CYTOKINES AND ENDOTOXIN-INDUCED ABORTION

了解妊娠失败的基础是重要的 医学/生物学目标。本研究旨在确定 巨噬细胞产生宫内细胞因子在内毒素中的作用 小鼠人工流产。小鼠子宫中含有大量的 处于雌激素调控下的巨噬细胞 孕激素。控制是通过荷尔蒙诱导的局部生产来实现的 子宫上皮细胞表达巨噬细胞集落刺激因子-L 细胞。子宫巨噬细胞功能，通过产生前- 炎性细胞因子、白介素L(IL-I)、白介素6(IL-6)和 肿瘤坏死因子α(TNFpha)相对于非 生殖器官。这一点很重要，因为受刺激的产品 巨噬细胞在许多病理过程中既有积极作用，也有消极作用。 过程，包括内毒素诱导的毒性。病理反应是 当巨噬细胞暴露在多种刺激下时，效果最好。例如, 干扰素-γ对巨噬细胞的刺激作用 导致显著的病理，但巨噬细胞的预刺激 干扰素-γ可大大增强内毒素诱导的效应。内毒素产生 小鼠流产的剂量水平对成年人来说没有临床毒性。 我们推测内毒素的引产能力可能是 与正常子宫巨噬细胞的高反应性有关 这可能是因为他们被预先刺激了 卵巢激素和脑脊液-1。我们进一步假设堕胎可能 由子宫内巨噬细胞有毒产物的过度产生所致 例如TNFGamma。为了检验这些假设，我们建议对IL-1进行量化。 1、IL-6和TNFpha mRNA、生物活性和免疫反应性(ELISA) 暴露前后的子宫、肝脏、脾、胎盘和胎儿 小鼠对产生流产的内毒素方案。统计比较 将在未处理的怀孕小鼠和处理过的小鼠之间进行 内毒素还是无毒内毒素与细胞因子的关系 水平对怀孕成功的影响。来检验这样的假设 细胞因子会导致流产，我们将确定小鼠是否能受到保护 通过用肿瘤坏死因子α抗体或 IL-1R拮抗剂。因为这些研究的理论基础是 内毒素诱导巨噬细胞产生细胞因子，研究将于 以确定内毒素诱导的细胞因子产生是否 巨噬细胞依赖型。细胞系的体外研究和体内研究 将对去卵巢的小鼠进行实验，以评估假设 子宫巨噬细胞，通过暴露于生理性的 雌激素-17β、孕酮和脑脊液-1的刺激物表现出高度的增强 对内毒素的反应。这些研究将提供更多的 了解胎儿衰竭的基础。

Understanding the basis for pregnancy failure is an important medical/biological goal. The present study is designed to determine the role of intrauterine cytokine production by macrophages in endotoxin- induced abortion in mice. The mouse uterus contains high numbers of macrophages that are under the regulatory control of estrogen and progesterone. Control is mediated through hormone-induced local production of macrophage colony stimulating factor (CSF-l) by uterine epithelial cells. Uterine macrophage function, assessed by production of the pro- inflammatory cytokines, interleukin l (IL-I), interleukin 6 (IL-6) and tumor necrosis factor alpha (TNFalpha) is increased relative to non- reproductive organs. This is important, because the products of stimulated macrophages are positively and negatively involved in many pathologic processes, including endotoxin-induced toxicity. Pathologic responses are greatest when macrophages are exposed to multiple stimuli. For example, stimulation of macrophages with interferon gamma (IFNgamma) does not result in significant pathology, but prestimulation of macrophages with IFNgamma greatly increases endotoxin-induced effects. Endotoxin produces abortions in mice at dose levels that are not clinically toxic for adults. We hypothesized that the abortifacient ability of endotoxin might be related to the heightened responsiveness of normal uterine macrophages that could occur as a results of their having been prestimulated with ovarian hormones and CSF-1. We further hypothesized that abortion might result from overproduction in the uterus of toxic products of macrophages such as TNFgamma. To test these hypotheses, we propose to quantitate IL- 1, IL-6 and TNFalpha mRNA, bioactivity and immunoreactivity (ELISA) in uterus, liver, spleen, placenta and fetus before and after exposure of mice to abortion-producing regimens of endotoxin. Statistical comparisons will be made between untreated pregnant mice and mice treated with endotoxin or non-toxic endotoxin to determine the relationship of cytokine levels to pregnancy success. To test the hypothesis that individual cytokines cause abortions, we will determine whether mice can be protected from endotoxin-induced abortion by treating them with TNFalpha antibody or IL-1r antagonist. Since the studies are based on the rationale that endotoxin induces macrophages to produce cytokines, studies will be performed to determine if endotoxin-induced cytokine production is macrophage-dependent. In vitro studies with cell lines and in vivo studies with ovariectomized mice will be performed to evaluate the hypothesis that uterine macrophages, preconditioned by exposure to the physiologic stimuli, estradiol- 17beta, progesterone and CSF-1, exhibit heightened responses to endotoxin . These studies will provide increased understanding of the basis for fetal failure.