二肽基肽酶-4抑制药研究进展

二肽基肽酶-4（DPP-4）抑制药是一类新型口服降糖药,可改善血糖控制,并且不会增加体质量和诱发低血糖,在2型糖尿病的治疗中发挥着越来越重要的作用。本文对DPP-4抑制药作用机制、药动学及临床应用等方面的研究进展进行综述,以期为临床应用提供一定参考。     

二肽基肽酶-4抑制剂研究进展

二肽基肽酶-4抑制剂为一类常用的2型糖尿病治疗药物,可通过抑制二肽基肽酶-4活性延长胰高血糖素样肽-1的作用时间和促进胰岛素分泌,从而降低血糖水平。根据化学结构类型的不同,将二肽基肽酶-4抑制剂分为拟肽类和非拟肽类抑制剂,并分别介绍其药理活性、构效关系及药动学特性等方面的研究进展。     

Dipeptidyl Peptidase-4 Inhibitor (Vildagliptin) Improves Glycemic Control After Meal Tolerance Test by Suppressing Glucagon Release

Aim

We aimed to evaluate changes in insulin and glucagon secretion, as well as glucose levels, with a meal tolerance test (MTT) before and after 6 months of treatment with vildagliptin in a clinical setting.

Materials and Methods

Participants were 15 patients with uncontrolled type 2 diabetes mellitus (glycated hemoglobin [HbA_1c] over 6.9 % for more than 3 months). MTTs were conducted before and 6 months after addition of vildagliptin (50 mg twice daily [bid]). Blood samples were collected immediately before, and 1 and 2 h after the test meal for measurement of blood glucose concentration, immune-reactive insulin (IRI), and glucagon. HbA_1c was measured at 6 months.

Results

Mean age of participants was 55.5 ± 2.8 years, and ten (66.7 %) were male. Mean HbA_1c significantly improved from 7.6 to 6.8 % at 6 months after addition of vildagliptin. Blood glucose at 1 and 2 h after the test meal was significantly reduced after addition of vildagliptin, while the reduction in glucagon showed borderline significance and IRI showed no difference. In a comparison of blood glucose-related parameters between subgroups based on median glucose change in area under the curve during MTT (ΔAUC_0–2h), glucagon ΔAUC_0–2h was significantly lower in the group with more improved glucose levels (ΔAUC_0–2h ≥65 mg/dL), but that of IRI did not differ.

Conclusion

Suppression of glucagon release by vildagliptin may improve glycemic control without increasing insulin levels in patients with type 2 diabetes.     

Combination of Mangiferin and Dipeptidyl Peptidase-4 Inhibitor Sitagliptin Improves Impaired Glucose Tolerance in Streptozotocin-Diabetic Rats

In this study, we combined the dipeptidyl peptidase-4 inhibitor sitagliptin with the antidiabetic drug mangiferin to examine the effects on active glucagon-like peptide-1 (GLP-1) and glucose tolerance in streptozotocin-diabetic rats. Active GLP-1 levels were measured by an ELISA kit. Insulin levels were measured by an RIA kit. Islet morphology was determined by double immunolabeling. Sitagliptin (1 mg/kg) or mangiferin (20 mg/kg) single treatment improved glucose tolerance during an oral glucose tolerance test. In addition, the combination therapy improved glucose tolerance with an increase in plasma insulin level and active GLP-1 levels. Islets from combination-treated diabetic rats had markedly increased β-cell/islet area ratio compared with islets from the diabetic or single-treatment rats. In conclusion, these results indicate that the combination therapy is useful as a therapeutic agent for impaired glucose tolerance and type 2 diabetes.     

