Prevention of inflammatory cellular responses by ethanol and hemin interplay between inflammasomes and processes inhibiting inflammation

The innate immune system responds to infection or injury by initiating nonspecific inflammation, which functions to limit the spread of harmful microbes or the damage caused by tissue injury. The cells of the innate immune system are the first to encounter danger signals, and they mediate the rapid local immune response. Inflammatory reactions are normally beneficial for the host, and inflammation is usually resolved when the threat has been removed. However, in chronic inflammatory diseases, the danger signals either are not cleared or continue to be formed. Pathogen-derived molecules and danger signals induce the activation of pattern recognition receptors (PRRs) in the innate immune cells. Several families of PRRs exist, and their interplay is needed for the induction of efficient immune defense reactions. Nucleotide-binding domain and leucine-rich repeat-containing receptors (NLRs) are intracellular receptors that respond to a plethora of danger- and pathogen-associated molecular patterns. Their activation induces the assembly and activation of cytosolic multiprotein complexes called inflammasomes. Inflammasomes act as a primary checkpoint for the activation and secretion of the strong proinflammatory cytokines interleukin (IL)-1β and IL-18. Similar to other cellular functions, innate immune responses are operated via a complicated interplay between signalosomes. To become activated inflammasomes require the coordinated activation of Toll-like receptors (TLRs) and NLRs, which induce the activation and assembly of inflammasome complexes. The consequent secretion of inflammasome-derived cytokines is, in turn, modulated by autophagy. Inflammasome activation and autophagy also interact with cellular death pathways. Cellular death acts to limit the spread of intracellular pathogens by denying a protective niche to these pathogens, thereby inhibiting their replication and predisposing them for detection by the immune system. The aim of this study was to investigate the roles of ethanol and hemin in the modulation of innate immune cell functions, as well as the mechanisms underlying the reported protective effects of ethanol and hemin against chronic inflammatory diseases. Alcohol is the most commonly and widely used drug in the world. The consequences of alcohol consumption depend on both the pattern of consumption and the amounts consumed. Alcohol abuse predisposes to more frequent and severe infections, whereas the light to moderate consumption of alcoholic beverages has been associated with a reduced incidence of chronic inflammatory conditions, such as cardiovascular diseases and rheumatoid arthritis. These seemingly different responses may both derive from attenuated reactions of innate immunity. In the present thesis study, ethanol was shown to reduce the viability and proliferation of mast cells. This reduced viability resulted from the immunologically silent apoptotic death of mast cells. In macrophages, ethanol reduced the pyroptotic cell death induced by inflammasome activation and instead directed cell death toward apoptosis. Excessive inflammasome activation is a prominent feature of several chronic inflammatory diseases. The mechanisms that restrain inflammasome activation were studied in greater detail in cultured macrophages. Ethanol dose-dependently inhibited inflammasome activation and the secretion of IL-1β in human macrophages. It was further shown that the inhibitory effect of ethanol was mediated by a reduction in lysosomal disruption and the release of active cathepsin B, which thus contributed to diminished inflammasome assembly. The majority of mammalian cells are