Virtual memory T cells are foreign antigen-inexperienced T cells that have acquired memory-like phenotype and constitute 10-20% of all peripheral CD8+ T cells in mice. Their origin, biological roles, and relationship to naïve and foreign antigen-experienced memory T cells are incompletely understood. By analyzing T-cell receptor repertoires and using retrogenic monoclonal T-cell populations, we demonstrate that the virtual memory T-cell formation is a so far unappreciated cell fate decision checkpoint. We describe two molecular mechanisms driving the formation of virtual memory T cells. First, virtual memory T cells originate exclusively from strongly self-reactive T cells. Second, the stoichiometry of the CD8 interaction with Lck regulates the size of the virtual memory T-cell compartment via modulating the self-reactivity of individual T cells. Although virtual memory T cells descend from the highly self-reactive clones and acquire a partial memory program, they are not more potent in inducing experimental autoimmune diabetes than naïve T cells. These data underline the importance of the variable level of self-reactivity in polyclonal T cells for the generation of functional T-cell diversity.
Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a death ligand with selective antitumor activity. However, many primary tumors are TRAIL resistant. Previous studies reported that roscovitine, a cyclin-dependent kinase inhibitor, sensitized various solid cancer cells to TRAIL. We show that roscovitine and TRAIL demonstrate synergistic cytotoxicity in hematologic malignant cell lines and primary cells. Pretreatment of TRAIL-resistant leukemia cells with roscovitine induced enhanced cleavage of death-inducing signaling complex-bound proximal caspases after exposure to TRAIL. We observed increased levels of both pro- and antiapoptotic BCL-2 proteins at the mitochondria following exposure to roscovitine. These results suggest that roscovitine induces priming of cancer cells for death by binding antiapoptotic BCL-2 proteins to proapoptotic BH3-only proteins at the mitochondria, thereby decreasing the threshold for diverse proapoptotic stimuli. We propose that the mitochondrial priming and enhanced processing of apical caspases represent major molecular mechanisms of roscovitine-induced sensitization to TRAIL in leukemia/lymphoma cells.
- MeSH
- apoptóza účinky léků MeSH
- cytotoxicita imunologická účinky léků MeSH
- genetická transkripce účinky léků MeSH
- leukemie genetika metabolismus patologie MeSH
- lidé MeSH
- ligand Fas farmakologie MeSH
- lymfom genetika metabolismus patologie MeSH
- mitochondrie účinky léků metabolismus MeSH
- myši MeSH
- nádorové buněčné linie MeSH
- protein bcl-X metabolismus MeSH
- protein TRAIL farmakologie MeSH
- proteosyntéza účinky léků MeSH
- protinádorové látky farmakologie MeSH
- protoonkogenní proteiny c-bcl-2 metabolismus MeSH
- puriny farmakologie MeSH
- signální adaptorové proteiny receptorové domény smrti metabolismus MeSH
- TNF-alfa farmakologie MeSH
- tumor burden účinky léků MeSH
- xenogenní modely - testy protinádorové aktivity MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Autosomal-dominant adult-onset neuronal ceroid lipofuscinosis (ANCL) is characterized by accumulation of autofluorescent storage material in neural tissues and neurodegeneration and has an age of onset in the third decade of life or later. The genetic and molecular basis of the disease has remained unknown for many years. We carried out linkage mapping, gene-expression analysis, exome sequencing, and candidate-gene sequencing in affected individuals from 20 families and/or individuals with simplex cases; we identified in five individuals one of two disease-causing mutations, c.346_348delCTC and c.344T>G, in DNAJC5 encoding cysteine-string protein alpha (CSPα). These mutations-causing a deletion, p.Leu116del, and an amino acid exchange, p.Leu115Arg, respectively-are located within the cysteine-string domain of the protein and affect both palmitoylation-dependent sorting and the amount of CSPα in neuronal cells. The resulting depletion of functional CSPα might cause in parallel the presynaptic dysfunction and the progressive neurodegeneration observed in affected individuals and lysosomal accumulation of misfolded and proteolysis-resistant proteins in the form of characteristic ceroid deposits in neurons. Our work represents an important step in the genetic dissection of a genetically heterogeneous group of ANCLs. It also confirms a neuroprotective role for CSPα in humans and demonstrates the need for detailed investigation of CSPα in the neuronal ceroid lipofuscinoses and other neurodegenerative diseases presenting with neuronal protein aggregation.
