitor reversed the deleterious effects of high fat diet on autonomic, myocardial, haemodynamic and cerebral microvascular parameters. GLP-1 agonist and DPP-4 inhibitor therapy also increased mitochondrial permeability transition pore resistance in brain and heart tissues of rats subjected to high fat diet. Incretin-based therapies improve deleterious cardiovascular effects induced by high fat diet and may have important contributions on the interplay between neuro-cardiovascular dynamic controls through mitochondrial dysfunction associated to metabolic disorders.

Adipose Dipeptidyl Peptidase-4 and Obesity

PubMed Central

Sell, Henrike; Blüher, Matthias; Klöting, Nora; Schlich, Raphaela; Willems, Miriam; Ruppe, Florian; Knoefel, Wolfram Trudo; Dietrich, Arne; Fielding, Barbara A.; Arner, Peter; Frayn, Keith N.; Eckel, Jürgen

2013-01-01

OBJECTIVE To study expression of the recently identified adipokine dipeptidyl peptidase-4 (DPP4) in subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) of patients with various BMIs and insulin sensitivities, as well as to assess circulating DPP4 in relation to obesity and insulin sensitivity. RESEARCH DESIGN AND METHODS DPP4 expression was measured in SAT and VAT from 196 subjects with a wide range of BMIs and insulin sensitivities. DPP4 release was measured ex vivo in paired biopsies from SAT and VAT as well as in vivo from SAT of lean and obese patients. Circulating DPP4 was measured in insulin-sensitive and insulin-resistant BMI-matched obese patients. RESULTS DPP4 expression was positively correlated with BMI in both SAT and VAT, with VAT consistently displaying higher expression than SAT. Ex vivo release of DPP4 from adipose tissue explants was higher in VAT than in SAT in both lean and obese patients, with obese patients displaying higher DPP4 release than lean controls. Net release of DPP4 from adipose tissue was also demonstrated in vivo with greater release in obese subjects than in lean subjects and in women than in men. Insulin-sensitive obese patients had significantly lower circulating DPP4 than did obesity-matched insulin-resistant patients. In this experiment, DPP4 positively correlated with the amount of VAT, adipocyte size, and adipose tissue inflammation. CONCLUSIONS DPP4, a novel adipokine, has a higher release from VAT that is particularly pronounced in obese and insulin-resistant patients. Our data suggest that DPP4 may be a marker for visceral obesity, insulin resistance, and the metabolic syndrome. PMID:24130353

30 CFR 250.241 - What must the DPP or DOCD include?

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 2 2011-07-01 2011-07-01 false What must the DPP or DOCD include? 250.241 Section 250.241 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, REGULATION, AND ENFORCEMENT... and Information Contents of Development and Production Plans (dpp) and Development Operations...

Dpp signaling inhibits proliferation in the Drosophila wing by Omb-dependent regional control of bantam.

PubMed

Zhang, Xubo; Luo, Dan; Pflugfelder, Gert O; Shen, Jie

2013-07-01

The control of organ growth is a fundamental aspect of animal development but remains poorly understood. The morphogen Dpp has long been considered as a general promoter of cell proliferation during Drosophila wing development. It is an ongoing debate whether the Dpp gradient is required for the uniform cell proliferation observed in the wing imaginal disc. Here, we investigated how the Dpp signaling pathway regulates proliferation during wing development. By systematic manipulation of Dpp signaling we observed that it controls proliferation in a region-specific manner: Dpp, via omb, promoted proliferation in the lateral and repressed proliferation in the medial wing disc. Omb controlled the regional proliferation rate by oppositely regulating transcription of the microRNA gene bantam in medial versus lateral wing disc. However, neither the Dpp nor Omb gradient was essential for uniform proliferation along the anteroposterior axis.

Drosophila bunched integrates opposing DPP and EGF signals to set the operculum boundary.

PubMed

Dobens, L L; Peterson, J S; Treisman, J; Raftery, L A

2000-02-01

The Drosophila BMP homolog DPP can function as a morphogen, inducing multiple cell fates across a developmental field. However, it is unknown how graded levels of extracellular DPP are interpreted to organize a sharp boundary between different fates. Here we show that opposing DPP and EGF signals set the boundary for an ovarian follicle cell fate. First, DPP regulates gene expression in the follicle cells that will create the operculum of the eggshell. DPP induces expression of the enhancer trap reporter A359 and represses expression of bunched, which encodes a protein similar to the mammalian transcription factor TSC-22. Second, DPP signaling indirectly regulates A359 expression in these cells by downregulating expression of bunched. Reduced bunched function restores A359 expression in cells that lack the Smad protein MAD; ectopic expression of BUNCHED suppresses A359 expression in this region. Importantly, reduction of bunched function leads to an expansion of the operculum and loss of the collar at its boundary. Third, EGF signaling upregulates expression of bunched. We previously demonstrated that the bunched expression pattern requires the EGF receptor ligand GURKEN. Here we show that activated EGF receptor is sufficient to induce ectopic bunched expression. Thus, the balance of DPP and EGF signals sets the boundary of bunched expression. We propose that the juxtaposition of cells with high and low BUNCHED activity organizes a sharp boundary for the operculum fate.

30 CFR 550.266 - After receiving the DPP or DOCD, what will BOEM do?

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 2 2012-07-01 2012-07-01 false After receiving the DPP or DOCD, what will BOEM do? 550.266 Section 550.266 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, DEPARTMENT OF THE... Review and Decision Process for the Dpp Or Docd § 550.266 After receiving the DPP or DOCD, what will BOEM...

30 CFR 250.266 - After receiving the DPP or DOCD, what will MMS do?

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 2 2010-07-01 2010-07-01 false After receiving the DPP or DOCD, what will MMS do? 250.266 Section 250.266 Mineral Resources MINERALS MANAGEMENT SERVICE, DEPARTMENT OF THE INTERIOR... Decision Process for the Dpp Or Docd § 250.266 After receiving the DPP or DOCD, what will MMS do? (a...

30 CFR 550.266 - After receiving the DPP or DOCD, what will BOEM do?

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 2 2013-07-01 2013-07-01 false After receiving the DPP or DOCD, what will BOEM do? 550.266 Section 550.266 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, DEPARTMENT OF THE... Review and Decision Process for the Dpp Or Docd § 550.266 After receiving the DPP or DOCD, what will BOEM...

30 CFR 550.266 - After receiving the DPP or DOCD, what will BOEM do?

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 2 2014-07-01 2014-07-01 false After receiving the DPP or DOCD, what will BOEM do? 550.266 Section 550.266 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, DEPARTMENT OF THE... Review and Decision Process for the Dpp Or Docd § 550.266 After receiving the DPP or DOCD, what will BOEM...

Involvement of DPP IV/CD26 in cutaneous wound healing process in mice.

PubMed

Baticic Pucar, Lara; Pernjak Pugel, Ester; Detel, Dijana; Varljen, Jadranka

2017-01-01

Dipeptidyl peptidase IV (DPP IV/CD26) is a widely distributed multifunctional protein that plays a significant role in different physiological as well as pathological processes having a broad spectrum of bioactive substrates and immunomodulative properties. It has potential influence on different processes crucial for wound healing, including cell adhesion, migration, apoptosis, and extracellular matrix degradation. However, despite its known enzymatic and immunomodulative functions, limited data characterize the role of DPP IV/CD26 in cutaneous wound healing mechanisms. The aim of this study was to investigate the process of wound healing in conditions of CD26 deficiency in order to obtain better insights on the role of DPP IV/CD26 in cutaneous regeneration. Experimental wounds were made on the dorsal part of CD26 deficient (CD26 -/- ) and wild-type mice (C57BL/6). The process of cutaneous wound healing was monitored on defined time schedule postwounding by macroscopic, microscopic, and biochemical analyses. Obtained results revealed a better rate of wound closure, revascularization and cell proliferation in CD26 -/- mice, with enhanced local expression of hypoxia-inducible factor 1α and vascular endothelial growth factor. CD26 deficiency induced prompt macrophage recruitment at the site of skin damage but did not influence mobilization of T-cells in comparison with wild-type mice. CD26 -/- mice have significantly higher values of IP-10 in serum and control skins compared with wild-type mice but values in wounds did not differ significantly on days 2, 4, and 7 of wound healing. DPP IV/CD26 activity was found to be decreased 4 days postwounding in serum and 2, 4, and 7 days postwounding in wounds of wild-type animals compared with control skins. These findings contribute to better understanding of wound healing mechanisms and could give a support in finding new therapeutic approaches for wound healing and tissue regeneration. © 2016 by the Wound Healing Society.

Sodium-glucose co-transporter-2 inhibitors, the latest residents on the block: Impact on glycaemic control at a general practice level in England.

PubMed

Heald, Adrian H; Fryer, Anthony A; Anderson, Simon G; Livingston, Mark; Lunt, Mark; Davies, Mark; Moreno, Gabriela Y C; Gadsby, Roger; Young, Robert J; Stedman, Mike

2018-03-08

To determine, using published general practice-level data, how differences in Type 2 diabetes mellitus (T2DM) prescribing patterns relate to glycaemic target achievement levels. Multiple linear regression modelling was used to link practice characteristics and defined daily dose (DDD) of different classes of medication in 2015/2016 and changes between that year and the year 2014/2015 in medication to proportion of patients achieving target glycaemic control (glycated haemoglobin A1c [HbA1c] ≤58 mmol/mol [7.5%]) and proportion of patients at high glycaemic risk (HbA1c >86 mmol/mol [10.0%]) for practices in the National Diabetes Audit with >100 people with T2DM on their register. Overall, HbA1c outcomes were not different between the years studied. Although, in percentage terms, most practices increased their use of sodium-glucose co-transporter-2 (SGLT2) inhibitors (96%), dipeptidyl peptidase-4 (DPP-4) inhibitors (76%) and glucagon-like peptide 1 (GLP-1) analogues (53%), there was wide variation in the use of older and newer therapies. For example, 12% of practices used >200% of the national average for some newer agents. In cross-sectional analysis, greater prescribing of metformin and analogue insulin were associated with a higher proportion of patients achieving HbA1c ≤58 mmol/mol; the use of SGLT2 inhibitors and metformin was associated with a reduced proportion of patients with HbA1c >86 mol/mol; otherwise associations for sulphonylureas, GLP-1 analogues, SGLT2 inhibitors and DPP-4 inhibitors were neutral or negative. In year-on-year analysis there was ongoing deterioration in glycaemic control, which was offset to some extent by increased use of SGLT2 inhibitors and GLP-1 analogues, which were associated with a greater proportion of patients achieving HbA1c levels ≤58 mmol/mol and a smaller proportion of patients with HbA1c levels >86 mmol/mol. SGLT2 inhibitor prescribing was associated with significantly greater improvements than those found

Difluoromethane, a new and improved inhibitor of methanotrophy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miller, L.G.; Sasson, C.; Oremland, R.S.

1998-11-01

Difluoromethane (HFC-32; DFM) is compared to acetylene and methyl fluoride as an inhibitor of methanotrophy in cultures and soils. DFM was found to be a reversible inhibitor of CH{sub 4} oxidation by Methylococcus capsulatus (Bath). Consumption of CH{sub 4} in soil was blocked by additions of low levels of DFM (0.03 kPa), and this inhibition was reversed by DFM removal. Although a small quantity of DFM was consumed during these incubations, its remaining concentration was sufficiently elevated to sustain inhibition. Methanogenesis in anaerobic soil slurries, including acetoclastic methanogenesis, was unaffected by levels of DFM which inhibit methanotrophy. Low levels ofmore » DFM (0.03 kPa) also inhibited nitrification and N{sub 2}O production by soils. DFM is proposed as an improved inhibitor of CH{sub 4} oxidation over acetylene and/or methyl fluoride on the basis of its reversibility, its efficacy at low concentrations, its lack of inhibition of methanogenesis, and its low cost.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nagamatsu, Shinya, E-mail: shinya@ks.kyorin-u.ac.jp; Ohara-Imaizumi, Mica; Nakamichi, Yoko

Highlights: {yields} Anti-diabetic new drug, DPP-4 inhibitor, can affect the insulin exocytosis. {yields} DPP-4 inhibitor treatment altered syntaxin 1 expression. {yields} Treatment of db/db mice with DPP-4 inhibitor increased insulin release. -- Abstract: Incretin promotes insulin secretion acutely. Recently, orally-administered DPP-4 inhibitors represent a new class of anti-hyperglycemic agents. Indeed, inhibitors of dipeptidyl peptidase-IV (DPP-4), sitagliptin, has just begun to be widely used as therapeutics for type 2 diabetes. However, the effects of sitagliptin-treatment on insulin exocytosis from single {beta}-cells are yet unknown. We therefore investigated how sitagliptin-treatment in db/db mice affects insulin exocytosis by treating db/db mice with des-F-sitagliptinmore » for 2 weeks. Perfusion studies showed that 2 weeks-sitagliptin treatment potentiated insulin secretion. We then analyzed insulin granule motion and SNARE protein, syntaxin 1, by TIRF imaging system. TIRF imaging of insulin exocytosis showed the increased number of docked insulin granules and increased fusion events from them during first-phase release. In accord with insulin exocytosis data, des-F-sitagliptin-treatment increased the number of syntaxin 1 clusters on the plasma membrane. Thus, our data demonstrated that 2-weeks des-F-sitagliptin-treatment increased the fusion events of insulin granules, probably via increased number of docked insulin granules and that of syntaxin 1 clusters.« less

30 CFR 250.242 - What information must accompany the DPP or DOCD?

Code of Federal Regulations, 2011 CFR

2011-07-01

...) Coastal zone management information required by § 250.260; (s) Environmental impact analysis information... 30 Mineral Resources 2 2011-07-01 2011-07-01 false What information must accompany the DPP or DOCD... SHELF Plans and Information Contents of Development and Production Plans (dpp) and Development...

