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1.
Hepatology ; 80(5): 1104-1119, 2024 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-38231043

RESUMO

BACKGROUND AND AIMS: Acute liver failure (ALF) is a rare but life-threatening condition, and DILI, particularly acetaminophen toxicity, is the leading cause of ALF. Innate immune mechanisms further perpetuate liver injury, while the role of the adaptive immune system in DILI-related ALF is unclear. APPROACH AND RESULTS: We analyzed liver tissue from 2 independent patient cohorts with ALF and identified hepatic T cell infiltration as a prominent feature in human ALF. CD8 + T cells were characterized by zonation toward necrotic regions and an activated gene expression signature. In murine acetaminophen-induced liver injury, intravital microscopy revealed zonation of CD8 + but not CD4 + T cells at necrotic areas. Gene expression analysis exposed upregulated C-C chemokine receptor 7 (CCR7) and its ligand CCL21 in the liver as well as a broadly activated phenotype of hepatic CD8 + T cells. In 2 mouse models of ALF, Ccr7-/- mice had significantly aggravated early-phase liver damage. Functionally, CCR7 was not involved in the recruitment of CD8 + T cells, but regulated their activation profile potentially through egress to lymphatics. Ccr7-/- CD8 + T cells were characterized by elevated expression of activation, effector, and exhaustion profiles. Adoptive transfer revealed preferential homing of CCR7-deficient CD8 + T cells to the liver, and depletion of CD8 + T cells attenuated liver damage in mice. CONCLUSIONS: Our study demonstrates the involvement of the adaptive immune system in ALF in humans and mice. We identify the CCR7-CCL21 axis as an important regulatory pathway, providing downstream protection against T cell-mediated liver injury.


Assuntos
Linfócitos T CD8-Positivos , Homeostase , Falência Hepática Aguda , Receptores CCR7 , Animais , Receptores CCR7/metabolismo , Receptores CCR7/genética , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Camundongos , Humanos , Falência Hepática Aguda/imunologia , Falência Hepática Aguda/induzido quimicamente , Falência Hepática Aguda/metabolismo , Falência Hepática Aguda/patologia , Masculino , Fígado/patologia , Fígado/metabolismo , Fígado/imunologia , Acetaminofen/toxicidade , Acetaminofen/efeitos adversos , Quimiocina CCL21/metabolismo , Quimiocina CCL21/genética , Doença Hepática Induzida por Substâncias e Drogas/imunologia , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/patologia , Modelos Animais de Doenças , Camundongos Endogâmicos C57BL , Feminino , Camundongos Knockout
2.
Gastroenterology ; 156(6): 1877-1889.e4, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30710528

RESUMO

BACKGROUND & AIMS: Inflammation in the liver provokes fibrosis, but inflammation is also important for tumor surveillance. Inhibitors of chemokine pathways, such as CXCL16 and CXCR6 regulation of lymphocyte trafficking, are being tested as antifibrotic agents, but their effects on the development of hepatocellular carcinoma (HCC) are unclear. We assessed the roles of CXCR6-dependent immune mechanisms in hepatocarcinogenesis. METHODS: C57BL/6J wild-type (WT) mice and CXCR6-deficient mice (Cxcr6eGfp/eGfp) were given injections of diethylnitrosamine (DEN) to induce liver cancer and α-galactosylceramide to activate natural killer T (NKT) cells. We also performed studies in mice with conditional, hepatocyte-specific deletion of NEMO, which develop inflammation-associated liver tumors (NemoLPC-KO and NemoLPC-KOCxcr6eGfp/eGfp mice). We collected liver tissues from patients with cirrhosis (n = 43), HCC (n = 35), and neither of these diseases (control individuals, n = 25). Human and mouse liver tissues were analyzed by histology, immunohistochemistry, flow cytometry, RNA expression arrays (from sorted hepatic lymphocytes), and matrix-assisted laser desorption/ionization imaging. Bone marrow was transferred from Cxcr6eGfp/eGfp or WT mice to irradiated C57BL/6J mice, and spleen and liver cells were analyzed by flow cytometry. CD4+ T cells or NKT cells were isolated from the spleen and liver of CD45.1+ WT mice and transferred into CXCR6-deficient mice after DEN injection. RESULTS: After DEN injection, CXCR6-deficient mice had a significantly higher tumor burden than WT mice and increased tumor progression, characterized by reduced intrahepatic numbers of invariant NKT and CD4+ T cells that express tumor necrosis factor and interferon gamma. Livers of NemoLPC-KOCxcr6eGfp/eGfp mice had significantly more senescent hepatocytes than livers of NemoLPC-KO mice. In studies of bone-marrow chimeras, adoptive cell transfer experiments, and analyses of NemoLPC-KO mice, we found that NKT and CD4 T cells promote the removal of senescent hepatocytes to prevent hepatocarcinogenesis, and that this process required CXCR6. Injection of WT with α-galactosylceramide increased removal of senescent hepatocytes by NKT cells. We observed peritumoral accumulation of CXCR6-associated lymphocytes in human HCC, which appeared reduced compared with cirrhosis tissues. CONCLUSIONS: In studies of mice with liver tumors, we found that CXCR6 mediated NKT-cell and CD4+ T-cell removal of senescent hepatocytes. Antifibrotic strategies to reduce CXCR6 activity in liver, or to reduce inflammation or modulate the immune response, should be tested for their effects on hepatocarcinogenesis.


