linagliptin and Disease-Models--Animal

Boehringer Ingelheim Corp is developing the novel, xanthine-based dipeptidyl peptidase (DPP)-4 inhibitor linagliptin for the potential treatment of type 2 diabetes mellitus. In vitro assays suggested that linagliptin was a potent DPP-4 inhibitor, with good selectivity for DPP-4 compared with other DPPs and proteases. The inhibition of DPP-4 by linagliptin was also demonstrated in vivo, resulting in increased glucagon-like peptide 1 levels and improved glucose tolerance in both healthy animals and models of disease. Furthermore, linagliptin exhibited prolonged pharmacodynamic activity, with long-lasting DPP-4 inhibition across different species. The prolonged DPP-4 inhibition observed in preclinical models has translated to humans; linagliptin demonstrated approximately 80% inhibition of DPP-4 activity at daily doses as low as 5 mg in phase II clinical trials. The effects were sustained, and no signs or symptoms of hypoglycemia were observed, even at high doses of up to 600 mg. The low therapeutic dose of linagliptin, the long-lasting inhibition of DPP-4 activity and the good safety/tolerability profile exhibited thus far suggest that linagliptin may be superior to competitors. The results from ongoing phase III clinical trials will provide further information on such aspects; however, from the available data, linagliptin appears to have promise for market success.

Topics: Animals; Controlled Clinical Trials as Topic; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Disease Models, Animal; Drug Evaluation, Preclinical; Humans; Hypoglycemic Agents; Linagliptin; Purines; Quinazolines; Species Specificity

Use of dipeptidyl peptidase-4 (DPP4) inhibitor in some clinical trials might have caused heart failure (HF), leading to increased hospitalizations. The aim of the present study was to determine whether linagliptin has any effect on chronic dilated HF, and its underlying mechanisms. Physiologic and pathologic studies were conducted on heart/muscle-specific manganese superoxide dismutase-deficient mice, which exhibited dilated cardiomyopathy, and were randomized to receive a low dose (1 mg/kg, HF-L group) or high dose (10 mg/kg, HF-H group) mixed with food, or normal food (HF group), for 8 weeks. Linagliptin increased mortality and heart/body weight ratio in mice with HF. Cardiac contractility and fibrosis worsened, whereas hepatic glycogen content and individual carbohydrate consumption decreased significantly in the HF-H group, when compared with the HF control group. Therefore, we performed a complementary experiment by supplementing glucose to the mice treated with high-dose linagliptin (HF-HG group). Adequate glucose supplementation reduced heart/body weight ratio and cardiac fibrosis, and improved cardiac contractility, without changing mortality. Following oral administration of

Topics: Animals; Body Weight; Dipeptidyl-Peptidase IV Inhibitors; Disease Models, Animal; Down-Regulation; Fibrosis; Glucose; Heart Failure; Hypoglycemic Agents; Linagliptin; Mice

Alzheimer's disease (AD) is an age-related, multifactorial progressive neurodegenerative disorder manifested by cognitive impairment and neuronal death in the brain areas like hippocampus, yet the precise neuropathology of AD is still unclear. Continuous failure of various clinical trial studies demands the utmost need to explore more therapeutic targets against AD. Type 2 Diabetes Mellitus and neuronal insulin resistance due to serine phosphorylation of Insulin Receptor Substrate-1 at 307 exhibits correlation with AD. Dipeptidyl Peptidase-4 inhibitors (DPP-4i) have also indicated therapeutic effects in AD by increasing the level of Glucagon-like peptide-1 in the brain after crossing Blood Brain Barrier. The present study is hypothesized to examine Linagliptin, a DPP-4i in intracerebroventricular streptozotocin induced neurodegeneration, and neuroinflammation and hippocampal insulin resistance in rat model of AD. Following infusion on 1st and 3rd day, animals were treated orally with Linagliptin (0.513 mg/kg, 3 mg/kg, and 5 mg/kg) and donepezil (5 mg/kg) as a standard for 8 weeks. Neurobehavioral, biochemical and histopathological analysis was done at the end of treatment. Dose-dependently Linagliptin significantly reversed behavioral alterations done through locomotor activity (LA) and morris water maze (MWM) test. Moreover, Linagliptin augmented hippocampal GLP-1 and Akt-ser473 level and mitigated soluble Aβ (1-42), IRS-1 (s307), GSK-3β, TNF-α, IL-1β, IL-6, AchE and oxidative/nitrosative stress level. Histopathological analysis also exhibited neuroprotective and anti-amylodogenic effect in Hematoxylin and eosin and Congo red staining respectively. The findings of our study concludes remarkable dose-dependent therapeutic potential of Linagliptin against neuronal insulin resistance via IRS-1 and AD-related complication. Thus, demonstrates unique molecular mechanism that underlie AD.

Topics: Alzheimer Disease; Animals; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Disease Models, Animal; Glycogen Synthase Kinase 3 beta; Insulin Resistance; Linagliptin; Neuroinflammatory Diseases; Rats; Streptozocin

Systemic sclerosis (SSc) is a connective tissue disease that often causes pulmonary fibrosis. Dipeptidyl peptidase 4 (DPP4) inhibitor has shown anti-fibrotic properties in various fibrotic diseases. However, only two studies have reported its anti-fibrosis effects in pulmonary fibrosis, and the mechanism is not completely clear. In the present study, we further investigated the protective effects of linagliptin, a highly specific DPP4 inhibitor, on pulmonary fibrosis in SSc mouse model and the potential mechanisms. The results showed that linagliptin ameliorated pulmonary fibrosis in SSc mouse model, as evidenced by improved pathological changes of lung and body weight loss induced by BLM. Linagliptin also reduced BLM-induced oxidative stress, inflammation in lung in vivo. We revealed that linagliptin attenuated BLM-induced endothelial-to-mesenchymal transition (EndMT) in vitro and in vivo. BLM-induced enhanced migration ability of endothelial cells was also alleviated by linagliptin. Moreover, we confirmed that the Akt/mammalian target of rapamycin pathway was involved in BLM-induced EndMT in vivo, which was suppressed by linagliptin. In summary, we further confirmed the therapeutic effects of linagliptin on pulmonary fibrosis in SSc mouse model, which is based on its inhibitory effects on EndMT, oxidative stress, and inflammation.

Topics: Animals; Bleomycin; Dipeptidyl-Peptidase IV Inhibitors; Disease Models, Animal; Endothelial Cells; Female; Linagliptin; Mice; Pulmonary Fibrosis; Scleroderma, Systemic

Ulcerative colitis is a chronic inflammatory disease, profoundly affecting the patient's quality of life and is associated with various complications. Linagliptin, a potent DPP- IV inhibitor, shows favorable anti-inflammatory effects in several animal model pathologies. To this end, the present study aimed to investigate the anti-inflammatory effect of linagliptin in a rat model of acetic acid-induced colitis. Moreover, the molecular mechanisms behind this effect were addressed. Accordingly, colitis was established by the administration of a 2 ml 6% acetic acid intrarectally and treatment with linagliptin (5 mg/kg) started 24 h after colitis induction and continued for 7 days. On one hand, the DPP-IV inhibitor alleviated the severity of colitis as evidenced by a decrease of disease activity index (DAI) scores, colon weight/length ratio, macroscopic damage, and histopathological deteriorations. Additionally, linagliptin diminished colon inflammation via attenuation of TNF-α, IL-6, and NF-κB p65 besides restoration of anti-inflammatory cytokine IL-10. On the other hand, linagliptin increased levels of p-AMPK, SIRT1, and PGC-1α while abolishing the increment in p-JAK2 and p-STAT3. In parallel linagliptin reduced mTOR levels and upregulated expression levels of SHP and MKP-1 which is postulated to mediate AMPK-driven JAK2/STAT3 inhibition. Based on these findings, linagliptin showed promising anti-inflammatory activity against acetic acid-induced colitis that is mainly attributed to the activation of the AMPK-SIRT1-PGC-1α pathway as well as suppression of the JAK2/STAT3 signaling pathway that might be partly mediated through AMPK activation.

Topics: Acetic Acid; AMP-Activated Protein Kinases; Animals; Anti-Inflammatory Agents; Colitis; Cytokines; Disease Models, Animal; Inflammation; Janus Kinase 2; Linagliptin; Male; Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; Rats; Signal Transduction; Sirtuin 1; STAT3 Transcription Factor

The pathophysiology of sepsis involves inflammation and hypercoagulability, which lead to microvascular thrombosis and compromised organ perfusion. Dipeptidyl peptidase (DPP)-4 inhibitors, e.g., linagliptin, are commonly used anti-diabetic drugs known to exert anti-inflammatory effects. However, whether these drugs confer an anti-thrombotic effect that preserves organ perfusion in sepsis remains to be investigated. In the present study, human umbilical vein endothelial cells (HUVECs) were treated with linagliptin to examine its anti-inflammatory and anti-thrombotic effects under tumor necrosis factor (TNF)-α treatment. To validate findings from in vitro experiments and provide in vivo evidence for the identified mechanism, a mouse model of lipopolysaccharide (LPS)-induced systemic inflammatory response syndrome was used, and pulmonary microcirculatory thrombosis was measured. In TNF-α-treated HUVECs and LPS-injected mice, linagliptin suppressed expressions of interleukin-1β (IL-1β) and intercellular adhesion molecule 1 (ICAM-1) via a nuclear factor-κB (NF-κB)-dependent pathway. Linagliptin attenuated tissue factor expression via the Akt/endothelial nitric oxide synthase pathway. In LPS-injected mice, linagliptin pretreatment significantly reduced thrombosis in the pulmonary microcirculation. These anti-inflammatory and anti-thrombotic effects were independent of blood glucose level. Together the present results suggest that linagliptin exerts protective effects against endothelial inflammation and microvascular thrombosis in a mouse model of sepsis.

