TREM-2 plays a protective role in cholestasis by acting as a negative regulator of inflammation

Background & Aims: Inflammation, particularly that mediated by bacterial components translocating from the gut to the liver and binding to toll-like receptors (TLRs), is central to cholestatic liver injury. The triggering receptor expressed on myeloid cells-2 (TREM-2) inhibits TLR-mediated signaling and exerts a protective role in hepatocellular injury and carcinogenesis. This study aims to evaluate the role of TREM-2 in cholestasis.Methods: TREM-2 expression was analyzed in the livers of pa-tients with primary biliary cholangitis (PBC) or primary scle-rosing cholangitis (PSC), and in mouse models of cholestasis. Wild-type (WT) and Trem-2 deficient (Trem-2-/-) mice were subjected to experimental cholestasis and gut sterilization. Pri-mary cultured Kupffer cells were incubated with lipopolysac-charide and/or ursodeoxycholic acid (UDCA) and inflammatory responses were analyzed.Results: TREM-2 expression was upregulated in the livers of patients with PBC or PSC, and in murine models of cholestasis. Compared to WT, the response to bile duct ligation (BDL)-induced obstructive cholestasis or alpha-naphtylisothiocyanate (ANIT)-induced cholestasis was exacerbated in Trem-2-/-mice. This was characterized by enhanced necroptotic cell death, in-flammatory responses and biliary expansion. Antibiotic treat-ment partially abrogated the effects observed in Trem-2-/-mice after BDL. Experimental overexpression of TREM-2 in the liver of WT mice downregulated ANIT-induced IL-33 expression and neutrophil recruitment. UDCA regulated Trem-1 and Trem-2 expression in primary cultured mouse Kupffer cells and damp-ened inflammatory gene transcription via a TREM-2-dependent mechanism.Conclusions: TREM-2 acts as a negative regulator of inflamma-tion during cholestasis, representing a novel potential thera-peutic target.Lay summary: Cholestasis (the reduction or cessation of bile flow) causes liver injury. This injury is exacerbated when gut-derived bacterial components interact with receptors (spe-cifically Toll-like receptors or TLRs) on liver-resident immune cells, promoting inflammation. Herein, we show that the anti-inflammatory receptor TREM-2 dampens TLR-mediated signaling and hence protects against cholestasis-induced liver injury. Thus, TREM-2 could be a potential therapeutic target in cholestasis.Spanish Carlos III Health Institute (ISCIII) [J.M. Banales (FIS PI18/01075, PI21/00922 and Miguel Servet Program CPII19/00008); M.J. Perugorria (FIS PI14/00399, PI17/00022 and PI20/00186); J.J.G. Marin (FIS PI16/00598 and PI19/00819); P.M. Rodrigues (Sara Borrell CD19/00254)] cofinanced by “Fondo Europeo de Desarrollo Regional” (FEDER); “Instituto de Salud Carlos III” [CIBERehd: M.J. Monte, J.J.G. Marin, J.M. Banales, M.J. Perugorria, P. Aspichueta, P.M. Rodrigues and L. Bujanda], Spain; “Diputación Foral de Gipuzkoa” (M.J. Perugorria: DFG18/114), Department of Health of the Basque Country (M.J. Perugorria: 2019111024, 2015111100 and J.M. Banales: 2021111021), “Euskadi RIS3” (J.M. Banales: 2019222054, 2020333010, 2021333003), and Department of Industry of the Basque Country (J.M. Banales: Elkartek: KK-2020/00008); “Junta de Castilla y Leon” (J.J.G. Marin: SA063P17). La Caixa Scientific Foundation (J.M. Banales: HR17-00601). “Fundación Científica de la Asociación Española Contra el Cáncer” (AECC Scientific Foundation, to J.M. Banales and J.J.G. Marin); “Centro Internacional sobre el Envejecimiento” (J.J.G. Marin: OLD-HEPAMARKER, 0348_CIE_6_E); Fundació Marato TV3 (J.J.G. Marin: Ref. 201916-31). O Sharif was funded by the Austrian Science Fund (FWF-P35168). Work in the lab of T. Luedde was funded by the European Research Council (ERC) (Grant Agreement 771083), the German Research Foundation (DFG – LU 1360/3-2 (279874820), LU 1360/4-(1461704932) and SFB-CRC 1382-Project A01) and the German Ministry of Health (BMG – DEEP LIVER 2520DAT111). Contributions of M. Marzioni were funded by the Università Politecnica delle Marche PSA2017_UNIVPM grant. Contributions of DAM were supported by programme grants from CRUK (C18342/A23390) and MRC (MR/K0019494/1 and MR/R023026/1). MJ Perugorria was funded by the Spanish Ministry of Economy and Competitiveness (MINECO: “Ramón y Cajal” Programme RYC-2015-17755), I. Labiano, A. Agirre-Lizaso, P. Olaizola, A. Echebarria and F. González-Romero by the Basque Government (PRE_2016_1_0152, PRE_2018_1_0184, PRE_2016_1_0269 PRE_2020_1_0080, PRE_2018_1_0120, respectively), I. Olaizola by the Ministry of Universities (FPU 19/03327) and A. Esparza-Baquer by the University of the Basque Country (PIF2014/11). The funding sources had no involvement in study design, data collection and analysis, decision to publish, or preparation of the article

