PMCCPMCCPMCC

Search tips
Search criteria 

Advanced

 
Logo of fibrotisrepBioMed CentralBiomed Central Web Sitesearchsubmit a manuscriptregisterthis articleFibrogenesis & Tissue RepairJournal Front Page
 
Fibrogenesis Tissue Repair. 2012; 5: 12.
Published online 2012 August 1. doi:  10.1186/1755-1536-5-12
PMCID: PMC3488464

Induction of microRNA-214-5p in human and rodent liver fibrosis

Abstract

Background

miRNAs are non-coding RNAs that regulate gene expression in a wide range of biological contexts, including a variety of diseases. The present study clarified the role of miR-214-5p in hepatic fibrogenesis using human clinical tissue samples, livers from rodent models, and cultured hepatic stellate cells.

Methods

The expression of miR-214-5p and genes that are involved in liver fibrosis were analyzed in hepatitis C virus-infected human livers, rodent fibrotic livers, a human stellate cell line (LX-2), and the cells from intact mouse livers using real-time PCR. The effect of miR-214-5p overexpression in LX-2 cells on cell function was investigated. Twist-1 expression in the liver tissues of mouse models and primary-cultured stellate cells was also analyzed.

Results

miR-214-5p was upregulated in human and mouse livers in a fibrosis progression–dependent manner. miR-214-5p expression increased during the culture-dependent activation of mouse primary stellate cells and was significantly higher in stellate cells than in hepatocytes. The overexpression of miR-214-5p in LX-2 cells increased the expression of fibrosis-related genes, such as matrix metalloproteinase (MMP)-2, MMP-9, α-smooth muscle actin, and transforming growth factor (TGF)-β1. TGF-β stimulation induced miR-214-5p in LX-2 cells. Twist-1 was increased in fibrotic mouse livers and induced during mouse stellate cell activation.

Conclusion

miR-214-5p may play crucial roles in the activation of stellate cells and the progression of liver fibrosis. Twist-1 may regulate miR-214-5p expression in the liver, particularly in stellate cells.

Keywords: Collagen, Hepatocyte, Non-coding RNA, Stellate cell, Transforming growth factor-β

Background

Liver fibrosis is a consequence of chronic liver trauma caused by hepatitis B or hepatitis C virus (HCV) infection, alcohol abuse, or steatohepatitis, which ultimately leads to liver cirrhosis, liver failure, and hepatocellular carcinoma [1]. Liver fibrosis is characterized by an abnormal accumulation of extracellular matrix (ECM) components, including types I and III collagen, laminin, and proteoglycans, in the liver parenchyma [2,3]. Transforming growth factor (TGF)-β, which is produced and released by activated macrophages and platelets at the site of local inflammation, is considered to play a primary role in the fibrotic process [3]. Hepatic stellate cells - which are localized in Disse’s space, store vitamin A and act as tissue-specific pericytes under physiological conditions - undergo activation and transformation into myofibroblast-like cells that express α-smooth muscle actin (α-SMA) during persistent inflammation. The activated stellate cells become an additional source of TGF-β and a principal producer of ECM components. However, the detailed molecular mechanisms of TGF-β production in these cells have not been determined [4].

miRNAs are 20 to 24 nucleotide non-coding RNAs that are involved in the post-transcriptional regulation of gene expression. Mature miRNAs are incorporated into an RNA-induced silencing complex that recognizes target mRNAs through imperfect base pairing with the miRNA. This action triggers the translational inhibition or destabilization of the target mRNA, which results in the regulation of crucial biological processes, such as development, differentiation, apoptosis and cellular proliferation [5,6]. Aberrant expression of miRNAs in tissues correlates with a variety of diseases, including proliferative vascular disease [7], cardiac disorders [8,9], polycystic kidney disease [10], and cancer [11,12]. Several miRNAs can be used as biomarkers for cancer [13,14] because miRNA expression patterns in human cancer are tissue specific [15].

miR-122 is the most abundant miRNA in the liver, where it regulates fat metabolism and the replication of HCV in hepatocytes and contributes to carcinogenesis [16,17]. miR-122 has been used as a novel biomarker for liver damage in rat models of hepatocellular injury caused by a methionine- and choline-deficient diet (MCDD), CCl4 or acetaminophen and bile duct ligation [18]. We previously reported that miR-29b regulates collagen expression by binding to the 3′-UTR of the type 1 collagen alpha 1 chain (Col1a1) and SP1 mRNAs [19], and miR-29b directly inhibits the activation of mouse stellate cells in primary culture [20]. It was recently reported that miR-19b suppresses the activation of stellate cells via the inhibition of TGF-β signaling by interacting with the type II TGF-β receptor [21].

