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3D bioprinting is a tissue engineering approach using additive manufacturing to fabricate tissue equivalents for regenerative medicine or medical drug testing. For this purpose, biomaterials that provide the essential microenvironment to support the viability of cells integrated directly or seeded after printing are processed into three-dimensional (3D) structures. Compared to extrusion-based 3D printing, which is most commonly used in bioprinting, stereolithography (SLA) offers a higher printing resolution and faster processing speeds with a wide range of cell-friendly materials such as gelatin- or collagen-based hydrogels and SLA is, therefore, well suited to generate 3D tissue constructs. While there have been numerous publications of conversions and upgrades for extrusion-based printers, this is not the case for state-of-the-art SLA technology in bioprinting. The high cost of proprietary printers severely limits teaching and research in SLA bioprinting. With mSLAb, we present a low-cost and open-source high-resolution 3D bioprinter based on masked SLA (mSLA). mSLAb is based on an entry-level (350) desktop mSLA printer (Phrozen Sonic Mini 4 K), equipped with temperature control and humidification of the printing chamber to enable the processing of cell-friendly hydrogels. Additionally, the build platform was redesigned for easy sample handling and microscopic analysis of the printed constructs. All modifications were done with off-the-shelf hardware and in-house designed 3D printed components, printed with the same printer that was being modified. We validated the system by printing macroscopic porous scaffolds as well as hollow channels from gelatin-based hydrogels as representative structures needed in tissue engineering.
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INTRODUCTION: Resection of colorectal liver metastasis has emerged as the standard treatment. Our study compares oncological outcomes of patients with resected synchronous bilobar versus unilobar colorectal liver metastasis. METHODS: This retrospective study presents long-term follow-up data of 105 consecutive patients with primary colorectal cancer and synchronous liver metastasis. All patients underwent primary tumor and metastasis resections between 2007 and 2019. RESULTS: Fifty-five patients with bilobar and 50 patients with unilobar colorectal liver metastases were included. No significant difference in overall, tumor-specific, or recurrence-free survival was observed between patients with bilobar and unilobar metastases. After case-control matching, the results were confirmed in patients with similar tumor burdens. In the multivariate analysis, chemotherapy following liver metastasis resection was a significant prognostic factor associated with improved overall survival (hazard ratio 0.518, 95% confidence interval: 0.302-0.888, p = 0.017). CONCLUSION: Overall survival, as well as tumor-specific and recurrence-free survival, did not differ between patients with unilobar and bilobar liver metastasis. These findings contribute to the understanding that primary tumor and metastasis resection in eligible patients improve long-term outcomes.
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INTRODUCTION: Cholangiocarcinoma is the second most common primary liver tumour worldwide with an increasing incidence in recent decades. While the effects of fibrosis on hepatocellular carcinoma have been widely demonstrated, the impact on cholangiocarcinoma remains unclear. The aim of this study was to evaluate the impact of liver fibrosis on overall survival (OS) and disease-free survival (DFS) in patients who have undergone liver resection for cholangiocarcinoma. METHODS: Eighty patients with cholangiocarcinoma who underwent curatively intended liver surgery between January 2007 and December 2020 were included in this retrospective single-centre study. Clinical and histopathological features were analysed. The primary endpoint was cause-specific survival. Secondary endpoints were DFS and identification of prognostic factors. RESULTS: The present study shows that the median OS is significantly reduced in patients with fibrosis (p < 0.001). The median OS in patients with fibrosis was three times shorter than in the group without fibrosis. In addition, a significantly shorter DFS was observed in patients with fibrosis (p < 0.002). Multivariate analysis showed that fibrosis is the strongest independent factor with a negative impact on OS and DFS. CONCLUSION: Liver fibrosis has a significant impact on OS and DFS in patients with cholangiocarcinoma. Patients with known liver fibrosis require thorough perioperative care and postoperative follow-up.
