Project description:Using heterogeneous stock (HS) rats, we have identified a region on rat chromosome 1 that maps multiple diabetic traits. We sought to use global expression analysis to determine if genes within this region are differentially expressed between HS rats with normal glucose tolerance and those with glucose intolerance HS rats were euthanized at 17 weeks of age and tail sample was taken. Genomic DNA was extracted from tail of 23 HS rats with glucose intolerance and 23 HS rats with normal glucose. The Affymetrix 10K SNP array was used to genotype these animals.
Project description:Using heterogeneous stock (HS) rats, we have identified a region on rat chromosome 1 that maps multiple diabetic traits. We sought to use global expression analysis to determine if genes within this region are differentially expressed between HS rats with normal glucose tolerance and those with glucose intolerance HS rats were euthanized at 17 weeks of age and liver was immediately frozen in liquid nitrogen. RNA was extracted from liver of 23 HS rats with glucose intolerance and 23 HS rats with normal glucose. The Affymetrix 230_2 array was used to probe transcript abundance levels.
Project description:A need exists for biomarkers in T1D that can 1) sensitively and specifically detect disease-related immune activity prior to, and independent of, measurement of auto-antibodies towards islet cell antigens; 2) define immunopathological mechanisms; and 3) monitor changes in the inflammatory state associated with disease progression or response to therapeutic intervention. In an effort to fill this gap, we have applied a novel bioassay to both human and BB rat T1D whereby the complex milieu of inflammatory mediators present in plasma can be indirectly detected through their ability to drive transcription in peripheral blood mononuclear cells (PBMCs) drawn from healthy, unrelated donors. The resultant gene expressions are comprehensively measured with a microarray. In our human studies, we find that plasma of recent-onset T1D patients induces expression of a pro-inflammatory signature consisting in part of many interleukin-1 (IL-1) regulated genes related to immunological activation and immunocyte chemotaxis compared to unrelated healthy controls. This signature has been found to resolve in long-standing T1D subjects (>10 years post-onset), thus associating it with active autoimmunity. Importantly, this signature has been detected in pre-onset samples of progressors to T1D years prior to onset and prior to development of auto-antibodies directed towards islet antigens. In applying this approach to the BN rat, we observed that samples collected from both sub-strains at 60 days of age induced transcription of genes encoding cytokines, immune receptors, and signaling molecules consistent with a their shared susceptibility and immune activation. The DRlyp/lyp signature was differentiated from that of the DR+/+ by more robust induction of many interleukin (IL)-1M-bM-^@M-^Sregulated genes. Treatment of DRlyp/lyp rats with IL-1 receptor antagonist (IL-1RN) delayed onset and, in part, normalized the signature, suggesting that this approach may prove useful in monitoring the effect of therapeutic interventions in human T1D. Consistent with the presence of TREG cells in DR+/+ rats, we observed induction of a signature possessing negative regulators of transcription and inflammation. Fresh PBMCs of healthy Brown Norway (BN) rats (~180 days old males, to avoid variation introduced by estrous or pubertal status) were isolated by density gradient centrifugation. Transcription was induced by culturing PBMCs for 6 h at 37M-BM-0C in 5% CO2 with 20% allogeneic BN (healthy-unrelated control), DRlyp/lyp, or DR+/+ plasma [PMID 18209091]. DRlyp/lyp and DR+/+ Plasma was pooled at various ages (30, 40, 50, 60 days old) to represent timepoints prior to onset in the DRlyp/lyp strain.
