Department of Cardiology, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi 530021, P.R. China.
Int J Mol Med. 2021 Sep;48(3). doi: 10.3892/ijmm.2021.5012. Epub 2021 Jul 23.
Rheumatic heart disease (RHD) affects numerous individuals annually; however, its pathogenesis remains unclear. The sphingosine 1‑phosphate receptor 1 (S1PR1) and signal transducer and activator of transcription 3 (STAT3) have recently been shown to be involved in valvular damage via the promotion of the differentiation of T helper 17 (Th17) cells during the development of RHD‑induced valvular damage. The present study investigated whether altering the expression of S1PR1 or STAT3 attenuates valvular damage due to RHD. Inactivated group A streptococcus (GAS) was used to establish a rat model of RHD. Recombinant adeno‑associated viral vectors carrying an S1PR1 overexpression sequence were used to overexpress S1PR1. STAT3 small interfering RNA (STAT3‑siRNA) was used to inhibit STAT3 expression. Reverse transcription‑quantitative PCR (RT‑qPCR) was performed to detect the mRNA expression of S1PR1, STAT3, collagen type III α1 chain (Col3a1) and fibroblast‑specific protein 1. Western blotting (WB) and immunohistochemistry were used to detect the levels of S1PR1, STAT3, phosphorylated (p‑) STAT3, and retinoic acid‑related orphan receptor γT (RORγt) proteins. Enzyme‑linked immunosorbent assays (ELISAs) and immunohistochemistry were used to detect the levels of interleukin (IL)‑6 and IL‑17. Hematoxylin and eosin (H&E) staining and Sirius Red staining were performed to evaluate the degree of inflammation and fibrosis in the valvular tissues. S1PR1 expression was decreased in the valvular tissues of the rats with RHD. The levels of IL‑6, IL‑17 and p‑STAT3 in the rats with RHD were increased. The degree of valvular inflammation and fibrosis in the rats with RHD was also increased. The overexpression of S1PR1 and the inhibition of STAT3 reduced the total p‑STAT3 level, resulting in decreased levels of IL‑6, IL‑17 and RORγt, and a reduced degree of valvular inflammation and fibrosis. These results suggest that the expression of S1PR1 and STAT3 may be involved in valvular tissue damage due to RHD. Thus, strategies designed to interfere with the expression of S1PR1 or STAT3 may affect the expression of Th17 cell‑related cytokines and may thus attenuate valvular damage due to RHD.
风湿性心脏病（Rheumatic heart disease，RHD）每年都会影响大量人群，但发病机制尚不清楚。最近的研究表明，在 RHD 诱导的瓣膜损伤发展过程中，通过促进辅助性 T 细胞 17（Th17）细胞的分化，鞘氨醇 1-磷酸受体 1（S1PR1）和信号转导和转录激活因子 3（STAT3）参与了瓣膜损伤。本研究旨在探讨改变 S1PR1 或 STAT3 的表达是否可以减轻 RHD 引起的瓣膜损伤。采用失活 A 组链球菌（group A streptococcus，GAS）建立 RHD 大鼠模型。采用携带 S1PR1 过表达序列的重组腺相关病毒载体过表达 S1PR1。采用 STAT3 小干扰 RNA（STAT3-small interfering RNA，STAT3-siRNA）抑制 STAT3 表达。采用反转录-定量聚合酶链反应（reverse transcription-quantitative PCR，RT-qPCR）检测 S1PR1、STAT3、Ⅲ型胶原α1 链（collagen type Ⅲα1 chain，Col3a1）和成纤维细胞特异性蛋白 1（fibroblast-specific protein 1，FSP1）的 mRNA 表达。采用蛋白质印迹法（Western blot，WB）和免疫组织化学染色检测 S1PR1、STAT3、磷酸化 STAT3（p-STAT3）和维甲酸相关孤儿受体γT（retinoic acid-related orphan receptor γT，RORγt）蛋白的水平。采用酶联免疫吸附试验（enzyme-linked immunosorbent assay，ELISA）和免疫组织化学染色检测白细胞介素（interleukin，IL）-6 和 IL-17 的水平。采用苏木精和伊红（hematoxylin and eosin，H&E）染色和天狼猩红染色评估瓣膜组织的炎症和纤维化程度。结果显示，RHD 大鼠瓣膜组织中 S1PR1 表达降低。RHD 大鼠 IL-6、IL-17 和 p-STAT3 水平升高。RHD 大鼠瓣膜炎症和纤维化程度也增加。S1PR1 过表达和 STAT3 抑制降低了总 p-STAT3 水平，导致 IL-6、IL-17 和 RORγt 水平降低，瓣膜炎症和纤维化程度减轻。这些结果表明，S1PR1 和 STAT3 的表达可能参与了 RHD 引起的瓣膜组织损伤。因此，设计干扰 S1PR1 或 STAT3 表达的策略可能会影响 Th17 细胞相关细胞因子的表达，从而减轻 RHD 引起的瓣膜损伤。
