Zhou Yong-Jie, Peng Hua, Chen Yan, Liu Ya-Lan
Department of Pediatrics, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430022, China.
Chin Med J (Engl). 2016 Jan 5;129(1):59-65. doi: 10.4103/0366-6999.172577.
Vascular endothelial growth factor (VEGF) in the thymus was mainly produced by the thymic epithelial cells (TECs), the predominant component of the thymic microenvironment. The progression of TECs and the roles of VEGF in the neonatal thymus during sepsis have not been reported. This study aimed to explore the alterations of TECs and VEGF level in the neonatal thymus involution and to explore the possible mechanisms at the cellular level.
By establishing a model of clinical sepsis, the changes of TECs were measured by hematoxylin-eosin staining, confocal microscopy, and flow cytometry. Moreover, the levels of VEGF in serum and thymus were assessed based on enzyme-linked immunosorbent assay and Western blotting.
The number of thymocytes and TECs was significantly decreased 24 h after lipopolysaccharide (LPS) challenge, (2.40 ± 0.46)×10 7 vs. (3.93 ± 0.66)×10 7 and (1.16 ± 0.14)×10 5 vs. (2.20 ± 0.19)×10 5 , P < 0.05, respectively. Cortical TECs and medullary TECs in the LPS-treated mice were decreased 1.5-fold and 3.9-fold, P < 0.05, respectively, lower than those in the controls. The number of thymic epithelial progenitors was also decreased. VEGF expression in TECs was down-regulated in a time-dependent manner.
VEGF in thymic cells subsets might contribute to the development of TECs in neonatal sepsis.
胸腺中的血管内皮生长因子（VEGF）主要由胸腺上皮细胞（TECs）产生，胸腺上皮细胞是胸腺微环境的主要组成部分。脓毒症期间新生胸腺中TECs的进展以及VEGF的作用尚未见报道。本研究旨在探讨新生胸腺退化过程中TECs和VEGF水平的变化，并在细胞水平上探讨其可能的机制。
通过建立临床脓毒症模型，采用苏木精-伊红染色、共聚焦显微镜和流式细胞术检测TECs的变化。此外，基于酶联免疫吸附测定和蛋白质免疫印迹法评估血清和胸腺中VEGF的水平。
脂多糖（LPS）攻击后24小时，胸腺细胞和TECs的数量显著减少，分别为（2.40±0.46）×10⁷ vs.（3.93±0.66）×10⁷和（1.16±0.14）×10⁵ vs.（2.20±0.19）×10⁵，P<0.05。LPS处理小鼠的皮质TECs和髓质TECs分别减少了1.5倍和3.9倍，P<0.05，低于对照组。胸腺上皮祖细胞的数量也减少。TECs中VEGF的表达呈时间依赖性下调。
胸腺细胞亚群中的VEGF可能有助于新生脓毒症中TECs的发育。
