Assessment of Gap Junction Protein Beta-2 rs3751385 Gene Polymorphism in Psoriasis Vulgaris

Background

Gap junction protein beta 2 (GJB2) upregulation in psoriasis transcriptome analysis as well as connexin 26 (Cx26, encoded by GJB2) expression upregulation in psoriatic plaques has already been substantiated. GJB2 rs72474224 and rs3751385 have been correlated with psoriasis vulgaris incidence in Chinese populations. Here we study the effect of rs3751385 in patients suffering from psoriasis vulgaris in a Caucasian Greek population at the prefecture of Thrace in Northern Greece.

Methods

One hundred and seventy-three (111 males and 62 females) psoriatic patients (108 were of early-onset psoriasis) and 171 matched controls were included in the study. Genomic DNA was extracted from peripheral blood leukocytes and genotyping was carried out by polymerase chain reaction-restriction-fragment length polymorphism (PCR-RFLP).

Results

A statistically significant lower frequency of C/T genotype in late-onset male psoriasis vulgaris (P = 0.029) as well as of T allele in female early-onset psoriasis vulgaris (P = 0.049) were ascertained.

Conclusions

On condition that all other genetic or environmental factors remain stable, the existence and possible interaction between GJB2 rs3751385 C and T alleles in male psoriatic patients may be considered as protective gene component against late-onset psoriasis appearance, while presence of the T allele in female might block the histogenetic mechanisms of early-onset psoriasis lesions.

Recombinant ISRAA ameliorates imiquimod-induced psoriasis and knocking out Israa delays its onset

Psoriasis, an inflammatory disease, is largely mediated by T-helper 17 cytokines. We have previously identified the immune system-released activating agent (Israa) as a novel gene that connects the nervous and immune systems. This research aims to investigate the role of the Israa gene in psoriasis in vivo using the imiquimod-induced psoriasis model. We established the model in C57BL/6 wildtype mice, which were then treated with 200 pg/mouse, 400 pg/mouse, or 800 pg/mouse of recombinant ISRAA compared to methotrexate. Subsequently, we also induced psoriasis in Israa-knockout mice to confirm the effect of Israa. Results consistently showed improvement in psoriasis in all groups receiving recombinant ISRAA. The 200 pg/mouse dose eliminated the disease, reduced the cutaneous release of IL-17 to one-third and TNF-α to one-sixth, increased IL-10 release to over 500 pg, completely resolved parakeratosis, decreased epidermal thickness to one-half, and reduced the expression of CD4 and neutrophil elastase in the skin (all p < 0.05). Israa-knockout mice exhibited less severe psoriasis in all scoring, biochemical, and histological parameters compared to wild-type mice (p < 0.05). This study highlights Israa as a crucial molecule in psoriasis and confirms its immunomodulatory role in inflammatory diseases.