Ectodysplasin signaling in development

Alternatively Spliced Variants of Gallus gallus TNFRSF23 Are Expressed in the Ovary and Differentially Regulated by Cell Signaling Pathways1

As a result of searching recently available chicken (ch) expressed sequence tag databases, a new Tumor Necrosis Factor Receptor Super Family (TNFRSF) member with similarity to the murine (m) TNFRSF23 decoy receptor (DcR) has been identified. However, by comparison with the mTNFRSF23, there exist at least two splice variants of chTNFRSF23, one of which includes an intracellular death domain (TNFRSF23.v1) characteristic of death receptors, and the other with a truncated cytoplasmic domain of a DcR (named TNFRSF23.v2). These two splice variants of chTNFRSF23 display differential patterns of mRNA expression across various hen tissues, with the highest levels observed within reproductive tissues. More specifically, TNFRSF23.v1 is most highly expressed in preovulatory follicle granulosa cells in the ovary, whereas TNFRSF23.v2 mRNA is found at highest levels in ovarian stromal tissue. Primary culture experiments with granulosa cells determined that expression of TNFRSF23.v1 mRNA was decreased by protein kinase A signaling and enhanced by transforming growth factor (TGF) alpha treatment. Interestingly, TGFbeta1 and signaling via protein kinase C also enhanced levels of TNFRSF23.v1 expression but only in undifferentiated granulosa cells from prehierarchal follicles. Based on patterns of mRNA expression and its endocrine/paracrine regulation, we predict that ovarian chTNFRSF23 represents a modulator of granulosa cell survival and/or differentiation. Finally, the characterization of these receptor variants is of considerable interest from an evolutionary perspective in that they provide additional evidence to support a continuing divergence of TNFRSF members throughout vertebrate evolution.

Alopecia areata in families: association with the HLA locus

Alopecia areata (AA) is a T cell mediated disease directed against hair follicles that results in bald patches. It can range in severity from patchy (AA), to total scalp hair loss (alopecia totalis; AT) or body hair loss (alopecia universalis; AU). We have previously shown that HLA-DR4 and DR11 as well as HLA-DQ*03 alleles are increased in unrelated AA patients compared with controls. To study whether class II HLA alleles are linked to AA, we investigated 81 extended families that included 192 AA patients, including 89 with AT or AU. We also performed the transmission disequilibrium test (TDT) in 143 nuclear families. Results showed an association between alleles of HLA-DQB (p = 0.014) and HLA-DR (p = 0.010). We also performed linkage analysis in 75 families whose members' genomic DNA were available for HLA typing. Results from this analysis support linkage between AA and class II loci with a maximal LOD score of 2.42 to HLA-DQB at 5% recombination, and with a maximal LOD score of 2.34 to HLA-DR at 0% recombination. There was an increased incidence of atopic dermatitis and autoimmune thyroiditis in families. AA appears to be a class II HLA restricted organ specific immune response to the hair follicle.