Bovine articular chondrocyte function in vitro depends upon oxygen tension

Area of Science:

• Biochemistry
• Cell Biology
• Tissue Engineering

Background:

• Articular cartilage is a hypoxic tissue with oxygen tension varying from 10% at the surface to <1% in deep layers.
• Chondrocyte behavior and gene expression are influenced by oxygen levels, which can be altered in joint diseases.
• Understanding chondrocyte responses to different oxygen tensions is crucial for cartilage research and treatment.

Purpose of the Study:

• To investigate the effects of varying oxygen tensions on bovine articular chondrocyte survival, metabolism, and matrix production.
• To determine the optimal oxygen levels for maintaining chondrocyte function in vitro.
• To assess chondrocyte response to anoxic conditions relevant to disease states.

Main Methods:

• Bovine articular chondrocytes were cultured in alginate beads for 7 days.
• Cells were exposed to different oxygen tensions: <0.1%, 5%, 10%, and 20% oxygen.
• Assessed chondrocyte survival, differentiation, cell division, viability, matrix production, and rRNA/mRNA abundance.

Main Results:

• Chondrocytes survived for 7 days at all tested oxygen tensions.
• Metabolic activity and matrix production were reduced under anoxic conditions (<0.1% oxygen).
• No significant differences in cell division or differentiation were observed across oxygen tensions; 5-10% oxygen supported full activity.

Conclusions:

• Articular chondrocytes can be successfully cultured in vitro at physiological oxygen levels (5-10% pO(2)).
• Anoxic conditions (<0.1% pO(2)) significantly compromise chondrocyte function, particularly metabolic activity and matrix synthesis.
• These findings highlight the importance of oxygen microenvironment for maintaining chondrocyte health and function.