Impact of polystyrene nanoplastics on human granulosa cell physiology using a 3D spheroid model

Details

Supervisors

Andrade Amorim, Christiani ; Tavares Sousa, Maria João

Faculty

Faculté de pharmacie et des sciences biomédicales

Degree label

Master [120] en sciences biomédicales, à finalité approfondie

Abstract

enPlastics, especially polystyrene, are deeply integrated into modern life due to their versatility and low cost. However, their persistent environmental accumulation leads to the formation of micro- and nanoplastics (NPs) capable of entering the human body through inhalation, ingestion, and dermal exposure. Owing to their nanoscale dimensions, NPs can cross biological barriers and have been detected in blood, lungs, placenta, ovarian tissue, and follicular fluid, raising significant concerns about their impact on human health and female reproduction. While several studies using mice and tumor-derived granulosa cells (GCs) indicate that the toxic effects of polystyrene NPs (PS-NPs) impair GC functions and steroidogenesis, no physiological relevant model using primary human GCs currently exists. Current in vitro systems do not accurately reproduce the architecture, intercellular communications, or endocrine responsiveness of the human ovarian follicles. To address these limitations, the present study develops 3D granulosa cell spheroid (GCSph) models generated from primary human GCs collected during In Vitro Fertilization (IVF) procedures. GCSphs were exposed to PS-NPs concentrations of 0, 10, 25, and 50 µg/mL during 72 hours. After NPs removal, spheroids were let in culture for an additional 6 days. Throughout this period, spheroids were evaluated for NPs penetration, morphology, viability, extracellular matrix (ECM), and 17β-estradiol secretion. This 3D human spheroid model offers substantial advantages for studying nanoparticle toxicity, as it better mimics follicular organization and overcomes the limitations of tumor derived cell lines. The model enabled comprehensive analysis of gap-junction communication (connexin 43), ECM components (collagen III/IV, fibronectin), reproductive hormone receptors (AMHR, LHR). In addition, the models allowed assessment of steroidogenic activity through CYP19A1 expression and 17β-estradiol secretion. Overall, this work provides essential insights into how PS-NPs may alter human GCs physiology. By using a physiologically relevant 3D model based on primary humans GCs, it establishes a solid foundation for evaluating the potential reproductive risks associated with nanoplastics exposure.