| 1. |
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| 2. |
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| 3. |
- Amirhosseini, Mehdi, et al.
(författare)
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Cyclin-dependent kinase 8/19 inhibition suppresses osteoclastogenesis by downregulating RANK and promotes osteoblast mineralization and cancellous bone healing.
- 2019
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Ingår i: Journal of Cellular Physiology. - : Wiley. - 0021-9541 .- 1097-4652. ; 234:9, s. 16503-16516
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Tidskriftsartikel (refereegranskat)abstract
- Cyclin-dependent kinase 8 (CDK8) is a mediator complex-associated transcriptional regulator that acts depending on context and cell type. While primarily under investigation as potential cancer therapeutics, some inhibitors of CDK8-and its paralog CDK19-have been reported to affect the osteoblast lineage and bone formation. This study investigated the effects of two selective CDK8/19 inhibitors on osteoclastogenesis and osteoblasts in vitro, and further evaluated how local treatment with a CDK8/19 inhibitor affects cancellous bone healing in rats. CDK8/19 inhibitors did not alter the proliferation of neither mouse bone marrow-derived macrophages (BMMs) nor primary mouse osteoblasts. Receptor activator of nuclear factor κΒ (NF-κB) ligand (RANKL)-induced osteoclastogenesis from mouse BMMs was suppressed markedly by inhibition of CDK8/19, concomitant with reduced tartrate-resistant acid phosphatase (TRAP) activity and C-terminal telopeptide of type I collagen levels. This was accompanied by downregulation of PU.1, RANK, NF-κB, nuclear factor of activated T-cells 1 (NFATc1), dendritic cell-specific transmembrane protein (DC-STAMP), TRAP, and cathepsin K in RANKL-stimulated BMMs. Downregulating RANK and its downstream signaling in osteoclast precursors enforce CDK8/19 inhibitors as anticatabolic agents to impede excessive osteoclastogenesis. In mouse primary osteoblasts, CDK8/19 inhibition did not affect differentiation but enhanced osteoblast mineralization by promoting alkaline phosphatase activity and downregulating osteopontin, a negative regulator of mineralization. In rat tibiae, a CDK8/19 inhibitor administered locally promoted cancellous bone regeneration. Our data indicate that inhibitors of CDK8/19 have the potential to develop into therapeutics to restrict osteolysis and enhance bone regeneration.
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| 4. |
- Amirhosseini, Mehdi, et al.
(författare)
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GSK-3 beta inhibition suppresses instability-induced osteolysis by a dual action on osteoblast and osteoclast differentiation
- 2018
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Ingår i: Journal of Cellular Physiology. - : WILEY. - 0021-9541 .- 1097-4652. ; 233:3, s. 2398-2408
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Tidskriftsartikel (refereegranskat)abstract
- Currently, there are no medications available to treat aseptic loosening of orthopedic implants. Using osteoprotegerin fusion protein (OPG-Fc), we previously blocked instability-induced osteoclast differentiation and peri-prosthetic osteolysis. Wnt/beta-catenin signaling, which regulates OPG secretion from osteoblasts, also modulates the bone tissue response to mechanical loading. We hypothesized that activating Wnt/beta-catenin signaling by inhibiting glycogen synthase kinase-3 beta (GSK-3 beta) would reduce instability-induced bone loss through regulation of both osteoblast and osteoclast differentiation. We examined effects of GSK-3 beta inhibition on regulation of RANKL and OPG in a rat model of mechanical instability-induced peri-implant osteolysis. The rats were treated daily with a GSK-3 beta inhibitor, AR28 (20 mg/kg bw), for up to 5 days. Bone tissue and blood serum were assessed by qRT-PCR, immunohistochemistry, and ELISA on days 3 and 5, and by micro-CT on day 5. After 3 days of treatment with AR28, mRNA levels of beta-catenin, Runx2, Osterix, Col1 alpha 1, and ALP were increased leading to higher osteoblast numbers compared to vehicle-treated animals. BMP-2 and Wnt16 mRNA levels were downregulated by mechanical instability and this was rescued by GSK-3 beta inhibition. Osteoclast numbers were decreased significantly after 3 days of GSK-3 beta inhibition, which correlated with enhanced OPG mRNA expression. This was accompanied by decreased serum levels of TRAP5b on days 3 and 5. Treatment with AR28 upregulated osteoblast differentiation, while osteoclastogenesis was blunted, leading to increased bone mass by day 5. These data suggest that GSK-3 beta inactivation suppresses osteolysis through regulating both osteoblast and osteoclast differentiation in a rat model of instability-induced osteolysis.
