Dipeptidyl peptidase Ⅲ在先天性白内障大鼠晶状体中的免疫活性变化

目的 观察 8、10、12、14周龄正常及先天性白内障大鼠晶状体中dipeptidylpep tidaseⅢ (DPPⅢ )的免疫活性变化 ,探讨其与白内障发病的关系。方法 分别于 8、10、12、14周龄鼠 ,摘取正常对照组以及先天性白内障大鼠晶状体 ,应用抗生物素蛋白 生物素 过氧化物酶复合体法 ,观察不同时期大鼠晶状体中DPPⅢ的免疫活性变化。结果 各周龄先天性白内障大鼠晶状体纤维部DPPⅢ的免疫活性明显高于正常对照组 ,特别是 12、14周白内障晶状体中DPPⅢ的免疫阳性产物扩展至晶状体核周部。结论 DPPⅢ在白内障大鼠晶状体中免疫活性增强 ,它有可能在白内障形成过程中参与晶状体蛋白的水解分化 ,从而促进白内障的形成。

Dipeptidyl peptidase-4 inhibitor for steroid-induced diabetes

The addition of the dipeptidyl peptidase-4 (DDP-4) inhibitor has been reported to achieve greater improvements in glucose metabolism with fewer adverse events compared to increasing the metformin dose in type 2 diabetic patients. We present a patient with steroid-induced diabetes whose blood glucose levels were ameliorated by the use of the DPP-4 inhibitor, showing that the DPP-4 inhibitors may be an effective and safe oral anti-diabetic drug for steroid-induced diabetes.

Anti-diabetic potential of Urena lobata leaf extract through inhibition of dipeptidyl peptidase IV activity

Objective: To evaluate the anti-diabetic potential of leaf extract from Urena lobata(U. lobata) through dipeptidyl peptidase IV(DPP-IV) inhibitory activity.Methods: U. lobata leaf was extracted in hot water and ethanol. The activity of DPPIV inhibitor was tested by in vitro study using gly-pro-p-nitroanilide as substrat of DPPIV and vildagliptin, as standard reference. A product of the reactions between gly-pro-pnitroanilide and DPP-IV, was observed by microplate readers with λ = 405 nm. All data were expressed as mean ± SD and the IC50 value was determined by non linear regression curve fit. Active substances in leaf extract of U. lobata was analyzed by liquid chromatography-mass spectrometry. DPP-IV inhibitory activity of active compounds was evaluated in silico using docking server. Results: The ethanolic extract of U. lobata showed stronger DPP-IV inhibitor activity than water extract with the IC50 values of 1 654.64 and 6 489.88 μg/mL, respectively. Vildagliptin, based on standard reference for DPP-IV inhibitor activity, has IC50 value of 57.44 μg/mL. Based on in silico analysis, mangiferin, stigmasterol and β-sitosterol in U. lobata extract have a strong inhibitory activity on DPP-IV. Conclusions: The results showed that DPP-IV inhibitory activity of U. lobata is related to its active compounds such as mangiferin, stigmasterol and β-sitosterol.

Role of dipeptidyl peptidase 4 inhibitors in the new era of antidiabetic treatment

The last few years important changes have occurred in the field of diabetes treatment.The priority in the therapy of patients with diabetes is not glycemic control per se rather an overall management of risk factors,while individualization of glycemic target is suggested.Furthermore,regulatory authorities now require evidence of cardiovascular(CV)safety in order to approve new antidiabetic agents.The most novel drug classes,i.e.,sodium-glucose transporter 2 inhibitors(SGLT2-i)and some glucagon-like peptide-1 receptor agonists(GLP-1 RA),have been demonstrated to reduce major adverse CV events and,thus,have a prominent position in the therapeutic algorithm of hyperglycemia.In this context,the role of previously used hypoglycemic agents,including dipeptidyl peptidase 4(DPP-4)inhibitors,has been modified.DPP-4 inhibitors have a favorable safety profile,do not cause hypoglycemia or weight gain and do not require dose uptitration.Furthermore,they can be administered in patients with chronic kidney disease after dose modification and elderly patients with diabetes.Still,though,they have been undermined to a third line therapeutic choice as they have not been shown to reduce CV events as is the case with SGLT2-i and GLP-1 RA.Overall,DPP-4 inhibitors appear to have a place in the management of patients with diabetes as a safe class of oral glucose lowering agents with great experience in their use.

