Transforming Academic Drug Discovery Meinke, Peter T
Chembiochem : a European journal of chemical biology,
April 20, 2022, Volume:
23, Issue:
8
Journal Article
Peer reviewed
A drug accelerator that partners the creative power of academic scientists with drug discovery professionals to consistently advance groundbreaking biological discoveries would be transformational. ...One such model, the Tri-Institutional Therapeutics Discovery Institute, evolved a series of best practices for identifying, selecting, executing, and completing academic-initiated drug discovery projects, is described.
Nearly half of all pregnancies are unintended; thus, existing family planning options are inadequate. For men, the only choices are condoms and vasectomy, and most current efforts to develop new ...contraceptives for men impact sperm development, meaning that contraception requires months of continuous pretreatment. Here, we provide proof-of-concept for an innovative strategy for on-demand contraception, where a man would take a birth control pill shortly before sex, only as needed. Soluble adenylyl cyclase (sAC) is essential for sperm motility and maturation. We show a single dose of a safe, acutely-acting sAC inhibitor with long residence time renders male mice temporarily infertile. Mice exhibit normal mating behavior, and full fertility returns the next day. These studies define sAC inhibitors as leads for on-demand contraceptives for men, and they provide in vivo proof-of-concept for previously untested paradigms in contraception; on-demand contraception after just a single dose and pharmacological contraception for men.
PPARs: therapeutic targets for metabolic disease Berger, Joel P.; Akiyama, Taro E.; Meinke, Peter T.
Trends in pharmacological sciences (Regular ed.),
05/2005, Volume:
26, Issue:
5
Journal Article
Peer reviewed
The three peroxisome-proliferator-activated receptor (PPAR) subtypes, PPAR-γ, PPAR-α and PPAR-δ, are nuclear receptors that have been the focus of extensive research during the past decade. These ...receptors function as lipid sensors that coordinately regulate the expression of large gene arrays and, thereby, modulate important metabolic events. They are also the targets of drugs that are effective in the treatment of metabolic disorders (type 2 diabetes mellitus and atherosclerosis) that afflict industrialized societies at epidemic levels. Ongoing research indicates that modulation of PPAR activity might be an effective therapy for additional maladies associated with the metabolic syndrome, including obesity. Novel PPAR ligands are now being developed that possess broader efficacies and improved tolerability compared with currently available therapeutic agents.
Abstract
Soluble adenylyl cyclase (sAC: ADCY10) has been genetically confirmed to be essential for male fertility in mice and humans. In mice, ex vivo studies of dormant, caudal epididymal sperm ...demonstrated that sAC is required for initiating capacitation and activating motility. We now use an improved sAC inhibitor, TDI-10229, for a comprehensive analysis of sAC function in mouse and human sperm. In contrast to caudal epididymal mouse sperm, human sperm are collected post-ejaculation, after sAC activity has already been stimulated. In addition to preventing the capacitation-induced stimulation of sAC and protein kinase A activities, tyrosine phosphorylation, alkalinization, beat frequency and acrosome reaction in dormant mouse sperm, sAC inhibitors interrupt each of these capacitation-induced changes in ejaculated human sperm. Furthermore, we show for the first time that sAC is required during acrosomal exocytosis in mouse and human sperm. These data define sAC inhibitors as candidates for non-hormonal, on-demand contraceptives suitable for delivery via intravaginal devices in women.
Tuberculosis remains a leading cause of death from a single infection worldwide. Drug resistance to existing and even new antimycobacterials calls for research into novel targets and unexplored ...mechanisms of action. Recently we reported on the development of tight‐binding inhibitors of Mycobacterium tuberculosis (Mtb) lipoamide dehydrogenase (Lpd), which selectively inhibit the bacterial but not the human enzyme based on a differential modality of inhibitor interaction with these targets. Here we report on the striking improvement in inhibitor residence time on the Mtb enzyme associated with scaffold progression from an indazole to 2‐cyanoindole. Cryo‐EM of Lpd with the bound 2‐cyanoindole inhibitor 19 confirmed displacement of the buried water molecule deep in the binding channel with a cyano group. The ensuing hours‐long improvement in on‐target residence time is associated with enhanced antibacterial activity in axenic culture and in primary mouse macrophages. Resistance to 2‐cyanoindole inhibitors involves mutations within the inhibitor binding site that have little effect on inhibitor affinity but change the modality of inhibitor‐target interaction, resulting in fast dissociation from Lpd. These findings underscore that on‐target residence time is a major determinant of antibacterial activity and in vivo efficacy.