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| 5. |
- Arnemo, Jon
(författare)
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MicroRNAs facilitate skeletal muscle maintenance and metabolic suppression in hibernating brown bears
- 2020
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Ingår i: Journal of Cellular Physiology. - : Wiley. - 0021-9541 .- 1097-4652. ; 235, s. 3984-3993
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Tidskriftsartikel (refereegranskat)abstract
- Hibernating brown bears, Ursus arctos, undergo extended periods of inactivity and yet these large hibernators are resilient to muscle disuse atrophy. Physiological characteristics associated with atrophy resistance in bear muscle have been examined (e.g., muscle mechanics, neural activity) but roles for molecular signaling/regulatory mechanisms in the resistance to muscle wasting in bears still require investigation. Using quantitative reverse transcription PCR (RT-qPCR), the present study characterized the responses of 36 microRNAs linked with development, metabolism, and regeneration of skeletal muscle, in the vastus lateralis of brown bears comparing winter hibernating and summer active animals. Relative levels of mRNA of selected genes (mef2a, pax7, id2, prkaa1, and mstn) implicated upstream and downstream of the microRNAs were examined. Results indicated that hibernation elicited a myogenic microRNA, or "myomiR", response via MEF2A-mediated signaling. Upregulation of MEF2A-controlled miR-1 and miR-206 and respective downregulation of pax7 and id2 mRNA are suggestive of responses that promote skeletal muscle maintenance. Increased levels of metabolic microRNAs, such as miR-27, miR-29, and miR-33, may facilitate metabolic suppression during hibernation via mechanisms that decrease glucose uptake and fatty acid oxidation. This study identified myomiR-mediated mechanisms for the promotion of muscle regeneration, suppression of ubiquitin ligases, and resistance to muscle atrophy during hibernation mediated by observed increases in miR-206, miR-221, miR-31, miR-23a, and miR-29b. This was further supported by the downregulation of myomiRs associated with a muscle injury and inflammation (miR-199a and miR-223) during hibernation. The present study provides evidence of myomiR-mediated signaling pathways that are activated during hibernation to maintain skeletal muscle functionality in brown bears.
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| 6. |
- Aslan, Cynthia, et al.
(författare)
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Tumor-derived exosomes: Implication in angiogenesis and antiangiogenesis cancer therapy
- 2019
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Ingår i: Journal of Cellular Physiology. - : WILEY. - 0021-9541 .- 1097-4652. ; 234:10, s. 16885-16903
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Forskningsöversikt (refereegranskat)abstract
- Tumor cells utilize different strategies to communicate with neighboring tissues for facilitating tumor progression and invasion, one of these strategies has been shown to be the release of exosomes. Exosomes are small nanovesicles secreted by all kind of cells in the body, especially cancer cells, and mediate cell to cell communications. Exosomes play an important role in cancer invasiveness by harboring various cargoes that could accelerate angiogenesis. Here first, we will present an overview of exosomes, their biology, and their function in the body. Then, we will focus on exosomes derived from tumor cells as tumor angiogenesis mediators with a particular emphasis on the underlying mechanisms in various cancer origins. Also, exosomes derived from stem cells and tumor-associated macrophages will be discussed in this regard. Finally, we will discuss the novel therapeutic strategies of exosomes as drug delivery vehicles against angiogenesis.
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| 7. |
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| 8. |
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| 9. |
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| 10. |
- Bratengeier, Cornelia, et al.
(författare)
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Mechanical loading releases osteoclastogenesis-modulating factors through stimulation of the P2X7 receptor in hematopoietic progenitor cells
- 2019
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Ingår i: Journal of Cellular Physiology. - : WILEY. - 0021-9541 .- 1097-4652. ; 234:8, s. 13057-13067
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Tidskriftsartikel (refereegranskat)abstract
- Mechanical instability of bone implants stimulate osteoclast differentiation and peri-implant bone loss, leading to prosthetic loosening. It is unclear which cells at the periprosthetic interface transduce mechanical signals into a biochemical response, and subsequently facilitate bone loss. We hypothesized that mechanical overloading of hematopoietic bone marrow progenitor cells, which are located near to the inserted bone implants, stimulates the release of osteoclast-inducing soluble factors. Using a novel in vitro model to apply mechanical overloading, we found that hematopoietic progenitor cells released adenosine triphosphate (ATP) after only 2min of mechanical loading. The released ATP interacts with its specific receptor P2X7 to stimulate the release of unknown soluble factors that inhibit (physiological loading) or promote (supraphysiological loading) the differentiation of multinucleated osteoclasts derived from bone marrow cultures. Inhibition of ATP-receptor P2X7 by Brilliant Blue G completely abolished the overloading-induced stimulation of osteoclast formation. Likewise, stimulation of P2X7 receptor on hematopoietic cells by BzATP enhanced the release of osteoclastogenesis-stimulating signaling molecules to a similar extent as supraphysiological loading. Supraphysiological loading affected neither gene expression of inflammatory markers involved in aseptic implant loosening (e.g., interleukin-1 (IL-1), IL-6, tumor necrosis factor-, and PTGES2) nor expression of the osteoclast modulators receptor activator of nuclear factor -B ligandand osteoprotegerin. Our findings suggest that murine hematopoietic progenitor cells are a potential key player in local mechanical loading-induced bone implant loosening via the ATP/P2X7-axis. Our approach identifies potential therapeutic targets to prevent prosthetic loosening.
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| 11. |
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| 12. |
- Cabrera, Gonzalo, et al.
(författare)
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DNA damage, RAD9 and fertility/infertility of Echinococcus granulosus hydatid cysts
- 2008
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Ingår i: Journal of Cellular Physiology. - : Wiley. - 0021-9541 .- 1097-4652. ; 216:2, s. 498-506
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Tidskriftsartikel (refereegranskat)abstract
- Hydatidosis, caused by the larval stage of the platyhelminth parasite Echinococcus granulosus, affects human and animal health. Hydatid fertile cysts are formed in intermediate hosts (human and herbivores) producing protoscoleces, the infective form to canines, at their germinal layers. Infertile cysts are also formed, but they are unable to produce protoscoleces. The molecular mechanisms involved in hydatid cysts fertility/infertility are unknown. Nevertheless, previous work from our laboratory has suggested that apoptosis is involved in hydatid cyst infertility and death. On the other hand, fertile hydatid cysts can resist oxidative damage due to reactive oxygen and nitrogen species. On these foundations, we have postulated that when oxidative damage of DNA in the germinal layers exceeds the capability of DNA repair mechanisms, apoptosis is triggered and hydatid cysts infertility occurs. We describe a much higher percentage of nuclei with oxidative DNA damage in dead protoscoleces and in the germinal layer of infertile cysts than in fertile cysts, suggesting that DNA repair mechanisms are active in fertile cysts. rad9, a conserved gene, plays a key role in cell cycle checkpoint modulation and DNA repair. We found that RAD9 of E. granulosus (EgRAD9) is expressed at the mRNA and protein levels. As it was found in other eukaryotes, EgRAD9 is hyperphosphorylated in response to DNA damage. Our results suggest that molecules involved in DNA repair in the germinal layer of fertile hydatid cysts and in protoscoleces, such as EgRAD9, may allow preserving the fertility of hydatid cysts in the presence of ROS and RNS.
