| 1. |
- Visuttijai, Kittichate, 1979-, et al.
(författare)
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Lowered Expression of Tumor Suppressor Candidate MYO1C Stimulates Cell Proliferation, Suppresses Cell Adhesion and Activates AKT
- 2016
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Ingår i: PLOS ONE. - : Public Library of Science. - 1932-6203. ; 11:10
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Tidskriftsartikel (refereegranskat)abstract
- Myosin-1C (MYO1C) is a tumor suppressor candidate located in a region of recurrent losses distal to TP53. Myo1c can tightly and specifically bind to PIP2, the substrate of Phosphoinositide 3-kinase (PI3K), and to Rictor, suggesting a role for MYO1C in the PI3K pathway. This study was designed to examine MYO1C expression status in a panel of well-stratified endometrial carcinomas as well as to assess the biological significance of MYO1C as a tumor suppressor in vitro. We found a significant correlation between the tumor stage and lowered expression of MYO1C in endometrial carcinoma samples. In cell transfection experiments, we found a negative correlation between MYO1C expression and cell proliferation, and MYO1C silencing resulted in diminished cell migration and adhesion. Cells expressing excess of MYO1C had low basal level of phosphorylated protein kinase B (PKB, a.k.a. AKT) and cells with knocked down MYO1C expression showed a quicker phosphorylated AKT (pAKT) response in reaction to serum stimulation. Taken together the present study gives further evidence for tumor suppressor activity of MYO1C and suggests MYO1C mediates its tumor suppressor function through inhibition of PI3K pathway and its involvement in loss of contact inhibition.
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| 2. |
- Nawaz, Muhammad, et al.
(författare)
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Lipid Nanoparticles Deliver the Therapeutic VEGFA mRNA In Vitro and In Vivo and Transform Extracellular Vesicles for Their Functional Extensions
- 2023
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Ingår i: Advanced Science. - : John Wiley & Sons. - 2198-3844. ; 10:12
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Tidskriftsartikel (refereegranskat)abstract
- Lipid nanoparticles (LNPs) are currently used to transport functional mRNAs, such as COVID-19 mRNA vaccines. The delivery of angiogenic molecules, such as therapeutic VEGF-A mRNA, to ischemic tissues for producing new blood vessels is an emerging strategy for the treatment of cardiovascular diseases. Here, the authors deliver VEGF-A mRNA via LNPs and study stoichiometric quantification of their uptake kinetics and how the transport of exogenous LNP-mRNAs between cells is functionally extended by cells’ own vehicles called extracellular vesicles (EVs). The results show that cellular uptake of LNPs and their mRNA molecules occurs quickly, and that the translation of exogenously delivered mRNA begins immediately. Following the VEGF-A mRNA delivery to cells via LNPs, a fraction of internalized VEGF-A mRNA is secreted via EVs. The overexpressed VEGF-A mRNA is detected in EVs secreted from three different cell types. Additionally, RNA-Seq analysis reveals that as cells’ response to LNP-VEGF-A mRNA treatment, several overexpressed proangiogenic transcripts are packaged into EVs. EVs are further deployed to deliver VEGF-A mRNA in vitro and in vivo. Upon equal amount of VEGF-A mRNA delivery via three EV types or LNPs in vitro, EVs from cardiac progenitor cells are the most efficient in promoting angiogenesis per amount of VEGF-A protein produced. Intravenous administration of luciferase mRNA shows that EVs could distribute translatable mRNA to different organs with the highest amounts of luciferase detected in the liver. Direct injections of VEGF-A mRNA (via EVs or LNPs) into mice heart result in locally produced VEGF-A protein without spillover to liver and circulation. In addition, EVs from cardiac progenitor cells cause minimal production of inflammatory cytokines in cardiac tissue compared with all other treatment types. Collectively, the data demonstrate that LNPs transform EVs as functional extensions to distribute therapeutic mRNA between cells, where EVs deliver this mRNA differently than LNPs.
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| 3. |
- Aronsson, Christopher, et al.
