| 1. |
- Tarbier, Marcel, 1990-, et al.
(författare)
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Landscape of microRNA and target expression variation and covariation in single mouse embryonic stem cells
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- MicroRNAs are small RNA molecules that can repress the expression of protein coding genes post-transcriptionally. Previous studies have shown that microRNAs can also have alternative functions including target noise buffering and co-expression, but these observations have been limited to a few microRNAs. Here we systematically study microRNA alternative functions in mouse embryonic stem cells, by genetically deleting Drosha - leading to global loss of microRNAs. We apply complementary single-cell RNA-seq methods to study the variation of the targets and the microRNAs themselves, and transcriptional inhibition to measure target half-lives. We find that microRNAs form four distinct co-expression groups across single cells. In particular the mir-290 and the mir-182 clusters are abundantly, variably and inversely expressed. Intriguingly, some cells have global biases towards specific miRNAs originating from either end of the hairpin precursor, suggesting the presence of unknown regulatory cofactors. We find that miRNAs generally increase variation and covariation of their targets at the RNA level, but we also find miRNAs such as miR-182 that appear to have opposite functions. In particular, miRNAs that are themselves variable in expression, such as miR-291a, are more likely to induce covariations. In summary, we apply genetic perturbation and multi-omics to give the first global picture of microRNA dynamics at the single cell level.
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| 2. |
- Tarbier, Marcel, et al.
(författare)
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Single-cell sequencing reveals heterogeneity in miRNA biogenesis and function
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- MiRNAs are ~22 nucleotide small RNAs that repress protein coding genes post- transcriptionally. They have been studied extensively in bulk studies that pool hundreds of thousands of cells, but there is a paucity of studies of their biogenesis and function in single cells. Here we present single-cell small RNA sequencing (sc- sRNAseq) data from 192 individual mouse embryonic stem cells. We find that some miRNAs are stably expressed across cells, while others have variable expression. In particular, we find that the miR-290 cluster, which promotes progression through the cell cycle and proliferation, and the miR-182/183 cluster, which targets differentiation factors, are negatively correlated. We also find that some cells have global biases towards 5’ or 3’ miRNA, suggesting the presence of protein cofactors. Complementing our data with single-cell mRNA sequencing and protein data from other studies in embryonic stem cells, we find that miRNAs generally increase variation of their targets at the RNA level, but we find examples of miRNAs that buffer variation of their targets at the protein level. In summary, we integrate single- cell gene expression data of small RNA, mRNA and protein to give new insights into miRNA biogenesis, dynamics and functions at the cell level.
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| 3. |
- Nikravesh, Abbas, et al.
(författare)
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Antisense PNA Accumulates in Escheria coli and mediates a Long Post-antibiotic Effect
- 2008
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Ingår i: Molecular Therapy. - : Elsevier BV. - 1525-0016 .- 1525-0024. ; 15:8, s. 1537-1542
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Tidskriftsartikel (refereegranskat)abstract
- Antisense agents that target growth-essential genes display surprisingly potent bactericidal properties. In particular, peptide nucleic acid (PNA) and phosphorodiamidate morpholino oligomers linked to cationic carrier peptides are effective in time kill assays and as inhibitors of bacterial peritonitis in mice. It is unclear how these relatively large antimicrobials overcome stringent bacterial barriers and mediate killing. Here we determined the transit kinetics of peptide–PNAs and observed an accumulation of cell-associated PNA in Escherichia coli and slow efflux. An inhibitor of drug efflux pumps did not alter peptide–PNA potency, indicating a lack of active efflux from cells. Consistent with cell retention, the post-antibiotic effect (PAE) of the anti-acyl carrier protein (acpP) peptide–PNA was greater than 11 hours. Bacterial cell accumulation and a long PAE are properties of significant interest for antimicrobial development.
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| 4. |
- Simonson, Oscar E., et al.
(författare)
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In Vivo Effects of Mesenchymal Stromal Cells in Two Patients With Severe Acute Respiratory Distress Syndrome
- 2015
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Ingår i: Stem Cells Translational Medicine. - : Oxford University Press (OUP). - 2157-6564 .- 2157-6580. ; 4:10, s. 1199-1213
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Tidskriftsartikel (refereegranskat)abstract
- Mesenchymal stromal cells (MSCs) have been investigated as a treatment for various inflammatory diseases because of their immunomodulatory and reparative properties. However, many basic questions concerning their mechanisms of action after systemic infusion remain unanswered. We performed a detailed analysis of the immunomodulatory properties and proteomic profile of MSCs systemically administered to two patients with severe refractory acute respiratory distress syndrome (ARDS) on a compassionate use basis and attempted to correlate these with in vivo anti-inflammatory actions. Both patients received 2 x 10(6) cells per kilogram, and each subsequently improved with resolution of respiratory, hemodynamic, and multiorgan failure. In parallel, a decrease was seen in multiple pulmonary and systemic markers of inflammation, including epithelial apoptosis, alveolar-capillary fluid leakage, and proinflammatory cytokines, microRNAs, and chemokines. In vitro studies of the MSCs demonstrated a broad anti-inflammatory capacity, including suppression of T-cell responses and induction of regulatory phenotypes in T cells, monocytes, and neutrophils. Some of these in vitro potency assessments correlated with, and were relevant to, the observed in vivo actions. These experiences highlight both the mechanistic information that can be gained from clinical experience and the value of correlating in vitro potency assessments with clinical effects. The findings also suggest, but do not prove, a beneficial effect of lung protective strategies using adoptively transferred MSCs in ARDS. Appropriate randomized clinical trials are required to further assess any potential clinical efficacy and investigate the effects on in vivo inflammation. STEM CELLS TRANSLATIONAL MEDICINE 2015;4:1199-1213
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| 5. |
- Zheleznyakova, Galina Yurevna, et al.
(författare)
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Small noncoding RNA profiling across cellular and biofluid compartments and their implications for multiple sclerosis immunopathology
- 2021
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 118:17
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Tidskriftsartikel (refereegranskat)abstract
- Multiple sclerosis (MS) is a chronic inflammatory demyelinating disease affecting the central nervous system (CNS). Small non-coding RNAs (sncRNAs) and, in particular, microRNAs (miRNAs) have frequently been associated with MS. Here, we performed a comprehensive analysis of all classes of sncRNAs in matching samples of peripheral blood mononuclear cells (PBMCs), plasma, cerebrospinal fluid (CSF) cells, and cell-free CSF from relapsing-remitting (RRMS, n = 12 in relapse and n = 11 in remission) patients, secondary progressive (SPMS, n = 6) MS patients, and noninflammatory and inflammatory neurological disease controls (NINDC, n = 11; INDC, n = 5). We show widespread changes in miRNAs and sncRNA-derived fragments of small nuclear, nucleolar, and transfer RNAs. In CSF cells, 133 out of 133 and 115 out of 117 differentially expressed sncRNAs were increased in RRMS relapse compared to remission and RRMS compared to NINDC, respectively. In contrast, 65 out of 67 differentially expressed PBMC sncRNAs were decreased in RRMS compared to NINDC. The striking contrast between the periphery and CNS suggests that sncRNA-mediated mechanisms, including alternative splicing, RNA degradation, and mRNA translation, regulate the transcriptome of pathogenic cells primarily in the CNS target organ.
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