- MeSH
- dominantní geny genetika MeSH
- dospělí MeSH
- exony genetika MeSH
- genetická vazba MeSH
- genová dávka genetika MeSH
- lidé MeSH
- lipoylace MeSH
- lyzozomy metabolismus ultrastruktura MeSH
- membránové proteiny genetika MeSH
- molekulární sekvence - údaje MeSH
- mozek metabolismus patologie ultrastruktura MeSH
- mutace genetika MeSH
- neuronální ceroidlipofuscinózy epidemiologie genetika patologie MeSH
- neurony metabolismus patologie ultrastruktura MeSH
- proteiny tepelného šoku HSP40 genetika MeSH
- regulace genové exprese MeSH
- rodina MeSH
- rodokmen MeSH
- segregace chromozomů genetika MeSH
- sekvence nukleotidů MeSH
- sekvenční analýza DNA MeSH
- transport proteinů MeSH
- věk při počátku nemoci MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
BACKGROUND: Tight regulation of testicular gene expression is a prerequisite for male reproductive success, while differentiation of gene activity in spermatogenesis is important during speciation. Thus, comparison of testicular transcriptomes between closely related species can reveal unique regulatory patterns and shed light on evolutionary constraints separating the species. METHODOLOGY/PRINCIPAL FINDINGS: Here, we compared testicular transcriptomes of two closely related mouse species, Mus musculus and Mus spretus, which diverged more than one million years ago. We analyzed testicular expression using tiling arrays overlapping Chromosomes 2, X, Y and mitochondrial genome. An excess of differentially regulated non-coding RNAs was found on Chromosome 2 including the intronic antisense RNAs, intergenic RNAs and premature forms of Piwi-interacting RNAs (piRNAs). Moreover, striking difference was found in the expression of X-linked G6pdx gene, the parental gene of the autosomal retrogene G6pd2. CONCLUSIONS/SIGNIFICANCE: The prevalence of non-coding RNAs among differentially expressed transcripts indicates their role in species-specific regulation of spermatogenesis. The postmeiotic expression of G6pdx in Mus spretus points towards the continuous evolution of X-chromosome silencing and provides an example of expression change accompanying the out-of-the X-chromosomal retroposition.
- MeSH
- antisense RNA genetika MeSH
- chromozom X genetika MeSH
- druhová specificita MeSH
- glukosa-6-fosfátdehydrogenasa genetika MeSH
- malá interferující RNA genetika MeSH
- meióza genetika MeSH
- molekulární evoluce MeSH
- myši MeSH
- nekódující RNA genetika MeSH
- retroelementy genetika MeSH
- testis cytologie metabolismus MeSH
- transkriptom MeSH
- umlčování genů MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Theory predicts that sexually antagonistic mutations will be over- or under-represented on the X and Z chromosomes, depending on their average dominance coefficients. However, as little is known about the dominance coefficients for new mutations, the effect of sexually antagonistic selection is difficult to predict. To elucidate the role of sexually antagonistic selection in the evolution of Z chromosome gene content in chicken, we analyzed publicly available microarray data from several somatic tissues as well as somatic and germ cells of the ovary. We found that the Z chromosome is enriched for genes showing preferential expression in ovarian somatic cells, but not for genes with preferential expression in primary oocytes or non-sex-specific somatic tissues. Our results suggest that sexual antagonism leads to a higher abundance of female-benefit alleles on the Z chromosome. No bias toward Z-linkage for oocyte-enriched genes can be explained by lower intensity of sexually antagonistic selection in ovarian germ cells compared to ovarian somatic cells. An alternative explanation would be that meiotic Z chromosome inactivation hinders accumulation of oocyte-expressed genes on the Z chromosome. Our results are consistent with findings in mammals and indicate that recessive rather than dominant sexually antagonistic mutations shape the gene content of the X and Z chromosomes.
