Fig. 7. Re-expressing Crabp1 in spinal MNs rescues motor defects, repairs NMJs and recovers neural Agrn expression.

A Experimental scheme for AAV-mediated rescue experiments. Control- or AAV.Crabp1-virus was injected into 3-weeks old mice. At 3-months old, spinal cord was collected for monitoring the expression rescue gene. At 10-months old, mice were subjected to behavioral tests, and then sacrificed. Spinal cord and lumbrical muscle were harvested for NMJ and gene expression analyses. B Western blots showing the efficiency and specificity of AAV virus-mediated expression of rescuing gene (GFP tagged Ctrl.AAV or GFP-tagged AAV.Crabp1), and the expression of AGRIN in spinal cord. Quantification of changes in CRABP1 and AGRIN expression in spinal cord is shown under the corresponding panel. N.S. indicates a non-specific signal above the band for CRABP1. C Left: Representative image of a spinal cord section from an AAV-infected mouse, detected with GFP (green) and MN marker, ChAT (red) (Scale bar is 50 um); Right: Quantification of GFP + (virus-infected cells) and ChAT+ MNs from Ctrl (GFP control) or AAV.Crabp1 injected mice. The results show greater than 60% MNs that harvest/express the injected Ctrl or AAV.Crabp1 (n = 2/group). D Grip strength. E Hanging tests (WT + Ctrl.AAV, n = 7; CKO + Ctrl.AAV, n = 9; CKO + AAV.Crabp1, n = 11). F Recovery in NMJ number of rescued CKO mice. G qPCR analysis showing recovered Agrn expression in spinal MN of rescued CKO mice (n = 6/group). Results are presented as means ± SD, *p  ≤  0.05, **p  ≤  0.01, compared with target group.