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Sample records for hiv peptidase inhibitors

  1. Decoding the Anti-Trypanosoma cruzi Action of HIV Peptidase Inhibitors Using Epimastigotes as a Model

    PubMed Central

    Sangenito, Leandro S.; Menna-Barreto, Rubem F. S.; d′Avila-Levy, Claudia M.; Branquinha, Marta H.

    2014-01-01

    Background Aspartic peptidase inhibitors have shown antimicrobial action against distinct microorganisms. Due to an increase in the occurrence of Chagas' disease/AIDS co-infection, we decided to explore the effects of HIV aspartic peptidase inhibitors (HIV-PIs) on Trypanosoma cruzi, the etiologic agent of Chagas' disease. Methodology and Principal Findings HIV-PIs presented an anti-proliferative action on epimastigotes of T. cruzi clone Dm28c, with IC50 values ranging from 0.6 to 14 µM. The most effective inhibitors, ritonavir, lopinavir and nelfinavir, also had an anti-proliferative effect against different phylogenetic T. cruzi strains. The HIV-PIs induced some morphological alterations in clone Dm28c epimastigotes, as reduced cell size and swollen of the cellular body. Transmission electron microscopy revealed that the flagellar membrane, mitochondrion and reservosomes are the main targets of HIV-PIs in T. cruzi epimastigotes. Curiously, an increase in the epimastigote-into-trypomastigote differentiation process of clone Dm28c was observed, with many of these parasites presenting morphological alterations including the detachment of flagellum from the cell body. The pre-treatment with the most effective HIV-PIs drastically reduced the interaction process between epimastigotes and the invertebrate vector Rhodnius prolixus. It was also noted that HIV-PIs induced an increase in the expression of gp63-like and calpain-related molecules, and decreased the cruzipain expression in epimastigotes as judged by flow cytometry and immunoblotting assays. The hydrolysis of a cathepsin D fluorogenic substrate was inhibited by all HIV-PIs in a dose-dependent manner, showing that the aspartic peptidase could be a possible target to these drugs. Additionally, we verified that ritonavir, lopinavir and nelfinavir reduced drastically the viability of clone Dm28c trypomastigotes, causing many morphological damages. Conclusions and Significance The results contribute to understand

  2. Beneficial Effects of HIV Peptidase Inhibitors on Fonsecaea pedrosoi: Promising Compounds to Arrest Key Fungal Biological Processes and Virulence

    PubMed Central

    Palmeira, Vanila F.; Kneipp, Lucimar F.; Rozental, Sonia; Alviano, Celuta S.; Santos, André L. S.

    2008-01-01

    Background Fonsecaea pedrosoi is the principal etiologic agent of chromoblastomycosis, a fungal disease whose pathogenic events are poorly understood. Current therapy for chromoblastomycosis is suboptimal due to toxicity of the available therapeutic agents and the emergence of drug resistance. Compounding these problems is the fact that endemic countries and regions are economically poor. Purpose and Principal Findings In the present work, we have investigated the effect of human immunodeficiency virus (HIV) peptidase inhibitors (PIs) on the F. pedrosoi conidial secreted peptidase, growth, ultrastructure and interaction with different mammalian cells. All the PIs impaired the acidic conidial-derived peptidase activity in a dose-dependent fashion, in which nelfinavir produced the best inhibitory effect. F. pedrosoi growth was also significantly reduced upon exposure to PIs, especially nelfinavir and saquinavir. PIs treatment caused profound changes in the conidial ultrastructure as shown by transmission electron microscopy, including invaginations in the cytoplasmic membrane, disorder and detachment of the cell wall, enlargement of fungi cytoplasmic vacuoles, and abnormal cell division. The synergistic action on growth ability between nelfinavir and amphotericin B, when both were used at sub-inhibitory concentrations, was also observed. PIs reduced the adhesion and endocytic indexes during the interaction between conidia and epithelial cells (CHO), fibroblasts or macrophages, in a cell type-dependent manner. Moreover, PIs interfered with the conidia into mycelia transformation when in contact with CHO and with the susceptibility killing by macrophage cells. Conclusions/Significance Overall, by providing the first evidence that HIV PIs directly affects F. pedrosoi development and virulence, these data add new insights on the wide-spectrum efficacy of HIV PIs, further arguing for the potential chemotherapeutic targets for aspartyl-type peptidase produced by this human

  3. Evolutionary families of peptidase inhibitors.

    PubMed Central

    Rawlings, Neil D; Tolle, Dominic P; Barrett, Alan J

    2004-01-01

    The proteins that inhibit peptidases are of great importance in medicine and biotechnology, but there has never been a comprehensive system of classification for them. Some of the terminology currently in use is potentially confusing. In the hope of facilitating the exchange, storage and retrieval of information about this important group of proteins, we now describe a system wherein the inhibitor units of the peptidase inhibitors are assigned to 48 families on the basis of similarities detectable at the level of amino acid sequence. Then, on the basis of three-dimensional structures, 31 of the families are assigned to 26 clans. A simple system of nomenclature is introduced for reference to each clan, family and inhibitor. We briefly discuss the specificities and mechanisms of the interactions of the inhibitors in the various families with their target enzymes. The system of families and clans of inhibitors described has been implemented in the MEROPS peptidase database (http://merops.sanger.ac.uk/), and this will provide a mechanism for updating it as new information becomes available. PMID:14705960

  4. Different modes of dipeptidyl peptidase IV (CD26) inhibition by oligopeptides derived from the N-terminus of HIV-1 Tat indicate at least two inhibitor binding sites.

    PubMed

    Lorey, Susan; Stöckel-Maschek, Angela; Faust, Jürgen; Brandt, Wolfgang; Stiebitz, Beate; Gorrell, Mark D; Kähne, Thilo; Mrestani-Klaus, Carmen; Wrenger, Sabine; Reinhold, Dirk; Ansorge, Siegfried; Neubert, Klaus

    2003-05-01

    Dipeptidyl peptidase IV (DP IV, CD26) plays an essential role in the activation and proliferation of lymphocytes, which is shown by the immunosuppressive effects of synthetic DP IV inhibitors. Similarly, both human immunodeficiency virus-1 (HIV-1) Tat protein and the N-terminal peptide Tat(1-9) inhibit DP IV activity and T cell proliferation. Therefore, the N-terminal amino acid sequence of HIV-1 Tat is important for the inhibition of DP IV. Recently, we characterized the thromboxane A2 receptor peptide TXA2-R(1-9), bearing the N-terminal MWP sequence motif, as a potent DP IV inhibitor possibly playing a functional role during antigen presentation by inhibiting T cell-expressed DP IV [Wrenger, S., Faust, J., Mrestani-Klaus, C., Fengler, A., Stöckel-Maschek, A., Lorey, S., Kähne, T., Brandt, W., Neubert, K., Ansorge, S. & Reinhold, D. (2000) J. Biol. Chem.275, 22180-22186]. Here, we demonstrate that amino acid substitutions at different positions of Tat(1-9) can result in a change of the inhibition type. Certain Tat(1-9)-related peptides are found to be competitive, and others linear mixed-type or parabolic mixed-type inhibitors indicating different inhibitor binding sites on DP IV, at the active site and out of the active site. The parabolic mixed-type mechanism, attributed to both non-mutually exclusive inhibitor binding sites of the enzyme, is described in detail. From the kinetic investigations and molecular modeling experiments, possible interactions of the oligopeptides with specified amino acids of DP IV are suggested. These findings give new insights for the development of more potent and specific peptide-based DP IV inhibitors. Such inhibitors could be useful for the treatment of autoimmune and inflammatory diseases. PMID:12752434

  5. Peptidases and peptidase inhibitors in gut of caterpillars and in the latex of their host plants.

    PubMed

    Ramos, Márcio V; Pereira, Danielle A; Souza, Diego P; Silva, Maria-Lídia S; Alencar, Luciana M R; Sousa, Jeanlex S; Queiroz, Juliany-Fátima N; Freitas, Cleverson D T

    2015-01-01

    Studies investigating the resistance-susceptibility of crop insects to proteins found in latex fluids have been reported. However, latex-bearing plants also host insects. In this study, the gut proteolytic system of Pseudosphinx tetrio, which feeds on Plumeria rubra leaves, was characterized and further challenged against the latex proteolytic system of its own host plant and those of other latex-bearing plants. The gut proteolytic system of Danaus plexippus (monarch) and the latex proteolytic system of its host plant (Calotropis procera) were also studied. The latex proteins underwent extensive hydrolysis when mixed with the corresponding gut homogenates of the hosted insects. The gut homogenates partially digested the latex proteins of foreign plants. The fifth instar of D. plexippus that were fed diets containing foreign latex developed as well as those individuals who were fed diets containing latex proteins from their host plant. In vitro assays detected serine and cysteine peptidase inhibitors in both the gut homogenates and the latex fluids. Curiously, the peptidase inhibitors of caterpillars did not inhibit the latex peptidases of their host plants. However, the peptidase inhibitors of laticifer origin inhibited the proteolysis of gut homogenates. In vivo analyses of the peritrophic membrane proteins of D. plexippus demonstrate resistance against latex peptidases. Only discrete changes were observed when the peritrophic membrane was directly treated with purified latex peptidases in vitro. This study concludes that peptidase inhibitors are involved in the defensive systems of both caterpillars and their host plants. Although latex peptidase inhibitors inhibit gut peptidases (in vitro), the ability of gut peptidases to digest latex proteins (in vivo) regardless of their origin seems to be important in governing the resistance-susceptibility of caterpillars. PMID:25246317

  6. Cardiovascular effects of dipeptidyl peptidase-4 inhibitors

    PubMed Central

    Papagianni, M; Tziomalos, K

    2015-01-01

    Dipeptidyl peptidase-4 (DPP-4) inhibitors are effective glucose-lowering agents that do not increase body weight and are associated with a low risk for hypoglycemia. Also, they appear to exert beneficial effects on other established cardiovascular risk factors, including dyslipidemia and hypertension. Moreover, DPP-4 inhibitors exert antiinflammatory and antioxidant actions, improve endothelial function and reduce urinary albumin excretion. In contrast to these favorable cardiovascular effects, three recent large, randomized, placebo-controlled trials in patients with type 2 diabetes mellitus (T2DM) and established cardiovascular disease or multiple cardiovascular risk factors showed that DPP-4 inhibitors do not affect the risk of myocardial infarction or ischemic stroke and might increase the risk of heart failure. The findings of the former randomized studies highlight the limitations of surrogate markers and show that beneficial effects on cardiovascular risk factors do not necessarily translate into reductions in hard clinical endpoints. Ongoing trials will shed more light on the safety profile of DPP-4 inhibitors and will clarify whether they will improve the cardiovascular outcomes of patients with T2DM. Hippokratia 2015; 19 (3): 195-199. PMID:27418775

  7. Dipeptidyl peptidase-4 inhibitor for steroid-induced diabetes

    PubMed Central

    Yanai, Hidekatsu; Masui, Yoshinori; Yoshikawa, Reo; Kunimatsu, Junwa; Kaneko, Hiroshi

    2010-01-01

    The addition of the dipeptidyl peptidase-4 (DDP-4) inhibitor has been reported to achieve greater improvements in glucose metabolism with fewer adverse events compared to increasing the metformin dose in type 2 diabetic patients. We present a patient with steroid-induced diabetes whose blood glucose levels were ameliorated by the use of the DPP-4 inhibitor, showing that the DPP-4 inhibitors may be an effective and safe oral anti-diabetic drug for steroid-induced diabetes. PMID:21537433

  8. Sugarcane Serine Peptidase Inhibitors, Serine Peptidases, and Clp Protease System Subunits Associated with Sugarcane Borer (Diatraea saccharalis) Herbivory and Wounding.

    PubMed

    Medeiros, Ane H; Mingossi, Fabiana B; Dias, Renata O; Franco, Flávia P; Vicentini, Renato; Mello, Marcia O; Moura, Daniel S; Silva-Filho, Marcio C

    2016-01-01

    Sugarcane's (Saccharum spp.) response to Diatraea saccharalis (F.) (Lepidoptera: (Crambidae) herbivory was investigated using a macroarray spotted with 248 sugarcane Expressed Sequence Tags (ESTs) encoding serine peptidase inhibitors, serine peptidases. and Clp protease system subunits. Our results showed that after nine hours of herbivory, 13 sugarcane genes were upregulated and nine were downregulated. Among the upregulated genes, nine were similar to serine peptidase inhibitors and four were similar to Bowman-Birk Inhibitors (BBIs). Phylogenetic analysis revealed that these sequences belong to a phylogenetic group of sugarcane BBIs that are potentially involved in plant defense against insect predation. The remaining four upregulated genes included serine peptidases and one homolog to the Arabidopsis AAA+ chaperone subunit ClpD, which is a member of the Clp protease system. Among the downregulated genes, five were homologous to serine peptidases and four were homologous to Arabidopsis Clp subunits (three homologous to Clp AAA+ chaperones and one to a ClpP-related ClpR subunit). Although the roles of serine peptidase inhibitors in plant defenses against herbivory have been extensively investigated, the roles of plant serine peptidases and the Clp protease system represent a new and underexplored field of study. The up- and downregulated D. saccharalis genes presented in this study may be candidate genes for the further investigation of the sugarcane response to herbivory. PMID:27598134

  9. Lipoprotein effects of incretin analogs and dipeptidyl peptidase 4 inhibitors

    PubMed Central

    Zhong, Jixin; Maiseyeu, Andrei; Rajagopalan, Sanjay

    2015-01-01

    Elevated post-prandial lipoprotein levels are common in patients with type 2 diabetes. Post-prandial lipoprotein alterations in type 2 diabetics are widely believed to drive inflammation and are considered a major risk factor for cardiovascular disease in diabetic patients. The incretins glucagon like peptide-1 (GLP-1) and glucose insulinotropic peptide (GIP) modulate post-prandial lipoproteins through a multitude of pathways that are independent of insulin and weight loss. Evidence from both animal models and humans seems to suggest an important effect on triglyceride rich lipoproteins (Apo48 containing) with little to no effects on other lipoproteins at least in humans. Dipeptidyl peptidase-4 (DPP4) inhibitors also appear to share these effects suggesting an important role for incretins in these effects. In this review, we will summarize lipid modulating effects of incretin analogs and DPP-4 inhibitors in both animal models and human studies and provide an overview of mechanisms responsible for these effects. PMID:26005496

  10. Comparative review of dipeptidyl peptidase-4 inhibitors and sulphonylureas.

    PubMed

    Deacon, C F; Lebovitz, H E

    2016-04-01

    Type 2 diabetes (T2DM) is a progressive disease, and pharmacotherapy with a single agent does not generally provide durable glycaemic control over the long term. Sulphonylurea (SU) drugs have a history stretching back over 60 years, and have traditionally been the mainstay choice as second-line agents to be added to metformin once glycaemic control with metformin monotherapy deteriorates; however, they are associated with undesirable side effects, including increased hypoglycaemia risk and weight gain. Dipeptidyl peptidase (DPP)-4 inhibitors are, by comparison, more recent, with the first compound being launched in 2006, but the class now globally encompasses at least 11 different compounds. DPP-4 inhibitors improve glycaemic control with similar efficacy to SUs, but do not usually provoke hypoglycaemia or weight gain, are relatively free from adverse side effects, and have recently been shown not to increase cardiovascular risk in large prospective safety trials. Because of these factors, DPP-4 inhibitors have become an established therapy for T2DM and are increasingly being positioned earlier in treatment algorithms. The present article reviews these two classes of oral antidiabetic drugs (DPP-4 inhibitors and SUs), highlighting differences and similarities between members of the same class, as well as discussing the potential advantages and disadvantages of the two drug classes. While both classes have their merits, the choice of which to use depends on the characteristics of each individual patient; however, for the majority of patients, DPP-4 inhibitors are now the preferred choice. PMID:26597596

  11. NAAG peptidase inhibitors and their potential for diagnosis and therapy.

    PubMed

    Zhou, Jia; Neale, Joseph H; Pomper, Martin G; Kozikowski, Alan P

    2005-12-01

    Modulation of N-acetyl-L-aspartyl-L-glutamate peptidase activity with small-molecule inhibitors holds promise for a wide variety of diseases that involve glutamatergic transmission, and has implications for the diagnosis and therapy of cancer. This new class of compounds, of which at least one has entered clinical trials and proven to be well tolerated, has demonstrated efficacy in experimental models of pain, schizophrenia, amyotrophic lateral sclerosis, traumatic brain injury and, when appropriately functionalized, can image prostate cancer. Further investigation of these promising drug candidates will be needed to bring them to the marketplace. The recent publication of the X-ray crystal structure for the enzymatic target of these compounds should facilitate the development of other new agents with enhanced activity that could improve both the diagnosis and treatment of neurological disorders. PMID:16341066

  12. Natural and synthetic inhibitors of kallikrein-related peptidases (KLKs).

    PubMed

    Goettig, Peter; Magdolen, Viktor; Brandstetter, Hans

    2010-11-01

    Including the true tissue kallikrein KLK1, kallikrein-related peptidases (KLKs) represent a family of fifteen mammalian serine proteases. While the physiological roles of several KLKs have been at least partially elucidated, their activation and regulation remain largely unclear. This obscurity may be related to the fact that a given KLK fulfills many different tasks in diverse fetal and adult tissues, and consequently, the timescale of some of their physiological actions varies significantly. To date, a variety of endogenous inhibitors that target distinct KLKs have been identified. Among them are the attenuating Zn(2+) ions, active site-directed proteinaceous inhibitors, such as serpins and the Kazal-type inhibitors, or the huge, unspecific compartment forming α(2)-macroglobulin. Failure of these inhibitory systems can lead to certain pathophysiological conditions. One of the most prominent examples is the Netherton syndrome, which is caused by dysfunctional domains of the Kazal-type inhibitor LEKTI-1 which fail to appropriately regulate KLKs in the skin. Small synthetic inhibitory compounds and natural polypeptidic exogenous inhibitors have been widely employed to characterize the activity and substrate specificity of KLKs and to further investigate their structures and biophysical properties. Overall, this knowledge leads not only to a better understanding of the physiological tasks of KLKs, but is also a strong fundament for the synthesis of small compound drugs and engineered biomolecules for pharmaceutical approaches. In several types of cancer, KLKs have been found to be overexpressed, which makes them clinically relevant biomarkers for prognosis and monitoring. Thus, down regulation of excessive KLK activity in cancer and in skin diseases by small inhibitor compounds may represent attractive therapeutical approaches. PMID:20615447

  13. NAAG peptidase inhibitors and deletion of NAAG peptidase gene enhance memory in novel object recognition test.

    PubMed

    Janczura, Karolina J; Olszewski, Rafal T; Bzdega, Tomasz; Bacich, Dean J; Heston, Warren D; Neale, Joseph H

    2013-02-15

    The peptide neurotransmitter N-acetylaspartylglutamate (NAAG) is inactivated by the extracellular enzyme glutamate carboxypeptidase II. Inhibitors of this enzyme reverse dizocilpine (MK-801)-induced impairment of short-term memory in the novel object recognition test. The objective of this study was to test the hypothesis that NAAG peptidase inhibition enhances long-term (24h delay) memory of C57BL mice. These mice and mice in which glutamate carboxypeptidase II had been knocked out were presented with two identical objects to explore for 10min on day 1 and tested with one of these familiar objects and one novel object on day 2. Memory was assessed as the degree to which the mice recalled the familiar object and explored the novel object to a greater extent on day 2. Uninjected mice or mice injected with saline prior to the acquisition session on day 1 demonstrated a lack of memory of the acquisition experience by exploring the familiar and novel objects to the same extent on day 2. Mice treated with glutamate carboxypeptidase II inhibitors ZJ43 or 2-PMPA prior to the acquisition trial explored the novel object significantly more time than the familiar object on day 2. Consistent with these results, mice in which glutamate carboxypeptidase II had been knocked out distinguished the novel from the familiar object on day 2 while their heterozygous colony mates did not. Inhibition of glutamate carboxypeptidase II enhances recognition memory, a therapeutic action that might be useful in treatment of memory deficits related to age and neurological disorders. PMID:23200894

  14. Navigating the chemical space of dipeptidyl peptidase-4 inhibitors

    PubMed Central

    Shoombuatong, Watshara; Prachayasittikul, Veda; Anuwongcharoen, Nuttapat; Songtawee, Napat; Monnor, Teerawat; Prachayasittikul, Supaluk; Prachayasittikul, Virapong; Nantasenamat, Chanin

    2015-01-01

    This study represents the first large-scale study on the chemical space of inhibitors of dipeptidyl peptidase-4 (DPP4), which is a potential therapeutic protein target for the treatment of diabetes mellitus. Herein, a large set of 2,937 compounds evaluated for their ability to inhibit DPP4 was compiled from the literature. Molecular descriptors were generated from the geometrically optimized low-energy conformers of these compounds at the semiempirical AM1 level. The origins of DPP4 inhibitory activity were elucidated from computed molecular descriptors that accounted for the unique physicochemical properties inherently present in the active and inactive sets of compounds as defined by their respective half maximal inhibitory concentration values of less than 1 μM and greater than 10 μM, respectively. Decision tree analysis revealed the importance of molecular weight, total energy of a molecule, topological polar surface area, lowest unoccupied molecular orbital, and number of hydrogen-bond donors, which correspond to molecular size, energy, surface polarity, electron acceptors, and hydrogen bond donors, respectively. The prediction model was subjected to rigorous independent testing via three external sets. Scaffold and chemical fragment analysis was also performed on these active and inactive sets of compounds to shed light on the distinguishing features of the functional moieties. Docking of representative active DPP4 inhibitors was also performed to unravel key interacting residues. The results of this study are anticipated to be useful in guiding the rational design of novel and robust DPP4 inhibitors for the treatment of diabetes. PMID:26309399

  15. Astacin Family Metallopeptidases and Serine Peptidase Inhibitors in Spider Digestive Fluid

    PubMed Central

    Foradori, Matthew J.; Tillinghast, Edward K.; Smith, J. Stephen; Townley, Mark A.; Mooney, Robert E.

    2006-01-01

    Digestive fluid of the araneid spider Argiope aurantia is known to contain zinc metallopeptidases. Using anion-exchange chromatography, size-exclusion chromatography, sucrose density gradient centrifugation, and gel electrophoresis, we isolated two lower-molecular-mass peptidases, designated p16 and p18. The N-terminal amino acid sequences of p16 (37 residues) and p18 (20 residues) are 85% identical over the first 20 residues and are most similar to the N-terminal sequences of the fully active form of meprin (β subunits) from several vertebrates (47–52% and 50–60% identical, respectively). Meprin is a peptidase in the astacin (M12A) subfamily of the astacin (M12) family. Additionally, a 66-residue internal sequence obtained from p16 aligns with the conserved astacin subfamily domain. Thus, at least some spider digestive peptidases appear related to astacin of decapod crustaceans. However, important differences between spider and crustacean metallopeptidases with regard to isoelectric point and their susceptibility to hemolymph-borne inhibitors are demonstrated. Anomalous behavior of the lower-molecular-mass Argiope peptidases during certain fractionation procedures indicates that these peptidases may take part in reversible associations with each other or with other proteins. A. aurantia digestive fluid also contains inhibitory activity effective against insect digestive peptidases. Here we present evidence for at least thirteen, heat-stable serine peptidase inhibitors ranging in molecular mass from about 15 to 32 kDa. PMID:16458560

  16. Prokaryote-derived protein inhibitors of peptidases: a sketchy occurrence and mostly unknown function

    PubMed Central

    Kantyka, Tomasz; Rawlings, Neil D.; Potempa, Jan

    2010-01-01

    In metazoan organisms protein inhibitors of peptidases are important factors essential for regulation of proteolytic activity. In vertebrates genes encoding peptidase inhibitors constitute up to 1% of genes reflecting a need for tight and specific control of proteolysis especially in extracellular body fluids. In stark contrast unicellular organisms, both prokaryotic and eukaryotic consistently contain only few, if any, genes coding for putative peptidase inhibitors. This may seem perplexing in the light of the fact that these organisms produce large numbers of proteases of different catalytic classes with the genes constituting up to 6% of the total gene count with the average being about 3%. Apparently, however, a unicellular life-style is fully compatible with other mechanisms of regulation of proteolysis and does not require protein inhibitors to control their intracellular and extracellular proteolytic activity. So in prokaryotes occurrence of genes encoding different types of peptidase inhibitors is infrequent and often scattered among phylogenetically distinct orders or even phyla of microbiota. Genes encoding proteins homologous to alpha-2-macroglobulin (family I39), serine carboxypeptidase Y inhibitor (family I51), alpha-1-peptidase inhibitor (family I4) and ecotin (family I11) are the most frequently represented in Bacteria. Although several of these gene products were shown to possess inhibitory activity, with an exception of ecotin and staphostatins, the biological function of microbial inhibitors is unclear. In this review we present distribution of protein inhibitors from different families among prokaryotes, describe their mode of action and hypothesize on their role in microbial physiology and interactions with hosts and environment. PMID:20558234

  17. Some properties and possible biological role of peptidase inhibitors from the entomopathogenic fungus Tolypocladium cylindrosporum.

    PubMed

    Popova, V V; Dunaevsky, Y E; Domash, V I; Semenova, T A; Beliakova, G A; Belozersky, M A

    2015-10-01

    The activities of secreted and mycelial inhibitors of proteolytic enzymes from fungi of the order Hypocreales have been investigated. Inhibitors of bromelain, papain, and trypsin of low molecular mass (about 1 kDa) and a subtilisin proteinaceous inhibitor with molecular mass of 45 kDa were revealed in the culture liquid of the fungus Tolypocladium cylindrosporum. The subtilisin inhibitor from T. cylindrosporum has antibiotic properties, significantly decreased the activity of purified bacterial enzymes, and prevented the growth of the bacterium Pseudomonas sp. Data suggesting the existence in fungi of the Hypocreales order of two pools of peptidase inhibitors have been obtained. PMID:26210235

  18. Phytomonas serpens: cysteine peptidase inhibitors interfere with growth, ultrastructure and host adhesion.

    PubMed

    Santos, André L S; d'Avila-Levy, Claudia M; Dias, Felipe A; Ribeiro, Rachel O; Pereira, Fernanda M; Elias, Camila G R; Souto-Padrón, Thaïs; Lopes, Angela H C S; Alviano, Celuta S; Branquinha, Marta H; Soares, Rosangela M A

    2006-01-01

    In this study, we report the ultrastructural and growth alterations caused by cysteine peptidase inhibitors on the plant trypanosomatid Phytomonas serpens. We showed that the cysteine peptidase inhibitors at 10 microM were able to arrest cellular growth as well as promote alterations in the cell morphology, including the parasites becoming short and round. Additionally, iodoacetamide induced ultrastructural alterations, such as disintegration of cytoplasmic organelles, swelling of the nucleus and kinetoplast-mitochondrion complex, which culminated in parasite death. Leupeptin and antipain induced the appearance of microvillar extensions and blebs on the cytoplasmic membrane, resembling a shedding process. A 40 kDa cysteine peptidase was detected in hydrophobic and hydrophilic phases of P. serpens cells after Triton X-114 extraction. Additionally, we have shown through immunoblotting that anti-cruzipain polyclonal antibodies recognised two major polypeptides in P. serpens, including a 40 kDa component. Flow cytometry analysis confirmed that this cruzipain-like protein has a location on the cell surface. Ultrastructural immunocytochemical analysis demonstrated the presence of the cruzipain-like protein on the surface and in small membrane fragments released from leupeptin-treated parasites. Furthermore, the involvement of cysteine peptidases of P. serpens in the interaction with explanted salivary glands of the phytophagous insect Oncopeltus fasciatus was also investigated. When P. serpens cells were pre-treated with either cysteine peptidase inhibitors or anti-cruzipain antibody, a significant reduction of the interaction process was observed. Collectively, these results suggest that cysteine peptidases participate in several biological processes in P. serpens including cell growth and interaction with the invertebrate vector. PMID:16310789

  19. Local administration of N-acetylaspartylglutamate (NAAG) peptidase inhibitors is analgesic in peripheral pain in rats.

    PubMed

    Yamamoto, Tatsuo; Saito, Osamu; Aoe, Tomohiko; Bartolozzi, Alessandra; Sarva, Jayaprakash; Zhou, Jia; Kozikowski, Alan; Wroblewska, Barbara; Bzdega, Tomasz; Neale, Joseph H

    2007-01-01

    The peptide neurotransmitter N-acetylaspartylglutamate (NAAG) selectively activates group II metabotropic glutamate receptors (mGluRs). Systemic administration of inhibitors of the enzymes that inactivate NAAG results in decreased pain responses in rat models of inflammatory and neuropathic pain. These effects are blocked by a group II mGluR antagonist. This research tested the hypothesis that some analgesic effects of NAAG peptidase inhibition are mediated by NAAG acting on sensory neurite mGluRs at the site of inflammation. Group II mGluR agonists, SLx-3095-1, NAAG and APDC, or NAAG peptidase inhibitors, ZJ-43 and 2-PMPA, injected into the rat footpad reduced pain responses in carrageenan or formalin models. The analgesic effects of SLx-3095-1, APDC, ZJ-43, 2-PMPA and NAAG were blocked by co-injection of LY341495, a selective group II mGluR antagonist. Injection of group II mGluR agonists, NAAG or the peptidase inhibitors into the contralateral rat footpad had no effect on pain perception in the injected paw. At 10-100 microm ZJ-43 and 2-PMPA demonstrated no consistent agonist activity at mGluR2 or mGluR3. Consistent with the conclusion that peripherally administered NAAG peptidase inhibitors increase the activation of mGluR3 by NAAG that is released from peripheral sensory neurites, we found that the tissue average concentration of NAAG in the unstimulated rat hind paw was about 6 microm. These data extend our understanding of the role of this peptide in sensory neurons and reveal the potential for treatment of inflammatory pain via local application of NAAG peptidase inhibitors at doses that may have little or no central nervous system effects. PMID:17241276

  20. Identification of dipeptidyl peptidase IV inhibitors: virtual screening, synthesis and biological evaluation.

    PubMed

    Xing, Junhao; Li, Qing; Zhang, Shengping; Liu, Haomiao; Zhao, Leilei; Cheng, Haibo; Zhang, Yuan; Zhou, Jinpei; Zhang, Huibin

    2014-09-01

    Inhibition of dipeptidyl peptidase IV is an important approach for the treatment of type-2 diabetes. In this study, we reported a multistage virtual screening workflow that integrated 3D pharmacophore models, structural consensus docking, and molecular mechanics/generalized Born surface area binding energy calculation to identify novel dipeptidyl peptidase IV inhibitors. After screening our in-house database, two hit compounds, HWL-405 and HWL-892, having persistent high performance in all stages of virtual screening were identified. These two hit compounds together with several analogs were synthesized and evaluated for in vitro inhibition of dipeptidyl peptidase IV. The experimental data indicated that most designed compounds exhibited significant dipeptidyl peptidase IV inhibitory activity. Among them, compounds 35f displayed the greatest potency against dipeptidyl peptidase IV in vitro with the IC50 value of 78 nm. In an oral glucose tolerance test in normal male Kunming mice, compound 35f reduced blood glucose excursion in a dose-dependent manner. PMID:24674599

  1. Aminopiperidine-Fused Imidazoles as Dipeptidyl Peptidase-IV Inhibitors

    SciTech Connect

    Edmondson, S.; Mastracchio, A; Cox, J; Eiermann, G; He, H; Lyons, K; Patel, R; Patel, S; Petrov, A; et. al.

    2009-01-01

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

  2. [Description of an acidic peptidase, insensitive to classical inhibitors, in protein extracts of Trypanosoma cruzi, from a rural area of Venezuela, where Chagas disease is endemic].

    PubMed

    Zambrano, Edgar Armando; de la Cruz, Henry Samuel; Coita, Blanca Elena

    2013-09-01

    Through two peptidase assay methods, one in liquid-phase and another, in gel-phase (gel zymography), an acid peptidase was detected in protein crude extracts of epimastigotes of Trypanosoma cruzi, from a rural area of Venezuela where Chagas disease is endemic. The peptidase shows activity at a pH range between 2.0 and 2.9. Under the experimental conditions described, the acid peptidase was insensitive to usual concentrations of peptidase inhibitors of the types: serine, cysteine, aspartic and metallopeptidases. Nevertheless, like porcine pepsin at pH 2.9, the peptidase was inhibited in the presence of 5mM DTT. PMID:24354241

  3. Whey proteins as source of dipeptidyl dipeptidase IV (dipeptidyl peptidase-4) inhibitors.

    PubMed

    Tulipano, Giovanni; Sibilia, Valeria; Caroli, Anna Maria; Cocchi, Daniela

    2011-04-01

    Preclinical and clinical studies suggest that whey proteins can reduce postprandial glucose levels and stimulate insulin release in healthy subjects and in subjects with type 2 diabetes by reducing dipeptidyl peptidase-4 (DPP-4) activity in the proximal bowel and hence increasing intact incretin levels. Our aim was to identify DPP-4 inhibitors among short peptides occurring in hydrolysates of β-lactoglobulin, the major whey protein found in the milk of ruminants. We proved that the bioactive peptide Ile-Pro-Ala can be regarded as a moderate DPP-4 inhibitor. PMID:21256171

  4. Three ileus cases associated with the use of dipeptidyl peptidase-4 inhibitors in diabetic patients.

    PubMed

    Kanasaki, Keizo; Konishi, Kazunori; Hayashi, Ranji; Shiroeda, Hisakazu; Nomura, Tomoe; Nakagawa, Atsushi; Nagai, Takako; Takeda-Watanabe, Ai; Ito, Hiroki; Tsuda, Shin-Ichi; Kitada, Munehiro; Fujii, Mizue; Kanasaki, Megumi; Nishizawa, Makoto; Nakano, Yasuharu; Tomita, Yasuto; Ueda, Nobuhiko; Kosaka, Takeo; Koya, Daisuke

    2013-11-27

    Dipeptidyl peptidase (DPP)-4 inhibitors are a new class of antidiabetic drugs that increase incretin hormone levels to enhance blood sugar level-dependent insulinotropic effects, suppress glucagon action, and reduce bowel motility. These incretin effects are ideal for blood sugar control. However, the safety profile of DPP-4 inhibitors is not yet established. Herein, we present three cases of ileus, considered to be closely related to the use of DPP-4 inhibitors, in diabetic patients. Each of the three patients exhibited some risk of a deficiency in bowel movement; the onset of ileus was within 40 days after strengthened inhibition of DPP-4. The use of a DPP-4 inhibitor could be safe, although the cases presented herein enable us to inform the scientific community to some of the potential adverse effects of the use of DPP-4 inhibitors in select populations. PMID:24843724

  5. Methionine AminoPeptidase Type-2 Inhibitors Targeting Angiogenesis.

    PubMed

    Ehlers, Tedman; Furness, Scott; Robinson, Thomas Philip; Zhong, Haizhen A; Goldsmith, David; Aribser, Jack; Bowen, J Phillip

    2016-01-01

    Angiogenesis has been identified as a crucial process in the development and spread of cancers. There are many regulators of angiogenesis which are not yet fully understood. Methionine aminiopeptidase is a metalloenzyme with two structurally distinct forms in humans, Type-1 (MetAP-1) and Type-2 (MetAP-2). It has been shown that small molecule inhibitors of MetAP-2 suppress endothelial cell proliferation. The initial discovery by Donald Ingber of MetAP-2 inhibition as a potential target in angiogenesis began with a fortuitous observation similar to the discovery of penicillin activity by Sir Alexander Fleming. From a drug design perspective, MetAP-2 is an attractive target. Fumagillin and ovalicin, known natural products, bind with IC50 values in low nanomolar concentrations. Crystal structures of the bound complexes provide 3-dimensional coordinates for advanced computational studies. More recent discoveries have shown other biological activities for MetAP-2 inhibition, which has generated new interests in the design of novel inhibitors. Semisynthetic fumagillin derivatives such as AGM-1470 (TNP-470) have been shown to have better drug properties, but have not been very successful in clinical trials. The rationale and development of novel multicyclic analogs of fumagillin are reviewed. PMID:26369821

  6. Effects of NAAG peptidase inhibitor 2-PMPA in model chronic pain - relation to brain concentration.

    PubMed

    Nagel, Jens; Belozertseva, Irina; Greco, Sergio; Kashkin, Vladimir; Malyshkin, Andrey; Jirgensons, Aigars; Shekunova, Elena; Eilbacher, Bernd; Bespalov, Anton; Danysz, Wojciech

    2006-12-01

    N-acetylated-alpha-linked-acidic peptidase (NAAG peptidase) converts N-acetyl-aspartyl-glutamate (NAAG, mGluR3 agonist) into N-acetyl-aspartate and glutamate. The NAAG peptidase inhibitor 2-PMPA (2-(phosphonomethyl)pentanedioic acid) had neuroprotective activity in an animal model of stroke and anti-allodynic activity in CCI model despite its uncertain ability to penetrate the blood-brain barrier. The NAAG concentration in brain ECF under basal conditions and its alteration in relation to the brain ECF concentration of 2-PMPA is unclear. We therefore assessed those brain concentrations after i.p. administration of 2-PMPA, using in vivo microdialysis combined with LC/MS/MS analysis. Administration of 2-PMPA (50mg/kg) produced a mean peak concentration of 2-PMPA of 29.66+/-8.1microM. This concentration is about 100,000 fold more than is needed for inhibition of NAAG peptidase, and indicates very good penetration to the brain. Application of 2-PMPA was followed by a linear increase of NAAG-concentration reaching a maximum of 2.89+/-0.42microM at the end of microdialysis. However, during the time the anti-allodynic effects of 2-PMPA were observed, the NAAG concentration in the ECF did not reach levels which are likely to have an impact on any known target. It appears therefore that the observed behavioural effects of 2-PMPA may not be mediated by NAAG nor, in turn, by mGluR3 receptors. PMID:16926034

  7. Antibacterial Activity of and Resistance to Small Molecule Inhibitors of the ClpP Peptidase

    PubMed Central

    Compton, Corey L.; Schmitz, Karl R.; Sauer, Robert T.; Sello, Jason K.

    2014-01-01

    There is rapidly mounting evidence that intracellular proteases in bacteria are compelling targets for antibacterial drugs. Multiple reports suggest that the human pathogen Mycobacterium tuberculosis and other actinobacteria may be particularly sensitive to small molecules that perturb the activities of self-compartmentalized peptidases, which catalyze intracellular protein turnover as components of ATP-dependent proteolytic machines. Here, we report chemical syntheses and evaluations of structurally diverse β-lactones, which have a privileged structure for selective, suicide inhibition of the self-compartmentalized ClpP peptidase. β-lactones with certain substituents on the α- and β-carbons were found to be toxic to M. tuberculosis. Using an affinity-labeled analog of a bioactive β-lactone in a series of chemical proteomic experiments, we selectively captured the ClpP1P2 peptidase from live cultures of two different actinobacteria that are related to M. tuberculosis. Importantly, we found that the growth inhibitory β-lactones also inactivate the M. tuberculosis ClpP1P2 peptidase in vitro via formation of a covalent adduct at the ClpP2 catalytic serine. Given the potent antibacterial activity of these compounds and their medicinal potential, we sought to identify innate mechanisms of resistance. Using a genome mining strategy, we identified a genetic determinant of β-lactone resistance in Streptomyces coelicolor, a non-pathogenic relative of M. tuberculosis. Collectively, these findings validate the potential of ClpP inhibition as a strategy in antibacterial drug development and define a mechanism by which bacteria could resist the toxic effects of ClpP inhibitors. PMID:24047344

  8. Serpin peptidase inhibitor clade A member 1 is a biomarker of poor prognosis in gastric cancer

    PubMed Central

    Kwon, C H; Park, H J; Lee, J R; Kim, H K; Jeon, T Y; Jo, H-J; Kim, D H; Kim, G H; Park, D Y

    2014-01-01

    Background: In a previous study, we reported that serpin peptidase inhibitor clade A member 1 (serpinA1) is upregulated in Snail-overexpressing gastric cancer. Although serpinA1 has been studied in several types of cancer, little is known about its roles and mechanisms of action. In this study, we examined the role of serpinA1 in the migration and invasion of gastric cancers and determined its underlying mechanism. Methods: Expression levels were assessed by western blot analyses and real-time PCR. Snail binding to serpinA1 promoter was analysed by chromatin immunoprecipitation (ChIP) assays. The roles of serpinA1 were studied using cell invasion and migration assays. In addition, the clinicopathologic and prognostic significance of serpinA1 expression were validated in 400 gastric cancer patients using immunohistochemical analysis. Results: Overexpression of Snail resulted in upregulation of serpinA1 in gastric cancer cell lines, AGS and MKN45, whereas knockdown of Snail inhibited serpinA1 expression. Chromatin immunoprecipitation analysis showed that overexpression of Snail increased Snail recruitment to the serpinA1 promoter. Overexpression of serpinA1 increased the migration and invasion of gastric cancer cells, whereas knockdown of serpinA1 decreased invasion and migration. Moreover, serpinA1 increased mRNA levels and release of metalloproteinase-8 in gastric cancer cells. Serpin peptidase inhibitor clade A member 1 was observed in the cytoplasm of tumour cells and the stroma by immunohistochemistry. Enhanced serpinA1 expression was significantly associated with increased tumour size, advanced T stage, perineural invasion, lymphovascular invasion, lymph node metastases, and shorter overall survival. Conclusions: Serpin peptidase inhibitor clade A member 1 induces the invasion and migration of gastric cancer cells and its expression is associated with the progression of gastric cancer. These results may provide a potential target to prevent invasion and

  9. Dipeptidyl peptidase-4 inhibitors and fracture risk: an updated meta-analysis of randomized clinical trials

    PubMed Central

    Fu, Jianying; Zhu, Jianhong; Hao, Yehua; Guo, Chongchong; Zhou, Zhikun

    2016-01-01

    Data on the effects of dipeptidyl peptidase-4 (DPP-4) inhibitors on fracture risk are conflicting. Here, we performed a systematic review and meta-analysis of randomized controlled trials (RCTs) assessing the effects of DPP-4 inhibitors. Electronic databases were searched for relevant published articles, and unpublished studies presented at ClinicalTrials.gov were searched for relevant clinical data. Eligible studies included prospective randomized trials evaluating DPP-4 inhibitors versus placebo or other anti-diabetic medications in patients with type 2 diabetes. Study quality was determined using Jadad scores. Statistical analyses were performed to calculate the risk ratios (RRs) and 95% confidence intervals (CIs) using fixed-effects models. There were 62 eligible RCTs with 62,206 participants, including 33,452 patients treated with DPP-4 inhibitors. The number of fractures was 364 in the exposed group and 358 in the control group. The overall risk of fracture did not differ between patients exposed to DPP-4 inhibitors and controls (RR, 0.95; 95% CI, 0.83–1.10; P = 0.50). The results were consistent across subgroups defined by type of DPP-4 inhibitor, type of control, and length of follow-up. The study showed that DPP-4 inhibitor use does not modify the risk of bone fracture compared with placebo or other anti-diabetic medications in patients with type 2 diabetes. PMID:27384445

  10. Dipeptidyl peptidase-4 inhibitors and fracture risk: an updated meta-analysis of randomized clinical trials.

    PubMed

    Fu, Jianying; Zhu, Jianhong; Hao, Yehua; Guo, Chongchong; Zhou, Zhikun

    2016-01-01

    Data on the effects of dipeptidyl peptidase-4 (DPP-4) inhibitors on fracture risk are conflicting. Here, we performed a systematic review and meta-analysis of randomized controlled trials (RCTs) assessing the effects of DPP-4 inhibitors. Electronic databases were searched for relevant published articles, and unpublished studies presented at ClinicalTrials.gov were searched for relevant clinical data. Eligible studies included prospective randomized trials evaluating DPP-4 inhibitors versus placebo or other anti-diabetic medications in patients with type 2 diabetes. Study quality was determined using Jadad scores. Statistical analyses were performed to calculate the risk ratios (RRs) and 95% confidence intervals (CIs) using fixed-effects models. There were 62 eligible RCTs with 62,206 participants, including 33,452 patients treated with DPP-4 inhibitors. The number of fractures was 364 in the exposed group and 358 in the control group. The overall risk of fracture did not differ between patients exposed to DPP-4 inhibitors and controls (RR, 0.95; 95% CI, 0.83-1.10; P = 0.50). The results were consistent across subgroups defined by type of DPP-4 inhibitor, type of control, and length of follow-up. The study showed that DPP-4 inhibitor use does not modify the risk of bone fracture compared with placebo or other anti-diabetic medications in patients with type 2 diabetes. PMID:27384445

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

    SciTech Connect

    Kozuka, Miyuki; Yamane, Takuya; Nakano, Yoshihisa; Nakagaki, Takenori; Ohkubo, Iwao; Ariga, Hiroyoshi

    2015-09-25

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

  12. Inhibitors of signal peptide peptidase (SPP) affect HSV-1 infectivity in vitro and in vivo

    PubMed Central

    Allen, Sariah J.; Mott, Kevin R.; Ghiasi, Homayon

    2014-01-01

    Recently we have shown that the highly conserved herpes simplex virus glycoprotein K (gK) binds to signal peptide peptidase (SPP), also known as minor histocompatibility antigen H13. In this study we have demonstrated for the first time that inhibitors of SPP, such as L685,458, (Z-LL)2 ketone, aspirin, ibuprofen and DAPT, significantly reduced HSV-1 replication in tissue culture. Inhibition of SPP activity via (Z-LL)2 ketone significantly reduced viral transcripts in the nucleus of infected cells. Finally, when administered during primary infection, (Z-LL)2 ketone inhibitor reduced HSV-1 replication in the eyes of ocularly infected mice. Thus, blocking SPP activity may represent a clinically effective and expedient approach to the reduction of viral replication and the resulting pathology. PMID:24768597