constantly renewed. Enormous numbers of senescent red blood cells are phagocytosed daily by macrophages. In certain pathologies, such as malarial infection, massive hemolysis occurs that exceeds the capacity of the scavenging and degradation systems of hemoglobin. As a consequence, free heme and hemin are released into the circulation. Free heme and hemin are cytotoxic and proinflammatory compounds. However, heme and hemin are also potent inducers of the heme oxygenase-1 (HO-1) enzyme, which possesses anti-inflammatory and cytoprotective effects. In the present thesis study, hemin and its synthetic derivative cobalt protoporphyrin (CoPP) blocked inflammasome activation and assembly. Decreased secretion of IL-1β was also observed in vivo in a nucleotide-binding domain and leucine-rich repeat-containing family, pyrin domain-containing 3 (NLRP3)-dependent peritonitis model in mice. The inhibitory effects of hemin and CoPP were partially dependent on the induction of HO-1 transcription by NF-E2-related factor-2 (Nrf2) and the enzymatic activity of HO-1. The inhibitory effects of hemin and CoPP were mediated by increased degradation of inflammasome components, which was due to elevated autophagy. Overall, the results of this study demonstrate that ethanol and hemin markedly prevent inflammatory cellular responses in macrophages and mast cells. This inhibition may contribute to the cardioprotective effect of ethanol and the anti-inflammatory effects of hemin. An enhanced molecular understanding of the mechanisms by which ethanol and hemin inhibit inflammation may help reveal new therapeutic options in the treatment of chronic inflammatory diseases.Synnynnäinen immuunipuolustusjärjestelmä käynnistää immuunivasteen kohdatessaan infektion aiheuttajan tai kudosvaurion. Immuunipuolustusreaktion tarkoituksena on rajoittaa vahingollisten mikrobien tai vaurion leviäminen. Synnynnäisen immuunipuolustuksen solut kohtaavat ensimmäisinä tulehdusta aiheuttavat tekijät tai niiden aiheuttamat vaarasignaalit. Vaarasignaalit käynnistävät synnynnäisen immuunipuolustuksen soluissa nopean paikallisen immuunivasteen. Tulehdusreaktio on yleensä hyödyllinen elimistölle. Tavallisesti tulehdusreaktio sammuu, kun sen aiheuttaja on poistunut ja uhka on eliminoitu. Aina tulehdusreaktio ei kuitenkaan palvele tarkoitustaan ja nykyään tiedetään, että epätarkoituksenmukainen tulehdus on merkittävä tekijä monen kroonisen sairauden taudinkehityksessä. Patogeenien rakenneyksiköt, ns. toistokuviot ja vaarasignaalit aktivoivat synnynnäisen immuunipuolustuksen solujen hahmontunnistusreseptoreita. Synnynnäisen immuunipuolustuksen soluilla on useita erilaisia eri reseptoriperheisiin lukeutuvia hahmontunnistusreseptoreita, joiden yhteistyötä tarvitaan tehokkaan immuunipuolustusreaktion käynnistämiseen. NOD-kaltaiset reseptorit (NLR) ovat solunsisäisiä liukoisia hahmontunnistusreseptoreita, jotka tunnistavat suuren määrän erilaisia vaarasta ja patogeeneista varoittavia rakenteita. NLR:n aktivaatio laukaisee inflammasomeiksi kutsuttujen solunsisäisten proteiinikompleksien muodostumisen ja aktivaation. Inflammasomi-kompleksi toimii voimakkaiden tulehdusta aiheuttavien sytokiinien interleukiini (IL)-1β ja IL-18 erityksen pääasiallisena säätelijänä. Synnynnäistä immuunivastetta säätelevät useiden eri signaalinvälitysreittien väliset vuorovaikutukset. Inflammasomi-kompleksin aktivaatio vaatii useimmiten Toll-kaltaisten reseptorien ja NLR:n koordinoidun aktivaation, joka johtaa inflammasomi-kompleksin muodostumiseen ja aktivaatioon. Kompleksin aktivaatiota seuraavaa inflammasomi-välitteisten sytokiinien eritystä puolestaan säädellään autofagian aktivaation kautta. Inflammasomin ja autofagian aktivoituminen taas vaikuttaa solukuolemaa ohjaaviin signalointireitteihin. Solukuolema