scholarly journals Small Interfering RNA–Mediated Suppression of Fas Modulate Apoptosis and Proliferation in Rat Intervertebral Disc Cells

2017 ◽  
Vol 11 (5) ◽  
pp. 686-693
Author(s):  
Jong-Beom Park ◽  
Chanjoo Park

<sec><title>Study Design</title><p><italic>In vitro</italic> cell culture model.</p></sec><sec><title>Purpose</title><p>To investigate the effect of small interfering RNA (siRNA) on Fas expression, apoptosis, and proliferation in serum-deprived rat disc cells.</p></sec><sec><title>Overview of Literature</title><p>Synthetic siRNA can trigger an RNA interference (RNAi) response in mammalian cells and precipitate the inhibition of specific gene expression. However, the potential utility of siRNA technology in downregulation of specific genes associated with disc cell apoptosis remains unclear.</p></sec><sec><title>Methods</title><p>Rat disc cells were isolated and cultured in the presence of either 10% fetal bovine serum (FBS) (normal control) or 0% FBS (serum deprivation to induce apoptosis) for 48 hours. Fas expression, apoptosis, and proliferation were determined. Additionally, siRNA oligonucleotides against Fas (Fas siRNA) were transfected into rat disc cells to suppress Fas expression. Changes in Fas expression were assessed by reverse transcription-polymerase chain reaction and semiquantitatively analyzed using densitometry. The effect of Fas siRNA on apoptosis and proliferation of rat disc cells were also determined. Negative siRNA and transfection agent alone (Mock) were used as controls.</p></sec><sec><title>Results</title><p>Serum deprivation increased apoptosis by 40.3% (<italic>p</italic>&lt;0.001), decreased proliferation by 45.3% (<italic>p</italic>&lt;0.001), and upregulated Fas expression. Additionally, Fas siRNA suppressed Fas expression in serum-deprived cultures, with 68.5% reduction at the mRNA level compared to the control cultures (<italic>p</italic>&lt;0.001). Finally, Fas siRNA–mediated suppression of Fas expression significantly inhibited apoptosis by 9.3% and increased proliferation by 21% in serum-deprived cultures (<italic>p</italic>&lt;0.05 for both).</p></sec><sec><title>Conclusions</title><p>The observed dual positive effect of Fas siRNA might be a powerful therapeutic approach for disc degeneration by suppression of harmful gene expression.</p></sec>

2007 ◽  
Vol 293 (6) ◽  
pp. H3593-H3601 ◽  
Author(s):  
Hanna Hlawaty ◽  
Aurélie San Juan ◽  
Marie-Paule Jacob ◽  
Roger Vranckx ◽  
Didier Letourneur ◽  
...  

Matrix metalloproteinase-2 (MMP-2) is constitutively expressed in vascular smooth muscle cells (VSMCs). Using small interfering RNA (siRNA), we evaluated the effect of MMP-2 inhibition in VSMCs in vitro and ex vivo. Rabbit VSMCs were transfected in vitro with 50 nmol/l MMP-2 siRNA or scramble siRNA. Flow cytometry and confocal microscopy showed cellular uptake of siRNA in ∼80% of VSMCs. MMP-2 mRNA levels evaluated by real-time RT-PCR, pro-MMP-2 activity from conditioned culture media evaluated by gelatin zymography, and VSMC migration were reduced by 44 ± 19%, 43 ± 14%, and 36 ± 14%, respectively, in MMP-2 siRNA-transfected compared with scramble siRNA-transfected VSMCs ( P < 0.005 for all). Ex vivo MMP-2 siRNA transfection was performed 2 wk after balloon injury of hypercholesterolemic rabbit carotid arteries. Fluorescence microscopy showed circumferential siRNA uptake in neointimal cells. Gelatin zymography of carotid artery culture medium demonstrated a significant decrease of pro-MMP-2 activity in MMP-2 siRNA-transfected compared with scramble siRNA-transfected arteries ( P < 0.01). Overall, our results demonstrate that in vitro MMP-2 siRNA transfection in VSMCs markedly inhibits MMP-2 gene expression and VSMC migration and that ex vivo delivery of MMP-2 siRNA in balloon-injured arteries reduces pro-MMP-2 activity in neointimal cells, suggesting that siRNA could be used to modify arterial biology in vivo.


Open Medicine ◽  
2011 ◽  
Vol 6 (2) ◽  
pp. 137-147 ◽  
Author(s):  
Anubrata Ghosal ◽  
Ahmad Kabir ◽  
Abul Mandal

AbstractRNA interference is a technique that has become popular in the past few years. This is a biological method to detect the activity of a specific gene within a cell. RNAi is the introduction of homologous double stranded RNA to specifically target a gene’s product resulting in null or hypomorphic phenotypes. This technique involves the degradation of specific mRNA by using small interfering RNA. Both microRNA (miRNA) and small interfering RNA (siRNA) are directly related to RNA interference. RNAi mechanism is being explored as a new technique for suppressing gene expression. It is an important issue in the treatment of various diseases. This review considers different aspects of RNAi technique including its history of discovery, molecular mechanism, gene expression study, advantages of this technique against previously used techniques, barrier associated with this technique, and its therapeutic application.


