Skip to main content
SpringerLink
Log in

Sam68 Promotes NF-κB Activation and Apoptosis Signaling in Articular Chondrocytes during Osteoarthritis

  • Original Research Paper
  • Published:
Inflammation Research Aims and scope Submit manuscript

Abstract

Objectives

To investigate the expression of Sam68 in articular cartilage of knee osteoarthritis (OA) and the relationship between Sam68 and NF-κB activation and apoptosis signaling in OA articular chondrocytes.

Methods

Sam68 expression in normal and osteoarthritic cartilage was assessed by immunohistochemistry and RT-PCR on both meniscal/ligamentous injury (MLI)-induced OA rat model and the clinical human OA cartilage tissues. Sam68 expression in chondrocytes under tumor necrosis factor-alpha (TNF-α) stimuli was also assessed by immunoblot. Inhibiting Sam68 in chondrocytes under TNF-α stimuli was conducted using small interfering RNA (siRNA) and its influence on the expression of apoptotic marker and catabolic genes was examined by immunoblot. The mechanism of how Sam68 stimulates NF-κB activity was determined by co-immunoprecipitation and immunoblot analysis of nuclear and cytoplasmic fractions of TNF-α-treated chondrocytes for p65 and Sam68.

Results

Sam68 expression was increased in OA cartilage tissues and chondrocytes under TNF-α stimuli. Inhibition of Sam68 by siRNA significantly decreased the expression of apoptotic markers (cleaved caspase-3 and cleaved PARP) in chondrocytes following TNF-α-stimulation. Sam68 knockdown suppressed Iκ-B degradation and p65 nuclear transportation in TNF-α-treated chondrocytes, indicating a suppressed NF-κB activation. Upon TNF-α exposure, the nuclear transportation of Sam68 and its interaction with p65 was detected in chondrocytes. Furthermore, Sam68 knockdown also alleviated the TNF-α-induced catabolic marker (MMP13, ADAMTS5, iNOS and IL-6) expression.

Conclusions

The highly expressed Sam68 promotes NF-κB signaling activation, catabolic gene expression and cellular apoptosis in TNF-α-treated chondrocytes, which may provide better insights into the pathophysiology of OA and a potential target for its treatment.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1
Fig. 2
Fig. 3
Fig. 4

Similar content being viewed by others

References

  1. Dean DD, Martel-Pelletier J, Pelletier JP, Howell DS, Woessner JF Jr. Evidence for metalloproteinase and metalloproteinase inhibitor imbalance in human osteoarthritic cartilage. J Clin Investig. 1989;84:678–85.

    Article  PubMed Central  CAS  PubMed  Google Scholar 

  2. Kronenberg HM. Developmental regulation of the growth plate. Nature. 2003;423:332–6.

    Article  CAS  PubMed  Google Scholar 

  3. Blanco FJ, Guitian R, Vazquez-Martul E, de Toro FJ, Galdo F. Osteoarthritis chondrocytes die by apoptosis. A possible pathway for osteoarthritis pathology. Arthritis Rheum. 1998;41:284–9.

    Article  CAS  PubMed  Google Scholar 

  4. Kim HA, Lee YJ, Seong SC, Choe KW, Song YW. Apoptotic chondrocyte death in human osteoarthritis. J Rheumatol. 2000;27:455–62.

    CAS  PubMed  Google Scholar 

  5. Aigner T, Soder S, Gebhard PM, McAlinden A, Haag J. Mechanisms of disease: role of chondrocytes in the pathogenesis of osteoarthritis–structure, chaos and senescence. Nat Clin Pract Rheumatol. 2007;3:391–9.

    Article  CAS  PubMed  Google Scholar 

  6. Hashimoto S, Ochs RL, Komiya S, Lotz M. Linkage of chondrocyte apoptosis and cartilage degradation in human osteoarthritis. Arthritis Rheum. 1998;41:1632–8.

    Article  CAS  PubMed  Google Scholar 

  7. Todd Allen R, Robertson CM, Harwood FL, Sasho T, Williams SK, Pomerleau AC, et al. Characterization of mature vs aged rabbit articular cartilage: analysis of cell density, apoptosis-related gene expression and mechanisms controlling chondrocyte apoptosis. Osteoarthr Cartil. 2004;12:917–23.

