Pancreatic beta-cell dysfunction and death are central in the pathogenesis of type 2 diabetes. Saturated fatty acids cause beta-cell failure and contribute to diabetes development in genetically predisposed individuals. Here we used RNA-sequencing to map transcripts expressed in five palmitate-treated human islet preparations, observing 1,325 modified genes. Palmitate induced fatty acid metabolism and endoplasmic reticulum (ER) stress. Functional studies identified novel mediators of adaptive ER stress signaling. Palmitate modified genes regulating ubiquitin and proteasome function, autophagy and apoptosis. Inhibition of autophagic flux and lysosome function contributed to lipotoxicity. Palmitate inhibited transcription factors controlling beta-cell phenotype including PAX4 and GATA6. 59 type 2 diabetes candidate genes were expressed in human islets, and 11 were modified by palmitate. Palmitate modified expression of 17 splicing factors and shifted alternative splicing of 3,525 transcripts. Ingenuity Pathway Analysis of modified transcripts and genes confirmed that top changed functions related to cell death. DAVID analysis of transcription binding sites in palmitate-modified transcripts revealed a role for PAX4, GATA and the ER stress response regulators XBP1 and ATF6. This human islet transcriptome study identified novel mechanisms of palmitate-induced beta-cell dysfunction and death. The data point to crosstalk between metabolic stress and candidate genes at the beta-cell level. Overall design: 5 human islet of Langerhans preparations examined under 2 conditions (control and palmitate treatment)
RNA sequencing identifies dysregulation of the human pancreatic islet transcriptome by the saturated fatty acid palmitate.
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View SamplesThis series contain mouse and rat lung samples treated with mechanical ventilation and corresponded controls.
Bioinformatic identification of novel early stress response genes in rodent models of lung injury.
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View SamplesPulmonary hypertension (PH) and cancer pathophysiology share common signal transduction pathways leading to abnormal endothelial and smooth muscle cell interactions and angioproliferative vasculopathy. Sorafenib (Sor) a drug in clinical trials for cancer treatment, is an inhibitor of multiple kinases important in angiogenesis (Raf-1 kinase, VEGFR-2, VEGFR-3, PDGFR-beta). In this study, we assessed the efficacy of Sor as a potential therapy for PH, and hypothesized that Sor prevents the development of both a conventional and an augmented rodent model of PH. We performed studies in Dahl Salt-Sensitive rats (SS) exposed to hypoxia alone and in combination with the VEGFR-2 inhibitor, SU5416, known to induce a well-characterized augmented PH phenotype. Rats were, thus, divided into 5 groups: normoxia/vehicle (Norm), hypoxia/vehicle (H), hypoxia/ SU5416 (H-SU), hypoxia/Sorafenib (H-Sor) and hypoxia/ SU5416/ Sorafenib (H-SU-Sor). Except for the Norm group, all rats were maintained in a hypoxia chamber with a FiO2 of 10%. Rats received a single injection of SU5416 on Day 1 (20 mg/kg) and Sor solution was administered daily by gavage (2.5mg/kg). After 3.5 weeks, all rats were assessed by open chest catheterizations for pulmonary vascular and right ventricular pressures. Lung and heart tissue were harvested for histological and microarray analyses. Our results showed H-SU rats developed severe PH with changes in hemodynamic and histologic parameters when compared to Norm controls while rats exposed to H alone only displayed mildly elevated pressures compared with Norm. There was no significant change in pressures in the H-Sor or H-SU-Sor compared to Norm. Histopathology demonstrated a dramatic prevention of the PH phenotype in the H-SU-Sor rats with no significant remodeling compared with H-SU rats. Expression profiling data from H (n=4) and H-SU (n=3) rat lungs were compared to Norm (n=4) using normalization in R and SAM (>.639,) (minimum fold change >1.4). With false discovery rates (FDR) of 6.5% in hypoxia and 1.6% in H-SU, 1019 and 465 genes, respectively, were differentially-regulated compared to Norm. In addition, 38 genes were differentially expressed between H-SU and H-SU-Sor (n=4, FDR 6.7%) revealing a molecular signature with potentially novel target genes of Sor. Five differentially expressed genes (Tgfbeta3, C1qg, Nexn, Frzb, and Plaur) were examined by real-time RT-PCR and three were further validated by immunohistochemistry confirming the regulation on protein level. Based on the known pathways of hypoxic-induced PH and Sor, we further utilized immunohistochemistry to show the up-regulation of mediators of the MAPK cascade in the H and H-SU models of PH with subsequent, down-regulation by Sor. We therefore present Sor as a novel treatment for the development of severe PH and theorize that the MAPK cascade is a canonical pathway involved both in the development of PH and in the attenuation by Sor.
