| 1. |
|
|
| 2. |
- Lorbek, G, et al.
(författare)
-
Lessons from hepatocyte-specific Cyp51 knockout mice: impaired cholesterol synthesis leads to oval cell-driven liver injury
- 2015
-
Ingår i: Scientific reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 5, s. 8777-
-
Tidskriftsartikel (refereegranskat)abstract
- We demonstrate unequivocally that defective cholesterol synthesis is an independent determinant of liver inflammation and fibrosis. We prepared a mouse hepatocyte-specific knockout (LKO) of lanosterol 14α-demethylase (CYP51) from the part of cholesterol synthesis that is already committed to cholesterol. LKO mice developed hepatomegaly with oval cell proliferation, fibrosis and inflammation, but without steatosis. The key trigger was reduced cholesterol esters that provoked cell cycle arrest, senescence-associated secretory phenotype and ultimately the oval cell response, while elevated CYP51 substrates promoted the integrated stress response. In spite of the oval cell-driven fibrosis being histologically similar in both sexes, data indicates a female-biased down-regulation of primary metabolism pathways and a stronger immune response in males. Liver injury was ameliorated by dietary fats predominantly in females, whereas dietary cholesterol rectified fibrosis in both sexes. Our data place defective cholesterol synthesis as a focus of sex-dependent liver pathologies.
|
|
| 3. |
- Ha, V. T., et al.
(författare)
-
Synergy between 15-lipoxygenase and secreted PLA2 promotes inflammation by formation of TLR4 agonists from extracellular vesicles
- 2021
-
Ingår i: FEBS Open Bio. - : John Wiley & Sons. - 2211-5463. ; 11:Suppl. 1, s. 480-480
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Damage assoiated molecular patterns (DAMPs) are endogenous ligands that induce innate immune response, thus promoting sterile inflammation. During oxidative stress, stress-derived EVs (stressEVs) were found to activate Toll-like receptor 4 (TLR4), but the activating ligands were not fully determined. Additionally, several enzymes such as 15-lipoxygenase (15-LO) and secreted phospholipase A2 (sPLA2) are induced during inflammation and were suggested to promote DAMP formation. Stress-EVs were produced from HEK293 exposed to 10uM A23187 and isolated with ultracentrifugation. 20:4 lysoPI was oxidized for 10 min with 15-LO. SynEVs were prepared from phospholipids (PLs), oxidized with 15-LO and hydrolyzed with sPLA2. Activity was measured by qPCR and ELISA on wt and KO cells. Ox 20:4 lysoPI was analyzed by MS. sPLA2 activity was measured in synovial fluid from patients using fluorometric assay. K/BxN serum transfer induced arthritis model on wt and TLR4 KO mice(C57Bl/6 mice) with sPLA2-IIA injection was performed. StressEVs released after oxidative stress were found to activate TLR4with a gene profile different from agonist lipopolysaccharide. StressEVs, 15-LO oxidized synEVs, but only 15-LO oxidized lysoPLs activated cytokine expression through TLR4/MD-2.Hydroxy, hydroperoxy and keto products of 20:4 lysoPI oxidation were determined by MS and they activated the same gene pattern as stressEVs. Furthermore, sPLA2 activity, which we detected in the SF from patients, promoted formation of TLR4 agonists after 15-LO oxidation. Injection of sPLA2-IIA into mice promoted K/BxN serum induced arthritis in TLR4-dependent manner. Both 15-LO and sPLA2 are induced during inflammation, therefore these results imply the role of oxidized lysoPLs in stressEVs in promoting sterile inflammation through TLR4 signaling. The formation of TLR4 agonists is enzyme driven so it provides an opportunity for therapy without compromising innate immunity against pathogens (Ha VT. et al., PNAS 2020).
|
|
| 4. |
|
|
| 5. |
|
|
| 6. |
|
|
| 7. |
- Yáñez-Mó, María, et al.
(författare)
-
Biological properties of extracellular vesicles and their physiological functions.
- 2015
-
Ingår i: Journal of extracellular vesicles. - : Wiley. - 2001-3078. ; 4
-
Forskningsöversikt (refereegranskat)abstract
- In the past decade, extracellular vesicles (EVs) have been recognized as potent vehicles of intercellular communication, both in prokaryotes and eukaryotes. This is due to their capacity to transfer proteins, lipids and nucleic acids, thereby influencing various physiological and pathological functions of both recipient and parent cells. While intensive investigation has targeted the role of EVs in different pathological processes, for example, in cancer and autoimmune diseases, the EV-mediated maintenance of homeostasis and the regulation of physiological functions have remained less explored. Here, we provide a comprehensive overview of the current understanding of the physiological roles of EVs, which has been written by crowd-sourcing, drawing on the unique EV expertise of academia-based scientists, clinicians and industry based in 27 European countries, the United States and Australia. This review is intended to be of relevance to both researchers already working on EV biology and to newcomers who will encounter this universal cell biological system. Therefore, here we address the molecular contents and functions of EVs in various tissues and body fluids from cell systems to organs. We also review the physiological mechanisms of EVs in bacteria, lower eukaryotes and plants to highlight the functional uniformity of this emerging communication system.
|
|