TREM-2 defends the liver against hepatocellular carcinoma through multifactorial protective mechanisms

[EN] Objective Hepatocellular carcinoma (HCC) is a prevalent and aggressive cancer usually arising on a background of chronic liver injury involving inflammatory and hepatic regenerative processes. The triggering receptor expressed on myeloid cells 2 (TREM-2) is predominantly expressed in hepatic non-parenchymal cells and inhibits Toll-like receptor signalling, protecting the liver from various hepatotoxic injuries, yet its role in liver cancer is poorly defined. Here, we investigated the impact of TREM-2 on liver regeneration and hepatocarcinogenesis. Design TREM-2 expression was analysed in liver tissues of two independent cohorts of patients with HCC and compared with control liver samples. Experimental HCC and liver regeneration models in wild type and Trem-2-/- mice, and in vitro studies with hepatic stellate cells (HSCs) and HCC spheroids were conducted. Results TREM-2 expression was upregulated in human HCC tissue, in mouse models of liver regeneration and HCC. Trem-2-/- mice developed more liver tumours irrespective of size after diethylnitrosamine (DEN) administration, displayed exacerbated liver damage, inflammation, oxidative stress and hepatocyte proliferation. Administering an antioxidant diet blocked DEN-induced hepatocarcinogenesis in both genotypes. Similarly, Trem-2-/- animals developed more and larger tumours in fibrosis-associated HCC models. Trem-2-/- livers showed increased hepatocyte proliferation and inflammation after partial hepatectomy. Conditioned media from human HSCs overexpressing TREM-2 inhibited human HCC spheroid growth in vitro through attenuated Wnt ligand secretion. Conclusion TREM-2 plays a protective role in hepatocarcinogenesis via different pleiotropic effects, suggesting that TREM-2 agonism should be investigated as it might beneficially impact HCC pathogenesis in a multifactorial manner.Spanish Ministry of Economy and Competitiveness and ’Instituto de Salud Carlos III’ grants (MJP (PI14/00399, PI17/00022 and Ramon y Cajal Programme RYC-2015–17755); JMB (PI12/00380, PI15/01132, PI18/01075, Miguel Servet Programme CON14/00129 and CPII19/00008) cofinanced by ’Fondo Europeo de Desarrollo Regional’ (FEDER); CIBERehd: MJP, JMB and LB), Spain; IKERBASQUE, Basque foundation for Science (MJP and JMB), Spain; ’Diputación Foral de Gipuzkoa’ (MJP: DFG18/114, DFG19/081; JMB: DFG15/010, DFG16/004); BIOEF (Basque Foundation for Innovation and Health Research: EiTB Maratoia BIO15/CA/016/ BD to JMB); Department of Health of the Basque Country (MJP: 2015111100 and 2019111024; JMB: 2017111010), Euskadi RIS3 (JMB: 2016222001, 2017222014, 2018222029, 2019222054, 2020333010) Department of Industry of the Basque Country (JMB: Elkartek: KK-2020/00008) and AECC Scientific Foundation (JMB). AE-B was funded by the University of the Basque Country (UPV/EHU) (PIF2014/11) and by the short-term training fellowship Andrew K Burroughs (European Association for the Study of the Liver, EASL). IL and AA-L were funded by the Department of Education, Language Policy and Culture of the Basque Government (PRE_2016_1_0152 and PRE_2018_1_0184). OS and SK were funded by the Austrian Science Fund (FWF25801-B22, FWF-P35168 to OS and L-Mac: F 6104-B21 to SK). FO and DAM were funded by a UK Medical Research Council programme Grant MR/R023026/1. DAM was also funded by the CRUK programme grant C18342/A23390, CRUK/AECC/AIRC Accelerator Award A26813 and the MRC MICA programme grant MR/R023026/1. JBA is supported by the Danish Medical Research Council, Danish Cancer Society, Nordisk Foundation, and APM Foundation. CJO’R and PM-G are supported by Marie Sklodowska-Curie Programme and EASL Sheila Sherlock postdoctoral fellowships

