Department of Pharmaceutical Sciences, University of Nebraska Medical Center, Omaha, NE 68198, USA.
Department of Pharmaceutical Sciences, University of Nebraska Medical Center, Omaha, NE 68198, USA.
Biomaterials. 2016 Jan;76:144-56. doi: 10.1016/j.biomaterials.2015.10.047. Epub 2015 Oct 23.
In liver fibrosis, secretion of growth factors and hedgehog (Hh) ligands by hepatic parenchyma upon repeated insults results in transdifferentiation of quiescent hepatic stellate cells (HSCs) into active myofibroblasts which secrete excessive amounts of extracellular matrix (ECM) proteins. An Hh inhibitor GDC-0449 and miR-29b1 can play an important role in treating liver fibrosis by inhibiting several pro-fibrotic genes. Our in-silico analysis indicate that miR-29b1 targets several profibrotic genes like collagen type I & IV, c-MYC, PDGF-β and PI3K/AKT which are upregulated in liver fibrosis. Common bile duct ligation (CBDL) resulted in an increase in Ptch-1, Shh and Gli-1 expression. miR-29b1 and GDC-0449 were co-formulated into micelles using methoxy poly(ethylene glycol)-block-poly(2-methyl-2-carboxyl-propylene carbonate-graft-dodecanol-graft-tetraethylenepentamine) (mPEG-b-PCC-g-DC-g-TEPA) copolymer, and injected systemically into CBDL mice. High concentrations of GDC-0449 and miR-29b1 were delivered to liver cells as determined by in situ liver perfusion at 30 min post systemic administration of their micelle formulation. There was a significant decrease in collagen deposition in the liver and serum injury markers, leading to improvement in liver morphology. Combination therapy was more effective in providing hepatoprotection, lowering liver injury related serum enzyme levels, reducing fibrotic protein markers such as collagen, α-SMA, FN-1 and p-AKT compared to monotherapy. In conclusion, inhibition of Hh pathway and restoration of miR-29b1 have the potential to act synergistically in treating CBDL-induced liver fibrosis in mice.
在肝纤维化中，肝脏实质在反复损伤后分泌生长因子和 Hedgehog（Hh）配体，导致静止的肝星状细胞（HSCs）向活跃的肌成纤维细胞转化，后者分泌大量细胞外基质（ECM）蛋白。Hh 抑制剂 GDC-0449 和 miR-29b1 可通过抑制多个促纤维化基因在治疗肝纤维化中发挥重要作用。我们的计算机分析表明，miR-29b1 靶向几个促纤维化基因，如胶原 I 和 IV、c-MYC、PDGF-β 和 PI3K/AKT，这些基因在肝纤维化中上调。胆总管结扎（CBDL）导致 Ptch-1、Shh 和 Gli-1 的表达增加。miR-29b1 和 GDC-0449 被共包封到胶束中，使用甲氧基聚乙二醇-嵌段-聚（2-甲基-2-羧基-丙内酯-接枝-十二醇-接枝-四乙五胺）（mPEG-b-PCC-g-DC-g-TEPA）共聚物，然后系统地注射到 CBDL 小鼠体内。通过系统给药后 30 分钟的原位肝灌注，确定高浓度的 GDC-0449 和 miR-29b1 被递送到肝细胞中。肝内胶原沉积和血清损伤标志物显著减少，导致肝形态改善。与单药治疗相比，联合治疗在提供肝保护、降低与肝损伤相关的血清酶水平、减少纤维化蛋白标志物（如胶原、α-SMA、FN-1 和 p-AKT）方面更有效。总之，抑制 Hh 通路和恢复 miR-29b1 有可能协同作用于治疗 CBDL 诱导的小鼠肝纤维化。
