Extracellular nucleotides are potent signaling molecules mediating cell-specific biological functions. We previously demonstrated that adenosine 5'-triphosphate (ATP) inhibits the proliferation while stimulating the migration, in vitro and in vivo, of human bone marrow-derived mesenchymal stem cells (BM-hMSC). Here, we investigated the effects of ATP on BM-hMSC differentiation capacity.
Extracellular purines promote the differentiation of human bone marrow-derived mesenchymal stem cells to the osteogenic and adipogenic lineages.
Specimen part, Treatment, Time
View SamplesHuman lymphoblastoid cell lines (EBV-immortalised B cells, LcL) obtained from subjects of different age (young 28-40 years, centenarians >95 years) were analysed for gene expression at basal culture conditions and after 48 hours of serum starvation. Lymphoid B cells from centenarians were more resistant to apoptosis induction and displayed a more developed lysosomal compartment, the most critical component of phagic machinery. In addition, cells from centenarians were capable of engulfing and digesting other cells, i.e. their siblings (even entire cells). This behavior was improved by nutrient deprivation, but strikingly, it was unaffected by the autophagy-modulating drugs rapamycin, an autophagy inducer, and 3-methyladenine, an autophagy inhibitor.
Survival features of EBV-stabilized cells from centenarians: morpho-functional and transcriptomic analyses.
Sex, Age, Specimen part, Subject
View SamplesIn the present study, we investigated whether, and to what extent, P2Rs and their ligands are involved in the regulation of AML cells. Our findings show that AML blasts express several receptors belonging to the P2X and P2Y family. Although different samples respond differently to ATP and UTP stimulation (reflecting the variability intrinsic to the group of acute myeloid leukemias), all the tested samples appear to be responsive to purinergic signalling, as demonstrated by intracellular calcium mobilization.
Purinergic signaling inhibits human acute myeloblastic leukemia cell proliferation, migration, and engraftment in immunodeficient mice.
Specimen part
View SamplesRecessive dystrophic epidermolysis bullosa (RDEB) is a genodermatosis characterized by fragile skin forming blisters that heal invariably with scars. It is due to mutations in the COL7A1 gene encoding type VII collagen, the major component of anchoring fibrils connecting the cutaneous basement membrane to the dermis. Identical COL7A1 mutations often result in inter- and intra-familial disease variability, suggesting that additional modifiers contribute to RDEB course. Here, we studied a monozygotic twin pair with RDEB presenting markedly different phenotypic manifestations, while expressing similar amounts of collagen VII. Genome-wide expression analysis in twins' fibroblasts showed differential expression of genes associated with TGF- pathway inhibition. In particular, decorin, a skin matrix component with anti-fibrotic properties, was found to be more expressed in the less affected twin. Accordingly, fibroblasts from the more affected sibling manifested a profibrotic and contractile phenotype characterized by enhanced -smooth muscle actin and plasminogen activator inhibitor 1 expression, collagen I release and collagen lattice contraction. These cells also produced increased amounts of proinflammatory cytokines interleukin 6 and monocyte chemoattractant protein-1. Both TGF- canonical (Smads) and non-canonical (MAPKs) pathways were basally more activated in the fibroblasts of the more affected twin. The profibrotic behaviour of these fibroblasts was suppressed by decorin delivery to cells. Our data show that the amount of type VII collagen is not the only determinant of RDEB clinical severity, and indicate an involvement of TGF- pathways in modulating disease variability. Moreover, our findings identify decorin as a possible anti-fibrotic/inflammatory agent for RDEB therapeutic intervention.
Monozygotic twins discordant for recessive dystrophic epidermolysis bullosa phenotype highlight the role of TGF-β signalling in modifying disease severity.
Specimen part, Disease
View SamplesWe show the molecular and functional characterization of a novel population of lineage-negative CD34-negative (Lin- CD34-) hematopoietic stem cells (HSCs) from chronic myelogenous leukemia (CML) patients at diagnosis. Molecular caryotyping and quantitative analysis of BCR/ABL transcript demonstrated that about one third of CD34- was leukemic. CML CD34- cells showed kinetic quiescence and limited clonogenic capacity. However, stroma-dependent cultures and cytokines induced CD34 expression on some HSCs, cell cycling, acquisition of clonogenic activity and increased expression of BCR/ABL transcript. CML CD34- cells showed an engraftment rate in immunodeficient mice similar to that of CD34+ cells. Gene expression profiling revealed the down-regulation of cell cycle arrest genes together with genes involved in antigen presentation and processing, while the expression of angiogenic factors was strongly up-regulated when compared to normal counterparts. Flow cytometry analysis confirmed the significant down-regulation of HLA class I and II molecules in CML CD34-cells. Increasing doses of imatinib mesilate (IM) did not affect fusion transcript levels, BCR-ABL kinase activity and the clonogenic efficiency of CML CD34- cells as compared to leukemic CD34+cells.
Molecular and functional analysis of the stem cell compartment of chronic myelogenous leukemia reveals the presence of a CD34- cell population with intrinsic resistance to imatinib.
