In several models of obesity-induced diabetes, increased lipid accumulation in the liver has been associated with decreased diabetes susceptibility. For instance, deficiency in leptin receptor (db/db) leads to hyperphagia and obesity in both C57BL/6 and C57BLKS mice but, only on the C57BLKS background do the mice develop beta-cell loss leading to severe diabetes while C57BL/6 mice are relatively resistant. Liver triglyceride levels in the resistant C57BL/6 mice are 3 to 4 fold higher than in C57BLKS.
Systems genetics of susceptibility to obesity-induced diabetes in mice.
Sex, Age
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Neuroprotective effects of brain-derived neurotrophic factor in rodent and primate models of Alzheimer's disease.
Treatment
View SamplesThe gene expression profile of peripheral Foxp3+ natural regulatory T cells isolated from Foxp3/EGFP bicistronic mice was compared to that of in vitro-induced regulatory T cells and to CD4+ conventional (Foxp3-) T cells. The role of the regulatory T cell transcription factor Foxp3 in shaping the transcriptosomes of natural and induced regulatory T cells was analyzed using mice expressing a mutant FOXP3-EGFP fusion protein (Foxp3deltaEGFP).
A central role for induced regulatory T cells in tolerance induction in experimental colitis.
No sample metadata fields
View SamplesPolymorphisms in the interleukin-4 receptor chain (IL-4R) have been linked to asthma incidence and severity, but a causal relationship has remained uncertain. In particular, a glutamine to arginine substitution at position 576 (Q576R) of IL-4R has been associated with severe asthma, especially in African Americans. We show that mice carrying the Q576R polymorphism exhibited intense allergen-induced airway inflammation and remodeling. The Q576R polymorphism did not affect proximal signal transducer and activator of transcription (STAT) 6 activation, but synergized with STAT6 in a gene target and tissue-specific manner to mediate heightened expression of a subset of IL-4 and IL-13responsive genes involved in allergic inflammation. Our findings indicate that the Q576R polymorphism directly promotes asthma in carrier populations by selectively augmenting IL-4Rdependent signaling.
Pathogenicity of a disease-associated human IL-4 receptor allele in experimental asthma.
No sample metadata fields
View SamplesWe examined transgenic (TG) mice expressing human APP695 bearing the double Swedish (671KM>NL) and Indiana (717V>F) amyloid precursor protein (APP) mutations. Lentiviral vectors constitutively expressing BDNF-GFP under control of the CMV/-actin hybrid promoter or GFP alone were injected into the entorhinal cortices of TG mice bilaterally at age 6 months, a time point by which neuropathological degeneration and cell loss are established. Age-matched wild-type littermates underwent sham surgery or injection of lentivirus expressing GFP into the entorhinal cortices bilaterally.
Neuroprotective effects of brain-derived neurotrophic factor in rodent and primate models of Alzheimer's disease.
Treatment
View SamplesEndothelium in embryonic hematopoietic tissues generates hematopoietic stem/progenitor cells; however, it is unknown how its unique potential is specified. We show that transcription factor Scl/Tal1 is essential for both establishing the hematopoietic transcriptional program in hemogenic endothelium and preventing its misspecification to a cardiomyogenic fate. Scl-/- embryos activated a cardiac transcriptional program in yolk sac endothelium, leading to the emergence of CD31+Pdgfr+ cardiogenic precursors that generated spontaneously beating cardiomyocytes. Ectopic cardiogenesis was also observed in Scl-/- hearts, where the disorganized endocardium precociously differentiated into cardiomyocytes. Induction of mosaic deletion of Scl in Sclfl/flRosa26Cre-ERT2 embryos revealed a cell-intrinsic, temporal requirement for Scl to prevent cardiomyogenesis from endothelium. Scl-/- endothelium also upregulated the expression of Wnt antagonists, which promoted rapid cardiomyocyte differentiation of ectopic cardiogenic cells. These results reveal unexpected plasticity in embryonic endothelium such that loss of a single master regulator can induce ectopic cardiomyogenesis from endothelial cells.
Scl represses cardiomyogenesis in prospective hemogenic endothelium and endocardium.
Specimen part
View SamplesWnt signaling is intrinsic to mouse embryonic stem cell self-renewal. Therefore it is surprising that reprogramming of somatic cells to induced pluripotent stem cells (iPSCs) is not strongly enhanced by Wnt signaling. Here, we demonstrate that active Wnt signaling inhibits the early stage of reprogramming to iPSCs, while it is required and even stimulating during the late stage. Mechanistically, this biphasic effect of Wnt signaling is accompanied by a change in the requirement of all four of its transcriptional effectors: Tcf1, Lef1, Tcf3, and Tcf4. For example, Tcf3 and Tcf4 are stimulatory early but inhibitory late in the reprogramming process. Accordingly, ectopic expression of Tcf3 early in reprogramming combined with its loss-of-function late enables efficient reprogramming in the absence of ectopic Sox2. Together, our data indicate that the step-wise process of reprogramming to iPSCs is critically dependent on the stage-specific control and action of all four Tcfs and Wnt signaling.
Stage-specific regulation of reprogramming to induced pluripotent stem cells by Wnt signaling and T cell factor proteins.
Specimen part, Time
View SamplesNeutrophil abscess formation is critical in innate immunity against many pathogens. Here, the mechanism of neutrophil abscess formation was investigated using a mouse model of Staphylococcus aureus cutaneous infection. Gene expression analysis of S. aureus-infected skin revealed that induction of neutrophil recruitment genes was largely dependent upon IL-1beta/IL-1R activation. Unexpectedly, using IL 1beta reporter mice, neutrophils were identified as the primary source of IL-1beta at the site of infection. Furthermore, IL-1beta-producing neutrophils were necessary and sufficient for abscess formation and bacterial clearance. S. aureus-induced IL 1beta production by neutrophils required TLR2, NOD2, FPRs and the ASC/NLRP3 inflammasome. Taken together, IL-1beta and neutrophil abscess formation during an infection are functionally, spatially and temporally linked as a consequence of direct IL-1beta production by neutrophils.
Neutrophil-derived IL-1β is sufficient for abscess formation in immunity against Staphylococcus aureus in mice.
Specimen part
View SamplesSSEA1+ cells sorted from mouse embryonic stem cells differentiated for 4 days in 10uM Retinoic acid do not form teratomas when transplated into SCID mice while Pten-/- cells do.
No associated publication
Specimen part
View SamplesThe airway epithelium is in contact with the environment and therefore constantly at risk for injury. Basal cells have been found to repair the surface epithelium, but the contribution of other stem cell populations to airway epithelial repair have not been identified. We demonstrated that airway submucosal gland duct cells, in addition to basal cells, survived severe hypoxic-ischemic injury. We developed a method to isolate duct cells from the airway. In vitro and in vivo models were used to compare the self-renewal and differentiation potential of duct cells and basal cells. We found that only duct cells were capable of regenerating submucosal gland tubules and ducts, as well as the surface epithelium overlying the submucosal glands. This is of importance to the field of lung regeneration as determining the repairing cell populations could lead to the identification of novel therapeutic targets and cell-based therapies for patients with airway diseases.
No associated publication
Specimen part
View Samples