ABSTRACT
The main objective of this study is to screen potential small molecule inhibitors against HPV (Human Papilloma Virus)-16 E6 protein (HPV16 E6P) using a fragment-based approach. Twenty-six natural HPV inhibitors were selected based on the review of the literature. Among them, Luteolin was selected as the reference compound. These 26 compounds were used to generate novel inhibitors against HPV16 E6P. Fragment script and BREED of Schrodinger software were used to build novel inhibitor molecules. The result in 817 novel molecules was docked into the active binding site of HPV E6 protein and the top ten compounds were screened based on binding affinity compared to Luteolin for further study. Compounds Cpd5, Cpd7, and Cpd10 were the most potent inhibitors of HPV16 E6P and these were non-toxic and showed high Gastrointestinal (GI) absorption and positive drug-likeness score. Complexes of these compounds were stable in the 200 ns Molecular Dynamics (MD) simulation. These 3 HPV16 E6P inhibitors could be the lead molecules as new drugs for HPV-related diseases.Communicated by Ramaswamy H. Sarma.
Subject(s)
Molecular Dynamics Simulation , Papillomavirus Infections , Humans , Luteolin , Binding Sites , Human Papillomavirus Viruses , Molecular Docking SimulationABSTRACT
Idiopathic pulmonary fibrosis (IPF) is a fatal fibrotic lung disease with a median 5-year survival of ~20%. Current U.S. Food and Drug Administration-approved pharmacotherapies slow progression of IPF, providing hope that even more effective treatments can be developed. Alveolar epithelial progenitor type II cell (AEC) apoptosis and proliferation, and accumulation of activated myofibroblasts or fibrotic lung fibroblasts (fLfs) contribute to the progression of IPF. Full-length caveolin-1 scaffolding domain peptide (CSP; amino acids 82 to 101 of Cav1: DGIWKASFTTFTVTKYWFYR) inhibits AEC apoptosis and fLf activation and expansion and attenuates PF in bleomycin (BLM)-induced lung injury in mice. Like full-length CSP, a seven-amino acid deletion fragment of CSP, CSP7 (FTTFTVT), demonstrated antifibrotic effects in murine models of lung fibrosis. When CSP7 was administered during the fibrotic phase in three preclinical models [single-dose BLM, repeated-dose BLM, and adenovirus expressing constitutively active transforming growth factor-ß1 (Ad-TGF-ß1)-induced established PF], CSP7 reduced extracellular matrix (ECM) markers characteristic of PF, increased AEC survival, and improved lung function. CSP7 is amenable to both systemic (intraperitoneal) or direct lung delivery in a nebulized or dry powder form. Furthermore, CSP7 treatment of end-stage human IPF lung tissue explants attenuated ECM production and promoted AEC survival. Ames testing for mutagenicity and in vitro human peripheral blood lymphocyte and in vivo mouse micronucleus transformation assays indicated that CSP7 is not carcinogenic. Together, these findings support the further development of CSP7 as an antifibrotic treatment for patients with IPF or other interstitial lung diseases.
Subject(s)
Caveolin 1/chemistry , Idiopathic Pulmonary Fibrosis/drug therapy , Peptides/therapeutic use , Alveolar Epithelial Cells/drug effects , Alveolar Epithelial Cells/metabolism , Alveolar Epithelial Cells/pathology , Amino Acid Sequence , Animals , Apoptosis/drug effects , Bleomycin , Dose-Response Relationship, Drug , Fibroblasts/drug effects , Fibroblasts/pathology , Humans , Idiopathic Pulmonary Fibrosis/pathology , Injections, Intraperitoneal , Lung/pathology , Lung/physiopathology , Mice , Mutagens/toxicity , Nebulizers and Vaporizers , Peptides/administration & dosage , Peptides/chemistry , Peptides/pharmacology , Transforming Growth Factor beta1 , Tumor Suppressor Protein p53/metabolismABSTRACT
Alveolar type II epithelial (ATII) cell injury precedes development of pulmonary fibrosis. Mice lacking urokinase-type plasminogen activator (uPA) are highly susceptible, whereas those deficient in plasminogen activator inhibitor (PAI-1) are resistant to lung injury and pulmonary fibrosis. Epithelial-mesenchymal transition (EMT) has been considered, at least in part, as a source of myofibroblast formation during fibrogenesis. However, the contribution of altered expression of major components of the uPA system on ATII cell EMT during lung injury is not well understood. To investigate whether changes in uPA and PAI-1 by ATII cells contribute to EMT, ATII cells from patients with idiopathic pulmonary fibrosis and chronic obstructive pulmonary disease, and mice with bleomycin-, transforming growth factor ß-, or passive cigarette smoke-induced lung injury were analyzed for uPA, PAI-1, and EMT markers. We found reduced expression of E-cadherin and zona occludens-1, whereas collagen-I and α-smooth muscle actin were increased in ATII cells isolated from injured lungs. These changes were associated with a parallel increase in PAI-1 and reduced uPA expression. Further, inhibition of Src kinase activity using caveolin-1 scaffolding domain peptide suppressed bleomycin-, transforming growth factor ß-, or passive cigarette smoke-induced EMT and restored uPA expression while suppressing PAI-1. These studies show that induction of PAI-1 and inhibition of uPA during fibrosing lung injury lead to EMT in ATII cells.