Efficacy and safety of canagliflozin when used in conjunction with incretin-mimetic therapy in patients with type 2 diabetes.

PubMed

Fulcher, G; Matthews, D R; Perkovic, V; de Zeeuw, D; Mahaffey, K W; Mathieu, C; Woo, V; Wysham, C; Capuano, G; Desai, M; Shaw, W; Vercruysse, F; Meininger, G; Neal, B

2016-01-01

To assess the efficacy and safety of canagliflozin, a sodium glucose co-transporter 2 (SGLT2) inhibitor, in patients with type 2 diabetes enrolled in the CANagliflozin cardioVascular Assessment Study (CANVAS) who were on an incretin mimetic [dipeptidyl peptidase-4 (DPP-4) inhibitor or glucagon-like peptide-1 (GLP-1) receptor agonist]. CANVAS is a double-blind, placebo-controlled study that randomized participants to canagliflozin 100 or 300 mg or placebo added to routine therapy. The present post hoc analysis assessed the efficacy and safety of canagliflozin 100 and 300 mg compared with placebo in subsets of patients from CANVAS who were taking background DPP-4 inhibitors or GLP-1 receptor agonists with or without other antihyperglycaemic agents at week 18. Of the 4330 patients in CANVAS, 316 were taking DPP-4 inhibitors and 95 were taking GLP-1 receptor agonists. At 18 weeks, canagliflozin 100 and 300 mg provided larger placebo-subtracted reductions in glycated haemoglobin (HbA1c) in patients taking DPP-4 inhibitors [-0.56% (95% confidence interval [CI]: -0.77, -0.35), and -0.75% (95% CI: -0.95, -0.54), respectively] and GLP-1 receptor agonists [-1.00% (95% CI: -1.35, -0.65), and -1.06% (95% CI: -1.43, -0.69), respectively]. Body weight and blood pressure (BP) reductions were seen with canagliflozin versus placebo in both subsets. Higher incidences of genital mycotic infections and osmotic diuresis-related adverse events (AEs) were seen with canagliflozin compared with placebo. The incidence of hypoglycaemia was numerically higher with canagliflozin versus placebo; nearly all events occurred in patients on background insulin or insulin secretagogues. In patients on background incretin mimetics, canagliflozin improved HbA1c, body weight and BP, with an increased incidence of AEs related to SGLT2 inhibition. © 2015 John Wiley & Sons Ltd.

Phosphodiesterase 4 inhibitors for chronic obstructive pulmonary disease.

PubMed

Chong, Jimmy; Leung, Bonnie; Poole, Phillippa

2017-09-19

Chronic obstructive pulmonary disease (COPD) is associated with cough, sputum production or dyspnoea and a reduction in lung function, quality of life and life expectancy. Apart from smoking cessation, there are no other treatments that slow lung function decline. Roflumilast and cilomilast are oral phosphodiesterase 4 (PDE 4 ) inhibitors proposed to reduce the airway inflammation and bronchoconstriction seen in COPD. This is an update of a Cochrane review first published in 2011 and updated in 2013. To evaluate the efficacy and safety of oral PDE 4 inhibitors in the management of stable COPD. We identified randomised controlled trials (RCTs) from the Cochrane Airways Trials Register (date of last search October 2016). We found other trials from web-based clinical trials registers. We included RCTs if they compared oral PDE 4 inhibitors with placebo in people with COPD. We allowed co-administration of standard COPD therapy. One review author extracted data and a second review author checked the data. We reported pooled data in Review Manager as mean differences (MD), standardised mean differences (SMD) or odds ratios (OR). We converted the odds ratios into absolute treatment effects in a 'Summary of findings' table. Thirty-four separate RCTs studying roflumilast (20 trials with 17,627 participants) or cilomilast (14 trials with 6457 participants) met the inclusion criteria, with a duration of between six weeks and one year. These included people across international study centres with moderate to very severe COPD (Global Initiative for Chronic Obstructive Lung Disease (GOLD) grades II-IV), with a mean age of 64 years.We considered that the methodological quality of the 34 published and unpublished trials was acceptable overall. Treatment with a PDE 4 inhibitor was associated with a significant improvement in forced expiratory volume in one second (FEV 1 ) over the trial period compared with placebo (MD 51.53 mL, 95% confidence interval (CI) 43.17 to 59.90, 27

30 CFR 250.262 - What administrative information must accompany the DPP or DOCD?

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 2 2010-07-01 2010-07-01 false What administrative information must accompany the DPP or DOCD? 250.262 Section 250.262 Mineral Resources MINERALS MANAGEMENT SERVICE, DEPARTMENT OF... Information Contents of Development and Production Plans (dpp) and Development Operations Coordination...

30 CFR 250.255 - What decommissioning information must accompany the DPP or DOCD?

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 2 2010-07-01 2010-07-01 false What decommissioning information must accompany the DPP or DOCD? 250.255 Section 250.255 Mineral Resources MINERALS MANAGEMENT SERVICE, DEPARTMENT OF... Information Contents of Development and Production Plans (dpp) and Development Operations Coordination...

30 CFR 250.262 - What administrative information must accompany the DPP or DOCD?

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 2 2011-07-01 2011-07-01 false What administrative information must accompany the DPP or DOCD? 250.262 Section 250.262 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT... OUTER CONTINENTAL SHELF Plans and Information Contents of Development and Production Plans (dpp) and...

30 CFR 250.255 - What decommissioning information must accompany the DPP or DOCD?

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 2 2011-07-01 2011-07-01 false What decommissioning information must accompany the DPP or DOCD? 250.255 Section 250.255 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT... OUTER CONTINENTAL SHELF Plans and Information Contents of Development and Production Plans (dpp) and...

30 CFR 250.243 - What general information must accompany the DPP or DOCD?

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 2 2011-07-01 2011-07-01 false What general information must accompany the DPP or DOCD? 250.243 Section 250.243 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, REGULATION, AND... SHELF Plans and Information Contents of Development and Production Plans (dpp) and Development...

Structures and mechanism of dipeptidyl peptidases 8 and 9, important players in cellular homeostasis and cancer.

PubMed

Ross, Breyan; Krapp, Stephan; Augustin, Martin; Kierfersauer, Reiner; Arciniega, Marcelino; Geiss-Friedlander, Ruth; Huber, Robert

2018-02-13

Dipeptidyl peptidases 8 and 9 are intracellular N-terminal dipeptidyl peptidases (preferentially postproline) associated with pathophysiological roles in immune response and cancer biology. While the DPP family member DPP4 is extensively characterized in molecular terms as a validated therapeutic target of type II diabetes, experimental 3D structures and ligand-/substrate-binding modes of DPP8 and DPP9 have not been reported. In this study we describe crystal and molecular structures of human DPP8 (2.5 Å) and DPP9 (3.0 Å) unliganded and complexed with a noncanonical substrate and a small molecule inhibitor, respectively. Similar to DPP4, DPP8 and DPP9 molecules consist of one β-propeller and α/β hydrolase domain, forming a functional homodimer. However, they differ extensively in the ligand binding site structure. In intriguing contrast to DPP4, where liganded and unliganded forms are closely similar, ligand binding to DPP8/9 induces an extensive rearrangement at the active site through a disorder-order transition of a 26-residue loop segment, which partially folds into an α-helix (R-helix), including R160/133, a key residue for substrate binding. As vestiges of this helix are also seen in one of the copies of the unliganded form, conformational selection may contributes to ligand binding. Molecular dynamics simulations support increased flexibility of the R-helix in the unliganded state. Consistently, enzyme kinetics assays reveal a cooperative allosteric mechanism. DPP8 and DPP9 are closely similar and display few opportunities for targeted ligand design. However, extensive differences from DPP4 provide multiple cues for specific inhibitor design and development of the DPP family members as therapeutic targets or antitargets.

Sitagliptin, an dipeptidyl peptidase-4 inhibitor, does not alter the pharmacokinetics of the sulphonylurea, glyburide, in healthy subjects

PubMed Central

Mistry, Goutam C; Bergman, Arthur J; Zheng, Wei; Hreniuk, David; Zinny, Miguel A; Gottesdiener, Keith M; Wagner, John A; Herman, Gary A; Ruddy, Marcella

2008-01-01

AIMS Sitagliptin, a dipeptidyl peptidase-4 inhibitor, is an incretin enhancer that is approved for the treatment of Type 2 diabetes. Sitagliptin is mainly renally eliminated and not an inhibitor of CYP450 enzymes in vitro. Glyburide, a sulphonylurea, is an insulin sensitizer and mainly metabolized by CYP2C9. Since both agents may potentially be co-administered, the purpose of this study was to examine the effects of sitagliptin on glyburide pharmacokinetics. METHODS In this open-label, randomized, two-period crossover study, eight healthy normoglycaemic subjects, 22–44 years old, received single 1.25-mg doses of glyburide alone in one period and co-administered with sitagliptin on day 5 following a multiple-dose regimen for sitagliptin (200-mg q.d. ×6 days) in the other period. RESULTS The geometric mean ratios and 90% confidence intervals [(glyburide + sitagliptin)/glyburide] for AUC0–∞ and Cmax were 1.09 (0.96, 1.24) and 1.01 (0.84, 1.23), respectively. CONCLUSION Sitagliptin does not alter the pharmacokinetics of glyburide in healthy subjects. WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT No data are available on the potential drug interaction of sitagliptin and glyburide.Sitagliptin belongs to a new class of drugs called DPP-4 inhibitors recently approved for the treatment of Type 2 diabetes. WHAT THIS STUDY ADDS Glyburide is a commonly used sulphonylurea medication to treat Type 2 diabetes.Combination therapy is often required to achieve adequate glucose control in Type 2 diabetes.Sitagliptin does not appear to interfere with glyburide pharmacokinetics and therefore may be potentially co-administered with glyburide for the treatment of Type 2 diabetes. PMID:18503607

Identification of novel dipeptidyl peptidase IV (DPP-IV) inhibitory peptides in camel milk protein hydrolysates.

PubMed

Nongonierma, Alice B; Paolella, Sara; Mudgil, Priti; Maqsood, Sajid; FitzGerald, Richard J

2018-04-01

Nine novel dipeptidyl peptidase IV (DPP-IV) inhibitory peptides (FLQY, FQLGASPY, ILDKEGIDY, ILELA, LLQLEAIR, LPVP, LQALHQGQIV, MPVQA and SPVVPF) were identified in camel milk proteins hydrolysed with trypsin. This was achieved using a sequential approach combining liquid chromatography tandem mass spectrometry (LC-MS/MS), qualitative/quantitative structure activity relationship (QSAR) and confirmatory studies with synthetic peptides. The most potent camel milk protein-derived DPP-IV inhibitory peptides, LPVP and MPVQA, had DPP-IV half maximal inhibitory concentrations (IC 50 ) of 87.0 ± 3.2 and 93.3 ± 8.0 µM, respectively. DPP-IV inhibitory peptide sequences identified within camel and bovine milk protein hydrolysates generated under the same hydrolysis conditions differ. This was linked to differences in enzyme selectivity for peptide bond cleavage of camel and bovine milk proteins as well as dissimilarities in their amino acid sequences. Camel milk proteins contain novel DPP-IV inhibitory peptides which may play a role in the regulation of glycaemia in humans. Copyright © 2017 Elsevier Ltd. All rights reserved.

30 CFR 550.273 - How do I submit a modified DPP or DOCD or resubmit a disapproved DPP or DOCD?

Code of Federal Regulations, 2013 CFR

2013-07-01

... MANAGEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Plans and Information Review and Decision Process for the Dpp Or Docd § 550.273 How do I submit a...

30 CFR 550.273 - How do I submit a modified DPP or DOCD or resubmit a disapproved DPP or DOCD?

Code of Federal Regulations, 2012 CFR

2012-07-01

... MANAGEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Plans and Information Review and Decision Process for the Dpp Or Docd § 550.273 How do I submit a...

Improvement of bioavailability of the HIV protease inhibitor SC-52151 in the beagle dog by coadministration of the CYP3A4 inhibitor, ketoconazole.

