Purpose

Previously we developed TAT-N24 as a synthetic cell-permeable peptide inhibitor of p55PIK signaling and demonstrated its anti-inflammatory effects. This study aimed to evaluate the potential of TAT-N24 as a new agent for the treatment of ocular inflammatory diseases.

Methods

The endotoxin-induced uveitis (EIU) model was established by intravitreal injection of lipopolysaccharide (LPS) in BALB/c mice and experimental autoimmune uveitis (EAU) model was established by subcutaneous injection of a peptide spanning amino acid residues 161–180 of interphotoreceptor retinoid binding protein (IRBP161-180) with complete Freund's adjuvant (CFA) in B10.RIII mice. TAT-N24 was topically administered in EIU model and intraperitoneally administered in EAU model. The severity levels of uveitis were assessed by clinical and histopathological scores. The mRNA levels of inflammatory cytokines in iris-ciliary body (ICB) and retina were analyzed by reverse transcription quantitative polymerase chain reaction (RT-qPCR). The protein levels of inflammatory factors were determined by ELISA or Western blotting.

Results

The results showed that TAT-N24 alleviated clinical signs, decreased inflammatory cell infiltration and the expression of inflammatory cytokines in both EIU and EAU models. Furthermore, protein levels of tumor necrosis factor-alpha (TNF-α), interleukin-1β (IL-1β) and interleukin-6 (IL-6) in aqueous humor and mRNA and protein levels of NF-κB p65 in the ICB significantly decreased in EIU model. In EAU model, TAT-N24 application induced a significant decrease of IFN-gamma (IFN-γ) and interleukin-17 (IL-17) in the retina, which were secreted by Th1 and Th17 cells, respectively.

Conclusion

In conclusion, TAT-N24 suppressed intraocular inflammation in both EIU and EAU models, and the anti-inflammatory effects were mediated by suppressing the expression of inflammatory cytokines by PI3K/NF-κB signaling pathway. TAT-N24 could be potential candidate for the treatment of ocular inflammatory diseases.

中文翻译：

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p55PIK信号传导的细胞可渗透肽抑制剂可减轻葡萄膜炎小鼠模型的眼部炎症。

目的

以前，我们开发了TAT-N24作为p55PIK信号传导的细胞渗透性肽合成抑制剂，并证明了其抗炎作用。这项研究旨在评估TAT-N24作为治疗眼炎性疾病的新药的潜力。

方法

通过玻璃体内注射BALB / c小鼠中的脂多糖（LPS）建立内毒素诱导的葡萄膜炎（EIU）模型，并通过皮下注射跨越光感受器间类维生素A氨基酸残基161–180的肽建立实验性自身免疫性葡萄膜炎（EAU）模型。 B10.RIII小鼠中具有完整弗氏佐剂（CFA）的结合蛋白（IRBP161-180）。TEI-N24在EIU模型中局部给药，在EAU模型中腹膜内给药。葡萄膜炎的严重程度通过临床和组织病理学评分进行评估。通过逆转录定量聚合酶链反应（RT-qPCR）分析虹膜睫状体（ICB）和视网膜中炎性细胞因子的mRNA水平。炎症因子的蛋白水平通过ELISA或Western blotting测定。

结果

结果表明，在EIU和EAU模型中，TAT-N24均可减轻临床症状，减少炎性细胞浸润和炎性细胞因子的表达。此外，房水中的肿瘤坏死因子-α（TNF-α），白介素-1β（IL-1β）和白介素-6（IL-6）的蛋白水平以及ICB中NF-κBp65的mRNA和蛋白水平显着EIU模型减少。在EAU模型中，TAT-N24的应用引起视网膜中IFN-γ（IFN-γ）和白介素17（IL-17）的显着降低，它们分别由Th1和Th17细胞分泌。

结论

总之，TAT-N24在EIU和EAU模型中均抑制眼内炎症，并且通过PI3K /NF-κB信号通路抑制炎症细胞因子的表达来介导抗炎作用。TAT-N24可能是治疗眼部炎症疾病的潜在候选药物。