Assuntos
Carcinogênese/imunologia , Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/patologia , Células T Matadoras Naturais/imunologia , Receptores CXCR6/genética , Receptores CXCR6/imunologia , Animais , Linfócitos T CD4-Positivos/metabolismo , Carcinogênese/genética , Carcinoma Hepatocelular/metabolismo , Senescência Celular , Dietilnitrosamina , Progressão da Doença , Galactosilceramidas/farmacologia , Hepatócitos/fisiologia , Humanos , Vigilância Imunológica/genética , Interferon gama/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/genética , Cirrose Hepática/patologia , Neoplasias Hepáticas/induzido quimicamente , Neoplasias Hepáticas/metabolismo , Ativação Linfocitária/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Células T Matadoras Naturais/metabolismo , Receptores CXCR6/metabolismo , Carga Tumoral/genética , Fator de Necrose Tumoral alfa/metabolismo
3.
Hepatology ; 67(4): 1270-1283, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-28940700

RESUMO

Macrophages are key regulators of liver fibrosis progression and regression in nonalcoholic steatohepatitis (NASH). Liver macrophages comprise resident phagocytes, Kupffer cells, and monocyte-derived cells, which are recruited through the chemokine receptor C-C motif chemokine receptor 2 (CCR2). We aimed at elucidating the therapeutic effects of inhibiting monocyte infiltration in NASH models by using cenicriviroc (CVC), an oral dual chemokine receptor CCR2/CCR5 antagonist that is under clinical evaluation. Human liver tissues from NASH patients were analyzed for CCR2+ macrophages, and administration of CVC was tested in mouse models of steatohepatitis, liver fibrosis progression, and fibrosis regression. In human livers from 17 patients and 4 controls, CCR2+ macrophages increased parallel to NASH severity and fibrosis stage, with a concomitant inflammatory polarization of these cluster of differentiation 68+ , portal monocyte-derived macrophages (MoMF). Similar to human disease, we observed a massive increase of hepatic MoMF in experimental models of steatohepatitis and liver fibrosis. Therapeutic treatment with CVC significantly reduced the recruitment of hepatic Ly-6C+ MoMF in all models. In experimental steatohepatitis with obesity, therapeutic CVC application significantly improved insulin resistance and hepatic triglyceride levels. In fibrotic steatohepatitis, CVC treatment ameliorated histological NASH activity and hepatic fibrosis. CVC inhibited the infiltration of Ly-6C+ monocytes, without direct effects on macrophage polarization, hepatocyte fatty acid metabolism, or stellate cell activation. Importantly, CVC did not delay fibrosis resolution after injury cessation. RNA sequencing analysis revealed that MoMF, but not Kupffer cells, specifically up-regulate multiple growth factors and cytokines associated with fibrosis progression, while Kupffer cells activated pathways related to inflammation initiation and lipid metabolism. CONCLUSION: Pharmacological inhibition of CCR2+ monocyte recruitment efficiently ameliorates insulin resistance, hepatic inflammation, and fibrosis, corroborating the therapeutic potential of CVC in patients with NASH. (Hepatology 2018;67:1270-1283).


