Inflammatory cytokine TNF-α promotes corneal endothelium apoptosis via upregulating TIPE2 transcription during corneal graft rejection
Inflammatory cytokine TNF-α promotes corneal endothelium apoptosis via upregulating TIPE2 transcription during corneal graft rejection
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角膜移植排斥过程中炎症细胞因子TNF-α通过上调TIPE2转录促进角膜内皮细胞凋亡
DOI：
10.1007/s00417-018-3913-0
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发表时间：
2018-04-01
影响因子：
2.7
通讯作者：
Shi, Weiyun
中科院分区：
文献类型：
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作者：
Wang, Qun;Wei, Chao;Shi, Weiyun
内皮功能障碍占角膜移植失败总数的50%，表明角膜内皮损伤是移植失败的主要原因。已知肿瘤坏死因子-α (TNF-α) 有助于角膜移植的负调节，但其作用机制仍不清楚。在此，我们报告了涉及 TNF-α、TNF-α 诱导蛋白 8 like 2（TNFAIP8L2 或 TIPE2）以及角膜移植排斥过程中细胞凋亡的调节环路。我们建立了穿透性角膜移植术的小鼠模型，以通过 ELISA 测定和免疫荧光染色验证同种异体角膜中 TNF-α 的定量是否得到增强。在角膜组织中，我们获得了角膜内皮并测量了去除的细胞的凋亡。同时采用实时定量PCR和Western blotting检测TIPE2 mRNA和蛋白的表达。在人角膜内皮细胞中，我们通过一些实验验证了结论。通过特异性敲除TIPE2，我们检测到了TIPE2在TNF-α触发的细胞凋亡中的重要性。在小鼠模型中，同种异体移植组的角膜和房水中TNF-α较高，TNF-α升高增加了角膜内皮细胞的凋亡。此外，在 TNF-α 升高后的同种异体移植排斥模型中发现高水平的 TIPE2。在人角膜内皮细胞 (HCEC) 中，TNF-α 明显增强 TIPE2 表达，并通过上调 TIPE2 转录促进细胞凋亡。敲除显着减少的细胞凋亡。我们的研究确定了同种异体移植排斥过程中 TNF-α、TIPE2 和细胞凋亡相互作用的分子机制，并表明 TNF-α 和 TIPE2 可能是成功移植的角膜内皮的潜在靶标。
Endothelial dysfunction accounts for 50% of total corneal transplantation failures, suggesting that corneal endothelial damage is the leading cause of graft failure. Tumor necrosis factor-alpha (TNF-alpha) is known to contribute to the negative regulation of corneal transplantation, but how it does so remains unclear. Here, we report a regulatory loop involving TNF-alpha, TNF-alpha-induced protein 8 like 2 (TNFAIP8L2 or TIPE2), and apoptosis during corneal graft rejection.We established mice models of penetrating keratoplasty to verify whether the quantification of TNF-alpha in allogeneic corneas is enhanced through ELISA assay and immunofluorescence staining. In cornea tissues, we obtained corneal endothelium and measured apoptosis of the removed cells. Meanwhile, quantitative real-time PCR and Western blotting were used to detect the mRNA and protein expression of TIPE2. In human corneal endothelial cells, we verified the conclusions through some experiments. By specifically knocking down TIPE2, we detected the importance of TIPE2 in TNF-alpha-triggered apoptosis.In mice models, TNF-alpha was higher in the cornea and aqueous humor in allograft group and TNF-alpha elevation increased the apoptosis of the corneal endothelium. In addition, high levels of TIPE2 were found in allograft rejection models following TNF-alpha elevation. In human corneal endothelial cells (HCECs), TNF-alpha clearly augments TIPE2 expression and promotes cell apoptosis through upregulating TIPE2 transcription. Knocking down markedly decreased cell apoptosis.Our study identifies the molecular mechanisms underlying the interplay of TNF-alpha, TIPE2, and apoptosis during allograft rejection, and it suggests that both TNF-alpha and TIPE2 might be potential targets for the successfully grafted corneal endothelium.