Regulation of dipeptidyl peptidase 8 and 9 expression in activated lymphocytes and injured liver

AIM:To investigate the expression of dipeptidyl peptidase(DPP) 8 and DPP9 in lymphocytes and various models of liver fibrosis.METHODS:DPP8 and DPP9 expression were measured in mouse splenic CD4 + T-cells,CD8 + T-cells and B-cells(B220 +),human lymphoma cell lines and mouse splenocytes stimulated with pokeweed mitogen(PWM) or lipopolysaccharide(LPS),and in dithiothreitol(DTT) and mitomycin-C treated Raji cells.DPP8 and DPP9 expression were measured in epidermal growth factor(EGF) treated Huh7 hepatoma cells,in fibrotic liver samples from mice treated with carbon tetrachloride(CCl 4) and from multidrug resistance gene 2(Mdr2 /Abcb4) gene knockout(gko) mice with biliary fibrosis,and in human end stage primary biliary cirrhosis(PBC).RESULTS:All three lymphocyte subsets expressed DPP8 and DPP9 mRNA.DPP8 and DPP9 expression were upregulated in both PWM and LPS stimulated mouse splenocytes and in both Jurkat T-and Raji B-cell lines.DPP8 and DPP9 were downregulated in DTT treated and upregulated in mitomycin-C treated Raji cells.DPP9transfected Raji cells exhibited more annexin V + cells and associated apoptosis.DPP8 and DPP9 mRNA were upregulated in CCl 4 induced fibrotic livers but not in the lymphocytes isolated from such livers,while DPP9 was upregulated in EGF stimulated Huh7 cells.In contrast,intrahepatic DPP8 and DPP9 mRNA expression levels were low in the Mdr2 gko mouse and in human PBC compared to non-diseased livers.CONCLUSION:These expression patterns point to biological roles for DPP8 and DPP9 in lymphocyte activation and apoptosis and in hepatocytes during liver disease pathogenesis.

Identification and dipeptidyl peptidase Ⅳ(DPP-Ⅳ) inhibitory activity verification of peptides from mouse lymphocytes

The objective of this study was to isolate and identify the intracellular bioactive peptides from mouse lymphocytes before and after lipopolysaccharide(LPS)stimulation,to explore novel peptides and to research the bioactive function.Mouse spleen lymphocytes were isolated and cultured with LPS stimulation(experimental group)or not(control group)to collect intracellular peptides.Totally 385 peptides were analyzed by nanoliter liquid phase-Q Exactive quadrupole ultra-high resolution orbitrap mass spectrometer(Nano LC-Q Exactive Plus)and identifi ed by PEAKS X software.After compared with peptides reported,131 novel peptides were discovered,which then were predicted bioactivity by Peptide Ranker and 6 peptides with high bioactivity were predicted function by BIOPEP-UMW database.Prediction data showed that they may have dipeptidyl peptidase IV(DPP-IV)inhibitory activity.Finally,two peptides showed better potent inhibition were verifi ed with competitive and noncompetitive modes.

