Supplementary Methods and Materials, Legends 1-2 from Farnesol-Induced Apoptosis in Human Lung Carcinoma Cells Is Coupled to the Endoplasmic Reticulum Stress Response
Supplementary Figure 2 from Farnesol-Induced Apoptosis in Human Lung Carcinoma Cells Is Coupled to the Endoplasmic Reticulum Stress Response
Supplementary Figure 1 from Farnesol-Induced Apoptosis in Human Lung Carcinoma Cells Is Coupled to the Endoplasmic Reticulum Stress Response
Global biological responses that reflect disease or exposure biology are kinetic and highly dynamic phenomena. While high-throughput DNA sequencing continues to drive genomics, the possibility of more broadly measuring changes in gene expression has been a recent development manifested by a diversity of technical platforms. Such technologies measure transcripts, proteins and small biological molecules, or metabolites, and respectively define the fields of transcriptomics, proteomics and metabolomics that can be performed at a cell-, tissue-, or organism-wide basis. Bioinformatics is the discipline that derives knowledge from the large quantity and diversity of biological, genetic, genomic and gene expression data by integrating computer science, mathematics, statistics and graphic arts. Gene, protein and metabolite expression profiles can be thought of as snapshots of the current, poorly-mapped molecular landscape. The ultimate aim of genomic platforms is to fully map this landscape to more completely describe all of the biological interactions within a living system, during disease and toxicity, and define the behaviour and relationships of all the components of a biological system. The development of databases and knowledge bases will support the integration of data from multiple domains, as well as computational modelling. This chapter will describe the technical platform methods involving DNA sequencing, mass spectrometry, nuclear magnetic resonance combined with separation systems, and bioinformatics to derive genomic and gene expression data and include the relevant bioinformatic tools for analysis. These genomic, or omics platforms should have wide application to epidemiological studies.
Granulosa cells of preovulatory follicles differentiate in response to FSH, and this differentiation is augmented by estradiol. We have previously shown that FSH-mediated granulosa cell differentiation requires functional estrogen receptor-beta (ERbeta) by demonstrating that the granulosa cells of ERbeta(-/-) FSH-treated mice are unable to maximally induce expression of the LH receptor (an indicator of granulosa cell differentiation) compared with ERbeta(+/+) controls. As a result, FSH-primed ERbeta(-/-) granulosa cells exhibit a reduced response to a subsequent ovulatory dose of LH. In this study, we further characterized the attenuated response of ERbeta(-/-) granulosa cells to stimulation by LH and FSH using isolated mouse granulosa cells and primary granulosa cell cultures. We observed a 50% reduction in cAMP levels in cultured ERbeta(-/-) granulosa cells exposed to LH compared with ERbeta(+/+) controls. We also observed an attenuated genomic response in granulosa cells isolated from FSH-primed ERbeta(-/-) mice compared with ERbeta(+/+) controls. Our data indicate that this attenuated response may result from inadequate levels of cAMP, because cAMP levels in cultured ERbeta(-/-) granulosa cells exposed to forskolin were approximately 50% lower than in ERbeta(+/+) granulosa cells. Phosphorylation of cAMP regulatory element binding protein, an indicator of protein kinase A activity, was also reduced in FSH-treated ERbeta(-/-) granulosa cells compared with ERbeta(+/+) controls. These are the first data to indicate that ERbeta plays a role in the induction of the cAMP pathway in mouse granulosa cells and that disruption of proper ERbeta signaling associated with this pathway may cause negative effects on ovulation and fertility.
Therapeutic strategies exist for human pulmonary neoplasia, however due to the heterogeneity of the disease, most are not very effective. The innate immunity gene, toll-like receptor 4 (TLR4), protects against chronic pulmonary inflammation and tumorigenesis in mice, but the mechanism is unclear. This study was designed to identify TLR4-mediated gene expression pathways that may be used as prognostic indicators of susceptibility to lung tumorigenesis in mice and provide insight into the mechanism.
