NLRP3 inflammasome driven liver injury and fibrosis: Roles of IL-17 and TNF in mice

Nutrients and Immunometabolism: Role of Macrophage NLRP3

Inflammation is largely mediated by immune cells responding to invading pathogens, whereas metabolism is oriented toward producing usable energy for vital cell functions. Immunometabolic alterations are considered key determinants of chronic inflammation, which leads to the development of chronic diseases. Studies have demonstrated that macrophages and the NOD-, LRR-, and pyrin domain-containing protein 3 (NLRP3) inflammasome are activated in key metabolic tissues to contribute to increased risk for type 2 diabetes mellitus, Alzheimer disease, and liver diseases. Thus, understanding the tissue-/cell-type-specific regulation of the NLRP3 inflammasome is crucial for developing intervention strategies. Currently, most of the nutrients and bioactive compounds tested to determine their inflammation-reducing effects are limited to animal models. Future studies need to address how dietary compounds regulate immune and metabolic cell reprograming in humans.

hsa_circ_0004018 suppresses the progression of liver fibrosis through regulating the hsa-miR-660-3p/TEP1 axis

Efforts have been made in the prevention and treatment of liver fibrosis. The inhibition or depletion of the hepatic stellate cells (HSCs) has been considered as a potential approach. Recently, there are numbers of studies about the role of the circular RNA in the disease progression. However, the role of circular RNA in the regulation of HSCs and the progression of liver fibrosis remained elusive. In this study, we constructed a CCl4-induced liver fibrosis mouse model and overexpressed hsa_circ_0004018 in HSCs. Then, salvianolic acid B was used to treat HSCs in vitro. We found that hsa_circ_0004018 is downregulated in liver fibrogenesis. Luciferase reporter assay was performed to verify the interaction of hsa_circ_0004018, hsa-miR-660-3p and TEP1. It showed that hsa_circ_0004018 may act as a sponge of hsa-miR-660-3p, which can target and downregulate the expression of TEP1. hsa_circ_0004018 expressing lentivirus was used to investigate the in-vivo function of hsa_circ_0004018 in CCl4-induced liver fibrosis mice. We also reveal that the hsa_circ_0004018/hsa-miR-660-3p/TEP1 axis contributes to the proliferation and activation of HSCs. In addition, the overexpression of hsa_circ_0004018 alleviated the progression of liver fibrosis. In conclusion, our study highlights hsa_circ_0004018 as a potential biomarker and therapeutic target for liver fibrosis.

Protective effect of exogenous hydrogen sulfide on diaphragm muscle fibrosis in streptozotocin-induced diabetic rats

IMPACT STATEMENT

Diabetes mellitus is a group of chronic metabolic disorders, which causes serious damage to a variety of organs, such as the retina, heart, and skeletal muscle. The diaphragm is an important skeletal muscle involved in respiration in mammals. Fibrosis of the diaphragm muscle affects its contractility, which in turn impairs respiratory function. Accumulating evidence suggests that exogenous hydrogen sulfide (H₂S) exhibits anti-fibrotic activity in diabetes mellitus, but whether and how H₂S exerts this anti-fibrotic effect in the diabetic diaphragm remains unclear. The current work for the first time reveals that exogenous H₂S attenuates hyperglycemia-induced fibrosis of the diaphragm muscle and strengthens diaphragmatic biomechanical properties in diabetes mellitus, and the mechanism may involve the alleviation of collagen deposition by suppression of the nucleotide-binding oligomerization domain-like receptor protein (NLRP) 3 inflammasome-mediated inflammatory reaction. Therefore, H₂S supplementation could be used as an efficient targeted therapy against the NLRP3 inflammasome in the diabetic diaphragm.

Saikosaponin A inhibits the activation of pancreatic stellate cells by suppressing autophagy and the NLRP3 inflammasome via the AMPK/mTOR pathway

Pancreatic stellate cells (PSCs) are the main effector cells in the development of pancreatic fibrosis. Finding substances that inhibit PSC activation is an important approach to inhibiting pancreatic fibrosis. Saikosaponin A (SSa) has numerous pharmacological activities, but its effect on PSCs remains unknown. This study was conducted to explore the effects of SSa on PSC activation in cultured rat PSCs. Cell viability, proliferation, migration and apoptosis were evaluated by MTT assays, the iCELLigence System, Transwell assays and flow cytometry. Markers of PSC activation, autophagy and the NLRP3 inflammasome were measured by real-time PCR, immunofluorescence and western blotting. Rapamycin and phenformin hydrochloride were used to determine the effect of SSa via the AMPK/mTOR pathway. The results showed that SSa suppressed PSC viability, proliferation, and migration and promoted apoptosis. SSa inhibited PSC activation, restrained PSC autophagy and suppressed the NLRP3 inflammasome. In addition, there was interaction between autophagy and the NLRP3 inflammasome during SSa inhibition of PSCs. Moreover, promotion of p-AMPK increased autophagy and the NLRP3 inflammasome. Inhibition of p-mTOR increased autophagy and decreased the NLRP3 inflammasome. Our results indicated that SSa inhibited PSC activation by inhibiting PSC autophagy and the NLRP3 inflammasome via the AMPK/mTOR pathway. These findings provide a theoretical basis for the use of SSa to treat pancreatic fibrosis and further suggest that targeting autophagy and the NLRP3 inflammasome may provide new strategies for the treatment of pancreatic fibrosis.

Paeoniflorin, a Natural Product With Multiple Targets in Liver Diseases-A Mini Review

Paeoniflorin is derived from Paeonia suffruticosa Andr., Paeonia lactiflora Pall., or Paeonia veitchii Lynch and has been used in traditional medical applications for more than 2,000 years. Paeoniflorin is a monoterpenoid glycoside with various effects on liver diseases. Recent studies have revealed that paeoniflorin demonstrates a wide range of activities, including hepatic protection, cholestasis alleviation, liver fibrosis attenuation, nonalcoholic fatty liver disease prevention, and hepatocellular carcinoma inhibition involved in multiple pathways. Moreover, anti-inflammation, antioxidation, and immune regulation with the regulation of TLR4-NF-κB, ROCK/NF-κB, HO-1, mitochondria-dependent as well as HMGB1‐TLR4 signaling pathways are correlated with hepatic protection in liver injury and nonalcoholic fatty liver disease. Antioxidative mechanisms, anti-inflammation, and hepatic transporter regulation involved in NOX4, PI3K/Akt/Nrf2, NF‐κB, NTCP, BSEP, as well as MRP2 signals are mainly relevant to the anticholestatic effect of paeoniflorin. The inhibition of hepatic stellate cell activation and alleviation of extracellular matrix deposition via vast signals such as mTOR/HIF-1α, TGF-β1/Smads, and JAK2/STAT6 are primarily involved in the antifibrotic effect of paeoniflorin. The regulation of macrophages also contributes to the alleviation effect on liver fibrosis. In addition, the reduction of invasion, metastasis, and adhesion and the induction of apoptosis-related targets, including Bax, Bcl-2, and caspase-3, are related to its effect on hepatocellular carcinoma. The literature indicates that paeoniflorin might have potent efficacy in complex liver diseases and demonstrates the profound medicinal value of paeoniflorin.