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Neoplasias de los Conductos Biliares , Carcinoma Hepatocelular , Colangiocarcinoma , Neoplasias Hepáticas , Humanos , Estudios Retrospectivos , Colangiocarcinoma/complicaciones , Colangiocarcinoma/cirugía , Carcinoma Hepatocelular/cirugía , Neoplasias Hepáticas/patología , Cirrosis Hepática/complicaciones , Fibrosis , Conductos Biliares Intrahepáticos/cirugía , Conductos Biliares Intrahepáticos/patología , Neoplasias de los Conductos Biliares/complicaciones , Neoplasias de los Conductos Biliares/cirugía , Pronóstico , Recurrencia Local de Neoplasia/patología , HepatectomíaRESUMEN
INTRODUCTION: Hepatic fibrosis is a progressive pathological process involving the exhaustion of hepatocellular regenerative capacity and ultimately leading to the development of cirrhosis and even hepatocellular carcinoma. Brg1, the core subunit of the SWI/SNF chromatin-remodeling complex, was recently identified as important for liver regeneration. This study investigates the role of Brg1 in hepatic fibrosis development. METHODS: Hepatocyte-specific Brg1 knockout mice were generated and injected with carbon tetrachloride (CCl4) for 4, 6, 8, and 12 weeks to induce liver fibrosis. Afterwards, liver fibrosis and liver damage were assessed. RESULTS: Brg1 expression was significantly increased in the fibrotic liver tissue of wild-type mice, as compared to that of untreated wild-type mice. The livers of the Brg1 knockout animals showed reduced liver inflammation, extracellular matrix accumulation, and liver fibrosis. TNF-α and NF-κB-mediated inflammatory response was reduced in Brg1 knockout animals. CONCLUSION: Brg1 promotes the progression of liver fibrosis in mice and may therefore be used as a potential therapeutic target for treating patients with liver fibrosis due to chronic injury.
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Carcinoma Hepatocelular , Hepatitis , Neoplasias Hepáticas , Animales , Ratones , Tetracloruro de Carbono/toxicidad , Carcinoma Hepatocelular/patología , Matriz Extracelular/metabolismo , Fibrosis , Hepatitis/patología , Inflamación/patología , Hígado/metabolismo , Cirrosis Hepática/inducido químicamente , Cirrosis Hepática/genética , Cirrosis Hepática/metabolismo , Neoplasias Hepáticas/patología , Ratones NoqueadosRESUMEN
Antisense oligonucleotides (ASOs) are a novel therapeutic strategy that targets a specific gene and suppresses its expression. The cryopyrin-associated periodic syndromes (CAPS) are a spectrum of autoinflammatory diseases characterized by systemic and tissue inflammation that is caused by heterozygous gain-of-function mutations in the nucleotide-binding and oligomerization domain-like receptor (NLR) family pyrin domain containing 3 (NLRP3) gene. The aim of this study was to investigate the efficacy of an Nlrp3-specific ASO treatment in CAPS. An Nlrp3-specific ASO was designed and tested in murine cell lines and bone marrow-derived macrophages (BMDMs) from wild-type and CAPS mouse models. Nlrp3 knock-in mice were treated in vivo with Nlrp3-specific ASO, survival was monitored, and expression of organ-specific Nlrp3 and IL-1ß was measured. Nlrp3-specific ASO treatment of murine cell lines and BMDMs showed a significant downregulation of Nlrp3 and mature IL-1ß protein expression. Ex vivo treatment of Nlrp3 mutant mouse-derived BMDMs with Nlrp3-specific ASO demonstrated significantly reduced IL-1ß release. In vivo, Nlrp3-specific ASO treatment of Nlrp3 mutant mice prolonged survival, reduced systemic inflammation, and decreased tissue-specific expression of Nlrp3 and mature IL-1ß protein. The results of this study demonstrate that Nlrp3-specific ASO treatment downregulates Nlrp3 expression and IL-1ß release in CAPS models, suggesting ASO therapy as a potential treatment of CAPS and other NLRP3-mediated diseases.