Genomic assessment of a multikinase inhibitor, sorafenib, in a rodent model of pulmonary hypertension.
No sample metadata fields
View SamplesPulmonary hypertension (PH) and cancer pathophysiology share common signal transduction pathways leading to abnormal endothelial and smooth muscle cell interactions and angioproliferative vasculopathy. Sorafenib (Sor) a drug in clinical trials for cancer treatment, is an inhibitor of multiple kinases important in angiogenesis (Raf-1 kinase, VEGFR-2, VEGFR-3, PDGFR-beta). In this study, we assessed the efficacy of Sor as a potential therapy for PH, and hypothesized that Sor prevents the development of both a conventional and an augmented rodent model of PH. We performed studies in Dahl Salt-Sensitive rats (SS) exposed to hypoxia alone and in combination with the VEGFR-2 inhibitor, SU5416, known to induce a well-characterized augmented PH phenotype. Rats were, thus, divided into 5 groups: normoxia/vehicle (Norm), hypoxia/vehicle (H), hypoxia/ SU5416 (H-SU), hypoxia/Sorafenib (H-Sor) and hypoxia/ SU5416/ Sorafenib (H-SU-Sor). Except for the Norm group, all rats were maintained in a hypoxia chamber with a FiO2 of 10%. Rats received a single injection of SU5416 on Day 1 (20 mg/kg) and Sor solution was administered daily by gavage (2.5mg/kg). After 3.5 weeks, all rats were assessed by open chest catheterizations for pulmonary vascular and right ventricular pressures. Lung and heart tissue were harvested for histological and microarray analyses. Our results showed H-SU rats developed severe PH with changes in hemodynamic and histologic parameters when compared to Norm controls while rats exposed to H alone only displayed mildly elevated pressures compared with Norm. There was no significant change in pressures in the H-Sor or H-SU-Sor compared to Norm. Histopathology demonstrated a dramatic prevention of the PH phenotype in the H-SU-Sor rats with no significant remodeling compared with H-SU rats. Expression profiling data from H (n=4) and H-SU (n=3) rat lungs were compared to Norm (n=4) using normalization in R and SAM (>.639,) (minimum fold change >1.4). With false discovery rates (FDR) of 6.5% in hypoxia and 1.6% in H-SU, 1019 and 465 genes, respectively, were differentially-regulated compared to Norm. In addition, 38 genes were differentially expressed between H-SU and H-SU-Sor (n=4, FDR 6.7%) revealing a molecular signature with potentially novel target genes of Sor. Five differentially expressed genes (Tgfbeta3, C1qg, Nexn, Frzb, and Plaur) were examined by real-time RT-PCR and three were further validated by immunohistochemistry confirming the regulation on protein level. Based on the known pathways of hypoxic-induced PH and Sor, we further utilized immunohistochemistry to show the up-regulation of mediators of the MAPK cascade in the H and H-SU models of PH with subsequent, down-regulation by Sor. We therefore present Sor as a novel treatment for the development of severe PH and theorize that the MAPK cascade is a canonical pathway involved both in the development of PH and in the attenuation by Sor.
Genomic assessment of a multikinase inhibitor, sorafenib, in a rodent model of pulmonary hypertension.