Project description:The long-term effects of neonatal intermittent hypoxia (IH), an accepted model of apnea-induced hypoxia, are unclear. We have previously shown lasting âprogrammingâ effects on the HPA axis in adult rats exposed to neonatal IH. We hypothesized that neonatal rat exposure to IH will subsequently result in a heightened inflammatory state in the adult. Rat pups were exposed to normoxia (control) or six cycles of 5% IH or 10% IH over one hour daily from postnatal day 2 â 6. Plasma samples from blood obtained at 114 days of age were analyzed by assessing the capacity to induce transcription in a healthy peripheral blood mononuclear cell (PBMC) population and read using a high-density microarray. The analysis of plasma from adult rats previously exposed to neonatal 5% IH vs. 10% IH resulted in 2,579 significantly regulated genes including increased expression of Cxcl1, Cxcl2, Ccl3, Il1a, and Il1b. We conclude that neonatal exposure to intermittent hypoxia elicits a long-lasting programming effect in the adult resulting in an upregulation of inflammatory-related genes. Apnea is the most common cause of neonatal hypoxia affecting about 50% of preterm births (30 â 31 weeks), usually due to immature respiratory development. Upregulation of inflammatory genes and pathways in children 7 â 10 years of age has been shown, and there is a known increased risk of insulin resistance in adulthood when the fetus is exposed to maternal hypoxia, but the mechanism is unclear. The long-term metabolic, endocrine, and immunological effects of neonatal intermittent hypoxia (IH) exposure, an accepted model of apnea-induced hypoxia, have not been thoroughly evaluated. Recent studies in rats have shown that perinatal IH exposure can result in oxidative stress, causing a permanent immune response subsequently resulting in features of diabetes mellitus. We have previously examined adult rats exposed to neonatal intermittent hypoxia and perinatal continuous hypoxia, and have found lasting âÂÂprogrammingâ effects on the HPA axis. We now assess the long term effects of an accepted model of apnea-induced hypoxia using a validated transcriptional bioassay to study the extracellular milieu of adult rats exposed to neonatal intermittent hypoxia. We hypothesize that exposure to neonatal intermittent hypoxia will result in an increased inflammatory state in the adult as a result of long-lasting programming. Sprague-Dawley (SD) rat pups were treated with neonatal normoxia (21% O2, control), 5% intermittent hypoxia (IH), or 10% IH on postnatal days (PD) 2-6, daily over 1 hr. They were reared normally by birth dams and weaned at PD22. Males were allowed to mature and sacrificed at age PD114 after an overnight fast. Whole blood collected by decapitation into tubes with EDTA, and plasma saved for further analysis. Two adult (~180 day) male Brown Norway (BN) rats served as PBMC donors. Cells were incubated with 20% plasma that was either autologous BN (self-control), or one of 3 pools: a) SD normoxic N=8, b) SD 5% IH treated N=5, and c) SD 10% IH N=3.
Project description:Autosomal recessive polycystic kidney disease (ARPKD) is caused by mutations in the PKHD1 gene in both humans and the orthologous PCK rat model. Although ARPKD results solely from PKHD1 mutations, the disease onset and severity are highly variable, indicating that other unknown genetic risk factor(s) modify ARPKD-associated phenotypes. To identify genetic modifiers of ARPKD severity, we created two genetically distinct Pkhd1 congenic rat strains on the Fawn-Hooded Hypertensive (FHH) and the Dahl S (SS) rat backgrounds (denoted FHH.Pkhd1 and SS.Pkhd1, respectively) that harbor the PCK-derived Pkhd1 allele. The FHH.Pkhd1 and SS.Pkhd1 strains had lower renal cyst formation at 30 days-of-age (5±2% and 8±2% cystic, respectively; P<0.001) compared to the PCK kidneys (26±4% cystic), which coincided with significantly reduced kidney weights in the FHH.Pkhd1 and SS.Pkhd1. Liver cyst formation and liver weight did not differ between PCK, FHH.Pkhd1, and SS.Pkhd1. These data indicated that the PCK genome harbors genetic modifier(s) of ARPKD severity that are not present in the FHH and SS genomes. Using high density SNP array genotyping and microarray expression analysis, we identified 50 potential modifiers of ARPKD severity in the PCK rat. Of these candidates, a damaging nonsynonymous variant in Nphp4 stood out as the most likely candidate based on variant segregation, protein modeling, network analysis, and gene ontology. Nphp4 is widely associated with the autosomal recessive cilliopathy and nephronopthisis, but had not been previously implicated in the molecular or cellular pathophysiology of ARPKD. Collectively, these data provide genetic evidence of disease modifier(s) in the PCK model of ARPKD and prioritized multiple candidates, including NPHP4, for further investigation in ARPKD pathogenesis. In this study, we used microarray to analyze transcript expression in the kidneys of 30 day old SD (n=4), PCK (n=4), FHH (n=4), FHH.Pkhd1 (n=4), SS (n=4), and SS.Pkhd1 (n=4). Samples were pooled and the pooled samples were run in triplicate. The 30 day timepoint was chosen because the differences in renal cyst formation between PCK, FHH.Pkhd1, and SS.Pkhd1 were greatest at this timepoint. To account for genetic strain differences that do not contribute to ARPKD severity, gene expression of each cystic rat strain was compared to its parental strain.