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Síndromes Periódicos Asociados a Criopirina , Proteína con Dominio Pirina 3 de la Familia NLR , Ratones , Animales , Proteína con Dominio Pirina 3 de la Familia NLR/genética , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo , Inflamasomas/metabolismo , Síndromes Periódicos Asociados a Criopirina/genética , Inflamación , Proteínas Portadoras/genética , Interleucina-1beta/metabolismoRESUMEN
The use of probiotics, prebiotics, and synbiotics has become an important therapy in numerous gastrointestinal diseases in recent years. Modifying the gut microbiota, this therapeutic approach helps to restore a healthy microbiome. Nonalcoholic fatty liver disease and alcohol-associated liver disease are among the leading causes of chronic liver disease worldwide. A disrupted intestinal barrier, microbial translocation, and an altered gut microbiome metabolism, or metabolome, are crucial in the pathogenesis of these chronic liver diseases. As pro-, pre-, and synbiotics modulate these targets, they were identified as possible new treatment options for liver disease. In this review, we highlight the current findings on clinical and mechanistic effects of this therapeutic approach in nonalcoholic fatty liver disease and alcohol-associated liver disease.
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Hepatopatías Alcohólicas , Enfermedad del Hígado Graso no Alcohólico , Probióticos , Simbióticos , Humanos , Prebióticos , Enfermedad del Hígado Graso no Alcohólico/terapia , Probióticos/uso terapéutico , IntestinosRESUMEN
Chitinase-3-like 1 protein (CHI3L1) is a secreted glycoprotein, strongly correlated with fibrosis severity in chronic liver diseases including non-alcoholic steatohepatitis (NASH). However, the mechanisms by which CHI3L1 contributes to fibrogenesis remain undefined. Here, we showed that infiltrating monocyte-derived liver macrophages represent the main source of CHI3L1 in murine NASH. We developed a floxed CHI3L1 knock-out (KO) mouse to further study the cell-specific role of CHI3L1 ablation. Wildtype (WT) and myeloid cell-specific CHI3L1 KO mice (CreLyz) were challenged with a highly inflammatory and fibrotic dietary model of NASH by administering choline-deficient high-fat diet for 10 weeks. Macrophage accumulation and inflammatory cell recruitment were significantly ameliorated in the CreLyz group compared to WT (F4/80 IHC p < 0.0001, CD11b IHC p < 0.0001). Additionally, hepatic stellate cell (HSC) activation and fibrosis were strongly decreased in this group (α-SMA IHC p < 0.0001, picrosirius red staining p < 0.0001). In vitro studies were performed stimulating bone marrow derived macrophages, THP-1 (human monocytes) and LX2 (human HSCs) cells with recombinant CHI3L1 to dissect its relationship with fibrosis development. Results showed an important role of CHI3L1 regulating fibrosis-promoting factors by macrophages (TGFB1 p < 0.05, CTGF p < 0.01) while directly activating HSCs (ACTA2 p < 0.01, COL1A1 p < 0.01), involving IL13Rα2 as the potential mediator. Our findings uncovered a novel role of CHI3L1 derived from liver macrophages in NASH progression and identifies this protein as a potential anti-fibrotic therapeutic target. KEY MESSAGES: We showed that CHI3L1 expression is increased in murine CDAA-HFAT diet NASH model, and that infiltrating macrophages are a key source of CHI3L1 production. Myeloid cell-specific CreLyz CHI3L1 knock-out in mice fed with CDAA-HFAT diet improved the NASH phenotype, with significantly reduced accumulation of pro-inflammatory macrophages and neutrophils compared with WT group. DEG and qPCR analysis of genes in CreLyz CHI3L1 knock-out mouse liver showed the mechanistic role of CHI3L1 in cellular chemotaxis. HSC is directly activated by CHI3L1 via receptor IL13Rα2, leading to upregulation of collagen deposition and pro-fibrotic gene, TIMP-1 and TIMP-2 release in whole liver. Direct stimulation of macrophages with CHI3L1 leads to upregulated expression of HSC-activation factors, suggesting its role in modulating macrophage-HSC crosstalk.