二肽基肽酶抑制剂联合参芪降糖颗粒治疗2型糖尿病患者临床效果观察

目的:观察并初步研究二肽基肽酶抑制剂联合参芪降糖颗粒治疗2型糖尿病的临床效果。方法:将106例入院的2型糖尿病患者随机分为两组,各53例。对照组采用参芪降糖颗粒治疗,治疗组采用西格列汀和参芪降糖颗粒治疗,对比分析两组患者的临床疗效。结果:术后治疗组总有效率为92.45%,显著高于对照组75.47%(P<0.05);与治疗前相比,治疗后两组患者的空腹血糖、餐后2 h血糖和糖化血红蛋白均有所改善,差异显著(P<0.05);治疗组各指标改善程度均优于对照组,差异有统计学意义(P<0.05);治疗期间,治疗组低血糖发生率(1.9%)低于对照组(9.4%),差异有统计学意义(P<0.05)。结论:二肽基肽酶抑制剂联合参芪降糖颗粒治疗2型糖尿病可明显改善患者的治疗效果,减少患者并发症的发生,在临床实践中值得广泛参考。     

Quantitative Model of the Relationship Between Dipeptidyl Peptidase-4 (DPP-4) Inhibition and Response: Meta-Analysis of Alogliptin, Saxagliptin, Sitagliptin, and Vildagliptin Efficacy Results

Dipeptidyl peptidase-4 (DPP-4) inhibition is a well- characterized treatment for type 2 diabetes mellitus (T2DM). The objective of this model-based meta-analysis was to describe the time course of HbA1c response after dosing with alogliptin (ALOG), saxagliptin (SAXA), sitagliptin (SITA), or vildagliptin (VILD). Publicly available data involving late-stage or marketed DPP-4 inhibitors were leveraged for the analysis. Nonlinear mixed-effects modeling was performed to describe the relationship between DPP-4 inhibition and mean response over time. Plots of the relationship between metrics of DPP-4 inhibition (ie, weighted average inhibition [WAI], time above 80% inhibition, and trough inhibition) and response after 12 weeks of daily dosing were evaluated. The WAI was most closely related to outcome, although other metrics performed well. A model was constructed that included fixed effects for placebo and drug and random effects for intertrial variability and residual error. The relationship between WAI and outcome was nonlinear, with an increasing response up to 98% WAI. Response to DPP-4 inhibitors could be described with a single drug effect. The WAI appears to be a useful index of DPP-4 inhibition related to HbA1c. Biomarker to response relationships informed by model-based meta-analysis can be leveraged to support study designs including optimization of dose, duration of therapy, and patient population.     

Association Between Urinary Albumin Excretion and Low-density Lipoprotein Heterogeneity Following Treatment of Type 2 Diabetes Patients with the Dipeptidyl Peptidase-4 Inhibitor, Vildagliptin: A Pilot Study

Background

Few data exist as to whether dipeptidyl peptidase (DPP)-4 inhibitors affect cardio-renal interaction, which is a strong independent prognostic factor for cardiovascular disease (CVD), in diabetic patients. We evaluated the effects of a DPP-4 inhibitor on atherogenic low-density lipoprotein (LDL) heterogeneity and albuminuria in diabetics as an indicator of the severity of diabetic nephropathy.

Methods

Type 2 diabetes patients (n = 47) inadequately controlled with diabetes therapy were treated with vildagliptin 50 mg bid for 8 weeks. LDL heterogeneity was evaluated on the basis of the patients’ small dense (sd) LDL levels and sd-LDL proportion (sd-LDL/LDL cholesterol [LDL-C]). The level of albuminuria was evaluated on the basis of the urinary albumin-to-creatinine ratio (UACR).

Results

After 8 weeks of treatment, there was no significant change in serum LDL-C level, but the serum sd-LDL level had decreased significantly by 8.8 %, and the UACR had also decreased significantly by 44.6 %. Triglyceride (TG)-metabolism-related markers (TG, remnant-like particle cholesterol, apolipoprotein [apo] B, apoC-2, and apoC-3) had decreased significantly. The Δ (absolute change from baseline) sd-LDL values correlated positively with ΔTG-metabolism-related markers, but not with the Δ hemoglobin (Hb) A_1c or Δ fasting blood sugar (ΔFBS). Furthermore, multivariate regression analysis revealed that Δsd-LDL proportion, but not ΔHbA_1c or ΔFBS, was an independent predictor of ΔUACR (β = 0.292, p = 0.0016).

