Glycosylation is one of the most important post-translational modifications. It is clear that the single step of β1,4-galactosylation
is performed by a family of β1,4-galactosyltransferases (β1,4-GalTs), and that each member of this family may play a distinct
role in different tissues and cells. β1,4-GalT I and V are involved in the biosynthesis of N-linked oligosaccharides and play
roles in sciatic nerve regeneration after sciatic nerve injury. In the present study, the expression of β1,4-galactosyltransferase
(β1,4-GalT) I, V mRNAs and Galβ1-4GlcNAc group were examined in rat gastrocnemius muscles after sciatic nerve crush and transection.
Real time PCR revealed that β1,4-GalT I and V mRNAs expressed at a high level in normal gastrocnemius muscles and decreased
gradually from 6 h, reached the lowest level at 2 weeks, then restored gradually to relatively normal level at 4 weeks after
sciatic nerve crush. In contrast, in sciatic nerve transection model, β1,4-GalT I and V mRNAs decreased gradually from 6 h,
and remained on a low level at 4 weeks in gastrocnemius muscles after sciatic nerve transection.
In situ hybridization indicated that β1,4-GalT I and V mRNAs localized in numerous myocytes and muscle satellite cells under normal
conditions and at 4 weeks after sciatic nerve crush, and in a few muscle satellite cells at 4 weeks after sciatic nerve transection.
Furthermore, lectin blotting showed that the expression level of the Galβ1–4GlcNAc group decreased from 6 h, reached the lowest
level at 2 weeks, and restored to relatively normal level at 4 weeks after sciatic nerve crush. RCA-I lectin histochemistry
demonstrated that Galβ1–4GlcNAc group localized in numerous membranes of myocytes and muscle satellite cells in normal and
at 4 weeks after sciatic nerve crush, and in a few muscle satellite cells at 2 and 4 weeks after sciatic nerve transection.
These results indicated that the expressions of β1,4-GalT I, V mRNAs and Galβ1–4GlcNAc group were involved in the process
of denervation and reinnervation, which suggests that β1,4-GalT I, V mRNAs and Galβ1-4GlcNAc group may play an important role
in the muscle regeneration.
Keywords β1,4-Galactosyltransferases I and V - Galβ1 - 4GlcNAc group - Sciatic nerve injury - Real-time PCR -
In situ hybridization - RCA