Assuntos
Antagonistas dos Receptores CCR5/farmacologia , Imidazóis/farmacologia , Cirrose Hepática/tratamento farmacológico , Monócitos/efeitos dos fármacos , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Adulto , Idoso , Animais , Quimiotaxia de Leucócito/efeitos dos fármacos , Citocinas/metabolismo , Modelos Animais de Doenças , Progressão da Doença , Feminino , Humanos , Imuno-Histoquímica , Resistência à Insulina , Fígado/patologia , Cirrose Hepática/patologia , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Macrófagos/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Pessoa de Meia-Idade , Monócitos/patologia , Hepatopatia Gordurosa não Alcoólica/patologia , Sulfóxidos
4.
Mol Cell Proteomics ; 15(8): 2699-714, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27281784

RESUMO

Pathogen components, such as lipopolysaccharides of Gram-negative bacteria that activate Toll-like receptor 4, induce mitogen activated protein kinases and NFκB through different downstream pathways to stimulate pro- and anti-inflammatory cytokine expression. Importantly, post-transcriptional control of the expression of Toll-like receptor 4 downstream signaling molecules contributes to the tight regulation of inflammatory cytokine synthesis in macrophages. Emerging evidence highlights the role of RNA-binding proteins (RBPs) in the post-transcriptional control of the innate immune response. To systematically identify macrophage RBPs and their response to LPS stimulation, we employed RNA interactome capture in LPS-induced and untreated murine RAW 264.7 macrophages. This combines RBP-crosslinking to RNA, cell lysis, oligo(dT) capture of polyadenylated RNAs and mass spectrometry analysis of associated proteins. Our data revealed 402 proteins of the macrophage RNA interactome including 91 previously not annotated as RBPs. A comparison with published RNA interactomes classified 32 RBPs uniquely identified in RAW 264.7 macrophages. Of these, 19 proteins are linked to biochemical activities not directly related to RNA. From this group, we validated the HSP90 cochaperone P23 that was demonstrated to exhibit cytosolic prostaglandin E2 synthase 3 (PTGES3) activity, and the hematopoietic cell-specific LYN substrate 1 (HCLS1 or HS1), a hematopoietic cell-specific adapter molecule, as novel macrophage RBPs. Our study expands the mammalian RBP repertoire, and identifies macrophage RBPs that respond to LPS. These RBPs are prime candidates for the post-transcriptional regulation and execution of LPS-induced signaling pathways and the innate immune response. Macrophage RBP data have been deposited to ProteomeXchange with identifier PXD002890.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Proteínas de Ligação a DNA/metabolismo , Macrófagos/metabolismo , Prostaglandina-E Sintases/metabolismo , Proteômica/métodos , Proteínas de Ligação a RNA/análise , Animais , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Lipopolissacarídeos/farmacologia , Macrófagos/efeitos dos fármacos , Camundongos , Mapas de Interação de Proteínas/efeitos dos fármacos , Células RAW 264.7 , RNA/metabolismo , Análise de Sequência de RNA/métodos
5.
Hepatology ; 64(5): 1667-1682, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27302828

RESUMO

Acetaminophen (APAP, paracetamol) poisoning is a leading cause of acute liver failure (ALF) in humans and induces hepatocyte necrosis, followed by activation of the innate immune system, further aggravating liver injury. The role of infiltrating monocytes during the early phase of ALF is still ambiguous. Upon experimental APAP overdose in mice, monocyte-derived macrophages (MoMFs) massively accumulated in injured liver within 12-24 hours, whereas the number of tissue-resident macrophages (Kupffer cells) decreased. Influx of MoMFs is dependent on the chemokine receptor, chemokine (C-C motif) receptor 2 (CCR2), given that Ccr2-/- mice display reduced infiltration of monocytes and attenuated liver injury post-APAP overdose at early time points. As evidenced by intravital multiphoton microscopy of Ccr2 reporter mice, CCR2+ monocytes infiltrate liver as early as 8-12 hours post-APAP overdose and form dense cellular clusters around necrotic areas. CCR2+ MoMFs express a distinct pattern of inflammatory, but also repair-associated, genes in injured livers. Adoptive transfer experiments revealed that MoMFs primarily exert proinflammatory functions early post-APAP, thereby aggravating liver injury. Consequently, early pharmacological inhibition of either chemokine (C-C motif) ligand (CCL2; by the inhibitor, mNOX-E36) or CCR2 (by the orally available dual CCR2/CCR5 inhibitor, cenicriviroc) reduces monocyte infiltration and APAP-induced liver injury (AILI) in mice. Importantly, neither the early nor continuous inhibition of CCR2 hinder repair processes during resolution from injury. In line with this, human livers of ALF patients requiring liver transplantation reveal increased CD68+ hepatic macrophage numbers with massive infiltrates of periportal CCR2+ macrophages that display a proinflammatory polarization. CONCLUSION: Infiltrating monocyte-derived macrophages aggravate APAP hepatotoxicity, and the pharmacological inhibition of either CCL2 or CCR2 might bear therapeutic potential by reducing the inflammatory reaction during the early phase of AILI. (Hepatology 2016;64:1667-1682).


