METHODS: Using a pre-designed unbiased PCR array for fibrotic markers, we analyzed the fibrotic signature in a subset of NR-COVID-19 lungs. We compared the expression profile against control lungs (donor lungs discarded for transplantation), and explanted tissue from patients with idiopathic pulmonary fibrosis (IPF). Subsequently, RT-qPCR, Western blots and immunohistochemistry were conducted to validate and localize selected pro-fibrotic targets. A total of 23 NR-COVID-19 lungs were used for RT-qPCR validation.
RESULTS: We revealed a unique fibrotic gene signature in NR-COVID-19 that is dominated by a hyper-expression of pro-fibrotic genes, including collagens and periostin. Our results also show a significantly increased expression of Collagen Triple Helix Repeat Containing 1(CTHRC1) which co-localized in areas rich in alpha smooth muscle expression, denoting myofibroblasts. We also show a significant increase in cytokeratin (KRT) 5 and 8 expressing cells adjacent to fibroblastic areas and in areas of apparent epithelial bronchiolization.
CONCLUSIONS: Our studies may provide insights into potential cellular mechanisms that lead to a fulminant presentation of lung fibrosis in NR-COVID-19.
BACKGROUND: National Institute of Health (NIH) Grants R01HL154720, R01DK122796, R01DK109574, R01HL133900, and Department of Defense (DoD) Grant W81XWH2110032 to H.K.E. NIH Grants: R01HL138510 and R01HL157100, DoD Grant W81XWH-19-1-0007, and American Heart Association Grant: 18IPA34170220 to H.K.-Q. American Heart Association: 19CDA34660279, American Lung Association: CA-622265, Parker B. Francis Fellowship, 1UL1TR003167-01 and The Center for Clinical and Translational Sciences, McGovern Medical School to X.Y.
方法:使用预先设计的无偏倚PCR阵列检测纤维化标志物,我们分析了NR-COVID-19肺子集中的纤维化特征。我们比较了对照肺(放弃移植的供体肺)的表达谱,和特发性肺纤维化(IPF)患者的外植组织。随后,RT-qPCR,进行Western印迹和免疫组织化学以验证和定位所选择的促纤维化靶标。共有23个NR-COVID-19肺用于RT-qPCR验证。
结果:我们在NR-COVID-19中发现了一个独特的纤维化基因特征,主要是促纤维化基因的过度表达,包括胶原蛋白和骨膜素。我们的结果还显示,胶原三螺旋重复序列1(CTHRC1)的表达显着增加,它共同定位在富含α平滑肌表达的区域,表示肌成纤维细胞。我们还显示了与成纤维细胞区域和明显的上皮支气管化区域相邻的细胞角蛋白(KRT)5和8表达细胞的显着增加。
结论:我们的研究可能提供对导致NR-COVID-19肺纤维化暴发性呈现的潜在细胞机制的见解。
背景:美国国立卫生研究院(NIH)授予R01HL154720,R01DK122796,R01DK109574,R01HL133900和国防部(DoD)授予W81XWH2110032至H.K.E.H授予:R01HL138510和R1HIPA18American-W177100,美国心脏协会:19CDA34660279,美国肺脏协会:CA-622265,ParkerB.Francis奖学金,1UL1TR003167-01和临床和转化科学中心,