No sample metadata fields
View SamplesPulmonary hypertension (PH) and cancer pathophysiology share common signal transduction pathways leading to abnormal endothelial and smooth muscle cell interactions and angioproliferative vasculopathy. Sorafenib (Sor) a drug in clinical trials for cancer treatment, is an inhibitor of multiple kinases important in angiogenesis (Raf-1 kinase, VEGFR-2, VEGFR-3, PDGFR-beta). In this study, we assessed the efficacy of Sor as a potential therapy for PH, and hypothesized that Sor prevents the development of both a conventional and an augmented rodent model of PH. We performed studies in Dahl Salt-Sensitive rats (SS) exposed to hypoxia alone and in combination with the VEGFR-2 inhibitor, SU5416, known to induce a well-characterized augmented PH phenotype. Rats were, thus, divided into 5 groups: normoxia/vehicle (Norm), hypoxia/vehicle (H), hypoxia/ SU5416 (H-SU), hypoxia/Sorafenib (H-Sor) and hypoxia/ SU5416/ Sorafenib (H-SU-Sor). Except for the Norm group, all rats were maintained in a hypoxia chamber with a FiO2 of 10%. Rats received a single injection of SU5416 on Day 1 (20 mg/kg) and Sor solution was administered daily by gavage (2.5mg/kg). After 3.5 weeks, all rats were assessed by open chest catheterizations for pulmonary vascular and right ventricular pressures. Lung and heart tissue were harvested for histological and microarray analyses. Our results showed H-SU rats developed severe PH with changes in hemodynamic and histologic parameters when compared to Norm controls while rats exposed to H alone only displayed mildly elevated pressures compared with Norm. There was no significant change in pressures in the H-Sor or H-SU-Sor compared to Norm. Histopathology demonstrated a dramatic prevention of the PH phenotype in the H-SU-Sor rats with no significant remodeling compared with H-SU rats. Expression profiling data from H (n=4) and H-SU (n=3) rat lungs were compared to Norm (n=4) using normalization in R and SAM (>.639,) (minimum fold change >1.4). With false discovery rates (FDR) of 6.5% in hypoxia and 1.6% in H-SU, 1019 and 465 genes, respectively, were differentially-regulated compared to Norm. In addition, 38 genes were differentially expressed between H-SU and H-SU-Sor (n=4, FDR 6.7%) revealing a molecular signature with potentially novel target genes of Sor. Five differentially expressed genes (Tgfbeta3, C1qg, Nexn, Frzb, and Plaur) were examined by real-time RT-PCR and three were further validated by immunohistochemistry confirming the regulation on protein level. Based on the known pathways of hypoxic-induced PH and Sor, we further utilized immunohistochemistry to show the up-regulation of mediators of the MAPK cascade in the H and H-SU models of PH with subsequent, down-regulation by Sor. We therefore present Sor as a novel treatment for the development of severe PH and theorize that the MAPK cascade is a canonical pathway involved both in the development of PH and in the attenuation by Sor.
Genomic assessment of a multikinase inhibitor, sorafenib, in a rodent model of pulmonary hypertension.
