Figure 3

Increased apoptotic and proliferative activities as SRF depleted in Srf KO SMCs. (a) Cryosection images of jejunum showing gradual depletion of SRF (green, nucleus) and reduction of SMA (red, cytoplasm) in KO SMCs compared with WT control at 10, 15, 21 and 28 days post-tamoxifen injection (PT10–PT28). (b) Cryosection images of PT10–PT28 showing reactivity of TUNEL (green, nucleus), which was significantly increased in KO SMCs at PT21, compared with WT control. Expression of MYH11 (red, cytoplasm) was significantly less in apoptotic SMCs. (c) Cryosection images of PT10–PT28 showing reactivity of Ki-67 (green, nucleus), which was slightly increased in KO SMCs at PT21, compared with WT control. Expression of MYH11 (red, cytoplasm) was significantly less in KO SMCs. (d) High-magnification images of TUNEL reactivity in longitudinal (LM) and circular muscle (CM) layers at PT21 of KO and WT. Quantification of SRF⁺ cells (e), apoptotic (TUNEL⁺) cells (f) and proliferating (Ki-67⁺) cells (g) in the jejunal muscle layers of KO and WT in cryosection images (a–c) of PT10–PT28 (each n=3). Values are expressed as means±S.E. *P<0.01, **P<0.001, ***P<0.0001 versus WT. (h) Analysis of apoptotic DNA. Genomic DNA (500 ng of each) isolated from PT19, PT21 and PT22 of WT and/or KO was analyzed on a 1% agarose gel with a 10-kb DNA ladder