title: Transgenic mouse models support HCR as an effector gene in the PSORS1 locus.
abstract: Genetic susceptibility for psoriasis is regulated to the greatest extent by the PSORS1 locus. Three psoriasis-associated susceptibility alleles have been identified within it, namely, HLACw6, HCR*WWCC and CDSN*5, but strong linkage disequilibrium between them has made it difficult to distinguish their individual genetic effects, and animal models to study their effects are not known. To study the function of HCR, we engineered transgenic mice with either a non-risk allele of HCR or the HCR*WWCC risk allele under the control of the cytokeratin-14 promoter. These choices were motivated by the apparently dominant effect of PSORS1 on psoriasis susceptibility and the physiological expression of HCR in basal keratinocytes. Transgenic mice appeared phenotypically normal and histologically their skin was indistinguishable from wild-type mice. Expression studies using Affymetrix arrays suggested that the HCR risk allele has specific functional consequences relevant to the pathogenesis of psoriasis. Comparison of gene expression changes between non-risk and risk allele mice revealed similarities to previous observations in human psoriatic skin, including upregulation of cytokeratins 6, 16 and 17 in risk allele mice. We also observed changes in the expression of genes associated with terminal differentiation and formation of the cornified cell envelope. Our results support the concept that HCR may constitute an essential gene in the PSORS1 locus. These observations are also compatible with a model that a susceptibility gene for psoriasis induces changes that are contributory but not sufficient by itself to produce the clinical phenotype.
authors.affiliation: Department of Medical Genetics, University of Helsinki, Helsinki University Central Hospital, Finland.
authors.forename: Outi
authors.initials: O
authors.lastname: Elomaa
authors.forename: Inkeri
authors.initials: I
authors.lastname: Majuri
authors.forename: Sari
authors.initials: S
authors.lastname: Suomela
authors.forename: Kati
authors.initials: K
authors.lastname: Asumalahti
authors.forename: Hong
authors.initials: H
authors.lastname: Jiao
authors.forename: Zahra
authors.initials: Z
authors.lastname: Mirzaei
authors.forename: Bjorn
authors.initials: B
authors.lastname: Rozell
authors.forename: Karin
authors.initials: K
authors.lastname: Dahlman-Wright
authors.forename: Johanna
authors.initials: J
authors.lastname: Pispa
authors.forename: Juha
authors.initials: J
authors.lastname: Kere
authors.forename: Ulpu
authors.initials: U
authors.lastname: Saarialho-Kere
mesh_terms: D000818:Animals; D016000:Cluster Analysis; D004195:Disease Models, Animal; D015870:Gene Expression / Q000502:physiology; D020022:Genetic Predisposition to Disease; D006801:Humans; D007150:Immunohistochemistry; D047908:Intracellular Signaling Peptides and Proteins; D051379:Mice; D008822:Mice, Transgenic; D005810:Multigene Family; D011506:Proteins / Q000235:genetics* / Q000276:immunology / Q000378:metabolism; D011565:Psoriasis / Q000235:genetics* / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012867:Skin / Q000378:metabolism
chemical_list: C412616:CCHCR1 protein, human; D047908:Intracellular Signaling Peptides and Proteins; D011506:Proteins