Project description:Dysfunction of the retinal pigmented epithelium (RPE) results in degeneration of photoreceptors and vision loss and is correlated with common blinding disorders in humans. Although many protein-coding genes are known to be expressed in RPEs and important for their development and maintenance, virtually nothing is known about the in vivo roles of non-protein coding transcripts in RPEs. The expression patterns of microRNAs (miRNAs) have been analyzed in a variety of ocular tissues, and few were implicated to play role in RPE based on studies in cell lines. Herein, through RPE specific conditional mutagenesis of Dicer1 or DGCR8, the importance of miRNA for RPE differentiation was uncovered. Interestingly, miRNAs were found to be dispensable for maintaining the RPE fate and survival, and yet they are essential for acquisition of important RPE properties such as the expression of genes involved in the visual cycle pathway, pigmentation and cell adhesion. Importantly miRNAs of the RPE were found to be required for maturation of the adjacent photoreceptors, specifically for the morphogenesis of the outer segments. The profiles of miRNA and mRNA altered in the Dicer1 deficient RPE point to a key role of miR-204 in regulation of RPE differentiation program in vivo and uncovers the importance of additional novel RPE miRNAs. The study exposes the combined regulatory activity of miRNAs of the RPE, which is required for RPE differentiation and for the development of the adjacent neuroretina. Effect of Dicer 1 deficiency on RPE miRNA and mRNA.
Project description:Dysfunction of the retinal pigmented epithelium (RPE) results in degeneration of photoreceptors and vision loss and is correlated with common blinding disorders in humans. Although many protein-coding genes are known to be expressed in RPEs and important for their development and maintenance, virtually nothing is known about the in vivo roles of non-protein coding transcripts in RPEs. The expression patterns of microRNAs (miRNAs) have been analyzed in a variety of ocular tissues, and few were implicated to play role in RPE based on studies in cell lines. Herein, through RPE specific conditional mutagenesis of Dicer1 or DGCR8, the importance of miRNA for RPE differentiation was uncovered. Interestingly, miRNAs were found to be dispensable for maintaining the RPE fate and survival, and yet they are essential for acquisition of important RPE properties such as the expression of genes involved in the visual cycle pathway, pigmentation and cell adhesion. Importantly miRNAs of the RPE were found to be required for maturation of the adjacent photoreceptors, specifically for the morphogenesis of the outer segments. The profiles of miRNA and mRNA altered in the Dicer1 deficient RPE point to a key role of miR-204 in regulation of RPE differentiation program in vivo and uncovers the importance of additional novel RPE miRNAs. The study exposes the combined regulatory activity of miRNAs of the RPE, which is required for RPE differentiation and for the development of the adjacent neuroretina. Effect of Dicer 1 deficiency on RPE miRNA and mRNA.
Project description:In vitro expansion of adult human islet M-NM-2 cells is an attractive solution for the shortage of tissue for cell replacement therapy of type 1 diabetes. Using a lineage tracing approach, we have demonstrated that M-NM-2-cell-derived (BCD) cells rapidly dedifferentiate in culture and can proliferate for up to 16 population doublings. Dedifferentiation is associated with changes resembling epithelial-mesenchymal transition (EMT). The WNT pathway has been shown to induce EMT and plays key roles in regulating replication and differentiation in many cell types. Here we show that BCD cell dedifferentiation is associated with M-NM-2-catenin translocation into the nucleus and activation of the WNT pathway. Inhibition of M-NM-2-catenin expression in expanded BCD cells using short hairpin RNA resulted in growth arrest, mesenchymal-epithelial transition, and redifferentiation, as judged by activation of M-NM-2-cell gene expression. Furthermore, inhibition of M-NM-2-catenin expression synergized with redifferentiation induced by a combination of soluble factors, as judged by an increase in the number of C-peptide-positive cells. Simultaneous inhibition of the WNT and NOTCH pathways also resulted in a synergistic effect on redifferentiation. These findings, which were reproducible in cells derived from multiple human donors, suggest that inhibition of the WNT pathway may contribute to a therapeutically applicable way for generation of functional insulin-producing cells following ex-vivo expansion. Gene expression was studied for beta-cells (4 donors). Dedifferentiation was induced by inhibition of M-NM-2-catenin expression using shRNA. The experiment was performed in 4 batches (see the 'Date' characteristic in the Sample records).