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| 13. |
- Cai, Demin, et al.
(författare)
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Co-option of PPARα in the regulation of lipogenesis and fatty acid oxidation in CLA-induced hepatic steatosis
- 2021
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Ingår i: Journal of Cellular Physiology. - : Wiley. - 0021-9541 .- 1097-4652. ; 236:6, s. 4387-4402
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Tidskriftsartikel (refereegranskat)abstract
- Nonalcoholic-fatty-liver-disease (NAFLD) is the result of imbalances in hepatic lipid partitioning and is linked to dietary factors. We demonstrate that conjugated linoleic acid (CLA) when given to mice as a dietary supplement, induced an enlarged liver, hepatic steatosis, and increased plasma levels of fatty acid (FA), alanine transaminase, and triglycerides. The progression of NAFLD and insulin resistance was reversed by GW6471 a small-molecule antagonist of peroxisome proliferator-activated receptor α (PPARα). Transcriptional profiling of livers revealed that the genes involved in FA oxidation and lipogenesis as two core gene programs controlled by PPARα in response to CLA and GW6471 including Acaca and Acads. Bioinformatic analysis of PPARα ChIP-seq data set and ChIP-qPCR showed that GW6471 blocks PPARα binding to Acaca and Acads and abolishes the PPARα-mediated local histone modifications of H3K27ac and H3K4me1 in CLA-treated hepatocytes. Thus, our findings reveal a dual role of PPARα in the regulation of lipid homeostasis and highlight its druggable nature in NAFLD.
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| 14. |
- Caja, Laia, et al.
(författare)
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The protein kinase LKB1 promotes self-renewal and blocks invasiveness in glioblastoma
- 2022
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Ingår i: Journal of Cellular Physiology. - : John Wiley & Sons. - 0021-9541 .- 1097-4652. ; 237:1, s. 743-762
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Tidskriftsartikel (refereegranskat)abstract
- The role of liver kinase B1 (LKB1) in glioblastoma (GBM) development remains poorly understood. LKB1 may regulate GBM cell metabolism and has been suggested to promote glioma invasiveness. After analyzing LKB1 expression in GBM patient mRNA databases and in tumor tissue via multiparametric immunohistochemistry, we observed that LKB1 was localized and enriched in GBM tumor cells that co-expressed SOX2 and NESTIN stemness markers. Thus, LKB1-specific immunohistochemistry can potentially reveal subpopulations of stem-like cells, advancing GBM patient molecular pathology. We further analyzed the functions of LKB1 in patient-derived GBM cultures under defined serum-free conditions. Silencing of endogenous LKB1 impaired 3D-gliomasphere frequency and promoted GBM cell invasion in vitro and in the zebrafish collagenous tail after extravasation of circulating GBM cells. Moreover, loss of LKB1 function revealed mitochondrial dysfunction resulting in decreased ATP levels. Treatment with the clinically used drug metformin impaired 3D-gliomasphere formation and enhanced cytotoxicity induced by temozolomide, the primary chemotherapeutic drug against GBM. The IC50 of temozolomide in the GBM cultures was significantly decreased in the presence of metformin. This combinatorial effect was further enhanced after LKB1 silencing, which at least partially, was due to increased apoptosis. The expression of genes involved in the maintenance of tumor stemness, such as growth factors and their receptors, including members of the platelet-derived growth factor (PDGF) family, was suppressed after LKB1 silencing. The defect in gliomasphere growth caused by LKB1 silencing was bypassed after supplementing the cells with exogenous PFDGF-BB. Our data support the parallel roles of LKB1 in maintaining mitochondrial homeostasis, 3D-gliomasphere survival, and hindering migration in GBM. Thus, the natural loss of, or pharmacological interference with LKB1 function, may be associated with benefits in patient survival but could result in tumor spread.
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| 15. |
- Caja, Laia, et al.
(författare)
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The transforming growth factor-beta (TGF-β) mediates acquisition of a mesenchymal stem cell-like phenotype in human liver cells.
- 2011
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Ingår i: Journal of Cellular Physiology. - : Wiley. - 0021-9541 .- 1097-4652. ; 226:5, s. 1214-1223
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Tidskriftsartikel (refereegranskat)abstract
- Transforming growth factor-beta (TGF-β) mediates several and sometime opposite effects in epithelial cells, inducing growth inhibition, and apoptosis but also promoting an epithelial to mesenchymal transition (EMT) process, which enhances cell migration and invasion. TGF-β plays relevant roles in different liver pathologies; however, very few is known about its specific signaling and cellular effects in human primary hepatocytes. Here we show that TGF-β inhibits proliferation and induces pro-apoptotic genes (such as BMF or BIM) in primary cultures of human fetal hepatocytes (HFH), but also up-regulates anti-apoptotic genes, such as BCL-XL and XIAP. Inhibition of the epidermal growth factor receptor (EGFR), using gefitinib, abrogates the increase in the expression of the anti-apoptotic genes and significantly enhances cell death. Simultaneously, TGF-β is able to induce an EMT process in HFH, coincident with Snail up-regulation and a decrease in E-cadherin levels, cells showing mesenchymal proteins and reorganization of the actin cytoskeleton in stress fibers. Interestingly, these cells show loss of expression of specific hepatic genes and increased expression of stem cell markers. Chronic treatment with TGF-β allows selection of a population of mesenchymal cells with a de-differentiated phenotype, reminiscent of progenitor-like cells. Process is reversible and the mesenchymal stem-like cells re-differentiate to hepatocytes under controlled experimental conditions. In summary, we show for the first time that human hepatocytes may respond to TGF-β inducing different signals, some of them might contribute to tumor suppression (growth inhibition and apoptosis), but others should mediate liver tumor progression and invasion (EMT and acquisition of a stem-like phenotype).