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Quitinasas , Subunidad alfa2 del Receptor de Interleucina-13 , Enfermedad del Hígado Graso no Alcohólico , Ratones , Humanos , Animales , Enfermedad del Hígado Graso no Alcohólico/genética , Enfermedad del Hígado Graso no Alcohólico/metabolismo , Quitinasas/metabolismo , Subunidad alfa2 del Receptor de Interleucina-13/metabolismo , Hígado/metabolismo , Cirrosis Hepática/metabolismo , Dieta Alta en Grasa/efectos adversos , Ratones Noqueados , Ratones Endogámicos C57BL , Modelos Animales de EnfermedadRESUMEN
BACKGROUND AND AIMS: Nucleotide-binding oligomerization domain-like receptor-family pyrin domain-containing 3 (NLRP3) inflammasome activation has been shown to result in liver fibrosis. Mechanisms and downstream signaling remain incompletely understood. Here, we studied the role of IL-18 in hepatic stellate cells (HSCs), and its impact on liver fibrosis. APPROACH AND RESULTS: We observed significantly increased serum levels of IL-18 (128.4 pg/ml vs. 74.9 pg/ml) and IL-18 binding protein (BP; 46.50 ng/ml vs. 15.35 ng/ml) in patients with liver cirrhosis compared with healthy controls. Single cell RNA sequencing data showed that an immunoregulatory subset of murine HSCs highly expresses Il18 and Il18r1 . Treatment of cultured primary murine HSC with recombinant mouse IL-18 accelerated their transdifferentiation into myofibroblasts. In vivo , IL-18 receptor-deficient mice had reduced liver fibrosis in a model of fibrosis induced by HSC-specific NLRP3 overactivation. Whole liver RNA sequencing analysis from a murine model of severe NASH-induced fibrosis by feeding a choline-deficient, L-amino acid-defined, high fat diet showed that genes related to IL-18 and its downstream signaling were significantly upregulated, and Il18-/- mice receiving this diet for 10 weeks showed protection from fibrotic changes with decreased number of alpha smooth muscle actin-positive cells and collagen deposition. HSC activation triggered by NLRP3 inflammasome activation was abrogated when IL-18 signaling was blocked by its naturally occurring antagonist IL-18BP. Accordingly, we observed that the severe inflammatory phenotype associated with myeloid cell-specific NLRP3 gain-of-function was rescued by IL-18BP. CONCLUSIONS: Our study highlights the role of IL-18 in the development of liver fibrosis by its direct effect on HSC activation identifying IL-18 as a target to treat liver fibrosis.
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Células Estrelladas Hepáticas , Inflamasomas , Ratones , Animales , Inflamasomas/metabolismo , Células Estrelladas Hepáticas/metabolismo , Interleucina-18 , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo , Cirrosis Hepática/patología , Fibrosis , Proteínas Portadoras/metabolismo , Hígado/patologíaRESUMEN
Sterile inflammation is a central element in liver diseases. The immune response following injurious stimuli involves hepatic infiltration of neutrophils and monocytes. Neutrophils are major effectors of liver inflammation, rapidly recruited to sites of inflammation, and can augment the recruitment of other leukocytes. The NLRP3 inflammasome has been increasingly implicated in severe liver inflammation, fibrosis, and cell death. In this study, the role of NLRP3 activation in neutrophils during liver inflammation and fibrosis was investigated. Mouse models with neutrophil-specific expression of mutant NLRP3 were developed. Mutant mice develop severe liver inflammation and lethal autoinflammation phenocopying mice with a systemic expression of mutant NLRP3. NLRP3 activation in neutrophils leads to a pro-inflammatory cytokine and chemokine profile in the liver, infiltration by neutrophils and macrophages, and an increase in cell death. Furthermore, mutant mice develop liver fibrosis associated with increased expression of pro-fibrogenic genes. Taken together, the present work demonstrates how neutrophils, driven by the NLRP3 inflammasome, coordinate other inflammatory myeloid cells in the liver, and propagate the inflammatory response in the context of inflammation-driven fibrosis.
