Abstract
Background & Aims: Hepatic recruitment of monocyte-derived macrophages (MoMFs) contributes to the inflammatory response in non-alcoholic steatohepatitis (NASH). However, how hepatocyte lipotoxicity promotes MoMF inflammation is unclear. Here we demonstrate that lipotoxic hepatocyte-derived extracellular vesicles (LPC-EVs) are enriched with active integrin β1 (ITGβ1), which promotes monocyte adhesion and liver inflammation in murine NASH. Methods: Hepatocytes were treated with either vehicle or the toxic lipid mediator lysophosphatidylcholine (LPC); EVs were isolated from the conditioned media and subjected to proteomic analysis. C57BL/6J mice were fed a diet rich in fat, fructose, and cholesterol (FFC) to induce NASH. Mice were treated with anti-ITGβ1 neutralizing antibody (ITGβ1Ab) or control IgG isotype. Results: Ingenuity® Pathway Analysis of the LPC-EV proteome indicated that ITG signaling is an overrepresented canonical pathway. Immunogold electron microscopy and nanoscale flow cytometry confirmed that LPC-EVs were enriched with activated ITGβ1. Furthermore, we showed that LPC treatment in hepatocytes activates ITGβ1 and mediates its endocytic trafficking and sorting into EVs. LPC-EVs enhanced monocyte adhesion to liver sinusoidal cells, as observed by shear stress adhesion assay. This adhesion was attenuated in the presence of ITGβ1Ab. FFC-fed, ITGβ1Ab-treated mice displayed reduced inflammation, defined by decreased hepatic infiltration and activation of proinflammatory MoMFs, as assessed by immunohistochemistry, mRNA expression, and flow cytometry. Likewise, mass cytometry by time-of-flight on intrahepatic leukocytes showed that ITGβ1Ab reduced levels of infiltrating proinflammatory monocytes. Furthermore, ITGβ1Ab treatment significantly ameliorated liver injury and fibrosis. Conclusions: Lipotoxic EVs mediate monocyte adhesion to LSECs mainly through an ITGβ1-dependent mechanism. ITGβ1Ab ameliorates diet-induced NASH in mice by reducing MoMF-driven inflammation, suggesting that blocking ITGβ1 is a potential anti-inflammatory therapeutic strategy in human NASH. Lay summary: Herein, we report that a cell adhesion molecule termed integrin β1 (ITGβ1) plays a key role in the progression of non-alcoholic steatohepatitis (NASH). ITGβ1 is released from hepatocytes under lipotoxic stress as a cargo of extracellular vesicles, and mediates monocyte adhesion to liver sinusoidal endothelial cells, which is an essential step in hepatic inflammation. In a mouse model of NASH, blocking ITGβ1 reduces liver inflammation, injury and fibrosis. Hence, ITGβ1 inhibition may serve as a new therapeutic strategy for NASH.
| Original language | English (US) |
|---|---|
| Journal | Journal of hepatology |
| DOIs | |
| State | Accepted/In press - Jan 1 2019 |
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Keywords
- Adhesion
- Extracellular vesicles
- Fibrosis
- Inflammation
- Integrin α
- Integrin β
- Liver sinusoidal endothelial cells
- Mass cytometry
- Monocytes
- NASH
ASJC Scopus subject areas
- Hepatology
Cite this
Integrin β1-enriched extracellular vesicles mediate monocyte adhesion and promote liver inflammation in murine NASH. / Guo, Qianqian; Furuta, Kunimaro; Lucien, Fabrice; Gutierrez Sanchez, Luz Helena; Hirsova, Petra; Krishnan, Anuradha; Kabashima, Ayano; Pavelko, Kevin D.; Madden, Benjamin; Alhuwaish, Husam; Gao, Yandong; Revzin, Alexander; Ibrahim, Samar H.
In: Journal of hepatology, 01.01.2019.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Integrin β1-enriched extracellular vesicles mediate monocyte adhesion and promote liver inflammation in murine NASH
AU - Guo, Qianqian
AU - Furuta, Kunimaro
AU - Lucien, Fabrice
AU - Gutierrez Sanchez, Luz Helena
AU - Hirsova, Petra
AU - Krishnan, Anuradha
AU - Kabashima, Ayano
AU - Pavelko, Kevin D.
AU - Madden, Benjamin
AU - Alhuwaish, Husam
AU - Gao, Yandong
AU - Revzin, Alexander
AU - Ibrahim, Samar H.