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View SamplesMutations in the mitochondrial DNA (mtDNA) have been proposed to be essential for metabolic adaptation, and because metabolism is intrinsically associated with multiple disease states, including obesity, we hypothesized that changes in the mtDNA would significantly influence adiposity and gene expression in response to diet. To test these predictions we used Mitochondrial-Nuclear eXchange mice, which have nuclear and mitochondrial genomes that have been exchanged from different M. musculus strains. Overall design: Purpose: Mutations in the mitochondrial DNA (mtDNA) have been proposed to be essential for metabolic adaptation, and because metabolism is intrinsically associated with multiple disease states, including obesity, we hypothesized that changes in the mtDNA would significantly influence adiposity and gene expression in response to diet. To test these predictions we used Mitochondrial-Nuclear eXchange mice, which have nuclear and mitochondrial genomes that have been exchanged from different M. musculus strains. Methods: Wild type (C57BL6/J – C57n:C57mt and C3H/HeN - C3Hn:C3Hmt) and MNX (C57n:C3Hmt and C3Hn:C57mt) mouse were weaned with Chor diet and continued with Chow or changed to high-fat diet from 6 to 12-13 weeks of age. RNA samples were isolated from white adipose tissues collected from epididymal (eWAT) and inguinal (iWAT) fat, representing visceral and subcutaneous fat depots, respectively with RNeasy kit (Qiagen). Reverse transcribed cDNA libraries were sequenced with an Illumina HiSeq 2000. Read mapping was conducted with a proprietary algorithm by Expression Analysis (www.q2labsolutions.com), and read counts were used as input for differential expression analysis in DESeq2 version 1.10.1, using default settings. Results: Using an optimized data analysis workflow, we mapped about 20 million sequence reads per sample to the mouse genome (build mm9). Transcriptional changes were interrogated for 961 genes previously reported to be associated with fat metabolism and 29,209 genes representing the entire mouse transcriptome. These results show that the C57 mtDNA increased the number of DE genes in response to high fat diet in mice harboring the C3H nuclear genome (209% increase; C3Hn:C57mt versus C3Hn:C3Hmt, 165/79) and the C3H mtDNA decreased response in animals carrying the C57 nucleus (46% decrease; C57n:C3Hmt versus C57n:C57mt, 112/206) in eWAT (Figure 2B). Similarly, the high fat diet resulted in 25 and 231 DE genes in the C3Hn:C3Hmt and C3Hn:C57mt iWAT, respectively, and 344 and 143 DE genes in C57n:C57mt and C57n:C3Hmt iWAT. This corresponded to a 924% increase in the number of DE genes responding to high fat diet C3Hn:C57mt versus C3Hn:C3Hmt, and a decreased response (58% decrease) in C57n:C3Hmt relative to C57n:C57mt iWAT. Further analysis showed that each MNX and corresponding wild-type shared and had distinct DE genes in eWAT and iWAT. Conclusions: Results also show that the degree of transcriptional response influenced by the mtDNA can vary based upon the type of adipose tissue, suggesting that mtDNA background can have varying effects on the number of nuclear genes differentially responding to stimuli, depending upon tissue and location.
Mitochondrial - nuclear genetic interaction modulates whole body metabolism, adiposity and gene expression in vivo.
Specimen part, Subject
View SamplesWe explored the mechanistic involvement of the growth arrest and DNA damageinducible gene, GADD45a, in LPS- and ventilator-induced inflammatory lung injury (VILI). Multiple biochemical and genomic parameters of inflammatory lung injury indicated GADD45a-/- mice to be modestly susceptible to intratracheal LPS-induced lung injury and profoundly susceptible to high tidal volume ventilation-induced lung injury (VILI) with increases in microvascular permeability and levels of inflammatory cytokines in bronchoalveolar lavage. Expression profiling of lung tissues from GADD45a-/- mice revealed strong dysregulation in the B cell receptor signaling pathway suggesting involvement of PI3 kinase/Akt signaling components while the wild type controls depicted no observable changes. Western blot analyses of lung homogenates confirmed ~50% reduction in Akt protein levels in GADD45a-/- mice accompanied by marked increases in Akt ubiquitination. Electrical resistance measurements across human lung endothelial cell monolayers with either reduced GADD45a or Akt expression (siRNAs) revealed significant potentiation of LPS-induced human lung endothelial barrier dysfunction which was attenuated by overexpression of a constitutively active Akt1 transgene. These studies validate GADD45a as a novel candidate gene in inflammatory lung injury and a significant participant in vascular barrier regulation via effects on Akt-mediated endothelial signaling
GADD45a is a novel candidate gene in inflammatory lung injury via influences on Akt signaling.
