TOLL-LIKE AND ADENOSINE RECEPTOR EXPRESSION IN INJURED SKELETAL MUSCLE

Introduction: Many aspects of skeletal muscle regeneration are now considered to be controlled by the innate immune system, specifically macrophages, but the mechanisms for activation and modulation of the innate immune system during injury are not well understood. Methods: We analyzed the expression of toll-like receptors (TLRs) and adenosine receptors during traumatic skeletal muscle injury. mRNA expression and immunostaining of these receptors were evaluated in mouse skeletal muscle injured by freezing. Results: Expression of nearly all mammalian TLRs was induced at 1 and/or 3 days postinjury with a common trend for higher expression at day 3. Injury also elicited a dramatic increase in the expression of adenosine receptors A(2B) and A(3) but not A(1) and A(2A). Conclusions: Both receptor types may be potential targets for stimulation of skeletal muscle tissue regeneration and functional restoration after injury. Muscle Nerve 44: 85-92, 2011