PDF(Pubmed)
Abstract：
BACKGROUND: The increasing production and usage of copper oxide nanoparticles (Nano-CuO) raise human health concerns. Previous studies have demonstrated that exposure to Nano-CuO could induce lung inflammation, injury, and fibrosis. However, the potential underlying mechanisms are still unclear. Here, we proposed that matrix metalloproteinase-3 (MMP-3) might play an important role in Nano-CuO-induced lung inflammation, injury, and fibrosis.
RESULTS: Exposure of mice to Nano-CuO caused acute lung inflammation and injury in a dose-dependent manner, which was reflected by increased total cell number, neutrophil count, macrophage count, lactate dehydrogenase (LDH) activity, and CXCL1/KC level in bronchoalveolar lavage fluid (BALF) obtained on day 3 post-exposure. The time-response study showed that Nano-CuO-induced acute lung inflammation and injury appeared as early as day 1 after exposure, peaked on day 3, and ameliorated over time. However, even on day 42 post-exposure, the LDH activity and macrophage count were still higher than those in the control group, suggesting that Nano-CuO caused chronic lung inflammation. The Nano-CuO-induced pulmonary inflammation was further confirmed by H&E staining of lung sections. Trichrome staining showed that Nano-CuO exposure caused pulmonary fibrosis from day 14 to day 42 post-exposure with an increasing tendency over time. Increased hydroxyproline content and expression levels of fibrosis-associated proteins in mouse lungs were also observed. In addition, Nano-CuO exposure induced MMP-3 overexpression and increased MMP-3 secretion in mouse lungs. Knocking down MMP-3 in mouse lungs significantly attenuated Nano-CuO-induced acute and chronic lung inflammation and fibrosis. Moreover, Nano-CuO exposure caused sustained production of cleaved osteopontin (OPN) in mouse lungs, which was also significantly decreased by knocking down MMP-3.
CONCLUSIONS: Our results demonstrated that short-term Nano-CuO exposure caused acute lung inflammation and injury, while long-term exposure induced chronic pulmonary inflammation and fibrosis. Knocking down MMP-3 significantly ameliorated Nano-CuO-induced pulmonary inflammation, injury, and fibrosis, and also attenuated Nano-CuO-induced cleaved OPN level. Our study suggests that MMP-3 may play important roles in Nano-CuO-induced pulmonary inflammation and fibrosis via cleavage of OPN and may provide a further understanding of the mechanisms underlying Nano-CuO-induced pulmonary toxicity.
RESULTS: Exposure of mice to Nano-CuO caused acute lung inflammation and injury in a dose-dependent manner, which was reflected by increased total cell number, neutrophil count, macrophage count, lactate dehydrogenase (LDH) activity, and CXCL1/KC level in bronchoalveolar lavage fluid (BALF) obtained on day 3 post-exposure. The time-response study showed that Nano-CuO-induced acute lung inflammation and injury appeared as early as day 1 after exposure, peaked on day 3, and ameliorated over time. However, even on day 42 post-exposure, the LDH activity and macrophage count were still higher than those in the control group, suggesting that Nano-CuO caused chronic lung inflammation. The Nano-CuO-induced pulmonary inflammation was further confirmed by H&E staining of lung sections. Trichrome staining showed that Nano-CuO exposure caused pulmonary fibrosis from day 14 to day 42 post-exposure with an increasing tendency over time. Increased hydroxyproline content and expression levels of fibrosis-associated proteins in mouse lungs were also observed. In addition, Nano-CuO exposure induced MMP-3 overexpression and increased MMP-3 secretion in mouse lungs. Knocking down MMP-3 in mouse lungs significantly attenuated Nano-CuO-induced acute and chronic lung inflammation and fibrosis. Moreover, Nano-CuO exposure caused sustained production of cleaved osteopontin (OPN) in mouse lungs, which was also significantly decreased by knocking down MMP-3.
CONCLUSIONS: Our results demonstrated that short-term Nano-CuO exposure caused acute lung inflammation and injury, while long-term exposure induced chronic pulmonary inflammation and fibrosis. Knocking down MMP-3 significantly ameliorated Nano-CuO-induced pulmonary inflammation, injury, and fibrosis, and also attenuated Nano-CuO-induced cleaved OPN level. Our study suggests that MMP-3 may play important roles in Nano-CuO-induced pulmonary inflammation and fibrosis via cleavage of OPN and may provide a further understanding of the mechanisms underlying Nano-CuO-induced pulmonary toxicity.
