Division of Biomedical Sciences, University of California, Riverside, CA, USA.
Department for Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland.
J Crohns Colitis. 2021 Mar 5;15(3):471-484. doi: 10.1093/ecco-jcc/jjaa182.
Loss-of-function variants in protein tyrosine phosphatase non-receptor type-2 [PTPN2] promote susceptibility to inflammatory bowel diseases [IBD]. PTPN2 regulates Janus-kinase [JAK] and signal transducer and activator of transcription [STAT] signalling, while protecting the intestinal epithelium from inflammation-induced barrier disruption. The pan-JAK inhibitor tofacitinib is approved to treat ulcerative colitis, but its effects on intestinal epithelial cell-macrophage interactions and on barrier properties are unknown. We aimed to determine if tofacitinib can rescue disrupted epithelial-macrophage interaction and barrier function upon loss of PTPN2.
Human Caco-2BBe intestinal epithelial cells [IECs] and THP-1 macrophages expressing control or PTPN2-specific shRNA were co-cultured with tofacitinib or vehicle. Transepithelial electrical resistance and 4 kDa fluorescein-dextran flux were measured to assess barrier function. Ptpn2fl/fl and Ptpn2-LysMCre mice, which lack Ptpn2 in myeloid cells, were treated orally with tofacitinib citrate twice daily to assess the in vivo effect on the intestinal epithelial barrier. Colitis was induced via administration of 1.5% dextran sulphate sodium [DSS] in drinking water.
Tofacitinib corrected compromised barrier function upon PTPN2 loss in macrophages and/or IECs via normalisation of: [i] tight junction protein expression; [ii] excessive STAT3 signalling; and [iii] IL-6 and IL-22 secretion. In Ptpn2-LysMCre mice, tofacitinib reduced colonic pro-inflammatory macrophages, corrected underlying permeability defects, and prevented the increased susceptibility to DSS colitis.
PTPN2 loss in IECs or macrophages compromises IEC-macrophage interactions and reduces epithelial barrier integrity. Both of these events were corrected by tofacitinib in vitro and in vivo. Tofacitinib may have greater therapeutic efficacy in IBD patients harbouring PTPN2 loss-of-function mutations.
蛋白酪氨酸磷酸酶非受体型 2 [PTPN2]的功能丧失性变异可增加炎症性肠病 [IBD] 的易感性。PTPN2 调节 Janus 激酶 [JAK] 和信号转导子和转录激活子 [STAT] 信号，同时保护肠上皮免受炎症诱导的屏障破坏。泛 JAK 抑制剂托法替尼被批准用于治疗溃疡性结肠炎，但它对肠上皮细胞-巨噬细胞相互作用和屏障特性的影响尚不清楚。我们旨在确定托法替尼是否可以挽救 PTPN2 缺失时破坏的上皮-巨噬细胞相互作用和屏障功能。
人 Caco-2BBe 肠上皮细胞 [IECs] 和表达对照或 PTPN2 特异性 shRNA 的 THP-1 巨噬细胞与托法替尼或载体共培养。通过测量跨上皮电阻和 4 kDa 荧光素右旋糖酐通量来评估屏障功能。缺乏髓细胞中 Ptpn2 的 Ptpn2fl/fl 和 Ptpn2-LysMCre 小鼠每天两次口服托法替尼柠檬酸盐，以评估其对肠上皮屏障的体内影响。通过在饮用水中给予 1.5%葡聚糖硫酸钠 [DSS] 来诱导结肠炎。
托法替尼通过以下方式纠正了巨噬细胞和/或 IEC 中 PTPN2 缺失导致的受损屏障功能：[i] 紧密连接蛋白表达正常化；[ii] 过度 STAT3 信号；和 [iii] IL-6 和 IL-22 分泌。在 Ptpn2-LysMCre 小鼠中，托法替尼减少了结肠促炎巨噬细胞，纠正了潜在的通透性缺陷，并防止了对 DSS 结肠炎的易感性增加。
IEC 或巨噬细胞中 PTPN2 的缺失会损害 IEC-巨噬细胞相互作用并降低上皮屏障完整性。这两种情况都在体外和体内被托法替尼纠正。托法替尼可能对患有 PTPN2 功能丧失性突变的 IBD 患者具有更大的治疗效果。
