• BMB Reports
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• 제42권4호
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• pp.212-216
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• 2009

The short in vivo half-life of GLP-1 prevents it from being used clinically. This short half-life occurs because GLP-1 is rapidly degraded by dipeptidyl peptidases such as DPP-IV. To overcome this obstacle, a GLP-1/Fc was constructed and evaluated to determine if it was degraded by DPP-IV and in serum. When the degradation of GLP-1/Fc by human DPP-IV and rabbit serum was compared with that of GLP-1 it was found to be reduced by approximately 5- and 4-fold, respectively. Furthermore, GLP-1/Fc showed a potent activity for human GLP-1 receptor activation ($EC_{50}$ approximately 6 nM). Taken together, these results indicate that GLP-1/Fc may have an extended half-life in vivo that occurs as a result of inhibition of degradation by human DPP-IV. Due to the extended half life, GLP-1/Fc may be useful for clinical treatments.

• 한국산학기술학회논문지
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• 제20권9호
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• pp.306-314
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• 2019

Dipeptidyl peptidase-4 (DPP-4) 저해제는 부작용이 적어 제2형 당뇨병의 2차 용법으로 널리 사용되고 있다. 우리는 human DPP-4 (hDPP-4) 유전자를 돼지 zygote의 전핵에 주입한 후, 1 세포 단계의 수정란을 외과적 방법으로 이식하였고, 마지막으로 꼬리에서 hDPP-4 유전자가 발현되는 형질 전환 돼지를 생산하는데 성공했다. 이식한 3두의 임신돈에서 16두의 자돈이 생산되었고, 이들 가운데 1두의 수컷 자돈에서 형질전환 개체가 확인되었다. Western blot과 RT-PCR 분석을 통해 hDPP-4가 형질 전환 돼지의 막 세포에서 강하게 발현되고, hDPP-4 유전자가 다양한 조직과 꼬리에서 각각 발현되고 있음을 확인하였다. 이것은 발현 벡터가 형질 전환 돼지에서 정상적으로 발현된다는 것을 시사한다. 이번 연구 결과는 인슐린 저항성에 대한 내분비 기능을 확인하는 모델 동물로, hDPP-4 형질 전환 돼지가 인슐린 저항성에 대한 내분비 기능을 확인할 수 있는 새로운 신약에 대한 검증의 소재로서 가치를 높일 것으로 기대된다.

• 한국임상약학회지
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• 제25권2호
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• pp.74-79
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• 2015

Objective: Treatment with sulfonylureas in combination with metformin improves glycemic control in type 2 diabetes mellitus (T2DM), but is associated with hypoglycemia and weight gain. This retrospective study aims to compare the effectiveness of dipeptidylpeptidase-4 (DPP-4) inhibitors and sulfonylureas as an add-on therapy to metformin in patients with T2DM. Methods: Data from medical records of 355 T2DM patients received therapy either DPP-4 inhibitors (DPP-4 inhibitor group) or sulfonylurea (SU group) in combination with metformin from 1 March 2009 to 30 September 2011 were retrospectively reviewed. Of total 355 patients, 231 patients were in DPP-4 inhibitor group and 124 patients were in SU group. Baseline Hemoglobin $A_{1c}$ ($HbA_{1c}$) level in SU group was higher than DPP-4 inhibitor group with a statistically significant difference (8.6% vs. 7.8%). Comparative analysis between DPP-4 inhibitor group and SU group was performed for $HbA_{1c}$ values, amounts of $HbA_{1c}$ changes, and rates of $HbA_{1c}$ changes from baseline at 6-month intervals and incidence rates of major cardiocerebral events. Results: SU group showed larger $HbA_{1c}$ changes in both amounts and rates compared to DPP-4 inhibitor group, although statistical significance was not found in all study periods. Proportions of patients with stable $HbA_{1c}$ <6.5% or 7% were significantly higher in DPP-4 inhibitor group than SU group (<6.5%: 30.4% vs. 13.4%, <7%: 72.3% vs. 41.2%). Time to achieve stable $HbA_{1c}$ <6.5% was not significantly different, but time to achieve stable $HbA_{1c}$ <7% was shorter in DPP4 inhibitor group than SU group with a significant difference. The incidence rate of cardiocerebral events in group of patients with or without previous events was 1.7%, not significantly lower than that in DPP-4 inhibitor group (4.0%). For newly encountered cardiocerebral events during the treatment, incidence rates of two groups did not differ significantly. Conclusion: DPP-4 inhibitors were as effective as sulfonylureas in achieving the $HbA_{1c}$ goal of less than 6.5% or 7% and cardiocerebral event rates did not differ between the two drugs.