Cardiovascular efficacy and safety of dipeptidyl peptidase-4 inhibitors:A meta-analysis of cardiovascular outcome trials

BACKGROUND Dipeptidyl peptidase-4(DPP-4)inhibitors are a generally safe and well tolerated antidiabetic drug class with proven efficacy in type 2 diabetes mellitus(T2DM).Recently,a series of large,randomized controlled trials(RCTs)addressing cardiovascular outcomes with DPP-4 inhibitors have been published.AIM To pool data from the aforementioned trials concerning the impact of DPP-4 inhibitors on surrogate cardiovascular efficacy outcomes and on major cardiac arrhythmias.METHODS We searched PubMed and grey literature sources for all published RCTs assessing cardiovascular outcomes with DPP-4 inhibitors compared to placebo until October 2020.We extracted data concerning the following“hard”efficacy outcomes:fatal and non-fatal myocardial infarction,fatal and non-fatal stroke,hospitalization for heart failure,hospitalization for unstable angina,hospitalization for coronary revascularization and cardiovascular death.We also extracted data regarding the risk for major cardiac arrhythmias,such as atrial fibrillation,atrial flutter,ventricular fibrillation and ventricular tachycardia.RESULTS We pooled data from 6 trials in a total of 52520 patients with T2DM assigned either to DPP-4 inhibitor or placebo.DPP-4 inhibitors compared to placebo led to a non-significant increase in the risk for fatal and non-fatal myocardial infarction[risk ratio(RR)=1.02,95%CI:0.94-1.11,I2=0%],hospitalization for heart failure(RR=1.09,95%CI:0.92-1.29,I2=65%)and cardiovascular death(RR=1.02,95%CI:0.93-1.11,I2=0%).DPP-4 inhibitors resulted in a non-significant decrease in the risk for fatal and non-fatal stroke(RR=0.96,95%CI:0.85-1.08,I2=0%)and coronary revascularization(RR=0.99,95%CI:0.90-1.09,I2=0%),Finally,DPP-4 inhibitors demonstrated a neutral effect on the risk for hospitalization due to unstable angina(RR=1.00,95%CI:0.85-1.18,I2=0%).As far as cardiac arrhythmias are concerned,DPP-4 inhibitors did not significantly affect the risk for atrial fibrillation(RR=0.95,95%CI:0.78-1.17,I2=0%),while they were associated with a significant increase in the risk for atrial flutter,equal to 52%(RR=1.52,95%CI:1.03-2.24,I2=0%).DPP-4 inhibitors did not have a significant impact on the risk for any of the rest assessed cardiac arrhythmias.CONCLUSION DPP-4 inhibitors do not seem to confer any significant cardiovascular benefit for patients with T2DM,while they do not seem to be associated with a significant risk for any major cardiac arrhythmias,except for atrial flutter.Therefore,this drug class should not be the treatment of choice for patients with established cardiovascular disease or multiple risk factors,except for those cases when newer antidiabetics(glucagon-like peptide-1 receptor agonists and sodium-glucose cotransporter-2 inhibitors)are not tolerated,contraindicated or not affordable for the patient.

Low expression of angiotensinogen and dipeptidyl peptidase 1 in saliva of patients with proliferative verrucous leukoplakia

AIM To elucidate the profile of the salivary proteome.METHODS Unstimulated whole mouth saliva was collected from 30 volunteers [15 proliferative verrucous leukoplakia(PVL) patients and 15 controls] and proteins were submitted for mass spectrometry-based proteomics using the discovery approach,followed by analyses of variance and logistic regression tests.RESULTS A total of two hundred and eighty-three proteins were confidently identified in saliva.By combining two low abundance proteins from the PVL group,angiotensinogen(AGT) and dipeptidyl peptidase 1(DPP1),a model for group differentiation was built with a concordance index of 94.2%,identifying both proteins as potential etiologic biomarkers for PVL.CONCLUSION This study suggests that both AGT and DPP1 may be involved in developmental mechanisms of PVL.

