Consequences of metabolic and oxidative modifications of cartilage tissue

Area of Science:

• Biochemistry
• Biomaterials Science
• Pathology

Background:

• Chronic metabolic diseases (e.g., diabetes, metabolic syndrome) and oxidative stress are linked to extensive protein post-translational modifications.
• These modifications, including glycation, glycoxidation, carbonylation, and nitrosylation, are found on structural cartilage proteins.

Purpose of the Study:

• To investigate the impact of protein post-translational modifications on cartilage structure and function.
• To understand the role of these modifications in the pathogenesis of joint and intervertebral disc degeneration.

Main Methods:

• Analysis of protein modifications in cartilage from affected joints and intervertebral discs.
• Assessment of the effects of modifications on protein folding, aggregation, and cartilage microanatomy.
• Evaluation of the impact on matrix degradation and cartilage viscoelasticity.

Main Results:

• Detected extensive protein modifications (glycation, glycoxidation, carbonylation, nitrosylation) on structural cartilage proteins.
• Observed that these modifications affect protein folding and induce aggregation, leading to microanatomical changes in the proteoglycan-collagen network.
• Demonstrated that modifications promote oxidative cleavage and enzymatic matrix degradation.

Conclusions:

• Biochemical changes in proteins are an early event in cartilage degeneration.
• These modifications compromise cartilage organization and viscoelasticity, impairing its ability to sustain pressure.
• Protein post-translational modifications significantly affect cartilage bio-performance in metabolic diseases and oxidative stress conditions.