Detention and mapping of iron and toxic environmental elements in human ovarian endometriosis: A suggested combined role

Abstract

BackgroundEndometriosis is a disease affecting 10–15 % of women worldwide, consisting in the ectopic growth of endometrial cells outside the uterine cavity.Whist the pathogenetic mechanisms of endometriosis remain elusive and contemplating even environmental causes, iron deposits are common in endometrial lesions, indicating an altered iron metabolism at this level. This study was undertaken to reveal a possible relationship between iron dysmetabolism and accumulation of environmental metals. MethodsBy combining histological and histochemical analysis (H&E and Perl's staining) with μ- and nano- synchrotron-based (SR-based) X-ray Fluorescence (XRF) microscopy, we investigated the distribution of iron and other elements in the ovarian endometriomas of 12 endometriosis patients and in 7 healthy endometrium samples. ResultsXRF microscopy expanded the findings obtained by Perl's staining, revealing with an exceptional sensitivity intracellular features of iron accumulation in the epithelial endometrium, stroma and macrophages of the endometriotic lesions. XRF evidenced that iron was specifically accumulated in multiple micro aggregates, reaching concentrations up to 10–20 % p/p. Moreover, by XRF analysis we revealed for the first time the retention of a number of exogenous and potentially toxic metals such as Pb, Br, Ti, Al Cr, Si and Rb partially or totally co-localizing with iron. ConclusionμXRF reveals accumulation and colocalization of iron and environmental metals in human ovarian endometriosis, suggesting a role in the pathogenesis of endometriosis.