scholarly journals The Role of CD147 in Leukocyte Aggregation in Liver Injury

2019 ◽  
Author(s):  
Christine Yee ◽  
Nathan Main ◽  
Alexandra Terry ◽  
Igor Stevanovski ◽  
Annette Maczurek ◽  
...  
Keyword(s):  
Liver Injury ◽  
Inflammatory Cell ◽  
Aggregate Formation ◽  
Liver Inflammation ◽  
Multicolor Flow Cytometry ◽  
Appreciable Increase ◽  
Aggregation Formation ◽  
Leukocyte Aggregation

AbstractBackgroundChronic inflammation is the driver of liver injury resulting in progressive fibrosis and eventual cirrhosis. The consequences include both liver failure and liver cancer. We have previously described increased expression of the highly multifunctional glycoprotein CD147 in liver injury. This work describes a novel role of CD147 in liver inflammation and the importance of leukocyte aggregates in determining the extent of liver injury.MethodsNon-diseased, progressive injury and cirrhotic liver from humans and mice were examined using mAb targeting CD147. Inflammatory cell subsets were assessed by multicolor flow cytometry.ResultsIn liver injury, we observe abundant intrahepatic leukocyte clusters defined as ≥5 adjacent CD45+cells which we have labelled “leukocyte aggregates”. We have shown that these leukocyte aggregates are significant in determining the extent of liver injury. If CD147 is blockedin vivo,these leukocyte aggregates diminish in size and number together with a marked significant reduction in liver injury including fibrosis. This accompanied by no change in overall intrahepatic leukocyte numbers. Further, blocking aggregation formation occurs prior to an appreciable increase in inflammatory markers or fibrosis. Additionally, there were no observed, “off-target” or unpredicted effects in targeting CD147.ConclusionCD147 mediates leukocyte aggregation which is associated with the development of liver injury. This is not a secondary effect, but a cause of injury as aggregate formation proceeds other markers of injury. Leukocyte aggregation has been previously described in inflammation dating back over many decades but till now been shown to determine the extent of injury.

scholarly journals Depdc5 deficiency exacerbates alcohol-induced hepatic steatosis via suppression of PPARα pathway

2021 ◽  
Vol 12 (7) ◽  
Author(s):  
Lin Xu ◽  
Xinge Zhang ◽  
Yue Xin ◽  
Jie Ma ◽  
Chenyan Yang ◽  
...  
Keyword(s):  
Liver Injury ◽  
Hepatic Steatosis ◽  
Liver Steatosis ◽  
Pharmacological Intervention ◽  
Acid Oxidation ◽  
Peroxisome Proliferator ◽  
Pathological Effect ◽  
Mtorc1 Pathway

AbstractAlcohol-related liver disease (ALD), a condition caused by alcohol overconsumption, occurs in three stages of liver injury including steatosis, hepatitis, and cirrhosis. DEP domain-containing protein 5 (DEPDC5), a component of GAP activities towards Rags 1 (GATOR1) complex, is a repressor of amino acid-sensing branch of the mammalian target of rapamycin complex 1 (mTORC1) pathway. In the current study, we found that aberrant activation of mTORC1 was likely attributed to the reduction of DEPDC5 in the livers of ethanol-fed mice or ALD patients. To further define the in vivo role of DEPDC5 in ALD development, we generated Depdc5 hepatocyte-specific knockout mouse model (Depdc5-LKO) in which mTORC1 pathway was constitutively activated through loss of the inhibitory effect of GATOR1. Hepatic Depdc5 ablation leads to mild hepatomegaly and liver injury and protects against diet-induced liver steatosis. In contrast, ethanol-fed Depdc5-LKO mice developed severe hepatic steatosis and inflammation. Pharmacological intervention with Torin 1 suppressed mTORC1 activity and remarkably ameliorated ethanol-induced hepatic steatosis and inflammation in both control and Depdc5-LKO mice. The pathological effect of sustained mTORC1 activity in ALD may be attributed to the suppression of peroxisome proliferator activated receptor α (PPARα), the master regulator of fatty acid oxidation in hepatocytes, because fenofibrate (PPARα agonist) treatment reverses ethanol-induced liver steatosis and inflammation in Depdc5-LKO mice. These findings provide novel insights into the in vivo role of hepatic DEPDC5 in the development of ALD.