toimiikin yhtenä keinona rajoittaa solunsisäisten patogeenien leviämistä, sillä solukuolema poistaa solunsisäisen ympäristön, jossa nämä patogeenit voisivat lisääntyä suojassa immuunijärjestelmän solujen pinnalla sijaitsevilta ja/tai veren liukoisilta reseptoreilta. Tämän väitöskirjan tavoitteena oli tutkia alkoholin ja hemiinin vaikutusta immuunipuolustuksen solujen toimintaan, sekä mekanismeja jotka välittävät alkoholin ja hemiinin immuunipuolustuksen reaktioita hiljentäviä vaikutuksia. Alkoholi on maailmanlaajuisesti yleisimmin käytetty päihde. Alkoholin käytön seuraukset riippuvat kulutuksen tavasta sekä kulutetuista määristä. Alkoholismi altistaa vakaville infektiosairauksille, kun taas alkoholin kohtuullinen käyttö on yhdistetty kroonisten tulehduksellisten sairauksien vähenemiseen, kuten pienentyneeseen riskiin sairastua sydän- ja verisuonisairauksiin sekä reumaan. Kumpikin edellä mainituista näennäisesti vastakkaisista seurauksista voi johtua heikentyneestä synnynnäisen immuunipuolustuksen vasteesta. Tässä tutkimuksessa alkoholin osoitettiin vähentävän syöttösolujen elinkelpoisuutta ja jakautumista. Vähentynyt elinkelpoisuus johtui syöttösolujen immunologisesti hiljaisesta apoptoottisesta solukuolemasta. Niin ikään alkoholi vähensi inflammasomin aktivaation laukaisemaa pyroptoottista solukuolemaa makrofageissa ja sen sijaan ohjasi makrofageja apoptoottiseen solukuolemaan. Inflammasomin liiallinen aktivaatio on yhdistetty useisiin kroonisiin tulehduksellisiin sairauksiin. Tässä tutkimuksessa inflammasomin aktivaatiota hillitseviä mekanismeja tutkittiin viljellyissä ihmisen makrofageissa. Tulosten perusteella voidaan todeta, että alkoholi hillitsee inflammasomin aktivaatiota ja IL-1β:n eritystä annosriippuvaisesti. Edelleen osoitettiin, että alkoholin inflammasomin aktivaatiota hillitsevä vaikutus johtui osittain vähentyneestä lysosomien vaurioitumisesta, joka taas vähensi katepsiini B:n vapautumista lysosomeista. Edellä mainitut tekijät vaikuttivat alkoholin inflammasomi-kompleksien muodostumista hillitsevään vaikutukseen. Makrofagit syövät päivittäin valtavia määriä vanhoja ja vaurioituneita punasoluja. Joissakin tautitiloissa, kuten malaria-infektion yhteydessä, punasolujen massiivinen hajoaminen ylittää elimistön hemoglobiinin sitomis- ja hajotusmekanismien kapasiteetin ja hemiä sekä hemiiniä vapautuu systeemiseen verenkiertoon. Hemoglobiiniin sitoutumaton vapaa hemi ja hemiini ovat soluille myrkyllisiä ja tulehdusta aiheuttavia molekyylejä. Toisaalta hemi ja hemiini ovat voimakkaita hemioksigenaasi-1 (HO-1) entsyymin indusoijia ja HO-1 entsyymillä puolestaan on soluja suojaavia ja tulehdusta hillitseviä vaikutuksia. Tässä osatutkimuksessa hemiinin ja sen synteettisen johdannaisen kobolttiprotoporfyriinin (CoPP) osoitettiin estävän inflammasomi-kompleksin muodostumista ja aktivaatiota. Niin ikään CoPP hillitsi IL-1β:n eritystä hiiren inflammasomi-välitteisessä vatsakalvontulehduksessa. Hemiinin ja CoPP:n inflammasomia hillitsevä vaikutus oli osittain riippuvainen transkriptiofaktori NF-E2-related factor-2:n välittämästä HO-1:n ilmentymisestä, sekä HO-1:n entsymaattisesta aktiivisuudesta. Signalointimekanismien tarkastelu osoitti hemiinin ja CoPP:n lisäävän autofagiaa, mikä johti inflammasomin komponenttien hajotukseen. Väitöskirjatutkimuksen tulosten perusteella voidaan todeta, että alkoholi ja hemiini hillitsevät voimakkaasti syöttösolujen ja makrofagien tulehdusvastetta. Tämä saattaa selittää alkoholin ja hemiinin todettuja tulehdusta hillitseviä vaikutuksia elimistössä. Alkoholin ja hemiinin tulehdusta estävien vaikutusten taustalla olevien molekulaaristen mekanismien parempi tuntemus saattaa tarjota uuden lähtökohdan tulehdusta hillitsevien hoitojen kehittämiselle kroonisiin tulehduksellisiin sairauksiin