- MeSH
- databáze genetické MeSH
- folikulární buňky metabolismus MeSH
- kompenzace dávky (genetika) genetika MeSH
- kur domácí genetika MeSH
- lineární modely MeSH
- meióza MeSH
- mutace MeSH
- oogeneze MeSH
- orgánová specificita MeSH
- ovarium cytologie metabolismus fyziologie MeSH
- pohlavní chromozomy genetika metabolismus MeSH
- rozdělení chí kvadrát MeSH
- sekvenční analýza hybridizací s uspořádaným souborem oligonukleotidů MeSH
- selekce (genetika) MeSH
- stanovení celkové genové exprese MeSH
- vývojová regulace genové exprese * MeSH
- zvířata MeSH
- Check Tag
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Through linkage analysis and candidate gene sequencing, we identified three unrelated families with the autosomal-dominant inheritance of early onset anemia, hypouricosuric hyperuricemia, progressive kidney failure, and mutations resulting either in the deletion (p.Leu16del) or the amino acid exchange (p.Leu16Arg) of a single leucine residue in the signal sequence of renin. Both mutations decrease signal sequence hydrophobicity and are predicted by bioinformatic analyses to damage targeting and cotranslational translocation of preprorenin into the endoplasmic reticulum (ER). Transfection and in vitro studies confirmed that both mutations affect ER translocation and processing of nascent preprorenin, resulting either in reduced (p.Leu16del) or abolished (p.Leu16Arg) prorenin and renin biosynthesis and secretion. Expression of renin and other components of the renin-angiotensin system was decreased accordingly in kidney biopsy specimens from affected individuals. Cells stably expressing the p.Leu16del protein showed activated ER stress, unfolded protein response, and reduced growth rate. It is likely that expression of the mutant proteins has a dominant toxic effect gradually reducing the viability of renin-expressing cells. This alters the intrarenal renin-angiotensin system and the juxtaglomerular apparatus functionality and leads to nephron dropout and progressive kidney failure. Our findings provide insight into the functionality of renin-angiotensin system and stress the importance of renin analysis in families and individuals with early onset hyperuricemia, anemia, and progressive kidney failure.
- MeSH
- anemie genetika metabolismus MeSH
- buněčné linie MeSH
- chronické selhání ledvin genetika metabolismus MeSH
- dítě MeSH
- dominantní geny MeSH
- dospělí MeSH
- genetická vazba MeSH
- hyperurikemie genetika metabolismus MeSH
- ledviny cytologie ultrastruktura MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- mutace MeSH
- počítačová simulace MeSH
- předškolní dítě MeSH
- renin genetika metabolismus MeSH
- rodokmen MeSH
- sekvenční analýza DNA MeSH
- věk při počátku nemoci MeSH
- Check Tag
- dítě MeSH
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- předškolní dítě MeSH
- ženské pohlaví MeSH
- Publikační typ
- práce podpořená grantem MeSH
A major outcome of the canonical Wnt/beta-catenin-signalling pathway is the transcriptional activation of a specific set of target genes. A typical feature of the transcriptional response induced by Wnt signalling is the involvement of Tcf/Lef factors that function in the nucleus as the principal mediators of signalling. Vertebrate Tcf/Lef proteins perform two well-characterized functions: in association with beta-catenin they activate gene expression, and in the absence of Wnt ligands they bind TLE/Groucho proteins to act as transcriptional repressors. Although the general characteristics of Tcf/Lef factors are well understood, the mechanisms that control their specific roles in various cellular backgrounds are much less defined. In this report we reveal that the evolutionary conserved Dazap2 protein functions as a TCF-4 interacting partner. We demonstrate that a short region proximal to the TCF-4 HMG box mediates the interaction and that all Tcf/Lef family members associate with Dazap2. Interestingly, knockdown of Dazap2 not only reduced the activity of Wnt signalling as measured by Tcf/beta-catenin reporters but additionally altered the expression of Wnt-signalling target genes. Finally, chromatin immunoprecipitation studies indicate that Dazap2 modulates the affinity of TCF-4 for its DNA-recognition motif.
- MeSH
- beta-katenin metabolismus MeSH
- buněčné linie MeSH
- DNA vazebné proteiny chemie metabolismus MeSH
- genetická transkripce MeSH
- genový knockdown MeSH
- lidé MeSH
- myši MeSH
- promotorové oblasti (genetika) MeSH
- proteiny vázající RNA antagonisté a inhibitory genetika metabolismus MeSH
- proteiny Wnt metabolismus MeSH
- regulace genové exprese MeSH
- transkripční faktory BHLH-Zip MeSH
- transkripční faktory chemie metabolismus MeSH
- vazebná místa MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- práce podpořená grantem MeSH
FLT3 is the most frequently mutated gene in acute myeloid leukemia (AML), with internal tandem duplications (ITDs) accounting for up to 30% of its mutations. To analyze the impact of individual ITDs on the expression profile of immature myeloid cells, we have established 32D cell lines expressing nine different FLT3/ITDs isolated from AML patients and subjected them to whole genome expression profiling and 2DE/LC/MS proteomics. Our data indicate that in comparison to the controls, FLT3/ITD-positive 32D cells exhibit less mature expression profiles resembling early hematopoietic progenitors. Moreover, our results suggest that there exist biological differences among individual ITD variants.