(författare)
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Dynamic peptide-folding mediated biofunctionalization and modulation of hydrogels for 4D bioprinting
- 2020
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Ingår i: Biofabrication. - : Institute of Physics Publishing (IOPP). - 1758-5082 .- 1758-5090. ; 12:3
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Tidskriftsartikel (refereegranskat)abstract
- Hydrogels are used in a wide range of biomedical applications, including three-dimensional (3D) cell culture, cell therapy and bioprinting. To enable processing using advanced additive fabrication techniques and to mimic the dynamic nature of the extracellular matrix (ECM), the properties of the hydrogels must be possible to tailor and change over time with high precision. The design of hydrogels that are both structurally and functionally dynamic, while providing necessary mechanical support is challenging using conventional synthesis techniques. Here, we show a modular and 3D printable hydrogel system that combines a robust but tunable covalent bioorthogonal cross-linking strategy with specific peptide-folding mediated interactions for dynamic modulation of cross-linking and functionalization. The hyaluronan-based hydrogels were covalently cross-linked by strain-promoted alkyne-azide cycloaddition using multi-arm poly(ethylene glycol). In addition, a de novo designed helix-loop-helix peptide was conjugated to the hyaluronan backbone to enable specific peptide-folding modulation of cross-linking density and kinetics, and hydrogel functionality. An array of complementary peptides with different functionalities was developed and used as a toolbox for supramolecular tuning of cell-hydrogel interactions and for controlling enzyme-mediated biomineralization processes. The modular peptide system enabled dynamic modifications of the properties of 3D printed structures, demonstrating a novel route for design of more sophisticated bioinks for four-dimensional bioprinting. © 2020 The Author(s). Published by IOP Publishing Ltd.
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| 4. |
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| 5. |
- Bauzá-Thorbrügge, Marco, et al.
(författare)
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NRF2 is essential for adaptative browning of white adipocytes.
- 2023
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Ingår i: Redox biology. - : Elsevier. - 2213-2317. ; 68
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Tidskriftsartikel (refereegranskat)abstract
- White adipose tissue browning, defined by accelerated mitochondrial metabolism and biogenesis, is considered a promising mean to treat or prevent obesity-associated metabolic disturbances. We hypothesize that redox stress acutely leads to increased production of reactive oxygen species (ROS), which activate electrophile sensor nuclear factor erythroid 2-Related Factor 2 (NRF2) that over time results in an adaptive adipose tissue browning process. To test this, we have exploited adipocyte-specific NRF2 knockout mice and cultured adipocytes and analyzed time- and dose-dependent effect of NAC and lactate treatment on antioxidant expression and browning-like processes. We found that short-term antioxidant treatment with N-acetylcysteine (NAC) induced reductive stress as evident from increased intracellular NADH levels, increased ROS-production, reduced oxygen consumption rate (OCR), and increased NRF2 levels in white adipocytes. In contrast, and in line with our hypothesis, longer-term NAC treatment led to a NRF2-dependent browning response. Lactate treatment elicited similar effects as NAC, and mechanistically, these NRF2-dependent adipocyte browning responses in vitro were mediated by increased heme oxygenase-1 (HMOX1) activity. Moreover, this NRF2-HMOX1 axis was also important for β3-adrenergic receptor activation-induced adipose tissue browning in vivo. In conclusion, our findings show that administration of exogenous antioxidants can affect biological function not solely through ROS neutralization, but also through reductive stress. We also demonstrate that NRF2 is essential for white adipose tissue browning processes.
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| 6. |
- Chaudhari, Aditi, et al.
(författare)
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p110α hot spot mutations E545K and H1047R exert metabolic reprogramming independently of p110α kinase activity
- 2015
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Ingår i: Molecular and Cellular Biology. - : American Society for Microbiology. - 0270-7306 .- 1098-5549. ; 35:19, s. 3258-3273
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Tidskriftsartikel (refereegranskat)abstract
- The phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K) catalytic subunit p110α is the most frequently mutated kinase in human cancer, and the hot spot mutations E542K, E545K, and H1047R are the most common mutations in p110α. Very little is known about the metabolic consequences of the hot spot mutations of p110α in vivo. In this study, we used adenoviral gene transfer in mice to investigate the effects of the E545K and H1047R mutations on hepatic and whole-body glucose metabolism. We show that hepatic expression of these hot spot mutations results in rapid hepatic steatosis, paradoxically accompanied by increased glucose tolerance, and marked glycogen accumulation. In contrast, wild-type p110α expression does not lead to hepatic accumulation of lipids or glycogen despite similar degrees of upregulated glycolysis and expression of lipogenic genes. The reprogrammed metabolism of the E545K and H1047R p110α mutants was surprisingly not dependent on altered p110α lipid kinase activity.
