| First Author | Ma J | Year | 2021 |
| Journal | Am J Physiol Lung Cell Mol Physiol | Volume | 321 |
| Issue | 3 | Pages | L555-L565 |
| PubMed ID | 34261337 | Mgi Jnum | J:320545 |
| Mgi Id | MGI:6726456 | Doi | 10.1152/ajplung.00499.2019 |
| Citation | Ma J, et al. (2021) Neutrophil Elastase-Regulated Macrophage Sheddome/ Secretome and Phagocytic Failure. Am J Physiol Lung Cell Mol Physiol |
| abstractText | Patients with cystic fibrosis (CF) have defective macrophage phagocytosis and efferocytosis. Several reports demonstrate that neutrophil elastase (NE) a major inflammatory protease in the CF airway, impairs macrophage phagocytic function. To date, NE-impaired macrophage phagocytic function has been attributed to cleavage of cell surface receptors or opsonins. We applied an unbiased proteomic approach to identify other potential macrophage targets of NE protease activity that may regulate phagocytic function. Using the murine macrophage cell line, RAW 264.7, human blood monocyte derived macrophages, and primary alveolar macrophages from Cftr-null and wild-type littermate mice, we demonstrated that NE exposure blocked phagocytosis of E. coli bio-particles. We performed LC-MS/MS proteomic analysis of the conditioned media from RAW264.7 treated either with active NE or inactive (boiled) NE as a control. Out of 840 proteins identified in the conditioned media, active NE upregulated 142 proteins and down-regulated 211 proteins. NE released not only cell surface proteins into the media but also released cytoskeletal, mitochondrial, cytosolic, and nuclear proteins that were detected in the conditioned media. At least 32 proteins were associated with the process of phagocytosis including 11 phagocytic receptors (including LRP1), 7 proteins associated with phagocytic cup formation, and 14 proteins involved in phagocytic maturation (including calpain-2) and phagolysosome formation. NE had a broad effect on the proteome required for regulation of all stages of phagocytosis and phagolysosome formation. Furthermore, the NE sheddome/ secretome included proteins from other macrophage cellular domains suggesting that NE may globally regulate macrophage structure and function. |
