Department of Gastrointestinal Surgery Center, Tongji Hospital, Huazhong University of Science and Technology, Wuhan 430030, China.
Department of Gastrointestinal Surgery Center, Tongji Hospital, Huazhong University of Science and Technology, Wuhan 430030, China; Renmin Hospital, Wuhan University, Wuhan 430060, China.
Int Immunopharmacol. 2020 Aug;85:106610. doi: 10.1016/j.intimp.2020.106610. Epub 2020 May 27.
Inflammatory bowel disease (IBD) are the major risk factor for developing colitis associated cancer (CAC). Previously, we have reported that Phosphoinositide-3-kinase regulatory subunit 3 (PIK3R3) was overexpressed in colorectal cancer (CRC), but we don't know the role of PIK3R3 in IBD.
We investigated the differential expression of PIK3R3 and ZO-1 in IBD patients by using Immunohistochemical (IHC) and Gene Expression Omnibus (GEO) database analysis. Caco-2 cells were exposed to different conditions to assess protein level changes of PIK3R3 and ZO-1. Caco-2 cell monolayers were transfected with PIK3R3/siPIK3R3 to assess transepithelial electrical resistance. Tight junction protein integrity was assessed by immunoblot and immunofluorescence. For further, intestinal permeability and tight junction protein integrity were assessed in animal study to assess the treatment role of PIK3R3 specific inhibitor TAT-N 15 (N15).
PIK3R3 was increased in IBD patients, and negatively controlled the expression of ZO-1. In vitro, PIK3R3 regulates ZO-1 by activating NF-kB pathway. Overexpression of PIK3R3 in Caco-2 cells decreased transepithelial electrical resistance (TEER), an opposite result was observed in siPIK3R3 cells. In animal study, inhibition of PIK3R3 by N15 contributed to amelioration of DSS-induced intestinal permeability. Mice treated with N15 exhibited less disruption of TJs in colon tissues.
PIK3R3 was increased in clinical IBD patients with accompanying disruption of ZO-1 expression. Inhibition of PIK3R3 attenuated DSS-induced IBD symptoms in a mouse model. These findings indicated that PIK3R3 could be a therapeutic target for IBD.
炎症性肠病（IBD）是发生结肠炎相关癌症（CAC）的主要危险因素。此前，我们已经报道过磷酸肌醇-3-激酶调节亚基 3（PIK3R3）在结直肠癌（CRC）中过表达，但我们并不清楚 PIK3R3 在 IBD 中的作用。
我们通过免疫组化（IHC）和基因表达综合数据库（GEO）分析，研究了 PIK3R3 和 ZO-1 在 IBD 患者中的差异表达。我们用不同的方法处理 Caco-2 细胞，以评估 PIK3R3 和 ZO-1 的蛋白水平变化。我们用 PIK3R3/siPIK3R3 转染 Caco-2 细胞单层，以评估跨上皮电阻。用免疫印迹和免疫荧光法评估紧密连接蛋白完整性。此外，我们在动物研究中评估了 PIK3R3 特异性抑制剂 TAT-N 15（N15）的治疗作用，以评估肠道通透性和紧密连接蛋白完整性的变化。
PIK3R3 在 IBD 患者中增加，并负调控 ZO-1 的表达。在体外，PIK3R3 通过激活 NF-kB 通路调节 ZO-1。在 Caco-2 细胞中过表达 PIK3R3 会降低跨上皮电阻（TEER），而在 siPIK3R3 细胞中则观察到相反的结果。在动物研究中，N15 抑制 PIK3R3 有助于改善 DSS 诱导的肠道通透性。用 N15 处理的小鼠结肠组织中的 TJ 破坏减少。
PIK3R3 在伴有 ZO-1 表达破坏的临床 IBD 患者中增加。抑制 PIK3R3 可减轻 DSS 诱导的小鼠 IBD 症状。这些发现表明 PIK3R3 可能是 IBD 的治疗靶点。
