Compared to men, women have a significantly lower incidence of severe psoriasis — a skin condition that causes rashes and leads to itchiness. The underlying reason for the sex differences that made men more prone to this condition, however, had remained unclear so far. Now a team of researchers has found that the female hormone estradiol suppresses psoriasis. The protective role of the hormone has provided a basis for its therapeutic potential, according to a media release from Kyoto University. The study has been published in the Journal of Allergy and Clinical Immunology. "Our results have not only revealed the molecular mechanisms of sex differences in psoriasis but also shed new light on our understanding of the physiological role of estradiol," the release quoted Hamamatsu University School of Medicine's Tetsuya Honda, formerly of Kyoto University, as saying. The team tested conditional knockout mice (cko mice), which means mice with specific genes removed or inactivated. Here, the mice had their ovaries removed, which were supplemented with estradiol pellets. In contrast to wild-type mice, the cko mice without the natural ovarian hormones estradiol showed symptoms of severe skin inflammation. Once these mice were given estradiol, the production of cytokines in immune cells was reversed, reducing the inflammation. This effect was also observed in human cells in vitro. “These results indicate that estradiol suppresses psoriatic inflammation by regulating neutrophil and macrophage cells,” the author was quoted as saying. Source: Kyoto University