The role of scavenger receptor MARCO in the immuno-oncology of intrahepatic cholangiocarcinoma: a novel prognostic and therapeutic target

200 p.El colangiocarcinoma (CCA) es un conjunto de tumores que se originan en la vía biliar y debido a su carácter asintomático, se diagnostican en fases muy avanzadas, limitando sustancialmente las posibles opciones terapéuticas. Por ello, existe la urgente necesidad de descubrir los mecanismos moleculares involucrados en el desarrollo y progresión del CCA con el fin de encontrar nuevas dianas terapéuticas, así como biomarcadores para su diagnóstico precoz y para poder predecir su pronóstico. Durante los últimos años, se ha observado que el receptor scavenger MARCO tiene un papel clave en la polarización de los macrófagos y en consecuencia en la respuesta inmune adaptativa. Evidencias recientes en tumores sólidos como el carcinoma de mama, colon y melanoma indican que el receptor MARCO se expresa en macrófagos asociados a tumor (TAMs) tipo M2 inmunosupresores en el microambiente tumoral, contribuyendo a la inmunosupresión y al desarrollo y progresión de estos cánceres. Sin embargo, el papel de MARCO en la etiopatogenia del CCA permanece prácticamente desconocido. Nuestros datos en muestras de pacientes con CCA intrahepático (iCCA) indican que MARCO se encuentra en TAMs involucrados en procesos asociados a la inmunosupresión y a la remodelación de la matriz extracelular. Además, elevados niveles de expresión de MARCO en muestras de iCCA están asociados con un peor pronóstico y también se relacionan con una disfuncionalidad de los linfocitos T. En este sentido, los ratones deficientes de MARCO (Marco-/-) han demostrado tener una protección frente al desarrollo y progresión del iCCA en diferentes modelos experimentales murinos, y estudios proteómicos llevados a cabo con células de iCCA murinas y macrófagos residentes del hígado demuestran una regulación de procesos clave implicados en la colangiocarcinogénesis.biodonostia EMBO. European Molecular Biology Organization Instituto de la Salud Carlos II

m6A Methylated Long Noncoding RNA LOC339803 Regulates Intestinal Inflammatory Response