Assuntos
Acetaminofen/efeitos adversos , Analgésicos não Narcóticos/efeitos adversos , Antipiréticos/efeitos adversos , Falência Hepática Aguda/induzido quimicamente , Receptores CCR2/fisiologia , Animais , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Monócitos/química , Receptores CCR2/análise , Índice de Gravidade de Doença
6.
Am J Physiol Gastrointest Liver Physiol ; 311(2): G203-9, 2016 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-27313175

RESUMO

The chemokine stromal cell-derived factor-1 (SDF-1) or CXCL12 is constitutively expressed in healthy liver. However, its expression increases following acute or chronic liver injury. Liver sinusoidal endothelial cells (LSEC), hepatic stellate cells (HSC), and malignant hepatocytes are important sources of SDF-1/CXCL12 in liver diseases. CXCL12 is able to activate two chemokine receptors with different downstream signaling pathways, CXCR4 and CXCR7. CXCR7 expression is relevant on LSEC, while HSC, mesenchymal stem cells, and tumor cells mainly respond via CXCR4. Here, we summarize recent developments in the field of liver diseases involving this chemokine and its receptors. SDF-1-dependent signaling contributes to modulating acute liver injury and subsequent tissue regeneration. By activating HSC and recruiting mesenchymal cells from bone marrow, CXCL12 can promote liver fibrosis progression, while CXCL12-CXCR7 interactions endorse proregenerative responses in chronic injury. Moreover, the SDF-1 pathway is linked to development of hepatocellular carcinoma (HCC) by promoting tumor growth, angiogenesis, and HCC metastasis. High hepatic CXCR4 expression has been suggested as a biomarker indicating poor prognosis of HCC patients. Tumor-infiltrating myeloid-derived suppressor cells (MDSC) also express CXCR4 and migrate toward CXCL12. Thus CXCL12 inhibition might not only directly block HCC growth but also modulate the tumor microenvironment (angiogenesis, MDSC), thereby sensitizing HCC patients to conventional or emerging novel cancer therapies (e.g., sorafenib, regorafenib, nivolumab, pembrolizumab). We herein summarize the current knowledge on the complex interplay between CXCL12 and CXCR4/CXCR7 in liver diseases and discuss approaches on the therapeutic targeting of these axes in hepatitis, fibrosis, and liver cancer.


Assuntos
Quimiocina CXCL12/metabolismo , Cirrose Hepática/metabolismo , Neoplasias Hepáticas/metabolismo , Fígado/metabolismo , Animais , Anti-Inflamatórios/uso terapêutico , Antineoplásicos/uso terapêutico , Quimiocina CXCL12/antagonistas & inibidores , Humanos , Fígado/efeitos dos fármacos , Fígado/lesões , Fígado/patologia , Cirrose Hepática/tratamento farmacológico , Cirrose Hepática/patologia , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/patologia , Terapia de Alvo Molecular , Receptores CXCR/metabolismo , Receptores CXCR4/metabolismo , Transdução de Sinais
7.
RNA ; 20(6): 899-911, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24751651

RESUMO

Macrophage activation by bacterial lipopolysaccharides (LPS) is induced through Toll-like receptor 4 (TLR4). The synthesis and activity of TLR4 downstream signaling molecules modulates the expression of pro- and anti-inflammatory cytokines. To address the impact of post-transcriptional regulation on that process, we performed RIP-Chip analysis. Differential association of mRNAs with heterogeneous nuclear ribonucleoprotein K (hnRNP K), an mRNA-specific translational regulator in differentiating hematopoietic cells, was studied in noninduced and LPS-activated macrophages. Analysis of interactions affected by LPS revealed several mRNAs encoding TLR4 downstream kinases and their modulators. We focused on transforming growth factor-ß-activated kinase 1 (TAK1) a central player in TLR4 signaling. HnRNP K interacts specifically with a sequence in the TAK1 mRNA 3' UTR in vitro. Silencing of hnRNP K does not affect TAK1 mRNA synthesis or stability but enhances TAK1 mRNA translation, resulting in elevated TNF-α, IL-1ß, and IL-10 mRNA expression. Our data suggest that the hnRNP K-3' UTR complex inhibits TAK1 mRNA translation in noninduced macrophages. LPS-dependent TLR4 activation abrogates translational repression and newly synthesized TAK1 boosts macrophage inflammatory response.