Carboxyl-Terminal Cleavage of Apolipoprotein A-I by Human Mast Cell Chymase Impairs Its Anti-Inflammatory Properties

Objective Apolipoprotein A-I (apoA-I) has been shown to possess several atheroprotective functions, including inhibition of inflammation. Protease-secreting activated mast cells reside in human atherosclerotic lesions. Here we investigated the effects of the neutral proteases released by activated mast cells on the anti-inflammatory properties of apoA-I. Approach and Results Activation of human mast cells triggered the release of granule-associated proteases chymase, tryptase, cathepsin G, carboxypeptidase A, and granzyme B. Among them, chymase cleaved apoA-I with the greatest efficiency and generated C-terminally truncated apoA-I, which failed to bind with high affinity to human coronary artery endothelial cells. In tumor necrosis factor--activated human coronary artery endothelial cells, the chymase-cleaved apoA-I was unable to suppress nuclear factor-B-dependent upregulation of vascular cell adhesion molecule-1 (VCAM-1) and to block THP-1 cells from adhering to and transmigrating across the human coronary artery endothelial cells. Chymase-cleaved apoA-I also had an impaired ability to downregulate the expression of tumor necrosis factor-, interleukin-1, interleukin-6, and interleukin-8 in lipopolysaccharide-activated GM-CSF (granulocyte-macrophage colony-stimulating factor)- and M-CSF (macrophage colony-stimulating factor)-differentiated human macrophage foam cells and to inhibit reactive oxygen species formation in PMA (phorbol 12-myristate 13-acetate)-activated human neutrophils. Importantly, chymase-cleaved apoA-I showed reduced ability to inhibit lipopolysaccharide-induced inflammation in vivo in mice. Treatment with chymase blocked the ability of the apoA-I mimetic peptide L-4F, but not of the protease-resistant D-4F, to inhibit proinflammatory gene expression in activated human coronary artery endothelial cells and macrophage foam cells and to prevent reactive oxygen species formation in activated neutrophils. Conclusions The findings identify C-terminal cleavage of apoA-I by human mast cell chymase as a novel mechanism leading to loss of its anti-inflammatory functions. When targeting inflamed protease-rich atherosclerotic lesions with apoA-I, infusions of protease-resistant apoA-I might be the appropriate approach.Peer reviewe

IL-17A and TNF synergistically drive expression of proinflammatory mediators in synovial fibroblasts via I kappa B zeta-dependent induction of ELF3

Objective IL-17A and TNF act in synergy to induce proinflammatory mediators in synovial fibroblasts thus contributing to diseases associated with chronic arthritis. Many of these factors are regulated by transcription factor E74-like factor-3 (ELF3). Therefore, we sought to investigate ELF3 as a downstream target of IL-17A and TNF signalling and to characterize its role in the molecular mechanism of synergy between IL-17A and TNF. Methods Regulation of ELF3 expression by IL-17A and TNF was studied in synovial fibroblasts of RA and OA patients and RA synovial explants. Signalling leading to ELF3 mRNA induction and the impact of ELF3 on the response to IL-17A and TNF were studied using siRNA, transient overexpression and signalling inhibitors in synovial fibroblasts and HEK293 cells. Results ELF3 was marginally affected by IL-17A or TNF alone, but their combination resulted in high and sustained expression. ELF3 expression was regulated by the nuclear factor-kappa B (NF-kappa B) pathway and CCAAT/enhancer-binding protein beta (C/EBP beta), but its induction required synthesis of the NF-kappa B co-factor I kappa B (inhibitor of NF-kappa B) zeta. siRNA-mediated depletion of ELF3 attenuated the induction of cytokines and matrix metalloproteinases by the combination of IL-17A and TNF. Overexpression of ELF3 or I kappa B zeta showed synergistic effect with TNF in upregulating expression of chemokine (C-C motif) ligand 8 (CCL8), and depletion of ELF3 abrogated CCL8 mRNA induction by the combination of I kappa B zeta overexpression and TNF. Conclusion Altogether, our results establish ELF3 as an important mediator of the synergistic effect of IL-17A and TNF in synovial fibroblasts. The findings provide novel information of the pathogenic mechanisms of IL-17A in chronic arthritis and implicate ELF3 as a potential therapeutic target.Peer reviewe