Palmitic acid stimulates NLRP3 inflammasome activation through TLR4-NF-κB signal pathway in hepatic stellate cells

Background

The NLRP3 inflammasome activation plays an important role in the development of NASH and fibrogenesis. However, the mechanisms involved in NLRP3 activation in hepatic stellate cells (HSCs) have been unclear. The aim of this study was to investigate the mechanism of NLRP3 activation in HSCs and the role of NLPR3 inflammasome activation in HSCs on the development of nonalcoholic steatohepatitis (NASH) to fibrosis.

Methods

Primary HSCs isolated from SD rats were incubated with palmitic acid and/or LPS, respectively. For in vivo animal experiment, 4-week-old SD rats were fed with high fat diet (HF-diet) for 12 weeks, SD rats were sacrificed at 0, 4, 8 and 12 w. In another group of animal experiment, 4-week-old SD rats were fed with HF-diet and a NLRP3 inhibitor (intraperitoneal injection of NLRP3 inhibitor glybenclamide 5 mg/kg, injected every 3 days) for 12 weeks. Liver tissue and serum were harvested. RT-PCR, WB, ELISA, immunofluorescence and immunohistochemistry were performed to assess the NLRP3 inflammasome activation and signal molecules.

Results

Palmitic acid stimulated NLPR3 inflammasome activation and fibrotic phenotype change in primary HSCs, LPS sensitizes the response of HSCs to palmitic acid. TLR4-NF-κB signal pathway was involved in NLRP3 inflammasome activation in palmitic acid-exposed HSCs and HF diet-induced NASH. It is evident that administration of NLRP3 inhibitor reduced the development of NASH to liver fibrosis in the NASH rat model.

Conclusions

Palmitic acid stimulates NLRP3 inflammasome activation through the TLR4-NF-κB signal pathway in HSCs. NLRP3 inflammasome activation in HSCs exacerbates the development of NASH to liver fibrosis.

Evodiamine and rutaecarpine from Tetradium ruticarpum in the treatment of liver diseases

BACKGROUND

Liver is the pivotal organ responsible for plasma protein production, biliary secretion, xenobiotic elimination, glucose and lipid homeostasis. Dysregulation of these functions usually leads to liver diseases and further related complications. The incidence of liver diseases is increasing worldwide, with high morbidity and mortality when at advanced stages, and has become significant public health concern and substential economic burden. Thus, novel therapeutic strategies for managing liver diseases progression are urgently required. T. ruticarpum is one of the most famous and frequently used herbal medicine and has been prescribed in traditional Chinese medicine (TCM) formulas for the treatment of various ailments, including liver diseases. A considerable amount of bioactive ingredients have been isolated and identified from the roots of T. ruticarpum, including alkaloids, saponins, phenols, volatile oils and other compounds. Among these compounds, evodiamine (EVO) and rutaecarpine (RUT) are believed to be the most bioactive compounds.

PURPOSE

To summarize recent findings regarding to the metabolism, pharmacological/toxicological effects of EVO and RUT and to highlight the potential therapeutic effects of them against liver diseases.

METHODS

Online academic databases (including PubMed, Google Scholar, Web of Science and CNKI) were searched using search terms of "T. ruticarpum", "Wu Zhu Yu", "evodiamine", "rutaecarpine", "liver" and combinations to include published studies of EVO and RUT primarily from 2004-2019. Several critical previous studies beyond this period were also included.

RESULTS

Evodiamine (EVO) and rutaecarpine (RUT) are believed to be the most bioactive alkaloids in T. ruticarpum, having anti-inflammation, anti-fibrosis, anti-lipotoxicity, anti-cancer activities, and thus having potential to improve liver disorders. In the current review, we comprehensively summarized recent progresses in the studies of EVO- and RUT-mediated promising hepatoprotective effects and also provide novel insights regarding the potential use of EVO and RUT as therapeutic options for the treatment of liver diseases.

CONCLUSION

With further in-depth pharmacology and pharmacokinetic studies, we believe that natural products in T. ruticarpum and their derivatives will become promising medicines with improved clinical efficacy for the treatment of liver diseases in the immediate future.

MicroRNA-21 Mediates the Inhibiting Effect of Praziquantel on NLRP3 Inflammasome in Schistosoma japonicum Infection

Praziquantel (PZQ), a traditional helminthicide drug, has been shown to exert an anti-inflammatory effect on splenomegaly induced by schistosomiasis via regulating macrophage polarization. Meanwhile, miR-21 has been demonstrated to control macrophage polarization. However, the role of miR-21 in the regulation of macrophage polarization by PZQ in schistosomiasis is still unclear. In the present study, we found that M1-type macrophages were the predominant splenic macrophages in chronic schistosomiasis and that NLRP3 inflammasome–related molecules were upregulated. PZQ inhibited NLRP3 inflammasome in M1 macrophages and reduced the expression of miR-21. Furthermore, using the methods of quantitative real-time PCR and transfection, the downregulation of NLRP3/IL-1β by PZQ in M1 macrophages were reversed by miR-21 overexpression. These results indicated that miR-21 was involved in the inhibiting effect of PZQ on activation of NLRP3 inflammasome. Moreover, miR-21 might target Smad7 to mediate the anti-inflammatory effect of PZQ in polarized macrophages. This study provides an in-depth mechanism of PZQ in the treatment of schistosomiasis.

Pretreatment of exosomes derived from hUCMSCs with TNF-α ameliorates acute liver failure by inhibiting the activation of NLRP3 in macrophage

AIMS

The management of acute liver failure (ALF) is a major challenge worldwide. The current study aimed to determine the therapeutic potential of TNF-α pretreatment of umbilical cord mesenchymal stem cell-derived exosomes (T-Exo) in ALF.

MAIN METHODS

Here, we enriched T-Exo and untreated exosomes (Exo), them were measured by nanoparticle tracking analysis (NTA) for particle size detection and identified surface marker by Western blot and flow cytometry. Then the cell proliferation was detected by CCK-8 and the effect of T-Exo on the expression levels of pro-inflammatory cytokines was tested by ELISA. ALF mouse models were induced by LPS and D-GalN. H&E staining, immunohistochemistry, and Western blot were used to detect the effect of T-Exo on the levels of NLRP3 and other inflammation-related pathway proteins. qPCR was used to detect the expression level of microRNA-299-3p in T-Exo and its transfer to macrophages. Laser confocal microscopy was used to detect colocalization of exosomes,Golgi and NLRP3 in macrophages.