  13. Inhibition of kallikrein-related peptidases by the serine protease inhibitor of Kazal-type 6.

    PubMed

    Kantyka, Tomasz; Fischer, Jan; Wu, Zhihong; Declercq, Wim; Reiss, Karina; Schröder, Jens-Michael; Meyer-Hoffert, Ulf

    2011-06-01

    Kallikrein-related peptidases (KLKs) are a group of serine proteases, expressed in several tissues. Their activity is regulated by inhibitors including members of the serine protease of Kazal-type (SPINK) family. Recently, we discovered that SPINK6 is expressed in human skin and inhibits KLK5, KLK7, KLK14 but not KLK8. In this study we tested whether SPINK6 inhibits other members of the KLK family and caspase-14. Using chromogenic substrates, SPINK6 exhibited inhibitory activity against KLK12 and KLK13 with K(i) around 1nM, KLK4 with K(i)=27.3nM, KLK6 with K(i)=140nM, caspase-14 with a K(i) approximating 1μM and no activity against KLK1, KLK3 and KLK11. Taken together, SPINK6 is a potent inhibitor of distinct KLKs members. PMID:21439340

  14. Dipeptidyl Peptidase-4 Inhibitor Increases Vascular Leakage in Retina through VE-cadherin Phosphorylation.

    PubMed

    Lee, Choon-Soo; Kim, Yun Gi; Cho, Hyun-Jai; Park, Jonghanne; Jeong, Heewon; Lee, Sang-Eun; Lee, Seung-Pyo; Kang, Hyun-Jae; Kim, Hyo-Soo

    2016-01-01

    The inhibitors of CD26 (dipeptidyl peptidase-4; DPP4) have been widely prescribed to control glucose level in diabetic patients. DPP4-inhibitors, however, accumulate stromal cell-derived factor-1α (SDF-1α), a well-known inducer of vascular leakage and angiogenesis both of which are fundamental pathophysiology of diabetic retinopathy. The aim of this study was to investigate the effects of DPP4-inhibitors on vascular permeability and diabetic retinopathy. DPP4-inhibitor (diprotin A or sitagliptin) increased the phosphorylation of Src and vascular endothelial-cadherin (VE-cadherin) in human endothelial cells and disrupted endothelial cell-to-cell junctions, which were attenuated by CXCR4 (receptor of SDF-1α)-blocker or Src-inhibitor. Disruption of endothelial cell-to-cell junctions in the immuno-fluorescence images correlated with the actual leakage of the endothelial monolayer in the transwell endothelial permeability assay. In the Miles assay, vascular leakage was observed in the ears into which SDF-1α was injected, and this effect was aggravated by DPP4-inhibitor. In the model of retinopathy of prematurity, DPP4-inhibitor increased not only retinal vascularity but also leakage. Additionally, in the murine diabetic retinopathy model, DPP4-inhibitor increased the phosphorylation of Src and VE-cadherin and aggravated vascular leakage in the retinas. Collectively, DPP4-inhibitor induced vascular leakage by augmenting the SDF-1α/CXCR4/Src/VE-cadherin signaling pathway. These data highlight safety issues associated with the use of DPP4-inhibitors. PMID:27381080

  15. Dipeptidyl Peptidase-4 Inhibitor Increases Vascular Leakage in Retina through VE-cadherin Phosphorylation

    PubMed Central

    Lee, Choon-Soo; Kim, Yun Gi; Cho, Hyun-Jai; Park, Jonghanne; Jeong, Heewon; Lee, Sang-Eun; Lee, Seung-Pyo; Kang, Hyun-Jae; Kim, Hyo-Soo

    2016-01-01

    The inhibitors of CD26 (dipeptidyl peptidase-4; DPP4) have been widely prescribed to control glucose level in diabetic patients. DPP4-inhibitors, however, accumulate stromal cell-derived factor-1α (SDF-1α), a well-known inducer of vascular leakage and angiogenesis both of which are fundamental pathophysiology of diabetic retinopathy. The aim of this study was to investigate the effects of DPP4-inhibitors on vascular permeability and diabetic retinopathy. DPP4-inhibitor (diprotin A or sitagliptin) increased the phosphorylation of Src and vascular endothelial-cadherin (VE-cadherin) in human endothelial cells and disrupted endothelial cell-to-cell junctions, which were attenuated by CXCR4 (receptor of SDF-1α)-blocker or Src-inhibitor. Disruption of endothelial cell-to-cell junctions in the immuno-fluorescence images correlated with the actual leakage of the endothelial monolayer in the transwell endothelial permeability assay. In the Miles assay, vascular leakage was observed in the ears into which SDF-1α was injected, and this effect was aggravated by DPP4-inhibitor. In the model of retinopathy of prematurity, DPP4-inhibitor increased not only retinal vascularity but also leakage. Additionally, in the murine diabetic retinopathy model, DPP4-inhibitor increased the phosphorylation of Src and VE-cadherin and aggravated vascular leakage in the retinas. Collectively, DPP4-inhibitor induced vascular leakage by augmenting the SDF-1α/CXCR4/Src/VE-cadherin signaling pathway. These data highlight safety issues associated with the use of DPP4-inhibitors. PMID:27381080

  16. Gene Pyramiding of Peptidase Inhibitors Enhances Plant Resistance to the Spider Mite Tetranychus urticae

    PubMed Central

    Santamaria, Maria Estrella; Cambra, Inés; Martinez, Manuel; Pozancos, Clara; González-Melendi, Pablo; Grbic, Vojislava; Castañera, Pedro; Ortego, Felix; Diaz, Isabel

    2012-01-01

    The two-spotted spider mite Tetranychus urticae is a damaging pest worldwide with a wide range of host plants and an extreme record of pesticide resistance. Recently, the complete T. urticae genome has been published and showed a proliferation of gene families associated with digestion and detoxification of plant secondary compounds which supports its polyphagous behaviour. To overcome spider mite adaptability a gene pyramiding approach has been developed by co-expressing two barley proteases inhibitors, the cystatin Icy6 and the trypsin inhibitor Itr1 genes in Arabidopsis plants by Agrobacterium-mediated transformation. The presence and expression of both transgenes was studied by conventional and quantitative real time RT-PCR assays and by indirect ELISA assays. The inhibitory activity of cystatin and trypsin inhibitor was in vitro analysed using specific substrates. Single and double transformants were used to assess the effects of spider mite infestation. Double transformed lines showed the lowest damaged leaf area in comparison to single transformants and non-transformed controls and different accumulation of H2O2 as defence response in the leaf feeding site, detected by diaminobenzidine staining. Additionally, an impact on endogenous mite cathepsin B- and L-like activities was observed after feeding on Arabidopsis lines, which correlates with a significant increase in the mortality of mites fed on transformed plants. These effects were analysed in view of the expression levels of the target mite protease genes, C1A cysteine peptidase and S1 serine peptidase, identified in the four developmental mite stages (embryo, larvae, nymphs and adults) performed using the RNA-seq information available at the BOGAS T. urticae database. The potential of pyramiding different classes of plant protease inhibitors to prevent plant damage caused by mites as a new tool to prevent pest resistance and to improve pest control is discussed. PMID:22900081

  17. The dipeptidyl peptidase-4 inhibitor sitagliptin suppresses mouse colon tumorigenesis in type 2 diabetic mice.

    PubMed

    Yorifuji, Naoki; Inoue, Takuya; Iguchi, Munetaka; Fujiwara, Kaori; Kakimoto, Kazuki; Nouda, Sadaharu; Okada, Toshihiko; Kawakami, Ken; Abe, Yosuke; Takeuchi, Toshihisa; Higuchi, Kazuhide

    2016-02-01

    Patients with type 2 diabetes mellitus are known to have an increased risk of colorectal neoplasia. Dipeptidyl peptidase-4 (DPP-4) inhibitors have been used as a new therapeutic tool for type 2 diabetes. Since the substrates for DPP-4 include intestinotrophic hormones and chemokines such as GLP-2 and stromal cell-derived factor-1 (SDF-1), which are associated with tumor progression, DPP-4 inhibitors may increase the risk of colorectal tumors. However, the influence of DPP-4 inhibitors on colorectal neoplasia in patients with type 2 diabetes remains unknown. In the present study, we show that long-term administration of a DPP-4 inhibitor, sitagliptin (STG), suppressed colon carcinogenesis in leptin-deficient (ob/ob) C57BL/6J mice. Colonic mucosal concentrations of glucagon‑like peptide-1 (GLP-1) and GLP-2 were significantly elevated in the ob/ob mice. However, mucosal GLP concentrations and the plasma level of SDF-1 were not affected by the administration of STG. Real‑time PCR analysis revealed that colonic mucosal IL-6 mRNA expression, which was significantly upregulated in the ob/ob mice, was significantly suppressed by the long-term administration of STG. These results suggest that a DPP-4 inhibitor may suppress colon carcinogenesis in mice with type 2 diabetes in a GLP-independent manner. Since DPP-4 has multiple biological functions, further studies analyzing other factors related to colon carcinogenesis are needed. PMID:26573958

  18. Combination therapy of dipeptidyl peptidase-4 inhibitors and metformin in type 2 diabetes: rationale and evidence.

    PubMed

    Liu, Y; Hong, T

    2014-02-01

    The main pathogenesis of type 2 diabetes mellitus (T2DM) includes insulin resistance and pancreatic islet dysfunction. Metformin, which attenuates insulin resistance, has been recommended as the first-line antidiabetic medication. Dipeptidyl peptidase-4 (DPP-4) inhibitors are novel oral hypoglycaemic agents that protect glucagon-like peptide-1 (GLP-1) from degradation, maintain the bioactivity of endogenous GLP-1, and thus improve islet dysfunction. Results from clinical trials have shown that the combination therapy of DPP-4 inhibitors and metformin [as an add-on, an initial combination or a fixed-dose combination (FDC)] provides excellent efficacy and safety in patients with T2DM. Moreover, recent studies have suggested that metformin enhances the biological effect of GLP-1 by increasing GLP-1 secretion, suppressing activity of DPP-4 and upregulating the expression of GLP-1 receptor in pancreatic β-cells. Conversely, DPP-4 inhibitors have a favourable effect on insulin sensitivity in patients with T2DM. Therefore, the combination of DPP-4 inhibitors and metformin provides an additive or even synergistic effect on metabolic control in patients with T2DM. This article provides an overview of clinical evidence and discusses the rationale for the combination therapy of DPP-4 inhibitors and metformin. PMID:23668534

  19. Differential Inhibition of Signal Peptide Peptidase Family Members by Established γ-Secretase Inhibitors

    PubMed Central

    Ran, Yong; Ladd, Gabriela Z.; Ceballos-Diaz, Carolina; Jung, Joo In; Greenbaum, Doron; Felsenstein, Kevin M.; Golde, Todd E.

    2015-01-01

    The signal peptide peptidases (SPPs) are biomedically important proteases implicated as therapeutic targets for hepatitis C (human SPP, (hSPP)), plasmodium (Plasmodium SPP (pSPP)), and B-cell immunomodulation and neoplasia (signal peptide peptidase like 2a, (SPPL2a)). To date, no drug-like, selective inhibitors have been reported. We use a recombinant substrate based on the amino-terminus of BRI2 fused to amyloid β 1-25 (Aβ1-25) (FBA) to develop facile, cost-effective SPP/SPPL protease assays. Co-transfection of expression plasmids expressing the FBA substrate with SPP/SPPLs were conducted to evaluate cleavage, which was monitored by ELISA, Western Blot and immunoprecipitation/MALDI-TOF Mass spectrometry (IP/MS). No cleavage is detected in the absence of SPP/SPPL overexpression. Multiple γ-secretase inhibitors (GSIs) and (Z-LL)2 ketone differentially inhibited SPP/SPPL activity; for example, IC50 of LY-411,575 varied from 51±79 nM (on SPPL2a) to 5499±122 nM (on SPPL2b), while Compound E showed inhibition only on hSPP with IC50 of 1465±93 nM. Data generated were predictive of effects observed for endogenous SPPL2a cleavage of CD74 in a murine B-Cell line. Thus, it is possible to differentially inhibit SPP family members. These SPP/SPPL cleavage assays will expedite the search for selective inhibitors. The data also reinforce similarities between SPP family member cleavage and cleavage catalyzed by γ-secretase. PMID:26046535

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

    PubMed

    Kozuka, Miyuki; Yamane, Takuya; Nakano, Yoshihisa; Nakagaki, Takenori; Ohkubo, Iwao; Ariga, Hiroyoshi

    2015-09-25

    Aronia berries have many potential effects on health, including an antioxidant effect, effect for antimutagenesis, hepatoprotection and cardioprotection, an antidiabetic effect and inhibition of cancer cell proliferation. Previous human studies have shown that aronia juice may be useful for treatment of obesity disorders. In this study, we found that aronia juice has an inhibitory effect against dipeptidyl peptidase IV (DPP IV) (EC 3.4.14.5). DPP IV is a peptidase that cleaves the N-terminal region of incretins such as glucagon-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1). Inactivation of incretins by DPP IV induces reduction of insulin secretion. Furthermore, we identified that cyanidin 3, 5-diglucoside as the DPP IV inhibitor in aronia juice. DPP IV was inhibited more strongly by cyanidin 3, 5-diglucoside than by cyanidin and cyanidin 3-glucoside. The results suggest that DPP IV is inhibited by cyanidin 3, 5-diglucoside present in aronia juice. The antidiabetic effect of aronia juice may be mediated through DPP IV inhibition by cyanidin 3, 5-diglucoside. PMID:26296465

  1. Clinical pharmacology of dipeptidyl peptidase 4 inhibitors indicated for the treatment of type 2 diabetes mellitus.

    PubMed

    Chen, Xiao-Wu; He, Zhi-Xu; Zhou, Zhi-Wei; Yang, Tianxin; Zhang, Xueji; Yang, Yin-Xue; Duan, Wei; Zhou, Shu-Feng

    2015-10-01

    Dipeptidyl peptidase-4 (DPP-4) inhibitors are a class of oral antidiabetic drugs that improve glycaemic control without causing weight gain or increasing hypoglycaemic risk in patients with type 2 diabetes mellitus (T2DM). The eight available DPP-4 inhibitors, including alogliptin, anagliptin, gemigliptin, linagliptin, saxagliptin, sitagliptin, teneligliptin, and vildagliptin, are small molecules used orally with identical mechanism of action and similar safety profiles in patients with T2DM. DPP-4 inhibitors may be used as monotherapy or in double or triple combination with other oral glucose-lowering agents such as metformin, thiazolidinediones, or sulfonylureas. Although DPP-4 inhibitors have the same mode of action, they differ by some important pharmacokinetic and pharmacodynamic properties that may be clinically relevant in some patients. The main differences between the eight gliptins include: potency, target selectivity, oral bioavailability, elimination half-life, binding to plasma proteins, metabolic pathways, formation of active metabolite(s), main excretion routes, dosage adjustment for renal and liver insufficiency, and potential drug-drug interactions. The off-target inhibition of selective DPP-4 inhibitors is responsible for multiorgan toxicities such as immune dysfunction, impaired healing, and skin reactions. As a drug class, the DPP-4 inhibitors have become accepted in clinical practice due to their excellent tolerability profile, with a low risk of hypoglycaemia, a neutral effect on body weight, and once-daily dosing. It is unknown if DPP-4 inhibitors can prevent disease progression. More clinical studies are needed to validate the optimal regimens of DPP-4 inhibitors for the management of T2DM when their potential toxicities are closely monitored. PMID:26173919

  2. HIV Entry Inhibitors and Their Potential in HIV Therapy

    PubMed Central

    Qian, Keduo; Morris-Natschke, Susan L.; Lee, Kuo-Hsiung

    2013-01-01

    This review discusses recent progress in the development of anti-HIV agents targeting the viral entry process. The three main classes (attachment inhibitors, co-receptor binding inhibitors, and fusion inhibitors) are further broken down by specific mechanism of action and structure. Many of these inhibitors are in advanced clinical trials, including the HIV maturation inhibitor bevirimat, from the authors’ laboratories. In addition, the CCR5 inhibitor maraviroc has recently been FDA-approved. Possible roles for these agents in anti-HIV therapy, including treatment of virus resistant to current drugs, are also discussed. PMID:18720513

  3. Emerging role of dipeptidyl peptidase-4 inhibitors in the management of type 2 diabetes

    PubMed Central

    Richter, Bernd; Bandeira-Echtler, Elizabeth; Bergerhoff, Karla; Lerch, Christian

    2008-01-01

    Background: In type 2 diabetes mellitus (T2DM) there is a progressive loss of β-cell function. One new approach yielding promising results is the use of the orally active dipeptidyl peptidase-4 (DPP-4) inhibitors. However, every new compound for T2DM has to prove long-term safety especially on cardiovascular outcomes. Objectives: Systematic review and meta-analysis of the effects of sitagliptin and vildagliptin therapy on main efficacy parameters and safety. Selection criteria, data collection, and analysis: Randomized controlled clinical studies of at least 12 weeks’ duration in T2DM. Results: DPP-4 inhibitors versus placebo showed glycosylated hemoglobin A1c(A1c) improvements of 0.7% versus placebo but not compared to monotherapy with other hypoglycemic agents (0.3% in favor of controls). The overall risk profile of DPP-4 inhibitors was low, however a 34% relative risk increase (95% confidence interval 10% to 64%, P = 0.004) was noted for all cause infection associated with sitagliptin use. No data on immune function, health-related quality of life and diabetic complications could be extracted. Conclusions: DPP-4 inhibitors have some theoretical advantages over existing therapies with oral antidiabetic compounds but should currently be restricted to individual patients. Long-term data on cardiovascular outcomes and safety are needed before widespread use of these new agents. PMID:19065993

  4. Synthesis and characterization of constrained peptidomimetic dipeptidyl peptidase IV inhibitors: amino-lactam boroalanines.

    PubMed

    Lai, Jack H; Wu, Wengen; Zhou, Yuhong; Maw, Hlaing H; Liu, Yuxin; Milo, Lawrence J; Poplawski, Sarah E; Henry, Gillian D; Sudmeier, James L; Sanford, David G; Bachovchin, William W

    2007-05-17

    We describe here the epimerization-free synthesis and characterization of a new class of conformationally constrained lactam aminoboronic acid inhibitors of dipeptidyl peptidase IV (DPP IV; E.C. 3.4.14.5). These compounds have the advantage that they cannot undergo the pH-dependent cyclization prevalent in most dipeptidyl boronic acids that attenuates their potency at physiological pH. For example, D-3-amino-1-[L-1-boronic-ethyl]-pyrrolidine-2-one (amino-D-lactam-L-boroAla), one of the best lactam inhibitors of DPP IV, is several orders of magnitude less potent than L-Ala-L-boroPro, as measured by Ki values (2.3 nM vs 30 pM, respectively). At physiological pH, however, it is actually more potent than L-Ala-L-boroPro, as measured by IC50 values (4.2 nM vs 1400 nM), owing to the absence of the potency-attenuating cyclization. In an interesting and at first sight surprising reversal of the relationship between stereochemistry and potency observed with the conformationally unrestrained Xaa-boroPro class of inhibitors, the L-L diastereomers of the lactams are orders of magnitude less effective than the D-L lactams. However, this interesting reversal and the unexpected potency of the D-L lactams as DPP IV inhibitors can be understood in structural terms, which is explained and discussed here. PMID:17458948

  5. A Nonhost Peptidase Inhibitor of ~14 kDa from Butea monosperma (Lam.) Taub. Seeds Affects Negatively the Growth and Developmental Physiology of Helicoverpa armigera

    PubMed Central

    Pandey, Prabhash K.; Singh, Dushyant; Singh, Sangram; Khan, M. Y.; Jamal, Farrukh

    2014-01-01

    Helicoverpa armigera is one of the major devastating pests of crop plants. In this context a serine peptidase inhibitor purified from the seeds of Butea monosperma was evaluated for its effect on developmental physiology of H. armigera larvae. B. monosperma peptidase inhibitor on 12% denaturing polyacrylamide gel electrophoresis exhibited a single protein band of ~14 kDa with or without reduction. In vitro studies towards total gut proteolytic enzymes of H. armigera and bovine trypsin indicated measurable inhibitory activity. B. monosperma peptidase inhibitor dose for 50% mortality and weight reduction by 50% were 0.5% w/w and 0.10% w/w, respectively. The IC50 of B. monosperma peptidase inhibitor against total H. armigera gut proteinases activity was 2.0 µg/mL. The larval feeding assays suggested B. monosperma peptidase inhibitor to be toxic as reflected by its retarded growth and development, consequently affecting fertility and fecundity of pest and prolonging the larval-pupal duration of the insect life cycle of H. armigera. Supplementing B. monosperma peptidase inhibitor in artificial diet at 0.1% w/w, both the efficiencies of conversion of ingested as well as digested food were downregulated, whereas approximate digestibility and metabolic cost were enhanced. The efficacy of Butea monosperma peptidase inhibitor against progressive growth and development of H. armigera suggest its usefulness in insect pest management of food crops. PMID:24860667

  6. Role of dipeptidyl peptidase-4 inhibitors in new-onset diabetes after transplantation

    PubMed Central

    Lim, Sun Woo; Jin, Ji Zhe; Jin, Long; Jin, Jian; Li, Can

    2015-01-01

    Despite strict pre- and post-transplantation screening, the incidence of new-onset diabetes after transplantation (NODAT) remains as high as 60%. This complication affects the risk of cardiovascular events and patient and graft survival rates. Thus, reducing the impact of NODAT could improve overall transplant success. The pathogenesis of NODAT is multifactorial, and both modifiable and nonmodifiable risk factors have been implicated. Monitoring and controlling the blood glucose profile, implementing multidisciplinary care, performing lifestyle modifications, using a modified immunosuppressive regimen, administering anti-metabolite agents, and taking a conventional antidiabetic approach may diminish the incidence of NODAT. In addition to these preventive strategies, inhibition of dipeptidyl peptidase-4 (DPP4) by the gliptin family of drugs has recently gained considerable interest as therapy for type 2 diabetes mellitus and NODAT. This review focuses on the role of DPP4 inhibitors and discusses recent literature regarding management of NODAT. PMID:26552451

  7. Dipeptidyl peptidase inhibitors as new drugs for the treatment of type 2 diabetes.

    PubMed

    Mest, H-J; Mentlein, R

    2005-04-01

    Inhibitors of the regulatory protease dipeptidyl peptidase-IV (DPP-IV) are currently under development in preclinical and clinical studies (several pharmaceutical companies, now in Phase III) as potential drugs for the treatment of type 2 diabetes. Their development is based on the observation that DPP-IV rapidly inactivates the incretin hormone glucagon-like peptide-1 (GLP-1), which is released postprandially from the gut and increases insulin secretion. DPP-IV inhibitors stabilise endogenous GLP-1 at physiological concentrations, and induce insulin secretion in a glucose-dependent manner; therefore, they do not demonstrate any hypoglycaemic effects. Furthermore, they are orally bioavailable. In addition to their ability to protect GLP-1 against degradation, DPP-IV inhibitors also stabilise other incretins, including gastric inhibitory peptide and pituitary adenylate cyclase-activating peptide. They also reduce the antagonistic and desensitising effects of the fragments formed by truncation of the incretins. In clinical studies, when used for the treatment of diabetes over a 1-year period, DPP-IV inhibitors show improved efficacy over time. This finding can be explained by a GLP-1-induced increase in the number of beta cells. Potential risks associated with DPP-IV inhibitors include the prolongation of the action of other peptide hormones, neuropeptides and chemokines cleaved by the protease, and their interaction with DPP-IV-related proteases. Based on their mode of action, DPP-IV inhibitors seem to be of particular value in early forms of type 2 diabetes, either alone or in combination with other types of oral agents. PMID:15770466

  8. Saxagliptin: a dipeptidyl peptidase-4 inhibitor ameliorates streptozotocin induced Alzheimer's disease.

    PubMed

    Kosaraju, Jayasankar; Gali, Chaitanya Chakravarthi; Khatwal, Rizwan Basha; Dubala, Anil; Chinni, Santhivardhan; Holsinger, R M Damian; Madhunapantula, V Subba Rao; Muthureddy Nataraj, Satish Kumar; Basavan, Duraiswamy

    2013-09-01

    Type 2 diabetes (T2D) is one of the major risk factors associated with Alzheimer's disease (AD). Recent studies have found similarities in molecular mechanisms that underlie the respective degenerative developments in the two diseases. Pharmacological agents, such as dipeptidyl peptidase-4 (DPP-4) inhibitors, which increase the level of glucagon-like peptide-1 (GLP-1) and ameliorate T2D, have become valuable candidates as disease modifying agents in the treatment of AD. In addition, endogenous GLP-1 levels decrease amyloid beta (Aβ) peptide and tau phosphorylation in AD. The present study examines the efficacy of Saxagliptin, a DPP-4 inhibitor in a streptozotocin (STZ) induced rat model of AD. Three months following induction of AD by intracerebral administration of streptozotocin, animals were orally administered Saxagliptin (0.25, 0.5 and 1 mg/kg) for 60 days. The effect of the DPP-4 inhibitor on hippocampal GLP-1 levels, Aβ burden, tau phosphorylation, inflammatory markers and memory retention were evaluated. The results reveal an attenuation of Aβ, tau phosphorylation and inflammatory markers and an improvement in hippocampal GLP-1 and memory retention following treatment. This remarkable therapeutic effect of Saxagliptin mediated through DPP-4 inhibition demonstrates a unique mechanism for Aβ and tau clearance by increasing GLP-1 levels and reverses the behavioural deficits and pathology observed in AD. PMID:23603201

  9. Lessons learned from cardiovascular outcome clinical trials with dipeptidyl peptidase 4 (DPP-4) inhibitors.

    PubMed

    Fiorentino, Teresa Vanessa; Sesti, Giorgio

    2016-08-01

    Previous trials of glucose-lowering strategies in subjects with type 2 diabetes have demonstrated a beneficial effect of intensive glycemic control on microvascular complications but failed to show a clear benefit on cardiovascular complications. The findings of meta-analyses of rosiglitazone trials suggesting that rosiglitazone might increase the risk of myocardial infarction have cast doubt on the cardiovascular safety of glucose-lowering drugs. In 2008, the US Food and Drug Administration has implemented rigorous criteria to approve new glucose-lowering drugs, requiring proof of cardiovascular safety. These regulatory requirements have led to a considerable increase in the number of cardiovascular outcome trials in type 2 diabetes to ensure that newer glucose-lowering drugs are not associated with increased cardiovascular risk. Incretin-based therapies including dipeptidyl peptidase 4 (DPP-4) inhibitors, and injectable glucagon-like peptide 1 (GLP-1) receptor agonists are novel treatment options for patients with inadequate glucose control. Although DPP-4 inhibitors have shown neutral effects on risk factors for cardiovascular diseases, it remains unclear whether treatment with these new glucose-lowering agents might be associated with a reduction in cardiovascular events. The results of the three cardiovascular outcome trials comparing DPP-4 inhibitors treatment to placebo in addition to other glucose-lowering drugs have been published. All the three DPP-4 inhibitor cardiovascular outcome trials have shown non-inferiority with regard to cardiovascular safety, compared with placebo, when added to usual care. In this review, we summarize cardiovascular outcome trials of DPP-4 inhibitors, and provide an overview of these trials and their limitations. PMID:26611248

  10. Post-injury administration of NAAG peptidase inhibitor prodrug, PGI-02776, in experimental TBI.

    PubMed

    Feng, Jun-Feng; Van, Ken C; Gurkoff, Gene G; Kopriva, Christina; Olszewski, Rafal T; Song, Minsoo; Sun, Shifeng; Xu, Man; Neale, Joseph H; Yuen, Po-Wai; Lowe, David A; Zhou, Jia; Lyeth, Bruce G

    2011-06-13

    Traumatic brain injury (TBI) leads to a rapid and excessive increase in glutamate concentration in the extracellular milieu, which is strongly associated with excitotoxicity and neuronal degeneration. N-acetylaspartylglutamate (NAAG), a prevalent peptide neurotransmitter in the vertebrate nervous system, is released along with glutamate and suppresses glutamate release by actions at pre-synaptic metabotropic glutamate autoreceptors. Extracellular NAAG is hydrolyzed to N-acetylaspartate and glutamate by peptidase activity. In the present study PGI-02776, a newly designed di-ester prodrug of the urea-based NAAG peptidase inhibitor ZJ-43, was tested for neuroprotective potential when administered intraperitoneally 30 min after lateral fluid percussion TBI in the rat. Stereological quantification of hippocampal CA2-3 degenerating neurons at 24 h post injury revealed that 10 mg/kg PGI-02776 significantly decreased the number of degenerating neurons (p<0.05). Both average latency analysis of Morris water maze performance and assessment of 24-hour memory retention revealed significant differences between sham-TBI and TBI-saline. In contrast, no significant difference was found between sham-TBI and PGI-02776 treated groups in either analysis indicating an improvement in cognitive performance with PGI-02776 treatment. Histological analysis on day 16 post-injury revealed significant cell death in injured animals regardless of treatment. In vitro NAAG peptidase inhibition studies demonstrated that the parent compound (ZJ-43) exhibited potent inhibitory activity while the mono-ester (PGI-02749) and di-ester (PGI-02776) prodrug compounds exhibited moderate and weak levels of inhibitory activity, respectively. Pharmacokinetic assays in uninjured animals found that the di-ester (PGI-02776) crossed the blood-brain barrier. PGI-02776 was also readily hydrolyzed to both the mono-ester (PGI-02749) and the parent compound (ZJ-43) in both blood and brain. Overall, these findings

  11. Synthesis and biological evaluation of bicyclo[3.3.0] octane derivatives as dipeptidyl peptidase 4 inhibitors for the treatment of type 2 diabetes.

    PubMed

    Cho, Tang Peng; Gang, Lin Zhi; Long, Yang Fang; Yang, Wang; Qian, Wang; Lei, Zhang; Jing, Luo Jing; Ying, Feng; Ke, Yan Pang; Ying, Leng; Jun, Feng

    2010-06-15

    A series of novel bicyclo[3.3.0]octane derivatives have been synthesized and found to be dipeptidyl peptidase 4 (DPP-4) inhibitors. Compounds 10a and 10b demonstrate good efficacies in oral glucose tolerance tests. PMID:20488704

  12. Effects of dipeptidyl peptidase-4 inhibitor in insulin-resistant rats with myocardial infarction.

    PubMed

    Apaijai, Nattayaporn; Inthachai, Tharnwimol; Lekawanvijit, Suree; Chattipakorn, Siriporn C; Chattipakorn, Nipon

    2016-06-01

    Adverse cardiac remodeling after myocardial infarction (MI) leads to progressive heart failure. Obese-insulin resistance increases risks of MI and heart failure. Although dipeptidyl peptidase-4 (DPP4) inhibitor is known to exert cardioprotection, its effects on adverse remodeling after MI in obese-insulin-resistant rats are unclear. We hypothesized that DPP4 inhibitor reduces adverse left ventricular (LV) remodeling and LV dysfunction in obese-insulin-resistant rats with MI. Rats were fed either normal diet (ND) or high-fat diet (HFD) for 12 weeks to induce obese-insulin resistance, followed by left anterior descending coronary artery ligation to induce MI. Then, rats in each dietary group were divided into five subgroups to receive vehicle, enalapril (10mg/kg/day), metformin (30mg/kg/day), DPP4 inhibitor vildagliptin (3mg/kg/day), or combined metformin and vildagliptin for 8 weeks. Heart rate variability (HRV), LV function, pathological and biochemical studies for LV remodeling, and cardiomyocyte apoptosis were determined. Obese-insulin-resistant rats had severe insulin resistance and LV dysfunction. HFD rats had a higher mortality rate than ND rats, and all treatments reduced the mortality rate in obese-insulin-resistant rats. Although all drugs improved insulin resistance, HRV, LV function as well as reduced cardiac hypertrophy and fibrosis, vildagliptin effectively reduced cardiomyocyte cross-sectional areas more than enalapril and was related to markedly decreased ERK1/2 phosphorylation. In ND rats with MI, metformin neither improved LV ejection fraction nor reduced cardiac fibrosis. The infarct size and transforming growth factor-β expression were not different among groups. In obese-insulin-resistant rats with chronic MI, DPP4 inhibitor vildagliptin exerts better cardioprotection than enalapril in attenuating adverse LV remodeling. PMID:27044778

  13. The Role of Dipeptidyl Peptidase – 4 Inhibitors in Diabetic Kidney Disease

    PubMed Central

    Panchapakesan, Usha; Pollock, Carol

    2015-01-01

    Despite major advances in the understanding of the molecular mechanisms that underpin the development of diabetic kidney disease, current best practice still leaves a significant proportion of patients with end-stage kidney disease requiring renal replacement therapy. This is on a background of an increasing diabetes epidemic worldwide. Although kidney failure is a major cause of morbidity the main cause of death remains cardiovascular in nature. Hence, diabetic therapies which are both “cardio-renal” protective seem the logical way forward. In this review, we discuss the dipeptidyl peptidase 4 (DPP4) inhibitors (DPP4inh), which are glucose-lowering agents used clinically and their role in diabetic kidney disease with specific focus on renoprotection and surrogate markers of cardiovascular disease. We highlight the novel pleiotropic effects of DPP4 that make it an attractive additional target to combat the fibrotic and inflammatory pathways in diabetic kidney disease and also discuss the current literature on the cardiovascular safety profile of DPP4inh. Clearly, these observed renoprotective effects will need to be confirmed by clinical trials to determine whether they translate into beneficial effects to patients with diabetes. PMID:26379674

  14. NAAG peptidase inhibitor reduces cellular damage in a model of TBI with secondary hypoxia.

    PubMed

    Feng, Jun-Feng; Gurkoff, Gene G; Van, Ken C; Song, Minsoo; Lowe, David A; Zhou, Jia; Lyeth, Bruce G

    2012-08-21

    Traumatic brain injury (TBI) leads to a rapid and excessive glutamate elevation in the extracellular milieu, resulting in neuronal degeneration and astrocyte damage. Posttraumatic hypoxia is a clinically relevant secondary insult that increases the magnitude and duration of glutamate release following TBI. N-acetyl-aspartyl glutamate (NAAG), a prevalent neuropeptide in the CNS, suppresses presynaptic glutamate release by its action at the mGluR3 (a group II metabotropic glutamate receptor). However, extracellular NAAG is rapidly converted into NAA and glutamate by the catalytic enzyme glutamate carboxypeptidase II (GCPII) reducing presynaptic inhibition. We previously reported that the GCPII inhibitor ZJ-43 and its prodrug di-ester PGI-02776 reduce the deleterious effects of excessive extracellular glutamate when injected systemically within the first 30 min following injury. We now report that PGI-02776 (10mg/kg) is neuroprotective when administered 30 min post-injury in a model of TBI plus 30 min of hypoxia (FiO(2)=11%). 24h following TBI with hypoxia, significant increases in neuronal cell death in the CA1, CA2/3, CA3c, hilus and dentate gyrus were observed in the ipsilateral hippocampus. Additionally, there was a significant reduction in the number of astrocytes in the ipsilateral CA1, CA2/3 and in the CA3c/hilus/dentate gyrus. Administration of PGI-02776 immediately following the cessation of hypoxia significantly reduced neuronal and astrocytic cell death across all regions of the hippocampus. These findings indicate that NAAG peptidase inhibitors administered post-injury can significantly reduce the deleterious effects of TBI combined with a secondary hypoxic insult. PMID:22750589

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

    PubMed

    Carr, R D

    2016-06-01

    The dipeptidyl peptidase-4 (DPP-4) inhibitor concept is an example of prospective drug design and development based upon a distinct endocrine hypothesis. The design of enzyme inhibitors is a pragmatic approach to drug design; being compatible with the identification and optimization of small molecules that have properties commensurate with oral administration, as well as acceptable drug metabolism, distribution and elimination characteristics. Glucagon-like peptide 1 (GLP-1), a hormone with a spectrum of favourable metabolic actions, including glucose-dependent stimulation of insulin and inhibition of glucagon secretion, provided the endocrine basis from which the idea of using DPP-4 inhibitors as anti-diabetic agents was developed. The origin of the DPP-4 inhibitor concept was inspired by the angiotensin-converting enzyme inhibitor approach, which succeeded in establishing a class of extensively used therapeutic agents for the treatment of cardiovascular disorders. PMID:26773271

  16. Dipeptidyl peptidase-4 inhibitors in type 2 diabetes therapy – focus on alogliptin

    PubMed Central

    Capuano, Annalisa; Sportiello, Liberata; Maiorino, Maria Ida; Rossi, Francesco; Giugliano, Dario; Esposito, Katherine

    2013-01-01

    Type 2 diabetes mellitus is a complex and progressive disease that is showing an apparently unstoppable increase worldwide. Although there is general agreement on the first-line use of metformin in most patients with type 2 diabetes, the ideal drug sequence after metformin failure is an area of increasing uncertainty. New treatment strategies target pancreatic islet dysfunction, in particular gut-derived incretin hormones. Inhibition of the enzyme dipeptidyl peptidase-4 (DPP-4) slows degradation of endogenous glucagon-like peptide-1 (GLP-1) and thereby enhances and prolongs the action of the endogenous incretin hormones. The five available DPP-4 inhibitors, also known as ‘gliptins’ (sitagliptin, vildagliptin, saxagliptin, linagliptin, alogliptin), are small molecules used orally with similar overall clinical efficacy and safety profiles in patients with type 2 diabetes. The main differences between the five gliptins on the market include: potency, target selectivity, oral bioavailability, long or short half-life, high or low binding to plasma proteins, metabolism, presence of active or inactive metabolites, excretion routes, dosage adjustment for renal and liver insufficiency, and potential drug–drug interactions. On average, treatment with gliptins is expected to produce a mean glycated hemoglobin (HbA1c) decrease of 0.5%–0.8%, with about 40% of diabetic subjects at target for the HbA1c goal <7%. There are very few studies comparing DPP-4 inhibitors. Alogliptin as monotherapy or added to metformin, pioglitazone, glibenclamide, voglibose, or insulin therapy significantly improves glycemic control compared with placebo in adult or elderly patients with inadequately controlled type 2 diabetes. In the EXAMINE trial, alogliptin is being compared with placebo on cardiovascular outcomes in approximately 5,400 patients with type 2 diabetes. In clinical studies, DPP-4 inhibitors were generally safe and well tolerated. However, there are limited data on their

  17. Effect of dipeptidyl peptidase-4 inhibitor, vildagliptin on plasminogen activator inhibitor-1 in patients with diabetes mellitus.

    PubMed

    Tani, Shigemasa; Takahashi, Atsuhiko; Nagao, Ken; Hirayama, Atsushi

    2015-02-15

    Dipeptidyl peptidase-4 (DPP-4) inhibitors may affect the serum levels of plasminogen activator inhibitor-1 (PAI-1) associated with triglyceride (TG) metabolism, which is a prognostic factor for cardiovascular disease, in diabetic patients. We conducted an 8-week, prospective, randomized study in which we assigned type 2 diabetic patients who were inadequately controlled with antidiabetic therapy to the vildagliptin group (50 mg bid, n = 49) or the control group (n = 49). The primary efficacy parameter was the change in the serum level of PAI-1, and the secondary end point was the change in the serum levels of TG-rich lipoproteins. In the vildagliptin group, significant decrease of the serum PAI-1 level by 16.3% (p <0.0001) and significant decreases of the serum TG, remnant-like particle cholesterol, and apolipoprotein B levels by 12.1% (p = 0.002), 13.9% (p = 0.003), and 9.5% (p <0.0001), respectively, were observed. No such changes were observed in the control group. Multivariate regression analyses identified the absolute change from the baseline (Δ) of the PAI-1, but not that of the fasting blood glucose or hemoglobin A1c, as independent predictors of the ΔTG, Δ remnant-like particle cholesterol, and Δ apolipoprotein B. In conclusion, treatment of type 2 diabetes with vildagliptin might prevent the progression of atherosclerotic cardiovascular disease in diabetic patients by decreasing the serum PAI-1 levels and improving TG metabolism. PMID:25637323

  18. Sequence-specific alterations of epitope production by HIV Protease Inhibitors

    PubMed Central

    Kourjian, Georgio; Xu, Yang; Mondesire-Crump, Ijah; Shimada, Mariko; Gourdain, Pauline; Le Gall, Sylvie

    2014-01-01

    Antigen processing by intracellular proteases and peptidases and epitope presentation are critical for recognition of pathogen-infected cells by CD8+ T lymphocytes. First generation HIV protease inhibitors (PIs) alter proteasome activity, but the effect of first or second generation PIs on other cellular peptidases, the underlying mechanism and impact on antigen processing and epitope presentation to CTL are still unknown. Here we demonstrate that several HIV PIs altered not only proteasome but also aminopeptidase activities in PBMC. Using an in vitro degradation assay involving PBMC cytosolic extracts we showed that PIs altered the degradation patterns of oligopeptides and peptide production in a sequence-specific manner, enhancing the cleavage of certain residues and reducing others’. PIs affected the sensitivity of peptides to intracellular degradation, altered the kinetics and amount of HIV epitopes produced intracellularly. Accordingly the endogenous degradation of incoming virions in the presence of PIs led to variations in CTL-mediated killing of HIV-infected cells. By altering host protease activities and the degradation patterns of proteins in a sequence-specific manner, HIV PIs may diversify peptides available for MHC-I presentation to CTL, alter the patters of CTL responses, and may provide a complementary approach to current therapies for the CTL-mediated clearance of abnormal cells in infection, cancer or other immune disease. PMID:24616479

  19. Serpin peptidase inhibitor (SERPINB5) haplotypes are associated with susceptibility to hepatocellular carcinoma

    NASA Astrophysics Data System (ADS)

    Yang, Shun-Fa; Yeh, Chao-Bin; Chou, Ying-Erh; Lee, Hsiang-Lin; Liu, Yu-Fan

    2016-05-01

    Hepatocellular carcinoma (HCC) represents the second leading cause of cancer-related death worldwide. The serpin peptidase inhibitor SERPINB5 is a tumour-suppressor gene that promotes the development of various cancers in humans. However, whether SERPINB5 gene variants play a role in HCC susceptibility remains unknown. In this study, we genotyped 6 SNPs of the SERPINB5 gene in an independent cohort from a replicate population comprising 302 cases and 590 controls. Additionally, patients who had at least one rs2289520 C allele in SERPINB5 tended to exhibit better liver function than patients with genotype GG (Child-Pugh grade A vs. B or C; P = 0.047). Next, haplotype blocks were reconstructed according to the linkage disequilibrium structure of the SERPINB5 gene. A haplotype “C-C-C” (rs17071138 + rs3744941 + rs8089204) in SERPINB5-correlated promoter showed a significant association with an increased HCC risk (AOR = 1.450 P = 0.031). Haplotypes “T-C-A” and “C-C-C” (rs2289519 + rs2289520 + rs1455555) located in the SERPINB5 coding region had a decreased (AOR = 0.744 P = 0.031) and increased (AOR = 1.981 P = 0.001) HCC risk, respectively. Finally, an additional integrated in silico analysis confirmed that these SNPs affected SERPINB5 expression and protein stability, which significantly correlated with tumour expression and subsequently with tumour development and aggressiveness. Taken together, our findings regarding these biomarkers provide a prediction model for risk assessment.

  20. Serpin peptidase inhibitor (SERPINB5) haplotypes are associated with susceptibility to hepatocellular carcinoma

    PubMed Central

    Yang, Shun-Fa; Yeh, Chao-Bin; Chou, Ying-Erh; Lee, Hsiang-Lin; Liu, Yu-Fan

    2016-01-01

    Hepatocellular carcinoma (HCC) represents the second leading cause of cancer-related death worldwide. The serpin peptidase inhibitor SERPINB5 is a tumour-suppressor gene that promotes the development of various cancers in humans. However, whether SERPINB5 gene variants play a role in HCC susceptibility remains unknown. In this study, we genotyped 6 SNPs of the SERPINB5 gene in an independent cohort from a replicate population comprising 302 cases and 590 controls. Additionally, patients who had at least one rs2289520 C allele in SERPINB5 tended to exhibit better liver function than patients with genotype GG (Child-Pugh grade A vs. B or C; P = 0.047). Next, haplotype blocks were reconstructed according to the linkage disequilibrium structure of the SERPINB5 gene. A haplotype “C-C-C” (rs17071138 + rs3744941 + rs8089204) in SERPINB5-correlated promoter showed a significant association with an increased HCC risk (AOR = 1.450; P = 0.031). Haplotypes “T-C-A” and “C-C-C” (rs2289519 + rs2289520 + rs1455555) located in the SERPINB5 coding region had a decreased (AOR = 0.744; P = 0.031) and increased (AOR = 1.981; P = 0.001) HCC risk, respectively. Finally, an additional integrated in silico analysis confirmed that these SNPs affected SERPINB5 expression and protein stability, which significantly correlated with tumour expression and subsequently with tumour development and aggressiveness. Taken together, our findings regarding these biomarkers provide a prediction model for risk assessment. PMID:27221742

  1. Synthesis and biological evaluation of azobicyclo[3.3.0] octane derivatives as dipeptidyl peptidase 4 inhibitors for the treatment of type 2 diabetes.