Assuntos
Ribonucleoproteínas Nucleares Heterogêneas Grupo K/genética , Lipopolissacarídeos/imunologia , MAP Quinase Quinase Quinases/genética , Ativação de Macrófagos/imunologia , Macrófagos/imunologia , Biossíntese de Proteínas/genética , RNA Mensageiro/genética , Regiões 3' não Traduzidas/genética , Regiões 3' não Traduzidas/imunologia , Animais , Linhagem Celular , Regulação da Expressão Gênica/genética , Regulação da Expressão Gênica/imunologia , Ribonucleoproteínas Nucleares Heterogêneas Grupo K/imunologia , Inflamação/genética , Inflamação/imunologia , Interleucina-10/genética , Interleucina-10/imunologia , Interleucina-1beta/genética , Interleucina-1beta/imunologia , MAP Quinase Quinase Quinases/imunologia , Ativação de Macrófagos/genética , Camundongos , Biossíntese de Proteínas/imunologia , Processamento Pós-Transcricional do RNA/genética , Processamento Pós-Transcricional do RNA/imunologia , RNA Mensageiro/imunologia , Transdução de Sinais/genética , Transdução de Sinais/imunologia , Receptor 4 Toll-Like/genética , Receptor 4 Toll-Like/imunologia , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/imunologia
8.
RNA Biol ; 13(1): 43-58, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26574931

RESUMO

To secure the functionality of activated macrophages in the innate immune response, efficient life span control is required. Recognition of bacterial lipopolysaccharides (LPS) by toll-like receptor 4 (TLR4) induces downstream signaling pathways, which merge to induce the expression of cytokine genes and anti-apoptotic genes. MicroRNAs (miRNAs) have emerged as important inflammatory response modulators, but information about their functional impact on apoptosis is scarce. To identify miRNAs differentially expressed in response to LPS, cDNA libraries from untreated and LPS-activated murine macrophages were analyzed by deep sequencing and regulated miRNA expression was verified by Northern blotting and qPCR. Employing TargetScan(TM) we identified CASPASE-3 (CASP-3) mRNA that encodes a key player in apoptosis as potential target of LPS-induced miR-155. LPS-dependent primary macrophage activation revealed TLR4-mediated enhancement of miR-155 expression and CASP-3 mRNA reduction. Endogenous CASP-3 and cleaved CASP-3 protein declined in LPS-activated macrophages. Accumulation of miR-155 and CASP-3 mRNA in miRNA-induced silencing complexes (miRISC) was demonstrated by ARGONAUTE 2 (AGO2) immunoprecipitation. Importantly, specific antagomir transfection effectively reduced mature miR-155 and resulted in significantly elevated CASP-3 mRNA levels in activated macrophages. In vitro translation assays demonstrated that the target site in the CASP-3 mRNA 3'UTR mediates miR-155-dependent Luciferase reporter mRNA destabilization. Strikingly, Annexin V staining of macrophages transfected with antagomir-155 and stimulated with LPS prior to staurosporine (SSP) treatment implied that LPS-induced miR-155 prevents apoptosis through CASP-3 mRNA down-regulation. In conclusion, we report that miR-155-mediated CASP-3 mRNA destabilization in LPS-activated RAW 264.7 macrophages suppresses apoptosis, as a prerequisite to maintain their crucial function in inflammation.


