Laser capture microdissected choroid plexuses were obtained and expression arrays were generated to investigate gene expression in wt and ApoE choroid plexuses; the choroid plexus forms the cerebrospinal fluid, the cerebrospinal fliod barrier, functions as the major gateway for blood-born leukocytes to enter the brain in degenerative and inflammatory brain diseases, and the principal neuroimmune interface in the brain. We found lipid deposits in the aged choroid plexus of hyperlipidemic mice but none in the wt control choroid plexuses. Here, we studied the functional impact and gene epressions in wt and ApoE-deficient choroid plexuses.
ApoE attenuates unresolvable inflammation by complex formation with activated C1q.
Sex, Age, Specimen part
View SamplesMolecular targeted compounds are emerging as important component to improve the efficacy of classical chemotherapeutics. In this study, we tested whether using low dose sorafenib to reduce off target inhibitions of kinases impacts the antitumor effect of alkylating agents in breast cancer models. Overall design: MDA-MB231 cells were treated with 1 µM sorafenib, 40 µg/mL MMS, or pre-incubated with 1 µM sorafenib for 12 h followed by 40 µg/mL MMS, each in two independent experiments. RNA was harvested 8 and 24 h, or post MMS treatment for combination treatment.
Sorafenib improves alkylating therapy by blocking induced inflammation, invasion and angiogenesis in breast cancer cells.
Specimen part, Cell line, Subject
View SamplesEwing's sarcoma family of tumors (ESFT) is an aggressive pediatric bone and soft tissue cancer. It is the prototypical example of mesenchymal tumors driven by a fusion oncogene involving the ewing sarcoma break point region 1 (EWSR1) gene, most frequently– EWS-FLI1. We have discovered that loss of EWSR1 leads to accumulation of R-loops, replication stress and impaired homologous recombination, recapitulating breast cancer 1, early onset (BRCA1) deficiency. EWS-FLI1 acts dominant negatively in ESFT to impart the same phenotypes. Further we demonstrate that in ESFT, BRCA1 predominantly associates with the elongating transcription machinery and is unavailable for DNA strand break repair. Gene expression profiling identified upregulated compensatory mechanisms in ESFT cells to process increased R-loops (RNASEH2 and FEN1) and replication stress (Fanconi Anemia). Taken together, our data identifies BRCA1 sequestration due to transcription stress as the mechanistic basis for ESFT chemosensitivity and suggests potential targets for the much lacking second-line therapy. Overall design: Examination of gene expression of four ESFT cell lines and two control cell lines. Cells were treated to LD65 dose of etoposideand samples collected at 6 hour intervals over 24 hours
EWS-FLI1 increases transcription to cause R-loops and block BRCA1 repair in Ewing sarcoma.
No sample metadata fields
View SamplesTertiary lymphoid organs (TLOs) emerge in response to nonresolving inflammation but their roles in adaptive immunity remain unknown. Here, we explored artery TLOs (ATLOs) to delineate atherosclerosis T cell responses in apoe-/- mice during aging. Though the T cell repertoire showed systemic age-associated contractions in size and modifications in subtype composition and activation, wt and apoe-/- mice were equally affected. In contrast, ATLOs - but not wt aortae, apoe-/- aorta segments without ATLOs or atherosclerotic plaques - promoted T cell recruitment, altered characteristics of T cell motility, primed and imprinted T cells in situ, generated CD4+/FoxP3-, CD4+/FoxP3+, CD8+/FoxP3- effector and central memory cells, and converted nave CD4+/FoxP3- T cells into induced Treg cells. ATLOs also showed substantially increased antigen presentation capability by conventional dendritic cells (DCs) and monocyte-derived DCs but not by plasmacytoid DCs. Thus, the senescent immune system specifically employs ATLOs to control dichotomic atherosclerosis T cell immune responses. We assembled transcriptome maps of wt and apoe-/- aortae and aorta-draining RLNs and identified ATLOs as major sites of atherosclerosis-specific T cell responses during aging: Transcriptome atlases of wt and apoe-/- abdominal aortae and associated draining RLNs were constructed from laser capture microdissection (LCM)-based whole genome mRNA expression microarrays yielding 6 maps: wt adventitia (tissue-1); wt RLN (tissue-2); apoe-/- ATLOs (tissue-3); apoe-/- RLN (tissue-4); apoe-/- adventitia without adjacent plaques (tissue-5), and plaques (tissue-6). Several two-tissue comparisons within the transcriptome atlases are noteworthy: Unexpectedly, transcriptomes of wt and apoe-/- RLNs were virtually identical; additonal data revealed that transcriptomes of RLNs were strikingly similar to those of inguinal LNs which do not drain the aorta adventitia (as shown of India ink injection experiments of surgically exposed aortae); in sharp contrast, wt adventitia versus ATLOs revealed 1405 differentially expressed transcripts many of which encoded members of GO terms immune response and inflammatory response; the ATLO-plaque comparison also showed > 1000 differentially expressed transcripts; however, wt adventitia versus apoe-/- adventitia without plaque showed few genes (< 5 % of differentially expressed transcripts of the wt adventitia-ATLO comparison). Thus, the aorta transcriptome atlases support the conclusion that neither aorta-draining apoe-/- RLNs