miR-214-5p is a product of the 110 bp miR-214 gene in the intron of the Dynamin-3 gene on human Chromosome 1-NC_000001.10, which produces a mature miRNA with a sequence of ugccugucuacacuugcugugc [22]. TGF-β induces miR-214 expression in rat tubular epithelial cells and mesangial cells [23], and miR-214 interacts with Quaking to inhibit angiogenesis [24]. However, the pathophysiological roles of miR-214 remain largely unknown. Here, we report the upregulation of miR-214-5p in a fibrosis progression–dependent manner in HCV-infected human livers and in the livers of a rodent fibrosis model. The role of miR-214-5p in hepatic stellate cell activation is also discussed.

Results

miR-214 expression in chronic hepatitis C patients

We previously found that, using microRNA array analysis, miR-221/222 expression was upregulated in a fibrosis progression–dependent manner in human livers that are chronically infected with HCV [25]. In addition, we quantitatively confirmed the miR-214-5p expression levels in 35 HCV patients with individual stages of liver fibrosis (Figure (Figure1A)1A) using real-time PCR. We found that miR-214-5p expression increased according to the stage of fibrosis (P = 0.000108) (Figure (Figure1B)1B) and was significantly higher in patients with advanced liver fibrosis than in those with mild fibrosis (F1/F2 versus F3/F4: 3.2-fold, P < 0.05; F1 versus F2-4: 3.1-fold, P < 0.05) (Figure (Figure1C,D).1C,D).

Figure 1
miR-214-5p expression in the livers of patients with chronic hepatitis C virus infection. miR-214-5p expression in the livers of 35 hepatitis C virus (HCV)-infected patients was analyzed using real-time PCR. (A) Representative sirius red staining of liver ...

miR-214 expression in a mouse model of liver fibrosis

Liver fibrosis was induced by feeding mice a MCDD for 5 or 15 weeks and then compared with mice fed a methionine- and choline-control diet (MCCD). Sirius red staining and α-SMA immunostaining confirmed the time-dependent induction of fibrosis in the liver of MCDD-fed mice, especially around the central vein area (Figure (Figure2A).2A). The mRNAs of liver fibrosis factors, such as α-SMA, Col1a1, platelet-derived growth factor receptor (PDGFR)-β, TGF-β1, fibronectin (FN) 1, discoidin domain receptor (DDR) 2, and β1 integrin (ITGB1), were upregulated in the livers of MCDD-fed mice compared to MCCD-fed mice B(Figure B(Figure2).2). miR-214-5p expression was significantly higher in the livers of MCDD-fed mice than in control mice (2.1-fold, P < 0.01 at 5 weeks; and 4.8-fold, P < 0.01 at 15 weeks) (Figure (Figure22C).

Figure 2
miR-214-5p expression in mouse livers with fibrosis induced by an methionine- and choline-deficient diet.(A) Sirius red staining (left and middle panels) and α-smooth muscle actin (SMA) immunostaining (right panels) of mouse liver tissues. Collagen ...

miR-214 expression in a rat resolution model of liver fibrosis

We previously demonstrated the resolution of liver fibrosis with steatohepatitis in a rat model induced by giving MCDD; that is, rats received either MCCD for 10 weeks, MCDD for 10 weeks, or MCDD for 8 weeks followed by MCCD for the last 2 weeks (the last of the these being the recovery group) [26]. miR-214-5p expression was significantly greater in the livers of rats that received MCDD for 10 weeks than in those that received MCCD for 10 weeks. However, these levels returned to control levels in the livers of rats that received the MCDD diet for 8 weeks followed by the MCCD diet for 2 weeks, consistent with recovery from the fibrosis (Figure (Figure3).3). These results clearly suggest a close correlation between miR-214-5p expression in the liver, fibrosis development, and fibrosis-related mRNA expression.

