Study objectives: Chronic obstructive pulmonary disease and obstructive sleep apnea overlap syndrome is associated with excess mortality, and outcomes are related to the degree of hypoxemia. People at high altitude are susceptible to periodic breathing, and hypoxia at altitude is associated with cardio-metabolic dysfunction. Hypoxemia in these scenarios may be described as superimposed sustained plus intermittent hypoxia, or overlap hypoxia (OH), the effects of which have not been investigated. We aimed to characterize the cardio-metabolic consequences of OH in mice. Methods: C57BL/6J mice were subjected to either sustained hypoxia (SH, FiO2=0.10), intermittent hypoxia (IH, FiO2=0.21 for 12 hours, and FiO2 oscillating between 0.21 and 0.06, 60 times/hour, for 12 hours), OH (FiO2=0.13 for 12 hours, and FiO2 oscillating between 0.13 and 0.06, 60 times/hour, for 12 hours), or room air (RA), n=8/group. Blood pressure and intraperitoneal glucose tolerance test were measured serially, and right ventricular systolic pressure (RVSP) was assessed. Results: Systolic blood pressure transiently increased in IH and OH relative to SH and RA. RVSP did not increase in IH, but increased in SH and OH by 52% (p<0.001) and 20% (p=0.001). Glucose disposal worsened in IH and improved in SH, with no change in OH. Serum LDL and VLDL increased in OH and SH, but not in IH. Hepatic oxidative stress increased in all hypoxic groups, with the highest increase in OH. Conclusions: Overlap hypoxia may represent a unique and deleterious cardio-metabolic stimulus, causing systemic and pulmonary hypertension, and without protective metabolic effects characteristic of sustained hypoxia. Overall design: Whole liver mRNA profiles of C57BL/6J mice exposed to RA, SH, IH, or OH.
Combined intermittent and sustained hypoxia is a novel and deleterious cardio-metabolic phenotype.
Age, Specimen part, Genotype, Treatment, Subject
View SamplesThe cytosolic protein Sharpin is as a component of the linear ubiquitin chain assembly complex (LUBAC), which regulates NF-B signaling in response to specific ligands. Its inactivating mutation in Cpdm (chronic proliferative dermatitis mutation) mice causes multi-organ inflammation, yet this phenotype is not transferable into wildtype mice by hematopoietic stem cell transfer. Recent evidence demonstrated that Cpdm mice additionally display low bone mass, but the cellular and molecular causes of this phenotype remained to be established. Here we have applied non-decalcified histology together with cellular and dynamic histomorphometry to perform a thorough skeletal phenotyping of Cpdm mice. We show that Cpdm mice display trabecular and cortical osteopenia, solely explained by impaired bone formation, whereas osteoclastogenesis is unaffected. We additionally found that Cpdm mice display a severe disturbance of articular cartilage integrity in the absence of joint inflammation, supporting the concept that Sharpin-deficiency affects mesenchymal cell differentiation. Consistently, Cpdm mesenchymal cells displayed reduced osteogenic capacitiy ex vivo, yet this defect was not associated with impaired NF-B signaling. A molecular comparison of wildtype and Cpdm bone marrow cell populations further revealed that Cpdm mesenchymal cells produce higher levels of Cxcl5 and lower levels of IL1ra. Collectively, our data demonstrate that skeletal defects of Cpdm mice are not caused by chronic inflammation, but that Sharpin is as a critical regulator of mesenchymal cell differentiation and gene expression. They additionally provide an alternative molecular explanation for the inflammatory phenotype of Cpdm mice and the absence of disease transfer by hematopoetic stem cell transplantation.
Sharpin Controls Osteogenic Differentiation of Mesenchymal Bone Marrow Cells.
Specimen part
View SamplesProliferative zone chondrocytes were microdissected from control and Ift88-deleted growth plates to determine gene expression profiles regulated by primary cilia.
Ift88 regulates Hedgehog signaling, Sfrp5 expression, and β-catenin activity in post-natal growth plate.
Specimen part
View SamplesComparative analysis of gene expression in cultured primary keratinocytes isolated from newborn control (K14-cre; GPx4fl/+) and knockout (K14-cre; GPx4fl/fl) mice.
