Centro di Ricerca E. Menni, Fondazione Poliambulanza-Istituto Ospedaliero, Via Bissolati 57, Brescia, Italy.
Cell Transplant. 2011;20(3):441-53. doi: 10.3727/096368910X522252. Epub 2010 Aug 18.
Biliary fibrosis and resultant cirrhosis are among the most common outcomes of chronic liver diseases. Currently, liver transplantation remains the only effective treatment. In seeking alternative therapeutic approaches, we focused on the potential use of the human amniotic membrane (AM). Indeed, AM has gained increasing importance for its antiscarring, anti-inflammatory, and wound-healing properties, as well as for the multipotent differentiation ability and immunomodulatory features of AM-derived cells. Intriguingly, we have recently demonstrated that placenta-derived cells reduce lung fibrosis in bleomycin-treated mice, and that AM patches reduce postischemic cardiac injury in rats. Hence, we have now investigated the effects of human AM on biliary fibrosis induced in rats through the bile duct ligation (BDL) procedure. A fragment of human AM was applied onto the liver surface after BDL and the effects on fibrosis establishment and progression were evaluated at different time points in comparison with fibrosis progression in control BDL rats. The degree of liver fibrosis was first assessed by the semiquantitative Knodell scoring system and, thereafter, by digital image morphometric analysis to quantify the area occupied by ductular reaction, activated myofibroblasts, and collagen deposition. We demonstrated a significant reduction in the severity of BDL-induced fibrosis in AM-treated rats. Indeed, while fibrosis progressed rapidly in control BDL rats, leading to cirrhosis within 6 weeks, AM-treated rats showed confined fibrosis at the portal/periportal area with no signs of cirrhosis, and a reduction in collagen deposition to about 50% of levels observed in control BDL rats. In addition, the AM was able to significantly slow the gradual progression of the ductular reaction and reduce, at all time points, the area occupied by activated myofibroblasts. These findings suggest that human AM, when applied as a patch onto the liver surface, might inhibit fibrosis progression in BDL-injured livers, and could protect against hepatic damage associated with fibrotic degeneration.
胆汁性纤维化和由此导致的肝硬化是慢性肝病最常见的后果之一。目前，肝移植仍然是唯一有效的治疗方法。在寻求替代治疗方法时，我们专注于人羊膜（AM）的潜在用途。事实上，AM 因其抗瘢痕形成、抗炎和伤口愈合特性，以及 AM 衍生细胞的多能分化能力和免疫调节特性而变得越来越重要。有趣的是，我们最近证明胎盘来源的细胞可减少博莱霉素处理的小鼠的肺纤维化，AM 贴片可减少大鼠的缺血性心脏损伤。因此，我们现在研究了人 AM 在胆管结扎（BDL）程序诱导的大鼠胆汁性纤维化中的作用。BDL 后将人 AM 的一个片段应用于肝表面，并在不同时间点与对照 BDL 大鼠的纤维化进展进行比较，评估其对纤维化形成和进展的影响。肝纤维化程度首先通过半定量 Knodell 评分系统进行评估，然后通过数字图像形态计量分析对胆管反应、活化肌成纤维细胞和胶原沉积所占据的面积进行定量分析。我们证明了 AM 处理大鼠的 BDL 诱导的纤维化严重程度显著降低。事实上，虽然对照组 BDL 大鼠的纤维化迅速进展，导致 6 周内发生肝硬化，但 AM 处理的大鼠在门脉/周围区域的纤维化局限，没有肝硬化的迹象，胶原沉积减少到对照组 BDL 大鼠的约 50%。此外，AM 能够显著减缓胆管反应的逐渐进展，并在所有时间点减少活化肌成纤维细胞所占据的面积。这些发现表明，当 AM 作为贴片应用于肝表面时，可能会抑制 BDL 损伤肝脏的纤维化进展，并防止与纤维变性相关的肝损伤。
