scholarly journals Integrin  3 in rat blastocysts and epithelial cells is essential for implantation in vitro: studies with Ishikawa cells and small interfering RNA transfection

2011 ◽  
Vol 26 (7) ◽  
pp. 1665-1674 ◽  
Author(s):  
Y. Kaneko ◽  
M. L. Day ◽  
C. R. Murphy
2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Yan Yang ◽  
Lili Ding ◽  
Qi Zhou ◽  
Li Fen ◽  
Yuhua Cao ◽  
...  

Abstract Background Aurora kinase A (AURKA) has been implicated in the regulation of cell cycle progression, mitosis and a key number of oncogenic signaling pathways in various malignancies including neuroblastoma. Small molecule inhibitors of AURKA have shown potential, but still not as good as expected effects in clinical trials. Little is known about this underlying mechanism. Here, we evaluated the inhibitory effects of AURKA inhibitor MLN8237 on neuroblastoma cells to understand the potential mechanisms responsible for tumor therapy. Methods MLN8237 treatment on neuroblastoma cell line IMR32 was done and in vivo inhibitory effects were investigated using tumor xenograft model. Cellular senescence was evaluated by senescence-associated β-gal Staining assay. Flow cytometry was used to tested cell cycle arrest and cell apoptosis. Senescence-associated signal pathways were detected by western blot. CD133 microbeads and microsphere formation were used to separate and enrich CD133+ cells. AURKA small interfering RNA transfection was carried to downregulate AURKA level. Finally, the combination of MLN8237 treatment with AURKA small interfering RNA transfection were adopted to evaluate the inhibitory effect on neuroblastoma cells. Results We demonstrate that MLN8237, an inhibitor of AURKA, induces the neuroblastoma cell line IMR32 into cellular senescence and G2/M cell phase arrest. Inactivation of AURKA results in MYCN destabilization and inhibits cell growth in vitro and in a mouse model. Although MLN8237 inhibits AURKA kinase activity, it has almost no inhibitory effect on the AURKA protein level. By contrast, MLN8237 treatment leads to abnormal high expression of AURKA in vitro and in vivo. Knockdown of AURKA reduces cell survival. The combination of MLN8237 with AURKA small interfering RNA results in more profound inhibitory effects on neuroblastoma cell growth. Moreover, MLN8237 treatment followed by AURKA siRNA forces senescent cells into apoptosis via suppression of the Akt/Stat3 pathway. Conclusions The effect of AURKA-targeted inhibition of tumor growth plays roles in both the inactivation of AURKA activity and the decrease in the AURKA protein expression level.


2007 ◽  
Vol 404 (1) ◽  
pp. 115-120 ◽  
Author(s):  
Xue-Ming Xu ◽  
Bradley A. Carlson ◽  
Robert Irons ◽  
Heiko Mix ◽  
Nianxin Zhong ◽  
...  

Selenophosphate synthetase (SelD) generates the selenium donor for selenocysteine biosynthesis in eubacteria. One homologue of SelD in eukaryotes is SPS1 (selenophosphate synthetase 1) and a second one, SPS2, was identified as a selenoprotein in mammals. Earlier in vitro studies showed SPS2, but not SPS1, synthesized selenophosphate from selenide, whereas SPS1 may utilize a different substrate. The roles of these enzymes in selenoprotein synthesis in vivo remain unknown. To address their function in vivo, we knocked down SPS2 in NIH3T3 cells using small interfering RNA and found that selenoprotein biosynthesis was severely impaired, whereas knockdown of SPS1 had no effect. Transfection of SPS2 into SPS2 knockdown cells restored selenoprotein biosynthesis, but SPS1 did not, indicating that SPS1 cannot complement SPS2 function. These in vivo studies indicate that SPS2 is essential for generating the selenium donor for selenocysteine biosynthesis in mammals, whereas SPS1 probably has a more specialized, non-essential role in selenoprotein metabolism.


2014 ◽  
Vol 99 (11) ◽  
pp. E2162-E2168 ◽  
Author(s):  
K. L. Roemer ◽  
S. L. Young ◽  
R. F. Savaris

