Volume 136, Issue 6 e202318459
Forschungsartikel

Real-Time Live Imaging of Osteoclast Activation via Cathepsin K Activity in Bone Diseases

Prof. Seyoung Koo

Prof. Seyoung Koo

Department of Chemistry, Korea University, Seoul, 02841 Korea

Department of Biomedical and Chemical Sciences, Hyupsung University, Hwaseong, 18330 Korea

These authors contributed equally to this work.

Search for more papers by this author
Dr. Eun Jung Lee

Dr. Eun Jung Lee

Department of Biochemistry and Molecular Biology, Korea University College of Medicine, Seoul, 02841 Korea

These authors contributed equally to this work.

Search for more papers by this author
Dr. Hao Xiong

Dr. Hao Xiong

Department of Chemistry, Korea University, Seoul, 02841 Korea

Search for more papers by this author
Da Hyeon Yun

Da Hyeon Yun

Department of Biochemistry and Molecular Biology, Korea University College of Medicine, Seoul, 02841 Korea

Search for more papers by this author
Prof. Michelle M. McDonald

Prof. Michelle M. McDonald

Skeletal Diseases Program, The Garvan Institute of Medical Research, Darlinghurst, NSW, 2010 Australia

St Vincent's Clinical Campus, School of Clinical Medicine, University of New South Wales, Kensington, NSW, 2052 Australia

School of Medicine Science, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW, 2006 Australia

Search for more papers by this author
Prof. Serk In Park

Corresponding Author

Prof. Serk In Park

Department of Biochemistry and Molecular Biology, Korea University College of Medicine, Seoul, 02841 Korea

Vanderbilt Center for Bone Biology, Vanderbilt University School of Medicine, Nashville, TN, 37232 USA

Search for more papers by this author
Prof. Jong Seung Kim

Corresponding Author

Prof. Jong Seung Kim

Department of Chemistry, Korea University, Seoul, 02841 Korea

TheranoChem Incorporation, Seoul, 02856 Korea

Search for more papers by this author
First published: 17 December 2023
Citations: 4

Abstract

Intravital fluorescence imaging of functional osteoclasts within their intact disease context provides valuable insights into the intricate biology at the microscopic level, facilitating the development of therapeutic approaches for osteoclast-associated bone diseases. However, there is a lack of studies investigating osteoclast activity within deep-seated bone lesions using appropriate fluorescent probes, despite the advantages offered by the multi-photon excitation system in enhancing deep tissue imaging resolution. In this study, we report on the intravital tracking of osteoclast activity in three distinct murine bone disease models. We utilized a cathepsin K (CatK)-responsive two-photon fluorogenic probe (CatKP1), which exhibited a notable fluorescence turn-on response in the presence of active CatK. By utilizing CatKP1, we successfully monitored a significant increase in osteoclast activity in hindlimb long bones and its attenuation through pharmacological intervention without sacrificing mice. Thus, our findings highlight the efficacy of CatKP1 as a valuable tool for unraveling pathological osteoclast behavior and exploring novel therapeutic strategies.

Conflict of interest

The authors declare no conflict of interest.

Data Availability Statement

The data that support the findings of this study are available in the supplementary material of this article.

The full text of this article hosted at iucr.org is unavailable due to technical difficulties.