Topics: Animals; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Dipeptidyl-Peptidases and Tripeptidyl-Peptidases; Disease Models, Animal; Human Umbilical Vein Endothelial Cells; Humans; Hypoglycemic Agents; Inflammation; Linagliptin; Lipopolysaccharides; Mice; Microcirculation; Sepsis; Thrombosis; Tumor Necrosis Factor-alpha

Effects of combination therapy of dipeptidyl peptidase-4 (DPP-4) inhibitor and sodium-glucose co-transporter 2 (SGLT2) inhibitor on β-cells are still unclear, although combination agent of these two drugs has become common in clinical practice. Therefore, we aimed to elucidate the effects of DPP-4 inhibitor and/or SGLT2 inhibitor on β-cell mass and function and compared their effects between in an early and advanced phase of diabetes. We used 7-week-old db/db mice as an early phase and 16-week-old mice as an advanced phase and treated them for 2 weeks with oral administration of linagliptin, empagliflozin, linagliptin + empagliflozin (L + E group), and 0.5% carboxymethylcellulose (Cont group). Blood glucose levels in Empa and L + E group were significantly lower than Cont group after treatment. In addition, β-cell mass in L + E group was significantly larger than Cont group only in an early phase, accompanied by increased Ki67-positive β-cell ratio. In isolated islets, mRNA expression levels of insulin and its transcription factors were all significantly higher only in L + E group in an early phase. Furthermore, mRNA expression levels related to β-cell differentiation and proliferation were significantly increased only in L + E group in an early phase. In conclusion, combination of DPP-4 inhibitor and SGLT2 inhibitor exerts more beneficial effects on β-cell mass and function, especially in an early phase of diabetes rather than an advanced phase.

Topics: Animals; Benzhydryl Compounds; Blood Glucose; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Disease Models, Animal; Drug Combinations; Glucosides; Hypoglycemic Agents; Insulin; Insulin-Secreting Cells; Linagliptin; Male; Mice; Mice, Inbred NOD; Mice, Inbred Strains; Sodium-Glucose Transporter 2; Sodium-Glucose Transporter 2 Inhibitors

When Zika virus emerged as a public health emergency there were no drugs or vaccines approved for its prevention or treatment. We used a high-throughput screen for Zika virus protease inhibitors to identify several inhibitors of Zika virus infection. We expressed the NS2B-NS3 Zika virus protease and conducted a biochemical screen for small-molecule inhibitors. A quantitative structure-activity relationship model was employed to virtually screen ∼138,000 compounds, which increased the identification of active compounds, while decreasing screening time and resources. Candidate inhibitors were validated in several viral infection assays. Small molecules with favorable clinical profiles, especially the five-lipoxygenase-activating protein inhibitor, MK-591, inhibited the Zika virus protease and infection in neural stem cells. Members of the tetracycline family of antibiotics were more potent inhibitors of Zika virus infection than the protease, suggesting they may have multiple mechanisms of action. The most potent tetracycline, methacycline, reduced the amount of Zika virus present in the brain and the severity of Zika virus-induced motor deficits in an immunocompetent mouse model. As Food and Drug Administration-approved drugs, the tetracyclines could be quickly translated to the clinic. The compounds identified through our screening paradigm have the potential to be used as prophylactics for patients traveling to endemic regions or for the treatment of the neurological complications of Zika virus infection.

Topics: Animals; Antiviral Agents; Artificial Intelligence; Chlorocebus aethiops; Disease Models, Animal; Drug Evaluation, Preclinical; High-Throughput Screening Assays; Immunocompetence; Inhibitory Concentration 50; Methacycline; Mice, Inbred C57BL; Protease Inhibitors; Quantitative Structure-Activity Relationship; Small Molecule Libraries; Vero Cells; Zika Virus; Zika Virus Infection

Dipeptidyl peptidase 4 (DPP-4) inhibitors have been shown to have neuroprotective effects in diabetic patients suffering from stroke, but less research has focused on patients with mild hyperglycemia below the threshold for a diagnosis of diabetes. In this investigation, a hyperglycemic mouse model was generated by intraperitoneal injection of streptozotocin and then subjected to focal cerebral ischemia. We demonstrated that the DPP-4 inhibitor linagliptin significantly decreased the infarct volume, reduced neuronal cell death, decreased inflammation, and improved neurological deficit compared with control mice. Linagliptin up-regulated the expression of p-Akt and p-mTOR and regulated the apoptosis factors Bcl-2, Bax, and caspase 9. Taken together, these results suggest that linagliptin exerts a neuroprotective action likely through activation of the Akt/mTOR pathway along with anti-apoptotic and anti-inflammatory mechanisms. Therefore, linagliptin may be considered as a therapeutic treatment for stroke patients with mild hyperglycemia.

Topics: Animals; Apoptosis; Cell Death; Dipeptidyl-Peptidase IV Inhibitors; Disease Models, Animal; Hyperglycemia; Linagliptin; Male; Mice; Mice, Inbred C57BL; Mice, Obese; Neuroprotective Agents; Proto-Oncogene Proteins c-akt; Stroke; TOR Serine-Threonine Kinases

Although the available therapeutic agents alleviate the symptoms in patients with temporal lobe epilepsy (TLE), these antiepileptic drugs do not provide adequate control of seizures in 30-40 % of patients. This study was conducted to evaluate anti-epileptic effects of simultaneous inhibition of dipeptidyl peptidase-4 and P2 × 7 purinoceptors in Kainate treated rats.. Brilliant Blue G)BBG(, linagliptin)lin(and lin + BBG were administrated 30 min prior to induction of the intrahippocampal kainate model of epilepsy in male Wistar rats. In the case of valproic acid group, the animals intraperitoneally received valproic acid for 7 consecutive days prior to induction of the model. We carried out histological evaluations, monitoring of behavior, recording of intracranial electroencepholography (IEEG), and determination of astrogliosis and DNA fragmentation using ELISA methods.. Our results showed that BBG and lin combination therapy had better effects on decrease in astrogliosis, DNA fragmentation and cognitive disturbances than ones whereas its effects on neuronal survival and seizure severity was similar to only BBG or lin. Likewise, the effects of lin + BBG on decrease in DNA fragmentation and cognitive disturbances were better than valproic acid group.. Our findings suggest that simultaneous inhibition of dipeptidyl peptidase-4 and P2 × 7 purinoceptors might more efficiently provide protection against progression of the kainate-induced TLE in rats.

Topics: Animals; Anticonvulsants; Dipeptidyl-Peptidase IV Inhibitors; Disease Models, Animal; DNA Fragmentation; Drug Therapy, Combination; Electroencephalography; Epilepsy; Gliosis; Hippocampus; Kainic Acid; Linagliptin; Male; Purinergic P2Y Receptor Antagonists; Rats; Rats, Wistar; Rosaniline Dyes; Seizures; Treatment Outcome

Recent studies demonstrated the reno-protective effects of two dipeptidyl peptidase-4 (DPP-4) inhibitors, saxagliptin and sitagliptin, against gentamycin-induced renal injury. However, none of these studies investigated whether renal DPP-4 contributes to the pathogenesis of this nephrotoxicity or not. This prompted us to test this hypothesis and to assess, for the first time, the potential reno-protective effect of linagliptin and whether this action is related or not to DPP-4 inhibition. Lingliptin was chosen since it is mainly excreted through a non-renal pathway and can therefore be used safely in individuals with renal injury.. Male Sprague-Dawley rats were administered gentamycin (100 mg/kg/day, ip for 10 days) alone or combined with linagliptin (3 mg/kg/day, orally for 14 days). Gentamycin was administered once daily during the last ten days of the linagliptin treatment.. Linagliptin administration ameliorated gentamycin-induced renal injury and restored renal functional, oxidative, inflammatory, apoptotic and histopathological changes. Furthermore, the current study highlighted the role of increased plasma and renal DPP-4 in the pathogenesis of gentamycin renal insults and showed that the potential reno-protective effect of linagliptin is partly, mediated via inhibition of DPP-4, in addition to other antioxidant, anti-inflammatory and anti-apoptotic actions.. Linagliptin may serve as a beneficial adjutant to reduce gentamycin-induced renal injury.

