Project description:To identify genes regulated by the homeodomain transcription factors Sxi1M-NM-1 and Sxi2a (Sex Inducer 1M-NM-1 and 2a) in Cryptococcus neoformans, we carried out a whole-genome expression experiment. We performed two independent whole-genome microarray experiments comparing transcript levels in cells that either possessed or were lacking the Sxi proteins. In the first experiment we compared the expression profile of a haploid sxi1M-NM-1M-NM-^T strain to that of a haploid strain expressing both SXI1M-NM-1 and an inducible copy of SXI2a (Sxi +). In the second experiment, we compared the expression profile of a wild type cross (JEC20 x JEC21) to the expression profile of a cross whose mating partners did not possess either of the transcription factors (sxi2aM-bM-^HM-^F x sxi1M-NM-1M-bM-^HM-^F)(Sxi -). In both experiments RNA from each condition was harvested, labeled, and hybridized competitively to a spotted oligonucleotide microarray representing the approximately 6,500 genes in the C. neoformans genome. The resulting data was analyzed in Limma using standard methods. In the Sxi (+) experiment, each strain (M-NM-^Tsxi1M-NM-1 and the Sxi-Inducible strain) were grown overnight in liquid YPD, diluted back to an OD600 of 0.2, grown to log phase, and then switched to growth in liquid YPGal media for 6 hrs. The M-NM-^Tsxi1M-NM-1 strain was designated the control condition. Two biological replicates were used and in the first replicate there were two technical replicates for each dye orientation (4 replicates total). For the second Sxi (+) biological replicate, there were three total technical replicates, and one of those was a dye swap. For Sxi deletion crosses, strains (JEC20 x JEC21 or M-NM-^Tsxi1M-NM-1 x M-NM-^Tsxi2a) were mixed and plated onto V8 media (pH 7.0) and incubated at 22M-BM-0C in the dark for approximately 16 hours. The wild type (JEC20 x JEC21) cross was designated as the control in this experiment. Eight total hybridizations were carried out that consisted of 2 biological replicates and four technical replicates for each biological replicate (2 technical replicates per dye swap).

Project description:Background. Differential gene expression in adipose tissue during diet-induced weight loss followed by a weight stability period is not well characterized. Markers of these processes may provide a deeper understanding of the underlying mechanisms. Objective. To identify differentially expressed genes in human adipose tissue during weight loss and weight maintenance after weight loss. Design. RNA from subcutaneous abdominal adipose tissue from nine obese subjects was obtained and analyzed at baseline, after weight reduction on a low calorie diet (LCD), and after a period of group therapy in order to maintain weight stability. Results. Subjects lost 18.8 + 5.4% of their body weight during the LCD and maintained this weight during group therapy. Insulin sensitivity (HOMA) improved after weight loss with no further improvement during weight maintenance. Cyclin-dependent kinase inhibitor 2B (CDKN2B) and JAZF zinc finger 1 (JAZF1), associated with type 2 diabetes, were downregulated. We could also confirm the downregulation of candidates for obesity and related traits, such as tenomodulin (TNMD) and matrix metallopeptidase 9 (MMP9), with weight loss. The expression of other candidates, such as cell death-inducing DFFA-like effector A (CIDEA) and stearoyl-CoA desaturase (SCD) were upregulated during weight loss but returned to baseline levels during weight maintenance. Conclusion. Genes in the adipose tissue are differentially expressed during weight loss and weight maintenance after weight loss. Genes that show sustained regulation may be of potential interest as markers of the beneficial effects of weight loss whereas others seem to be primarily involved in the process of weight loss itself. Nine participants were prescribed a low calorie diet (LCD) containing 1200 kcal/day for approximately three months (101 ± 26 days). Following the weight reduction phase the participants attended a six month follow-up period (167 ± 37 days). By protocol design, subjects were eligible to enter the study if they had lost at least 10% of their initial body weight during the LCD-period and maintained this weight (+5%) after group therapy. Subcutaneous adipose tissue samples were obtained at three time-points: (i) at baseline, (ii) after weight reduction when subjects were no longer losing weight, and (iii) after the group therapy weight maintenance phase.