Figure 3
miR-214-5p expression in rat livers with fibrosis induced by a methionine- and choline-deficient diet. Expression of miR-214-5p in methionine- and choline-deficient diet (MCDD)-induced liver fibrosis and recovery phase in rats. The results are expressed ...

miR-214-5p expression in hepatic stellate cells

We assessed the contribution of activated hepatic stellate cells to the increase in miR-214-5p in fibrotic mouse livers. miR-214-5p expression increased during the culture-dependent activation process in mouse stellate cells (2.7-fold increase at day 7 compared to day 1, P < 0.05) (Figure (Figure4A).4A). As expected, the induction of miR-214-5p was accompanied by an increase in the expression of α-SMA, Col1a1, PDGFR-β, and FN1 mRNA (Figure (Figure4B).4B). In addition, miR-214-5p expression was markedly higher in LX-2, a widely used human hepatic stellate cell line, than in human liver cancer cell lines such as HepG2 and Huh7 (108- and 39-fold, respectively) (Figure (Figure44C).

Figure 4
miR-214-5p expression in liver cells, including stellate cells. (A) miR-214-5p expression in mouse stellate cells during primary culture was analyzed using real-time PCR. Stellate cells were isolated from mouse livers and cultured for 1, 4 or 7 days. ...

We next isolated individual hepatocytes, non-parenchymal cells, and hepatic stellate cells from intact mouse livers to verify the cellular source of miR-214-5p. miR-214-5p was localized to non-parenchymal cells and hepatic stellate cells but expressed at negligible levels in hepatocytes (Figure (Figure4D).4D). These results suggest that miR-214 induction in fibrotic livers reflects the number and activation status of hepatic stellate cells.

The effect of miR-214 overexpression on gene expression in stellate cells

We investigated the effect of miR-214-5p overexpression on fibrosis-related gene expression in stellate cells to clarify the role of this miRNA in stellate cell activation. miR-214-5p was overexpressed in LX-2 cells by transfection with an miR-214 precursor. The overexpression of miR-214 significantly increased the expression of matrix metalloproteinase-2 (MMP-2), MMP-9, α-SMA, and TGF-β1 compared to cells transfected with control microRNA (1.7-, 2.8-, 1.7- and 2.0-fold, respectively; P < 0.01) (Figure (Figure5).5). These results indicate the strong participation of miR-214 in the activation of stellate cells.

Figure 5
Effect of miR-214 overexpression on mRNA expression in LX-2 cells. (A) LX-2 cells were transfected with a miR-214 precursor or a negative control (control) at a final concentration of 50 nM and incubated for 24 hours. miR-214 expression was quantitated ...

Induction of miR-214 expression by TGF-β1

TGF-β1 induces miR-214 expression in rat tubular epithelial cells and mesangial cells [23]. TGF-β1 is essential for hepatic stellate cell activation. We assessed the stimulatory effect of TGF-β on miR-214-5p expression in LX-2 cells. TGF-β1 (3 and 10 ng/ml) significantly stimulated miR-214-5p expression in LX-2 cells after 24 hours (1.75-fold, P < 0.05)(Figure 6A). In contrast, the expression of the miR-214/199a cluster is controlled by the transcription factor Twist-1 [22]. Real-time PCR analysis revealed that Twist-1 expression increased in the livers of mice that received MCDD compared to those of MCCD-fed mice (2.2-fold at 5 weeks, P < 0.05; and 3.6-fold at 15 weeks, P < 0.05) (Figure (Figure6B).6B). Twist-1 mRNA expression was also induced in a time-dependent manner after culture initiation in primary-cultured mouse stellate cells (Figure (Figure6C).6C).

Figure 6
Regulation of miR-214-5p expression. (A) The effect of transforming growth factor (TGF)-β1 on miR-214-5p expression. LX-2 cells were treated with recombinant human TGF-β1 (3 or 10 ng/ml) for 24 hours in DMEM containing 0.1% fetal bovine ...

Discussion

This is the first report to show that miR-214-5p is involved in organ fibrogenesis, specifically in the liver. miR-214 has previously been predicted to be a key molecule in proliferation in breast [27] and ovarian cancer cells [28], tumor progression in melanoma [29], and growth in HeLa cells [30]. miR-214 and miR-199a are encoded in a region that contains an E-box DNA promoter sequence [22]. A transcription factor, Twist-1, binds to the E-box region, regulating miR-214 and miR-199a expression [22]. The present study showed that miR-214 expression is upregulated in a fibrosis progression-dependent manner in the livers of patients with chronic HCV infection and in mice with diet-induced steatohepatitis (Figures 1 and and2).2). We previously reported an increase in miR-199a in the fibrotic livers of patients with chronic HCV infection [25], and similar findings have been reported by others [31-33]. These data and the upregulation of Twist-1 in MCDD-induced mouse liver fibrosis (Figure (Figure4)4) suggest that Twist-1 controls the expression of the miR-214/199a cluster in the liver. Further studies will be needed to clarify the possible involvement of Twist-1 in the expression of miR-214-5p in LX-2 cells.

