UV irradiation alters COLI protein expression in rat skin in vivo - immunohistology. Biopsied skin samples were obtained 8 weeks after exposure to UVB, and were localized by immunohistology, as described in Materials and Methods. A, non-irradiated skin; B, UVB-irradiated induced photoaging skin; C, ADSCs pretreatment after 7 d; D, ADSCs pretreatment after 14 d; E, combined treatment group after 7 d; F, combined treatment group after 14 d; G, CO2 fractional laser pretreatment after 7 d; H, CO2 fractional laser pretreatment after 14 d. Panels show results for a single individual, but are representative of six individuals. Immunostain, ×400. Scale bars are 100 μm.