■IgG4相关性胆管炎(IRC)是IgG4相关性疾病的肝胆表现。抗层粘连蛋白511-E8自身抗体已在其胰腺表现中被鉴定。层粘连蛋白511-E8促进内皮屏障功能,淋巴细胞募集,和胆管细胞分化。这里,我们调查了IRC中抗层粘连蛋白511-E8自身抗体的存在,以及层粘连蛋白511可能有助于保护胆管细胞的机制。
通过ELISA评估抗层粘连蛋白511-E8血清自身抗体阳性。在用重组层粘连蛋白511-E8处理的人H69胆管细胞上进行RNA测序和RT-qPCR。使H69胆管细胞经受编码层粘连蛋白511(LAMA5、LAMB1、LAMC1)的shRNA敲低靶向基因或用重组层粘连蛋白511-E8处理。使用22,23-3H-糖脱氧胆酸(GCDC)进行放射性化学定量胆总管胆汁酸流入。通过Caspase-3/7测定确定GCDC诱导的细胞凋亡。通过FITC-葡聚糖通透性测定评估胆管细胞屏障功能。对对照和抗IRC层粘连蛋白511-E8阳性个体的肝外胆管组织进行层粘连蛋白511和claudin1的免疫荧光染色。
■52个IRC个体中有7个具有抗层粘连蛋白511-E8的自身抗体。重组层粘连蛋白511-E8导致参与分泌的基因的差异表达,屏障功能,和炎症。层粘连蛋白511成分的敲除增加了毒性胆汁酸渗透和GCDC诱导的细胞凋亡。层粘连蛋白511-E8处理降低了毒性胆汁酸渗透并剂量依赖性地减轻了GCDC诱导的细胞凋亡。LAMA5和LAMC1敲低增加跨上皮通透性。层粘连蛋白511-E8治疗降低跨上皮通透性并预防T淋巴细胞诱导的屏障功能障碍。层粘连蛋白511和claudin1染色模式在具有IRC的抗层粘连蛋白511-E8阳性个体中出现改变。
■层粘连蛋白511-E8是IRC个体亚群的自身抗原。层粘连蛋白511增强胆管细胞屏障功能,保护胆管细胞免受T淋巴细胞诱导的屏障功能障碍,毒性胆汁酸渗透和胆汁酸诱导的细胞凋亡。
■IgG4相关性胆管炎(IRC)患者的一个子集具有抗层粘连蛋白511-E8的自身抗体。在人类胆管细胞中,层粘连蛋白511可防止(T淋巴细胞诱导的)上皮屏障功能障碍和疏水性胆汁酸。层粘连蛋白511和claudin1染色可能在抗层粘连蛋白511-E8阳性的IRC患者的肝外胆管中改变。这使得人们倾向于推测,由于自身抗体结合导致的层粘连蛋白511的功能障碍,降低的上皮屏障功能和免疫细胞的吸引力以及受损的碳酸氢盐分泌可能潜在地是IgG4-RD患者亚组中常见的全身性致病机制。
UNASSIGNED: IgG4-related cholangitis (IRC) is the hepatobiliary manifestation of IgG4-related disease. Anti-laminin 511-E8 autoantibodies have been identified in its pancreatic manifestation. Laminin 511-E8 promotes endothelial barrier function, lymphocyte recruitment, and cholangiocyte differentiation. Here, we investigate anti-laminin 511-E8 autoantibody presence in IRC, and mechanisms via which laminin 511 may contribute to cholangiocyte protection.
UNASSIGNED: Anti-laminin 511-E8 serum autoantibody positivity was assessed by ELISA. RNA sequencing and RT-qPCR were performed on human H69 cholangiocytes treated with recombinant laminin 511-E8. H69 cholangiocytes were subjected to shRNA knockdown targeting genes encoding laminin 511 (LAMA5, LAMB1, LAMC1) or treated with recombinant laminin 511-E8. Cholangiocellular bile acid influx was quantified radiochemically using 22,23-3H-glycochenodeoxycholic acid (GCDC). GCDC-induced apoptosis was determined by Caspase-3/7 assays. Cholangiocellular barrier function was assessed by FITC-Dextran permeability assays. Immunofluorescent staining of laminin 511 and claudin 1 was performed on extrahepatic bile duct tissue of control and anti-laminin 511-E8 positive individuals with IRC.
UNASSIGNED: Seven out of 52 individuals with IRC had autoantibodies against laminin 511-E8. Recombinant laminin 511-E8 led to differential expression of genes involved in secretion, barrier function, and inflammation. Knockdown of laminin 511 constituents increased toxic bile acid permeation and GCDC-induced apoptosis. Laminin 511-E8 treatment decreased toxic bile acid permeation and dose-dependently alleviated GCDC-induced apoptosis. LAMA5 and LAMC1 knockdown increased transepithelial permeability. Laminin 511-E8 treatment reduced transepithelial permeability and prevented T lymphocyte-induced barrier dysfunction. Laminin 511 and claudin 1 staining patterns appeared altered in anti-laminin 511-E8 positive individuals with IRC.
UNASSIGNED: Laminin 511-E8 is an autoantigen in subsets of individuals with IRC. Laminin 511 enhances cholangiocellular barrier function and protects cholangiocytes against T lymphocyte-induced barrier dysfunction, toxic bile acid permeation and bile acid-induced apoptosis.
UNASSIGNED: A subset of patients with IgG4-related cholangitis (IRC) has autoantibodies against laminin 511-E8. In human cholangiocytes, laminin 511 protects against (T lymphocyte-induced) epithelial barrier dysfunction and hydrophobic bile acids. Laminin 511 and claudin 1 staining may be altered in extrahepatic bile ducts of patients with IRC who are anti-laminin 511-E8 positive. This makes it tempting to speculate that a decreased epithelial barrier function with attraction of immune cells and impaired bicarbonate secretion as a result of dysfunction of laminin 511 by autoantibody binding could potentially be a common systemic pathogenic mechanism in a subset of patients with IgG4-RD.