Figure 3.

Specific knockout of Kindlin-2 in adult smooth muscle causes individual death from intestinal obstruction. (A) A body-weight based growth curve for Kindlin-2^fl/fl;MYH-cre-(WT) and Kindlin-2^fl/fl;MYH-cre+ mice ³⁹ after tamoxifen injection (n=4), *p < 0.05, **p < 0.01, ***p < 0.001. (B) Food intake and feces excretion after 4 weeks of tamoxifen injection (n=4 each group), *p < 0.05, **p < 0.01. (C) Whole-gut transit time for WT and adult iKO mice (n=4), ***p < 0.001. (D) Systolic blood pressure curve for WT and iKO mice, tamoxifen injection was treated at day 1, n=4, *p < 0.05 (E) Diastolic blood pressure curve for WT and iKO mice, tamoxifen injection was treated at day 1, n=4, *p < 0.05. (F) Kaplan-Meier survival plot of WT (n=11) versus iKO littermates (n=10). Mice were treated with tamoxifen at 6-8 weeks, and the plot begins 1 day later. All iKO mice developed huge colon-like obstruction and died before 40 days, while the control mice grown normally. p = 0.0006. (G) Left, ventral view of colons on WT and iKOmice at the time of necropsy, 5 weeks after tamoxifen treatment, iKO mice displayed a huge colon-like phenotype (white arrows). Middle, intestinal swiss roll after HE staining. Scale bar, 3mm (the second column), 100μm (the third and fourth columns). (H) Western blot analysis of Kindlin-2, smooth muscle markers Myh11, CNN and Actin protein expression of colon in three types of control mice, Kindlin-2^fl/fl;MYH-cre-, Kindlin-2^wt/wt; MYH-cre+ mice underwent tamoxifen injections, and Kindlin-2^fl/fl;MYH-cre+ with corn oil injections, colons were harvested after 4 weeks of rest period, no significant difference was found. (I) Western blot analysis of Kindlin-2, smooth muscle markers Myh11, CNN and Actin protein expression of colon in WT, Kindlin-2^fl/wt;MYH-cre+, and iKO mice. 4 weeks after tamoxifen treatment. (J) Quantitation of Fig I, *p < 0.05, **p < 0.01, ***p < 0.001. See Figure S4 for additional information.