Fig. 3: Increased Ca²⁺ influx through the mutant Cav3.2 channel causes exaggerated mTORC1 signaling in F2688-1-derived NPCs, which, in turn, contributes to impaired Reelin signaling in these cells.

A Intracellular Ca²⁺ measurements in control-derived NPCs (n = 4) and in F2688-1-derived NPCs (NPCs derived from 2 iPSC clones) depolarized with 100 mM KCl and cultured in the absence (vehicle) or presence of 10 μM of the T-type Ca²⁺ channels blocker NNC 55-0396 (NNC). The bar graph shows the median value and interquartile range for each group. F2688-1 NPCs show significantly increased Ca²⁺ influx compared with control NPCs, which was rescued by treatment with NNC. B Representative immunoblots showing the expression levels of pRPS6, pSRC, SRC, pDAB1, DAB1, and β-actin (used as loading control) in control-derived NPCs (n = 4) and in F2688-1-derived NPCs (NPCs derived from 2 iPSC clones) cultured in the absence (−) or presence (+) of 10uM of NNC. The bar graph shows the median levels and interquartile ranges of normalized pRPS6, pSRC, and pDAB1 for each group. While F2688-1-derived NPCs cultured in the absence of NNC show elevated levels of pRPS6 and diminished levels of pSRC and pDAB1, treatment with NNC significantly rescued pRPS6 and pSRC expression to levels similar to the untreated control NPCs. On the other hand, while treatment with NNC significantly improved pDab1 levels in F2688-1 NPCs, there is still a clear trend towards diminished expression of pDAB1 in these cells compared to untreated control cells. *p < 0.05, **p ≤ 0.01, ****p ≤ 0.0001.