Consensus Virtual Screening and Ex Vivo Evaluation of Novel JAK2/STAT1,3 Inhibitors

Area of Science:

• Pharmacology
• Computational Chemistry
• Immunology

Background:

• The Janus kinase (JAK)/signal transducer and activator of transcription (STAT) pathway is crucial for inflammatory and neoplastic diseases.
• Existing JAK inhibitors have adverse effects, necessitating the search for safer alternatives.
• JAK2 is a key target for therapeutic intervention in conditions like rheumatoid arthritis and cancer.

Purpose of the Study:

• To identify novel, safer inhibitors of the JAK2 signaling pathway.
• To screen FDA-approved drugs using computer-aided methods for potential JAK2 inhibitory activity.
• To validate computationally identified compounds through in vitro functional assays.

Main Methods:

• Consensus molecular docking and molecular dynamics simulations were employed to filter 3330 FDA-approved drugs against the JAK2 structure.
• Virtual hits were evaluated in an ex vivo functional model assessing STAT1,3 phosphorylation in human lymphocytes stimulated by IL-6.
• Stability of potential inhibitors was confirmed using 200 ns molecular dynamics simulations.

Main Results:

• Pitavastatin (PIT), eltrombopag (ELT), flavoxate (FLA), and empagliflozin (EMP) were identified as potential JAK2 inhibitors.
• Molecular dynamics simulations confirmed the stability of these compounds, showing comparable stability to baricitib (BAR).
• Ex vivo assays demonstrated that PIT, ELT, FLA, and EMP effectively inhibited STAT1 and STAT3 phosphorylation, similar to tofacitinib citrate (TOF).

Conclusions:

• Pitavastatin, eltrombopag, flavoxate, and empagliflozin are promising candidates for novel JAK2 inhibitors.
• These compounds exhibit favorable binding interactions within the JAK2 ATP-binding site.
• Further preclinical studies are warranted to explore the therapeutic potential of these identified JAK2 inhibitors.