Vitamin D inhibits TGFβ₁-mediated myofibroblast contraction.

<p>Representative images of 48 hour timepoint from collagen gel contraction assay are shown in A-D. A) Untreated HCF-av; B) HCF-av treated with TGFβ₁; C) HCF-av treated with 1,25(OH)₂D₃; D) HCF-av treated with TGFβ₁ + 1,25(OH)₂D₃. A time course of gel contraction over 96 hours is shown in (E). Active vitamin D treatment significantly inhibited TGFβ₁-induced gel contraction at all time points post-treatment. All data points represent mean ± SEM. p-values calculated using two way repeated measures analysis of variance with Bonferroni multiple comparison test. *p<0.05, ***p<0.001. F and G) Confocal images of HCF-av at 48 hours following treatment. Stress fibers were stained with phalloidin. HCF-av treated with TGFβ₁(F) demonstrate increased presence of clearly defined stress fibers (white) as compared with cells treated with TGFβ₁ + 1,25(OH)₂D₃ (G). Scale bar: 70μm.