PubMed

Yuan, J H; Stolzenbach, J C; Salamon, C M; Snook, S S; Schoenhard, G L

1997-05-01

1. SC-52151, an HIV protease inhibitor, is mainly metabolized by CYP3A4 and is poorly bioavailable after oral administration. After i.v. administration of SC-52151 to the female beagle dog (2.5 mg/kg), SC-52151 was rapidly eliminated in plasma with an elimination half-life of about 1 h, a plasma clearance of 44 ml/min/kg and an apparent steady-state volume distribution of 2.2 litre/kg. The high value of plasma clearance of SC-52151 suggests an extensive hepatic first-pass metabolism since SC-52151 is highly protein bound and does not partition itself into red blood cells. 2. The extensive hepatic first-pass metabolism was reduced by coadministration of a CYP3A4 inhibitor, ketoconazole. 3. Dogs were dosed daily with ketoconazole at dose of 100 mg ketoconazole per dog (approximately 10 mg/kg) for 5 days prior to the initiation of coadministration of SC-52151 for 15 days. The doses used for SC-52151 was 0, 60 and 120 mg SC-52151/kg/day (divided t.i.d., 8-h dosing interval). Coadministration of ketoconazole improved the bioavailability of SC-52151 from 4.1 to 9.6% and also improved the Cmax of SC-52151 from 0.41 to 0.83 microgram/ml. 4. Although the absolute bioavailability of SC-52151 was still low (approximately 10%), the Cmax and AUC achieved in this study were satisfactory for conducting chronic toxicology studies. No toxicity associated with the coadministration of ketoconazole was evident. Results from this study suggest that coadministration of ketoconazole might be a practical approach to increase the exposure of SC-52151 in both preclinical and clinical studies.

Interaction Analysis of FABP4 Inhibitors by X-ray Crystallography and Fragment Molecular Orbital Analysis

PubMed Central

2016-01-01

X-ray crystal structural determination of FABP4 in complex with four inhibitors revealed the complex binding modes, and the resulting observations led to improvement of the inhibitory potency of FABP4 inhibitors. However, the detailed structure–activity relationship (SAR) could not be explained from these structural observations. For a more detailed understanding of the interactions between FABP4 and inhibitors, fragment molecular orbital analyses were performed. These analyses revealed that the total interfragment interaction energies of FABP4 and each inhibitor correlated with the ranking of the Ki value for the four inhibitors. Furthermore, interactions between each inhibitor and amino acid residues in FABP4 were identified. The oxygen atom of Lys58 in FABP4 was found to be very important for strong interactions with FABP4. These results might provide useful information for the development of novel potent FABP4 inhibitors. PMID:27096055

Interaction Analysis of FABP4 Inhibitors by X-ray Crystallography and Fragment Molecular Orbital Analysis.

PubMed

Tagami, Uno; Takahashi, Kazutoshi; Igarashi, Shunsuke; Ejima, Chieko; Yoshida, Tomomi; Takeshita, Sen; Miyanaga, Wataru; Sugiki, Masayuki; Tokumasu, Munetaka; Hatanaka, Toshihiro; Kashiwagi, Tatsuki; Ishikawa, Kohki; Miyano, Hiroshi; Mizukoshi, Toshimi

2016-04-14

X-ray crystal structural determination of FABP4 in complex with four inhibitors revealed the complex binding modes, and the resulting observations led to improvement of the inhibitory potency of FABP4 inhibitors. However, the detailed structure-activity relationship (SAR) could not be explained from these structural observations. For a more detailed understanding of the interactions between FABP4 and inhibitors, fragment molecular orbital analyses were performed. These analyses revealed that the total interfragment interaction energies of FABP4 and each inhibitor correlated with the ranking of the K i value for the four inhibitors. Furthermore, interactions between each inhibitor and amino acid residues in FABP4 were identified. The oxygen atom of Lys58 in FABP4 was found to be very important for strong interactions with FABP4. These results might provide useful information for the development of novel potent FABP4 inhibitors.

Circulating dipeptidyl peptidase-4 activity correlates with measures of hepatocyte apoptosis and fibrosis in non-alcoholic fatty liver disease in type 2 diabetes mellitus and obesity: A dual cohort cross-sectional study.

PubMed

Williams, Kathryn H; Vieira De Ribeiro, Ana Júlia; Prakoso, Emilia; Veillard, Anne-Sophie; Shackel, Nicholas A; Brooks, Belinda; Bu, Yangmin; Cavanagh, Erika; Raleigh, Jim; McLennan, Susan V; McCaughan, Geoffrey W; Keane, Fiona M; Zekry, Amany; Gorrell, Mark D; Twigg, Stephen M

2015-11-01

Intrahepatic expression of dipeptidyl peptidase-4 (DPP4), and circulating DPP4 (cDPP4) levels and its enzymatic activity, are increased in non-alcoholic fatty liver disease (NAFLD) and in type 2 diabetes mellitus and/or obesity. DPP4 has been implicated as a causative factor in NAFLD progression but few studies have examined associations between cDPP4 activity and NAFLD severity in humans. This study aimed to examine the relationship of cDPP4 activity with measures of liver disease severity in NAFLD in subjects with diabetes and/or obesity. cDPP4 was measured in 106 individuals with type 2 diabetes who had transient elastography (Cohort 1) and 145 individuals with morbid obesity who had liver biopsy (Cohort 2). Both cohorts had caspase-cleaved keratin-18 (ccK18) measured as a marker of apoptosis. Natural log increases in cDPP4 activity were associated with increasing quartiles of ccK18 (Cohorts 1 and 2) and with median liver stiffness ≥10.3 kPa (Cohort 1) and significant fibrosis (F ≥ 2) on liver biopsy (Cohort 2). In diabetes and/or obesity, cDPP4 activity is associated with current apoptosis and liver fibrosis. Given the pathogenic mechanisms by which DPP4 may progress NAFLD, measurement of cDPP4 activity may have utility to predict disease progression and DPP4 inhibition may improve liver histology over time. © 2014 Ruijin Hospital, Shanghai Jiaotong University School of Medicine and Wiley Publishing Asia Pty Ltd.

PTP1B, α-glucosidase, and DPP-IV inhibitory effects for chromene derivatives from the leaves of Smilax china L.

PubMed

Zhao, Bing Tian; Le, Duc Dat; Nguyen, Phi Hung; Ali, Md Yousof; Choi, Jae-Sue; Min, Byung Sun; Shin, Heung Mook; Rhee, Hae Ik; Woo, Mi Hee

2016-06-25

Two new flavonoids, bismilachinone (11) and smilachinin (14), were isolated from the leaves of Smilax china L. together with 14 known compounds. Their structures were elucidated using spectroscopic methods. The PTP1B, α-glucosidase, and DPP-IV inhibitory activities of compounds 1-16 were evaluated at the molecular level. Among them, compounds 4, 7, and 10 showed moderate DPP-IV inhibitory activities with IC50 values of 20.81, 33.12, and 32.93 μM, respectively. Compounds 3, 4, 6, 11, 12, and 16 showed strong PTP1B inhibitory activities, with respective IC50 values of 7.62, 10.80, 0.92, 2.68, 9.77, and 24.17 μM compared with the IC50 value for the positive control (ursolic acid: IC50 = 1.21 μM). Compounds 2-7, 11, 12, 15, and 16 showed potent α-glucosidase inhibitory activities, with respective IC50 values of 8.70, 81.66, 35.11, 35.92, 7.99, 26.28, 11.28, 62.68, 44.32, and 70.12 μM. The positive control, acarbose, displayed an IC50 value of 175.84 μM. In the kinetic study for the PTP1B enzyme, compounds 6, 11, and 12 displayed competitive inhibition with Ki values of 3.20, 8.56, and 5.86 μM, respectively. Compounds 3, 4, and 16 showed noncompetitive inhibition with Ki values of 18.75, 5.95, and 22.86 μM, respectively. Molecular docking study for the competitive inhibitors (6, 11, and 12) radically corroborates the binding affinities and inhibition of PTP1B enzymes. These results indicated that the leaves of Smilax china L. may contain compounds with anti-diabetic activity. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

30 CFR 550.252 - What environmental monitoring information must accompany the DPP or DOCD?

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 2 2013-07-01 2013-07-01 false What environmental monitoring information must... Coordination Documents (docd) § 550.252 What environmental monitoring information must accompany the DPP or DOCD? The following environmental monitoring information, as applicable, must accompany your DPP or...

30 CFR 550.252 - What environmental monitoring information must accompany the DPP or DOCD?

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 2 2012-07-01 2012-07-01 false What environmental monitoring information must... Coordination Documents (docd) § 550.252 What environmental monitoring information must accompany the DPP or DOCD? The following environmental monitoring information, as applicable, must accompany your DPP or...

30 CFR 550.252 - What environmental monitoring information must accompany the DPP or DOCD?

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 2 2014-07-01 2014-07-01 false What environmental monitoring information must... Coordination Documents (docd) § 550.252 What environmental monitoring information must accompany the DPP or DOCD? The following environmental monitoring information, as applicable, must accompany your DPP or...

30 CFR 250.252 - What environmental monitoring information must accompany the DPP or DOCD?

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 2 2010-07-01 2010-07-01 false What environmental monitoring information must... Documents (docd) § 250.252 What environmental monitoring information must accompany the DPP or DOCD? The following environmental monitoring information, as applicable, must accompany your DPP or DOCD: (a...

30 CFR 250.253 - What lease stipulations information must accompany the DPP or DOCD?

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 2 2010-07-01 2010-07-01 false What lease stipulations information must accompany the DPP or DOCD? 250.253 Section 250.253 Mineral Resources MINERALS MANAGEMENT SERVICE, DEPARTMENT... Information Contents of Development and Production Plans (dpp) and Development Operations Coordination...

30 CFR 250.254 - What mitigation measures information must accompany the DPP or DOCD?

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 2 2010-07-01 2010-07-01 false What mitigation measures information must accompany the DPP or DOCD? 250.254 Section 250.254 Mineral Resources MINERALS MANAGEMENT SERVICE, DEPARTMENT... Information Contents of Development and Production Plans (dpp) and Development Operations Coordination...

30 CFR 250.259 - What sulphur operations information must accompany the DPP or DOCD?

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 2 2010-07-01 2010-07-01 false What sulphur operations information must accompany the DPP or DOCD? 250.259 Section 250.259 Mineral Resources MINERALS MANAGEMENT SERVICE, DEPARTMENT... Information Contents of Development and Production Plans (dpp) and Development Operations Coordination...

Determinants of saxagliptin use among patients with type 2 diabetes mellitus treated with oral anti-diabetic drugs.

PubMed

Saine, M Elle; Carbonari, Dena M; Newcomb, Craig W; Nezamzadeh, Melissa S; Haynes, Kevin; Roy, Jason A; Cardillo, Serena; Hennessy, Sean; Holick, Crystal N; Esposito, Daina B; Gallagher, Arlene M; Bhullar, Harshvinder; Strom, Brian L; Lo Re, Vincent

2015-04-02

The patterns and determinants of saxagliptin use among patients with type 2 diabetes mellitus (T2DM) are unknown in real-world settings. We compared the characteristics of T2DM patients who were new initiators of saxagliptin to those who were new initiators of non-dipeptidyl peptidase-4 (DPP-4) inhibitor oral anti-diabetic drugs (OADs) and identified factors associated with saxagliptin use. We conducted a cross-sectional study within the Clinical Practice Research Datalink (CPRD), The Health Improvement Network (THIN), US Medicare, and the HealthCore Integrated Research Database (HIRD(SM)) across the first 36 months of saxagliptin availability (29 months for US Medicare). Patients were included if they were: 1) ≥18 years old, 2) newly prescribed saxagliptin or a non-DPP-4 inhibitor OAD, and 3) enrolled in their respective database for 180 days. For each saxagliptin initiator, we randomly selected up to ten non-DPP-4 inhibitor OAD initiators matched on age, sex, and geographic region. Conditional logistic regression was used to identify determinants of saxagliptin use. We identified 64,079 saxagliptin initiators (CPRD: 1,962; THIN: 2,084; US Medicare: 51,976; HIRD(SM): 8,057) and 610,660 non-DPP-4 inhibitor OAD initiators (CPRD: 19,484; THIN: 19,936; US Medicare: 493,432; HIRD(SM): 77,808). Across all four data sources, prior OAD use, hypertension, and hyperlipidemia were associated with saxagliptin use. Saxagliptin initiation was also associated with hemoglobin A1c results >8% within the UK data sources, and a greater number of hemoglobin A1c measurements in the US data sources. In these UK and US data sources, initiation of saxagliptin was associated with prior poor glycemic control, prior OAD use, and diagnoses of hypertension and hyperlipidemia. ClinicalTrials.gov identifiers NCT01086280 , NCT01086293 , NCT01086319 , NCT01086306 , and NCT01377935.

30 CFR 550.249 - What air emissions information must accompany the DPP or DOCD?

Code of Federal Regulations, 2013 CFR

2013-07-01

... and Information Contents of Development and Production Plans (dpp) and Development Operations Coordination Documents (docd) § 550.249 What air emissions information must accompany the DPP or DOCD? The... 30 Mineral Resources 2 2013-07-01 2013-07-01 false What air emissions information must accompany...

30 CFR 550.249 - What air emissions information must accompany the DPP or DOCD?

Code of Federal Regulations, 2012 CFR

2012-07-01

... and Information Contents of Development and Production Plans (dpp) and Development Operations Coordination Documents (docd) § 550.249 What air emissions information must accompany the DPP or DOCD? The... 30 Mineral Resources 2 2012-07-01 2012-07-01 false What air emissions information must accompany...

