, 201 3). In the present study, we aimed to analyse further putative targets of the Ago2 neuronal miRNA complex, namely Notch 1, KLF4, and Lin28. Methods: Notch 1, KLF4, and Lin28 gene expression was quantified in primary rat HSC cultures by real time PC R. 3∽UTR sites of Notch 1, KLF4, and Lin28 transcripts, putatively targeted by neuronal miR-9, miR-125b, mTOR inhibitor miR-128, were cloned downstream to a luciferase reporter gene and used for reporter assays in myofibroblastic HSC treated with miRNA mimics

or with scrambled miRNA. Notch 1 and Lin28 were overexpressed by lentiviral vector transduction and the influence on HSC was determined by expression profiling using PCR arrays. Results: Since the pluripotency involved factors, Notch 1, KLF4, and Lin28 were suggested to be targets of posttranscriptional neuronal miRNA repression, we investigated the expression of these mediators during myofibroblastic HSC transition. Whereas the neuronal miRNAs miR-9, miR-125b, and miR-128 were highly increased,

the putative targets Notch 1 and Lin28, but not KLF4 were markedly decreased during myofibroblastic differentiation of HSC. Next, we analysed the 3∽UTR of Notch1, KLF4, and Lin28 transcripts for putative binding sites XL765 of the three neuronal miRNAs. Reporter assays of the luciferase constructs, harboring the putative 3∽UTR sites of Notch1, KLF4, and Lin28 MCE mRNA in comparison to the corresponding mutants definitively demonstrate the inhibitory interaction of all

neuronal miRNAs to Lin28 and Notch1, and of miR-128 to KLF4 mRNA. Furthermore, neuronal miRNA over-expression in HSC resulted in a prominent decrease of Notch1 and Lin28. In order to proof the impact of the neuronal miRNA Notch1 axis, lentiviral overexpression was performed. Expression profiling of Notch1 overexpressing cells revealed that members of the Notch signaling pathway were highly upregu-lated whereas some fibrogenic mediators are downregulated. Conclusion: Upregulation of neuronal miR-9, miR-125b, and miR-128 during myofibroblastic transition and the identified interaction with factors involved in pluripotency and cell differentiation suggests a prominent role of these miRNAs in HSC differentiation and activation during fibrosis. Disclosures: The following people have nothing to disclose: Jia Huang, Andrea Noetel, Moritz Perrech, Ingo Strack, Jürgen Hescheler, Reinhard Buettner, Tomo Saric, Margarete Odenthal C5a and its cognate receptor C5aR are critical modulators of both liver immunity and liver fibrosis. However, the molecular mechanism for the cross talk between the complement system and liver fibrosis is not well understood. C5a is a potent chemokine regulating the migration of cells in the innate immune system.