Risk of pancreatic adverse events associated with the use of glucagon-like peptide-1 receptor agonist and dipeptidyl peptidase-4 inhibitor drugs: A systematic review and metaanalysis of randomized trials

AIM: To systematically assess risk of pancreatic adverse events with glucagon-like peptide-1(GLP-1) receptor agonist and dipeptidyl peptidase-4(DPP-4) inhibitor drugs.METHODS: We searched Pub Med, Embase, CINAHL, Cochrane review of clinical trials, pharmaceutical company clinical trials register, United States Food and Drug Administration website, European Medicines Agency website and Clinical Trials.gov for randomized controlled trials from inception to October 2013. Randomized control trial studies were selected for inclusion if they reported on pancreatic complication events and/or changes in pancreatic enzyme levels(serum amylase and serum lipase) as adverse events or as serious adverse events for patients who were on GLP-1 receptor agonist and DPP-4 inhibitor drugs. Two independent reviewers extracted data directly. We performed Peto odds ratio(OR) fixed effect meta-analysis of pancreatic adverse events a, and assessed heterogeneity with the I^2 statistic.RESULTS: Sixty-eight randomized controlled trials were eligible. A total of 60720 patients were included in our analysis of the association of risk of pancreatic complication events with GLP-1 agents. A total of 89 pancreatic related adverse events occurred among the GLP-1 agents compared to 74 events among the controls. There was a statistically significant increased risk of elevation of pancreatic enzymes associated with GLP-1 agents compared with control(Peto OR = 3.15, 95%CI: 1.56-6.39, P = 0.001, I2 = 0%). There was no statistically significant difference in the risk of pancreatic adverse event associated with GLP-1 agent compared with controls(Peto OR = 1.00, 95%CI: 0.73-1.37, P = 1.00, I2 = 0%). There were a total of 71 pancreatitis events in patients on GLP-1 agents and 56 pancreatitis events occurred in the control patients. There were 36 reports of pancreatic cancer in these studies. Of these cases, 2 used linagliptin, 2 used alogliptin, 1 used vildagliptin, 7 used saxagliptin while 6 used sitagliptin. The remaining 18 cases occurred among controls.CONCLUSION: Although GLP-1 based agents are associated with pancreatic enzyme elevation, we were unable to confirm a significant risk of pancreatitis or pancreatic cancer.

Neonatal Exposure to the Dipeptidyl Peptidase-IV Inhibitors Diprotin A and Sitagliptin Induces Depression-Like Behavior, Anxiety, and Latent Aggression in Adolescent and Adult Rats

Emotional and motivational disorders in adults are often considered to be the result of altered neurodevelopment. Clinical and experimental data provide evidence that serine protease dipeptidyl peptidase-IV (DPP-IV, EC 3.4.14.5) is involved in the pathophysiology of psycho-emotional disorders. Recently, we have shown that adolescent and adult rats exhibit an increase in anxiety and depression-related behaviors after neonatal administration of a synthetic non-competitive inhibitor of DPP-IV, methionyl-2(S)-cyano-pyrrolidine. In the present study, we tested the effects of two competitive, selective DPP-IV inhibitors, sitagliptin (4 mg/kg) and diprotin A (2 mg/kg), administered at postnatal days 5 - 18 on the emotional and motivational behavior of adolescent and adult rats. We observed increased anxiety in one-month-old diprotin A- or sitagliptin-treated rats in the elevated plus maze;diprotin A also enhanced the animals’ anxiety score using a ranked scale for evaluating anxiety and phobias. In the sucrose consumption and preference test, depressive-like behavior was pronounced in both the diprotin A- and sitagliptin-treated one-month-old animals, while only the diprotin A-treated rats exhibited a decrease in sucrose consumption at the age of 2 months. The diprotin A-treated rats also demonstrated behavioral despair and decreased activity in the forced swimming test within 1 - 3 months of age. Increased aggression was observed in 1 - 3-month-old diprotin A-treated rats and in two-month-old sitagliptin-treated rats. These findings support the hypothesis that DPP-IV is involved in the genesis of emotional and motivational disorders. Additionally, the results show that diprotin А impairs the adolescent and adult rats’ behavior more significantly than sitagliptin when the animals were treated with the DPP-IV inhibitors in the early postnatal period.