30 CFR 550.249 - What air emissions information must accompany the DPP or DOCD?

Code of Federal Regulations, 2014 CFR

2014-07-01

... and Information Contents of Development and Production Plans (dpp) and Development Operations Coordination Documents (docd) § 550.249 What air emissions information must accompany the DPP or DOCD? The... 30 Mineral Resources 2 2014-07-01 2014-07-01 false What air emissions information must accompany...

30 CFR 250.253 - What lease stipulations information must accompany the DPP or DOCD?

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 2 2011-07-01 2011-07-01 false What lease stipulations information must accompany the DPP or DOCD? 250.253 Section 250.253 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT... OUTER CONTINENTAL SHELF Plans and Information Contents of Development and Production Plans (dpp) and...

30 CFR 250.259 - What sulphur operations information must accompany the DPP or DOCD?

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 2 2011-07-01 2011-07-01 false What sulphur operations information must accompany the DPP or DOCD? 250.259 Section 250.259 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT... OUTER CONTINENTAL SHELF Plans and Information Contents of Development and Production Plans (dpp) and...

Effects of sitagliptin on coronary atherosclerosis evaluated using integrated backscatter intravascular ultrasound in patients with type 2 diabetes: rationale and design of the TRUST study.

PubMed

Nozue, Tsuyoshi; Fukui, Kazuki; Koyama, Yutaka; Fujii, Hiroyuki; Kunishima, Tomoyuki; Hikita, Hiroyuki; Hibi, Kiyoshi; Miyazawa, Akiyoshi; Michishita, Ichiro

2016-05-01

Patients with diabetes mellitus are at high risk for developing coronary artery disease (CAD), even if they are treated with statins. Several studies have shown the beneficial effects of dipeptidyl peptidase-4 (DPP-4) inhibitors on the cardiovascular system in an animal model. However, recent clinical trials using DPP-4 inhibitors have shown that these inhibitors fail to reduce the occurrence of cardiovascular events. Therefore, this study will be performed to evaluate the effects of sitagliptin, a DPP-4 inhibitor, on coronary atherosclerosis in patients with type 2 diabetes. This study will be a prospective, open-label, randomized multicenter trial performed in 6 centers in Japan. Stable CAD patients with type 2 diabetes who have undergone successful percutaneous coronary intervention under integrated backscatter (IB)-intravascular ultrasound (IVUS) guidance will be studied. They will be randomly assigned to either the sitagliptin group or a control group. After 48 weeks' treatment, the IVUS examination will be repeated in the same coronary artery as at baseline. The primary end point will be the percentage change in plaque volume measured using grayscale IVUS from baseline to the 48-week follow-up. This study will be the first multicenter trial to evaluate the effects of a DPP-4 inhibitor on coronary atherosclerosis evaluated using IB-IVUS, and the findings will clarify the anti-atherogenic effects of sitagliptin.

Cathepsin D plays a role in endothelial-pericyte interactions during alteration of the blood-retinal barrier in diabetic retinopathy.

PubMed

Monickaraj, Finny; McGuire, Paul; Das, Arup

2018-05-01

Inflammation plays an important role in the pathogenesis of diabetic retinopathy. We have previously demonstrated the effect of cathepsin D (CD) on the mechanical disruption of retinal endothelial cell junctions and increased vasopermeability, as well as increased levels of CD in retinas of diabetic mice. Here, we have also examined the effect of CD on endothelial-pericyte interactions, as well as the effect of dipeptidyl peptidase-4 (DPP4) inhibitor on CD in endothelial-pericyte interactions in vitro and in vivo. Cocultured cells that were treated with pro-CD demonstrated a significant decrease in the expression of platelet-derived growth factor receptor-β, a tyrosine kinase receptor that is required for pericyte cell survival; N-cadherin, the key adherens junction protein between endothelium and pericytes; and increases in the vessel destabilizing agent, angiopoietin-2. The effect was reversed in cells that were treated with DPP4 inhibitor along with pro-CD. With pro-CD treatment, there was a significant increase in the phosphorylation of the downstream signaling protein, PKC-α, and Ca 2+ /calmodulin-dependent protein kinase II in endothelial cells and pericytes, which disrupts adherens junction structure and function, and this was significantly reduced with DPP4 inhibitor treatment. Increased CD levels, vasopermeability, and alteration in junctional-related proteins were observed in the retinas of diabetic rats, which were significantly changed with DPP4 inhibitor treatment. Thus, DPP4 inhibitors may be used as potential adjuvant therapeutic agents to treat increased vascular leakage observed in patients with diabetic macular edema.-Monickaraj, F., McGuire, P., Das, A. Cathepsin D plays a role in endothelial-pericyte interactions during alteration of the blood-retinal barrier in diabetic retinopathy.

Lower dipeptidyl peptidase-4 following exercise training plus weight loss is related to increased insulin sensitivity in adults with metabolic syndrome.

PubMed

Malin, Steven K; Huang, Hazel; Mulya, Anny; Kashyap, Sangeeta R; Kirwan, John P

2013-09-01

Dipeptidyl peptidase-4 (DPP-4) is a circulating glycoprotein that impairs insulin-stimulated glucose uptake and is linked to obesity and metabolic syndrome. However, the effect of exercise on plasma DPP-4 in adults with metabolic syndrome is unknown. Therefore, we determined the effect of exercise on DPP-4 and its role in explaining exercise-induced improvements in insulin sensitivity. Fourteen obese adults (67.9±1.2 years, BMI: 34.2±1.1kg/m(2)) with metabolic syndrome (ATP III criteria) underwent a 12-week supervised exercise intervention (60min/day for 5 days/week at ∼85% HRmax). Plasma DPP-4 was analyzed using an enzyme-linked immunosorbent assay. Insulin sensitivity was measured using the euglycemic-hyperinsulinemic clamp (40mU/m(2)/min) and estimated by HOMA-IR. Visceral fat (computerized tomography), 2-h glucose levels (75g oral glucose tolerance), and basal fat oxidation as well as aerobic fitness (indirect calorimetry) were also determined before and after exercise. The intervention reduced visceral fat, lowered blood pressure, glucose and lipids, and increased aerobic fitness (P<0.05). Exercise improved clamp-derived insulin sensitivity by 75% (P<0.001) and decreased HOMA-IR by 15% (P<0.05). Training decreased plasma DPP-4 by 10% (421.8±30.1 vs. 378.3±32.5ng/ml; P<0.04), and the decrease in DPP-4 was associated with clamp-derived insulin sensitivity (r=-0.59; P<0.04), HOMA-IR (r=0.59; P<0.04) and fat oxidation (r=-0.54; P<0.05). Increased fat oxidation also correlated with lower 2-h glucose levels (r=-0.64; P<0.02). Exercise training reduces plasma DPP-4, which may be linked to elevated insulin sensitivity and fat oxidation. Maintaining low plasma DPP-4 concentrations is a potential mechanism whereby exercise plus weight loss prevents/delays the onset of type 2 diabetes in adults with metabolic syndrome. Copyright © 2013 Elsevier Inc. All rights reserved.

30 CFR 250.246 - What mineral resource conservation information must accompany the DPP or DOCD?

Code of Federal Regulations, 2011 CFR

2011-07-01

... OPERATIONS IN THE OUTER CONTINENTAL SHELF Plans and Information Contents of Development and Production Plans (dpp) and Development Operations Coordination Documents (docd) § 250.246 What mineral resource... information, as applicable, must accompany your DPP or DOCD: (a) Technology and reservoir engineering...

30 CFR 250.271 - For what reasons will MMS disapprove the DPP or DOCD?

Code of Federal Regulations, 2010 CFR

2010-07-01

... Decision Process for the Dpp Or Docd § 250.271 For what reasons will MMS disapprove the DPP or DOCD? The...), implementing regulations, or other applicable Federal laws. (b) No consistency concurrence. (1) An affected State has not yet issued a final decision on your coastal zone consistency certification (see 15 CFR 930...

Newer treatments of psoriasis regarding IL-23 inhibitors, phosphodiesterase 4 inhibitors, and Janus kinase inhibitors.

PubMed

Wcisło-Dziadecka, Dominika; Zbiciak-Nylec, Martyna; Brzezińska-Wcisło, Ligia; Bebenek, Katarzyna; Kaźmierczak, Agata

2017-11-01

The rapid progress of genetic engineering furthermore opens up new prospects in the therapy of this difficult-to-treat disease. IL-23 inhibitors, phosphodiesterase 4 (PDE4) inhibitors, and Janus kinase (JAK) inhibitors are currently encouraging further research. Two drugs which are IL-23 inhibitors are now in phase III of clinical trials. The aim of the action of both drugs is selective IL-23 inhibition by targeting the p19 subunit. Guselkumab is a fully human monoclonal antibody. Tildrakizumab is a humanized monoclonal antibody, which also belongs to IgG class and is targeted to subunit p19 of interleukin 23 (IL-23). Phosphodiesterase inhibitors exert an anti-inflammatory action and their most common group is the PDE4 family. PDE4 inhibits cAMP, which reduces the inflammatory response of the pathway of Th helper lymphocytes, Th17, and type 1 interferon which modulates the production of anti-inflammatory cytokines such as IL-10 interleukins. The Janus kinase (JAK) signaling pathway plays an important role in the immunopathogenesis of psoriasis. Tofacitinib suppresses the expression of IL-23, IL-17A, IL-17F, and IL-22 receptors during the stimulation of lymphocytes. Ruxolitinib is a selective inhibitor of JAK1 and JAK2 kinases and the JAK-STAT signaling pathway. This article is a review of the aforementioned drugs as described in the latest available literature. © 2017 Wiley Periodicals, Inc.

30 CFR 250.246 - What mineral resource conservation information must accompany the DPP or DOCD?

Code of Federal Regulations, 2010 CFR

2010-07-01

..., DEPARTMENT OF THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Plans and Information Contents of Development and Production Plans (dpp) and Development Operations... DPP or DOCD: (a) Technology and reservoir engineering practices and procedures. A description of the...

30 CFR 550.271 - For what reasons will BOEM disapprove the DPP or DOCD?

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 2 2012-07-01 2012-07-01 false For what reasons will BOEM disapprove the DPP or DOCD? 550.271 Section 550.271 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, DEPARTMENT OF... Information Review and Decision Process for the Dpp Or Docd § 550.271 For what reasons will BOEM disapprove...

30 CFR 550.271 - For what reasons will BOEM disapprove the DPP or DOCD?

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 2 2013-07-01 2013-07-01 false For what reasons will BOEM disapprove the DPP or DOCD? 550.271 Section 550.271 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, DEPARTMENT OF... Information Review and Decision Process for the Dpp Or Docd § 550.271 For what reasons will BOEM disapprove...

Effect of Trelagliptin on Quality of Life in Patients with Type 2 Diabetes Mellitus: Study Protocol.

PubMed

Ishii, Hitoshi; Suzaki, Yuki; Miyata, Yuko

2017-12-01

Long-term glycemic control in type 2 diabetes is critical to prevent or delay the onset of macrovascular and microvascular complications. Medication adherence is an integral component of type 2 diabetes management. Minimizing the dosing frequency of antidiabetic drugs may reduce treatment burden for patients and improve medication adherence. This study has been proposed to assess the reduction in treatment burden during 12 weeks' administration of trelagliptin, a weekly dosing dipeptidyl peptidase-4 (DPP-4) inhibitor, compared with a daily dosing DPP-4 inhibitor in patients with type 2 diabetes. This is a multicenter, randomized, open-label, parallel-group, comparative study to be conducted at approximately 15 sites across Japan. A total of 240 patients are to be randomized 1:1 to receive trelagliptin or a daily DPP-4 inhibitor for 12 weeks. Efficacy and safety will be compared between the two groups. The primary endpoint is the change in total score for all items of the diabetes-therapy-related QOL questionnaire from treatment start to treatment end. The study will be conducted with the highest respect for the individual participants in accordance with the protocol, the Declaration of Helsinki, the Ethical Guidelines for Clinical Research, the ICH Consolidated Guideline for Good Clinical Practice, and applicable local laws and regulations. Takeda Pharmaceutical Company Limited. Japic CTI-173482.

The consumer welfare implications of governmental policies and firm strategy in markets for medicines.

PubMed

Chatterjee, Chirantan; Kubo, Kensuke; Pingali, Viswanath

2015-12-01

This paper empirically examines the consumer welfare implications of changes in government policies related to patent protection and compulsory licensing in the Indian market for oral anti-diabetic (OAD) medicines. In contrast to previous studies on the impact of pharmaceutical patents in India, we observe, and estimate the welfare effects accruing from differential pricing and voluntary licensing strategies of patent-holding innovator firms. Three novel molecules belonging to the dipeptidyl peptidase-4 (DPP-4) inhibitor class of OADs have been launched in India by the patent holders, at lower prices than those prevailing in the developed countries. Using aggregate market transaction data, we structurally estimate demand and supply and use the parameter estimates in our model to simulate consumer welfare under various counterfactual scenarios. Our results suggest that the introduction of DPP-4 inhibitors generated a consumer surplus gain of around 7.6 cents per day for a typical DPP-4 inhibitor user under the existing differential pricing and voluntary licensing strategies. If the innovators decide to price at developed-country levels, this surplus is eliminated almost entirely. The issuance of compulsory licensing does not always improve consumer welfare because if innovators defer or delay the introduction of new drugs in response, the loss in consumer welfare could be substantial. Copyright © 2015 Elsevier B.V. All rights reserved.

