Defective Fas expression exacerbates neurotoxicity in a model of Parkinson's disease

Fas (CD95), a member of the tumor necrosis factor-receptor superfamily, has been studied extensively as a death-inducing receptor in the immune system. However, Fas is also widely expressed in a number of other tissues, including in neurons. Here, we report that defects in the Fas/Fas ligand system unexpectedly render mice highly susceptible to neural degeneration in a model of Parkinson's disease. We found that Fas-deficient lymphoproliferative mice develop a dramatic phenotype resembling clinical Parkinson's disease, characterized by extensive nigrostriatal degeneration accompanied by tremor, hypokinesia, and loss of motor coordination, when treated with the neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) at a dose that causes no neural degeneration or behavioral impairment in WT mice. Mice with generalized lymphoproliferative disease, which express a mutated Fas ligand, display an intermediate phenotype between that of lymphoproliferative and WT mice. Moreover, Fas engagement directly protects neuronal cells from MPTP/1-methyl-4-phenylpyridinium ion toxicity in vitro. Our data show that decreased Fas expression renders dopaminergic neurons highly susceptible to degeneration in response to a Parkinson-causing neurotoxin. These findings constitute the first evidence for a neuroprotective role for Fas in vivo

C (Control) raw RNA-Seq BAM file

C/C’ pre-B cells sorted from control mice. This is the BAM file containing the unprocessed, raw reads for the control sample. The data is provided in BAM format for convenience. MD5: 1db0c4591f24b1e9d4b21b75d33df61

Data from: Tungsten blocks murine B lymphocyte differentiation and proliferation through downregulation of IL-7 receptor/Pax5 signaling

Tungsten is an emerging environmental toxicant associated with several pediatric leukemia clusters, although a causal association has not been established. Our previous work demonstrated that tungsten exposure resulted in an accumulation of pre-B cells in the bone marrow, the same cell type that accumulates in pediatric acute lymphoblastic leukemia (ALL). To better understand the relevant molecular mechanisms, we performed RNA sequencing on flow sorted pre-B cells from control and tungsten-exposed mice. Tungsten decreased the expression of multiple genes critical for B cell development, including members of the IL-7R and pre-BCR signaling pathways, such as Jak1, Stat5a, Erb1, Pax5, Syk, and Ikzf3. These results were confirmed in an in vitro model of B cell differentiation, where tungsten arrested differentiation at the pro-B cell stage and inhibited proliferation. These changes were associated with decreased expression of multiple genes in the IL-7R signaling pathway and decreased percentage of IL-7R, phosphorylated STAT5 (pSTAT5) double-positive cells. Supplementation with IL-7 or overexpression of Pax5, the transcription factor downstream of IL-7R, rescued the tungsten-induced differentiation block. Together, these data support the hypothesis that IL-7R/Pax5 signaling axis is critical to tungsten-mediated effects on pre-B cell development. Importantly, many of these molecules are modulated in ALL

Stem cell microvesicles transfer cystinosin to human cystinotic cells and reduce cystine accumulation in vitro

Contains fulltext : 109597.pdf (publisher's version ) (Open Access)Cystinosis is a rare disease caused by homozygous mutations of the CTNS gene, encoding a cystine efflux channel in the lysosomal membrane. In Ctns knockout mice, the pathologic intralysosomal accumulation of cystine that drives progressive organ damage can be reversed by infusion of wildtype bone marrow-derived stem cells, but the mechanism involved is unclear since the exogeneous stem cells are rarely integrated into renal tubules. Here we show that human mesenchymal stem cells, from amniotic fluid or bone marrow, reduce pathologic cystine accumulation in co-cultured CTNS mutant fibroblasts or proximal tubular cells from cystinosis patients. This paracrine effect is associated with release into the culture medium of stem cell microvesicles (100-400 nm diameter) containing wildtype cystinosin protein and CTNS mRNA. Isolated stem cell microvesicles reduce target cell cystine accumulation in a dose-dependent, Annexin V-sensitive manner. Microvesicles from stem cells expressing CTNS(Red) transfer tagged CTNS protein to the lysosome/endosome compartment of cystinotic fibroblasts. Our observations suggest that exogenous stem cells may reprogram the biology of mutant tissues by direct microvesicle transfer of membrane-associated wildtype molecules

Analysis of stem cell microvesicles and their effects on cystine content of <i>CTNS</i>(−/−) mutant fibroblasts.

<p>(a) diameter of bmMSC microparticles released into conditioned medium. (b) effect of increasing amounts of bmMSC microvesicles on cystine in mutant fibroblasts after 24 hour incubation, compared to the effect of 1 mM cysteamine. (c) diameter of amMSC microparticles released into conditioned medium. (d) effect of increasing amounts of amMSC microvesicles on cystine in mutant fibroblasts after 24 hour incubation, compared to the effect of 1 mM cysteamine and in the presence of annexin V. Statistical significance is indicated by the corresponding p-value.</p

Characterization of mesenchymal stem cells and <i>CTNS</i>(−/−) mutant target cells.

<p>(a) FACS analysis (left) of bmMSC surface markers (blue) and isotype controls (red) and bmMSC differentiation from baseline (upper right) to Alizarin Red S-stained calcium-containing osteogenic (middle right) and Oil-Red O-stained adipocyte (bottom right) phenotypes. (b) same FACS and differentiation analysis of amMSC cells. (c) schematic diagram depicting the common 57 Kb deletion removing the 5′ portion of the <i>CTNS</i> gene and PCR-proven genotype of control and mutant fibroblasts from a cystinosis patient. Intracellular cystine content of control and homozygous <i>CTNS</i> mutant fibroblasts is shown on the right bar-graph.</p

Effect of co-culture with CTNS-expressing cells on cystine content of mutant <i>CTNS</i> cells.

<p>(a) Cystine content of <i>CTNS</i>(−/−) fibroblasts co-cultured with increasing amounts of wildtype amMSC. (b) Cystine content of GFP-tagged <i>CTNS</i>(−/−) ciPTEC isolated by FACS after co-culture with unlabelled wildtype amMSC, mutant ciPTEC or <i>CTNS</i>-corrected ciPTEC as donors. Statistical significance is indicated by the corresponding p-value.</p