Neuroprotection by dipeptidyl-peptidase-4 inhibitors and glucagonlike peptide-1 analogs via the modulation of AKT-signaling pathway in Alzheimer’s disease

Alzheimer’s disease(AD)is the most common reason for progressive dementia in the elderly.It has been shown that disorders of the mammalian/mechanistic target of rapamycin(mTOR)signaling pathways are related to the AD.On the other hand,diabetes mellitus(DM)is a risk factor for the cognitive dysfunction.The pathogenesis of the neuronal impairment caused by diabetic hyperglycemia is intricate,which contains neuro-inflammation and/or neurodegeneration and dementia.Glucagon-like peptide-1(GLP1)is interesting as a possible link between metabolism and brain impairment.Modulation of GLP1 activity can influence amyloid-beta peptide aggregation via the phosphoinositide-3 kinase/AKT/mTOR signaling pathway in AD.The GLP1 receptor agonists have been shown to have favorable actions on the brain such as the improvement of neurological deficit.They might also exert a beneficial effect with refining learning and memory on the cognitive impairment induced by diabetes.Recent experimental and clinical evidence indicates that dipeptidyl-peptidase-4(DPP4)inhibitors,being currently used for DM therapy,may also be effective for AD treatment.The DPP-4 inhibitors have demonstrated neuroprotection and cognitive improvements in animal models.Although further studies for mTOR,GLP1,and DPP4 signaling pathways in humans would be intensively required,they seem to be a promising approach for innovative AD-treatments.We would like to review the characteristics of AD pathogenesis,the key roles of mTOR in AD and the preventive and/or therapeutic suggestions of directing the mTOR signaling pathway.

Effect of Urena lobataleaves extract on glucagon like peptide-1 serum level by inhibition of dipeptidyl peptidase-Ⅳ on diabetic rats

OBJECTIVE To investigate effect of Urenalobataleaves extract on glucagon like peptide-1(GLP-1)serum level by inhibition of dipeptidyl peptidase-Ⅳ(DPP-Ⅳ)on diabetic rat. METHODS This study uses control group post test only with male spraque dawley rats.Diabetic rats was induced by High Fructose Diet(HFD)and single dose streptozotocin 25mg·kg-1 bw intra peritoneal.The rat was administrated orally with ethanolic extract of U.lobataleaves in dose of 250,500 and 1000mg·kg-1 for 4weeks.Blood sample were collected from the tail vein at 15 min after oral glucose administration and then DPP-Ⅳserum level and GLP-1were examined using a rat elisa kits of DPP-Ⅳ and GLP-1.The data was analyzed using ANOVA test continued with LSD test(P<0.05).RESULTS The oral administration of U.lobataleaves extract at dose of 250,500 and 1000mg·kg-1 bw were able to prolong GLP-1 bioavaibility approximately 5,2and 2.5-fold respectively compared to diabetic group(P<0.05),while the DPP-Ⅳ serum level was decreased by 60%,50% and 40%(P<0.05),respectively.In diabetic groups,DPP-Ⅳ serum level was increased more and less 4-fold compared to normal group(P<0.05)while the GLP level were decreased by 8-fold(P<0.05).CONCLUSION U.lobataleaves extract could prolong GLP-1 bioavaibility by reducing of DPP-Ⅳserum level.This effect may be related to active compounds that act as an DPP-Ⅳinhibitor in U.lobata extract.

Accurate Assessment and Tracking the Process of Liver-Specific Injury by the Residual Tissue Activity of Carboxylesterase 1 and Dipeptidyl Peptidase 4

