Effects of microplastics on bone cells metabolism: investigation of mecanisms involved in Osteoporosis

• Grant number: 23/17546-8
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: June 01, 2024
• End date: November 30, 2026
• Field of knowledge: Health Sciences - Medicine - Medical Clinics
• Principal Investigator: Rodrigo Bueno de Oliveira
• Grantee: Mariana Cassani de Oliveira
• Host Institution: Faculdade de Ciências Médicas (FCM). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil

Abstract

Microplastics (MP) are plastic fibers < 5 mm in diameter. Currently, it is considered the most relevant synthetic contaminant on the surface of the planet. Evidence indicates that MP interacts negatively with biological structures. For example, the presence of MP has been demonstrated in bone marrow, with negative effects. In an animal model, MP was associated with activation of the Wnt/²-Catenin pathway and cardiac fibrosis. However, there is no consistent information about the effects of MP on bone formation and resorption pathways, as well as on the synthesis of proteins that confer metabolic regulation and bone strength. We hypothesize is that MP affects the metabolic pathways and expression of proteins involved in the pathophysiology of metabolic bone diseases, such as osteoporosis. Objectives: To evaluate the effect of polystyrene MP on cell viability and proliferation, intensity of cell uptake, anabolic and catabolic cellular pathways, and expression of bone proteins. Methods: In vitro assay with the cultivation of primary human osteoblasts exposed to polystyrene MP (microspheres of 1 ¼m in diameter, at concentrations from 50 to 500 ¼g/mL). The study consists of four steps: (i) morphological characterization of polystyrene using scanning electron microscopy, confirmation of polystyrene composition using Fourier transform infrared spectrometry; (ii) cell viability and proliferation studies (MTT assay, and Transwell cell migration, respectively), and intensity of fluorescent polystyrene internalization by cells by means of confocal microscopy; (iii) evaluation of the effects of polystyrene on anabolic (Wnt/²-Catenin, TGF-², BMP-4, Runx-2) and catabolic (RANK, and RANK-L) pathways; (iv) effects of polystyrene on the expression of osteoprotegerin, osteocalcin, and osteopontin, through the MILLIPLEX Assay. (AU)