Neutrophil homeostasis is maintained, in part, by the regulated release of neutrophils from the bone marrow. Constitutive expression of the chemokine CXCL12 by bone marrow stromal cells provides a key retention signal for neutrophils in the bone marrow through activation of its receptor CXCR4. Herein, we show that the ELR chemokines CXCL1 and CXCL2 are constitutively expressed by bone marrow endothelial cells and osteoblasts, and CXCL2 expression is induced in endothelial cells during granulocyte colony-stimulating factor (G-CSF)-induced neutrophil mobilization. Neutrophils lacking CXCR2, the receptor for CXCL1 and CXCL2, are preferentially retained in the bone marrow, reproducing a myelokathexis phenotype. Transient disruption of CXCR4 failed to mobilize CXCR2 neutrophils. However, doubly deficient neutrophils (CXCR2-/- CXCR4-/-) displayed constitutive mobilization, showing that CXCR4 plays a dominant role. Collectively, these data suggest that CXCR2 signaling is a second chemokine axis that interacts antagonistically with CXCR4 to regulate neutrophil release from the bone marrow.
CXCR2 and CXCR4 antagonistically regulate neutrophil trafficking from murine bone marrow.
Specimen part, Treatment
View SamplesWe sought to identify critical factors regulating muscle stem cell activation and commitment, and determined through loss-of-function analyses that HMGA2 (high mobility group AT-hook 2) is a key regulator of myogenesis both in vitro and in vivo.
An HMGA2-IGF2BP2 axis regulates myoblast proliferation and myogenesis.
Sex, Specimen part
View SamplesMolecular mechanisms underlying sarcopenia, the age-related loss of skeletal muscle mass and function, remain unclear. To identify molecular changes that correlated best with sarcopenia and might contribute to its pathogenesis, we determined global gene expression profiles in muscles of rats aged 6, 12, 18, 21, 24, and 27 months. These rats exhibit sarcopenia beginning at 21 months. Correlation of the gene expression versus muscle mass or age changes, and functional annotation analysis identified gene signatures of sarcopenia distinct from gene signatures of aging. Specifically, mitochondrial energy metabolism (e.g., tricarboxylic acid cycle and oxidative phosphorylation) pathway genes were the most downregulated and most significantly correlated with sarcopenia. Also, perturbed were genes/pathways associated with neuromuscular junction patency (providing molecular evidence of sarcopenia-related functional denervation and neuromuscular junction remodeling), protein degradation, and inflammation. Proteomic analysis of samples at 6, 18, and 27 months confirmed the depletion of mitochondrial energy metabolism proteins and neuromuscular junction proteins. Together, these findings suggest that therapeutic approaches that simultaneously stimulate mitochondrogenesis and reduce muscle proteolysis and inflammation have potential for treating sarcopenia.
Genomic and proteomic profiling reveals reduced mitochondrial function and disruption of the neuromuscular junction driving rat sarcopenia.
Sex, Age, Specimen part
View SamplesA375P melanoma cells were treated with 1uM of the MEK inhibitor PD184352 or 0.4uM of the V600EBRAF inhibitor PLX4720 for 2hr, 6hr and 24hrs.
Identification of direct transcriptional targets of (V600E)BRAF/MEK signalling in melanoma.
Cell line, Treatment, Time
View SamplesWe previoiusly identified WDR11 as a potential tumor suppressor in murine medulloblastoma models. To determine additional genes/pathways affected by WDR11 overexpression.To compare somatic mutations of murine models with human medulloblastoma (MB), we performed whole-exome sequencing of mouse tumors representing three distinct MB subgroups: Wnt, Sonic Hedgehog (Shh) and Group 3 (G3). 64 somatic mutations were identified and validated, including 40 predicted to cause amino acid changes. After filtering and cross-species analysis with 366 human MBs from four independent studies, human orthologs for 16 of the 40 mouse genes were found to harbor non-silent mutations in human MB. Loss-of-function Mll2 mutations detected in one mouse tumor were previously reported in 30 of 366 human MBs. In mice with G3 MB, one mouse that died at least 15 days earlier than the others had four novel candidate genes harboring non-silent somatic mutations, Lrfn2, Smyd1, Ubn2 and Wdr11. To test whether these genes had tumor suppressive activity, we constitutively overexpressed each wild type gene in murine G3 tumorspheres followed by intracranial implantation. Mice harboring mouse G3 MB overexpressing WDR11 showed extended survival compared to the other three genes. Genes in the KEGG WNT signaling pathway, including Ccnd1/2/3, Myc and Tcf7l1, were down-regulated in G3 MB tumorspheres overexpressing WDR11, consistent with reduced tumor progression. In conclusion, we demonstrated that common spontaneous mutations were shared between human and murine models of MB suggesting similar molecular mechanisms of tumorigenesis, and identified WDR11 as a protein with tumor suppressive activity in G3 MB. Overall design: Compare differentially expressed genes in WDR11 overexpression group versus control group.