• 식품과학과 산업
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• 제51권4호
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• pp.302-312
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• 2018

우유 단백질과 같은 식이 단백질은 분해되기 전에는 대사 조절을 위한 생물학적인 활성을 나타내지 않으나 장에서의 소화과정이나 단백질 분해 효소, 또는 미생물 발효 과정을 통하여 저분자의 펩타이드로 분해되어 수용체 결합을 통하여 생체조절기능을 발휘하거나, 체내 대사의 조절에 관여하는 다양한 효소의 활성을 억제함으로써 기능을 발휘하기도 한다. 우유단백질의 섭취에 의한 혈당 감소 효과는 여러 연구자에 의하여 확인되었으며, 그 작용 기전은 주로 분지사슬 아미노산에 의한 인슐린 분비촉진 기전과 음식물의 소화 과정 중 위장관에서 췌장에서 인슐린 분비 촉진, glucagon의 분비를 감소시켜 혈당을 감소시키는 역할을 담당하는 내분비 호르몬의 일종인 GLP-1의 작용에 영향을 미치는 기전을 생각할 수 있다. 생리적 환경에서 GLP-1은 GLP-1을 가수분해하여 불활성화시키는 DPP-4에 의하여 빠르게 분해되어 생물학적 활성을 소실하기 때문에 DPP-4 억제제는 제 2형 당뇨의 새로운 치료 방법으로써 주목을 받고 있다. DPP-4의 억제 효능을 가진 다수의 기능성 펩타이드가 우유단백질의 분해에 의하여 생성됨이 보고되었으며 그 효능이 in vitro 연구는 물론 동물 모델을 이용한 연구에서도 증명되었다. 이상의 연구 결과를 근거로 할 때 우유 단백질 유래 DPP-4 억제 펩타이드는 인체 적용 연구를 통하여 혈당 조절에 도움을 주는 기능성 소재로 개발될 수 있는 충분한 가능성을 가지고 있다고 판단된다.

• Biomolecules & Therapeutics
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• 제29권2호
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• pp.154-165
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• 2021

This study aimed to investigate whether the antidiabetic drugs dipeptidyl peptidase 4 (DPP4) inhibitors such as evogliptin and sitagliptin affect the membrane DPP4 (mDPP4) enzymatic activity and immune function of T helper1 (Th1) cells in terms of cytokine expression and cell profiles. The mDPP4 enzymatic activity, cytokine expression, and cell profiles, including cell counts, cell viability, DNA synthesis, and apoptosis, were measured in pokeweed mitogen (PWM)-activated CD4+CD26+ H9 Th1 cells with or without the DPP4 inhibitors, evogliptin and sitagliptin. PWM treatment alone strongly stimulated the expression of mDPP4 and cytokines such as interleukin (IL)-2, IL-10, tumor necrosis factor-alpha, interferon-gamma, IL-13, and granulocyte-macrophage colony stimulating factor in the CD4+CD26+ H9 Th1 cells. Evogliptin or sitagliptin treatment potently inhibited mDPP4 activity in a dose-dependent manner but did not affect either the cytokine profile or cell viability in PWM-activated CD4+CD26+ H9 Th1 cells. These results suggest that, following immune stimulation, Th1 cell signaling pathways for cytokine expression function normally after treatment with evogliptin or sitagliptin, which efficiently inhibit mDPP4 enzymatic activity in Th1 cells.

• The Korean Journal of Pain
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• 제37권1호
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• pp.26-33
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• 2024

Background: Sitagliptin is an antidiabetic drug that inhibits dipeptidyl peptidase-4 enzyme. This study aimed to investigate the antinociceptive and anti-inflammatory effects of sitagliptin in formalin and carrageenan tests and determine the possible mechanism(s) of its antinociceptive activity. Methods: Male Swiss mice (25-30 g) and male Wistar rats (180-220 g) were used for formalin and carrageenan tests, respectively. In the formalin test, paw licking time and in the carrageenan test, paw thickness were considered as indexes of pain behavior and inflammation respectively. Three doses of sitagliptin (2.5, 5, and 10 mg/kg) were used in these tests. Also, several antagonists and enzyme inhibitors were used to evaluate the role of adrenergic, serotonergic, dopaminergic, and opioid receptors as well as the NO/cGMP/K_ATP pathway in the antinociceptive effect of sitagliptin (5 mg/kg). Results: Sitagliptin showed significant antinociceptive and anti-inflammatory effects in the formalin and carrageenan tests respectively. In the carrageenan test, all three doses of sitagliptin significantly (P < 0.001) reduced paw thickness. Pretreatment with yohimbine, prazosin, propranolol, naloxone, and cyproheptadine could not reverse the antinociceptive effect of sitagliptin (5 mg/Kg), which indicates that adrenergic, opioid, and serotonin receptors (5HT₂) are not involved in the antinociceptive effects. L-NAME, methylene blue, glibenclamide, ondansetron, and sulpiride were able to reverse this effect. Conclusions: NO/cGMP/K_ATP, 5HT₃ and D₂ pathways play an important role in the antinociceptive effect of sitagliptin. Additionally significant anti-inflammatory effects observed in the carrageenan test might contribute in reduction of pain response in the second phase of the formalin test.