- MeSH
- akutní myeloidní leukemie genetika patologie MeSH
- blastická krize genetika patologie MeSH
- buněčná diferenciace MeSH
- buněčné dělení MeSH
- exony MeSH
- genetická variace MeSH
- klonování DNA MeSH
- lidé MeSH
- molekulární sekvence - údaje MeSH
- mutace MeSH
- myši MeSH
- nádorové buněčné linie MeSH
- polymerázová řetězová reakce s reverzní transkripcí MeSH
- Retroviridae genetika MeSH
- sekvence aminokyselin MeSH
- sekvenční analýza hybridizací s uspořádaným souborem oligonukleotidů MeSH
- stanovení celkové genové exprese MeSH
- tandemové repetitivní sekvence genetika MeSH
- tyrosinkinasa 3 podobná fms genetika MeSH
- western blotting MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- práce podpořená grantem MeSH
BACKGROUND: To strengthen research and differential diagnostics of mitochondrial disorders, we constructed and validated an oligonucleotide microarray (h-MitoArray) allowing expression analysis of 1632 human genes involved in mitochondrial biology, cell cycle regulation, signal transduction and apoptosis. Using h-MitoArray we analyzed gene expression profiles in 9 control and 13 fibroblast cell lines from patients with F1Fo ATP synthase deficiency consisting of 2 patients with mt9205deltaTA microdeletion and a genetically heterogeneous group of 11 patients with not yet characterized nuclear defects. Analysing gene expression profiles, we attempted to classify patients into expected defect specific subgroups, and subsequently reveal group specific compensatory changes, identify potential phenotype causing pathways and define candidate disease causing genes. RESULTS: Molecular studies, in combination with unsupervised clustering methods, defined three subgroups of patient cell lines--M group with mtDNA mutation and N1 and N2 groups with nuclear defect. Comparison of expression profiles and functional annotation, gene enrichment and pathway analyses of differentially expressed genes revealed in the M group a transcription profile suggestive of synchronized suppression of mitochondrial biogenesis and G1/S arrest. The N1 group showed elevated expression of complex I and reduced expression of complexes III, V, and V-type ATP synthase subunit genes, reduced expression of genes involved in phosphorylation dependent signaling along MAPK, Jak-STAT, JNK, and p38 MAP kinase pathways, signs of activated apoptosis and oxidative stress resembling phenotype of premature senescent fibroblasts. No specific functionally meaningful changes, except of signs of activated apoptosis, were detected in the N2 group. Evaluation of individual gene expression profiles confirmed already known ATP6/ATP8 defect in patients from the M group and indicated several candidate disease causing genes for nuclear defects. CONCLUSION: Our analysis showed that deficiency in the ATP synthase protein complex amount is generally accompanied by only minor changes in expression of ATP synthase related genes. It also suggested that the site (mtDNA vs nuclear DNA) and the severity (ATP synthase content) of the underlying defect have diverse effects on cellular gene expression phenotypes, which warrants further investigation of cell cycle regulatory and signal transduction pathways in other OXPHOS disorders and related pharmacological models.
- MeSH
- analýza hlavních komponent MeSH
- buněčné linie MeSH
- fenotyp MeSH
- fibroblasty MeSH
- financování organizované MeSH
- genom mitochondriální MeSH
- lidé MeSH
- mitochondriální DNA genetika MeSH
- mitochondriální nemoci MeSH
- mitochondriální protonové ATPasy genetika nedostatek MeSH
- modely genetické MeSH
- sekvenční analýza hybridizací s uspořádaným souborem oligonukleotidů metody statistika a číselné údaje MeSH
- sekvenční delece MeSH
- shluková analýza MeSH
- stanovení celkové genové exprese metody statistika a číselné údaje MeSH
- Check Tag
- lidé MeSH