Discovery of novel cathepsin K inhibitors for osteoporosis treatment using a deep learning-based strategy

Qi Li1,2, Xue-Chun Han1,2, Si-Rui Zhou1,2

  • 1Beijing Key Laboratory of Diabetes Research and Care, Beijing Diabetes Institute, Beijing Tongren Hospital, Capital Medical University, Beijing, China.

Abstract

Insights

Researchers developed a deep learning model to find new Cathepsin K (CTSK) inhibitors for osteoporosis. Quercetin, γ-Linolenic acid (GLA), and Benzyl isothiocyanate (BITC) show promise as potent CTSK inhibitors and for reducing osteoclast formation.

Area of Science:

  • Biochemistry
  • Pharmacology
  • Computational Chemistry

Background:

  • Cathepsin K (CTSK) is a key target for osteoporosis treatment due to its high expression in osteoclasts.
  • Currently, no CTSK inhibitors are approved for clinical use, highlighting an unmet medical need.

Purpose of the Study:

  • To identify novel Cathepsin K (CTSK) inhibitors using a combination of deep learning and experimental validation.
  • To evaluate the inhibitory potential and mechanisms of action of identified compounds against CTSK.
  • To assess the efficacy of lead compounds in inhibiting osteoclastogenesis.

Main Methods:

  • Developed a predictive deep learning model (Chemprop) for CTSK inhibition.
  • Screened 100 predicted molecules experimentally, followed by enzyme kinetics, molecular docking, and molecular dynamics simulations.
  • Conducted in-vitro assays using RAW264.7 cells to evaluate inhibition of RANKL-induced osteoclastogenesis.

Main Results:

  • Identified six compounds with concentration-dependent CTSK inhibitory activity.
  • Quercetin, γ-Linolenic acid (GLA), and Benzyl isothiocyanate (BITC) emerged as the most potent inhibitors.
  • Enzyme kinetics and molecular dynamics revealed distinct inhibition mechanisms and stable active site interactions for Quercetin and BITC.
  • Quercetin and GLA significantly inhibited osteoclast formation in vitro.

Conclusions:

  • A deep learning model for predicting CTSK inhibitors was successfully developed.
  • Quercetin, GLA, and BITC are identified as promising therapeutic candidates for osteoporosis treatment.
  • The study provides a foundation for developing novel CTSK-targeted osteoporosis therapies.