Dpp Signaling Activity Requires Pentagone to Scale with Tissue Size in the Growing Drosophila Wing Imaginal Disc

PubMed Central

Pyrowolakis, George; Bergmann, Sven; Affolter, Markus

2011-01-01

The wing of the fruit fly, Drosophila melanogaster, with its simple, two-dimensional structure, is a model organ well suited for a systems biology approach. The wing arises from an epithelial sac referred to as the wing imaginal disc, which undergoes a phase of massive growth and concomitant patterning during larval stages. The Decapentaplegic (Dpp) morphogen plays a central role in wing formation with its ability to co-coordinately regulate patterning and growth. Here, we asked whether the Dpp signaling activity scales, i.e. expands proportionally, with the growing wing imaginal disc. Using new methods for spatial and temporal quantification of Dpp activity and its scaling properties, we found that the Dpp response scales with the size of the growing tissue. Notably, scaling is not perfect at all positions in the field and the scaling of target gene domains is ensured specifically where they define vein positions. We also found that the target gene domains are not defined at constant concentration thresholds of the downstream Dpp activity gradients P-Mad and Brinker. Most interestingly, Pentagone, an important secreted feedback regulator of the pathway, plays a central role in scaling and acts as an expander of the Dpp gradient during disc growth. PMID:22039350

Genetic ablation or pharmacological blockade of dipeptidyl peptidase IV does not impact T cell-dependent immune responses

PubMed Central

Vora, Kalpit A; Porter, Gene; Peng, Roche; Cui, Yan; Pryor, Kellyann; Eiermann, George; Zaller, Dennis M

2009-01-01

Background Current literature suggests that dipeptidyl peptidase IV (DPP-IV; CD26) plays an essential role in T-dependent immune responses, a role that could have important clinical consequences. To rigorously define the role of DPP-IV in the immune system, we evaluated genetic and pharmacological inhibition of the enzyme on T-dependent immune responses in vivo. Results The DPP-IV null animals mounted robust primary and secondary antibody responses to the T dependent antigens, 4-hydroxy-3-nitrophenylacetyl-ovalbumin (NP-Ova) and 4-hydroxy-3-nitrophenylacetyl-chicken gamma globulin (NP-CGG), which were comparable to wild type mice. Serum levels of antigen specific IgM, IgG1, IgG2a, IgG2b and IgG3 were similar between the two groups of animals. DPP-IV null animals mounted an efficient germinal center reaction by day 10 after antigen stimulation that was comparable to wild type mice. Moreover, the antibodies produced by DPP-IV null animals after repeated antigenic challenge were affinity matured. Similar observations were made using wild type animals treated with a highly selective DPP-IV inhibitor during the entire course of the experiments. T cell recall responses to ovalbumin and MOG peptide, evaluated by measuring proliferation and IL-2 release from cells isolated from draining lymph nodes, were equivalent in DPP-IV null and wild type animals. Furthermore, mice treated with DPP-IV inhibitor had intact T-cell recall responses to MOG peptide. In addition, female DPP-IV null and wild type mice treated with DPP-IV inhibitor exhibited normal and robust in vivo cytotoxic T cell responses after challenge with cells expressing the male H-Y minor histocompatibility antigen. Conclusion These data indicate Selective inhibition of DPP-IV does not impair T dependent immune responses to antigenic challenge. PMID:19358731

Biocatalytic ammonolysis of (5S)-4,5-dihydro-1H-pyrrole-1,5-dicarboxylic acid, 1-(1,1-dimethylethyl)-5-ethyl ester: preparation of an intermediate to the dipeptidyl peptidase IV inhibitor Saxagliptin.

PubMed

Gill, Iqbal; Patel, Ramesh

2006-02-01

An efficient biocatalytic method has been developed for the conversion of (5S)-4,5-dihydro-1H-pyrrole-1,5-dicarboxylic acid, 1-(1,1-dimethylethyl)-5-ethyl ester (1) into the corresponding amide (5S)-5-aminocarbonyl-4,5-dihydro-1H-pyrrole-1-carboxylic acid, 1-(1,1-dimethylethyl)ester (2), which is a critical intermediate in the synthesis of the dipeptidyl peptidase IV (DPP4) inhibitor Saxagliptin (3). Candida antartica lipase B mediates ammonolysis of the ester with ammonium carbamate as ammonia donor to yield up to 71% of the amide. The inclusion of Ascarite and calcium chloride as adsorbents for carbon dioxide and ethanol byproducts, respectively, increases the yield to 98%, thereby offering an efficient and practical alternative to chemical routes which yield 57-64%.

Cardiovascular Biology of the Incretin System

PubMed Central

Ussher, John R.; Drucker, Daniel J.

2012-01-01

Glucagon-like peptide-1 (GLP-1) is an incretin hormone that enhances glucose-stimulated insulin secretion and exerts direct and indirect actions on the cardiovascular system. GLP-1 and its related incretin hormone, glucose-dependent insulinotropic polypeptide (GIP), are rapidly inactivated by the enzyme dipeptidyl peptidase 4 (DPP-4), a key determinant of incretin bioactivity. Two classes of medications that enhance incretin action, GLP-1R agonists and DPP-4 inhibitors, are used for the treatment of type 2 diabetes mellitus (T2DM). We review herein the cardiovascular biology of GLP-1R agonists and DPP-4 inhibitors, including direct and indirect effects on cardiomyocytes, blood vessels, adipocytes, the control of blood pressure and postprandial lipoprotein secretion. Both GLP-1R activation and DPP-4 inhibition exert multiple cardioprotective actions in preclinical models of cardiovascular dysfunction, and short term studies in human subjects appear to demonstrate modest yet beneficial actions on cardiac function in subjects with ischemic heart disease. Incretin-based agents control body weight, improve glycemic control with a low risk of hypoglycemia, decrease blood pressure, inhibit the secretion of intestinal chylomicrons, and reduce inflammation in preclinical studies. Nevertheless, there is limited information on the cardiovascular actions of these agents in patients with diabetes and established cardiovascular disease. Hence, a more complete understanding of the cardiovascular risk:benefit ratio of incretin-based therapies will require completion of long term cardiovascular outcome studies currently underway in patients with T2DM. PMID:22323472

Inhibitory effect of collagen-derived tripeptides on dipeptidylpeptidase-IV activity.

PubMed

Hatanaka, Tadashi; Kawakami, Kayoko; Uraji, Misugi

2014-12-01

The collagen tripeptide fragments Gly-Ala-Hyp, Gly-Pro-Ala and Gly-Pro-Hyp were generated by hydrolyzing collagen from pig-skin, cattle-skin, fish-scales and chicken-feet, respectively, with Streptomyces collagenase. Collagenase treatment increased the concentration of tripeptides in the hydrolysates by 13-15% (w/w). Of the three peptides, Gly-Pro-Hyp was a true peptidic inhibitor of dipeptidylpeptidase-IV (DPP-IV), because DPP-IV could not hydrolyze the bond between Pro-Hyp. This tripeptide was a moderately competitive inhibitor (Ki=4.5 mM) of DPP-IV, and its level in the collagen hydrolysates could be greatly increased (4-9% [w/w]) using Streptomyces collagenase.

Treating ER+ Breast Cancer with CDK4/6 Inhibitors.

PubMed

2017-08-01

Data from the MONARCH2, PALOMA-1, and TREnd trials strongly support using CDK4/6 inhibitors alongside standard endocrine therapy for advanced ER-positive breast cancer. Including these targeted agents not only improves progression-free survival but may reverse acquired resistance to hormone treatment. ©2017 American Association for Cancer Research.

Hydrogen-bonded diketopyrrolopyrrole (DPP) pigments as organic semiconductors

DOE PAGES

Glowacki, Eric Daniel; Coskun, Halime; Blood-Forsythe, Martin A.; ...

2014-10-13

Diketopyrrolopyrroles (DPPs) have recently gained attention as building-blocks for organic semiconducting polymers and small molecules, however the semiconducting properties of their hydrogen-bonded (H-bonded) pigment forms have not been explored. Herein we report on the performance of three archetypical H-bonded DPP pigments, which show ambipolar carrier mobilities in the range 0.01–0.06 cm 2/V s in organic field-effect transistors. Their semiconducting properties are correlated with crystal structure, where an H-bonded crystal lattice supports close and relatively cofacial π–π stacking. To better understand transport in these systems, density functional theory calculations were carried out, indicating theoretical maximum ambipolar mobility values of ~0.3 cmmore » 2/V s. Furthermore, based on these experimental and theoretical results, H-bonded DPPs represent a viable alternative to more established DPP-containing polymers and small molecules where H-bonding is blocked by N-alkylation.« less

A molecular connection of Pterocarpus marsupium, Eugenia jambolana and Gymnema sylvestre with dipeptidyl peptidase-4 in the treatment of diabetes.

PubMed

Kosaraju, Jayasankar; Dubala, Anil; Chinni, Santhivardhan; Khatwal, Rizwan Basha; Satish Kumar, M N; Basavan, Duraiswamy

2014-02-01

Pterocarpus marsupium (PM) (Leguminosae), Eugenia jambolana (EJ) (Myrtaceae) and Gymnema sylvestre (GS) (Asclepiadaceae) are the most important medicinal plants in the Indian system of traditional medicine for the treatment of hyperglycemia. Dipeptidyl peptidase-4 (DPP-4) inhibitors are the emerging class of anti-diabetic agents. However, only few compounds are commercially available. Therefore, in the present study we tried to explore the naturally occurring PM, EJ and GS semi-standardized extracts for their potential DPP-4 inhibition in vitro and in vivo. DPP-4 inhibition was evaluated by in vitro inhibitory assay, and enzyme kinetics were calculated using one-phase exponential decay equation. Glucose load (2 g/kg) was administered to control and diabetic rats 30 min following extract administration (100, 200 and 400 mg/kg) orally once, and blood samples were withdrawn at 0, 0.5, 1, 1.5, 2 and 3 h to measure plasma active glucagon-like peptide-1 (GLP-1) levels. PM and EJ inhibit DPP-4 potently with IC50 values of 273.73 ± 2.96 and 278.94 ± 6.73 µg/mL, respectively, compared to GS (773.22 ± 9.21 µg/mL). PM, EJ and GS exhibit long duration of action with enzyme inhibitory half-lives of 462.3, 317.2 and 153.8 min, respectively. Extracts significantly increase GLP-1 levels compared to negative control groups and peak GLP-1 level was observed at 2 h for PM and EJ, whereas for GS it was at 1.5 h Taken together, results suggest the extracts may have potent DPP-4 inhibitory action, and their hypoglycemic action attributed through an increase in plasma active GLP-1 levels.

30 CFR 250.247 - What biological, physical, and socioeconomic information must accompany the DPP or DOCD?

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 2 2010-07-01 2010-07-01 false What biological, physical, and socioeconomic information must accompany the DPP or DOCD? 250.247 Section 250.247 Mineral Resources MINERALS MANAGEMENT... SHELF Plans and Information Contents of Development and Production Plans (dpp) and Development...

30 CFR 250.256 - What related facilities and operations information must accompany the DPP or DOCD?

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 2 2010-07-01 2010-07-01 false What related facilities and operations information must accompany the DPP or DOCD? 250.256 Section 250.256 Mineral Resources MINERALS MANAGEMENT... SHELF Plans and Information Contents of Development and Production Plans (dpp) and Development...

Utility of Saxagliptin in the Treatment of Type 2 Diabetes: Review of Efficacy and Safety.

PubMed

Jain, Rajeev

2015-11-01

Type 2 diabetes mellitus (T2DM) is a complex disease in which multiple organs and hormones contribute to the pathogenesis of disease. The intestinal hormone, glucagon-like peptide-1 (GLP-1), secreted in response to nutrient ingestion, increases insulin secretion from pancreatic β-cells and reduces glucagon secretion from pancreatic α-cells. GLP-1 is inactivated by the dipeptidyl peptidase-4 (DPP-4) enzyme. Saxagliptin is a DPP-4 inhibitor that prevents the degradation of endogenous GLP-1 and prolongs its actions on insulin and glucagon secretion. This article reviews the efficacy and safety of saxagliptin in patients with T2DM. A PubMed literature search was conducted to identify relevant, peer-reviewed saxagliptin clinical trial articles published between January 2008 and June 2015. Search terms included "saxagliptin" and "DPP-4 inhibitors". In clinical trials, saxagliptin significantly improved glycemic control when used as monotherapy or as add-on therapy to other antidiabetes agents and was associated with a low risk of hypoglycemia. In a large cardiovascular (CV) outcomes trial (SAVOR) in patients with T2DM and with established CV disease or multiple CV risk factors, saxagliptin neither increased nor decreased CV risk compared with placebo as assessed by the composite end point of death from CV causes, nonfatal myocardial infarction, or nonfatal stroke. Unexpectedly, more patients in the saxagliptin (3.5%) than in the placebo group (2.8%) were hospitalized for heart failure. Saxagliptin demonstrated statistically significant and clinically meaningful improvements in glycemic control and a low risk of hypoglycemia in patients with T2DM. However, this positive profile needs to be tempered by the observation of an increased risk of hospitalization for heart failure in the SAVOR trial. Results from ongoing CV outcome trials with other DPP-4 inhibitors may provide additional data on how best to manage patients with T2DM who are at risk for heart failure. Astra

Inhibition of dipeptidyl peptidase IV prevents high fat diet-induced liver cancer angiogenesis by downregulating chemokine ligand 2.

