Mechanistic assessment of cadmium toxicity in association with the functions of estrogen receptors in the Langerhans islets

Diabetes is a metabolic disease with an increasing prevalence for which finding new and efficient therapeutic approaches has always been a challenge. Preserving integrity and functionality of pancreatic β-cells as the only source of insulin in the body is such a case. To achieve this goal different cellular targets have been proposed among which pancreatic estrogen receptors have gotten much attention. In this work, we evaluated the integrity and function of islets of Langerhans under the influence of factors known to intervene with estrogen receptors. Cadmium, a toxic heavy metal, has been recently shown to interact with estrogen receptors but its toxicity in the pancreatic islets regarding this mechanism remains unclear. Isolated islets of Langerhans from the pancreas of rats were grouped and treated with cadmium chloride and also cadmium chloride plus β-estradiol. After 24 hr incubation, parameters of cellular viability, oxidative stress, apoptosis, and insulin secretion were measured. The results indicated that cadmium reduced viability of the islets along with an increase in the formation of reactive oxygen species and apoptosis markers, and β-estradiol, in turn, was able to alleviate these disturbances to some extent, implicating the protective role of β-estradiol against pancreatic toxicity of cadmium. It can be concluded that modification of estrogen receptors in the endocrine pancreas and especially β-cells may be a promising target to find a new therapeutic strategy for diabetes and even uncovering mechanisms of environmental toxicants that have been known as risk factors of diabetes.