Age-related changes to macrophages are detrimental to fracture healing in mice
| Autor: | Clark, Daniel, Brazina, Sloane, Yang, Frank, Hu, Diane, Hsieh, Christine L, Niemi, Erene C, Miclau, Theodore, Nakamura, Mary C, Marcucio, Ralph |
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| Rok vydání: | 2020 |
| Předmět: |
Aminopyridines
macrophage Inbred C57BL Regenerative Medicine Medical and Health Sciences Mice Models Genetics Animals 2.1 Biological and endogenous factors Pyrroles Bony Callus Aetiology Bone Cellular Senescence osteoimmunology Tibia Animal Macrophages Inflammatory and immune system aging Age Factors Biological Sciences fracture healing inflammation Musculoskeletal Injury (total) Accidents/Adverse Effects RNA-seq Transcriptome Fractures Developmental Biology |
| Zdroj: | Aging cell, vol 19, iss 3 |
| Popis: | The elderly population suffers from higher rates of complications during fracture healing that result in increased morbidity and mortality. Inflammatory dysregulation is associated with increased age and is a contributing factor to the myriad of age-related diseases. Therefore, we investigated age-related changes to an important cellular regulator of inflammation, the macrophage, and the impact on fracture healing outcomes. We demonstrated that old mice (24months) have delayed fracture healing with significantly less bone and more cartilage compared to young mice (3months). The quantity of infiltrating macrophages into the fracture callus was similar in old and young mice. However, RNA-seq analysis demonstrated distinct differences in the transcriptomes of macrophages derived from the fracture callus of old and young mice, with an up-regulation of M1/pro-inflammatory genes in macrophages from old mice as well as dysregulation of other immune-related genes. Preventing infiltration of the fracture site by macrophages in old mice improved healing outcomes, with significantly more bone in the calluses of treated mice compared to age-matched controls. After preventing infiltration by macrophages, the macrophages remaining within the fracture callus were collected and examined via RNA-seq analysis, and their transcriptome resembled macrophages from young calluses. Taken together, infiltrating macrophages from old mice demonstrate detrimental age-related changes, and depleting infiltrating macrophages can improve fracture healing in old mice. |
| Databáze: | OpenAIRE |
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