Prenatal LPS-induced changes in gene expression

描述(由申请人提供)：我们先前证明，接受细菌毒素脂多糖(LPS)治疗的怀孕雌性所生的幼崽出生时多巴胺(DA)神经元比正常少。我们将这些研究延长到16个月，发现暴露于脂多糖的大鼠在出生前表现出DA神经元的进行性丢失(46%)，伴随着DA活性的增加，促炎细胞因子肿瘤坏死因子(TNFpha)的升高，α-突触核蛋白聚集体和路易样小体的增加。我们最近收到了来自NINDS的资金，用于在22个月内表征这种新的帕金森氏病(PD)动物模型。然而，这种DA神经元在发育过程中丢失的机制(S)目前尚不清楚。最近的初步数据(Real-Time RT-PCR)表明，促炎/抗炎细胞因子mRNA的比例增加。因此，在特定的目标1中，我们将评估中脑、纹状体和小脑(对照区域)中肿瘤坏死因子-α、白介素113、白介素6、转化生长因子β和白介素6的mRNA和细胞因子蛋白(ELISA)含量，以确定产前内毒素是否改变了这些因子在发育或出生后早期的转录和翻译控制(P1-21)。由于NurR-1、Sonic Hedgehog、PTX-3、成纤维细胞生长因子-8(FGF8)和胶质细胞系衍生神经营养因子(GDNF)分别是调节DA神经元表型发育的转录因子和神经营养因子，我们将在特定的目标2中评估这些因子的mRNA和蛋白水平，以确定它们在内毒素诱导的DA神经元减少中的作用。我们的初步数据进一步表明，内毒素诱导小胶质细胞中的肿瘤坏死因子-α增加，我们将在目标3中评估小胶质细胞和星形胶质细胞在内毒素效应中的具体作用。这些研究的结果不仅将补充我们的长期研究，而且将检验这样一个假设，即产前内毒素永久性地改变调节DA神经元发育的基因并影响其在成年生活中的表型。这些研究的结果还将提供一个独特的机会，以确定产前神经毒素暴露是否可以永久性地改变增加以后生活中神经退行性疾病风险的基因。

DESCRIPTION (provided by applicant): We previously demonstrated that pups born to gravid females treated with the bacteriotoxin lipopolysaccharide (LPS) were born with fewer than normal dopamine (DA) neurons. We have extended these studies out through 16 months and showed that rats exposed to LPS prenatally exhibit progressive loss of DA neurons (46%) associated with increased DA activity, elevations in the proinflammatory cytokine tumor necrosis factor (TNFalpha), aggregates of alpha-synuclein, and Lewy-like bodies. We have recently received funding from NINDS to characterize this new animal model of Parkinson's disease (PD) through 22 months. However, the mechanism(s) responsible for this DA neuron loss during development are currently unknown. Recent preliminary data (Real-time RT-PCR) suggests that the ratio of pro-/anti-inflammatory cytokine mRNA is increased. In specific aim 1 we will therefore assess both mRNA and cytokine protein (ELISA) content for TNF-a, interleukin (IL) -113, IL-6, transforming growth factor (TGFbeta), and IL-6 in the mesencephalon, striatum, and cerebellum (control region) to determine if prenatal LPS alters transcriptional and translational control of these factors during development or early postnatal life (P 1-21). Since Nurr-1, sonic hedgehog, Ptx-3, fibroblast growth factor-8 (FGF8) and glial cell line derived neurotrophic factor (GDNF) are transcriptional and neurotrophic factors, respectively, that regulate the development of the DA neuron phenotype, we will assess mRNA and protein levels of these factors in Specific Aim 2 to determine their involvement in the LPS-induced reduction in DA neurons. Our preliminary data further suggests that LPS induces increases in TNF-alpha in microglia and we will assess the specific roles of both microglia and astrocytes in the LPS effect in Aim 3. The results of these studies will not only compliment our long-term studies, but will test the hypothesis that prenatal LPS permanently alters genes that regulate the development of the DA neuron and affect its phenotype during adult life. The results of these studies will also provide a unique opportunity to determine if prenatal neurotoxin exposure can permanently alter genes that increase the risk of neurodegenerative disease in later life.