Both ovarian and pituitary hormones are required for the pubertal development of the mouse mammary gland. Estradiol directs ductal elongation and branching, while progesterone leads to tertiary branching and alveolar development. The purpose of this investigation was to identify estrogen‐responsive genes associated with pubertal ductal growth in the mouse mammary gland in the absence of other ovarian hormones and at different stages of development. We hypothesized that the estrogen‐induced genes and their associated functions at early stages of ductal elongation would be distinct from those induced after significant ductal elongation had occurred. Therefore, ovariectomized prepubertal mice were exposed to 17β‐estradiol from two to 28 days, and mammary gland global gene expression analyzed by microarray analysis at various times during this period. We found that: (a) gene expression changes in our estrogen‐only model mimic those changes that occur in normal pubertal development in intact mice, (b) both distinct and overlapping gene profiles were observed at varying extents of ductal elongation, and (c) cell proliferation, the immune response, and metabolism/catabolism were the most common functional categories associated with mammary ductal growth. Particularly striking was the novel observation that genes active during carbohydrate metabolism were rapidly and robustly decreased in response to estradiol. Lastly, we identified mammary estradiol‐responsive genes that are also co‐expressed with estrogen receptor α in human breast cancer. In conclusion, our genomic data support the physiological observation that estradiol is one of the primary hormonal signals driving ductal elongation during pubertal mammary development. Mol. Reprod. Dev. 76: 733–750, 2009. Published 2009 Wiley‐Liss, Inc.
Steroid hormone receptors, like glucocorticoid (GR) and estrogen receptors (ER), are master regulators of genes that control many biological processes implicated in health and disease. Gene expression is dependent on receptor levels which are tightly regulated by the ubiquitin-proteasome system. Previous studies have shown that proteasome inhibition increases GR, but decreases ER-mediated gene expression. At the gene expression level this divergent role of the proteasome in receptor-dependent transcriptional regulation is not well understood. We have used a genomic approach to examine the impact of proteasome activity on GR- and ER-mediated gene expression in MCF-7 breast cancer cells treated with dexamethasone (DEX) or 17beta-estradiol (E2), the proteasome inhibitor MG132 (MG) or MG132 and either hormone (MD or ME2) for 24 h. Transcript profiling reveals that inhibiting proteasome activity modulates gene expression by GR and ER in a similar manner in that several GR and ER target genes are upregulated and downregulated after proteasome inhibition. In addition, proteasome inhibition modulates receptor-dependent genes involved in the etiology of a number of human pathological states, including multiple myeloma, leukemia, breast/prostate cancer, HIV/AIDS, and neurodegenerative disorders. Importantly, our analysis reveals that a number of transcripts encoding histone and DNA modifying enzymes, prominently histone/DNA methyltransferases and demethylases, are altered after proteasome inhibition. As proteasome inhibitors are currently in clinical trials as therapy for multiple myeloma, HIV/AIDS and leukemia, the possibility that some of the target molecules are hormone regulated and chromatin modifying enzymes is intriguing in this era of epigenetic therapy.
To obtain insight into the physiological functions of the Krüppel-like zinc finger protein Gli-similar 2 (Glis2), mice deficient in Glis2 expression were generated. Glis2 mutant (Glis2mut) mice exhibit significantly shorter life spans than do littermate wild-type (WT) mice due to the development of progressive chronic kidney disease with features resembling nephronophthisis. Glis2mut mice develop severe renal atrophy involving increased cell death and basement membrane thickening in the proximal convoluted tubules. This development is accompanied by infiltration of lymphocytic inflammatory cells and interstitial/glomerular fibrosis. The severity of the fibrosis, inflammatory infiltrates, and glomerular and tubular changes progresses with age. Blood urea nitrogen and creatinine increase, and Glis2mut mice develop proteinuria and ultimately die prematurely of renal failure. A comparison of the gene expression profiles of kidneys from 25-day-old/60-day-old WT and Glis2mut mice by microarray analysis showed increased expressions of many genes involved in immune responses/inflammation and fibrosis/tissue remodeling in kidneys of Glis2mut mice, including several cytokines and adhesion and extracellular matrix proteins. Our data demonstrate that a deficiency in Glis2 expression leads to tubular atrophy and progressive fibrosis, similar to nephronophthisis, that ultimately results in renal failure. Our study indicates that Glis2 plays a critical role in the maintenance of normal kidney architecture and functions.
Regulation of gene expression is integral to the development and survival of all organisms. Transcription begins with the assembly of a pre-initiation complex at the gene promoter 1 , followed by initiation of RNA synthesis and the transition to productive elongation 2 , 3 , 4 . In many cases, recruitment of RNA polymerase II (Pol II) to a promoter is necessary and sufficient for activation of genes. However, there are a few notable exceptions to this paradigm, including heat shock genes and several proto-oncogenes, whose expression is attenuated by regulated stalling of polymerase elongation within the promoter-proximal region 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 . To determine the importance of polymerase stalling for transcription regulation, we carried out a genome-wide search for Drosophila melanogaster genes with Pol II stalled within the promoter-proximal region. Our data show that stalling is widespread, occurring at hundreds of genes that respond to stimuli and developmental signals. This finding indicates a role for regulation of polymerase elongation in the transcriptional responses to dynamic environmental and developmental cues.