KEY FINDINGS

Our study shows that T-Exo can reduce serum ALT, AST and proinflammatory cytokines level and inhibit activation of NLRP3 inflammation-associated pathway proteins. T-Exo treatment reduces pathological liver damage caused by ALF. Anti-inflammatory-related miRNA-299-3p is up-regulated in TNF-α-stimulated MSCs and selectively packaged into exosomes for role in exosomal treatment. And conducted preliminary exploration and hypothesis on the specific mechanism of this effect.

SIGNIFICANCE

These in vitro and in vivo studies indicate that T-Exo attenuates inflammatory damage caused by ALF and promotes liver tissue repair by inhibiting the activation of the NLRP3 pathway.

Epitranscriptomic 5-Methylcytosine Profile in PM2.5-induced Mouse Pulmonary Fibrosis

Exposure of airborne particulate matter (PM) with an aerodynamic diameter less than 2.5 μm (PM2.5) is epidemiologically associated with lung dysfunction and respiratory symptoms, including pulmonary fibrosis. However, whether epigenetic mechanisms are involved in PM2.5-induced pulmonary fibrosis is currently poorly understood. Herein, using a PM2.5-induced pulmonary fibrosis mouse model, we found that PM2.5 exposure leads to aberrant mRNA 5-methylcytosine (m5C) gain and loss in fibrotic lung tissues. Moreover, we showed the m5C-mediated regulatory map of gene functions in pulmonary fibrosis after PM2.5 exposure. Several genes act as m5C gain-upregulated factors, probably critical for the development of PM2.5-induced fibrosis in mouse lungs. These genes, including Lcn2, Mmp9, Chi3l1, Adipoq, Atp5j2, Atp5l, Atpif1, Ndufb6, Fgr, Slc11a1, and Tyrobp, are highly related to oxidative stress response, inflammatory responses, and immune system processes. Our study illustrates the first epitranscriptomic RNA m5C profile in PM2.5-induced pulmonary fibrosis and will be valuable in identifying biomarkers for PM2.5 exposure-related lung pathogenesis with translational potential.

Transcriptional Suppression of the NLRP3 Inflammasome and Cytokine Release in Primary Macrophages by Low-Dose Anthracyclines

Tissue-resident macrophages play critical roles in controlling homeostasis, tissue repair, and immunity. Inflammatory macrophages can sustain tissue damage and promote the development of fibrosis during infections and sterile tissue injury. The NLRP3 inflammasome and its effector cytokine IL-1β have been identified as important mediators of fibrosis. Epirubicin, an anthracycline topoisomerase II inhibitor, has been reported to inhibit myeloid inflammatory cytokine production and to promote tissue tolerance following bacterial infection. We investigated the anti-inflammatory properties of epirubicin on the NLRP3 inflammasome and TLR4-mediated inflammation in PMA-primed THP-1 and in primary human peritoneal macrophages (PM). Low-dose epirubicin at non-cytotoxic doses downregulated NLRP3 inflammasome components and reduced the release of cleaved caspase-1, bioactive IL-1β, and TNF-α following NLRP3 activation in a dose-dependent fashion. In addition, epirubicin attenuated inflammatory macrophage responses after TLR4 and TLR2 ligation. These anti-inflammatory effects were not mediated by the induction of autophagy or altered MAPK signaling, but as the result of a global transcriptional suppression of LPS-dependent genes. Epirubicin-treated macrophages displayed reduced acetylation of histone 3 lysine 9 (H3K9ac), suggesting anti-inflammatory epigenetic imprinting as one underlying mechanism.

Effect of dehydroepiandrosterone on the immune response and gut microbiota in dextran sulfate sodium-induced colitis mice

Dehydroepiandrosterone (DHEA) possess anti-inflammatory, anti-oxidant and immune-regulating function in animals and humans, but there is not enough information about the mechanisms underlying its beneficial effects. The present study investigated the effect and mechanism of DHEA in dextran sulfate sodium (DSS)-induced colitis mice. The findings showed that DHEA relieved the decreasing of body weight, the increasing of disease activity index, the enhancing of spleen weight, the shortening of colon length and the rising of myeloperoxidase activity; meanwhile, histopathological analysis showed that DHEA maintained a relatively intact structure of colon in DSS-induced colitis mice. DHEA decreased the malondialdehyde content, superoxide dismutase activity and inducible nitric oxide synthase protein level; meanwhile, DHEA also inhibited the secretion of tumor necrosis factor-α, interleukin-1β and interleukin-6 in DSS-induced colitis mice. Importantly, our results showed that DHEA blocked the activation of nuclear factor-kappa B (NF-κB) and p38 mitogen-activated protein kinase (MAPK) pathways; and it inhibited the Nod-like receptor protein 3 inflammasome activation in DSS-induced colitis mice. Furthermore, DHEA markedly promoted the intestinal barrier function by up-regulation zonula occludens-1 expression level. The 16S rDNA gene sequencing demonstrated that DHEA decreased the Pseudomonas abundance in DSS-induced colitis mice. In conclusion, our data demonstrated that DHEA reduces oxidative damage through regulating antioxidant enzyme activity; inhibits pro-inflammatory cytokines production by blocking the activation of p38 MAPK and NF-κB signal pathway; protects colon barrier integrity via increasing tight junction protein expression and modulating gut microbiota taxa; all that finally alleviates DSS-induced experimental colitis in mice.

Oxidative stress, inflammatory reactions and apoptosis mediated the negative effect of chronic stress induced by maternal separation on the reproductive system in male mice

Exposure to severe and long-lasting stressors during early postnatal life negatively affects development of the brain and associated biological networks. Maternal separation (MS) is a valid stressful experience in early life that adversely affects neurobiological circuits. In the present study, we aimed to evaluate the effects of MS on sperm quality and histology of the testis in adult male mice. In this study, male mice were subjected to MS during post-natal days (PND) 2-14. Sperm parameters, histological alterations in the testicular tissue, ROS production (using DCFH-DA assay), gene expression of TLR4, NLRP3, TNFα, BAX, ASC, caspase-1 and BCL-2 (using RT-PCR), protein levels of caspase-3 and caspase-8 (using western blotting), and protein levels of IL-1β, IL-18, GPx and ATP (using ELISA) as well as protein expression of caspase-1 and NLRP3 (using immunocytochemistry) were evaluated. Findings showed that MS decreased count, morphology and viability of spermatozoa. MS decreased the diameter of seminiferous tubules and decreased the thickness of seminiferous epithelium. Furthermore, MS increased the level of ROS production and decreased the concentrations of GPx and ATP. MS led to increased expression of TLR4, NlRP3, TNFα, caspase-1, ASC, IL-1β and IL-18. In addition, MS induced apoptosis as evidenced by increased BAX, caspase-3 and caspase-8 as well as decreased BCL-2 expression. We concluded that early life stress induced by MS has detrimental effects on sperm parameters and testicular tissue. Our results suggest that these effects are mediated by activation of ROS production, and alterations in mitochondrial function, inflammatory processes and apoptosis pathways.

