Disrupting Development: Unraveling the Interplay of Aryl Hydrocarbon Receptor (AHR) and Wnt/β-Catenin Pathways in Kidney Development Under the Influence of Environmental Pollutants.

Abstract

Understanding the intricate molecular mechanisms governing aryl hydrocarbon receptor (AHR) and Wnt/β-Catenin pathways crosstalk is of paramount importance for elucidating normal development. We investigated the repercussions of aberrant activation of these signaling pathways on kidney development. HEK-293 cells were subjected to AHR and Wnt activators and inhibitors for 3 and 24 h. Subsequently, pregnant adult female BALB/c mice were administered treatments at gestation day 9 (GD-9), and embryos were analyzed at GD-18 using a combination of cellular, molecular, stereological, and histopathological techniques. Our results demonstrated a noteworthy escalation in oxidative stress and gene expression endpoints associated with apoptosis. Moreover, stereological analyses exhibited alterations in cortex, proximal tubule, and kidney tissue vessels volumes. Remarkably, co-treatment with 6-formylindolo [3,2-b] carbazole (FICZ) and cadmium (Cd) resulted in a significant reduction in glomerulus volume, while elevating the volumes of distal tubule, Henle loop, and connective tissue, compared to the control group. Histopathological investigations further confirmed structural changes in the loop of Henle and proximal tubule, alongside a decline in glomerular volume. Additionally, the expression levels of AHR and Ctnnb1 genes significantly increased in the Cd-treated group compared to the control group. Enhanced expression of apoptosis-related genes, including Bcl-x, Bax, and Caspase3, along with alterations in mitochondrial membrane potential and cytochrome C release, was observed. In contrast, Gsk3 gene expression was significantly decreased. Our findings robustly establish that chemical pollutants, such as Cd, disrupt the AHR and Wnt/β-Catenin physiological roles during developmental stages by inhibiting the metabolic degradation of FICZ.