The cardiovascular effects of pulmonary exposure to engineered nanomaterials (ENM) are poorly understood, and the reproductive consequences are even less understood. Inflammation remains the most frequently explored mechanism of ENM toxicity. However, the key mediators and steps between lung exposure and uterine health remain to be fully defined. The purpose of this study was to determine the uterine inflammatory and vascular effects of pulmonary exposure to titanium dioxide nanoparticles (nano-TiO2). We hypothesized that pulmonary nano-TiO2 exposure initiates a Th2 inflammatory response mediated by Group II innate lymphoid cells (ILC2), which may be associated with an impairment in uterine microvascular reactivity. Female, virgin, Sprague-Dawley rats (8–12 weeks) were exposed to 100 μg of nano-TiO2 via intratracheal instillation 24 h prior to microvascular assessments. Serial blood samples were obtained at 0, 1, 2 and 4 h post-exposure for multiplex cytokine analysis. ILC2 numbers in the lungs were determined. ILC2s were isolated and phosphorylated nuclear factor kappa-light-chain-enhancer of activated B cells (NF-ĸB) levels were measured. Pressure myography was used to assess vascular reactivity of isolated radial arterioles. Pulmonary nano-TiO2 exposure was associated with an increase in IL-1ß, 4, 5 and 13 and TNF- α 4 h post-exposure, indicative of an innate Th2 inflammatory response. ILC2 numbers were significantly increased in lungs from exposed animals (1.66 ± 0.19%) compared to controls (0.19 ± 0.22%). Phosphorylation of the transactivation domain (Ser-468) of NF-κB in isolated ILC2 and IL-33 in lung epithelial cells were significantly increased (126.8 ± 4.3% and 137 ± 11% of controls respectively) by nano-TiO2 exposure. Lastly, radial endothelium-dependent arteriolar reactivity was significantly impaired (27 ± 12%), while endothelium-independent dilation (7 ± 14%) and α-adrenergic sensitivity (8 ± 2%) were not altered compared to control levels. Treatment with an anti- IL-33 antibody (1 mg/kg) 30 min prior to nano-TiO2 exposure resulted in a significant improvement in endothelium-dependent dilation and a decreased level of IL-33 in both plasma and bronchoalveolar lavage fluid. These results provide evidence that the uterine microvascular dysfunction that follows pulmonary ENM exposure may be initiated via activation of lung-resident ILC2 and subsequent systemic Th2-dependent inflammation.

中文翻译：

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肺二氧化钛纳米粒子暴露引起的II组先天性淋巴样细胞和微血管功能障碍

人们很少了解肺对工程纳米材料（ENM）的心血管影响，对生殖后果的了解甚至更少。炎症仍然是最常见的ENM毒性机制。然而，肺接触与子宫健康之间的关键介体和步骤仍有待完全确定。这项研究的目的是确定肺部暴露于二氧化钛纳米颗粒（nano-TiO2）对子宫的炎症和血管的影响。我们假设，肺部纳米TiO2暴露会引发由II组先天性淋巴样细胞（ILC2）介导的Th2炎症反应，这可能与子宫微血管反应性受损有关。女，处女，在微血管评估前24小时，通过气管内滴注将Sprague-Dawley大鼠（8–12周）暴露于100μg纳米TiO2中。在暴露后0、1、2和4小时获得连续血样，以进行多重细胞因子分析。确定了肺中的ILC2数量。分离ILC2，并测量活化的B细胞的磷酸化核因子κ轻链增强子（NF-ĸB）水平。压力肌成像用于评估孤立的radial骨小动脉的血管反应性。肺部纳米TiO2暴露与暴露后4 hIL-1ß，4、5和13以及TNF-α的升高有关，表明先天的Th2炎症反应。与对照组（0.19±0.22％）相比，暴露动物肺部的ILC2数量显着增加（1.66±0.19％）。通过纳米TiO2暴露，分离的ILC2和IL-33在肺上皮细胞中NF-κB的反式激活域（Ser-468）的磷酸化显着增加（分别为对照的126.8±4.3％和137±11％）。最后，径向内皮依赖性小动脉反应性显着受损（27±12％），而内皮依赖性扩张（7±14％）和α-肾上腺素能敏感性（8±2％）与对照组相比没有改变。在纳米TiO2暴露之前30分钟用抗IL-33抗体（1 mg / kg）进行治疗，可显着改善内皮依赖性舒张功能，并降低血浆和支气管肺泡灌洗液中IL-33的水平。