    PubMed

    Cho, Tang Peng; Long, Yang Fang; Gang, Lin Zhi; Yang, Wang; Jun, Lu He; Yuan, Shen Guang; Hong, Fu Jian; Lin, Wang; Liang, Guan Dong; Lei, Zhang; Jing, Luo Jing; Shen, Gong Ai; Hong, She Gao; Dan, Wang; Ying, Feng; Ke, Yan Pang; Ying, Leng; Jun, Feng; Tai, Mong Xian

    2010-06-15

    A series of novel azobicyclo[3.3.0]octane derivatives were synthesized and evaluated as dipeptidyl peptidase 4 (DPP-4) inhibitors. The effort resulted in the discovery of inhibitor 2a, which exhibited excellent efficacies in an oral glucose tolerance test. Introduction of methyl group (2j) could prolong the inhibition of serum DPP-4 activity. PMID:20488702

  2. NAAG peptidase inhibitor improves motor function and reduces cognitive dysfunction in a model of TBI with secondary hypoxia.

    PubMed

    Gurkoff, Gene G; Feng, Jun-Feng; Van, Ken C; Izadi, Ali; Ghiasvand, Rahil; Shahlaie, Kiarash; Song, Minsoo; Lowe, David A; Zhou, Jia; Lyeth, Bruce G

    2013-06-17

    Immediately following traumatic brain injury (TBI) and TBI with hypoxia, there is a rapid and pathophysiological increase in extracellular glutamate, subsequent neuronal damage and ultimately diminished motor and cognitive function. N-acetyl-aspartyl glutamate (NAAG), a prevalent neuropeptide in the CNS, is co-released with glutamate, binds to the presynaptic group II metabotropic glutamate receptor subtype 3 (mGluR3) and suppresses glutamate release. However, the catalytic enzyme glutamate carboxypeptidase II (GCP II) rapidly hydrolyzes NAAG into NAA and glutamate. Inhibition of the GCP II enzyme with NAAG peptidase inhibitors reduces the concentration of glutamate both by increasing the duration of NAAG activity on mGluR3 and by reducing degradation into NAA and glutamate resulting in reduced cell death in models of TBI and TBI with hypoxia. In the following study, rats were administered the NAAG peptidase inhibitor PGI-02776 (10mg/kg) 30 min following TBI combined with a hypoxic second insult. Over the two weeks following injury, PGI-02776-treated rats had significantly improved motor function as measured by increased duration on the rota-rod and a trend toward improved performance on the beam walk. Furthermore, two weeks post-injury, PGI-02776-treated animals had a significant decrease in latency to find the target platform in the Morris water maze as compared to vehicle-treated animals. These findings demonstrate that the application of NAAG peptidase inhibitors can reduce the deleterious motor and cognitive effects of TBI combined with a second hypoxic insult in the weeks following injury. PMID:23562458

  3. The dipeptidyl peptidase IV inhibitors vildagliptin and K-579 inhibit a phospholipase C: a case of promiscuous scaffolds in proteins

    PubMed Central

    Dutta, Mouparna; Ghosh, Anindya S.; Oda, Masataka; Venkatramani, Ravindra; Rao, Basuthkar J.; Dandekar, Abhaya M.; Goñi, Félix M.

    2015-01-01

    The long term side effects of any newly introduced drug is a subject of intense research, and often raging controversies. One such example is the dipeptidyl peptidase-IV (DPP4) inhibitor used for treating type 2 diabetes, which is inconclusively implicated in increased susceptibility to acute pancreatitis. Previously, based on a computational analysis of the spatial and electrostatic properties of active site residues, we have demonstrated that phosphoinositide-specific phospholipase C (PI-PLC) from Bacillus cereus is a prolyl peptidase using in vivo experiments. In the current work, we first report the inhibition of the native activity of PI-PLC by two DPP4 inhibitors - vildagliptin (LAF-237) and K-579. While vildagliptin inhibited PI-PLC at micromolar concentrations, K-579 was a potent inhibitor even at nanomolar concentrations. Subsequently, we queried a comprehensive, non-redundant set of 5000 human proteins (50% similarity cutoff) with known structures using serine protease (SPASE) motifs derived from trypsin and DPP4. A pancreatic lipase and a gastric lipase are among the proteins that are identified as proteins having promiscuous SPASE scaffolds that could interact with DPP4 inhibitors. The presence of such scaffolds in human lipases is expected since they share the same catalytic mechanism with PI-PLC. However our methodology also detects other proteins, often with a completely different enzymatic mechanism, that have significantly congruent domains with the SPASE motifs. The reported elevated levels of serum lipase, although contested, could be rationalized by inhibition of lipases reported here. In an effort to further our understanding of the spatial and electrostatic basis of DPP4 inhibitors, we have also done a comprehensive analysis of all 76 known DPP4 structures liganded to inhibitors till date. Also, the methodology presented here can be easily adopted for other drugs, and provide the first line of filtering in the identification of pathways that

  4. Identification of novel functional sequence variants in the gene for peptidase inhibitor 3

    PubMed Central

    Chowdhury, Mahboob A; Kuivaniemi, Helena; Romero, Roberto; Edwin, Samuel; Chaiworapongsa, Tinnakorn; Tromp, Gerard

    2006-01-01

    Background Peptidase inhibitor 3 (PI3) inhibits neutrophil elastase and proteinase-3, and has a potential role in skin and lung diseases as well as in cancer. Genome-wide expression profiling of chorioamniotic membranes revealed decreased expression of PI3 in women with preterm premature rupture of membranes. To elucidate the molecular mechanisms contributing to the decreased expression in amniotic membranes, the PI3 gene was searched for sequence variations and the functional significance of the identified promoter variants was studied. Methods Single nucleotide polymorphisms (SNPs) were identified by direct sequencing of PCR products spanning a region from 1,173 bp upstream to 1,266 bp downstream of the translation start site. Fourteen SNPs were genotyped from 112 and nine SNPs from 24 unrelated individuals. Putative transcription factor binding sites as detected by in silico search were verified by electrophoretic mobility shift assay (EMSA) using nuclear extract from Hela and amnion cell nuclear extract. Deviation from Hardy-Weinberg equilibrium (HWE) was tested by χ2 goodness-of-fit test. Haplotypes were estimated using expectation maximization (EM) algorithm. Results Twenty-three sequence variations were identified by direct sequencing of polymerase chain reaction (PCR) products covering 2,439 nt of the PI3 gene (-1,173 nt of promoter sequences and all three exons). Analysis of 112 unrelated individuals showed that 20 variants had minor allele frequencies (MAF) ranging from 0.02 to 0.46 representing "true polymorphisms", while three had MAF ≤ 0.01. Eleven variants were in the promoter region; several putative transcription factor binding sites were found at these sites by database searches. Differential binding of transcription factors was demonstrated at two polymorphic sites by electrophoretic mobility shift assays, both in amniotic and HeLa cell nuclear extracts. Differential binding of the transcription factor GATA1 at -689C>G site was confirmed by a

  5. NAAG peptidase inhibitor reduces acute neuronal degeneration and astrocyte damage following lateral fluid percussion TBI in rats.

    PubMed

    Zhong, Chunlong; Zhao, Xueren; Sarva, Jayaprakash; Kozikowski, Alan; Neale, Joseph H; Lyeth, Bruce G

    2005-02-01

    Traumatic brain injury (TBI) produces a rapid and excessive elevation in extracellular glutamate associated with excitotoxicity and secondary brain pathology. The peptide neurotransmitter Nacetylaspartylglutamate (NAAG) suppresses glutamate transmission through selective activation of presynaptic Group II metabotropic glutamate receptor subtype 3 (mGluR3). Thus, inhibition of NAAG peptidase activity and the prolong presence of synaptic NAAG were hypothesized to have significant potential for cellular protection following TBI. In the present study, a novel NAAG peptidase inhibitor, ZJ-43, was used in four different doses (0, 50, 100, or 150 mg/kg). Each dose was repeatedly administered i.p. (n=5/group) by multiple injections at three times (0 time, 8 h, 16 h) after moderate lateral fluid percussion TBI in the rat. An additional group was co-administered ZJ-43 (150 mg/kg) and the Group II mGluR antagonist, LY341495 (1 mg/kg), which was predicted to abolish any protective effects of ZJ-43. Rats were euthanized at 24 h after TBI, and brains were processed with a selective marker for degenerating neurons (Fluoro-Jade B) and a marker for astrocytes (GFAP). Ipsilateral neuronal degeneration and bilateral astrocyte loss in the CA2/3 regions of the hippocampus were quantified using stereological techniques. Compared with vehicle, ZJ-43 significantly reduced the number of the ipsilateral degenerating neurons (p<0.01) with the greatest neuroprotection at the 50 mg/kg dose. Moreover, LY341495 successfully abolished the protective effects of ZJ-43. 50 mg/kg of ZJ-43 also significantly reduced the ipsilateral astrocyte loss (p<0.05). We conclude that the NAAG peptidase inhibitor ZJ-43 is a potential novel strategy to reduce both neuronal and astrocyte damage associated with the glutamate excitotoxicity after TBI. PMID:15716632

  6. Angiotensin-Converting Enzyme Inhibitor Use and Major Cardiovascular Outcomes in Type 2 Diabetes Mellitus Treated With the Dipeptidyl Peptidase 4 Inhibitor Alogliptin.

    PubMed

    White, William B; Wilson, Craig A; Bakris, George L; Bergenstal, Richard M; Cannon, Christopher P; Cushman, William C; Heller, Simon K; Mehta, Cyrus R; Nissen, Steven E; Zannad, Faiez; Kupfer, Stuart

    2016-09-01

    Activation of the sympathetic nervous system when there is dipeptidyl peptidase 4 inhibition in the presence of high-dose angiotensin-converting enzyme (ACE) inhibition has led to concerns of potential increases in cardiovascular events when the 2 classes of drugs are coadministered. We evaluated cardiovascular outcomes from the EXAMINE (Examination of Cardiovascular Outcomes With Alogliptin versus Standard of Care) trial according to ACE inhibitor use. Patients with type 2 diabetes mellitus and a recent acute coronary syndrome were randomly assigned to receive the dipeptidyl peptidase 4 inhibitor alogliptin or placebo added to existing antihyperglycemic and cardiovascular prophylactic therapies. Risks of adjudicated cardiovascular death, nonfatal myocardial infarction and stroke, and hospitalized heart failure were analyzed using a Cox proportional hazards model in patients according to ACE inhibitor use and dose. There were 3323 (62%) EXAMINE patients treated with an ACE inhibitor (1681 on alogliptin and 1642 on placebo). The composite rates of cardiovascular death, nonfatal myocardial infarction, and nonfatal stroke were comparable for alogliptin and placebo with ACE inhibitor (11.4% versus 11.8%; hazard ratio, 0.97; 95% confidence interval, 0.79-1.19; P=0.76) and without ACE inhibitor use (11.2% versus 11.9%; hazard ratio, 0.94; 95% confidence interval, 0.73-1.21; P=0.62). Composite rates for cardiovascular death and heart failure in patients on ACE inhibitor occurred in 6.8% of patients on alogliptin versus 7.2% on placebo (hazard ratio, 0.93; 95% confidence interval, 0.72-1.2; P=0.57). There were no differences for these end points nor for blood pressure or heart rate in patients on higher doses of ACE inhibitor. Cardiovascular outcomes were similar for alogliptin and placebo in patients with type 2 diabetes mellitus and coronary disease treated with ACE inhibitors. PMID:27480840

  7. The crystal structure of human dipeptidyl peptidase I (cathepsin C) in complex with the inhibitor Gly-Phe-CHN2

    PubMed Central

    Mølgaard, Anne; Arnau, Jose; Lauritzen, Conni; Larsen, Sine; Petersen, Gitte; Pedersen, John

    2006-01-01

    hDDPI (human dipeptidyl peptidase I) is a lysosomal cysteine protease involved in zymogen activation of granule-associated proteases, including granzymes A and B from cytotoxic T-lymphocytes and natural killer cells, cathepsin G and neutrophil elastase, and mast cell tryptase and chymase. In the present paper, we provide the first crystal structure of an hDPPI–inhibitor complex. The inhibitor Gly-Phe-CHN2 (Gly-Phe-diazomethane) was co-crystallized with hDPPI and the structure was determined at 2.0 Å (1 Å=0.1 nm) resolution. The structure of the native enzyme was also determined to 2.05 Å resolution to resolve apparent discrepancies between the complex structure and the previously published structure of the native enzyme. The new structure of the native enzyme is, within the experimental error, identical with the structure of the enzyme–inhibitor complex presented here. The inhibitor interacts with three subunits of hDPPI, and is covalently bound to Cys234 at the active site. The interaction between the totally conserved Asp1 of hDPPI and the ammonium group of the inhibitor forms an essential interaction that mimics enzyme–substrate interactions. The structure of the inhibitor complex provides an explanation of the substrate specificity of hDPPI, and gives a background for the design of new inhibitors. PMID:17020538

  8. Sifuvirtide, a potent HIV fusion inhibitor peptide

    SciTech Connect

    Wang, Rui-Rui; Yang, Liu-Meng; Wang, Yun-Hua; Pang, Wei; Tam, Siu-Cheung; Tien, Po; Zheng, Yong-Tang

    2009-05-08

    Enfuvirtide (ENF) is currently the only FDA approved HIV fusion inhibitor in clinical use. Searching for more drugs in this category with higher efficacy and lower toxicity seems to be a logical next step. In line with this objective, a synthetic peptide with 36 amino acid residues, called Sifuvirtide (SFT), was designed based on the crystal structure of gp41. In this study, we show that SFT is a potent anti-HIV agent with relatively low cytotoxicity. SFT was found to inhibit replication of all tested HIV strains. The effective concentrations that inhibited 50% viral replication (EC{sub 50}), as determined in all tested strains, were either comparable or lower than benchmark values derived from well-known anti-HIV drugs like ENF or AZT, while the cytotoxic concentrations causing 50% cell death (CC{sub 50}) were relatively high, rendering it an ideal anti-HIV agent. A GST-pull down assay was performed to confirm that SFT is a fusion inhibitor. Furthermore, the activity of SFT on other targets in the HIV life cycle was also investigated, and all assays showed negative results. To further understand the mechanism of action of HIV peptide inhibitors, resistant variants of HIV-1{sub IIIB} were derived by serial virus passage in the presence of increasing doses of SFT or ENF. The results showed that there was cross-resistance between SFT and ENF. In conclusion, SFT is an ideal anti-HIV agent with high potency and low cytotoxicity, but may exhibit a certain extent of cross-resistance with ENF.

  9. A novel proteasome inhibitor suppresses tumor growth via targeting both 19S proteasome deubiquitinases and 20S proteolytic peptidases

    PubMed Central

    Liu, Ningning; Liu, Chunjiao; Li, Xiaofen; Liao, Siyan; Song, Wenbin; Yang, Changshan; Zhao, Chong; Huang, Hongbiao; Guan, Lixia; Zhang, Peiquan; Liu, Shouting; Hua, Xianliang; Chen, Xin; Zhou, Ping; Lan, Xiaoying; Yi, Songgang; Wang, Shunqing; Wang, Xuejun; Dou, Q. Ping; Liu, Jinbao

    2014-01-01

    The successful development of bortezomib-based therapy for treatment of multiple myeloma has established proteasome inhibition as an effective therapeutic strategy, and both 20S proteasome peptidases and 19S deubiquitinases (DUBs) are becoming attractive targets of cancer therapy. It has been reported that metal complexes, such as copper complexes, inhibit tumor proteasome. However, the involved mechanism of action has not been fully characterized. Here we report that (i) copper pyrithione (CuPT), an alternative to tributyltin for antifouling paint biocides, inhibits the ubiquitin-proteasome system (UPS) via targeting both 19S proteasome-specific DUBs and 20S proteolytic peptidases with a mechanism distinct from that of the FDA-approved proteasome inhibitor bortezomib; (ii) CuPT potently inhibits proteasome-specific UCHL5 and USP14 activities; (iii) CuPT inhibits tumor growth in vivo and induces cytotoxicity in vitro and ex vivo. This study uncovers a novel class of dual inhibitors of DUBs and proteasome and suggests a potential clinical strategy for cancer therapy. PMID:24912524

  10. A novel proteasome inhibitor suppresses tumor growth via targeting both 19S proteasome deubiquitinases and 20S proteolytic peptidases.

    PubMed

    Liu, Ningning; Liu, Chunjiao; Li, Xiaofen; Liao, Siyan; Song, Wenbin; Yang, Changshan; Zhao, Chong; Huang, Hongbiao; Guan, Lixia; Zhang, Peiquan; Liu, Shouting; Hua, Xianliang; Chen, Xin; Zhou, Ping; Lan, Xiaoying; Yi, Songgang; Wang, Shunqing; Wang, Xuejun; Dou, Q Ping; Liu, Jinbao

    2014-01-01

    The successful development of bortezomib-based therapy for treatment of multiple myeloma has established proteasome inhibition as an effective therapeutic strategy, and both 20S proteasome peptidases and 19S deubiquitinases (DUBs) are becoming attractive targets of cancer therapy. It has been reported that metal complexes, such as copper complexes, inhibit tumor proteasome. However, the involved mechanism of action has not been fully characterized. Here we report that (i) copper pyrithione (CuPT), an alternative to tributyltin for antifouling paint biocides, inhibits the ubiquitin-proteasome system (UPS) via targeting both 19S proteasome-specific DUBs and 20S proteolytic peptidases with a mechanism distinct from that of the FDA-approved proteasome inhibitor bortezomib; (ii) CuPT potently inhibits proteasome-specific UCHL5 and USP14 activities; (iii) CuPT inhibits tumor growth in vivo and induces cytotoxicity in vitro and ex vivo. This study uncovers a novel class of dual inhibitors of DUBs and proteasome and suggests a potential clinical strategy for cancer therapy. PMID:24912524

  11. The hunt for HIV-1 integrase inhibitors.

    PubMed

    Lataillade, Max; Kozal, Michael J

    2006-07-01

    Currently, there are three distinct mechanistic classes of antiretrovirals: inhibitors of the HIV- 1 reverse transcriptase and protease enzymes and inhibitors of HIV entry, including receptor and coreceptor binding and cell fusion. A new drug class that inhibits the HIV-1 integrase enzyme (IN) is in development and may soon be available in the clinic. IN is an attractive drug target because it is essential for a stable and productive HIV-1 infection and there is no mammalian homologue of IN. Inhibitors of integrase enzyme (INI) block the integration of viral double-stranded DNA into the host cell's chromosomal DNA. HIV-1 integration has many potential steps that can be inhibited and several new compounds that target specific integration steps have been identified by drug developers. Recently, two INIs, GS-9137 and MK-0518, demonstrated promising early clinical trial results and have been advanced into later stage trials. In this review, we describe how IN facilitates HIV-1 integration, the needed enzyme cofactors, and the resultant byproducts created during integration. Furthermore, we review the different INIs under development, their mechanism of actions, site of IN inhibition, potency, resistance patterns, and discuss the early clinical trial results. PMID:16839248

  12. Effects of addition of a dipeptidyl peptidase IV inhibitor to metformin on sirolimus-induced diabetes mellitus.

    PubMed

    Jin, Long; Lim, Sun Woo; Jin, Jian; Chung, Byung Ha; Yang, Chul Woo

    2016-08-01

    The guideline for the management of new-onset diabetes after transplantation recommends metformin (MET) as a first-line drug, and addition of a second-line drug is needed to better control of hyperglycemia. We tested the effect of addition of a dipeptidyl peptidase IV (DPP IV) inhibitor to MET on sirolimus (SRL)-induced diabetes mellitus (DM). In animal model of SRL-induced DM, MET treatment improved pancreatic islet function (blood glucose level and insulin secretion) and attenuated oxidative stress and apoptotic cell death. Addition of a DPP IV inhibitor to MET improved these parameters more than MET alone. An in vitro study showed that SRL treatment increased pancreas beta cell death and production of reactive oxygen species (ROS), and pretreatment of ROS inhibitor, or p38MAPK inhibitor effectively decreased SRL-induced islet cell death. Exendin-4 (EXD), a substrate of DPP IV or MET significantly improved cell viability and decreased ROS production compared with SRL treatment, and combined treatment with the 2 drugs improved both parameters. At the subcellular level, impaired mitochondrial respiration by SRL were partially improved by MET or EXD and much improved further after addition of EXD to MET. Our data suggest that addition of a DPP IV inhibitor to MET decreases SRL-induced oxidative stress and improves mitochondrial respiration. This finding provides a rationale for the combined use of a DPP IV inhibitor and MET in treating SRL-induced DM. PMID:27059001

  13. Overview of Glucagon-like Peptide-1 Analogs and Dipeptidyl Peptidase-4 Inhibitors for Type 2 Diabetes

    PubMed Central

    Pratley, Richard E.

    2008-01-01

    Context Impairment of incretin activity is now recognized as integral to the metabolic derangement underlying type 2 diabetes. Glucoregulatory agents that target the incretin system have recently been developed, and the place of these drugs in the treatment of type 2 diabetes can be assessed based on a growing body of clinical data. Evidence Acquisition A PubMed search was conducted to identify clinical studies of incretin therapies in type 2 diabetes. Article reference lists were also searched for relevant information, and supplemental material such as conference abstracts, drug prescribing information, and treatment guidelines were included as appropriate. Evidence Synthesis Two classes of therapies target the incretin system. The first, glucagon-like peptide-1 (GLP-1) agonists (exemplified by exenatide and liraglutide), have demonstrated considerable efficacy in clinical trials, reducing hemoglobin A1c (HbA1c) by up to 1.3%, decreasing fasting and postprandial glucose concentrations, reducing weight by approximately 3.0 kg, and improving cardiovascular risk factors. The second class, the dipeptidyl peptidase-4 inhibitors (such as sitagliptin and vildagliptin) rely on production of endogenous GLP-1 and act by reducing its turnover. The dipeptidyl peptidase-4 (DPP-4) inhibitors produce modest reductions in HbA1c (< 1%) compared with GLP-1 agonists and are generally weight-neutral. Neither GLP-1 agonists nor DPP-4 inhibitors cause hypoglycemia unless used with other agents known to increase risk. Conclusions GLP-1 agonists and DPP-4 inhibitors provide a valuable new treatment option for patients with type 2 diabetes and may be associated with a wider range of therapeutic benefits than older drugs. PMID:18769687

  14. HIV pharmacotherapy: A review of integrase inhibitors.

    PubMed

    Wong, Elaine; Trustman, Nathan; Yalong, April

    2016-02-01

    Integrase strand transfer inhibitors (INSTIs) are a class of antiretroviral agents used to treat HIV. These drugs--raltegravir, elvitegravir, and dolutegravir--are preferred options for treatment-naïve patients when used in combination with two nucleoside reverse transcriptase inhibitors. Based on clinical trials, INSTIs have been proven to be effective with minimal safety concerns. This article reviews the pharmacologic profile, role in therapy, and safety and efficacy of each agent. PMID:26818644

  15. NAAG peptidase inhibitors block cognitive deficit induced by MK-801 and motor activation induced by d-amphetamine in animal models of schizophrenia.

    PubMed

    Olszewski, R T; Janczura, K J; Ball, S R; Madore, J C; Lavin, K M; Lee, J C-M; Lee, M J; Der, E K; Hark, T J; Farago, P R; Profaci, C P; Bzdega, T; Neale, J H

    2012-01-01

    The most widely validated animal models of the positive, negative and cognitive symptoms of schizophrenia involve administration of d-amphetamine or the open channel NMDA receptor blockers, dizocilpine (MK-801), phencyclidine (PCP) and ketamine. The drug ZJ43 potently inhibits glutamate carboxypeptidase II (GCPII), an enzyme that inactivates the peptide transmitter N-acetylaspartylglutamate (NAAG) and reduces positive and negative behaviors induced by PCP in several of these models. NAAG is an agonist at the metabotropic glutamate receptor 3 (mGluR3). Polymorphisms in this receptor have been associated with expression of schizophrenia. This study aimed to determine whether two different NAAG peptidase inhibitors are effective in dopamine models, whether their efficacy was eliminated in GCPII knockout mice and whether the efficacy of these inhibitors extended to MK-801-induced cognitive deficits as assessed using the novel object recognition test. ZJ43 blocked motor activation when given before or after d-amphetamine treatment. (R,S)-2-phosphono-methylpentanedioic acid (2-PMPA), another potent NAAG peptidase inhibitor, also reduced motor activation induced by PCP or d-amphetamine. 2-PMPA was not effective in GCPII knockout mice. ZJ43 and 2-PMPA also blocked MK-801-induced deficits in novel object recognition when given before, but not after, the acquisition trial. The group II mGluR antagonist LY341495 blocked the effects of NAAG peptidase inhibition in these studies. 2-PMPA was more potent than ZJ43 in a test of NAAG peptidase inhibition in vivo. By bridging the dopamine and glutamate theories of schizophrenia with two structurally different NAAG peptidase inhibitors and demonstrating their efficacy in blocking MK-801-induced memory deficits, these data advance the concept that NAAG peptidase inhibition represents a potentially novel antipsychotic therapy. PMID:22850437

  16. Economic Impact of Combining Metformin with Dipeptidyl Peptidase-4 Inhibitors in Diabetic Patients with Renal Impairment in Spanish Patients

    PubMed Central

    Navarro-Artieda, Ruth

    2015-01-01

    Background To evaluate resource use and health costs due to the combination of metformin and dipeptidyl peptidase-4 (DPP-4) inhibitors in patients with diabetes and renal impairment in routine clinical practice. Methods An observational, retrospective study was performed. Patients aged ≥30 years treated with metformin who initiated a second oral antidiabetic treatment in 2009 to 2010 were included. Two groups of patients were analysed: metformin+DPP-4 inhibitors and other oral antidiabetics. The main measures were: compliance, persistence, metabolic control (glycosylated hemoglobin< 7%) and complications (hypoglycemia, cardiovascular events) and total costs. Patients were followed up for 2 years. Results We included 395 patients, mean age 70.2 years, 56.5% male: 135 patients received metformin+DPP-4 inhibitors and 260 patients received metformin+other oral antidiabetics. Patients receiving DPP-4 inhibitors showed better compliance (66.0% vs. 60.1%), persistence (57.6% vs. 50.0%), and metabolic control (63.9% vs. 57.3%), respectively, compared with those receiving other oral antidiabetics (P<0.05), and also had a lower rate of hypoglycemia (20.0% vs. 47.7%) and lower total costs (€ 2,486 vs. € 3,002), P=0.001. Conclusion Despite the limitations of the study, patients with renal impairment treated with DPP-4 inhibitors had better metabolic control, lower rates (association) of hypoglycaemia, and lower health costs for the Spanish national health system. PMID:25729716

  17. Dipeptide boronic acid inhibitors of dipeptidyl peptidase IV: determinants of potency and in vivo efficacy and safety.

    PubMed

    Connolly, Beth A; Sanford, David G; Chiluwal, Amrita K; Healey, Sarah E; Peters, Diane E; Dimare, Matthew T; Wu, Wengen; Liu, Yuxin; Maw, Hlaing; Zhou, Yuhong; Li, Youhua; Jin, Zhiping; Sudmeier, James L; Lai, Jack H; Bachovchin, William W

    2008-10-01

    Dipeptidyl peptidase IV (DPP-IV; E.C. 3.4.14.5), a serine protease that degrades the incretin hormones GLP-1 and GIP, is now a validated target for the treatment of type 2 diabetes. Dipeptide boronic acids, among the first, and still among the most potent DPP-IV inhibitors known, suffer from a concern over their safety. Here we evaluate the potency, in vivo efficacy, and safety of a selected set of these inhibitors. The adverse effects induced by boronic acid-based DPP-IV inhibitors are essentially limited to what has been observed previously for non-boronic acid inhibitors and attributed to cross-reactivity with DPP8/9. While consistent with the DPP8/9 hypothesis, they are also consistent with cross-reactivity with some other intracellular target. The results further show that the potency of simple dipeptide boronic acid-based inhibitors can be combined with selectivity against DPP8/9 in vivo to produce agents with a relatively wide therapeutic index (>500) in rodents. PMID:18783201

  18. Effects of dipeptidyl peptidase IV inhibitor sitagliptin on immunological parameters of lymphocytes in intact animals and animals with experimental autoimmune process.

    PubMed

    Robinson, M V; Mel'nikova, E V; Trufakin, V A

    2014-11-01

    The effects of dipeptidyl peptidase IV inhibitor sitagliptin on immunological parameters were studied in animals with experimental autoimmune process. The effects of the drug administered in preventive (before manifestation of autoimmune processes) and therapeutic (after manifestation of autoimmune process) modes were studied. PMID:25408522

  19. Leishmania inhibitor of serine peptidase prevents TLR4 activation by neutrophil elastase promoting parasite survival in murine macrophages

    PubMed Central

    Faria, Marilia S.; Reis, Flavia C. G.; Azevedo-Pereira, Ricardo L.; Morrison, Lesley S.; Mottram, Jeremy C.; Lima, Ana Paula C. A.

    2011-01-01

    Leishmania major is a protozoan parasite that causes skin ulcerations in cutaneous leishmaniasis. In the mammalian host, the parasite resides in professional phagocytes and has evolved to avoid killing by macrophages. We identified L. major genes encoding inhibitors of serine peptidases, ISPs, which are orthologues of bacterial ecotins and found that ISP2 inhibits trypsin-fold S1A family peptidases. Here we show that L. major mutants deficient in ISP2 and ISP3 (Δisp2/3) trigger higher phagocytosis by macrophages through a combined action of the complement type-3 receptor (CR3), toll-like receptor 4 (TLR4) and unregulated activity of neutrophil elastase (NE), leading to parasite killing. While all three components are required to mediate enhanced parasite uptake, only TLR4 and NE are necessary to promote parasite killing after infection. We found that the production of superoxide by macrophages in the absence of ISP2 is the main mechanism controlling the intracellular infection. Furthermore, we show that NE modulates macrophage infection in vivo, and that the lack of ISP leads to reduced parasite burdens at later stages of the infection. Our findings support the hypothesis that ISPs function to prevent the activation of TLR4 by NE during the Leishmania-macrophage interaction in order to promote parasite survival and growth. PMID:21098233

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

    PubMed Central

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

    2012-01-01

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

  1. Effect of Dipeptidyl Peptidase-4 Inhibitor on All-Cause Mortality and Coronary Revascularization in Diabetic Patients

    PubMed Central

    Park, Hyo Eun; Jeon, Jooyeong; Hwang, In-Chang; Sung, Jidong; Lee, Seung-Pyo; Kim, Hyung-Kwan; Cho, Goo-Yeong; Sohn, Dae-Won

    2015-01-01

    Background Anti-atherosclerotic effect of dipeptidyl peptidase-4 (DPP-4) inhibitors has been suggested from previous studies, and yet, its association with cardiovascular outcome has not been demonstrated. We aimed to evaluate the effect of DPP-4 inhibitors in reducing mortality and coronary revascularization, in association with baseline coronary computed tomography (CT). Methods The current study was performed as a multi-center, retrospective observational cohort study. All subjects with diabetes mellitus who had diagnostic CT during 2007-2011 were included, and 1866 DPP-4 inhibitor users and 5179 non-users were compared for outcome. The primary outcome was all-cause mortality and secondary outcome included any coronary revascularization therapy after 90 days of CT in addition to all-cause mortality. Results DPP-4 inhibitors users had significantly less adverse events [0.8% vs. 4.4% in users vs. non-users, adjusted hazard ratios (HR) 0.220, 95% confidence interval (CI) 0.102-0.474, p = 0.0001 for primary outcome, 4.1% vs. 7.6% in users vs. non-users, HR 0.517, 95% CI 0.363-0.735, p = 0.0002 for secondary outcome, adjusted variables were age, sex, presence of hypertension, high sensitivity C-reactive protein, glycated hemoglobin, statin use, coronary artery calcium score and degree of stenosis]. Interestingly, DPP-4 inhibitor seemed to be beneficial only in subjects without significant stenosis (adjusted HR 0.148, p = 0.0013 and adjusted HR 0.525, p = 0.0081 for primary and secondary outcome). Conclusion DPP-4 inhibitor is associated with reduced all-cause mortality and coronary revascularization in diabetic patients. Such beneficial effect was significant only in those without significant coronary stenosis, which implies that DPP-4 inhibitor may have beneficial effect in earlier stage of atherosclerosis. PMID:26755932

  2. Aspartic Peptidases of Human Pathogenic Trypanosomatids: Perspectives and Trends for Chemotherapy

    PubMed Central

    Santos, L.O.; Garcia-Gomes, A.S.; Catanho, M.; Sodré, C.L.; Santos, A.L.S.; Branquinha, M.H.; d’Avila-Levy, C.M.

    2013-01-01

    Aspartic peptidases are proteolytic enzymes present in many organisms like vertebrates, plants, fungi, protozoa and in some retroviruses such as human immunodeficiency virus (HIV). These enzymes are involved in important metabolic processes in microorganisms/virus and play major roles in infectious diseases. Although few studies have been performed in order to identify and characterize aspartic peptidase in trypanosomatids, which include the etiologic agents of leishmaniasis, Chagas’ disease and sleeping sickness, some beneficial properties of aspartic peptidase inhibitors have been described on fundamental biological events of these pathogenic agents. In this context, aspartic peptidase inhibitors (PIs) used in the current chemotherapy against HIV (e.g., amprenavir, indinavir, lopinavir, nelfinavir, ritonavir and saquinavir) were able to inhibit the aspartic peptidase activity produced by different species of Leishmania. Moreover, the treatment of Leishmania promastigotes with HIV PIs induced several perturbations on the parasite homeostasis, including loss of the motility and arrest of proliferation/growth. The HIV PIs also induced an increase in the level of reactive oxygen species and the appearance of irreversible morphological alterations, triggering parasite death pathways such as programed cell death (apoptosis) and uncontrolled autophagy. The blockage of physiological parasite events as well as the induction of death pathways culminated in its incapacity to adhere, survive and escape of phagocytic cells. Collectively, these results support the data showing that parasites treated with HIV PIs have a significant reduction in the ability to cause in vivo infection. Similarly, the treatment of Trypanosoma cruzi cells with pepstatin A showed a significant inhibition on both aspartic peptidase activity and growth as well as promoted several and irreversible morphological changes. These studies indicate that aspartic peptidases can be promising targets in

  3. In silico screening of novel inhibitors of M17 Leucine Amino Peptidase (LAP) of Plasmodium vivax as therapeutic candidate.

    PubMed

    Rout, Subhashree; Mahapatra, Rajani Kanta

    2016-08-01

    M17 LAP (Leucine Amino Peptidase) plays an important role in the hydrolysis of amino acids essential for growth and development of Plasmodium vivax (Pv), the pathogen causing malaria. In this paper a homology model of PvLAP was generated using MODELLER v9.15. From different in-silico methods such as structure based, ligand based and de novo drug designing a total of 90 compounds were selected for docking studies. A final list of 10 compounds was prepared. The study reported the identification of 2-[(3-azaniumyl-2-hydroxy-4-phenylbutanoyl) amino]-4-methylpentanoate as the best inhibitor in terms of docking score and pharmacophoric features. The reliability of the binding mode of the inhibitor is confirmed by molecular dynamics (MD) simulation study with GROMACS software for a simulation time of 20ns in water environment. Finally, in silico ADMET analysis of the inhibitors using MedChem Designer v3 evaluated the drug likeness of the best hits to be considered for industrial pharmaceutical research. PMID:27470355

  4. Pyridoxine hydroxamic acids as novel HIV-integrase inhibitors.

    PubMed

    Stranix, Brent R; Wu, Jinzi J; Milot, Guy; Beaulieu, Françis; Bouchard, Jean-Emanuel; Gouveia, Kristine; Forte, André; Garde, Seema; Wang, Zhigang; Mouscadet, Jean-François; Delelis, Olivier; Xiao, Yong

    2016-02-15

    A series of pyridoxine hydroxamic acid analog bearing a 5-aryl-spacers were synthesized. Evaluation of these novel HIV integrase complex inhibitors revealed compounds with high potency against wild-type HIV virus. PMID:26826732

  5. Addition of dipeptidyl peptidase-4 inhibitors to sulphonylureas and risk of hypoglycaemia: systematic review and meta-analysis

    PubMed Central

    Moore, Nicholas; Arnaud, Mickael; Robinson, Philip; Raschi, Emanuel; De Ponti, Fabrizio; Bégaud, Bernard; Pariente, Antoine

    2016-01-01

    Objective To quantify the risk of hypoglycaemia associated with the concomitant use of dipeptidyl peptidase-4 (DPP-4) inhibitors and sulphonylureas compared with placebo and sulphonylureas. Design Systematic review and meta-analysis. Data sources Medline, ISI Web of Science, SCOPUS, Cochrane Central Register of Controlled Trials, and clinicaltrial.gov were searched without any language restriction. Study selection Placebo controlled randomised trials comprising at least 50 participants with type 2 diabetes treated with DPP-4 inhibitors and sulphonylureas. Review methods Risk of bias in each trial was assessed using the Cochrane Collaboration tool. The risk ratio of hypoglycaemia with 95% confidence intervals was computed for each study and then pooled using fixed effect models (Mantel Haenszel method) or random effect models, when appropriate. Subgroup analyses were also performed (eg, dose of DPP-4 inhibitors). The number needed to harm (NNH) was estimated according to treatment duration. Results 10 studies were included, representing a total of 6546 participants (4020 received DPP-4 inhibitors plus sulphonylureas, 2526 placebo plus sulphonylureas). The risk ratio of hypoglycaemia was 1.52 (95% confidence interval 1.29 to 1.80). The NNH was 17 (95% confidence interval 11 to 30) for a treatment duration of six months or less, 15 (9 to 26) for 6.1 to 12 months, and 8 (5 to 15) for more than one year. In subgroup analysis, no difference was found between full and low doses of DPP-4 inhibitors: the risk ratio related to full dose DPP-4 inhibitors was 1.66 (1.34 to 2.06), whereas the increased risk ratio related to low dose DPP-4 inhibitors did not reach statistical significance (1.33, 0.92 to 1.94). Conclusions Addition of DPP-4 inhibitors to sulphonylurea to treat people with type 2 diabetes is associated with a 50% increased risk of hypoglycaemia and to one excess case of hypoglycaemia for every 17 patients in the first six months of treatment. This

  6. Treatment progression in sulfonylurea and dipeptidyl peptidase-4 inhibitor cohorts of type 2 diabetes patients on metformin

    PubMed Central

    Peng, Xiaomei; Jiang, Dingfeng; Liu, Dongju; Varnado, Oralee J; Bae, Jay P

    2016-01-01

    Background Metformin is an oral antidiabetic drug (OAD) widely used as first-line therapy in type 2 diabetes (T2D) treatments. Numerous treatment pathways after metformin failure exist. It is important to understand how treatment choices influence subsequent therapy progressions. This retrospective study compares adherence to, persistence with, and treatment progression in sulfonylurea (SU) and dipeptidyl peptidase-4 (DPP-4) inhibitor patient cohorts with T2D on metformin. Methods Using health insurance claims data, matched patient cohorts were created and OAD use was compared in patients with T2D initiating SU or DPP-4 inhibitors (index drugs) since January 1, 2010, to December 31, 2010, with background metformin therapy. Propensity score matching adjusted for possible selection bias. Persistence was measured via Cox regression as days to a ≥60-day gap in index drug possession; adherence was defined as proportion of days covered (PDC) ≥80%. Evolving treatment patterns were traced at 6-month intervals for 24 months following index drug discontinuation. Results From among 19,621 and 7,484 patients in the SU and DPP-4 inhibitor cohorts, respectively, 6,758 patient pairs were matched. Persistence at 12 months in the SU cohort was 48.0% compared to 52.5% for the DPP-4 inhibitor cohort. PDC adherence (mean [SD]) during the 12-month follow-up period was 63.3 (29.7) for the SU cohort and 65.5 (28.7) for the DPP-4 inhibitor cohort. PDC ≥80% was 40.5% and 43.4% in the SU and DPP-4 inhibitor cohorts, respectively. A higher percentage of patients in the SU cohort remained untreated. Following index drug discontinuation, monotherapy was more common in the SU cohort, while use of two or three OADs was more common in the DPP-4 inhibitor cohort. Insulin therapy initiation was higher in the SU cohort. Conclusion Slightly better adherence and persistence were seen in the DPP-4 inhibitor cohort. Adherence and persistence remain a challenge to many patients; understanding

  7. Dipeptidyl peptidase-4 inhibitors can minimize the hypoglycaemic burden and enhance safety in elderly people with diabetes.

    PubMed

    Avogaro, A; Dardano, A; de Kreutzenberg, S V; Del Prato, S

    2015-02-01

    The prevalence of type 2 diabetes mellitus (T2DM) among elderly people is increasing. Often associated with disabilities/comorbidities, T2DM lowers the chances of successful aging and is independently associated with frailty and an increased risk of hypoglycaemia, which can be further exacerbated by antihyperglycaemic treatment. From this perspective, the clinical management of T2DM in the elderly is challenging and requires individualization of optimum glycaemic targets depending on comorbidities, cognitive functioning and ability to recognize and self-manage the disease. The lack of solid evidence-based medicine supporting treatment guidelines for older people with diabetes further complicates the matter. Several classes of medicine for the treatment of T2DM are currently available and different drug combinations are often required to achieve individualized glycaemic goals. Many of these drugs, however, carry disadvantages such as the propensity to cause weight gain or hypoglycaemia. Dipeptidyl peptidase-4 (DPP-4) inhibitors, a recent addition to the pharmacological armamentarium, have become widely accepted in clinical practice because of their efficacy, low risk of hypoglycaemia, neutral effect on body weight, and apparently greater safety in patients with kidney failure. Although more information is needed to reach definitive conclusions, growing evidence suggests that DPP-4 inhibitors may become a valuable component in the pharmacological management of elderly people with T2DM. The present review aims to delineate the potential advantages of this pharmacological approach in the treatment of elderly people with T2DM. PMID:24867662

  8. ASP4000, a slow-binding dipeptidyl peptidase 4 inhibitor, has antihyperglycemic activity of long duration in Zucker fatty rats.

    PubMed

    Tanaka-Amino, Keiko; Matsumoto, Kazumi; Hatakeyama, Yoshifumi; Takakura, Shoji; Mutoh, Seitaro

    2010-03-01

    ASP4000 ((2S)-1-{[(1R,3S,4S,6R)-6-hydroxy-2-azabicyclo[2.2.1]hept-3-yl]carbonyl}-2-pyrrolidinecarbonitrile hydrochloride) is a novel, potent and selective dipeptidyl peptidase 4 (DPP IV, EC 3.4.14.5) inhibitor (Keiko Tanaka-Amino et al. in Eur J pharmacol 59:444-449, 2008). The aim of the present study was to characterize the kinetic profile of and identify the long duration effect of the antihyperglycemic activity of ASP4000. ASP4000 was found to inhibit human recombinant DPP4 activity with a K(i) of 1.05 nM, a k(on) value of 22.3 x 10(5) M(-1) s(-1), and a k (off) of 2.35 x 10(-3) M(-1) s(-1), with higher affinity than that of vildagliptin. The kinetic studies indicate that both the formation and dissociation of ASP4000/DPP4 complex were faster than those of vildagliptin, and that ASP4000 slow-bindingly inhibits DPP4 with a different mode of inhibition than vildagliptin. In addition, ASP4000 augmented the insulin response and ameliorated the glucose excursion during the oral glucose tolerance test in Zucker fatty rats at 4 h post dosing. ASP4000 is expected to be a promising, long duration DPP4 inhibitor for type 2 diabetes. PMID:19238312

  9. Identification of lympho-epithelial Kazal-type inhibitor 2 in human skin as a kallikrein-related peptidase 5-specific protease inhibitor.

    PubMed

    Meyer-Hoffert, Ulf; Wu, Zhihong; Schröder, Jens-Michael

    2009-01-01

    Kallikreins-related peptidases (KLKs) are serine proteases and have been implicated in the desquamation process of the skin. Their activity is tightly controlled by epidermal protease inhibitors like the lympho-epithelial Kazal-type inhibitor (LEKTI). Defects of the LEKTI-encoding gene serine protease inhibitor Kazal type (Spink)5 lead to the absence of LEKTI and result in the genodermatose Netherton syndrome, which mimics the common skin disease atopic dermatitis. Since many KLKs are expressed in human skin with KLK5 being considered as one of the most important KLKs in skin desquamation, we proposed that more inhibitors are present in human skin. Herein, we purified from human stratum corneum by HPLC techniques a new KLK5-inhibiting peptide encoded by a member of the Spink family, designated as Spink9 located on chromosome 5p33.1. This peptide is highly homologous to LEKTI and was termed LEKTI-2. Recombinant LEKTI-2 inhibited KLK5 but not KLK7, 14 or other serine proteases tested including trypsin, plasmin and thrombin. Spink9 mRNA expression was detected in human skin samples and in cultured keratinocytes. LEKTI-2 immune-expression was focally localized at the stratum granulosum and stratum corneum at palmar and plantar sites in close localization to KLK5. At sites of plantar hyperkeratosis, LEKTI-2 expression was increased. We suggest that LEKTI-2 contributes to the regulation of the desquamation process in human skin by specifically inhibiting KLK5. PMID:19190773

  10. Efficacy of different dipeptidyl peptidase-4 (DPP-4) inhibitors on metabolic parameters in patients with type 2 diabetes undergoing dialysis.

