Project description:Epilepsy is a common neurological disease, manifested in unprovoked recurrent seizures. Epileptogenesis may develop due to genetic or pharmacological origins or following injury, but it remains unclear how the unaffected brain escapes this susceptibility to seizures. Here, we report that dynamic changes in forebrain microRNA (miR)-211 in the mouse brain shift the threshold for spontaneous and pharmacologically-induced seizures alongside changes in the cholinergic pathway genes, implicating this miR in the avoidance of seizures. We identified miR-211 as a putative attenuator of cholinergic-mediated seizures by intersecting forebrain miR profiles that were Ago-precipitated, synaptic vesicle target-enriched or differentially expressed under pilocarpine-induced seizures, and validated TGFBR2 and the nicotinic anti-inflammatory acetylcholine receptor nAChRa7 as murine and human miR-211 targets, respectively. To explore the link between miR-211 and epilepsy, we engineered dTg-211 mice with doxycycline-suppressible forebrain overexpression of miR-211. These mice reacted to doxycycline exposure by spontaneous electrocorticography-documented non-convulsive seizures, accompanied by forebrain accumulation of the convulsive seizures-mediating miR-134. RNA-sequencing demonstrated in doxycycline-treated dTg-211 cortices over-representation of synaptic activity, Ca2+ transmembrane transport, TGFβR-II signaling and cholinergic synapse pathways. Additionally, a cholinergic dis-regulated mouse model over-expressing a miR-refractory acetylcholinesterase-R splice variant showed a parallel propensity for convulsions, miR-211 decreases and miR-134 elevation. Our findings demonstrate that in mice, dynamic miR-211 decreases induce hyper-synchronization, non-convulsive and convulsive seizures, accompanied by expression changes in cholinergic and TGFBR2 pathways as well as in miR-134. Realizing the importance of miR-211 dynamics opens new venues for translational diagnosis of and interference with epilepsy.
Project description:MicroRNAs (miRNAs) influence cancer development through post-transcriptional negative regulation of both tumor suppressors and oncogenes. We subjected melanoma cell lines, normal melanocytes, and keratinocytes to array based miRNA profiling, and identified several distinct miRNAs with differential expression. Specifically, miR-211 levels were depleted in all eight melanoma cell lines examined, and also in 23 of 30 distinct patient melanoma samples (graded as primary in situ, regional metastatic, distant metastatic and nodal metastatic). Putative target genes of miR-211 were identified, and their anticipated increased expression levels were confirmed in melanoma cell lines, which were reduced in two melanoma cell lines that artificially over-expressed miR-211. Four such target genes (TCF12, RAB22A, KCNMA1 and SLC37A3) were confirmed by a target cleavage assay. Stable over-expression of miR-211 in two melanoma cell lines caused significant growth inhibition and reduced invasiveness. The differential expression of miR-211 in a variety of melanoma cell lines and clinical samples, consistent inverse correlation between miR-211 and its target mRNA levels, and growth retardation and reduced invasiveness of melanoma cell lines by miR-211 are all consistent with the idea that the depletion of miR-211 is a key step in melanoma development and/or progression
Project description:To investigate the role of miR-211 in medulloblastoma, next-generation sequencing analysis of RNA extracted from DAOY, D425, and CHLA01 cells expressing vector only (V/O) or miR-211 were performed.
Project description:MicroRNAs (miRNAs) influence cancer development through post-transcriptional negative regulation of both tumor suppressors and oncogenes. We subjected melanoma cell lines, normal melanocytes, and keratinocytes to array based miRNA profiling, and identified several distinct miRNAs with differential expression. Specifically, miR-211 levels were depleted in all eight melanoma cell lines examined, and also in 23 of 30 distinct patient melanoma samples (graded as primary in situ, regional metastatic, distant metastatic and nodal metastatic). Putative target genes of miR-211 were identified, and their anticipated increased expression levels were confirmed in melanoma cell lines, which were reduced in two melanoma cell lines that artificially over-expressed miR-211. Four such target genes (TCF12, RAB22A, KCNMA1 and SLC37A3) were confirmed by a target cleavage assay. Stable over-expression of miR-211 in two melanoma cell lines caused significant growth inhibition and reduced invasiveness. The differential expression of miR-211 in a variety of melanoma cell lines and clinical samples, consistent inverse correlation between miR-211 and its target mRNA levels, and growth retardation and reduced invasiveness of melanoma cell lines by miR-211 are all consistent with the idea that the depletion of miR-211 is a key step in melanoma development and/or progression The 15 Samples in this submission represent gene-level expression profiling of isolated total RNA from WM1552C, WM1552+miRNA211, A375, A375+miRNA211 and melanocytes hybridized to Affymetrix exon ararys.