The present study revealed that miR-214-5p overexpression in LX-2 cells significantly increased MMP-2, MMP-9, α-SMA, and TGF-β1 mRNA expression. The overexpression of miR-199a in LX-2 cells triggers the upregulation of tissue inhibitor of metalloproteinase (TIMP)-1, Col1a1, and MMP-13 mRNA [34]. These results suggest that the miR-214/199a cluster plays a primary role in stellate cell activation. However, an understanding of the precise molecular events involved requires further research.

Conversely, the overexpression of miR-214-5p in LX-2 cells did not alter the expression of MAPK/Erk kinase 3 (MEK3), transcription factor AP-2 gamma (TFAP2C) [29], Plenxin-B1 [30], c-Jun N-terminal kinase 1 (Jnk1) [34], phosphatase and tensin homolog (PTEN) [35], enhancer of zeste homolog 2 (Ezh2) [36], and Quaking mRNA [24], which had been reported to be targets of miR-214 (MEK3: 0.72- to 0.77-fold, Jnk1: 1.05- to 1.20-fold, PTEN: 0.97- to 1.12-fold, Plenxin-B1: 0.99-fold, Ezh2: 0.96-fold, TFAP2C: 0.94-fold, and Quaking: 0.88- to 1.18-fold change compared with cells transfected with control miRNA). The PTEN 3′-UTR did not interact with miR-214-5p in a luciferase reporter assay in LX-2 cells (data not shown). We also found that miR-214-5p overexpression had a negligible effect on LX-2 proliferation and migration. Therefore, the mRNA targets of miR-214-5p in LX-2 cells are not identical to those in previous reports.

Conclusions

We report an increase in miR-214-5p in liver fibrosis in humans and mice and the possible association of miR-214-5p with stellate cell activation. miR-214 expression in stellate cells is regulated by TGF-β and possibly by the transcription factor Twist-1. These results should be pursued further to identify the role of miR-214-5p in liver fibrogenesis and to develop a biomarker that reflects the stage of liver fibrosis more accurately than a pathological staging score.

Methods

Ethics Statement

The Ethics Committee of the Osaka City University Graduate School of Medicine approved this study (Approval No. 1358), which complied with the principles of the Declaration of Helsinki (2008 revision). All of the patients provided written, informed consent.

Liver biopsy specimens

Liver biopsy specimens were obtained from 35 patients with chronic HCV (genotype 1) infection as described previously [25]. The stage of liver fibrosis was evaluated using the METAVIR scoring system [37]. Normal liver tissues were taken as control samples from four patients who underwent resection for metastatic liver tumors.

Animals

Eight- to 12-week-old male C57BL/6N mice were purchased from Japan SLC, Inc. (Shizuoka, Japan). All animal procedures were performed according to the guidelines of the Osaka City University and Faculty of Medicine Animal Research Committee and were approved by the committee. The mice received either a MCDD (n = 7, MP Biomedicals, Solon, OH, USA) or a MCCD (n = 7, MP Biomedicals) for 5 or 15 weeks, as previously described [26]. A similar protocol was followed in rats purchased from Japan SLC, Inc. Rats received MCCD for 10 weeks, MCDD for 10 weeks, or MCDD for 8 weeks followed by MCCD for the last 2 weeks (the last of the these being the recovery group) [26].

Cells

LX-2 cells (donated by Dr Scott Friedman [38]) and Huh7 cells were maintained in plastic culture plates in DMEM (Sigma Chemical Co., St Louis, MO, USA) supplemented with 10% fetal bovine serum (FBS) (Invitrogen, Carlsbad, CA, USA). HepG2 cells (JCRB1054) were obtained from the Health Science Research Resources Bank (Osaka, Japan) and maintained in plastic culture plates in Minimum Essential Medium (Invitrogen) supplemented with 10% FBS, 1 mM sodium pyruvate (Invitrogen), and 1% non-essential amino acids (Invitrogen). Primary hepatic stellate cells and hepatocyte-rich and Kupffer cell-rich fractions were prepared from mouse livers according to the previously reported method [39].