Assuntos
Caspase 3/genética , Lipopolissacarídeos/farmacologia , Macrófagos/efeitos dos fármacos , MicroRNAs/genética , RNA Mensageiro/metabolismo , Animais , Apoptose , Linhagem Celular , Regulação da Expressão Gênica/efeitos dos fármacos , Biblioteca Gênica , Macrófagos/citologia , Camundongos , MicroRNAs/metabolismo , Células RAW 264.7 , RNA Mensageiro/efeitos dos fármacos , Análise de Sequência de RNA , Receptor 4 Toll-Like/metabolismo
9.
Hepatol Commun ; 7(4)2023 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-36972392

RESUMO

BACKGROUND: Acute liver failure (ALF) is characterized by rapid clinical deterioration and high mortality. Acetaminophen (APAP or paracetamol) overdose is a leading cause of ALF, resulting in hepatocellular necrosis with subsequent inflammation, inflicting further liver damage. Infiltrating myeloid cells are early drivers of liver inflammation. However, the role of the abundant population of liver-resident innate lymphocytes, which commonly express the chemokine receptor CXCR6, is incompletely understood in ALF. METHODS: We investigated the role of CXCR6-expressing innate lymphocytes using the model of acute APAP toxicity in mice deficient in CXCR6 (Cxcr6gfp/gfp). RESULTS: APAP-induced liver injury was strongly aggravated in Cxcr6gfp/gfp mice compared with wild-type counterparts. Immunophenotyping using flow cytometry revealed a reduction in liver CD4+T cells, natural killer (NK) cells, and most prominently, NKT cells, whereas CXCR6 was dispensable for CD8+ T-cell accumulation. CXCR6-deficient mice exhibited excessive neutrophil and inflammatory macrophage infiltration. Intravital microscopy revealed dense cellular clusters of neutrophils in necrotic liver tissue, with higher numbers of clustering neutrophils in Cxcr6gfp/gfp mice. Gene expression analysis linked hyperinflammation in CXCR6 deficiency to increased IL-17 signaling. Although reduced in overall numbers, CXCR6-deficient mice had a shift in NKT cell subsets with increased RORγt-expressing NKT17 cells as a likely source of IL-17. In patients with ALF, we found a prominent accumulation of IL-17-expressing cells. Accordingly, CXCR6-deficient mice lacking IL-17 (Cxcr6gfp/gfpx Il17-/-) had ameliorated liver damage and reduced inflammatory myeloid infiltrates. CONCLUSIONS: Our study identifies a crucial role of CXCR6-expressing liver innate lymphocytes as orchestrators in acute liver injury containing IL-17-mediated myeloid cell infiltration. Hence, strengthening the CXCR6-axis or downstream inhibition of IL-17 could yield novel therapeutics in ALF.


Assuntos
Doença Hepática Induzida por Substâncias e Drogas , Interleucina-17 , Receptores CXCR6 , Animais , Camundongos , Acetaminofen/toxicidade , Inflamação , Células Matadoras Naturais , Receptores CXCR6/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/imunologia , Linfócitos T
10.
Sci Rep ; 10(1): 947, 2020 01 22.
Artigo em Inglês | MEDLINE | ID: mdl-31969629

RESUMO

Elective cardiac surgery has low procedural complications. However, about 40% of patients develop extracardiac complications including delirium and acute kidney injury. We hypothesized that inflammatory processes and immune cell activation might be associated with these complications. We therefore prospectively included 104 patients undergoing cardiac surgery in our study. We assessed peripheral blood leukocyte populations by flow cytometry and circulating cytokines before operation, after surgery and at days one and four post-operatively. Patients undergoing cardiac surgery showed significantly elevated leukocytes and neutrophils after surgery. On the contrary, monocytes decreased after surgery and significantly increased at days 1 and 4, particularly classical (Mon1,CD14++CD16-) and intermediate (Mon2,CD14++CD16+) monocytes. While peripheral leukocyte subsets were unaltered in patients with infectious (n = 15) or cardiac complications (n = 31), post-operative leukocytes (p = 0.0016), neutrophils (p = 0.0061) and Mon2 (p = 0.0007) were clearly raised in patients developing extracardiac complications (n = 35). Using multiple logistic regression analyses, patient's age, ICU days, number of blood transfusions and elevated post-surgery Mon2 independently predicted extracardiac complications. Our findings demonstrate that elevated Mon2 after cardiac surgery are associated with an increased risk for extracardiac complications. These findings might improve the risk estimation after cardiac operations and the role of Mon2 for inflammation in cardiac surgery.


