Fig. 3.

CCN2 R22P variant impairs CCN2 protein secretion. a, b Immunofluorescence analyses of intracellular distribution of Flag-tagged hCCN2 protein in C3H10T1/2 cells infected with plasmids encoding Flag-tagged wild-type or mutant hCCN2 (p.Arg22Pro) after 48 h. Scale bar = 10 μm. Data are represented as mean ± SD (n = 7 for wild-type, n = 6 for mutant). Student’s t test was used. ****P < 0.000 1. c Western blot analysis of Flag-tagged hCCN2 protein abundance in the cell lysates and culture medium of HEK293T cells transfected with indicated plasmids after 48 h. The relative expression of hCCN2 was monitored with the use of monoclonal antibody to Flag, showing bands of the expected size (~40 kD). d RT-PCR of total mRNA of CCN2 from HEK293T cells transfected with indicated plasmids after 48 h. Data are represented as mean ± SD, normalized by the housekeeping Gapdh. Student’s t test was used. ****P < 0.000 1; ns, not significant. e Serum CCN2 levels in affected subjects with SEMD (n = 7) and healthy controls (n = 15), data are represented as median with interquartile range. Mann–Whitney test was used. *P < 0.05