Topics: Adamantane; Animals; Dipeptides; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Disease Models, Animal; Gentamicins; Kidney; Kidney Diseases; Linagliptin; Male; Rats; Rats, Sprague-Dawley; Sitagliptin Phosphate

The effect of DPP-4 inhibitor on the electrical and structural remodeling in myocardial injury has not been evaluated. We hypothesized that linagliptin, DPP-4 inhibitor, suppresses myocardial remodeling in the isoproterenol (ISP)-induced myocardial injury model.Sprague-Dawley rats were assigned to 3 groups: 1) sham group, 2) ISP group (subcutaneous ISP injection of 70 mg/kg), and 3) ISP + linagliptin (ISP + Lin) (5 mg/kg/day, p.o.) group. Serum was sampled on day 1 (acute phase) and day 7 (sub-acute phase) to evaluate derivatives of reactive oxidative metabolites (d-ROMs). The electrophysiological study was performed in sub-acute phase for the evaluation of the ventricular effective refractory period (VERP) and monophasic action potential duration (MAPD). The VERP and MAPD were markedly prolonged in the ISP group in comparison with the sham (MAPD20: 14 ± 6 versus 11 ± 3 ms, MAPD90: 57 ± 8 versus 44 ± 7 ms, VERP: 74 ± 22 versus 38 ± 10 ms, P < 0.05). In contrast in the ISP + Lin group, such prolongations were suppressed, and the parameters were shorter than the ISP group (MAPD20: 9 ± 2 ms, MAPD90: 35 ± 6 ms, VERP: 52 ± 13 ms, P < 0.05). ISP treatment induced myocardial injury. The injured area was reduced in the ISP + Lin group in comparison with the ISP group (P < 0.05). Serum d-ROMs level in acute phase was higher in ISP group than the other 2 groups (sham: 214 ± 55 versus ISP: 404 ± 45 versus ISP + Lin: 337 ± 20 U.CARR, P < 0.05).Linagliptin suppressed structural and electrical changes, possibly through the antioxidative effect, in this myocardial injury model.

Topics: Animals; Antioxidants; Atrial Remodeling; Cardiotonic Agents; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Disease Models, Animal; Electrophysiologic Techniques, Cardiac; Isoproterenol; Linagliptin; Myocardial Infarction; Oxidative Stress; Rats; Rats, Sprague-Dawley; Treatment Outcome; Ventricular Remodeling

Dipeptidyl peptidase type 4 (DPP-4) inhibitors were reported to have beneficial effects in experimental models of chronic kidney disease. The underlying mechanisms are not completely understood. However, these effects could be mediated via the glucagon-like peptide-1 (GLP-1)/GLP-1 receptor (GLP1R) pathway. Here we investigated the renal effects of the DPP-4 inhibitor linagliptin in Glp1r-/- knock out and wild-type mice with 5/6 nephrectomy (5/6Nx). Mice were allocated to groups: sham+wild type+placebo; 5/6Nx+ wild type+placebo; 5/6Nx+wild type+linagliptin; sham+knock out+placebo; 5/6Nx+knock out+ placebo; 5/6Nx+knock out+linagliptin. 5/6Nx caused the development of renal interstitial fibrosis, significantly increased plasma cystatin C and creatinine levels and suppressed renal gelatinase/collagenase, matrix metalloproteinase-1 and -13 activities; effects counteracted by linagliptin treatment in wildtype and Glp1r-/- mice. Two hundred ninety-eight proteomics signals were differentially regulated in kidneys among the groups, with 150 signals specific to linagliptin treatment as shown by mass spectrometry. Treatment significantly upregulated three peptides derived from collagen alpha-1(I), thymosin β4 and heterogeneous nuclear ribonucleoprotein A1 (HNRNPA1) and significantly downregulated one peptide derived from Y box binding protein-1 (YB-1). The proteomics results were further confirmed using western blot and immunofluorescence microscopy. Also, 5/6Nx led to significant up-regulation of renal transforming growth factor-β1 and pSMAD3 expression in wild type mice and linagliptin significantly counteracted this up-regulation in wild type and Glp1r-/- mice. Thus, the renoprotective effects of linagliptin cannot solely be attributed to the GLP-1/GLP1R pathway, highlighting the importance of other signaling pathways (collagen I homeostasis, HNRNPA1, YB-1, thymosin β4 and TGF-β1) influenced by DPP-4 inhibition.

Topics: Animals; Collagen Type I; Collagen Type I, alpha 1 Chain; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Disease Models, Animal; Down-Regulation; Glucagon-Like Peptide-1 Receptor; Heterogeneous Nuclear Ribonucleoprotein A1; Humans; Kidney; Linagliptin; Male; Mice; Mice, Knockout; Nephrectomy; Renal Insufficiency, Chronic; RNA-Seq; Signal Transduction; Thymosin; Transcription Factors; Transforming Growth Factor beta1; Up-Regulation

Vascular risk factors, such as type 2 diabetes mellitus (T2DM), are associated with the increased risk of Alzheimer's disease. One of the common T2DM medications, dipeptidyl peptidase (DPP)-4 inhibitors, have a minimum risk for hypoglycemia and have recently been suggested to ameliorate β-amyloid pathology. However, conflicting results have been reported regarding the effects of DPP-4 inhibition on cognitive function and tau pathology. Thus, we investigated whether inhibiting DPP-4 affects tau pathology and cognition in a mouse model of tauopathy with hyperglycemia. Male mice overexpressing the P301S mutant human microtubule-associated protein tau gene (PS19) were fed either a low or high-fat diet. PS19 mice were then administered either linagliptin, a DPP-4 inhibitor, or vehicle, from 6 weeks to 8 months of age. Linagliptin-treated mice exhibited higher levels of glucagon-like peptide-1 and decreased fasting blood glucose, compared with the vehicle-treated mice at 8 months. Linagliptin treatment significantly restored spatial reference memory and increased cerebral blood flow without affecting phosphorylation levels of tau or endothelial nitric oxide synthase (eNOS) in the brain. Linagliptin may ameliorate HFD-induced cognitive worsening in tauopathy, at least partially, by increasing cerebral perfusion via the eNOS-independent pathway.

Topics: Animals; Cognitive Dysfunction; Diet, High-Fat; Dipeptidyl-Peptidase IV Inhibitors; Disease Models, Animal; Humans; Hyperglycemia; Hypoglycemic Agents; Linagliptin; Male; Mice; Mice, Inbred C57BL; Tauopathies

To verify whether the treatment with linagliptin induces the browning of the subcutaneous WAT (sWAT) and thermogenesis in murine diet-induced obesity (DIO) model.. Forty animals were randomly assigned to receive a control diet (C, 10% lipids as energy) or a high-fat diet (HF, 50% lipids as energy) for 10 weeks. Each group was re-divided to begin the 5-week treatment, totalizing four experimental groups: C, C-L (C plus linagliptin, 30 mg/kg body mass; BM), HF, and HF-L (HF plus linagliptin, 30 mg/kg BM). The drug was mixed with diet.. HF animals showed overweight, glucose intolerance, and a greater cross-sectional area of adipocytes. The treatment with linagliptin was able to normalize the BM, restore the glucose tolerance and the cross-sectional area of adipocytes. These observations comply with the observation of UCP1-positive multilocular adipocytes in the sWAT of treated animals. Both treated groups (C-L and HF-L) showed high expression of thermogenic and type 2 cytokines genes, which agree with the enhanced body temperature and the lower respiratory exchange ratio, implying enhanced thermogenesis with the use of lipids as fuel.. The reduced BM, the enhanced body temperature, and the presence of positive UCP1 beige cells in the sWAT point to the activation of the browning cascade on the sWAT of linagliptin-treated mice, and hence, linagliptin could induce the thermogenic pathway as a pleiotropic effect that can have translational potential.

Topics: Adipocytes, Brown; Adiposity; Animals; Biomarkers; Diet, High-Fat; Dipeptidyl-Peptidase IV Inhibitors; Disease Models, Animal; Insulin; Linagliptin; Male; Mice, Inbred C57BL; Obesity; Random Allocation; Subcutaneous Fat; Thermogenesis

Non-Alcoholic SteatoHepatitis (NASH) is the more severe form of Non-Alcoholic Fatty Liver Disease (NAFLD) and is characterized by the presence of hepatic steatosis, oxidative stress, inflammation, hepatocyte injury with or without fibrosis. Recently, GPR119 receptor has emerged as a novel therapeutic target for the treatment of dyslipidemia and non-alcoholic steatohepatitis. In the present study, we investigated the effect of APD668, a GPR119 agonist alone or in combination with linagliptin, a DPPIV inhibitor on the progression of steatohepatitis in mice fed on a high trans-fat diet. In this study, monotherapy with either APD668 or linagliptin caused a reduction in the levels of ALT, AST, glucose, cholesterol and epididymal fat mass but the effect was more pronounced upon treatment with combination of both drugs. On the other hand, combined treatment of APD668 with linagliptin demonstrated a non-significant additive effect in reduction of hepatic triglyceride (-78%) and cholesterol (-56%) compared to monotherapy groups. Moreover, co-administration of APD668 and linagliptin resulted in enhanced levels of active GLP-1 with additional benefit of significant synergistic decrease in body weight gain (-19%) in mice. We speculated that the enhanced effect observed with the combination treatment could be due to either 1) direct activation of GPR119 receptors present in liver and intestine or 2) enhanced active GLP-1 levels or 3) decreased degradation of GLP-1 in-vivo through DPPIV inhibition. Therefore, these findings clearly suggest that GPR119 receptor agonists in combination with DPPIV inhibitors may represent a promising therapeutic strategy for the treatment of non-alcoholic steatohepatitis.