Efforts to develop new male or female nonhormonal, orally available contraceptives assume that to be effective and safe, targets must be (1) essential for fertility; (2) amenable to targeting by ...small-molecule inhibitors; and (3) restricted to the germline. In this perspective, we question the third assumption and propose that despite its wide expression, soluble adenylyl cyclase (sAC: ADCY10), which is essential for male fertility, is a valid target. We hypothesize that an acute-acting sAC inhibitor may provide orally available, on-demand, nonhormonal contraception for men without adverse, mechanism-based effects. To test this concept, we describe a collaboration between academia and the unique capabilities of a public-private drug discovery institute. Summary sentence An acute-acting inhibitor of soluble adenylyl cyclase (sAC: ADCY10) may provide orally available, on-demand, non-hormonal contraception for men without adverse, mechanism-based effects.
In mammalian cells, 10 different adenylyl cyclases produce the ubiquitous second messenger, cyclic adenosine monophosphate (cAMP). Amongst these cAMP-generating enzymes, bicarbonate (HCO
)-regulated ...soluble adenylyl cyclase (sAC; ADCY10) is uniquely essential in sperm for reproduction. For this reason, sAC has been proposed as a potential therapeutic target for non-hormonal contraceptives for men. Here, we describe key sAC-focused
assays to identify and characterize sAC inhibitors for therapeutic use. The affinity and binding kinetics of an inhibitor can greatly influence
efficacy, therefore, we developed improved assays for assessing these efficacy defining features.
Soluble adenylyl cyclase (sAC: ADCY10) is an enzyme involved in intracellular signaling. Inhibition of sAC has potential therapeutic utility in a number of areas. For example, sAC is integral to ...successful male fertility: sAC activation is required for sperm motility and ability to undergo the acrosome reaction, two processes central to oocyte fertilization. Pharmacologic evaluation of existing sAC inhibitors for utility as on-demand, nonhormonal male contraceptives suggested that both high intrinsic potency, fast on and slow dissociation rates are essential design elements for successful male contraceptive applications. During the course of the medicinal chemistry campaign described here, we identified sAC inhibitors that fulfill these criteria and are suitable for in vivo evaluation of diverse sAC pharmacology.
The NS5A protein plays a critical role in the replication of HCV and has been the focus of numerous research efforts over the past few years. NS5A inhibitors have shown impressive in vitro potency ...profiles in HCV replicon assays, making them attractive components for inclusion in all oral combination regimens. Early work in the NS5A arena led to the discovery of our first clinical candidate, MK-4882 2-((S)-pyrrolidin-2-yl)-5-(2-(4-(5-((S)-pyrrolidin-2-yl)-1H-imidazol-2-yl)phenyl)benzofuran-5-yl)-1H-imidazole. While preclinical proof-of-concept studies in HCV-infected chimpanzees harboring chronic genotype 1 infections resulted in significant decreases in viral load after both single- and multiple-dose treatments, viral breakthrough proved to be a concern, thus necessitating the development of compounds with increased potency against a number of genotypes and NS5A resistance mutations. Modification of the MK-4882 core scaffold by introduction of a cyclic constraint afforded a series of tetracyclic inhibitors, which showed improved virologic profiles. Herein we describe the research efforts that led to the discovery of MK-8742, a tetracyclic indole-based NS5A inhibitor, which is currently in phase 2b clinical trials as part of an all-oral, interferon-free regimen for the treatment of HCV infection.
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