PubMed

Qin, Chen-Jie; Zhao, Ling-Hao; Zhou, Xu; Zhang, Hui-Lu; Wen, Wen; Tang, Liang; Zeng, Min; Wang, Ming-Da; Fu, Gong-Bo; Huang, Shuai; Huang, Wei-Jian; Yang, Yuan; Bao, Zhi-Jun; Zhou, Wei-Ping; Wang, Hong-Yang; Yan, He-Xin

2018-04-28

Obesity is a major risk factor for hepatocellular carcinoma (HCC) and is typically accompanied by higher levels of serum dipeptidyl peptidase 4 (DPP4). However, the role of DPP4 in obesity-promoted HCC is unclear. Here, we found that consumption of a high-fat diet (HFD) promoted HCC cell proliferation and metastasis and led to poor survival in a carcinogen-induced model of HCC in rats. Notably, genetic ablation of DPP4 or treatment with a DPP4 inhibitor (vildagliptin) prevented HFD-induced HCC. Moreover, HFD-induced DPP4 activity facilitated angiogenesis and cancer cell metastasis in vitro and in vivo, and vildagliptin prevented tumor progression by mediating the pro-angiogenic role of chemokine ligand 2 (CCL2). Loss of DPP4 effectively reversed HFD-induced CCL2 production and angiogenesis, indicating that the DPP4/CCL2/angiogenesis cascade had key roles in HFD-associated HCC progression. Furthermore, concomitant changes in serum DPP4 and CCL2 were observed in 210 patients with HCC, and high serum DPP4 activity was associated with poor clinical prognosis. These results revealed a link between obesity-related high serum DPP4 activity and HCC progression. Inhibition of DPP4 may represent a novel therapeutic intervention for patients with HCC. Copyright © 2018 Elsevier B.V. All rights reserved.

Gliptins in managing diabetes - Reviewing computational strategy.

PubMed

Sneha, P; Doss, C George Priya

2016-12-01

The pace of anti-diabetic drug discovery is very slow in spite of increasing rate of prevalence of Type 2 Diabetes which remains a major public health concern. Though extensive research steps are taken in the past decade, yet craves for better new treatment strategies to overcome the current scenario. One such general finding is the evolution of gliptins which discriminately inhibits DPP4 (Dipeptidyl peptidase-4) enzyme. Although the mechanism of action of gliptin is highly target oriented and accurate, still its long-term use stands unknown. This step calls for a fast, flexible, and cost-effective strategies to meet the demands of producing arrays of high-content lead compounds with improved efficiency for better clinical success. The present review highlights the available gliptins in the market and also other naturally occurring DPP4 enzyme inhibitors. Along with describing the known inhibitors and their origin in this review, we attempted to identify a probable new lead compounds using advanced computational techniques. In this context, computational methods that integrate the knowledge of proteins and drug responses were utilized in prioritizing targets and designing drugs towards clinical trials with better efficacy. The compounds obtained as a result of virtual screening were compared with the commercially available gliptin in the market to have better efficiency in the identification and validation of the potential DPP4 inhibitors. The combinatorial computational methods used in the present study identified Compound 1: 25022354 as promising inhibitor. Copyright © 2016 Elsevier Inc. All rights reserved.

Evaluation of Corrosion Inhibitors as Lubricity Improvers

DTIC Science & Technology

1988-07-01

IF AFWAL-TR-88-2036 I. ov EVALUATION OF CORROSION , INHIBITORS AS LUBRICITY IMPROVERS 0 T.B. Biddle W. H. Edwards United Technologies Corporation...TASK WORK UNIT ELEMENT NO. NO. NO. NO. ITL (include Security C.aulf.cal.on) 6220 F .--- 3048-_ 05 51 valuation of Corrosion Inhibitors as Lubricity...numkr) o GROUP SUB. GR. Bal12nQ ylinder Lubricity)Eva ator, BOCLE, Corrosion Inhibitor , Fuel 01 03 Lubricity, MIL!AI5017, QPL-2 17 Reverse Phase) High

Increased avidity for Dpp/BMP2 maintains the proliferation of progenitors-like cells in the Drosophila eye.

PubMed

Neto, Marta; Aguilar-Hidalgo, Daniel; Casares, Fernando

2016-10-01

During organ development, the progenitor state is transient, and depends on specific combinations of transcription factors and extracellular signals. Not surprisingly, abnormal maintenance of progenitor transcription factors may lead to tissue overgrowth, and the concurrence of signals from the local environment is often critical to trigger this overgrowth. Therefore, identifying specific combinations of transcription factors/signals promoting -or opposing- proliferation in progenitors is essential to understand normal development and disease. We have investigated this issue using the Drosophila eye as model. Transcription factors hth and tsh are transiently expressed in eye progenitors causing the expansion of the progenitor pool. However, if their co-expression is maintained experimentally, cell proliferation continues and differentiation is halted. Here we show that Hth+Tsh-induced tissue overgrowth requires the BMP2 Dpp and the abnormal hyperactivation of its pathway. Rather than using autocrine Dpp expression, Hth+Tsh cells increase their avidity for Dpp, produced locally, by upregulating extracellular matrix components. During normal development, Dpp represses hth and tsh ensuring that the progenitor state is transient. However, cells in which Hth+Tsh expression is forcibly maintained use Dpp to enhance their proliferation. Copyright © 2016 Elsevier Inc. All rights reserved.

30 CFR 250.261 - What environmental impact analysis (EIA) information must accompany the DPP or DOCD?

Code of Federal Regulations, 2011 CFR

2011-07-01

... analysis (EIA) information must accompany the DPP or DOCD? The following EIA information must accompany... 30 Mineral Resources 2 2011-07-01 2011-07-01 false What environmental impact analysis (EIA) information must accompany the DPP or DOCD? 250.261 Section 250.261 Mineral Resources BUREAU OF OCEAN ENERGY...

30 CFR 550.269 - How will BOEM evaluate the environmental impacts of the DPP or DOCD?

Code of Federal Regulations, 2014 CFR

2014-07-01

... impacts of the DPP or DOCD? 550.269 Section 550.269 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT... environmental impacts of the DPP or DOCD? The Regional Supervisor will evaluate the environmental impacts of the... through 1508). (a) Environmental impact statement (EIS) declaration. At least once in each OCS planning...

Pyroptosis and Apoptosis Pathways Engage in Bidirectional Crosstalk in Monocytes and Macrophages.

PubMed

Taabazuing, Cornelius Y; Okondo, Marian C; Bachovchin, Daniel A

2017-04-20

Pyroptosis is a lytic form of programmed cell death mediated by the inflammatory caspase-1, -4, and -5. We recently discovered that small-molecule inhibitors of the serine peptidases DPP8 and DPP9 (DPP8/9) induce pro-caspase-1-dependent pyroptosis in monocytes and macrophages. Notably, DPP8/9 inhibitors, unlike microbial agents, absolutely require caspase-1 to induce cell death. Therefore, DPP8/9 inhibitors are useful probes to study caspase-1 in cells. Here, we show that, in the absence of the pyroptosis-mediating substrate gasdermin D (GSDMD), caspase-1 activates caspase-3 and -7 and induces apoptosis, demonstrating that GSDMD is the only caspase-1 substrate that induces pyroptosis. Conversely, we found that, during apoptosis, caspase-3/-7 specifically block pyroptosis by cleaving GSDMD at a distinct site from the inflammatory caspases that inactivates the protein. Overall, this work reveals bidirectional crosstalk between apoptosis and pyroptosis in monocytes and macrophages, further illuminating the complex interplay between cell death pathways in the innate immune system. Copyright © 2017 Elsevier Ltd. All rights reserved.

Molecular simulations reveal that the long range fluctuations of human DPP III change upon ligand binding.

PubMed

Tomić, A; Berynskyy, M; Wade, R C; Tomić, S

2015-11-01

The experimentally determined structures of human dipeptidyl peptidase III (DPP III) for the wild-type protein and for the complex of its E451A mutant with the peptide substrate, tynorphin, differ significantly in their overall shape. The two domains of the enzyme are separated by a wide cleft in the structure of the ligand-free enzyme, while in the ligand-bound mutant they are very close to each other, and the protein structure is extremely compact. Here, we applied a range of molecular dynamics simulation techniques to investigate the DPP III conformational landscape and the influence of ligand binding on the protein structure and dynamics. We used conventional, accelerated and steered methods to simulate DPP III and its complexes with tynorphin and with the preferred, synthetic, substrate Arg-Arg-2-naphthylamide. We found that DPP III can adopt a number of different forms in solution. The compact forms are more stable, but the open and partially closed states, spanning a wide range of conformations, can more effectively recognize the substrate which preferentially binds to the five-stranded β-core of the lower DPP III domain. The simulations indicated the existence of a dynamic equilibrium between open and semi-closed states and revealed two ways that the protein can close, leading to two distinct compact structures. The way in which the protein closes depends on the presence of the ligand.

Dipeptidyl peptidase-4 inhibitor induced angioedema - an overlooked and potentially lethal adverse drug reaction?

PubMed

Scott, Susanne Irene; Andersen, Michelle Fog; Aagaard, Lise; Buchwald, Christian Von; Rasmussen, Eva Rye

2017-02-14

Introduction Angioedema is a potentially fatal adverse drug reaction of some medications, as swellings of the upper airways can cause death by asphyxiation. Angiotensin converting enzyme-inhibitors are widely known to cause angioedema but less is known about the association between dipeptidyl peptidase-4 inhibitors (gliptins) and angioedema. Dipeptidyl peptidase-4 inhibitors are anti-diabetic drugs used to improve glycaemic control. They, as a class effect, inadvertently affect the degradation of the vasoactive kinins bradykinin and substance P, both of which can cause angioedema due to vasodilatation and increase in vascular permeability in the capillaries. Objective To assess the risk and pathomechanism of angioedema due to inhibition of dipeptidyl peptidase-4 inhibitors when used as monotherapy and in combination with angiotensin converting enzyme-inhibitors. Method PubMed, Embase, the Cochrane Library, PubMed Central, Web of Science, Google Scholar and clinicaltrials.gov were searched using different combinations of keywords "angioedema", "dipeptidyl peptidase 4", "dipeptidyl peptidase 4 inhibitors", "gliptins", "bradykinin", "substance P" and "angiotensin converting enzyme-inhibitors". Original research papers were preferably used as references and their bibliographies were used to further the search for original research results. Results Both angiotensin converting enzyme and dipeptidyl peptidase-4 are major enzymes in the degradation pathway of bradykinin and substance P, and when inhibited pharmacologically - especially at the same time - the theoretical risk of angioedema is increased due to accumulation of vasoactive kinins. Conclusion Treatment with dipeptidyl peptidase-4 inhibitors must be carefully considered and monitored especially during concurrent treatment with angiotensin converting enzyme-inhibitors or when treating patients with a known predisposition to angioedema. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Discovery of Dengue Virus NS4B Inhibitors

PubMed Central

Wang, Qing-Yin; Dong, Hongping; Zou, Bin; Karuna, Ratna; Wan, Kah Fei; Zou, Jing; Susila, Agatha; Yip, Andy; Shan, Chao; Yeo, Kim Long; Xu, Haoying; Ding, Mei; Chan, Wai Ling; Gu, Feng; Seah, Peck Gee; Liu, Wei; Lakshminarayana, Suresh B.; Kang, CongBao; Lescar, Julien; Blasco, Francesca; Smith, Paul W.

2015-01-01

ABSTRACT The four serotypes of dengue virus (DENV-1 to -4) represent the most prevalent mosquito-borne viral pathogens in humans. No clinically approved vaccine or antiviral is currently available for DENV. Here we report a spiropyrazolopyridone compound that potently inhibits DENV both in vitro and in vivo. The inhibitor was identified through screening of a 1.8-million-compound library by using a DENV-2 replicon assay. The compound selectively inhibits DENV-2 and -3 (50% effective concentration [EC50], 10 to 80 nM) but not DENV-1 and -4 (EC50, >20 μM). Resistance analysis showed that a mutation at amino acid 63 of DENV-2 NS4B (a nonenzymatic transmembrane protein and a component of the viral replication complex) could confer resistance to compound inhibition. Genetic studies demonstrate that variations at amino acid 63 of viral NS4B are responsible for the selective inhibition of DENV-2 and -3. Medicinal chemistry improved the physicochemical properties of the initial “hit” (compound 1), leading to compound 14a, which has good in vivo pharmacokinetics. Treatment of DENV-2-infected AG129 mice with compound 14a suppressed viremia, even when the treatment started after viral infection. The results have proven the concept that inhibitors of NS4B could potentially be developed for clinical treatment of DENV infection. Compound 14a represents a potential preclinical candidate for treatment of DENV-2- and -3-infected patients. IMPORTANCE Dengue virus (DENV) threatens up to 2.5 billion people and is now spreading in many regions in the world where it was not previously endemic. While there are several promising vaccine candidates in clinical trials, approved vaccines or antivirals are not yet available. Here we describe the identification and characterization of a spiropyrazolopyridone as a novel inhibitor of DENV by targeting the viral NS4B protein. The compound potently inhibits two of the four serotypes of DENV (DENV-2 and -3) both in vitro and in vivo. Our

30 CFR 550.250 - What oil and hazardous substance spills information must accompany the DPP or DOCD?

Code of Federal Regulations, 2014 CFR

2014-07-01

... SHELF Plans and Information Contents of Development and Production Plans (dpp) and Development... accompany your DPP or DOCD: (a) Oil spill response planning. The material required under paragraph (a)(1) or... conduct your proposed development and production activities prepared according to the requirements of 30...