Project description:Insults to the cerebral cortex, such as trauma, ischemia or infections, may result in the development of epilepsy, one of the most common neurological disorders. Previous studies have suggested that perturbations in neurovascular integrity and breakdown of the blood-brain barrier (BBB) lead to neuronal hypersynchronization and epileptiform activity, but the underlying mechanisms are unknown. As with BBB opening, treatment with albumin or with TGF-β1 results in the development of hypersynchronized epileptiform activity. Given the latent period before the appearance of epileptiform activity, we hypothesized the underlying mechanism is a transcriptional response which would be similar for BBB breakdown and exposure to albumin or TGF-β1. In search of a common pathway and transcriptional activation pattern we performed a genome wide analysis. Genomic expression analyses demonstrated similar expression patterns for BBB opening, albumin and TGF-β1 exposure. Most importantly, TGF-β pathway blockers suppressed most albumin-induced transcriptional changes.
Project description:Despite increasing amounts of experimental evidence depicting the involvement of non-coding RNAs in cancer, the study of BRAFV600E-regulated genes has thus far focused mainly on protein-coding ones. Here, we identify and study the microRNAs that BRAFV600E regulates through the ERK pathway. By performing small RNA sequencing on A375 melanoma cells and a vemurafenib- resistant clone that was taken as negative control, we discover miR-204 and miR-211 as the miRNAs most induced by vemurafenib. We also demonstrate that, although belonging to the same family, these two miRNAs have distinctive features. miR-204 is under the control of STAT3 and its expression is induced in amelanotic melanoma cells, where it acts as an effector of vemurafenib’s anti-motility activity by targeting AP1S2. Conversely, miR-211, a known transcriptional target of MITF, is induced in melanotic melanoma cells, where it targets EDEM1 and consequently impairs the degradation of TYROSINASE (TYR) through the ER-associated degradation (ERAD) pathway. In doing so, miR-211 serves as an effector of vemurafenib’s pro-pigmentation activity. We also show that such an increase in pigmentation in turn represents an adaptive response that needs to be overcome using appropriate inhibitors in order to increase the ef cacy of vemurafenib. In summary, we unveil the distinct and context-dependent activities exerted by miR-204 family members in melanoma cells. Our work challenges the widely accepted “same miRNA family = same function” rule and provides a rationale for a novel treatment strategy for melanotic melanomas that is based on the combination of ERK pathway inhibitors with pigmentation inhibitors.
Project description:Despite increasing amounts of experimental evidence depicting the involvement of non-coding RNAs in cancer, the study of BRAFV600E-regulated genes has thus far focused mainly on protein-coding ones. Here, we identify and study the microRNAs that BRAFV600E regulates through the ERK pathway. By performing small RNA sequencing on A375 melanoma cells and a vemurafenib- resistant clone that was taken as negative control, we discover miR-204 and miR-211 as the miRNAs most induced by vemurafenib. We also demonstrate that, although belonging to the same family, these two miRNAs have distinctive features. miR-204 is under the control of STAT3 and its expression is induced in amelanotic melanoma cells, where it acts as an effector of vemurafenib’s anti-motility activity by targeting AP1S2. Conversely, miR-211, a known transcriptional target of MITF, is induced in melanotic melanoma cells, where it targets EDEM1 and consequently impairs the degradation of TYROSINASE (TYR) through the ER-associated degradation (ERAD) pathway. In doing so, miR-211 serves as an effector of vemurafenib’s pro-pigmentation activity. We also show that such an increase in pigmentation in turn represents an adaptive response that needs to be overcome using appropriate inhibitors in order to increase the ef cacy of vemurafenib. In summary, we unveil the distinct and context-dependent activities exerted by miR-204 family members in melanoma cells. Our work challenges the widely accepted “same miRNA family = same function” rule and provides a rationale for a novel treatment strategy for melanotic melanomas that is based on the combination of ERK pathway inhibitors with pigmentation inhibitors.
