Thursday, January 18, 2018

What does Propionibacterium do to living tissue?

Propionibacterium acnes induces intervertebral disc degeneration by promoting nucleus pulposus cell apoptosis via the TLR2/JNK/mitochondrial-mediated pathway

These authors point out the evidence that intervertebral disc degeneration can be induced by Propionibacterium acnes (P. acnes).

They analyzed the pathological changes in degenerated human intervertebral discs infected with P. acnes, finding that compared with P. acnes-negative samples, P. acnes-positive discs showed increased apoptosis of nucleus pulposus cells concomitant with severe intervertebral disc degeneration. 

They then established a P. acnes inoculated intervertebral disc degeneration animal model, finding that severe intervertebral disc degeneration was induced by P. acnes infection by promoting nucleus pulposus cell apoptosis. 

Their results suggested that P.acnes-induced apoptosis of nucleus pulposus cells via the Toll-like receptor 2 (TLR2)/c-Jun N terminal kinase (JNK) pathway and mitochondrial-mediated cell death. 

Furthermore P. acnes was found to activate autophagy (the orderly degradation and recycling of cellular components), which likely plays a role in apoptosis of nucleus pulposus cells

Overall, these findings further validated the involvement of P. acnes in the pathology of intervertebral disc degeneration and provided evidence that P. acnes-induced apoptosis of nucleus pulposus cells via the TLR2/JNK pathway is likely responsible for the pathology of intervertebral disc degeneration

Comment: While this study concerns intervertebral disc degeneration caused by Propionibacterium, it elucidates the mechanism by which this bacteria can destroy tissue. This same mechanism may be involved in the destruction of bone and soft tissue by this organism in failed arthroplasty and cuff repair.