Fig. 4: Cells rapidly adapt to fluid interface via lipid raft/FAK pathway, that direct neuronal differentiation of hMSCs.

a Representative confocal images of lipid rafts of non-treated and MβCD-treated hMSCs. Cells cultured on coverslip as control. Lipid rafts were labeled with Alexa Fluor 488-conjugated CTB. Scale bar: 50 μm. b Quantification of CTB intensity. *P < 0.05, one-way ANOVA with Bonferroni post hoc test. Expression of neurogenesis markers TUBB3 (c) and MAP2 (d) of non-treated, MβCD-treated and pFAK inhibitor (pFAKi)-treated hMSCs cultured at the PFO/water interface (pH 2). Gene expression was normalized to GAPDH. n = 3, mean ± s.d., *P < 0.05, **P < 0.01, two-tailed Student’s t-test. e Representative confocal images (magnifications in the second column) of the colocalization of pFAK and vinculin of non-treated and MβCD-treated hMSCs on protein nanosheets at the PFO/water interface (pH 2). Pink lines in the second column indicate the pixel regions for intensity profiles. Scale bars: 20 μm. f Quantification of pFAK localization to FA area by fluorescence intensity. g Quantification of percentage of FA area positive for pFAK. f, g n = 5 cells for control and nanofibril at PFO; n = 4 cells for monomer at PFO; Lines and error bars indicate the mean ± s.d., *P < 0.05, **P < 0.01, one-way ANOVA with Bonferroni post hoc test.