scholarly journals Role of nitric oxide in hepatic microvascular injury elicited by acetaminophen in mice

2004 ◽  
Vol 286 (1) ◽  
pp. G60-G67 ◽  
Author(s):  
Yoshiya Ito ◽  
Edward R. Abril ◽  
Nancy W. Bethea ◽  
Robert S. McCuskey
Keyword(s):  
Nitric Oxide ◽  
Liver Injury ◽  
Cell Injury ◽  
Parenchymal Cell ◽  
Protective Role ◽  
Hepatic Expression ◽  
Inos Inhibitor ◽  
Microcirculatory Disturbances

Nitric oxide (NO) is suggested to play a role in liver injury elicited by acetaminophen (APAP). Hepatic microcirculatory dysfunction also is reported to contribute to the development of the injury. As a result, the role of NO in hepatic microcirculatory alterations in response to APAP was examined in mice by in vivo microscopy. A selective inducible NO synthase (iNOS) inhibitor,l- N6-(1-iminoethyl)-lysine (l-NIL), or a nonselective NOS inhibitor, NG-nitro-l-arginine methyl ester (l-NAME), was intraperitoneally administered to animals 10 min before APAP gavage. l-NIL suppressed raised alanine aminotransferase (ALT) values 6 h after APAP, whereas l-NAME increased those 1.7-fold. Increased ALT levels were associated with hepatic expression of iNOS. l-NIL, but not l-NAME, reduced the expression. APAP caused a reduction (20%) in the numbers of perfused sinusoids. l-NIL restored the sinusoidal perfusion, but l-NAME was ineffective. APAP increased the area occupied by infiltrated erythrocytes into the extrasinusoidal space. l-NIL tended to minimize this infiltration, whereas l-NAME further enhanced it. APAP caused an increase (1.5-fold) in Kupffer cell phagocytic activity. This activity in response to APAP was blunted by l-NIL, whereas l-NAME further elevated it. l-NIL suppressed APAP-induced decreases in hepatic glutathione levels. These results suggest that NO derived from iNOS contributes to APAP-induced parenchymal cell injury and hepatic microcirculatory disturbances. l-NIL exerts preventive effects on the liver injury partly by inhibiting APAP bioactivation. In contrast, NO derived from constitutive isoforms of NOS exerts a protective role in liver microcirculation against APAP intoxication and thereby minimizes liver injury.

scholarly journals Molecular Mechanisms of Liver Injury and Hepatocarcinogenesis: Focusing on the Role of Stress-Activated MAPK

2012 ◽  
Vol 2012 ◽  
pp. 1-14 ◽  
Author(s):  
Hayato Nakagawa ◽  
Shin Maeda
Keyword(s):  
Liver Injury ◽  
Molecular Mechanisms ◽  
Mapk Pathway ◽  
Mitogen Activated Protein Kinase ◽  
Cellular Effects ◽  
Wide Range ◽  
Mitogen Activated Protein ◽  
Compensatory Proliferation

Hepatocellular carcinoma (HCC) is the third most common cause of cancer mortality. Short-term prognosis of patients with HCC has improved recently due to advances in early diagnosis and treatment, but long-term prognosis is still unsatisfactory. Therefore, obtaining a further understanding of the molecular carcinogenic mechanisms and the unique pathogenic biology of HCC is important. The most characteristic process in hepatocarcinogenesis is underlying chronic liver injury, which leads to repeated cycles of hepatocyte death, inflammation, and compensatory proliferation and subsequently provides a mitogenic and mutagenic environment leading to the development of HCC. Recent in vivo studies have shown that the stress-activated mitogen-activated protein kinase (MAPK) cascade converging on c-Jun NH2-terminal kinase (JNK) and p38 plays a central role in these processes, and it has attracted considerable attention as a therapeutic target. However, JNK and p38 have complex functions and a wide range of cellular effects. In addition, crosstalk with each other and the nuclear factor-kappaB pathway further complicate these functions. A full understanding is essential to bring these observations into clinical settings. In this paper, we discuss the latest findings regarding the mechanisms of liver injury and hepatocarcinogenesis focusing on the role of the stress-activated MAPK pathway.