Topics: Animals; Diet, High-Fat; Dipeptidyl-Peptidase IV Inhibitors; Disease Models, Animal; Disease Progression; Drug Synergism; Drug Therapy, Combination; Linagliptin; Liver; Male; Mice; Mice, Inbred C57BL; Non-alcoholic Fatty Liver Disease; Pyrazoles; Pyrimidines; Receptors, G-Protein-Coupled; Weight Gain

Our aim was to assess the effect of different doses of linagliptin with or without l-dopa/Carbidopa on 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced parkinsonism in mice.. Eighty Balb/c mice were divided into 8 equal groups: Control; MPTP; MPTP + l-dopa/Carbidopa; MPTP + linagliptin 3 mg/kg/day; MPTP + linagliptin 10 mg/kg/day; MPTP + Carboxymethyl cellulose; MPTP + l-dopa/Carbidopa + linagliptin 3 mg/kg/day and MPTP + l-dopa/Carbidopa + linagliptin 10 mg/kg/day. Striatal dopamine, tumor necrosis factor alpha (TNF-α), interleukin 10 (IL-10), transforming growth factor beta 1 (TGF-β1), toll-like receptor 4 (TLR4), antioxidant enzymes, adenosine triphosphate (ATP), glucagon-like peptide-1 (GLP-1), receptors of advanced glycation end products (RAGE), nuclear factor (erythroid-derived 2)-like 2 (Nrf2), heme oxygenase-1 (HO-1), mitochondrial complex I activity, catalepsy and total swim scores were measured. Also, the substantia nigra was subjected to immunohistochemical examination.. The combination of l-dopa/Carbidopa and linagliptin in a dose-dependent manner resulted in significant improvement of the behavioural changes, striatal dopamine, antioxidant parameters, Nrf2/HO-1 content, GLP-1, ATP and mitochondrial complex I activity with significant decrease in striatal RAGE, TGF-β1, TNF-α, IL-10, TLR4 and alleviated the immunohistochemical changes better than the groups that received either l-dopa/Carbidopa or linagliptin alone.. The combination of l-dopa/Carbidopa and linagliptin might represent a promising therapeutic modality for management of parkinsonism.

Topics: 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine; Animals; Antiparkinson Agents; Carbidopa; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Combinations; Drug Synergism; Glucagon-Like Peptide 1; Levodopa; Linagliptin; Mice; Mice, Inbred BALB C; NF-kappa B; Parkinsonian Disorders; Toll-Like Receptor 4; Transforming Growth Factor beta1

Dipeptidyl peptidase 4 (DPP-4) inhibitors have recently been reported to exhibit additional cardioprotective effects; however, their effect in atrial remodeling, such as in atrial fibrillation (AF), remains unclear. In this study, the effect of linagliptin on atrial electrical and structural remodeling was evaluated in a canine AF model. Sixteen beagle dogs with 3-week atrial rapid stimulation were divided into the linagliptin group (9 mg/kg/day, n = 8) and pacing control group (n = 8). Three additional dogs without rapid pacing were assigned into non-pacing group, which was used as sham in this study. In the dogs with rapid pacing, the atrial effective refractory period (AERP), conduction velocity (CV), and AF inducibility were evaluated and blood was sampled every week. After the entire protocol, atrial tissue was sampled for histological examinations using HE, Azan, and dihydroethidium (DHE) staining to evaluate any tissue damage or oxidative stress. The pacing control group exhibited a gradual AERP shortening and CV decrease along the time course as previously reported. In the linagliptin group, the AERP shortening was not affected, but the CV decrease was suppressed in comparison to the control group (p < 0.05). The AF inducibility was increased in the control group and suppressed in the linagliptin group (p < 0.05). The control group exhibited tissue fibrosis, the degree of which was suppressed in the linagliptin group. DHE staining exhibited suppression of the reactive oxygen species expression in the linagliptin group in comparison to the pacing control group. Linagliptin, a DPP-4-inhibitor, suppressed the AF inducibility, CV decrease, and overexpression of oxidative stress in the canine AF model. Such suppressive effects of linagliptin on AF in the canine model may possibly be related to the anti-oxidative effect.

Topics: Animals; Atrial Fibrillation; Atrial Function, Left; Atrial Remodeling; Dipeptidyl-Peptidase IV Inhibitors; Disease Models, Animal; Dogs; Dose-Response Relationship, Drug; Female; Heart Conduction System; Linagliptin; Oxidative Stress

Multiple sclerosis is a chronic inflammatory demyelinating central nervous system disorder leading to serious neurological deficits. Linagliptin, a dipeptidyl peptidase-4 inhibitor, recently showed neuroprotective properties against neurodegenerative diseases. This study investigated the possible neuroprotective effect of linagliptin against cuprizone-induced demyelination in mice and its potential early-remyelinating properties. C57Bl/6 mice were fed chow containing 0.7% cuprizone for 1 week, followed by 3 weeks of a 0.2% cuprizone diet. Linagliptin (10 mg/kg/day, p.o.) was given for 3 weeks starting from the second week. Linagliptin treatment improved behavioural and motor abnormalities induced by cuprizone, as demonstrated by open field, rotarod and grip strength tests. In parallel, linagliptin lessened the demyelination through enhancing Olig2 gene expression, as shown by increased myelin basic protein, myelin proteolipid protein levels and Luxol fast blue-staining intensity. Linagliptin attenuated cuprizone-induced oxidative stress by decreasing brain thiobarbituric acid reactive substances along with restoring reduced glutathione levels. Linagliptin exerted an anti-inflammatory effect by reducing brain tumor necrosis factor-alpha. Interestingly, linagliptin diminished phosphorylated JAK2, phosphorylated STAT3 and NF-κB p65 protein expression while up-regulating phosphorylated AMP-activated protein kinase (p-AMPK) protein and SIRT1 gene expression levels. In conclusion, linagliptin exerted a neuroprotective effect in mice with cuprizone-induced demyelination possibly by modulating AMPK/SIRT1 and JAK2/STAT3/NF-κB signalling pathways.

Topics: AMP-Activated Protein Kinases; Animals; Behavior, Animal; Brain; Cuprizone; Demyelinating Diseases; Disease Models, Animal; Janus Kinase 2; Linagliptin; Male; Mice, Inbred C57BL; Motor Activity; Myelin Sheath; Neuroprotective Agents; NF-kappa B; Oxidative Stress; Remyelination; Signal Transduction; Sirtuin 1; STAT3 Transcription Factor

Linagliptin has protective effects on the retinal neurovascular unit but, in proliferative retinopathy, dipeptidyl peptidase 4 (DPP-4) inhibition could be detrimental. The aim of this study was to assess the effect of linagliptin on ischaemia-induced neovascularisation of the retina.. Systemic treatment with linagliptin demonstrated GLP-1R-independent anti-angiogenic effects mediated by an inhibition of VEGF receptor downstream signalling. The specific effects of linagliptin on diabetic retinopathy are of potential benefit for individuals with diabetes, independent of metabolic effects.

Topics: Animals; Diabetic Retinopathy; Dipeptidyl-Peptidase IV Inhibitors; Disease Models, Animal; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Human Umbilical Vein Endothelial Cells; Humans; Hypoxia-Inducible Factor 1, alpha Subunit; Linagliptin; Male; Mice; Mice, Inbred C57BL; Oxygen; Retina; Retinal Neovascularization; Signal Transduction; Vascular Endothelial Growth Factor A

The mortality rate of patients who develop sepsis-related cardiac dysfunction is high. Many disease conditions (e.g., diabetes) increase the susceptibility to infections and subsequently sepsis. Activation of the NF-κB pathway plays a crucial role in the pathophysiology of sepsis-associated cardiac dysfunction and diabetic cardiomyopathy. The effect of diabetes on outcomes in patients with sepsis is still highly controversial. We here hypothesized that type 2 diabetes (T2DM) augments the cardiac (organ) dysfunction associated with sepsis, and that inhibition of the NF-κB pathway with linagliptin attenuates the cardiac (organ) dysfunction in mice with T2DM/sepsis. To investigate this, 10-week old male C57BL/6 mice were randomized to receive normal chow or high fat diet (HFD), 60% of calories derived from fat). After 12 weeks, mice were subjected to sham surgery or cecal ligation and puncture (CLP) for 24 h. At 1 hour after surgery, mice were treated with linagliptin (10 mg/kg, i.v.), IKK-16 (1 mg/kg, i.v.), or vehicle (2% DMSO, 3 ml/kg, i.v.). Mice also received analgesia, fluids and antibiotics at 6 and 18 h after surgery. Mice that received HFD showed a significant increase in body weight, impairment in glucose tolerance, reduction in ejection fraction (%EF), and increase in alanine aminotransferase (ALT). Mice on HFD subjected to CLP showed further reduction in %EF, increase in ALT, developed acute kidney dysfunction and lung injury. They also showed significant increase in NF-κB pathway, iNOS expression, and serum inflammatory cytokines compared to sham surgery group. Treatment of HFD-CLP mice with linagliptin or IKK-16 resulted in significant reductions in (i) cardiac, liver, kidney, and lung injury associated with CLP-sepsis, (ii) NF-κB activation and iNOS expression in the heart, and (iii) serum inflammatory cytokine levels compared to HFD-CLP mice treated with vehicle. Our data show that pre-existing type 2 diabetes phenotype worsens the organ dysfunction/injury associated with CLP-sepsis in mice. Most notably, inhibition of NF-κB reduces the organ dysfunction/injury associated with sepsis in mice with pre-existing T2DM.

