| 1. |
- Jönsson, Maria, 1977-, et al.
(författare)
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FLT3 ligand regulates apoptosis through AKT-dependent inactivation of transcription factor Fox03
- 2004
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Ingår i: Biochemical and Biophysical Research Communications. - : Elsevier BV. - 1090-2104 .- 0006-291X. ; 318:4, s. 899-903
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Tidskriftsartikel (refereegranskat)abstract
- Proliferation, differentiation, and survival of hematopoietic cells are regulated by cytokines, acting through specific receptors. FLT3 ligand (FL) is one of the most important cytokines for regulation of the hematopoietic system, and its receptor FLT3 is expressed on both stem cells and progenitors. Regulation of Forkhead transcription factors has been described as an important mechanism to control apoptosis and cell cycle progression in hematopoietic progenitors. Here we report that FL induces AKT/PKB activation, which in turn phosphorylates and thereby inactivates the Forkhead protein FoxO3 in the progenitor cell line FDC-P1 stably expressing murine FLT3 receptor. Phosphorylation of AKT and FoxO3 was blocked by the PI-3 kinase inhibitor LY294002 but not by the MAP kinase inhibitor PD98059. Expression of a mutated FoxO3, in which all three inhibitory phosphorylation sites were mutated to alanine, led to rapid increase of apoptotic cells in the presence of FL. These results suggest that FL-induced regulation of apoptosis is executed by FoxO3. (C) 2004 Elsevier Inc. All rights reserved.
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| 2. |
- Mjösberg, Jenny, et al.
(författare)
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Systemic reduction of functionally suppressive CD4dimCD25highFoxp3+ T-regs in human second trimester pregnancy is induced by progesterone and 17 beta-estradiol
- 2009
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Ingår i: Journal of Reproductive Immunology(ISSN 0165-0378), vol 81, issue 2. - : Elsevier BV. ; , s. 160-161
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Konferensbidrag (refereegranskat)abstract
- CD4+CD25high regulatory T cells (Tregs) are implicated in maintenance of murine pregnancy. However, reports regarding circulating Treg frequencies in human pregnancy are inconsistent and the functionality and phenotype of these cells in pregnancy have not been clarified. The aim was to determine the frequency, phenotype and function of circulating Tregs in second trimester human pregnancy and the influence of progesterone and 17β-estradiol on Treg phenotype and frequency. Based on expression of Foxp3, CD127 and HLA-DR, as determined by multi-color flow cytometry, we defined a proper CD4dimCD25high Treg population and showed, in contrast to most previous reports, that this population was reduced in second trimester pregnancy. Unexpectedly, Foxp3 expression was decreased in the Treg, as well as in the CD4+ population. These changes could be replicated in an in vitro system resembling the pregnancy hormonal milieu, where 17β-estradiol, and in particular progesterone, induced, in line with the pregnancy situation, a reduction of CD4dimCD25highFoxp3+ cells in PBMC from non-pregnant women. By co-culturing FACS-sorted Tregs and autologous CD4+CD25- responder cells, we showed that Tregs from pregnant women still displayed the same suppressive capacity as non-pregnant women in terms of suppressing IL-2, TNF-α and IFN-γ secretion from responder cells while efficiently producing IL-4 and IL-10. Our findings support the view of hormones, particularly progesterone, as critical regulators of Tregs in pregnancy. Further, we suggest that in the light of the results of this study, early data on circulating Treg frequencies in pregnancy need re-evaluation.
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| 3. |
- Mjösberg, Jenny, et al.
