scholarly journals S100A6 Promotes Inflammation and Infiltration of Mononuclear/Macrophages via the p-P38 and p-JNK Pathways in Acute Liver Injury

2021 ◽  
Author(s):  
He Tong ◽  
Li Wang ◽  
Kefan Zhang ◽  
Jing Shi ◽  
yongshuai Wu ◽  
...  
Keyword(s):  
Liver Injury ◽  
Inflammatory Response ◽  
Inflammatory Responses ◽  
Acute Liver Injury ◽  
S100 Protein ◽  
Inflammatory Cells ◽  
Liver Cells ◽  
Danger Signal ◽  
Tnf Α

Abstract BackgroundThe phagocytic S100 protein, which mediates inflammatory responses and recruits inflammatory cells to sites of tissue damage, has long been known to be expressed in cells of myeloid origin. S100A6 belongs to the A group of the S100 protein family of Ca2+-binding proteins. Currently, the mechanism by which S100A6 mediates the inflammatory response and recruits inflammatory cells to the tissue injury site is unknown.MethodsA mouse model of carbon tetrachloride (CCl4)-induced acute liver injury (ALI) was established, and the transcriptomes of postinjury 2d and 5d liver tissues were sequenced. Enzyme-linked immunosorbent assay was used to determine the expression of inflammatory factors (TNF-α, IL-1β, IL-6, and IL-8) in the supernatant of the liver. Immunohistochemical analysis confirmed the expression of S100A6 in the liver cells. In vitro experiments proved the pro-inflammatory function of S100A6, and western blotting (WB) showed that the pathways were activated. The transwell experiment showed the infiltration of mononuclear/macrophages.ResultsWe found that S100A6 is highly expressed in liver cells during the most severe period of ALI, suggesting that it acts as an endogenous danger signal and has a pro-inflammatory function. In vitro, the mouse S100A6 recombinant protein was used to stimulate liver Kupffer cells to promote the secretion of TNF-α, IL-1β, IL-6, and IL-8. Further mechanistic experiments revealed that S100A6 acts as an endogenous danger signal to activate p-P38 and p-JNK downstream of the TLR4 and P65 pathways. Similarly, transcriptome data showed that S100A6 can activate the inflammatory response in Kuffer cells. WB revealed that S100A6 had no significant effect on cell apoptosis. To continue to explore the mechanism of monocyte/macrophage infiltration, we found that TNF-α stimulates liver cells as the main source of CCL2. TNF-α can initiate the p-P38 and p-JNK pathways of liver cells to produce CCL2, thereby recruiting the infiltration of mononuclear/macrophages. ConclusionsTaken together, S100A6 is an endogenous danger signal that mediates inflammatory responses and recruits inflammatory cells to sites of tissue damage.

scholarly journals Modulation of Immune Complex–induced Inflammation In Vivo by the Coordinate Expression of Activation and Inhibitory Fc Receptors

1999 ◽  
Vol 189 (1) ◽  
pp. 179-186 ◽  
Author(s):  
Raphael Clynes ◽  
Jay S. Maizes ◽  
Rodolphe Guinamard ◽  
Masao Ono ◽  
Toshiyuki Takai ◽  
...  
Keyword(s):  
Inflammatory Response ◽  
Immune Complexes ◽  
Inflammatory Responses ◽  
Fc Receptors ◽  
Inflammatory Cells ◽  
Neutrophil Infiltration ◽  
Calcium Flux ◽  
Deficient Mice

