PMID- 36858195 OWN - NLM STAT- MEDLINE DCOM- 20230619 LR - 20240216 IS - 1522-9653 (Electronic) IS - 1063-4584 (Print) IS - 1063-4584 (Linking) VI - 31 IP - 7 DP - 2023 Jul TI - CAMKK2 is upregulated in primary human osteoarthritis and its inhibition protects against chondrocyte apoptosis. PG - 908-918 LID - S1063-4584(23)00696-9 [pii] LID - 10.1016/j.joca.2023.02.072 [doi] AB - OBJECTIVE: To investigate the role of calcium/calmodulin-dependent protein kinase kinase 2 (CAMKK2) in human osteoarthritis. MATERIALS AND METHODS: Paired osteochondral plugs and articular chondrocytes were isolated from the relatively healthier (intact) and damaged portions of human femoral heads collected from patients undergoing total hip arthroplasty for primary osteoarthritis (OA). Cartilage from femoral plugs were either flash frozen for gene expression analysis or histology and immunohistochemistry. Chondrocyte apoptosis in the presence or absence of CAMKK2 inhibition was measured using flow cytometry. CAMKK2 overexpression and knockdown in articular chondrocytes were achieved via Lentivirus- and siRNA-mediated approaches respectively, and their effect on pro-apoptotic and cartilage catabolic mechanisms was assessed by immunoblotting. RESULTS: CAMKK2 mRNA and protein levels were elevated in articular chondrocytes from human OA cartilage compared to paired healthier intact samples. This increase was associated with elevated catabolic marker matrix metalloproteinase 13 (MMP-13), and diminished anabolic markers aggrecan (ACAN) and type II collagen (COL2A1) levels. OA chondrocytes displayed enhanced apoptosis, which was suppressed following pharmacological inhibition of CAMKK2. Levels of MMP13, pSTAT3, and the pro-apoptotic marker BAX became elevated when CAMKK2, but not its kinase-defective mutant was overexpressed, whereas knockdown of the kinase decreased the levels of these proteins. CONCLUSIONS: CAMKK2 is upregulated in human OA cartilage and is associated with elevated levels of pro-apoptotic and catabolic proteins. Inhibition or knockdown of CAMKK2 led to decreased chondrocyte apoptosis and catabolic protein levels, whereas its overexpression elevated them. CAMKK2 may be a therapeutic target to prevent or mitigate human OA. CI - Copyright (c) 2023 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved. FAU - Dilley, J E AU - Dilley JE AD - Department of Anatomy, Cell Biology and Physiology, Indiana University School of Medicine, Indianapolis, IN 46202, USA; Department of Orthopaedic Surgery, Indiana University School of Medicine, Indianapolis, IN 46202, USA; Indiana Center for Musculoskeletal Health, Indiana University School of Medicine, Indianapolis, IN 46202, USA. Electronic address: jedilley@indiana.edu. FAU - Seetharam, A AU - Seetharam A AD - Department of Anatomy, Cell Biology and Physiology, Indiana University School of Medicine, Indianapolis, IN 46202, USA; Department of Orthopaedic Surgery, Indiana University School of Medicine, Indianapolis, IN 46202, USA; Indiana Center for Musculoskeletal Health, Indiana University School of Medicine, Indianapolis, IN 46202, USA. Electronic address: abhiseet@iu.edu. FAU - Ding, X AU - Ding X AD - Department of Anatomy, Cell Biology and Physiology, Indiana University School of Medicine, Indianapolis, IN 46202, USA; Indiana Center for Musculoskeletal Health, Indiana University School of Medicine, Indianapolis, IN 46202, USA. Electronic address: xinding@iu.edu. FAU - Bello, M A AU - Bello MA AD - Department of Anatomy, Cell Biology and Physiology, Indiana University School of Medicine, Indianapolis, IN 46202, USA; Indiana Center for Musculoskeletal Health, Indiana University School of Medicine, Indianapolis, IN 46202, USA. Electronic address: belloma@iu.edu. FAU - Shutter, J AU - Shutter J AD - Department of Anatomy, Cell Biology and Physiology, Indiana University School of Medicine, Indianapolis, IN 46202, USA; Indiana Center for Musculoskeletal Health, Indiana University School of Medicine, Indianapolis, IN 46202, USA. Electronic address: jeshut@iu.edu. FAU - Burr, D B AU - Burr DB AD - Department of Anatomy, Cell Biology and Physiology, Indiana University School of Medicine, Indianapolis, IN 46202, USA; Indiana Center for Musculoskeletal Health, Indiana University School of Medicine, Indianapolis, IN 46202, USA. Electronic address: dburr@iu.edu. FAU - Natoli, R M AU - Natoli RM AD - Department of Orthopaedic Surgery, Indiana University School of Medicine, Indianapolis, IN 46202, USA; Indiana Center for Musculoskeletal Health, Indiana University School of Medicine, Indianapolis, IN 46202, USA. Electronic address: rnatoli@iuhealth.org. FAU - McKinley, T O AU - McKinley TO AD - Department of Anatomy, Cell Biology and Physiology, Indiana University School of Medicine, Indianapolis, IN 46202, USA; Department of Orthopaedic Surgery, Indiana University School of Medicine, Indianapolis, IN 46202, USA; Indiana Center for Musculoskeletal Health, Indiana University School of Medicine, Indianapolis, IN 46202, USA. Electronic address: tmckinley@iuhealth.org. FAU - Sankar, U AU - Sankar U AD - Department of Anatomy, Cell Biology and Physiology, Indiana University School of Medicine, Indianapolis, IN 46202, USA; Indiana Center for Musculoskeletal Health, Indiana University School of Medicine, Indianapolis, IN 46202, USA. Electronic address: usankar@iu.edu. LA - eng GR - R01 AR076477/AR/NIAMS NIH HHS/United States GR - T32 AR065971/AR/NIAMS NIH HHS/United States GR - UL1 TR002529/TR/NCATS NIH HHS/United States PT - Journal Article DEP - 20230227 PL - England TA - Osteoarthritis Cartilage JT - Osteoarthritis and cartilage JID - 9305697 RN - EC 2.7.11.17 (CAMKK2 protein, human) RN - EC 2.7.11.17 (Calcium-Calmodulin-Dependent Protein Kinase Kinase) SB - IM MH - Humans MH - Chondrocytes/metabolism MH - *Cartilage, Articular/pathology MH - Cells, Cultured MH - *Osteoarthritis/metabolism MH - Apoptosis MH - Calcium-Calmodulin-Dependent Protein Kinase Kinase/genetics PMC - PMC10272098 MID - NIHMS1879738 OTO - NOTNLM OT - Apoptosis OT - CAMKK2 OT - Catabolism OT - Chondrocyte OT - Osteoarthritis COIS- Conflict of interest All authors of this manuscript state that they have no conflict of interest. The authors further state that there are no restrictions on full access for all authors to all raw data, statistical analyses and material used in the study reported in this manuscript. EDAT- 2023/03/02 06:00 MHDA- 2023/06/19 13:08 PMCR- 2024/07/01 CRDT- 2023/03/01 19:25 PHST- 2022/07/22 00:00 [received] PHST- 2023/02/15 00:00 [revised] PHST- 2023/02/15 00:00 [accepted] PHST- 2024/07/01 00:00 [pmc-release] PHST- 2023/06/19 13:08 [medline] PHST- 2023/03/02 06:00 [pubmed] PHST- 2023/03/01 19:25 [entrez] AID - S1063-4584(23)00696-9 [pii] AID - 10.1016/j.joca.2023.02.072 [doi] PST - ppublish SO - Osteoarthritis Cartilage. 2023 Jul;31(7):908-918. doi: 10.1016/j.joca.2023.02.072. Epub 2023 Feb 27.