scholarly journals Role of interleukin-18 in intrahepatic inflammatory cell recruitment in acute liver injury

2010 ◽  
Vol 89 (3) ◽  
pp. 433-442 ◽  
Author(s):  
Kiminori Kimura ◽  
Satoshi Sekiguchi ◽  
Seishu Hayashi ◽  
Yukiko Hayashi ◽  
Tsunekazu Hishima ◽  
...  
Keyword(s):  
Liver Injury ◽  
Inflammatory Cell ◽  
Acute Liver Injury ◽  
Interleukin 18 ◽  
Cell Recruitment ◽  
Inflammatory Cell Recruitment

scholarly journals Cofilin loss in Drosophila contributes to myopathy through defective sarcomerogenesis and aggregate formation during muscle growth

2019 ◽  
Author(s):  
Mridula Balakrishnan ◽  
Shannon F. Yu ◽  
Samantha M. Chin ◽  
David B. Soffar ◽  
Stefanie E. Windner ◽  
...  
Keyword(s):  
Point Mutation ◽  
Muscle Function ◽  
Muscle Growth ◽  
Nemaline Myopathy ◽  
Aggregate Formation ◽  
Thin Filaments ◽  
Sarcomeric Protein ◽  
Thick Filaments

SUMMARYSarcomeres, the fundamental contractile units of muscles, are conserved structures composed of actin thin filaments and myosin thick filaments. How sarcomeres are formed and maintained is not well understood. Here, we show that knockdown of Drosophila Cofilin (DmCFL), an actin depolymerizing factor, leads to the progressive disruption of sarcomere structure and muscle function in vivo. Loss of DmCFL also results in the formation of sarcomeric protein aggregates and impairs sarcomere addition during growth. Strikingly, activation of the proteasome delayed muscle deterioration in our model. Further, we investigate how a point mutation in CFL2 that causes nemaline myopathy (NM) in humans, affects CFL function and leads to the muscle phenotypes observed in vivo. Our data provide significant insights to the role of CFLs during sarcomere formation as well as mechanistic implications for disease progression in NM patients.

scholarly journals Aggravated Liver Injury but Attenuated Inflammation in PTPRO-Deficient Mice Following LPS/D-GaIN Induced Fulminant Hepatitis

2015 ◽  
Vol 37 (1) ◽  
pp. 214-224 ◽  
Author(s):  
Xiaochen Wang ◽  
Shushan Yan ◽  
Donghua Xu ◽  
Jun Li ◽  
Yu Xie ◽  
...  
Keyword(s):  
Liver Injury ◽  
Fulminant Hepatitis ◽  
Feedback Regulation ◽  
Adaptive Immune ◽  
Hepatic Cells ◽  
Ifn Γ ◽  
Deficient Mice

Background/Aims: Critical roles of PTPRO and TLR4 have been implicated in hepatocellular carcinoma. However, little is known about their modifying effects on inflammation-related diseases in liver, particularly fulminant hepatitis (FH). We aim to investigate the potential role of PTPRO and its interaction with TLR4 in LPS/D-GaIN induced FH. Methods: A LPS/D-GaIN induced mouse FH model was used. RAW264.7 cells were transfected with PTPRO over-expressed lentiviral plasmids for further investigation. Results: The mortality of PTPRO KO mice is higher than WT mice after LPS/D-GaIN administration. Aggravated liver injury was demonstrated by increased level of serous ALT and AST and numerous hepatic cells death in PTPRO KO mice following LPS/D-GaIN administration. Interestingly, inflammation was attenuated in PTPRO-deficient mice following LPS/D-GaIN administration, which was suggested by decreased inflammatory cytokines (TNF-a, IFN-γ, IL-1ß, IL-6, IL-17A and IL-12) and cells infiltrating into spleen (CD3+IFN-γ+ cells, CD3+TNF-a+ cells, F4/80+/TLR4+ cells). A feedback regulation between PTPRO and TLR4 dependent on NF-γB signaling pathway was demonstrated in vivo and in vitro. Conclusion: PTPRO plays an important role in FH by interacting with TLR4. The crosstalk between PTPRO and TLR4 is a novel bridge linking innate immune and adaptive immune in acute liver injury.

