Neuropeptides and Articular Cartilage Pathology: Harmful or Helpful or Both?

Abstract

BACKGROUND: Osteoarthritis, a major cause of chronic disabling pain among older adults has long been considered a non-inflammatory “wear and tear” disease associated with aging that largely implicates the loss of articular cartilage of one or more freely moving joints such the knee and hip as a result of biomechanical mechanisms. Recent findings however, imply that in addition to mechanical disruption of an affected joint, its disabling features, including pain, inflammatory mechanisms, and changes in the synovium surrounding the joint play a pivotal role in this regard.

QUESTIONS: Do neuropeptides, small protein like molecules involved in neural transmission processes play a pivotal role in pathogenesis of osteoarthritis associated articular cartilage pathological changes, and can this information be applied clinically, to prevent or ameliorate the condition, and if so how?

METHODS: PUBMED, SCOPUS, and WEB OF SCIENCE articles related to the topic were searched and examined and reported in narrative form. RESULTS: Neuropeptides are widespread neural modulators within the central and peripheral nervous system. Both excess as well as deficient neuropeptide production may prove harmful to articular cartilage, the tissue affected most clearly in osteoarthritis. Some neuropeptides appear trophic rather than catabolic, but very little definitive information prevails that can guide clinical practice safely and effectively.

CONCLUSION: More research to tease out a distinctive role for neuropeptides in the context of articular cartilage destruction and/or repair is strongly indicated.