Accurately assessing and tracking the progression of liver-specific injury remains a major challenge in the field of biomarker research.Here,we took a retrospective validation approach built on the mutuality between serum and tissue biomarkers to characterize the liver-specific damage of bile duct cells caused by a-naphthyl isothiocyanate(ANIT).We found that carboxylesterase 1(CES1),as an intrahepatic marker,and dipeptidyl peptidase 4(DPP-IV),as an extrahepatic marker,can reflect the different pathophysiologies of liver injury.Levels of CES1 and DPP-IV can be used to identify liver damage itself and the inflammatory state,respectively.While the levels of the conventional serological biomarkers alkaline phosphatase(ALP),alanine aminotransferase(ALT),and aspartate aminotransferase(AST)were all concomitantly elevated in serum and tissues after ANIT-induced injury,the levels of bile acids decreased in bile,increased in serum,and ascended in intrahepatic tissue.Although the level of γ-glutamyl transpeptidase(γ-GT)changed in an opposite direction,the duration was much shorter than that of CES1 and was quickly restored to normal levels.Therefore,among the abovementioned biomarkers,only CES1 made it possible to specifically determine whether the liver cells were destroyed or damaged without interference from inflammation.CES1 also enabled accurate assessment of the anti-cholestasis effects of ursodeoxycholic acid(UDCA;single component)and Qing Fei Pai Du Decoction(QFPDD;multicomponent).We found that both QFPDD and UDCA attenuated ANIT-induced liver damage.UDCA was more potent in promoting bile excretion but showed relatively weaker anti-injury and antiinflammatory effects than QFPDD,whereas QFPDD was more effective in blocking liver inflammation and repairing liver damage.Our data highlights the potential of the combined use of CES1(as an intrahepatic marker of liver damage)and DPP-IV(as an extrahepatic marker of inflammation)for the accurate evaluation and tracking of liver-specific injury—an application that allows for the differentiation of liver damage and inflammatory liver injury.

Dipeptidyl peptidase-4 inhibitor-induced autoimmune diseases:Current evidence

Dipeptidyl peptidase-4 inhibitors(DPP-4i)have an important place in the management of type 2 diabetes.The DPP-4 enzyme is ubiquitously distributed throughout the human body and has multiple substrates through which it regulates several important physiological functions.DPP-4 regulates several immune functions,including T-cell activation,macrophage function,and secretion of cytokines.Studies have reported an increase in autoimmune diseases like bullous pemphigoid,inflammatory bowel disease,and arthritis with DPP-4i use.The relationship of DPP-4i and autoimmune diseases is a complex one and warrants further research into the effect of DPP-4 inhibition on the immune system to understand the pathogenesis more clearly.Whether a particular cluster of autoimmune diseases is associated with DPP-4i use remains an important contentious issue.Nevertheless,a heightened awareness from the clinicians is required to identify and treat any such diseases.Through this review,we explore the clinical and pathophysiological characteristics of this association in light of recent evidence.

Safety, Tolerability, Pharmacokinetics and Pharmacodynamics of E3024, a Novel and Selective Dipeptidyl Peptidase-IV Inhibitor, in Healthy Japanese Male Subjects: Rash Development in Men and Its Possible Mechanism

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 that was expected to be an antidiabetic agent. Its safety, tolerability, pharmacokinetics (PK), and pharmacodynamics (PD) were investigated in a randomized, double-blind, placebo-controlled, ascending single-dose study in 48 healthy Japanese male subjects. Fasted subjects were orally administered E3024 (5, 10, 20, 40, or 80 mg) or placebo. E3024 was rapidly absorbed, with tmax values ranging between 0.33 and 3 h after dosing. The mean t1/2 ranged from 5.34 to 11.68 h. AUC0-inf and Cmax increased dose-proportionately. PK-PD relationship of E3024 was evaluated by using an Imax model, indicating that plasma E3024 concentrations and inhibitory effects of plasma DPP-IV activity were well correlated. The IC50 value was calculated as 33.7 ng/mL, which was consistent with in vitro data. Thus, E3024 showed a good PK profile and inhibited DPP-IV dose-dependently. Of 30 subjects administered E3024, 12 (40%) experienced adverse events (AEs). Dose escalation to 160 mg was abandoned owing to undesired subjective/objective findings in 4 of 6 subjects receiving 40 mg and 5 of 6 subjects receiving 80 mg. The most prominent AE was rash, but there were no serious AEs or deaths. The maximum tolerated dose was considered to be 20 mg. We hypothesized that histamine was a cause of the rash induction, and examined blood histamine levels of normal Fischer rats treated with E3024. Blood histamine levels were increased significantly by E3024 at 500 mg/kg (p < 0.001), but not by vildagliptin or valine-pyrrolidide (DPP-IV inhibitors) at the same dose. No blood histamine increases were observed in genetically mast cell-deficient Ws/Ws rats treated with E3024 at 500 mg/kg. In in vitro assays, E3024 induced histamine release from normal rat peritoneal mast cells in a concentration-dependent manner, but not from basophils. The structure-activity relationship study suggested that a piperazine group N-linked to the 2-position of the 5,6-membered fused heterocyclic rings was a key structural element for triggering histamine release.

