Project description:MicroRNAs have emerged as key regulators of B cell fate decisions and immune function. Deregulation of several microRNAs in B cells leads to the development of autoimmune disease and cancer in mice. We demonstrate that the microRNA-212/132 cluster (miR-212/132) is induced in B cells in response to B cell receptor signaling. Enforced expression of miR-132 results in a block in early B cell development at the pre-pro-B cell to pro-B cell transition and induces apoptosis in primary bone marrow B cells. Importantly, loss of miR-212/132 results in increased B cell output under non-homeostatic conditions. We find that miR-212/132 regulates B lymphopoiesis by targeting the transcription factor SOX4. Co-expression of SOX4 with miR-132 rescues the defect in B cell development from over-expression of miR-132 alone. In addition, we show that the expression of miR-132 in cells that are prone to spontaneous B cell cancers can have a protective effect on cancer development. We have thus uncovered a novel regulator of B cell lineage specification that may potential applications in B cell cancer therapy RNA-seq of wild-type and microRNA-212/132 knock-out B-cells after IgM stimulation
Project description:MicroRNAs have emerged as key regulators of B cell fate decisions and immune function. Deregulation of several microRNAs in B cells leads to the development of autoimmune disease and cancer in mice. We demonstrate that the microRNA-212/132 cluster (miR-212/132) is induced in B cells in response to B cell receptor signaling. Enforced expression of miR-132 results in a block in early B cell development at the prepro-B cell to pro-B cell transition and induces apoptosis in primary bone marrow B cells. Importantly, loss of miR-212/132 results in accelerated B cell recovery after antibody-mediated B cell depletion. We find that Sox4 is a target of miR-132 in B cells. Co-expression of SOX4 with miR-132 rescues the defect in B cell development from overexpression of miR-132 alone, thus suggesting that miR-132 may regulate B lymphopoiesis through Sox4. In addition, we show that the expression of miR-132 can inhibit cancer development in cells that are prone to B cell cancers, such as B cells expressing the c-Myc oncogene. We have thus uncovered miR-132 as a novel contributor to B cell development.
Project description:Background:Esophageal squamous cell carcinoma (ESCC) is the predominant subtype of esophageal cancer in East Asia, with approximately half of ESCC cases occurring in China. ESCC poses a serious threat to the quality of life of patients. MicroRNAs (miRNAs) are extremely important in the occurrence and development of ESCC. Current studies have shown that miR-212-3p is expressed at low levels in esophageal adenocarcinoma tumor tissues; however, its function and mechanism in ESCC have not been studied. Methods:The expression levels of miR-212-3p and SOX4 were detected by quantitative polymerase chain reaction (qPCR) in ESCC tissues and adjacent tissues, and ESCC cell lines from 60 patients. The interaction of miR-212-3p and SOX4 was determined using a dual-luciferase reporter gene system. EC9706 Cells were transfected with miR-212-3p mimic, NC mimic, si-NC and si-SOX4 and miR-212-3p mimic + overexpressing-SOX4, and the effects on miR-212-3p and SOX4 expression were observed, respectively. An MTT assay was carried out to detect the proliferation ability of ESCC. The invasion ability and apoptosis level of the cells were determined by Transwell assay and flow cytometry, respectively. qPCR was used to detect expression of miR-212-3p and SOX4. Western blot was performed to observe the expression of SOX4, Wnt1, ?-catenin, c-Myc, and Cyclin D1. Results:miR-212-3P was observed to be down-regulated in ESCC tissues and cells, while SOX4 expression was up-regulated; the two were negatively correlated. The dual-luciferase reporter gene further confirmed that miR-212-3p targeted SOX4. miR-212-3p overexpression and interference with SOX4 significantly inhibited the proliferation and invasion of ESCC EC970 cells, and promoted apoptosis. Furthermore, the results of Western blot confirmed that miR-212-3p overexpression and interference with SOX4 down-regulated the expression of Wnt1, ?-catenin, c-Myc, and Cyclin D1. Meanwhile, SOX4 overexpression reversed the effect of up-regulation of miR-212-3p on EC970 function. Conclusions:miR-212-3p mediates the apoptosis and invasion of ESCC cells through inhibiting the Wnt/?-catenin signal pathway by targeting SOX4.