Autoantibodies and immune complexes are major pathogenic factors in autoimmune injury, responsible for initiation of the inflammatory cascade and its resulting tissue damage. This activation results from the interaction of immunoglobulin (Ig)G Fc receptors containing an activation motif (ITAM) with immune complexes (ICs) and cytotoxic autoantibodies which initiates and propagates an inflammatory response. In vitro, this pathway can be interrupted by coligation to FcγRIIB, an IgG Fc receptor containing an inhibitory motif (ITIM). In this report, we describe the in vivo consequences of FcγRII deficiency in the inflammatory response using a mouse model of IC alveolitis. At subthreshold concentrations of ICs that fail to elicit inflammatory responses in wild-type mice, FcγRII-deficient mice developed robust inflammatory responses characterized by increased hemorrhage, edema, and neutrophil infiltration. Bronchoalveolar fluids from FcγRII−/− stimulated mice contain higher levels of tumor necrosis factor and chemotactic activity, suggesting that FcγRII deficiency lowers the threshold of IC stimulation of resident cells such as the alveolar macrophage. In contrast, complement- and complement receptor–deficient mice develop normal inflammatory responses to suprathreshold levels of ICs, while FcRγ−/− mice are completely protected from inflammatory injury. An inhibitory role for FcγRII on macrophages is demonstrated by analysis of FcγRII−/− macrophages which show greater phagocytic and calcium flux responses upon FcγRIII engagement. These data reveal contrasting roles for the cellular receptors for IgG on inflammatory cells, providing a regulatory mechanism for setting thresholds for IC sensitivity based on the ratio of ITIM to ITAM FcγR expression. Exploiting the FcγRII inhibitory pathway could thus provide a new therapeutic approach for modulating antibody-triggered inflammation.

scholarly journals The Role of Inflammation in the Mechanisms of Bile Acid-Induced Liver Damage

2017 ◽  
Vol 35 (3) ◽  
pp. 232-234 ◽  
Author(s):  
Shi-Ying Cai ◽  
James L. Boyer
Keyword(s):  
Bile Acid ◽  
Liver Injury ◽  
Inflammatory Response ◽  
Bile Acids ◽  
Liver Damage ◽  
Inflammatory Cytokine ◽  
Early Time ◽  
Liver Cells ◽  
Wild Type Littermate

Background: The mechanism by which bile acids induce liver injury in cholestasis remains controversial. Although high levels of bile acids are toxic when applied to liver cells, the level of toxic bile acids in the liver of most cholestatic animals and patients is <10 μM, indicating there must be alternative mechanisms. Recent studies suggest that the inflammatory response may play an important role in bile acid-induced liver injury, as pro-inflammatory cytokine expression is stimulated by bile acids in mouse hepatocyte cultures. To elucidate the mechanisms of bile acid-induced liver injury, we assessed signs of liver damage and gene expression in Abcb4-/- mice, a well-known model for cholestasis. Key Messages: Elevated plasma levels of bile acids were detected as early as 10 days after birth and at all later ages in Abcb4-/- mice compared to their wild-type littermate controls. Parallel increases in expression of Tnfα, Ccl2, Cxcl1, and Cxcl2 mRNA occurred at these early time points and throughout 12 weeks in Abcb4-/- livers. Marked hepatic neutrophil infiltration was first detected in 3-week mice, whereas histological evidence of liver injury was not detected until 6-weeks of age. Subsequent in vitro studies demonstrated that normal hepatocytes but not other non-parenchymal liver cells responded to bile acids with inflammatory cytokine induction. Conclusion: Bile acids induce the expression of pro-inflammatory cytokines in hepatocytes in Abcb4-/- mice that initiates an inflammatory response. This inflammatory response plays an important role in the development of cholestatic liver injury in this and other cholestatic conditions. Furthermore, understanding of these inflammatory mechanisms should lead to new therapeutic approaches for cholestatic liver diseases.

scholarly journals TNF-alpha but not IL-1alpha are Correlated with PGE1-Dependent Protection Against Acute D-Galactosamine-Induced Liver Injury

2000 ◽  
Vol 14 (3) ◽  
pp. 175-180 ◽  
Author(s):  
J Muntané ◽  
JL Montero ◽  
JM Lozano ◽  
A Miranda-Vizuete ◽  
M de la Mata ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Liver Injury ◽  
Acute Liver Injury ◽  
Experimental Studies ◽  
Acute Hepatic Failure ◽  
Inflammatory Cells ◽  
Control Group ◽  
Prostaglandin E ◽  
Necrosis Factor Alpha ◽  
Tnf Α

