From the Emergency Medical Center, Nagasaki University Hospital (G.T., A.T., O.T.), Nagasaki, Japan; Division of Forensic Pathology and Science, Nagasaki University Graduate School of Biomedical Sciences (T.U., K.I.), Nagasaki, Japan; and Clinical Research Center, Nagasaki University Hospital (J.M., S.S.), Nagasaki, Japan.
J Trauma Acute Care Surg. 2018 Apr;84(4):583-589. doi: 10.1097/TA.0000000000001789.
Infection in patients with systemic inflammation is difficult to diagnose with a single biomarker. We aimed to clarify the time course of change in the gene expression profile of innate immune receptors in infectious or sterile inflammation and to establish an early diagnostic method using canonical discriminant analysis (CDA) of the gene expression profile.
To compare infectious and sterile inflammation, we used cecal ligation and puncture (CLP) and 20% full-thickness burn injury (Burn) models. C57BL/6 mice underwent sham treatment (n = 9 × three groups), CLP (n = 12 × three groups), or Burn (n = 12 × three groups) injury. Mice were killed at 6, 12, and 24 hours after injury, and total RNA was extracted from whole blood. We used quantitative real-time polymerase chain reaction to investigate gene expression of innate immune receptors Toll-like receptor 2 (TLR2), TLR4, TLR9, NLRP3 (nucleotide-binding oligomerization domain-like receptor family pyrin domain containing 3), and retinoic acid-inducible gene I. To evaluate all gene expression together as patterns, each value was standardized, and CDA was performed at each time point.
Gene expression of TLR2 and TLR4 was already significantly increased in both CLP and Burn compared with sham mice at 6 hours after injury (p < 0.05). Gene expression of TLR9 was significantly decreased in CLP compared with sham and Burn mice at 12 hours and 24 hours after injury (p < 0.05) but not at 6 hours. Gene expression of NLRP3 was significantly increased in CLP and Burn compared with sham mice at 6 hours and 24 hours after injury (p < 0.05). In the CDA, each group showed distinctive gene expression patterns at only 6 hours after injury. Each group was clearly classified, and the classification error rates were 0% at all of the time points.
Canonical discriminant analysis of the gene expression profile of innate immune receptors could be a novel approach for diagnosing the pathophysiology of complicated systemic inflammation from the early stage of injury.
患有全身炎症的患者的感染很难用单一的生物标志物进行诊断。我们旨在阐明固有免疫受体基因表达谱在感染性或无菌性炎症中的变化过程，并通过对基因表达谱进行典型判别分析（CDA）来建立一种早期诊断方法。
为了比较感染性和无菌性炎症，我们使用盲肠结扎穿孔（CLP）和 20%全层烧伤（Burn）模型。C57BL/6 小鼠接受假手术（n=9×3 组）、CLP（n=12×3 组）或烧伤（n=12×3 组）损伤。在损伤后 6、12 和 24 小时处死小鼠，并从全血中提取总 RNA。我们使用定量实时聚合酶链反应来研究固有免疫受体 Toll 样受体 2（TLR2）、TLR4、TLR9、NLRP3（核苷酸结合寡聚化结构域样受体家族含吡咯结构域 3）和视黄酸诱导基因 I 的基因表达。为了评估所有基因表达的整体模式，我们对每个值进行了标准化，并在每个时间点进行 CDA。
与 sham 组相比，TLR2 和 TLR4 的基因表达在 CLP 和 Burn 损伤后 6 小时均显著增加（p<0.05）。TLR9 的基因表达在 CLP 组与 sham 和 Burn 组相比在损伤后 12 小时和 24 小时显著降低（p<0.05），但在 6 小时时没有降低。NLRP3 的基因表达在 CLP 和 Burn 组与 sham 组相比在损伤后 6 小时和 24 小时均显著增加（p<0.05）。在 CDA 中，各组在损伤后仅 6 小时显示出独特的基因表达模式。各组均得到清晰分类，在所有时间点的分类错误率均为 0%。
固有免疫受体基因表达谱的典型判别分析可能是一种从损伤早期诊断复杂全身炎症病理生理学的新方法。