    PubMed

    Park, Se Hee; Nam, Joo Young; Han, Eugene; Lee, Yong-Ho; Lee, Byung-Wan; Kim, Beom Seok; Cha, Bong-Soo; Kim, Chul Sik; Kang, Eun Seok

    2016-08-01

    Hyperglycemia is associated with increased mortality and morbidity in patients with type 2 diabetes mellitus (T2DM) who are undergoing dialysis. Although dipeptidyl peptidase-4 (DPP-4) inhibitors have been widely used in end-stage renal disease (ESRD) patients with T2DM, there are few studies on their efficacy in this population. We studied the effect of 3 different DPP-4 inhibitors on metabolic parameters in ESRD patients with T2DM.Two hundred ESRD patients with T2DM who were treated with DPP-4 inhibitors (sitagliptin, vildagliptin, or linagliptin) were enrolled and analyzed retrospectively. The changes in glycated hemoglobin (HbA1c), fasting plasma glucose, and lipid profiles were assessed before and after 3 months of treatment with DPP-4 inhibitors. Subgroup analysis was done for each hemodialysis (HD) and peritoneal dialysis (PD) group.There was no significant difference in the decrease in the HbA1c level among sitagliptin, vildagliptin, and linagliptin treatment groups (-0.74 ± 1.57, -0.39 ± 1.45, and -0.08 ± 1.40, respectively, P = 0.076). The changes in fasting blood glucose and lipid profiles were also not significantly different. In HD patients (n = 115), there was no difference in the HbA1c level among the 3 groups. In contrast, in PD patients (n = 85), HbA1c was reduced more after 3 months of treatment with sitagliptin compared with vildagliptin and linagliptin (-1.58 ± 0.95, -0.46 ± 0.98, -0.04 ± 1.22, respectively, P = 0.001).There was no significant difference in the glucose-lowering effect between the different DPP-4 inhibitors tested in ESRD patients. In PD patients, sitagliptin tends to lower the HbA1c level more than the other inhibitors. The glucose-lowering efficacy of the 3 DPP-4 inhibitors was comparable. PMID:27512877

  11. Efficacy of different dipeptidyl peptidase-4 (DPP-4) inhibitors on metabolic parameters in patients with type 2 diabetes undergoing dialysis

    PubMed Central

    Park, Se Hee; Nam, Joo Young; Han, Eugene; Lee, Yong-ho; Lee, Byung-Wan; Kim, Beom Seok; Cha, Bong-Soo; Kim, Chul Sik; Kang, Eun Seok

    2016-01-01

    Abstract Hyperglycemia is associated with increased mortality and morbidity in patients with type 2 diabetes mellitus (T2DM) who are undergoing dialysis. Although dipeptidyl peptidase-4 (DPP-4) inhibitors have been widely used in end-stage renal disease (ESRD) patients with T2DM, there are few studies on their efficacy in this population. We studied the effect of 3 different DPP-4 inhibitors on metabolic parameters in ESRD patients with T2DM. Two hundred ESRD patients with T2DM who were treated with DPP-4 inhibitors (sitagliptin, vildagliptin, or linagliptin) were enrolled and analyzed retrospectively. The changes in glycated hemoglobin (HbA1c), fasting plasma glucose, and lipid profiles were assessed before and after 3 months of treatment with DPP-4 inhibitors. Subgroup analysis was done for each hemodialysis (HD) and peritoneal dialysis (PD) group. There was no significant difference in the decrease in the HbA1c level among sitagliptin, vildagliptin, and linagliptin treatment groups (−0.74 ± 1.57, −0.39 ± 1.45, and −0.08 ± 1.40, respectively, P = 0.076). The changes in fasting blood glucose and lipid profiles were also not significantly different. In HD patients (n = 115), there was no difference in the HbA1c level among the 3 groups. In contrast, in PD patients (n = 85), HbA1c was reduced more after 3 months of treatment with sitagliptin compared with vildagliptin and linagliptin (−1.58 ± 0.95, −0.46 ± 0.98, −0.04 ± 1.22, respectively, P = 0.001). There was no significant difference in the glucose-lowering effect between the different DPP-4 inhibitors tested in ESRD patients. In PD patients, sitagliptin tends to lower the HbA1c level more than the other inhibitors. The glucose-lowering efficacy of the 3 DPP-4 inhibitors was comparable. PMID:27512877

  12. Renoprotective Effect of Gemigliptin, a Dipeptidyl Peptidase-4 Inhibitor, in Streptozotocin-Induced Type 1 Diabetic Mice

    PubMed Central

    Jung, Gwon-Soo; Jeon, Jae-Han; Choe, Mi Sun; Kim, Sung-Woo; Lee, In-Kyu

    2016-01-01

    Background Dipeptidyl peptidase-4 (DPP-4) inhibitors are widely used in the treatment of patients with type 2 diabetes and have proven protective effects on diabetic kidney disease (DKD). Whether DPP-4 inhibitors have renoprotective effects on insulin-deficient type 1 diabetes has not been comprehensively examined. The aim of this study was to determine whether gemigliptin, a new DPP-4 inhibitor, has renoprotective effects in streptozotocin (STZ)-induced type 1 diabetic mice. Methods Diabetes was induced by intraperitoneal administration of a single dose of STZ. Mice with diabetes were treated without or with gemigliptin (300 mg/kg) for 8 weeks. Morphological changes of the glomerular basement membrane (GBM) were observed by electron microscopy and periodic-acid Schiff staining. In addition, we measured blood glucose and urinary albumin excretion and evaluated fibrotic markers using immunohistochemical staining, quantitative reverse transcription polymerase chain reaction analysis, and Western blot analysis. Results Gemigliptin did not reduce the blood glucose levels of STZ-treated mice. In gemigliptin-treated mice with STZ, a significant reduction in urinary albumin excretion and GBM thickness was observed. Immunohistological examination revealed that gemigliptin attenuated renal fibrosis induced by STZ and decreased extracellular matrix protein levels, including those of type I collagen and fibronectin, and Smad3 phosphorylation. In cultured rat renal cells, gemigliptin inhibited transforming growth factor β-stimulated type I collagen and fibronectin mRNA and protein levels via down-regulation of Smad3 phosphorylation. Conclusion Our data demonstrate that gemigliptin has renoprotective effects on DKD, regardless of its glucose-lowering effect, suggesting that it could be used to prevent DKD, including in patients with type 1 diabetes. PMID:27098503

  13. Dipeptidyl Peptidase-4 Inhibitor Decreases Abdominal Aortic Aneurysm Formation through GLP-1-Dependent Monocytic Activity in Mice

    PubMed Central

    Lu, Hsin Ying; Huang, Chun Yao; Shih, Chun Ming; Chang, Wei Hung; Tsai, Chein Sung; Lin, Feng Yen; Shih, Chun Che

    2015-01-01

    Abdominal aortic aneurysm (AAA) is a life-threatening situation affecting almost 10% of elders. There has been no effective medication for AAA other than surgical intervention. Dipeptidyl peptidase-4 (DPP-4) inhibitors have been shown to have a protective effect on cardiovascular disease. Whether DPP-4 inhibitors may be beneficial in the treatment of AAA is unclear. We investigated the effects of DPP-4 inhibitor sitagliptin on the angiotensin II (Ang II)-infused AAA formation in apoE-deficient (apoE-/-) mice. Mice with induced AAA were treated with placebo or 2.5, 5 or 10 mg/kg/day sitagliptin. Ang II-infused apoE-/- mice exhibited a 55.6% incidence of AAA formation, but treatment with sitagliptin decreased AAA formation. Specifically, administered sitagliptin in Ang II-infused mice exhibited decreased expansion of the suprarenal aorta, reduced elastin lamina degradation of the aorta, and diminished vascular inflammation by macrophage infiltration. Treatment with sitagliptin decreased gelatinolytic activity and apoptotic cells in aorta tissues. Sitaglipitn, additionally, was associated with increased levels of plasma active glucagon-like peptide-1 (GLP-1). In vitro studies, GLP-1 decreased reactive oxygen species (ROS) production, cell migration, and MMP-2 as well as MMP-9 activity in Ang II-stimulated monocytic cells. The results conclude that oral administration of sitagliptin can prevent abdominal aortic aneurysm formation in Ang II-infused apoE-/-mice, at least in part, by increasing of GLP-1 activity, decreasing MMP-2 and MMP-9 production from macrophage infiltration. The results indicate that sitagliptin may have therapeutic potential in preventing the development of AAA. PMID:25876091

  14. Potential for combination of dipeptidyl peptidase-4 inhibitors and sodium-glucose co-transporter-2 inhibitors for the treatment of type 2 diabetes

    PubMed Central

    Sharma, M D

    2015-01-01

    In individuals with advanced type 2 diabetes (T2DM), combination therapy is often unavoidable to maintain glycaemic control. Currently metformin is considered the first line of defence, but many patients experience gastrointestinal adverse events, necessitating an alternative treatment approach. Established therapeutic classes, such as sulphonylureas and thiazolidinediones, have some properties undesirable in individuals with T2DM, such as hypoglycaemia risk, weight gain and fluid retention, highlighting the need for newer agents with more favourable safety profiles that can be combined and used at all stages of T2DM. New treatment strategies have focused on both dipeptidyl peptidase (DPP)-4 inhibitors, which improve hyperglycaemia by stimulating insulin secretion in a glucose-dependent fashion and suppressing glucagon secretion, and sodium-glucose co-transporter-2 (SGLT2) inhibitors, which reduce renal glucose reabsorption and induce urinary glucose excretion, thereby lowering plasma glucose. The potential complimentary mechanism of action and good tolerance profile of these two classes of agents make them attractive treatment options for combination therapy with any of the existing glucose-lowering agents, including insulin. Together, the DPP-4 and SGLT2 inhibitors fulfill a need for treatments with mechanisms of action that can be used in combination with a low risk of adverse events, such as hypoglycaemia or weight gain. PMID:25690671

  15. Cardiovascular safety of dipeptidyl peptidase-4 inhibitors: recent evidence on heart failure.

    PubMed

    Kankanala, Saumya Reddy; Syed, Rafay; Gong, Quan; Ren, Boxu; Rao, Xiaoquan; Zhong, Jixin

    2016-01-01

    The cardiovascular safety of DPP4 inhibitors as a class, especially in regards to heart failure, has been questioned after the publication of first trials (SAVOR-TIMI 53 and EXAMINE) assessing the cardiovascular risks of DPP4 inhibitors alogliptin and sitagliptin in 2013. Although there were no increased risks in composite cardiovascular outcomes, the SAVOR-TIMI 53 trial reported a 27% increase in hospitalization for heart failure in diabetic patients who received the DPP4 inhibitor saxagliptin. There has been substantial increase in knowledge on the heart failure effect of DPP4 inhibition since 2013. This review will summarize the role of the DPP4/incretin axis in heart failure and discuss the findings from recent large scale clinical trials assessing the effects of DPP4 inhibitors on heart failure. PMID:27347354

  16. Cardiovascular safety of dipeptidyl peptidase-4 inhibitors: recent evidence on heart failure

    PubMed Central

    Kankanala, Saumya Reddy; Syed, Rafay; Gong, Quan; Ren, Boxu; Rao, Xiaoquan; Zhong, Jixin

    2016-01-01

    The cardiovascular safety of DPP4 inhibitors as a class, especially in regards to heart failure, has been questioned after the publication of first trials (SAVOR-TIMI 53 and EXAMINE) assessing the cardiovascular risks of DPP4 inhibitors alogliptin and sitagliptin in 2013. Although there were no increased risks in composite cardiovascular outcomes, the SAVOR-TIMI 53 trial reported a 27% increase in hospitalization for heart failure in diabetic patients who received the DPP4 inhibitor saxagliptin. There has been substantial increase in knowledge on the heart failure effect of DPP4 inhibition since 2013. This review will summarize the role of the DPP4/incretin axis in heart failure and discuss the findings from recent large scale clinical trials assessing the effects of DPP4 inhibitors on heart failure. PMID:27347354

  17. Treatment with metformin and a dipeptidyl peptidase-4 inhibitor elevates apelin levels in patients with type 2 diabetes mellitus

    PubMed Central

    Fan, Yujuan; Zhang, Yu; Li, Xuesong; Zheng, Hui; Song, Yuping; Zhang, Ning; Shen, Chunfang; Fan, Xiaofang; Ren, Fengdong; Shen, Jiayi; Ren, Guoguang; Yang, Jialin

    2015-01-01

    Background The objective of this study was to assess the effects of metformin monotherapy or combined treatment with a dipeptidyl peptidase-4 inhibitor (vildagliptin) on apelin levels in patients with type 2 diabetes mellitus. Methods Twenty-five patients with poor glycemic control (glycosylated hemoglobin >6.5% [48 mmol/mol]) taking 1,000 mg of metformin daily and 25 healthy controls matched for age and body mass index were enrolled in this study. Anthropometric parameters, glycemic and lipid profile, insulin resistance (homeostasis model assessment of insulin resistance index), and apelin levels were measured at baseline and at 12-week and 24-week visits. Results At baseline, apelin levels were higher in the T2DM patients than in the controls (1.93±1.81 ng/mL versus 6.09±4.90 ng/mL; P<0.05). After 12 weeks, when vildagliptin was added, fasting blood glucose and glycosylated hemoglobin decreased, and apelin levels increased further (from 6.09±4.90 ng/mL to 24.23±12.59 ng/mL; P<0.05). Follow-up at 24 weeks showed no further improvement in the glycemic profile and no further increase in apelin levels. Conclusion Both metformin and vildagliptin favorably changed glycemic indices and apelin levels. For patients inadequately controlled on a low dose of metformin, addition of vildagliptin may be helpful. PMID:26316706

  18. Gemigliptin, a novel dipeptidyl peptidase-4 inhibitor, exhibits potent anti-glycation properties in vitro and in vivo.

    PubMed

    Jung, Eunsoo; Kim, Junghyun; Kim, Sung Ho; Kim, Sanghwa; Cho, Myung-Haing

    2014-12-01

    This study evaluated the inhibitory effects of gemigliptin, a highly selective dipeptidyl peptidase-4 inhibitor, on the formation of advanced glycation end products (AGEs) and AGE cross-links with proteins in in vitro as well as in type 2 diabetic db/db mice. In in vitro assay, gemigliptin dose-dependently inhibited methylglyoxal-modified AGE-bovine serum albumin (BSA) formation (IC50=11.69 mM). AGE-collagen cross-linking assays showed that gemigliptin had a potent inhibitory effect (IC50=1.39 mM) on AGE-BSA cross-links to rat tail tendon collagen, and its activity was stronger than aminoguanidine (IC50=26.4 mM). In addition, gemigliptin directly trapped methylglyoxal in a concentration-dependent manner in vitro. To determine whether gemigliptin inhibits the in vivo glycation processes, gemigliptin (100 mg/kg/day) was orally administered into type 2 diabetic db/db mice for 12 weeks. Elevated serum levels of AGEs in db/db mice were suppressed by the administration of gemigliptin. These inhibitory effects of gemigliptin on the glycation process in both in vitro and in vivo suggest its therapeutic potential for ameliorating AGE-related diabetic complications. PMID:25448307

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

    PubMed

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

    2016-08-25

    The binding kinetics and thermodynamics of dipeptidyl peptidase (DPP)-4 inhibitors (gliptins) were investigated using surface plasmon resonance and isothermal titration calorimetry. Binding of gliptins to DPP-4 is a rapid electrostatically driven process. Off-rates were generally slow partly because of reversible covalent bond formation by some gliptins, and partly because of strong and extensive interactions. Binding of all gliptins is enthalpy-dominated due to strong ionic interactions and strong solvent-shielded hydrogen bonds. Using a congeneric series of molecules which represented the intermediates in the lead optimization program of linagliptin, the onset of slow binding kinetics and development of the thermodynamic repertoire were analyzed in the context of incremental changes of the chemical structures. All compounds rapidly associated, and therefore the optimization of affinity and residence time is highly correlated. The major contributor to the increasing free energy of binding was a strong increase of binding enthalpy, whereas entropic contributions remained low and constant despite significant addition of lipophilicity. PMID:27438064

  20. Design, synthesis and biological evaluation of hetero-aromatic moieties substituted pyrrole-2-carbonitrile derivatives as dipeptidyl peptidase IV inhibitors.

    PubMed

    Ji, Xun; Su, Mingbo; Wang, Jiang; Deng, Guanghui; Deng, Sisi; Li, Zeng; Tang, Chunlan; Li, Jingya; Li, Jia; Zhao, Linxiang; Jiang, Hualiang; Liu, Hong

    2014-03-21

    A series of novel hetero-aromatic moieties substituted α-amino pyrrole-2-carbonitrile derivatives was designed and synthesized based on structure-activity relationships (SARs) of pyrrole-2-carbonitrile inhibitors. All compounds demonstrated good dipeptidyl peptidase IV (DPP4) inhibitory activities (IC50 = 0.004-113.6 μM). Moreover, compounds 6h (IC50 = 0.004 μM) and 6n (IC50 = 0.01 μM) showed excellent inhibitory activities against DPP4, good selectivity (compound 6h, selective ratio: DPP8/DPP4 = 450.0; DPP9/DPP4 = 375.0; compound 6n, selective ratio: DPP8/DPP4 = 470.0; DPP9/DPP4 = 750.0) and good efficacy in an oral glucose tolerance test in ICR mice. Furthermore, compounds 6h and 6n demonstrated moderate PK properties (compound 6h, F% = 37.8%, t1/2 = 1.45 h; compound 6n, F% = 16.8%, t1/2 = 3.64 h). PMID:24531224

  1. Pancreatic gene variants potentially associated with dipeptidyl peptidase-4 inhibitor treatment response in Type 2 diabetes.

    PubMed

    Jamaluddin, Jazlina Liza; Huri, Hasniza Zaman; Vethakkan, Shireene Ratna; Mustafa, Norlaila

    2014-02-01

    In the adult pancreas, the expression of the genes PAX4, KCNQ1, TCF7L2, KCNJ11, ABCC8, MTNR1B and WFS1 are mainly restricted to β cells to maintain glucose homeostasis. We have identified these genes as the main regulators of incretin-mediated actions, and therefore they may potentially influence the response of DPP-4 inhibitors. This review represents the first detailed exploration of pancreatic β-cell genes and their variant mechanisms, which could potentially affect the response of DPP-4 inhibitors in Type 2 diabetes. We have focused on the signaling pathways of these genes to understand their roles in gastrointestinal incretin-mediated effects; and finally, we sought to associate gene mechanisms with their Type 2 diabetes risk variants to predict the responses of DPP-4 inhibitors for this disease. PMID:24444412

  2. Dipeptidyl peptidase 4 inhibitor improves brain insulin sensitivity, but fails to prevent cognitive impairment in orchiectomy obese rats.

    PubMed

    Pintana, Hiranya; Pongkan, Wanpitak; Pratchayasakul, Wasana; Chattipakorn, Nipon; Chattipakorn, Siriporn C

    2015-08-01

    It is unclear whether the dipeptidyl peptidase 4 (DPP4) inhibitor can counteract brain insulin resistance, brain mitochondrial dysfunction, impairment of hippocampal synaptic plasticity and cognitive decline in testosterone-deprived obese rats. We hypothesized that DPP4 inhibitor vildagliptin improves cognitive function in testosterone-deprived obese rats by restoring brain insulin sensitivity, brain mitochondrial function and hippocampal synaptic plasticity. Thirty male Wistar rats received either a sham-operated (S, n=6) or bilateral orchiectomy (ORX, n=24). ORX rats were divided into two groups and fed with either a normal diet (ND (NDO)) or a high-fat diet (HFO) for 12 weeks. Then, ORX rats in each dietary group were divided into two subgroups (n=6/subgroup) to receive either a vehicle or vildagliptin (3 mg/kg per day, p.o.) for 4 weeks. After treatment, cognitive function, metabolic parameters, brain insulin sensitivity, hippocampal synaptic plasticity and brain mitochondrial function were determined in each rat. We found that HFO rats exhibited peripheral and brain insulin resistance, brain mitochondrial dysfunction, impaired hippocampal synaptic plasticity and cognitive decline. NDO rats did not develop peripheral and brain insulin resistance. However, impaired hippocampal synaptic plasticity and cognitive decline occurred. Vildagliptin significantly improved peripheral insulin sensitivity, restored brain insulin sensitivity and decreased brain mitochondrial reactive oxygen species production in HFO rats. However, vildagliptin did not restore hippocampal synaptic plasticity and cognitive function in both NDO and HFO rats. These findings suggest that vildagliptin could not counteract the impairment of hippocampal synaptic plasticity and cognitive decline in testosterone-deprived subjects, despite its effects on improved peripheral and brain insulin sensitivity as well as brain mitochondrial function. PMID:26016746

  3. Clinical Characteristics of the Responders to Dipeptidyl Peptidase-4 Inhibitors in Korean Subjects with Type 2 Diabetes

    PubMed Central

    Oh, Tae Jung; Bae, Jae Hyun; Kim, Yeong Gi; Park, Kyeong Seon; Cho, Young Min; Park, Kyong Soo; Kim, Seong Yeon

    2013-01-01

    We investigated characteristics associated with the efficacy of dipeptidyl peptidase-4 inhibitors (DPP4i) in Korean patients with type 2 diabetes. We reviewed medical records of 477 patients who had taken sitagliptin or vildagliptin longer than 40 weeks. Response to DPP4i was evaluated with HbA1c change after therapy (ΔHbA1c). The Student's t-test between good responders (GR: ΔHbA1c > 1.0%) and poor responders (PR: ΔHbA1c < 0.5%), a correlation analysis among clinical parameters, and a linear multivariate regression analysis were performed. The mean age was 60 yr, duration of diabetes 11 yr and HbA1c was 8.1%. Baseline fasting plasma glucose (FPG), HbA1c, C-peptide, and creatinine were significantly higher in the GR compared to the PR. Duration of diabetes, FPG, HbA1c, C-peptide and creatinine were significantly correlated with ΔHbA1c. In the multivariate analysis, age (r2 = 0.006), duration of diabetes (r2 = 0.019), HbA1c (r2 = 0.296), and creatinine levels (r2 = 0.024) were independent predictors for the response to DPP4i. Body mass index and insulin resistance were not associated with the response to DPP4i. In conclusion, better response to DPP4i would be expected in Korean patients with type 2 diabetes who have higher baseline HbA1c and creatinine levels with shorter duration of diabetes. PMID:23772153

  4. Pharmacokinetic and pharmacodynamic interactions between metformin and a novel dipeptidyl peptidase-4 inhibitor, evogliptin, in healthy subjects.

    PubMed

    Rhee, Su-Jin; Choi, YoonJung; Lee, SeungHwan; Oh, Jaeseong; Kim, Sung-Jin; Yoon, Seo Hyun; Cho, Joo-Youn; Yu, Kyung-Sang

    2016-01-01

    Evogliptin is a newly developed dipeptidyl peptidase-4 (DPP-4) inhibitor, which is expected to be combined with metformin for treating type 2 diabetes mellitus. We investigated the potential pharmacokinetic and pharmacodynamic interactions between evogliptin and metformin. A randomized, open-label, multiple-dose, six-sequence, three-period crossover study was conducted in 36 healthy male subjects. All subjects received three treatments, separated by 7-day washout intervals: evogliptin, 5 mg od for 7 days (EVO); metformin IR, 1,000 mg bid for 7 days (MET); and the combination of EVO and MET (EVO + MET). After the last dose in a period, serial blood samples were collected for 24 hours for pharmacokinetic assessments. During steady state, serial blood samples were collected for 2 hours after an oral glucose tolerance test, and DPP-4, active glucagon-like peptide-1, glucose, glucagon, insulin, and C-peptide were measured to assess pharmacodynamic properties. EVO + MET and EVO showed similar steady state maximum concentration and area under the concentration-time curve at steady state values for evogliptin; the geometric mean ratios (90% confidence interval) were 1.06 (1.01-1.12) and 1.02 (0.99-1.06), respectively. EVO + MET slightly reduced steady state maximum concentration and area under the concentration-time curve at steady state values for metformin compared to MET, with geometric mean ratios (90% confidence interval) of 0.84 (0.79-0.89) and 0.94 (0.89-0.98), respectively. EVO + MET and EVO had similar DPP-4 inhibition efficacy, but EVO + MET increased active glucagon-like peptide-1 and reduced glucose to larger extents than either EVO or MET alone. Our results suggested that EVO+MET could provide therapeutic benefits without clinically significant pharmacokinetic interactions. Thus, the EVO + MET combination is a promising option for treating type 2 diabetes mellitus. PMID:27570447

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

    PubMed

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

    2016-07-15

    Although previous studies have shown an important role of renal dipeptidyl peptidase-4 (DPP-4) inhibition in ameliorating kidney injury in hypertensive rats, the renal distribution of DPP-4 and mechanisms of renoprotective action of DPP-4 inhibition remain unclear. In this study, we examined the effects of the DPP-4 inhibitor saxagliptin on DPP-4 activity in renal cells (using in situ DPP-4 staining) and on renal gene expression related to inflammation and fibrosis in the renal injury in hypertensive Dahl salt-sensitive (Dahl-S) rats. Male rats fed a high-salt (8% NaCl) diet received vehicle (water) or saxagliptin (12.7mg/kg/day) for 4 weeks. Blood pressure (BP), serum glucose and 24-h urinary albumin and sodium excretions were measured, and renal histopathology was performed. High salt-diet increased BP and urinary albumin excretion, consequently resulting in glomerular sclerosis and tubulointerstitial fibrosis. Although saxagliptin did not affect BP and blood glucose levels, it significantly ameliorated urinary albumin excretion. In situ staining showed DPP-4 activity in glomerular and tubular cells. Saxagliptin significantly suppressed DPP-4 activity in renal tissue extracts and in glomerular and tubular cells. Saxagliptin also significantly attenuated the increase in inflammation and fibrosis-related gene expressions in the kidney. Our results demonstrate that saxagliptin inhibited the development of renal injury independent of its glucose-lowering effect. Glomerular and tubular DPP-4 inhibition by saxagliptin was associated with improvements in albuminuria and the suppression of inflammation and fibrosis-related genes. Thus, local glomerular and tubular DPP-4 inhibition by saxagliptin may play an important role in its renoprotective effects in Dahl-S rats. PMID:27063445

  6. Pharmacokinetic and pharmacodynamic interactions between metformin and a novel dipeptidyl peptidase-4 inhibitor, evogliptin, in healthy subjects

    PubMed Central

    Rhee, Su-jin; Choi, YoonJung; Lee, SeungHwan; Oh, Jaeseong; Kim, Sung-Jin; Yoon, Seo Hyun; Cho, Joo-Youn; Yu, Kyung-Sang

    2016-01-01

    Evogliptin is a newly developed dipeptidyl peptidase-4 (DPP-4) inhibitor, which is expected to be combined with metformin for treating type 2 diabetes mellitus. We investigated the potential pharmacokinetic and pharmacodynamic interactions between evogliptin and metformin. A randomized, open-label, multiple-dose, six-sequence, three-period crossover study was conducted in 36 healthy male subjects. All subjects received three treatments, separated by 7-day washout intervals: evogliptin, 5 mg od for 7 days (EVO); metformin IR, 1,000 mg bid for 7 days (MET); and the combination of EVO and MET (EVO + MET). After the last dose in a period, serial blood samples were collected for 24 hours for pharmacokinetic assessments. During steady state, serial blood samples were collected for 2 hours after an oral glucose tolerance test, and DPP-4, active glucagon-like peptide-1, glucose, glucagon, insulin, and C-peptide were measured to assess pharmacodynamic properties. EVO + MET and EVO showed similar steady state maximum concentration and area under the concentration–time curve at steady state values for evogliptin; the geometric mean ratios (90% confidence interval) were 1.06 (1.01–1.12) and 1.02 (0.99–1.06), respectively. EVO + MET slightly reduced steady state maximum concentration and area under the concentration–time curve at steady state values for metformin compared to MET, with geometric mean ratios (90% confidence interval) of 0.84 (0.79–0.89) and 0.94 (0.89–0.98), respectively. EVO + MET and EVO had similar DPP-4 inhibition efficacy, but EVO + MET increased active glucagon-like peptide-1 and reduced glucose to larger extents than either EVO or MET alone. Our results suggested that EVO+MET could provide therapeutic benefits without clinically significant pharmacokinetic interactions. Thus, the EVO + MET combination is a promising option for treating type 2 diabetes mellitus. PMID:27570447

  7. Natural dipeptidyl peptidase-IV inhibitor mangiferin mitigates diabetes- and metabolic syndrome-induced changes in experimental rats

    PubMed Central

    Suman, Rajesh Kumar; Mohanty, Ipseeta Ray; Maheshwari, Ujwala; Borde, Manjusha K; Deshmukh, YA

    2016-01-01

    Background Mangiferin (MNG) is known to possess antidiabetic and antioxidant activity. However, there is no experimental evidence presently available in the literature with regard to its ameliorating effects on diabetes mellitus coexisting with metabolic syndrome. Objective The present study was designed to evaluate the protective effects of MNG on various components of metabolic syndrome with diabetes as an essential component. Material and methods Adult Wistar rats were fed high-fat diets for 10 weeks and challenged with streptozotocin (40 mg/kg) at week three (high-fat diabetic control group). After the confirmation of metabolic syndrome in the setting of diabetes, MNG 40 mg/kg was orally fed to these rats from the fourth to tenth week. Results The treatment with MNG showed beneficial effects on various components of metabolic syndrome, such as reduced dyslipidemia (decreased triglyceride, total cholesterol, low-density lipoprotein cholesterol, and increased high-density lipoprotein cholesterol) and diabetes mellitus (reduced blood glucose and glycosylated hemoglobin). In addition, an increase in serum insulin, C-peptide, and homeostasis model assessment-β and a reduction in homeostasis model assessment of insulin resistance-IR were observed in MNG-treated group compared with high-fat diabetic control group. MNG was also found to be cardioprotective (reduction in creatine phosphokinase-MB levels, atherogenic index, high-sensitivity C-reactive protein). Reduction in serum dipeptidyl peptidase–IV levels in the MNG-treated group correlated with improvement in insulin resistance and enhanced β-cell function. Conclusion The present study has demonstrated antidiabetic, hypolipidemic, and cardioprotective effects of MNG in the setting of diabetes with metabolic syndrome. Thus, MNG has the potential to be developed as a natural alternative to synthetic dipeptidyl peptidase-IV inhibitors beneficial in this comorbid condition. PMID:27621658

  8. Grassypeptolides As Natural Inhibitors of Dipeptidyl Peptidase 8 and T-Cell Activation

    PubMed Central

    Kwan, Jason C.; Liu, Yanxia; Ratnayake, Ranjala; Hatano, Ryo; Kuribara, Akiko; Morimoto, Chiko; Ohnuma, Kei; Paul, Valerie J.; Ye, Tao

    2014-01-01

    Natural products made by marine cyanobacteria are often highly modified peptides and depsipeptides that have the potential to act as inhibitors for proteases. In the interest of finding novel protease inhibition activity and selectivity grassypeptolide A (1) was screened against a panel of proteases and found to selectively inhibit DPP8 over DPP4. Grassypeptolides were also found to inhibit IL-2 production and proliferation in activated T-cells, consistent with a putative role of DPP8 in the immune system. These effects were also observed in Jurkat cells, and DPP activity in Jurkat cell cytosol was shown to be inhibited by grassypeptolides. In silico docking suggests two possible binding modes of grassypeptolides – both at the active site of DPP8 and at one of the entrances to the internal cavity. Collectively these results suggest that grassypeptolides may be useful tool compounds in the study of DPP8 function. PMID:24591193

  9. Antinociceptive effects of N-acetylaspartylglutamate (NAAG) peptidase inhibitors ZJ-11, ZJ-17 and ZJ-43 in the rat formalin test and in the rat neuropathic pain model.

    PubMed

    Yamamoto, Tatsuo; Hirasawa, Serabi; Wroblewska, Barbara; Grajkowska, Ewa; Zhou, Jia; Kozikowski, Alan; Wroblewski, Jarda; Neale, Joseph H

    2004-07-01

    The peptide neurotransmitter N-acetylaspartylglutamate (NAAG) acts as an agonist at group II metabotropic glutamate receptors (mGluRs). NAAG is inactivated by extracellular peptidase activity yielding glutamate and N-acetylaspartate. We recently developed a series of potent NAAG peptidase inhibitors, including ZJ-11, ZJ-17 and ZJ-43. In the present study, we examined the effects of intrathecally administered ZJ-11 and ZJ-17 and intravenously administered ZJ-11 and ZJ-43 in the rat formalin test (an inflammatory pain model) and in the rat partial sciatic nerve ligation model (a neuropathic pain model). Intrathecal injection of ZJ-11 or ZJ-17 or intravenous injection of ZJ-11 or ZJ-43 suppressed both phases of the agitation behaviour induced by paw formalin injection. Intrathecal and intravenous injection of ZJ-11 suppressed the expression of Fos-like immunoreactivity, induced by paw formalin injection, in laminae I-II in segments L4-L5 of the spinal cord, suggesting an action on sensory spinal transmission. Partial sciatic nerve ligation induced significant mechanical allodynia 7 days after the nerve injury. Intrathecal injection of ZJ-11 or ZJ-17 or intravenous administration of ZJ-11 or ZJ-43 attenuated the level of mechanical allodynia induced by this nerve ligation. These effects of intrathecally or intravenously administered ZJ compounds in both the formalin test and the partial sciatic nerve ligation model were completely antagonized by pretreatment with LY-341495, a highly selective group II mGluR antagonist. Thus, elevation of extracellular NAAG, induced by the inhibition of NAAG peptidase, activates group II mGluRs and produces an analgesic effect in neuropathic and inflammatory and pain models. In contrast, peptidase inhibition did not affect the threshold for withdrawal from a noxious mechanical stimulus or from an acute thermal stimulus in the hotplate test. PMID:15233757

  10. Synergy between Colistin and the Signal Peptidase Inhibitor MD3 Is Dependent on the Mechanism of Colistin Resistance in Acinetobacter baumannii.

    PubMed

    Martínez-Guitián, Marta; Vázquez-Ucha, Juan C; Odingo, Joshua; Parish, Tanya; Poza, Margarita; Waite, Richard D; Bou, German; Wareham, David W; Beceiro, Alejandro

    2016-07-01

    Synergy between colistin and the signal peptidase inhibitor MD3 was tested against isogenic mutants and clinical pairs of Acinetobacter baumannii isolates. Checkerboard assays and growth curves showed synergy against both colistin-susceptible strains (fractional inhibitory concentration index [FICindex] = 0.13 to 0.24) and colistin-resistant strains with mutations in pmrB and phosphoethanolamine modification of lipid A (FICindex = 0.14 to 0.25) but not against colistin-resistant Δlpx strains with loss of lipopolysaccharide (FICindex = 0.75 to 1). A colistin/MD3 combination would need to be targeted to strains with specific colistin resistance mechanisms. PMID:27139471

  11. Sodium-glucose co-transporter-2 inhibitors and dipeptidyl peptidase-4 inhibitors combination therapy in type 2 diabetes: A systematic review of current evidence

    PubMed Central

    Singh, Awadhesh Kumar; Singh, Ritu

    2016-01-01

    As type 2 diabetes mellitus (T2DM) is a chronic and progressive disease with multiple pathophysiologic defects, no single anti-diabetic agent can tackle all these multi-factorial pathways. Consequently, multiple agents working through the different mechanisms will be required for the optimal glycemic control. Moreover, the combination therapies of different anti-diabetic agents may complement their actions and possibly act synergistic. Furthermore, these combinations could possess the additional properties to counter their undesired physiological compensatory response. Sodium-glucose co-transporter-2 inhibitors (SGLT-2I) are newly emerging class of drugs, with a great potential to reduce glucose effectively with an additional quality of lowering cardiovascular events as demonstrated very recently by one of the agents of this class. However, increase in endogenous glucose production (EGP) from the liver, either due to the increase in glucagon or compensatory response to glucosuria can offset the glucose-lowering potential of SGLT-2I. Interestingly, another class of drugs such as dipeptidyl peptidase-4 inhibitors (DPP-4I) effectively decrease glucagon and reduce EGP. In light of these findings, combination therapies with SGLT-2I and DPP-4I are particularly appealing and are expected to produce a synergistic effect. Preclinical studies of combination therapies with DPP-4I and SGLT-2I have already demonstrated a significant lowering of hemoglobin A1c potential and human studies also find no drug-drug interaction between these agents. This article aims to systematically review the efficacy and safety of combination therapy of SGLT-2I and DPP-4I in T2DM. PMID:27042423

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

    PubMed Central

    Singh, Awadhesh Kumar; Singh, Ritu

    2016-01-01

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

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

    PubMed

    Singh, Awadhesh Kumar; Singh, Ritu

    2016-01-01

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

  14. Sodium-glucose co-transporter-2 inhibitors and dipeptidyl peptidase-4 inhibitors combination therapy in type 2 diabetes: A systematic review of current evidence.

    PubMed

    Singh, Awadhesh Kumar; Singh, Ritu

    2016-01-01

    As type 2 diabetes mellitus (T2DM) is a chronic and progressive disease with multiple pathophysiologic defects, no single anti-diabetic agent can tackle all these multi-factorial pathways. Consequently, multiple agents working through the different mechanisms will be required for the optimal glycemic control. Moreover, the combination therapies of different anti-diabetic agents may complement their actions and possibly act synergistic. Furthermore, these combinations could possess the additional properties to counter their undesired physiological compensatory response. Sodium-glucose co-transporter-2 inhibitors (SGLT-2I) are newly emerging class of drugs, with a great potential to reduce glucose effectively with an additional quality of lowering cardiovascular events as demonstrated very recently by one of the agents of this class. However, increase in endogenous glucose production (EGP) from the liver, either due to the increase in glucagon or compensatory response to glucosuria can offset the glucose-lowering potential of SGLT-2I. Interestingly, another class of drugs such as dipeptidyl peptidase-4 inhibitors (DPP-4I) effectively decrease glucagon and reduce EGP. In light of these findings, combination therapies with SGLT-2I and DPP-4I are particularly appealing and are expected to produce a synergistic effect. Preclinical studies of combination therapies with DPP-4I and SGLT-2I have already demonstrated a significant lowering of hemoglobin A1c potential and human studies also find no drug-drug interaction between these agents. This article aims to systematically review the efficacy and safety of combination therapy of SGLT-2I and DPP-4I in T2DM. PMID:27042423

  15. A concise review of the bioanalytical methods for the quantitation of sitagliptin, an important dipeptidyl peptidase-4 (DPP4) inhibitor, utilized for the characterization of the drug.

    PubMed

    Suresh, P S; Srinivas, Nuggehally R; Mullangi, Ramesh

    2016-05-01

    Inhibition of dipeptidyl peptidase-4 (DPP4) is an emerging therapeutic approach for treating type 2 diabetes and has revolutionized the concept of diabetes management. Sitagliptin is the first approved orally active, potent, selective and nonpeptidomimetic DPP4 inhibitor. Incidence of hypoglycemia and weight gain is negligible with sitagliptin treatment. It is used as monotherapy or in combination with other anti-diabetic drugs to treat type 2 diabetes. There are numerous bioanalytical methods published for the analysis of sitagliptin in preclinical and clinical samples. This review focuses on the various HPLC and LC-MS/MS methods that have been used to analyze sitagliptin in various biological matrices. A small section is devoted to the bioanalysis of other DPP4 inhibitors such as vildagliptin, saxagliptin and linagliptin. This review provides key information in a concise manner regarding sample processing options, chromatographic/detection conditions and validation parameters of the chosen methods for sitagliptin and other DPP4 inhibitors. PMID:26873580

  16. Use of Dipeptidyl-Peptidase-4 Inhibitors and the Risk of Pneumonia: A Population-Based Cohort Study

    PubMed Central

    Wvan der Zanden, Rogier; de Vries, Frank; Lalmohamed, Arief; Driessen, Johanna H. M.; de Boer, Anthonius; Rohde, Gernot; Neef, Cees; den Heijer, Casper

    2015-01-01

    Background Dipeptidyl-peptidase-4 inhibitors (DPP4Is) are drugs for the treatment of type 2 diabetes mellitus (T2DM). There is increasing evidence that DPP4Is may result in suppression of the immune system and may increase the risk of infections such as pneumonia. Aim of this study was to evaluate the association between the use of DPP4Is and the risk of pneumonia in a population-based study. Methods We conducted a population-based cohort study using data from the world’s largest primary care database, the UK Clinical Practice Research Datalink (CPRD). We selected all users of non-insulin antidiabetic drugs (NIADs), including DPP4Is, between 2007 and 2012. To each NIAD user, we matched randomly selected non-users. The NIAD user’s first prescription defined the index date, which was then assigned to the matched non-users. Patients were followed from their first prescription until end of data collection or the first event of pneumonia, whichever came first. Cox regression analysis estimated the association between pneumonia and current use of DPP4Is versus 1) current use of other NIADs and 2) non-users. DPP4I use was then stratified to daily and cumulative dose. Analyses were statistically adjusted for age, sex, lifestyle factors and comorbidities and concomitant use of various other drugs. Results Risk of pneumonia was not increased with current DPP4I use versus use of other NIADs, adjusted Hazard Ratio (HR) 0.70; 95% Confidence Interval (CI) 0.55–0.91. Also higher cumulative doses or daily doses did not further increase risk of pneumonia. Conclusion We found no increased risk of pneumonia in T2DM patients using DPP4Is compared to T2DM patients using other NIADs. Our finding is in line with direct and indirect evidence from observational studies and RCTs. There is probably no need to avoid prescribing of DPP4Is to elderly patients who are at risk of pneumonia. PMID:26468883

  17. Multiple-dose pharmacokinetics and pharmacodynamics of evogliptin (DA-1229), a novel dipeptidyl peptidase IV inhibitor, in healthy volunteers

    PubMed Central

    Gu, Namyi; Park, Min Kyu; Kim, Tae-Eun; Bahng, Mi Young; Lim, Kyoung Soo; Cho, Sang-Heon; Yoon, Seo Hyun; Cho, Joo-Youn; Jang, In-Jin; Yu, Kyung-Sang

    2014-01-01

    Purpose Evogliptin (DA-1229) is a novel, potent, and selective dipeptidyl peptidase IV (DPP-IV) inhibitor in clinical development for the treatment of type 2 diabetes mellitus. This study aimed to investigate the pharmacokinetic and pharmacodynamic profiles and tolerability of evogliptin after repeated oral administration in healthy subjects. Patients and methods A block-randomized, double-blind, placebo-controlled, multiple-dose, dose-escalation study was performed in a total of 30 subjects. Repeated once-daily doses of 5, 10, or 20 mg evogliptin or the same doses of placebo were orally administered to ten subjects in each dosage group for 10 days. Subjects in each group were randomized to receive evogliptin or placebo with a ratio of 8:2. Pharmacokinetics of evogliptin were evaluated, with its concentrations in serial plasma and urine samples collected following the first and last administrations. DPP-IV activity and glucagon-like peptide-1, glucose, and insulin levels were quantified to evaluate evogliptin’s pharmacodynamics on the first and last dosing days. Results All participants completed the study without any serious or severe adverse event. The evogliptin plasma concentration reached its peak within 4–5 hours and decreased relatively slowly, with a terminal elimination half-life of 33–39 hours. Repeated administration resulted in a 1.4- to 1.5-fold accumulation. Evogliptin’s systemic exposure and inhibition of plasma DPP-IV activity increased in a dose-dependent manner. Inhibition of DPP-IV activity >80% was sustained over 24 hours in all evogliptin dose groups and provided an increase in postprandial active glucagon-like peptide-1 levels by 1.5- to 2.4-fold. Postprandial glucose levels in the evogliptin-treated groups were reduced 20%–35% compared to placebo, but were not accompanied by increased insulin levels. Conclusion Repeated administration of evogliptin in healthy subjects was well tolerated and exhibited linear pharmacokinetics within

  18. HIV-1 reverse transcriptase inhibitor from Phyllanthus niruri.

    PubMed

    Ogata, T; Higuchi, H; Mochida, S; Matsumoto, H; Kato, A; Endo, T; Kaji, A; Kaji, H

    1992-11-01

    An aqueous extract of Phyllanthus niruri (Euphorbiaceae) inhibited human immunodeficiency virus type-1 reverse transcriptase (HIV-1-RT). The inhibitor against HIV-1-RT in this plant was purified by combination of three column chromatographies, Sephadex LH-20, cellulose, and reverse-phase high-performance liquid chromatography. The inhibitor was then identified by nuclear magnetic resonance (NMR) spectra as repandusinic acid A monosodium salt (RA) which was originally isolated from Mallotus repandus. The 50% inhibitory doses (ID50) of RA on HIV-1-RT and DNA polymerase alpha (from HeLa cells) were 0.05 microM and 0.6 microM, respectively, representing approximately a 10-fold more sensitivity of HIV-1-RT compared with DNA polymerase alpha. RA was shown to be a competitive inhibitor with respect to the template-primer while it was a noncompetitive inhibitor with respect to the substrate. RA as low as 10.1 microM inhibited HIV-1-induced cytopathogenicity in MT-4 cells. In addition, 4.5 microM of RA inhibited HIV-1-induced giant cell formation of SUP-T1 approximately 50%. RA (2.5 microM) inhibited up to 90% of HIV-1 specific p24 antigen production in a Clone H9 cell system. PMID:1283310

  19. Action of anti-HIV drugs and resistance: reverse transcriptase inhibitors and protease inhibitors.

    PubMed

    Imamichi, Tomozumi

    2004-01-01

    Currently, 20 drugs have been approved for Human Immunodeficiency Virus type-1 (HIV-1) clinical therapy. These drugs inhibit HIV-1 reverse transcriptase, protease, or virus entry. Introduction of a combination therapy with reverse transcriptase inhibitors and protease inhibitors has resulted in a drastic decrease in HIV-1 related mortality. Although the combination therapy can suppress viral replication below detection levels in current available assays, low levels of on-going viral replication still persist in some patients. Long-term administration of the combination therapy may increase selective pressure against viruses, and subsequently induce emergence of multiple drug-resistant HIV-1 variants. Attempts have been made to design novel antiretroviral drugs that would be able to suppress replication of the resistant variants. At present, several investigational drugs are being tested in clinical trials. These drugs target not only the resistant variants, but also improvement in oral bioavilability or other viral proteins such as HIV-1 integrase, ribonuclease H, and HIV-1 entry (CD4 attachment inhibitors, chemokine receptors antagonists, and fusion inhibitors). Understanding mechanism(s) of action of the drugs and mechanisms of drug resistance is necessary for successful designs in the next generation of anti-HIV-1 drugs. In this review, the mechanisms of action of reverse transcriptase- and protease-inhibitors, and the mechanism of resistance to these inhibitors, are described. PMID:15579086

  20. A novel small-molecule inhibitor of HIV-1 entry

    PubMed Central

    Heredia, Alonso; Latinovic, Olga S; Barbault, Florent; de Leeuw, Erik PH

    2015-01-01

    Background Antiretroviral therapy has transformed HIV-1 infection into a managed condition with near-normal life expectancy. However, a significant number of patients remain with limited therapeutic options due to HIV-1 resistance, side effects, or drug costs. Further, it is likely that current drugs will not retain efficacy, due to risks of side effects and transmitted resistance. Results We describe compound 5660386 (3-ethyl-2-[3-(1,3,3-trimethyl-1,3-dihydro-2H-indol-2-ylidene)-1-propen-1-yl]-1,3-benzothiazol-3-ium) as a novel inhibitor of HIV-1 entry. Compound 5660386 inhibits HIV-1 entry in cell lines and primary cells, binds to HIV-1 envelope protein, and inhibits the interaction of GP120 to CD4. Further, compound 5660386 showed a unique and broad-range activity against primary HIV-1 isolates from different subtypes and geographical areas. Conclusion Development of small-molecule entry inhibitors of HIV-1 such as 5660386 may lead to novel classes of anti-HIV-1 therapeutics. These inhibitors may be particularly effective against viruses resistant to current antiretroviral drugs and could have potential applications in both treatment and prevention. PMID:26491257

  1. The Discovery of Potent, Selective, and Reversible Inhibitors of the House Dust Mite Peptidase Allergen Der p 1: An Innovative Approach to the Treatment of Allergic Asthma

    PubMed Central

    2014-01-01

    Blocking the bioactivity of allergens is conceptually attractive as a small-molecule therapy for allergic diseases but has not been attempted previously. Group 1 allergens of house dust mites (HDM) are meaningful targets in this quest because they are globally prevalent and clinically important triggers of allergic asthma. Group 1 HDM allergens are cysteine peptidases whose proteolytic activity triggers essential steps in the allergy cascade. Using the HDM allergen Der p 1 as an archetype for structure-based drug discovery, we have identified a series of novel, reversible inhibitors. Potency and selectivity were manipulated by optimizing drug interactions with enzyme binding pockets, while variation of terminal groups conferred the physicochemical and pharmacokinetic attributes required for inhaled delivery. Studies in animals challenged with the gamut of HDM allergens showed an attenuation of allergic responses by targeting just a single component, namely, Der p 1. Our findings suggest that these inhibitors may be used as novel therapies for allergic asthma. PMID:25365789

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

    SciTech Connect

    Kodera, Ryo; Shikata, Kenichi; Takatsuka, Tetsuharu; Oda, Kaori; Miyamoto, Satoshi; Kajitani, Nobuo; Hirota, Daisho; Ono, Tetsuichiro; Usui, Hitomi Kataoka; Makino, Hirofumi

    2014-01-17

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

  3. Comparative analysis of expression profiling of the trypsin and chymotrypsin genes from Lepidoptera species with different levels of sensitivity to soybean peptidase inhibitors.