PY - 2019/1/1
Y1 - 2019/1/1
N2 - Background & Aims: Hepatic recruitment of monocyte-derived macrophages (MoMFs) contributes to the inflammatory response in non-alcoholic steatohepatitis (NASH). However, how hepatocyte lipotoxicity promotes MoMF inflammation is unclear. Here we demonstrate that lipotoxic hepatocyte-derived extracellular vesicles (LPC-EVs) are enriched with active integrin β1 (ITGβ1), which promotes monocyte adhesion and liver inflammation in murine NASH. Methods: Hepatocytes were treated with either vehicle or the toxic lipid mediator lysophosphatidylcholine (LPC); EVs were isolated from the conditioned media and subjected to proteomic analysis. C57BL/6J mice were fed a diet rich in fat, fructose, and cholesterol (FFC) to induce NASH. Mice were treated with anti-ITGβ1 neutralizing antibody (ITGβ1Ab) or control IgG isotype. Results: Ingenuity® Pathway Analysis of the LPC-EV proteome indicated that ITG signaling is an overrepresented canonical pathway. Immunogold electron microscopy and nanoscale flow cytometry confirmed that LPC-EVs were enriched with activated ITGβ1. Furthermore, we showed that LPC treatment in hepatocytes activates ITGβ1 and mediates its endocytic trafficking and sorting into EVs. LPC-EVs enhanced monocyte adhesion to liver sinusoidal cells, as observed by shear stress adhesion assay. This adhesion was attenuated in the presence of ITGβ1Ab. FFC-fed, ITGβ1Ab-treated mice displayed reduced inflammation, defined by decreased hepatic infiltration and activation of proinflammatory MoMFs, as assessed by immunohistochemistry, mRNA expression, and flow cytometry. Likewise, mass cytometry by time-of-flight on intrahepatic leukocytes showed that ITGβ1Ab reduced levels of infiltrating proinflammatory monocytes. Furthermore, ITGβ1Ab treatment significantly ameliorated liver injury and fibrosis. Conclusions: Lipotoxic EVs mediate monocyte adhesion to LSECs mainly through an ITGβ1-dependent mechanism. ITGβ1Ab ameliorates diet-induced NASH in mice by reducing MoMF-driven inflammation, suggesting that blocking ITGβ1 is a potential anti-inflammatory therapeutic strategy in human NASH. Lay summary: Herein, we report that a cell adhesion molecule termed integrin β1 (ITGβ1) plays a key role in the progression of non-alcoholic steatohepatitis (NASH). ITGβ1 is released from hepatocytes under lipotoxic stress as a cargo of extracellular vesicles, and mediates monocyte adhesion to liver sinusoidal endothelial cells, which is an essential step in hepatic inflammation. In a mouse model of NASH, blocking ITGβ1 reduces liver inflammation, injury and fibrosis. Hence, ITGβ1 inhibition may serve as a new therapeutic strategy for NASH.
AB - Background & Aims: Hepatic recruitment of monocyte-derived macrophages (MoMFs) contributes to the inflammatory response in non-alcoholic steatohepatitis (NASH). However, how hepatocyte lipotoxicity promotes MoMF inflammation is unclear. Here we demonstrate that lipotoxic hepatocyte-derived extracellular vesicles (LPC-EVs) are enriched with active integrin β1 (ITGβ1), which promotes monocyte adhesion and liver inflammation in murine NASH. Methods: Hepatocytes were treated with either vehicle or the toxic lipid mediator lysophosphatidylcholine (LPC); EVs were isolated from the conditioned media and subjected to proteomic analysis. C57BL/6J mice were fed a diet rich in fat, fructose, and cholesterol (FFC) to induce NASH. Mice were treated with anti-ITGβ1 neutralizing antibody (ITGβ1Ab) or control IgG isotype. Results: Ingenuity® Pathway Analysis of the LPC-EV proteome indicated that ITG signaling is an overrepresented canonical pathway. Immunogold electron microscopy and nanoscale flow cytometry confirmed that LPC-EVs were enriched with activated ITGβ1. Furthermore, we showed that LPC treatment in hepatocytes activates ITGβ1 and mediates its endocytic trafficking and sorting into EVs. LPC-EVs enhanced monocyte adhesion to liver sinusoidal cells, as observed by shear stress adhesion assay. This adhesion was attenuated in the presence of ITGβ1Ab. FFC-fed, ITGβ1Ab-treated mice displayed reduced inflammation, defined by decreased hepatic infiltration and activation of proinflammatory MoMFs, as assessed by immunohistochemistry, mRNA expression, and flow cytometry. Likewise, mass cytometry by time-of-flight on intrahepatic leukocytes showed that ITGβ1Ab reduced levels of infiltrating proinflammatory monocytes. Furthermore, ITGβ1Ab treatment significantly ameliorated liver injury and fibrosis. Conclusions: Lipotoxic EVs mediate monocyte adhesion to LSECs mainly through an ITGβ1-dependent mechanism. ITGβ1Ab ameliorates diet-induced NASH in mice by reducing MoMF-driven inflammation, suggesting that blocking ITGβ1 is a potential anti-inflammatory therapeutic strategy in human NASH. Lay summary: Herein, we report that a cell adhesion molecule termed integrin β1 (ITGβ1) plays a key role in the progression of non-alcoholic steatohepatitis (NASH). ITGβ1 is released from hepatocytes under lipotoxic stress as a cargo of extracellular vesicles, and mediates monocyte adhesion to liver sinusoidal endothelial cells, which is an essential step in hepatic inflammation. In a mouse model of NASH, blocking ITGβ1 reduces liver inflammation, injury and fibrosis. Hence, ITGβ1 inhibition may serve as a new therapeutic strategy for NASH.
KW - Adhesion
KW - Extracellular vesicles
KW - Fibrosis
KW - Inflammation
KW - Integrin α
KW - Integrin β
KW - Liver sinusoidal endothelial cells
KW - Mass cytometry
KW - Monocytes
KW - NASH
UR - http://www.scopus.com/inward/record.url?scp=85073027735&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85073027735&partnerID=8YFLogxK
U2 - 10.1016/j.jhep.2019.07.019
DO - 10.1016/j.jhep.2019.07.019
M3 - Article
C2 - 31433301
AN - SCOPUS:85073027735
JO - Journal of Hepatology
JF - Journal of Hepatology
SN - 0168-8278
ER -