RESUMO
Liver transplantation (LT) rejection remains the most pervasive problem associated with this procedure, while the mechanism involved is still complicated and undefined. One promising solution may involve the use of myeloid-derived suppressor cells (MDSC). However, the immunological mechanisms underlying the effects of MDSC after LT remain unclear. This study is meant to clarify the role MDSCs play after liver transplantation. In this study, we collected liver tissue and peripheral blood mononuclear cells (PBMC) from LT patients showing varying degrees of rejection, as well as liver and spleen tissue samples from mice LT models. These samples were then analyzed using flow cytometry, immunohistochemistry and multiple immunofluorescence. M-MDSCs and CD8 + T-cells extracted from C57/BL6 mice were enriched and cocultured for in vitro experiments. Results, as obtained in both LT patients and LT mice model, revealed that the proportion and frequency of M-MDSC and PD-1 + T-cells increased significantly under conditions associated with a high degree of LT rejection. Within the LT rejection group, our immunofluorescence results showed that a close spatial contiguity was present between PD-1 + T-cells and M-MDSCs in these liver tissue samples and the proportion of CD84/PD-L1 double-positive M-MDSC was greater than that of G-MDSC. There was a positive correlation between the activity of CD84 and immunosuppressive function of M-MDSCs including PD-L1 expression and reactive oxygen species (ROS) production, as demonstrated in our in vitro model. M-MDSCs treated with CD84 protein were able to induce co-cultured CD8 + T-cells to express high levels of exhaustion markers. We found that CD84 regulated M-MDSC function via expression of PD-L1 through activation of the Akt/Stat3 pathway. These results suggest that the capacity for CD84 to regulate M-MDSC induction of CD8 + T-cell exhaustion may play a key role in LT rejection. Such findings provide important, new insights into the mechanisms of tolerance induction in LT.
Assuntos
Linfócitos T CD8-Positivos , Rejeição de Enxerto , Transplante de Fígado , Camundongos Endogâmicos C57BL , Células Supressoras Mieloides , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Animais , Células Supressoras Mieloides/metabolismo , Células Supressoras Mieloides/imunologia , Rejeição de Enxerto/imunologia , Humanos , Camundongos , Masculino , Pessoa de Meia-Idade , Feminino , Adulto , Fator de Transcrição STAT3/metabolismo , Receptor de Morte Celular Programada 1/metabolismo , Fígado/patologia , Fígado/metabolismoRESUMO
Fms-like tyrosine kinase 3 (FLT3) is a receptor tyrosine kinase (RTK) primarily expressed in hematopoietic stem cells and dendritic cells (DCs). While FLT3 plays a critical role in the proliferation, development and maintenance of DCs, thus influencing immune responses under both normal and pathological conditions, there also exists some evidence that FLT3+DC may be involved with immune responses in liver transplantation (LT). In this study, results from single-cell sequencing data analysis revealed a clear relationship between FLT3+DCs and Regulatory T cells (Tregs) in liver tissue of LT recipients. In peripheral blood samples of LT patients, levels of FLT3+DCs were decreased post-LT-surgery, while Tregs were increased. In a LT mouse model, levels of FLT3+DCs in the liver and bone marrow exhibited an initial time-dependent decrease followed by an increase after LT surgery. Results as obtained with co-culture experiments using mature BMDCs and CD4+ T cells revealed fluctuations in Tregs in response to FLT3 inhibitors and the FLT3 ligand. These findings suggest that FLT3+DCs could emerge as a novel target for mitigating immune rejection in LT.