BACKGROUND: Prostaglandin E1(PGE1) treatment of humans and rodents during acute hepatic failure ameliorates different parameters of hepatic dysfunction.PURPOSE: To investigate whether prevention of acute liver injury induced by D-galactosamine (D-GalN) with preadministration of PGE1is correlated with a change in the concentration of two proinflammatory cytokines, as tumour necrosis factor-alpha (TNF-α) and interleukin (IL)-1α, and/or nitrite+nitrate (NOx), as nitric oxide-related end products in serum.RESULTS: D-GalN significantly increased alanine aminotransferase (ALT) and TNF- αconcentration in serum 5 and 10 mins, respectively, after treatment compared with the control group (P&#8804;0.05). D-GalN did not change the IL-1α concentration at any time during the study. Preadministration of PGE1to D-GalN-treated rats significantly reduced the ALT content and increased significantly the TNF-α concentration in serum 1, 2.5, 5 and 10 mins after D-GalN treatment compared with the D-GalN group (P&#8804;0.05). Nitric oxide was not involved in either the toxic effect due to D-GalN or the protection observed with PGE1against D-GalN toxicity.CONCLUSIONS: Acute liver injury induced by D-GalN is correlated with an increased TNF-α release. Preadministration of PGE1to D-GalN-treated rats exerted a priming effect on inflammatory cells to release enhanced levels of TNF-α but not IL-1α. These findings indicate that stimulation of TNF-α release may be involved in the acute D-GalN-induced liver injury and also in PGE1protection from hepatotoxicity in clinical and experimental studies.

scholarly journals IL-22 ameliorates LPS-induced acute liver injury by autophagy activation through ATF4-ATG7 signaling

2020 ◽  
Vol 11 (11) ◽  
Author(s):  
Lujing Shao ◽  
Xi Xiong ◽  
Yucai Zhang ◽  
Huijie Miao ◽  
Yuqian Ren ◽  
...  
Keyword(s):  
Liver Injury ◽  
Inflammatory Responses ◽  
Acute Liver Injury ◽  
Mrna Levels ◽  
Protective Effects ◽  
Activating Transcription Factor 4 ◽  
Pre Treatment ◽  
Underlying Mechanisms

Abstract Uncontrollable inflammatory response acts as a driver of sepsis-associated liver injury (SALI). IL-22 plays an important role in regulating inflammatory responses, but its role in SALI remains unknown. The aim of the study was to assess the association of serum IL-22 with SALI in pediatric patients and to enclose the underlying mechanisms of IL-22 involved in lipopolysaccharide (LPS) - induced acute liver injury (ALI) in mice. Serum IL-22 levels in patients with SALI were significantly lower than in septic patients without liver injury, and the area under receiver operating characteristic (ROC) curve of IL-22 for discriminating SALI was 0.765 (95% CI: 0.593–0.937). Pre-administration of recombinant murine IL-22 alleviated LPS-induced ALI in mice, and serum IL-6 levels and the mRNA levels of TNF-α, IL-1β, and IL-6 in livers were decreased in response to IL-22 pre-treatment in mice. More importantly, IL-22 pre-treatment activated hepatic autophagy mediated by activating transcription factor 4 (ATF4)-autophagy-related gene 7 (ATG7) signaling in vivo and in vitro in response to LPS administration. Moreover, knockdown of ATF4 in mice aggravated LPS-induced ALI, which was associated with suppressed ATG7-related autophagy. In addition, the protective effects of IL-22 on LPS-induced ALI was partially blocked by ATF4 knockdown, which was associated with lower expression of LC3II/I in the livers of ATF4 knockdown (HT or Atf4+/−) mice compared with wild-type mice (WT or Atf4+/+) mice. In conclusion, low serum IL-22 level is associated with SALI occurrence, and IL-22 pre-administration activates autophagy in hepatocytes and protects mice against LPS-induced ALI partially related to ATF4-ATG7 signaling pathway.