No sample metadata fields
View SamplesCalorie restriction (CR) is a dietary regimen that supports healthy aging. In this study we investigated the systemic and liver-specific responses caused by a diet switch to a medium-fat (MF) diet in 24-month-old life-long, CR-exposed mice. This study aimed to increase the knowledge base on dietary alterations of gerontological relevance. Nine-week-old C57BL/6J mice were exposed either to a control, CR or MF diet. At the age of 24 months, a subset of mice of the CR group was transferred to ad libitum MF feeding (CR-MF).The mice were sacrificed at the age of 28 months, then biochemical and molecular analyses were performed. Our results showed that, despite the long-term exposure to the CR regimen, mice in the CR-MF group displayed hyperphagia, rapid weight gain, and hepatic steatosis. However, no hepatic fibrosis/injury or alteration in CR-improved survival was observed in the diet switch group. The liver transcriptomic profile of CR-MF mice largely shifted to a profile similar to the MF-fed animals but leaving ~22% of the 1578 differentially regulated genes between the CR and MF diet groups comparable with the expression of the life-long CR group. Therefore, although the diet switch was performed at an old age, the CR-MF-exposed mice showed plasticity in coping with the challenge of a MF diet without developing severe liver pathologies.
Plasticity of lifelong calorie-restricted C57BL/6J mice in adapting to a medium-fat diet intervention at old age.
Sex
View SamplesThe study was aimed at identifying genes directly or indirectly regulated by miR-205 in the prostate. To this purpose, DU145 prostate cancer cells, which express miR-205 at very low levels, were transfected with miR-205 synthetic precursor and consequent alterations of gene expression analyzed using a microarray approach.
miR-205 Exerts tumor-suppressive functions in human prostate through down-regulation of protein kinase Cepsilon.
No sample metadata fields
View SamplesNucleotides triphosphates are extracellular messengers binding to specific plasma membrane receptors (P2Rs) that modulate responses as different as proliferation, differentiation, migration or cell death on several cell types including hematopoietic stem cells. Little and controversial information is available on the role of extracellular nucleotides in human mesenchimal stem cells (hMSCs). In this study, we assessed whether P2Rs are expressed and functional in bone marrow-derived hMSCs. Our results demonstrated, at the mRNA and protein level, the expression of all P2X and P2Y receptor subtypes identified so far. P2R activation by their natural ligands adenosine triphosphate (ATP) and uridine triphosphate (UTP) induced in hMSCs, intracellular Ca2+ concentration changes, plasma membrane depolarization and permeabilization. hMSCs were resistant to the cytotoxic effects of high dose ATP despite the expression of permeabilizing P2Rs as demonstrated by the lack of morphological changes, significant release of intracellular markers of cell death or modification of the mitochondrial network. Gene expression profiling revealed the down-regulation of cell proliferation genes whereas genes involved in cell migration and cytokine production were strongly up-regulated by ATP. Functional studies confirmed the inhibitory activity of ATP on proliferation of hMSCs and clonogenic progenitors. Moreover, ATP exerted a chemotactic effect on hMSCs and increased their migration in response to the chemokine CXCL12. Finally, whereas ATP did not affect T-cell inhibitory activity of hMSCs, the nucleotide increased the production of pro-inflammatory cytokines by hMSCs. Thus, our data show that purinergic signaling modulates hMSC functions and point to a role for extracellular nucleotides on hMSCs biology.
Purinergic stimulation of human mesenchymal stem cells potentiates their chemotactic response to CXCL12 and increases the homing capacity and production of proinflammatory cytokines.
No sample metadata fields
View SamplesDiminishment of colonic health is associated with various age-related pathologies. Calorie restriction (CR) is an efficient strategy to increase healthy lifespan, although underlying mechanisms are not fully elucidated. Here we report the effects of lifelong CR on markers of colonic health in aging mice. We show that 30% energy reduction, as compared to a control (C) and moderate-fat (MF) diet, is associated with attenuated immune-related gene expression and lower levels of bile acids in the colon. Pronounced shifts in microbiota composition, together with lowered plasma levels of interleukin 6, in mice exposed to CR are in line with these findings. Furthermore, expression of genes involved in lipid metabolism was higher upon CR as compared to C and MF, pointing towards efficient regulation of energy metabolism. Switching from CR to an ad libitum MF diet at old age revealed remarkable phenotypic plasticity, although expression of a small subset of genes remained CR-associated. This research demonstrates that CR beneficially affects markers of colonic health in aging mice and as such may attenuate the progressive age-related decline in health.
Lifelong calorie restriction affects indicators of colonic health in aging C57Bl/6J mice.
Sex, Specimen part
View SamplesBitter taste receptors (T2Rs) are typical G-protein coupled receptors expressed in various tissue where they are involved in the regulation of physiological processes, thus suggesting a wider function in sensing microenvironment. We analyzed their expression and role in acute myeloid leukemia (AML). AML cells express functional T2Rs and their stimulation with the agonist, denatonium benzoate, substantially modified the AML cell transcriptomic profile and functions. GEP analysis identified relevant cellular processes affected by denatonium treatment in AML, including cell cycle, survival, migration and metabolism. More precisely, T2R activation reduced proliferation by inducing cell cycle arrest in G0/G1 phase or induced apoptosis via caspase cascade activation; impaired AML cell motility and migratory capacity; inhibited cellular respiration by decreasing glucose uptake and oxidative phosphorylation.
Denatonium as a Bitter Taste Receptor Agonist Modifies Transcriptomic Profile and Functions of Acute Myeloid Leukemia Cells.
Specimen part, Cell line, Treatment
View Samples