Exome sequencing analysis of murine medulloblastoma models identifies WDR11 as a potential tumor suppressor in Group 3 tumors.
Specimen part, Treatment, Subject
View SamplesThe aim of this study was to investigate the association of gene expression profiles in subcutaneous adipose tissue with percent of total body weight change in 26 kidney transplant recipients.
Expression levels of obesity-related genes are associated with weight change in kidney transplant recipients.
Sex, Race
View SamplesWe''ve recently shown that we can accelerate disease in a model of SLE (the NZB/W F1 model) using an anti-Ox40 mAb treatment regimen. The disease acceleration is rapid (within 2 weeks) but its unclear, mechanistically, how OX40 functions to promote disease. To that end we want to perform RNASeq on the sorted OX40-expressing CD4 T cells during treatment to understand how they function in response to OX40 signaling in vivo Overall design: RNASeq was performed on FACS sorted CD4 T cells from the spleen and kidney of NZB/W F1 lupus mice following anti-Ox40 agonist mAb treatment and disease acceleration
The Ox40/Ox40 Ligand Pathway Promotes Pathogenic Th Cell Responses, Plasmablast Accumulation, and Lupus Nephritis in NZB/W F1 Mice.
Cell line, Treatment, Subject
View SamplesWe''ve recently shown that we can accelerate disease in a model of SLE (the NZB/W F1 model) using an anti-Ox40 mAb treatment regimen. The disease acceleration is rapid (within 2 weeks) but its unclear, mechanistically, how Ox40 promotes disease. To that end we performed RNASeq on in vitro cultured CD4 T cells during Ox40 and TCR stimulation (in a reductionist setting) to understand how Ox40 signaling impacts cellular phenotype and function, including with and without TCR stimulation Overall design: RNASeq was performed on in vitro cultured CD4 T cells from the spleen of NZB/W F1 lupus prone mice, following anti-Ox40 mAb and anti-CD3/CD28 bead stimulation
The Ox40/Ox40 Ligand Pathway Promotes Pathogenic Th Cell Responses, Plasmablast Accumulation, and Lupus Nephritis in NZB/W F1 Mice.
Cell line, Subject
View SamplesDNA microarrays were conducted on E. coli K12 cells stressed with 10 M in N,N,N',N'-tetrakis(2-pyridylmethyl)ethylenediamine (TPEN). Overall, 260 genes varied in expression, 114 up-regulated and 146 down-regulated by Zn deprivation
Characterization of Zn(II)-responsive ribosomal proteins YkgM and L31 in E. coli.
No sample metadata fields
View SamplesIn an effort to understand the mechanisms of acquired resistance to BRAF inhibitors, we isolated clones that acquired resistance to the BRAF inhibitor GSK2118436 derived from the A375 BRAF V600E mutant melanoma cell line. This resistance clones acquired mutations in NRAS and MEK1. One clones, 16R6-4, acquired two mutations in NRAS Q61K and A146T. Proliferation and western blot analyses demonstrated that these clones were insensitive to single agent GSK2118436 or GSK1120212 (an allosteric MEK inhibitor) but were sensitive to the combination of GSK2118436 and GSK1120212. To further characterize this combination, global transcriptomic analysis was performed in A375 and 16R6-4 after 24 hour treatment with GSK2118436, GSK1120212 or the combination of GSK2118436 and GSK1120212.
Combinations of BRAF, MEK, and PI3K/mTOR inhibitors overcome acquired resistance to the BRAF inhibitor GSK2118436 dabrafenib, mediated by NRAS or MEK mutations.
Specimen part, Cell line, Treatment
View Samples