Department of Forensic Medicine, Faculty of Basic Medical Science, Chongqing Medical University, Chongqing, China.
Int J Exp Pathol. 2022 Oct;103(5):190-197. doi: 10.1111/iep.12443. Epub 2022 May 8.
The purpose of the present study was to investigate the expression of α-SMA and SM22α in airway smooth muscle (ASM) of bronchioles from children younger than 14 years who died of acute interstitial pneumonia (AIP). This is based upon the hypothesis that as contractile marker proteins α-SMA and SM22α can serve as an index of the overcontractile phenotype of ASM that is seen in AIP. Lung tissue samples of children were obtained from autopsies and divided into the AIP group (55.9% male and 44.1% female, between 0.4 and 132 months old, n = 34) and the control group (60% male and 40% female, between 2 and 156 months old, n = 10). We recorded the post-mortem interval (PMI), height, clinical symptoms and abdominal fat thickness (AFT) of each case. Haematoxylin-and-eosin-stained sections were used to examine the luminal area and observe the morphological changes in the bronchioles. Immunohistochemistry and Masson's trichrome staining were used to detect the expression of contractile marker proteins and the degree of pulmonary fibrosis respectively. Compared with the control group, the luminal areas of bronchioles in the AIP group were smaller (p < .001). The expression differences in α-SMA and SM22α between the two groups were statistically significant (p = .01 and p = .02 respectively). Also, there was no significant correlation of the contractile marker proteins expression with PMI, height, clinical symptoms and AFT. The collagen deposition difference in lung between the two groups was not statistically significant (p = .224). These findings suggest that enhancement of ASM contractile function appears to be involved in the death mechanism of children with AIP, which affords more insights into the understanding of AIP.
本研究旨在探讨小于 14 岁因急性间质性肺炎（AIP）死亡的儿童细支气管气道平滑肌（ASM）中α-SMA 和 SM22α 的表达。这是基于这样一种假设，即作为收缩标记蛋白的α-SMA 和 SM22α 可以作为 AIP 中看到的 ASM 过度收缩表型的指标。从尸检中获取儿童的肺组织样本，并分为 AIP 组（55.9%为男性，44.1%为女性，年龄在 0.4 至 132 个月之间，n=34）和对照组（60%为男性，40%为女性，年龄在 2 至 156 个月之间，n=10）。我们记录了每个病例的死后间隔时间（PMI）、身高、临床症状和腹部脂肪厚度（AFT）。苏木精-伊红染色切片用于检查管腔面积，并观察细支气管的形态变化。免疫组织化学和 Masson 三色染色分别用于检测收缩标记蛋白的表达和肺纤维化的程度。与对照组相比，AIP 组细支气管的管腔面积更小（p <.001）。两组间α-SMA 和 SM22α 的表达差异有统计学意义（p=.01 和 p=.02）。此外，收缩标记蛋白的表达与 PMI、身高、临床症状和 AFT 之间无显著相关性。两组间肺胶原沉积差异无统计学意义（p=.224）。这些发现表明，ASM 收缩功能的增强似乎参与了 AIP 患儿的死亡机制，为进一步了解 AIP 提供了更多的认识。
