Project description:The intestinal epithelium is a key physical interface that integrates dietary and microbial signals to regulate nutrient uptake and mucosal homeostasis. Intestinal epithelial cells (IECs) have a high turnover rate driven by the death of terminally differentiated cells with concurrent stem cell proliferation, a process critical for maintaining intestinal homeostasis and protecting against mucosal inflammation. The transcriptional programs that regulate IEC quiescence, proliferation, and differentiation have been well-characterized. However, how gene expression networks critical for IEC functions are regulated at the post-transcriptional level during homeostasis or inflammatory disease remains poorly understood. Herein, we show that a conserved family of microRNAs, miR-181, is significantly downregulated in IECs from patients with inflammatory bowel disease and mice with chemical-induced colitis. Strikingly, we showed that miR-181 expression within IECs, but not the hematopoietic system, is required for protection against the development of severe colonic inflammation in response to epithelial injury in mice. Mechanistically, we showed that miR-181 expression increases the proliferative capacity of IECs, likely through the regulation of Wnt signaling, independently of gut microbiota composition. As epithelial reconstitution is crucial for restoring intestinal homeostasis after injury, the miR-181 family represents a potential novel therapeutic target in IECs for protection against severe intestinal inflammation.
Project description:Analysis of HeLa cells at 24 hours after transfection with wild type miR-1, miR-124, miR-181 versus control transfected HeLa cells. Results were compared to protein down-regulation at 48 hours measured by SILAC-MS. Analysis of HeLa cells at 24 hours after transfection with wild type miR-1, miR-124, miR-181 versus control transfected HeLa cells. Results were compared to protein down-regulation at 48 hours measured by SILAC-MS.
Project description:Study designed to determine the immediate effects of supplementing OSK reprogramming with miR-294 or miR-181. MEFs were infected on day 0, and transfected with miR-294, miR-181 or control mimic on day 1. On day 3 RNA was extracted. OSK infected MEFs samples were compared to non-infected MEFs and to fully reprogrammed iPSCs.
Project description:Analysis of HeLa cells at 24 hours after transfection with wild type miR-1, miR-124, miR-181 versus control transfected HeLa cells. Results were compared to protein down-regulation at 48 hours measured by SILAC-MS.
Project description:miR-181 is often dysregulated in several types of cancer. This dataset can represent a further insight into gene expression changes and GO Terms associated with miR-181 over-expression. miR-181 was over-expressed in Jurkat cells by transduction with a lentiviral transgenic construct encoding for miR-181 under a PGK promoter. A cognate vector encoding for a control hairpin was used to generate control cell line. mRNA Microarray gene expression profiling of Jurkat cells tranduced with either a miR-181 sponge or control construct. 3 biological replicas have been performed. Note that the control samples are the same as those used in the related experiment E-MTAB-4588
Project description:Parkinson’s disease (PD) is caused by loss of dopaminergic (DA) neurons in the substantia nigra (SN). Although PD pathogenesis is not fully understood, studies implicate perturbations in gene regulation, mitochondrial function, and neuronal activity. MicroRNAs (miRs) are small gene regulatory RNAs that inhibit diverse subsets of target mRNAs, and several studies have noted miR expression alterations in PD brains. For example, miR-181a is abundant in brain and is increased in PD patient brain samples; however, the disease relevance of this remains unclear. Herein, we show that miR-181 target mRNAs are broadly down-regulated in aging and PD brains. To address if the miR‑181 family plays a role in PD pathogenesis, we generated adeno-associated viruses (AAV) to overexpress and inhibit miR-181 isoforms. After co-injection with AAV overexpressing alpha-synuclein (aSyn) into mouse SN (PD model), we found that moderate miR-181a/b overexpression exacerbated aSyn-induced DA neuronal loss, whereas miR‑181 inhibition was neuroprotective, relative to controls (GFP-alone and/or scrambled RNA). Also, prolonged miR-181 overexpression in SN alone elicited measurable neurotoxicity coincident with an increased immune response. RNA-seq analyses revealed that miR-181a/b inhibits genes involved in synaptic transmission, neurite outgrowth, and mitochondrial respiration, along with several genes having known protective roles and genetic links in PD.
Project description:We report that high levels of miR-181, a miRNA enriched in neurons of the brain and spinal cord, predicts a >2 fold risk of death in ALS patients
Project description:Increased expression levels of miR-181 family members have been shown to be associated with favorable outcome in patients with cytogenetically normal acute myeloid leukemia. Here we show that increased expression of miR-181a and miR-181b is also significantly (P < .05; Cox regression) associated with favorable overall survival in cytogenetically abnormal AML (CA-AML) patients. We further show that up-regulation of a gene signature composed of 4 potential miR-181 targets (including HOXA7, HOXA9, HOXA11, and PBX3), associated with down-regulation of miR-181 family members, is an independent predictor of adverse overall survival on multivariable testing in analysis of 183 CA-AML patients. The independent prognostic impact of this 4-homeobox-gene signature was confirmed in a validation set of 271 CA-AML patients. Furthermore, our in vitro and in vivo studies indicated that ectopic expression of miR-181b significantly promoted apoptosis and inhibited viability/proliferation of leukemic cells and delayed leukemogenesis; such effects could be reversed by forced expression of PBX3. Thus, the up-regulation of the 4 homeobox genes resulting from the down-regulation of miR-181 family members probably contribute to the poor prognosis of patients with nonfavorable CA-AML. Restoring expression of miR-181b and/or targeting the HOXA/PBX3 pathways may provide new strategies to improve survival substantially. In addition, this data set has been used to identify a common prognostic gene signature (Li Z. et al. unpublished). 65 human AML samples bearing various cytogenetic and molecular abnormalities are used to identify miR-181 target genes and a common prognostic gene signature.
Project description:Increased expression levels of miR-181 family members have been shown to be associated with favorable outcome in patients with cytogenetically normal acute myeloid leukemia. Here we show that increased expression of miR-181a and miR-181b is also significantly (P < .05; Cox regression) associated with favorable overall survival in cytogenetically abnormal AML (CA-AML) patients. We further show that up-regulation of a gene signature composed of 4 potential miR-181 targets (including HOXA7, HOXA9, HOXA11, and PBX3), associated with down-regulation of miR-181 family members, is an independent predictor of adverse overall survival on multivariable testing in analysis of 183 CA-AML patients. The independent prognostic impact of this 4-homeobox-gene signature was confirmed in a validation set of 271 CA-AML patients. Furthermore, our in vitro and in vivo studies indicated that ectopic expression of miR-181b significantly promoted apoptosis and inhibited viability/proliferation of leukemic cells and delayed leukemogenesis; such effects could be reversed by forced expression of PBX3. Thus, the up-regulation of the 4 homeobox genes resulting from the down-regulation of miR-181 family members probably contribute to the poor prognosis of patients with nonfavorable CA-AML. Restoring expression of miR-181b and/or targeting the HOXA/PBX3 pathways may provide new strategies to improve survival substantially. In addition, this data set has been used to identify a common prognostic gene signature (Li Z. et al. unpublished).