Histamine H-3 Receptor Signaling Regulates the NLRP3 Inflammasome Activation in C2C12 Myocyte During Myogenic Differentiation

NLRP3 inflammasome has been implicated in impaired post-injury muscle healing and in muscle atrophy. Histamine receptors play an important role in inflammation, but the role of histamine H-3 receptor (H3R) in myocyte regeneration and in the regulation of NLRP3 inflammasome is not known. We studied the effects of H3R signaling on C2C12 myocyte viability, apoptosis, and tumor necrosis factor alpha (TNF alpha)-induced NLRP3 inflammasome activation during striated myogenic differentiation at three time points (days 0, 3, and 6). Expression of Nlrp3, interleukin-1 beta (IL-1 beta), and myogenesis markers were determined. TNF alpha reduced overall viability of C2C12 cells, and exposure to TNF alpha induced apoptosis of cells at D6. Activation of H3R had no effect on viability or apoptosis, whereas inhibition of H3R increased TNF alpha-induced apoptosis. Stimulation of C2C12 cells with TNF alpha increased Nlrp3 mRNA expression at D3 and D6. Moreover, TNF alpha reduced the expression of myogenesis markers MyoD1, Myogenin, and Myosin-2 at D3 and D6. H3R attenuated TNF alpha-induced expression of Nlrp3 and further inhibited the myogenesis marker expression; while H3R -blockage enhanced the proinflammatory effects of TNF alpha and increased the myogenesis marker expression. TNF alpha-induced secretion of mature IL-1 beta was dependent on the activation of the NLRP3 inflammasome, as shown by the reduced secretion of mature IL-1 beta upon treatment of the cells with the small molecule inhibitor of the NLRP3 inflammasome (MCC950). The activation of H3R reduced TNF alpha-induced IL-1 beta secretion, while the H3R blockage had an opposite effect. In conclusion, the modulation of H3R activity regulates the effects of TNF alpha on C2C12 myocyte differentiation and TNF alpha-induced activation of NLRP3 inflammasome. Thus, H3R signaling may represent a novel target for limiting postinjury muscle inflammation and muscle atrophy.Peer reviewe

Forskolin attenuates the NLRP3 inflammasome activation and IL-1 beta secretion in human macrophages

BACKGROUND: The treatment of nucleotide-binding domain and leucine-rich repeat containing family, pyrin domain containing 3 (NLRP3) inflammasome-mediated pediatric inflammatory diseases is challenging. Here we studied whether cyclic adenosine monophosphate (cAMP) elevator forskolin could attenuate the nigericin-induced NLRP3-inflammasome activation and interleukin-1 beta (IL-1 beta) secretion in human macrophages. METHODS: The proteins and messenger RNA (mRNA) levels of inflammasome structural proteins and proinflammatory cytokines were measured in forskolin-stimulated nigericin-activated human THP-1 macrophages and primary macrophages. RESULTS: Activation of THP-1 macrophages with nigericin increased the mRNA expression of NLRP3, IL-1 beta, and caspase-1 (P 0.05), while their protein levels were significantly decreased (P <0.05). Forskolin-mediated increase in cytoplasmic cAMP in non-activated cells was attenuated in nigericin-activated macrophages (P <0.05). Basal IL-1 beta secretion increased from 584 to 2696 pg/ml (P <0.01) in nigericin-activated macrophages; forskolin dose-dependently reduced the nigericin-induced secretion of mature IL-1 beta (P <0.01). Forskolin also inhibited the IL-1 beta secretion from activated human primary macrophages. CONCLUSIONS: Forskolin inhibits the NLRP3 inflammasome activation and the secretion of mature IL-1 beta, in human macrophages. Forskolin and other cAMP elevator drugs could represent a novel approach for treatment of diseases associated with excessive inflammasome activation, like pediatric inflammatory diseases.Peer reviewe

