During sexual dimorphism, the loss of one entire X chromosome in Drosophila males is achieved largely via a broad genome-wide aneuploid effect. Exploring how MSL proteins and two large non coding RNAs (roX1 and roX2) modulate trans-acting aneuploid effect for equality to females, we employ a system biology approach (microarray) to investigate the global aneuploid effect of maleless(mle) mutation by disrupting MSL binding. A large number of the genes (144) that encode a broad spectrum of cellular transport proteins and transcription factors are located in the autosomes of Drosophila melanogaster.
Drosophila maleless gene counteracts X global aneuploid effects in males.
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View SamplesIn obesity an increase in -cell mass occurs to cope with the rise in insulin demand. This -cell plasticity is essential to avoid the onset of hyperglycemia, although the molecular mechanisms that regulate this process remain unclear. This study analyzed the role of adipose tissue in the control of -cell replication. Using a diet-induced model of obesity, we obtained conditioned media from three different white adipose tissue depots. Only in the adipose tissue depot surrounding the pancreas did the diet induce changes that led to an increase in INS1E cells and the islet replication rate. To identify the factors responsible for this proliferative effect, adipose tissue gene expression analysis was conducted by microarrays and quantitative RT-PCR. Of all the differentially expressed proteins, only the secreted ones were studied. IGF binding protein 3 (Igfbp3) was identified as the candidate for this effect. Furthermore, in the conditioned media, although the blockage of IGFBP3 led to an increase in the proliferation rate, the blockage of IGF-I receptor decreased it. Taken together, these data show that obesity induces specific changes in the expression profile of the adipose tissue depot surrounding the pancreas, leading to a decrease in IGFBP3 secretion. This decrease acts in a paracrine manner, stimulating the -cell proliferation rate, probably through an IGF-I-dependent mechanism. This cross talk between the visceral-pancreatic adipose tissue and -cells is a novel mechanism that participates in the control of -cell plasticity. (Endocrinology 153: 177187, 2012)
Role of IGFBP-3 in the regulation of β-cell mass during obesity: adipose tissue/β-cell cross talk.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Downregulation of Sfrp5 promotes beta cell proliferation during obesity in the rat.
Specimen part
View SamplesObesity is associated with an increase in -cell mass in response tothe rising demand for insulin. -cell plasticity is essential to maintaining glucose homeostasis, however,the cellular and molecular mechanisms by which -cell mass is regulated remain poorly understood.Recently, we described the existence of a crosstalk between the peripancreatic adipose tissue and -cells as a novel mechanism that participates in the regulation of -cell plasticity. Here, we identify the secreted frizzled-related protein (Sfrp) 5 as down-regulated in the pancreatic islets of obese rats as well as in the pancreatic islets of human obese patients. Our results demonstrate that the silencing of Sfrp5 induces an increase in -cell proliferation, which we correlate with the activation of Wnt signaling and of the MAPK and PI3 kinase pathways. Together, these findings expand our understanding of the mechanisms underlying -cell proliferation under conditions of obesity. Furthermore, this study opens new insights into the specific targeting of Sfrp5 as a novel therapeutic strategy for balancing -cell mass.
Downregulation of Sfrp5 promotes beta cell proliferation during obesity in the rat.
Specimen part
View SamplesObesity is associated with an increase in -cell mass in response tothe rising demand for insulin. -cell plasticity is essential to maintaining glucose homeostasis, however,the cellular and molecular mechanisms by which -cell mass is regulated remain poorly understood.Recently, we described the existence of a crosstalk between the peripancreatic adipose tissue and -cells as a novel mechanism that participates in the regulation of -cell plasticity. Here, we identify the secreted frizzled-related protein (Sfrp) 5 as down-regulated in the pancreatic islets of obese rats as well as in the pancreatic islets of human obese patients. Our results demonstrate that the silencing of Sfrp5 induces an increase in -cell proliferation, which we correlate with the activation of Wnt signaling and of the MAPK and PI3 kinase pathways. Together, these findings expand our understanding of the mechanisms underlying -cell proliferation under conditions of obesity. Furthermore, this study opens new insights into the specific targeting of Sfrp5 as a novel therapeutic strategy for balancing -cell mass.
Downregulation of Sfrp5 promotes beta cell proliferation during obesity in the rat.
Specimen part
View SamplesChanges in the secretion profile of visceral-pancreatic white adipose tissue (pWAT) due to diet-induced obesity are partially responsible for increased beta cell replication, suggesting that a crosstalk between pWAT and beta cells may play a role in regulating beta cell plasticity. The molecular mechanisms underlying this cross-talk are still not fully understood.
Downregulation of Sfrp5 promotes beta cell proliferation during obesity in the rat.
Specimen part
View SamplesNeutrophils are short-lived innate immune cells. Upon encountering appropriate stimuli, neutrophils generate and release neutrophil extracellular traps (NETs), primarily via NADPH oxidase (Nox)-dependent (~2 hours) or Nox-independent NETosis (~15-60 minutes). Ironically, DNA transcription in dying neutrophils remains an enigma. We hypothesized that transcriptional activation, regulated by NETosis-specific kinases, is important to drive the chromatin decondensation necessary for NETosis. For the first time, we show here that (i) the degree of NETosis corresponds to the degree of genome-wide transcription; (ii) kinase-specific transcriptional activation reflects transcriptional firing during different types of NETosis; and (iii) Transcriptomics suggests that NETosis could differentially regulate inflammation. Therefore, we propose that the initial steps of transcriptional firing, but neither transcription per se help to drive NETosis.
Transcriptional firing helps to drive NETosis.
Sex, Specimen part, Disease
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Liver X receptors inhibit proliferation of human colorectal cancer cells and growth of intestinal tumors in mice.
Age, Specimen part
View SamplesChanges in gene expression profile of intestinal (ILEUM) Tumors from APCmin/+/VP16LXRa vs APCmin/+/VP16. The hypothesis tested in the present study was that LXRa overexpression influence cancer growth modulating lipid metabolism in cancer cells. Results provide the information that LXRa induces genes encoding proteins able to regulate cholesterol efflux.
Liver X receptors inhibit proliferation of human colorectal cancer cells and growth of intestinal tumors in mice.
Age, Specimen part
View SamplesWe compared gene expression in the Drosophila fat body on control and high-sugar diets in order to gain insight into the role of this organ during caloric overload. Differential expression analysis revealed changes in gene expression suggestive of a role for CoA metabolism in the ability to tolerate high-sugar feeding. This led us to perform biochemical and mutant studies supporting a model where CoA is limiting in the face of caloric overload. Overall design: Wild-type Drosophila were reared on control (0.15M sucrose) and high-sugar (0.7M sucrose) diets until the wandering stage. Fat bodies were isolated and RNA extracted to determine the effects of diet on gene expression using Illumina RNA-seq.
CoA protects against the deleterious effects of caloric overload in Drosophila.
Sex, Specimen part, Subject
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