Assuntos
Células Dendríticas , Rejeição de Enxerto , Transplante de Fígado , Camundongos Endogâmicos C57BL , Linfócitos T Reguladores , Tirosina Quinase 3 Semelhante a fms , Linfócitos T Reguladores/imunologia , Animais , Células Dendríticas/imunologia , Tirosina Quinase 3 Semelhante a fms/metabolismo , Humanos , Rejeição de Enxerto/imunologia , Rejeição de Enxerto/prevenção & controle , Masculino , Camundongos , Fígado/imunologia , Feminino , Técnicas de Cocultura , Pessoa de Meia-Idade , Células Cultivadas , Camundongos Endogâmicos BALB C , Proteínas de MembranaRESUMO
BACKGROUND: Exosomes exert considerable influence in mediating regulatory T (Treg) cells differentiation, which attach great importance to attenuating acute cellular rejection after liver transplantation (LT). And, miRNAs are known to play essential roles in cell-cell communication delivered by exosomes. However, the function of exosomal miRNAs in regulating Treg cells after LT remains unknown. Here, we performed an expression profiling analysis of exosome-miRNAs from human plasma after LT and investigated their immunoregulatory effects on Treg cells. METHODS: Fifty-eight LT patients and nine donors were included in this report. miRNA profiles in plasma exosomes were analyzed using next-generation sequencing. Flow cytometry, HE and multiplex immunofluorescent staining were used to identify Treg cells in the liver and peripheral blood. A lentiviral vector system was used to overexpress miR-193b-3p in dendritic cells (DCs), and exosomes isolated from these transfected cells were co-cultured with spleen lymphocytesin vitro. A quantitative Real-time PCR and enzyme-linked immunosorbent assay were used to detect the expression of cytokines. RESULTS: Treg cell infiltration was increased in the liver along with Th17 and CD8+ T cell, and it was down-regulated in peripheral blood in the acute rejection group. High-throughput sequencing revealed that miR-193b-3p was markedly up-regulated in plasma exosomes of non-rejection LT patients. The NLRP3 inflammasome was screened as a target for miR-193b-3p based on target prediction and functional enrichment analyses. Exosomal miR-193b-3p derived from DCs increased Treg cells as demonstrated in vitro. miR-193b-3p overexpression down-regulated NLRP3 as well as the inflammatory cytokines IL-1ß and IL-17A while increasing levels of the cytokines IL-10 and TGF-ß. CONCLUSION: DC derived exosomal miR-193b-3p promoted Treg cells by inhibiting NLRP3 expression. These findings not only provide a new perspective on the mechanisms, but also hold great promise for the treatment or prevention of liver allograft rejection.
Assuntos
Transplante de Fígado , MicroRNAs , Humanos , Linfócitos T Reguladores/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR , MicroRNAs/metabolismo , Fator de Crescimento Transformador beta , Células Dendríticas/metabolismoRESUMO
BACKGROUND: Ischemia-reperfusion injury (IRI) is a major risk associated with liver surgery and transplantation, and its pathological mechanism is complex. Interleukin-1 receptor antagonist (IL-1ra) can protect the liver from IRI. However, the regulatory mechanism of IL-1ra expression is still unclear. AIM: To identify the mechanism that could protect the liver in the early stage of IRI. METHODS: To screen the key genes in hepatic IRI, we performed RNA sequencing and gene enrichment analysis on liver tissue from mice with hepatic IRI. Subsequently, we verified the expression and effect of IL-1ra in hepatic IRI. We also used promoter mutagenesis and chromatin immunoprecipitation assay to search for the transcriptional regulatory sites of hypoxia-inducible factor (HIF)-1α. Finally, to explore the protective mechanism of ischemic preconditioning (IP), we examined the expression of HIF-1α and IL-1ra after IP. RESULTS: We identified IL-1ra as a key regulator in hepatic IRI. The expression of IL-1ra was significantly upregulated after hepatic IRI both in vivo and in vitro. Furthermore, we found that HIF-1α regulated Il-1ra transcription in response to hypoxia. Increased HIF-1α accumulation promoted IL-1ra expression, whereas inhibition of HIF-1α exhibited the opposite effect. We also confirmed a predominant role for hypoxia response element in the regulation of Il1ra transcription by HIF-1α activation. Of note, we demonstrated that IP protects against hepatic IRI by inducing IL-1ra expression, which is mediated through HIF-1α. CONCLUSION: We demonstrated that ischemia or hypoxia leads to increased expression of IL-1ra through HIF-1α. Importantly, IP protects the liver from IRI via the HIF-1α-IL-1ra pathway.