Histochemistry and immunohistochemistry

The sections were stained with 0.1% (w/v) Sirius red in a saturated aqueous solution of picric acid (Direct Red 80; Aldrich, Milwaukee, WI, USA) for 1 hour at room temperature to visualize collagen fibers. Immunostaining for α-SMA was performed as previously described [25]. Mouse liver tissue was fixed in 10% formaldehyde, embedded in paraffin, and cut into 4 μm thick sections.

Quantitative real-time PCR

Gene expression was measured by real-time PCR using cDNA, real-time PCR Master Mix Reagents (Toyobo, Osaka, Japan), and gene-specific oligonucleotide primers (Table (Table1)1) in an ABI Prism 7500 Real-Time PCR System (Applied Biosystems, Foster City, CA, USA), as previously described [25].

Table 1
List of primers

Transforming growth factor-β1 stimulation of LX-2 cells

LX-2 cells were seeded on 24-well plates in DMEM supplemented with 10% FBS at a density of 2 × 105 cells/ml. The cells were cultured for 14 hours, and the medium was changed to DMEM supplemented with 0.1% FBS plus TGF-β1 (3 or 10 ng/ml). The culture was continued for an additional 24 hours.

Transient transfection of miRNA precursors

miR-214-5p precursors and negative control miRNA were transfected into LX-2 cells using Lipofectamine 2000 (Invitrogen) at a final concentration of 50 nM, as described previously [20,25]. The cells were collected after 24 hours, and total RNA was extracted.

Statistical analysis

The data shown in the bar graphs represent the means ± SD of at least three independent experiments. Statistical analysis was performed using the Student’s t-test. The Jonckheere-Terpstra test was used to compare differences between the four groups in the progressive stages of liver fibrosis. P < 0.05 was considered statistically significant.

Abbreviations

bp: base pair; Col1a1: the type 1 collagen alpha 1 chain; DDR: discoidin domain receptor; DMEM: Dulbecco’s modified Eagle’s medium; ECM: extracellular matrix; FBS: fetal bovine serum; FN: fibronectin; HCV: hepatitis C virus; ITGB1: β1 integrin; MCCD: methionine- and choline-control diet; MCDD: methionine- and choline-deficient diet; miRNA: microRNA; MMP: matrix metalloproteinase; PCR: polymerase chain reaction; PDGFR: platelet-derived growth factor receptor; α-SMA: α-smooth muscle actin; TGF: transforming growth factor; UTR: untranslated region.

Competing interests

KY is an employee of PhoenixBio Co. Ltd as an academic advisor. There is no direct financial benefit to KY for the publication of this manuscript. All other authors declare that they have no competing interests.

Authors’ contributions

Conception and design (MI, TO, KI, NK); data acquisition (TO, ME, YM), data analysis and interpretation (MI, TO, KY); writing and review of the manuscript (MI, KY, KI, NK). All authors read and approved the final manuscript.

Acknowledgments

The authors thank Dr Hideki Fujii for the preparation of the mouse liver fibrosis tissue samples and Drs Hiroyuki Motoyama, Le Thi Thanh Thuy, and Tohru Komiya for valuable comments on this study. This work was supported by a Grant-in-Aid for Scientific Research from the Japan Society for the Promotion of Science (JSPS) (no. 21390232; 2009–2011) (to NK), a grant from the Ministry of Health, Labour and Welfare of Japan (2008–2010) (to NK), a Thrust Area Research Grant from Osaka City University (2008–2012) (to NK), and a Grant-in-Aid for Scientific Research from the JSPS (no. 22790666; 2010–2011) (to TO).