    Article  CAS  PubMed  Google Scholar 

  8. Li J, Yuan J. Caspases in apoptosis and beyond. Oncogene. 2008;27:6194–206.

    Article  CAS  PubMed  Google Scholar 

  9. Shi J, Schmitt-Talbot E, DiMattia DA, Dullea RG. The differential effects of IL-1 and TNF-alpha on proinflammatory cytokine and matrix metalloproteinase expression in human chondrosarcoma cells. Inflamm Res. 2004;53:377–89.

    Article  CAS  PubMed  Google Scholar 

  10. Marcu KB, Otero M, Olivotto E, Borzi RM, Goldring MB. NF-kappaB signaling: multiple angles to target OA. Curr Drug Targets. 2010;11:599–613.

    Article  PubMed Central  CAS  PubMed  Google Scholar 

  11. Hayden MS, Ghosh S. Signaling to NF-kappaB. Genes Dev. 2004;18:2195–224.

    Article  CAS  PubMed  Google Scholar 

  12. Burd CG, Dreyfuss G. Conserved structures and diversity of functions of RNA-binding proteins. Science. 1994;265:615–21.

    Article  CAS  PubMed  Google Scholar 

  13. Lukong KE, Richard S. Sam68, the KH domain-containing superSTAR. Biochim Biophys Acta. 2003;1653:73–86.

    CAS  PubMed  Google Scholar 

  14. Najib S, Martin-Romero C, Gonzalez-Yanes C, Sanchez-Margalet V. Role of Sam68 as an adaptor protein in signal transduction. Cell Mol life sci CMLS. 2005;62:36–43.

    Article  CAS  PubMed  Google Scholar 

  15. Ramakrishnan P, Baltimore D. Sam68 is required for both NF-kappaB activation and apoptosis signaling by the TNF receptor. Mol Cell. 2011;43:167–79.

    Article  PubMed Central  CAS  PubMed  Google Scholar 

  16. Hamada D, Sampson ER, Maynard RD, Zuscik MJ. Surgical induction of posttraumatic osteoarthritis in the mouse. Methods Mol Biol. 2014;1130:61–72.

    Article  PubMed  Google Scholar 

  17. Kamekura S, Hoshi K, Shimoaka T, Chung U, Chikuda H, Yamada T, et al. Osteoarthritis development in novel experimental mouse models induced by knee joint instability. Osteoarthr Cartil. 2005;13:632–41.

    Article  CAS  PubMed  Google Scholar 

  18. Sampson ER, Beck CA, Ketz J, Canary KL, Hilton MJ, Awad H, et al. Establishment of an index with increased sensitivity for assessing murine arthritis. J Orthop Res. 2011;29:1145–51.

    Article  PubMed Central  PubMed  Google Scholar 

  19. Mainil-Varlet P, Schiavinato A, Ganster MM. Efficacy evaluation of a new hyaluronan derivative HYADD 4-G to maintain cartilage integrity in a rabbit model of osteoarthritis. Cartilage. 2013;4:28–41.

    Article  PubMed Central  PubMed  Google Scholar 

  20. Yui N, Yoshioka H, Fujiya H, Musha H, Beppu M, Karasawa R, et al. The DNA repair enzyme apurinic/apyrimidinic endonuclease (Apex nuclease) 2 has the potential to protect against down-regulation of chondrocyte activity in osteoarthritis. Int J Mol Sci. 2014;15:14921–34.

    Article  PubMed Central  CAS  PubMed  Google Scholar 

  21. Glasson SS, Chambers MG, Van Den Berg WB, Little CB. The OARSI histopathology initiative - recommendations for histological assessments of osteoarthritis in the mouse. Osteoarthr Cartil. 2010;18(Suppl 3):S17–23.

    Article  PubMed  Google Scholar 

  22. Abedian R, Willbold E, Becher C, Hurschler C. In vitro electro-mechanical characterization of human knee articular cartilage of different degeneration levels: a comparison with ICRS and Mankin scores. J Biomech. 2013;46:1328–34.

    Article  PubMed  Google Scholar 

  23. Zhang D, Sun L, Zhu H, Wang L, Wu W, Xie J, et al. Microglial LOX-1 reacts with extracellular HSP60 to bridge neuroinflammation and neurotoxicity. Neurochem Int. 2012;61:1021–35.