Assuntos
Subunidade alfa do Fator 1 Induzível por Hipóxia , Proteína Antagonista do Receptor de Interleucina 1 , Traumatismo por Reperfusão , Animais , Camundongos , Hipóxia/patologia , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Fígado/patologia , Traumatismo por Reperfusão/patologiaRESUMO
BACKGROUND: Explanted livers from patients with inherited metabolic liver diseases possess the potential to be a cell source of good-quality hepatocytes for hepatocyte transplantation (HT). This study evaluated the therapeutic effects of domino HT using hepatocytes isolated from explanted human livers for acute liver failure (ALF). METHODS: Isolated hepatocytes were evaluated for viability and function and then transplanted into D-galactosamine/lipopolysaccharide-induced ALF mice via splenic injection. The survival rate was analyzed by the Kaplan-Meier method and log-rank test. Liver function was evaluated by serum biochemical parameters, and inflammatory cytokine levels were measured by ELISA. The pathological changes in the liver tissues were assessed by hematoxylin-eosin staining. Hepatocyte apoptosis was investigated by TUNEL, and hepatocyte apoptosis-related proteins were detected by western blot. The localization of human hepatocytes in the injured mouse livers was detected by immunohistochemical analyses. RESULTS: Hepatocytes were successfully isolated from explanted livers of 10 pediatric patients with various liver-based metabolic disorders, with an average viability of 85.3% ± 13.0% and average yield of 9.2 × 106 ± 3.4 × 106 cells/g. Isolated hepatocytes had an excellent ability to secret albumin, produce urea, uptake indocyanine green, storage glycogen, and express alpha 1 antitrypsin, albumin, cytokeratin 18, and CYP3A4. Domino HT significantly reduced mortality, decreased serum levels of alanine aminotransferase and aspartate aminotransferase, and improved the pathological damage. Moreover, transplanted hepatocytes inhibited interleukin-6 and tumor necrosis factor-α levels. Domino HT also ameliorates hepatocyte apoptosis, as evidenced by decreased TUNEL positive cells. Positive staining for human albumin suggested the localization of human hepatocytes in ALF mice livers. CONCLUSION: Explanted livers from patients with inheritable metabolic disorders can serve as a viable cell source for cell-based therapies. Domino HT using hepatocytes with certain metabolic defects has the potential to be a novel therapeutic strategy for ALF.
Assuntos
Hepatócitos , Falência Hepática Aguda , Doenças Metabólicas , Animais , Criança , Humanos , Camundongos , Alanina Transaminase/metabolismo , Albuminas/metabolismo , alfa 1-Antitripsina/metabolismo , Aspartato Aminotransferases/metabolismo , Citocromo P-450 CYP3A/metabolismo , Galactosamina/efeitos adversos , Glicogênio/metabolismo , Interleucina-6/metabolismo , Queratina-18/metabolismo , Lipopolissacarídeos , Falência Hepática Aguda/induzido quimicamente , Falência Hepática Aguda/cirurgia , Doenças Metabólicas/induzido quimicamente , Doenças Metabólicas/cirurgia , Albumina Sérica Humana/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Ureia/metabolismo , Hepatócitos/transplanteAssuntos
Artropatia Neurogênica , Coxa Vara , Proteoglicanas , Humanos , Coxa Vara/genética , Mutação , Proteoglicanas/genéticaRESUMO
Liver transplantation (LT) is an effective strategy for the treatment of end-stage liver disease, but immune rejection remains a significant detriment to the survival and prognosis of these LT patients. While immune rejection is closely related to cytokines, the cytokines investigated within previous studies have been limited and have not included a systematic analysis of proinflammatory cytokines. In the present study, we used a protein chip system and proteomics to detect and analyze serum proinflammatory cytokines and differentially expressed proteins in liver tissue in a mouse model of liver transplantation. In addition, bioinformatics analysis was employed to analyze the proinflammatory cytokines and differential changes in proteins in response to this procedure. With these analyses, we found that serum contents of GC-CSF, CXCL-1, MCP-5, and CXCL-2 were significantly increased after liver transplantation, while IL-5, IL-10, and IL-17 were significantly decreased. Results from Gene Ontology (GO) and KEGG pathway analyses revealed that the cytokine-cytokine receptor, Th1/Th2 cell differentiation, and JAK-STAT signaling pathway were enriched in a network associated with the activation of immune response. Results from our proteomic analysis of liver tissue samples revealed that 470 proteins are increased and 50 decreased, including Anxa1, Anxa2, Acsl4, Sirpa, S100a8, and S100a9. KEGG pathway analysis indicated that the neutrophil extracellular trap formation, NOD-like receptor signaling pathway, and leukocyte transendothelial migration were all associated with liver transplant rejection in these mice. Bioinformatics analysis results demonstrated that CXCL-1/CXCL-2 and S100a8/S100a9 were the genes most closely related to the functions of neutrophils and the mononuclear phagocyte system. These findings provide new insights into some of the critical factors associated with liver transplant rejection and thus offer new targets for the treatment and prevention of this condition.