References

  • Friedman SL. Evolving challenges in hepatic fibrosis. Nat Rev Gastroenterol Hepatol. 2010;7:425–436. doi: 10.1038/nrgastro.2010.97. [PubMed] [Cross Ref]
  • Friedman SL. Molecular regulation of hepatic fibrosis, an integrated cellular response to tissue injury. J Biol Chem. 2000;275:2247–2250. doi: 10.1074/jbc.275.4.2247. [PubMed] [Cross Ref]
  • Kawada N. Evolution of hepatic fibrosis research. Hepatol Res. 2011;41:199–208. doi: 10.1111/j.1872-034X.2011.00776.x. [PubMed] [Cross Ref]
  • Bataller R, Brenner DA. Hepatic stellate cells as a target for the treatment of liver fibrosis. Semin Liv Dis. 2001;21:437–451. doi: 10.1055/s-2001-17558. [PubMed] [Cross Ref]
  • Bartel DP. MicroRNAs: genomics, biogenesis, mechanism, and function. Cell. 2004;116:281–297. doi: 10.1016/S0092-8674(04)00045-5. [PubMed] [Cross Ref]
  • Ambros V. The functions of animal microRNAs. Nature. 2004;16:350–355. [PubMed]
  • Ji R, Cheng Y, Yue J, Yang J, Liu X, Chen H, Dean DB, Zhang C. MicroRNA expression signature and antisense-mediated depletion reveal an essential role of microRNA in vascular neointimal lesion formation. Circ Res. 2007;100:1579–1588. doi: 10.1161/CIRCRESAHA.106.141986. [PubMed] [Cross Ref]
  • Ikeda S, Kong SW, Lu J, Bisping E, Zhang H, Allen PD, Golub TR, Pieske B, Pu WT. Altered microRNA expression in human heart disease. Physiol Genomics. 2007;31:367–373. doi: 10.1152/physiolgenomics.00144.2007. [PubMed] [Cross Ref]
  • Carè A, Catalucci D, Felicetti F, Bonci D, Addario A, Gallo P, Bang ML, Segnalini P, Gu Y, Dalton ND, Elia L, Latronico MV, Høydal M, Autore C, Russo MA, Dorn GW 2nd, Ellingsen O, Ruiz-Lozano P, Peterson KL, Croce CM, Peschle C, Condorelli G. MicroRNA-133 controls cardiac hypertrophy. Nat Med. 2007;13:613–618. doi: 10.1038/nm1582. [PubMed] [Cross Ref]
  • Pandey P, Brors B, Srivastava PK, Bott A, Boehn SN, Groene HJ, Gretz N. Microarray-based approach identifies microRNAs and their target functional patterns in polycystic kidney disease. BMC Genomics. 2008;9:624. doi: 10.1186/1471-2164-9-624. [PMC free article] [PubMed] [Cross Ref]
  • Dillhoff M, Wojcik SE, Bloomston M. MicroRNAs in solid tumors. J Surg Res. 2009;154:349–354. doi: 10.1016/j.jss.2008.02.046. [PubMed] [Cross Ref]
  • Huang Q, Gumireddy K, Schrier M, le Sage C, Nagel R, Nair S, Egan DA, Li A, Huang G, Klein-Szanto AJ, Gimotty PA, Katsaros D, Coukos G, Zhang L, Puré E, Agami R. The microRNAs miR-373 and miR-520c promote tumour invasion and metastasis. Nat Cell Biol. 2008;10:202–210. doi: 10.1038/ncb1681. [PubMed] [Cross Ref]
  • Mitchell PS, Parkin RK, Kroh EM, Fritz BR, Wyman SK, Pogosova-Agadjanyan EL, Peterson A, Noteboom J, O’Briant KC, Allen A, Lin DW, Urban N, Drescher CW, Knudsen BS, Stirewalt DL, Gentleman R, Vessella RL, Nelson PS, Martin DB, Tewari M. Circulating microRNAs as stable blood-based markers for cancer detection. Proc Natl Acad Sci U S A. 2008;105:10513–10518. doi: 10.1073/pnas.0804549105. [PubMed] [Cross Ref]
  • Chen X, Ba Y, Ma L, Cai X, Yin Y, Wang K, Guo J, Zhang Y, Chen J, Guo X, Li Q, Li X, Wang W, Zhang Y, Wang J, Jiang X, Xiang Y, Xu C, Zheng P, Zhang J, Li R, Zhang H, Shang X, Gong T, Ning G, Wang J, Zen K, Zhang J, Zhang CY. Characterization of microRNAs in serum: a novel class of biomarkers for diagnosis of cancer and other diseases. Cell Res. 2008;18:997–1006. doi: 10.1038/cr.2008.282. [PubMed] [Cross Ref]