Targeted disruption of glutathione peroxidase 4 in mouse skin epithelial cells impairs postnatal hair follicle morphogenesis that is partially rescued through inhibition of COX-2.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Molecular profiling of the developing mouse axial skeleton: a role for Tgfbr2 in the development of the intervertebral disc.
Specimen part
View SamplesVery little is known about how intervertebral disc (IVD) is formed or maintained. Members of the TGF- superfamily are secreted signaling proteins that regulate many aspects of development including cellular differentiation. We recently showed that deletion of Tgfbr2 in Col2a expressing tissue results in alterations in development of IVD annulus fibrosus. The results suggested TGF- has an important role in regulating development of the axial skeleton, however, the mechanistic basis of TGF- action in these specialized joints is not known. To understand the mechanism of TGF- action in IVD development, we undertook a global analysis of gene expression comparing gene expression profiles in sclerotome cultures treated with TGF- or BMP4. As expected, treatment with BMP4 resulted in up-regulation of cartilage marker genes including Acan, Sox 5, Sox6, and Sox9. In contrast, treatment with TGF-1 did not regulate expression of cartilage markers but instead resulted in up-regulation of many IVD markers including Fmod and Adamtsl2. We propose TGF- has two functions in IVD development: 1) to prevent chondrocyte differentiation in the presumptive IVD and 2) to promote differentiation of annulus fibrosus from sclerotome. We have identified genes that are enriched in the IVD and regulated by TGF- that warrant further investigation as regulators of IVD development.
Molecular profiling of the developing mouse axial skeleton: a role for Tgfbr2 in the development of the intervertebral disc.
No sample metadata fields
View SamplesWe used microarrays to compare the global programme of gene expression in primary cultures of neurons and astrocytes. These data sets were compared to the expression profiles of other tissues, including pancreatic islets, in order to identify a specific neuroendocrine program in pancreatic islets.
Glucose regulation of a cell cycle gene module is selectively lost in mouse pancreatic islets during ageing.
Specimen part
View SamplesAnalysis of expression profiles of pDCs from wild type and heterozygous E2-2 mice. Results show the control by E2-2 of the expression of pDC-enriched genes.
Transcription factor E2-2 is an essential and specific regulator of plasmacytoid dendritic cell development.
No sample metadata fields
View SamplesDendritic cells (DC) develop from hematopoietic stem cells, which is guided by instructive signals through cytokines. DC development progresses from multipotent progenitors (MPP) via common DC progenitors (CDP) into DC. Flt3 ligand (Flt3L) signaling via the Flt3/Stat3 pathway is of pivotal importance for DC development under steady state conditions. Additional factors produced during steady state or inflammation, such as TGF-beta1 or GM-CSF, also influence the differentiation potential of MPP and CDP. Here, we studied how gp130, GM-CSF and TGF-beta1 signaling influence DC lineage commitment from MPP to CDP and further into DC. We observed that activation of gp130 signaling promotes expansion of MPP. Additionally, gp130 signaling inhibited Flt3L-driven DC differentiation, but had little effect on GM-CSF-driven DC development. The inflammatory cytokine GM-CSF induces differentiation of MPP into inflammatory DC and blocks steady state DC development. Global transcriptome analysis revealed a GM-CSF-driven gene expression repertoire that primes MPP for differentiation into inflammatory DC. Finally, TGF-beta1 induces expression of DC-lineage affiliated genes in MPP, including Flt3, Irf-4 and Irf-8. Under inflammatory conditions, however, the effect of TGF- beta1 is altered: Flt3 is not upregulated, indicating that an inflammatory environment inhibits steady state DC development. Altogether, our data indicate that distinct cytokine signals produced during steady state or inflammation have a different outcome on DC lineage commitment and differentiation.
Dendritic cell lineage commitment is instructed by distinct cytokine signals.
Specimen part, Treatment
View SamplesNotch signaling is one of the central regulators of differentiation in a variety of organisms and tissue types. Within the hematopoietic system, Notch is essential for the emergence of definitive HSC during fetal life and controls adult HSC differentiation to the T-cell lineage. Notch activation is controlled by the gamma-secretase complex complex, composed of presenilin, nicastrin (Ncstn), anterior pharynx-1 (Aph1), and presenilin enhancer-2
A novel tumour-suppressor function for the Notch pathway in myeloid leukaemia.
Sex, Age
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