Aging, physical activity and toll-like receptor 4.

白细胞介素-1 β（IL-1 β）、白细胞介素-6（IL-6）和肿瘤坏死因子-α（TNF-α）在许多“年龄”和“不活动”相关疾病的发病机制中起重要作用，但年龄和身体活动诱导的炎性细胞因子产生差异的机制尚未阐明。Toll样受体4（TLR 4）与CD 14一起转导脂多糖（LPS）信号，但没有研究人员记录衰老或体力活动对TLR 4的影响。本申请的广泛目的是检查年龄或身体活动水平是否影响TLR 4的细胞表面表达，并确定这些变化与炎性细胞因子产生差异的相关程度。这项研究的主要目的是评估年龄和身体状况对儿童的影响。 活性水平对TLR 4表达的影响，并评估LPS刺激的炎性细胞因子产生、单细胞因子产生和MAP激酶活化的伴随变化。热休克蛋白（HSP 60/72）在运动后从肌肉中释放出来，并且已知其结合并激活TLR 4。因此，我们也将奋进确定热休克蛋白在这些关系中发挥的作用。据推测，无论是年轻的和身体活跃的受试者， 与年长者和久坐者相比，他们的细胞表面TLR 4表达和细胞因子产生都较低。我们还假设LPS刺激的MAP激酶活化与TLR 4的细胞表面表达成比例，但当参与替代刺激途径（抗CD 40）时，组间无差异。我们将招募16名受试者，分为四组：18-35岁，身体不活动; 18-35岁，身体不活动。 活跃; 65-85，身体不活跃; 65-85，身体活跃。在24小时饮食控制后，将从72小时未运动的受试者中采集血样。将测定TLR 4/CD 14的细胞表面表达和单细胞细胞因子产生（流式细胞术）、体外细胞因子刺激（LPS、HSP 72和HSP 60）和MAP激酶活化。将采用2 × 2析因设计，以年龄（18-35岁和65-85岁）和体力活动水平（活动和非活动）作为两个实验因素。这些实验将有助于确定年龄和身体活动相关的细胞因子产生差异是否与TLR 4有关，以及热休克蛋白是否在TLR 4调节中发挥作用。

Interleukin-1beta (IL-1beta), interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha), play an important role in the pathogenesis of many "age" and "inactivity"-related diseases, but the mechanism for age- and physical activity-induced differences in inflammatory cytokine production has not been elucidated. Toll-like receptor 4 (TLR4), in concert with CD14, transduces the lipopolysaccharide (LPS) signal, but no researchers have documented the effects of either aging or physical activity on TLR4. The broad objective of this application is to examine whether age or physical activity level influence the cell-surface expression of TLR4 and to determine to what extent these changes are related to differences in inflammatory cytokine production. The primary aims of the proposed research will be to assess the influence of age and physical activity level on TLR4 expression and to assess concomitant changes in LPS-stimulated inflammatory cytokine production, single-cell cytokine production and MAP kinase activation. Heat shock proteins (HSP60/72) are released from muscle following exercise and are known to bind and activate TLR4. Thus, we will also endeavor to determine the role heat shock proteins play in these relationships. It is hypothesized that both younger and physically active subjects will have both lower cell-surface expression of TLR4 and cytokine production than their older and more sedentary counterparts. We also hypothesize that LPS-stimulated MAP kinase activation will be proportional to cell-surface expression of TLR4, but will not be different between groups when alternative stimulation pathways are engaged (anti CD40). We will recruit 16 subjects into each of four groups: 18-35 years of age, physically inactive; 18-35, physically active; 65-85, physically inactive and 65-85, physically active. Blood samples will be obtained from subjects who have not exercised for 72 hours, following 24 h dietary control. Cell-surface expression of TLR4/CD14 and single-cell cytokine production (flow cytometry), in vitro cytokine stimulation (LPS, HSP72 and HSP60) and MAP kinase activation will be determined. A 2 x 2 factorial design with age (18-35 and 65-85) and physical activity level (active and inactive) as the two experimental factors, will be employed. These experiments will help to determine whether age and physical activity related differences in cytokine production are linked to TLR4 and whether heat shock proteins play a role in TLR4 regulation.