Previous studies have suggested that CD133+ cells isolated from human kidney biopsies have the potential to ameliorate injury following intravenous (IV) administration in rodent models of kidney disease by integrating into damaged renal tissue and generating specialised renal cells. However, whether renal engraftment of CD133+ cells is prerequisite for ameliorating injury has not yet been unequivocally resolved. Here, we have established a cisplatin-induced nephropathy model in immunodeficient rats to assess the efficacy of CD133+ human kidney cells in restoring renal health, and to determine the fate of these cells after systemic administration. Specifically, following IV administration, we evaluated the impact of the CD133+ cells on renal function by undertaking longitudinal measurements of the glomerular filtration rate using a novel transcutaneous device. Furthermore, using histological assays, we assessed whether the human kidney cells could promote renal regeneration, and if this was related to their ability to integrate into the damaged kidneys. Our results show that both CD133+ and CD133- cells improve renal function and promote renal regeneration to a similar degree. However, this was not associated with engraftment of the cells into the kidneys. Instead, after IV administration, both cell types were exclusively located in the lungs, and had disappeared by 24 hours. Our data therefore indicate that renal repair is not mediated by CD133+ cells homing to the kidneys and generating specialised renal cells. Instead, renal repair is likely to be mediated by paracrine or endocrine factors.
Human Kidney-Derived Cells Ameliorate Acute Kidney Injury Without Engrafting into Renal Tissue.
Specimen part, Disease stage
View SamplesSIRT1 deacetylase functions in a variety of cells and tissues to mitigate age- and disease-induced damages. However, it remains unknown if SIRT1 also acts to prevent pathological changes that accrue in motor units, and specifically alpha-motor neurons, with advancing age and during the progression of amyotrophic lateral sclerosis (ALS). Here, we show that SIRT1 expression decreases in the spinal cord of wild type mice with advancing age. Using mouse models that overexpress or inactivate SIRT1 in motor neurons, we discovered that SIRT1 prevents age-related degeneration of motor neurons' presynaptic sites at neuromuscular junctions (NMJs). We also found that increasing SIRT1 in motor neurons delays degeneration of presynaptic sites at NMJs and extends the lifespan of SOD1G93A mice. Thus, SIRT1 has a similar effect on aging and ALS-affected motor neurons, two conditions in which a remarkable number of transcripts are similarly altered in the spinal cord. These include genes involved in inflammatory and immune responses and genes with known function at synapses. These findings show that SIRT1 functions to mitigate pathological changes induced by aging and ALS, two conditions with a surprising degree of overlap in the spinal cord. Overall design: Eight replicates spinal cords from mice aged 18-24 months, eight replicates of spinal cords from mice aged 3-4 months, 3 replicates of spinal cords from ALS symptomatic mice aged 5-6 months and 3 replicates of spinal cords from wt controls aged 5-6 months.
SIRT1 deacetylase in aging-induced neuromuscular degeneration and amyotrophic lateral sclerosis.
Cell line, Subject
View SamplesGlucocorticoid resistance is a major driver of therapeutic failure in T-cell acute lymphoblastic leukemia (T-ALL). Here we used a systems biology approach, based on the reverse engineering of signaling regulatory networks, which identified the AKT1 kinase as a signaling factor driving glucocorticoid resistance in T-ALL. Indeed, activation of AKT1 in T-ALL lymphoblasts impairs glucocorticoid-induced apoptosis. Mechanistically, AKT1 directly phosphorylates the glucocorticoid receptor NR3C1 protein at position S134 and blocks glucocorticoid-induced NR3C1 translocation to the nucleus. Consistently, inhibition of AKT1 with MK-2206 increases the response of T-ALL cells to glucocorticoid therapy both in T-ALL cell lines and in primary patient samples thus effectively reversing glucocorticoid resistance in vitro and in vivo. These results warrant the clinical testing of ATK1 inhibitors and glucocorticoids, in combination, for the treatment of T-ALL.
Direct reversal of glucocorticoid resistance by AKT inhibition in acute lymphoblastic leukemia.
Specimen part
View SamplesGlucocorticoid resistance is a major driver of therapeutic failure in T-cell acute lymphoblastic leukemia (T-ALL). Here we identify the AKT1 kinase as a signaling factor driving glucocorticoid resistance in T-ALL. Mechanistically, AKT1 directly phosphorylates the glucocorticoid receptor NR3C1 protein and blocks glucocorticoid-induced NR3C1 transcription by inhibiting glucocorticoid-induced NT3C1 translocation to the nucleus. Consistently, pharmacologic inhibition of AKT1 increases the response of T-ALL cells to glucocorticoid therapy and effectively reverses glucocorticoid resistance in vitro and in vivo. These results warrant the clinical testing of AKT1 inhibitors and glucocorticoids in combination for the treatment of T-ALL.
