Downregulation of expression and activity levels of the astroglial glutamate transporter EAAT2 is thought to be implicated in motor neuron excitotoxicity in amyotrophic lateral sclerosis (ALS). We previously reported that EAAT2 is cleaved by caspase-3 at the cytosolic C-terminus domain, impairing the transport activity and generating a proteolytic fragment found to be SUMO1 conjugated (CTE-SUMO1). We show here that this fragment accumulates in the nucleus of spinal cord astrocytes in vivo throughout the disease stages of the SOD1-G93A mouse model of ALS. In vitro expression in spinal cord astrocytes of the C-terminus peptide of EAAT2 (CTE), which was artificially fused to SUMO1 (CTE-SUMO1fus) to mimic the endogenous SUMOylation reaction, recapitulates the nuclear accumulation of the fragment seen in vivo and causes caspase-3 activation and axonal growth impairment in motor neuron-derived NSC-34 cells and primary motor neurons co-cultured with CTE-SUMO1fus-expressing spinal cord astrocytes. This indicates that CTE-SUMO1fus could trigger non-cell autonomous mechanisms of neurodegeneration. Prolonged nuclear accumulation of CTE-SUMO1fus in astrocytes leads to their degeneration, although the time frame of the cell-autonomous toxicity is longer than the one for the indirect toxic effect on motor neurons. As more evidence on the implication of SUMO substrates in neurodegenerative diseases emerges, our observations strongly suggest that the nuclear accumulation in spinal cord astrocytes of a SUMOylated proteolytic fragment of the astroglial glutamate transporter EAAT2 could take part to the pathogenesis of ALS and suggest a novel, unconventional role for EAAT2 in motor neuron degeneration in ALS.
Motor neuron impairment mediated by a sumoylated fragment of the glial glutamate transporter EAAT2.
Specimen part
View SamplesThe role of sphingolipids (SLs) in the immune system has come under increasing scrutiny recently due to the emerging contributions that these important membrane components play in regulating a variety of immunological processes. The acyl chain length of SLs appears particularly critical in determining SL function. Here we show a role for very-long acyl chain SLs (VLC-SLs) in invariant natural killer T (iNKT) cell maturation in the thymus and homeostasis in the liver. Ceramide synthase 2 (CerS2) null mice, which lack VLC-SLs, were susceptible to a hepatotropic strain of lymphocytic choriomeningitis virus, which is due to a reduction in the number of iNKT cells. Bone marrow chimera experiments indicated that hematopoietic-derived VLC-SLs are essential for maturation of iNKT cells in the thymus, whereas parenchymal-derived VLC-SLs are crucial for iNKT cell survival and maintenance in the liver. Our findings suggest a critical role for VLC-SL in iNKT cell physiology. Overall design: Liver mRNA profiles of 3-4 month old wild type (WT), WT iNKT cell transfered and CerS2-/-mice, infected or not with LCMV were generated by deep sequencing. Several replicateswere included and pocessed using the MARS-seq protocol (Jaitin et al. 2014 Science.343:776-9) and sequencing in the Illumina NextSeq 500 instrument
Critical Role for Very-Long Chain Sphingolipids in Invariant Natural Killer T Cell Development and Homeostasis.
Specimen part, Cell line, Treatment, Subject
View SamplesIdentifying the effect of the co-chaperone SGTA on global androgen receptor transcriptional activity in C4-2B prostate cancer cells with view to further elucidating the broader biological role of SGTA on other signaling pathways within prostate cancer cells
Knockdown of the cochaperone SGTA results in the suppression of androgen and PI3K/Akt signaling and inhibition of prostate cancer cell proliferation.
Specimen part, Treatment
View SamplesThe goal of the study was to evaluate the influence of mutations in MLK4 on the protein function and the process of tumorigenesis in colorectal cancers. Biochemical data imply that a majority of MLK4 mutations in colon cancer are loss-of-function, including, E314K and Y330H mutations.
Recurrent MLK4 Loss-of-Function Mutations Suppress JNK Signaling to Promote Colon Tumorigenesis.