Project description:Molecular profiling of infiltrating monocyte-derived macrophages versus resident kupffer cells following acute liver injury The liver has a remarkable capacity to regenerate after injury; yet, the role of macrophages (MF) in this process remains controversial mainly due to difficulties in distinguishing between different MF-subsets. Here, we utilized a murine model of acute liver injury caused by overdose of acetaminophen (APAP) and defined three distinct MF subsets that populate the liver following injury. Accordingly, resident Kupffer cells (KC) were significantly reduced upon APAP-challenge and started recovering by self-renewal at resolution phase without contribution of circulating Ly6Chi monocytes. The latter were recruited in a CCR2 and M-CSF mediated pathway at the necro-inflammatory phase and differentiated into ephemeral Ly6Clo MF subset at resolution phase. Moreover, their inducible ablation resulted in impaired recovery. Microarray based molecular profiling uncovered high similarity between steady state KC and those recovered at the resolution phase. In contrast, KC and monocyte-derived MF displayed distinct pro-restorative genetic signature at the resolution phase. Finally, we show that infiltrating monocytes acquire a pro-restorative polarization manifested by unique expression of pro-angiogenesis mediators and genes involved with inhibition of neutrophil activity and recruitment and promotion of their clearance. Collectively, our results present a novel phenotypic, ontogenic and molecular definition of liver-MF compartment following acute injury. 11 Samples (arrays) were performed. We generated pairwise comparison between all the different macrophages stages, using Partek Genomics Suite. Genes with p?5%[FDR] and a fold-change difference of ?2 or <-2 were selected.
Project description:Accumulating data indicate translation plays a role in cancer biology, particularly its rate limiting stage of initiation. Despite this evolving recognition, the function and importance of specific translation initiation factors is unresolved. The eukaryotic translation initiation complex eIF4F consists of eIF4E and eIF4G at a 1:1 ratio. Although it is expected that they display interdependent functions, several publications suggest independent mechanisms. This study is the first to directly assess the relative contribution of eIF4F components to the expressed cellular proteome, transcription factors, microRNAs, and phenotype in a malignancy known for extensive protein synthesis- multiple myeloma (MM). Previously, we have shown that eIF4E/eIF4GI attenuation (siRNA/ Avastin) deleteriously affected MM cells' fate and reduced levels of eIF4E/eIF4GI established targets. Here, we demonstrated that eIF4E/eIF4GI indeed have individual influences on cell proteome. We used an objective, high throughput assay of mRNA microarrays to examine the significance of eIF4E/eIF4GI silencing to several cellular facets such as transcription factors, microRNAs and phenotype. We showed different imprints for eIF4E and eIF4GI in all assayed aspects. These results promote our understanding of the relative contribution and importance of eIF4E and eIF4GI to the malignant phenotype and shed light on their function in eIF4F translation initiation complex. This study concentrated on a particular cancer model and studied the role of eIF4E and eIF4GI in the design of the cells' proteome. We used an unbiased, high throughput system to evaluate the individual importance of eIF4E and eIF4GI levels in MM. We used models of eIF4E or eIF4GI knocked down (KD) MM cell line RPMI 8226 and profiled their respective translated transcription factors (TF), often tumor suppressors or oncogenes. Furthermore, we assessed the KDs' microRNAs repertoires and cells' phenotype. Significant differences were observed between eIF4E and eIF4GI knockdown imprints.
Project description:The prevalence of some autoimmune diseases (AID) is greater in females compared with males, notwithstanding that disease severity is often greater in males. The reason for this sexual dimorphism (SD) is unknown, but may reflect negative selection of Y chromosome (ChrY) bearing sperm during spermatogenesis or male fetuses early in the course of conception/pregnancy. Previously, we showed that the SD in experimental autoimmune encephalomyelitis (EAE) is associated with copy number variation (CNV) in ChrY multicopy genes. Here, we test the hypothesis that CNV in ChrY multicopy genes influences the paternal parent-of-origin effect on EAE susceptibility in female mice. We show that C57BL/6J consomic strains of mice possessing an identical ChrX and CNV in ChrY multicopy genes exhibit a female biased sex-ratio and sperm head abnormalities, consistent with X-Y intragenomic conflict arising from an imbalance in CNV between homologous ChrX:ChrY multicopy genes. These males also display paternal transmission of EAE to female offspring and differential loading of miRNAs within the sperm nucleus. These findings provide evidence for a genetic mechanism at the level of the male gamete that contributes to the SD in EAE and paternal parent-of-origin effects in female mice, raising the possibility that a similar mechanism may contribute to the SD in MS. miRNA expression was analyzed in epidydimal sperm pooled from 5 mice for each replicate per strain.