Retinoid-related orphan receptors alpha (RORα) and gamma (RORγ) are both expressed in liver; however, their physiological functions in this tissue have not yet been clearly defined. The RORα1 and RORγ1 isoforms, but not RORα4, show an oscillatory pattern of expression during circadian rhythm. To obtain insight into the physiological functions of ROR receptors in liver, we analyzed the gene expression profiles of livers from WT, RORα-deficient staggerer (sg) mice ( RORα sg/sg), RORγ−/−, and RORα sg/sg RORγ−/− double knockout (DKO) mice by microarray analysis. DKO mice were generated to study functional redundancy between RORα and RORγ. These analyses demonstrated that RORα and RORγ affect the expression of a number of genes. RORα and RORγ are particularly important in the regulation of genes encoding several phase I and phase II metabolic enzymes, including several 3β-hydroxysteroid dehydrogenases, cytochrome P450 enzymes, and sulfotransferases. In addition, our results indicate that RORα and RORγ each affect the expression of a specific set of genes but also exhibit functional redundancy. Our study shows that RORα and RORγ receptors influence the regulation of several metabolic pathways, including those involved in the metabolism of steroids, bile acids, and xenobiotics, suggesting that RORs are important in the control of metabolic homeostasis.
Abstract Farnesol (FOH) and other isoprenoid alcohols induce apoptosis in various carcinoma cells and inhibit tumorigenesis in several in vivo models. However, the mechanisms by which they mediate their effects are not yet fully understood. In this study, we show that FOH is an effective inducer of apoptosis in several lung carcinoma cells, including H460. This induction is associated with activation of several caspases and cleavage of poly(ADP-ribose) polymerase (PARP). To obtain insight into the mechanism involved in FOH-induced apoptosis, we compared the gene expression profiles of FOH-treated and control H460 cells by microarray analysis. This analysis revealed that many genes implicated in endoplasmic reticulum (ER) stress signaling, including ATF3, DDIT3, HERPUD1, HSPA5, XBP1, PDIA4, and PHLDA1, were highly up-regulated within 4 h of FOH treatment, suggesting that FOH-induced apoptosis involves an ER stress response. This was supported by observations showing that treatment with FOH induces splicing of XBP1 mRNA and phosphorylation of eIF2α. FOH induces activation of several mitogen-activated protein kinase (MAPK) pathways, including p38, MAPK/extracellular signal–regulated kinase (ERK) kinase (MEK)-ERK, and c-jun NH2-terminal kinase (JNK). Inhibition of MEK1/2 by U0126 inhibited the induction of ER stress response genes. In addition, knockdown of the MEK1/2 and JNK1/2 expression by short interfering RNA (siRNA) effectively inhibited the cleavage of caspase-3 and PARP and apoptosis induced by FOH. However, only MEK1/2 siRNAs inhibited the induction of ER stress–related genes, XBP1 mRNA splicing, and eIF2α phosphorylation. Our results show that FOH-induced apoptosis is coupled to ER stress and that activation of MEK1/2 is an early upstream event in the FOH-induced ER stress signaling cascade. [Cancer Res 2007;67(16):7929–36]
Glucocorticoids are widely used in the treatment of inflammatory and other diseases. However, high-dose or chronic administration often triggers troublesome side effects such as metabolic syndrome and osteoporosis. We recently described that one glucocorticoid receptor gene produces eight translational glucocorticoid receptor isoforms that have distinct gene-regulatory abilities. We show here that specific, but not all, glucocorticoid receptor isoforms induced apoptosis in human osteosarcoma U-2 OS bone cells. Whole human genome microarray analysis revealed that the majority of the glucocorticoid target genes were selectively regulated by specific glucocorticoid receptor isoforms. Real-time PCR experiments confirmed that proapoptotic enzymes necessary for cell death, granzyme A and caspase-6, were induced by specific glucocorticoid receptor isoforms. Chromatin immunoprecipitation assays further suggested that glucocorticoid receptor isoform-dependent induction of proapoptotic genes was likely due to selective coregulator recruitment and chromatin modification. Interestingly, the capabilities to transrepress proinflammatory genes were similar among glucocorticoid receptor isoforms. Together, these findings provide new evidence that translational glucocorticoid receptor isoforms can elicit distinct glucocorticoid responses and may be useful for the development of safe glucocorticoids with reduced side effects.
