Expansion of beta cells from the limited number of adult human islet donors is an attractive prospect for increasing cell availability for cell therapy of diabetes. However, while evidence supports the replicative capacity of adult beta cells in vivo, attempts at expanding human islet cells in tissue culture resulted in loss of beta-cell phenotype. Using a genetic lineage-tracing approach we have provided evidence for massive proliferation of beta-cell-derived (BCD) cells within these cultures. Expansion involves dedifferentiation resembling epithelial-mesenchymal transition (EMT). Epigenetic analyses indicate that key beta-cell genes maintain a partially open chromatin structure in expanded BCD cells, although they are not transcribed. Here we report that BCD cells can be induced to redifferentiate by a combination of soluble factors. The redifferentiated cells express beta-cell genes, store insulin in typical secretory vesicles, and release it in response to glucose. The redifferentiation process involves mesenchymal-epithelial transition, as judged from changes in gene expression. Moreover, inhibition of the EMT effector SLUG using shRNA results in stimulation of redifferentiation. BCD cells also give rise at a low rate to cells expressing other islet hormones, suggesting transition through an islet progenitor-like stage during redifferentiation. These findings suggest that ex-vivo expansion of adult human islet cells is a promising approach for generation of insulin-producing cells for transplantation, as well as basic research, toxicology studies, and drug screening.
Insulin-producing cells generated from dedifferentiated human pancreatic beta cells expanded in vitro.
Specimen part
View SamplesIn vitro differentiation of human stem cells can produce pancreatic beta cells, the insulin-secreting cell type whose loss underlies Type 1 Diabetes. As a step towards mastery of this process, we report on transcriptional profiling of >100,000 individual cells sampled during in vitro beta cell differentiation and describe the cells that emerge. We resolve populations corresponding to beta cells, alpha-like poly-hormonal cells, non-endocrine cells that resemble pancreatic exocrine cells and a previously unreported population resembling enterochromaffin cells. We show that the beta and alpha-like cells are stable for weeks in culture without exogenous growth factors and that gene expression changes associated with in vivo beta cell maturation are recapitulated in vitro. We demonstrate that stem-cell derived enterochromaffin cells can synthesize and secrete serotonin in vitro. To remove exocrine cells, we characterize a scalable re-aggregation technique that efficiently selects endocrine cells. Finally, we use a high-resolution sequencing time course to characterize gene expression dynamics during human pancreatic endocrine induction from which we develop a lineage model of in vitro beta cell differentiation. This study provides a deeper perspective on the current state of human stem cell differentiation and is a jumping-off point for future endeavors in in vitro differentiation of pancreatic islet cells and their application in regenerative medicine. Overall design: Single-cell mRNA sequencing of pluripotent stem cells differentiating in vitro towards pancreatic beta cells. The data & metadata match the initial submission of the manuscript, not the final version.
Charting cellular identity during human in vitro β-cell differentiation.
Specimen part, Subject
View SamplesWe report here that human mitochondria contain small RNA including microRNA, piRNA, tRNA, rRNA, and RNA repeats. Mitochondria from human cells were purified and RNA isolated. Small RNAs were purified, library generated and analyzed by Illumina Hiseq 2000 system. The sequencing generated 19.5 and 17.7 million reads from HEK-293 and HeLa respectively. 91% and 97% sequences of HEK293 and HeLa respectively were annotated to various classes of small RNA. The total percentage of 4.21 and 2.58 sequences from HEK293 and HeLa respectively was found to be of miRNA. Further, we found only 1.2 % sequences from both the libraries aligned to mitochondrial genome. These results suggest that there is efficient transport of nuclear encoded small RNA to mitochondria. The small RNA in mitochondria may regulate critical cellular processes. Overall design: Analyzing the smallRNA in human mitochondria from two human cell lines (HEK-293 and HeLa).
Systematic analysis of small RNAs associated with human mitochondria by deep sequencing: detailed analysis of mitochondrial associated miRNA.
Specimen part, Cell line, Subject
View SamplesThe aim of this study was to minimize the number of candidate genes responsible for salt tolerance between a pair of rice varieties (CSR27 and MI48) with contrasting level of salt tolerance by bulked segregant analysis of their recombinant inbred lines. Microarray analysis of RNA extracted from the tolerant and susceptible parents without and with stress showed 798 and 2407 differentially expressed genes, respectively. The number of differentially expressed genes was drastically reduced to 70 and 30, by pooling the RNAs from ten extreme tolerant and ten extreme susceptible RILs due to normalization of irrelevant differentially expressed genes between the parents.