scholarly journals Inflammatory Responses in Oro-Maxillofacial Region Expanded Using Anisotropic Hydrogel Tissue Expander

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4436
Author(s):  
Kholoud Mohamed Ali Salim ◽  
Aminah Abd Jalil ◽  
Zamri Radzi ◽  
Siti Mazlipah Ismail ◽  
Jan T. Czernuszka ◽  
...  
Keyword(s):  
Inflammatory Response ◽  
Inflammatory Responses ◽  
Tissue Expander ◽  
Inflammatory Cells ◽  
Sprague Dawley ◽  
Maxillofacial Region ◽  
Tissue Samples ◽  
Tissue Expanders ◽  
Tnf Α ◽  
Significant Difference

Objective: Reconstruction of oral and facial defects often necessitate replacement of missing soft tissue. The purpose of tissue expanders is to grow healthy supplementary tissue under a controlled force. This study investigates the inflammatory responses associated with the force generated from the use of anisotropic hydrogel tissue expanders. Methods: Sprague Dawley rats (n = 7, body weight = 300 g ± 50 g) were grouped randomly into two groups—control (n = 3) and expanded (n = 4). Anisotropic hydrogel tissue expanders were inserted into the frontal maxillofacial region of the rats in the expanded group. The rats were sacrificed, and skin samples were harvested, fixed in formalin, and embedded in paraffin wax for histological investigation. Hematoxylin and eosin staining was performed to detect histological changes between the two groups and to investigate the inflammatory response in the expanded samples. Three inflammatory markers, namely interleukin (IL)-1α, IL-6, and tumor necrosis factor-α (TNF-α), were analyzed by immunohistochemistry. Result: IL-1-α expression was only observed in the expanded tissue samples compared to the controls. In contrast, there was no significant difference in IL-6, and TNF-α production. Histological analysis showed the absence of inflammatory response in expanded tissues, and a negative non-significant correlation (Spearman’s correlation coefficient) between IL-1-α immune-positive cells and the inflammatory cells (r = −0.500). In conclusion, tissues that are expanded and stabilized using an anisotropic self-inflating hydrogel tissue expander might be useful for tissue replacement and engraftment as the expanded tissue does not show any sign of inflammatory responses. Detection of IL-1-α in the expanded tissues warrants further investigation for its involvement without any visible inflammatory response.

scholarly journals Puerarin Prevents Acute Liver Injury via Inhibiting Inflammatory Responses and ZEB2 Expression

2021 ◽  
Vol 12 ◽  
Author(s):  
Junfa Yang ◽  
Maomao Wu ◽  
Hui Fang ◽  
Yue Su ◽  
Lingling Zhang ◽  
...  
Keyword(s):  
Liver Injury ◽  
Signaling Pathway ◽  
Inflammatory Cytokines ◽  
Inflammatory Responses ◽  
Acute Liver Injury ◽  
Expression Level ◽  
Inflammatory Factors ◽  
Tnf Α ◽  
Zeb2 Expression ◽  
Pro Inflammatory Cytokines

Puerarin, an isoflavone component extracted from herb radix puerariae, is widely used in China in the treatment of immune diseases and inflammation. Previous studies have demonstrated that puerarin prevented acute lung injury by regulating inflammatory responses. However, the effect of puerarin on acute liver injury (ALI) was unclear. The purpose of this study was to explore the beneficial effects of puerarin when applied to ALI. We found that puerarin inhibited liver injury and inflammatory cell infiltration in lipopolysaccharide (LPS)/D-galactose (D-Gal)-induced acute liver failure and the liver pro-inflammatory cytokines interleukin (IL)-1β, IL-6, and tumor necrosis factor-alpha (TNF-α) in liver tissues with ALI and LPS-induced L-02 cells but upregulated the expression level of zinc finger E-box-binding homeobox 2 (ZEB2). Significantly, the results of this study showed that the inhibition of liver pro-inflammatory cytokine (IL-1β, IL-6, and TNF-α) production in LPS-induced L-02 cells was caused by ZEB2 overexpression. However, knocking down ZEB2 promoted LPS-mediated secretion of liver pro-inflammatory cytokines in L-02 cells. Additional experiments showed that puerarin inhibited the activation of the NF-κB signaling pathway by elevating ZEB2 expression in L-02 cells. In summary, puerarin most likely prevented activation of the pro-inflammatory factors and reduced LPS/D-Gal-induced liver injury by enhancing the ZEB2 expression level and, consequently, blocking activation of the NF-κB signaling pathway in the liver.