30 CFR 550.250 - What oil and hazardous substance spills information must accompany the DPP or DOCD?

Code of Federal Regulations, 2013 CFR

2013-07-01

... SHELF Plans and Information Contents of Development and Production Plans (dpp) and Development... accompany your DPP or DOCD: (a) Oil spill response planning. The material required under paragraph (a)(1) or... conduct your proposed development and production activities prepared according to the requirements of 30...

30 CFR 550.250 - What oil and hazardous substance spills information must accompany the DPP or DOCD?

Code of Federal Regulations, 2012 CFR

2012-07-01

... SHELF Plans and Information Contents of Development and Production Plans (dpp) and Development... accompany your DPP or DOCD: (a) Oil spill response planning. The material required under paragraph (a)(1) or... conduct your proposed development and production activities prepared according to the requirements of 30...

30 CFR 550.269 - How will BOEM evaluate the environmental impacts of the DPP or DOCD?

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 2 2012-07-01 2012-07-01 false How will BOEM evaluate the environmental impacts of the DPP or DOCD? 550.269 Section 550.269 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT... and Information Review and Decision Process for the Dpp Or Docd § 550.269 How will BOEM evaluate the...

30 CFR 550.269 - How will BOEM evaluate the environmental impacts of the DPP or DOCD?

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 2 2013-07-01 2013-07-01 false How will BOEM evaluate the environmental impacts of the DPP or DOCD? 550.269 Section 550.269 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT... and Information Review and Decision Process for the Dpp Or Docd § 550.269 How will BOEM evaluate the...

30 CFR 250.250 - What oil and hazardous substance spills information must accompany the DPP or DOCD?

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 2 2010-07-01 2010-07-01 false What oil and hazardous substance spills information must accompany the DPP or DOCD? 250.250 Section 250.250 Mineral Resources MINERALS MANAGEMENT... SHELF Plans and Information Contents of Development and Production Plans (dpp) and Development...

Sec61α is required for dorsal closure during Drosophila embryogenesis through its regulation of Dpp signaling

PubMed Central

Wang, Xiaochen; Ward, Robert E.

2010-01-01

During dorsal closure in Drosophila, signaling events in the dorsalmost row of epidermal cells (DME cells) direct the migration of lateral epidermal sheets towards the dorsal midline where they fuse to enclose the embryo. A Jun amino-terminal kinase (JNK) cascade in the DME cells induces the expression of Decapentaplegic (Dpp). Dpp signaling then regulates the cytoskeleton in the DME cells and amnioserosa to affect the cell shape changes necessary to complete dorsal closure. We identified a mutation in Sec61α that specifically perturbs dorsal closure. Sec61α encodes the main subunit of the translocon complex for co-translational import of proteins into the ER. JNK signaling is normal in Sec61α mutant embryos, but Dpp signaling is attenuated and the DME cells fail to maintain an actinomyosin cable as epithelial migration fails. Consistent with this model, dorsal closure is rescued in Sec61α mutant embryos by an activated form of the Dpp receptor Thick veins. PMID:20112345

Adipocyte fatty acid binding protein 4 (FABP4) inhibitors. A comprehensive systematic review.

PubMed

Floresta, Giuseppe; Pistarà, Venerando; Amata, Emanuele; Dichiara, Maria; Marrazzo, Agostino; Prezzavento, Orazio; Rescifina, Antonio

2017-09-29

Small molecule inhibitors of adipocyte fatty acid binding protein 4 (FABP4) have attracted interest following the recent publications of beneficial pharmacological effects of these compounds. FABP4 is predominantly expressed in macrophages and adipose tissue where it regulates fatty acids (FAs) storage and lipolysis and is an important mediator of inflammation. In the past years, hundreds FABP4 inhibitors have been synthesized for effective atherosclerosis and diabetes treatments, including derivatives of niacin, quinoxaline, aryl-quinoline, bicyclic pyridine, urea, aromatic compounds and other novel heterocyclic compounds. This review provides an overview of the synthesized and discovered molecules as adipocyte fatty acid binding protein 4 inhibitors (FABP4is) since the synthesis of the putative FABP4i, BMS309403, highlighting the interactions of the different classes of inhibitors with the targets. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Incretinomimetic and Insulinomimetic Effect of (2E)-N'-(1'-Naphthyl)-3,4,5-Trimethoxybenzohydrazide for Glycemic Homeostasis.

PubMed

Frederico, Marisa Jádna Silva; Mascarello, Alessandra; Castro, Allisson Jhonatan Gomes; Da Luz, Gabrielle; Altenhofen, Delsi; Mendes, Camila Pires; Leal, Paulo Cesar; Yunes, Rosendo Augusto; Nunes, Ricardo José; Silva, Fátima Regina Mena Barreto

2016-05-01

To characterize the role and the mechanism of action of (2E)-N'-(1'-naphthyl)-3,4,5-trimethoxybenzohydrazide (BZD) on incretin secretion, glucose uptake in skeletal muscle and α-glucosidase activity on intestine, targets for glucose homeostasis. It was assayed on glucose tolerance test (GTT) to analyze GLP-1 secretion and the activity of DPP-4 enzyme in vitro. In skeletal muscle, mechanism of action on glucose uptake was carried out by in vitro experiments. The activity of intestinal disaccharidases was performed after in vivo and in vitro experiments. The compound improved the glucose tolerance around 30%, 25%, and 20% at 15, 30, and 60 min, respectively and potentiated the sitagliptin effect, an inhibitor of the enzyme that removes GLP-1, about 50, 45, and 54% at 15, 30, and 60 min, respectively. Additionally, BZD did not modify the activity of DPP-4 enzyme. The acute effect of BZD on glucose uptake is mediated by increasing GLUT4 expression (around 140%) and its translocation to the plasma membrane in soleus muscle. The genomic effect as well as GLUT4 translocation involve the activation of PI-3K and MAPK pathways and require the microtubules integrity to the complete stimulatory effect of this compound on glucose uptake. Beyond, BZD acts in an alternative target to ameliorate glycaemia, intestinal disaccharidases. In a whole, these data point an incretino- and insulinomimetic effect of the compound for glycemic control. © 2015 Wiley Periodicals, Inc.

30 CFR 550.244 - What geological and geophysical (G&G) information must accompany the DPP or DOCD?

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 2 2014-07-01 2014-07-01 false What geological and geophysical (G&G... Operations Coordination Documents (docd) § 550.244 What geological and geophysical (G&G) information must accompany the DPP or DOCD? The following G&G information must accompany your DPP or DOCD: (a) Geological...

30 CFR 550.244 - What geological and geophysical (G&G) information must accompany the DPP or DOCD?

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 2 2013-07-01 2013-07-01 false What geological and geophysical (G&G... Operations Coordination Documents (docd) § 550.244 What geological and geophysical (G&G) information must accompany the DPP or DOCD? The following G&G information must accompany your DPP or DOCD: (a) Geological...

30 CFR 550.244 - What geological and geophysical (G&G) information must accompany the DPP or DOCD?

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 2 2012-07-01 2012-07-01 false What geological and geophysical (G&G... Operations Coordination Documents (docd) § 550.244 What geological and geophysical (G&G) information must accompany the DPP or DOCD? The following G&G information must accompany your DPP or DOCD: (a) Geological...

Inhibition of dipeptidyl-peptidase IV catalyzed peptide truncation by Vildagliptin ((2S)-{[(3-hydroxyadamantan-1-yl)amino]acetyl}-pyrrolidine-2-carbonitrile).

PubMed

Brandt, Inger; Joossens, Jurgen; Chen, Xin; Maes, Marie-Berthe; Scharpé, Simon; De Meester, Ingrid; Lambeir, Anne-Marie

2005-07-01

Vildagliptin (NVP-LAF237/(2S)-{[(3-hydroxyadamantan-1-yl)amino]acetyl}-pyrrolidine-2-carbonitrile) was described as a potent, selective and orally bio-available dipeptidyl-peptidase IV (DPP IV, EC 3.4.14.5) inhibitor [Villhauer EB, Brinkman JA, Naderi GB, Burkey BF, Dunning BE, Prasad K, et al.1-[[(3-Hydroxy-1-adamantyl)amino]acetyl]-2-cyano-(S)-pyrrolidine: a potent, selective, and orally bioavailable dipeptidyl peptidase IV inhibitor with antihyperglycemic properties. J Med Chem 2003;46:2774-89]. Phase III clinical trials for the use of this compound in the treatment of Type 2 diabetes were started in the first quarter of 2004. In this paper, we report on (1) the kinetics of binding, (2) the type of inhibition, (3) the selectivity with respect to other peptidases, and (4) the inhibitory potency on the DPP IV catalyzed degradation of glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP) and substance P. Vildagliptin behaved as a slow-binding DPP IV inhibitor with an association rate constant of 1.4x10(5)M(-1)s(-1) and a K(i) of 17nM. It is a micromolar inhibitor for dipeptidyl-peptidase 8 and does not significantly inhibit dipeptidyl-peptidase II (EC 3.4.11.2), prolyl oligopeptidase (EC 3.4.21.26), aminopeptidase P (EC 3.4.11.9) or aminopeptidase M (EC 3.4.11.2). There was no evidence for substrate specific inhibition of DPP IV by Vildagliptin or for important allosteric factors affecting the inhibition constant in presence of GIP and GLP-1.

Combination of TS-021 with metformin improves hyperglycemia and synergistically increases pancreatic β-cell mass in a mouse model of type 2 diabetes.

PubMed

Tajima, Atsushi; Hirata, Takashi; Taniguchi, Kazuo; Kondo, Yukiko; Kato, Sota; Saito-Hori, Masako; Ishimoto, Tsuyoshi; Yamamoto, Koji

2011-10-24

The objectives of this study were to elucidate the effects of a potent dipeptidyl peptidase (DPP)-IV inhibitor, TS-021, combined with/without metformin on glycemic control and pathological changes in pancreatic islets in high-fat diet and streptozotocin-induced (HFD-STZ) diabetic mice. The anti-diabetic effects of TS-021 and/or metformin in HFD-STZ mice were examined in both acute and chronic treatment studies. In addition, we performed immunohistochemical analysis after repeated administration of TS-021 and/or metformin to HFD-STZ mice twice a day for 5 weeks. In the acute treatment study, TS-021 and/or metformin significantly improved glucose tolerance and glucagon-like peptide-1 (GLP-1) level, and TS-021 alone or in combination with metformin significantly increased the plasma insulin level after nutrient ingestion. In the chronic treatment study, TS-021 in combination with metformin significantly lowered the glycosylated hemoglobin level, plasma insulin level, and α-cell-to-β-cell area ratio in pancreatic islets. In particular, the combined treatment synergistically increased the insulin-positive area in pancreatic islets from 32.3% in diabetic mice treated with the vehicle to 51.1% (TS-021 alone, 35.3%; metformin alone, 30.6%). The present study demonstrated that the coadministration of TS-021 and metformin synergistically improved the islet morphology by increasing the circulating level of biologically active GLP-1, which is thought to result from two different mechanisms (namely, an increase in GLP-1 secretion and DPP-IV inhibition). These findings strongly support the rationale for combined treatment with DPP-IV inhibitors plus metformin in clinical practice by clearly demonstrating an anti-diabetic effect associated with the remarkable improvement in pancreatic β-cell morphology. Copyright © 2011 Elsevier Inc. All rights reserved.

30 CFR 250.267 - What actions will MMS take after the DPP or DOCD is deemed submitted?

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 2 2010-07-01 2010-07-01 false What actions will MMS take after the DPP or DOCD is deemed submitted? 250.267 Section 250.267 Mineral Resources MINERALS MANAGEMENT SERVICE... and Information Review and Decision Process for the Dpp Or Docd § 250.267 What actions will MMS take...

Phosphodiesterase 4 Inhibitor Therapies for Atopic Dermatitis: Progress and Outlook.

PubMed

Ahluwalia, Jusleen; Udkoff, Jeremy; Waldman, Andrea; Borok, Jenna; Eichenfield, Lawrence F

2017-09-01

Phosphodiesterase 4 (PDE4) is a cyclic AMP degrading enzyme in leukocytes. Several decades ago, increased PDE activity was demonstrated in patients with atopic dermatitis (AD). Currently, several PDE4 inhibitors in both topical and oral formulation have been developed to target the inflammatory cascade of AD. This review shows the pathogenic rationale behind these inhibitors, and discusses multiple PDE4 inhibitors that are under evaluation or in the market. PDE4 inhibitors may be considered as favorable agents in the repertoire of current interventions for AD.

