Fig. 4

Impaired differentiation of CRS-ONS into OSNs. A Western blot analysis of immature OSN markers TrkB and GAP43 in DNS- and CRS-ONS, and DNS- and CRS-OSNs at day 7 post-OSN induction. B Immunostaining images of ONS and OSNs from DNS and CRS patients at day 7, stained for OMP and AC3. Scale bars, 20 µm. C Western blot analysis of nuclear fractions from DNS- and CRS-ONS and OSNs collected at day 7 post-induction, with Anti-LaminA as a control. D RT-PCR quantification of relative gene expression levels of BDNF and GDNF in DNS- and CRS-ONS exposed to OSN induction medium on days 4 and 7, compared to undifferentiated cells. E Western blot analysis of BDNF and GDNF expression in DNS- and CRS-ONS and DNS- and CRS-OSNs at day 7 post-induction. F Luminex assays quantifying BDNF and GDNF levels in the culture supernatants of DNS- and CRS-ONS, untreated and after OSN induction medium treatment on day 7 (n = 11 per group). Statistical analyses used one-way ANOVA with Tukey’s post-hoc test. Data are presented as mean ± standard deviation. *P < 0.05 and #P < 0.01 differentiate ONS from OSNs groups; **P < 0.05 and ##P < 0.01 comparing DNS- to CRS-OSNs (n = 5 per group)