Uptake of oxLDL and IL-10 production by macrophages requires PAFR and CD36 recruitment into the same lipid rafts

Macrophage interaction with oxidized low-density lipoprotein (oxLDL) leads to its differentiation into foam cells and cytokine production, contributing to atherosclerosis development. In a previous study, we showed that CD36 and the receptor for platelet-activating factor (PAFR) are required for oxLDL to activate gene transcription for cytokines and CD36. Here, we investigated the localization and physical interaction of CD36 and PAFR in macrophages stimulated with oxLDL. We found that blocking CD36 or PAFR decreases oxLDL uptake and IL-10 production. OxLDL induces IL-10 mRNA expression only in HEK293T expressing both receptors (PAFR and CD36). OxLDL does not induce IL-12 production. The lipid rafts disruption by treatment with βCD reduces the oxLDL uptake and IL-10 production. OxLDL induces co-immunoprecipitation of PAFR and CD36 with the constitutive raft protein flotillin-1, and colocalization with the lipid raft-marker GM1-ganglioside. Finally, we found colocalization of PAFR and CD36 in macrophages from human atherosclerotic plaques. Our results show that oxLDL induces the recruitment of PAFR and CD36 into the same lipid rafts, which is important for oxLDL uptake and IL-10 production. This study provided new insights into how oxLDL interact with macrophages and contributing to atherosclerosis development

Pyruvate dehydrogenase kinase regulates vascular inflammation in atherosclerosis and increases cardiovascular risk

Aims Recent studies have revealed a close connection between cellular metabolism and the chronic inflammatory process of atherosclerosis. While the link between systemic metabolism and atherosclerosis is well established, the implications of altered metabolism in the artery wall are less understood. Pyruvate dehydrogenase kinase (PDK)-dependent inhibition of pyruvate dehydrogenase (PDH) has been identified as a major metabolic step regulating inflammation. Whether the PDK/PDH axis plays a role in vascular inflammation and atherosclerotic cardiovascular disease remains unclear. Methods and results Gene profiling of human atherosclerotic plaques revealed a strong correlation between PDK1 and PDK4 transcript levels and the expression of pro-inflammatory and destabilizing genes. Remarkably, the PDK1 and PDK4 expression correlated with a more vulnerable plaque phenotype, and PDK1 expression was found to predict future major adverse cardiovascular events. Using the small-molecule PDK inhibitor dichloroacetate (DCA) that restores arterial PDH activity, we demonstrated that the PDK/PDH axis is a major immunometabolic pathway, regulating immune cell polarization, plaque development, and fibrous cap formation in Apoe−/− mice. Surprisingly, we discovered that DCA regulates succinate release and mitigates its GPR91-dependent signals promoting NLRP3 inflammasome activation and IL-1β secretion by macrophages in the plaque. Conclusions We have demonstrated for the first time that the PDK/PDH axis is associated with vascular inflammation in humans and particularly that the PDK1 isozyme is associated with more severe disease and could predict secondary cardiovascular events. Moreover, we demonstrate that targeting the PDK/PDH axis with DCA skews the immune system, inhibits vascular inflammation and atherogenesis, and promotes plaque stability features in Apoe−/− mice. These results point toward a promising treatment to combat atherosclerosis

Genetic deficiency of indoleamine 2,3-dioxygenase aggravates vascular but not liver disease in a nonalcoholic steatohepatitis and atherosclerosis comorbidity model

Nonalcoholic steatohepatitis (NASH) is a chronic liver disease that increases cardiovascular disease risk. Indoleamine 2,3-dioxygenase-1 (IDO1)-mediated tryptophan (Trp) metabolism has been proposed to play an immunomodulatory role in several diseases. The potential of IDO1 to be a link between NASH and cardiovascular disease has never been investigated. Using Apoe−/− and Apoe−/−Ido1−/− mice that were fed a high-fat, high-cholesterol diet (HFCD) to simultaneously induce NASH and atherosclerosis, we found that Ido1 deficiency significantly accelerated atherosclerosis after 7 weeks. Surprisingly, Apoe−/−Ido1−/− mice did not present a more aggressive NASH phenotype, including hepatic lipid deposition, release of liver enzymes, and histopathological parameters. As expected, a lower L-kynurenine/Trp (Kyn/Trp) ratio was found in the plasma and arteries of Apoe−/−Ido1−/− mice compared to controls. However, no difference in the hepatic Kyn/Trp ratio was found between the groups. Hepatic transcript analyses revealed that HFCD induced a temporal increase in tryptophan 2,3-dioxygenase (Tdo2) mRNA, indicating an alternative manner to maintain Trp degradation during NASH development in both Apoe−/− and Apoe−/−Ido1−/mice−. Using HepG2 hepatoma cell and THP1 macrophage cultures, we found that iron, TDO2, and Trp degradation may act as important mediators of cross-communication between hepatocytes and macrophages regulating liver inflammation. In conclusion, we show that Ido1 deficiency aggravates atherosclerosis, but not liver disease, in a newly established NASH and atherosclerosis comorbidity model. Our data indicate that the overexpression of TDO2 is an important mechanism that helps in balancing the kynurenine pathway and inflammation in the liver, but not in the artery wall, which likely determined disease outcome in these two target tissues