Conclusions

Although this was a single-arm study, treatment of type 2 diabetes with vildagliptin might prevent the progression of CVD complicating diabetes by improving LDL heterogeneity, and it might improve renal function by decreasing albuminuria. A randomized controlled trial is warranted.     

Dipeptidyl peptidase-4 inhibitor improves neovascularization by increasing circulating endothelial progenitor cells

BACKGROUND AND PURPOSE

Current methods used to treat critical limb ischaemia (CLI) are hampered by a lack of effective strategies, therefore, therapeutic vasculogenesis may open up a new field for the treatment of CLI. In this study we investigated the ability of the DPP-4 inhibitor, sitagliptin, originally used as a hypoglycaemic agent, to induce vasculogenesis in vivo.

EXPERIMENTAL APPROACH

Sitagliptin were administered daily to C57CL/B6 mice and eGFP transgenic mouse bone marrow-transplanted ICR mice that had undergone hindlimb ischaemic surgery. Laser Doppler imaging and flow cytometry were used to evaluate the degree of neovasculogenesis and circulating levels of endothelial progenitor cells (EPCs) respectively. Cell surface markers of EPCs and endothelial NOS (eNOS) in vessels were studied.

KEY RESULTS

Sitagliptin elevated plasma glucagon-like peptide-1 (GLP-1) levels in mice subjected to ischaemia, decreased plasma dipeptidyl peptidase-4 (DPP-4) concentration, and augmented ischaemia-induced increases in stromal cell-derived factor-1 (SDF-1) in a dose-dependent manner. Blood flow in the ischaemic limb was significantly improved in mice treated with sitagliptin. Circulating levels of EPCs were also increased after sitagliptin treatment. Sitagliptin also enhanced the expression of CD 34 and eNOS in ischaemic muscle. In addition, sitagliptin promoted EPC mobilization and homing to ischaemic tissue in eGFP transgenic mouse bone marrow-transplanted ICR mice.

CONCLUSION AND IMPLICATIONS

Circulating EPC levels and neovasculogenesis were augmented by the DPP-4 inhibitor, sitagliptin and this effect was dependent on an eNOS-related pathway in a mouse model of hindlimb ischaemia. The results indicate that oral administration of sitagliptin has therapeutic potential as an inducer of vasculogenesis.     

Dipeptidyl peptidase-4 inhibition by gemigliptin prevents abnormal vascular remodeling via NF-E2-related factor 2 activation

Dipeptidyl peptidase-4 (DPP-4) inhibitors exert a potent anti-hyperglycemic effect and reduce cardiovascular risk in type 2 diabetic patients. Several studies have shown that DPP-4 inhibitors including sitagliptin have beneficial effects in atherosclerosis and cardiac infarction involving reactive oxygen species. Here, we show that gemigliptin can directly attenuate the abnormal proliferation and migration of vascular smooth muscle cells (VSMCs) via enhanced NF-E2-related factor 2 (Nrf2) activity. Gemigliptin dramatically prevented ligation injury-induced neointimal hyperplasia in mouse carotid arteries. Likewise, the proliferation of primary VSMCs was significantly attenuated by gemigliptin in a dose-dependent manner consistent with a decrease in phospho-Rb, resulting in G1 cell cycle arrest. We found that gemigliptin enhanced Nrf2 activity not only by mRNA expression, but also by increasing Keap1 proteosomal degradation by p62, leading to the induction of Nrf2 target genes such as HO-1 and NQO1. The anti-proliferative role of gemigliptin disappeared with DPP-4 siRNA knockdown, indicating that the endogenous DPP-4 in VSMCs contributed to the effect of gemigliptin. In addition, gemigliptin diminished TNF-α-mediated cell adhesion molecules such as MCP-1 and VCAM-1 and reduced MMP2 activity in VSMCs. Taken together, our data indicate that gemigliptin exerts a preventative effect on the proliferation and migration of VSMCs via Nrf2.     