Sex-dependent differences in inflammatory responses during liver regeneration in a murine model of acute liver injury

2018 ◽  
Vol 132 (2) ◽  
pp. 255-272 ◽  
Author(s):  
Debora Bizzaro ◽  
Marika Crescenzi ◽  
Rosa Di Liddo ◽  
Diletta Arcidiacono ◽  
Andrea Cappon ◽  
...  
Keyword(s):  
Liver Injury ◽  
Inflammatory Responses ◽  
Acute Liver Injury ◽  
Inflammatory Cells ◽  
Tissue Response ◽  
Drug Induced ◽  
Gender Dimorphism ◽  
Inflammatory Phase ◽  
Inflammatory Monocytes ◽  
Ccl4 Treatment

A sexual dimorphism in liver inflammation and repair was previously demonstrated. Its cellular dissection in the course of acute liver injury (ALI) was explored. BALB/c mice were treated with carbon tetrachloride (CCl4) by intraperitoneal injection and killed after 3, 5, and 8 days. Histological and hepatic cell population analyses were performed. The correlation between androgen receptor (AR) expression and liver recruited inflammatory cells was investigated by treatment with the AR antagonist flutamide. Additionally, patients with a diagnosis of drug induced liver injury (DILI) were included in the study, with a particular focus on gender dimorphism in circulating monocytes. A delayed resolution of necrotic damage and a higher expression of proinflammatory cytokines were apparent in male mice along with a slower recruitment of inflammatory monocytes. F4/80+CD11b+ macrophages and CD11bhighGr-1high monocytes expressed AR and were recruited later in male compared with female livers after CCl4 treatment. Moreover, CD11bhighAR+Gr-1high recruitment was negatively modulated by flutamide in males. Analysis of DILI patients showed overall a significant reduction in circulating mature monocytes compared with healthy subjects. More interestingly, male patients had higher numbers of immature monocytes compared with female patients. A stronger cytotoxic tissue response was correlated with an impaired recruitment of CD11bhighAR+Gr-1high cells and F4/80+CD11b+ macrophages in the early inflammatory phase under AR signaling. During DILI, a dimorphic immune response was apparent, characterized by a massive recruitment of monocytes to the liver both in males and females, but only in males was this recruitment sustained by a turnover of immature monocytes.

Mass Spectrometry-based Label-free Quantitative Proteomic Analysis of CCl4-induced Acute Liver Injury in Mice Intervened by Total Glycosides from Ligustri Lucidi Fructus

2020 ◽  
Vol 17 ◽  
Author(s):  
Qian Lu ◽  
Hai-Zhu Xing ◽  
Nian-Yun Yang
Keyword(s):  
Insulin Resistance ◽  
Liver Injury ◽  
Protein Expression ◽  
Signaling Pathway ◽  
Proteomic Analysis ◽  
Acute Liver Injury ◽  
Liver Cells ◽  
Differentially Expressed ◽  
Liver Protein ◽  
Differentially Expressed Proteins

