MiRNA degradation in frozen tissue
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE19104 | GEO | 2009/11/24
SECONDARY ACCESSION(S): PRJNA120451
REPOSITORIES: GEO
Similar Datasets
Project description:To determine the effect of RNA degradation on miRNA expression profiling. To mimic total RNA degradation in snap-frozen livers and duodenums from mice (wild type female, C57/Bl6) tissues were stored in a -80°C freezer and then transferred to dry ice. Each frozen tissue was sliced into five identical pieces which then were transferred into eppendorf tubes. At time point zero (T0), all samples were placed on ice and total RNA was extracted immediately from (T0) and at later time points [30 min (T30), 60 min (T60), 120 min (T120) and 240 min (T240)]. RNA integrities were assessed using the Agilent Bioanalyzer 2100 which calculates RIN values of assayed RNAs. We found that at T0, the RNA integrity for both liver and duodenum was above 7, indicating good quality total RNA. However, 30 min on ice was sufficient to reduce RNA integrity, indicated by the decrease in RINs. These findings indicate that RNA degradation can take place in defrosted tissue at low temperature (i.e. on ice). For comparison, we assessed the extent to which RNA integrity is preserved in freshly harvested tissues when tissue processing is delayed. Liver and duodenum samples were collected from mice and either processed immediately or maintained on ice, as described above. Bioanalyzer electropherograms of the liver samples did not indicate any significant total RNA degradation even when samples remained on ice for up to 4 hrs. By contrast, duodenal samples (which are rich in RNases) do show high susceptibility to degradation similar to the snap-frozen defrosted material. These findings suggest that tissues such as duodenum or pancreas should either be processed immediately or snap-frozen and processed individually. To assess to which extent total RNA degradation affects miRNA expression profiles, we hybridized to the miCHIP microarray total RNAs extracted from freshly harvested livers and duodenums liver and from snap frozen livers and duodenums. Hierarchical clustering (HCL), by Pearson correlation, was used to cluster samples based on their miRNA expression profiles. Our analysis shows that miRNAs extracted from freshly harvested liver is less degraded (matrix plot analyses). Consistent with high level of RNases present in duodenum, miRNAs from freshly harvested duodenum are extensively degraded. Based on these data, we conclude that samples with low RIN values (less than 7) do not merit analysis on miRNA arrays.
2010-05-19 | E-GEOD-19104 | biostudies-arrayexpress
Project description:MiRNA degradation by NS3 of JEV [miRNA]
| PRJNA622917 | ENA
Project description:MiRNA degradation by NS3 of JEV
| PRJNA622915 | ENA
Project description:3’ end methylation catalyzed by HUA ENHANCER1 (HEN1) is a crucial step of small RNA stabilization in plants, yet how unmethylated small RNAs undergo degradation remains largely unknown. Using a reverse genetic approach, we here show that ATRIMMER2 (ATRM2), a DEDDy-type 3’ to 5’ exoribonuclease, acts in the degradation of unmethylated miRNAs and miRNA*s in Arabidopsis. A loss-of-function mutations in ATRM2 partially suppress the morphological defects caused by HEN1 malfunction, with restored levels of a subset of miRNAs and receded expression of corresponding miRNA targets. Loss of ATRM2 has negligible effect on miRNA trimming, and further increase the fertility of hen1 heso1 urt1, a mutant with an almost complete abolishment of miRNA uridylation, indicating that ATRM2 may neither be involved in 3’ to 5’ trimming nor be the enzyme that specifically degrades uridylated miRNAs. Notably, the fold changes of miRNAs and their corresponding miRNA*s were significantly co-regulated in hen1 atrm2 as compared with those in hen1. Unexpectedly, we also observed a markedly increase of 3’ to 5’ trimming of several miRNA*s but not miRNAs in ATRM2 compromised backgrounds. These data suggest an action of ATRM2 on miRNA/miRNA* duplexes, and the existence of an unknown exoribonuclease for specific trimming of miRNA*. This asymmetric effect on miRNA/miRNA* is likely related to ARGONAUTE (AGO) proteins, which can distinguish miRNAs from miRNA*s. Finally, we show that ATRM2 colocalizes and physically interacts with ARGONAUTE1 (AGO1). Taken together, our results suggest that ATRM2 may be involved in the surveillance of unmethylated miRNA/miRNA* duplexes during the initiation step of RISC assembly.