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| 16. |
- Carthy, Jon M., et al.
(författare)
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Tamoxifen Inhibits TGF-beta-Mediated Activation of Myofibroblasts by Blocking Non-Smad Signaling Through ERK1/2
- 2015
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Ingår i: Journal of Cellular Physiology. - : Wiley. - 0021-9541 .- 1097-4652. ; 230:12, s. 3084-3092
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Tidskriftsartikel (refereegranskat)abstract
- Transforming growth factor-beta (TGF-beta) is a multifunctional cytokine which stimulates the differentiation of fibroblasts into myofibroblasts. Myofibroblasts are critical for normal wound healing, but also accumulate pathologically in a number of chronic inflammatory conditions where they are key contributors to aberrant tissue remodeling and fibrosis, and in cancer stroma. In the current study, we identified a role for tamoxifen as a potent inhibitor of the TGF-beta-mediated activation of primary human skin and breast fibroblasts. Our data indicate that tamoxifen does not interfere with canonical Smad signaling downstream of TGF-beta but rather blocks non-Smad signaling through ERK1/2 MAP-kinase and the AP-1 transcription factor FRA2. We further demonstrate by siRNA-mediated knockdown that FRA2 is critical for the induced expression of myogenic proteins in response to TGF-beta. Functionally, TGF-beta-stimulated fibroblast-mediated contraction of collagen gels was impaired in the presence of tamoxifen. Altogether, these data demonstrate that tamoxifen prevents myofibroblast differentiation and, therefore, may provide therapeutic benefits to patients suffering from chronic inflammatory conditions or cancer.
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| 17. |
- Chaillou, Thomas, 1985-, et al.
(författare)
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Expression of Muscle-Specific Ribosomal Protein L3-Like Impairs Myotube Growth
- 2016
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Ingår i: Journal of Cellular Physiology. - : Wiley-Blackwell. - 0021-9541 .- 1097-4652. ; 231:9, s. 1894-1902
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Tidskriftsartikel (refereegranskat)abstract
- The ribosome has historically been considered to have no cell-specific function but rather serve in a "housekeeping" capacity. This view is being challenged by evidence showing that heterogeneity in the protein composition of the ribosome can lead to the functional specialization of the ribosome. Expression profiling of different tissues revealed that ribosomal protein large 3-like (Rpl3l) is exclusively expressed in striated muscle. In response to a hypertrophic stimulus, Rpl3l expression in skeletal muscle was significantly decreased by 82% whereas expression of the ubiquitous paralog Rpl3 was significantly increased by ∼fivefold. Based on these findings, we developed the hypothesis that Rpl3l functions as a negative regulator of muscle growth. To test this hypothesis, we used the Tet-On system to express Rpl3l in myoblasts during myotube formation. In support of our hypothesis, RPL3L expression significantly impaired myotube growth as assessed by myotube diameter (-23%) and protein content (-14%). Further analysis showed that the basis of this impairment was caused by a significant decrease in myoblast fusion as the fusion index was significantly lower (-17%) with RPL3L expression. These findings are the first evidence to support the novel concept of ribosome specialization in skeletal muscle and its role in the regulation of skeletal muscle growth.
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| 18. |
- Changhui, Yu, et al.
(författare)
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Platelet-Derived CCL5 Regulates CXC Chemokine Formation and Neutrophil Recruitment in Acute Experimental Colitis.
- 2016
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Ingår i: Journal of Cellular Physiology. - : Wiley. - 1097-4652 .- 0021-9541. ; 231:2, s. 370-376
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Tidskriftsartikel (refereegranskat)abstract
- Accumulating data suggest that platelets not only regulate thrombosis and haemostasis but also inflammatory processes. Platelets contain numerous potent pro-inflammatory compounds, including the chemokines CCL5 and CXCL4 although their role in acute colitis remains elusive. The aim of this study was to examine the role of platelets and platelet-derived chemokines in acute colitis. Acute colitis was induced in female Balb/c mice by administration of 5% dextran sodium sulphate (DSS) for five days. Animals received a platelet-depleting, anti-CCL5, anti-CXCL4 or a control antibody prior to DSS challenge. Colonic tissue was collected for quantification of myeloperoxidase (MPO) activity, CXCL5, CXCL2, interleukin-6 (IL-6) and CCL5 levels as well as morphological analyses. Platelet depletion reduced tissue damage and clinical disease activity index in DSS-exposed animals. Platelet depletion not only reduced levels of CXCL2 and CXCL5 but also levels of CCL5 in the inflamed colon. Immunoneutralization of CCL5 but not CXCL4 reduced tissue damage, CXC chemokine expression and neutrophil recruitment in DSS-treated animals. These findings show that platelets play a key role in acute colitis by regulating CXC chemokine generation, neutrophil infiltration and tissue damage in the colon. Moreover, our results suggest that platelet-derived CCL5 is an important link between platelet activation and neutrophil recruitment in acute colitis. This article is protected by copyright. All rights reserved.
