Research Department, Central Texas Veterans Health Care System, Temple, TX.
Baylor Scott & White Digestive Disease Research Center, Baylor Scott & White Health, Temple, TX.
Hepatology. 2019 Jun;69(6):2562-2578. doi: 10.1002/hep.30542. Epub 2019 Apr 12.
Cholangiopathies are diseases that affect cholangiocytes, the cells lining the biliary tract. Liver stem cells (LSCs) are able to differentiate into all cells of the liver and possibly influence the surrounding liver tissue by secretion of signaling molecules. One way in which cells can interact is through secretion of extracellular vesicles (EVs), which are small membrane-bound vesicles that contain proteins, microRNAs (miRNAs), and cytokines. We evaluated the contents of liver stem cell-derived EVs (LSCEVs), compared their miRNA contents to those of EVs isolated from hepatocytes, and evaluated the downstream targets of these miRNAs. We finally evaluated the crosstalk among LSCs, cholangiocytes, and human hepatic stellate cells (HSCs). We showed that LSCEVs were able to reduce ductular reaction and biliary fibrosis in multidrug resistance protein 2 (MDR2) mice. Additionally, we showed that cholangiocyte growth was reduced and HSCs were deactivated in LSCEV-treated mice. Evaluation of LSCEV contents compared with EVs derived from hepatocytes showed a large increase in the miRNA, lethal-7 (let-7). Further evaluation of let-7 in MDR2 mice and human primary sclerosing cholangitis samples showed reduced levels of let-7 compared with controls. In liver tissues and isolated cholangiocytes, downstream targets of let-7 (identified by ingenuity pathway analysis), Lin28a (Lin28 homolog A), Lin28b (Lin28 homolog B), IL-13 (interleukin 13), NR1H4 (nuclear receptor subfamily 1 group H member 4) and NF-κB (nuclear factor kappa B), are elevated in MDR2 mice, but treatment with LSCEVs reduced levels of these mediators of ductular reaction and biliary fibrosis through the inhibition of NF-κB and IL-13 signaling pathways. Evaluation of crosstalk using cholangiocyte supernatants from LSCEV-treated cells on cultured HSCs showed that HSCs had reduced levels of fibrosis and increased senescence. Conclusion: Our studies indicate that LSCEVs could be a possible treatment for cholangiopathies or could be used for target validation for future therapies.
胆管疾病是影响胆管细胞的疾病，胆管细胞是胆管的衬里细胞。肝干细胞（LSCs）能够分化为肝脏的所有细胞，并通过分泌信号分子影响周围的肝组织。细胞相互作用的一种方式是通过分泌细胞外囊泡（EVs），EVs 是含有蛋白质、microRNAs（miRNAs）和细胞因子的小膜结合囊泡。我们评估了肝干细胞衍生的 EVs（LSCEVs）的内容物，将其 miRNA 含量与从肝细胞分离的 EVs 的 miRNA 含量进行比较，并评估了这些 miRNAs 的下游靶标。我们最终评估了 LSCs、胆管细胞和人肝星状细胞（HSCs）之间的串扰。我们表明，LSCEVs 能够减少多药耐药蛋白 2（MDR2）小鼠的胆管反应和胆管纤维化。此外，我们表明在 LSCEV 处理的小鼠中，胆管细胞生长减少，HSCs 失活。与源自肝细胞的 EVs 相比，LSCEV 内容物的评估显示 miRNA 大量增加，即致死-7（let-7）。对 MDR2 小鼠和人原发性硬化性胆管炎样本中的 let-7 的进一步评估表明，与对照组相比，let-7 水平降低。在肝组织和分离的胆管细胞中，let-7 的下游靶标（通过 ingenuity 通路分析鉴定），Lin28a（Lin28 同源物 A）、Lin28b（Lin28 同源物 B）、IL-13（白细胞介素 13）、NR1H4（核受体亚家族 1 组 H 成员 4）和 NF-κB（核因子 kappa B），在 MDR2 小鼠中升高，但 LSCEV 的治疗通过抑制 NF-κB 和 IL-13 信号通路降低了这些胆管反应和胆管纤维化的介质水平。使用 LSCEV 处理细胞的胆管细胞上清液在培养的 HSCs 上评估串扰表明，HSCs 的纤维化水平降低，衰老增加。结论：我们的研究表明，LSCEVs 可能是胆管疾病的一种潜在治疗方法，也可用于未来治疗的靶标验证。
