EXPRESSION OF CYTOSOLIC RETINOID-BINDING PROTEIN GENES IN HUMAN SKIN BIOPSIES AND CULTURED KERATINOCYTES AND FIBROBLASTS

Using reverse transcription coupled to polymerase chain reaction we ha ve studied the mRNA expression of serum retinol-binding protein and cy tosolic receptors for retinol and retinoic acid in skin biopsies, and in cultured epidermal keratinocytes and dermal fibroblasts. Transcript s for cellular retinol-binding protein (CRBP) I and cellular retinoic- acid-binding protein (CRABP) I were found in normal skin, keratinocyte s, and fibroblasts. CRABP II transcripts were detected in skin and ker atinocytes. A decreased mRNA expression of CRABP I and an increased mR NA expression of CRABP II were found in lesional psoriatic skin compar ed with uninvolved skin, mRNA transcripts for serum retinol-binding pr otein (s-RBP) were detected in all tissues and cells. The biological i mportance of s-RBP expression in keratinocytes and fibroblasts is not known, but hypothetically this protein may be involved in the intracel lular shuttling of retinol and retinoic acid, or in the retransportati on of cellular retinoids into the extracellular space.