  • Lu J, Getz G, Miska EA, Alvarez-Saavedra E, Lamb J, Peck D, Sweet-Cordero A, Ebert BL, Mak RH, Ferrando AA, Downing JR, Jacks T, Horvitz HR, Golub TR. MicroRNA expression profiles classify human cancers. Nature. 2005;435:834–838. doi: 10.1038/nature03702. [PubMed] [Cross Ref]
  • Jopling CL, Yi M, Lancaster AM, Lemon SM, Sarnow P. Modulation of hepatitis C virus RNA abundance by a liver-specific microRNA. Science. 2005;309:1577–1581. doi: 10.1126/science.1113329. [PubMed] [Cross Ref]
  • Li YP, Gottwein JM, Scheel TK, Jensen TB, Bukh J. MicroRNA-122 antagonism against hepatitis C virus genotypes 1–6 and reduced efficacy by host RNA insertion or mutations in the HCV 5′ UTR. Proc Natl Acad Sci U S A. 2011;108:4991–4996. doi: 10.1073/pnas.1016606108. [PubMed] [Cross Ref]
  • Yamaura Y, Nakajima M, Takagi S, Fukami T, Tsuneyama K, Yokoi T. Plasma microRNA profiles in rat models of hepatocellular injury, cholestasis, and steatosis. PLoS One. 2012;7:e30250. doi: 10.1371/journal.pone.0030250. [PMC free article] [PubMed] [Cross Ref]
  • Ogawa T, Iizuka M, Sekiya Y, Yoshizato K, Ikeda K, Kawada N. Suppression of type I collagen production by microRNA-29b in cultured human stellate cells. Biochem Biophys Res Commun. 2010;391:316–321. doi: 10.1016/j.bbrc.2009.11.056. [PubMed] [Cross Ref]
  • Sekiya Y, Ogawa T, Yoshizato K, Ikeda K, Kawada N. Suppression of hepatic stellate cell activation by microRNA-29b. Biochem Biophys Res Commun. 2011;412:74–79. doi: 10.1016/j.bbrc.2011.07.041. [PubMed] [Cross Ref]
  • Lakner AM, Steuerwald NM, Walling TL, Ghosh S, Li T, McKillop IH, Russo MW, Bonkovsky HL, Schrum LW. Inhibitory effects of microRNA 19b in hepatic stellate cell-mediated fibrogenesis. Hepatology. 2012;56:300–310. [PMC free article] [PubMed]
  • Lee YB, Bantounas I, Lee DY, Phylactou L, Caldwell MA, Uney JB. Twist-1 regulates the miR-199a/214 cluster during development. Nucleic Acids Res. 2009;37:123–128. doi: 10.1093/nar/gkn920. [PMC free article] [PubMed] [Cross Ref]
  • Denby L, Ramdas V, McBride MW, Wang J, Robinson H, McClure J, Crawford W, Lu R, Hillyard DZ, Khanin R, Agami R, Dominiczak AF, Sharpe CC, Baker AH. miR-21 and miR-214 are consistently modulated during renal injury in rodent models. Am J Pathol. 2011;179:661–672. doi: 10.1016/j.ajpath.2011.04.021. [PubMed] [Cross Ref]
  • van Mil A, Grundmann S, Goumans MJ, Lei Z, Oerlemans MI, Jaksani S, Doevendans PA, Sluijter JP. MicroRNA-214 inhibits angiogenesis by targeting Quaking and reducing angiogenic growth factor release. Cardiovasc Res. 2012;93:655–665. doi: 10.1093/cvr/cvs003. [PubMed] [Cross Ref]
  • Ogawa T, Enomoto M, Fujii H, Sekiya Y, Yoshizato K, Ikeda K, Kawada N. MicroRNA-221/222 upregulation indicates the activation of stellate cells and the progression of liver fibrosis. Gut. 2012. Epub ahead of print. [PubMed]
  • Mu YP, Ogawa T, Kawada N. Reversibility of fibrosis, inflammation, and endoplasmic reticulum stress in the liver of rats fed a methionine-choline-deficient diet. Lab Invest. 2010;90:245–56. doi: 10.1038/labinvest.2009.123. [PubMed] [Cross Ref]
  • Derfoul A, Juan AH, Difilippantonio MJ, Palanisamy N, Ried T, Sartorelli V. Decreased microRNA-214 levels in breast cancer cells coincides with increased cell proliferation, invasion and accumulation of the Polycomb Ezh2 methyltransferase. Carcinogenesis. 2011;32:1607–1614. doi: 10.1093/carcin/bgr184. [PMC free article] [PubMed] [Cross Ref]