(författare)
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Systemic reduction of functionally suppressive CD4dimCD25highFoxp3+ Tregs in human second trimester pregnancy is induced by progesterone and 17θ-estradiol
- 2009
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Ingår i: Journal of Immunology. - : The American Association of Immunologists. - 0022-1767 .- 1550-6606. ; 183:1, s. 759-769
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Tidskriftsartikel (refereegranskat)abstract
- CD4+CD25high regulatory T cells (Tregs) are implicated in the maintenance of murine pregnancy. However, reports regarding circulating Treg frequencies in human pregnancy are inconsistent, and the functionality and phenotype of these cells in pregnancy have not been clarified. The aim of this study was to determine the frequency, phenotype, and function of circulating Tregs in the second trimester of human pregnancy and the influence of progesterone and 17β-estradiol on Treg phenotype and frequency. Based on expressions of Foxp3, CD127, and HLA-DR as determined by multicolor flow cytometry, we defined a proper CD4dimCD25high Treg population and showed, in contrast to most previous reports, that this population was reduced in second trimester of pregnancy. Unexpectedly, Foxp3 expression was decreased in the Treg, as well as in the CD4+ population. These changes could be replicated in an in vitro system resembling the pregnancy hormonal milieu, where 17β-estradiol, and in particular progesterone, induced, in line with the pregnancy situation, a reduction of CD4dimCD25highFoxp3+ cells in PBMC from nonpregnant women. By coculturing FACS-sorted Tregs and autologous CD4+CD25– responder cells, we showed that Tregs from pregnant women still displayed the same suppressive capacity as nonpregnant women in terms of suppressing IL-2, TNF-, and IFN- secretion from responder cells while efficiently producing IL-4 and IL-10. Our findings support the view of hormones, particularly progesterone, as critical regulators of Tregs in pregnancy. Furthermore, we suggest that in the light of the results of this study, early data on circulating Treg frequencies in pregnancy need reevaluation.The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked advertisement in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
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| 4. |
- Abrahamson, Alexandra, et al.
(författare)
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Gill EROD in monitoring of CYP1A inducers in fish : A study in rainbow trout (Oncorhynchus mykiss) caged in Stockholm and Uppsala waters
- 2007
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Ingår i: Aquatic Toxicology. - : Elsevier BV. - 0166-445X .- 1879-1514. ; 85:1, s. 1-8
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Tidskriftsartikel (refereegranskat)abstract
- The gill filament 7-ethoxyresorufin O-deethylase (EROD) assay was evaluated as a monitoring tool for waterborne cytochrome P4501 A (CYP1A) inducers using rainbow trout (Oncorhynchus mykiss) caged in urban area waters in Sweden. To compare the CYP1A induction response in different tissues, EROD activity was also analyzed in liver and kidney microsomes. Immunohistochemistry was used to localize CYP1A protein in gill and kidney. In two separate experiments fish were caged at sites with fairly high expected polyaromatic hydrocarbon (PAH) contamination. In the first experiment, gill EROD activities were analyzed in fish exposed for 1-21 days in a river running through Uppsala. The reference site was upstream of Uppsala. In the second, gill, liver and kidney EROD activities were analyzed in fish exposed for 1-5 days in fresh or brackish waters of Stockholm and in a reference lake 60 km north of Stockholm. Fish exposed for 5 days followed by 2 days of recovery in tap water in the laboratory were also examined. The gill consistently showed a higher EROD induction compared with the liver and the kidney. After I day of caging, gill EROD activity was markedly induced (6-17-fold) at all sites examined. Induction in gill was pronounced (5-7-fold) also in fish caged at the reference sites. In the 21-day exposure study gill EROD activity remained highly induced throughout the experiment (26-fold at most) and the induced CYP1A protein was exclusively confined to the gill secondary lamellae. In the 5-day exposure experiment, EROD activity peaked after I day and then declined in both gill and liver, while CYP1A immunostaining in the gill remained intense over the 5-day period. In the kidney, CYP1A staining was weak or absent. We conclude that gill EROD activity is a more sensitive biomarker of exposure to waterborne CYP1A inducers than EROD activity in liver and kidney.
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| 5. |
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| 6. |
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| 7. |
- Ansell, Anna, et al.