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| 7. |
- Delsing, Louise, et al.
(författare)
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Barrier properties and transcriptome expression in human iPSC-derived models of the blood-brain barrier
- 2018
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Ingår i: Stem Cells. - : AlphaMed Press, Inc.. - 1066-5099 .- 1549-4918. ; 36:12, s. 1816-1827
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Tidskriftsartikel (refereegranskat)abstract
- Cell-based models of the blood-brain barrier (BBB) are important for increasing the knowledge of BBB formation, degradation and brain exposure of drug substances. Human models are preferred over animal models because of inter-species differences in BBB structure and function. However, access to human primary BBB tissue is limited and has shown degeneration of BBB functions in vitro. Human induced pluripotent stem cells (iPSCs) can be used to generate relevant cell types to model the BBB with human tissue. We generated a human iPSC-derived model of the BBB that includes endothelial cells in co-culture with pericytes, astrocytes and neurons. Evaluation of barrier properties showed that the endothelial cells in our co-culture model have high transendothelial electrical resistance, functional efflux and ability to discriminate between CNS permeable and non-permeable substances. Whole genome expression profiling revealed transcriptional changes that occur in co-culture, including upregulation of tight junction proteins such as claudins and neurotransmitter transporters. Pathway analysis implicated changes in the WNT, TNF and PI3K-Akt pathways upon co-culture. Our data suggests that co-culture of iPSC-derived endothelial cells promotes barrier formation on a functional and transcriptional level. The information about gene expression changes in co-culture can be used to further improve iPSC-derived BBB models through selective pathway manipulation.
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| 9. |
- Doktorova, Tatyana Y., et al.
(författare)
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Transcriptomic responses generated by hepatocarcinogens in a battery of liver-based in vitro models
- 2013
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Ingår i: Carcinogenesis. - : Oxford University Press. - 0143-3334 .- 1460-2180. ; 34:6, s. 1393-1402
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Tidskriftsartikel (refereegranskat)abstract
- As the conventional approach to assess the potential of a chemical to cause cancer in humans still includes the 2-year rodent carcinogenicity bioassay, development of alternative methodologies is needed. In the present study, the transcriptomics responses following exposure to genotoxic (GTX) and non-genotoxic (NGTX) hepatocarcinogens and non-carcinogens (NC) in five liver-based in vitro models, namely conventional and epigenetically stabilized cultures of primary rat hepatocytes, the human hepatoma-derived cell lines HepaRG and HepG2 and human embryonic stem cell-derived hepatocyte-like cells, are examined. For full characterization of the systems, several bioinformatics approaches are employed including gene-based, ConsensusPathDB-based and classification analysis. They provide convincingly similar outcomes, namely that upon exposure to carcinogens, the HepaRG generates a gene classifier (a gene classifier is defined as a selected set of characteristic gene signatures capable of distinguishing GTX, NGTX carcinogens and NC) able to discriminate the GTX carcinogens from the NGTX carcinogens and NC. The other in vitro models also yield cancer-relevant characteristic gene groups for the GTX exposure, but some genes are also deregulated by the NGTX carcinogens and NC. Irrespective of the tested in vitro model, the most uniformly expressed pathways following GTX exposure are the p53 and those that are subsequently induced. The NGTX carcinogens triggered no characteristic cancer-relevant gene profiles in all liver-based in vitro systems. In conclusion, liver-based in vitro models coupled with transcriptomics techniques, especially in the case when the HepaRG cell line is used, represent valuable tools for obtaining insight into the mechanism of action and identification of GTX carcinogens.
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