Project description:The relative contribution of polarized macrophages to the maintenance of tolerance is unknown. We examined their roles by in vivo adoptive transfer immunotherapy of M0, M1 and M2a macrophages as pre-treatment of colitis. In other experiments, M2a macrophages were used as pre-treatment or treatment of established colitis followed by immunotherapy with nTreg cells. Survival, weight gain, tissue infiltration, iTreg and Th17 cell development, T cell activation, and the frequency of proinflammatory cytokines were used as outcome measurements. Pre-treatment with M2a but not M1 macrophages increased the development of iTreg and Th17 cells. M2a macrophages used as pre-treatment or in treatment of established colitis allowed for successful therapy with nTreg cells. M1 and M2a macrophages have distinct gene expression profiles. M0, M1 and M2a macrophages were cell sorted and were used to generate total RNA for each array set, which was labeled and hybridized to Affymetrix Mouse Genome 430 2.0 GeneChips in accordance to the manufacturerâ??s protocol. Three sets of arrays were performed, and the results were averaged. The subset of probe sets whose expression increased or decreased by two-fold or more relative to M0 cells as a common standard was identified and used for further analysis.
Project description:E-cadherin downregulation in cancer cells is associated with epithelial-to-mesenchymal transition (EMT) and metastatic prowess, but the underlying mechanisms are incompletely characterized. In this study, we probed E-cadherin expression at the plasma membrane as a functional assay to identify genes involved in E-cadherin downregulation. The assay was based on the E-cadherin-dependent invasion properties of the intracellular pathogen Listeria monocytogenes. On the basis of a functional readout, automated microscopy and computer-assisted image analysis were used to screen siRNAs targeting 7,000 human genes. The validity of the screen was supported by its definion of several known regulators of E-cadherin expression, including ZEB1, HDAC1 and MMP14. We identified three new regulators (FLASH, CASP7 and PCGF1), the silencing of which was sufficient to restore high levels of E-cadherin transcription. Additionally, we identified two new regulators (FBXL5 and CAV2), the silencing of which was sufficient to increase E-cadherin expression at a post-transcriptional level. FLASH silencing regulated the expression of E-cadherin and other ZEB1-dependent genes, through post-transcriptional regulation of ZEB1, but it also regulated the expression of numerous ZEB1-independent genes with functions predicted to contribute to a restoration of the epithelial phenotype. Finally, we also report the identification of siRNA duplexes that potently restored the epithelial phenotype by mimicking the activity of known and putative microRNAs. Our findings suggest new ways to enforce epithelial phenotypes as a general strategy to treat cancer by blocking invasive and metastatic phenotypes associated with EMT The experiment is designed to compare gene expression in a mock treated HeLa229 cells versus FLASH-depleted and ZEB1-depleted cells in order to asses the specific role of ZEB1 and FLASH in epithelial-to- mezenchymal transition.
Project description:The complex milieu of inflammatory mediators associated with many diseases is often too dilute to directly measure in the periphery, necessitating development of more sensitive measurements suitable for mechanistic studies, earlier diagnosis, guiding selection of therapy, and monitoring interventions. Previously we determined that plasma of recent-onset (RO) Type 1 diabetes (T1D) patients induce a proinflammatory transcriptional signature in fresh peripheral blood mononuclear cells (PBMC) relative to that of unrelated healthy controls (HC). Here, using an optimized cryopreserved PBMC-based protocol, we compared the signature found in pre H1N1 samples to the signature associated with active H1N1 flu. UPN727 cells were stimulated with plasma that was collected pre-H1N1 (healthy) or during active-H1N1 from 5 different individuals. Gene expression analysis was perfromed in order to evaluate the transcriptional signature associated with the H1N1 influenza virus.
Project description:The complex milieu of inflammatory mediators associated with many diseases is often too dilute to directly measure in the periphery, necessitating development of more sensitive measurements suitable for mechanistic studies, earlier diagnosis, guiding selection of therapy, and monitoring interventions. Previously, we determined that plasma of recent-onset (RO) Type 1 diabetes (T1D) patients induce a proinflammatory transcriptional signature in fresh peripheral blood mononuclear cells (PBMC) relative to that of unrelated healthy controls (HC). Here, using an optimized cryopreserved PBMC-based protocol, we compared the signature found between unrelated healthy controls and patients with bacterial pneumonia. UPN727 cells were stimulated with either plasma from unrelated healthy controls (n=18) or plasma from patients with bacterial pneumonia (n=10). Gene expression analysis was perfromed in order to evaluate the transcriptional signature associated with bacterial pneumonia.