Assuntos
Procedimentos Cirúrgicos Cardíacos/efeitos adversos , Contagem de Leucócitos , Receptores de Lipopolissacarídeos , Monócitos , Complicações Pós-Operatórias/etiologia , Receptores de IgG , Medição de Risco/métodos , Injúria Renal Aguda/etiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/sangue , Delírio/etiologia , Feminino , Citometria de Fluxo , Humanos , Masculino , Pessoa de Meia-Idade , Monócitos/imunologia , Risco , Adulto Jovem
11.
J Clin Med ; 9(1)2020 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-31906585

RESUMO

Critical illness and sepsis are characterized by drastic changes in the systemic innate immune response, particularly involving monocytes. The exact monocyte activation profile during sepsis, however, has remained obscure. Therefore, we prospectively analyzed the gene expression profile of circulating CD14+ monocytes from healthy volunteers (n = 54) and intensive care unit (ICU) patients (n = 76), of which n = 36 had sepsis. RNA sequencing of selected samples revealed that monocytes from septic ICU patients display a peculiar activation pattern, which resembles characteristic functional stages of monocyte-derived macrophages and is distinct from controls or non-sepsis ICU patients. Focusing on 55 highly variable genes selected for further investigation, arachidonate 5-lipoxygenase-activating protein (ALOX5AP) was highly upregulated in monocytes of ICU patients and only normalized during 7 days in the ICU in non-sepsis patients. Strikingly, low monocytic guanine nucleotide exchange factor 10-like protein (ARHGEF10L) mRNA expression was associated with the disease severity and mortality of ICU patients. Collectively, our comprehensive analysis of circulating monocytes in critically ill patients revealed a distinct activation pattern, particularly in ICU patients with sepsis. The association with disease severity, the longitudinal recovery or lack thereof during the ICU stay, and the association with prognosis indicate the clinical relevance of monocytic gene expression profiles during sepsis.

12.
Biochim Biophys Acta Mol Basis Dis ; 1865(2): 391-402, 2019 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-30476545

RESUMO

Chronic inflammation in the liver provokes fibrosis and, on long-term, carcinogenesis. This sequence is prototypically recapitulated in mice with hepatocyte-specific knock-out of the NF-κB essential modulator (NEMO), termed NEMOLPC-KO mice, in which increased hepatocyte apoptosis and compensatory regeneration cause steatosis, inflammation and fibrosis. Natural killer T (NKT) cells carrying the chemokine receptor CXCR6 participate in liver inflammation and injury responses. Here, we investigated the role of CXCR6 in the NEMOLPC-KO mouse model. Unexpectedly, genetic deletion of CXCR6 enhanced hepatocyte death, inflammation and fibrosis in NEMOLPC-KO mice. Although CXCR6 expression is restricted to immune cells in the liver, the adoptive transfer of CXCR6+ cells did not protect NEMOLPC-KOCxcr6-/- mice from hepatic injury. Gene array analyses revealed up-regulated stress response and metabolism pathways in hepatocytes from NEMOLPC-KOCxcr6-/- mice, functionally corresponding to an increased susceptibility of these hepatocytes to TNFα-induced cell death in vitro. These data revealed a novel CXCR6-dependent mechanism of suppressing inflammatory hepatocytic responses to cellular stress.


Assuntos
Fígado Gorduroso/metabolismo , Fígado Gorduroso/prevenção & controle , Inflamação/metabolismo , Inflamação/prevenção & controle , Peptídeos e Proteínas de Sinalização Intracelular/deficiência , Receptores CXCR6/metabolismo , Transferência Adotiva , Animais , Apoptose , Células Cultivadas , Citocromo P-450 CYP4A/metabolismo , Fígado Gorduroso/patologia , Hepatócitos/metabolismo , Hepatócitos/patologia , Inflamação/patologia , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Fígado/lesões , Fígado/metabolismo , Fígado/patologia , Masculino , Camundongos Knockout , Receptores CXCR6/deficiência , Estresse Fisiológico , Fator de Necrose Tumoral alfa/efeitos adversos , Regulação para Cima
13.
Cells ; 8(9)2019 09 18.
Artigo em Inglês | MEDLINE | ID: mdl-31540356

