First Clinical College, Shandong University of Traditional Chinese Medicine, No. 4655, Daxue Road, University Science Park, Changqing District, Jinan, Shandong 250355, China.
Department of Pediatrics, Cao County People's Hospital, Qinghe Road East, Fumin Avenue South, Caoxian Development District, Heze, Shandong 274400, China.
J Healthc Eng. 2022 Feb 26;2022:3889318. doi: 10.1155/2022/3889318. eCollection 2022.
We aimed at exploring the role of let-7a in the pathogenesis of pediatric Henoch-Schönlein purpura (HSP) and its related mechanism.
Fifty-five pediatric HSP patients and 20 paired healthy controls were included. The expressions of let-7a and TNFAIP3 were detected by RT-qPCR or/and western blot. Vessel fibrinoid necrosis was evaluated in skin tissues by PTAH staining. The serum IgA level was measured by ELISA. Cells were transfected with let-7a inhibitor and/or TNFAIP3 siRNA, accompanied by pretreatment with NF-B inhibitor PDTC or not. After being cultured in HSP serum, the changes in cell viability, cell apoptosis, apoptosis-related proteins, and NF-B pathway-related proteins were detected by CCK8, flow cytometry, and western blot.
The let-7a expression level was positively correlated with the serum IgA level and severity degree of vascular fibrinoid necrosis in HSP patients. Let-7a expression was significantly increased, whereas cell viability and TNFAIP3 expression were obviously decreased 48 h after HUVECs were incubated with HSP serum. Let-7a knockdown upregulated the cell viability, whereas it reduced the apoptotic ratio, apoptosis protein expressions (Bax/Bcl2 ratio, cleaved-caspase 3), and NF-B pathway activation (reflected by reduced P65 nuclear translocation and p-IB expression) in HUVECs (all < 0.05). The changes induced by let-7a knockdown were obviously reversed by TNFAIP3 siRNA transfection ( < 0.05). Besides, PDTC treatment remarkably diminished the anti-apoptosis effect of let-7a knockdown and pro-apoptosis effect of TNFAIP3 siRNA on HUVECs induced by HSP serum.
Let-7a knockdown significantly suppressed vascular endothelial cell apoptosis induced by HSP serum by targeting TNFAPI3 via NF-B signaling pathway. Our findings provided a potential therapeutic target for the treatment of HSP.
探讨 let-7a 在小儿过敏性紫癜（HSP）发病机制中的作用及其相关机制。
纳入 55 例 HSP 患儿和 20 例配对健康对照，采用 RT-qPCR 或/和 Western blot 检测 let-7a 和 TNFAIP3 的表达，PTAH 染色评估皮肤组织血管纤维蛋白坏死，ELISA 法检测血清 IgA 水平。用 let-7a 抑制剂和/或 TNFAIP3 siRNA 转染细胞，同时用 NF-B 抑制剂 PDTC 预处理或不预处理。用 HSP 血清培养细胞后，通过 CCK8、流式细胞术和 Western blot 检测细胞活力、细胞凋亡、凋亡相关蛋白和 NF-B 通路相关蛋白的变化。
HSP 患者 let-7a 表达水平与血清 IgA 水平和血管纤维蛋白坏死严重程度呈正相关。HUVEC 孵育 HSP 血清 48 h 后，let-7a 表达明显增加，细胞活力和 TNFAIP3 表达明显降低。Let-7a 敲低后可上调细胞活力，降低凋亡率、凋亡蛋白表达（Bax/Bcl2 比值、cleaved-caspase 3）和 NF-B 通路激活（反映为 P65 核转位和 p-IB 表达减少）（均 < 0.05）。用 TNFAIP3 siRNA 转染后，let-7a 敲低引起的变化明显逆转（ < 0.05）。此外，PDTC 处理显著减弱了 HSP 血清对 HUVEC 凋亡的抑制作用和对 TNFAIP3 siRNA 的促凋亡作用。
Let-7a 敲低通过 NF-B 信号通路靶向 TNFAPI3 显著抑制 HSP 血清诱导的血管内皮细胞凋亡。我们的研究结果为 HSP 的治疗提供了一个潜在的治疗靶点。
