■胆管细胞衰老在原发性硬化性胆管炎(PSC)的发病机理中很重要。我们发现CDKN2A(p16),细胞周期蛋白依赖性激酶抑制剂和衰老介质,PSC患者和PSC小鼠模型的胆管细胞增加(多药耐药性2;Mdr2-/-)。鉴于最近的数据表明衰老细胞的减少对不同的疾病是有益的,我们假设抑制胆管细胞衰老可以改善Mdr2-/-小鼠的疾病。
■我们使用了2种新的小鼠遗传模型来减少胆管细胞衰老:(i)p16Ink4a通过靶向激活caspase(INK-ATTAC)xMdr2-/-,其中二聚化分子AP20187促进表达p16的细胞的选择性凋亡去除;和(ii)缺乏p16和Mdr2的小鼠。Mdr2-/-小鼠也用非瑟酮治疗,一种选择性杀死衰老细胞的类黄酮分子。p16、p21和炎症标志物(肿瘤坏死因子[TNF]-α,IL-1β,和单核细胞趋化蛋白-1[MCP-1])通过PCR测量,和肝纤维化通过羟脯氨酸测定和天狼星红染色。
■AP20187治疗使p16和p21表达降低了约35%和约70%(p>0.05),分别。炎症标志物(TNF-α,IL-1β,和MCP-1)下降(60%,40%,60%,分别),纤维化降低~60%(p>0.05)。同样,p16-/-xMdr2-/-小鼠表现出减少的p21表达(70%),TNF-α表达降低,IL-1β(60%),与Mdr2-/-小鼠相比,MCP-1(65%)和减少的纤维化(〜50%)(p>0.05)。Fisetin处理降低p16和p21的表达(80%和90%,分别),TNF-α(50%),IL-1β(50%),MCP-1(70%),纤维化(60%)(p>0.05)。
■我们的数据支持胆管细胞衰老在PSC进展中的病理生理作用,靶向去除衰老的胆管细胞是一种合理的治疗方法。
■原发性硬化性胆管炎是一种纤维炎症,无法治愈的胆道疾病.我们先前报道,胆管上皮细胞衰老(细胞周期停滞和促纤维化分子的过度分泌)是原发性硬化性胆管炎的重要表型。在这里,我们证明,减少衰老的胆管细胞的数量导致炎症表达的减少,纤维化,和与疾病相关的衰老标志物。
UNASSIGNED: Cholangiocyte senescence is important in the pathogenesis of primary sclerosing cholangitis (PSC). We found that CDKN2A (p16), a cyclin-dependent kinase inhibitor and mediator of senescence, was increased in cholangiocytes of patients with PSC and from a PSC mouse model (multidrug resistance 2; Mdr2 -/-). Given that recent data suggest that a reduction of senescent cells is beneficial in different diseases, we hypothesised that inhibition of cholangiocyte senescence would ameliorate disease in Mdr2 -/- mice.
UNASSIGNED: We used 2 novel genetic murine models to reduce cholangiocyte senescence: (i) p16Ink4a apoptosis through targeted activation of caspase (INK-ATTAC)xMdr2 -/-, in which the dimerizing molecule AP20187 promotes selective apoptotic removal of p16-expressing cells; and (ii) mice deficient in both p16 and Mdr2. Mdr2 -/- mice were also treated with fisetin, a flavonoid molecule that selectively kills senescent cells. p16, p21, and inflammatory markers (tumour necrosis factor [TNF]-α, IL-1β, and monocyte chemoattractant protein-1 [MCP-1]) were measured by PCR, and hepatic fibrosis via a hydroxyproline assay and Sirius red staining.
UNASSIGNED: AP20187 treatment reduced p16 and p21 expression by ~35% and ~70% (p >0.05), respectively. Expression of inflammatory markers (TNF-α, IL-1β, and MCP-1) decreased (by 60%, 40%, and 60%, respectively), and fibrosis was reduced by ~60% (p >0.05). Similarly, p16 -/- xMdr2 -/- mice exhibited reduced p21 expression (70%), decreased expression of TNF-α, IL-1β (60%), and MCP-1 (65%) and reduced fibrosis (~50%) (p >0.05) compared with Mdr2 -/- mice. Fisetin treatment reduced expression of p16 and p21 (80% and 90%, respectively), TNF-α (50%), IL-1β (50%), MCP-1 (70%), and fibrosis (60%) (p >0.05).
UNASSIGNED: Our data support a pathophysiological role of cholangiocyte senescence in the progression of PSC, and that targeted removal of senescent cholangiocytes is a plausible therapeutic approach.
UNASSIGNED: Primary sclerosing cholangitis is a fibroinflammatory, incurable biliary disease. We previously reported that biliary epithelial cell senescence (cell-cycle arrest and hypersecretion of profibrotic molecules) is an important phenotype in primary sclerosing cholangitis. Herein, we demonstrate that reducing the number of senescent cholangiocytes leads to a reduction in the expression of inflammatory, fibrotic, and senescence markers associated with the disease.