From: Implications for the mammalian sialidases in the physiopathology of skeletal muscle
 | NEU1 | NEU2 | NEU3 | NEU4 |
---|---|---|---|---|
Human chromosomal localization | 6p21.31 | 2q37.1 | 11q13.5 | 2q37.3 |
Human disorders due to inherited deficiency | Sialidosis and Galactosialidosis[55] | none | none | none |
Sialidase animal models | NEU1 −/− mice exhibit muscle degeneration[47] | none | Transgenic NEU3 mice develop insulin resistance[126] | none |
Expression in myoblasts | not detected | |||
Role proposed in muscle cells | NEU1 regulates the ECM deposition in skeletal muscle by limiting the lysosomal exocytosis in the fibroblasts sorrounding the myofibers[47] | NEU2 silencing prevents myoblast differentiation of rat L6 myoblasts[99] | NEU3 behaves as a negative regulator of glucose uptake[126] | Â |
NEU1 can desialylate both IR or IGF1R and influence insulin responsiveness[82] | NEU2 over-expression enhances C2C12 differentiation[98] | NEU3 is involved in C2C12 myoblast fusion by controlling the levels of GM3[137] | Â | |
NEU1 expression increases during the early stages of mouse C2C12 myoblast differentiation[83] | NEU2 expression increases through the PI3K/AKT pathway during differentiation and hypertrophy of C2C12 myotubes[103, 104] | NEU3 over-expression delays differentiation but finally promotes the formation of hypertrophic myotubes[138] | Â | |
NEU1 over-expression impairs C2C12 differentiation[84] | NEU2 is degraded through an autophagic-dependent pathway during atrophy of C2C12 myotubes[104, 107] | Â | Â | |
Muscle-derived tumors: rhabdomyosarcomas | - | NEU2 expression is undetectable in the human embryonal RD cells[109] | Â | Â |