Inflammatory Processes Associated with Canine Intervertebral Disc Herniation.

Area of Science:

• Veterinary Medicine
• Immunology
• Molecular Biology

Background:

• Intervertebral disc herniation (IVDH) is a common condition in both humans and dogs.
• While human IVDH mechanisms are well-studied, canine IVDH inflammatory mediators remain largely unknown.
• Understanding canine IVDH can help elucidate human disease mechanisms and validate dogs as a comparative model.

Purpose of the Study:

• To investigate if pro-inflammatory cytokines involved in human IVDH are also key in canine IVDH.
• To assess the suitability of dogs with naturally occurring IVDH as a model for human clinical trials.
• To analyze the expression of IL-1β, IL-6, IL-8, and TNF-α in canine IVDH tissues.

Main Methods:

• Analysis of 59 canine IVDH samples (herniated, non-herniated, adjacent discs) and 11 healthy controls.
• Quantification of cytokine gene and protein expression using qPCR and ELISA.
• Immunohistochemical analysis of cell infiltration and MAP kinase pathway activation.

Main Results:

• Elevated gene expression of IL-6 and TNF-α, and down-regulation of IL-1β in canine IVDH tissues compared to controls.
• Increased IL-8 and TNF-α protein levels, while IL-6 protein levels were higher in dogs with better clinical outcomes.
• Presence of monocytes and macrophages with activated p38 MAP kinase in herniated disc material.

Conclusions:

• Canine IVDH shares some inflammatory cytokine profiles with human IVDH, supporting its use as a comparative model.
• Partial divergence in inflammatory mechanisms between canine and human IVDH necessitates further investigation.
• IL-6 appears to play a significant pathological role in canine IVDH and represents a potential therapeutic target.