TNF and chronic obstructive pulmonary disease: PM2.5 induced and upregulated the circRNA hsa_circ_0005045 in exosomes derived from plasma, and from bronchial and alveolar epithelial cells of COPD patientsIn a murine COPD model, hsa_circ_0005045 homologous, through the binding to exosomal PRDX2, caused the release of TNF-α by inflammatory cells in lung tissue