Pesticides derived from egg yolks modulate cellular metabolic activity and proliferation, and increase steroidogenesis and oxidative stress in primary pheasant ovarian cells

To investigate pesticide impacts on declining French pheasant populations, unhatched wild eggs were screened for over 600 compounds using mass spectrometry, identifying a mixture of six pesticides. Pheasant ovarian cells (granulosa (GCs) and theca interstitial (TICs) were exposed in vitro to this mixture at environmentally relevant concentrations in basal state and in response to exogenous hormones (IGF-1 and gonadotropins). Effects were evaluated using CCK8 (cellular metabolic activity), BrdU (proliferation), ELISA (hormone production), and RTqPCR (gene expression). While cellular metabolic activity mainly increased, proliferation significantly decreased. Basal and stimulated progesterone and testosterone production increased in GCs and TICs, respectively. Furthermore, TOS, TAC, and OSI analyses revealed marked oxidative stress in both cell types, accompanied by the upregulation of genes involved in mitochondrial fusion including MFN1 in GCs. Overall, these endocrine and cellular disruptions could contribute to the ongoing decline of bird populations across agricultural landscapes.