Attenuation of trace element-mediated injury during ischemia and reperfusion by an N-terminus analogue of human albumin (H4DUS60131)

The N-terminus region of human albumin binds strongly to trace metals (Co, Cu, Ni). Ischemia, acidosis and reperfusion can cause a marked increase in plasma free Cu and its normal regulation by plasma proteins may be overwhelmed and predispose to oxidative injury by Cu-catalyzed oxyradical production. H4DUS60131 is an analogue of the N-terminus of human albumin, it binds copper tightly and in vitro, is a potent inhibitor of Cu-catalyzed radical formation. We have tested the ability of H4DUS60131 to reduce injury during ischemia and reperfusion in isolated blood-perfused rat hearts (n = 6/group) subjected to 20-min aerobic perfusion, followed by a 2-min infusion of saline or saline plus H4DUS60131. Following infusion, hearts were subjected to 30-min global ischemia plus 40-min reperfusion. The 2-min infusion was repeated in both groups at the start of reperfusion. In the vehicle controls, left ventricular developed pressure recovered to only 15.3 +/- 3.2%, whereas the H4DUS60131 group recovered to 50.5 +/- 9.3% (p < 0.005). The H4DUS60131 group normalised their left ventricular end diastolic pressure more quickly and completely than the controls (44.1 +/- 11.5 vs. 91.5 +/- 5.5 mm Hg). In conclusion, H4DUS60131 greatly improves the recovery of the rat heart from ischemia and reperfusion and may represent a novel approach to the limitation of myocardial injury.     

Meta-Analysis of the Cardiovascular Outcomes with Dipeptidyl Peptidase 4 Inhibitors: Validation of the Current FDA Mandate

Background

Earlier meta-analyses have demonstrated a significant reduction in major adverse cardiovascular events (MACE) with dipeptidyl peptidase 4-inhibitor (DPPI) use, as compared with placebo or alternative anti-diabetic therapies. However, the large phase III/IV trials, namely SAVOR-TIMI 53 and the EXAMINE trials, failed to demonstrate any significant differences in MACE between DPPI and placebo. We aimed to perform an updated meta-analysis of randomized controlled trials (RCTs) to investigate the differences in cardiovascular death, myocardial infarction (MI), and stroke between DPPI and placebo/alternative agents.

Methods

We searched the MEDLINE, EMBASE, and Cochrane databases for relevant phase III/IV RCTs. Unpublished trials with results available on national clinical trials registers were also included. RCTs with follow-up duration ≥24 weeks were included if they compared DPPI with placebo or an alternative anti-diabetic agent.

Results

A total of 82 RCTs including 73,678 patients were included. We did not observe any significant difference in the pooled odds of cardiovascular death, MI, or stroke in the composite DPPI arm as compared with the control arm. Similarly, the pooled odds of all-cause death and MACE were statistically similar between the two groups. None of the clinical outcomes studied demonstrated evidence of statistical heterogeneity or publication bias. Due to a larger sample size and a longer duration of follow-up, both SAVOR-TIMI 53 and EXAMINE trials had a considerably larger contribution to the pooled estimates in our meta-analysis, driving the updated pooled estimates towards null for all clinical outcomes assessed.

Conclusions

DPPI use was not associated with increased incidence of cardiovascular mortality, MI, stroke, or MACE compared with placebo or alternative anti-diabetic agents.     

Dipeptidyl peptidase-4 inhibitors for the treatment of type 2 diabetes: comparison,efficacy and safety

Introduction: Dipeptidyl peptidase (DPP)-4 inhibitors belong to one class of drugs that have been approved for treatment of type 2 diabetes (T2D) based on the glucose-lowering actions of the gastrointestinal hormone glucagon-like peptide (GLP)-1. Several different compounds are now available, and although their mechanism of action (inhibition of the catalytic activity of DPP-4) is the same, there are fundamental differences between them.