Hesperetin derivative attenuates CCl4-induced hepatic fibrosis and inflammation by Gli-1-dependent mechanisms

Hepatic fibrosis, a common pathological feature and leading cause of various chronic liver diseases, still lacks effective therapy. Hesperetin derivative (HD) is a derivative of Traditional Chinese Medicine monomer isolated from the fruit peel of Citrusaurantium L. (Rutaceae). In the present study, we revealed the anti-fibrotic effects of HD in CCl₄-induced mouse hepatic fibrosis model and in TGF-β1-activated LX-2 cells, in vivo and in vitro. Results showed that HD prevented CCl₄-induced liver injury and histological damage. Consistently, HD inhibited the up-regulation of liver fibrogenesis markers α-SMA, Col1α1, Col3α1 and TIMP-1 in primary hepatic stellate cells (HSCs) and suppressed inflammatory responses in primary liver macrophages from hepatic fibrosis mice. Furthermore, HD promoted the apoptosis of activated HSCs, a key step in the onset of fibrosis regression. Mechanistically, the Hedgehog pathway was involved in HD-treated hepatic fibrosis, and HD specifically contributed to attenuate the aberrant expression of Glioma associated oncogene-1 (Gli-1). Interestingly, blockade of Gli-1 removed the inhibitory effect of HD on activated HSCs, indicating that Gli-1 may play a pivotal role in mediating the anti-fibrotic effect of HD in hepatic fibrosis. Collectively, our results suggest that HD may be a potential anti-fibrotic Traditional Chinese Medicine monomer for the treatment of hepatic fibrosis.

The different expression of caspase-1 in HBV-related liver disease and acts as a biomarker for acute-on-chronic liver failure

Background

Caspase-1 is an evolutionarily conserved enzyme that proteolytically cleaves the precursors of the inflammatory cytokines interleukin 1β and interleukin 18. However, the role of caspase-1 in determining the severity of acute-on-chronic liver failure (ACLF) has yet to be elucidated. We evaluated the expression levels of caspase-1 in HBV-related liver disease and assessed its utility as a biomarker predicting the severity of ACLF.

Methods

The gene, protein and activity levels of caspase-1 were measured in the liver and/or serum of subjects with HBV-related disease. We also analysed the correlation between the expression levels of caspase-1 and liver injury of ACLF.

Results

Compared with the values observed in normal subjects, the relative caspase-1 mRNA and protein levels in livers were decreased in patients with CHB, LC, and HCC but increased in those with ACLF; moreover, ACLF patients had the lowest serum level and hepatic activity of caspase-1 among the five groups. The serum caspase-1 levels in ACLF patients showed a negative correlation with total serum bilirubin and a positive correlation with serum total protein and albumin. Importantly, the serum caspase-1 levels in the surviving group with ACLF were higher than those in the non-surviving group and showed different dynamic trends. Analyses of the area under the receiver operating characteristic curve indicated that caspase-1 (AUC = 0.84, AUC of MELD score = 0.72) may be a useful marker for independently predicting ACLF.

Conclusion

Caspase-1 is a potential non-invasive biomarker of disease progression and prognosis in ACLF.

Attenuation of hyperoxic acute lung injury by Lycium barbarum polysaccharide via inhibiting NLRP3 inflammasome

Lycium barbarum polysaccharide (LBP), an active component from Goji berry which is a traditional Chinese medicine, has anti-inflammatory and antioxidant features. The aim of our study was to investigate whether LBP has any role in hyperoxia-induced acute lung injury (ALI). Using a murine model of hyperoxia-induced ALI, we investigate the effect of LBP on pulmonary pathological changes as well as Sirtuin 1 (SIRT1) and the nucleotide binding domain and leucine-rich repeat pyrin domain containing 3 (NLRP3) inflammasome. Exposure to 100% oxygen for 72 h in male C57BL/6 mice resulted in increased protein levels of tumor necrosis factor-α and interleukin-1β in lung tissues, and aggravated lung histological alterations. These hyperoxia-induced changes and mortality were improved by LBP. LBP markedly suppressed the activation of NLRP3 inflammasome both in vivo and in vitro. Moreover, LBP upregulated SIRT1 expression compared with vehicle-treated group. Importantly, knockdown of SIRT1 reversed the inhibitory effect of LBP on NLRP3 inflammasome activation in vitro. LBP meliorated hyperoxia-induced ALI in mice by SIRT1-dependent inhibition of NLRP3 inflammasome activation.

Anti-PCSK9 antibodies inhibit pro-atherogenic mechanisms in APOE*3Leiden.CETP mice

LDL-cholesterol (LDL-C) is a causal pathogenic factor in atherosclerosis. Monoclonal anti-proprotein convertase subtilisin/kexin type 9 (PCSK9) neutralizing antibodies are novel potent LDL-lowering drugs which reduce cardiovascular events. To characterize their effect on atherogenesis, APOE*3Leiden.CETP mice were fed a high cholesterol/high fat diet (WTD) or normal chow (NC) for 18 weeks. Mice on WTD were injected with the human anti-PCSK9 antibody mAb1 (PL-45134, 10 mg*kg^-1 s.c.) or 0.9% saline every 10 days. PCSK9 inhibition decreased total cholesterol in serum of APOE*3Leiden.CETP mice and prevented the development of atherosclerosis. The plaque area in the aortic root was reduced by half and macrophage infiltration determined by Ly6c and Mac-3 staining was ameliorated. PCSK9 inhibition decreased markers of inflammation in mononuclear cells (Il-6, Tnfa mRNA), and in serum (CXCL-1,-10,-13; complement factor C5a) compared to control WTD fed animals. The number of circulating Sca-1/VEGF-R2 positive endothelial progenitor cells of the peripheral blood and spleen-derived diLDL/lectin double positive circulating angiogenic cells was increased. To conclude, the PCSK9-mediated anti-atherosclerotic effect involves the upregulation of pro-regeneratory endothelial progenitor cells, a reduction of inflammation and change of plaque composition.