Topics: Animals; Cecum; Diabetes Mellitus, Type 2; Diet, High-Fat; Disease Models, Animal; Heart Diseases; Humans; Linagliptin; Male; Mice; Mice, Inbred C57BL; NF-kappa B; Piperidines; Pyrrolidines; Sepsis; Signal Transduction

Diastolic dysfunction (DD), a hallmark of obesity and primary defect in heart failure with preserved ejection fraction, is a predictor of future cardiovascular events. We previously reported that linagliptin, a dipeptidyl peptidase-4 inhibitor, improved DD in Zucker Obese rats, a genetic model of obesity and hypertension. Here we investigated the cardioprotective effects of linagliptin on development of DD in western diet (WD)-fed mice, a clinically relevant model of overnutrition and activation of the renin-angiotensin-aldosterone system.. Female C56Bl/6 J mice were fed an obesogenic WD high in fat and simple sugars, and supplemented or not with linagliptin for 16 weeks.. WD induced oxidative stress, inflammation, upregulation of Angiotensin II type 1 receptor and mineralocorticoid receptor (MR) expression, interstitial fibrosis, ultrastructural abnormalities and DD. Linagliptin inhibited cardiac DPP-4 activity and prevented molecular impairments and associated functional and structural abnormalities. Further, WD upregulated the expression of TRAF3IP2, a cytoplasmic adapter molecule and a regulator of multiple inflammatory mediators. Linagliptin inhibited its expression, activation of its downstream signaling intermediates NF-κB, AP-1 and p38-MAPK, and induction of multiple inflammatory mediators and growth factors that are known to contribute to development and progression of hypertrophy, fibrosis and contractile dysfunction. Linagliptin also inhibited WD-induced collagens I and III expression. Supporting these in vivo observations, linagliptin inhibited aldosterone-mediated MR-dependent oxidative stress, upregulation of TRAF3IP2, proinflammatory cytokine, and growth factor expression, and collagen induction in cultured primary cardiac fibroblasts. More importantly, linagliptin inhibited aldosterone-induced fibroblast activation and migration.. Together, these in vivo and in vitro results suggest that inhibition of DPP-4 activity by linagliptin reverses WD-induced DD, possibly by targeting TRAF3IP2 expression and its downstream inflammatory signaling.

Topics: Adaptor Proteins, Signal Transducing; Animals; Cardiomyopathies; Cells, Cultured; Diastole; Diet, Western; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Disease Models, Animal; Down-Regulation; Female; Fibrosis; Linagliptin; Mice, Inbred C57BL; Myocarditis; Myocardium; NF-kappa B; Nitrosative Stress; Obesity; Oxidative Stress; p38 Mitogen-Activated Protein Kinases; Recovery of Function; Signal Transduction; Time Factors; Transcription Factor AP-1; Ventricular Dysfunction, Left; Ventricular Function, Left

Glucagon-like peptide-1 (GLP-1) is an incretin hormone shown to be active in the treatment of type-2 diabetes (T2D) and has also been shown as efficacious in Alzheimer's disease (AD). Dipeptidyl peptidase-4 (DPP-4), an enzyme that is expressed in numerous cells, rapidly inactivates endogenous GLP-1. Therefore, DPP-4 inhibition is employed as a therapeutic avenue to increase GLP-1 levels in the management of T2D. The effectiveness of DPP-4 inhibitors in the treatment of AD has been reported in various animal models of AD. With this background, the present study was designed to examine the effectiveness of linagliptin, a DPP-4 inhibitor in the 3xTg-AD mouse model of Alzheimer's disease. Nine-month-old 3xTg-AD mice were administered linagliptin orally (5, 10, and 20 mg/kg) for 8 weeks. At the end of the linagliptin treatment, mice were evaluated for cognitive ability on the Morris Water Maze and Y-maze. Following cognitive evaluation, mice were sacrificed to determine the effect of the linagliptin on brain incretin levels, amyloid burden, tau phosphorylation, and neuroinflammation. We confirm that linagliptin treatment for 8 weeks mitigates the cognitive deficits present in 3xTg-AD mice. Moreover, linagliptin also improves brain incretin levels and attenuates amyloid beta, tau phosphorylation as well as neuroinflammation. In conclusion, linagliptin possesses neuroprotective properties that may be attributed to the improvement of incretin levels in the brain.

Topics: Alzheimer Disease; Amyloid beta-Peptides; Animals; Blood Glucose; Cognition Disorders; Dipeptidyl-Peptidase IV Inhibitors; Disease Models, Animal; Female; Glucagon-Like Peptide 1; Linagliptin; Maze Learning; Mice; Mice, Transgenic; tau Proteins

The present study aimed to investigate the synergistic action of telmisartan and linagliptin in ameliorating pancreatic islet functions and morphology in type 2 diabetes mellitus and to delineate the molecular signaling pathway involved.. db/db mice were given telmisartan (3 mg/kg) or linagliptin (3 mg/kg) alone or in combination, daily for 8 weeks, and were studied in vivo by fasting and random blood glucose tests, oral glucose tolerance tests, and intraperitoneal insulin tolerance tests, as well as ex vivo by glucose-stimulated insulin secretion and morphology of pancreatic islets. The underlying signaling pathways were examined by Western blot, real-time quantitative polymerase chain reaction, and dihydroethidium staining analyses using mouse pancreatic islets and rat β-insulinoma cells.. Telmisartan/linagliptin combination induced significantly better glucose homeostasis than the monotherapies. Posttreatment reactive oxygen species level was suppressed most significantly after the telmisartan/linagliptin combined therapy, whereas no significant change in peroxisome proliferator-activated receptor γ expressions was observed after treatments.. The telmisartan/linagliptin combination preserved pancreatic islet cell functions and morphology via reduction of oxidative stress but independent of the peroxisome proliferator-activated receptor γ pathway. Our data shed light on the therapeutic potential of using the telmisartan/linagliptin combination in the treatment of human type 2 diabetes mellitus and its related complications.

Topics: Angiotensin II Type 1 Receptor Blockers; Animals; Benzimidazoles; Benzoates; Blotting, Western; Cell Line, Tumor; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidase IV Inhibitors; Disease Models, Animal; Drug Therapy, Combination; Female; Glucose Tolerance Test; Humans; Immunohistochemistry; Islets of Langerhans; Linagliptin; Mice; Mice, Inbred C57BL; Oxidative Stress; Pancreas; PPAR gamma; Reactive Oxygen Species; Telmisartan

Dipeptidyl peptidase (DPP)-4 inhibitors delay chronic kidney disease (CKD) progression in experimental diabetic nephropathy in a glucose-independent manner. Here we compared the effects of the DPP-4 inhibitor linagliptin versus telmisartan in preventing CKD progression in non-diabetic rats with 5/6 nephrectomy. Animals were allocated to 1 of 4 groups: sham operated plus placebo; 5/6 nephrectomy plus placebo; 5/6 nephrectomy plus linagliptin; and 5/6 nephrectomy plus telmisartan. Interstitial fibrosis was significantly decreased by 48% with linagliptin but a non-significant 24% with telmisartan versus placebo. The urine albumin-to-creatinine ratio was significantly decreased by 66% with linagliptin and 92% with telmisartan versus placebo. Blood pressure was significantly lowered by telmisartan, but it was not affected by linagliptin. As shown by mass spectrometry, the number of altered peptide signals for linagliptin in plasma was 552 and 320 in the kidney. For telmisartan, there were 108 peptide changes in plasma and 363 in the kidney versus placebo. Linagliptin up-regulated peptides derived from collagen type I, apolipoprotein C1, and heterogeneous nuclear ribonucleoproteins A2/B1, a potential downstream target of atrial natriuretic peptide, whereas telmisartan up-regulated angiotensin II. A second study was conducted to confirm these findings in 5/6 nephrectomy wild-type and genetically deficient DPP-4 rats treated with linagliptin or placebo. Linagliptin therapy in wild-type rats was as effective as DPP-4 genetic deficiency in terms of albuminuria reduction. Thus, linagliptin showed comparable efficacy to telmisartan in preventing CKD progression in non-diabetic rats with 5/6 nephrectomy. However, the underlying pathways seem to be different.