Specimen part, Cell line
View SamplesStat1-null mice (129S6/SvEvTac-Stat1tm1Rds homozygous) uniquely develop estrogen-receptor-positive mammary tumors with incomplete penetrance and long latency. We studied the growth and development of the mammary glands in Stat1-null mice. Stat1-null MGs have faulty branching morphogenesis with abnormal terminal end buds. The Stat1-null MG also fails to sustain growth of 129S6/SvEv wild-type and null epithelium. These abnormalities are partially reversed by added progesterone and prolactin. Transplantation of wild-type bone-marrow into Stat1-null mice does not reverse the mammary gland developmental defects. Media conditioned by Stat1-null epithelium-cleared mammary fat pads does not stimulate epithelial proliferation whereas it is stimulated by conditioned media derived from either wild-type or progesterone and prolactin-treated Stat1-null epithelium-cleared mammary fat pads. Microarrays and multiplex cytokine protein assays showed that the mammary gland of Stat1-null mice had lower levels of growth factors that have been implicated in normal mammary gland growth and development. Transplanted Stat1-null tumors and their isolated cells also grow slower in Stat1-null mammary gland compared to wild-type recipient mammary gland. Stat1-null hosts responded to tumor transplants with granulocytic infiltrates while wild-type hosts show a mononuclear response. These studies demonstrate that growth of normal and neoplastic Stat1-null epithelium primarily depends on the hormonal milieu and factors, such as cytokines, from the mammary stroma.
Abnormal Mammary Development in 129:STAT1-Null Mice is Stroma-Dependent.
No sample metadata fields
View SamplesProtein C (PC) deficiency increases the risk of venous thrombosis (VT) among members of Kindred Vermont II, but fails to fully account for the inheritance pattern. A genome scan of the pedigree supported the presence of a prothrombotic gene on chromosome 11q23 with weaker support on chromosomes 10p12 and 18p11.2-q11.
Cell adhesion molecule 1: a novel risk factor for venous thrombosis.
Sex, Age, Specimen part, Race
View SamplesThis dataset contains microarray data from normal controls (aged 20-99 yrs) and Alzheimer's disease cases, from 4 brain regions: hippocampus, entorhinal cortex, superior frontal cortex, post-central gyrus. Changes in expression of synaptic and immune related genes were analyzed, investigating age-related changes and AD-related changes, and region-specific patterns of change.
Gene expression changes in the course of normal brain aging are sexually dimorphic.
Sex, Subject
View SamplesThis dataset of cognitively normal controls is a subset of the GSE48350 dataset, which additionally contains microarray data from AD brains.
Gene expression changes in the course of normal brain aging are sexually dimorphic.
Sex, Subject
View SamplesOxidative injury and inflammation have been implicated in the genesis of hypertension but the mechanisms involved are not fully understood. We describe a new pathway in which angiotensin II promotes dendritic cell (DC) activation of T cells and ultimately hypertension. NADPH oxidase-dependent superoxide production is increased 5-fold in DCs isolated from hypertensive mice as compared to sham-treated mice. This is associated with DC accumulation of protein-isoketal adducts and production of IL-6, IL-1 and IL-23. DCs from hypertensive mice but not sham mice promote survival and proliferation of CD8+ T cells in culture. Chemically diverse isoketal scavengers not only prevent activation and immunogenicity of DCs, but also attenuate angiotensin II-induced hypertension. Moreover, adaptive transfer of DCs from hypertensive mice prime development of hypertension in response to a subpressor dose of angiotensin II. Exposure of DCs to tert butyl hypdroperoxide promoted isoketal formation, DC stimulation of CD8+ T cell proliferation and primed hypertension in response to low dose angiotensin II. Serum isoprostanes, precursors to isoketals, were found to be elevated in humans with treated hypertension and were markedly elevated in patients with resistant hypertension. These studies show that angiotensin II-induced hypertension activates DCs, in large part by causing superoxide production and formation of isoketals. They define a new mechanism of hypertension and identify a potential new therapeutic approach for this disease.
DC isoketal-modified proteins activate T cells and promote hypertension.
Age, Specimen part
View SamplesPBMC from house dust mite (HDM) sensitized atopics with or without asthma (or nonallergic controls) were cultured in the presence or absence of HDM extract for 24 hours.
Differential gene network analysis for the identification of asthma-associated therapeutic targets in allergen-specific T-helper memory responses.
Specimen part, Disease stage, Subject
View Samples