1. ¹Therapeutics Research Unit, School of Medicine, University of Queensland, Princess Alexandra Hospital, Queensland, Australia
2. ²Southern Clinical Division, School of Medicine, University of Queensland, Princess Alexandra Hospital, Queensland, Australia
3. ³Division of Population Studies and Human Genetics, Queensland Institute of Medical Research, Brisbane, Queensland, Australia

Correspondence: Dr Sheree E. Cross, Department of Medicine, University of Queensland, Princess Alexandra Hospital Ipswich Road, Brisbane, Queensland 4102, Australia. E-mail: shereec@soms.uq.edu.au

Received 30 January 2006; Revised 8 May 2006; Accepted 13 June 2006; Published online 28 September 2006.

Abstract

The presence of surfactant proteins (SPs), critical to local barrier and defense functions and usually associated with the lung, was revealed in adult and fetal human skin complementary deoxyribonucleic acid, in skin samples from three adult female donors and also in cultured fibroblasts, keratinocytes, and melanocytes. Using reverse transcription-PCR, SP-A, SP-B, SP-C, and SP-D messenger ribonucleic acid expression was detected to varying extents in the different skin sources. The stronger expression of SP-C in fetal skin, compared to adult skin, suggested that the role of this protein alters with age. Immunohistochemical studies showed variable distribution of SPs in human epidermis and dermis, confirming that these proteins are indeed translated and expressed in skin tissue. In vitro studies showed that the surface tension of SP-deficient artificial sebum is (a) lowered by skin-extracted SP-B and (b) further reduced to a level comparable to normal sebum by the additional presence of skin-extracted SP-A and SP-D, consistent with their surface tension-lowering capabilities in lung. The possible roles of SPs in skin, based on their known functions in the lung are discussed. However, their potential as therapeutic targets or diagnostic markers of skin disease remains to be elucidated.