Ryota Mori
Development Laboratory, SEPTEM-SOKEN Co., Ltd.,
Masamichi Ishigami
Development Laboratory, SEPTEM-SOKEN Co., Ltd.,
Masanori Okada
Development Laboratory, SEPTEM-SOKEN Co., Ltd.,
Hitoshi Masaki
Tokyo University of Technology

[Abstract]
Recently, carbonylated proteins (CPs) as final product of lipid peroxidation have been attracted attention about function on skin physiology. The accumulation of the CPs in intracellular and extracellular matrix is considered to accelerate skin aging. On the other hand, it has been reported that CPs are decomposed by oxidized protein hydrolase (OPH). The aims of the study were to identify contribution of OPH on decomposition of CPs and to discuss the effects of carbonyl protein accumulation on expressions of basement membrane relating proteins.
In order to examine the first issue, HaCaT keratinocytes which was exposed to hydrogen peroxide chronically, were prepared as oxidative-stressed keratinocytes. Oxidative-stressed keratinocytes accumulated CPs in a high incident intracellularly. Oxidative-stressed keratinocytes showed a significant lower OPH activity associating with the mRNA expression and also the protein than those of control cells. A OPH inhibitor gave increase of CPs in HaCaT　keratinocytes. These results indicated followings; OPH is actually involved in degradation of intracellular CPs. Oxidative-stressed keratinocytes showed down-regulations of basement membrane relating proteins such as type IV and VII collagens. Gathering results, we concluded that chronic oxidative stress reduces potentials on reconstruction of basement membrane through accumulation of CPs and decreasing OPH concomitantly.