PDF(Pubmed)
Abstract：
UNASSIGNED: Inflammatory cytokines play key pathogenic roles in liver fibrosis. IL-15 is a proinflammatory cytokine produced by myeloid cells. IL-15 promotes pathogenesis of several chronic inflammatory diseases. However, increased liver fibrosis has been reported in mice lacking IL-15 receptor alpha chain (IL-15Rα), suggesting an anti-fibrogenic role for IL-15. As myeloid cells are key players in liver fibrosis and IL-15 signaling can occur independently of IL-15Rα, we investigated the requirement of IL-15 and IL-15Rα in liver fibrosis.
UNASSIGNED: We induced liver fibrosis in Il15-/- , Il15ra-/- and wildtype C57BL/6 mice by the administration of carbon tetrachloride (CCl4). Liver fibrosis was evaluated by Sirius red and Mason\'s trichrome staining and α-smooth muscle acting immunostaining of myofibroblasts. Gene expression of collagens, matrix modifying enzymes, cytokines and chemokines was quantified by RT-qPCR. The phenotype and the numbers of intrahepatic lymphoid and myeloid cell subsets were evaluated by flow cytometry.
UNASSIGNED: Both Il15-/- and Il15ra-/- mice developed markedly reduced liver fibrosis compared to wildtype control mice, as revealed by reduced collagen deposition and myofibroblast content. Il15ra-/- mice showed further reduction in collagen deposition compared to Il15-/- mice. However, Col1a1 and Col1a3 genes were similarly induced in the fibrotic livers of wildtype, Il15-/- and Il15ra-/- mice, although notable variations were observed in the expression of matrix remodeling enzymes and chemokines. As expected, Il15-/- and Il15ra-/- mice showed markedly reduced numbers of NK cells compared to wildtype mice. They also showed markedly less staining of CD45+ immune cells and CD68+ macrophages, and significantly reduced inflammatory cell infiltration into the liver, with fewer pro-inflammatory and anti-inflammatory monocyte subsets compared to wildtype mice.
UNASSIGNED: Our findings indicate that IL-15 exerts its profibrogenic role in the liver by promoting macrophage activation and that this requires trans-presentation of IL-15 by IL-15Rα.
UNASSIGNED: We induced liver fibrosis in Il15-/- , Il15ra-/- and wildtype C57BL/6 mice by the administration of carbon tetrachloride (CCl4). Liver fibrosis was evaluated by Sirius red and Mason\'s trichrome staining and α-smooth muscle acting immunostaining of myofibroblasts. Gene expression of collagens, matrix modifying enzymes, cytokines and chemokines was quantified by RT-qPCR. The phenotype and the numbers of intrahepatic lymphoid and myeloid cell subsets were evaluated by flow cytometry.
UNASSIGNED: Both Il15-/- and Il15ra-/- mice developed markedly reduced liver fibrosis compared to wildtype control mice, as revealed by reduced collagen deposition and myofibroblast content. Il15ra-/- mice showed further reduction in collagen deposition compared to Il15-/- mice. However, Col1a1 and Col1a3 genes were similarly induced in the fibrotic livers of wildtype, Il15-/- and Il15ra-/- mice, although notable variations were observed in the expression of matrix remodeling enzymes and chemokines. As expected, Il15-/- and Il15ra-/- mice showed markedly reduced numbers of NK cells compared to wildtype mice. They also showed markedly less staining of CD45+ immune cells and CD68+ macrophages, and significantly reduced inflammatory cell infiltration into the liver, with fewer pro-inflammatory and anti-inflammatory monocyte subsets compared to wildtype mice.
UNASSIGNED: Our findings indicate that IL-15 exerts its profibrogenic role in the liver by promoting macrophage activation and that this requires trans-presentation of IL-15 by IL-15Rα.
摘要：
■炎性细胞因子在肝纤维化中起着关键的致病作用。IL-15是由骨髓细胞产生的促炎细胞因子。IL-15促进多种慢性炎症性疾病的发病机制。然而,已报道缺乏IL-15受体α链（IL-15Rα）的小鼠肝纤维化增加，提示IL-15的抗纤维化作用。由于骨髓细胞是肝纤维化的关键参与者，IL-15信号可以独立于IL-15Rα发生，我们调查了肝纤维化中IL-15和IL-15Rα的需求。
■我们在Il15-/-中诱导了肝纤维化，Il15ra-/-和野生型C57BL/6小鼠经由过程施用四氯化碳(CCl4)。通过天狼星红和梅森三色染色和肌成纤维细胞的α-平滑肌作用免疫染色评估肝纤维化。胶原蛋白的基因表达，基质修饰酶，通过RT-qPCR定量细胞因子和趋化因子。通过流式细胞术评估肝内淋巴和骨髓细胞亚群的表型和数量。
■与野生型对照小鼠相比，Il15-/-和Il15ra-/-小鼠的肝纤维化均明显减少，胶原蛋白沉积和肌成纤维细胞含量减少。与Il15-/-小鼠相比,Il15ra-/-小鼠显示胶原沉积进一步减少。然而,Col1a1和Col1a3基因在野生型纤维化肝脏中被类似地诱导，Il15-/-和Il15ra-/-小鼠，尽管在基质重塑酶和趋化因子的表达中观察到显着差异。不出所料,与野生型小鼠相比,Il15-/-和Il15ra-/-小鼠显示出显著减少的NK细胞数量。他们还显示CD45+免疫细胞和CD68+巨噬细胞的染色明显减少，并显著减少炎症细胞向肝脏的浸润，与野生型小鼠相比，具有更少的促炎和抗炎单核细胞亚群。
■我们的发现表明，IL-15通过促进巨噬细胞活化而在肝脏中发挥其促纤维化作用，这需要IL-15Rα对IL-15的反式呈递。
■我们在Il15-/-中诱导了肝纤维化，Il15ra-/-和野生型C57BL/6小鼠经由过程施用四氯化碳(CCl4)。通过天狼星红和梅森三色染色和肌成纤维细胞的α-平滑肌作用免疫染色评估肝纤维化。胶原蛋白的基因表达，基质修饰酶，通过RT-qPCR定量细胞因子和趋化因子。通过流式细胞术评估肝内淋巴和骨髓细胞亚群的表型和数量。
■与野生型对照小鼠相比，Il15-/-和Il15ra-/-小鼠的肝纤维化均明显减少，胶原蛋白沉积和肌成纤维细胞含量减少。与Il15-/-小鼠相比,Il15ra-/-小鼠显示胶原沉积进一步减少。然而,Col1a1和Col1a3基因在野生型纤维化肝脏中被类似地诱导，Il15-/-和Il15ra-/-小鼠，尽管在基质重塑酶和趋化因子的表达中观察到显着差异。不出所料,与野生型小鼠相比,Il15-/-和Il15ra-/-小鼠显示出显著减少的NK细胞数量。他们还显示CD45+免疫细胞和CD68+巨噬细胞的染色明显减少，并显著减少炎症细胞向肝脏的浸润，与野生型小鼠相比，具有更少的促炎和抗炎单核细胞亚群。
■我们的发现表明，IL-15通过促进巨噬细胞活化而在肝脏中发挥其促纤维化作用，这需要IL-15Rα对IL-15的反式呈递。
