Relationship Between Macrophage Differentiation And The Chemotactic Activity Toward Damaged Muscle Cells

Aim: We investigated the effect of macrophage differentiation on the chemotactic activity to invade local damaged muscle using in vitro models of muscle injury. Methods: C2C12 cell myoblasts, and J774 cell macrophages were used. The “killed-C2C12” cells were combined with live C2C12 cells (live:killed C2C12 = 1:0.5) as a partially damaged muscle model. The J774 cells were stimulated with LPS and DEX. The chemotactic activity of J774 cells was examined using TAXIScan device. Results: Although the velocity of J774 cells was little affected by each type of C2C12 cells (live, killed and combination), the directionality of the J774 cells was increased. The highest directionality of J774 cells was observed when the ratio of live-:killed-C2C12 cells was 1:0.5.The TLR4 and CD11c expressions of LPS cells were higher than those in both Ctrl and DEX cells. The LPS cells were strongly stained around the cell membrane by phalloidin, but the F-actin expression in DEX cells was in an orderly line along the long axis of cells. DEX cells showed stretching toward C2C12 cells, and their length/width ratio was higher than that in both Ctrl and LPS cells. Although the chemotactic activity of LPS cells disappeared completely, DEX cells exhibited accelerated chemotactic activity toward damaged muscle cells. The MCP-1 production in live-:killed-C2C12 cells was higher than that in the live-C2C12 cells. The CCR2 expression in DEX cells was higher than that in both Ctrl and LPS cells. Conclusion: Our conclusion is that: 1) the chemotactic activity of macrophages toward areas of damaged muscle induces more live myoblasts than damaged cells, 2) the chemotactic activity of macrophages is not due to velocity, but depends on the directionality toward damaged muscle cells, and 3) macrophage differentiation influences their chemotactic activity toward damaged muscle cells through the expression of CCR2 and/or F-actin

Exhaustive Exercise Enhances Immune Response To Flagellin Via Adrenaline-Mediated Up-Regulation of TLR5 Expression

Objective: We already reported that lipopolysacchride (LPS)-induced tumor necrosis factor (TNF)-α production as a bacterial infection model to induce immune response, was inhibited by exhaustive exercise. However, it remains unclear whether or not the immune response to flagellin (FG), which binds to toll like receptor 5(TLR5) and induces pro-inflammatory cytokine production, is also inhibited by this severe exercise. The aim of this study was to determine whether or not exhaustive exercise affects TNF-α productions after FG injection in mice. Methods: Both exhaustive-exercised (EX; n=12) and non-exercised (N-EX; n=12) male C3H/HeN mice were injected with FG (1 mg/kg, i.v), and blood samples were collected. In addition, to clarify the effect of catecholamine on immune response macrophage and intestinal cells after FG stimulation, RAW264 cells and Caco2 cells were cultured 30min after propranolol (Prop; β-adrenergic receptors blocker) or Ly294002 (Ly; PI3K inhibitor) treatments, and were then stimulated with adrenaline (AD; 1 μM) and FG (5 μg/ml). Moreover, the effect of Prop (10 mg/kg, n=12) on FG-induced TNF-α production in EX mice was also examined. Results: TNF-α in EX group was significantly higher than that in N-EX group after FG injection. In epithelium cells, more intensity of TLR5 localization was observed on the plasma membrane area than in the cytosol area in EX mice, but not N-EX mice. Caco2 cells, but not RAW264 cells, significantly increased the FG-induced TNF-α production using AD treatment. Moreover, Prop treatment attenuated the AD-induced TNF-α production in response to FG in Caco2 cells. Although TLR5 expression on RAW264 cells was significantly decreased after AD treatment, the expression on Caco2 cells was rapidly increased. In fact, we observed the AD-dependent TLR5 translocation from cytoplasm to cell membrane in Caco2 cells, and the membrane translocation was inhibited by Prop and Ly treatment. Moreover, the pretreatment with Prop attenuated the exercise-induced plasma TNF-α response to FG in vivo. Conclusion: Our results suggest that immune response to FG via TLR5 might be enhanced by exhaustive exercise in mice

The Search for the Hero\u27s Soul in the Alchemist

The Alchemist touches upon two major themes in mythology : The hero journey and a person\u27s spiritual quest to find out his or her true nature. Coelho is asking his reader to take the same journey his character Santiago does. Coelho believes that if we do we will be better people and in turn the world will be a better place

Initiation Ritual and the Moral Self in The Secret Sharer

The relationship between the Captain and Leggatt is analyzed with emphasis on Leggatt\u27s influence on the Captain\u27s understanding of his moral self. The novella centers on this theme of a young, as yet untested, captain\u27s finding of his moral self. Only when he understands his own morality, through the influence of Leggatt, can he be confident enough to command his ship