Aging-related loss of the chromatin protein HMGB2 in articular cartilage is linked to reduced cellularity and osteoarthritis

Noboru Taniguchi, Beatriz Caramés, Lorenza Ronfani, Ulrich Ulmer, Setsuro Komiya, Marco E. Bianchi, Martin Lotz

Research output: Contribution to journalArticlepeer-review


Osteoarthritis (OA) is the most common joint disease and typically begins with an aging-related disruption of the articular cartilage surface. Mechanisms leading to the aging-related cartilage surface degeneration remain to be determined. Here, we demonstrate that nonhistone chromatin protein high-mobility group box (HMGB) protein 2 is uniquely expressed in the superficial zone (SZ) of human articular cartilage. In human and murine cartilage, there is an aging-related loss of HMGB2 expression, ultimately leading to its complete absence. Mice genetically deficient in HMGB2 (Hmgb2-/-) show earlier onset of and more severe OA. This is associated with a profound reduction in cartilage cellularity attributable to increased cell death. These cellular changes precede glycosaminoglycan depletion and progressive cartilage erosions. Chondrocytes from Hmgb2-/- mice are more susceptible to apoptosis induction in vitro. In conclusion, HMGB2 is a transcriptional regulator specifically expressed in the SZ of human articular cartilage and supports chondrocyte survival. Aging is associated with a loss of HMGB2 expression and reduced cellularity, and this contributes to the development of OA.

Original languageEnglish
Pages (from-to)1181-1186
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Issue number4
Publication statusPublished - Jan 27 2009


  • Apoptosis
  • Chondrocytes
  • HMGB
  • Superficial zone

ASJC Scopus subject areas

  • General


Dive into the research topics of 'Aging-related loss of the chromatin protein HMGB2 in articular cartilage is linked to reduced cellularity and osteoarthritis'. Together they form a unique fingerprint.

Cite this