Association between plasma dipeptidyl peptidase-4 levels and cognitive function in perinatal pregnant women with gestational diabetes mellitus

BACKGROUND Dipeptidyl peptidase-4(DPP4)is associated with cognitive dysfunction in patients with type 2 diabetes.AIM To assess a possible relationship between serum DPP4 and cognitive function in perinatal pregnant women with gestational diabetes mellitus(GDM).METHODS The study subjects were divided into three groups:GDM group(n=81),healthy pregnant(HP)group(n=85),and control group(n=51).The Montreal Cognitive Assessment(MoCA)was used to assess the cognitive status of each group.Venous blood samples were collected to measure blood lipids,glycated hemoglobin,and glucose levels.For each participant,a 3-mL blood sample was collected and centrifuged,and the serum was collected.Blood samples were stored at-80℃,and DPP4,interleukin-6(IL-6),and 8-iso-prostaglandin F2α(8-iso-PGF2α),and brain-derived neurotrophic factor(BDNF)were detected using ELISA.RESULTS The MoCA scores in the GDM and HP groups were significantly different from those in the control group in terms of visuospatial/executive function and attention(P<0.05);however,the scores were not significantly different between the GDM and HP groups(P>0.05).In terms of language,the GDM group had significantly different scores from those in the other two groups(P<0.05).In terms of memory,a significant difference was found between the HP and control groups(P<0.05),as well as between the GDM and HP groups.The levels of DPP4,IL-6,and 8-iso-PGF2αin the GDM group were significantly higher than those in the HP and control groups(P<0.05);however,the differences between these levels in the HP and control groups were not significant(P>0.05).The level of BDNF in the GDM group was significantly lower than that in the HP and control groups(P<0.05),although the difference in this level between the HP and control groups was not significant(P>0.05).CONCLUSION Cognitive dysfunction in perinatal pregnant women with GDM mainly manifested as memory loss,which might be associated with elevated DPP4 levels.

Efficacy of omarigliptin,once-weekly dipeptidyl peptidase-4 inhibitor,in patients with type 2 diabetes

BACKGROUND Omarigliptin is one of several once-weekly dipeptidyl peptidase-4 inhibitors(DPP-4is).Despite the high frequency of switching from various daily DPP-4is to omarigliptin in actual clinical practice,data regarding its efficacy in patients with type 2 diabetes(T2D)after switching are limited.AIM To analyze the efficacy of omarigliptin in Japanese patients with T2D who had previously received treatment with other glucose-lowering agents.METHODS Forty-nine T2D patients treated for the first time with omarigliptin were recruited retrospectively and divided into four groups defined as either add-on or switched from daily DPP-4is:switched from linagliptin,switched from sitagliptin,and switched from vildagliptin.During a 3-mo follow-up,the clinical parameters among these groups were assessed and compared,with the impact of the switch on glycemic variability as measured by continuous glucose monitoring also being evaluated in the switched groups.RESULTS Hemoglobin A1c levels saw a significant decrease of-0.32%±0.41%in the add-on group(P=0.002).However,the other groups’variables depended on the preswitch daily DPP-4i:switched from linagliptin,-0.05%±0.22%;switched from sitagliptin,-0.17%±0.33%;and switched from vildagliptin,0.45%±0.42%,which saw significant worsening(P=0.0007).Multivariate logistic regression analysis revealed that switching from vildagliptin to omarigliptin was independently associated with worsening glycemic control(P=0.0013).The mean and standard deviation of sensor glucose value,the mean amplitude of glycemic excursions,and the mean of daily difference significantly improved when switching the patient from either linagliptin or sitagliptin to omarigliptin.However,in patients switched from vildagliptin,not only did the glucose variability indices see no improvements,the mean of daily difference even underwent significant worsening.CONCLUSION Administering omarigliptin as add-on therapy or switching to it from sitagliptin and linagliptin,but not vildagliptin,improves glycemic control and thus should help in decision making when selecting DPP-4is for T2D patients.