Previously, we described a mouse model where the well-known reproductive carcinogen with estrogenic activity, diethylstilbestrol (DES), caused uterine adenocarcinoma following neonatal treatment. Tumor incidence was dose-dependent reaching >90% by 18 mo following neonatal treatment with 1000 mu g/kg/d of DES. These tumors followed the initiation/promotion model of hormonal carcinogenesis with developmental exposure as initiator, and exposure to ovarian hormones at puberty as the promoter. To identify molecular pathways involved in DES-initiation events, uterine gene expression profiles were examined in prepubertal mice exposed to DES (1, 10, or 1000 mu g/kg/d) on days 1-5 and compared to controls. Of more than 20 000 transcripts, approximately 3% were differentially expressed in at least one DES treatment group compared to controls; some transcripts demonstrated dose-responsiveness. Assessment of gene ontology annotation revealed alterations in genes associated with cell growth, differentiation, and adhesion. When expression profiles were compared to published studies of uteri from 5-d-old DES-treated mice, or adult mice treated with 17 beta estradiol, similarities were seen suggesting persistent differential expression of estrogen responsive genes following developmental DES exposure. Moreover, several altered genes were identified in human uterine adenocarcinomas. Four altered genes [lactotransferrin (Ltf), transforming growth factor beta inducible (Tgfb1), cyclin D1 (Ccnd1), and secreted frizzled-related protein 4 (Sfrp4)], selected for real-time RT-PCR analysis, correlated well with the directionality of the microarray data. These data suggested altered gene expression profiles observed 2 wk after treatment ceased, were established at the time of developmental exposure and maybe related to the initiation events resulting in carcinogenesis. (C) 2007 Wiley-Liss, Inc.
Rationale: Nuclear receptors play a critical role in the regulation of inflammation, thus representing attractive targets for the treatment of asthma.Objective: In this study, we assess the potential regulatory function of retinoid-related orphan receptor alpha (ROR alpha) in the adaptive immune response using ovalbumin (OVA)-induced airway inflammation as a model.Methods: Allergen-induced inflammation was compared between wild-type (WT) and staggerer (ROR alpha(sg/sg)) mice, a natural mutant strain that is deficient in ROR alpha expression.Measurements and Main Results: Despite robust increases in OVA-specific IgE, ROR alpha(sg/sg) mice developed significantly less pulmonary inflammation, mucous cell hyperplasia, and eosinophilia compared with similarly treated WT animals. Induction of Th2 cytokines, including interleukin (IL)-4, IL-5, and IL-13, was also significantly less in ROR alpha(sg/sg) mice. Microarray analysis using lung RNA showed increased expression of many genes, previously implicated in inflammation, in OVA-treated WT mice. These include mucin Muc5b, the chloride channel calcium-activated 3 (Clca3), macrophage inflammatory protein (MIP) 1 alpha and 1 beta, eotaxin-2, serum amyloid A3 (Saa3), and insulin-like growth factor 1 (Igf1). These genes were induced to a greater extent in OVA-treated WT mice relative to ROR alpha(sg/sg) mice.Conclusions: Our study demonstrates that mice deficient in ROR alpha exhibit an attenuated allergic inflammatory response, indicating that ROR alpha plays a critical role in the development of Th2-driven allergic lung inflammation in mice, and suggests that this nuclear receptor should be further evaluated as a potential asthma target.
RORγ2 (retinoid-related orphan receptor γ2) plays a critical role in the regulation of thymopoiesis. Microarray analysis was performed in order to uncover differences in gene expression between thymocytes of wild-type and RORγ−/− mice. This analysis identified a novel gene encoding a 22 kDa protein, referred to as NABP1 (nucleic-acid-binding protein 1). This subsequently led to the identification of an additional protein, closely related to NABP1, designated NABP2. Both proteins contain an OB (oligonucleotide/oligosaccharide binding) motif at their N-terminus. This motif is highly conserved between the two proteins. NABP1 is highly expressed in the thymus of wild-type mice and is greatly suppressed in RORγ−/− mice. During thymopoiesis, NABP1 mRNA expression is restricted to CD4+CD8+ thymocytes, an expression pattern similar to that observed for RORγ2. These observations appear to suggest that NABP1 expression is regulated either directly or indirectly by RORγ2. Confocal microscopic analysis showed that the NABP1 protein localizes to the nucleus. Analysis of nuclear proteins by size-exclusion chromatography indicated that NABP1 is part of a high molecular-mass protein complex. Since the OB-fold is frequently involved in the recognition of nucleic acids, the interaction of NABP1 with various nucleic acids was examined. Our results demonstrate that NABP1 binds single-stranded nucleic acids, but not double-stranded DNA, suggesting that it functions as a single-stranded nucleic acid binding protein.