Direct reversal of glucocorticoid resistance by AKT inhibition in acute lymphoblastic leukemia.
Cell line
View SamplesAlthough heterochromatin is enriched with repressive traits, it is also actively transcribed, giving rise to large amounts of non-coding RNAs. Although these RNAs are responsible for the formation and maintenance of heterochromatin, little is known about how their transcription is regulated. Here we show that the Snail1 transcription factor represses pericentromeric transcription, acting through the H3K4 deaminase LOXL2. Since Snail1 plays a key role in the epithelial to mesenchymal transition (EMT), we analyzed the regulation of mouse heterochromatin transcription in this process. At the onset of EMT, one of the major structural heterochromatin proteins, HP1a, is transiently released from heterochromatin foci in a Snail1/LOXL2dependent manner during EMT, concomitantly with a down-regulation of major satellite transcription. Global transcriptome analysis indicated that ectopic expression of heterochromatin transcripts affects the transcription profile of EMT-related genes. Additionally, preventing the down-regulation of major satellite transcripts compromised the migratory and invasive behavior of mesenchymal cells. We propose that Snail1 regulates heterochromatin transcription through the histone-modifying enzyme, LOXL2, thus creating the favorable transcriptional state necessary for completing EMT.
Regulation of heterochromatin transcription by Snail1/LOXL2 during epithelial-to-mesenchymal transition.
Cell line, Treatment
View SamplesBiotin is cofactor of crucial enzymes for intermediary metabolism, and its deficiency affects the transcription of some critical genes of mammalian glucose metabolism. However, the precise mechanisms of biotin starvation on gene expression are unknown. Here we show that metabolic changes ushered by deficiency of this vitamin sets in motion extensive reorganization of carbon metabolism gene expression, consistent across three diverse eukaryotes, that is mediated through a regulatory circuitry at the genome level similar in the three species.
Biotin starvation with adequate glucose provision causes paradoxical changes in fuel metabolism gene expression similar in rat (Rattus norvegicus), nematode (Caenorhabditis elegans) and yeast (Saccharomyces cerevisiae).
Age, Specimen part
View SamplesWe used microarray analysis to investigate if keratinocytes excert an immuno-inflammatory response towards streptococcal M1 protein.
Vigilant keratinocytes trigger pathogen-associated molecular pattern signaling in response to streptococcal M1 protein.
Specimen part, Cell line
View SamplesTo analyze expression differences between Trp53 pro-and deficient as well as Atm pro- and deficient murine CLL tumors developing in the E-TCL1 mouse model, we analyzed splenocytes isolated from heavily infiltrated spleens of sick mice.
Two mouse models reveal an actionable PARP1 dependence in aggressive chronic lymphocytic leukemia.
Specimen part
View SamplesBackground: Gliomas are the most common type of primary brain tumours, and in this group glioblastomas (GBMs) are the higher-grade gliomas with fast progression and unfortunate prognosis. Two major aspects of glioma biology that contributes to its awful prognosis are the formation of new blood vessels through the process of angiogenesis and the invasion of glioma cells. Despite of advances, two-year survival for GBM patients with optimal therapy is less than 30%. Even in those patients with low-grade gliomas, that imply a moderately good prognosis, treatment is almost never curative. Recent studies have demonstrated the existence of a small fraction of glioma cells with characteristics of neural stem cells which are able to grow in vitro forming neurospheres and that can be isolated in vivo using surface markers such as CD133. The aim of this study was to define the molecular signature of GBM cells expressing CD133 in comparison with non expressing CD133 cells. This molecular classification could lead to the finding of new potential therapeutic targets for the rationale treatment of high grade GBM.
Molecular analysis of ex-vivo CD133+ GBM cells revealed a common invasive and angiogenic profile but different proliferative signatures among high grade gliomas.
Specimen part, Disease
View SamplesPlants typically contain two different types of cell walls: a primary wall that is being deposited around all growing cells, and a secondary wall that is produced in cells with specialized functions once they have ceased to grow. In Arabidopsis, VND7 is a transcription factor that is sufficient to activate secondary cell wall synthesis. To artificially turn on the secondary cell wall synthesis, VND7 was fused to the activation domain of the herpes virus VP16 protein and the glucocorticoid receptor (GR) domain. Thus, the transgenic plants harbouring the constructs can then be treated with dexamethasone (DEX), a glucocorticoid derivative, to induce the secondary cell wall formation.
A Transcriptional and Metabolic Framework for Secondary Wall Formation in Arabidopsis.
Specimen part, Treatment
View Samples