• 한국수정란이식학회지
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• 제31권4호
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• pp.319-322
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• 2016

CD26, also known as Dipeptidyl peptidase IV (DPP-4), is a cell surface glycoprotein that belongs to the serine protease family and has wide spread organ distribution throughout the body. CD26 was previously characterized in immune cells but also has important metabolic functions which are not yet fully understood. Thus, we investigated the effect of CD26 in porcine parthenogenetic embryos. We attempted CD26 downregulation of porcine embryos by siRNA, and evaluated CD26 suppression of developmental competencies. Although the porcine embryos injected with CD26 siRNA were able to develop to the early stage, these embryos were decreased to form blastocysts. Our results indicated that CD26 is one of factors for the regulation of development of porcine embryos.

• 생약학회지
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• 제52권2호
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• pp.77-83
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• 2021

The number of people suffering from diabetes have been increased around the world. In this study, we investigated the antidiabetic and antioxidant effects of Anthriscus sylvestris(L.) Hoffm and its main compounds. It was divided into root(R) and aerial part(AP) for comparative analysis. Total polyphenol, total flavonoid content was higher in AP extract, but nodakenin content was higher in R(1169.13 ± 6.00 mg/g) extract. Antioxidant activity was also higher in AP extract. To compare antidiabetic efficacy, we analyzed the effects of R and AP extracts on ɑ-glucosidase inhibition(AGI), dipeptidyl peptidase-4(DPP-4) and protein tyrosine phosphatase(PTP)1B activity. R and AP extracts showed similar effects on AGI and DPP-4 activity in a concentration dependent manner, and there was no effect on PTP1B activation. Glucose uptake(139.51 ± 3.19%) in 3T3-L1 cells was more effective in the AP extract-treated group than the positive control, rosiglitazone, group. Both R and AP extracts were effective in protecting against pancreatic beta cell damage caused by hyperglycemia. These results suggest that Anthriscus sylvestris(L.) Hoffm. could be used as a candidate for diabetes treatment.

• 한국미생물·생명공학회지
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• 제40권3호
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• pp.180-185
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• 2012

Type 2 Diabetes Mellitus, a chronic metabolic disorder which results from a high blood glucose level, is one of the most prevalent and costly diseases of our time. Considering increasing rates of obesity and the aging population in Korea, the number of diabetic patients is likely to rise rapidly in the future. There are five conventional diabetic drugs which work through different mechanisms; sulfonylureas, biguanide, meglitinide, alpha-glucosidase inhibitors, and thiazolidinedione. Although they all have antidiabetic effects, some side effects such as hypoglycemia, weight gain and gastrointestinal intolerance are associated with them. Incretin based therapies, utilizing glucagon-like peptide-1 (GLP-1) and dipeptidyl peptidase-4 (DPP-4) inhibitors, which have a lower risk of adverse side effects, have recently been introduced. At present PPAR-targeting drugs are being actively developed. In this research review, particular emphasis has been placed on the current trends and possible biological targets for the new generation of antidiabetic drugs.

• Journal of Microbiology and Biotechnology
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• 제30권3호
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• pp.427-438
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• 2020

Middle East respiratory syndrome coronavirus (MERS-CoV) infects the lower respiratory airway of humans, leading to severe acute respiratory failure. Unlike human dipeptidyl peptidase 4 (hDPP4), a receptor for MERS-CoV, mouse DPP4 (mDPP4) failed to support MERS-CoV infection. Consequently, diverse transgenic mouse models expressing hDPP4 have been developed using diverse methods, although some models show no mortality and/or only transient and mild-to-moderate clinical signs following MERS-CoV infection. Additionally, overexpressed hDPP4 is associated with neurological complications and breeding difficulties in some transgenic mice, resulting in impeding further studies. Here, we generated stable hDPP4-transgenic mice that were sufficiently susceptible to MERS-CoV infection. The transgenic mice showed weight loss, decreased pulmonary function, and increased mortality with minimal perturbation of overexpressed hDPP4 after MERS-CoV infection. In addition, we observed histopathological signs indicative of progressive pulmonary fibrosis, including thickened alveolar septa, infiltration of inflammatory monocytes, and macrophage polarization as well as elevated expression of profibrotic molecules and acute inflammatory response in the lung of MERS-CoV-infected hDPP4-transgenic mice. Collectively, we suggest that this hDPP4-transgenic mouse is useful in understanding the pathogenesis of MERS-CoV infection and for antiviral research and vaccine development against the virus.