The gain-of-function MUC5B promoter variant rs35705950 is the dominant risk factor for developing idiopathic pulmonary fibrosis (IPF). Here we show in humans that MUC5B, a mucin thought to be restricted to conducting airways, is co-expressed with surfactant protein C (SFTPC) in type 2 alveolar epithelia and in epithelial cells lining honeycomb cysts, indicating that cell types involved in lung fibrosis in distal airspace express MUC5B. In mice, we demonstrate that Muc5b concentration in bronchoalveolar epithelia is related to impaired mucociliary clearance (MCC) and to the extent and persistence of bleomycin-induced lung fibrosis. We also establish the ability of the mucolytic agent P-2119 to restore MCC and to suppress bleomycin-induced lung fibrosis in the setting of Muc5b overexpression. Our findings suggest that mucociliary dysfunction might play a causative role in bleomycin-induced pulmonary fibrosis in mice overexpressing Muc5b, and that MUC5B in distal airspaces is a potential therapeutic target in humans with IPF.

To search for TNF-alpha (tumor necrosis factor alpha) converting enzyme (TACE) inhibitors, we designed a new class of macrocyclic hydroxamic acids by linking the P1 and P2' residues of acyclic anti-succinate-based hydroxamic acids. A variety of residues including amide, carbamate, alkyl, sulfonamido, Boc-amino, and amino were found to be suitable P1-P2' linkers. With an N-methylamide at P3', the 13-16-membered macrocycles prepared exhibited low micromolar activities in the inhibition of TNF-alpha release from LPS-stimulated human whole blood. Further elaboration in the P3'-P4' area using the cyclophane and cyclic carbamate templates led to the identification of a number of potent analogues with IC(50) values of

The binding of tumor necrosis factor alpha (TNF-α) to the type-1 TNF receptor (TNFRc1) plays an important role in inflammation. Despite the clinical success of biologics (antibodies, soluble receptors) for treating TNF-based autoimmune conditions, no potent small molecule antagonists have been developed. Our screening of chemical libraries revealed that N -alkyl 5-arylidene-2-thioxo-1,3-thiazolidin-4-ones were antagonists of this protein–protein interaction. After chemical optimization, we discovered IW927, which potently disrupted the binding of TNF-α to TNFRc1 (IC 50 = 50 nM) and also blocked TNF-stimulated phosphorylation of Iκ-B in Ramos cells (IC 50 = 600 nM). This compound did not bind detectably to the related cytokine receptors TNFRc2 or CD40, and did not display any cytotoxicity at concentrations as high as 100 μM. Detailed evaluation of this and related molecules revealed that compounds in this class are “photochemically enhanced” inhibitors, in that they bind reversibly to the TNFRc1 with weak affinity ( ca. 40–100 μM) and then covalently modify the receptor via a photochemical reaction. We obtained a crystal structure of IV703 (a close analog of IW927) bound to the TNFRc1. This structure clearly revealed that one of the aromatic rings of the inhibitor was covalently linked to the receptor through the main-chain nitrogen of Ala-62, a residue that has already been implicated in the binding of TNF-α to the TNFRc1. When combined with the fact that our inhibitors are reversible binders in light-excluded conditions, the results of the crystallography provide the basis for the rational design of nonphotoreactive inhibitors of the TNF-α–TNFRc1 interaction.

No abstract

In our continuing effort to expand the SAR of the quinoline domain of dihydropyrrolopyrazole series, we have discovered compound 15d, which demonstrated the antitumor efficacy with oral bioavailability. This effort also demonstrated that the PK/PD in vivo target inhibition paradigm is an effective approach to assess potential for antitumor efficacy. The dihydropyrrolopyrazole inhibitor 15d (LY2109761) is representative of a novel series of antitumor agents.

No abstract

Mistletoe lectin is thought to constitute the active principle in extract preparations from mistletoe, which are widely used as immunomodulators in adjuvant tumor therapy. However, no study exists which compares the immunological potency of different well‐defined mistletoe lectin preparations on human immune cells. Therefore, in the present study the biological effects of an aqueous mistletoe extract, standardized for mistletoe lectin I (eML), the isolated natural mistletoe lectin (nML), and the recombinant form of this lectin (rML) on human peripheral blood monocytes and lymphocytes were compared with respect to cell viability and cytokine induction. After 48‐hr incubation of peripheral blood mononuclear cells (PBMC) with rML, nML, and eML, a continuous concentration‐dependent decrease in cell viability was found with an IC50 of about 3 ng/ml for rML and nML and 10 ng/ml for eML, respectively. This effect also was seen when isolated lymphocytes and monocytes were separately incubated with the lectin preparations. After incubation of PBMC and isolated monocytes of 5/10 blood donors with eML, an increase in cell viability was found at lectin concentrations between 10 and 1,000 pg/ml. This effect was not seen with the pure lectin preparations nML and rML. After 48‐hr incubation of PBMC with rML, nML, and eML, induction of IL‐1‐β, TNF‐α, IL‐2, IL‐6, and IL‐10 but not IFN‐γ was measured. For IL‐1‐β it could be shown that cytokine induction took place at a broad lectin concentration range (0.1–100 ng/ml). Cytokine levels varied greatly in the PBMC cultures of the different blood donors. When monocytes were separately incubated with eML, nML, and rML for 48 hr, high levels of IL‐1‐β were found. In contrast, in cultures of separated lymphocytes from the same donors only a minimal production of IL‐1‐β and no production of IFN‐γ was found after incubation with rML, nML, and eML. It is concluded that there are quantitative differences in the immunomodulatory effects of the mistletoe lectin preparations on human monocytes and lymphocytes. Therefore, measurement of cell viability and cytokine induction may be a diagnostic laboratory tool to determine the immunological potency of various mistletoe preparations and may help to clarify the clinical benefit of therapies with these substances. J. Clin. Lab. Anal. 14:255–259, 2000. © 2000 Wiley‐Liss, Inc.

Identification of low-dose, low-molecular-weight, drug-like inhibitors of protein–protein interactions (PPIs) is a challenging area of research. Despite the challenges, the therapeutic potential of PPI inhibition has driven significant efforts toward this goal. Adding to recent success in this area, we describe herein our efforts to optimize a novel purine carboxylic acid-derived inhibitor of the HDM2–p53 PPI into a series of low-projected dose inhibitors with overall favorable pharmacokinetic and physical properties. Ultimately, a strategy focused on leveraging known binding hot spots coupled with biostructural information to guide the design of conformationally constrained analogs and a focus on efficiency metrics led to the discovery of MK-4688 (compound 56), a highly potent, selective, and low-molecular-weight inhibitor suitable for clinical investigation.