NLRP6 deficiency aggravates liver injury after allogeneic hematopoietic stem cell transplantation

This study aims to observe the expression and role of NLRP6 in liver injury after allogeneic hematopoietic stem cell transplantation (Allo-HSCT). Allo-HSCT model was established through infusion of 5 × 10⁶ bone marrow mononuclear cells into whole body irradiated mice. On days 7, 14, 21 and 28 after transplantation, the peripheral blood was collected to detect liver function. The liver of the mice was obtained to assess the pathological changes of liver tissues after allo-HSCT by H&E staining and Mason staining. Meanwhile, expression of NLRP6, phosphorylated p38-MAPK and IκBα, caspase-1 and NLRP3 in liver were detected by Western blot. ELISA was used for detection of the level of interleukin (IL)-1β, IL-18, tumor necrosis factor (TNF)-α, IL-6, myeloperoxidase (MPO) and tumor growth factor (TGF)-β1. Increased expression of NLRP6, phosphorylated Iκbα, phosphorylated p38-MAPK, pro-caspase-1, and p20, in liver tissue with injury and fibrosis in mice after allo-HSCT were observed. Meanwhile, the level of IL-1β, IL-18, IL-6 and TNF-α was also increased. However, NLRP6^-/- mice showed more severe liver damage and liver fibrosis after transplantation together with higher level of phosphorylated Iκbα, phosphorylated p38-MAPK, Pro-caspase-1, p20 expression as well as IL-1β, IL-18, IL-6, and TNF-α secretion compared with wide-type. Interestingly, the expression of NLRP3 in the liver of NLRP6^-/- mice was significantly higher than that of wild-type. In conclusion, the expression of NLRP6 in host's liver is associated with liver injury after allo-HSCT. NLRP6 deficiency in host's liver leads to more severe liver damage, indicating a protective role of NLRP6 in host's liver to liver damage after allo-HSCT.

Chalcone Derivative L6H21 Reduces EtOH + LPS-Induced Liver Injury Through Inhibition of NLRP3 Inflammasome Activation

BACKGROUND

Chronic alcohol intake increases circulating endotoxin levels causing excessive inflammation that aggravates the liver injury. (E)-2,3-dimethoxy-4'-methoxychalcone (L6H21), a derivative of chalcone, has been found to inhibit inflammation in cardiac diseases and nonalcoholic fatty liver disease. However, the use of L6H21 in alcoholic liver disease to inhibit exotoxin-associated inflammation has not been explored. In this study, we examined the effects of L6H21 on EtOH + LPS-induced hepatic inflammation, steatosis, and liver injury and investigated the underlying mechanisms.

METHODS

C57BL6 mice were treated with 5% EtOH for 10 days, and LPS was given to the mice 6 hours before sacrificing. One group of mice was supplemented with L6H21 with EtOH and LPS. RAW264.7 cells were used to analyze the effects of L6H21 on macrophage activation.

RESULTS

EtOH + LPS treatment significantly increased hepatic steatosis and serum levels of alanine transaminase (ALT) and aspartate transaminase (AST), which were reduced by L6H21 treatment. EtOH + LPS treatment increased hepatic inflammation, as shown by the increased hepatic protein levels of Toll-like receptor-4, p65, and p-IκB, and increased oxidative stress, as shown by protein carbonyl levels and reactive oxygen species formation, which were reduced by L6H21 treatment. In addition, L6H21 treatment markedly inhibited EtOH + LPS-elevated hepatic protein levels of NLRP3, cleaved caspase-1, cleaved IL-1β, and caspase-1-associated apoptosis.

CONCLUSIONS

Our results demonstrate that L6H21 treatment inhibits EtOH + LPS-induced liver steatosis and injury through suppression of NLRP3 inflammasome activation. L6H21 may be used as an alternative strategy for ALD prevention/treatment.

Interleukin-17 pathways in systemic sclerosis-associated fibrosis

Fibrosis is unregulated tissue repair that may cause impairment of organ function, especially in end-organ damage. Systemic sclerosis (SSc) is the prototype systemic fibrosing disorder. Classical targets for fibrosis in SSc like transforming growth factor Beta (TGF-β), Interleukin-6 (IL-6), and multiple tyrosine kinases, have not yielded therapeutic benefit. There is multitude of evidence from across different tissues like the heart, lung, skin, liver, colon, and, to some extent, the kidney, that interleukin-17 (IL-17) and its downstream pathways are strongly associated with the initiation and propagation of fibrosis. Data from scleroderma patients, as well as from animal models of SSc, mirror these findings. Interestingly, hitherto unknown to be related to IL-17, newer molecules like Programmed Death-protein1 (PD-1), the phosphatase SHP2, along with known signal transducers like signal transducer and activator of transcription (STAT3), have been recently shown to be involved in the pathogenesis of fibrosis. Related molecules include the intracellular signalling molecules Ras/Erk, mammalian target organ of rapamycin (mTOR), and complement components. The biology of these pathways has not yet been fully elucidated to predict regulatory mechanisms, redundancies, and potential off-target effects. All these need to be better understood in the context of each other, in an effort to arrive at the optimal target to modulate fibrosis.

The Role of Myeloid-Derived Cells in the Progression of Liver Disease

Control of homeostasis and rapid response to tissue damage in the liver is orchestrated by crosstalk between resident and infiltrating inflammatory cells. A crucial role for myeloid cells during hepatic injury and repair has emerged where resident Kupffer cells, circulating monocytes, macrophages, dendritic cells and neutrophils control local tissue inflammation and regenerative function to maintain tissue architecture. Studies in humans and rodents have revealed a heterogeneous population of myeloid cells that respond to the local environment by either promoting regeneration or driving the inflammatory processes that can lead to hepatitis, fibrogenesis, and the development of cirrhosis and malignancy. Such plasticity of myeloid cell responses presents unique challenges for therapeutic intervention strategies and a greater understanding of the underlying mechanisms is needed. Here we review the role of myeloid cells in the establishment and progression of liver disease and highlight key pathways that have become the focus for current and future therapeutic strategies.

CAPS and NLRP3

Cryopyrin-associated periodic syndrome (CAPS) is a rare inherited autoinflammatory disorder characterized by systemic, cutaneous, musculoskeletal, and central nervous system inflammation. Gain-of-function mutations in NLRP3 in CAPS patients lead to activation of the cryopyrin inflammasome, resulting in the inappropriate release of inflammatory cytokines including IL-1β and CAPS-related inflammatory symptoms. Several mechanisms have been identified that are important for the normal regulation of the cryopyrin inflammasome in order to prevent uncontrolled inflammation. Investigators have taken advantage of some of these pathways to develop and apply novel targeted therapies, which have resulted in improved quality of life for patients with this orphan disease.

