Trichinella spiralis muscle larvae excretory-secretory products induce changes in cytoskeletal and myogenic transcription factors in primary myoblast cultures.

Trichinella spiralis infection in skeletal muscle culminates with nurse cell formation. The participation of excretory-secretory products of the muscle larvae has been implicated in this process through different studies performed in infected muscle and the muscle cell line C2C12. In this work, we developed primary myoblast cultures to analyse the changes induced by excretory-secretory products of the muscle larvae in muscle cells. Microarray analyses revealed expression changes in muscle cell differentiation, proliferation, cytoskeleton organisation, cell motion, transcription, cell cycle, apoptosis and signalling pathways such as MAPK, Jak-STAT, Wnt and PI3K-Akt. Some of these changes were further evaluated by other methodologies such as quantitative real-time PCR (qRT-PCR) and western blot, confirming that excretory-secretory products of the muscle larvae treated primary mouse myoblasts undergo increased proliferation, decreased expression of MHC and up-regulation of α-actin. In addition, changes in relevant muscle transcription factors (Pax7, Myf5 and Mef2c) were observed. Taken together, these results provide new information about how T. spiralis could alter the normal process of skeletal muscle repair after ML invasion to accomplish nurse cell formation.