Project description:Understanding the DNA elements that constitute and control the regulatory genome is critical for the appropriate therapeutic management of complex diseases. Here, using chromosome Y (ChrY) consomic mouse strains on the C57BL/6J background, we show that susceptibility to two diverse animal models of autoimmune disease, including experimental allergic encephalomyelitis (EAE) and experimental myocarditis, correlates with the natural variation in copy number of Sly and Rbmy multicopy ChrY genes. In the B6 background, ChrY possesses gene regulatory properties that impact both genome-wide gene expression and the presence of alternative splice variants, but not miRNA expression in pathogenic CD4+ T cells. An inverse correlation exists between the number of Sly and Rbmy ChrY gene copies and the number of significantly upregulated genes in immune cells, thereby supporting a link between copy number variation of Sly and Rbmy and the ChrY genetic element exerting regulatory properties. Thus, these data establish ChrY as a member of the regulatory genome in mammals due to its ability to regulate gene expression and alternative splicing in immune cells linked to disease. Three biological replicates for each strain were pooled from the axillary, brachial, and inguinal lymph nodes from 5 mice for each replicate. RNA was isolated from CD4+TCRB+ FAC sorted cells.
Project description:DUOC-01 is a macrophage-like cell therapy product manufactured from human umbilical cord blood (CB) mononuclear cells (MNCs) and intended for use in treatment of demyelinating diseases. During the 21-day manufacturing process, most initiating MNCs die in culture, but a highly active, adherent population of cells that resemble hematopoietic lineage macrophage in morphology, phagocytic activity, and antigen expression emerges; this population comprises the final DUOC-01 product [Kurtzberg et al. 2015]. Using the cuprizone-mediated murine demyelination model, we have found that DUOC-01 cells are capable of accelerating the remyelination process. In the same demyelination model, human cord blood-derived CD14+ cells (CBCD14) were less active. In another cellular therapy project, we have found that CBCD14 protects brain cells from oxygen-glucose-deprivation (OGD), but adult peripheral blood-derived CD14+ monocytes (PBCD14) did not. To address the functional differences between these cell types, we have analyzed differential gene expression by these three cell types. We used four cord blood (CB) samples (from Carolinas Cord Blood Bank) that were collected within 24hrs of delivery. Then, highly purified CB CD14+ monocytes were isolated by flow sorting. We collected the peripheral blood (PB) from four healthy volunteers and isolated the purified PB CD14+ monocytes by cell sorting. Three separate batches of cultured DUOC-01 cells were collected from Robertson Cell and Translational Cell Therapy cGMP facility. Total RNAs were isolated at the same time and kept frozen. RNA samples were given to Duke Microarray core facility to analyse the gene expression profile using Affymetrix GeneChip® Human Genome U133 Plus 2.0 Assay.
Project description:The relationships between cancer cells and the microenvironment play a critical role in cancer growth and development. The bone stroma consists of mesenchymal stem cells (MSCs) and mature osteoblasts that promote cancer growth. Yet it is not completely understood what are the molecular processes guiding cancer cells progression to the bone. In this study, a co-culture assay and subsequent gene profiling arrays were used to compare the gene expression profile of a pre-osteoblastic cell line (MBA-15) with that of a mammary adenocarcinoma (DA3) cells. Following co-culture, cells were separated by magnetic beads based on the expression of CD326 antigen. RNA was purified and hybridized on gene expression array. The gene expression pattern changes were followed by qRT-PCR. We demonstrate that co-cultured DA3 cells express elevated levels of genes that regulate growth and responses to both hormonal stimulus and wounding, as well as reduced expression of genes related to lipid metabolism. Also, co-cultured pre-osteoblastic cells showed reduced expression of cell-junction genes. The study presents a simplified model system, composed of pre-osteoblastic and mammary cancer cells, that potentially mimics the molecular interactions in the tumor microenvironment which contribute to tumor-progression. Gene expression was studied in 2 mouse cell lines: MBA-15, a pre-osteoblastic stromal cell line, and DA3, a mammary adenocarcinomal cell line. The interaction between these 2 cell lines was also analysed by gene expression. The experiment was performed in duplicates (see Date in the Sample characteristics field).