New incompatible pair of TCM: Epimedii Folium combined with Psoraleae Fructus induces idiosyncratic hepatotoxicity under immunological stress conditions

Epimedii Folium (EF) combined with Psoraleae Fructus (PF) is a common modern preparation, but liver injury caused by Chinese patent medicine preparations containing EF and PF has been frequently reported in recent years. Zhuangguguanjiewan pills (ZGW), which contain EF and PF, could induce immune idiosyncratic liver injury according to clinical case reports and a nonhepatotoxic dose of lipopolysaccharide (LPS) model. This present study evaluated the liver injury induced by EF or PF alone or in combination and investigated the related mechanism by using the LPS model. Liver function indexes and pathological results showed that either EF or PF alone or in combination led to liver injury in normal rats; however, EF or PF alone could lead to liver injury in LPS-treated rats. Moreover, EF combined with PF could induce a greater degree of injury than that caused by EF or PF alone in LPS-treated rats. Furthermore, EF or PF alone or in combination enhanced the LPS-stimulated inflammatory cytokine production, implying that IL-1β, which is processed and released by activating the NLRP3 inflammasome, is a specific indicator of EF-induced immune idiosyncratic hepatotoxicity. Thus, EF may induce liver injury through enhancing the LPS-mediated proinflammatory cytokine production and activating the NLRP3 inflammasome. In addition, the metabolomics analysis results showed that PF affected more metabolites in glycerophospholipid and sphingolipid metabolic pathways compared with EF in LPS model, suggesting that PF increased the responsiveness of the liver to LPS or other inflammatory mediators via modulation of multiple metabolic pathways. Therefore, EF and PF combination indicates traditional Chinese medicine incompatibility, considering that it induces idiosyncratic hepatotoxicity under immunological stress conditions.

NLR Family Pyrin Domain-Containing 3 Inflammasome Activation in Hepatic Stellate Cells Induces Liver Fibrosis in Mice

The NLR family pyrin domain-containing 3 (NLRP3) inflammasome plays an important role in liver fibrosis (LF) development. However, the mechanisms involved in NLRP3-induced fibrosis are unclear. Our aim was to test the hypothesis that the NLRP3 inflammasome in hepatic stellate cells (HSCs) can directly regulate their activation and contribute to LF. Primary HSCs isolated from wild-type (WT), Nlrp3^-/- , or Nlrp3^L351PneoR knock-in crossed to inducible (estrogen receptor Cre-CreT) mice were incubated with lipopolysaccharide (LPS) and adenosine triphosphate (ATP), or 4OH-tamoxifen, respectively. HSC-specific Nlrp3^L351P knock-in mice were generated by crossing transgenic mice expressing lecithin retinol acyltransferase (Lrat)-driven Cre and maintained on standard rodent chow for 6 months. Mice were then sacrificed; liver tissue and serum were harvested. Nlrp3 inflammasome activation along with HSC phenotype and fibrosis were assessed by RT-PCR, western blotting, fluorescence-activated cell sorting (FACS), enzyme-linked immunosorbent assay, immunofluorescence (IF), and immunohistochemistry (IHC). Stimulated WT HSCs displayed increased levels of NLRP3 inflammasome-induced reactive oxygen species (ROS) production and cathepsin B activity, accompanied by an up-regulation of mRNA and protein levels of fibrotic makers, an effect abrogated in Nlrp3^-/- HSCs. Nlrp3^L351P CreT HSCs also showed elevated mRNA and protein expression of fibrotic markers 24 hours after inflammasome activation induced with 4-hydroxytamoxifen (4OHT). Protein and mRNA expression levels of fibrotic markers were also found to be increased in isolated HSCs and whole liver tissue from Nlrp3^L351P Lrat Cre mice compared to WT. Liver sections from 24-week-old Nlrp^L351P Lrat Cre mice showed fibrotic changes with increased alpha smooth muscle actin (αSMA) and desmin-positive cells and collagen deposition, independent of inflammatory infiltrates; these changes were also observed after LPS challenge in 8-week-old Nlrp^L351P Lrat Cre mice. Conclusion: Our results highlight a direct role for the NLRP3 inflammasome in the activation of HSCs directly triggering LF.

NLRP3 inflammasome activation from Kupffer cells is involved in liver fibrosis of Schistosoma japonicum-infected mice via NF-κB

BACKGROUND

NOD-like receptor protein 3 (NLRP3) inflammasome was reported as expressed in schistosomiasis-induced liver fibrosis (SSLF). We used an NLRP3 inflammasome inhibitor, MCC950, to investigate whether it inhibited liver fibrosis, and explored the preliminary molecular mechanism.

METHODS

BALB/c mice were infected with 15 cercariae through the abdominal skin. They received intraperitoneal injections of MCC950 on the day of infection and at day 22 post-infection. We examined their SSLF phenotype and the effect on liver fibrosis, primary Kupffer cells (KCs), and HSCs. Human hepatic stellate cell lines (human LX-2 cells) were treated with soluble egg antigen (SEA) released from the eggs. We then determined the expression of NLRP3 inflammasome and liver fibrosis-associated markers, liver granuloma and ALT/AST.

RESULTS

NLRP3 inflammasome expression in the liver was significantly increased, and eosinophilic granuloma and collagen deposition were found around the eggs in mice infected for 56 days. Additionally, IL-1β, ALT/AST in plasma, and NF-κB in liver tissue and in KCs were all greatly significantly increased. The above-mentioned indicators were largely reduced in mice treated with MCC950 on the day of infection. In vitro, lipopolysaccharide (LPS)/SEA could induce LX-2 cells to express NLRP3 and fibrosis markers, and the SEA-treated group was reversed by MCC950. Furthermore, NLRP3 inflammasome and liver fibrosis-associated markers were both increased in the primary KCs and HSCs isolated from infected mice. However, this effect was not observed in the same cells from the mice treated with MCC950 on the day of infection. Contrary to the aforementioned results, MCC950 treatment at day 22 post-infection aggravated this process. Surprisingly, NLRP3 inflammasome was involved in liver fibrosis mostly from KCs.

CONCLUSIONS

MCC950 acts dually on SSLF pathology and fibrosis in infected mice. Although MCC950 treatment improved SSLF on the day of infection, it exacerbated the pathological effects at day 22 post-infection. These dual effects were mediated via NF-κB. Moreover, NLRP3 inflammasome mainly came from KCs. Our results suggest that blocking NLRP3 on the day of infection may prove to be a promising direction in preventing SSLF.

Roles of the inflammasome in the gut‑liver axis (Review)

The gut-liver axis connects the liver with the intestine via bile acid metabolism. Bile acid dysregulation leads to intestinal dysbiosis, that allows enterogenous pathogenic bacteria, including Gram-negative bacteria and their products lipopolysaccharide (LPS), into the liver via the portal vein, triggering inflammation in the liver. The inflammasome serves as an intracellular pattern recognition receptor that detects pathogens or danger signals and mediates innate immunity in the liver or gut. Specifically, the NACHT, LRR and PYD domains-containing protein (NLRP)6 inflammasome maintains intestinal microbial balance, by promoting interleukin (IL)-18-dependent antimicrobial peptide synthesis and mucus secretion from goblet cells. The NLRP3 inflammasome, in contrast, primarily induces IL-1β and aggravates inflammatory liver injury. Furthermore, the NLRP3 inflammasome affects the epithelial integrity of cholangiocytes by inducing the production of pro-inflammatory cytokines. In addition, bile acids, including deoxycholic acid and chenodeoxycholic acid, are able to activate the NLRP3 inflammasome in macrophages; however, bile acids have the potential to exert the opposite role by interacting with the membrane-bound Takeda G-protein receptor 5 or by activating nuclear farnesoid-X receptor. Therefore, further investigation of the molecular mechanisms underlying the inflammasome, involved in the gut-liver axis, may provide important insights into the identification of a potential therapeutic target for the treatment of liver and gut diseases. The present review discusses the roles of the inflammasome in the gut-liver axis, and the emerging associations between the inflammasome and the intestinal microbiota or the bile acids in the gut-liver axis.

