Dept. of Biological Sciences, Bowling Green State University, Bowling Green, Ohio, United States of America.
Dept. of Exercise Science, Bowling Green State University, Bowling Green, Ohio, United States of America.
PLoS One. 2020 Aug 24;15(8):e0237705. doi: 10.1371/journal.pone.0237705. eCollection 2020.
Polychlorinated biphenyls (PCBs) are environmental pollutants and endocrine disruptors, harmfully affecting reproductive, endocrine, neurological and immunological systems. This broad influence has implications for processes such as wound healing, which is modulated by the immunological response of the body. Conversely, while PCBs can be linked to diminished wound healing, outside of PCB pollution systems, exercise has been shown to accelerate wound healing. However, the potential for moderate intensity exercise to modulate or offset the harmful effects of a toxin like PCB are yet unknown. A key aim of the present study was to examine how PCB exposure at different doses (0, 100, 500, 1000 ppm i.p.) altered wound healing in exercised versus non-exercised subgroups of mice. We examined PCB effects on immune function in more depth by analyzing the concentrations of cytokines, interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), Interleukin-6 (IL-6) and granulocyte macrophage colony stimulating factor (GM-CSF) in these wounds inflicted by punch biopsy. Mice were euthanized at Day 3 or Day 5 after PCB injection (n = 3-6) and skin excised from the wound area was homogenized and analyzed for cytokine content. Results revealed that wound healing was not signficantly impacted by either PCB exposure or exercise, but there were patterns of delays in healing that depended on PCB dose. Changes in cytokines were also observed and depended on PCB dose and exercise experience. For example, IL-1β concentrations in Day 5 mice without PCB administration were 33% less in exercised mice than mice not exercised. However, IL-1β concentrations in Day 3 mice administered 100 ppm were 130% greater in exercised mice than not exercisedmice. Changes in the other measured cytokines varied with mainly depressions at lesser PCB doses and elevations at higher doses. Exercise had diverse effects on cytokine levels, but increased cytokine levels in the two greater doses. Explanations for these diverse effects include the use of young animals with more rapid wound healing rates less affected by toxin exposure, as well as PCB-mediated compensatory effects at specific doses which could actually enhance immune function. Future work should examine these interactions in more detail across a developmental time span. Understanding how manipulating the effects of exposure to environemntal contaminants using behavioral modification could be very useful in certain high risk populations or exposed individuals.
多氯联苯（PCBs）是环境污染物和内分泌干扰物，对生殖、内分泌、神经和免疫系统造成有害影响。这种广泛的影响与伤口愈合等过程有关，而身体的免疫反应会调节这些过程。相反，虽然 PCB 会导致伤口愈合减弱，但在 PCB 污染系统之外，运动已被证明可以加速伤口愈合。然而，中度强度运动是否能够调节或抵消像 PCB 这样的毒素的有害影响尚不清楚。本研究的一个主要目标是检查不同剂量（0、100、500、1000 ppm 腹腔注射）的 PCB 暴露如何改变运动和非运动亚组小鼠的伤口愈合。我们通过分析这些通过穿孔活检造成的伤口中细胞因子、白细胞介素-1β（IL-1β）、肿瘤坏死因子-α（TNF-α）、白细胞介素-6（IL-6）和粒细胞巨噬细胞集落刺激因子（GM-CSF）的浓度，更深入地研究了 PCB 对免疫功能的影响。在 PCB 注射后第 3 天或第 5 天处死小鼠（n = 3-6），从伤口区域切除皮肤并匀浆分析细胞因子含量。结果表明，伤口愈合不受 PCB 暴露或运动的显著影响，但存在依赖于 PCB 剂量的愈合延迟模式。还观察到细胞因子的变化，并且取决于 PCB 剂量和运动经验。例如，没有 PCB 给药的第 5 天小鼠的 IL-1β 浓度在运动小鼠中比不运动的小鼠低 33%。然而，在接受 100 ppm PCB 治疗的第 3 天小鼠中，运动小鼠的 IL-1β 浓度比不运动的小鼠高 130%。其他测量细胞因子的变化主要取决于较低 PCB 剂量的抑制和较高剂量的升高。运动对细胞因子水平有不同的影响，但在两个更高剂量下增加了细胞因子水平。这些不同影响的解释包括使用伤口愈合速度更快、受毒素暴露影响较小的年轻动物，以及在特定剂量下 PCB 介导的代偿效应，这些效应实际上可能增强免疫功能。未来的工作应该更详细地研究整个发育时间跨度内这些相互作用。了解如何通过行为改变来操纵环境污染物暴露的影响，对于某些高危人群或暴露个体可能非常有用。