    PubMed

    Souza, Thais P; Dias, Renata O; Castelhano, Elaine C; Brandão, Marcelo M; Moura, Daniel S; Silva-Filho, Marcio C

    2016-01-01

    Peptidase inhibitors (PIs) are essential proteins involved in plant resistance to herbivorous insects, yet many insect species are able to escape the negative effects of these molecules. We compared the effects of acute and chronic ingestion of soybean peptidase inhibitors (SPIs) on Spodoptera frugiperda and Diatraea saccharalis, two Lepidoptera species with different sensitivities to SPI ingestion. We analyzed the trypsin and chymotrypsin gene expression profiles in both species. Acute exposure of S. frugiperda to the inhibitors activated seven genes (SfChy5, SfChy9, SfChy19, SfChy22, SfTry6, SfTry8, and SfTry10), whereas chronic exposure activated 16 genes (SfChy2, SfChy4, SfChy5, SfChy8, SfChy9, SfChy11, SfChy12, SfChy15, SfChy17, SfChy21, SfChy22, SfTry6, SfTry8, SfTry9, SfTry10, and SfTry12). By contrast, the challenge of D. saccharalis with SPIs did not differentially induce the expression of trypsin- or chymotrypsin-encoding genes, with the exception of DsChy7. Bayesian phylogenetic analysis of S. frugiperda trypsin protein sequences revealed two gene clades: one composed of genes responsive to the SPIs and a second composed of the unresponsive genes. D. saccharalis trypsin proteins were clustered nearest to the S. frugiperda unresponsive genes. Overall, our findings support a hypothesized mechanism of resistance of Noctuidae moths to SPIs, involving gene number expansion of trypsin and chymotrypsin families and regulation of gene expression, which could also explain the variable susceptibility between S. frugiperda and D. saccharalis to these plant inhibitors. PMID:26944308

  4. Inhibitors of HIV infection via the cellular CD4 receptor.

    PubMed

    Vermeire, Kurt; Schols, Dominique; Bell, Thomas W

    2006-01-01

    Recent advances in our understanding of cellular and molecular mechanisms of viral penetration of the target cell have provided the basis for novel chemotherapy and prophylaxis of HIV-1 infections. This knowledge has been successfully applied to the development of inhibitors that target discrete steps of the entry process. Interesting approaches for prevention of HIV-1 entry include the use of small-molecule inhibitors, natural ligands and/or monoclonal antibodies that interfere with gp120/CD4 interaction. Other compounds acting by novel mechanisms have recently been identified as anti-HIV agents and seem worthy of further preclinical development. Of particular interest in this regard are cyclotriazadisulfonamide (CADA) compounds, which down-modulate the cellular receptor, CD4. A series of analogues of 9-benzyl-3-methylene-1,5-di-p-toluenesulfonyl-1,5,9-triazacyclododecane (CADA) has been synthesized and tested for CD4 down-modulation and anti-HIV activity. Some derivatives proved to be highly effective in decreasing cellular CD4 and in acting as HIV entry inhibitors. Three-dimensional quantitative structure-activity relationship (3D-QSAR) studies correlating molecular features with potency have been used to produce a computational model. This model can be used to design more potent CD4 down-modulating drugs for HIV therapy and prophylaxis. This review summarizes the results of recent studies relating to inhibitors of HIV infection via CD4 and discusses the therapeutic potential of targeting this cellular receptor. Special attention is given to our own work on small-molecule HIV entry inhibitors endowed with CD4 down-modulating properties. PMID:16611063

  5. Past, present, and future of entry inhibitors as HIV microbicides.

    PubMed

    Gibson, Richard M; Arts, Eric J

    2012-01-01

    Preventing the transmission of human immunodeficiency virus (HIV) is the main goal of numerous studies trying to develop an effective vaccine and microbicide agents. Here we review the use of antiretroviral drugs to inhibit viral entry as potential HIV microbicides. After the failure of nonoxynol-9 microbicide strategies shifted towards the use of compounds creating a physical barrier to virus attachment (e.g., surfactants) or inhibit the virus in the vaginal milieu (e.g., polyanions). These early, non-specific inhibitors showed promise in both in vitro and in vivo(non-human primates) studies but provided only modest protection from HIV transmission in clinical efficacy trials. The next generation of HIV entry microbicides was based on specifically blocking virus from entering host cells by targeting CD4 attachment, gp120 binding, and virus-cell membrane fusion events. Although protection from an SIV-HIV hybrid was evident in non-human primates treated and challenged in the vaginal cavity, none of these compounds have advanced to clinical trials as a microbicide. Here we will discuss the reasons for these failures, including the selection of drug resistant HIV variants, which raises questions as to the future of broadly effective microbicides based on HIV entry inhibitors. The outcome of continued research and potential efficacy trials on the next generation of entry inhibitors might reveal whether or not an effective entry microbicide can be developed. PMID:22264042

  6. The triple threat of HIV-1 protease inhibitors.

    PubMed

    Potempa, Marc; Lee, Sook-Kyung; Wolfenden, Richard; Swanstrom, Ronald

    2015-01-01

    Newly released human immunodeficiency virus type 1 (HIV-1) particles obligatorily undergo a maturation process to become infectious. The HIV-1 protease (PR) initiates this step, catalyzing the cleavage of the Gag and Gag-Pro-Pol structural polyproteins. Proper organization of the mature virus core requires that cleavage of these polyprotein substrates proceeds in a highly regulated, specific series of events. The vital role the HIV-1 PR plays in the viral life cycle has made it an extremely attractive target for inhibition and has accordingly fostered the development of a number of highly potent substrate-analog inhibitors. Though the PR inhibitors (PIs) inhibit only the HIV-1 PR, their effects manifest at multiple different stages in the life cycle due to the critical importance of the PR in preparing the virus for these subsequent events. Effectively, PIs masquerade as entry inhibitors, reverse transcription inhibitors, and potentially even inhibitors of post-reverse transcription steps. In this chapter, we review the triple threat of PIs: the intermolecular cooperativity in the form of a cooperative dose-response for inhibition in which the apparent potency increases with increasing inhibition; the pleiotropic effects of HIV-1 PR inhibition on entry, reverse transcription, and post-reverse transcription steps; and their potency as transition state analogs that have the potential for further improvement that could lead to an inability of the virus to evolve resistance in the context of single drug therapy. PMID:25778681

  7. A symmetric inhibitor binds HIV-1 protease asymmetrically.

    PubMed

    Dreyer, G B; Boehm, J C; Chenera, B; DesJarlais, R L; Hassell, A M; Meek, T D; Tomaszek, T A; Lewis, M

    1993-01-26

    Potential advantages of C2-symmetric inhibitors designed for the symmetric HIV-1 protease include high selectivity, potency, stability, and bioavailability. Pseudo-C2-symmetric monools and C2-symmetric diols, containing central hydroxymethylene and (R,R)-dihydroxyethylene moieties flanked by a variety of hydrophobic P1/P1' side chains, were studied as HIV-1 protease inhibitors. The monools and diols were synthesized in 8-10 steps from D-(+)-arabitol and D-(+)-mannitol, respectively. Monools with ethyl or isobutyl P1/P1' side chains were weak inhibitors of recombinant HIV-1 protease (Ki > 10 microM), while benzyl P1/P1' side chains afforded a moderately potent inhibitor (apparent Ki = 230 nM). Diols were 100-10,000x more potent than analogous monools, and a wider range of P1/P1' side chains led to potent inhibition. Both classes of compounds exhibited lower apparent Ki values under high-salt conditions. Surprisingly, monool and diol HIV-1 protease inhibitors were potent inhibitors of porcine pepsin, a prototypical asymmetric monomeric aspartic protease. These results were evaluated in the context of the pseudosymmetric structure of monomeric aspartic proteases and their evolutionary kinship with the retroviral proteases. The X-ray crystal structure of HIV-1 protease complexed with a symmetric diol was determined at 2.6 A. Contrary to expectations, the diol binds the protease asymmetrically and exhibits 2-fold disorder in the electron density map. Molecular dynamics simulations were conducted beginning with asymmetric and symmetric HIV-1 protease/inhibitor model complexes. A more stable trajectory resulted from the asymmetric complex, in agreement with the observed asymmetric binding mode. A simple four-point model was used to argue more generally that van der Waals and electrostatic force fields can commonly lead to an asymmetric association between symmetric molecules. PMID:8422397

  8. Finding a Potential Dipeptidyl Peptidase-4 (DPP-4) Inhibitor for Type-2 Diabetes Treatment Based on Molecular Docking, Pharmacophore Generation, and Molecular Dynamics Simulation.

    PubMed

    Meduru, Harika; Wang, Yeng-Tseng; Tsai, Jeffrey J P; Chen, Yu-Ching

    2016-01-01

    Dipeptidyl peptidase-4 (DPP-4) is the vital enzyme that is responsible for inactivating intestinal peptides glucagon like peptide-1 (GLP-1) and Gastric inhibitory polypeptide (GIP), which stimulates a decline in blood glucose levels. The aim of this study was to explore the inhibition activity of small molecule inhibitors to DPP-4 following a computational strategy based on docking studies and molecular dynamics simulations. The thorough docking protocol we applied allowed us to derive good correlation parameters between the predicted binding affinities (pKi) of the DPP-4 inhibitors and the experimental activity values (pIC50). Based on molecular docking receptor-ligand interactions, pharmacophore generation was carried out in order to identify the binding modes of structurally diverse compounds in the receptor active site. Consideration of the permanence and flexibility of DPP-4 inhibitor complexes by means of molecular dynamics (MD) simulation specified that the inhibitors maintained the binding mode observed in the docking study. The present study helps generate new information for further structural optimization and can influence the development of new DPP-4 inhibitors discoveries in the treatment of type-2 diabetes. PMID:27304951

  9. Finding a Potential Dipeptidyl Peptidase-4 (DPP-4) Inhibitor for Type-2 Diabetes Treatment Based on Molecular Docking, Pharmacophore Generation, and Molecular Dynamics Simulation

    PubMed Central

    Meduru, Harika; Wang, Yeng-Tseng; Tsai, Jeffrey J. P.; Chen, Yu-Ching

    2016-01-01

    Dipeptidyl peptidase-4 (DPP-4) is the vital enzyme that is responsible for inactivating intestinal peptides glucagon like peptide-1 (GLP-1) and Gastric inhibitory polypeptide (GIP), which stimulates a decline in blood glucose levels. The aim of this study was to explore the inhibition activity of small molecule inhibitors to DPP-4 following a computational strategy based on docking studies and molecular dynamics simulations. The thorough docking protocol we applied allowed us to derive good correlation parameters between the predicted binding affinities (pKi) of the DPP-4 inhibitors and the experimental activity values (pIC50). Based on molecular docking receptor-ligand interactions, pharmacophore generation was carried out in order to identify the binding modes of structurally diverse compounds in the receptor active site. Consideration of the permanence and flexibility of DPP-4 inhibitor complexes by means of molecular dynamics (MD) simulation specified that the inhibitors maintained the binding mode observed in the docking study. The present study helps generate new information for further structural optimization and can influence the development of new DPP-4 inhibitors discoveries in the treatment of type-2 diabetes. PMID:27304951

  10. NAAG peptidase inhibitor increases dialysate NAAG and reduces glutamate, aspartate and GABA levels in the dorsal hippocampus following fluid percussion injury in the rat.

    PubMed

    Zhong, Chunlong; Zhao, Xueren; Van, Ken C; Bzdega, Tomasz; Smyth, Aoife; Zhou, Jia; Kozikowski, Alan P; Jiang, Jiyao; O'Connor, William T; Berman, Robert F; Neale, Joseph H; Lyeth, Bruce G

    2006-05-01

    Traumatic brain injury (TBI) produces a rapid and excessive elevation in extracellular glutamate that induces excitotoxic brain cell death. The peptide neurotransmitter N-acetylaspartylglutamate (NAAG) is reported to suppress neurotransmitter release through selective activation of presynaptic group II metabotropic glutamate receptors. Therefore, strategies to elevate levels of NAAG following brain injury could reduce excessive glutamate release associated with TBI. We hypothesized that the NAAG peptidase inhibitor, ZJ-43 would elevate extracellular NAAG levels and reduce extracellular levels of amino acid neurotransmitters following TBI by a group II metabotropic glutamate receptor (mGluR)-mediated mechanism. Dialysate levels of NAAG, glutamate, aspartate and GABA from the dorsal hippocampus were elevated after TBI as measured by in vivo microdialysis. Dialysate levels of NAAG were higher and remained elevated in the ZJ-43 treated group (50 mg/kg, i.p.) compared with control. ZJ-43 treatment also reduced the rise of dialysate glutamate, aspartate, and GABA levels. Co-administration of the group II mGluR antagonist, LY341495 (1 mg/kg, i.p.) partially blocked the effects of ZJ-43 on dialysate glutamate and GABA, suggesting that NAAG effects are mediated through mGluR activation. The results are consistent with the hypothesis that inhibition of NAAG peptidase may reduce excitotoxic events associated with TBI. PMID:16606367

  11. Effects of Dipeptidyl Peptidase-4 Inhibitors on Hyperglycemia and Blood Cyclosporine Levels in Renal Transplant Patients with Diabetes: A Pilot Study

    PubMed Central

    Bae, Jaehyun; Lee, Min Jung; Choe, Eun Yeong; Jung, Chang Hee; Wang, Hye Jin; Kim, Myoung Soo; Kim, Yu Seun

    2016-01-01

    Background The use of dipeptidyl peptidase-4 (DPP-4) inhibitors is increasing among renal transplant patients with diabetes. However, the glucose-lowering efficacies of various DPP-4 inhibitors and their effects on blood cyclosporine levels have not been fully investigated. We compared the glucose-lowering efficacies of DPP 4 inhibitors and evaluate their effects on the blood levels of cyclosporine in renal transplant recipients with diabetes. Methods Sixty-five renal allograft recipients who received treatment with DPP-4 inhibitors (vildagliptin, sitagliptin, or linagliptin) following kidney transplant were enrolled. The glucose-lowering efficacies of the DPP-4 inhibitors were compared according to the changes in the hemoglobin A1c (HbA1c) levels after 3 months of treatment. Changes in the trough levels of the cyclosporine were also assessed 2 months after treatment with each DPP-4 inhibitor. Results HbA1c significantly decreased in the linagliptin group in comparison with other DPP-4 inhibitors (vildagliptin –0.38%±1.03%, sitagliptin –0.53%±0.95%, and linagliptin –1.40±1.34; P=0.016). Cyclosporine trough levels were significantly increased in the sitagliptin group compared with vildagliptin group (30.62±81.70 ng/mL vs. –24.22±53.54 ng/mL, P=0.036). Cyclosporine trough levels were minimally changed in patients with linagliptin. Conclusion Linagliptin demonstrates superior glucose-lowering efficacy and minimal effect on cyclosporine trough levels in comparison with other DPP-4 inhibitors in kidney transplant patients with diabetes. PMID:26754588

  12. Identification of HIV Inhibitors Guided by Free Energy Perturbation Calculations

    PubMed Central

    Acevedo, Orlando; Ambrose, Zandrea; Flaherty, Patrick T.; Aamer, Hadega; Jain, Prashi; Sambasivarao, Somisetti V.

    2013-01-01

    Free energy perturbation (FEP) theory coupled to molecular dynamics (MD) or Monte Carlo (MC) statistical mechanics offers a theoretically precise method for determining the free energy differences of related biological inhibitors. Traditionally requiring extensive computational resources and expertise, it is only recently that its impact is being felt in drug discovery. A review of computer-aided anti-HIV efforts employing FEP calculations is provided here that describes early and recent successes in the design of human immunodeficiency virus type 1 (HIV-1) protease and non-nucleoside reverse transcriptase inhibitors. In addition, our ongoing work developing and optimizing leads for small molecule inhibitors of cyclophilin A (CypA) is highlighted as an update on the current capabilities of the field. CypA has been shown to aid HIV-1 replication by catalyzing the cis/trans isomerization of a conserved Gly-Pro motif in the N-terminal domain of HIV-1 capsid (CA) protein. In the absence of a functional CypA, e.g., by the addition of an inhibitor such as cyclosporine A (CsA), HIV-1 has reduced infectivity. Our simulations of acylurea-based and 1-indanylketone-based CypA inhibitors have determined that their nanomolar and micromolar binding affinities, respectively, are tied to their ability to stabilize Arg55 and Asn102. A structurally novel 1-(2,6-dichlorobenzamido) indole core was proposed to maximize these interactions. FEP-guided optimization, experimental synthesis, and biological testing of lead compounds for toxicity and inhibition of wild-type HIV-1 and CA mutants have demonstrated a dose-dependent inhibition of HIV-1 infection in two cell lines. While the inhibition is modest compared to CsA, the results are encouraging. PMID:22316150

  13. Design of HIV Protease Inhibitors Based on Inorganic Polyhedral Metallacarboranes

    SciTech Connect

    Rezacova, Pavlina; Pokorna, Jana; Brynda, Ji; Kozisek, Milan; Cigler, Petr; Lesik, Martin; Fanfrlik, Jindrich; Rezac, Jan; Saskova, Klara Grantz; Sieglova, Irena; Plesek, Jaromir; Sicha, Vaclav; Gruner, Bohumir; Oberwinkler, Heike; Sedlacek, Juraj; Krausslich, Hans-Georg; Hobza, Pavel; Kral, Vladimir; Konvalinka, Jan

    2010-04-19

    HIV protease (HIV PR) is a primary target for anti-HIV drug design. We have previously identified and characterized substituted metallacarboranes as a new class of HIV protease inhibitors. In a structure-guided drug design effort, we connected the two cobalt bis(dicarbollide) clusters with a linker to substituted ammonium group and obtained a set of compounds based on a lead formula [H{sub 2}N-(8-(C{sub 2}H{sub 4}O){sub 2}-1,2-C{sub 2}B{sub 9}H{sub 10})(1',2'-C{sub 2}B{sub 9}H{sub 11})-3,3'-Co){sub 2}]Na. We explored inhibition properties of these compounds with various substitutions, determined the HIV PR:inhibitor crystal structure, and computationally explored the conformational space of the linker. Our results prove the capacity of linker-substituted dual-cage cobalt bis(dicarbollides) as lead compounds for design of more potent inhibitors of HIV PR.

  14. Antimalarial activity of HIV-1 protease inhibitor in chromone series.

    PubMed

    Lerdsirisuk, Pradith; Maicheen, Chirattikan; Ungwitayatorn, Jiraporn

    2014-12-01

    Increasing parasite resistance to nearly all available antimalarial drugs becomes a serious problem to human health and necessitates the need to continue the search for new effective drugs. Recent studies have shown that clinically utilized HIV-1 protease (HIV-1 PR) inhibitors can inhibit the in vitro and in vivo growth of Plasmodium falciparum. In this study, a series of chromone derivatives possessing HIV-1 PR inhibitory activity has been tested for antimalarial activity against P. falciparum (K1 multi-drug resistant strain). Chromone 15, the potent HIV-1 PR inhibitor (IC50=0.65μM), was found to be the most potent antimalarial compound with IC50=0.95μM while primaquine and tafenoquine showed IC50=2.41 and 1.95μM, respectively. Molecular docking study of chromone compounds against plasmepsin II, an aspartic protease enzyme important in hemoglobin degradation, revealed that chromone 15 exhibited the higher binding affinity (binding energy=-13.24kcal/mol) than the known PM II inhibitors. Thus, HIV-1 PR inhibitor in chromone series has the potential to be a new class of antimalarial agent. PMID:25462990

  15. HIV Protease Inhibitors: Effect on the Opportunistic Protozoan Parasites

    PubMed Central

    Alfonso, Yenisey; Monzote, Lianet

    2011-01-01

    The impact of highly active antiretroviral therapy (HAART) in the natural history of AIDS disease has been allowed to prolong the survival of people with HIV infection, particularly whose with increased HIV viral load. Additionally, the antiretroviral therapy could exert a certain degree of protection against parasitic diseases. A number of studies have been evidenced a decrease in the incidence of opportunistic parasitic infections in the era of HAART. Although these changes have been attributed to the restoration of cell-mediated immunity, induced by either non-nucleoside reverse transcriptase inhibitors or HIV protease inhibitors, in combination with at least two nucleoside reverse transcriptase inhibitors included in HAART, there are evidence that the control of these parasitic infections in HIV-positive persons under HAART, is also induced by the inhibition of the proteases of the parasites. This review focuses on the principal available data related with therapeutic HIV-protease inhibitors and their in vitro and in vivo effects on the opportunistic protozoan parasites. PMID:21629510

  16. Chemically Programmed Antibodies As HIV-1 Attachment Inhibitors

    PubMed Central

    2013-01-01

    Herein, we describe the design and application of two small-molecule anti-HIV compounds for the creation of chemically programmed antibodies. N-Acyl-β-lactam derivatives of two previously described molecules BMS-378806 and BMS-488043 that inhibit the interaction between HIV-1 gp120 and T-cells were synthesized and used to program the binding activity of aldolase antibody 38C2. Discovery of a successful linkage site to BMS-488043 allowed for the synthesis of chemically programmed antibodies with affinity for HIV-1 gp120 and potent HIV-1 neutralization activity. Derivation of a successful conjugation strategy for this family of HIV-1 entry inhibitors enables its application in chemically programmed antibodies and vaccines and may facilitate the development of novel bispecific antibodies and topical microbicides. PMID:23750312

  17. Identification of potent maturation inhibitors against HIV-1 clade C

    PubMed Central

    Timilsina, Uddhav; Ghimire, Dibya; Timalsina, Bivek; Nitz, Theodore J.; Wild, Carl T.; Freed, Eric O.; Gaur, Ritu

    2016-01-01

    Antiretroviral therapy has led to a profound improvement in the clinical care of HIV-infected patients. However, drug tolerability and the evolution of drug resistance have limited treatment options for many patients. Maturation inhibitors are a new class of antiretroviral agents for treatment of HIV-1. They act by interfering with the maturation of the virus by blocking the last step in Gag processing: the cleavage of the capsid-spacer peptide 1 (CA-SP1) intermediate to mature CA by the viral protease (PR). The first-in-class maturation inhibitor bevirimat (BVM) failed against a subset of HIV-1 isolates in clinical trials due to polymorphisms present in the CA-SP1 region of the Gag protein. Sequence analysis indicated that these polymorphisms are more common in non-clade B strains of HIV-1 such as HIV-1 clade C. Indeed, BVM was found to be ineffective against HIV-1 clade C molecular clones tested in this study. A number of BVM analogs were synthesized by chemical modifications at the C-28 position to improve its activity. The new BVM analogs displayed potent activity against HIV-1 clade B and C and also reduced infectivity of the virus. This study identifies novel and broadly active BVM analogs that may ultimately demonstrate efficacy in the clinic. PMID:27264714

  18. Identification of potent maturation inhibitors against HIV-1 clade C.

    PubMed

    Timilsina, Uddhav; Ghimire, Dibya; Timalsina, Bivek; Nitz, Theodore J; Wild, Carl T; Freed, Eric O; Gaur, Ritu

    2016-01-01

    Antiretroviral therapy has led to a profound improvement in the clinical care of HIV-infected patients. However, drug tolerability and the evolution of drug resistance have limited treatment options for many patients. Maturation inhibitors are a new class of antiretroviral agents for treatment of HIV-1. They act by interfering with the maturation of the virus by blocking the last step in Gag processing: the cleavage of the capsid-spacer peptide 1 (CA-SP1) intermediate to mature CA by the viral protease (PR). The first-in-class maturation inhibitor bevirimat (BVM) failed against a subset of HIV-1 isolates in clinical trials due to polymorphisms present in the CA-SP1 region of the Gag protein. Sequence analysis indicated that these polymorphisms are more common in non-clade B strains of HIV-1 such as HIV-1 clade C. Indeed, BVM was found to be ineffective against HIV-1 clade C molecular clones tested in this study. A number of BVM analogs were synthesized by chemical modifications at the C-28 position to improve its activity. The new BVM analogs displayed potent activity against HIV-1 clade B and C and also reduced infectivity of the virus. This study identifies novel and broadly active BVM analogs that may ultimately demonstrate efficacy in the clinic. PMID:27264714

  19. Selective Serotonin Reuptake Inhibitor Suppression of HIV Infectivity and Replication

    PubMed Central

    Benton, Tami; Lynch, Kevin; Dubé, Benoit; Gettes, David R.; Tustin, Nancy B.; Lai, Jian Ping; Metzger, David S.; Blume, Joshua; Douglas, Steven D.; Evans, Dwight L.

    2010-01-01

    Objective To test the hypothesis that the selective serotonin reuptake inhibitor (SSRI) citalopram would down regulate HIV infectivity and that the greatest effects would be seen in people with depression. Depression is a risk factor for morbidity and mortality in HIV/AIDS. Serotonin (5-HT) neurotransmission has been implicated in the pathobiology of depression, and pharmacologic therapies for depression target this system. The 5-HT transporter and 5-HT receptors are widely distributed throughout the central nervous and immune systems. Depression has been associated with suppression of natural killer cells (NK) cells and CD8+ lymphocytes, key regulators of HIV infection. Methods Ex-vivo models for acute and chronic HIV infection were used to study the effects of citalopram on HIV viral infection and replication, in 48 depressed and non-depressed women. For both the acute and chronic infection models, HIV reverse transcriptase (RT) activity was measured in the citalopram treatment condition and the control condition. Results The SSRI significantly downregulated the RT response in both the acute and chronic infection models. Specifically, citalopram significantly decreased the acute HIV infectivity of macrophages. Citalopram also significantly decreased HIV viral replication in the latently infected T-cell line and in the latently infected macrophage cell line. There was no difference in down-regulation by depression status. Conclusions These studies suggest that an SSRI enhances NK/CD8 non-cytolytic HIV suppression in HIV/AIDS and decreases HIV viral infectivity of macrophages, ex vivo, suggesting the need for in vivo studies to determine a potential role for agents targeting serotonin in the host defense against HIV. PMID:20947783

  20. Clinical Characteristics and Metabolic Predictors of Rapid Responders to Dipeptidyl Peptidase-4 Inhibitor as an Add-on Therapy to Sulfonylurea and Metformin

    PubMed Central

    Kim, Ye An; Yoo, Won Sang; Hong, Eun Shil; Ku, Eu Jeong; Park, Kyeong Seon; Lim, Soo; Cho, Young Min; Park, Kyong Soo; Jang, Hak Chul

    2015-01-01

    Background Dipeptidyl peptidase-4 (DPP-4) inhibitor add-on therapy is a new option for patients with inadequately controlled type 2 diabetes who are taking combined metformin and sulfonylurea (SU). We evaluated the efficacy and safety of this triple therapy and the characteristics of rapid responders and hypoglycemia-prone patients. Methods We included 807 patients with type 2 diabetes who were prescribed a newly added DPP-4 inhibitor to ongoing metformin and SU in 2009 to 2011. Glycemia and other metabolic parameters at baseline, 12, 24, and 52 weeks, as well as episodes of hypoglycemia were analyzed. Rapid responders were defined as patients with ≥25% reduction in glycosylated hemoglobin (HbA1c) within 12 weeks. Results At baseline, while on the submaximal metformin and SU combination, the mean HbA1c level was 8.4%. Twelve weeks after initiation of DPP-4 inhibitor add-on, 269 patients (34.4%) achieved an HbA1c level ≤7%. Sixty-six patients (8.2%, 47 men) were rapid responders. The duration of diabetes was shorter in rapid responders, and their baseline fasting plasma glucose (FPG), HbA1c, C-peptide, and homeostasis model assessment of insulin resistance were significantly higher. Patients who experienced hypoglycemia after taking DPP-4 inhibitor add-on were more likely to be female, to have a lower body weight and lower triglyceride and FPG levels, and to have higher homeostasis model assessment of β-cells. Conclusion An oral hypoglycemic triple agent combination including a DPP-4 inhibitor was effective in patients with uncontrolled diabetes. Proactive dose reduction of SU should be considered when a DPP-4 inhibitor is added for rapid responders and hypoglycemia-prone patients. PMID:26616595

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

    PubMed Central

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

    2015-01-01

    Non-alcoholic fatty liver disease (NAFLD), which is strongly associated with metabolic syndrome, is increasingly a major cause of hepatic disorder. Dipeptidyl peptidase (DPP)-4 inhibitors, anti-diabetic agents, are expected to be effective for the treatment of NAFLD. In the present study, we established a novel NAFLD model mouse using monosodium glutamate (MSG) and a high-fat diet (HFD) and investigated the effects of a DPP-4 inhibitor, teneligliptin, on the progression of NAFLD. Male MSG/HFD-treated mice were divided into two groups, one of which received teneligliptin in drinking water. Administration of MSG and HFD caused mice to develop severe fatty changes in the liver, but teneligliptin treatment improved hepatic steatosis and inflammation, as evaluated by the NAFLD activity score. Serum alanine aminotransferase and intrahepatic triglyceride levels were significantly decreased in teneligliptin-treated mice (p < 0.05). Hepatic mRNA levels of the genes involved in de novo lipogenesis were significantly downregulated by teneligliptin (p < 0.05). Moreover, teneligliptin increased hepatic expression levels of phosphorylated AMP-activated protein kinase (AMPK) protein. These findings suggest that teneligliptin attenuates lipogenesis in the liver by activating AMPK and downregulating the expression of genes involved in lipogenesis. DPP-4 inhibitors may be effective for the treatment of NAFLD and may be able to prevent its progression to non-alcoholic steatohepatitis. PMID:26670228

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

    PubMed

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

    2015-01-01

    Non-alcoholic fatty liver disease (NAFLD), which is strongly associated with metabolic syndrome, is increasingly a major cause of hepatic disorder. Dipeptidyl peptidase (DPP)-4 inhibitors, anti-diabetic agents, are expected to be effective for the treatment of NAFLD. In the present study, we established a novel NAFLD model mouse using monosodium glutamate (MSG) and a high-fat diet (HFD) and investigated the effects of a DPP-4 inhibitor, teneligliptin, on the progression of NAFLD. Male MSG/HFD-treated mice were divided into two groups, one of which received teneligliptin in drinking water. Administration of MSG and HFD caused mice to develop severe fatty changes in the liver, but teneligliptin treatment improved hepatic steatosis and inflammation, as evaluated by the NAFLD activity score. Serum alanine aminotransferase and intrahepatic triglyceride levels were significantly decreased in teneligliptin-treated mice (p < 0.05). Hepatic mRNA levels of the genes involved in de novo lipogenesis were significantly downregulated by teneligliptin (p < 0.05). Moreover, teneligliptin increased hepatic expression levels of phosphorylated AMP-activated protein kinase (AMPK) protein. These findings suggest that teneligliptin attenuates lipogenesis in the liver by activating AMPK and downregulating the expression of genes involved in lipogenesis. DPP-4 inhibitors may be effective for the treatment of NAFLD and may be able to prevent its progression to non-alcoholic steatohepatitis. PMID:26670228

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

    PubMed Central

    Godinho, Ricardo; Carvalho, Eugénia; Teixeira, Frederico

    2015-01-01

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

  4. Sulfonation Pathway Inhibitors Block Reactivation of Latent HIV-1

    PubMed Central

    Murry, Jeffrey P.; Godoy, Joseph; Mukim, Amey; Swann, Justine; Bruce, James W.; Ahlquist, Paul; Bosque, Alberto; Planelles, Vicente; Spina, Celsa A.; Young, John A. T.

    2015-01-01

    Long-lived pools of latently infected cells are a significant barrier to the development of a cure for HIV-1 infection. A better understanding of the mechanisms of reactivation from latency is needed to facilitate the development of novel therapies that address this problem. Here we show that chemical inhibitors of the sulfonation pathway prevent virus reactivation, both in latently infected J-Lat and U1 cell lines and in a primary human CD4+ T cell model of latency. In each of these models, sulfonation inhibitors decreased transcription initiation from the HIV-1 promoter. These inhibitors block transcription initiation at a step that lies downstream of nucleosome remodeling and affects RNA polymerase II recruitment to the viral promoter. These results suggest that the sulfonation pathway acts by a novel mechanism to regulate efficient virus transcription initiation during reactivation from latency, and further that augmentation of this pathway could be therapeutically useful. PMID:25310595

  5. An updated systematic review and meta-analysis on the efficacy and tolerability of dipeptidyl peptidase-4 inhibitors in patients with type 2 diabetes with moderate to severe chronic kidney disease

    PubMed Central

    Singh-Franco, Devada; Harrington, Catherine; Tellez-Corrales, Eglis

    2016-01-01

    Objective: This updated meta-analysis determines the effect of dipeptidyl peptidase-4 inhibitors on glycemic and tolerability outcomes in patients with type 2 diabetes mellitus and chronic kidney disease with glomerular filtration rate of ⩽60 mL/min or on dialysis. Methods: In all, 14 citations were identified from multiple databases. Qualitative assessments and quantitative analyses were performed. Results: There were 2261 participants, 49–79 years of age, 49% men and 44% Caucasians. In seven placebo-comparator studies, reduction in hemoglobin A1c at weeks 12–24 was 0.55% (95% confidence interval: −0.68 to −0.43), P < 0.00001). In three sulfonylurea-comparator studies, dipeptidyl peptidase-4 inhibitors did not significantly reduce hemoglobin A1c at weeks 52–54 (−0.15% (95% confidence interval: −0.32 to 0.02)). In one sitagliptin versus albiglutide study, albiglutide significantly reduced hemoglobin A1c in patients with moderate renal impairment (−0.51%). A similar reduction in hemoglobin A1c was seen with sitagliptin versus vildagliptin (−0.56% vs −0.54%). Compared with placebo or sulfonylurea, dipeptidyl peptidase-4 inhibitors did not significantly reduce hemoglobin A1c after 12 and 54 weeks in patients on dialysis. Hypoglycemia was reported by ~30% of patients in both dipeptidyl peptidase-4 inhibitors and placebo groups over 24–52 weeks. While hypoglycemia was more common with a sulfonylurea at 52–54 weeks (risk ratio: 0.46 (95% confidence interval: 0.18 to 1.18)), there was significant heterogeneity (I2 = 87%). Limitations included high drop-out rate from most studies and small number of active-comparator studies. Conclusions: Dipeptidyl peptidase-4 inhibitors in patients with chronic kidney disease caused a modest reduction in hemoglobin A1c versus placebo, but not when compared with sulfonylureas or albiglutide, or when used in patients on dialysis. Additional active-comparator studies are needed to further

  6. 2-PMPA, a NAAG peptidase inhibitor, attenuates magnetic resonance BOLD signals in brain of anesthetized mice: evidence of a link between neuron NAAG release and hyperemia.

    PubMed

    Baslow, Morris H; Dyakin, Victor V; Nowak, Karen L; Hungund, Basalingappa L; Guilfoyle, David N

    2005-01-01

    N-acetylaspartylglutamate (NAAG), a dipeptide derivative of N-acetylaspartate (NAA) and glutamate (Glu), is present in neurons. Upon neurostimulation, NAAG is exported to astrocytes where it activates a specific metabotropic Glu surface receptor (mGluR3), and is then hydrolyzed by an astrocyte-specific enzyme, NAAG peptidase, liberating Glu, which can then be taken up by the astrocyte. NAAG is a selective mGluR3 agonist, one of several mGluRs that, when activated, triggers Ca2+ waves that spread to astrocytic endfeet in contact with the vascular system, where a secondary release of vasoactive agents induces a focal hyperemic response providing increased oxygen and nutrient availability to the stimulated neurons. Changes in blood oxygen levels can be assessed in vivo using a blood oxygenation level-dependent (BOLD) magnetic resonance imaging technique that reflects a paramagnetic effect of deoxyhemoglobin. In this study we used the competitive NAAG peptidase inhibitor 2-(phosphonomethyl) pentanedioic acid (2-PMPA) as a probe to interrupt the NAAG-mGluR3- Glu-astrocyte Ca2+ activation sequence. Using this probe, we investigated the relationship between release of the endogenous neuropeptide NAAG and brain blood oxygenation levels, as measured by changes in BOLD signals. In an anesthetized mouse, using an overtly nontoxic dose of 2-PMPA of 250 mg/kg i.p., there was an initial global BOLD signal increase of about 3% above control, lasting about 4 min, followed by a decrease from control of about 4%, sustained over a 32.5-min period of the drug test procedure. Similar changes, but of reduced magnitude and duration, were observed at a dose of 167 mg/kg. The 2-PMPA-induced decreases in BOLD signals appear to indicate that blood deoxyhemoglobin is elevated when endogenous NAAG cannot be hydrolyzed, thus linking the efflux of NAAG from neurons and its hydrolysis by astrocytes to hyperemic oxygenation responses in brain. PMID:15968081

  7. Real-world evaluation of glycemic control among patients with type 2 diabetes mellitus treated with canagliflozin versus dipeptidyl peptidase-4 inhibitors.

    PubMed

    Thayer, Sarah; Chow, Wing; Korrer, Stephanie; Aguilar, Richard

    2016-06-01

    Objective To evaluate glycemic control among patients with type 2 diabetes mellitus (T2DM) treated with canagliflozin (CANA) vs. dipeptidyl peptidase-4 (DPP-4) inhibitors. Methods Using integrated claims and lab data from a US health plan of commercial and Medicare Advantage enrollees, this matched-control cohort study assessed adult T2DM patients receiving treatment with CANA or DPP-4 inhibitors (1 April 2013-31 December 2013). Cohorts were chosen hierarchically; the first pharmacy claim for CANA was identified as the index date; then the first pharmacy claim for a DPP-4 inhibitor was identified and index date set. Eligible patients had 6 months of continuous health plan enrollment before the index date (baseline) and 9 months after (follow-up) and no evidence of index drug in baseline. Patients were matched 1:1 using propensity score matching. Changes in glycated hemoglobin (HbA1c) and percentages of patients with HbA1c <8% and <7% during the follow-up were evaluated. Results The matched CANA and DPP-4 inhibitor cohorts (53.2% treated with sitagliptin) included 2766 patients each (mean age: 55.7 years). Among patients with baseline and follow-up HbA1c results, mean baseline HbA1c values were similar, 8.62% and 8.57% (p = 0.615) for the CANA (n = 729) and DPP-4 inhibitor (n = 710) cohorts, respectively. Change in HbA1c was greater among patients in the CANA cohort than for those in the DPP-4 inhibitor cohort (-0.92% vs. -0.63%, p < 0.001), and also among the subset of patients with baseline HbA1c ≥7% (-1.07% [n = 624] vs. -0.79% [n = 603], p = 0.004). During follow-up, greater percentages of the CANA cohort relative to the DPP-4 inhibitor cohort achieved HbA1c of <8% (66.0% vs. 58.6%, p = 0.004) and <7% (35.4% vs. 29.9%, p = 0.022). Limitations This study was observational and residual confounding remains a possibility. Conclusions In this real-world study of patients with T2DM, CANA use was associated with greater HbA1c

  8. Vildagliptin, a novel dipeptidyl peptidase IV inhibitor, has no pharmacokinetic interactions with the antihypertensive agents amlodipine, valsartan, and ramipril in healthy subjects.

