The retinal pigment epithelium (RPE) provides vital support to photoreceptor cells and its dysfunction is associated with the onset and progression of age-related macular degeneration (AMD). Surgical provision of RPE cells may ameliorate AMD and thus it would be valuable to develop sources of patient-matched RPE cells for this application of regenerative medicine. We describe here the generation of functional RPE-like cells from fibroblasts that represent an important step toward that goal. We identified candidate master transcriptional regulators of RPEs using a novel computational method and then used these regulators to guide exploration of the transcriptional regulatory circuitry of RPE cells and to reprogram human fibroblasts into RPE-like cells. The RPE-like cells share key features with RPEs derived from healthy individuals, including morphology, gene expression and function, and thus represent a step toward the goal of generating patient-matched RPE cells for treatment of macular degeneration.
A Systematic Approach to Identify Candidate Transcription Factors that Control Cell Identity.
Specimen part
View SamplesCartilage plays a fundamental role in the development of the human skeleton. Early in embryogenesis, mesenchymal cells condense and differentiate to chondrocytes to shape the early skeleton. Subsequently, the cartilage anlagen differentiate to form the growth plates, which are responsible for linear bone growth, and the articular chondrocytes, which facilitate joint function. However, despite the multiplicity of roles of cartilage during human fetal life, surprisingly little is known about its transcriptome. To address this, a whole genome microarray expression profile was generated using RNA isolated from 18-22 week human distal femur fetal cartilage and compared with a database of control normal human tissues aggregated at UCLA, termed CELSIUS. From the wealth of data, 161 cartilage-selective genes were identified, defined as genes significantly expressed in cartilage with low expression and little variation across a panel of 34 non-cartilage tissues. Among these 161 genes were cartilage-specific genes such as collagen genes and 25 genes which have been associated with skeletal phenotypes in humans and/or mice. Many of the other cartilage-selective genes do not have established roles in cartilage or are novel, unannotated genes. Quantitative RT-PCR confirmed the unique pattern of gene expression observed by microarray analysis. Defining the gene expression pattern for cartilage has identified new genes that may contribute to human skeletogenesis as well as provided further candidate genes for skeletal dysplasias. The data suggest that fetal cartilage is a complex and transcriptionally active tissue and demonstrate that the set of genes selectively expressed in the tissue has been greatly underestimated.
Cartilage-selective genes identified in genome-scale analysis of non-cartilage and cartilage gene expression.
No sample metadata fields
View SamplesSurface expression of the viral Envelope protein (Env) was used to enrich reactivated latent T cells producing HIV-RNA, and single cell RNASeq was performed to study gene expression differences between latent cells and controls. Overall design: Latent CD4+ T cells from virologically suppressed patients were reactivated in vitro and isolated using antibodies against HIV-1 Env. Single cell RNASeq was performed comparing reactivated latent cells with control, unpurified cells from the same donor and with cells actively infected in vitro using HIV-1(YU2).
Clonal CD4<sup>+</sup> T cells in the HIV-1 latent reservoir display a distinct gene profile upon reactivation.
Subject
View SamplesWe study the effect of four QTN in RME1, IME1 & RSF1 that are causative for variation in sporulation efficiency. We investigate the relationship between genotype, gene expression and phenotype and whether the amount of gene expression variation explained by the sporulation QTN is predictive of the amount of phenotypic variation explained by them. Overall design: RNA-Seq analysis of 4 replicates each of 16 allele replacement panel strains containing all combinations of the four sporulation QTN after 2 hours in sporulation medium.
Single nucleotide variants in transcription factors associate more tightly with phenotype than with gene expression.