Project description:mRNA profiles generated from primary fibroblast upon treatment with miR-211, miR-302 or melanoma melanosomes. Abstract: Melanoma originates in the epidermis and enters the metastatic and lethal phase upon invasion into the dermis. However, the interactions between melanoma cells and the dermis prior to this invasion have been poorly studied. Here we uncover that melanoma cells directly affect the formation of the dermal tumor niche by microRNA (miRNA) trafficking prior to invading the dermis. Melanocytes, the cells of melanoma origin, are specialized in trafficking of pigment vesicles, termed melanosomes and, interestingly, melanoma cells retain this trafficking ability. In melanoma in-situ specimens, we found melanosome markers in distal fibroblasts prior to the invasion of melanoma cells into the dermis. Melanoma-derived melanosomes carry miRNAs into primary fibroblasts that trigger changes in the fibroblasts, including increased proliferation, migration, and expression of pro-inflammatory genes, all known features of cancer-associated fibroblasts (CAFs). Specifically, we found that melanosomal miRNA-211 directly targets IGF2R and leads to MAPK signaling activation in fibroblasts, which reciprocally encourages melanoma growth. Treatment of melanoma cells with a melanosome release-inhibitor prevented CAF formation. Since the first interaction of melanoma cells with blood vessels occurs in the dermis, our data suggest a promising opportunity to block melanoma cell invasion by preventing the formation of the dermal tumor niche. In the paper we showed the 10% of most differentially expressed mRNA upon miR-211, miR-320c and melanosomes treatment and overlap of 2000 downregulated mRNA upon miR-211 and melanosomes treatment with predicted target gene miR-211 and CAFs related genes Expresssion profiling was performed for primary fibroblasts transfected with miRNA-211 mimic and miRNA-320c mimic.
Project description:Insults to the cerebral cortex, such as trauma, ischemia or infections, may result in the development of epilepsy, one of the most common neurological disorders. Previous studies have suggested that perturbations in neurovascular integrity and breakdown of the blood-brain barrier (BBB) lead to neuronal hypersynchronization and epileptiform activity, but the underlying mechanisms are unknown. As with BBB opening, treatment with albumin or with TGF-?1 results in the development of hypersynchronized epileptiform activity. Given the latent period before the appearance of epileptiform activity, we hypothesized the underlying mechanism is a transcriptional response which would be similar for BBB breakdown and exposure to albumin or TGF-?1. In search of a common pathway and transcriptional activation pattern we performed a genome wide analysis. Genomic expression analyses demonstrated similar expression patterns for BBB opening, albumin and TGF-?1 exposure. Most importantly, TGF-? pathway blockers suppressed most albumin-induced transcriptional changes. RNA was extracted from cortical regions of rats treated with sodium deoxycholate (DOC, to induce BBB opening), albumin or TGF-?1 for various durations (7/8, 24, 48hr). Control RNA was extracted from a sham-operated animal and one array was run for each treatment and time point A second set of animals (labeled as Set 2) was treated with either albumin (n=3) or albumin in the presence of TGF-? receptor blockers (n=4; TGF-?R1 kinase activity inhibitor SB431542 and TGF-?R2 antibody) and sacrificed 24 hr following treatment. Sham-operated animals served as controls (n=2).
Project description:Purpose: Next-generation sequencing (NGS) has revolutionized systems-based analysis of cellular pathways. The goals of this study are to compare NGS transcriptome profiling (RNA-seq) from whole eye, after removal of the lens and cornea from 1-2 month old miR-211-/- mice and compare it with wt mice Methods: Whole eye (after removal of the lens and cornea) mRNA profiles of 1-2 month old wild-type (WT) and neural miR-211-/-mice were generated by deep sequencing, in multiple biological replicates, five for WT and six for miR-211-/- animals, using Illumina GAIIx. The sequence reads that passed quality filters were analyzed at the transcript isoform level with two methods: Burrows–Wheeler Aligner (BWA) followed by ANOVA (ANOVA) and TopHat followed by Cufflinks. qRT–PCR validation was performed using TaqMan and SYBR Green assays RNA-Seq libraries were prepared from whole eye, after removal of the lens and cornea from miR-211-/- mice. Results: Each library was sequenced using 100 bp paired-end sequencing on the Illumina HiSeq 1000 system. Gene abundances from RNA-Seq data were quantified using RSEM45. Using an optimized data analysis workflow, we mapped about 30 million sequence reads per sample to the mouse genome. This approach yielded read count values for a total of 38253 mouse genes annotated in GenCode. We only considered genes that had at least 1 count per million in at least five out of 11 samples as expressed, yielding a total of 15590 genes. Next we performed differential gene expression analysis to determine the transcriptional effects of miR-211 deletion. This analysis yielded a total of 63 genes that were differentially expressed with a False Discovery Rate (FDR) <0.1 (Fig. 4). Of these, the expression levels of 61 genes were significantly decreased upon miR-211 deletion, while only 2 genes were upregulated. Conclusions: Our study represents the first detailed analysis of whole eye transcriptomes, with biologic replicates, generated by RNA-seq technology on miR-211-/-.