(författare)
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Molecular cross-talk between head and neck squamous cell carcinoma cells and cancer-associated fibroblasts
- 2013
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Cancer-associated fibroblasts (CAFs) are one of the main components of the tumor stroma and are known to increase tumor growth and stimulate invasion and metastasis. Increasing evidence suggests that CAFs may also be an important determinant of the response to various treatments. In this study we aimed to characterize the molecular cross-talk between CAFs and head and neck squamous cell carcinoma (HNSCC) cells.HNSCC cell lines were co-cultured with their patient-matched CAFs for seven days, after which the gene expression of tumor cells was investigated by Affymetrix microarray. 58 protein coding genes were found to be differentially expressed (Q≤0.05) in tumor cells cocultured with CAFs when compared to tumor cells cultured alone. The top functions of these genes were cancer, cellular movement, and embryonic development as analyzed by Ingenuity Pathway Analysis. Nine genes were upregulated by ≥1.5-fold while the expression of 35 genes was found to be reduced by ≤ 0.67-fold. Several of the differentially expressed genes have been associated with epithelial-to-mesenchymal transition (EMT). The change in the expression of POSTN, GREM1, COL1A2, VIM, and MMP7 was verified by qPCR analysis. Moreover, the influence of CAFs on the proliferation, migration and cetuximab sensitivity of tumor cells was investigated, and was found to vary among the tumor cell-CAF pairs.In conclusion, we demonstrate that CAF-derived signals cause changes in the expression of multiple genes, several of which are associated with an EMT phenotype of tumor cells. Furthermore, CAFs modulate the proliferation, migration and cetuximab treatment response of tumor cells.
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| 8. |
- Bahrampour, Shahrzad
(författare)
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Genetic mechanisms regulating proliferation and cell specification in the Drosophila embryonic CNS
- 2017
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The central nervous system (CNS) consists of an enormous number of cells, and large cellular variance, integrated into an elaborate network. The CNS is the most complex animal organ, and therefore its establishment must be controlled by many different genetic programs. Considering the high level of complexity in the human CNS, addressing issues related to human neurodevelopment represents a major challenge. Since comparative studies have revealed that neurodevelopmental programs are well conserved through evolution, on both the genetic and functional levels, studies on invertebrate neurodevelopmental programs are often translatable to vertebrates. Indeed, the basis of our current knowledge about vertebrate CNS development has been greatly aided by studies on invertebrates, and in particular on the Drosophila melanogaster (fruit fly) model system.This thesis attempted to identify novel genes regulating neural cell specification and proliferation in the CNS, using the Drosophila model system. Moreover, I aimed to address how those genes govern neural progenitor cells (neuroblasts; NBs) to obtain/maintain their stemness identity and proliferation capacity, and how they drive NBs through temporal windows and series of programmed asymmetric division, which gradually reduces their stemness identity in favor of neural differentiation, resulting in appropriate lineage progression. In the first project, we conducted a forward genetic screen in Drosophila embryos, aimed at isolating genes involved in regulation of neural proliferation and specification, at the single cell resolution. By taking advantage of the restricted expression of the neuropeptide FMRFa in the last-born cell of the NB lineage 5-6T, the Ap4 neuron, we could monitor the entire lineage progression. This screen succeeded in identifying 43 novel genes controlling different aspects of CNS development. One of the genes isolated, Ctr9, displayed extra Ap4/FMRFa neurons. Ctr9 encodes a component of the RNA polymerase II complex Paf1, which is involved in a number of transcriptional processes. The Paf1C, including Ctr9, is highly conserved from yeast to human, and in the past couple of years, its importance for transcription has become increasingly appreciated. However, studies in the Drosophila system have been limited. In the screen, we isolated the first mutant of Drosophila Ctr9 and conducted the first detailed phenotypic study on its function in the Drosophila embryonic CNS. Loss of function of Ctr9 leads to extra NB numbers, higher proliferation ratio and lower expression of neuropeptides. Gene expression analysis identified several other genes regulated by Ctr9, which may explain the Ctr9 mutant phenotypes. In summary, we identified Ctr9 as an essential gene for proper CNS development in Drosophila, and this provides a platform for future study on the Drosophila Paf1C. Another interesting gene isolated in the screen was worniou (wor), a member of the Snail family of transcription factors. In contrast to Ctr9, whichdisplayed additional Ap4/FMRFa neurons, wor mutants displayed a loss of these neurons. Previous studies in our group have identified many genes acting to stop NB lineage progression, but how NBs are pushed to proliferate and generate their lineages was not well known. Since wor may constitute a “driver” of proliferation, we decided to study it further. Also, we identified five other transcription factors acting together with Wor as pro-proliferative in both NBs and their daughter cells. These “drivers” are gradually replaced by the previously identified late-acting “stoppers.” Early and late factors regulate each other and the cell cycle, and thereby orchestrate proper neural lineage progression.