    Article  CAS  PubMed  Google Scholar 

  24. Tetsunaga T, Nishida K, Furumatsu T, Naruse K, Hirohata S, Yoshida A, et al. Regulation of mechanical stress-induced MMP-13 and ADAMTS-5 expression by RUNX-2 transcriptional factor in SW1353 chondrocyte-like cells. Osteoarthr Cartil. 2011;19:222–32.

    Article  CAS  PubMed  Google Scholar 

Download references

Acknowledgments

This work was supported by the National Basic Research Program of China (973 Program, No. 2012CB822104); National Natural Science Foundation of China (31170766, 31500647, 81171140); Key Project Natural Science Foundation of Jiangsu University and College (No. 15KJA310003); the Natural Science Foundation of Jiangsu Province (SBK2015041233); Nantong City Social Development Projects funds (HS2012032); a project funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD); Development Fund for Collaborative Innovation Center of Glycoscience of Shandong University.

Author information

Author notes

    Authors and Affiliations

    1. Department of Orthopaedics, Affiliated Hospital of Nantong University, Nantong, 226001, Jiangsu Province, China

      Libin Xu, Chi Sun, Sihui Zhang, Xinbao Xu, Leilei Zhai, Youhua Wang, Shitao Wang, Zhongbing Liu, Ran Tao & Dongmei Zhang

    2. Jiangsu Province Key Laboratory for Inflammation and Molecular Drug Target, Nantong University, Nantong, 226001, Jiangsu Province, China

      Libin Xu, Chi Sun, Sihui Zhang, Xinbao Xu, Leilei Zhai, Youhua Wang, Shitao Wang, Zhongbing Liu, Ran Tao & Dongmei Zhang

    3. Department of Pathogen Biology, Medical College, Nantong University, Nantong, 226001, Jiangsu Province, China

      Dongmei Zhang

    4. Department of Orthopaedics, Traditional Chinese Medical Hospital of Nantong City, Nantong, 226001, Jiangsu Province, China

      Hongbing Cheng

    5. National Glycoengineering Research Center and State Key Laboratory of Microbial Technology, Shandong University, Jinan, 250100, Shandong Province, China

      Min Xiao

    Authors
    1. Libin Xu
      View author publications

      You can also search for this author in PubMed Google Scholar

    2. Chi Sun
      View author publications

      You can also search for this author in PubMed Google Scholar

    3. Sihui Zhang
      View author publications

      You can also search for this author in PubMed Google Scholar

    4. Xinbao Xu
      View author publications

      You can also search for this author in PubMed Google Scholar

    5. Leilei Zhai
      View author publications

      You can also search for this author in PubMed Google Scholar

    6. Youhua Wang
      View author publications

      You can also search for this author in PubMed Google Scholar

    7. Shitao Wang
      View author publications

      You can also search for this author in PubMed Google Scholar

    8. Zhongbing Liu
      View author publications

      You can also search for this author in PubMed Google Scholar

    9. Hongbing Cheng
      View author publications

      You can also search for this author in PubMed Google Scholar

    10. Min Xiao
      View author publications

      You can also search for this author in PubMed Google Scholar

    11. Ran Tao
      View author publications

      You can also search for this author in PubMed Google Scholar

    12. Dongmei Zhang
      View author publications

      You can also search for this author in PubMed Google Scholar

    Corresponding author

    Correspondence to Dongmei Zhang.

    Additional information

    Responsible Editor: Jason J. McDougall.

    L. Xu and C. Sun contributed equally to this work.

    Rights and permissions

    Reprints and permissions

    About this article

    Check for updates. Verify currency and authenticity via CrossMark

    Cite this article

    Xu, L., Sun, C., Zhang, S. et al. Sam68 Promotes NF-κB Activation and Apoptosis Signaling in Articular Chondrocytes during Osteoarthritis. Inflamm. Res. 64, 895–902 (2015). https://doi.org/10.1007/s00011-015-0872-3

    Download citation

    • Received:

    • Revised:

    • Accepted:

    • Published:

    • Issue Date:

    • DOI: https://doi.org/10.1007/s00011-015-0872-3

    Keywords

    Search

    Navigation