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Hepatitis , Inflamasomas , Ratones , Animales , Inflamasomas/genética , Proteína con Dominio Pirina 3 de la Familia NLR/genética , Neutrófilos/metabolismo , Hepatitis/genética , Fibrosis , Inflamación/metabolismo , Interleucina-1beta/metabolismoRESUMEN
BACKGROUND & AIMS: Nonalcoholic fatty liver disease (NAFLD) is the leading cause of chronic liver disease worldwide. The NLRP3 inflammasome, a platform for caspase-1 activation and release of interleukin 1ß, is increasingly recognized in the induction of inflammation and liver fibrosis during NAFLD. However, the cell-specific contribution of NLRP3 inflammasome activation in NAFLD remains unknown. METHODS: To investigate the role of NLRP3 inflammasome activation in hepatocytes, hepatic stellate cells (HSCs) and myeloid cells, a conditional Nlrp3 knock-out mouse was generated and bred to cell-specific Cre mice. Both acute and chronic liver injury models were used: lipopolysaccharide/adenosine-triphosphate to induce in vivo NLRP3 activation, choline-deficient, L-amino acid-defined high-fat diet, and Western-type diet to induce fibrotic nonalcoholic steatohepatitis (NASH). In vitro co-culture studies were performed to dissect the crosstalk between myeloid cells and HSCs. RESULTS: Myeloid-specific deletion of Nlrp3 blunted the systemic and hepatic increase in interleukin 1ß induced by lipopolysaccharide/adenosine-triphosphate injection. In the choline-deficient, L-amino acid-defined high-fat diet model of fibrotic NASH, myeloid-specific Nlrp3 knock-out but not hepatocyte- or HSC-specific knock-out mice showed significant reduction in inflammation independent of steatosis development. Moreover, myeloid-specific Nlrp3 knock-out mice showed ameliorated liver fibrosis and decreased HSC activation. These results were validated in the Western-type diet model. In vitro co-cultured studies with human cell lines demonstrated that HSC can be activated by inflammasome stimulation in monocytes, and this effect was significantly reduced if NLRP3 was downregulated in monocytes. CONCLUSIONS: The study provides new insights in the cell-specific role of NLRP3 in liver inflammation and fibrosis. NLRP3 inflammasome activation in myeloid cells was identified as crucial for the progression of NAFLD to fibrotic NASH. These results may have implications for the development of cell-specific strategies for modulation of NLRP3 activation for treatment of fibrotic NASH.
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Inflamasomas , Cirrosis Hepática , Células Mieloides , Proteína con Dominio Pirina 3 de la Familia NLR , Enfermedad del Hígado Graso no Alcohólico , Adenosina , Aminoácidos , Animales , Caspasas , Colina , Hepatitis/genética , Hepatitis/inmunología , Humanos , Inflamasomas/genética , Inflamasomas/inmunología , Inflamación , Interleucina-1beta/inmunología , Lipopolisacáridos , Cirrosis Hepática/genética , Cirrosis Hepática/inmunología , Ratones , Ratones Noqueados , Células Mieloides/inmunología , Proteína con Dominio Pirina 3 de la Familia NLR/genética , Proteína con Dominio Pirina 3 de la Familia NLR/inmunología , Enfermedad del Hígado Graso no Alcohólico/genética , Enfermedad del Hígado Graso no Alcohólico/inmunología , PolifosfatosRESUMEN
Biomaterials composed of synthetic cells have the potential to adapt and differentiate guided by physicochemical environmental cues. Inspired by biological systems in development, which extract positional information (PI) from morphogen gradients in the presence of uncertainties, we here investigate how well synthetic cells can determine their position within a multicellular structure. To calculate PI, we created and analyzed a large number of synthetic cellular assemblies composed of emulsion droplets connected via lipid bilayer membranes. These droplets contained cell-free feedback gene circuits that responded to gradients of a genetic inducer acting as a morphogen. PI is found to be limited by gene expression noise and affected by the temporal evolution of the morphogen gradient and the cell-free expression system itself. The generation of PI can be rationalized by computational modeling of the system. We scale our approach using three-dimensional printing and demonstrate morphogen-based differentiation in larger tissue-like assemblies.