Hemin and Cobalt Protoporphyrin Inhibit NLRP3 Inflammasome Activation by Enhancing Autophagy : A Novel Mechanism of Inflammasome Regulation

Inflammasomes are intracellular protein platforms, which, upon activation, produce the highly proinflammatory cytokines interleukin (IL)-1 beta and IL-18. Heme, hemin and their degradation products possess significant immunomodulatory functions. Here, we studied whether hemin regulates inflammasome function in macrophages. Both hemin and its derivative, cobalt protoporphyrin (CoPP), significantly reduced IL-1 beta secretion by cultured human primary macrophages, the human monocytic leukemia cell line and also mouse bone marrow-derived and peritoneal macrophages. Intraperitoneal administration of CoPP to mice prior to urate crystal-induced peritonitis alleviated IL-1 beta secretion to the peritoneal cavity. In cultured macrophages, hemin and CoPP inhibited NLRP3 inflammasome assembly by reducing the amount of intracellular apoptosis-associated speck-like protein containing a caspase-recruitment domain (ASC). The reduction of ASC was associated with enhanced autophagosome formation and autophagic flux. Inhibition of autophagy prevented the CoPP-induced depletion of ASC, implying that the depletion was caused by increased autophagy. Our data indicate that hemin functions as an endogenous negative regulator of the NLRP3 inflammasome. The inhibition is mediated via enhanced autophagy that results in increased degradation of ASC. This regulatory mechanism may provide a novel approach for the treatment of inflammasome-related diseases. (C) 2016 S. Karger AG, BaselPeer reviewe

Antibiotic Resistomes and Microbiomes in the Surface Water along the Code River in Indonesia Reflect Drainage Basin Anthropogenic Activities

Water and sanitation are important factors in the emergence of antimicrobial resistance in low-and middle-income countries. Drug residues, metals, and various wastes foster the spread of antibiotic resistance genes (ARGs) with the help of mobile genetic elements (MGEs), and therefore, rivers receiving contaminants and enfluents from multiple sources are of special interest. We followed both the microbiome and resistome of the Code River in Indonesia from its pristine origin at the Merapi volcano through rural and then city areas to the coast of the Indian Ocean. We used a SmartChip quantitative PCR with 382 primer pairs for profiling the resistome and MGEs and 16S rRNA gene amplicon sequencing to analyze the bacterial communities. The community structure explained the resistome composition in rural areas, while the city sampling sites had lower bacterial diversity and more ARGs, which correlated with MGEs, suggesting increased mobility potential in response to pressures from human activities. Importantly, the vast majority of ARGs and MGEs were no longer detectable in marine waters at the ocean entrance. Our work provides information on the impact of different influents on river health as well as sheds light on how land use contributes to the river resistome and microbiome.Peer reviewe

Lääketietovarannon jatkoselvitys : Lääketietovarannon toimintaedellytykset valtakunnallisena palveluna

Lääketietovaranto koostaisi eri viranomaisen tehtäviin ja palveluihin liittyviä tietoaineistoja lääkevalmisteista, kasvirohdosvalmisteista sekä korvattavista perusvoiteista ja kliinisistä ravintovalmisteista. Se olisi useiden toimijoiden käyttöön suunniteltu ja ylläpidetty tietovaranto, jonka tiedot olisivat hyödynnettävissä erityisesti lääkehoidon ja -logistiikan erilaisiin käyttötarkoituksiin sekä ohjauksen, valvonnan, varautumisen ja tiedolla johtamisen tarpeisiin. Fimea on tuottanut lääketietovarannon jatkotyön sosiaali- ja terveysministeriön toimeksiannosta. Työn tavoite on tarkentaa lääketietovarannon lähtökohtia ja täydentäen aikaisempaa selvitystä (STM raportteja ja muistioita 2021:3). Laaja-alaisena tavoitteena on muodostaa kattava perusta kansalliseen päätöksentekoon, jotta voidaan tehdä tarkoituksenmukaiset päätökset kansallisen lääketietovarannon toimeenpanosta. Jatkotyö sisältää ehdotuksen lääketietovarannon tietoaineistoista ja toimintamallista. Toimintamalli kuvaa tietovarannon toiminnalliset rakenteet, mukaan lukien tiedon tuottamiseen ja hallintaan liittyvät keskeiset toimijat ja toimintaprosessit, lääketietovarannon palvelut sekä palveluiden käyttötarkoitukset ja asiakaskunnan. Raportti sisältää myös nykytilan puuteanalyysin ja yhteenvedon tietosisältöjen kehittämistarpeista sekä ehdotuksen tietovarannon kehittämispolusta