30 CFR 550.245 - What hydrogen sulfide (H2S) information must accompany the DPP or DOCD?

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 2 2012-07-01 2012-07-01 false What hydrogen sulfide (H2S) information must accompany the DPP or DOCD? 550.245 Section 550.245 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT... Coordination Documents (docd) § 550.245 What hydrogen sulfide (H2S) information must accompany the DPP or DOCD...

30 CFR 550.245 - What hydrogen sulfide (H2S) information must accompany the DPP or DOCD?

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 2 2013-07-01 2013-07-01 false What hydrogen sulfide (H2S) information must accompany the DPP or DOCD? 550.245 Section 550.245 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT... Coordination Documents (docd) § 550.245 What hydrogen sulfide (H2S) information must accompany the DPP or DOCD...

30 CFR 550.245 - What hydrogen sulfide (H2S) information must accompany the DPP or DOCD?

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 2 2014-07-01 2014-07-01 false What hydrogen sulfide (H2S) information must accompany the DPP or DOCD? 550.245 Section 550.245 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT... Coordination Documents (docd) § 550.245 What hydrogen sulfide (H2S) information must accompany the DPP or DOCD...

30 CFR 550.267 - What actions will BOEM take after the DPP or DOCD is deemed submitted?

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 2 2013-07-01 2013-07-01 false What actions will BOEM take after the DPP or DOCD is deemed submitted? 550.267 Section 550.267 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT... and Information Review and Decision Process for the Dpp Or Docd § 550.267 What actions will BOEM take...

30 CFR 550.267 - What actions will BOEM take after the DPP or DOCD is deemed submitted?

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 2 2012-07-01 2012-07-01 false What actions will BOEM take after the DPP or DOCD is deemed submitted? 550.267 Section 550.267 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT... and Information Review and Decision Process for the Dpp Or Docd § 550.267 What actions will BOEM take...

Reduction of soluble dipeptidyl peptidase 4 levels in plasma of patients infected with Middle East respiratory syndrome coronavirus.

PubMed

Inn, Kyung-Soo; Kim, Yuri; Aigerim, Abdimadiyeva; Park, Uni; Hwang, Eung-Soo; Choi, Myung-Sik; Kim, Yeon-Sook; Cho, Nam-Hyuk

2018-05-01

Dipeptidyl peptidase 4 (DPP4) is a receptor for MERS-CoV. The soluble form of DPP4 (sDPP4) circulates systematically and can competitively inhibit MERS-CoV entry into host cells. Here, we measured the concentration of sDPP4 in the plasma and sputa of 14 MERS-CoV-infected patients of various degrees of disease severity. The concentration of sDPP4 in the plasma of MERS patients (474.76 ± 108.06 ng/ml) was significantly lower than those of healthy controls (703.42 ± 169.96 ng/ml), but there were no significant differences among the patient groups. Interestingly, plasma levels of IL-10 and EGF were negatively and positively correlated with sDPP4 concentrations, respectively. The sDPP4 levels in sputa were less than 300 ng/ml. Viral infection was inhibited by 50% in the presence of more than 8000 ng/ml of sDPP4. Therefore, sDPP4 levels in the plasma of MERS patients are significantly reduced below the threshold needed to exert an antiviral effect against MERS-CoV infection. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

Improvement of kynurenine aminotransferase-II inhibitors guided by mimicking sulfate esters.

PubMed

Jayawickrama, Gayan S; Nematollahi, Alireza; Sun, Guanchen; Church, William Bret

2018-01-01

The mammalian kynurenine aminotransferase (KAT) enzymes are a family of related isoforms that are pyridoxal 5'-phosphate-dependent, responsible for the irreversible transamination of kynurenine to kynurenic acid. Kynurenic acid is implicated in human diseases such as schizophrenia where it is found in elevated levels and consequently KAT-II, as the isoform predominantly responsible for kynurenic acid production in the brain, has been targeted for the development of specific inhibitors. One class of compounds that have also shown inhibitory activity towards the KAT enzymes are estrogens and their sulfate esters. Estradiol disulfate in particular is very strongly inhibitory and it appears that the 17-sulfate makes a significant contribution to its potency. The work here demonstrates that the effect of this moiety can be mirrored in existing KAT-II inhibitors, from the development of two novel inhibitors, JN-01 and JN-02. Both inhibitors were based on NS-1502 (IC50: 315 μM), but the deliberate placement of a sulfonamide group significantly improved the potency of JN-01 (IC50: 73.8 μM) and JN-02 (IC50: 112.8 μM) in comparison to the parent compound. This 3-4 fold increase in potency shows the potential of these moieties to be accommodated in the KAT-II active site and the effect they can have on improving inhibitors, and the environments in the KAT-II have been suitably modelled using docking calculations.

Berry and Citrus Phenolic Compounds Inhibit Dipeptidyl Peptidase IV: Implications in Diabetes Management

PubMed Central

Fan, Junfeng; Lila, Mary Ann; Yousef, Gad

2013-01-01

Beneficial health effects of fruits and vegetables in the diet have been attributed to their high flavonoid content. Dipeptidyl peptidase IV (DPP-IV) is a serine aminopeptidase that is a novel target for type 2 diabetes therapy due to its incretin hormone regulatory effects. In this study, well-characterized anthocyanins (ANC) isolated from berry wine blends and twenty-seven other phenolic compounds commonly present in citrus, berry, grape, and soybean, were individually investigated for their inhibitory effects on DPP-IV by using a luminescence assay and computational modeling. ANC from blueberry-blackberry wine blends strongly inhibited DPP-IV activity (IC50, 0.07 ± 0.02 to >300 μM). Of the twenty-seven phenolics tested, the most potent DPP-IV inhibitors were resveratrol (IC50, 0.6 ± 0.4 nM), luteolin (0.12 ± 0.01 μM), apigenin (0.14 ± 0.02 μM), and flavone (0.17 ± 0.01 μM), with IC50 values lower than diprotin A (4.21 ± 2.01 μM), a reference standard inhibitory compound. Analyses of computational modeling showed that resveratrol and flavone were competitive inhibitors which could dock directly into all three active sites of DPP-IV, while luteolin and apigenin docked in a noncompetitive manner. Hydrogen bonding was the main binding mode of all tested phenolic compounds with DPP-IV. These results indicate that flavonoids, particularly luteolin, apigenin, and flavone, and the stilbenoid resveratrol can act as naturally occurring DPP-IV inhibitors. PMID:24069048

Molecular and clinical roles of incretin-based drugs in patients with heart failure.

PubMed

Orabi, Bassant; Kaddoura, Rasha; Omar, Amr S; Carr, Cornelia; Alkhulaifi, Abdulaziz

2018-05-01

Glucagon-like peptide-1 (GLP-1) agonists and dipeptidyl peptidase-4 (DPP-4) inhibitors produce some beneficial and deleterious effects in diabetic patients not mediated by their glycemic lowering effects, and there is a need for better understanding of the molecular basis of these effects. They possess antioxidant and anti-inflammatory effects with some direct vasodilatory action (animal and human trial data) that may indirectly influence heart failure (HF). Unlike GLP-1R agonists, signaling for HF adverse effects was observed with two DPP-4 inhibitors, saxagliptin and alogliptin. Accordingly, these drugs should be used with caution in heart failure patients.

30 CFR 250.270 - What decisions will MMS make on the DPP or DOCD and within what timeframe?

Code of Federal Regulations, 2011 CFR

2011-07-01

..., REGULATION, AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Plans and Information Review and Decision Process for the Dpp Or Docd § 250.270... provide monitoring information. (2) Require you to modify your proposed DPP or DOCD It fails to make...

30 CFR 550.270 - What decisions will BOEM make on the DPP or DOCD and within what timeframe?

Code of Federal Regulations, 2014 CFR

2014-07-01

... MANAGEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Plans and Information Review and Decision Process for the Dpp Or Docd § 550.270 What decisions... provide monitoring information. (2) Require you to modify your proposed DPP or DOCD, It fails to make...

Sitagliptin on carotid intima-media thickness in type 2 diabetes patients receiving primary or secondary prevention of cardiovascular disease: A subgroup analysis of the PROLOGUE study.

PubMed

Tanaka, Atsushi; Yoshida, Hisako; Nanasato, Mamoru; Oyama, Jun-Ichi; Ishizu, Tomoko; Ajioka, Masayoshi; Ishiki, Ryoji; Saito, Makoto; Shibata, Yoshisato; Kaku, Kohei; Maemura, Koji; Higashi, Yukihito; Inoue, Teruo; Murohara, Toyoaki; Node, Koichi

2018-05-19

Whether a dipeptidyl peptidase-4 (DPP-4) inhibitor can attenuate atherosclerosis is still controversial. Some clinical trials reported that DPP-4 inhibitors in diabetes patients without a previous history of cardiovascular (CV) events could reduce carotid intima-media thickness (IMT). However, in the PROLOGUE study, which enrolled diabetes patients both with and without previous CV events, sitagliptin failed to slow the progression of carotid IMT relative to conventional therapy. We hypothesized that the effect of DPP-4 inhibitors on carotid atherosclerosis might be different between the primary and secondary prevention groups. We performed a post hoc analysis of the PROLOGUE study and compared the effects of sitagliptin and conventional therapy on changes in carotid IMT in subgroups with or without previous CV events. No significant difference in the IMT changes between the treatment groups was found in the secondary prevention subgroup (sitagliptin, N = 102; conventional, 111). However, in the primary prevention subgroup (sitagliptin, 120; conventional, 109), we found significant inhibitory effects of sitagliptin on mean and max internal carotid artery IMT [estimated group difference: -0.096 mm (95% CI -0.175 to -0.018, p = 0.017) and -0.162 mm (95% CI -0.272 to -0.052, p = 0.004), respectively], although there was no significant difference in the common carotid artery IMT. Our data suggest that there is a favorable effect of DPP-4 inhibitor treatment on carotid atherosclerosis in diabetes patients without previous CV events. Copyright © 2017 Elsevier B.V. All rights reserved.

The Evaluation of Dipeptidyl Peptidase (DPP)-IV, α-Glucosidase and Angiotensin Converting Enzyme (ACE) Inhibitory Activities of Whey Proteins Hydrolyzed with Serine Protease Isolated from Asian Pumpkin (Cucurbita ficifolia).

PubMed

Konrad, Babij; Anna, Dąbrowska; Marek, Szołtysik; Marta, Pokora; Aleksandra, Zambrowicz; Józefa, Chrzanowska

2014-01-01

In the present study, whey protein concentrate (WPC-80) and β-lactoglobulin were hydrolyzed with a noncommercial serine protease isolated from Asian pumpkin ( Cucurbita ficifolia ). Hydrolysates were further fractionated by ultrafiltration using membranes with cut-offs equal 3 and 10 kDa. Peptide fractions of molecular weight lower than 3 and 3-10 kDa were further subjected to the RP-HPLC. Separated preparations were investigated for their potential as the natural inhibitors of dipeptidyl peptidase (DPP-IV), α-glucosidase and angiotensin converting enzyme (ACE). WPC-80 hydrolysate showed higher inhibitory activities against the three tested enzymes than β-lactoglobulin hydrolysate. Especially high biological activities were exhibited by peptide fractions of molecular weight lower than 3 kDa, with ACE IC50 <0.64 mg/mL and DPP-IV IC50 <0.55 mg/mL. This study suggests that peptides generated from whey proteins may support postprandial glycemia regulation and blood pressure maintenance, and could be used as functional food ingredients in the diet of patients with type 2 diabetes.

Dipeptidyl-peptidase IV inhibitory activity of peptides derived from tuna cooking juice hydrolysates.

PubMed

Huang, Shih-Li; Jao, Chia-Ling; Ho, Kit-Pan; Hsu, Kuo-Chiang

2012-05-01

The in vitro DPP-IV inhibitory activity of isolated peptides from of tuna cooking juice hydrolyzed by Protease XXIII (PR) and orientase (OR) was determined. The results showed that the peptide fractions with the molecular weight over 1,422 Da possessed the greatest DPP-IV inhibitory activity. The amino acid sequences of the three peptides isolated from PR and OR hydrolysates were identified by MALDI-TOF/TOF MS/MS, and they were Pro-Gly-Val-Gly-Gly-Pro-Leu-Gly-Pro-Ile-Gly-Pro-Cys-Tyr-Glu (1412.7 Da), Cys-Ala-Tyr-Gln-Trp-Gln-Arg-Pro-Val-Asp-Arg-Ile-Arg (1690.8 Da) and Pro-Ala-Cys-Gly-Gly-Phe-Try-Ile-Ser-Gly-Arg-Pro-Gly (1304.6 Da), while they showed the dose-dependent inhibition effect of DPP-IV with IC(50) values of 116.1, 78.0 and 96.4 μM, respectively. In vitro simulated gastrointestinal digestion retained or even improved the DPP-IV inhibitory activities of the three peptides. The results suggest that tuna cooking juice would be a good precursor of DPP-IV inhibitor, and the DPP-IV inhibitory peptides can successfully passed through the digestive tract. Copyright © 2012 Elsevier Inc. All rights reserved.

Ubx dynamically regulates Dpp signaling by repressing Dad expression during copper cell regeneration in the adult Drosophila midgut