Punch biopsies of human skin were obtained 1 day after irradiation with two minimal-erythema doses (MED) from either a UVB light source or a Solar Simulator and incubated in organ culture for 72 h. Organ culture fluids obtained at 24, 48 and 72 h were analyzed for collagenolytic activity and for reactivity with antibodies to matrix metalloproteinase-1 (MMP-1; interstitial collagenase) and MMP-13 (collagenase-3). High levels of collagenolytic activity were seen in organ culture fluid from skin exposed to either light source. MMP-1 was strongly induced in parallel, increasing from less than 100 ng/ml in organ culture fluid from control skin to approximately 1.1 μg/ml in culture fluid from UV-treated skin. Whereas most of the detectable MMP-1 in control culture fluid was represented by the latent form of the enzyme, approximately 50% of the enzyme was present as the active form in organ culture fluid of UV-exposed skin. In contrast, there was no detectable MMP-13 in control organ culture fluid and very little change after UV exposure (less than 100 ng/ml in both cases). Finally, neutralization studies with a blocking antibody to MMP-1 removed 95 ± 4% of the collagenolytic activity in the organ culture fluid from UV-treated skin. These findings strongly implicate MMP-1 rather than MMP-13 as the major collagenolytic enzyme responsible for collagen damage in photoaging.
You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither BioOne nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the BioOne website.
Vol. 78 • No. 1