Resistance exercise increases NF-κB activity in human skeletal muscle

Abstract

Intense resistance exercise causes a significant inflammatory response. NF-κB has been identified as a prospective key transcription factor mediating the postexercise inflammatory response. The purpose of this study was to determine whether a single bout of intense resistance exercise regulates NF-κB signaling in human skeletal muscle. Muscle biopsy samples were obtained from the vastus lateralis of five recreationally active, but not strength-trained, males (21.9 ± 1.3 yr) prior to, and at 2 and 4 h following, a single bout of intense resistance exercise. A further five subjects (4 males, 1 female) (23 ± 0.89 yr) were recruited as a nonexercise control group to examine the effect of the muscle biopsy protocol on key markers of skeletal muscle inflammation. Protein levels of IκBα and phosphorylated NF-κB (p65), as well as the mRNA expression of inflammatory myokines monocyte chemoattractant protein 1 (MCP-1), IL-6, and IL-8 were measured. Additionally, NF-κB (p65) DNA binding to the promoter regions of MCP-1, IL-6, and IL-8 was investigated. IκBα protein levels decreased, while p-NF-κB (p65) protein levels increased 2 h postexercise and returned to near-baseline levels by 4-h postexercise. Immunohistochemical data verified these findings, illustrating an increase in p-NF-κB (p65) protein levels, and nuclear localization at 2 h postexercise. Furthermore, NF-κB DNA binding to MCP-1, IL-6, and IL-8 promoter regions increased significantly 2 h postexercise as did mRNA levels of these myokines. No significant change was observed in the nonexercise control group. These novel data provide evidence that intense resistance exercise transiently activates NF-κB signaling in human skeletal muscle during the first few hours postexercise. These findings implicate NF-κB in the transcriptional control of myokines known to be central to the postexercise inflammatory response.

Heat therapy promotes the expression of angiogenic regulators in human skeletal muscle

“…In agreement with our findings, prior studies have demonstrated that the mRNA expression of CX3CL1 tends to decrease slightly over time in resting/nonexercising skeletal muscle (6,70). Intriguingly, however, the expression of CCL2 has been reported to increase, albeit not significantly, in resting muscle 2-4 h following a baseline biopsy (6,70,78). These changes in the expression of key myokines illustrate the critical importance of incorporating a control group in long experiments to account for time-dependent variations in skeletal muscle gene expression in humans.…”

Human inflammatory and resolving lipid mediator responses to resistance exercise and ibuprofen treatment

“…Exercises were performed sequentially in a circuit manner with participants resting for 1 min between each exercise and 3 min between each set. This same exercise protocol has been previously used by our research group to induce local proinflammatory cytokine expression and associated NF-B signaling in human skeletal muscle (106). Following completion of the exercise bout, subjects rested supine throughout a 3-h recovery period, during which postexercise blood samples were obtained.…”

Oxygen Consumption and Usage During Physical Exercise: The Balance Between Oxidative Stress and ROS-Dependent Adaptive Signaling

“…Through the activation of satellite cell proliferation, NO is important in damage repair/remodeling in the skeletal muscle, which might be important in delayed muscle soreness (315). B Redox sensor, regulates genes related with inflammation, cell growth, stress responses, including oxidative stress, and apoptosis E Activation of NF-jB binding to DNA in rat skeletal muscle in response to acute treadmill running (111,139,142,162) NF-jB activation in human peripheral blood lymphocytes in response to acute spring and endurance exercise (76,420) Acute treadmill exercise activates NF-jB in an intensity-dependent manner in human peripheral blood lymphocytes (182) Acute eccentric exercise induces and submaximal eccentric training decreases NF-kB activation in PBMC (101,165) Acute intensive resistance exercise increases NF-jB activity in human skeletal muscle (418) Acute fatiguing resistance exercise decreases NF-jB binding to DNA in skeletal muscle from healthy humans and mice (87) NF-jB activation in response to moderate-intensity cycle exercise in muscle from nondiabetic subjects, but not in type II diabetics (392) Increased basal NF-jB activity in muscle from insulin-resistant and type II diabetic subjects, and in diabetic rat (197,392) NF-jB activation for DNA binding by isometric contraction in muscle of adult, but not old mice (416) Muscle unloading increases NF-jB activity in mice (87,150) NF-jB -/ -mice is resistant to unloading-induced muscle atrophy (149) Training increases basal levels, but blunts isometric contraction-induced NF-jB activation in skeletal muscle of mice (53) Treadmill training increases nuclear levels of NF-jB in skeletal muscle of adult and old rats (105) T Activator protein-1 (AP-1)…”