Immunohistochemical Expression of Placental Form of Glutathione S-transferase (GST-pi) in Fetal Skin

Son, Ho Chan; Park, See Ryong; Kim, Mi Kyung; Song, Kye Yong

Abstract

BACKGROUND
Glutathione S-transferases(GST) are a family of multi-functional enzymes involved in cellular detoxification and excretion of a variety of exogenous and endogenous toxic or carcinogenic compounds. The GST family has been divided into three classes, alpha, mu, and pi, based on substrate specificity and sequence homology. GST-pi is an acidic type and predominant in skin, small intestine, breast, lung and prostate. The overexpression of GST-pi associated with skin tumor and tumor-like lesion suggests that GST-pi is a major detoxifying enzyme in skin tumors. OBJECTIVE: The purpose of this study was to observe the expression and the distribution pattern of GST-pi in the human fetal skin. METHODS: Skin was obtained from the scalp, chest, and sole of 49 human fetuses, ranging from 8th to 40th weeks of gestational age. Immunohistochemical staining was performed using avidin biotin peroxidase complex method on paraffin embedded tissue using antirabbit polyclonal antibody against the human GST-pi. RESULTS: GST-pi was expressed in intermediated layer of epidermis at 8th week, and gradually increased in strength of expression stronger in suprabasal layer. In hair unit, GST-pi was expressed in sebaceous gland, bulge, hair matrix cell and outer root sheath cell from 15th week. In eccrine gland, also GST-pi was expressed in central differentiated cells of intradermal eccrine duct from 18th week, and in terminal duct and acini from 26th week of fetal age. CONCLUSION: GST-pi was expressed from the 8th week of gestation suggesting that GST-pi plays an important role in detoxification for the protection of the skin in fetal stage from the various toxic agent.