Tässä olen nyt : draamaprojekti ikäihmisten ja uussuomalaisten kanssa

Tämä on monimuotoisen opinnäytetyön kirjallinen osa. Työn keskiössä on Kinaporin palvelukeskuksessa syksyllä 2012 toteutettu Tässä olen nyt -draamaprojekti kantasuomalaisten ikäihmisten sekä somalialaistaustaisten uussuomalaisnaisten kanssa. Kirjoittaja toimi prosessin ohjaajana. Tässä olen nyt -projektissa käsiteltiin kahta aihetta, äitiyttä ja omia juuria, erilaisilla draama- ja devising-menetelmillä. Aiheita lähestyttiin henkilökohtaisella tasolla ja materiaalina käytettiin ryhmäläisten muistoja ja tarinoita. Prosessissa syntyneestä materiaalista koottiin esitys Tässä olen nyt, jota esitettiin kolme kertaa Kinaporin palvelukeskuksessa marraskuussa 2012. Esityksen kesto oli noin tunti. Kirjallisessa opinnäytetyössä tarkastellaan Tässä olen nyt -draamaprojektin työtapoja ja tutkitaan minkälaiset työtavat helpottavat kahden eritaustaisen ryhmän kohtaamista. Työssä käsitellään rakentavan vuorovaikutuksen ja dialogin merkitystä ihmisten välisen kohtaamisen aikaansaamiseksi. Työ kuvaa aikajärjestyksessä eri vaiheita ja ilmiöitä ryhmässä prosessin aikana. Rinnalla kulkee kirjoittajan oma reflektio ohjaajan työstä. Luvussa neljä käsitellään Tässä olen nyt -draamaprojektin aikana syntyneitä oivalluksia ja erilaisia haasteita, joita ryhmän kanssa on tullut vastaan. Lopussa listataan asioita, joita muiden tekijöiden kannattaisi ottaa huomioon vastaavanlaisia projekteja suunnitellessa. Opinnäytetyö pyrkii avaamaan konkreettisella tavalla teatteri-ilmaisun ohjaajan työtä ryhmän kanssa. Opinnäytetyö tarjoaa myös palvelukeskuksille mallia, miten draama voitaisiin hyödyntää keskuksen arjessa. Työssä todetaan, että yhtä laajamittaisen prosessin toteuttamiseen tarvitaan ammattilaisia työn tekijöiksi, mutta osia prosessista voidaan nähdä osana palvelukeskuksen arkea.The present multiformed final thesis forms the written part of the final project. Here I Am Now drama project took place in autumn 2012 in Kinapori sheltered home in Helsinki. It was carried out with Finnish elderly people and with Somali immigrant women. The author worked as an instructor and director of the project. During the Here I Am Now drama project, the participants surveyed two themes: motherhood and one's own roots, with varied drama methods and devising tools. The themes were surveyed at a personal level using memories and stories as a material to make a script. The play was performed in Kinapori sheltered home. The duration of the show was one hour and it was performed three times in November 2012. The present thesis analyses the drama methods and devising tools used when working at Here I Am Now drama project, and it examines especially the kind of methods which would ease the encounters between two groups with different backgrounds. The thesis deals with constructive interaction and the meaning of the dialogue to achieve encounters between people. The present thesis introduces the process of the group in a chronological order, together with the author's own reflection of her own work. Chapter four introduces insights and challenges in the group process found by the author during the process. In the end, the author lists affairs, which other authors should take into consideration when executing similar community theater projects. The present thesis aims at answering how a drama instructor could work with a group similar to Here I am now. The thesis also provides a model or a pattern for a sheltered home to utilize drama in everyday routines. The thesis suggests that the process in such a large scale would need a competent drama instructor, but parts of it could also be used in everyday routines

Hyperlipidaemia elicits an atypical, T helper 1-like CD4⁺T-cell response:A key role for very low-density lipoprotein

Aims: Hyperlipidemia and T cell driven inflammation are important drivers of atherosclerosis, the main underlying cause of cardiovascular disease. Here, we detailed the effects of hyperlipidemia on T cells. Methods and results: In vitro, exposure of human and murine CD4+ T cells to very low-density lipoprotein (VLDL), but not to low-density lipoprotein (LDL) resulted in upregulation of Th1 associated pathways. VLDL was taken up via a CD36-dependent pathway and resulted in membrane stiffening and a reduction in lipid rafts. To further detail this response in vivo, T cells of mice lacking the LDL receptor (LDLr), which develop a strong increase in VLDL cholesterol and triglyceride levels upon high cholesterol feeding were investigated. CD4+ T cells of hyperlipidemic Ldlr-/-mice exhibited an increased expression of the C-X-C-chemokine receptor 3 (CXCR3) and produced more interferon-?(IFN-?). Gene set enrichment analysis identified IFN-?-mediated signaling as the most upregulated pathway in hyperlipidemic T cells. However, the classical Th1 associated transcription factor profile with strong upregulation of Tbet and Il12rb2 was not observed. Hyperlipidemia did not affect levels of the CD4+ T cell's metabolites involved in glycolysis or other canonical metabolic pathways but enhanced amino acids levels. However, CD4+ T cells of hyperlipidemic mice showed increased cholesterol accumulation and an increased arachidonic acid (AA) to docosahexaenoic acid (DHA) ratio, which was associated with inflammatory T cell activation. Conclusions: Hyperlipidemia, and especially its VLDL component induces an atypical Th1 response in CD4+ T cells. Underlying mechanisms include CD36 mediated uptake of VLDL, and an altered AA/DHA ratio