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| 19. |
- Chen, Y., et al.
(författare)
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Translocation of Endogenous Danger Signal HMGB1 From Nucleus to Membrane Microvesicles in Macrophages
- 2016
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Ingår i: Journal of Cellular Physiology. - : Wiley. - 0021-9541 .- 1097-4652. ; 231:11, s. 2319-2326
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Tidskriftsartikel (refereegranskat)abstract
- High mobility group box 1 (HMGB1) is a nuclear protein that can be released from activated or dead cells. Extracellular HMGB1 can serve as a “danger signal” and novel cytokine that mediates sterile inflammation. In addition to its soluble form, extracellular HMGB1 can also be carried by membrane microvesicles. However, the cellular mechanisms responsible for nuclear HMGB1 translocation to the plasma membrane and release onto membrane microvesicles have not been investigated. Tobacco smoking is a major cause of sterile inflammation in many diseases. Smoking also increases blood levels of HMGB1. In this study, we found that exposure of macrophages to tobacco smoke extract (TSE) stimulated HMGB1 expression, redistribution, and release into the extracellular milieu both as a soluble molecule and, surprisingly, as a microvesicle-associated form (TSE-MV). Inhibition of chromosome region maintenance-1 (CRM1), a nuclear exporter, attenuated TSE-induced HMGB1 redistribution from the nucleus to the cytoplasm, and then its release on TSE-MVs. Our study demonstrates a novel mechanism for the translocation of nuclear HMGB1 to the plasma membrane, and then its release in a microvesicle-associated form. J. Cell. Physiol. 231: 2319–2326, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.
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| 20. |
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| 21. |
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| 22. |
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| 23. |
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| 24. |
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| 25. |
- Eliasson, Pernilla, et al.
(författare)
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The Hematopoietic Stem Cell Niche: Low in Oxygen but a Nice Place to be
- 2010
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Ingår i: Journal of Cellular Physiology. - : Wiley. - 0021-9541 .- 1097-4652. ; 222:1, s. 17-22
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Forskningsöversikt (refereegranskat)abstract
- The enormous regenerative capacity of the blood system to sustain functionally mature cells are generated from highly proliferative, short-lived progenitors, which in turn arise from a rare population of pluripotent and self-renewing hematopoietic stem cells (HSC). In the bone marrow, these stem cells are kept in a low proliferative, relatively quiescent state in close proximity to stromal cells and osteoblasts, forming specialized niches. The interaction in particular to bone is crucial to prevent exhaustion of HSCs from uncontrolled cell-cycle entry and to excessive proliferation. In addition, the niche and its components protect stem cells from stress, such as accumulation of reactive oxygen species and DNA damage. One of the key issues is to identify conditions to increase the number of HSCs, either in vivo or during ex vivo growth cultures. This task has been very difficult to resolve and most attempts have been unsuccessful. However, the mechanistic insights to HSC self-renewal and preservation are gradually increasing and there is now hope that future research will enable scientists and clinicians to modulate the process. In this review, we will focus on the molecular mechanisms of self-renewal and HSC maintenance in the light of novel findings that HSCs reside at the lowest end of an oxygen gradient. Hypoxia appears to regulate hematopoiesis in the bone marrow by maintaining important HSC functions, such as cell cycle control, survival, metabolism, and protection against oxidative stress. To improve the therapeutic expansion of HSCs we need to learn more about the molecular mechanisms of hypoxia-mediated regulation.
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| 26. |
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| 27. |
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| 28. |
- Fernando, Joan, et al.
(författare)
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Sorafenib sensitizes hepatocellular carcinoma cells to physiological apoptotic stimuli.
- 2012
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Ingår i: Journal of Cellular Physiology. - : Wiley. - 0021-9541 .- 1097-4652. ; 227:4, s. 1319-25
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Tidskriftsartikel (refereegranskat)abstract
- Sorafenib increases survival rate of patients with advanced hepatocellular carcinoma (HCC). The mechanism underlying this effect is not completely understood. In this work we have analyzed the effects of sorafenib on autocrine proliferation and survival of different human HCC cell lines. Our results indicate that sorafenib in vitro counteracts autocrine growth of different tumor cells (Hep3B, HepG2, PLC-PRF-5, SK-Hep1). Arrest in S/G2/M cell cycle phases were observed coincident with cyclin D1 down-regulation. However, sorafenib's main anti-tumor activity seems to occur through cell death induction which correlated with caspase activation, increase in the percentage of hypodiploid cells, activation of BAX and BAK and cytochrome c release from mitochondria to cytosol. In addition, we observed a rise in mRNA and protein levels of the pro-apoptotic "BH3-domain only" PUMA and BIM, as well as decreased protein levels of the anti-apoptotic MCL1 and survivin. PUMA targeting knock-down, by using specific siRNAs, inhibited sorafenib-induced apoptotic features. Moreover, we obtained evidence suggesting that sorafenib also sensitizes HCC cells to the apoptotic activity of transforming growth factor-β (TGF-β) through the intrinsic pathway and to tumor necrosis factor-α (TNF) through the extrinsic pathway. Interestingly, sensitization to sorafenib-induced apoptosis is characteristic of liver tumor cells, since untransformed hepatocytes did not respond to sorafenib inducing apoptosis, either alone or in combination with TGF-β or TNF. Indeed, sorafenib effectiveness in delaying HCC late progression might be partly related to a selectively sensitization of HCC cells to apoptosis by disrupting autocrine signals that protect them from adverse conditions and pro-apoptotic physiological cytokines.
