RESUMEN
Objective: MicroRNAs [miRNAs] are small endogenous non-coding regulatory RNAs that control mRNAs post-transcriptionally. Several mouse stem cells miRNAs are cloned differentially regulated in different hematopoietic lineages, suggesting their possible role in hematopoietic lineage differentiation. Recent studies have shown that specific miRNAs such as Mir-451 have key roles in erythropoiesis
Materials and Methods: In this experimental study, murine embryonic stem cells [mESCs] were infected with lentiviruses containing pCDH-Mir-451. Erythroid differentiation was assessed based on the expression level of transcriptional factors [Gata-1, Klf-1, Epor] and hemoglobin chains [alpha, beta, gamma, epsilon and zeta] genes using quantitative reverse transcriptase-polymerase chain reaction [qRT-PCR] and presence of erythroid surface antigens [TER-119 and CD235a] using flow cytometery. Colony-forming unit [CFU] assay was also on days 14thand 21thafter transduction
Results: Mature Mir-451 expression level increased by 3.434-fold relative to the untreated mESCs on day 4 after transduction [P<0.001]. Mir-451 up-regulation correlated with the induction of transcriptional factor [Gata-1, Klf-1, Epor] and hemoglobin chain [alpha, beta, gamma, epsilon and zeta] genes in mESCs [P<0.001] and also showed a strong correlation with presence of CD235a and Ter- 119 markers in these cells [13.084and 13.327-fold increse, respectively] [P<0.05]. Moreover, mESCs treated with pCDH-Mir-451 showed a significant raise in CFU-erythroid [CFU-E] colonies [5.2-fold] compared with untreated control group [P<0.05]
Conclusion: Our results showed that Mir-451 up-regulation strongly induces erythroid differentiation and maturation of mESCs. Overexpression of Mir-451 may have the potential to produce artificial red blood cells [RBCs] without the presence of any stimulatory cytokines
RESUMEN
MicroRNAs [miRNAs] are a class of small non coding regulatory RNAs that have key functions in multiple cell processes. Deregulation of these tiny miRNAs are involved in various human diseases. MiR-155 is one of the multifunctional miRNA that its over-expression has been found to be associated with different kinds of cancer such as leukemia, breast and colon cancers. It is thought that deregulation and over-expression of this microRNA may be associated with PC12 cell proliferation. So, the aim of this study was to investigate the role of miR-155 expression on PC12 cell growth. For this reason, PC12 cells were cultured and transfected by 3 different concentration [25, 50 and 75 nmol] of either LNA anti-miR-155 or scramble antisense in 24-well plate. Then, total RNA was extracted from transfected cells. miRNA cDNAs were synthesized from isolated total RNA. In the second step, miR-155 expression level was analyzed using the quantitative real-time polymerase chain reaction [QRT-PCR]. MTT test was performed to evaluate cell viability. In the next step, apoptosis assay was assessed to investigate anti miR-155 effect on PC12 cells death. Obtained results were analyzed with t-test. MTT test revealed that cell viability of transfected cells with 75 nM of anti-miR- 155 to be reduced by half of the control and scramble groups [0.5 vs. 0.97 and 0.94]. Our data suggest that miR-155 over-expression is associated with PC12 cell growth. So, miR-155 down regulation by anti-miR-155 could open up new ways to restrain brain tumor growth, as anti-miR-155 causes PC12 cells to repress