Project description:Merkel cell carcinoma (MCC) is an aggressive cutaneous neuroendocrine tumor with high mortality rates. Merkel cell polyomavirus (MCPyV), identified in the majority of MCC, may drive tumorigenesis via viral T antigens. However, mechanisms underlying pathogenesis in MCPyV-negative MCC remain poorly understood. To nominate genes contributing to pathogenesis of MCPyV-negative MCC, we performed DNA microarray analysis on 30 MCCs. MCPyV status of MCCs was determined by PCR for viral DNA and RNA. 1593 probe-sets were differentially expressed between MCPyV-negative and -positive MCC, with significant differential expression defined as at least 2-fold change in either direction and p-value of ≤ 0.05. MCPyV-negative tumors showed decreased RB1 expression, whereas MCPyV-positive tumors were enriched for immune response genes. Validation studies included immunohistochemistry demonstration of decreased RB protein expression in MCPyV-negative tumors and increased peritumoral CD8+ T lymphocytes surrounding MCPyV-positive tumors. In conclusion, our data suggest that loss of RB1 expression may play an important role in tumorigenesis of MCPyV-negative MCC. Functional and clinical validation studies are needed to determine whether this tumor suppressor pathway represents an avenue for targeted therapy. We used microarrays to characterize global gene expression patterns related to Merkel cell polyomavirus status in Merkel cell carcinoma. Furthermore, we compared Merkel cell carcinoma to less aggressive primary cutaneous carcinomas. We utilized flash-frozen tumor tissue from primary Merkel cell carcinomas, metastatic Merkel cell carcinomas, primary cutaneous squamous cell carcinomas, and basal cell carcinomas. Merkel cell carcinoma cell lines, which represent a pure population of tumor cells, were also included. Merkel cell polyomavirus status was determined at the DNA and RNA level using multiple primers for viral T-antigen and capsid protein sequences. This Series represents two analyses - one with new Samples normalized together, and another with some of the new Samples re-normalized with Samples previously submitted under Series GSE13355. The latter group contain 'renormalized' in the titles.

Project description:Extrahepatic cholestasis leads to complex injury and repair processes that result in bile infarct formation, neutrophil infiltration, cholangiocyte and hepatocyte proliferation, extracellular matrix remodeling, and fibrosis. To identify early molecular mechanisms of injury and repair after bile duct obstruction, microarray analysis was performed on liver tissue 24 hours after bile duct ligation (BDL) or sham surgery. The most upregulated gene identified encodes plasminogen activator inhibitor 1 (PAI-1, Serpine 1), a protease inhibitor that blocks urokinase plasminogen activator (uPA) and tissue-type plasminogen activator (tPA) activity. Because PAI-1, uPA, and tPA influence growth factor and cytokine processing as well as extracellular matrix remodeling, we evaluated the role of PAI-1 in cholestatic liver injury by comparing the injury and repair processes in wild-type (WT) and PAI-1-deficient (PAI-1-/-) mice after BDL. PAI-1-/- mice had fewer and smaller bile infarcts, less neutrophil infiltration, and higher levels of cholangiocyte and hepatocyte proliferation than WT animals after BDL. Furthermore, PAI-1-/- mice had higher levels of tPA activation and mature hepatocyte growth factor (HGF) after BDL than WT mice, suggesting that PAI-1 effects on HGF activation critically influence cholestatic liver injury. This was further supported by elevated levels of c-Met and Akt phosphorylation in PAI-1-/- mice after BDL. In conclusion, PAI-1 deficiency reduces liver injury after BDL in mice. These data suggest that inhibiting PAI-1 might attenuate liver injury in cholestatic liver diseases. Total RNA isolated using TRI Reagent (Sigma, St. Louis, MO) was purified with an RNeasy mini kit (Qiagen, Valencia, CA). Twenty micrograms cRNA was hybridized to a mouse GeneChip (U74Av2, Affymetrix, Santa Clara, CA) at the Siteman Cancer Center GeneChip facility as described by the manufacturer. Analyses used one mouse per chip. Gene expression changes were analyzed using Affymetrix MicroArray Suite 4.0 and GeneChip 3.1 Expression Analysis and Statistical Algorithms (Affymetrix). The complete methodology and full data sets for all 6 analyzed chips are available at http://bioinformatics.wustl.edu.beckerproxy.wustl.edu This study compares the injury and repair processed in wild-type mice after BDL.

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