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| 29. |
- Gao, Yun, et al.
(författare)
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MiR-127 attenuates adipogenesis by targeting MAPK4 and HOXC6 in porcine adipocytes
- 2019
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Ingår i: Journal of Cellular Physiology. - : Wiley. - 0021-9541 .- 1097-4652. ; 234:12, s. 21838-21850
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Tidskriftsartikel (refereegranskat)abstract
- MicroRNAs (miRNAs) have critical roles during adipogenesis; however, their precise functions are not completely understood. Porcine miRNA expression profiles show that miR-127 is dramatically downregulated with age in adipose tissue. We aimed to identify the precise functions and mechanisms of miR-127 in proliferation and adipogenesis. Preadipocytes were cultured under conditions to induce proliferation or differentiation and the effect of miR-127 overexpression on these processes, and the associated bioinformatically predicted target genes, were assessed using luciferase assays, quantitative real-time PCR, western blot analysis, and cell staining techniques. miR-127 increased proliferation by promoting cell cycling, whereas it suppressed differentiation, which was accompanied by reduced lipid accumulation. miR-127 targeted mitogen-activated protein kinase 4 and homeobox C6 (HOXC6) to activate preadipocyte proliferation. During differentiation, miR-127 targeted HOXC6 to attenuate adipogenesis. These findings identify miR-127 as an inhibitor of porcine adipogenesis, which may inform future strategies to reduce porcine fat deposition and treat human obesity.
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| 30. |
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| 31. |
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| 32. |
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| 33. |
- Grossi, Mario, et al.
(författare)
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Inhibition of polyamine uptake potentiates the anti-proliferative effect of polyamine synthesis inhibition and preserves the contractile phenotype of vascular smooth muscle cells.
- 2015
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Ingår i: Journal of Cellular Physiology. - : Wiley. - 1097-4652 .- 0021-9541.
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Tidskriftsartikel (refereegranskat)abstract
- Increased vascular smooth muscle cell (VSMC) proliferation is a factor in atherosclerosis and injury-induced arterial (re)stenosis. Inhibition of polyamine synthesis by α-difluoro-methylornithine (DFMO), an irreversible inhibitor of ornithine decarboxylase, attenuates VSMC proliferation with high sensitivity and specificity. However, cells can escape polyamine synthesis blockade by importing polyamines from the environment. To address this issue, polyamine transport inhibitors (PTIs) have been developed. We investigated the effects of the novel trimer44NMe (PTI-1) alone and in combination with DFMO on VSMC polyamine uptake, proliferation and phenotype regulation. PTI-1 efficiently inhibited polyamine uptake in primary mouse aortic and human coronary VSMCs in the absence as well as in the presence of DFMO. Interestingly, culture with DFMO for 2 days substantially (>95%) reduced putrescine (Put) and spermidine (Spd) contents without any effect on proliferation. Culture with PTI-1 alone had no effect on either polyamine levels or proliferation rate, but the combination of both treatments reduced Put and Spd levels below the detection limit and inhibited proliferation. Treatment with DFMO for a longer time period (4 days) reduced Put and Spd below their detection limits and reduced proliferation, showing that only a small pool of polyamines is needed to sustain VSMC proliferation. Inhibited proliferation by polyamine depletion was associated with maintained expression of contractile smooth marker genes. In cultured intact mouse aorta, PTI-1 potentiated the DFMO-induced inhibition of cell proliferation. The combination of endogenous polyamine synthesis inhibition with uptake blockade is thus a viable approach for targeting unwanted vascular cell proliferation in vivo, including vascular restenosis. This article is protected by copyright. All rights reserved.
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| 34. |
- Gustafsson, Mikael, et al.
(författare)
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Lateral diffusion of the secretory component (SC) in the basolateral membrane of the human colon carcinoma cell line HT29 assessed with fluorescence recovery after photobleaching
- 1988
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Ingår i: Journal of Cellular Physiology. - : John Wiley & Sons. - 0021-9541 .- 1097-4652. ; 137:3, s. 608-611
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Tidskriftsartikel (refereegranskat)abstract
- The lateral diffusion of the secretory component (SC), acting as a receptor for dimeric IgA in the basolateral side of intestinal epithelial cells, was studied in the human colonic carcinoma cell line HT29. The HT29 cells were grown in Dulbecco's modified Eagle's medium in which galactose had been substituted for glucose to promote development of small intestine-like cells, with a distinct separation of the basolateral side from the apical surface. The SC was stained with rhodamine-labeled polyclonal anti-human SC rabbit antibodies (Ig) or Fab fragments, and the lateral mobility was assessed with the fluorescence recovery after photobleaching technique. The average lateral diffusion was consistent with a diffusion constant of 7.7 ± 2.0 (mean value ± SD; n = 29) and 7.1 ± 2.3 (n = 30) × 10−10 cm2s−1 for Ig-and Fab-labeled receptors, respectively, which is slower than lipid diffusion but is similar to that found for other membrane receptors. The corresponding values for the fraction of mobile receptors were 66 ± 13% and 71 ± 12%, respectively. Cells were labeled from the top of the culture plate, and cells adjacent to a mechanically made rift or a natural opening in the cell monolayer were labeled more strongly, confirming the microscope-based impression that the basolateral surface primarily harboured the SC receptor.
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| 35. |
- Hamidouche, Zahia, et al.