Cytokine mediated sustained inflammation increases the risk to develop different complex chronic inflammatory diseases, but the implicated mechanisms remain unclear. Increasing evidence shows that long noncoding RNAs (lncRNAs) play key roles in the pathogenesis of inflammatory disorders, while inflammation associated variants are described to affect their function or essential RNA modifications as N6-methyladenosine (m6A) methylation, increasing predisposition to inflammatory diseases. Here, the functional implication of the intestinal inflammation associated lncRNA LOC339803 in the production of cytokines by intestinal epithelial cells is described. Allele-specific m6A methylation is found to affect YTHDC1 mediated protein binding affinity. LOC339803-YTHDC1 interaction dictates chromatin localization of LOC339803 ultimately inducing the expression of NFκB mediated proinflammatory cytokines and contributing to the development of intestinal inflammation. These findings are confirmed using human intestinal biopsy samples from different intestinal inflammatory conditions and controls. Additionally, it is demonstrated that LOC339803 targeting can be a useful strategy for the amelioration of intestinal inflammation in vitro and ex vivo. Overall, the results support the importance of the methylated LOC339803 lncRNA as a mediator of intestinal inflammation, explaining genetic susceptibility and presenting this lncRNA as a potential novel therapeutic target for the treatment of inflammatory intestinal disorders.This research was supported by Ministerio de Ciencia, Innovación y Universidades grant PGC2018-097573-A-I00 and Departamento de Salud, Gobierno Vasco grant 2023111056 (ACR), Ministerio de Ciencia, Innovación y Universidades grant PID2019-104475GA-I00 (IS), The European Foundation for the Study of Diabetes grant (EFSD)-EFSD/JDRF/Lilly Programme on Type 1 Diabetes Research (IS), Basque Government predoctoral grant PRE_2018_2_0039 and post-doctoral grant ESPDOC21/56 (AOG), Ministerio de Ciencia, Innovación y Universidades predoctoral FPI grant PGC2018-097573-A-I00 (HRM), UPV-EHU predoctoral grant and Fundación Catedra Cajal grant (MSdlC). The authors thank the general proteomic service from SGIker (UPV/EHU/ ERDF, EU) for technical and human support provided

TREM-2 plays a protective role in cholestasis by acting as a negative regulator of inflammation

Background & Aims: Inflammation, particularly that mediated by bacterial components translocating from the gut to the liver and binding to toll-like receptors (TLRs), is central to cholestatic liver injury. The triggering receptor expressed on myeloid cells-2 (TREM-2) inhibits TLR-mediated signaling and exerts a protective role in hepatocellular injury and carcinogenesis. This study aims to evaluate the role of TREM-2 in cholestasis.Methods: TREM-2 expression was analyzed in the livers of pa-tients with primary biliary cholangitis (PBC) or primary scle-rosing cholangitis (PSC), and in mouse models of cholestasis. Wild-type (WT) and Trem-2 deficient (Trem-2-/-) mice were subjected to experimental cholestasis and gut sterilization. Pri-mary cultured Kupffer cells were incubated with lipopolysac-charide and/or ursodeoxycholic acid (UDCA) and inflammatory responses were analyzed.Results: TREM-2 expression was upregulated in the livers of patients with PBC or PSC, and in murine models of cholestasis. Compared to WT, the response to bile duct ligation (BDL)-induced obstructive cholestasis or alpha-naphtylisothiocyanate (ANIT)-induced cholestasis was exacerbated in Trem-2-/-mice. This was characterized by enhanced necroptotic cell death, in-flammatory responses and biliary expansion. Antibiotic treat-ment partially abrogated the effects observed in Trem-2-/-mice after BDL. Experimental overexpression of TREM-2 in the liver of WT mice downregulated ANIT-induced IL-33 expression and neutrophil recruitment. UDCA regulated Trem-1 and Trem-2 expression in primary cultured mouse Kupffer cells and damp-ened inflammatory gene transcription via a TREM-2-dependent mechanism.Conclusions: TREM-2 acts as a negative regulator of inflamma-tion during cholestasis, representing a novel potential thera-peutic target.Lay summary: Cholestasis (the reduction or cessation of bile flow) causes liver injury. This injury is exacerbated when gut-derived bacterial components interact with receptors (spe-cifically Toll-like receptors or TLRs) on liver-resident immune cells, promoting inflammation. Herein, we show that the anti-inflammatory receptor TREM-2 dampens TLR-mediated signaling and hence protects against cholestasis-induced liver injury. Thus, TREM-2 could be a potential therapeutic target in cholestasis