SREBP-1 is dispensable but not required for neuritogenic effect of SIM.

<p>A) Immunoblot showing time dependent effect of SIM on SREBP-1 cleavage. p125 represents the immature form whereas p68 represents the mature cleaved form of SREBP-1. SIM led no change on SREBP-1 cleavage except that a significant (<i>p</i> < 0.05^*) decrease was observed at 2 hrs. Error bar graph represents the fold change (normalized to actin) in p68 protein form at different time points in presence of SIM (mean ± SEM; n = 3). <b>B</b>) Confocal image at 60 X magnification showing immunofluorescence of SREBP-1 in cytoplasm and nucleus till 6 hrs. An increase in SREBP-1 fluorescence (red) intensity is seen in cytoplasm whereas nucleus represents no change in colour. Nuclei have been stained with DAPI (blue). Error bar graph shows fold change in SREBP (p125) fluorescence before and after SIM treatment. Scale Bar = 10µm. <b>C</b>) Semi quantitative RT-PCR showing expression of ACC1, ACC2 and FAS at different time points in presence of SIM. No significant change was observed in transcripts of ACC1. FAS transcripts showed a small decrease at 12 hrs whereas ACC2 transcript showed a significant (<i>p</i> < 0.05^*) decrease at 2 hrs and 12 hrs. Error bar graph represents the comparative fold change (normalized to actin) in ACC1, ACC2 and FAS mRNA levels till 12 hrs in presence of SIM (mean ± SEM; n = 4). <b>D</b>) Morphology of SH-S5Y cells under light microscope showing abrogation of SIM induced neuritogenesis in presence of 25-hydroxy-cholesterol during 12 hrs time period. Scale Bar = 100 µm.