Subject
View SamplesPurpose: We observed protein homeostasis modulations when anc-1 is knocked-down. We wanted to measure changes in gene expression profiles following this manipulation. Methods: We treated wild type (strain N2) or polyQ35-YFP (strain AM140) nematodes, which express toxic aggregative proteins that challenge their protein homeostasis, with anc-1 RNAi until day six of adulthood, and compared their gene expression levels to those of untreated worms. Results: The knockdown of anc-1 leads to modified expression levels of hundreds of genes. There is an enrichment of transcription factors and protein homeostasis modulators, such as E3 ubiquitin ligases. Conclusions: anc-1 regulates protection from toxic aggregative proteins, at least partially, by regulating the expression of genes that encode protein homeostasis factors. Overall design: Wild type strain, three repeats; polyQ35-YFP strain, four repeats. Each repeat has two conditions: untreated (EV), and RNAi toward anc-1.
Gene expression modulation by the linker of nucleoskeleton and cytoskeleton complex contributes to proteostasis.
Cell line, Subject
View SamplesVon Willebrand factor is a paracrine/autocrine regulator of human mesenchymal stem cell adhesion to distressed/apoptotic endothelial cells.
Von willebrand factor increases endothelial cell adhesiveness for human mesenchymal stem cells by activating p38 mitogen-activated protein kinase.
Specimen part
View SamplesBackground. Multiple myeloma (MM) cells depend on the bone marrow (BM) niche for growth and survival. However, the tumor genes regulated by the niche are largely unknown.
Niche-modulated and niche-modulating genes in bone marrow cells.
Disease, Disease stage, Time
View SamplesGene expression profile (GEP) was analyzed in bone marrow (BM) samples from patients with leukemia or leukemic phase of lymphoma at different time points following aspiration. Among numerous changes in GEP evolved over time a discrete subset of > 60 genes exhibited prompt and sustained switch in expression consistently. Similar results were discovered recently in BM samples from patients with multiple myeloma (GSE36036). GEP was also examined in peripheral blood as well as in BM samples depleted of red blood cells (=WBC) and in cultured cells from some of the patients.
Niche-modulated and niche-modulating genes in bone marrow cells.
Specimen part, Disease
View SamplesPhosphatidylcholine transfer protein (PC-TP, a.k.a StarD2) is abundantly expressed in liver and is regulated by PPAR. When fed the synthetic PPAR ligand fenofibrate, Pctp-/- mice exhibited altered lipid and glucose homeostasis. Microarray profiling of liver from fenofibrate fed wild type and Pctp-/- mice revealed differential expression of a broad array of metabolic genes, as well as their regulatory transcription factors. Because its expression controlled the transcriptional activities of both PPAR and HNF4 in cell culture, the broader impact of PC-TP on nutrient metabolism is most likely secondary to its role in fatty acid metabolism.
Regulatory role for phosphatidylcholine transfer protein/StarD2 in the metabolic response to peroxisome proliferator activated receptor alpha (PPARalpha).
Sex, Age, Specimen part
View SamplesHow animals coordinate gene expression in response to starvation is an outstanding problem closely linked to aging, obesity, and cancer. Newly hatched Caenorhabditis elegans respond to food deprivation by halting development and promoting long-term survival (L1 diapause), thereby providing an excellent model to study starvation response. Through a genetic search, we have discovered that the tumor suppressor Rb critically promotes survival during L1 diapause and likely does so by regulating the expression of genes in both insulin-IGF-1 signaling (IIS)-dependent and -independent pathways mainly in neurons and the intestine. Global gene expression analyses suggested that Rb maintains the starvation-induced transcriptome and represses the re-feeding induced transcriptome, including the repression of many pathogen/toxin/oxidative stress-inducible and metabolic genes, as well as the activation of many other stress-resistant genes, mitochondrial respiratory chain genes, and potential IIS receptor antagonists. Notably, the majority of genes dysregulated in starved L1 Rb(-) animals were not found to be dysregulated in fed conditions. Together, these findings identify Rb as a critical regulator of the starvation response and suggest a link between functions of tumor suppressors and starvation survival. These results may provide mechanistic insights into why cancer cells are often hypersensitive to starvation treatment.
The tumor suppressor Rb critically regulates starvation-induced stress response in C. elegans.
No sample metadata fields
View Samples