Topics: Albuminuria; Angiotensin II Type 1 Receptor Blockers; Animals; Benzimidazoles; Benzoates; Biomarkers; Blood Pressure; Chromatography, Liquid; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Disease Models, Animal; Disease Progression; Fibrosis; Kidney; Linagliptin; Male; Mass Spectrometry; Nephrectomy; Rats, Inbred F344; Rats, Sprague-Dawley; Rats, Transgenic; Renal Insufficiency, Chronic; Renin-Angiotensin System; Signal Transduction; Telmisartan; Time Factors

Studies have indicated that dipeptidyl peptidase-4 (DPP-4) inhibitors and glucagon-like peptide-1 (GLP-1) agonists reduce infarct size after myocardial ischaemia. Whether these agents modify cardiac remodelling after ischaemia is unclear. Furthermore, it is not known if combination of the two types of drugs is superior to either agent alone. We investigated the modulatory effect of the DPP-4 inhibitor linagliptin alone, the GLP-1 activator liraglutide alone, or the two agents together on myocardial infarct size, left ventricular contractile function and cardiac remodelling signals after a brief period of left coronary artery (LCA) occlusion. C57BL/6 mice were treated with vehicle, the DPP-4 inhibitor linagliptin, the GLP-1 activator liraglutide, or both agents together for 5 days, and then subjected to LCA occlusion (1 h) and reperfusion (3 h). Ischaemia-reperfusion increased reactive oxygen species (ROS) generation and expression of NADPH oxidase (p47(phox), p22(phox) and gp91(phox) subtypes), collagens, fibronectin and proinflammatory cytokines (interleukin 6, tumour necrosis factor α and monocyte chemoattractant protein-1) in the LCA-supplied regions. Pre-treatment with linagliptin or liraglutide reduced infarct size, protected cardiomyocytes from injury and preserved cardiac contractile function in a similar fashion. It is interesting that profibrotic (collagen deposition) signals were expressed soon after ischaemia-reperfusion. Both linagliptin and liraglutide suppressed ROS generation, NADPH oxidase and proinflammatory signals, and reduced collagen deposition. Addition of linagliptin or liraglutide had no significant additive effect above and beyond that of liraglutide and linagliptin given alone. In conclusion, linagliptin and liraglutide can improve cardiac contractile function and indices of cardiac remodelling, which may be related to their role in inhibition of ROS production and proinflammatory cytokines after ischaemia.

Topics: Animals; Anti-Inflammatory Agents; Antioxidants; Cardiotonic Agents; Collagen; Cytokines; Cytoprotection; Dipeptidyl-Peptidase IV Inhibitors; Disease Models, Animal; Drug Therapy, Combination; Hypertrophy, Left Ventricular; Incretins; Inflammation Mediators; Linagliptin; Liraglutide; Male; Mice, Inbred C57BL; Myocardial Contraction; Myocardial Infarction; Myocardial Reperfusion Injury; Myocardium; NADPH Oxidases; Oxidative Stress; Reactive Oxygen Species; Ventricular Function, Left; Ventricular Remodeling

The role of stromal cell-derived factor-1 (SDF-1) in the pathogenesis of diabetic nephropathy and its modification by dipeptidyl peptidase-4 (DPP-4) inhibition are uncertain. Therefore, we studied this independent of glucagon-like peptide-1 receptor (GLP-1R) signaling using two Akita diabetic mouse models, the diabetic-resistant C57BL/6-Akita and diabetic-prone KK/Ta-Akita. Increased SDF-1 expression was found in glomerular podocytes and distal nephrons in the diabetic-prone mice, but not in kidneys from diabetic-resistant mice. The DPP-4 inhibitor linagliptin, but not the GLP-1R agonist liraglutide, further augmented renal SDF-1 expression in both Glp1r(+/+) and Glp1r(-/-) diabetic-prone mice. Along with upregulation of renal SDF-1 expression, the progression of albuminuria, glomerulosclerosis, periglomerular fibrosis, podocyte loss, and renal oxidative stress was suppressed in linagliptin-treated Glp1r(+/+) diabetic-prone mice. Linagliptin treatment increased urinary sodium excretion and attenuated the increase in glomerular filtration rate which reflects glomerular hypertension and hyperfiltration. In contrast, selective SDF-1 receptor blockade with AMD3100 reduced urinary sodium excretion and aggravated glomerular hypertension in the Glp1r(+/+) diabetic-prone mice. Thus, DPP-4 inhibition, independent of GLP-1R signaling, contributes to protection of the diabetic kidney through SDF-1-dependent antioxidative and antifibrotic effects and amelioration of adverse renal hemodynamics.

Topics: Albuminuria; Animals; Benzylamines; Chemokine CXCL12; Cyclams; Diabetes Mellitus, Type 1; Diabetic Nephropathies; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Disease Models, Animal; Female; Fibrosis; Glomerular Filtration Rate; Glucagon-Like Peptide-1 Receptor; Heterocyclic Compounds; Humans; Hypoglycemic Agents; Kidney; Linagliptin; Liraglutide; Male; Mice; Mice, Inbred C57BL; Oxidative Stress; Receptors, CXCR4; Up-Regulation

Our previous clinical indicated that urinary cyclophilin A was a good marker for diabetic nephropathy.. We used animal and cell models of diabetic nephropathy to examine the role of cyclophilin A in disease progression.. Significantly increased urinary cyclophilin A could be detected in db/db at the 8th week. Linagliptin (3mg/kg/day and 15mg/kg/day) could suppress urinary 8-hydroxy-2'-deoxyguanosine at the 8th and 16th week but only the high dose Linagliption could suppress cyclophilin A at the 8th week. Compared to 8-hydroxy-2'-deoxyguanosine, cyclophilin A was a stronger, earlier, and more sensitive marker. Immunohistochemical staining for cyclophilin A was also positive for db/db. In cell studies, oxidative stress and hyperglycemia could stimulate MES-13 and HK-2 cells to secrete cyclophilin A. Hyperglycemia stimulated HK-2 cells to secrete TGFβ1, which caused secretion of cyclophilin A. The secreted cyclophilin A further stimulated CD 147 to move outward from cytosol onto cell membrane in confocal microscopy, which was associated with the p38 MAPK pathway in the downstream.. Secreted cyclophilin A may play an important role in diabetic nephropathy in the mouse model and is associated with TGFβ1, CD 147, and the p38 MAPK pathway.

Topics: 8-Hydroxy-2'-Deoxyguanosine; Animals; Cells, Cultured; Cyclophilin A; Deoxyguanosine; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Dipeptidyl-Peptidase IV Inhibitors; Disease Models, Animal; Kidney Diseases; Linagliptin; Mice; Mice, Transgenic

Dipeptidyl peptidase (DPP)-4 inhibitors are used to treat hyperglycemia by increasing the incretin glucagon-like peptide-1 (GLP-1). Previous studies showed anti-inflammatory and antiatherosclerotic effects of DPP-4 inhibitors. Here, we compared the effects of linagliptin versus sitagliptin and liraglutide on survival and vascular function in animal models of endotoxic shock by prophylactic therapy and treatment after lipopolysaccharide (LPS) injection. Gliptins were administered either orally or subcutaneously: linagliptin (5 mg/kg/day), sitagliptin (50 mg/kg/day) or liraglutide (200 µg/kg/day). Endotoxic shock was induced by LPS injection (mice 17.5-20 mg/kg i.p., rats 10 mg/kg/day). Linagliptin and liraglutide treatment or DPP-4 knockout improved the survival of endotoxemic mice, while sitagliptin was ineffective. Linagliptin, liraglutide and sitagliptin ameliorated LPS-induced hypotension and vascular dysfunction in endotoxemic rats, suppressed inflammatory parameters such as whole blood nitrosyl-iron hemoglobin (leukocyte-inducible nitric oxide synthase activity) or aortic mRNA expression of markers of inflammation as well as whole blood and aortic reactive oxygen species formation. Hemostasis (tail bleeding time, activated partial thromboplastin time) was impaired in endotoxemic rats and recovered under cotreatment with linagliptin and liraglutide. Finally, the beneficial effects of linagliptin on vascular function and inflammatory parameters in endotoxemic mice were impaired in AMP-activated kinase (alpha1) knockout mice. The improved survival of endotoxemic animals and other data shown here may warrant further clinical evaluation of these drugs in patients with septic shock beyond the potential improvement of inflammatory complications in diabetic individuals with special emphasis on the role of AMP-activated kinase (alpha1) in the DPP-4/GLP-1 cascade.

