Project description:Among the fundamental unresolved questions in psychiatry is why symptoms of psychosis, such as auditory hallucinations in schizophrenia, fail to appear until early adulthood. Here we report that in mouse models of 22q11.2 deletion syndrome (22q11DS), a leading genetic cause of schizophrenia, synaptic transmission at thalamocortical inputs to the auditory cortex becomes disrupted later in life, thereby recapitulating the adult onset of psychosis. Age-dependent disruption of thalamocortical synaptic transmission in 22q11DS is mediated by dopamine receptor Drd2-targeting microRNA miR-338-3p, which is enriched in the thalamus but becomes depleted due to haploinsufficiency of the microRNA-processing 22q11DS gene Dgcr8. Deletion/knockdown of miR-338-3p causes the Drd2 increase in the auditory thalamus and abnormal sensitivity of 22q11DS thalamocortical inputs to antipsychotics, replicates auditory synaptic and behavioral abnormalities in 22q11DS, and eliminates age dependence of these auditory deficits. These results suggest that miR-338-3p mediates the pathogenic mechanism of 22q11DS-related psychosis and controls its late onset.
Project description:Progressive ventricular enlargement is one of the most reproducible and recognizable structural abnormalities in schizophrenia, and is associated with more severe symptoms and poorer clinical outcome. The mechanisms of ventricular enlargement in schizophrenia is unknown. We identified that progressive ventricular enlargement is associated with deceleration of motile cilia beating in ependymal cells lining ventricular walls in murine models of schizophrenia-associated 22q11 deletion syndrome (22q11DS). The cilia beating deficit is caused by an aberrant elevation of Drd1, which is highly enriched in the motile cilia. Haploinsufficiency of the microRNA-processing gene Dgcr8 is responsible for the Drd1 elevation in ependymal cells of 22q11DS mice, and is mediated by reduction of Drd1-targeting microRNAs miR-674-3p and miR-382-3p. Replenishing miR-674-3p or miR-382-3p in 22q11DS mice rescued the motile cilia beating abnormalities and normalized the ventricular size. Knockdown of these microRNA mimicked cilia beating and ventricular deficits. Ventricular enlargement was also caused by Crispr/cas9-mediated deletion of the Drd1 seed site for miR-674-3p/miR-382-3p. This suggests that Dgcr8-miR-674-3p/miR-382-3p-Drd1–dependent disruption of cilia motility in ependymal cells is a pathogenic event underlying schizophrenia-associated ventricular enlargement.
Project description:Oxaliplatin (oxPt) resistance in colorectal cancers (CRC) is a major unsolved problem. Consequently, predictive markers and a better understanding of resistance mechanisms are urgently needed. To investigate if the recently identified predictive miR-625-3p is functionally involved in oxPt resistance, stable and inducible models of miR-625-3p dysregulation were analyzed. Ectopic expression of miR-625-3p in CRC cells led to increased resistance towards oxPt. The mitogen-activated protein kinase (MAPK) kinase 6 (MAP2K6/MKK6) – an activator of p38 MAPK - was identified as a functional target of miR-625-3p, and, in agreement, was down-regulated in patients not responding to oxPt therapy. The miR-625-3p resistance phenotype could be reversed by anti-miR-625-3p treatment and by ectopic expression of a miR-625-3p insensitive MAP2K6 variant. Transcriptome, proteome and phosphoproteome profiles revealed inactivation of MAP2K6-p38 signaling as a possible driving force behind oxPt resistance. We conclude that miR-625-3p induces oxPt resistance by abrogating MAP2K6-p38 regulated apoptosis and cell cycle control networks.
Project description:MicroRNAs are small non-coding RNA species, some of which are playing important roles in cell differentiation. However, the level of participations of microRNAs in epithelial cell differentiation is largely unknown. Here, we found that expression levels of four microRNAs (miR-210, miR-338-3p, miR-33a and miR-451) were significantly increased in differentiated stage of T84 cells, compared with undifferentiated stage. Additionally, we demonstrate that miR-338-3p and miR-451 contribute to the formation of epithelial basolateral polarity by facilitating translocalization of beta1 integrin to the basolateral membrane. However, candidate target mRNAs of miR-338-3p and miR-451 and the mechanism behind observed phenomena is uncertain. Then, we performed comprehensive gene expression analysis to identify candidate target mRNAs and understand their mechanisms.
Project description:MicroRNAs are small non-coding RNA species, some of which are playing important roles in cell differentiation. However, the level of participations of microRNAs in epithelial cell differentiation is largely unknown. Here, we found that expression levels of four microRNAs (miR-210, miR-338-3p, miR-33a and miR-451) were significantly increased in differentiated stage of T84 cells, compared with undifferentiated stage. Additionally, we demonstrate that miR-338-3p and miR-451 contribute to the formation of epithelial basolateral polarity by facilitating translocalization of beta1 integrin to the basolateral membrane. However, candidate target mRNAs of miR-338-3p and miR-451 and the mechanism behind observed phenomena is uncertain. Then, we performed comprehensive gene expression analysis to identify candidate target mRNAs and understand their mechanisms. T84 cells were seeded in transwell chambers and were transfected with microRNAs. Total RNA was extracted by the acid guanidinium thiocyanate-phenol-chloroform method, and was labeled and prepared for hybridization to GeneChip Human Genome U133 Plus 2.0 arrays (Affymetrix) according to the manufacture’s instructions (standard protocol).
Project description:We found that in rodents, b-cell mass expansion during pregnancy and obesity is associated with changes in the expression of a group of islet microRNAs. We were able to reproduce in isolated pancreatic islets the decrease of miR-338-3p level observed in gestation and obesity by activating the G-protein coupled estrogen receptor GPR30 and the GLP1 receptor. Blockade of miR-338-3p in b-cells using specific anti-miR molecules mimicked gene expression changes occurring during b-cell mass expansion and resulted in increased proliferation and improved survival both in vitro and in vivo. These findings point to a major role for miR-338-3p in compensatory b-cell mass expansion occurring under different insulin resistance states.