RESUMO

Recent evidence suggests that hepatic dendritic cells (HDCs) contribute to the evolution of chronic liver diseases. However, the HDC subsets involved and the mechanisms driving these responses are still poorly understood. In this study, we have investigated the role of the fractalkine receptor CX3CR1 in modulating monocyte-derived dendritic cell (moDC) differentiation during liver inflammation. The phenotype of HDC and functional relevance of CX3CR1 was assessed in mice following necro-inflammatory liver injury induced by the hepatotoxic agent carbon tetrachloride (CCl4) and in steatohepatitis caused by a methionine/choline-deficient (MCD) diet. In both the experimental models, hepatic inflammation was associated with a massive expansion of CD11c+/MHCIIhigh/CD11b+ myeloid HDCs. These cells also expressed the monocyte markers Ly6C, chemokine (C-C Motif) receptor 2 (CCR2), F4/80 and CD88, along with CX3CR1, allowing their tentative identification as moDCs. Mice defective in CX3CR1 showed a reduction in liver-moDC recruitment following CCl4 poisoning in parallel with a defective maturation of monocytes into moDCs. The lack of CX3CR1 also affected moDC differentiation from bone marrow myeloid cells induced by granulocyte-macrophage colony stimulating factor (GM-CSF) and interleukin-4 (IL-4) in vitro. In wild-type mice, treatment with the CX3CR1 antagonist CX3-AT (150 µg, i.p.) 24 h after CCl4 administration reduced liver moDCS and significantly ameliorated hepatic injury and inflammation. Altogether, these results highlight the possible involvement of moDCs in promoting hepatic inflammation following liver injury and indicated a novel role of CX3CL1/CX3CR1 dyad in driving the differentiation of hepatic moDCs.


Assuntos
Receptor 1 de Quimiocina CX3C/metabolismo , Células Dendríticas/química , Inflamação/metabolismo , Fígado/metabolismo , Monócitos/química , Animais , Receptor 1 de Quimiocina CX3C/antagonistas & inibidores , Tetracloreto de Carbono/administração & dosagem , Diferenciação Celular , Doença Hepática Induzida por Substâncias e Drogas , Células Dendríticas/metabolismo , Modelos Animais de Doenças , Inflamação/induzido quimicamente , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Monócitos/metabolismo
14.
Cell Mol Gastroenterol Hepatol ; 7(2): 371-390, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30704985

RESUMO

BACKGROUND & AIMS: Hepatocellular carcinoma (HCC) typically arises in fibrotic or cirrhotic livers, which are characterized by pathogenic angiogenesis. Myeloid immune cells, specifically tumor-associated macrophages (TAMs), may represent potential novel therapeutic targets in HCC, complementing current ablative or immune therapies. However, the detailed functions of TAM subsets in hepatocarcinogenesis have remained obscure. METHODS: TAM subsets were analyzed in-depth in human HCC samples and a combined fibrosis-HCC mouse model, established by i.p. injection with diethylnitrosamine after birth and repetitive carbon tetrachloride (CCl4) treatment for 16 weeks. Based on comprehensively phenotyping TAM subsets (fluorescence-activated cell sorter, transcriptomics) in mice, the function of CCR2+ TAM was assessed by a pharmacologic chemokine inhibitor. Angiogenesis was evaluated by contrast-enhanced micro-computed tomography and histology. RESULTS: We show that human CCR2+ TAM accumulate at the highly vascularized HCC border and express the inflammatory marker S100A9, whereas CD163+ immune-suppressive TAM accrue in the HCC center. In the fibrosis-cancer mouse model, we identified 3 major hepatic myeloid cell populations with distinct messenger RNA profiles, of which CCR2+ TAM particularly showed activated inflammatory and angiogenic pathways. Inhibiting CCR2+ TAM infiltration using a pharmacologic chemokine CCL2 antagonist in the fibrosis-HCC model significantly reduced pathogenic vascularization and hepatic blood volume, alongside attenuated tumor volume. CONCLUSIONS: The HCC microenvironment in human patients and mice is characterized by functionally distinct macrophage populations, of which the CCR2+ inflammatory TAM subset has pro-angiogenic properties. Understanding the functional differentiation of myeloid cell subsets in chronically inflamed liver may provide novel opportunities for modulating hepatic macrophages to inhibit tumor-promoting pathogenic angiogenesis.


Assuntos
Carcinoma Hepatocelular/irrigação sanguínea , Cirrose Hepática/patologia , Neoplasias Hepáticas/irrigação sanguínea , Macrófagos/patologia , Neovascularização Patológica/patologia , Receptores CCR2/metabolismo , Idoso , Animais , Carcinogênese/patologia , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patologia , Quimiocina CCL2/antagonistas & inibidores , Quimiocina CCL2/metabolismo , Estudos de Coortes , Modelos Animais de Doenças , Progressão da Doença , Células Endoteliais/patologia , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , Masculino , Camundongos Endogâmicos C57BL , Pessoa de Meia-Idade , Células Mieloides/metabolismo , Células Mieloides/patologia , Fenótipo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Carga Tumoral
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