| 1. |
- Saliba-Gustafsson, P., et al.
(författare)
-
Subclinical atherosclerosis and its progression are modulated by PLIN2 through a feed-forward loop between LXR and autophagy
- 2019
-
Ingår i: Journal of Internal Medicine. - : Wiley. - 0954-6820 .- 1365-2796. ; 286:6, s. 660-675
-
Tidskriftsartikel (refereegranskat)abstract
- Background Hyperlipidaemia is a major risk factor for cardiovascular disease, and atherosclerosis is the underlying cause of both myocardial infarction and stroke. We have previously shown that the Pro251 variant of perilipin-2 reduces plasma triglycerides and may therefore be beneficial to reduce atherosclerosis development. Objective We sought to delineate putative beneficial effects of the Pro251 variant of perlipin-2 on subclinical atherosclerosis and the mechanism by which it acts. Methods A pan-European cohort of high-risk individuals where carotid intima-media thickness has been assessed was adopted. Human primary monocyte-derived macrophages were prepared from whole blood from individuals recruited by perilipin-2 genotype or from buffy coats from the Karolinska University hospital blood central. Results The Pro251 variant of perilipin-2 is associated with decreased intima-media thickness at baseline and over 30 months of follow-up. Using human primary monocyte-derived macrophages from carriers of the beneficial Pro251 variant, we show that this variant increases autophagy activity, cholesterol efflux and a controlled inflammatory response. Through extensive mechanistic studies, we demonstrate that increase in autophagy activity is accompanied with an increase in liver-X-receptor (LXR) activity and that LXR and autophagy reciprocally activate each other in a feed-forward loop, regulated by CYP27A1 and 27OH-cholesterol. Conclusions For the first time, we show that perilipin-2 affects susceptibility to human atherosclerosis through activation of autophagy and stimulation of cholesterol efflux. We demonstrate that perilipin-2 modulates levels of the LXR ligand 27OH-cholesterol and initiates a feed-forward loop where LXR and autophagy reciprocally activate each other; the mechanism by which perilipin-2 exerts its beneficial effects on subclinical atherosclerosis.
|
|
| 2. |
- Barker, Roger A., et al.
(författare)
-
GDNF and Parkinson's Disease : Where Next? A Summary from a Recent Workshop
- 2020
-
Ingår i: Journal of Parkinson's Disease. - 1877-7171. ; 10:3, s. 875-891
-
Tidskriftsartikel (refereegranskat)abstract
- The concept of repairing the brain with growth factors has been pursued for many years in a variety of neurodegenerative diseases including primarily Parkinson's disease (PD) using glial cell line-derived neurotrophic factor (GDNF). This neurotrophic factor was discovered in 1993 and shown to have selective effects on promoting survival and regeneration of certain populations of neurons including the dopaminergic nigrostriatal pathway. These observations led to a series of clinical trials in PD patients including using infusions or gene delivery of GDNF or the related growth factor, neurturin (NRTN). Initial studies, some of which were open label, suggested that this approach could be of value in PD when the agent was injected into the putamen rather than the cerebral ventricles. In subsequent double-blind, placebo-controlled trials, the most recent reporting in 2019, treatment with GDNF did not achieve its primary end point. As a result, there has been uncertainty as to whether GDNF (and by extrapolation, related GDNF family neurotrophic factors) has merit in the future treatment of PD. To critically appraise the existing work and its future, a special workshop was held to discuss and debate this issue. This paper is a summary of that meeting with recommendations on whether there is a future for this therapeutic approach and also what any future PD trial involving GDNF and other GDNF family neurotrophic factors should consider in its design.
|
|
| 3. |
- Huttunen, Roope J., et al.
(författare)
-
Quantitative detection of cell surface protein expression by time-resolved fluorimetry
- 2007
-
Ingår i: Luminescence. - : Wiley. - 1522-7243 .- 1522-7235. ; 22:3, s. 163-170
-
Tidskriftsartikel (refereegranskat)abstract
- A method is introduced for quantitative detection of cell surface protein expression. The method is based on immunocytochemistry, the use of long decay time europium(III) chelate and platinum(II) porphyrin labels, and detection of photoluminescence emission from adhered cells by time-resolved fluorimetry. After immunocytochemistry, the assay wells are evaporated to dryness and measured in the dry state. This protocol allows repeated and postponed analysis and microscopy imaging. In order to investigate the performance of the method, we chose expression of intercellular adhesion molecule-1 (ICAM-1) of endothelial cell line EAhy926 as a research target. The expression of ICAM-1 on the cells was enhanced by introduction of a cytokine, tumour necrosis factor-alpha (TNF alpha). The method gave signal: background ratios (S:B) of 20 and 9 for europium and platinum labels, respectively, whereas prompt fluorescent FITC label gave a S:13 of 3. Screening window coefficients (=Z'-factor) were >0.5 for all the three labels, thus indicating a score for an excellent screening assay. In conclusion, the method appears to be an appropriate choice for protein expression analysis, both in high-throughput screening applications, and for detailed sample investigation by fluorescent microscopy imaging. Copyright (C) 2007 John Wiley & Sons, Ltd.
|
|
| 4. |
- Tirri, M E, et al.
(författare)
-
Two-photon excitation in fluorescence polarization receptor-ligand binding assay
- 2005
-
Ingår i: Journal of Biomolecular Screening. - : Elsevier BV. - 1087-0571. ; 10:4, s. 314-319
-
Tidskriftsartikel (refereegranskat)abstract
- Fluorescence polarization is one of the most commonly used homogeneous assay principles in drug discovery for screening of potential lead compounds. In this article, the fluorescence polarization technique is combined with 2-photon excitation of fluorescence. Theoretically, the use of 2-photon excitation of fluorescence increases the volumetric sensitivity and polarization contrast of fluorescence polarization assays. The work in this report demonstrates these predictions for an estrogen receptor ligand binding assay.
|
|