nor ILNs participate in atherosclerosis-specific T cell responses. In addition, they demonstrate that T cell responses in the diseased aorta are highly territorialized. Finally, these data show that the immune responses carried out in ATLOs differ significantly from those carried out in plaques. We next identified three major clusters within the transcriptome atlases through ANOVA analyses and application of strict filters: An adventitia cluster, a plaque/ATLO cluster, and a LN/plaque cluster. The total number of differentially expressed genes in each cluster were examined for GO terms immune response, inflammatory response, T cell activation, positive regulation of T cell response, and T cell proliferation. Within the adventitia cluster, similarities of transcriptomes of wt adventitia and apoe-/- adventitia without associated plaque versus ATLOs indicate that a robust number of immune response-regulating genes are selectively expressed in ATLOs which are located within a distance of few m of the adventitia without associated plaques indicating a very high degree of territoriality of the atherosclerosis T cell response. Furthermore, unlike the total number of differentially regulated transcripts, the majority of transcripts among GO terms immune response and inflammatory response, was up-regulated. Inspection of the plaque/ATLO cluster provided further information: The majority of immune response regulating genes where expressed at a higher level in ATLOs when compared to plaques though plaques also contained a significant number of immune response regulating genes; the reverse is true for genes regulating inflammation. Finally, the lymph node cluster revealed that though the majority of immune response regulating genes resides in both wt and apoe-/- RLNs (with little differences between them) ATLOs express a selected set of immune response regulating genes at a higher level when compared to LNs. In addition, the inflammatory component of ATLOs when compared to LNs is documented by the finding that many more genes regulating inflammation reside in ATLOs even when compared to those of plaques.
Generation of Aorta Transcript Atlases of Wild-Type and Apolipoprotein E-null Mice by Laser Capture Microdissection-Based mRNA Expression Microarrays.
Sex, Age, Specimen part
View SamplesAtherosclerosis is a transmural chronic inflammatory condition of small and large arteries that is associated with adaptive immune responses at all disease stages. However, impacts of adaptive immune reactions on clinically apparent atherosclerosis such as intima lesion (plaque) rupture, thrombosis, myocardial infarction, and aneurysm largely remain to be identified. It is increasingly recognized that leukocyte infiltrates in plaque, media, and adventitia are distinct but their specific roles have not been defined. To map these infiltrates, we employed laser capture microdissection (LCM) to isolate the three arterial wall laminae using apoE-/- mouse aorta as a model. RNA from LCM-separated tissues was extracted and large scale whole genome expression microarrays were prepared. We observed that the quality of the resulting gene expression maps was compromised by tissue RNA carried over from adjacent laminae during LCM. To account for these flaws, we established quality controls and algorithms to improve the predictive power of LCM-derived microarray data. Our approach creates robust transcriptome atlases of normal and atherosclerotic aorta. Assessing LCM transcriptomes for immunity-related mRNAs indicated markedly distinctive gene expression patterns in the three laminae of the atherosclerotic aorta. These mouse mRNA expression data banks can now be mined to address a wide range of questions in cardiovascular biology.
The lamina adventitia is the major site of immune cell accumulation in standard chow-fed apolipoprotein E-deficient mice.
Sex, Age, Specimen part
View SamplesPPAR is known for its anti-inflammatory actions in macrophages. However, which macrophage populations express PPAR in vivo and how it regulates tissue homeostasis in the steady state and during inflammation is not completely understood. We show that lung and spleen macrophages constitutively expressed PPAR, while other macrophage populations did not. Recruitment of monocytes to sites of inflammation was associated with induction of PPAR as they differentiated to macrophages. Its absence in these macrophages led to failed resolution of inflammation, characterized by persistent, low-level recruitment of leukocytes. Conversely, PPAR agonists supported an earlier cessation in leukocyte recruitment during resolution of acute inflammation and likewise suppressed monocyte recruitment to chronically inflamed atherosclerotic vessels. In the steady state, PPAR deficiency in macrophages had no obvious impact in the spleen but profoundly altered cellular lipid homeostasis in lung macrophages. Reminiscent of pulmonary alveolar proteinosis, LysM-Cre x PPARflox/flox mice displayed mild leukocytic inflammation in the steady-state lung and succumbed faster to mortality upon infection with S. pneumoniae. Surprisingly, this mortality was not due to overly exuberant inflammation, but instead to impaired bacterial clearance. Thus, in addition to its anti-inflammatory role in promoting resolution of inflammation, PPAR sustains functionality in lung macrophages and thereby has a pivotal role in supporting pulmonary host defense.