Role of miR-223 in the pathophysiology of liver diseases. Exp Mol Med. 2018;50:128. [PMID: 30258086 PMCID: PMC6158210 DOI: 10.1038/s12276-018-0153-7]

MiRNAs are small, noncoding RNAs, which can regulate gene expression posttranscriptionally, and they have emerged as key factors in disease biology by aiding in disease development and progression. MiR-223 is highly conserved during evolution and it was first described as a modulator of hematopoietic lineage differentiation. MiR-223 has an essential part in inflammation by targeting the nuclear factor-κB pathway and the nucleotide-binding oligomerization domain-like receptor protein 3 inflammasome. Recent studies have shown that miR-223 expression is deregulated in various types of liver diseases, including hepatitis virus infections, alcohol-induced liver injury, drug-induced liver injury, non-alcoholic fatty liver disease, cirrhosis, and hepatocellular carcinoma. As inflammatory and immune factors are involved in the occurrence and progress of liver diseases, deregulated miR-223 may participate in the pathogenesis of these conditions by influencing neutrophil infiltration, macrophage polarization, and inflammasome activation. This review first summarizes the present understanding of the biological functions of miR-223, including its gene location and transcription regulation, as well as its physiological role in hematopoietic differentiation. This review then focuses on the role of miR-223 in liver pathophysiology and its potential applications as a diagnostic biomarker and therapeutic target in liver diseases.

A tiny RNA molecule involved with gene regulation may offer an appealing target for diagnosing and treating various liver diseases. MicroRNA-223 (miR-223) was first identified as controlling gene activity in a wide variety of immune cells. A review from researchers led by Yanning Liu at China’s Zhejiang University in Hangzhou details how abnormal miR-223 also contributes to liver damage in a variety of conditions, although questions still remain about how it functions in different liver disorders. The authors highlight studies linking miR-223 with the development of fibrosis and cirrhosis, and with the inflammatory response to injury from drugs, alcohol, or infection. This could make this microRNA a useful diagnostic biomarker. The authors also identify therapeutic opportunities to modulate this molecule, referring to several studies on the manipulation of miR-223 to treat hepatitis.

Inflammasome: A Double-Edged Sword in Liver Diseases

Inflammasomes have emerged as critical innate sensors of host immune that defense against pathogen infection, metabolism syndrome, cellular stress and cancer metastasis in the liver. The assembly of inflammasome activates caspase-1, which promotes the maturation of interleukin-1β (IL-1β) and interleukin-18 (IL-18), and initiates pyroptotic cell death (pyroptosis). IL-18 exerts pleiotropic effects on hepatic NK cells, priming FasL-mediated cytotoxicity, and interferon-γ (IFN-γ)-dependent responses to prevent the development of liver diseases. However, considerable attention has been attracted to the pathogenic role of inflammasomes in various acute and chronic liver diseases, including viral hepatitis, nanoparticle-induced liver injury, alcoholic and non-alcoholic steatohepatitis. In this review, we summarize the latest advances on the physiological and pathological roles of inflammasomes for further development of inflammasome-based therapeutic strategies for human liver diseases.

Loss of NLRP3 Function Alleviates Murine Hepatic Graft-versus-Host Disease

NLRP3 is associated with multiple risks in graft-versus-host disease, though unifying principles for these findings remain largely unknown. To explore the effects and mechanisms of the absence of NLRP3 function on hepatic graft-versus-host-disease, we established an allogeneic hematopoietic cell transplantation mice model by infusing bone marrow mononuclear cells and spleno-T cells of the BALB/c mouse into either NLRP3 knockout (NLRP3^-/- ) or wild-type C57BL/6 mice. Elevated inflammatory cell infiltration, liver fibrosis, and secretions of alanine aminotransferase (ALT) and aspartate transaminase (AST), together with weight loss, were observed in C57BL/6 recipients after transplantation. However, moderate injury pathology was detected in the liver of NLRP3^-/- recipients at day 14, which gradually improved over time. Likewise, proinflammatory cytokine IL-1β, a downstream effecter of NLRP3 inflammasome activation, showed significantly lower expression (P < .05) in the liver of NLRP3^-/- recipients relative to C57BL/6 recipients at day 7 and day 21. Moreover, compared with C57BL/6 recipients, the expression of both TNF-α and IL-1β were decreased 3-fold and 4.7-fold, respectively, at day 21 in NLRP3^-/- recipients. Interestingly, NLRP1a was expressed at a significantly reduced level in the liver of NLRP3^-/- recipients (P < .001). Furthermore, systemic inflammation was analyzed by measuring the concentration of IL-1β and adenosine triphosphate (ATP) in serum. The concentration of IL-1β achieved a maximum at day 14, then decreased at day 21 and day 28 in NLRP3^-/- recipients. In contrast, the concentration of IL-1β in C57BL/6 recipients gradually increased from day 7 to day 28. ATP levels reduced from day 7 to day 28 in NLRP3^-/- recipients, but were extremely high in C57BL/6 recipients from day 14 to day 28 (P < .01). The decreased levels of P2X7R were connected to less ATP in NLRP3^-/- recipients at day 21 and day 28. In conclusion, NLRP3 knockout in recipients could significantly relieve liver injury after transplantation and block the NLRP3 inflammasome pathway, thus providing a promising strategy for the treatment of graft-versus-host disease prophylaxis.

The Role of the Gut Microbiome in Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is the leading cause of chronic liver disease, with prevalence increasing in parallel with the rising incidence in obesity. Believed to be a "multiple-hit" disease, several factors contribute to NAFLD initiation and progression. Of these, the gut microbiome is gaining interest as a significant factor in NAFLD prevalence. In this paper, we provide an in-depth review of the progression of NAFLD, discussing the mechanistic modes of hepatocyte injury and the potential role for manipulation of the gut microbiome as a therapeutic strategy in the prevention and treatment of NAFLD.

