Project description:Corneal epithelial RCE1(5T5) cells follow a sequential process that leads to the formation of a 4-5 layered stratified epithelium with a gene expression pattern similar to that shown in primary cultures of corneal epithelial cells. We have previously identified three different developmental stages during the differentiation of the rabbit corneal epithelial cell line RCE1(5T5). In this analysis we describe the participation of miR-141-3p as a regulator of the proliferative phenotype and its participation on maintaining differentiation of corneal eptihelial cells.
Project description:Exosomes which are nano-vesicles and released from living cells, have attracted more attention as an important mediator for cell-to-cell communication. Given that obesity often causes insulin resistance, it is significant to test whether exosomes derived from obesity adipose tissue possess any capacity in regulating insulin sensitivity. In this study we purified exosomes from the adipose tissue. Exosomes derived from ob/ob mice (Ob-exosomes) and B6 mice fed a high-fat diet (HFD-exosomes) displayed similar size and molecular maker to those originated from the normal B6 mice (WT-exosomes), but their regulatory role in insulin sensitivity was opposite. Abundant exosomal miRNAs were detected by the Next Generation Sequencing. Ob-exosomes encapsulated the lower levels of miR-141-3p compared to WT-exosomes, furthermore, miR-141-3p can be effectively delivered into AML12 cells accompanied by the absorption of Ob-exosomes and WT-exosomes. But the absorption of miR-141-3p from adipose tissues to AML12 cells could be blocked by GW4869, an inhibitor of exosome biogenesis and release. Importantly, the exosomal miR-141-3p functionally down-regulated its target gene Pten expression in AML12 cells, and the knockdown of miR-141-3p inhibited the insulin response and glucose uptake in AML12 cells, however Ob-exosomes-mediated inhibitory effects on insulin function disappeared after overexpression of miR-141-3p. These data indicate that the absorption of exosomes released from obesity adipose tissue including lower level of miR-141-3p than healthy adipose tissue into hepatocytes can significantly inhibit the insulin sensitivity and glucose uptake. Thus, our study may certify a novel mechanism that the secretion of “harmful” exosomes from obesity adipose tissues cause insulin resistance.
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:To identify putative novel specific targets of miR-141-3p, we overexpressed this miRNAs in primary keratinocytes using a synthetic mimic (pre-miR-141-3p) or a synthetic “negative” control mimic (pre-miR-ctrl). RNA samples were harvested 30 hours post-transfection and 3 independent experiments were carried out.
Project description:This is a prospective-retrospective study to determine if the expression of the miRNA’s miR-31-3p and miR-31-5p are prognostic of patient outcomes or predictive of the benefit from anti-EGFR therapy in stage III Colon Cancer. The present study will utilize FFPE tumor samples collected from patients enrolled in the PETACC-8 study conducted by the Fédération Francophone de Cancérologie Digestive (FFCD). This phase 3 clinical trial prospectively randomized fully resected stage III colon cancer patients to receive adjuvant treatment with either FOLFOX-4 plus cetuximab or FLOFOX-4 alone.
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:We performed RNA sequencing of gene expression in primary human bronchial epithelial cells that have undergone CRISPR/Cas9-based targeting of MIR141. The goal was to identify the role of miR-141 in goblet cell mucus production. CRISPR-targeted cells were differentiated at air-liquid-interface and stimulated with IL-13 to induce goblet cell hyperplasia.
Project description:The mouse incisor is a remarkable tooth that grows throughout the animal’s lifetime. This continuous renewal is fueled by epithelial stem cells that give rise to ameloblasts, which generate enamel, and little is known about the function of specific miRNAs in this process. Here we describe the role of a novel Pitx2:miR-200c/141:Noggin regulatory pathway in dental epithelial cell differentiation. miR-200c repressed noggin, an antagonist of Bmp signaling. Pitx2 expression caused an up-regulation of miR-200c and chromatin immunoprecipitation (ChIP) assays revealed endogenous Pitx2 binding to the miR-200c/141 promoter. A positive feedback loop was discovered between miR-200c and Bmp signaling. miR-200c/141 induced expression of E-cadherin and the dental epithelial cell differentiation marker, amelogenin. In addition, miR-203 expression was activated by endogenous Pitx2 and targeted the Bmp antagonist Bmper to further regulate Bmp signaling. miR-200c/141 knockout mice showed defects in enamel formation with decreased E-cadherin and amelogenin expression and increased noggin expression. Our in vivo and in vitro studies reveal a multistep transcriptional program involving the Pitx2:miR-200c/141:Noggin regulatory pathway that is important in epithelial cell differentiation and tooth development.
Project description:The mouse incisor is a remarkable tooth that grows throughout the animalM-bM-^@M-^Ys lifetime. This continuous renewal is fueled by epithelial stem cells that give rise to ameloblasts, which generate enamel, and little is known about the function of specific miRNAs in this process. Here we describe the role of a novel Pitx2:miR-200c/141:Noggin regulatory pathway in dental epithelial cell differentiation. miR-200c repressed noggin, an antagonist of Bmp signaling. Pitx2 expression caused an up-regulation of miR-200c and chromatin immunoprecipitation (ChIP) assays revealed endogenous Pitx2 binding to the miR-200c/141 promoter. A positive feedback loop was discovered between miR-200c and Bmp signaling. miR-200c/141 induced expression of E-cadherin and the dental epithelial cell differentiation marker, amelogenin. In addition, miR-203 expression was activated by endogenous Pitx2 and targeted the Bmp antagonist Bmper to further regulate Bmp signaling. miR-200c/141 knockout mice showed defects in enamel formation with decreased E-cadherin and amelogenin expression and increased noggin expression. Our in vivo and in vitro studies reveal a multistep transcriptional program involving the Pitx2:miR-200c/141:Noggin regulatory pathway that is important in epithelial cell differentiation and tooth development. Lower incisors of 3-5 P0 WT and Pitx2-Cre;Dicer1 cKO mices from same litter were dissected and combined for RNA extraction. Two different litters were analyzed. For mRNA microarray, CodeLink Mouse Whole Genome chips (Applied Microarrays) were used according to manufacturerM-bM-^@M-^Ys instruction (done at Genomics Core of TAMU). miRNA from P0 Lower Incisor ameloblast and cervical loops.