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| 9. |
- Barrett, Jennifer H., et al.
(författare)
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Genome-wide association study identifies three new melanoma susceptibility loci
- 2011
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Ingår i: Nature Genetics. - : Springer Science and Business Media LLC. - 1546-1718 .- 1061-4036. ; 43:11, s. 1108-1113
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Tidskriftsartikel (refereegranskat)abstract
- We report a genome-wide association study for melanoma that was conducted by the GenoMEL Consortium. Our discovery phase included 2,981 individuals with melanoma and 1,982 study-specific control individuals of European ancestry, as well as an additional 6,426 control subjects from French or British populations, all of whom were genotyped for 317,000 or 610,000 single-nucleotide polymorphisms (SNPs). Our analysis replicated previously known melanoma susceptibility loci. Seven new regions with at least one SNP with P < 10(-5) and further local imputed or genotyped support were selected for replication using two other genome-wide studies (from Australia and Texas, USA). Additional replication came from case-control series from the UK and The Netherlands. Variants at three of the seven loci replicated at P < 10(-3): an SNP in ATM (rs1801516, overall P = 3.4 x 10(-9)), an SNP in MX2 (rs45430, P = 2.9 x 10-9) and an SNP adjacent to CASP8 (rs13016963, P = 8.6 x 10(-10)). A fourth locus near CCND1 remains of potential interest, showing suggestive but inconclusive evidence of replication (rs1485993, overall P = 4.6 x 10(-7) under a fixed-effects model and P = 1.2 x 10(-3) under a random-effects model). These newly associated variants showed no association with nevus or pigmentation phenotypes in a large British case-control series.
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| 10. |
- Baumgartner, Johanna, et al.
(författare)
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Switchable presentation of cytokines on electroactive polypyrrole surfaces for hematopoietic stem and progenitor cells
- 2018
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Ingår i: Journal of Materials Chemistry B. - Cambridge : Royal Society of Chemistry. - 2050-750X .- 2050-7518. ; 6:28, s. 4665-4675
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Tidskriftsartikel (refereegranskat)abstract
- Hematopoietic stem cells are used in transplantations for patients with hematologic malignancies. Scarce sources require efficient strategies of expansion, including polymeric biomaterials mimicking architectures of bone marrow tissue. Tissue microenvironment and mode of cytokine presentation strongly influence cell fate. Although several cytokines with different functions as soluble or membrane-bound mediators have already been identified, their precise roles have not yet been clarified. A need exists for in vitro systems that mimic the in vivo situation to enable such studies. One way is to establish surfaces mimicking physiological presentation using protein-immobilization onto polymer films. However these films merely provide a static presentation of the immobilized proteins. It would be advantageous to also dynamically change protein presentation and functionality to better reflect the in vivo conditions. The electroactive polymer polypyrrole shows excellent biocompatibility and electrochemically alters its surface properties, becoming an interesting choice for such setups. Here, we present an in vitro system for switchable presentation of membrane-bound cytokines. We use interleukin IL-3, known to affect hematopoiesis, and show that when immobilized on polypyrrole films, IL-3 is bioavailable for the bone marrow-derived FDC-P1 progenitor cell line. Moreover, IL-3 presentation can be successfully altered by changing the redox state of the film, in turn influencing FDC-P1 cell viability. This novel in vitro system provides a valuable tool for stimuli-responsive switchable protein presentation allowing the dissection of relevant mediators in stem and progenitor cell behavior.
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