Bone Morphogenetic Protein–Inducer Tilorone Identified by High-Throughput Screening Is Antifibrotic In Vivo

Abstract

Idiopathic pulmonary fibrosis (IPF) is a progressive lung disease with a poor prognosis and very few therapeutic options. On the molecular level, patients with IPF have increased amounts of the bone morphogenetic protein (BMP) inhibitor gremlin in their lungs, which results in decreased BMP signaling, and an increase in transforming growth factor-β signaling. Based on these findings, we hypothesized that restoration of the impaired BMP signaling would offer a novel strategy for the prevention of fibrosis progression or for the treatment of pulmonary fibrosis. We used reporter cell lines and high-throughput screening of a chemical compound library as an approach to finding molecules that increase BMP signaling in lung epithelial cells, without increasing transforming growth factor-β signaling. The most promising candidate drug was analyzed further by studying its effects on BMP target gene expression, Smad protein phosphorylation, and a mouse model of silica-induced pulmonary fibrosis. The most promising drug candidate, tilorone, induced BMP signaling in the reporter cells and increased the expression of BMP-7 and a BMP target gene, Id3, in lung epithelial A549 cells. In a mouse model of pulmonary fibrosis, tilorone decreased lung hydroxyproline content and the expression of collagen genes Col1A1 and Col3A1. Mice treated with tilorone showed markedly decreased histological changes, compared with untreated mice. These findings indicate that tilorone has biologically significant antifibrotic properties.

Gremlin1 preferentially binds to bone morphogenetic protein-2 (BMP-2) and BMP-4 over BMP-7

“…However, our data suggests that this is unlikely to occur via a direct interaction between Grem1 and BMP-7, given their low binding affinity. Small molecules such as tilerone (which induces BMP-7) and Thr123 (which activates the Alk3 BMP receptor) have been shown to reduce kidney fibrosis in vivo [47,48]. Together with a recent report showing that an anti-Grem1 antibody can reduce fibrosis in a model of pulmonary artery hypertension (PAH) [49], these data illustrate that manipulation of the Grem1-BMP signalling axis may still be a useful therapeutic avenue for the treatment of diabetic kidney disease.…”

Efficacy of Tilorone Dihydrochloride against Ebola Virus Infection

“…These observations support the hypothesis that tilorone's antiviral activity is acting through an IFN-related innate immunity pathway. Tilorone has been shown to possess a broad array of other biological activities, including cell growth inhibition in PC3 CDK5dn prostate cancer cells (IC 50 , 8 to 12 M) (13) and inhibition of primase DnaG from Bacillus anthracis (IC 50 ,7.1 M) (14), and in a mouse model of pulmonary fibrosis it decreased lung hydroxyproline content and the expression of collagen genes (15). Other biologically important activities include ␣7 nicotinic receptor (nAChR) agonist activity (K i , 56 nM) (16) and activated human alpha7 nAChR with an EC 50 of 2.5 M (17), which is a target for various central nervous system diseases.…”

“…Sold under the trade name Amixin or Lavomax, tilorone is approved for use in Russia, Ukraine, Kazakhstan, Belarus, Armenia, Georgia, Kyrgyzstan, Moldova, Turkmenistan, and Uzbekistan for multiple viral disease indications (i.e., influenza, acute respiratory viral infection, viral hepatitis, viral encephalitis, myelitis, and others) and is included in the list of vital and essential medicines of the Russian Federation. Tilorone has a broad array of biological activities (13)(14)(15)(16)(17)(18)(19)(20) and was first reported to be a small-molecule interferon (IFN) inducer with broad-spectrum antiviral activities (21)(22)(23). IFNs are pleiotropic cytokines with a long history of involvement in the development and treatment of viral infections and can inhibit viral replication by direct or indirect means such that combining IFNs with other antiviral drugs is a proven clinical strategy.…”

Machine learning models identify molecules active against the Ebola virus in vitro

“…Tilorone is an investigational agent that has been known for over 40 years as an antiviral 56 and is an inducer of interferon in mice 57 . It has been shown to possess a broad array of biological activities including cell growth inhibition in PC3 CDK5dn prostate cancer cells (IC 50 8–12 μM) 58 , inhibition of Primase DnaG from Bacillus anthracis (IC 50 7.1 μM) 59 , in a mouse model of pulmonary fibrosis it decreased lung hydroxyproline content and the expression of collagen genes 60 , α7 nicotinic receptor (nAChR) agonist activity (K i 56 nM) 61 , activated human alpha7 nAChR with an EC 50 value of 2.5 μM 62 , radioprotective activity 63 , potent modulation of HIF-mediated gene expression in neurons with neuroprotective properties 64 and induction of the accumulation of glycosaminoglycans, delay infectious prion clearance, and prolong prion disease incubation time 65 . Quinacrine is an old antimalarial drug now more widely used as an antiprotozoal for the treatment of giardiasis 66 and as an anthelmintic.…”