Abstract: PUB057
Effects of Polystyrene Microplastics on Bone-Related Protein Expression, Mineralization Capacity, and Mitochondrial Function in Osteoblastlike Cells (MG-63)
Session Information
Category: Bone and Mineral Metabolism
- 501 Bone and Mineral Metabolism: Basic
Authors
- Pelepenko, Lauter E., Laboratory for Evaluation of Mineral and Bone Disorders in Nephrology (LEMON), School of Medical Sciences, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
- Oliveira, Mariana Cassani, Laboratory for Evaluation of Mineral and Bone Disorders in Nephrology (LEMON), School of Medical Sciences, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
- Masaro, Daniela Annunziata, Medical School, Pontifícia Universidade Católica, Campinas, São Paulo, Brazil
- Chiteculo, Pedro Bonifácio, Laboratory for Evaluation of Mineral and Bone Disorders in Nephrology (LEMON), School of Medical Sciences, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
- Camargo, Jessica Martins, Laboratory for Evaluation of Mineral and Bone Disorders in Nephrology (LEMON), School of Medical Sciences, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
- dos Reis, Luciene, LIM 16–Laboratório de Fisiopatologia Renal, Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo (HCFMUSP), Universidade de São Paulo, São Paulo, Brazil
- Siqueira-Santos, Edilene, Department of Pathology, School of Medical Sciences, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
- Castilho, Roger Frigerio, Department of Pathology, School of Medical Sciences, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
- Louvet, Loïc, Pathophysiological Mechanisms and Consequences of Cardiovascular Calcifications (MP3CV), Picardie Jules Verne University, Unité de recherche (UR) 7517 Université de Picardie Jules Verne (UPJV), Amiens, France
- Oliveira, Rodrigo Bueno, Laboratory for Evaluation of Mineral and Bone Disorders in Nephrology (LEMON), School of Medical Sciences, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil
Group or Team Name
- Laboratory for Evaluation of Mineral and Bone Disorders in Nephrology (LEMON).
Background
Microplastics (MPs) were recently evidenced in the human skeleton. Since bone complications are frequent in patients with CKD, understanding the role of MPs in bone has been gaining prominence. We aimed to evaluate the effects of polystyrene (PS-MPs) on bone-related protein expression, mineralization, and bioenergetics.
Methods
Osteoblast-like cells (MG-63) were exposed to PS-MPs at 5-50 µg/mL. Internalization of PS-MPs was analyzed by confocal microscopy. Osteoprotegerin, osteocalcin, osteopontin, and DKK1 levels in cell lysates/supernatants were measured by MilliplexTM human bone panel. Cell mineralization was evaluated through alkaline phosphatase activity and calcium deposition. Mitochondrial function was assessed by monitoring oxygen consumption (high-resolution respirometry). Glucose consumption and lactate production were measured by colorimetric assays.
Results
MG-63 internalized PS-MPs into the cytoplasm. Compared to the control, cells exposed to PS-MPs at 10 and 25 µg/mL decreased osteocalcin (137±117.6 vs. 109±8.7 pg/mL, p=0.04; and 137±117.6 vs. 100±16.9 pg/mL, p=0.03) and osteoprotegerin (8719±593.2 vs. 7402±527.7 pg/mL, p=0.04; 8719±593.2 vs. 6950±689.2 pg/mL, p=0.01) expression. DKK1 concentration was also reduced following PS exposure at 25 µg/mL (10431(8937-12003) vs. 7789±1683.3 pg/mL, p=0.04). Similar PNP production and calcium deposition were observed. No changes were observed in oxygen consumption between control and PS-MPs-treated cells. Glucose concentrations (mg/dL) in the cell culture medium at 48 h (100 mg/mL at baseline) were 40.4±21.4 for the control, 49.9±20.2 for the 5 µg/mL group, and 45.2±19 for the 50 µg/mL group (p>0.05). Lactate concentrations were significantly higher at 48 h (p<0.001) for all conditions compared to their 24-h baseline, without differences between groups.
Conclusion
PS-MPs altered the expression of key bone-related proteins without affecting calcium deposition induced by alkaline phosphatase activity. No significant differences were found in bioenergetics assessed parameters.