2018-12-01 | GSE107070 | GEO
Project description:MicroRNAs (miRNAs) are small non-coding RNAs that repress gene expression at the post transcriptional level via an antisense RNA-RNA interaction. Generally, miRNAs derived from snap frozen or fresh samples are used for array based profiling. Since tissues in most pathology departments are available only in formalin fixed and paraffin embedded state, we sought to evaluate the miRNA derived from formalin fixed and paraffin embedded (FFPE) samples for microarray analysis. In this study, miRNAs extracted from matched snap frozen and FFPE samples were profiled using the Agilent miRNA array platform. Each miRNA sample was hybridized to arrays containing probes interrogating 470 human miRNAs. A total of seven cases were compared in either duplicate or triplicate. Intrachip and interchip analyses demonstrated that the processes of miRNA extraction, labeling and hybridization from both frozen and FFPE samples are highly reproducible and add little variation to the results, as technical replicates showed high correlations (Kendall tau=0.722-0.853, Spearman rank correlation coefficient=0.891-0.954). Our results showed consistent high correlation between matched frozen and FFPE samples (Kendall tau=0.669-0.815, Spearman rank correlation coefficient=0.847-0.948), supporting the use of FFPE-derived miRNAs for profiling. Keywords: formalin-fixed and paraffin-embedded (FFPE) miRNA profiling
2008-11-01 | GSE12458 | GEO
Project description:MiRNA degradation by NS3 of JEV [mRNA]
| PRJNA622918 | ENA
Project description:In order to further determine the je virus (JEV) infection in C57BL / 6 mice after its miRNA levels change, we use the Agilent micrornas chip as a platform, to detect the uninfected group (control group) and the experimental mouse total RNA, it is found that the miRNA levels decrease infection group, and picked out the ten changes obviously micrornas verification, the result is the same.
2020-04-04 | GSE148030 | GEO
Project description:How many RNA transcripts can induce degradation of microRNAs (miRNA) via the mechanism known as target-directed miRNA degradation (TDMD) is currently unknown. We developed TDMDfinder, a bioinformatics pipeline and webtool, which is based on combined sequence alignment and feature selection approaches to identify ‘high confidence’ TDMD interactions either in Human or Mouse transcriptomes. Predictions suggest that TDMD is widespread, and every miRNA is possibly under the control of endogenous targets. Experimental validations support the validity of TDMDfinder predictions with 49% accuracy, revealing novel endogenous TDMDs for miR-17, miR-19, miR-30, miR-221, miR-26 and miR-23 families. TDMD can selectively target specific miRNA family/cluster members. Features like complementarity to the miRNA 3’ region, bulge size and hybridization energy can explain the different sensitivity. A set of computational analyses performed using the multiomic TCGA platform support the involvement of TDMD in human cancer. Many TDMD transcripts showed significant anti-correlations with both miRNA levels and miRNA activity in multiple tumors and 36 highly significant Pan-cancer interactions were highlighted. A proof-of-principle TDMD-pair was experimentally dissected in breast cancer, showing that fully-functioning TDMD could impact on cancer phenotypes, such as mammosphere growth and resistance to drug treatment. Our tool unveils TDMD as a widespread mechanism and pinpoints it as new potential oncogenic mechanism.
2022-01-31 | GSE168566 | GEO
Project description:Little is known about how miRNAs are turned over, in particular in mammalian cells. A target-dependent miRNA degradation mechanism (TDMD) has been recently suggested, in which RNA targets may induce miRNA degradation. However, endogenous RNA targets involved in TDMD have not been yet identified. During serum stimulation of quiescent fibroblasts, a deep change of miRNA expression occurs in few hours. We scanned the mammalian genome for targets eligible for TDMD and found a dominant miRNA:target pair, consisting of a target (SerpinE1) extraordinarily induced upon serum stimulation and two matched miRNAs (miR-30b/c) quickly downregulated. We verified directly the occurrence of TDMD by interfering specifically with the miR-:target interaction, keeping target and miRNA expression at endogenous levels, using CRISPR/cas9 mediated deletion of the miR-30 responsive element (MRE) of SerpinE1. In MRE-KO cells, we observed the stabilization of the predicted miRNAs, with no evidence of alterations in precursors or unrelated miRNAs, suggesting that TDMD is occurring and has been disrupted by a single MRE deletion. At molecular level miRNA degradation occurs within physiological ranges of target expression (upon 1000 copies per cells) and is accompanied by modification on 3’ends (tailing, mostly through adenylation). TDMD suppression was sufficient to shift the activity of miR-30b/c towards other shared targets, modulate significantly gene expression and, thus, influence cellular functions, including cell proliferation, apoptosis, and adhesion. In conclusion, these data strongly support the existence of a novel and sophisticated regulatory layer of miRNA and gene expression mediated by specific endogenous targets in mammalian cells.
2018-06-26 | GSE104598 | GEO