Topics: Animals; Dipeptidyl-Peptidase IV Inhibitors; Disease Models, Animal; Endotoxemia; Glucagon-Like Peptide 1; Inflammation; Linagliptin; Lipopolysaccharides; Liraglutide; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Oxidative Stress; Purines; Pyrazines; Quinazolines; Rats; Rats, Wistar; Real-Time Polymerase Chain Reaction; Sitagliptin Phosphate; Triazoles

Myocarditis is a critical inflammatory disorder which causes life-threatening conditions. No specific or effective treatment has been established. DPP-4 inhibitors have salutary effects not only on type 2 diabetes but also on certain cardiovascular diseases. However, the role of a DPP-4 inhibitor on myocarditis has not been investigated. To clarify the effects of a DPP-4 inhibitor on myocarditis, we used an experimental autoimmune myocarditis (EAM) model in Balb/c mice. EAM mice were assigned to the following groups: EAM mice group treated with a DPP-4 inhibitor (linagliptin) (n = 19) and those untreated (n = 22). Pathological analysis revealed that the myocardial fibrosis area ratio in the treated group was significantly lower than in the untreated group. RT-PCR analysis demonstrated that the levels of mRNA expression of IL-2, TNF-α, IL-1β and IL-6 were significantly lower in the treated group than in the untreated group. Lymphocyte proliferation assay showed that treatment with the DPP-4 inhibitor had no effect on antigen-induced spleen cell proliferation. Administration of the DPP-4 inhibitor remarkably suppressed cardiac fibrosis and reduced inflammatory cytokine gene expression in EAM mice. Thus, the agents present in DPP-4 inhibitors may be useful to treat and/or prevent clinical myocarditis.

Topics: Animals; Autoimmune Diseases; Cell Proliferation; Dipeptidyl-Peptidase IV Inhibitors; Disease Models, Animal; Fibrosis; Heart; Heart Function Tests; Inflammation; Linagliptin; Lung; Lymphocytes; Male; Mice; Mice, Inbred BALB C; Myocarditis; Organ Size

The aim of the study was to investigate the effect of the DPP-4 inhibitor linagliptin on the mechanism(s) of endothelium-dependent relaxation in mesenteric arteries from STZ-induced diabetic rats. Both normal and diabetic animals received linagliptin (2 mg/kg) daily by oral gavage for a period of 4 weeks. To measure superoxide generation in mesenteric arteries, lucigenin-enhanced chemiluminescence was used. ACh-induced relaxation of mesenteric arteries was assessed using organ bath techniques and Western blotting was used to investigate protein expression. Pharmacological tools (1 μM TRAM-34, 1 μM apamin, 100 nM Ibtx, 100 μM L-NNA, 10 μM ODQ) were used to distinguish between NO and EDH-mediated relaxation. Linagliptin did not affect plasma glucose, but did decrease vascular superoxide levels. Diabetes reduced responses to ACh but did not affect endothelium-independent responses to SNP. Linagliptin improved endothelial function indicated by a significant increase in responses to ACh. Diabetes impaired the contribution of both nitric oxide (NO) and endothelium-dependent hyperpolarization (EDH) to endothelium-dependent relaxation and linagliptin treatment significantly enhanced the contribution of both relaxing factors. Western blotting demonstrated that diabetes also increased expression of Nox2 and decreased expression and dimerization of endothelial NO synthase, effects that were reversed by linagliptin. These findings demonstrate treatment of type 1 diabetic rats with linagliptin significantly reduced vascular superoxide levels and preserved both NO and EDH-mediated relaxation indicating that linagliptin can improve endothelial function in diabetes independently of any glucose lowering activity.

Topics: Animals; Blood Glucose; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 1; Dipeptidyl-Peptidase IV Inhibitors; Disease Models, Animal; Endothelium, Vascular; Gene Expression Regulation; Linagliptin; Male; Membrane Glycoproteins; Mesenteric Arteries; NADPH Oxidase 2; NADPH Oxidases; Nitric Oxide Synthase; Rats; Superoxides

To clarify the role of dipeptidyl peptidase-4 (DPP-4) inhibition in vascular tissues, we compared the effects of the poorly tissue-penetrative DPP-4 inhibitor sitagliptin to the highly tissue-penetrative DPP-4 inhibitor linagliptin in Zucker diabetic fatty (ZDF) rats. Six-week-old ZDF rats were orally treated with placebo, sitagliptin (10 mg/kg), or linagliptin (3 mg/kg) for 4 weeks. Sitagliptin and linagliptin produced equivalent decreases in blood glucose concentrations and increased plasma insulin concentrations during oral glucose tolerance tests after the first and the last treatments. In isolated arteries, acetylcholine-induced vascular relaxation was significantly augmented by sitagliptin and linagliptin, with significantly stronger relaxation observed with linagliptin compared to sitagliptin. Vascular DPP-4 activity was attenuated by these drugs, with linagliptin producing significant greater attenuation than sitagliptin. Vascular malondialdehide levels were significantly lower with linagliptin compared to sitagliptin. Significantly greater attenuation of vascular gene expressions of p22(phox) and monocyte chemoattractant protein-1 by linagliptin, compared with sitagliptin, was also observed. In conclusion, the superior vascular protection by linagliptin compared with sitagliptin was unrelated to the regulation of circulating glucose and insulin levels, and the stronger vascular DPP-4 inhibition by linagliptin may contribute to the mechanism of vascular protection.

Topics: Animals; Atherosclerosis; Blood Glucose; Carotid Arteries; Chemokine CCL2; Diabetes Mellitus, Type 2; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Disease Models, Animal; Gene Expression; Glucose Tolerance Test; In Vitro Techniques; Insulin; Linagliptin; Malondialdehyde; NADPH Oxidases; Purines; Pyrazines; Quinazolines; Rats, Zucker; Sitagliptin Phosphate; Triazoles; Vasodilation

Despite the beneficial effects of type 4 dipeptidyl peptidase (DPP-4) inhibitors on glucose levels, its effects on diabetic nephropathy remain unclear.. This study examined the long-term renoprotective effects of DPP-4 inhibitor linagliptin in db/db mice, a model of type 2 diabetes. Results were compared with the known beneficial effects of renin-angiotensin system blockade by enalapril. Ten-week-old male diabetic db/db mice were treated for 3 months with either vehicle (n = 10), 3 mg linagliptin/kg per day (n = 8), or 20 mg enalapril/kg per day (n = 10). Heterozygous db/m mice treated with vehicle served as healthy controls (n = 8).. Neither linagliptin nor enalapril had significant effects on the parameters of glucose metabolism or blood pressure in diabetic db/db mice. However, linagliptin treatment reduced albuminuria and attenuated kidney injury. In addition, expression of podocyte marker podocalyxin was normalized. We also analysed DPP-4 expression by immunofluorescence in human kidney biopsies and detected upregulation of DPP-4 in the glomeruli of patients with diabetic nephropathy, suggesting that our findings might be of relevance for human kidney disease as well.. Treatment with DPP-4 inhibitor linagliptin delays the progression of diabetic nephropathy damage in a glucose-independent and blood-pressure-independent manner. The observed effects may be because of the attenuation of podocyte injury and inhibition of myofibroblast transformation.

Topics: Albuminuria; Angiotensin-Converting Enzyme Inhibitors; Animals; Blood Pressure; Diabetes Mellitus, Type 2; Diabetic Nephropathies; Dipeptidyl-Peptidase IV Inhibitors; Disease Models, Animal; Enalapril; Glucose; Hypoglycemic Agents; Kidney; Kidney Glomerulus; Linagliptin; Male; Mice; Mice, Inbred Strains; Renin-Angiotensin System

It remains to be elucidated whether dipeptidylpeptidase-4 (DPP-4) inhibitor can ameliorate cardiovascular injury in salt-sensitive hypertension. The present study was undertaken to test our hypothesis that linagliptin, a DPP-4 inhibitor, administration initiated after onset of hypertension and cardiac hypertrophy can ameliorate cardiovascular injury in Dahl salt-sensitive hypertensive rats (DS rats).. High-salt loaded DS rats with established hypertension and cardiac hypertrophy were divided into two groups, and were orally given (1) vehicle or (2) linagliptin (3 mg/kg/day) once a day for 4 weeks, and cardiovascular protective effects of linagliptin in DS rats were evaluated.. Linagliptin did not significantly affect blood pressure and blood glucose levels in DS rats. Linagliptin significantly lessened cardiac hypertrophy in DS rats, as estimated by cardiac weight and echocardiographic parameters. Linagliptin significantly ameliorated cardiac fibrosis, cardiac macrophage infiltration, and coronary arterial remodeling in DS rats. Furthermore, linagliptin significantly mitigated the impairment of vascular function in DS rats, as shown by the improvement of acetylcholine-induced or sodium nitroprusside-induced vascular relaxation by linagliptin. These cardiovascular protective effects of linagliptin were associated with the attenuation of oxidative stress, NADPH oxidase subunits, p67phox and p22 phox, and angiotensin-converting enzyme (ACE).. Our results provided the experimental evidence that linagliptin treatment initiated after the appearance of hypertension and cardiac hypertrophy protected against cardiovascular injury induced by salt-sensitive hypertension, independently of blood pressure and blood glucose. These beneficial effects of linagliptin seem to be attributed to the reduction of oxidative stress and ACE.

