Fig. 5

BPA decreases collagen matrix permeability and increases mammary gland stiffness. a An in vitro assay was utilized to measure fibroblast organization of a collagen matrix. A PDMS microfluidic channel was pre-coated with fibronectin and then, fibroblasts isolated from 12-week-old mice were plated with collagen. After 48 h of fibroblast-mediated remodeling of the collagen matrix, a fluorescent liquid was pumped through the channel. Measurement of the pressure and flow velocity was used to calculate the permeability (K) of the collagen matrix arranged by the fibroblasts. b Mammary fibroblasts were isolated from BPA and control 12-week-old mice and cultured within the channel as depicted in a. ECM permeability was measured, and the graph represents the mean ± SD. Control represents the permeability of collagen with no cultured fibroblasts. N = 4 for oil and N = 6 for BPA. c The diagram depicts the methodology to measure mammary gland stiffness. A circular section approximately 4 mm diameter and 1 mm thick was removed adjacent to the lymph node from mammary glands. The amount of applied stress required to compress these disks is measured to determine the stiffness of the gland. d Mammary glands from 4- and 12-week-old mice were analyzed as described in c for stiffness. Measurements of the elastic modulus are graphed as mean ± SD. For 4-week-old samples, N = 4 for oil and N = 4 for BPA, from a minimum of three separate litters. For 12-week-old samples, N = 3 for oil and N = 4 for BPA, from a minimum of three separate litters. e A cohort of mice were treated in utero with either 100 μg/kg · bodyweight DES, 25 μg/kg · bodyweight BPS, or oil control from E9.5 through E18.5. At 12 weeks of age, mammary glands were harvested and gland stiffness measured as depicted in c. Measurements are graphed as mean ± SD. N = 5 for oil, N = 11 for BPS, and N = 5 for DES. *p < 0.05; **p < 0.01