Author(s):  
Yoko Yamada ◽  
Gillian Forbes ◽  
Qingyou Du ◽  
Takefumi Kawata ◽  
Pauline Schaap

The 1-phosphatidylinositol-3-phosphate 5-kinase PIKfyve generates PtdIns3,5P2 on late phagolysosomes, which by recruiting the scission protein Atg18, results in their fragmentation in the normal course of endosome processing. Loss of PIKfyve function causes cellular hypervacuolization in eukaryotes and organ failure in humans. We identified pikfyve as the defective gene in a Dictyostelium mutant that failed to form spores. The amoebas normally differentiated into prespore cells and initiated spore coat protein synthesis in Golgi-derived prespore vesicles. However, instead of exocytosing, the prespore vesicles fused into the single vacuole that typifies the stalk and basal disc cells that support the spores. This process was accompanied by stalk wall biosynthesis, loss of spore gene expression and overexpression of ecmB, a basal disc and stalk-specific gene, but not of the stalk-specific genes DDB_G0278745 and DDB_G0277757. Transdifferentiation of prespore into stalk-like cells was previously observed in mutants that lack early autophagy genes, like atg5, atg7, and atg9. However, while autophagy mutants specifically lacked cAMP induction of prespore gene expression, pikfyve− showed normal early autophagy and prespore induction, but increased in vitro induction of ecmB. Combined, the data suggest that the Dictyostelium endosomal system influences cell fate by acting on cell type specific gene expression.


2017 ◽  
Author(s):  
Jian Yan ◽  
Shi-An A Chen ◽  
Andrea Local ◽  
Tristin Liu ◽  
Yunjiang Qiu ◽  
...  

SUMMARYRegulation of gene expression in mammalian cells depends on long-range chromatin interactions between enhancers and promoters. Currently, the exact mechanisms that connect distal enhancers to their specific target promoters remain to be fully elucidated. Here we show that the histone H3 Lysine 4 monomethylation (H3K4me1) writer proteins MLL3 and MLL4 (MLL3/4) play an active role in this process. We demonstrate that in differentiating mouse embryonic stem cells, MLL3/4-dependent deposition of H3K4me1 at enhancers correlates with increased levels of chromatin interactions, whereas loss of MLL3/4 leads to greatly reduced frequencies of chromatin interactions and failure of lineage-specific gene expression programs. We further show that H3K4me1 facilitates recruitment of the Cohesin complex to chromatin in vitro and in vivo, providing a potential mechanism for MLL3/4 to promote chromatin looping. Taken together, our results support an active role for MLL3/4 in modulating chromatin organization at enhancers in mammalian cells.


2004 ◽  
Vol 16 (2) ◽  
pp. 87 ◽  
Author(s):  
Le Ann Blomberg ◽  
Kurt A. Zuelke

Functional genomics provides a powerful means for delving into the molecular mechanisms involved in pre-implantation development of porcine embryos. High rates of embryonic mortality (30%), following either natural mating or artificial insemination, emphasise the need to improve the efficiency of reproduction in the pig. The poor success rate of live offspring from in vitro-manipulated pig embryos also hampers efforts to generate transgenic animals for biotechnology applications. Previous analysis of differential gene expression has demonstrated stage-specific gene expression for in vivo-derived embryos and altered gene expression for in vitro-derived embryos. However, the methods used to date examine relatively few genes simultaneously and, thus, provide an incomplete glimpse of the physiological role of these genes during embryogenesis. The present review will focus on two aspects of applying functional genomics research strategies for analysing the expression of genes during elongation of pig embryos between gestational day (D) 11 and D12. First, we compare and contrast current methodologies that are being used for gene discovery and expression analysis during pig embryo development. Second, we establish a paradigm for applying serial analysis of gene expression as a functional genomics tool to obtain preliminary information essential for discovering the physiological mechanisms by which distinct embryonic phenotypes are derived.


2003 ◽  
Vol 78 (2) ◽  
pp. 109-117 ◽  
Author(s):  
He Gruber ◽  
Ja Ingram ◽  
K Leslie ◽  
Hj Norton ◽  
En Hanley Jr

EMBO Reports ◽  
2003 ◽  
Vol 4 (6) ◽  
pp. 609-615 ◽  
Author(s):  
Marc van de Wetering ◽  
Irma Oving ◽  
Vanesa Muncan ◽  
Menno Tjon Pon Fong ◽  
Helen Brantjes ◽  
...  

2006 ◽  
Vol 174 (5) ◽  
pp. 677-687 ◽  
Author(s):  
Hak Kyun Kim ◽  
Yong Sun Lee ◽  
Umasundari Sivaprasad ◽  
Ankit Malhotra ◽  
Anindya Dutta

Three muscle-specific microRNAs, miR-206, -1, and -133, are induced during differentiation of C2C12 myoblasts in vitro. Transfection of miR-206 promotes differentiation despite the presence of serum, whereas inhibition of the microRNA by antisense oligonucleotide inhibits cell cycle withdrawal and differentiation, which are normally induced by serum deprivation. Among the many mRNAs that are down-regulated by miR-206, the p180 subunit of DNA polymerase α and three other genes are shown to be direct targets. Down-regulation of the polymerase inhibits DNA synthesis, an important component of the differentiation program. The direct targets are decreased by mRNA cleavage that is dependent on predicted microRNA target sites. Unlike small interfering RNA–directed cleavage, however, the 5′ ends of the cleavage fragments are distributed and not confined to the target sites, suggesting involvement of exonucleases in the degradation process. In addition, inhibitors of myogenic transcription factors, Id1-3 and MyoR, are decreased upon miR-206 introduction, suggesting the presence of additional mechanisms by which microRNAs enforce the differentiation program.


Sign in / Sign up

Export Citation Format

Share Document