Systemic analysis of PPARγ in mouse macrophage populations reveals marked diversity in expression with critical roles in resolution of inflammation and airway immunity.
Sex, Treatment
View SamplesHuman and mouse blood each contain two monocyte subsets. Here, we investigated the extent of their similarity using a microarray approach. Approximately 300 genes in human and 550 genes in mouse were differentially expressed between subsets. More than 130 of these gene expression differences were conserved between mouse and human monocyte subsets. We confirmed numerous differences at the cell surface protein level. Despite overall conservation, some molecules were conversely expressed between the two species subsets, including CD36, CD9, and TREM-1. Furthermore, other differences existed, including a prominent PPAR signature in mouse monocytes absent in human. Overall, human and mouse monocyte subsets are far more broadly conserved than currently recognized. Thus, studies in mice may indeed yield relevant information regarding the biology of human monocyte subsets. However, differences between the species deserve consideration in models of human disease studied in the mouse.
Comparison of gene expression profiles between human and mouse monocyte subsets.
No sample metadata fields
View SamplesHuman and mouse blood each contain two monocyte subsets. Here, we investigated the extent of their similarity using a microarray approach. Approximately 300 genes in human and 550 genes in mouse were differentially expressed between subsets. More than 130 of these gene expression differences were conserved between mouse and human monocyte subsets. We confirmed numerous differences at the cell surface protein level. Despite overall conservation, some molecules were conversely expressed between the two species subsets, including CD36, CD9, and TREM-1. Furthermore, other differences existed, including a prominent PPAR signature in mouse monocytes absent in human. Overall, human and mouse monocyte subsets are far more broadly conserved than currently recognized. Thus, studies in mice may indeed yield relevant information regarding the biology of human monocyte subsets. However, differences between the species deserve consideration in models of human disease studied in the mouse.
Comparison of gene expression profiles between human and mouse monocyte subsets.
No sample metadata fields
View SamplesMouse aorta smooth muscle cells (SMCs) express TNF receptor superfamily member 1A (TNFR1) and lymphotoxin receptor (LTR). Circumstantial evidence has linked the SMC LTR to tertiary lymphoid organogenesis in diseased aortae of hyperlipidemic mice. Here, we explored potential roles of TNFR1 and LTR activation in cultured SMCs. TNFR1 signaling by TNF activated the classical RelA NF-B pathway, whereas LTR signaling by agonistic anti LTR antibody activated both the classical RelA and alternative RelB NF-B pathways. Addition of both agonists synergized to enhance p100 inhibitor processing to the p52 subunit of NF-B and promoted its nuclear translocation suggesting RelA-RelB cross-talk in transcription regulation. Correspondingly, microarrays showed that simultaneous TNFR1 and LTR activation when compared to activation of single receptors was followed by markedly elevated levels of mRNAs encoding leukocyte homeostatic chemokines CCL2, CCL5, CXCL1, and CX3CL1. Furthermore, SMCs acquired prototypical features of mesenchymal cells known as lymphoid tissue organizers (LTOs), which control tertiary lymphoid organogenesis in autoimmune diseases, through hyperinduction of CCL7, CCL9, CXCL13, CCL19, CXCL16, VCAM-1, and ICAM-1. Experiments with ltbr-/- SMCs suggested that the LTR-RelB activation component of NF-B signaling was obligatory to generate the LTO phenotype. TNFR1-LTR crosstalk also resulted in augmented synthesis and prolonged secretion of lymphorganogenic chemokine proteins into the culture medium. Thus, combined TNFR1-LTR signaling triggers SMC transdifferentiation into a phenotype that strikingly resembles LTOs. LTO-like SMCs may adopt a thus far unrecognized role in diseased arteries, i.e. to coordinate tertiary lymphoid organogenesis in atherosclerosis, aortic aneurysm, and transplant vasculopathy.
Mouse aorta smooth muscle cells differentiate into lymphoid tissue organizer-like cells on combined tumor necrosis factor receptor-1/lymphotoxin beta-receptor NF-kappaB signaling.
No sample metadata fields
View SamplesCultured mouse aorta endothelial cells (from 8-12 weeks old C57BL/6J mice, passage 2-3) were exposed to phosphate buffered saline (control) or a combination of TNFalpha plus agonistic alpha-LTR antibody for 24 hours as described in Ltzer et al. 2009. Arterioscler. Thromb. Vasc. Biol., in press. Total RNA was extracted and microarrays were prepared.
Mouse aorta smooth muscle cells differentiate into lymphoid tissue organizer-like cells on combined tumor necrosis factor receptor-1/lymphotoxin beta-receptor NF-kappaB signaling.
Specimen part
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