FIG. 4.

Subcutaneous injection of DA-CM alleviates the reduction of collagen and improves the arrangement of collagen in the photoaged mouse skin dermis. Two hundred microliters of concentrated DA-CM was subcutaneously injected into the skin of photoaged mice. Skin samples were taken on indicated days and subjected to stain with H&E (A) and Masson trichrome (B). Collagen fibers were stained blue and background red. The pictures were taken under ×200 magnification. The thicknesses of the dermis and epidermis by H&E staining were measured by ImageJ and the relative thickness of the dermis (the ratio of thickness of dermis to that of dermis plus epidermis) was calculated (C). The Masson staining positive areas were analyzed by ImageJ and the average percentage of stained area was calculated (D). Data are mean±SD, n=8, *P<0.05 versus injection of same volume of concentrated DMEM as a control. DA-CM, conditioned medium from DA. Color images available online at www.liebertpub.com/scd