    PubMed

    He, Yan-Ling; Ligueros-Saylan, Monica; Sunkara, Gangadhar; Sabo, Ron; Zhao, Charlie; Wang, Yibin; Campestrini, Joelle; Pommier, Francoise; Dole, Kiran; Marion, Alan; Dole, William P; Howard, Dan

    2008-01-01

    We conducted 3 open-label, multiple-dose, 3-period, randomized, crossover studies in healthy subjects to assess the potential pharmacokinetic interaction between vildagliptin, a novel dipeptidyl peptidase IV inhibitor for the treatment of type 2 diabetes, and representatives of 3 commonly prescribed antihypertensive drug classes: (1) the calcium channel blocker, amlodipine; (2) the angiotensin receptor blocker, valsartan; and (3) the angiotensin-converting enzyme inhibitor, ramipril. Coadministration of vildagliptin 100 mg with amlodipine 5 mg, valsartan 320 mg, or ramipril 5 mg had no clinically significant effect on the pharmacokinetics of these drugs. The 90% confidence intervals of the geometric mean ratios for area under the plasma concentration-time curve from time zero to 24 hours (AUC0-24h) and maximum plasma concentration (Cmax) for vildagliptin, amlodipine, and ramipril (and its active metabolite, ramiprilat) were contained within the acceptance range for bioequivalence (0.80-1.25). Valsartan AUC0-24h and Cmax increased by 24% and 14%, respectively, following coadministration of vildagliptin, but this was not considered clinically significant. Vildagliptin was generally well tolerated when given alone or in combination with amlodipine, valsartan, or ramipril in healthy subjects at steady state. No adjustment in dosage based on pharmacokinetic considerations is required should vildagliptin be coadministered with amlodipine, valsartan, or ramipril in patients with type 2 diabetes and hypertension. PMID:17986525

  9. Development of Small-molecule HIV Entry Inhibitors Specifically Targeting gp120 or gp41

    PubMed Central

    Lu, Lu; Yu, Fei; Cai, Lifeng; Debnath, Asim K.; Jiang, Shibo

    2015-01-01

    Human immunodeficiency virus type 1 (HIV-1) envelope (Env) glycoprotein surface subunit gp120 and transmembrane subunit gp41 play important roles in HIV-1 entry, thus serving as key targets for the development of HIV-1 entry inhibitors. T20 peptide (enfuvirtide) is the first U.S. FDA-approved HIV entry inhibitor; however, its clinical application is limited by the lack of oral availability. Here, we have described the structure and function of the HIV-1 gp120 and gp41 subunits and reviewed advancements in the development of small-molecule HIV entry inhibitors specifically targeting these two Env glycoproteins. We then compared the advantages and disadvantages of different categories of HIV entry inhibitor candidates and further predicted the future trend of HIV entry inhibitor development. PMID:26324044

  10. Differential Cardiovascular Outcomes after Dipeptidyl Peptidase-4 Inhibitor, Sulfonylurea, and Pioglitazone Therapy, All in Combination with Metformin, for Type 2 Diabetes: A Population-Based Cohort Study

    PubMed Central

    Shin, Ju-Young; Chang, Yoosoo; Kim, Ye-Jee; Lee, Joongyub; Kim, Ju-Young; Park, Byung-Joo

    2015-01-01

    Background/Objectives Data on the comparative effectiveness of oral antidiabetics on cardiovascular outcomes in a clinical practice setting are limited. This study sought to determine whether a differential risk of cardiovascular disease (CVD) exists for the combination of a dipeptidyl peptidase-4 (DPP-4) inhibitor plus metformin versus a sulfonylurea derivative plus metformin or pioglitazone plus metformin. Methods We conducted a cohort study of 349,476 patients who received treatment with a DPP-4 inhibitor, sulfonylurea, or pioglitazone plus metformin for type 2 diabetes using the Korean national health insurance claims database. The incidence of total CVD and individual outcomes of myocardial infarction (MI), heart failure (HF), and ischemic stroke (IS) were assessed using the hazard ratios (HRs) estimated from a Cox proportional-hazards model weighted for a propensity score. Results During follow-up, 3,881 patients developed a CVD, including 428 MIs, 212 HFs, and 1,487 ISs. The adjusted HR with 95% confidence interval (CI) for a sulfonylurea derivative plus metformin compared with a DPP-4 inhibitor plus metformin was 1.20 (1.09-1.32) for total CVD; 1.14 (1.04-1.91) for MI; 1.07 (0.71-1.62) for HF; and 1.51 (1.28-1.79) for IS. The HRs with 95% CI for total CVD, MI, HF, and IS for pioglitazone plus metformin were 0.89 (0.81-0.99), 1.05 (0.76-1.46), 4.81 (3.53-6.56), and 0.81 (0.67-0.99), respectively. Conclusions Compared with a DPP-4 inhibitor plus metformin, treatment with a sulfonylurea drug plus metformin was associated with increased risks of total CVD, MI, and IS, whereas the use of pioglitazone plus metformin was associated with decreased total CVD and IS risks. PMID:25992614

  11. Purification and characterization of tenerplasminin-1, a serine peptidase inhibitor with antiplasmin activity from the coral snake (Micrurus tener tener) venom

    PubMed Central

    Vivas, Jeilyn; Ibarra, Carlos; Salazar, Ana M.; Neves-Ferreira, Ana G.C.; Sánchez, Elda E.; Perales, Jonás; Rodríguez-Acosta, Alexis; Guerrero, Belsy

    2015-01-01

    A plasmin inhibitor, named tenerplasminin-1 (TP1), was isolated from Micrurus tener tener (Mtt) venom. It showed a molecular mass of 6542 Da, similarly to Kunitz-type serine peptidase inhibitors. The amidolytic activity of plasmin (0.5 nM) on synthetic substrate S-2251 was inhibited by 91% following the incubation with TP1 (1 nM). Aprotinin (2 nM) used as the positive control of inhibition, reduced the plasmin amidolytic activity by 71%. Plasmin fibrinolytic activity (0.05 nM) was inhibited by 67% following incubation with TP1 (0.1 nM). The degradation of fibrinogen chains induced by plasmin, trypsin or elastase was inhibited by TP1 at a 1:2, 1:4 and 1:20 enzyme:inhibitor ratio, respectively. On the other hand, the proteolytic activity of crude Mtt venom on fibrinogen chains, previously attributed to metallopeptidases, was not abolished by TP1. The tPA-clot lysis assay showed that TP1 (0.2 nM) acts like aprotinin (0.4 nM) inducing a delay in lysis time and lysis rate which may be associated with the inhibition of plasmin generated from the endogenous plasminogen activation. TP1 is the first serine protease plasmin-like inhibitor isolated from Mtt snake venom which has been characterized in relation to its mechanism of action, formation of a plasmin:TP1 complex and therapeutic potential as anti-fibrinolytic agent, a biological characteristic of great interest in the field of biomedical research. They could be used to regulate the fibrinolytic system in pathologies such as metastatic cancer, parasitic infections, hemophilia and other hemorrhagic syndromes, in which an intense fibrinolytic activity is observed. PMID:26419785

  12. Origin of decrease in potency of darunavir and two related antiviral inhibitors against HIV-2 compared to HIV-1 protease.

    PubMed

    Kar, Parimal; Knecht, Volker

    2012-03-01

    Acquired immune deficiency syndrome (AIDS) is caused by the human immunodeficiency virus (HIV) type 1 and 2 (HIV-1 and HIV-2). HIV-1 is observed worldwide while HIV-2 though prevalent in West Africa is persistently spreading to other parts of the world. An important target for AIDS treatment is the use of HIV protease (PR) inhibitors preventing the replication of the virus. In this work, the popular molecular mechanics Poisson-Boltzmann surface area (MM-PBSA) method has been used to investigate the effectiveness of the HIV-1 PR inhibitors darunavir, GRL-06579A, and GRL-98065 against HIV-2 and HIV-1 protease. The affinity of the inhibitors for both HIV-1 and HIV-2 PR decreases in the order GRL-06579A > darunavir > GRL-98065, in accordance with experimental data. On the other hand, our results show that all these inhibitors bind less strongly to HIV-2 than to HIV-1 protease, again in agreement with experimental findings. The decrease in binding affinity for HIV-2 relative to HIV-1 PR is found to arise from an increase in the energetic penalty from the desolvation of polar groups (DRV) or a decrease in the size of the electrostatic interactions between the inhibitor and the PR (GRL-06579A and GRL-98065). For GRL-98065, also a decrease in the magnitude of the van der Waals interactions contributes to the reduction in binding affinity. A detailed understanding of the molecular forces governing binding and drug resistance might assist in the design of efficient inhibitors against HIV-2 protease. PMID:22280246

  13. The efficacy and safety of dipeptidyl peptidase-4 inhibitors for treatment of type 2 diabetes mellitus patients with severe renal impairment: a meta-analysis.

    PubMed

    Chen, Maosheng; Liu, Yueming; Jin, Juan; He, Qiang

    2016-05-01

    Aims/introduction Dipeptidyl peptidase-4 (DPP-4) inhibitors are a new class of oral antidiabetic agents, and have been increasingly and widely used in the treatment of diabetes mellitus (DM). However, information of DPP-4 inhibitors in type 2 DM patients with severe renal impairment (RI) is limited. Our study aimed to assess the efficacy and safety of DPP-4 inhibitors as compared to placebos or other hypoglycemic drugs in type 2 DM patients with severe RI. Materials and methods A meta-analysis was conducted to examine the literature comparing the effects of DPP-4 inhibitors on hemoglobin A1c (HbA1c) and fasting blood glucose (FBG). Randomized control trials (RCTs) including adults with type 2 DM and severe RI were analyzed. Safety was evaluated based on the percentage of patients who developed hypoglycemia and the occurrence of adverse events (AEs) as well as the incidence of peripheral edema, urinary tract infection, diarrhea, and death. Results Five RCTs including 503 patients were analyzed. Compared with a placebo or no treatment, DPP-4 inhibitors were associated with a larger decline in HbA1c (mean difference (MD) = -0.57, 95% confidence interval (CI): -0.73 to -0.41; p < 0.01) but not with FBG (MD = -0.26, 95% CI: -1.40 to 0.8; p = 0.66). Compared with glipizide monotherapy, no significant differences in HbA1c (MD = 0.15, 95% CI: -0.19 to 0.49; p = 0.38) or FBG (MD = -0.26, 95% CI: -1.16 to 0.64; p = 0.57) were found. Similar odds of experiencing an AE were found in both the DPP-4 inhibitor groups and comparison groups. Conclusions In type 2 DM patients with severe RI, treatment with DPP-4 inhibitors is safe and it effectively lowers HbA1c. PMID:26915531

  14. Structure based activity prediction of HIV-1 reverse transcriptase inhibitors.

    PubMed

    de Jonge, Marc R; Koymans, Lucien M H; Vinkers, H Maarten; Daeyaert, Frits F D; Heeres, Jan; Lewi, Paul J; Janssen, Paul A J

    2005-03-24

    We have developed a fast and robust computational method for prediction of antiviral activity in automated de novo design of HIV-1 reverse transcriptase inhibitors. This is a structure-based approach that uses a linear relation between activity and interaction energy with discrete orientation sampling and with localized interaction energy terms. The localization allows for the analysis of mutations of the protein target and for the separation of inhibition and a specific binding to the enzyme. We apply the method to the prediction of pIC(50) of HIV-1 reverse transcriptase inhibitors. The model predicts the activity of an arbitrary compound with a q(2) of 0.681 and an average absolute error of 0.66 log value, and it is fast enough to be used in high-throughput computational applications. PMID:15771460

  15. Beneficial Effects of Evogliptin, a Novel Dipeptidyl Peptidase 4 Inhibitor, on Adiposity with Increased Ppargc1a in White Adipose Tissue in Obese Mice

    PubMed Central

    Kim, Mi-Kyung; Shin, Chang-Yell; Jung, Il-Hoon; Sohn, Yong Sung; Son, Moon-Ho

    2015-01-01

    Although dipeptidyl peptidase 4 (DPP4) is an adipokine known to positively correlate with adiposity, the effects of pharmacological DPP4 inhibition on body composition have not been fully understood. This study was aimed to assess the effects of DPP4 inhibitors on adiposity for the first time in the established obese mice model. The weight loss effects of multiple DPP4 inhibitors were compared after a 4 week treatment in diet-induced obese mice. In addition, a 2 week study was performed to explore and compare the acute effects of evogliptin, a novel DPP4 inhibitor, and exenatide, a glucagon-like peptide-1 (GLP-1) analogue, on whole body composition, energy consumption, various plasma adipokines and gene expression in white adipose tissue (WAT). After the 4 week treatment, weight loss and blood glucose reductions were consistently observed with multiple DPP4 inhibitors. Moreover, after 2-week treatment, evogliptin dose-dependently reduced whole body fat mass while increasing the proportion of smaller adipocytes. However, insulin sensitivity or plasma lipid levels were not significantly altered. In addition to increased active GLP-1 levels by plasma DPP4 inhibition, evogliptin also enhanced basal metabolic rate without reduction in caloric intake, in contrast to exenatide; this finding suggested evogliptin's effects may be mediated by pathways other than via GLP-1. Evogliptin treatment also differentially increased Ppargc1a expression, a key metabolic regulator, in WAT, but not in skeletal muscle and brown adipose tissue. The increased expression of the downstream mitochondrial gene, Cox4i1, was also suggestive of the potential metabolic alteration in WAT by DPP4 inhibitors. We are the first to demonstrate that pharmacological DPP4 inhibition by evogliptin directly causes fat loss in established obese mice. In contradistinction to exenatide, the fat-loss effect of DPP4 inhibitor is partly attributed to enhanced energy expenditure along with metabolic changes in WAT

  16. Novel dual small-molecule HIV inhibitors: scaffolds and discovery strategies.

    PubMed

    Song, Anran; Yu, Haiqing; Wang, Changyuan; Zhu, Xingqi; Liu, Kexin; Ma, Xiaodong

    2015-01-01

    Searching for safe and effective treatments for HIV infection is still a great challenge worldwide in spite of the 27 marketed anti-HIV drugs and the powerful highly active antiretroviral therapy (HAART). As a promising prospect for generation of new HIV therapy drugs, multiple ligands (MDLs) were greatly focused on recently due to their lower toxicity, simplified dosing and patient adherence than single-target drugs. Till now, by disrupting two active sites or steps of HIV replications, a number of HIV dual inhibitors, such as CD4-gssucap120 inhibitors, CXCR4-gp20 inhibitors, RT-CXCR4 inhibitors, RT-protease inhibitors, RT-integrase inhibitors, and RTassociated functions inhibitors have been identified. Generally, these dual inhibitors were discovered mainly through screening approaches and design strategies. Of these compounds, the molecules bearing small skeletons exhibited strong anti-HIV activity and aroused great attention recently. Reviewing the progress of the dual small-molecule HIV inhibitors from the point of view of their scaffolds and discovery strategies will provide valuable information for producing more effective anti-HIV drugs. In this regard, novel dual small-molecule HIV inhibitors were illustrated, and their discovery paradigms as the major contents were also summarized in this manuscript. PMID:25269561

  17. Effect of transcription peptide inhibitors on HIV-1 replication.

    PubMed

    Van Duyne, Rachel; Cardenas, Jessica; Easley, Rebecca; Wu, Weilin; Kehn-Hall, Kylene; Klase, Zak; Mendez, Susana; Zeng, Chen; Chen, Hao; Saifuddin, Mohammed; Kashanchi, Fatah

    2008-07-01

    HIV-1 manipulates cellular machineries such as cyclin dependent kinases (cdks) and their cyclin elements, to stimulate virus production and maintain latent infection. Specifically, the HIV-1 viral protein Tat increases viral transcription by binding to the TAR promoter element. This binding event is mediated by the phosphorylation of Pol II by complexes such as cdk9/Cyclin T and cdk2/Cyclin E. Recent studies have shown that a Tat 41/44 peptide derivative prevents the loading of cdk2 onto the HIV-1 promoter, inhibiting gene expression and replication. Here we show that Tat peptide analogs computationally designed to dock at the cyclin binding site of cdk2 have the ability to bind to cdk2 and inhibit the association of cdk2 with the HIV promoter. Specifically, the peptide LAALS dissociated the complex and decreased kinase activity in vitro. We also describe our novel small animal model which utilizes humanized Rag2(-/-)gamma(c)(-/-) mice. This small peptide inhibitor induces a decrease in HIV-1 viral transcription in vitro and minimizes viral loads in vivo. PMID:18455747

  18. Comparative activity of proline-containing dipeptide noopept and inhibitor of dipeptidyl peptidase-4 sitagliptin in a rat model of developing diabetes.

    PubMed

    Ostrovskaya, R U; Ozerova, I V; Gudascheva, T A; Kapitsa, I G; Ivanova, E A; Voronina, T A; Seredenin, S B

    2014-01-01

    Developing diabetes was modeled on adult male Wistar rats by repeated intraperitoneal injections of streptozotocin in a subdiabetogenic dose of 30 mg/kg for 3 days. Proline-containing dipeptide drug Noopept or a standard diabetic drug dipeptidyl peptidase-4 inhibitor sitagliptin was administered per os in a dose of 5 mg/kg before each injection of the toxin and then for 16 days after streptozotocin course. In active control group, spontaneously increase glucose level and reduced tolerance to glucose load (1000 mg/kg intraperitoneally) were observed on the next day after the third administration of toxin. Basal glucose level decreased by day 16, but glucose tolerance remained impaired. Noopept normalized the basal blood glucose level and tolerance to glucose load on the next day after administration of streptozotocin. The effect of Noopept persisted to the end of the experiment. At early terms of the experiment, sitagliptin was somewhat superior to Noopept by the effect on baseline glucose level, but was inferior by the influence on glucose tolerance.. By the end of the experiment, Noopept significantly (by 2 times) surpassed sitagliptin by its effect on glucose tolerance. PMID:24771372

  19. An update on the clinical pharmacology of the dipeptidyl peptidase 4 inhibitor alogliptin used for the treatment of type 2 diabetes mellitus.

    PubMed

    Chen, Xiao-Wu; He, Zhi-Xu; Zhou, Zhi-Wei; Yang, Tianxin; Zhang, Xueji; Yang, Yin-Xue; Duan, Wei; Zhou, Shu-Feng

    2015-12-01

    Alogliptin, a dipeptidyl peptidase-4 (DPP-4) inhibitor that is a class of relatively new oral hypoglycaemic drugs used in patients with type 2 diabetes (T2DM), can be used as monotherapy or in combination with other anti-diabetic agents, including metformin, pioglitazone, sulfonylureas and insulin with a considerable therapeutic effect. Alogliptin exhibits favorable pharmacokinetic and pharmacodynamic profiles in humans. Alogliptin is mainly metabolized by cytochrome P450 (CYP2D6) and CYP3A4. Dose reduction is recommended for patients with moderate or worse renal impairment. Side effects of alogliptin include nasopharyngitis, upper-respiratory tract infections and headache. Hypoglycaemia is seen in about 1.5% of the T2DM patients. Rare but severe adverse reactions such as acute pancreatitis, serious hypersensitivity including anaphylaxis, angioedema and severe cutaneous reactions such as Stevens-Johnson syndrome have been reported from post-marketing monitoring. Pharmacokinetic interactions have not been observed between alogliptin and other drugs including glyburide, metformin, pioglitazone, insulin and warfarin. The present review aimed to update the clinical information on pharmacodynamics, pharmacokinetics, adverse effects and drug interactions, and to discuss the future directions of alogliptin. PMID:26218204

  20. Design, synthesis and biological evaluation of 4-fluoropyrrolidine-2-carbonitrile and octahydrocyclopenta[b]pyrrole-2-carbonitrile derivatives as dipeptidyl peptidase IV inhibitors.

    PubMed

    Ji, Xun; Xia, Chunmei; Wang, Jiang; Su, Mingbo; Zhang, Lei; Dong, Tiancheng; Li, Zeng; Wan, Xia; Li, Jingya; Li, Jia; Zhao, Linxiang; Gao, Zhaobing; Jiang, Hualiang; Liu, Hong

    2014-10-30

    Based on the previous work in our group and the principle of computer-aided drug design, a series of novel β-amino pyrrole-2-carbonitrile derivatives was designed and synthesized. Compounds 8l and 9l were efficacious and selective DPP4 inhibitors resulting in decreased blood glucose in vivo. Compound 8l had moderate DPP4 inhibitory activity (IC50 = 0.05 μM) and good oral bioavailability (F = 53.2%). Compound 9l showed excellent DPP4 inhibitory activity (IC50 = 0.01 μM), good selectivity (selective ratio: DPP8/DPP4 = 898.00; DPP9/DPP4 = 566.00) against related peptidases, and good efficacy in an oral glucose tolerance tests in ICR mice and moderate PK profiles (F = 22.8%, t1/2 = 2.74 h). Moreover, compound 9l did not block hERG channel and exhibited no inhibition of liver metabolic enzymes such as CYP2C9. PMID:25164763

  1. HIV Structural Database using Chem BLAST for all classes of AIDS inhibitors

    National Institute of Standards and Technology Data Gateway

    SRD 155 HIV Structural Database using Chem BLAST for all classes of AIDS inhibitors (Web, free access)   The HIV structural database (HIVSDB) is a comprehensive collection of the structures of HIV protease, both of unliganded enzyme and of its inhibitor complexes. It contains abstracts and crystallographic data such as inhibitor and protein coordinates for 248 data sets, of which only 141 are from the Protein Data Bank (PDB).

  2. The Dose-Dependent Organ-Specific Effects of a Dipeptidyl Peptidase-4 Inhibitor on Cardiovascular Complications in a Model of Type 2 Diabetes

    PubMed Central

    Seo, Jung-Woo; Lee, Arah; Kim, Dong Jin; Kim, Yang-Gyun; Kim, Se-Yeun; Lee, Kyung Hye; Lim, Sung-Jig; Cheng, Xian Wu; Lee, Sang-Ho; Kim, Weon

    2016-01-01

    Objective Although dipeptidyl peptidase-4 (DPP-4) inhibitors have been suggested to have a non-glucoregulatory protective effect in various tissues, the effects of long-term inhibition of DPP-4 on the micro- and macro-vascular complications of type 2 diabetes remain uncertain. The aim of the present study was to investigate the organ-specific protective effects of DPP-4 inhibitor in rodent model of type 2 diabetes. Methods Eight-week-old diabetic and obese db/db mice and controls (db/m mice) received vehicle or one of two doses of gemigliptin (0.04 and 0.4%) daily for 12 weeks. Urine albumin excretion and echocardiography measured at 20 weeks of age. Heart and kidney tissue were subjected to molecular analysis and immunohistochemical evaluation. Results Gemigliptin effectively suppressed plasma DPP-4 activation in db/db mice in a dose-dependent manner. The HbA1c level was normalized in the 0.4% gemigliptin, but not in the 0.04% gemigliptin group. Gemigliptin showed a dose-dependent protective effect on podocytes, anti-apoptotic and anti-oxidant effects in the diabetic kidney. However, the dose-dependent effect of gemigliptin on diabetic cardiomyopathy was ambivalent. The lower dose significantly attenuated left ventricular (LV) dysfunction, apoptosis, and cardiac fibrosis, but the higher dose could not protect the LV dysfunction and cardiac fibrosis. Conclusion Gemigliptin exerted non-glucoregulatory protective effects on both diabetic nephropathy and cardiomyopathy. However, high-level inhibition of DPP-4 was associated with an organ-specific effect on cardiovascular complications in type 2 diabetes. PMID:26959365

  3. The dipeptidyl peptidase inhibitor linagliptin and the angiotensin II receptor blocker telmisartan show renal benefit by different pathways in rats with 5/6 nephrectomy.

    PubMed

    Tsuprykov, Oleg; Ando, Ryotaro; Reichetzeder, Christoph; von Websky, Karoline; Antonenko, Viktoriia; Sharkovska, Yuliya; Chaykovska, Lyubov; Rahnenführer, Jan; Hasan, Ahmed A; Tammen, Harald; Alter, Markus; Klein, Thomas; Ueda, Seiji; Yamagishi, Sho-Ichi; Okuda, Seiya; Hocher, Berthold

    2016-05-01

    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. PMID:27083282

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

    PubMed

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

    2015-06-01

    Dipeptidyl-peptidase IV (DPP-IV) is an enzyme responsible for the metabolism of endogenous gut-derived hormone, glucagon-like peptide-1 (GLP-1). DPP-IV is known for its role in energy homeostasis and pharmacological blockade of this enzyme is a recently approved clinical strategy for the management of type II diabetes. Accumulating evidences suggest that enzyme DPP-IV can affect spectrum of central nervous system (CNS) functions. However, little is known about the role of this enzyme in ethanol-mediated neurobehavioral complications. The objective of the present study was to examine the impact of DPP-IV inhibitor, sitagliptin on the development of tolerance to anxiolytic effect of ethanol and anxiety associated with ethanol withdrawal in rats. A dose-response study revealed that sitaglitpin (20 mg/kg, p.o.) per se exhibit anxiolytic effect in the elevated plus maze (EPM) test in rats. Tolerance to anxiolytic effect of ethanol (2 g/kg, i.p.; 8 % w/v) was observed from 7(th) day of ethanol-diet (6 % v/v) consumption. In contrast, tolerance to anxiolytic effect of ethanol was delayed in rats that were treated daily with sitagliptin (20 mg/kg, p.o.) as tolerance was observed from 13(th)day since commencement of ethanol-diet consumption. Discontinuation of rats from ethanol-diet after 15-days of ethanol consumption resulted in withdrawal anxiety between 8 h and 12 h post-abstinence. However, rats on 15-day ethanol-diet with concomitant sitagliptin (20 mg/kg, p.o.) treatment exhibited delay in appearance (24 h post-withdrawal) of withdrawal anxiety. In summary, DPP-IV inhibitors may prove as an attractive research strategy against ethanol tolerance and dependence. PMID:25129124

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

    PubMed

    Nauck, M

    2016-03-01

    Over the last few years, incretin-based therapies have emerged as important agents in the treatment of type 2 diabetes (T2D). These agents exert their effect via the incretin system, specifically targeting the receptor for the incretin hormone glucagon-like peptide 1 (GLP-1), which is partly responsible for augmenting glucose-dependent insulin secretion in response to nutrient intake (the 'incretin effect'). In patients with T2D, pharmacological doses/concentrations of GLP-1 can compensate for the inability of diabetic β cells to respond to the main incretin hormone glucose-dependent insulinotropic polypeptide, and this is therefore a suitable parent compound for incretin-based glucose-lowering medications. Two classes of incretin-based therapies are available: GLP-1 receptor agonists (GLP-1RAs) and dipeptidyl peptidase-4 (DPP-4) inhibitors. GLP-1RAs promote GLP-1 receptor (GLP-1R) signalling by providing GLP-1R stimulation through 'incretin mimetics' circulating at pharmacological concentrations, whereas DPP-4 inhibitors prevent the degradation of endogenously released GLP-1. Both agents produce reductions in plasma glucose and, as a result of their glucose-dependent mode of action, this is associated with low rates of hypoglycaemia; however, there are distinct modes of action resulting in differing efficacy and tolerability profiles. Furthermore, as their actions are not restricted to stimulating insulin secretion, these agents have also been associated with additional non-glycaemic benefits such as weight loss, improvements in β-cell function and cardiovascular risk markers. These attributes have made incretin therapies attractive treatments for the management of T2D and have presented physicians with an opportunity to tailor treatment plans. This review endeavours to outline the commonalities and differences among incretin-based therapies and to provide guidance regarding agents most suitable for treating T2D in individual patients. PMID:26489970

  6. Investigational reverse transcriptase inhibitors for the treatment of HIV

    PubMed Central

    Cory, Theodore J; Midde, Narasimha M; Rao, PSS; Kumar, Santosh

    2015-01-01

    Introduction While considerable advances have been made in the development of antiretroviral agents, there is still work to be done. Reverse transcriptase inhibitors are important drugs for the treatment of HIV, and considerable research is currently ongoing to develop new agents and to modify currently existing agents. Areas covered Herein, the authors discuss both investigational nucleoside reverse transcriptase inhibitors (NRTIs) and non-nucleoside reverse transcriptase inhibitors (NNRTIs), including agents that are in various stages of development. They also discuss novel formulations that are being investigated for currently available drugs, and discuss the advantages that these new formulations may provide. Expert opinion New formulations and co-formulations of currently existing antiretrovirals will represent an important area of development, as a means to improve adherence for HIV-positive individuals. New formulations will continue to be developed, with a focus on allowing for less-frequent administration, as well increasing drug concentrations at local sites such as vaginal tissue, rectal tissue and sites in the immune system. PMID:26088266

  7. Convenient cell fusion assay for rapid screening for HIV entry inhibitors

    NASA Astrophysics Data System (ADS)

    Jiang, Shibo; Radigan, Lin; Zhang, Li

    2000-03-01

    Human immunodeficiency viruses (HIV)-induced cell fusion is a critical pathway of HIV spread from infected cells to uninfected cells. A rapid and simple assay was established to measure HIV-induce cell fusion. This study is particularly useful to rapid screen for HIV inhibitors that block HIV cell-to-cell transmission. Present study demonstrated that coculture of HIV-infected cells with uninfected cells at 37 degree(s)C for 2 hours resulted in the highest cell fusion rate. Using this cell fusion assay, we have identified several potent HIV inhibitors targeted to the HIV gp41 core. These antiviral agents can be potentially developed as antiviral drugs for chemotherapy and prophylaxis of HIV infection and AIDS.

  8. Effect of a Dipeptidyl Peptidase-IV Inhibitor, Des-Fluoro-Sitagliptin, on Neointimal Formation after Balloon Injury in Rats

    PubMed Central

    Lim, Soo; Choi, Sung Hee; Shin, Hayley; Cho, Bong Jun; Park, Ho Seon; Ahn, Byung Yong; Kang, Seon Mee; Yoon, Ji Won; Jang, Hak Chul; Kim, Young-Bum; Park, Kyong Soo

    2012-01-01

    Background Recently, it has been suggested that enhancement of incretin effect improves cardiac function. We investigated the effect of a DPP-IV inhibitor, des-fluoro-sitagliptin, in reducing occurrence of restenosis in carotid artery in response to balloon injury and the related mechanisms. Methods and Findings Otsuka Long-Evans Tokushima Fatty rats were grouped into four: control (normal saline) and sitagliptin 100, 250 and 500 mg/kg per day (n = 10 per group). Sitagliptin or normal saline were given orally from 1 week before to 2 weeks after carotid injury. After 3 weeks of treatment, sitagliptin treatment caused a significant and dose-dependent reduction in intima-media ratio (IMR) in obese diabetic rats. This effect was accompanied by improved glucose homeostasis, decreased circulating levels of high-sensitivity C-reactive protein (hsCRP) and increased adiponectin level. Moreover, decreased IMR was correlated significantly with reduced hsCRP, tumor necrosis factor-α and monocyte chemoattractant protein-1 levels and plasminogen activator inhibitor-1 activity. In vitro evidence with vascular smooth muscle cells (VSMCs) demonstrated that proliferation and migration were decreased significantly after sitagliptin treatment. In addition, sitagliptin increased caspase-3 activity and decreased monocyte adhesion and NFκB activation in VSMCs. Conclusions Sitagliptin has protective properties against restenosis after carotid injury and therapeutic implications for treating macrovascular complications of diabetes. PMID:22493727

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

    NASA Astrophysics Data System (ADS)

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

    2016-05-01

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

  10. Antiviral activity of a Rac GEF inhibitor characterized with a sensitive HIV/SIV fusion assay

    SciTech Connect

    Pontow, Suzanne; Harmon, Brooke; Campbell, Nancy; Ratner, Lee

    2007-11-10

    A virus-dependent fusion assay was utilized to examine the activity of a panel of HIV-1, -2, and SIV isolates of distinct coreceptor phenotypes. This assay allowed identification of entry inhibitors, and characterization of an antagonist of a Rac guanine nucleotide exchange factor, as an inhibitor of HIV-mediated fusion.

  11. Discovery of MK-8718, an HIV Protease Inhibitor Containing a Novel Morpholine Aspartate Binding Group.

    PubMed

    Bungard, Christopher J; Williams, Peter D; Ballard, Jeanine E; Bennett, David J; Beaulieu, Christian; Bahnck-Teets, Carolyn; Carroll, Steve S; Chang, Ronald K; Dubost, David C; Fay, John F; Diamond, Tracy L; Greshock, Thomas J; Hao, Li; Holloway, M Katharine; Felock, Peter J; Gesell, Jennifer J; Su, Hua-Poo; Manikowski, Jesse J; McKay, Daniel J; Miller, Mike; Min, Xu; Molinaro, Carmela; Moradei, Oscar M; Nantermet, Philippe G; Nadeau, Christian; Sanchez, Rosa I; Satyanarayana, Tummanapalli; Shipe, William D; Singh, Sanjay K; Truong, Vouy Linh; Vijayasaradhi, Sivalenka; Wiscount, Catherine M; Vacca, Joseph P; Crane, Sheldon N; McCauley, John A

    2016-07-14

    A novel HIV protease inhibitor was designed using a morpholine core as the aspartate binding group. Analysis of the crystal structure of the initial lead bound to HIV protease enabled optimization of enzyme potency and antiviral activity. This afforded a series of potent orally bioavailable inhibitors of which MK-8718 was identified as a compound with a favorable overall profile. PMID:27437081

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

    PubMed Central

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

    2016-01-01

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

  13. Targeting the AKT pathway: Repositioning HIV protease inhibitors as radiosensitizers

    PubMed Central

    Goda, Jayant S.; Pachpor, Tejaswini; Basu, Trinanjan; Chopra, Supriya; Gota, Vikram

    2016-01-01

    Cellular resistance in tumour cells to different therapeutic approaches has been a limiting factor in the curative treatment of cancer. Resistance to therapeutic radiation is a common phenomenon which significantly reduces treatment options and impacts survival. One of the mechanisms of acquiring resistance to ionizing radiation is the overexpression or activation of various oncogenes like the EGFR (epidermal growth factor receptor), RAS (rat sarcoma) oncogene or loss of PTEN (phosphatase and tensin homologue) which in turn activates the phosphatidyl inositol 3-kinase/protein kinase B (PI3-K)/AKT pathway responsible for radiation resistance in various tumours. Blocking the pathway enhances the radiation response both in vitro and in vivo. Due to the differential activation of this pathway (constitutively activated in tumour cells and not in the normal host cells), it is an excellent candidate target for molecular targeted therapy to enhance radiation sensitivity. In this regard, HIV protease inhibitors (HPIs) known to interfere with PI3-K/AKT signaling in tumour cells, have been shown to sensitize various tumour cells to radiation both in vitro and in vivo. As a result, HPIs are now being investigated as possible radiosensitizers along with various chemotherapeutic drugs. This review describes the mechanisms by which PI3-K/AKT pathway causes radioresistance and the role of HIV protease inhibitors especially nelfinavir as a potential candidate drug to target the AKT pathway for overcoming radioresistance and its use in various clinical trials for different malignancies. PMID:27121513

  14. Potent D-Peptide Inhibitors of HIV-1 Entry

    SciTech Connect

    Welch,B.; VanDemark, A.; Heroux, A.; Hill, C.; Kay, M.

    2007-01-01

    During HIV-1 entry, the highly conserved gp41 N-trimer pocket region becomes transiently exposed and vulnerable to inhibition. Using mirror-image phage display and structure-assisted design, we have discovered protease-resistant D-amino acid peptides (D-peptides) that bind the N-trimer pocket with high affinity and potently inhibit viral entry. We also report high-resolution crystal structures of two of these D-peptides in complex with a pocket mimic that suggest sources of their high potency. A trimeric version of one of these peptides is the most potent pocket-specific entry inhibitor yet reported by three orders of magnitude (IC50 = 250 pM). These results are the first demonstration that D-peptides can form specific and high-affinity interactions with natural protein targets and strengthen their promise as therapeutic agents. The D-peptides described here address limitations associated with current L-peptide entry inhibitors and are promising leads for the prevention and treatment of HIV/AIDS.

  15. Functional characterization of polymorphisms in the peptidase inhibitor 3 (elafin) gene and validation of their contribution to risk of acute respiratory distress syndrome.

    PubMed

    Tejera, Paula; O'Mahony, D Shane; Owen, Caroline A; Wei, Yongyue; Wang, Zhaoxi; Gupta, Kushagra; Su, Li; Villar, Jesus; Wurfel, Mark; Christiani, David C

    2014-08-01

    Elafin (peptidase inhibitor 3 [PI3]) and its biologically active precursor, pre-elafin, are neutrophil serine proteinase inhibitors with an important role in preventing excessive tissue injury during inflammatory events. Recently, we reported an association between single-nucleotide polymorphism (SNP) rs2664581 in the PI3 gene, increased risk of acute respiratory distress syndrome (ARDS) and pre-elafin circulating levels. This study aims to validate the legitimacy of this association by using a cohort of patients who met the criteria for systemic inflammatory response syndrome and were at risk of developing ARDS (n = 840). A comprehensive functional study of SNPs in PI3 gene was also performed. Luciferase assays and electrophoretic mobility shift assays were conducted to determine the functional relevance of promoter region variants. The effect of the coding SNP rs2664581 on the neutrophil elastase inhibitory activity and transglutaminase binding properties of pre-elafin was also investigated. The variant allele of rs2664581 (C) was significantly associated with increased ARDS risk, mainly among subjects with sepsis (odds ratio = 1.44; 95% confidence interval = 1.04-1.99; P = 0.0276, adjusted by age, sex, and Acute Physiology and Chronic Health Evaluation III). Pre-elafin recombinant protein carrying the amino acid change associated with rs2664581 (Thr34Pro, mutant protein [MT]) had greater capacity to undergo transglutaminase-mediated cross-linking to immobilized fibronectin than wild-type protein in vitro (P < 0.003). No differences were observed in the neutrophil elastase inhibitory activities of wild-type versus MT proteins. In addition, the risk allele-promoter construct had significantly lower cytokine-induced transcriptional activity. Electrophoretic mobility shift assay results indicated a differential binding of nuclear proteins to the G and A alleles of SNP -338G > A. Our results confirm the association between SNP rs2664581 and enhanced risk of ARDS

  16. Functional Characterization of Polymorphisms in the Peptidase Inhibitor 3 (Elafin) Gene and Validation of Their Contribution to Risk of Acute Respiratory Distress Syndrome

    PubMed Central

    Tejera, Paula; O’Mahony, D. Shane; Owen, Caroline A.; Wei, Yongyue; Wang, Zhaoxi; Gupta, Kushagra; Su, Li; Villar, Jesus; Wurfel, Mark

    2014-01-01

    Elafin (peptidase inhibitor 3 [PI3]) and its biologically active precursor, pre-elafin, are neutrophil serine proteinase inhibitors with an important role in preventing excessive tissue injury during inflammatory events. Recently, we reported an association between single-nucleotide polymorphism (SNP) rs2664581 in the PI3 gene, increased risk of acute respiratory distress syndrome (ARDS) and pre-elafin circulating levels. This study aims to validate the legitimacy of this association by using a cohort of patients who met the criteria for systemic inflammatory response syndrome and were at risk of developing ARDS (n = 840). A comprehensive functional study of SNPs in PI3 gene was also performed. Luciferase assays and electrophoretic mobility shift assays were conducted to determine the functional relevance of promoter region variants. The effect of the coding SNP rs2664581 on the neutrophil elastase inhibitory activity and transglutaminase binding properties of pre-elafin was also investigated. The variant allele of rs2664581 (C) was significantly associated with increased ARDS risk, mainly among subjects with sepsis (odds ratio = 1.44; 95% confidence interval = 1.04–1.99; P = 0.0276, adjusted by age, sex, and Acute Physiology and Chronic Health Evaluation III). Pre-elafin recombinant protein carrying the amino acid change associated with rs2664581 (Thr34Pro, mutant protein [MT]) had greater capacity to undergo transglutaminase-mediated cross-linking to immobilized fibronectin than wild-type protein in vitro (P < 0.003). No differences were observed in the neutrophil elastase inhibitory activities of wild-type versus MT proteins. In addition, the risk allele–promoter construct had significantly lower cytokine-induced transcriptional activity. Electrophoretic mobility shift assay results indicated a differential binding of nuclear proteins to the G and A alleles of SNP −338G > A. Our results confirm the association between SNP rs2664581 and enhanced risk of

  17. Expedient screening for HIV-1 protease inhibitors using a simplified immunochromatographic assay.

    PubMed

    Kitidee, Kuntida; Khamaikawin, Wannisa; Thongkum, Weeraya; Tawon, Yardpiroon; Cressey, Tim R; Jevprasesphant, Rachaneekorn; Kasinrerk, Watchara; Tayapiwatana, Chatchai

    2016-05-15

    A colloidal gold-based immunochromatographic (IC) strip test was developed and validated for the detection of HIV-1 protease (HIV-PR) activity and inhibitory effect of HIV-PR inhibitors (PIs). It is a unique 'two-step' process requiring the combination of proteolysis of HIV-PR and an immunochromatographic reaction. Monoclonal antibodies to the free C-terminus of HIV matrix protein (HIV-MA) conjugated to gold particles and a monoclonal antibody against intact and cleaved forms of the HIV-MA are immobilized on the 'Test'-line of the IC strip. Using lopinavir, a potent HIV protease inhibitor, the IC-strip was optimized to detect inhibitory activity against HIV-protease. At a lopinavir concentration of 1000ng/mL (its suggested minimum effective concentration), a HIV-PRH6 concentration of 6mg/mL and incubation period of 60min were the optimal conditions. A preliminary comparison between a validated high-performance liquid chromatography assay and the IC-strip to semi-quantify HIV protease inhibitor concentrations (lopinavir and atazanavir) demonstrated good agreement. This simplified method is suitable for the rapid screening of novel protease inhibitors for future therapeutic use. Moreover, the IC strip could also be optimized to semi-quantify PIs concentrations in plasma samples. PMID:26490422

  18. Dipeptidyl Peptidase-4 Inhibitor Use Is Not Associated With Acute Pancreatitis in High-Risk Type 2 Diabetic Patients

    PubMed Central

    Chang, Chia-Hsuin; Lin, Jou-Wei; Chen, Shu-Ting; Lai, Mei-Shu; Chuang, Lee-Ming; Chang, Yi-Cheng

    2016-01-01

    Abstract To analyze the association between use of DPP-4 inhibitors and acute pancreatitis in high-risk type 2 diabetic patients. A retrospective nationwide cohort study was conducted using the Taiwan National Health Insurance claim database. The risk associated with sitagliptin was compared to that with acarbose, a second-line antidiabetic drug prescribed for patients with similar diabetes severity and with a known neutral effect on pancreatitis. Between January 1, 2009 and December 31, 2010, a total of 8526 sitagliptin initiators and 8055 acarbose initiators who had hypertriglyceridemia or prior hospitalization history for acute pancreatitis were analyzed for the risk of hospitalization due to acute pancreatitis stratified for baseline propensity score. In the crude analysis, sitagliptin was associated with a decreased risk of acute pancreatitis (hazard ratio [HR] 0.74; 95% confidence interval [CI]: 0.62–0.88) compared to acarbose in diabetic patients with prior history of hospitalization for pancreatitis or hypertriglyceridemia. The association was abolished after stratification for propensity score quintiles (adjusted HR 0.95; 95% CI: 0.79–1.16). Similar results were found separately in both patients’ histories of prior hospitalization of acute pancreatitis (adjusted HR 0.97; 95% CI: 0.76–1.24) and those with hypertriglyceridemia (adjusted HR 0.86; 95% CI: 0.65–1.13). No significant association was found for different durations or accumulative doses of sitagliptin. In the stratified analysis, no significant effect modification was found in relation to patients’ characteristics. Use of sitagliptin was not associated with an increased risk of acute pancreatitis in high-risk diabetic patients with hypertriglyceridemia or with history of acute pancreatitis. PMID:26886601

  19. Approaches for identification of HIV-1 entry inhibitors targeting gp41 pocket.

    PubMed

    Yu, Fei; Lu, Lu; Du, Lanying; Zhu, Xiaojie; Debnath, Asim K; Jiang, Shibo

    2013-01-01

    The hydrophobic pocket in the HIV-1 gp41 N-terminal heptad repeat (NHR) domain plays an important role in viral fusion and entry into the host cell, and serves as an attractive target for development of HIV-1 fusion/entry inhibitors. The peptide anti-HIV drug targeting gp41 NHR, T-20 (generic name: enfuvirtide; brand name: Fuzeon), was approved by the U.S. FDA in 2003 as the first HIV fusion/entry inhibitor for treatment of HIV/AIDS patients who fail to respond to the current antiretroviral drugs. However, because T20 lacks the pocket-binding domain (PBD), it exhibits low anti-HIV-1 activity and short half-life. Therefore, several next-generation HIV fusion inhibitory peptides with PBD have been developed. They possess longer half-life and more potent antiviral activity against a broad spectrum of HIV-1 strains, including the T-20-resistant variants. Nonetheless, the clinical application of these peptides is still limited by the lack of oral availability and the high cost of production. Thus, development of small molecule compounds targeting the gp41 pocket with oral availability has been promoted. This review describes the main approaches for identification of HIV fusion/entry inhibitors targeting the gp41 pocket and summarizes the latest progress in developing these inhibitors as a new class of anti-HIV drugs. PMID:23344560

  20. 3-Hydroxypyrimidine-2,4-diones as an Inhibitor Scaffold of HIV Integrase

    PubMed Central

    Tang, Jing; Maddali, Kasthuraiah; Sham, Yuk Y.; Vince, Robert; Pommier, Yves; Wang, Zhengqiang

    2011-01-01

    Integrase (IN) represents a clinically validated target for the development of antivirals against human immunodeficiency virus (HIV). Inhibitors with a novel structure core are essential for combating resistance associated with known IN inhibitors (INIs). We have previously disclosed a novel dual inhibitor scaffold of HIV IN and reverse transcriptase (RT). Here we report the complete structure-activity relationship (SAR), molecular modeling and resistance profile of this inhibitor type on IN inhibition. These studies support an antiviral mechanism of dual inhibition against both IN and RT and validate 3-hydroxypyrimidine-2,4-diones as an IN inhibitor scaffold. PMID:21381765

  1. 3-Hydroxypyrimidine-2,4-diones as an inhibitor scaffold of HIV integrase.