Background: CCl4 acute liver injury (ALI) is a classical model for experimental research. However, there are few reports involved in the fundamental research of CCl4-induced ALI Ligustri Lucidi Fructus (LLF) are and its prescription have been used to treat hepatitis illness clinically. LLF and its active ingredients displayed anti-hepatitis effects, but the mechanism of function has not been fully clarified Objective: To investigate the proteomic analysis of CCl4-induced ALI, and examine the effects of active total glycosides (TG) from LLF on ALI of mice4, including histopathological survey and proteomic changes of liver tissues, and delineate the possible underlying mechanism. Methods: CCl4 was used to produce ALI mice model. The model mice were intragastrically administrated with TG and the liver his-topathological changes of mice were examined. At the end of test, mice liver samples were collected, after protein denaturation, re-duction, desalination and enzymatic hydrolysis, identification was carried out by nano LC-ESI-OrbiTrap MS/MS technology. The data was processed by Maxquant software. The differentially-expressed proteins were screened and identified, and their biological information was also analyzed based on GO and KEGG analysis. Key protein expression was validated by Western blot analysis Results: A total of 705 differentially-expressed proteins were identified during the normal, model and administration group. 9 signifi-cant differential proteins were focused based on analysis. Liver protein expression changes of CCl4-induced ALI mice were mainly involved in several important signal channels, namely FoxO signaling pathway, autophagy-animal, insulin signaling pathway. TG has anti-liver damnification effect in ALI mice, the mechanism of which is related to FoxO1 and autophagy pathways Conclusion: CCl4 inhibited expression of insulin-Like growth factor 1 (Igf1) and 3-phosphoinositide-dependent protein kinase 1 (Pdpk1) in liver cells and induced insulin resistance, thus interfered with mitochondrial autophagy and regeneration of liver cells and the metabolism of glucose and lipid, and caused hepatic necrosis in mice. TG resisted liver injury in mice. TG adjusted the expression level of key proteins Igf1 and Pdpk1 after liver injury and improved insulin resistance, thus promoted autophagy and resisted the liver damage

AAnti-Inflammatory Effects of Plasma Circulating Exosomes Obtained from Normal-Weight and Obese Subjects on Hepatocytes

2020 ◽  
Vol 20 ◽  
Author(s):  
Reza Afrisham ◽  
Sahar Sadegh-Nejadi ◽  
Reza Meshkani ◽  
Solaleh Emamgholipour ◽  
Molood Bagherieh ◽  
...  
Keyword(s):  
Inflammatory Cytokines ◽  
Hepg2 Cells ◽  
Human Liver ◽  
Liver Cells ◽  
Normal Weight ◽  
Protein Levels ◽  
Human Liver Cells ◽  
Tnf Α ◽  
Anti Inflammatory

Introduction: Obesity is a disorder with low-grade chronic inflammation that plays a key role in the hepatic inflammation and steatosis. Moreover, there are studies to support the role of exosomes in the cellular communications, the regulation of metabolic homeostasis and immunomodulatory activity. Accordingly, we aimed to evaluate the influence of plasma circulating exosomes derived from females with normal-weight and obesity on the secretion of inflammatory cytokines in human liver cells. Methods: Plasma circulating exosomes were isolated from four normal (N-Exo) and four obese (O-Exo) women. The exosomes were characterized and approved for CD63 expression (common exosomal protein marker) and morphology/size using the western blot and TEM methods, respectively. The exosomes were used for stimulation of HepG2 cells in vitro. After 24 h incubation, the protein levels of TNF-α,IL-6, and IL-1β were measured in the culture supernatant of HepG2 cells using the ELISA kit. Results: The protein levels of IL-6 and TNF-α in the cells treated with O-Exo and N-Exo reduced significantly in comparison with control group (P=0.039 and P<0.001 respectively), while significance differences were not found between normal and obese groups (P=0.808, and P=0.978 respectively). However, no significant differences were found between three groups in term of IL-1β levels (P=0.069). Based on the correlation analysis, the protein levels of IL-6 were positively correlated with TNF-α (r 0.978, P<0.001). Conclusion: These findings suggest that plasma circulating exosomes have probably anti-inflammatory properties independently from body mass index and may decrease the secretion of inflammatory cytokines in liver. However, further investigations in vitro and in vivo are needed to address the anti-inflammatory function of N-Exo and O-Exo in human liver cells and/or other cells.

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