A systems genomics approach identifies SIGLEC15 as a susceptibility factor in recurrent vulvovaginal candidiasis

Candida vaginitis is a frequent clinical diagnosis with up to 8% of women experiencing recurrent vulvovaginal candidiasis (RVVC) globally. RVVC is characterized by at least three episodes per year. Most patients with RVVC lack known risk factors, suggesting a role for genetic risk factors in this condition. Through integration of genomic approaches and immunological studies in two independent cohorts of patients with RVVC and healthy individuals, we identified genes and cellular processes that contribute to the pathogenesis of RVVC, including cellular morphogenesis and metabolism, and cellular adhesion. We further identified SIGLEC15, a lectin expressed by various immune cells that binds sialic acid-containing structures, as a candidate gene involved in RVVC susceptibility. Candida stimulation induced SIGLEC15 expression in human peripheral blood mononuclear cells (PBMCs) and a polymorphism in the SIGLEC15 gene that was associated with RVVC in the patient cohorts led to an altered cytokine profile after PBMC stimulation. The same polymorphism led to an increase in IL1B and NLRP3 expression after Candida stimulation in HeLa cells in vitro. Last, Siglec15 expression was induced by Candida at the vaginal surface of mice, where in vivo silencing of Siglec15 led to an increase in the fungal burden. Siglec15 silencing was additionally accompanied by an increase in polymorphonuclear leukocytes during the course of infection. Identification of these pathways and cellular processes contributes to a better understanding of RVVC and may open new therapeutic avenues.

Soy isoflavone supplements antagonize reproductive behavior and estrogen receptor alpha- and beta-dependent gene expression in the brain

Epidemiological evidence suggests that isoflavone phytoestrogens may reduce the risk of cancer, osteoporosis, and heart disease, effects at least partially mediated by estrogen receptors alpha and beta (ERalpha and ERbeta). Because isoflavone dietary supplements are becoming increasingly popular and are frequently advertised as natural alternatives to estrogen replacement therapy, we have examined the effects of one of these supplements on estrogen-dependent behavior and ERalpha- and ERbeta-dependent gene expression in the brain. In the adult female rat brain, 17beta-estradiol treatment decreased ERbeta messenger RNA signal in the paraventricular nucleus by 41%, but supplement treatment resulted in a 27% increase. The regulation of ERbeta in the paraventricular nucleus is probably via an ERbeta-dependent mechanism. Similarly, in the ventromedial nucleus of the hypothalamus, supplement treatment diminished the estrogen-dependent up-regulation of oxytocin receptor by 10.5%. The regulation of oxytocin receptor expression in the ventromedial nucleus of the hypothalamus is via an ERalpha-dependent mechanism. Supplement treatment also resulted in a significant decrease in receptive behavior in estrogen- and progesterone-primed females. The observed disruption of sexual receptivity by the isoflavone supplement is probably due to antiestrogenic effects observed in the brain. These results suggest that isoflavone phytoestrogens are antiestrogenic on both ERalpha- and ERbeta-dependent gene expression in the brain and estrogen-dependent behavior.