2,3,7,8‐tetrachlorodibenzo‐p‐dioxin alters the differentiation of SZ95 sebocytes in vitro

Abstract

Introduction: Chloracne is an acneiform skin disease, which is considered to be the most specific and sensitive clinical condition of dioxin intoxication. Sebogenesis is decreased and skin xerosis is one of the most prominent clinical characteristics compared with acne vulgaris. However, the activity of dioxin on the sebaceous glands is still unclear. We studied the effects of 2,3,7,8‐tetrachlorodibenzo‐p‐dioxin (TCDD), which is a representative for a group of dioxins, on sebaceous lipid synthesis and expression of markers related to sebocyte differentiation in vitro.Materials and Methods: After pretreatment with and without linoleic acid (LA) 10−4 M for 3 days, SZ95 sebocytes were treated again with TCDD with and without linoleic acid 10−4 M for 3 additional days. Neutral lipids in SZ95 sebocytes were measured by the nile red microassay. Immunohistology and western blotting were used to detect expression of keratin 7 (a marker of undifferentiated sebocytes), EMA (a marker of differentiated sebocytes) and keratin 10 (a marker of keratinocyte differentiation).Results: The neutral lipid content of SZ95 sebocytes was markedly inhibited under treatment with TCDD in concentrations of 10−8 M, 10−9 M and 10−10 M (P < 0.001 respectively), in the presence of LA. SZ95 sebocyte lipid content was not affected by TCDD alone. Moreover, expression of keratin 7 and EMA decreased and keratin 10 increased under TCDD treatment.Conclusions: Dioxin affects sebaceous gland cell lipogenesis and differentiation in vitro, probably by switching the sebocyte into a kerationocyte lineage. These findings indicate that altered sebaceous gland differentiation is likely to be the major reason of decreased sebogenesis in patients with chloracne.