Evidence for differential S100 gene over-expression in psoriatic patients from genetically heterogeneous pedigrees

S Semprini, F Capon, A Tacconelli, E Giardina… - Human genetics, 2002 - Springer
S Semprini, F Capon, A Tacconelli, E Giardina, A Orecchia, R Mingarelli, T Gobello…
Human genetics, 2002Springer
Psoriasis is an inflammatory skin disorder characterised by keratinocyte hyper-proliferation
and altered differentiation. To date, linkage analyses have identified at least seven distinct
disease susceptibility regions (PSORS1–7). The PSORS4 locus was mapped by our group
to chromosome 1q21, within the Epidermal Differentiation Complex. This cluster contains 13
genes encoding S100 calcium-binding proteins, some of which (S100A7, S100A8 and
S100A9) are known to be up-regulated in individual patient keratinocytes. In this study, we …
Abstract
Psoriasis is an inflammatory skin disorder characterised by keratinocyte hyper-proliferation and altered differentiation. To date, linkage analyses have identified at least seven distinct disease susceptibility regions (PSORS1–7). The PSORS4 locus was mapped by our group to chromosome 1q21, within the Epidermal Differentiation Complex. This cluster contains 13 genes encoding S100 calcium-binding proteins, some of which (S100A7, S100A8 and S100A9) are known to be up-regulated in individual patient keratinocytes. In this study, we analysed S100 gene expression in psoriatic individuals from families characterised by linkage studies. We first selected individuals from two large pedigrees, one of which was linked to the 1q21 locus, whereas the other was unlinked to that region. We studied the expression of 12 S100 genes, by semi-quantitative RT-PCR and Northern blot. These analyses demonstrated up-regulation of S100A8, S100A9 and, to a lesser extent, S100A7 and S100A12, only in the 1q21 linked family. We subsequently analysed S100A7, S100A8, S100 A9 and S100 A12 in three additional samples and were able to confirm S100A8/S100A9-specific over-expression in 1q-linked pedigrees. Thus, our data provide preliminary evidence for a locus-specific molecular mechanism underlying psoriasis susceptibility.
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