Aging impairs mouse skeletal muscle macrophage polarization and muscle-specific abundance during recovery from disuse.

Aging impairs mouse skeletal muscle macrophage polarization and muscle-specific abundance during recovery from disuse. Am J Physiol Endocrinol Metab. 2019 Apr 09;: Authors: Reidy PT, McKenzie AI, Mahmassani ZS, Petrocelli JJ, Nelson DB, Lindsay CC, Gardner JE, Morrow VR, Keefe AC, Huffaker TB, Stoddard GJ, Kardon G, O'Connell RM, Drummond MJ Abstract Impaired recovery of aged muscle following a disuse event is unresolved issue facing the older adult population. Although investigations in young animals has suggested that rapid regrowth of skeletal muscle following a disuse event involves a coordinated involvement of skeletal muscle macrophages, this phenomenon has not yet been thoroughly tested as an explaination for impaired muscle recovery in aging. To examine this hypothesis, young (3 month) and old (24-26 month) malemice were examined as controls, following 2 weeks of hindlimb unloading (HU) and following 4 (RL4)and 7 (RL7)days of reloading after HU. Muscles were harvested to assess muscle weight, myofiber-specifc cross-sectional area, and skeletal muscle macrophages via IF. Flow cytometry was used on gastrocnemius and soleus (at RL4)single cell suspensions to immunophenotype skeletal muscle macrophages. Our data demonstrated an impaired muscle regrowth in aged compared to young mice following disuse, which is characterized by divergent muscle macrophage polarization patterns and muscle-specifc macrophage abundance. During reloadi...
Source: American Journal of Physiology. Endocrinology and Metabolism - Category: Physiology Authors: Tags: Am J Physiol Endocrinol Metab Source Type: research