Silent saboteurs: How microplastics disrupt stem cells and tissue regeneration

Figure 1 Pathways of microplastic uptake by humans. Microplastics can enter the human body through three main pathways: Ingestion (via the digestive system), inhalation (via the respiratory system) and potentially through direct skin contact. Created in BioRender (Supplementary material). MPs: Microplastics; PE: Polyethylene; PP: Polypropylene; PVC: Polyvinyl chloride; PS: Polystyrene; PA: Polyamides; PEst: Polyesters; PET: Polyethylene terephthalate.

Figure 2 Microplastics interfere with stem cell function and tissue regeneration. Created in BioRender (Supplementary material). NSCs: Neural stem cells; HSCs: Hematopoietic stem cells; BMSCs: Bone marrow mesenchymal stem cells; ROS: Reactive oxygen species.

Figure 3 The key mechanism of microplastics’ effect on stem cells based on existing evidence. A: Microplastics affect neural stem cells; B: Microplastics affect hematopoietic stem cells by disrupting the gut microbiota-hypoxanthine-Wnt axis; C: Microplastics affect bone marrow mesenchymal stem cells; D: Microplastics affect kidney progenitor cells through DNA damage inducible transcript 4-mediated autophagy and apoptosis. Created in BioRender (Supplementary material). p-H2AX: Phosphorylated H2A histone family member; p21: Cyclin-dependent kinase inhibitor 1A; p27: Cyclin-dependent kinase inhibitor 1B; CDK4: Cyclin dependent kinase 4; p16: Cyclin-dependent kinase inhibitor 2A; SASP: Senescence-associated secretory phenotype; BCL2: B-cell lymphoma-2; BAX: B-cell lymphoma-2 associated X; TUBB3: Tubulin beta 3 class III; GFAP: Glial fibrillary acidic protein; HPRT: Hypoxanthine-guanine phosphoribosyltransferase; HSC: Hematopoietic stem cell; BMSCs: Bone marrow mesenchymal stem cells; NF-κB: Nuclear factor kappa B; TNF-α: Tumor necrosis factor-α; RANKL: Receptor activator of nuclear factor kappa B ligand; DDIT4: DNA damage inducible transcript 4; mTOR: Mechanistic target of rapamycin; LC3-II: Light chain 3 II; LC3-I: Light chain 3 I.