scholarly journals The protein tyrosine kinase SYK regulates the alternative p38 activation in liver during acute liver inflammation

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Bo-Ram Bang ◽  
Kyung Ho Han ◽  
Goo-Young Seo ◽  
Michael Croft ◽  
Young Jun Kang
Keyword(s):  
Cell Death ◽  
Liver Injury ◽  
Host Defense ◽  
Protein Tyrosine Kinase ◽  
Inflammatory Responses ◽  
Acute Liver Injury ◽  
Critical Role ◽  
Liver Inflammation ◽  
Hepatocyte Death

AbstractTwo distinct p38 signaling pathways, classical and alternative, have been identified to regulate inflammatory responses in host defense and disease development. The role of alternative p38 activation in liver inflammation is elusive, while classical p38 signaling in hepatocytes plays a role in regulating the induction of cell death in autoimmune-mediated acute liver injury. In this study, we found that a mutation of alternative p38 in mice augmented the severity of acute liver inflammation. Moreover, TNF-induced hepatocyte death was augmented by a mutation of alternative p38, suggesting that alternative p38 signaling in hepatocytes contributed more significantly to the pathology of acute liver injury. Furthermore, SYK-Vav-1 signaling regulates alternative p38 activation and the downregulation of cell death in hepatocytes. Therefore, it is suggested that alternative p38 signaling in the liver plays a critical role in the induction and subsequent pathological changes of acute liver injury. Collectively, our results imply that p38 signaling in hepatocytes plays a crucial role to prevent excessive liver injury by regulating the induction of cell death and inflammation.

scholarly journals Myeloid Differentiation Protein 2 Mediates Angiotensin II-Induced Liver Inflammation and Fibrosis in Mice

Molecules ◽  
2019 ◽  
Vol 25 (1) ◽  
pp. 25 ◽  
Author(s):  
Yi Zhang ◽  
Hui Liu ◽  
Wenjing Jia ◽  
Jiayu Qi ◽  
Wentao Zhang ◽  
...  
Keyword(s):  
Angiotensin Ii ◽  
Liver Injury ◽  
Critical Role ◽  
Myeloid Differentiation ◽  
Ang Ii ◽  
Liver Inflammation ◽  
Protein Levels ◽  
Extracellular Signal ◽  
Injury Model

Angiotensin II (Ang II) participates in the pathogenesis of liver injury. Our previous publications reported that myeloid differentiation protein 2 (MD2) mediates Ang II-induced cardiac and kidney inflammation by directly binding to Ang II. Thus, we hypothesize that MD2 is critical to Ang II-induced liver injury. Subcutaneous injections of Ang II for 8 weeks were adopted to build the liver injury model. With a specific MD2 inhibitor L6H21 and MD2 knockout mice, we reported that MD2 inhibition and knockout significantly mitigate liver inflammation and fibrosis in mice injected with Ang II. To be more specific, the functional and pathological damages induced by Ang II were mitigated by L6H21 or MD2 knockout. MD2 knockout or L6H21 administration inhibited the Ang II-induced upregulation of fibrosis markers, inflammatory cytokines, and adhesion molecules in gene or protein levels. The activation of NF-κB and Extracellular signal-regulated kinases (ERK) induced by Ang II was also reversed by L6H21 treatment or MD2 deficiency. Note that the co-immunoprecipitation study showed that L6H21 downregulated the ANG II-induced toll-like receptor 4 (TLR4)/MD2 complex in liver tissues while having no effects on MD2 expression. Our results reported the critical role of MD2 in the progress of liver injury and suggested that MD2 is a potential therapeutic target for liver injury.

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