(författare)
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Autocrine Fibroblast Growth Factor 18 Mediates Dexamethasone-Induced Osteogenic Differentiation of Murine Mesenchymal Stem Cells
- 2010
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Ingår i: Journal of Cellular Physiology. - : Wiley. - 1097-4652 .- 0021-9541. ; 224:2, s. 509-515
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Tidskriftsartikel (refereegranskat)abstract
- The potential of mesenchymal stem cells (MSC) to differentiate into functional bone forming cells provides an important tool for bone regeneration. The identification of factors capable of promoting osteoblast differentiation in MSCs is therefore critical to enhance the osteogenic potential of MSCs. Using microarray analysis combined with biochemical and molecular approach, we found that FGF18, a member of the FGF family, is upregulated during osteoblast differentiation induced by dexamethasone in murine MSCs. We showed that overexpression of FGF18 by lentiviral (LV) infection, or treatment of MSCs with recombinant human (rh)FGF18 increased the expression of the osteoblast specific transcription factor Runx2, and enhanced osteoblast phenotypic marker gene expression and in vitro osteogenesis. Molecular silencing using lentiviral shRNA demonstrated that downregulation of FGFR1 or FGFR2 abrogated osteoblast gene expression induced by either LV-FGF18 or rhFGF18, indicating that FGF18 enhances osteoblast differentiation in MSCs via activation of FGFR1 or FGFR2 signaling. Biochemical and pharmacological analyses showed that the induction of phenotypic osteoblast markers by LV-FGF18 is mediated by activation of ERK1/2-MAPKs and PI3K signaling in MSCs. These results reveal that FGF18 is an essential autocrine positive regulator of the osteogenic differentiation program in murine MSCs and indicate that osteogenic differentiation induced by FGF18 in MSCs is triggered by FGFR1/FGFR2-mediated ERK1/2-MAPKs and PI3K signaling. J. Cell. Physiol. 224: 509-515, 2010. (C) 2010 Wiley-Liss, Inc.
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| 36. |
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| 37. |
- Hassel, Sylke, et al.
(författare)
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Interaction and functional cooperation between the serine/threonine kinase bone morphogenetic protein type II receptor with the tyrosine kinase stem cell factor receptor
- 2006
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Ingår i: Journal of Cellular Physiology. - : Wiley. - 0021-9541 .- 1097-4652. ; 206:2, s. 457-467
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Tidskriftsartikel (refereegranskat)abstract
- Transmembrane receptors with intrinsic serine/threonine or tyrosine kinase domains regulate vital functions of cells in multicellular eukaryotes, e.g., differentiation, apoptosis, and proliferation. Here, we show that bone morphogenetic protein type II receptor (BMPR-II) which has a serine/threonine kinase domain, and stem cell factor receptor (c-kit) which contains a tyrosine kinase domain form a complex in vitro and in vivo; the interaction is induced upon treatment of cells with BMP2 and SCF. Stem cell factor (SCF) modulated BMP2-dependent activation of Smad1/5/8 and phosphorylation of Erk kinase. SCF also enhanced BMP2-dependent differentiation of C2C12 cells. We found that BMPR-II was phosphorylated at Ser757 upon co-expression with and activation of c-kit. BMPR-II phosphorylation required intact kinase activity of BMPR-II. Abrogation of the c-kit/SCF-dependent phosphorylation of BMPR-II at the Ser757 interfered with the cooperative effect of BMP2 and SCF. Our data suggest that the complex formation between c-kit and BMPR-II leads to phosphorylation of BMPR-II at Ser757, which modulates BMPR-II-dependent signaling.
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| 38. |
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| 39. |
- Hien, Tran T., et al.
(författare)
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MicroRNA-dependent regulation of KLF4 by glucose in vascular smooth muscle
- 2018
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Ingår i: Journal of Cellular Physiology. - : Wiley. - 0021-9541 .- 1097-4652. ; 233:9, s. 7195-7205
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Tidskriftsartikel (refereegranskat)abstract
- Diabetes is a major risk factor for cardiovascular disease and this is in part due to the effects of hyperglycemia on vascular smooth muscle cells. Small non-coding microRNAs are known to control smooth muscle phenotype and arterial contractility and are dysregulated in diabetes. The effect of microRNAs on smooth muscle differentiation is in part mediated by the transcription factor KLF4 but the role of this mechanism in diabetic vascular disease is not fully understood. Herein, we have investigated the importance of hyperglycemia and diabetes for the expression of KLF4 in vascular smooth muscle and the involvement of miRNAs in this regulation. Hyperglycemia down-regulated KLF4 in vascular smooth muscle cells and similar results were found in arteries of diabetic mice and patients. This correlated with a Foxa2-dependent up-regulation of miR-29c, which targeted KLF4 in vascular smooth muscle cells. Importantly, by preventing downregulation of KLF4, the induction of smooth muscle contractile protein markers by glucose was inhibited. In conclusion, miR-29 mediated inhibition of KLF4 in hyperglycemic conditions contributes to increased expression of contractile markers in vascular smooth muscle cells. Further studies are warranted to determine the therapeutic implications of miR-29 inhibition in diabetic vascular disease.
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| 40. |
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| 41. |
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| 42. |
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| 43. |
- Karlsson, Roger, et al.
(författare)
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Profilin-A master coordinator of actin and microtubule organization in mammalian cells
- 2021
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Ingår i: Journal of Cellular Physiology. - : Wiley. - 0021-9541 .- 1097-4652. ; 236:10, s. 7256-7265
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Forskningsöversikt (refereegranskat)abstract
- The last two decades have witnessed a tremendous increase in cell biology data. Not least is this true for studies of the dynamic organization of the microfilament and microtubule systems in animal cells where analyses of the molecular components and their interaction patterns have deepened our understanding of these complex force-generating machineries. Previous observations of a molecular cross-talk between the two systems have now led to the realization of the existence of several intricate mechanisms operating to maintain their coordinated cellular organization. In this short review, we relate to this development by discussing new results concerning the function of the actin regulator profilin 1 as a control component of microfilament-microtubule cross-talk.