Topics: Animals; Blood Glucose; Blood Pressure; Blood Pressure Determination; Cardiovascular Diseases; Dipeptidyl-Peptidase IV Inhibitors; Disease Models, Animal; Heart; Hypertension; Linagliptin; Male; Purines; Quinazolines; Rats; Rats, Inbred Dahl; Sodium Chloride, Dietary

The effects of linagliptin on fat content in diet-induced obese rats were compared with those of the appetite suppressant sibutramine. Female Wistar rats fed a high-fat diet (HFD) for 3 months received vehicle, linagliptin (10 mg/kg) or sibutramine (5 mg/kg) treatment orally, once daily for 6 additional weeks, while continuing the HFD. Magnetic resonance spectroscopy analysis of fat content was performed at baseline and at the end of the 6-week treatment period. Linagliptin treatment profoundly reduced hepatic fat compared with vehicle, with an effect comparable to that of sibutramine. The vehicle-corrected mean change (95% CI) from baseline in hepatic fat and intramyocellular lipid was -59.0% (-104.3%, -13.6%; p = 0.015) and -62.1% (-131.6%, 7.4%; p = 0.073), respectively, for linagliptin compared with -54.3% (-101.5%, -7.1%; p = 0.027) and -72.4% (-142.4%, -2.4%; p = 0.044), respectively, for sibutramine.

Topics: Adiposity; Animals; Appetite Depressants; Body Composition; Cyclobutanes; Disease Models, Animal; Female; Linagliptin; Obesity; Purines; Quinazolines; Rats; Rats, Wistar

Recent data indicate that dipeptidyl peptidase 4 (DPP4) inhibitors have anti-inflammatory and β-cell-sparing effects in animal models of type 1 diabetes. To evaluate the effects of the DPP4 inhibitor linagliptin on β-cell mass and insulinitis, we examined the progression of diabetes (blood glucose >11  mmol/l) in non-obese diabetic (NOD) mice with terminal stereological assessment of cellular pancreatic changes. Female NOD mice were fed a normal chow diet or a diet containing linagliptin 0.083  g/kg chow for 60 days. At study end, the incidence of diabetes in linagliptin-treated mice was reduced by almost 50% compared with vehicle (10 of 31 mice vs 18 of 30 mice, P=0.021). The total islet mass and total β-cell mass, identified by insulin immunoreactivity, were greater in non-diabetic linagliptin-treated mice compared with non-diabetic vehicle-treated mice (P<0.01 for both) but were greatly reduced in diabetic mice irrespective of treatment. No changes were seen in the α, δ and γ endocrine cell pool. Moreover, the total mass of lymphocyte insulinitis was significantly reduced in linagliptin-treated mice compared with vehicle. The data indicate that linagliptin treatment delays the onset of diabetes in NOD mice by protecting β-cell mass.

Topics: Age of Onset; Animals; Diabetes Mellitus, Type 1; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Disease Models, Animal; Disease Progression; Female; Insulin; Insulin-Secreting Cells; Linagliptin; Mice; Mice, Inbred NOD; Purines; Quinazolines

The need for an improved treatment for diabetic nephropathy is greatest in patients who do not adequately respond to angiotensin II receptor blockers (ARBs). This study investigated the effect of the novel dipeptidyl peptidase-4 inhibitor linagliptin alone and in combination with the ARB telmisartan on the progression of diabetic nephropathy in diabetic endothelial nitric oxide synthase (eNOS) knockout mice.. Sixty male eNOS knockout C57BL/6J mice were divided into four groups after receiving intraperitoneal highdose streptozotocin: telmisartan (1 mg/kg), linagliptin (3 mg/kg), linagliptin + telmisartan (3 mg/kg + 1 mg/kg) and vehicle. Fourteen mice were used as non-diabetic controls.. After 12 weeks, urine and blood were obtained and blood pressure measured. Glucose concentrations were increased and similar in all diabetic groups. Telmisartan alone reduced systolic blood pressure by 5.9 mmHg versus diabetic controls (111.2 ± 2.3 mmHg vs 117.1 ± 2.2 mmHg; mean ± SEM; P=0.071). Combined treatment significantly reduced albuminuria compared with diabetic controls (71.7 ± 15.3 µg/24 h vs. 170.8 ± 34.2 µg/24 h; P=0.017), whereas the effects of single treatment with either telmisartan (97.8 ± 26.4 µg/24 h) or linagliptin (120.8 ± 37.7 µg/24 h) were not statistically significant. DPP-4 inhibition, alone and in combination, led to significantly lower plasma osteopontin levels compared with telmisartan alone. Histological analysis revealed reduced glomerulosclerosis after Linagliptin alone and in combination with telmisartan in comparison to non treated diabetic animals (p<0.01 and p<0.05). Kidney malonaldehyde immune-reactivity, a marker of oxidative stress, was significantly lower in animals treated with linagliptin.. DPP-4 inhibition on top of ARB treatment significantly reduced urinary albumin excretion and oxidative stress in diabetic eNOS knockout mice. Linagliptin on top of an angiotensin II receptor blocker may offer a new therapeutic approach for patients with diabetic nephropathy.

Topics: Angiotensin Receptor Antagonists; Animals; Benzimidazoles; Benzoates; Blood Pressure; Diabetes Mellitus, Experimental; Diabetic Nephropathies; Dipeptidyl Peptidase 4; Disease Models, Animal; Drug Therapy, Combination; Enzyme Inhibitors; Linagliptin; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Nitric Oxide Synthase Type III; Oxidative Stress; Purines; Quinazolines; Streptozocin; Telmisartan; Treatment Outcome

Uremic cardiomyopathy contributes substantially to mortality in chronic kidney disease (CKD) patients. Glucagon-like peptide-1 (GLP-1) may improve cardiac function, but is mainly degraded by dipeptidyl peptidase-4 (DPP-4).. In a rat model of chronic renal failure, 5/6-nephrectomized [5/6N] rats were treated orally with DPP-4 inhibitors (linagliptin, sitagliptin, alogliptin) or placebo once daily for 4 days from 8 weeks after surgery, to identify the most appropriate treatment for cardiac dysfunction associated with CKD. Linagliptin showed no significant change in blood level AUC(0-∞) in 5/6N rats, but sitagliptin and alogliptin had significantly higher AUC(0-∞) values; 41% and 28% (p = 0.0001 and p = 0.0324), respectively. No correlation of markers of renal tubular and glomerular function with AUC was observed for linagliptin, which required no dose adjustment in uremic rats. Linagliptin 7 µmol/kg caused a 2-fold increase in GLP-1 (AUC 201.0 ng/l*h) in 5/6N rats compared with sham-treated rats (AUC 108.6 ng/l*h) (p = 0.01). The mRNA levels of heart tissue fibrosis markers were all significantly increased in 5/6N vs control rats and reduced/normalized by linagliptin.. DPP-4 inhibition increases plasma GLP-1 levels, particularly in uremia, and reduces expression of cardiac mRNA levels of matrix proteins and B-type natriuretic peptides (BNP). Linagliptin may offer a unique approach for treating uremic cardiomyopathy in CKD patients, with no need for dose-adjustment.

Topics: Animals; Area Under Curve; Cardiomyopathies; Dipeptidyl Peptidase 4; Dipeptidyl-Peptidase IV Inhibitors; Disease Models, Animal; Gene Expression Regulation; Glomerular Filtration Rate; Glucagon-Like Peptide 1; Heart; Humans; Kidney Failure, Chronic; Linagliptin; Myocardium; Natriuretic Peptide, Brain; Nephrectomy; Piperidines; Purines; Pyrazines; Quinazolines; Rats; Reverse Transcriptase Polymerase Chain Reaction; Sitagliptin Phosphate; Triazoles; Uracil; Uremia

Antidiabetic effects of dipeptidyl peptidase-4 (DPP-4) inhibitors are exerted by potentiation of the biological activity of incretin hormones like glucagon-like peptide (GLP)-1. BI 1356 [proposed trade name Ondero; (R)-8-(3-amino-piperidin-1-yl)-7-but-2-ynyl-3-methyl-1-(4-methyl-quinazolin-2-ylmethyl)-3,7-dihydro-purine-2,6-dione] is a novel competitive, selective, potent, and long-acting DPP-4 inhibitor under clinical development for the treatment of type 2 diabetes. The effect of 1 to 2 months of chronic dosing of BI 1356 in two different animal models was investigated. The first is a primarily genetic model (Zucker diabetic fatty rats), and the second is a nongenetic model (mice with diabetes induced by a combination of high-fat diet and low-dose streptozotocin). BI 1356 was shown to lower HbA1c after multiple dosing in both models. The improvement of glycemic control achieved in disease models of different etiology suggests that BI 1356 would also be efficacious in treating a broad spectrum of type 2 diabetic patients. In addition, multiple dosing of BI 1356 leads to a sustained increase in basal levels of active GLP-1 in the systemic circulation, with expected long-term benefits on pancreatic alpha- and beta-cells. The effects on HbA1c and GLP-1 were superior to the short-acting DPP-4 inhibitor vildagliptin, demonstrating the potential of BI 1356 as a once daily treatment for type 2 diabetes at low therapeutic doses.

Topics: Animals; Diabetes Mellitus; Disease Models, Animal; Female; Glucagon-Like Peptide 1; Glycemic Index; Humans; Hypoglycemic Agents; Linagliptin; Male; Mice; Purines; Quinazolines; Rats; Rats, Zucker; Tumor Cells, Cultured