Project description:Aryl hydrocarbon receptor (AHR) plays critical roles in various autoimmune diseases such as multiple sclerosis by controlling interleukin-17 (IL-17)-producing T-helper (TH17) and regulatory T cells. Although various transcription factors and cytokines have been identified as key participants in TH17 generation, the role of microRNAs in this process is poorly understood. In this study, we found that expression of the microRNA (miR)-132/212 cluster is up-regulated by AHR activation under TH17-inducing, but not regulatory T-inducing conditions. Deficiency of the miR-132/212 cluster prevented the enhancement of TH17 differentiation by AHR activation. We also identified B-cell lymphoma 6, a negative regulator of TH17 differentiation, as a potential target of the miR-212. Finally, we investigated the roles of the miR-132/212 cluster in experimental autoimmune encephalomyelitis, a murine model of multiple sclerosis. Mice deficient in the miR-132/212 cluster exhibited significantly higher resistance to the development of experimental autoimmune encephalomyelitis and lower frequencies of both TH1 and TH17 cells in draining lymph nodes. Our findings reveal a unique mechanism of AHR-dependent TH17 differentiation that depends on the miR-132/212 cluster.
Project description:MicroRNAs are critical post-transcriptional regulators of hematopoietic cell-fate decisions, though little remains known about their role in aging hematopoietic stem cells (HSCs). The microRNA-212/132 cluster (miR-212/132) is enriched in HSCs and is up-regulated during hematopoietic aging. Both over-expression and deletion of microRNAs in this cluster leads to inappropriate hematopoiesis with age. Enforced expression of miR-132 in the bone marrow compartment of mice led to rapid HSC cycling followed by their depletion. A genetic deletion of the miR-212/132 cluster in mice resulted in HSCs that had altered cycling, function, and survival in response to growth factor starvation. We found that miR-212/132 exerts its effect on aging HSCs by targeting the transcription factor FOXO3, a known aging associated gene. Our data demonstrates that miR-212/132 plays a role in maintaining balanced hematopoietic output by buffering FOXO3 expression. We have thus identified a novel target that may play a role in age-related hematopoietic defects. Overall design: RNA-seq (SMART-Seq2 protocol) for LT-HSCs (LSK CD150+ CD48-), ST-HSCs (LSK CD150- CD48-) and MPPs (LSK CD150- CD48+) from WT and miR-212/132-/- mice
Project description:Pathological growth of cardiomyocytes (hypertrophy) is a major determinant for the development of heart failure, one of the leading medical causes of mortality worldwide. Here we show that the microRNA (miRNA)-212/132 family regulates cardiac hypertrophy and autophagy in cardiomyocytes. Hypertrophic stimuli upregulate cardiomyocyte expression of miR-212 and miR-132, which are both necessary and sufficient to drive the hypertrophic growth of cardiomyocytes. MiR-212/132 null mice are protected from pressure-overload-induced heart failure, whereas cardiomyocyte-specific overexpression of the miR-212/132 family leads to pathological cardiac hypertrophy, heart failure and death in mice. Both miR-212 and miR-132 directly target the anti-hypertrophic and pro-autophagic FoxO3 transcription factor and overexpression of these miRNAs leads to hyperactivation of pro-hypertrophic calcineurin/NFAT signalling and an impaired autophagic response upon starvation. Pharmacological inhibition of miR-132 by antagomir injection rescues cardiac hypertrophy and heart failure in mice, offering a possible therapeutic approach for cardiac failure.
Project description:Frontotemporal lobar degeneration with TDP-43 inclusions (FTLD-TDP) is a fatal neurodegenerative disease with no available treatments. Mutations in the progranulin gene (GRN) causing impaired production or secretion of progranulin are a common Mendelian cause of FTLD-TDP; additionally, common variants at chromosome 7p21 in the uncharacterized gene TMEM106B were recently linked by genome-wide association to FTLD-TDP with and without GRN mutations. Here we show that TMEM106B is neuronally expressed in postmortem human brain tissue, and that expression levels are increased in FTLD-TDP brain. Furthermore, using an unbiased, microarray-based screen of >800 microRNAs (miRs), we identify microRNA-132 as the top microRNA differentiating FTLD-TDP and control brains, with <50% normal expression levels of three members of the microRNA-132 cluster (microRNA-132, microRNA-132*, and microRNA-212) in disease. Computational analyses, corroborated empirically, demonstrate that the top mRNA target of both microRNA-132 and microRNA-212 is TMEM106B; both microRNAs repress TMEM106B expression through shared microRNA-132/212 binding sites in the TMEM106B 3'UTR. Increasing TMEM106B expression to model disease results in enlargement and poor acidification of endo-lysosomes, as well as impairment of mannose-6-phosphate-receptor trafficking. Finally, endogenous neuronal TMEM106B colocalizes with progranulin in late endo-lysosomes, and TMEM106B overexpression increases intracellular levels of progranulin. Thus, TMEM106B is an FTLD-TDP risk gene, with microRNA-132/212 depression as an event which can lead to aberrant overexpression of TMEM106B, which in turn alters progranulin pathways. Evidence for this pathogenic cascade includes the striking convergence of two independent, genomic-scale screens on a microRNA:mRNA regulatory pair. Our findings open novel directions for elucidating miR-based therapies in FTLD-TDP.