Areas covered: The authors discuss the differences between different DPP-4 inhibitors and review their therapeutic efficacy and key safety data. The literature covered includes original studies and meta-analyses identified in PubMed, recent abstracts presented at major diabetes scientific conferences, and clinical trials registered at ClinicalTrials.gov.

Expert opinion: Although there are some differences in the pharmacokinetic and pharmacodynamic profiles of the different DPP-4 inhibitors, all are small orally active compounds with broadly similar HbA1c-lowering efficacy. They improve glycaemic control in T2D, without increasing the risk of hypoglycaemia or causing weight gain. They can be used as monotherapy or in combination with other anti-diabetic therapies, including insulin, regardless of renal or hepatic function, and are efficacious across the spectrum of patients with T2D, including those with long-standing disease duration. DPP-4 inhibitors may also have beneficial effects beyond glycaemic control, although this remains to be demonstrated in purpose-designed clinical trials.     

UPLC-MS/MS法测定不同温度定向炮制黄芪中8种苷类和4种苷元成分的含量

目的:建立测定黄芪中8种苷类(黄芪皂苷Ⅰ、Ⅱ、Ⅲ、Ⅳ和毛蕊异黄酮苷、芒柄花苷、黄芪异黄烷苷、黄芪紫檀烷苷)及4种苷元(毛蕊异黄酮、芒柄花素、黄芪异黄烷、黄芪紫檀素)成分含量的方法,并考察不同炮制温度对上述12种成分含量的影响。方法:分别以生黄芪和不同温度(120、140、160、180、200℃)烘制后的黄芪为样品,采用超高效液相色谱-串联质谱(UPLC-MS/MS)法测定其中12种成分的含量。色谱柱为ACQUITY UPLC HSS T3,流动相为0.1%甲酸水溶液-0.1%甲酸乙腈溶液(梯度洗脱),流速为0.5 mL/min,柱温为30℃,检测波长为260 nm,进样量为2μL。采用电喷雾离子源,在正离子模式下进行监测扫描,扫描范围为质菏比50～1 500,毛细管电压为2 000 V,离子源温度为100℃,脱溶剂温度为400 v,雾化气(N2)流速为40 L/h,脱溶剂气(N2)流速为800 L/h,碰撞能量为20～30 V,数据采集速率为0.5 s/scan。结果:黄芪皂苷Ⅰ、黄芪皂苷Ⅱ、黄芪皂苷Ⅲ、黄芪皂苷Ⅳ、毛蕊异黄酮苷、毛蕊异黄酮、芒柄花苷、芒柄花素、黄芪异黄烷苷、黄芪异黄...     

二肽基肽酶4及其抑制剂在新型冠状病毒肺炎防治中的研究进展

新型冠状病毒肺炎(COVID-19)全球大流行给世界健康造成巨大威胁,然而到目前为止尚没有临床证实有效的治疗方法。最近研究显示二肽基肽酶4(DPP4)可能是新型冠状病毒的功能受体,然而DPP4是否直接参与新型冠状病毒与靶细胞的黏附与感染,抑制或者调节DPP4的表达与活性能否阻止COVID-19的发生发展尚需要进一步研究。以往研究显示DPP4抑制剂具有抗炎和抗纤维化作用,因此推测DPP4抑制剂可能具有抑制COVID-19患者高炎症反应状态、改善患者肺纤维化的作用,尚需临床试验加以证实。     

HPLC法测定秦艽炮制品中龙胆苦苷的含量

通过测定秦艽及秦艽炮制品中龙胆苦苷的含量,以探讨炮制方法对秦艽中龙胆苦苷的含量影响.采用高效液相色谱法,Waters C18色谱柱;流动相:甲醇水(3∶7);流速:1.0mL·min-1;检测波长:272nm.龙胆苦苷在1.104～8.280μg范围内具有良好线性关系,平均回收率为102.23%(RSD=2.9%).不同的炮制方法对秦艽中龙胆苦苷含量有一定影响.     