Project description:Glioblastoma multiforme (GBM) is the most aggressive form of brain tumors. Despite radical surgery and radiotherapy supported by chemotherapy, the disease still remains incurable with extremely low median survival rate of 12-15 months from the time of initial diagnosis. The main cause of treatment failure is considered to be the presence of cells that are resistant to such treatment. MicroRNAs (miRNAs) as regulators of gene expression are involved in the tumor pathogenesis, including GBM. MiR-338 is a brain specific miRNA which has been described to target pathways involved in proliferation and differentiation. In our study, miR-338-3p and -5p were differentially expressed in GBM tissue in comparison to non-tumor brain tissue. Overexpression of miR-338-3p with miRNA mimic did not show any changes in proliferation rates in GBM cell lines (A172, T98G, U87MG). On the other hand, pre-miR-338-5p notably decreased proliferation and caused cell cycle arrest. Since radiation is currently the main treatment modality in GBM, we combined overexpression of pre-miR-338-5p with radiation, which led to significantly decreased of cell proliferation, and increased cell cycle arrest and apoptosis in comparison to only irradiated cells. To better elucidate the mechanism of action, we performed gene expression profiling analysis that revealed targets of miR-338-5p being Ndfip1, Rheb, ppp2R5a. These genes have been described to be involved in DNA damage response, proliferation and cell cycle regulation. To our knowledge, this is the first study to describe role of miR-338-5p in GBM and its potential to improve sensitivity of GBM to radiation.
Project description:Oxaliplatin (oxPt) resistance in colorectal cancers (CRC) is a major unsolved problem. Consequently, predictive markers and a better understanding of resistance mechanisms are urgently needed. To investigate if the recently identified predictive miR-625-3p is functionally involved in oxPt resistance, stable and inducible models of miR-625-3p dysregulation were analyzed. Ectopic expression of miR-625-3p in CRC cells led to increased resistance towards oxPt. The mitogen-activated protein kinase (MAPK) kinase 6 (MAP2K6/MKK6) – an activator of p38 MAPK - was identified as a functional target of miR-625-3p, and, in agreement, was down-regulated in patients not responding to oxPt therapy. The miR-625-3p resistance phenotype could be reversed by anti-miR-625-3p treatment and by ectopic expression of a miR-625-3p insensitive MAP2K6 variant. Transcriptome, proteome and phosphoproteome profiles revealed inactivation of MAP2K6-p38 signaling as a possible driving force behind oxPt resistance. We conclude that miR-625-3p induces oxPt resistance by abrogating MAP2K6-p38 regulated apoptosis and cell cycle control networks. Experimental design for mass spectrometry SILAC experiments can be found at https://figshare.com/s/8e79f008e0e58ec6efc2 or https://doi.org/10.6084/m9.figshare.4888139
Project description:Glioblastoma multiforme (GBM) is the most aggressive form of brain tumors. Despite radical surgery and radiotherapy supported by chemotherapy, the disease still remains incurable with extremely low median survival rate of 12-15 months from the time of initial diagnosis. The main cause of treatment failure is considered to be the presence of cells that are resistant to such treatment. MicroRNAs (miRNAs) as regulators of gene expression are involved in the tumor pathogenesis, including GBM. MiR-338 is a brain specific miRNA which has been described to target pathways involved in proliferation and differentiation. In our study, miR-338-3p and -5p were differentially expressed in GBM tissue in comparison to non-tumor brain tissue. Overexpression of miR-338-3p with miRNA mimic did not show any changes in proliferation rates in GBM cell lines (A172, T98G, U87MG). On the other hand, pre-miR-338-5p notably decreased proliferation and caused cell cycle arrest. Since radiation is currently the main treatment modality in GBM, we combined overexpression of pre-miR-338-5p with radiation, which led to significantly decreased of cell proliferation, and increased cell cycle arrest and apoptosis in comparison to only irradiated cells. To better elucidate the mechanism of action, we performed gene expression profiling analysis that revealed targets of miR-338-5p being Ndfip1, Rheb, ppp2R5a. These genes have been described to be involved in DNA damage response, proliferation and cell cycle regulation. To our knowledge, this is the first study to describe role of miR-338-5p in GBM and its potential to improve sensitivity of GBM to radiation. Study was performed on three glioblastoma multiforme cell lines A172, T98G and U87MG. This experiment was performed on Affymetrix GeneChip Human Gene ST 1.0 to elucidate the targets of miRNA-338-5p. Cell lines were seeded 24 hours prior transfection. After transfection with pre-miR338-5p or negative control cell were cultured for 24 hours and harvested. RNA was isolated using MirVana miRNA Isolation Kit (Ambion, USA) and checked for RNA integrity by Bioanalyzer 2100 and purity by ratios 260/280>1.8 and 260/230>1.8 by Nanodrop2000.
Project description:The placental renin-angiotensin system (RAS) is important for placentation. RAS expression is greatest in early gestation. This may be due (in part) to suppression of miRNAs that target the placental RAS, but this has never been explored. In this study, human placental miRNAs were measured at 10–11 (early), 14–18 (mid), and 38–40 (term) weeks gestation, as well as in placentae from women with early- or late-onset preeclampsia (n=4/group), using an Agilent miRNA microarray (V19). All miRNAs showed a gestational increase and could influence the transgestational profile of the human placental RAS. Additionally, on the array, three miRNAs predicted to target the RAS (miR-892c-3p, miR-378c and miR-514-3p ) were overexpressed in placentae of late-onset preeclamptic women.