Project description:Alzheimer's disease (AD) and related tauopathies comprise a large group of neurodegenerative diseases associated with the pathological aggregation of tau protein. While much effort has focused on understanding the function of tau, little is known about the endogenous mechanisms regulating tau metabolism in vivo and how these contribute to disease. Previously, we have shown that the microRNA (miRNA) cluster miR-132/212 is downregulated in tauopathies such as AD. Here, we report that miR-132/212 deficiency in mice leads to increased tau expression, phosphorylation and aggregation. Using reporter assays and cell-based studies, we demonstrate that miR-132 directly targets tau mRNA to regulate its expression. We identified GSK-3? and PP2B as effectors of abnormal tau phosphorylation in vivo. Deletion of miR-132/212 induced tau aggregation in mice expressing endogenous or human mutant tau, an effect associated with autophagy dysfunction. Conversely, treatment of AD mice with miR-132 mimics restored in part memory function and tau metabolism. Finally, miR-132 and miR-212 levels correlated with insoluble tau and cognitive impairment in humans. These findings support a role for miR-132/212 in the regulation of tau pathology in mice and humans and provide new alternatives for therapeutic development.
Project description:The B-cell receptor (BCR) plays an important role in the pathogenesis and progression of chronic lymphocytic leukemia (CLL). By global microRNA profiling of CLL cells stimulated or not stimulated by anti-IgM, significant up-regulation of microRNAs from the miR-132~212 cluster was observed both in IGHV gene unmutated (UM) and mutated (M) CLL cells. Parallel gene expression profiling identified SIRT1, a deacetylase targeting several proteins including TP53, among the top-ranked miR-132 target genes down-regulated upon anti-IgM exposure. The direct regulation of SIRT1 expression by miR-132 was demonstrated using luciferase assays. The reduction of SIRT1 mRNA and protein (P = 0.001) upon anti-IgM stimulation was associated with an increase in TP53 acetylation (P = 0.007), and the parallel up-regulation of the TP53 target gene CDKN1A. Consistently, miR-132 transfections of CLL-like cells resulted in down-regulation of SIRT1 and an induction of a TP53-dependent apoptosis. Finally, in a series of 134 CLL samples, miR-132, when expressed above the median value, associated with prolonged time-to-first-treatment in patients with M CLL (HR = 0.41; P = 0.02). Collectively, the miR-132/SIRT1/TP53 axis was identified as a novel pathway triggered by BCR engagement that further increases the complexity of the interactions between tumor microenvironments and CLL cells.
Project description:miR-132 and miR-212 are structurally related microRNAs that have been found to exert powerful modulatory effects within the central nervous system (CNS). Notably, these microRNAs are tandomly processed from the same noncoding transcript, and share a common seed sequence: thus it has been difficult to assess the distinct contribution of each microRNA to gene expression within the CNS. Here, we employed a combination of conditional knockout and transgenic mouse models to examine the contribution of the miR-132/-212 gene locus to learning and memory, and then to assess the distinct effects that each microRNA has on hippocampal gene expression. Using a conditional deletion approach, we show that miR-132/-212 double-knockout mice exhibit significant cognitive deficits in spatial memory, recognition memory, and in tests of novel object recognition. Next, we utilized transgenic miR-132 and miR-212 overexpression mouse lines and the miR-132/-212 double-knockout line to explore the distinct effects of these two miRNAs on the transcriptional profile of the hippocampus. Illumina sequencing revealed that miR-132/-212 deletion increased the expression of 1138 genes; Venn analysis showed that 96 of these genes were also downregulated in mice overexpressing miR-132. Of the 58 genes that were decreased in animals overexpressing miR-212, only four of them were also increased in the knockout line. Functional gene ontology analysis of downregulated genes revealed significant enrichment of genes related to synaptic transmission, neuronal proliferation, and morphogenesis, processes known for their roles in learning, and memory formation. These data, coupled with previous studies, firmly establish a role for the miR-132/-212 gene locus as a key regulator of cognitive capacity. Further, although miR-132 and miR-212 share a seed sequence, these data indicate that these miRNAs do not exhibit strongly overlapping mRNA targeting profiles, thus indicating that these two genes may function in a complex, nonredundant manner to shape the transcriptional profile of the CNS. The dysregulation of miR-132/-212 expression could contribute to signaling mechanisms that are involved in an array of cognitive disorders.