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BACKGROUND AND AIMS: The NOD-like receptor protein 3 (NLRP3) inflammasome is a central contributor to human acute and chronic liver disease, yet the molecular and cellular mechanisms by which its activation precipitates injury remain incompletely understood. Here, we present single cell transcriptomic profiling of livers from a global transgenic tamoxifen-inducible constitutively activated Nlrp3A350V mutant mouse, and we investigate the changes in parenchymal and nonparenchymal liver cell gene expression that accompany inflammation and fibrosis. APPROACH AND RESULTS: Our results demonstrate that NLRP3 activation causes chronic extramedullary myelopoiesis marked by myeloid progenitors that differentiate into proinflammatory neutrophils, monocytes, and monocyte-derived macrophages. We observed prominent neutrophil infiltrates with increased Ly6gHI and Ly6gINT cells exhibiting transcriptomic signatures of granulopoiesis typically found in the bone marrow. This was accompanied by a marked increase in Ly6cHI monocytes differentiating into monocyte-derived macrophages that express transcriptional programs similar to macrophages of NASH models. NLRP3 activation also down-regulated metabolic pathways in hepatocytes and shifted hepatic stellate cells toward an activated profibrotic state based on expression of collagen and extracellular matrix regulatory genes. CONCLUSIONS: These results define the single cell transcriptomes underlying hepatic inflammation and fibrosis precipitated by NLRP3 activation. Clinically, our data support the notion that NLRP3-induced mechanisms should be explored as therapeutic target in NASH-like inflammation.
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Proteína con Dominio Pirina 3 de la Familia NLR , Enfermedad del Hígado Graso no Alcohólico , Animales , Fibrosis , Humanos , Inflamasomas/metabolismo , Inflamación , Ratones , Proteína con Dominio Pirina 3 de la Familia NLR/fisiología , Proteínas NLRRESUMEN
Inflammatory changes in the liver represent a key feature of non-alcoholic steatohepatitis (NASH), the progressive form of non-alcoholic fatty liver disease (NAFLD). Innate immune activation including hepatic neutrophilic infiltration acts as an important inflammatory trigger as well as a potential mediator of inflammation resolution. In this study, we dissected the effects of neutrophil depletion via anti-lymphocyte antigen 6 complex locus G6D (Ly6G) antibodies administration during ongoing high fat-fructose-cholesterol (FFC) diet-induced murine NASH and during inflammation resolution by switching into a low-fat control diet. During NASH progression, protective effects were shown as HSC activation, cell infiltration and activation of pro-inflammatory macrophages were ameliorated. Furthermore, these changes were contrasted with the effects observed when neutrophil depletion was performed during the resolution phase. Impaired resolving mechanisms, such as a failure to balance the pro and anti-inflammatory cytokines ratio, deficient macrophage phenotypic switch into a pro-restorative profile, and defective repair and remodeling processes were observed when neutrophils were depleted in this scenario. This study described phase-dependent contrasting roles of neutrophils as triggers and pro-resolutive mediators of liver injury and fibrosis associated with diet-induced NASH in mice. These findings have important translational implications at the time of designing NASH therapeutic strategies.
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Cirrosis Hepática/metabolismo , Neutrófilos/metabolismo , Animales , Citocinas/metabolismo , Dieta Alta en Grasa , Modelos Animales de Enfermedad , Fructosa/metabolismo , Hidroxiprolina/metabolismo , Hígado , Macrófagos/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Enfermedad del Hígado Graso no Alcohólico/metabolismoRESUMEN
The acronym nonalcoholic fatty-liver disease (NAFLD) groups a heterogeneous patient population. Although in many patients the primary driver is metabolic dysfunction, a complex and dynamic interaction of different factors (i.e., sex, presence of one or more genetic variants, coexistence of different comorbidities, diverse microbiota composition, and various degrees of alcohol consumption among others) takes place to determine disease subphenotypes with distinct natural history and prognosis and, eventually, different response to therapy. This review aims to address this topic through the analysis of existing data on the differential contribution of known factors to the pathogenesis and clinical expression of NAFLD, thus determining the different clinical subphenotypes observed in practice. To improve our understanding of NAFLD heterogeneity and the dominant drivers of disease in patient subgroups would predictably impact on the development of more precision-targeted therapies for NAFLD.
