Fig. 1: Loss of oligodendroglial AnkG leads to destabilization of paranodal junctions during aging.

a Schematic of the Ank3 conditional allele and NG2^Cre-mediated recombination. b Immunoblot for AnkG in whole brain homogenates from 2 month-old control (Ank3^F/F), AnkG cHT (NG2^Cre+;Ank3^F/+), and AnkG cKO (NG2^Cre+;Ank3^F/F) animals. All three major isoforms of AnkG (480 kDa, 270 kDa, 190 kDa) are detected. β-Actin is the loading control. c Densitometry analysis of AnkG (270 and 190 kDa isoforms) in the brains of 2 month-old control, cHT, and cKO mice. N = 4 for each genotype. Two-way ANOVA with multiple comparisons. 270 kDa WT vs cHT: t = 2.423, DF = 18.00; WT vs cKO: t = 2.084, DF = 18.00; cHT vs cKO: t = 4.507, DF = 18.00. 190 kDa WT vs cHT: t = 3.108, DF = 18.00; WT vs cKO: t = 5.445, DF = 18.00; cHT vs cKO: t = 2.337, DF = 18.00. d Representative immunofluorescence staining of AnkG and βIV spectrin in the optic nerve of 2 month-old control and cKO mice. Arrowheads indicate paranodes. Scale bar, 10 µm. (Cyan: AnkG, Magenta: βIV-spectrin) from at least 3 independent experiments. e Immunofluorescence labeling of nodal (Yellow: Neurofascin186), paranodal (Cyan: Caspr) and juxtaparanodal (Magenta: Kv1.2) proteins in the spinal cord of 14 month-old control and cKO mice. Severe paranodal unwinding is only observed in the large-diameter axons. From at least 3 independent experiments. Scale bar, 10 µm. f–g Line-scan analysis of nodes of Ranvier on large-diameter axons of control (f) and cKO (g) mice. Black: Neurofascin186, cyan: Caspr, magenta: Kv1.2. h Quantification of the frequency of paranodal abnormalities (unwinding of Caspr and invasion of Kv1.2 into paranodes) in large- and small-diameter axons. Two-way ANOVA with multiple comparisons. Large diameter: t = 6.293, DF = 18.00, N = 5; small diameter: t = 0.9374, DF = 18.00, N = 6. Data are plotted as Mean±SEM. Each data point represents an individual animal. All p-values are labeled on the graphs. Source data are provided as a Source Data file.