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Mir-34a is upregulated during liver regeneration in rats and is associated with the suppression of hepatocyte proliferation.

Chen H, Sun Y, Dong R, Yang S, Pan C, Xiang D, Miao M, Jiao B - PLoS ONE (2011)

Bottom Line: In BRL-3A cells, INHBB was identified as a direct target of miR-34a by luciferase reporter assay.A decrease of INHBB and Met was detected in regenerating liver.MiR-34a expression was upregulated during the late phase of liver regeneration.

View Article: PubMed Central - PubMed

Affiliation: Department of Biochemistry and Molecular Biology, Second Military Medical University, Shanghai, China.

ABSTRACT

Background: MicroRNAs are a class of small regulatory RNAs that modulate a variety of biological processes, including cellular differentiation, apoptosis, metabolism and proliferation. This study aims to explore the effect of miR-34a in hepatocyte proliferation and its potential role in liver regeneration termination.

Methodology/principal finding: MiR-34a was highly induced after partial hepatectomy. Overexpression of miR-34a in BRL-3A cells could significantly inhibit cell proliferation and down-regulate the expression of inhibin βB (INHBB) and Met. In BRL-3A cells, INHBB was identified as a direct target of miR-34a by luciferase reporter assay. More importantly, INHBB siRNA significantly repressed cell proliferation. A decrease of INHBB and Met was detected in regenerating liver.

Conclusion/significance: MiR-34a expression was upregulated during the late phase of liver regeneration. MiR-34a-mediated regulation of INHBB and Met may collectively contribute to the suppression of hepatocyte proliferation.

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Related in: MedlinePlus

INHBB downregulation repressed hepatocyte proliferation.(A) Fluorescence (right) and bright light (left) photomicrographs of FAM-positive cells transfected by FAM-siRNA. Pictures were taken 6 h after transfection. (B) Identification of INHBB knockdown efficiency by siRNA via qRT-PCR. Actin was used as fold control. (C) INHBB silencing led to growth inhibition in BRL-3A cells by MTT cell proliferation analysis. (siRNA: INHBB siRNA; Control: control siRNA) *P<0.05 compared to control.
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pone-0020238-g004: INHBB downregulation repressed hepatocyte proliferation.(A) Fluorescence (right) and bright light (left) photomicrographs of FAM-positive cells transfected by FAM-siRNA. Pictures were taken 6 h after transfection. (B) Identification of INHBB knockdown efficiency by siRNA via qRT-PCR. Actin was used as fold control. (C) INHBB silencing led to growth inhibition in BRL-3A cells by MTT cell proliferation analysis. (siRNA: INHBB siRNA; Control: control siRNA) *P<0.05 compared to control.

Mentions: In the present study, Met and INHBB were confirmed as the target gene of miR-34a. Met is known to play a critical role in the progressing and termination stage of liver regeneration [13]. However, the function of INHBB in hepatocyte proliferation still needs to be clarified. In order to prove that INHBB functions as a promoter in proliferation like Met, we then studied the effect of INHBB siRNA on hepatocyte proliferation. Cells were transfected with INHBB siRNA, Control siRNA or FAM-siRNA Control. The FAM-siRNA Control enables visualization of transfection efficiency 4–6 hours post transfection via bright (Figure 4A, left) and fluorescence (Figure 4A, right) microscope. The knockdown efficiency of INHBB was verified by real-time PCR (Figure 4B). In MTT cell proliferation assay, cells treated with INHBB siRNA or Control siRNA sequences were re-seeded in 96-well plates 48 h post transfection (described in “Materials and methods”) and were allowed to grow for indicated times. As revealed in Figure 4C, INHBB siRNA strongly repressed BRL-3A cell proliferation (P<0.05).


Mir-34a is upregulated during liver regeneration in rats and is associated with the suppression of hepatocyte proliferation.

Chen H, Sun Y, Dong R, Yang S, Pan C, Xiang D, Miao M, Jiao B - PLoS ONE (2011)

INHBB downregulation repressed hepatocyte proliferation.(A) Fluorescence (right) and bright light (left) photomicrographs of FAM-positive cells transfected by FAM-siRNA. Pictures were taken 6 h after transfection. (B) Identification of INHBB knockdown efficiency by siRNA via qRT-PCR. Actin was used as fold control. (C) INHBB silencing led to growth inhibition in BRL-3A cells by MTT cell proliferation analysis. (siRNA: INHBB siRNA; Control: control siRNA) *P<0.05 compared to control.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3105003&req=5

pone-0020238-g004: INHBB downregulation repressed hepatocyte proliferation.(A) Fluorescence (right) and bright light (left) photomicrographs of FAM-positive cells transfected by FAM-siRNA. Pictures were taken 6 h after transfection. (B) Identification of INHBB knockdown efficiency by siRNA via qRT-PCR. Actin was used as fold control. (C) INHBB silencing led to growth inhibition in BRL-3A cells by MTT cell proliferation analysis. (siRNA: INHBB siRNA; Control: control siRNA) *P<0.05 compared to control.
Mentions: In the present study, Met and INHBB were confirmed as the target gene of miR-34a. Met is known to play a critical role in the progressing and termination stage of liver regeneration [13]. However, the function of INHBB in hepatocyte proliferation still needs to be clarified. In order to prove that INHBB functions as a promoter in proliferation like Met, we then studied the effect of INHBB siRNA on hepatocyte proliferation. Cells were transfected with INHBB siRNA, Control siRNA or FAM-siRNA Control. The FAM-siRNA Control enables visualization of transfection efficiency 4–6 hours post transfection via bright (Figure 4A, left) and fluorescence (Figure 4A, right) microscope. The knockdown efficiency of INHBB was verified by real-time PCR (Figure 4B). In MTT cell proliferation assay, cells treated with INHBB siRNA or Control siRNA sequences were re-seeded in 96-well plates 48 h post transfection (described in “Materials and methods”) and were allowed to grow for indicated times. As revealed in Figure 4C, INHBB siRNA strongly repressed BRL-3A cell proliferation (P<0.05).

Bottom Line: In BRL-3A cells, INHBB was identified as a direct target of miR-34a by luciferase reporter assay.A decrease of INHBB and Met was detected in regenerating liver.MiR-34a expression was upregulated during the late phase of liver regeneration.

View Article: PubMed Central - PubMed

Affiliation: Department of Biochemistry and Molecular Biology, Second Military Medical University, Shanghai, China.

ABSTRACT

Background: MicroRNAs are a class of small regulatory RNAs that modulate a variety of biological processes, including cellular differentiation, apoptosis, metabolism and proliferation. This study aims to explore the effect of miR-34a in hepatocyte proliferation and its potential role in liver regeneration termination.

Methodology/principal finding: MiR-34a was highly induced after partial hepatectomy. Overexpression of miR-34a in BRL-3A cells could significantly inhibit cell proliferation and down-regulate the expression of inhibin βB (INHBB) and Met. In BRL-3A cells, INHBB was identified as a direct target of miR-34a by luciferase reporter assay. More importantly, INHBB siRNA significantly repressed cell proliferation. A decrease of INHBB and Met was detected in regenerating liver.

Conclusion/significance: MiR-34a expression was upregulated during the late phase of liver regeneration. MiR-34a-mediated regulation of INHBB and Met may collectively contribute to the suppression of hepatocyte proliferation.

Show MeSH
Related in: MedlinePlus