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Enfermedad del Hígado Graso no Alcohólico , Comorbilidad , Humanos , Enfermedad del Hígado Graso no Alcohólico/diagnóstico , Enfermedad del Hígado Graso no Alcohólico/epidemiología , Enfermedad del Hígado Graso no Alcohólico/genética , PronósticoRESUMEN
Traditional concepts have classically viewed resolution of inflammation as a passive process yet insight into the pathways by which inflammation is resolved has challenged this idea. Resolution has been revealed as a highly dynamic and active event that is essential to counteract the dysregulated inflammatory response that drives diverse disease states. Abrogation of the hepatic inflammatory response through the stimulation of proresolving mechanisms represents a new paradigm in the setting of chronic inflammatory-driven liver diseases. Elucidation of the role of different cells of the innate and adaptive immune system has highlighted the interplay between them as an important orchestrator of liver repair. A finely tuned interaction between neutrophils and macrophages has risen as revolutionary mechanism that drives the restoration of hepatic function and architecture. Specialized proresolving mediators have also been shown to act as stop signals of the inflammatory response and promote resolution as well as tissue regeneration. In this review, we discuss the discovery and understanding of the mechanisms by which inflammation is resolved and highlight novel proresolving pathways that represent promising therapeutic strategies.
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Hepatitis , Inflamación , Humanos , Mediadores de Inflamación , MacrófagosRESUMEN
BACKGROUND: Nonalcoholic fatty liver disease (NAFLD) has become the most common form of chronic liver disease in both adults and children worldwide. Understanding the pathogenic mechanisms behind NAFLD provides the basis for identifying risk factors, such as metabolic syndrome, pancreatoduodenectomy, and host genetics, that lead to the onset and progression of the disease. The progression from steatosis to more severe forms, such as steatohepatitis, fibrosis, and cirrhosis, leads to an increased number of liver and non-liver complications. PURPOSE: NAFLD-associated end-stage liver disease (ESLD) and hepatocellular carcinoma (HCC) often require surgery as the only curative treatment. In particular, the presence of NAFLD together with the coexisting metabolic comorbidities that usually occur in these patients requires careful preoperative diagnosis and peri-/postoperative management. Bariatric surgery, liver resection, and liver transplantation (LT) have shown favorable results for weight loss, HCC, and ESLD in patients with NAFLD. The LT demand and the increasing spread of NAFLD in the donor pool reinforce the already existing lack of donor organs. CONCLUSION: In this review, we will discuss the diverse mechanisms underlying NAFLD, its implications for surgery, and the challenges for patient management.
