Journal of Cellular Biochemistry 115:1582–1593 (2014)

MicroRNA-122 Overexpression Promotes Hepatic Differentiation of Human Adipose Tissue Derived Stem Cells

Nahid Davoodian, Abbas S Lotfi, Masoud Soleimani, Javad Mola

Department of Clinical Biochemistry, Faculty of Medical Science, Tarbiat Modares University, Tehran, Iran

 

Abstract

MicroRNAs are the regulatory molecules in post-transcriptional regulation of gene expression, which affect diverse biological processes and have been found to play important roles in regulating stem cell character in plants and animals. The aim of this study was to identify the role of miR-122 during hepatic differentiation of human adipose tissue derived stem cells (hADSCs), and also to investigate whether overexpression of miR-122 could enhance differentiation of ADSCs toward functional hepatocyte-like cells without any extrinsic factor. To investigate this, the level of miR-122 was monitored by quantitative real-time PCR (qRT-PCR) at specific time intervals following hepatic differentiation of hADSCs using growth factors. For the next step, lentiviral transduction was applied to overexpress miR-122 in hADSCs for up to 21 days. Hepatic functionality was evaluated by analyzing specific hepatocyte genes and biochemical markers at different time points of differentiation induction. The qRT-PCR results revealed that miR-122 was upregulated during hepatic differentiation of hADSCs. Additionally, the stable miR-122 overexpression in hADSCs resulted in increased expression of specific hepatocyte markers such as ALB, AFP, CK18, CK19 and HNF4a compared with the negative control cells. Moreover, urea and albumin production as well as glycogen deposits were observed in the treated cells. Therefore, our findings demonstrate that the hepatic differentiation process could be improved by the overexpression of miR-122 in hADSCs, making it a potential therapeutic resource for liver disorders.

PMID: 24733606

 

Supplements:

The striking role of liver-specific microRNA, miR-122 in the regulation of liver development has been reported recently. Additionally, miR-122 has been described as an important facilitator of some liver functions. Likewise, several studies have indicated that the expression of miR-122 increase during hepatic differentiation of some kind of stem cells, notably, embryonic stem cells (ESCs) and liver progenitor cells (LDPCs). Based on these reports clearly demonstrating the critical role of miR-122 in liver function and differentiation, this study focused at the influence of miR-122 on differentiation process, and determined whether miR-122 can be applied as an alternative factor for hepatic differentiation of hADSCs, instead of the expensive and time consuming of cytokins and growth factors. To confirm the role of this microRNA in hepatic differentiation of hADSCs, we revealed a gradual increase of miR-122 upon induction of hepatic differentiation in hADSCs using growth factors. Afterwards, following miR-122 overexpression in hADSCs applying lentiviral transduction, functionality of hepatocyte- like cells was significantly evaluated by analyzing several liver specific genes, and markers as compare with presence of growth factors and cytokins .

Interestingly, overexpression of miR-122 resulted in expression of hepatocyte-specific genes including albumin (ALB), alpha fetoprotein (AFP), cytokeratin 18 (CK18), cytokeratin 19 (CK19) and specially HNF4α. HNF4α is a prominent factor controlling the expression of several hepatocyte specific genes. Moreover, this transcription factor has been shown as an important regulator of miR-122. Therefore, according to these results, it is hypothesized a positive feedback loop between miR-122 and HNF4α to induce hepatic differentiation. Albumin secretion, urea production and glycogen ability storage were also confirmed the hepatic characterization of hepatocyte-like cells.

Collectively, our study provide an evidence that miR-122 can act as an important factor in differentiation of hADSCs toward hepatocyte-like cells without need to external factors.

  

Acknowledgements:

The authors acknowledge from Iran National Science Foundation (INSF) and Tarbiat Modares University for financial supporting of this project .

Contact : Lotfi-ab@modares.ac.ir

  Supplement2[3]

Figure : A recommended model for mir-122 regulatory role in hepatic differentiation of hADSCs

 

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