摘要：
背景：氧化铜纳米颗粒（Nano-CuO）的生产和使用增加引起了人类健康问题。以前的研究表明，暴露于纳米CuO可以诱发肺部炎症，损伤,和纤维化。然而,潜在的潜在机制仍不清楚.这里,我们提出基质金属蛋白酶-3(MMP-3)可能在纳米CuO诱导的肺部炎症中起重要作用,损伤,和纤维化。
结果：小鼠暴露于Nano-CuO以剂量依赖性方式引起急性肺部炎症和损伤，这反映在细胞总数的增加上，中性粒细胞计数,巨噬细胞计数,乳酸脱氢酶（LDH）活性，暴露后第3天获得的支气管肺泡灌洗液（BALF）中的CXCL1/KC水平。时间响应研究表明，纳米CuO引起的急性肺部炎症和损伤早在暴露后第1天出现，在第3天达到峰值，并随着时间的推移而改善。然而,即使在曝光后的第42天，LDH活性和巨噬细胞计数仍高于对照组，表明Nano-CuO引起慢性肺部炎症。通过肺切片的H&E染色进一步证实了纳米CuO诱导的肺部炎症。三色染色显示,从暴露后第14天至第42天,纳米-CuO暴露引起肺纤维化,并且随着时间的推移有增加的趋势。还观察到小鼠肺中羟脯氨酸含量和纤维化相关蛋白的表达水平增加。此外,纳米CuO暴露诱导小鼠肺MMP-3过表达并增加MMP-3分泌。敲除小鼠肺中的MMP-3可显着减轻Nano-CuO诱导的急性和慢性肺部炎症和纤维化。此外，纳米CuO暴露导致小鼠肺中持续产生裂解的骨桥蛋白（OPN），通过敲低MMP-3也显着降低。
结论：我们的结果表明，短期纳米CuO暴露会引起急性肺部炎症和损伤，而长期暴露会导致慢性肺部炎症和纤维化。抑制MMP-3显著改善Nano-CuO诱导的肺部炎症,损伤,和纤维化，并且还减弱了纳米CuO诱导的切割的OPN水平。我们的研究表明，MMP-3可能通过OPN的裂解在Nano-CuO诱导的肺部炎症和纤维化中起重要作用，并可能进一步了解Nano-CuO诱导的肺毒性的潜在机制。
结果：小鼠暴露于Nano-CuO以剂量依赖性方式引起急性肺部炎症和损伤，这反映在细胞总数的增加上，中性粒细胞计数,巨噬细胞计数,乳酸脱氢酶（LDH）活性，暴露后第3天获得的支气管肺泡灌洗液（BALF）中的CXCL1/KC水平。时间响应研究表明，纳米CuO引起的急性肺部炎症和损伤早在暴露后第1天出现，在第3天达到峰值，并随着时间的推移而改善。然而,即使在曝光后的第42天，LDH活性和巨噬细胞计数仍高于对照组，表明Nano-CuO引起慢性肺部炎症。通过肺切片的H&E染色进一步证实了纳米CuO诱导的肺部炎症。三色染色显示,从暴露后第14天至第42天,纳米-CuO暴露引起肺纤维化,并且随着时间的推移有增加的趋势。还观察到小鼠肺中羟脯氨酸含量和纤维化相关蛋白的表达水平增加。此外,纳米CuO暴露诱导小鼠肺MMP-3过表达并增加MMP-3分泌。敲除小鼠肺中的MMP-3可显着减轻Nano-CuO诱导的急性和慢性肺部炎症和纤维化。此外，纳米CuO暴露导致小鼠肺中持续产生裂解的骨桥蛋白（OPN），通过敲低MMP-3也显着降低。
结论：我们的结果表明，短期纳米CuO暴露会引起急性肺部炎症和损伤，而长期暴露会导致慢性肺部炎症和纤维化。抑制MMP-3显著改善Nano-CuO诱导的肺部炎症,损伤,和纤维化，并且还减弱了纳米CuO诱导的切割的OPN水平。我们的研究表明，MMP-3可能通过OPN的裂解在Nano-CuO诱导的肺部炎症和纤维化中起重要作用，并可能进一步了解Nano-CuO诱导的肺毒性的潜在机制。