    PubMed

    Tang, Jing; Maddali, Kasthuraiah; Metifiot, Mathieu; Sham, Yuk Y; Vince, Robert; Pommier, Yves; Wang, Zhengqiang

    2011-04-14

    Integrase (IN) represents a clinically validated target for the development of antivirals against human immunodeficiency virus (HIV). Inhibitors with a novel structure core are essential for combating resistance associated with known IN inhibitors (INIs). We have previously disclosed a novel dual inhibitor scaffold of HIV IN and reverse transcriptase (RT). Here we report the complete structure-activity relationship (SAR), molecular modeling, and resistance profile of this inhibitor type on IN inhibition. These studies support an antiviral mechanism of dual inhibition against both IN and RT and validate 3-hydroxypyrimidine-2,4-diones as an IN inhibitor scaffold. PMID:21381765

  2. Synthesis and anti-HIV activity of some [Nucleoside Reverse Transcriptase Inhibitor]-C5'-linker-[Integrase Inhibitor] heterodimers as inhibitors of HIV replication.

    PubMed

    Sugeac, Elena; Fossey, Christine; Ladurée, Daniel; Schmidt, Sylvie; Laumond, Geraldine; Aubertin, Anne-Marie

    2004-12-01

    Selected for their expected ability to inhibit HIV replication, a series of eight heterodimers containing a Nucleoside Reverse Transcriptase Inhibitor (NRTI) and an Integrase Inhibitor (INI), bound by a linker, were designed and synthesized. For the NRTIs, d4U, d2U and d4T were chosen. For the INIs, 4-[1-(4-fluorobenzyl)-1H-pyrrol-2-yl]-2,4-dioxobutyric acid (6) and 4-(3,5-dibenzyloxyphenyl)-2,4-dioxobutyric acid (9) (belonging to the beta-diketo acids class) were chosen. The conjugation of the two different inhibitors (NRTI and INI) was performed using an amino acid (glycine or beta-alanine) as a cleavable linker. PMID:15662954

  3. Crystal structures of HIV-1 nonnucleoside reverse transcriptase inhibitors: N-benzyl-4-methyl-benzimidazoles

    NASA Astrophysics Data System (ADS)

    Ziółkowska, Natasza E.; Michejda, Christopher J.; Bujacz, Grzegorz D.

    2009-07-01

    HIV-1 nonnucleoside reverse transcriptase inhibitors are potentially specific and effective drugs in AIDS therapy. The presence of two aromatic systems with an angled orientation in the molecule of the inhibitor is crucial for interactions with HIV-1 RT. The inhibitor drives like a wedge into the cluster of aromatic residues of RT HIV-1 and restrains the enzyme in a conformation that blocks the chemical step of nucleotide incorporation. Structural studies provide useful information for designing new, more active inhibitors. The crystal structures of four NNRTIs are presented here. The investigated compounds are derivatives of N-benzyl-4-methyl-benzimidazole with various aliphatic and aromatic substituents at carbon 2 positions and a 2,6-dihalogeno-substituted N-benzyl moiety. Structural data reported here show that the conformation of the investigated compounds is relatively rigid. Such feature is important for the nonnucleoside inhibitor binding to HIV-1 reverse transcriptase.

  4. Methylene bisphosphonates as the inhibitors of HIV RT phosphorolytic activity.

    PubMed

    Yanvarev, D V; Korovina, A N; Usanov, N N; Khomich, O A; Vepsäläinen, J; Puljula, E; Kukhanova, M K; Kochetkov, S N

    2016-08-01

    The structure-function analysis of 36 methylenebisphosphonates (BPs) as inhibitors of the phosphorolytic activity of native and drug-resistant forms of HIV-1 reverse transcriptase (RT) was performed. It was shown that with the increase of the inhibitory potential of BPs towards the phosphorolytic activity raises their ability to inhibit the RT-catalyzed DNA elongation. Herein, we report the impact of the thymidine analog mutations (TAM) on the activity of bisphosphonates, as well as some structural features of the BPs, allowing them to maintain the inhibitory activity on the enzyme resistant to nucleoside analog therapy. We estimated the Mg(2+)-coordinating group structure, the linker and the aromatic pharmacophore influence on the inhibitory potential of the BPs. Based on the 31 BPs SAR, several BPs with improved inhibitory properties were designed and synthesized. PMID:27230835

  5. HIV-1 integrase inhibitor resistance and its clinical implications.

    PubMed

    Blanco, Jose-Luis; Varghese, Vici; Rhee, Soo-Yon; Gatell, Jose M; Shafer, Robert W

    2011-05-01

    With the approval in 2007 of the first integrase inhibitor (INI), raltegravir, clinicians became better able to suppress virus replication in patients infected with human immunodeficiency virus type 1 (HIV-1) who were harboring many of the most highly drug-resistant viruses. Raltegravir also provided clinicians with additional options for first-line therapy and for the simplification of regimens in patients with stable virological suppression. Two additional INIs in advanced clinical development-elvitegravir and S/GSK1349572-may prove equally versatile. However, the INIs have a relatively low genetic barrier to resistance in that 1 or 2 mutations are capable of causing marked reductions in susceptibility to raltegravir and elvitegravir, the most well-studied INIs. This perspective reviews the genetic mechanisms of INI resistance and their implications for initial INI therapy, the treatment of antiretroviral-experienced patients, and regimen simplification. PMID:21459813

  6. QSAR study of curcumine derivatives as HIV-1 integrase inhibitors.

    PubMed

    Gupta, Pawan; Sharma, Anju; Garg, Prabha; Roy, Nilanjan

    2013-03-01

    A QSAR study was performed on curcumine derivatives as HIV-1 integrase inhibitors using multiple linear regression. The statistically significant model was developed with squared correlation coefficients (r(2)) 0.891 and cross validated r(2) (r(2) cv) 0.825. The developed model revealed that electronic, shape, size, geometry, substitution's information and hydrophilicity were important atomic properties for determining the inhibitory activity of these molecules. The model was also tested successfully for external validation (r(2) pred = 0.849) as well as Tropsha's test for model predictability. Furthermore, the domain analysis was carried out to evaluate the prediction reliability of external set molecules. The model was statistically robust and had good predictive power which can be successfully utilized for screening of new molecules. PMID:23286784

  7. Design of HIV Protease Inhibitors Targeting Protein Backbone: An Effective Strategy for Combating Drug Resistance

    SciTech Connect

    Ghosh, Arun K.; Chapsal, Bruno D.; Weber, Irene T.; Mitsuya, Hiroaki

    2008-06-03

    The discovery of human immunodeficiency virus (HIV) protease inhibitors (PIs) and their utilization in highly active antiretroviral therapy (HAART) have been a major turning point in the management of HIV/acquired immune-deficiency syndrome (AIDS). However, despite the successes in disease management and the decrease of HIV/AIDS-related mortality, several drawbacks continue to hamper first-generation protease inhibitor therapies. The rapid emergence of drug resistance has become the most urgent concern because it renders current treatments ineffective and therefore compels the scientific community to continue efforts in the design of inhibitors that can efficiently combat drug resistance.

  8. HOW IMMUNE PEPTIDASES CHANGE SPECIFICITY

    PubMed Central

    Raymond, Wilfred W.; Trivedi, Neil N.; Makarova, Anastasia; Ray, Manisha; Craik, Charles S.; Caughey, George H.

    2014-01-01

    Cathepsin G is a major secreted serine peptidase of neutrophils and mast cells. Studies in Ctsg-null mice suggest that cathepsin G supports antimicrobial defenses but can injure host tissues. The human enzyme has unusual “Janus-faced” ability to cleave peptides at basic (tryptic) as well as aromatic (chymotryptic) sites. Tryptic activity has been attributed to acidic Glu226 in the primary specificity pocket and underlies proposed important functions such as activation of pro-urokinase. However, most mammals, including mice, substitute Ala for Glu226, suggesting that human tryptic activity may be anomalous. To test this hypothesis, human cathepsin G was compared with mouse wild type and humanized active site mutants, revealing that mouse primary specificity is markedly narrower than that of human cathepsin G, with much greater Tyr activity and selectivity and near absence of tryptic activity. It also differs from human in resisting tryptic peptidase inhibitors (e.g., aprotinin), while favoring angiotensin destruction at Tyr4 over activation at Phe8. Ala226Glu mutants of mouse cathepsin G acquire tryptic activity and human ability to activate pro-urokinase. Phylogenetic analysis reveals that the Ala226Glu missense mutation appearing in primates 31–43 million years ago represented an apparently unprecedented way to create tryptic activity in a serine peptidase. We propose that tryptic activity is not an attribute of ancestral mammalian cathepsin G, which was primarily chymotryptic, and that primate-selective broadening of specificity opposed the general trend of increased specialization by immune peptidases and allowed acquisition of new functions. PMID:20889553

  9. Design of mutation-resistant HIV protease inhibitors with the substrate envelope hypothesis.

    PubMed

    Chellappan, Sripriya; Kiran Kumar Reddy, G S; Ali, Akbar; Nalam, Madhavi N L; Anjum, Saima Ghafoor; Cao, Hong; Kairys, Visvaldas; Fernandes, Miguel X; Altman, Michael D; Tidor, Bruce; Rana, Tariq M; Schiffer, Celia A; Gilson, Michael K

    2007-05-01

    There is a clinical need for HIV protease inhibitors that can evade resistance mutations. One possible approach to designing such inhibitors relies upon the crystallographic observation that the substrates of HIV protease occupy a rather constant region within the binding site. In particular, it has been hypothesized that inhibitors which lie within this region will tend to resist clinically relevant mutations. The present study offers the first prospective evaluation of this hypothesis, via computational design of inhibitors predicted to conform to the substrate envelope, followed by synthesis and evaluation against wild-type and mutant proteases, as well as structural studies of complexes of the designed inhibitors with HIV protease. The results support the utility of the substrate envelope hypothesis as a guide to the design of robust protease inhibitors. PMID:17539822

  10. In vitro Isolation and Identification of Human Immunodeficiency Virus (HIV) Variants with Reduced Sensitivity to C-2 Symmetrical Inhibitors of HIV Type 1 Protease

    NASA Astrophysics Data System (ADS)

    Otto, M. J.; Garber, S.; Winslow, D. L.; Reid, C. D.; Aldrich, P.; Jadhav, P. K.; Patterson, C. E.; Hodge, C. N.; Cheng, Y.-S. E.

    1993-08-01

    Protease inhibitors are another class of compounds for treatment of human immunodeficiency virus (HIV)-caused disease. The emergence of resistance to the current anti-HIV drugs makes the determination of potential resistance to protease inhibitors imperative. Here we describe the isolation of an HIV type 1 (HIV-1) resistant to an HIV-protease inhibitor. Serial passage of HIV-1 (strain RF) in the presence of the inhibitor, [2-pyridylacetylisoleucylphenylalanyl-psi(CHOH)]_2 (P9941), failed to yield a stock of virus with a resistance phenotype. However, variants of the virus with 6- to 8-fold reduced sensitivity to P9941 were selected by using a combination of plaque assay and endpoint titration. Genetic analysis and computer modeling of the variant proteases revealed a single change in the codon for amino acid 82 (Val -> Ala), which resulted in a protease with lower affinity and reduced sensitivity to this inhibitor and certain, but not all, related inhibitors.

  11. Impact of Stereochemistry on Ligand Binding: X-ray Crystallographic Analysis of an Epoxide-Based HIV Protease Inhibitor.

    PubMed

    Benedetti, Fabio; Berti, Federico; Campaner, Pietro; Fanfoni, Lidia; Demitri, Nicola; Olajuyigbe, Folasade M; De March, Matteo; Geremia, Silvano

    2014-09-11

    A new pseudopeptide epoxide inhibitor, designed for irreversible binding to HIV protease (HIV-PR), has been synthesized and characterized in solution and in the solid state. However, the crystal structure of the complex obtained by inhibitor-enzyme cocrystallization revealed that a minor isomer, with inverted configuration of the epoxide carbons, has been selected by HIV-PR during crystallization. The structural characterization of the well-ordered pseudopeptide, inserted in the catalytic channel with its epoxide group intact, provides deeper insights into inhibitor binding and HIV-PR stereoselectivity, which aids development of future epoxide-based HIV inhibitors. PMID:25221650

  12. Novel indole-3-sulfonamides as potent HIV non-nucleoside reverse transcriptase inhibitors (NNRTIs)

    SciTech Connect

    Zhao, Zhijian; Wolkenberg, Scott E.; Lu, Meiqing; Munshi, Vandna; Moyer, Gregory; Feng, Meizhen; Carella, Anthony V.; Ecto, Linda T.; Gabryelski, Lori J.; Lai, Ming-Tain; Prasad, Sridar G.; Yan, Youwei; McGaughey, Georgia B.; Miller, Michael D.; Lindsley, Craig W.; Hartman, George D.; Vacca, Joseph P.; Williams, Theresa M.

    2008-09-29

    This Letter describes the design, synthesis, and biological evaluation of novel 3-indole sulfonamides as potent non-nucleoside reverse transcriptase inhibitors (NNRTIs) with balanced profiles against common HIV RT mutants K103N and Y181C.

  13. De novo design and discovery of potent, nonpeptidal HIV-1 protease inhibitors

    SciTech Connect

    Lam, P.Y.S.; Eyermann, C.J.; Hodge, C.N.; Jadhav, P.K.; Ru, Yu; Bacheler, L.T.; Meek, J.L.; Otto, M.J.; Rayner, M.M.; Wong, N.Y.; Chang, C.H.; Weber, P.C.; Jackson, D.A.; Sharpe, T.R.; Erickson-Viitanen, S.K.

    1993-12-31

    Intense worldwide research in HIV-1 protease inhibition has resulted in many inhibitors with nanomolar Ki. However, they are mostly pseudopeptides (containing amide bonds) and substrate-like. In this work the authors report that using 3-D database searching, computer modeling and x-ray structures of the HIV-1 protease/inhibitor complex, a completely novel class of potent nonpeptides has been designed and synthesized. The Ki is in the subnanomolar range and the IC90 for the cell assays in the submicromolar range. Confirmation of the mode of binding was achieved by a high resolution x-ray structure of a HIV-1 protease/inhibitor complex. Molecular recognition studies between HIV-1 protease and these inhibitors will also be discussed.

  14. Triggering HIV polyprotein processing by light using rapid photodegradation of a tight-binding protease inhibitor.

    PubMed

    Schimer, Jiří; Pávová, Marcela; Anders, Maria; Pachl, Petr; Šácha, Pavel; Cígler, Petr; Weber, Jan; Majer, Pavel; Řezáčová, Pavlína; Kräusslich, Hans-Georg; Müller, Barbara; Konvalinka, Jan

    2015-01-01

    HIV protease (PR) is required for proteolytic maturation in the late phase of HIV replication and represents a prime therapeutic target. The regulation and kinetics of viral polyprotein processing and maturation are currently not understood in detail. Here we design, synthesize, validate and apply a potent, photodegradable HIV PR inhibitor to achieve synchronized induction of proteolysis. The compound exhibits subnanomolar inhibition in vitro. Its photolabile moiety is released on light irradiation, reducing the inhibitory potential by 4 orders of magnitude. We determine the structure of the PR-inhibitor complex, analyze its photolytic products, and show that the enzymatic activity of inhibited PR can be fully restored on inhibitor photolysis. We also demonstrate that proteolysis of immature HIV particles produced in the presence of the inhibitor can be rapidly triggered by light enabling thus to analyze the timing, regulation and spatial requirements of viral processing in real time. PMID:25751579

  15. Triggering HIV polyprotein processing by light using rapid photodegradation of a tight-binding protease inhibitor

    PubMed Central

    Schimer, Jiří; Pávová, Marcela; Anders, Maria; Pachl, Petr; Šácha, Pavel; Cígler, Petr; Weber, Jan; Majer, Pavel; Řezáčová, Pavlína; Kräusslich, Hans-Georg; Müller, Barbara; Konvalinka, Jan

    2015-01-01

    HIV protease (PR) is required for proteolytic maturation in the late phase of HIV replication and represents a prime therapeutic target. The regulation and kinetics of viral polyprotein processing and maturation are currently not understood in detail. Here we design, synthesize, validate and apply a potent, photodegradable HIV PR inhibitor to achieve synchronized induction of proteolysis. The compound exhibits subnanomolar inhibition in vitro. Its photolabile moiety is released on light irradiation, reducing the inhibitory potential by 4 orders of magnitude. We determine the structure of the PR-inhibitor complex, analyze its photolytic products, and show that the enzymatic activity of inhibited PR can be fully restored on inhibitor photolysis. We also demonstrate that proteolysis of immature HIV particles produced in the presence of the inhibitor can be rapidly triggered by light enabling thus to analyze the timing, regulation and spatial requirements of viral processing in real time. PMID:25751579

  16. Structural Evidence for Effectiveness of Darunavir and Two Related Antiviral Inhibitors against HIV-2 Protease

    SciTech Connect

    Kovalevsky, Andrey Y.; Louis, John M.; Aniana, Annie; Ghosh, Arun K.; Weber, Irene T.

    2008-12-08

    No drug has been targeted specifically for HIV-2 (human immunodeficiency virus type 2) infection despite its increasing prevalence worldwide. The antiviral HIV-1 (human immunodeficiency virus type 1) protease (PR) inhibitor darunavir and the chemically related GRL98065 and GRL06579A were designed with the same chemical scaffold and different substituents at P2 and P2' to optimize polar interactions for HIV-1 PR (PR1). These inhibitors are also effective antiviral agents for HIV-2-infected cells. Therefore, crystal structures of HIV-2 PR (PR2) complexes with the three inhibitors have been solved at 1.2-{angstrom} resolution to analyze the molecular basis for their antiviral potency. Unusually, the crystals were grown in imidazole and zinc acetate buffer, which formed interactions with the PR2 and the inhibitors. Overall, the structures were very similar to the corresponding inhibitor complexes of PR1 with an RMSD of 1.1 {angstrom} on main-chain atoms. Most hydrogen-bond and weaker C-H...O interactions with inhibitors were conserved in the PR2 and PR1 complexes, except for small changes in interactions with water or disordered side chains. Small differences were observed in the hydrophobic contacts for the darunavir complexes, in agreement with relative inhibition of the two PRs. These near-atomic-resolution crystal structures verify the inhibitor potency for PR1 and PR2 and will provide the basis for the development of antiviral inhibitors targeting PR2.

  17. Critical differences in HIV-1 and HIV-2 protease specificity for clinical inhibitors

    SciTech Connect

    Tie, Yunfeng; Wang, Yuan-Fang; Boross, Peter I.; Chiu, Ting-Yi; Ghosh, Arun K.; Tozser, Jozsef; Louis, John M.; Harrison, Robert W.; Weber, Irene T.

    2012-03-15

    Clinical inhibitor amprenavir (APV) is less effective on HIV-2 protease (PR{sub 2}) than on HIV-1 protease (PR{sub 1}). We solved the crystal structure of PR{sub 2} with APV at 1.5 {angstrom} resolution to identify structural changes associated with the lowered inhibition. Furthermore, we analyzed the PR{sub 1} mutant (PR{sub 1M}) with substitutions V32I, I47V, and V82I that mimic the inhibitor binding site of PR{sub 2}. PR{sub 1M} more closely resembled PR{sub 2} than PR{sub 1} in catalytic efficiency on four substrate peptides and inhibition by APV, whereas few differences were seen for two other substrates and inhibition by saquinavir (SQV) and darunavir (DRV). High resolution crystal structures of PR{sub 1M} with APV, DRV, and SQV were compared with available PR{sub 1} and PR{sub 2} complexes. Val/Ile32 and Ile/Val47 showed compensating interactions with SQV in PR{sub 1M} and PR{sub 1}, however, Ile82 interacted with a second SQV bound in an extension of the active site cavity of PR{sub 1M}. Residues 32 and 82 maintained similar interactions with DRV and APV in all the enzymes, whereas Val47 and Ile47 had opposing effects in the two subunits. Significantly diminished interactions were seen for the aniline of APV bound in PR{sub 1M} and PR{sub 2} relative to the strong hydrogen bonds observed in PR{sub 1}, consistent with 15- and 19-fold weaker inhibition, respectively. Overall, PR{sub 1M} partially replicates the specificity of PR{sub 2} and gives insight into drug resistant mutations at residues 32, 47, and 82. Moreover, this analysis provides a structural explanation for the weaker antiviral effects of APV on HIV-2.

  18. Integrase Inhibitor Prodrugs: Approaches to Enhancing the Anti-HIV Activity of β-Diketo Acids.

    PubMed

    Nair, Vasu; Okello, Maurice

    2015-01-01

    HIV integrase, encoded at the 3'-end of the HIV pol gene, is essential for HIV replication. This enzyme catalyzes the incorporation of HIV DNA into human DNA, which represents the point of "no-return" in HIV infection. Integrase is a significant target in anti-HIV drug discovery. This review article focuses largely on the design of integrase inhibitors that are β-diketo acids constructed on pyridinone scaffolds. Methodologies for synthesis of these compounds are discussed. Integrase inhibition data for the strand transfer (ST) step are compared with in vitro anti-HIV data. The review also examines the issue of the lack of correlation between the ST enzymology data and anti-HIV assay results. Because this disconnect appeared to be a problem associated with permeability, prodrugs of these inhibitors were designed and synthesized. Prodrugs dramatically improved the anti-HIV activity data. For example, for compound, 96, the anti-HIV activity (EC50) improved from 500 nM for this diketo acid to 9 nM for its prodrug 116. In addition, there was excellent correlation between the IC50 and IC90 ST enzymology data for 96 (6 nM and 97 nM, respectively) and the EC50 and EC90 anti-HIV data for its prodrug 116 (9 nM and 94 nM, respectively). Finally, it was confirmed that the prodrug 116 was rapidly hydrolyzed in cells to the active compound 96. PMID:26184144

  19. Enantioselective Synthesis of Dioxatriquinane Structural Motifs for HIV-1 Protease Inhibitors Using a Cascade Radical Cyclization†

    PubMed Central

    Ghosh, Arun K.; Xu, Chun-Xiao; Osswald, Heather L.

    2015-01-01

    Synthesis of novel HIV-1 protease inhibitors incorporating dioxatriquinane-derived P2-ligands is described. The tricyclic ligand alcohol contains five contiguous chiral centers. The ligand alcohols were prepared in optically active form by an enzymatic asymmetrization of mesodiacetate, cascade radical cyclization, and Lewis acid catalyzed reduction as the key steps. Inhibitors with dioxatriquinane-derived P2-ligands exhibited low nanomolar HIV-1 protease activity. PMID:26185337

  20. Evolutionary families of peptidases.

    PubMed Central

    Rawlings, N D; Barrett, A J

    1993-01-01

    The available amino acid sequences of peptidases have been examined, and the enzymes have been allocated to evolutionary families. Some of the families can be grouped together in 'clans' that show signs of distant relationship, but nevertheless, it appears that there may be as many as 60 evolutionary lines of peptidases with separate origins. Some of these contain members with quite diverse peptidase activities, and yet there are some striking examples of convergence. We suggest that the classification by families could be used as an extension of the current classification by catalytic type. PMID:8439290

  1. HIV-1 protease mutations and protease inhibitor cross-resistance.

    PubMed

    Rhee, Soo-Yon; Taylor, Jonathan; Fessel, W Jeffrey; Kaufman, David; Towner, William; Troia, Paolo; Ruane, Peter; Hellinger, James; Shirvani, Vivian; Zolopa, Andrew; Shafer, Robert W

    2010-10-01

    The effects of many protease inhibitor (PI)-selected mutations on the susceptibility to individual PIs are unknown. We analyzed in vitro susceptibility test results on 2,725 HIV-1 protease isolates. More than 2,400 isolates had been tested for susceptibility to fosamprenavir, indinavir, nelfinavir, and saquinavir; 2,130 isolates had been tested for susceptibility to lopinavir; 1,644 isolates had been tested for susceptibility to atazanavir; 1,265 isolates had been tested for susceptibility to tipranavir; and 642 isolates had been tested for susceptibility to darunavir. We applied least-angle regression (LARS) to the 200 most common mutations in the data set and identified a set of 46 mutations associated with decreased PI susceptibility of which 40 were not polymorphic in the eight most common HIV-1 group M subtypes. We then used least-squares regression to ascertain the relative contribution of each of these 46 mutations. The median number of mutations associated with decreased susceptibility to each PI was 28 (range, 19 to 32), and the median number of mutations associated with increased susceptibility to each PI was 2.5 (range, 1 to 8). Of the mutations with the greatest effect on PI susceptibility, I84AV was associated with decreased susceptibility to eight PIs; V32I, G48V, I54ALMSTV, V82F, and L90M were associated with decreased susceptibility to six to seven PIs; I47A, G48M, I50V, L76V, V82ST, and N88S were associated with decreased susceptibility to four to five PIs; and D30N, I50L, and V82AL were associated with decreased susceptibility to fewer than four PIs. This study underscores the greater impact of nonpolymorphic mutations compared with polymorphic mutations on decreased PI susceptibility and provides a comprehensive quantitative assessment of the effects of individual mutations on susceptibility to the eight clinically available PIs. PMID:20660676

  2. Identification of mechanistically distinct inhibitors of HIV-1 reverse transcriptase through fragment screening.

    PubMed

    La, Jennifer; Latham, Catherine F; Tinetti, Ricky N; Johnson, Adam; Tyssen, David; Huber, Kelly D; Sluis-Cremer, Nicolas; Simpson, Jamie S; Headey, Stephen J; Chalmers, David K; Tachedjian, Gilda

    2015-06-01

    Fragment-based screening methods can be used to discover novel active site or allosteric inhibitors for therapeutic intervention. Using saturation transfer difference (STD) NMR and in vitro activity assays, we have identified fragment-sized inhibitors of HIV-1 reverse transcriptase (RT) with distinct chemical scaffolds and mechanisms compared to nonnucleoside RT inhibitors (NNRTIs) and nucleoside/nucleotide RT inhibitors (NRTIs). Three compounds were found to inhibit RNA- and DNA-dependent DNA polymerase activity of HIV-1 RT in the micromolar range while retaining potency against RT variants carrying one of three major NNRTI resistance mutations: K103N, Y181C, or G190A. These compounds also inhibit Moloney murine leukemia virus RT but not the Klenow fragment of Escherichia coli DNA polymerase I. Steady-state kinetic analyses demonstrate that one of these fragments is a competitive inhibitor of HIV-1 RT with respect to deoxyribonucleoside triphosphate (dNTP) substrate, whereas a second compound is a competitive inhibitor of RT polymerase activity with respect to the DNA template/primer (T/P), and consequently also inhibits RNase H activity. The dNTP competing RT inhibitor retains activity against the NRTI-resistant mutants K65R and M184V, demonstrating a drug resistance profile distinct from the nucleotide competing RT inhibitors indolopyridone-1 (INDOPY-1) and 4-dimethylamino-6-vinylpyrimidine-1 (DAVP-1). In antiviral assays, the T/P competing compound inhibits HIV-1 replication at a step consistent with an RT inhibitor. Screening of additional structurally related compounds to the three fragments led to the discovery of molecules with improved potency against HIV-1 RT. These fragment inhibitors represent previously unidentified scaffolds for development of novel drugs for HIV-1 prevention or treatment. PMID:26038551

  3. Identification of mechanistically distinct inhibitors of HIV-1 reverse transcriptase through fragment screening

    PubMed Central

    La, Jennifer; Latham, Catherine F.; Tinetti, Ricky N.; Johnson, Adam; Tyssen, David; Huber, Kelly D.; Sluis-Cremer, Nicolas; Simpson, Jamie S.; Headey, Stephen J.; Chalmers, David K.; Tachedjian, Gilda

    2015-01-01

    Fragment-based screening methods can be used to discover novel active site or allosteric inhibitors for therapeutic intervention. Using saturation transfer difference (STD) NMR and in vitro activity assays, we have identified fragment-sized inhibitors of HIV-1 reverse transcriptase (RT) with distinct chemical scaffolds and mechanisms compared to nonnucleoside RT inhibitors (NNRTIs) and nucleoside/nucleotide RT inhibitors (NRTIs). Three compounds were found to inhibit RNA- and DNA-dependent DNA polymerase activity of HIV-1 RT in the micromolar range while retaining potency against RT variants carrying one of three major NNRTI resistance mutations: K103N, Y181C, or G190A. These compounds also inhibit Moloney murine leukemia virus RT but not the Klenow fragment of Escherichia coli DNA polymerase I. Steady-state kinetic analyses demonstrate that one of these fragments is a competitive inhibitor of HIV-1 RT with respect to deoxyribonucleoside triphosphate (dNTP) substrate, whereas a second compound is a competitive inhibitor of RT polymerase activity with respect to the DNA template/primer (T/P), and consequently also inhibits RNase H activity. The dNTP competing RT inhibitor retains activity against the NRTI-resistant mutants K65R and M184V, demonstrating a drug resistance profile distinct from the nucleotide competing RT inhibitors indolopyridone-1 (INDOPY-1) and 4-dimethylamino-6-vinylpyrimidine-1 (DAVP-1). In antiviral assays, the T/P competing compound inhibits HIV-1 replication at a step consistent with an RT inhibitor. Screening of additional structurally related compounds to the three fragments led to the discovery of molecules with improved potency against HIV-1 RT. These fragment inhibitors represent previously unidentified scaffolds for development of novel drugs for HIV-1 prevention or treatment. PMID:26038551

  4. Structure-Based Design of Novel HIV-1 Protease Inhibitors to Combat Drug Resistance

    SciTech Connect

    Ghosh,A.; Sridhar, P.; Leshchenko, S.; Hussain, A.; Li, J.; Kovalevsky, A.; Walters, D.; Wedelind, J.; Grum-Tokars, V.; et al.

    2006-01-01

    Structure-based design and synthesis of novel HIV protease inhibitors are described. The inhibitors are designed specifically to interact with the backbone of HIV protease active site to combat drug resistance. Inhibitor 3 has exhibited exceedingly potent enzyme inhibitory and antiviral potency. Furthermore, this inhibitor maintains impressive potency against a wide spectrum of HIV including a variety of multi-PI-resistant clinical strains. The inhibitors incorporated a stereochemically defined 5-hexahydrocyclopenta[b]furanyl urethane as the P2-ligand into the (R)-(hydroxyethylamino)sulfonamide isostere. Optically active (3aS,5R,6aR)-5-hydroxy-hexahydrocyclopenta[b]furan was prepared by an enzymatic asymmetrization of meso-diacetate with acetyl cholinesterase, radical cyclization, and Lewis acid-catalyzed anomeric reduction as the key steps. A protein-ligand X-ray crystal structure of inhibitor 3-bound HIV-1 protease (1.35 Angstroms resolution) revealed extensive interactions in the HIV protease active site including strong hydrogen bonding interactions with the backbone. This design strategy may lead to novel inhibitors that can combat drug resistance.

  5. Four Amino Acid Changes in HIV-2 Protease Confer Class-Wide Sensitivity to Protease Inhibitors

    PubMed Central

    Smith, Robert A.; Gottlieb, Geoffrey S.

    2015-01-01

    ABSTRACT Protease is essential for retroviral replication, and protease inhibitors (PI) are important for treating HIV infection. HIV-2 exhibits intrinsic resistance to most FDA-approved HIV-1 PI, retaining clinically useful susceptibility only to lopinavir, darunavir, and saquinavir. The mechanisms for this resistance are unclear; although HIV-1 and HIV-2 proteases share just 38 to 49% sequence identity, all critical structural features of proteases are conserved. Structural studies have implicated four amino acids in the ligand-binding pocket (positions 32, 47, 76, and 82). We constructed HIV-2ROD9 molecular clones encoding the corresponding wild-type HIV-1 amino acids (I32V, V47I, M76L, and I82V) either individually or together (clone PRΔ4) and compared the phenotypic sensitivities (50% effective concentration [EC50]) of mutant and wild-type viruses to nine FDA-approved PI. Single amino acid replacements I32V, V47I, and M76L increased the susceptibility of HIV-2 to multiple PI, but no single change conferred class-wide sensitivity. In contrast, clone PRΔ4 showed PI susceptibility equivalent to or greater than that of HIV-1 for all PI. We also compared crystallographic structures of wild-type HIV-1 and HIV-2 proteases complexed with amprenavir and darunavir to models of the PRΔ4 enzyme. These models suggest that the amprenavir sensitivity of PRΔ4 is attributable to stabilizing enzyme-inhibitor interactions in the P2 and P2′ pockets of the protease dimer. Together, our results show that the combination of four amino acid changes in HIV-2 protease confer a pattern of PI susceptibility comparable to that of HIV-1, providing a structural rationale for intrinsic HIV-2 PI resistance and resolving long-standing questions regarding the determinants of differential PI susceptibility in HIV-1 and HIV-2. IMPORTANCE Proteases are essential for retroviral replication, and HIV-1 and HIV-2 proteases share a great deal of structural similarity. However, only three of nine

  6. MEROPS: the peptidase database

    PubMed Central

    Rawlings, Neil D.; Barrett, Alan J.

    2000-01-01

    Important additions have been made to the MEROPS database (http://www.bi.bbsrc.ac.uk/Merops/Merops.htm ). These include sequence alignments and cladograms for many of the families of peptidases, and these have proved very helpful in the difficult task of distinguishing the sequences of peptidases that are simply species variants of already known enzymes from those that represent novel enzymes. PMID:10592261

  7. Solubility profiling of HIV protease inhibitors in human intestinal fluids.

    PubMed

    Wuyts, Benjamin; Brouwers, Joachim; Mols, Raf; Tack, Jan; Annaert, Pieter; Augustijns, Patrick

    2013-10-01

    The present study pursued to profile the intestinal solubility of nine HIV protease inhibitors (PIs) in fasted- and fed-state human intestinal fluids (FaHIF, FeHIF) aspirated from four volunteers. In addition, the ability of fasted- and fed-state simulated intestinal fluids (FaSSIF, FeSSIF) to predict the intestinal solubility was evaluated. All PIs were poorly soluble in FaHIF (from 7 μM for ritonavir to 327 μM for darunavir) and FeHIF (from 15 μM for atazanavir to 409μM for darunavir). For four of nine PIs, food intake significantly enhanced the solubilizing capacity of intestinal fluids (up to 18.4-fold increase for ritonavir). The intersubject variability (average coefficient of variance CVfed = 60.6%, CVfasted = 40.4%) was higher as compared with the intrasubject variability (CVfed = 41.3%, CVfasted = 20.5%). PI solubilities correlated reasonably well between FaSSIF and FaHIF (R = 0.817), but not between FeSSIF and FeHIF (R = 0.617). To conclude, postprandial conditions increased the inter- and intrasubject variability of the PIs. The inability of FeSSIF to accurately predict the FeHIF solubility emphasizes the need for a multivariate approach to determine solubility profiles, taking into account solid-state characteristics, pH, mixed bile acid/phospholipid micelles, and digestive products. PMID:23939880

  8. Structural investigation of HIV-1 nonnucleoside reverse transcriptase inhibitors: 2-Aryl-substituted benzimidazoles

    NASA Astrophysics Data System (ADS)

    Ziółkowska, Natasza E.; Michejda, Christopher J.; Bujacz, Grzegorz D.

    2009-11-01

    Acquired immunodeficiency syndrome (AIDS) caused by the human immunodeficiency virus (HIV) is one of the most destructive epidemics in history. Inhibitors of HIV enzymes are the main targets to develop drugs against that disease. Nonnucleoside reverse transcriptase inhibitors of HIV-1 (NNRTIs) are potentially effective and nontoxic. Structural studies provide information necessary to design more active compounds. The crystal structures of four NNRTI derivatives of 2-aryl-substituted N-benzyl-benzimidazole are presented here. Analysis of the geometrical parameters shows that the structures of the investigated inhibitors are rigid. The important geometrical parameter is the dihedral angle between the planes of the π-electron systems of the benzymidazole and benzyl moieties. The values of these dihedral angles are in a narrow range for all investigated inhibitors. There is no significant difference between the structure of the free inhibitor and the inhibitor in the complex with RT HIV-1. X-ray structures of the investigated inhibitors are a good basis for modeling enzyme-inhibitor interactions in rational drug design.

  9. Comparative docking and CoMFA analysis of curcumine derivatives as HIV-1 integrase inhibitors.

    PubMed

    Gupta, Pawan; Garg, Prabha; Roy, Nilanjan

    2011-08-01

    The docking studies and comparative molecular field analysis (CoMFA) were performed on highly active molecules of curcumine derivatives against 3' processing activity of HIV-1 integrase (IN) enzyme. The optimum CoMFA model was selected with statistically significant cross-validated r(2) value of 0.815 and non-cross validated r (2) value of 0.99. The common pharmacophore of highly active molecules was used for screening of HIV-1 IN inhibitors. The high contribution of polar interactions in pharmacophore mapping is well supported by docking and CoMFA results. The results of docking, CoMFA, and pharmacophore mapping give structural insights as well as important binding features of curcumine derivatives as HIV-1 IN inhibitors which can provide guidance for the rational design of novel HIV-1 IN inhibitors. PMID:21327540

  10. Substituted indoles as HIV-1 non-nucleoside reverse transcriptase inhibitors: a patent evaluation (WO2015044928).

    PubMed

    Li, Xiao; Gao, Ping; Zhan, Peng; Liu, Xinyong

    2016-05-01

    The invention described in this patent (WO2015044928) is related to compounds based on the substituted indole scaffold, their synthetic process and application to inhibit HIV-1 replication as non-nucleoside reverse transcriptase inhibitors (NNRTIs). Some of the newly claimed compounds presented improved potency against wild-type (WT) HIV-1 strain in comparison to previously disclosed indole-based NNRTIs and were also shown to be effective against common resistant HIV-1 strains. In light of their novel structural characteristics, simple synthetic route and improved anti-HIV activity, these compounds deserve further study as promising NNRTIs. PMID:26742549

  11. Basic Quinolinonyl Diketo Acid Derivatives as Inhibitors of HIV Integrase and their Activity against RNase H Function of Reverse Transcriptase

    PubMed Central

    2015-01-01

    A series of antiviral basic quinolinonyl diketo acid derivatives were developed as inhibitors of HIV-1 IN. Compounds 12d,f,i inhibited HIV-1 IN with IC50 values below 100 nM for strand transfer and showed a 2 order of magnitude selectivity over 3′-processing. These strand transfer selective inhibitors also inhibited HIV-1 RNase H with low micromolar potencies. Molecular modeling studies based on both the HIV-1 IN and RNase H catalytic core domains provided new structural insights for the future development of these compounds as dual HIV-1 IN and RNase H inhibitors. PMID:24684270

  12. Evaluation of the substrate envelope hypothesis for inhibitors of HIV-1 protease.

    PubMed

    Chellappan, Sripriya; Kairys, Visvaldas; Fernandes, Miguel X; Schiffer, Celia; Gilson, Michael K

    2007-08-01

    Crystallographic data show that various substrates of HIV protease occupy a remarkably uniform region within the binding site; this region has been termed the substrate envelope. It has been suggested that an inhibitor that fits within the substrate envelope should tend to evade viral resistance because a protease mutation that reduces the affinity of the inhibitor will also tend to reduce the affinity of substrate, and will hence decrease the activity of the enzyme. Accordingly, inhibitors that fit the substrate envelope better should be less susceptible to clinically observed resistant mutations, since these must also allow substrates to bind. The present study describes a quantitative measure of the volume of a bound inhibitor falling outside the substrate envelope, and observes that this quantity correlates with the inhibitor's losses in affinity to clinically relevant mutants. This measure may thus be useful as a penalty function in the design of robust HIV protease inhibitors. PMID:17474129

  13. Impact of protease inhibitors on intracellular concentration of tenofovir-diphosphate among HIV-1 infected patients

    PubMed Central

    Lahiri, Cecile D.; Tao, Sijia; Jiang, Yong; Sheth, Anandi N.; Acosta, Edward P.; Marconi, Vincent C.; Armstrong, Wendy S.; Schinazi, Raymond F.; Vunnava, Aswani; Sanford, Sara; Ofotokun, Ighovwerha

    2015-01-01

    Intracellular nucleoside reverse transcriptase inhibitor (NRTI) concentrations are associated with plasma HIV-1 response. Coadministration of protease inhibitors with NRTIs can affect intra-cellular concentrations due to protease inhibitor inhibition of efflux transporters. Tenofovir-diphosphate (TFV-DP) concentrations within peripheral blood mononuclear cells were compared among individuals receiving either atazanavir or darunavir-based regimens. There was a trend towards higher TFV-DP concentrations among women and among participants receiving atazanavir. TFV-DP intracellular concentrations were positively associated with undetectable plasma HIV-1 RNA. PMID:25870991

  14. Akt inhibitors as an HIV-1 infected macrophage-specific anti-viral therapy

    PubMed Central

    Chugh, Pauline; Bradel-Tretheway, Birgit; Monteiro-Filho, Carlos MR; Planelles, Vicente; Maggirwar, Sanjay B; Dewhurst, Stephen; Kim, Baek

    2008-01-01

    Background Unlike CD4+ T cells, HIV-1 infected macrophages exhibit extended life span even upon stress, consistent with their in vivo role as long-lived HIV-1 reservoirs. Results Here, we demonstrate that PI3K/Akt inhibitors, including clinically available Miltefosine, dramatically reduced HIV-1 production from long-living virus-infected macrophages. These PI3K/Akt inhibitors hyper-sensitize infected macrophages to extracellular stresses that they are normally exposed to, and eventually lead to cell death of infected macrophages without harming uninfected cells. Based on the data from these Akt inhibitors, we were able to further investigate how HIV-1 infection utilizes the PI3K/Akt pathway to establish the cytoprotective effect of HIV-1 infection, which extends the lifespan of infected macrophages, a key viral reservoir. First, we found that HIV-1 infection activates the well characterized pro-survival PI3K/Akt pathway in primary human macrophages, as reflected by decreased PTEN protein expression and increased Akt kinase activity. Interestingly, the expression of HIV-1 or SIV Tat is sufficient to mediate this cytoprotective effect, which is dependent on the basic domain of Tat – a region that has previously been shown to bind p53. Next, we observed that this interaction appears to contribute to the downregulation of PTEN expression, since HIV-1 Tat was found to compete with PTEN for p53 binding; this is known to result in p53 destabilization, with a consequent reduction in PTEN protein production. Conclusion Since HIV-1 infected macrophages display highly elevated Akt activity, our results collectively show that PI3K/Akt inhibitors may be a novel therapy for interfering with the establishment of long-living HIV-1 infected reservoirs. PMID:18237430

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

    PubMed

    Gill, Iqbal; Patel, Ramesh

    2006-02-01

    An efficient biocatalytic method has been developed for the conversion of (5S)-4,5-dihydro-1H-pyrrole-1,5-dicarboxylic acid, 1-(1,1-dimethylethyl)-5-ethyl ester (1) into the corresponding amide (5S)-5-aminocarbonyl-4,5-dihydro-1H-pyrrole-1-carboxylic acid, 1-(1,1-dimethylethyl)ester (2), which is a critical intermediate in the synthesis of the dipeptidyl peptidase IV (DPP4) inhibitor Saxagliptin (3). Candida antartica lipase B mediates ammonolysis of the ester with ammonium carbamate as ammonia donor to yield up to 71% of the amide. The inclusion of Ascarite and calcium chloride as adsorbents for carbon dioxide and ethanol byproducts, respectively, increases the yield to 98%, thereby offering an efficient and practical alternative to chemical routes which yield 57-64%. PMID:16257208

  16. Sargassum fusiforme fraction is a potent and specific inhibitor of HIV-1 fusion and reverse transcriptase

    PubMed Central

    Paskaleva, Elena E; Lin, Xudong; Duus, Karen; McSharry, James J; Veille, Jean-Claude L; Thornber, Carol; Liu, Yanze; Lee, David Yu-Wei; Canki, Mario

    2008-01-01

    Sargassum fusiforme (Harvey) Setchell has been shown to be a highly effective inhibitor of HIV-1 infection. To identify its mechanism of action, we performed bioactivity-guided fractionation on Sargassum fusiforme mixture. Here, we report isolation of a bioactive fraction SP4-2 (S. fusiforme), which at 8 μg/ml inhibited HIV-1 infection by 86.9%, with IC50 value of 3.7 μg. That represents 230-fold enhancement of antiretroviral potency as compared to the whole extract. Inhibition was mediated against both CXCR4 (X4) and CCR5 (R5) tropic HIV-1. Specifically, 10 μg/ml SP4-2 blocked HIV-1 fusion and entry by 53%. This effect was reversed by interaction of SP4-2 with sCD4, suggesting that S. fusiforme inhibits HIV-1 infection by blocking CD4 receptor, which also explained observed inhibition of both X4 and R5-tropic HIV-1. SP4-2 also inhibited HIV-1 replication after virus entry, by directly inhibiting HIV-1 reverse transcriptase (RT) in a dose dependent manner by up to 79%. We conclude that the SP4-2 fraction contains at least two distinct and biologically active molecules, one that inhibits HIV-1 fusion by interacting with CD4 receptor, and another that directly inhibits HIV-1 RT. We propose that S. fusiforme is a lead candidate for anti-HIV-1 drug development. PMID:18197976

  17. Pyrroloaryls and pyrroloheteroaryls: Inhibitors of the HIV fusion/attachment, reverse transcriptase and integrase.

    PubMed

    Patel, Rahul V; Park, Se Won

    2015-09-01

    Heterocyclic compounds execute a very important role in drug design and discovery. This article provides the basic milestones of the research for pyrroloaryl and pyrroloheteroaryl based components targeting HIV viral replication cycle. Anti-HIV activity is elaborated for several classes of pyrrolo-compounds as pyrrolopyridines, pyrrolopyrimidines, pyrrolopyridazines, pyrrolobenzodiazepinones, pyrrolobenzothiazepines, pyrrolobenzoxazepinones, pyrrolophenanthridines, pyrroloquinoxalines, pyrrolotriazines, pyrroloquinolines, pyrrolopyrazinones, pyrrolothiatriazines, arylthiopyrroles and pyrrolopyrazolones targeting two essential HIV enzymes, reverse transcriptase and integrase as well as attachment/fusion of HIV virons to the host CD-4 cell. Such attempts were resulted in a discovery of highly potent anti-HIV agents suitable for clinical trials, for example, BMS-378806, BMS-585248, BMS-626529, BMS-663068, BMS-488043 and BMS-663749, etc. as anti-HIV attachment agents, triciribine, QX432, BI-1 and BI-2 as HIV RT inhibitors which are in preclinical or clinical development. Mechanism of action of compounds presented in this article towards the suppression of HIV attachment/fusion as well as against the activities of HIV enzymes reverse transcriptase and integrase has been discussed. Relationships of new compounds' molecular framework and HIV viral target has been overviewed in order to facilitate further construction of promising anti-HIV agents in future drug discovery process. PMID:26116177

  18. The Janus kinase inhibitor ruxolitinib reduces HIV replication in human macrophages and ameliorates HIV encephalitis in a murine model.