Different degrees of a toxic response between and within the various lobes of the liver have been observed in rodents following treatment with acetaminophen. This study was designed to compare 2 sampling methods of the rat liver for gene-expression analysis. Ten male Fischer 344/N rats, 12–14 weeks of age, were treated with vehicle (0.5% aqueous ethyl cellulose) or acetaminophen (APAP, 1500 mg/kg) and sacrificed 24 hours following dose administration. Two representative sections were collected from the left liver lobe, stained with hematoxylin and eosin (H&E), and evaluated independently by 2 pathologists. The central core of the left lobe was cubed and frozen. Five random cubes were conserved, while the remaining left lobe core was pulverized. From each of the 10 animals, 2 random cubes and 2 samples from the homogeneous, pulverized samples were prepared for microarray analysis. Histopathologic evaluation revealed a variable response of centrilobular necrosis within the left lobe. Multiple methods used to analyze the microarray data indicated that sampling technique was not a major contributor to the variability observed in the gene expression data; however, only the powdered samples clustered for all animals, even those with disparate histopathologic results. Additionally, a powdered sample provided the advantages of a homogenous sample pool and the ability to use sample aliquots for other analyses to include proteomics, metabonomics, and other molecular techniques.
A proposed membrane-mediated mechanism of rapid nongenomic response to estrogen has been the intense focus of recent research. Estren, a synthetic steroid, is reported to act selectively through a rapid membrane-mediated pathway, rather than through the classical nuclear estrogen receptor (ER)-mediated pathway, to maintain bone density in ovariectomized mice without uterotropic effects. To evaluate the mechanism and physiological effects of estren, we studied responses in adult ovariectomized mice. In a 3-d uterine bioassay, we found that 300 microg estren significantly increased uterine weight; in comparison, a more maximal response was seen with 1 mug estradiol (E2). The estren response was partly ERalpha independent, because ERalpha knockout (alphaERKO) uteri also exhibited a more moderate weight increase. Estren induced epithelial cell proliferation in wild-type, but not alphaERKO, mice, indicating ERalpha dependence of the epithelial growth response. Examination of estren-regulated uterine genes by microarray indicated that early (2 h) changes in gene expression are similar to the early responses to E2. These gene responses are ERalpha dependent, because they are not seen in alphaERKO mice. Later estren-induced changes in gene expression (24 h) are blunted compared with those seen 24 h after E2. In contrast to early genes, these later estren responses are independent of ERalpha, because the alphaERKO shows a similar response to estren at 24 h. We found that E2 or estren treatments lead to depletion of ERalpha in the uterine cytosol fraction and accumulation in the nuclear fraction within 30-60 min, consistent with the ability of estren to regulate genes through a nuclear ERalpha rather than a nongenomic mechanism. Interestingly, estren, but not E2, induces accumulation of androgen receptor (AR) in the nuclear fraction of both wild-type and alphaERKO samples, suggesting that AR might be involved in the later ERalpha-independent genomic responses to estren. In conclusion, our studies suggest that estren is weakly estrogenic in the mouse uterus and might induce nuclear ERalpha- and AR-mediated responses. Given its activity in our uterine model, the use of estren as a bone-selective clinical compound needs to be reconsidered.
Regulatory factor X4 variant transcript 3 (Rfx4_v3) gene disruption in mice demonstrated that interruption of a single allele (heterozygous, +/-) prevented formation of the subcommissural organ, resulting in congenital hydrocephalus, while interruption of two alleles (homozygous, -/-) caused fatal failure of dorsal midline brain structure formation. To identify potential target genes for RFX4_v3, we used microarray analysis to identify differentially expressed genes in Rfx4_v3-deficient mouse brains at embryonic day 10.5, before gross structural changes were apparent. Of 109 differentially expressed transcripts, 24 were chosen for validation and 22 were confirmed by real-time PCR. Many validated genes encoded critical proteins involved in brain morphogenesis, such as the signaling components in the Wnt, bone morphogenetic protein (BMP) and retinoic acid (RA) pathways. Cx3cl1, a CX3C-type chemokine gene that is highly expressed in brain, was down-regulated in the Rfx4_v3-null mice. Both human and mouse Cx3cl1 proximal promoters contained highly conserved X-boxes, known cis-acting elements for RFX protein binding. Using the Cx3cl1 promoter as an example of a target gene, we demonstrated direct binding of RFX4_v3 to the Cx3cl1 promoter, and trans-acting activity of RFX4_v3 protein to stimulate gene expression. These data suggest that RFX4_v3 may act upstream of critical signaling pathways in the process of brain development.