Recently I was reading about the structure of musculature with a focus on the difficulties of muscular regeneration in polymyositis. My attention was drawn to the mention that the stem cells for the regeneration of muscle were located in the luminal / sub luminal layer of the muscle. This is probably well-known, but I had not really considered it before.
It reminded me of the excellent article by Drs. Schubert, Masters et al Entitled “APP+ T lymphocytes selectively sorted to endomysial tubes in polymyositis displace NCAM-expressing muscle fibers”.[1] In this article the what interested me was the suggestion that a combined expression of CDT8+, CD4+, and APP+ may form as an invasive front or ‘attack complex.
What particularly struck my notice was the statement that the attack complex so formed attacked the lamina layer in particular, effectively destroying the NCAM adhesion molecules and loosening the endomysial basal lamina, displacing the muscle fibers. The idea is interesting, and I wonder about the effect of this proposed attack complex on the muscular stem cells.
Is it possible that muscular regeneration in polymyositis is thwarted at least in part due to the disruption of the stem cells from their natural habitat by the attack complex targeting the stem cells home in the basal lamina?
Schubert W, Masters CL, Beyreuther K, APP+ T lymphocytes selectively sorted to endomysial tubes in polymyositis displace NCAM-expressing muscle fibers., European Journal of Cell Biology [1993, 62(2):333-342] as found at http://europepmc.org/abstract/med/7925489