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| 44. |
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| 45. |
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| 46. |
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| 47. |
- Leiva, Maria Carmen, et al.
(författare)
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Breast cancer patient-derived scaffolds as a tool to monitor chemotherapy responses in human tumor microenvironments
- 2021
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Ingår i: Journal of Cellular Physiology. - : Wiley. - 0021-9541 .- 1097-4652. ; 236:6, s. 4709-4724
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Tidskriftsartikel (refereegranskat)abstract
- Breast cancer is a heterogeneous disease where the tumor microenvironment, including extracellular components, plays a crucial role in tumor progression, potentially modulating treatment response. Different approaches have been used to develop three-dimensional models able to recapitulate the complexity of the extracellular matrix. Here, we use cell-free patient-derived scaffolds (PDSs) generated from breast cancer samples that were recellularized with cancer cell lines as an in vivo-like culture system for drug testing. We show that PDS cultured MCF7 cancer cells increased their resistance against the front-line chemotherapy drugs 5-fluorouracil, doxorubicin and paclitaxel in comparison to traditional two-dimensional cell cultures. The gene expression of the environmentally adapted cancer cells was modulated in different ways depending on the drug and the concentration used. High doses of doxorubicin reduced cancer stem cell features, whereas 5-fluorouracil increased stemness and decreased the proliferative phenotype. By using PDSs repopulated with other breast cancer cell lines, T-47D and MDA-MB-231, we observed both general and cell line specific drug responses. In summary, PDSs can be used to examine the extracellular matrix influence on cancer drug responses and for testing novel compounds in in vivo-like microenvironments.
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| 48. |
- Li, Xinyi, et al.
(författare)
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Phylogenetic analysis and functional characterization of norcoclaurine synthase involved in benzylisoquinoline alkaloids biosynthesis in Stephania tetrandra
- 2023
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Ingår i: Journal of Cellular Physiology. - 1097-4652 .- 0021-9541. ; In Press
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Tidskriftsartikel (refereegranskat)abstract
- Benzylisoquinoline alkaloids (BIAs) are a class of secondary metabolites that possess diverse pharmaceutical properties and are exclusively accumulated in specific plant genera. The Pictet–Spengler condensation, catalyzed by norcoclaurine synthase (NCS), represents a key enzymatic reaction in the biosynthetic pathway of BIAs. While NCS genes have been identified in several plant families such as Papaveraceae, Berberidaceae, and Ranunculaceae, no NCS genes have been reported in Menispermaceae, which is another genus known to accumulate BIAs. Here, NCSs were isolated and functionally characterized from the Menispermaceae family plant Stephania tetrandra. In vitro enzyme assay identified two functional StNCSs which could catalyze the formation of (S)-norcoclaurine. These functionally characterized genes were then integrated into engineered yeast to enable the production of norcoclaurine. Phylogenetic analysis of the NCS enzymes revealed that the StNCSs predominantly clustered into two clades. The functional StNCSs clustered with known NCSs, highlighting the presence of a specific NCS catalytic domain. This study not only provides additional genetic components for the synthetic biology-based production of BIAs in yeast but also contributes to the understanding of the phylogenetic relationships and structure–function relationship of NCS genes involved in the origin and production of BIAs.
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| 49. |
- Lin, Yingbo, et al.
(författare)
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SUMO-modified insulin-like growth factor 1 receptor (IGF-1R) increases cell cycle progression and cell proliferation
- 2017
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Ingår i: Journal of Cellular Physiology. - : John Wiley & Sons. - 0021-9541 .- 1097-4652. ; 232:10, s. 2722-2730
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Tidskriftsartikel (refereegranskat)abstract
- Increasing number of studies have shown nuclear localization of the insulin-like growth factor 1 receptor (nIGF-1R) in tumor cells and its links to adverse clinical outcome in various cancers. Any obvious cell physiological roles of nIGF-1R have, however, still not been disclosed. Previously, we reported that IGF-1R translocates to cell nucleus and modulates gene expression by binding to enhancers, provided that the receptor is SUMOylated. In this study, we constructed stable transfectants of wild type IGF1R (WT) and triple-SUMO-site-mutated IGF1R (TSM) using igf1r knockout mouse fibroblasts (R-). Cell clones (R-WT and R-TSM) expressing equal amounts of IGF1R were selected for experiments. Phosphorylation of IGF-1R, Akt, and Erk upon IGF-1 stimulation was equal in R-WT and R-TSM. WT was confirmed to enter nuclei. TSM did also undergo nuclear translocation, although to a lesser extent. This may be explained by that TSM heterodimerizes with insulin receptor, which is known to translocate to cell nuclei. R-WT proliferated substantially faster than R-TSM, which did not differ significantly from the empty vector control. Upon IGF-1 stimulationG1-S-phase progression of R-WT increased from 12 to 38%, compared to 13 to 20% of R-TSM. The G1-S progression of R-WT correlated with increased expression of cyclin D1, A, and CDK2, as well as downregulation of p27. This suggests that SUMO-IGF-1R affects upstream mechanisms that control and coordinate expression of cell cycle regulators. Further studies to identify such SUMO-IGF-1R dependent mechanisms seem important.
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| 50. |
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