Triggering and resolution of inflammation in NASH

Nonalcoholic steatohepatitis (NASH) is considered the progressive form of nonalcoholic fatty liver disease (NAFLD) and is characterized by liver steatosis, inflammation, hepatocellular injury and different degrees of fibrosis. A central issue in this field relates to the identification of those factors that trigger inflammation, thus fuelling the transition from nonalcoholic fatty liver to NASH. These triggers of liver inflammation might have their origins outside the liver (such as in adipose tissue or the gut) as well as inside the organ (for instance, lipotoxicity, innate immune responses, cell death pathways, mitochondrial dysfunction and endoplasmic reticulum stress), both of which contribute to NASH development. In this Review, we summarize the currently available information on the key upstream triggers of inflammation in NASH. We further delineate the mechanisms by which liver inflammation is resolved and the implications of a defective pro-resolution process. A better knowledge of these mechanisms should help to design targeted therapies able to halt or reverse disease progression.

NLRP3 Promotes Glioma Cell Proliferation and Invasion via the Interleukin-1β/NF-κB p65 Signals

Because of the characteristics of high invasiveness, relapse, and poor prognosis, the management of malignant gliomas has always been a great challenge. Nod-like receptor (NLR) family pyrin domain containing 3 (NLRP3) is a crucial component of the NLRP3 inflammasome, a multiprotein complex that can trigger caspase 1/interleukin-1 (IL-1)-mediated inflammatory response once activated and participates in the pathogeny of diverse inflammatory diseases as well as cancers. We examined the function of NLRP3 in the development of glioma. Glioma cells were treated with NLRP3 interference or overexpression vectors, recombinant IL-1β, IL-1β antibody, and NF-κB inhibitor. Cell proliferation and invasion were assessed by CCK-8 and Transwell assays. Gene expression was detected by PCR, Western blot, and ELISA. NLRP3 and NF-κB p65 increased and were positively correlated in glioma tissues. NLRP3 knockdown suppressed glioma cell growth and invasion with the decrease of IL-1β and NF-κB p65. Conversely, forced expression of NLRP3 promoted cell growth. NLRP3 silencing suppressed ectogenous IL-1β-elevated cell proliferation and invasion, whereas IL-1β elimination impaired the proproliferation effect of NLRP3 hyperexpression. Furthermore, NF-κB blockage abrogated IL-1β and NLRP3 hyperexpression increased cell growth and invasion. NLRP3 promoted the growth and invasion of gliomas via the IL-1β/NF-κB p65 signals.

Influence of Dietary Supplementation of Propolis and Bee Pollen on Liver Pathology in Broiler Chickens

Simple Summary

Today, there are increased demands for consumers to use natural products as alternative additives in broiler feeding. In this study, we evaluated the effects of propolis and bee pollen as potential new additives on liver pathology in broilers. The results of this study showed that supplementation of broilers with propolis and/or bee pollen has a strong protective effect on liver pathology. Thus, these natural agents can be used as alternative additives in modern broiler production. Such an approach will enable the production of chicken meat enriched with bioactive substances from propolis and/or bee pollen, such as flavonoids, that have been proven beneficial for human health.

Abstract

One of the major problems in intensive breeding of chickens is liver damage. The objective of this study was to determine the influence of dietary supplementation with propolis and bee pollen on liver pathology in broiler chickens. The study was conducted on 200 Ross 308 chickens equally distributed by sex that were divided into five groups. Throughout the whole study, the control group of chickens was fed with a basal diet, while the experimental groups of chickens were fed with the same diet further supplemented with propolis and bee pollen, each supplement given separately or in combination in a certain proportion. The study showed that the clusters of lymphocytes in the hepatocytes, the vacuolar degeneration and necrosis of the liver parenchyma, the bile ductule hyperplasia, and the various forms of pathological changes in the liver arteries and veins were more frequent in liver tissue samples of the control group compared to liver tissue samples of all the experimental groups (p < 0.001). The study further showed that all the previously mentioned histopathological lesions of liver tissue were always more extensive in the liver tissue samples of the control group than in the liver tissue samples of all the experimental groups (p < 0.001). The supplementation of broiler chickens with propolis and/or bee pollen has a strong protective effect on liver pathology in broiler chickens.

Interleukin-17A participates in podocyte injury by inducing IL-1β secretion through ROS-NLRP3 inflammasome-caspase-1 pathway

Studies show that the Th17/IL-17A axis plays an important role in the pathogenesis of kidney diseases. Previously, we also showed that IL-17A may play a role in the pathogenesis of primary nephrotic syndrome; however, the underlying mechanism(s) is unclear. The aim of this study was to explore the molecular mechanism of IL-17A-inducing podocyte injury in vitro. In this study, the NLRP3 inflammasome activation and the morphology of podocytes were detected by Western blot and immunofluorescence. The results showed that podocytes persistently expressed IL-17A receptor and that NLRP3 inflammasome in these cells was activated upon exposure to IL-17A. Also, activity of caspase-1 and secretion of IL-1β increased in the presence of IL-17A. In addition, IL-17A disrupted podocyte morphology by decreasing expression of podocin and increasing expression of desmin. Blockade of intracellular ROS or inhibition of caspase-1 prevented activation of the NLRP3 inflammasome, thereby restoring podocyte morphology. Taken together, the results suggest that IL-17A induces podocyte injury by activating the NLRP3 inflammasome and IL-1β secretion and contributes to disruption of the kidney's filtration system.

Deficiency of the Purinergic Receptor 2X7 Attenuates Nonalcoholic Steatohepatitis Induced by High-Fat Diet: Possible Role of the NLRP3 Inflammasome

Molecular mechanisms driving transition from simple steatosis to nonalcoholic steatohepatitis (NASH), a critical step in the progression of nonalcoholic fatty liver disease (NAFLD) to cirrhosis, are poorly defined. This study aimed at investigating the role of the purinergic receptor 2X₇ (PR2X₇), through the NLRP3 inflammasome, in the development of NASH. To this end, mice knockout for the Pr2x₇ gene (Pr2x₇^−/−) and coeval wild-type (WT) mice were fed a high-fat diet (HFD) or normal-fat diet for 16 weeks. NAFLD grade and stage were lower in Pr2x₇^−/− than WT mice, and only 1/7 Pr2x₇^−/− animals showed evidence of NASH, as compared with 4/7 WT mice. Molecular markers of inflammation, oxidative stress, and fibrosis were markedly increased in WT-HFD mice, whereas no or significantly reduced increments were detected in Pr2x₇^−/− animals, which showed also decreased modulation of genes of lipid metabolism. Deletion of Pr2x₇ gene was associated with blunted or abolished activation of NLRP3 inflammasome and expression of its components, which were induced in liver sinusoidal endothelial cells challenged with appropriate stimuli. These data show that Pr2x₇ gene deletion protects mice from HFD-induced NASH, possibly through blunted activation of NLRP3 inflammasome, suggesting that PR2X₇ and NLRP3 may represent novel therapeutic targets.