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Carcinoma Hepatocelular , Neoplasias Hepáticas , Enfermedad del Hígado Graso no Alcohólico , Carcinoma Hepatocelular/patología , Progresión de la Enfermedad , Humanos , Hígado/patología , Cirrosis Hepática/patología , Neoplasias Hepáticas/epidemiología , Neoplasias Hepáticas/patología , Neoplasias Hepáticas/cirugía , Enfermedad del Hígado Graso no Alcohólico/epidemiología , Enfermedad del Hígado Graso no Alcohólico/patologíaRESUMEN
BACKGROUND & AIMS: Increased hepatocyte death contributes to the pathology of acute and chronic liver diseases. However, the role of hepatocyte pyroptosis and extracellular inflammasome release in liver disease is unknown. METHODS: We used primary mouse and human hepatocytes, hepatocyte-specific leucine 351 to proline Nlrp3KICreA mice, and GsdmdKO mice to investigate pyroptotic cell death in hepatocytes and its impact on liver inflammation and damage. Extracellular NOD-, LRR-, and pyrin domain-containing protein 3 (NLRP3) inflammasomes were isolated from mutant NLRP3-YFP HEK cells and internalisation was studied in LX2 and primary human hepatic stellate cells. We also examined a cohort of 154 adult patients with biopsy-proven non-alcoholic fatty liver disease (Sir Charles Gairdner Hospital, Nedlands, Western Australia). RESULTS: We demonstrated that primary mouse and human hepatocytes can undergo pyroptosis upon NLRP3 inflammasome activation with subsequent release of NLRP3 inflammasome proteins that amplify and perpetuate inflammasome-driven fibrogenesis. Pyroptosis was inhibited by blocking caspase-1 and gasdermin D activation. The activated form of caspase-1 was detected in the livers and in serum from patients with non-alcoholic steatohepatitis and correlated with disease severity. Nlrp3KICreA mice showed spontaneous liver fibrosis under normal chow diet, and increased sensitivity to liver damage and inflammation after treatment with low dose lipopolysaccharide. Mechanistically, hepatic stellate cells engulfed extracellular NLRP3 inflammasome particles leading to increased IL-1ß secretion and α-smooth muscle actin expression. This effect was abrogated when cells were pre-treated with the endocytosis inhibitor cytochalasin B. CONCLUSIONS: These results identify hepatocyte pyroptosis and release of inflammasome components as a novel mechanism to propagate liver injury and liver fibrosis development. LAY SUMMARY: Our findings identify a novel mechanism of inflammation in the liver. Experiments in cell cultures, mice, and human samples show that a specific form of cell death, called pyroptosis, leads to the release of complex inflammatory particles, the NLRP3 inflammasome, from inside hepatocytes into the extracellular space. From there they are taken up by other cells and thereby mediate inflammatory and pro-fibrogenic stress signals. The discovery of this mechanism may lead to novel treatments for chronic liver diseases in the future.
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Hepatocitos , Inflamasomas/metabolismo , Interleucina-1beta/metabolismo , Cirrosis Hepática , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo , Piroptosis/inmunología , Animales , Caspasa 1/metabolismo , Células Estrelladas Hepáticas/metabolismo , Células Estrelladas Hepáticas/patología , Hepatocitos/metabolismo , Hepatocitos/patología , Humanos , Cirrosis Hepática/inmunología , Cirrosis Hepática/metabolismo , Ratones , Ratones Endogámicos NOD , Enfermedad del Hígado Graso no Alcohólico/metabolismo , Enfermedad del Hígado Graso no Alcohólico/patología , Sistemas de Translocación de Proteínas/metabolismo , Especies Reactivas de Oxígeno/metabolismoRESUMEN
Between 2007 and 2016, 140 consecutive patients who underwent resection of colorectal cancer with simultaneous liver metastases at a single university hospital were retrospectively analysed. In order to gather information regarding potential survival differences for nâ¯=â¯68 simultaneous versus nâ¯=â¯72 staged resections of the colorectal primary tumor and the liver metastases, Clinical, histopathological, serological, and survival data were compared for those two patient groups. The rate of simultaneous tumor resections increased from approximately 25% in 2007 to >75% in 2016. There was no difference in tumor specific survival for patients with simultaneous vs. staged resection (pâ¯=â¯0.631). This effect continued after excluding patients with extrahepatic metastases (pâ¯=â¯0.440). Further, neoadjuvant treatment did not lead to differences in the tumor-specific survival (pâ¯=â¯0.123). Factors associated with an increased tumor-specific survival were low ASA score (p < 0.001), low number of tumor-affected lymph nodes (p < 0.001), histological grading G1/2 (pâ¯=â¯0.001), and a low number of liver metastases (pâ¯=â¯0.044). There was no significant survival difference for the primary tumor stage (pT), the Clavien-Dindo complication rate, the resection status (R0), and minor versus major hepatectomies.