Context: In a previous microarray analysis, GRB2-associated binding protein 1 (GAB1), a docking protein closely related to the insulin receptor substrate, was down-regulated in endometrium of women with polycystic ovary syndrome (PCOS). Objective: The objective of the study was to characterize the cyclic expression of endometrial GAB1 in vivo in normal women and those with PCOS as well as investigate the possible mechanisms of endometrial regulation of GAB1 expression and action in vitro. Design: This was an experimental and case-control study. Setting: The study was conducted at a tertiary university hospital. Patients: Normal proven fertile women (controls; n = 31) and women with PCOS (cases; n = 26) participated in the study. Interventions: Interventions included timed endometrial biopsies at different phases of the menstrual cycle. Ishikawa cells were cultured with β-estradiol (E2), medroxyprogesterone acetate, and E2 + medroxyprogesterone acetate. Transfection of small interfering RNA for GAB1 in Ishikawa cells incubated with or without insulin. Main Outcome Measures: GAB1 mRNA expression in Ishikawa cells and in endometrium of cases and controls was measured. Protein expression of phosphorylated MAPK by Western blot was also measured. Immunohistochemical localization and expression of phosphorylated GAB1 in endometrium was also measured, using a digital histological score. Results: In endometrial tissue, GAB1 mRNA was reduced in the proliferative phase of PCOS women, compared with controls (P = .003; ANOVA). When all the phases of the menstrual cycle were grouped, GAB1 protein expression was reduced in endometrium of PCOS women (P < .0001; Student t test). E2 increases GAB1 mRNA expression in Ishikawa cells (P = .001; ANOVA). Phosphorylated MAPK is reduced in cells transfected with small interfering RNA for GAB1 (P = .008; ANOVA) and incubated with insulin. Conclusions: GAB1 mRNA expression is positively modulated by E2. Endometrial GAB1 protein and mRNA expression are reduced in women with PCOS, suggesting that the endometrium of PCOS women have a defect in insulin signaling due to GAB1 down-regulation.


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.


Author(s):  
Korakot Nganvongpanit ◽  
Patama Chaochird ◽  
Puntita Siengdee ◽  
Peraphan Pothacharoen ◽  
Kasisin Klunklin ◽  
...  

2007 ◽  
Vol 12 (4) ◽  
pp. 546-559 ◽  
Author(s):  
Jason Borawski ◽  
Alicia Lindeman ◽  
Frank Buxton ◽  
Mark Labow ◽  
L. Alex Gaither

High-throughput screening of RNAi libraries has become an essential part of functional analysis in academic and industrial settings. The transition of a cell-based RNAi assay into a 384-well format requires several optimization steps to ensure the phenotype being screened is appropriately measured and that the signal-to-background ratio is above a certain quantifiable threshold. Methods currently used to assess small interfering RNA (siRNA) efficacy after transfection, including quantitative PCR or branch DNA analysis, face several technical limitations preventing the accurate measurement of mRNA levels in a 384-well format. To overcome these difficulties, the authors developed an approach using a viral-based transfection system that measures siRNA efficacy in a standardized 384-well assay. This method allows measurement of siRNA activity in a phenotypically neutral manner by quantifying the knockdown of an exogenous luciferase gene delivered by a lentiviral vector. In this assay, the efficacy of a luciferase siRNA is compared to a negative control siRNA across many distinct assay parameters including cell type, cell number, lipid type, lipid volume, time of the assay, and concentration of siRNA. Once the siRNA transfection is optimized as a 384-well luciferase knockdown, the biologically relevant phenotypic analysis can proceed using the best siRNA transfection conditions. This approach provides a key technology for 384-well assay development when direct measurement of mRNA knockdown is not possible. It also allows for direct comparison of siRNA activity across cell lines from almost any mammalian species. Defining optimal conditions for siRNA delivery into mammalian cells will greatly increase the speed and quality of large-scale siRNA screening campaigns. ( Journal of Biomolecular Screening 2007:546-559)


2008 ◽  
Vol 26 (1) ◽  
pp. 93-101 ◽  
Author(s):  
Izabella ZA Pawluczyk ◽  
Eddie KC Tan ◽  
David Lodwick ◽  
Kevin PG Harris

Endocrinology ◽  
2009 ◽  
Vol 150 (5) ◽  
pp. 2463-2471 ◽  
Author(s):  
Kyung-Bon Lee ◽  
Anilkumar Bettegowda ◽  
Gabbine Wee ◽  
James J. Ireland ◽  
George W. Smith

Previous studies established a positive relationship between oocyte competence and follistatin mRNA abundance. Herein, we used the bovine model to test the hypothesis that follistatin plays a functional role in regulation of early embryogenesis. Treatment of early embryos with follistatin during in vitro culture (before embryonic genome activation) resulted in a dose-dependent decrease in time to first cleavage, increased numbers of blastocysts, and increased blastocyst total and trophectoderm cell numbers. To determine the requirement of endogenous follistatin for early embryogenesis, follistatin ablation/replacement studies were performed. Microinjection of follistatin small interfering RNA into zygotes reduced follistatin mRNA and protein and was accompanied by a reduction in number of embryos developing to eight- to 16-cell and blastocyst stages and reduced blastocyst total and trophectoderm cell numbers. Effects of follistatin ablation were rescued by culture of follistatin small interfering RNA-injected embryos in the presence of exogenous follistatin. To investigate whether follistatin regulation of early embryogenesis is potentially mediated via inhibition of endogenous activin activity, the effects of treatment of embryos with exogenous activin, SB-431542 (inhibitor of activin, TGF-β, and nodal type I receptor signaling) and follistatin plus SB-431542 were investigated. Activin treatment mimicked positive effects of follistatin on time to first cleavage and blastocyst development, whereas negative effects of SB-431542 treatment were observed. Stimulatory effects of follistatin on embryogenesis were not blocked by SB-431542 treatment. Results support a functional role for oocyte-derived follistatin in bovine early embryogenesis and suggest that observed effects of follistatin are likely not mediated by classical inhibition of activin activity.


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