Dipeptidyl peptidase Ⅳ(DPP Ⅳ):a novel emerging target for thetreatment of type 2 diabetes

The enzyme, dipeptidyl peptidase Ⅳ(DPP Ⅳ), is a novel target for the treatment of type 2 diabetes. Dipeptidyl peptidase Ⅳ inhibition improves the impaired insulin secretion and decrease postprandial concentrations of glucagon by enhancing the incretin hormone levels lucagon-like peptide-1(GLP-1) and glucose-dependent insulinotropic polypeptide/gastric inhibitory polypeptide(GIP). Recently, DPP Ⅳ inhibitors have attracted more and more attention, several of which have entered pre-clinical and clinical trials, and one has received approval for use as an anti-diabetic agent. Among the DPP Ⅳ inhibitors, two leading agents(sitagliptin and vildagliptin) have been shown to be effective in reducing glycosylated hemoglobin(HbA1c) and fasting plasma glucose(FPG) in patients with type 2 diabetes. This review summarizes the evidence supporting DPP IV inhibitors as potential antidiabetic agents.

Review on the Effect of Glucagon-Like Peptide-1 Receptor Agonists and Dipeptidyl Peptidase-4 Inhibitors for the Treatment of Non-Alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease(NAFLD) is a common liver disease and it represents the hepatic manifestation of metabolic syndrome, which includes type 2 diabetes mellitus(T2DM), dyslipidemia, central obesity and hypertension. Glucagon-like peptide-1(GLP-1) analogues and dipeptidyl peptidase-4(DPP-4) inhibitors were widely used to treat T2 DM. These agents improve glycemic control, promote weight loss and improve lipid metabolism. Recent studies have demonstrated that the GLP-1 receptor(GLP-1R) is present and functional in human and rat hepatocytes. In this review, we present data from animal researches and human clinical studies that showed GLP-1 analogues and DPP-4 inhibitors can decrease hepatic triglyceride(TG) content and improve hepatic steatosis, although some effects could be a result of improvements in metabolic parameters. Multiple hepatocyte signal transduction pathways and m RNA from key enzymes in fatty acid metabolism appear to be activated by GLP-1 and its analogues. Thus, the data support the need for more rigorous prospective clinical trials to further investigate the potential of incretin therapies to treat patients with NAFLD.

Expression of a novel dipeptidyl peptidase 8(DPP8)transcript variant,DPP8-v3,in human testis

瞄准：调查新奇 dipeptidyl 肽酶的角色在睾丸开发或精子发生的 8 抄本变体(DPP8-v3 ) 基因。方法：人的睾丸 cDNA 微数组是有人的成年、胎儿的睾丸的 mRNA 的 hybridized。差别表示了克隆被定序并且描绘并且他们的表示被即时反向的抄写聚合酶链反应(RT-PCR ) 和南部污点的分析分析。结果：人的 dipeptidyl 肽酶(DPP8 ) 的新抄本变体，比在胎儿的睾丸，被克隆并且是展出更高的表示在人的成年人铺平的 5 褶层把 DPP8 称为变体 3 (DPP8-v3 ) 。DPP8-v3 的全身的顺序是 3,030 bp，编码 898 氨基酸的蛋白质。结论：DPP8-v3 是高度在成年睾丸表示的新奇人的 DPP8 抄本变体。类似于 DPPIV， DPP8-v3 可以在睾丸的免疫规定起一个关键作用并且可以因此影响精子发生和男富饶。