miRNA as a Potenial Treatment

1. miRNA as a Potenial Treatment Ashraf Omar MD Prof Hepatology Cairo University

2. Background Micro RNAs (miRNAs) are 15-22 nucleotide, short, non-coding RNAs that function in transcriptional and post-transcriptional regulation of gene expression affecting a multitude of biological processes including cell proliferation ,differentiation, survival and motility miRNAs have been shown to participate in the pathogenesis of both HBV HCV NASH .PBC alcoholic liver disease . miRNAs also have significant clinical value in the early diagnosis of HCC since they are present in the blood and can be used as diagnostic markers and potential targets for specific systemic tt . Chen K and Rajewsky N: Nat Rev Genet 8(2):93-103 (2007) Li et al Post graduate medical journal,(2013)

3. Liver fibrogenesis Liver fibrogenesis Ismail and Pinzani, Hepatic Medicin: Educationand Research 2011

4. Altered expression pattern of microRNAs during myofibroblastic activation of hepatic stellate cells (HSCs). Huange et alInt. J. Mol. Sci. 2014

5. Roles of miRNAs in the pathogenesis of chronic liver disease and cancer

6. THERAPEUTIC miRNA MODALITIES In general, there are two approaches to developing miRNA-based therapeutics: 1. miRNA antagonists (inhibitors) and 2.miRNA mimics (replacement)

7. 1.miRNA antagonists (inhibitors) - introduction of a highly chemically-modified miRNA passenger strand (anti-miR or antagomiR) that binds with high affinity to the active miRna strand . - may also non-specifically bind to other RNAs, which could result in unwanted side effects.

8. 2.miRNA mimics are used to restore a loss of function aims to re-introduce miRNAs into diseased cells that are normally expressed in healthy cells Highly specific well tolerated less side effects (Tumour supressor gen)

9. THERAPUITIC Delivery of miRNAs to the Liver miRNA-based therapy needs a delivery vehicles. Different methods, using mainly viral and nonviral vehicles, have been developed to increase the targeting and efficiency of miRNAs.

10. Nonviral vehicles, *liposomal delivery system, YSK05-MEND, A cationic lipid-based nanoparticle system reflects a novel systemic delivery agent for miRNA.) *Lipid-based nanoparticles (LNPs)containing oleic acid (OA), an unsaturated fatty acid, also demonstrate the delivery efficacy of miRNA *Peptide vector (MPG) has recently proved to be another type of miRNA delivery system is capable of delivering both miR-122 mimic and inhibitor into mouse liver cells and effectively regulating cholesterol levels . Viral vectors, Including adenovirus, adeno-associated virus (AAV), and lentivirus, have been widely employed to deliver miRNAs into liver cells (hepatocytes, HSCs, etc.).

11. miRNAs IN THERAPEUTIC DEVELOPMENT Roles of microRNA-29a in the Antifibrotic Effect of Farnesoid X Receptor in Hepatic Stellate Cells (Mol Pharmacol 80:191–200, 2011) miR-29, a potential therapeutic target for liver fibrosis (SciencDirect 2014) Therapeutic Potential of MicroRNA: A New Target to Treat Intrahepatic Portal Hypertension.( Biomed Res Int 2014) MicroRNA-101 suppresses liver fibrosis by targeting TGFβ signaling pathway (Yuet al Journal of Pathology 2014)

12. MicroRNA in hepatic fibrosis and cirrhosis Xin et al ;(Frontiers in Bioscience 19, 1418-1424, June 1, 2014) *miR-602 also, miR-885-5p, miR-574-3p, miR-224, miR-215 and miR-146a suggesting miRNAs may participate the development of liver cirrhosis and HCC from HBV *miR-122 play a crucial role in the HCV injury of liver .miR-122 expression may be abnormal in the stage of liver cirrhosis from HCV infection. miR-122 may be a biomarker for HCV patients to become hepatic fibrosis

13. HSCs and intrahepatic modulation of portal pressure. TGF-β and VEGF are two important signaling pathways that may promote portal hypertension through multiple mechanisms

14.  miRNAs and the TGF-β pathway involved in HSCs

15. miRNAs and the VEGF pathway involved in HSC

16. Serum miR-122 levels in the validation cohort and overall survival in the combined cohort. Waidmann O, Köberle V, Brunner F, Zeuzem S, et al. (2012) Serum MicroRNA-122 Predicts Survival in Patients with Liver Cirrhosis. PLoS ONE 7(9): e45652. doi:10.1371/journal.pone.0045652

17. Conclusion The high impact of miRNAs on the progression of fibrosis by the inhibition of ECM or by interfering with profibrogenic pathways announces the promising potential of miRNAs as biomarkers and targets of novel antifibrotic therapeutic strategies miRNAs exhibit a unique, namely, multitargeted, pattern of action so, different signal pathways may be under the control of one miRNA. *A new mechanism of action, the ability to function as master regulators of the genome and an apparent lack of adverse events in normal tissue make ‘drug target miRNA’ a promising technology for current and future product development *Extensive investigations ex vivo suggest therapeutic opportunities in areas of unmet medical need; some of these have already been validated in clinically-relevant animal models, and a few are in (pre)clinical development.

18. Conclusion cont, • TGF-β and VEGF are two important signaling pathways that may promote portal hypertension through multiple mechanisms , miRNA therapy offers novel possibilities by restoring some intracellular miRNAs lead to reduced HSC proliferation and contractility and suppressed angiogenesis by targeting the TGF-β and VEGF-mediated signaling pathway, thereby reducing hepatic portal shunting and improving the sinusoidal microcirculation The poor pharmacokinetic properties of therapeutic miRNAs define an urgent need for delivery companies to generate adjuvant carrier systems that increase stability, prevent renal clearance and enhance cellular uptake by target tissues .

19. RECOMMENDATION Further understanding of the miRNAs in hepatic fibrosis and cirrhosis may provide noval therapeutic targets for hepatic fibrosis and cirrhosis Further analyses needed for promising agents such as synthetic anti–miR-122 molecules to control HCV infection and reduce fibrosis and the prevalence of HCC. The ability of miR-122 to reduce metastasis of HCC and its down-regulation in metastatic HCC are interesting areas for future studies. Further analyses are needed to determine whether inhibiting miR-122 promotes metastasis. .

20. miR-101 and mi29a having promising roles in hepatic fibrogensis suggest they could be a potential therapeutic target for liver fibrosis need further validation The poor pharmacokinetic properties of therapeutic miRNAs define an urgent need to generate adjuvant carrier systems that increase stability, prevent renal clearance and enhance cellular uptake by target tissues