Dipeptidyl peptidase IV inhibition upregulates GLUT4 translocation and expression in heart and skeletal muscle of spontaneously hypertensive rats

The purpose of the current study was to test the hypothesis that the dipeptidyl peptidase IV (DPPIV) inhibitor sitagliptin, which exerts anti-hyperglycemic and anti-hypertensive effects, upregulates GLUT4 translocation, protein levels, and/or mRNA expression in heart and skeletal muscle of spontaneously hypertensive rats (SHRs). Ten days of treatment with sitagliptin (40 mg/kg twice daily) decreased plasma DPPIV activity in both young (Y, 5-week-old) and adult (A, 20-week-old) SHRs to similar extents (～85%). However, DPPIV inhibition only lowered blood pressure in Y-SHRs (119±3 vs. 136±4 mmHg). GLUT4 translocation, total protein levels and mRNA expression were decreased in the heart, soleus and gastrocnemius muscle of SHRs compared to age-matched Wistar Kyoto (WKY) normotensive rats. These differences were much more pronounced between A-SHRs and A-WKY rats than between Y-SHRs and Y-WKY rats. In Y-SHRs, sitagliptin normalized GLUT4 expression in the heart, soleus and gastrocnemius. In A-SHRs, sitagliptin increased GLUT4 expression to levels that were even higher than those of A-WKY rats. Sitagliptin enhanced the circulating levels of the DPPIV substrate glucagon-like peptide-1 (GLP-1) in SHRs. In addition, stimulation of the GLP-1 receptor in cardiomyocytes isolated from SHRs increased the protein level of GLUT4 by 154±13%. Collectively, these results indicate that DPPIV inhibition upregulates GLUT4 in heart and skeletal muscle of SHRs. The underlying mechanism of sitagliptin-induced upregulation of GLUT4 in SHRs may be, at least partially, attributed to GLP-1.     

不同微波烘烤程度的山绿茶炮制品降血压作用比较研究

摘要：目的：对广西特产药材山绿茶Ilex hainanensis Merr.进行中药炮制实验研究,并对其进行降血压实验研究。方法：使用不同炮制方法对山绿茶进行炮制;采用尾动脉法测原发性高血压大鼠（SHR）血压,对不同炮制品山绿茶进行降血压实验研究。结果：通过不同微波程度药材炮制,共得到6种山绿茶炮制药材;与模型组比较,不同炮制工艺山绿茶均有明显的降血压效果。不同微波炮制品种,以60g药材微波11min组降压作用最佳。结论：初步确定山绿茶最佳微波炮制程度以60g药材微波11min组降压作用最佳,此方法炮制出的山绿茶药材对SHR血压的作用效果最好。     

山萸肉炮制前后4种环烯醚萜苷类成分的含量变化研究

目的:研究山萸肉炮制前后4种环烯醚萜苷类成分的含量变化情况。方法:以同一种山萸肉为原料,分别依法炮制,制成酒蒸、酒炖、加压酒蒸萸肉,再采用高效液相色谱法测定各样品中4种环烯醚萜苷类成分的含量。色谱柱为Waters sunfire C18(250mm×4.6 mm,5μm),流动相为甲醇-水(梯度洗脱),柱温为(30±1)℃,流速为0.8 ml/min,进样量为10μl,莫诺苷、獐牙菜苷、马钱苷和山茱萸新苷的检测波长分别为240、246、237、219 nm。结果:炮制前,莫诺苷、獐牙菜苷、马钱苷和山茱萸新苷在山萸肉中的含量分别为10.66、0.56、4.90、1.48 mg/g,但炮制后4种成分均有不同程度的下降,其中酒炖萸肉中莫诺苷、獐牙菜苷和马钱苷的含量最低,加压酒蒸萸肉中山茱萸新苷的含量最低。结论:山萸肉炮制后4种环烯醚萜苷类成分的含量均有下降。