Noriaki Kawanishi1,2,3, Shuichi Machida2,3. 1. Faculty of Advanced Engineering, Chiba Institute of Technology, Narashino, Japan. 2. Graduate School of Health and Sports Science, Juntendo University, Inzai, Japan. 3. Institute of Health & Sports Science and Medicine, Juntendo University, Inzai, Japan.
Abstract
BACKGROUND: Skeletal muscle inflammation and oxidative stress are associated with aging-related loss of muscle mass and may be attributable to alterations in the number and types of leukocytes in skeletal muscle. Here, we tested the hypothesis that aging changes the number and composition of leukocyte subsets in skeletal muscle tissue. METHODS: Skeletal muscle was sampled from 4-mo-old (young) and 27-mo-old (old) C57BL/6J mice. Mononuclear cells of the gastrocnemius muscle were isolated, and flow cytometry was used to characterize the number and types of immune cells. RESULTS: The number of neutrophils and Ly-6C+ inflammatory macrophages in the skeletal muscle was significantly higher in old mice than in young mice. Inflammation and oxidative stress (measured using the markers phosphorylated JNK and nitrotyrosine) were also higher in the skeletal muscle of old mice than in that of young mice. CONCLUSIONS: Increasing age promotes skeletal muscle inflammation and oxidative stress, as well as infiltration of inflammatory macrophages and neutrophils.
BACKGROUND:Skeletal muscle inflammation and oxidative stress are associated with aging-related loss of muscle mass and may be attributable to alterations in the number and types of leukocytes in skeletal muscle. Here, we tested the hypothesis that aging changes the number and composition of leukocyte subsets in skeletal muscle tissue. METHODS: Skeletal muscle was sampled from 4-mo-old (young) and 27-mo-old (old) C57BL/6J mice. Mononuclear cells of the gastrocnemius muscle were isolated, and flow cytometry was used to characterize the number and types of immune cells. RESULTS: The number of neutrophils and Ly-6C+ inflammatory macrophages in the skeletal muscle was significantly higher in old mice than in young mice. Inflammation and oxidative stress (measured using the markers phosphorylated JNK and nitrotyrosine) were also higher in the skeletal muscle of old mice than in that of young mice. CONCLUSIONS: Increasing age promotes skeletal muscle inflammation and oxidative stress, as well as infiltration of inflammatory macrophages and neutrophils.
Authors: James F Markworth; Lemuel A Brown; Eunice Lim; Jesus A Castor-Macias; Jacqueline Larouche; Peter C D Macpherson; Carol Davis; Carlos A Aguilar; Krishna Rao Maddipati; Susan V Brooks Journal: Aging Cell Date: 2021-06-02 Impact factor: 11.005