Hydroxychloroquine reduces interleukin-6 levels after myocardial infarction : The randomized, double-blind, placebo-controlled OXI pilot trial

Objectives: To determine the anti-inflammatory effect and safety of hydroxychloroquine after acute myocardial infarction. Method: In this multicenter, double-blind, placebo-controlled OXI trial, 125 myocardial infarction patients were randomized at a median of 43 h after hospitalization to receive hydroxychloroquine 300 mg (n = 64) or placebo (n = 61) once daily for 6 months and, followed for an average of 32 months. Laboratory values were measured at baseline, 1, 6, and 12 months. Results: The levels of interleukin-6 (IL-6) were comparable at baseline between study groups (p = 0.18). At six months, the IL-6 levels were lower in the hydroxychloroquine group (p = 0.042, between groups), and in the on-treatment analysis, the difference at this time point was even more pronounced (p = 0.019, respectively). The high-sensitivity C-reactive protein levels did not differ significantly between study groups at any time points. Eleven patients in the hydroxychloroquine group and four in the placebo group had adverse events leading to in-terruption or withdrawal of study medication, none of which was serious (p = 0.10, between groups). Conclusions: In patients with myocardial infarction, hydroxychloroquine reduced IL-6 levels significantly more than did placebo without causing any clinically significant adverse events. A larger randomized clinical trial is warranted to prove the potential ability of hydroxychloroquine to reduce cardiovascular endpoints after myocar-dial infarction. (c) 2021 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http:// creativecommons.org/licenses/by/4.0/).Peer reviewe

Insights From Liver-Humanized Mice on Cholesterol Lipoprotein Metabolism and LXR-Agonist Pharmacodynamics in Humans

Background and Aims Genetically modified mice have been used extensively to study human disease. However, the data gained are not always translatable to humans because of major species differences. Liver-humanized mice (LHM) are considered a promising model to study human hepatic and systemic metabolism. Therefore, we aimed to further explore their lipoprotein metabolism and to characterize key hepatic species-related, physiological differences. Approach and Results Fah(-/-), Rag2(-/-), and Il2rg(-/-) knockout mice on the nonobese diabetic (FRGN) background were repopulated with primary human hepatocytes from different donors. Cholesterol lipoprotein profiles of LHM showed a human-like pattern, characterized by a high ratio of low-density lipoprotein to high-density lipoprotein, and dependency on the human donor. This pattern was determined by a higher level of apolipoprotein B100 in circulation, as a result of lower hepatic mRNA editing and low-density lipoprotein receptor expression, and higher levels of circulating proprotein convertase subtilisin/kexin type 9. As a consequence, LHM lipoproteins bind to human aortic proteoglycans in a pattern similar to human lipoproteins. Unexpectedly, cholesteryl ester transfer protein was not required to determine the human-like cholesterol lipoprotein profile. Moreover, LHM treated with GW3965 mimicked the negative lipid outcomes of the first human trial of liver X receptor stimulation (i.e., a dramatic increase of cholesterol and triglycerides in circulation). Innovatively, LHM allowed the characterization of these effects at a molecular level. Conclusions LHM represent an interesting translatable model of human hepatic and lipoprotein metabolism. Because several metabolic parameters displayed donor dependency, LHM may also be used in studies for personalized medicine.Peer reviewe