    PubMed

    Haile, Woldeab B; Gavegnano, Christina; Tao, Sijia; Jiang, Yong; Schinazi, Raymond F; Tyor, William R

    2016-08-01

    A hallmark of persistent HIV-1 infection in the central nervous system is increased activation of mononuclear phagocytes and surrounding astrogliosis, conferring persistent HIV-induced inflammation. This inflammation is believed to result in neuronal dysfunction and the clinical manifestations of HIV-associated neurocognitive disorders (HAND). The Jak/STAT pathway is activated in macrophages/myeloid cells upon HIV-1 infection, modulating many pro-inflammatory pathways that result in HAND, thereby representing an attractive cellular target. Thus, the impact of ruxolitinib, a Janus Kinase (Jak) 1/2 inhibitor that is FDA approved for myelofibrosis and polycythemia vera, was assessed for its potential to inhibit HIV-1 replication in macrophages and HIV-induced activation in monocytes/macrophages in culture. In addition, a murine model of HIV encephalitis (HIVE) was used to assess the impact of ruxolitinib on histopathological features of HIVE, brain viral load, as well as its ability to penetrate the blood-brain-barrier (BBB). Ruxolitinib was found to inhibit HIV-1 replication in macrophages, HIV-induced activation of monocytes (CD14/CD16) and macrophages (HLA-DR, CCR5, and CD163) without apparent toxicity. In vivo, systemically administered ruxolitinib was detected in the brain during HIVE in SCID mice and markedly inhibited astrogliosis. Together, these data indicate that ruxolitinib reduces HIV-induced activation and infiltration of monocytes/macrophages in vitro, reduces the replication of HIV in vitro, penetrates the BBB when systemically administered in mice and reduces astrogliosis in the brains of mice with HIVE. These data suggest that ruxolitinib will be useful as a novel therapeutic to treat humans with HAND. PMID:26851503

  19. Topical application of entry inhibitors as "virustats" to prevent sexual transmission of HIV infection

    PubMed Central

    Lederman, Michael M; Jump, Robin; Pilch-Cooper, Heather A; Root, Michael; Sieg, Scott F

    2008-01-01

    With the continuing march of the AIDS epidemic and little hope for an effective vaccine in the near future, work to develop a topical strategy to prevent HIV infection is increasingly important. This stated, the track record of large scale "microbicide" trials has been disappointing with nonspecific inhibitors either failing to protect women from infection or even increasing HIV acquisition. Newer strategies that target directly the elements needed for viral entry into cells have shown promise in non-human primate models of HIV transmission and as these agents have not yet been broadly introduced in regions of highest HIV prevalence, they are particularly attractive for prophylaxis. We review here the agents that can block HIV cellular entry and that show promise as topical strategies or "virustats" to prevent mucosal transmission of HIV infection PMID:19094217

  20. Inhibition Profiling of Retroviral Protease Inhibitors Using an HIV-2 Modular System.

    PubMed

    Mahdi, Mohamed; Szojka, Zsófia; Mótyán, János András; Tőzsér, József

    2015-12-01

    Retroviral protease inhibitors (PIs) are fundamental pillars in the treatment of HIV infection and acquired immunodeficiency syndrome (AIDS). Currently used PIs are designed against HIV-1, and their effect on HIV-2 is understudied. Using a modular HIV-2 protease cassette system, inhibition profiling assays were carried out for protease inhibitors both in enzymatic and cell culture assays. Moreover, the treatment-associated resistance mutations (I54M, L90M) were introduced into the modular system, and comparative inhibition assays were performed to determine their effect on the susceptibility of the protease. Our results indicate that darunavir, saquinavir, indinavir and lopinavir were very effective HIV-2 protease inhibitors, while tipranavir, nelfinavir and amprenavir showed a decreased efficacy. I54M, L90M double mutation resulted in a significant reduction in the susceptibility to most of the inhibitors with the exception of tipranavir. To our knowledge, this modular system constitutes a novel approach in the field of HIV-2 protease characterization and susceptibility testing. PMID:26633459

  1. Inhibitors of HIV-1 entry and integration: recent developments and impact on treatment.

    PubMed

    Sharma, Anil K; George, Varghese; Valiathan, Ranjini; Pilakka-Kanthikeel, Sudheesh; Pallikkuth, Suresh

    2013-05-01

    Advances in the drug development against HIV-1 have lead to the identification of new compounds which could be used to target cellular entry and nuclear integration of virus in addition to drugs that commonly target reverse transcriptase and protease. These additional targets have added a new dimension to fight against HIV. Cellular entry of HIV is a multistep procedure involving a range of cellular and molecular interactions between virus envelope protein and receptors expressed on the surface of the target cells, thus providing many opportunities to block infection. Some of these entry inhibitors are currently being used in the clinic and more compounds are under various stages of development. Integration of the HIV-1 DNA is required and essential to maintain the viral DNA in the infected cell. The design and discovery of integrase inhibitors were first focused at targeting the catalytic site of integrase that selectively acting on strand transfer and thus inhibits integration of virus DNA with host cell genome. Thus, entry and integrase inhibitors present a real added value in combined treatment against HIV infection. This review discusses the recent development in the discovery of inhibitors of HIV entry and integration along with some of recent patents in the field. PMID:23578097

  2. Inhibition Profiling of Retroviral Protease Inhibitors Using an HIV-2 Modular System

    PubMed Central

    Mahdi, Mohamed; Szojka, Zsófia; Mótyán, János András; Tőzsér, József

    2015-01-01

    Retroviral protease inhibitors (PIs) are fundamental pillars in the treatment of HIV infection and acquired immunodeficiency syndrome (AIDS). Currently used PIs are designed against HIV-1, and their effect on HIV-2 is understudied. Using a modular HIV-2 protease cassette system, inhibition profiling assays were carried out for protease inhibitors both in enzymatic and cell culture assays. Moreover, the treatment-associated resistance mutations (I54M, L90M) were introduced into the modular system, and comparative inhibition assays were performed to determine their effect on the susceptibility of the protease. Our results indicate that darunavir, saquinavir, indinavir and lopinavir were very effective HIV-2 protease inhibitors, while tipranavir, nelfinavir and amprenavir showed a decreased efficacy. I54M, L90M double mutation resulted in a significant reduction in the susceptibility to most of the inhibitors with the exception of tipranavir. To our knowledge, this modular system constitutes a novel approach in the field of HIV-2 protease characterization and susceptibility testing. PMID:26633459

  3. Elevated adiponectin prevents HIV protease inhibitor toxicity and preserves cerebrovascular homeostasis in mice.

    PubMed

    Dasuri, Kalavathi; Pepping, Jennifer K; Fernandez-Kim, Sun-Ok; Gupta, Sunita; Keller, Jeffrey N; Scherer, Philipp E; Bruce-Keller, Annadora J

    2016-06-01

    HIV protease inhibitors are key components of HIV antiretroviral therapies, which are fundamental in the treatment of HIV infection. However, the protease inhibitors are well-known to induce metabolic dysfunction which can in turn escalate the complications of HIV, including HIV associated neurocognitive disorders. As experimental and epidemiological data support a therapeutic role for adiponectin in both metabolic and neurologic homeostasis, this study was designed to determine if increased adiponectin could prevent the detrimental effects of protease inhibitors in mice. Adult male wild type (WT) and adiponectin-overexpressing (ADTg) mice were thus subjected to a 4-week regimen of lopinavir/ritonavir, followed by comprehensive metabolic, neurobehavioral, and neurochemical analyses. Data show that lopinavir/ritonavir-induced lipodystrophy, hypoadiponectinemia, hyperglycemia, hyperinsulinemia, and hypertriglyceridemia were attenuated in ADTg mice. Furthermore, cognitive function and blood-brain barrier integrity were preserved, while loss of cerebrovascular markers and white matter injury were prevented in ADTg mice. Finally, lopinavir/ritonavir caused significant increases in expression of markers of brain inflammation and decreases in synaptic markers in WT, but not in ADTg mice. Collectively, these data reinforce the pathophysiologic link from metabolic dysfunction to loss of cerebrovascular and cognitive homeostasis; and suggest that preservation and/or replacement of adiponectin could prevent these key aspects of HIV protease inhibitor-induced toxicity in clinical settings. PMID:26912411

  4. The BET inhibitor OTX015 reactivates latent HIV-1 through P-TEFb

    PubMed Central

    Lu, Panpan; Qu, Xiying; Shen, Yinzhong; Jiang, Zhengtao; Wang, Pengfei; Zeng, Hanxian; Ji, Haiyan; Deng, Junxiao; Yang, Xinyi; Li, Xian; Lu, Hongzhou; Zhu, Huanzhang

    2016-01-01

    None of the currently used anti-HIV-1 agents can effectively eliminate latent HIV-1 reservoirs, which is a major hurdle to a complete cure for AIDS. We report here that a novel oral BET inhibitor OTX015, a thienotriazolodiazepine compound that has entered phase Ib clinical development for advanced hematologic malignancies, can effectively reactivate HIV-1 in different latency models with an EC50 value 1.95–4.34 times lower than JQ1, a known BET inhibitor that can reactivate HIV-1 latency. We also found that OTX015 was more potent when used in combination with prostratin. More importantly, OTX015 treatment induced HIV-1 full-length transcripts and viral outgrowth in resting CD4+ T cells from infected individuals receiving suppressive antiretroviral therapy (ART), while exerting minimal toxicity and effects on T cell activation. Finally, biochemical analysis showed that OTX015-mediated activation of HIV-1 involved an increase in CDK9 occupancy and RNAP II C-terminal domain (CTD) phosphorylation. Our results suggest that the BET inhibitor OTX015 may be a candidate for anti-HIV-1-latency therapies. PMID:27067814

  5. Novel HIV-1 Integrase Inhibitor Development by Virtual Screening Based on QSAR Models.

    PubMed

    Guasch, Laura; Zakharov, Alexey V; Tarasova, Olga A; Poroikov, Vladimir V; Liao, Chenzhong; Nicklaus, Marc C

    2016-01-01

    HIV-1 integrase (IN) plays an important role in the life cycle of HIV and is responsible for integration of the virus into the human genome. We present computational approaches used to design novel HIV-1 IN inhibitors. We created an IN inhibitor database by collecting experimental data from the literature. We developed quantitative structure-activity relationship (QSAR) models of HIV-1 IN strand transfer (ST) inhibitors using this database. The prediction accuracy of these models was estimated by external 5-fold cross-validation as well as with an additional validation set of 308 structurally distinct compounds from the publicly accessible BindingDB database. The validated models were used to screen a small combinatorial library of potential synthetic candidates to identify hits, with a subsequent docking approach applied to further filter out compounds to arrive at a small set of potential HIV-1 IN inhibitors. As result, 236 compounds with good druglikeness properties and with correct docking poses were identified as potential candidates for synthesis. One of the six compounds finally chosen for synthesis was experimentally confirmed to inhibit the ST reaction with an IC50(ST) of 37 µM. The IN inhibitor database is available for download from http://cactus.nci.nih.gov/download/iidb/. PMID:26268340

  6. Simian-tropic HIV as a model to study drug resistance against integrase inhibitors.

    PubMed

    Wares, Melissa; Hassounah, Said; Mesplède, Thibault; Sandstrom, Paul A; Wainberg, Mark A

    2015-04-01

    Drug resistance represents a key aspect of human immunodeficiency virus (HIV) treatment failure. It is important to develop nonhuman primate models for studying issues of drug resistance and the persistence and transmission of drug-resistant viruses. However, relatively little work has been conducted using either simian immunodeficiency virus (SIV) or SIV/HIV recombinant viruses for studying resistance against integrase strand transfer inhibitors (INSTIs). Here, we used a T-cell-tropic SIV/HIV recombinant virus in which the capsid and vif regions of HIV-1 were replaced with their SIV counterparts (simian-tropic HIV-1 [stHIV-1](SCA,SVIF)) to study the impact of a number of drug resistance substitutions in the integrase coding region at positions E92Q, G118R, E138K, Y143R, S153Y, N155H, and R263K on drug resistance, viral infectivity, and viral replication capacity. Our results show that each of these substitutions exerted effects that were similar to their effects in HIV-1. Substitutions associated with primary resistance against dolutegravir were more detrimental to stHIV-1(SCA,SVIF) infectiousness than were resistance substitutions associated with raltegravir and elvitegravir, consistent with data that have been reported for HIV-1. These findings support the role of stHIV-1(SCA,SVIF) as a useful model with which to evaluate the role of INSTI resistance substitutions on viral persistence, transmissibility, and pathogenesis in a nonhuman primate model. PMID:25583721

  7. Discovery of HIV-1 integrase inhibitors: pharmacophore mapping, virtual screening, molecular docking, synthesis, and biological evaluation.

    PubMed

    Bhatt, Hardik; Patel, Paresh; Pannecouque, Christophe

    2014-02-01

    HIV-1 integrase enzyme plays an important role in the life cycle of HIV and responsible for integration of virus into human genome. Here, both computational and synthetic approaches were used to design and synthesize newer HIV-1 integrase inhibitors. Pharmacophore mapping was performed on 20 chemically diverse molecules using DISCOtech, and refinement was carried out using GASP. Ten pharmacophore models were generated, and model 2, containing four features including two donor sites, one acceptor atom, and one hydrophobic region, was considered the best model as it has the highest fitness score. It was used as a query in NCI and Maybridge databases. Molecules having more than 99% Q(fit) value were used to design 30 molecules bearing pteridine ring and were docked on co-crystal structure of HIV-1 integrase enzyme. Among these, six molecules, showing good docking score compared with the reference standards, were synthesized by conventional as well as microwave-assisted methods. All compounds were characterized by physical and spectral data and evaluated for in vitro anti-HIV activity against the replication of HIV-1 (IIIB) in MT-4 cells. The used approach of molecular docking and anti-HIV activity data of designed molecules will provide significant insights to discover novel HIV-1 Integrase Inhibitors. PMID:23957390

  8. In Vitro Reactivation of Replication-Competent and Infectious HIV-1 by Histone Deacetylase Inhibitors

    PubMed Central

    Banga, Riddhima; Procopio, Francesco Andrea; Cavassini, Matthias

    2015-01-01

    ABSTRACT The existence of long-lived HIV-1-infected resting memory CD4 T cells is thought to be the primary obstacle to HIV-1 eradication. In the search for novel therapeutic approaches that may reverse HIV-1 latency, inhibitors of histone deacetylases (HDACis) have been tested to reactivate HIV-1 replication with the objective of rendering HIV-1-infected cells susceptible to elimination either by HIV-specific CD8 T cells or through virus-mediated cytopathicity. In the present study, we evaluated the efficiency of HDACis to reactivate HIV-1 replication from resting memory CD4 T cells isolated from aviremic long-term-treated HIV-1-infected subjects. We demonstrate that following prolonged/repeated treatment of resting memory CD4 T cells with HDACis, HIV-1 replication may be induced from primary resting memory CD4 T cells isolated from aviremic long-term-treated HIV-1-infected subjects. More importantly, we demonstrate that HIV-1 reactivated in the cell cultures was not only replication competent but also infectious. Interestingly, givinostat, an HDACi that has not been investigated in clinical trials, was more efficient than vorinostat, panobinostat, and romidepsin in reversing HIV-1 latency in vitro. Taken together, these results support further evaluation of givinostat as a latency-reversing agent (LRA) in aviremic long-term-treated HIV-1-infected subjects. IMPORTANCE The major barrier to HIV cure is the existence of long-lived latently HIV-1-infected resting memory CD4 T cells. Latently HIV-1-infected CD4 T cells are transcriptionally silent and are therefore not targeted by conventional antiretroviral therapy (ART) or the immune system. In this context, one strategy to target latently infected cells is based on pharmacological molecules that may force the virus to replicate and would therefore render HIV-1-infected cells susceptible to elimination either by HIV-specific CD8 T cells or through virus-mediated cytopathicity. In this context, we developed an

  9. Computer tools in the discovery of HIV-I integrase inhibitors

    PubMed Central

    Liao, Chenzhong; Nicklaus, Marc C

    2010-01-01

    Computer-aided drug design (CADD) methodologies have made great advances and contributed significantly to the discovery and/or optimization of many clinically used drugs in recent years. CADD tools have likewise been applied to the discovery of inhibitors of HIV-I integrase, a difficult and worthwhile target for the development of efficient anti-HIV drugs. This article reviews the application of CADD tools, including pharmacophore search, quantitative structure–activity relationships, model building of integrase complexed with viral DNA and quantum-chemical studies in the discovery of HIV-I integrase inhibitors. Different structurally diverse integrase inhibitors have been identified by, or with significant help from, various CADD tools. PMID:21426160

  10. 6,7-Dihydroxy-1-oxoisoindoline-4-sulfonamide-containing HIV-1 Integrase Inhibitors

    PubMed Central

    Zhao, Xue Zhi; Maddali, Kasthuraiah; Smith, Steven J.; Métifiot, Mathieu; Johnson, Barry C.; Marchand, Christophe; Hughes, Stephen H.; Pommier, Yves; Burke, Terrence R.

    2012-01-01

    Although an extensive body of scientific and patent literature exists describing the development of HIV-1 integrase (IN) inhibitors, Merck’s raltegravir and Gilead’s elvitegravir remain the only IN inhibitors FDA-approved for the treatment of AIDS. The emergence of raltegravir-resistant strains of HIV-1 containing mutated forms of IN underlies the need for continued efforts to enhance the efficacy of IN inhibitors against resistant mutants. We have previously described bicyclic 6,7-dihydroxyoxoisoindolin-1-ones that show good IN inhibitory potency. This report describes the effects of introducing substituents into the 4- and 5- positions of the parent 6,7-dihydroxyoxoisoindolin-1-one platform. We have developed several sulfonamide-containing analogs that enhance potency in cell-based HIV assays by more than two orders-of-magnitude and we describe several compounds that are more potent than raltegravir against the clinically relevant Y143R IN mutant. PMID:23149229

  11. 6,7-Dihydroxy-1-oxoisoindoline-4-sulfonamide-containing HIV-1 integrase inhibitors.

    PubMed

    Zhao, Xue Zhi; Maddali, Kasthuraiah; Smith, Steven J; Métifiot, Mathieu; Johnson, Barry C; Marchand, Christophe; Hughes, Stephen H; Pommier, Yves; Burke, Terrence R

    2012-12-15

    Although an extensive body of scientific and patent literature exists describing the development of HIV-1 integrase (IN) inhibitors, Merck's raltegravir and Gilead's elvitegravir remain the only IN inhibitors FDA-approved for the treatment of AIDS. The emergence of raltegravir-resistant strains of HIV-1 containing mutated forms of IN underlies the need for continued efforts to enhance the efficacy of IN inhibitors against resistant mutants. We have previously described bicyclic 6,7-dihydroxyoxoisoindolin-1-ones that show good IN inhibitory potency. This report describes the effects of introducing substituents into the 4- and 5-positions of the parent 6,7-dihydroxyoxoisoindolin-1-one platform. We have developed several sulfonamide-containing analogs that enhance potency in cell-based HIV assays by more than two orders-of-magnitude and we describe several compounds that are more potent than raltegravir against the clinically relevant Y143R IN mutant. PMID:23149229

  12. Identification of peptidases in highly pathogenic vs. weakly pathogenic Naegleria fowleri amebae.

    PubMed

    Vyas, Ishan K; Jamerson, Melissa; Cabral, Guy A; Marciano-Cabral, Francine

    2015-01-01

    Naegleria fowleri, a free-living ameba, is the causative agent of Primary Amebic Meningoencephalitis. Highly pathogenic mouse-passaged amebae (Mp) and weakly pathogenic axenically grown (Ax) N. fowleri were examined for peptidase activity. Zymography and azocasein peptidase activity assays demonstrated that Mp and Ax N. fowleri exhibited a similar peptidase pattern. Prominent for whole cell lysates, membranes and conditioned medium (CM) from Mp and Ax amebae was the presence of an activity band of approximately 58 kDa that was sensitive to E64, a cysteine peptidase inhibitor. However, axenically grown N. fowleri demonstrated a high level of this peptidase activity in membrane preparations. The inhibitor E64 also reduced peptidase activity in ameba-CM consistent with the presence of secreted cysteine peptidases. Exposure of Mp amebae to E64 reduced their migration through matrigel that was used as an extracellular matrix, suggesting a role for cysteine peptidases in invasion of the central nervous system (CNS). The collective results suggest that the profile of peptidases is not a discriminative marker for distinguishing Mp from Ax N. fowleri. However, the presence of a prominent level of activity for cysteine peptidases in N. fowleri membranes and CM, suggests that these enzymes may serve to facilitate passage of the amebae into the CNS. PMID:25066578

  13. The design of 8-hydroxyquinoline tetracyclic lactams as HIV-1 integrase strand transfer inhibitors.

    PubMed

    Velthuisen, Emile J; Johns, Brian A; Temelkoff, David P; Brown, Kevin W; Danehower, Susan C

    2016-07-19

    A novel series of HIV-1 integrase strand transfer inhibitors were designed using the venerable two-metal binding pharmacophore model and incorporating structural elements from two different literature scaffolds. This manuscript describes a number of 8-hydroxyquinoline tetracyclic lactams with exceptional antiviral activity against HIV-1 and little loss of potency against the IN signature resistance mutations Q148K and G140S/Q148H. PMID:27092410

  14. Structure-activity relationships of boronic acid inhibitors of dipeptidyl peptidase IV. 1. Variation of the P2 position of Xaa-boroPro dipeptides.

    PubMed

    Coutts, S J; Kelly, T A; Snow, R J; Kennedy, C A; Barton, R W; Adams, J; Krolikowski, D A; Freeman, D M; Campbell, S J; Ksiazek, J F; Bachovchin, W W

    1996-05-10

    A series of prolineboronic acid (boroPro) containing dipeptides were synthesized and assayed for their ability to inhibit the serine protease dipeptidyl peptidase IV (DPPIV). Inhibitory activity, which requires the (R)-stereoisomer of boroPro in the P1 position, appears to tolerate a variety of L-amino acids in the P2 position. Substitution at the P2 position which is not tolerated include the D-amino acids, alpha,alpha-disubstituted amino acids, and glycine. Specificity against DPPII and proline specific endopeptidase is reported. A correlation between the ability to inhibit DPPIV in cell culture and in the human mixed lymphocyte reaction is demonstrated. A synthesis of prolineboronic acid is reported as well as conditions for generating the fully unprotected boronic acid dipeptides in either their cyclic or acyclic forms. PMID:8642568

  15. Probing Multidrug-Resistance and Protein-Ligand Interactions with Oxatricyclic Designed Ligands in HIV-1 Protease Inhibitors

    SciTech Connect

    Ghosh, Arun K.; Xu, Chun-Xiao; Rao, Kalapala V.; Baldridge, Abigail; Agniswamy, Johnson; Wang, Yuan-Fang; Weber, Irene T.; Aoki, Manabu; Miguel, Salcedo Pedro; Amano, Masayuki; Mitsuya, Hiroaki

    2010-10-29

    We report the design, synthesis, biological evaluation, and X-ray crystallographic analysis of a new class of HIV-1 protease inhibitors. Compound 4 proved to be an extremely potent inhibitor toward various multidrug-resistant HIV-1 variants, representing a near 10-fold improvement over darunavir (DRV). Compound 4 also blocked protease dimerization with at least 10-fold greater potency than DRV.

  16. Ebselen, a Small-Molecule Capsid Inhibitor of HIV-1 Replication.

    PubMed

    Thenin-Houssier, Suzie; de Vera, Ian Mitchelle S; Pedro-Rosa, Laura; Brady, Angela; Richard, Audrey; Konnick, Briana; Opp, Silvana; Buffone, Cindy; Fuhrmann, Jakob; Kota, Smitha; Billack, Blase; Pietka-Ottlik, Magdalena; Tellinghuisen, Timothy; Choe, Hyeryun; Spicer, Timothy; Scampavia, Louis; Diaz-Griffero, Felipe; Kojetin, Douglas J; Valente, Susana T

    2016-04-01

    The human immunodeficiency virus type 1 (HIV-1) capsid plays crucial roles in HIV-1 replication and thus represents an excellent drug target. We developed a high-throughput screening method based on a time-resolved fluorescence resonance energy transfer (HTS-TR-FRET) assay, using the C-terminal domain (CTD) of HIV-1 capsid to identify inhibitors of capsid dimerization. This assay was used to screen a library of pharmacologically active compounds, composed of 1,280in vivo-active drugs, and identified ebselen [2-phenyl-1,2-benzisoselenazol-3(2H)-one], an organoselenium compound, as an inhibitor of HIV-1 capsid CTD dimerization. Nuclear magnetic resonance (NMR) spectroscopic analysis confirmed the direct interaction of ebselen with the HIV-1 capsid CTD and dimer dissociation when ebselen is in 2-fold molar excess. Electrospray ionization mass spectrometry revealed that ebselen covalently binds the HIV-1 capsid CTD, likely via a selenylsulfide linkage with Cys198 and Cys218. This compound presents anti-HIV activity in single and multiple rounds of infection in permissive cell lines as well as in primary peripheral blood mononuclear cells. Ebselen inhibits early viral postentry events of the HIV-1 life cycle by impairing the incoming capsid uncoating process. This compound also blocks infection of other retroviruses, such as Moloney murine leukemia virus and simian immunodeficiency virus, but displays no inhibitory activity against hepatitis C and influenza viruses. This study reports the use of TR-FRET screening to successfully identify a novel capsid inhibitor, ebselen, validating HIV-1 capsid as a promising target for drug development. PMID:26810656

  17. Safety and effectiveness of dipeptidyl peptidase-4 inhibitors versus intermediate-acting insulin or placebo for patients with type 2 diabetes failing two oral antihyperglycaemic agents: a systematic review and network meta-analysis

    PubMed Central

    Tricco, Andrea C; Antony, Jesmin; Khan, Paul A; Ghassemi, Marco; Hamid, Jemila S; Ashoor, Huda; Blondal, Erik; Soobiah, Charlene; Yu, Catherine H; Hutton, Brian; Hemmelgarn, Brenda R; Moher, David; Majumdar, Sumit R; Straus, Sharon E

    2014-01-01

    Objective To evaluate the effectiveness and safety of dipeptidyl peptidase-4 (DPP-4) inhibitors versus intermediate-acting insulin for adults with type 2 diabetes mellitus (T2DM) and poor glycaemic control despite treatment with two oral agents. Setting Studies were multicentre and multinational. Participants Ten studies including 2967 patients with T2DM. Interventions Studies that examined DPP-4 inhibitors compared with each other, intermediate-acting insulin, no treatment or placebo in patients with T2DM. Primary and secondary outcome measures Primary outcome was glycosylated haemoglobin (HbA1c). Secondary outcomes were healthcare utilisation, body weight, fractures, quality of life, microvascular complications, macrovascular complications, all-cause mortality, harms, cost and cost-effectiveness. Results 10 randomised clinical trials with 2967 patients were included after screening 5831 titles and abstracts, and 180 full-text articles. DPP-4 inhibitors significantly reduced HbA1c versus placebo in network meta-analysis (NMA; mean difference (MD) −0.62%, 95% CI −0.93% to −0.33%) and meta-analysis (MD −0.61%, 95% CI −0.81% to −0.41%), respectively. Significant differences in HbA1c were not observed for neutral protamine Hagedorn (NPH) insulin versus placebo and DPP-4 inhibitors versus NPH insulin in NMA. In meta-analysis, no significant differences were observed between DPP-4 inhibitors and placebo for severe hypoglycaemia, weight gain, cardiovascular disease, overall harms, treatment-related harms and mortality, although patients receiving DPP-4 inhibitors experienced less infections (relative risk 0.72, 95% CI 0.57 to 0.91). Conclusions DPP-4 inhibitors were superior to placebo in reducing HbA1c levels in adults with T2DM taking at least two oral agents. Compared with placebo, no safety signals were detected with DPP-4 inhibitors and there was a reduced risk of infection. There was no significant difference in HbA1c observed between NPH and placebo or

  18. Novel Neuroprotective GSK-3β Inhibitor Restricts Tat-Mediated HIV-1 Replication

    PubMed Central

    Guendel, Irene; Iordanskiy, Sergey; Van Duyne, Rachel; Kehn-Hall, Kylene; Saifuddin, Mohammed; Das, Ravi; Jaworski, Elizabeth; Sampey, Gavin C.; Senina, Svetlana; Shultz, Leonard; Narayanan, Aarthi; Chen, Hao; Lepene, Benjamin; Zeng, Chen

    2014-01-01

    The implementation of new antiretroviral therapies targeting transcription of early viral proteins in postintegrated HIV-1 can aid in overcoming current therapy limitations. Using high-throughput screening assays, we have previously described a novel Tat-dependent HIV-1 transcriptional inhibitor named 6-bromoindirubin-3′-oxime (6BIO). The screening of 6BIO derivatives yielded unique compounds that show potent inhibition of HIV-1 transcription. We have identified a second-generation derivative called 18BIOder as an inhibitor of HIV-1 Tat-dependent transcription in TZM-bl cells and a potent inhibitor of GSK-3β kinase in vitro. Structurally, 18BIOder is half the molecular weight and structure of its parental compound, 6BIO. More importantly, we also have found a different GSK-3β complex present only in HIV-1-infected cells. 18BIOder preferentially inhibits this novel kinase complex from infected cells at nanomolar concentrations. Finally, we observed that neuronal cultures treated with Tat protein are protected from Tat-mediated cytotoxicity when treated with 18BIOder. Overall, our data suggest that HIV-1 Tat-dependent transcription is sensitive to small-molecule inhibition of GSK-3β. PMID:24227837

  19. [Research progress of dual inhibitors targeting HIV-1 reverse transcriptase and integrase].

    PubMed

    Liu, Hong; Zhan, Peng; Liu, Xin-Yong

    2013-04-01

    Both reverse transcriptase (RT) and integrase (IN) play crucial roles in the life cycle of HIV-1, which are also key targets in the area of anti-HIV drug research. Reverse transcriptase inhibitors are involved in the most employed drugs used to treat AIDS patients and HIV-infected people, while one of the integrase inhibitors has already been approved by US FDA to appear on the market. Great achievement has been made in the research on both, separately. Recently, much more attention of medicinal chemistry researchers has been attracted to the strategies of multi-target drugs. Compounds with excellent potency against both HIV RT and IN, evidently defined as dual inhibitors targeting both enzymes, have been obtained through considerable significant exploration, which can be classified into two categories according to different strategies. Combinatorial chemistry approach together with high throughput screening methods and multi-target-based virtual screening strategy have been useful tools for identifying selective anti-HIV compounds for long times; Rational drug design based on pharmacophore combination has also led to remarkable results. In this paper, latest progress of both categories in the discovery and structural modification will be covered, with a view to contribute to the career of anti-HIV research. PMID:23833931

  20. Mass Spectrometric Characterization of HIV-1 Reverse Transcriptase Interactions with Non-nucleoside Reverse Transcriptase Inhibitors.

    PubMed

    Thammaporn, Ratsupa; Ishii, Kentaro; Yagi-Utsumi, Maho; Uchiyama, Susumu; Hannongbua, Supa; Kato, Koichi

    2016-01-01

    Non-nucleoside reverse transcriptase inhibitors (NNRTIs) of human immunodeficiency virus type 1 reverse transcriptase (HIV-1 RT) have been developed for the treatment of acquired immunodeficiency syndrome. HIV-1 RT binding to NNRTIs has been characterized by various biophysical techniques. However, these techniques are often hampered by the low water solubility of the inhibitors, such as the current promising diarylpyrimidine-based inhibitors rilpivirine and etravirine. Hence, a conventional and rapid method that requires small sample amounts is desirable for studying NNRTIs with low water solubility. Here we successfully applied a recently developed mass spectrometric technique under non-denaturing conditions to characterize the interactions between the heterodimeric HIV-1 RT enzyme and NNRTIs with different inhibitory activities. Our data demonstrate that mass spectrometry serves as a semi-quantitative indicator of NNRTI binding affinity for HIV-1 RT using low and small amounts of samples, offering a new high-throughput screening tool for identifying novel RT inhibitors as anti-HIV drugs. PMID:26934936

  1. Modulation of the LDL receptor and LRP levels by HIV protease inhibitors.

    PubMed

    Tran, Huan; Robinson, Susan; Mikhailenko, Irina; Strickland, Dudley K

    2003-10-01

    Inhibitors of the human immunodeficiency virus (HIV)-1 protease have proven to be effective antiretroviral drugs. However, patients receiving these drugs develop serious metabolic abnormalities, including hypercholesterolemia. The objective of the present study was to identify mechanisms by which HIV protease inhibitors increase plasma cholesterol levels. We hypothesized that HIV protease inhibitors may affect gene regulation of certain LDL receptor (LDLR) family members, thereby altering the catabolism of cholesterol-containing lipoproteins. In this present study we investigated the effect of several HIV protease inhibitors (ABT-378, Amprenavir, Indinavir, Nelfinavir, Ritonavir, and Saquinavir) on mRNA, protein, and functional levels of LDLR family members. Our results demonstrate that one of these drugs, Nelfinavir, significantly decreases LDLR and LDLR-related protein (LRP) mRNA and protein levels, resulting in the reduced functional activity of these two receptors. Nelfinavir exerts its effect by reducing levels of active SREBP1 in the nucleus. The finding that Nelfinavir reduces the levels of two key receptors (LRP and LDLR) involved in lipoprotein catabolism and maintenance of vessel wall integrity identifies a mechanism that causes hypercholesterolemia complications in HIV patients treated with this drug and raises concerns about the atherogenic nature of Nelfinavir. PMID:12837856

  2. Virtual screening of Indonesian herbal database as HIV-1 reverse transcriptase inhibitor

    PubMed Central

    Syahdi, Rezi Riadhi; Mun'im, Abdul; Suhartanto, Heru; Yanuar, Arry

    2012-01-01

    HIV-1 (Human immunodeficiency virus type 1) is a member of retrovirus family that could infect human and causing AIDS disease. AIDS epidemic is one of most destructive diseases in modern era. There were more than 33 million people infected by HIV until 2010. Various studies have been widely employed to design drugs that target the essential enzymes of HIV-1 that is, reverse transcriptase, protease and integrase. In this study, in silico virtual screening approach is used to find lead molecules from the library or database of natural compounds as HIV-1 reverse transcriptase inhibitor. Virtual screening against Indonesian Herbal Database using AutoDock4 performed on HIV-1 reverse transcriptase. From the virtual screening, top ten compounds were mulberrin, plucheoside A, vitexilactone, brucine N-oxide, cyanidin 3-arabinoside, alpha-mangostin, guaijaverin, erycristagallin, morusin and sanggenol N. PMID:23275721

  3. Discovery and crystallography of bicyclic arylaminoazines as potent inhibitors of HIV-1 reverse transcriptase.

    PubMed

    Lee, Won-Gil; Frey, Kathleen M; Gallardo-Macias, Ricardo; Spasov, Krasimir A; Chan, Albert H; Anderson, Karen S; Jorgensen, William L

    2015-11-01

    Non-nucleoside inhibitors of HIV-1 reverse transcriptase (HIV-RT) are reported that incorporate a 7-indolizinylamino or 2-naphthylamino substituent on a pyrimidine or 1,3,5-triazine core. The most potent compounds show below 10 nanomolar activity towards wild-type HIV-1 and variants bearing Tyr181Cys and Lys103Asn/Tyr181Cys resistance mutations. The compounds also feature good aqueous solubility. Crystal structures for two complexes enhance the analysis of the structure-activity data. PMID:26166629

  4. Development of tricyclic hydroxy-1H-pyrrolopyridine-trione containing HIV-1 integrase inhibitors.

    PubMed

    Zhao, Xue Zhi; Maddali, Kasthuraiah; Metifiot, Mathieu; Smith, Steven J; Vu, B Christie; Marchand, Christophe; Hughes, Stephen H; Pommier, Yves; Burke, Terrence R

    2011-05-15

    New tricyclic HIV-1 integrase (IN) inhibitors were prepared that combined structural features of bicyclic pyrimidinones with recently disclosed 4,5-dihydroxy-1H-isoindole-1,3(2H)-diones. This combination resulted in the introduction of a nitrogen into the aryl ring and the addition of a fused third ring to our previously described inhibitors. The resulting analogues showed low micromolar inhibitory potency in in vitro HIV-1 integrase assays, with good selectivity for strand transfer relative to 3'-processing. PMID:21493066

  5. An effective conjugation strategy for designing short peptide-based HIV-1 fusion inhibitors.

    PubMed

    Liang, Guodong; Wang, Huixin; Chong, Huihui; Cheng, Siqi; Jiang, Xifeng; He, Yuxian; Wang, Chao; Liu, Keliang

    2016-08-16

    Lengthy peptides corresponding to the C-terminal heptad repeat (C-peptides) of human immunodeficiency virus type 1 (HIV-1) gp41 are potent inhibitors against virus-cell fusion. Designing short C-peptide-based HIV-1 fusion inhibitors could potentially redress the physicochemical and technical liabilities of a long-peptide therapeutic. However, designing such inhibitors with high potency has been challenging. We generated a conjugated architecture by incorporating small-molecule inhibitors of gp41 into the N-terminus of a panel of truncated C-peptides. Among these small molecule-capped short peptides, the 26-residue peptide Indole-T26 inhibited HIV-1 Env-mediated cell-cell fusion and viral replication at low nanomolar levels, reaching the potency of the only clinically used 36-residue peptide T20 (enfuvirtide). Collectively, our work opens up a new avenue for developing short peptide-based HIV-1 fusion inhibitors, and may have broad applicability to the development of modulators of other class I fusion proteins. PMID:27454320

  6. HIV-1 Integrase Strand Transfer Inhibitors with Reduced Susceptibility to Drug Resistant Mutant Integrases.

    PubMed

    Zhao, Xue Zhi; Smith, Steven J; Maskell, Daniel P; Metifiot, Mathieu; Pye, Valerie E; Fesen, Katherine; Marchand, Christophe; Pommier, Yves; Cherepanov, Peter; Hughes, Stephen H; Burke, Terrence R

    2016-04-15

    HIV integrase (IN) strand transfer inhibitors (INSTIs) are among the newest anti-AIDS drugs; however, mutant forms of IN can confer resistance. We developed noncytotoxic naphthyridine-containing INSTIs that retain low nanomolar IC50 values against HIV-1 variants harboring all of the major INSTI-resistant mutations. We found by analyzing crystal structures of inhibitors bound to the IN from the prototype foamy virus (PFV) that the most successful inhibitors show striking mimicry of the bound viral DNA prior to 3'-processing and the bound host DNA prior to strand transfer. Using this concept of "bi-substrate mimicry," we developed a new broadly effective inhibitor that not only mimics aspects of both the bound target and viral DNA but also more completely fills the space they would normally occupy. Maximizing shape complementarity and recapitulating structural components encompassing both of the IN DNA substrates could serve as a guiding principle for the development of new INSTIs. PMID:26808478

  7. Solvation effects are responsible for the reduced inhibitor affinity of some HIV-1 PR mutants.

    PubMed Central

    Sussman, F.; Villaverde, M. C.; Davis, A.

    1997-01-01

    The formulation of HIV-1 PR inhibitors as anti-viral drugs has been hindered by the appearance of protease strains that present drug resistance to these compounds. The mechanism by which the HIV-1 PR mutants lower their affinity for the inhibitor is not yet fully understood. We have applied a modified Poisson-Boltzmann method to the evaluation of the molecular interactions that contribute to the lowering of the inhibitor affinity to some polar mutants at position 82. These strains present drug resistance behavior and hence are ideally suited for these studies. Our results indicate that the reduction in binding affinity is due to the solvation effects that penalize the binding to the more polar mutants. The inhibitor binding ranking of the different mutants can be explained from the analysis of the different components of our free energy scoring function. PMID:9144773

  8. Protease inhibitors effectively block cell-to-cell spread of HIV-1 between T cells

    PubMed Central

    2013-01-01

    Background The Human Immunodeficiency Virus type-1 (HIV-1) spreads by cell-free diffusion and by direct cell-to-cell transfer, the latter being a significantly more efficient mode of transmission. Recently it has been suggested that cell-to-cell spread may permit ongoing virus replication in the presence of antiretroviral therapy (ART) based on studies performed using Reverse Transcriptase Inhibitors (RTIs). Protease Inhibitors (PIs) constitute an important component of ART; however whether this class of inhibitors can suppress cell-to-cell transfer of HIV-1 is unexplored. Here we have evaluated the inhibitory effect of PIs during cell-to-cell spread of HIV-1 between T lymphocytes. Results Using quantitative assays in cell line and primary cell systems that directly measure the early steps of HIV-1 infection we find that the PIs Lopinavir and Darunavir are equally potent against both cell-free and cell-to-cell spread of HIV-1. We further show that a protease resistant mutant maintains its resistant phenotype during cell-to-cell spread and is transmitted more efficiently than wild-type virus in the presence of drug. By contrast we find that T cell-T cell spread of HIV-1 is 4–20 fold more resistant to inhibition by the RTIs Nevirapine, Zidovudine and Tenofovir. Notably, varying the ratio of infected and uninfected cells in co-culture impacted on the degree of inhibition, indicating that the relative efficacy of ART is dependent on the multiplicity of infection. Conclusions We conclude that if the variable effects of antiviral drugs on cell-to-cell virus dissemination of HIV-1 do indeed impact on viral replication and maintenance of viral reservoirs this is likely to be influenced by the antiviral drug class, since PIs appear particularly effective against both modes of HIV-1 spread. PMID:24364896

  9. Synergistic reduction of HIV-1 infectivity by 5-azacytidine and inhibitors of ribonucleotide reductase.

    PubMed

    Rawson, Jonathan M O; Roth, Megan E; Xie, Jiashu; Daly, Michele B; Clouser, Christine L; Landman, Sean R; Reilly, Cavan S; Bonnac, Laurent; Kim, Baek; Patterson, Steven E; Mansky, Louis M

    2016-06-01

    Although many compounds have been approved for the treatment of human immunodeficiency type-1 (HIV-1) infection, additional anti-HIV-1 drugs (particularly those belonging to new drug classes) are still needed due to issues such as long-term drug-associated toxicities, transmission of drug-resistant variants, and development of multi-class resistance. Lethal mutagenesis represents an antiviral strategy that has not yet been clinically translated for HIV-1 and is based on the use of small molecules to induce excessive levels of deleterious mutations within the viral genome. Here, we show that 5-azacytidine (5-aza-C), a ribonucleoside analog that induces the lethal mutagenesis of HIV-1, and multiple inhibitors of the enzyme ribonucleotide reductase (RNR) interact in a synergistic fashion to more effectively reduce the infectivity of HIV-1. In these drug combinations, RNR inhibitors failed to significantly inhibit the conversion of 5-aza-C to 5-aza-2'-deoxycytidine, suggesting that 5-aza-C acts primarily as a deoxyribonucleoside even in the presence of RNR inhibitors. The mechanism of antiviral synergy was further investigated for the combination of 5-aza-C and one specific RNR inhibitor, resveratrol, as this combination improved the selectivity index of 5-aza-C to the greatest extent. Antiviral synergy was found to be primarily due to the reduced accumulation of reverse transcription products rather than the enhancement of viral mutagenesis. To our knowledge, these observations represent the first demonstration of antiretroviral synergy between a ribonucleoside analog and RNR inhibitors, and encourage the development of additional ribonucleoside analogs and RNR inhibitors with improved antiretroviral activity. PMID:27117260

  10. Bis-Tetrahydrofuran: a Privileged Ligand for Darunavir and a New Generation of HIV Protease Inhibitors That Combat Drug Resistance

    SciTech Connect

    Ghosh, Arun K.; Sridhar, Perali Ramu; Kumaragurubaran, Nagaswamy; Koh, Yasuhiro; Weber, Irene T.; Mitsuya, Hiroaki

    2008-06-06

    Two inhibitors that incorporate bis-THF as an effective high-affinity P{sub 2} ligand for the HIV-1 protease substrate binding site maintain impressive potency against mutant strains resistant to currently approved protease inhibitors. Crystallographic structures of protein-ligand complexes help to explain the superior antiviral property of these inhibitors and their potency against a wide spectrum of HIV-1 strains.