  • Vaksman O, Stavnes HT, Kaern J, Trope CG, Davidson B, Reich R. miRNA profiling along tumour progression in ovarian carcinoma. J Cell Mol Med. 2011;15:1593–1602. doi: 10.1111/j.1582-4934.2010.01148.x. [PubMed] [Cross Ref]
  • Penna E, Orso F, Cimino D, Tenaglia E, Lembo A, Quaglino E, Poliseno L, Haimovic A, Osella-Abate S, De Pittà C, Pinatel E, Stadler MB, Provero P, Bernengo MG, Osman I, Taverna D. microRNA-214 contributes to melanoma tumour progression through suppression of TFAP2C. EMBO J. 2011;30:1990–2007. doi: 10.1038/emboj.2011.102. [PubMed] [Cross Ref]
  • Qiang R, Wang F, Shi LY, Liu M, Chen S, Wan HY, Li YX, Li X, Gao SY, Sun BC, Tang H. Plexin-B1 is a target of miR-214 in cervical cancer and promotes the growth and invasion of HeLa cells. Int J Biochem Cell Biol. 2011;43:632–641. doi: 10.1016/j.biocel.2011.01.002. [PubMed] [Cross Ref]
  • Murakami Y, Toyoda H, Tanaka M, Kuroda M, Harada Y, Matsuda F, Tajima A, Kosaka N, Ochiya T, Shimotohno K. The progression of liver fibrosis is related with overexpression of the miR-199 and 200 families. PLoS One. 2011;6:e16081. doi: 10.1371/journal.pone.0016081. [PMC free article] [PubMed] [Cross Ref]
  • Roderburg C, Urban GW, Bettermann K, Vucur M, Zimmermann H, Schmidt S, Janssen J, Koppe C, Knolle P, Castoldi M, Tacke F, Trautwein C, Luedde T. Micro-RNA profiling reveals a role for miR-29 in human and murine liver fibrosis. Hepatology. 2011;53:209–218. doi: 10.1002/hep.23922. [PubMed] [Cross Ref]
  • Venugopal SK, Jiang J, Kim TH, Li Y, Wang SS, Torok NJ, Wu J, Zern MA. Liver fibrosis causes downregulation of miRNA-150 and miRNA-194 in hepatic stellate cells, and their overexpression causes decreased stellate cell activation. Am J Physiol Gastrointest Liver Physiol. 2010;298:G101–106. doi: 10.1152/ajpgi.00220.2009. [PubMed] [Cross Ref]
  • Yang Z, Chen S, Luan X, Li Y, Liu M, Li X, Liu T, Tang H. MicroRNA-214 is aberrantly expressed in cervical cancers and inhibits the growth of HeLa cells. IUBMB Life. 2009;61:1075–1082. doi: 10.1002/iub.252. [PubMed] [Cross Ref]
  • Yang H, Kong W, He L, Zhao JJ, O’Donnell JD, Wang J, Wenham RM, Coppola D, Kruk PA, Nicosia SV, Cheng JQ. MicroRNA expression profiling in human ovarian cancer: miR-214 induces cell survival and cisplatin resistance by targeting PTEN. Cancer Res. 2008;68:425–433. doi: 10.1158/0008-5472.CAN-07-2488. [PubMed] [Cross Ref]
  • Juan AH, Kumar RM, Marx JG, Young RA, Sartorelli V. Mir-214-dependent regulation of the polycomb protein Ezh2 in skeletal muscle and embryonic stem cells. Mol Cell. 2009;36:61–74. doi: 10.1016/j.molcel.2009.08.008. [PMC free article] [PubMed] [Cross Ref]
  • Bedossa P, Poynard T. An algorithm for the grading of activity in chronic hepatitis C. The METAVIR Cooperative Study Group. Hepatology. 1996;24:289–293. [PubMed]
  • Xu L, Hui AY, Albanis E, Arthur MJ, O’Byrne SM, Blaner WS, Mukherjee P, Friedman SL, Eng FJ. Human hepatic stellate cell lines, LX-1 and LX-2: new tools for analysis of hepatic fibrosis. Gut. 2005;54:142–151. doi: 10.1136/gut.2004.042127. [PMC free article] [PubMed] [Cross Ref]
  • Kristensen DB, Kawada N, Imamura K, Miyamoto Y, Tateno C, Seki S, Kuroki T, Yoshizato K. Proteome analysis of rat hepatic stellate cells. Hepatology. 2000;32:268–277. doi: 10.1053/jhep.2000.9322. [PubMed] [Cross Ref]

Articles from Fibrogenesis & Tissue Repair are provided here courtesy of BioMed Central