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View SamplesLung transplantation remains the only viable therapy for patients with end-stage lung disease; however, full utilization of this treatment strategy is severely compromised by the lack of donor lung availability. For example, the vast majority of donor lungs available for transplantation are obtained from brain death (BD) individuals. Unfortunately, the autonomic storm which accompanies BD often results in neurogenic pulmonary edema (NPE), thereby either producing irreversible lung injury or leading to primary graft dysfunction following lung transplantation. We previously demonstrated that sphingosine 1-phosphate (S1P), a phospholipid angiogenic factor and major barrier-enhancing agent, as well as S1P analogues serve to reduce vascular permeability and ischemia/reperfusion (I/R) lung injury in rodents via ligation of the S1P1 receptor, S1PR1. As primary lung graft dysfunction is induced by lung vascular endothelial cell barrier dysfunction, we hypothesized that SEW-2871, a S1PR1 agonist, may attenuate NPE when administered to the donor shortly after BD. Significant lung injury was observed 4h after BD in a rat BD model with ~60% increases in BAL total protein, BAL cell counts, and lung tissue W/D weight ratios. In contrast, rats receiving SEW-2871 (0.1 mg/kg) 15 minutes after the induction of BD and assessed 4h later exhibited significant lung protection (~50% reduction, p=0.01) reflected by reduced BAL total protein, BAL cytokines concentrations, BAL albumin, BAL total cell count and lung tissue wet/dry (W/D) weights ratio. Microarray analysis at 4hrs revealed a global impact of both BD and SEW on lung gene expression with differential expression of a subclass of genes enriched in immune/inflammation response pathways across the 4 experimental groups. Overall, SEW served to attenuate the BD-mediated ie gene expression upregulation. Two potentially useful biomarkers, Tnf and Ccrl2, exhibited gene dysregulation by microarray analysis, which was validated by qPCR. We conclude that SEW-2871 significantly attenuates BD-induced lung injury and may serve as a potential candidate to improve human lung donor availability and transplantation outcomes.
A sphingosine 1-phosphate 1 receptor agonist modulates brain death-induced neurogenic pulmonary injury.
Sex, Specimen part, Treatment
View SamplesSerrated adenocarcinomas are morphologically different from conventional adenocarcinomas. The serrated pathway has recently been proposed to represent a novel mechanism of colorectal cancer (CRC) formation. However, whether they are biologically different and truly form a distinct subclass of CRC, is not known. This study shows that the gene expression profile of serrated and conventional CRCs differs from each others and that serrated CRCs are not only morphologically novel, but also biologically distinct subclass of CRC.
Serrated carcinomas form a subclass of colorectal cancer with distinct molecular basis.
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View SamplesMelanocytes within benign human nevi are the paradigm for tumor suppressive senescent cells in a pre-malignant neoplasm. These cells typically contain mutations in either the BRAF or N-RAS oncogene and express markers of senescence, including p16. However, a nevus can contain 10s to 100s of thousands of clonal melanocytes and approximately 20-30% of melanoma are thought to arise in association with a pre-existing nevus. Neither observation is indicative of fail-safe senescence-associated proliferation arrest and tumor suppression. We set out to better understand the status of nevus melanocytes. Proliferation-promoting Wnt target genes, such as cyclin D1 and c-myc, were repressed in oncogene-induced senescent melanocytes in vitro, and repression of Wnt signaling in these cells induced a senescent-like state. In contrast, cyclin D1 and c-myc were expressed in many melanocytes of human benign nevi. Specifically, activated Wnt signalling in nevi correlated inversely with nevus maturation, an established dermatopathological correlate of clinical benignancy. Single cell analyses of lone epidermal melanocytes and nevus melanocytes showed that expression of proliferation-promoting Wnt targets correlates with prior proliferative expansion of p16-expressing nevus melanocytes. In a mouse model, activation of Wnt signaling delayed, but did not bypass, senescence of oncogene-expressing melanocytes, leading to massive accumulation of proliferation-arrested, p16-positive non-malignant melanocytes. We conclude that clonal hyperproliferation of oncogene-expressing melanocytes to form a nevus is facilitated by transient delay of senescence due to activated Wnt signaling. The observation that activation of Wnt signaling correlates inversely with nevus maturation, an indicator of clinical benignancy, supports the notion that persistent destabilization of senescence by Wnt signaling contributes to the malignant potential of nevi. Overall design: We used RNA-Seq to detail the global programme of gene expression in human melanoma cell lines
MLL1 is essential for the senescence-associated secretory phenotype.
Cell line, Subject
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