Combining QTL mapping and transcriptome profiling of bulked RILs for identification of functional polymorphism for salt tolerance genes in rice (Oryza sativa L.).
No sample metadata fields
View SamplesThe aim of this study was to identify candidate genes responsible for grain number per panicle between a pair of rice varieties (Pusa 1266 and Pusa Basmati 1) by combining QTL analysis with expression analysis. Microarray analysis of RNA extracted from the panicle primordia showed 2741 differentially expressed genes. The differentially expressed genes were shortened to 18 on the basis of their occurance in the QTL region (responsible for grain number regulation) detected in RIL population derived from Pusa 1266 and Pusa Basmati 1.
Identification of candidate genes for grain number in rice (Oryza sativa L.).
No sample metadata fields
View SamplesLiver stage of malaria parasite exports SLTRiP and PB268 to the cytosol of parasite infected host cell. To know the host genes perturbed by WT-PBANKA, SLTRiP-KO and PB268-KO parasite growth, we did transcriptomic sequencing of infected host cells. We did mRNA sequencing of four samples for comparative analysis of WT and PB-knockout parasites infected host cells at 22 hours of post sporozoites infection. Overall design: mRNA profiles of Plasmodium PBANKA, PBSLTRiP-KO, PB268-KO parasite infected and uninfected HepG2 cells after 22hrs of sporozoites infections were generated by deep sequencing using Illumina GAIIx.
A Sporozoite- and Liver Stage-expressed Tryptophan-rich Protein Plays an Auxiliary Role in Plasmodium Liver Stage Development and Is a Potential Vaccine Candidate.
No sample metadata fields
View SamplesNon-switched memory (ME-M) B cells are an enigmatic population of IgM+ memory lymphocytes that are thought to emerge from germinal centers during systemic antibody responses against T cell-dependent antigens. To gain new insights into the properties of ME-M B cells generated during intestinal antibody responses, we performed global gene transcriptome expression analysis on nave, ME-M and canonical memory class-switched (ME-SW) B cells purified from human gut samples. Marginal zone (MZ) and ME-SW B cells isolated from human spleen samples were used for comparison.
Human Secretory IgM Emerges from Plasma Cells Clonally Related to Gut Memory B Cells and Targets Highly Diverse Commensals.
Specimen part
View SamplesAbiotic stresses like drought, salinity, high and low temperature, and submergence are major factors that limit the crop productivity. Hence, identification of genes associated with stress response in crops is a prerequisite for improving their tolerance to adverse environmental conditions. In this study, we have analyzed the expression profiles of three genotypes WT, TaVAP mutant and TaVAPOE plants in Arabidopsis thaliana in col-0 background using microarray technology to identify the genes differentially expressed under control conditions.
Gene encoding vesicle-associated membrane protein-associated protein from Triticum aestivum (TaVAP) confers tolerance to drought stress.
Specimen part
View SamplesTwenty one day old seedlings of the mutant and WT grown in hydroponic culture in three replications were subjected to 25% PEG stress for one hour. The leaf samples of stressed and control seedlings were collected and preserved in liquid nitrogen for RNA isolation. Total RNA from four samples i.e. mutant control (MC), mutant stress (MS), Nagina22 control (NC) and Nagina22 stress (NS) was extracted by following the manufacturer‰۪s instructions provided with SV Total RNA isolation system Kit (PROMEGA, USA). All the steps starting from cRNA preparation to hybridization were conducted following the instructions of Affymetrix (AffymetrixGeneChip Expression Analysis Technical Manual). Chips were washed and stained in the Affymetrix Fluidics Station 450, and then scanned using the Affymetrix Gene Chip Scanner 3000. The cell intensity data files (.CEL) generated by the Gene Chip Operating Software (GCOS 1.2).
Physiological, anatomical and transcriptional alterations in a rice mutant leading to enhanced water stress tolerance.
Specimen part
View SamplesArabidopsis fc2-1 mutants fail to properly de-etiolate after a prolonged period in the dark. Our goal was to monitor whole genome expression during the first 2 hours of de-etiolation to determine the cuase of this growth arrest.
Ubiquitin facilitates a quality-control pathway that removes damaged chloroplasts.
Specimen part
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