Assuntos
Citocinas , Transplante de Fígado , Animais , Citocinas/metabolismo , Modelos Animais de Doenças , Camundongos , Proteômica , Transdução de SinaisRESUMO
Hepatic ischemia-reperfusion injury (IRI) is an adverse consequence of hepatectomy or liver transplantation. Recently, immune mechanisms involved in hepatic IRI have attracted increased attention of investigators working in this area. In specific, group 2 innate lymphoid cells (ILC2s), have been strongly implicated in mediating type 2 inflammation. However, their immune mechanisms as involved with hepatic IRI remain unclear. Here, we reported that the population of ILC2s is increased with the development of hepatic IRI as shown in a mouse model in initial stage. Moreover, M2 type CD45+CD11b+F4/80high macrophages increased and reached maximal levels at 24 h followed by a significant elevation in IL-4 levels. We injected exogenous IL-33 into the tail vein of mice as a mean to stimulate ILC2s production. This stimulation of ILC2s resulted in a protective effect upon hepatic IRI along with an increase in M2 type CD45+CD11b+F4/80high macrophages. In contrast, depletion of ILC2s as achieved with use of an anti-CD90.2 antibody substantially abolished this protective effect of exogenous IL-33 and M2 type CD45+CD11b+F4/80high macrophage polarization in hepatic IRI. Therefore, this exogenous IL-33 induced potentiation of ILC2s appears to regulate the polarization of CD45+CD11b+F4/80high macrophages to alleviate IRI. Such findings provide the foundation for the development of new targets and strategies in the treatment of hepatic IRI.
Assuntos
Interleucina-33 , Hepatopatias , Fígado , Macrófagos , Traumatismo por Reperfusão , Animais , Imunidade Inata , Interleucina-33/farmacologia , Fígado/irrigação sanguínea , Fígado/imunologia , Hepatopatias/imunologia , Linfócitos , Macrófagos/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Traumatismo por Reperfusão/imunologiaRESUMO
Accumulating evidence indicates the critical roles of group 2 innate lymphoid cells (ILC2s) in immunoregulation. However, the role of ILC2s in acute rejection after liver transplantation (LT) remains elusive. In this study, we analyzed the frequency, counts, and signature cytokines of ILC2s in liver transplant recipients by flow cytometric analysis and multiplex immunofluorescence assay. We also assessed the spatial distribution and correlation between hepatic ILC2s and Treg cells. The changes of ILC2s were dynamically monitored in the mouse LT model. We found that the frequencies of circulating ILC2s were comparable in liver transplant recipients with either rejection or non-rejection compared with the control group. The hepatic ILC2s counts were significantly increased in the rejection group than in the non-rejection and control groups, and a similar trend was observed for Treg cells. In the mouse LT model, allograft infiltrating ILC2s dramatically increased within 14 days post-transplant. The frequency of ILC2s in bone marrow significantly increased at 7 days post-transplant and rapidly decreased at 14 days after LT. Similarly, there was a significant increase in the frequency of splenic ILC2s within two weeks post-transplant. Multiplex immunofluorescence assay showed a close correlation between hepatic ILC2s and Treg cells by analyzing their spatial distribution and distance. In conclusion, the number of allograft infiltrating ILC2s was closely related to rejection after LT. Allograft infiltrating ILC2s may play inhibitory roles in posttransplant immune homeostasis, favoring resolution of liver allograft rejection by interacting with Treg cells or promoting the migration of Tregs cells into the liver allograft.
Assuntos
Transplante de Fígado , Aloenxertos , Animais , Rejeição de Enxerto , Imunidade Inata , Transplante de Fígado/efeitos adversos , Linfócitos , CamundongosRESUMO
Although double positive CD4+CD8+ T (DPT) cells has been reported to be involved in some diseases, their trajectory and function as associated with liver transplantation (LT) remain unclear. In the present study, we found that the number of DPT cells was increased in the blood and liver tissue of LT patients. Meanwhile, we compared the distribution of DPT cells in peripheral blood samples and in penetrating liver tissue between liver rejection versus non-rejection patients, as well as the proportion of DPT cells as a function of the extent of liver rejection. The number of DPT cells in the rejection group was significantly increased. An analysis of the spatial distance and correlations between DPT and Treg cells, revealed that these cells showed a high degree of contiguity. In a mouse liver transplant model, the number of DPT cells were significantly increased in liver tissue, and the number of CD8+ T cells gradually increased, while CD4+ T cells decreased as a function of time post-transplantation. Expression level of PD-1 in DPT cells also increased in a temporally-dependent manner post liver transplantation and the changes of PD-1+ DPT cells were related to the degree of liver transplant rejection. In DPT cells interacting with Treg, there was an increased expression of PD-1, which enhanced cellular exhaustion. In conclusion, the capacity for DPT cells to induce immune tolerance may represent a new and important protocol for use in targeting treatments for the prevention of liver transplant rejection.
Assuntos
Transplante de Fígado , Animais , Linfócitos T CD4-Positivos , Linfócitos T CD8-Positivos , Rejeição de Enxerto , Camundongos , Receptor de Morte Celular Programada 1 , Linfócitos T ReguladoresRESUMO
BACKGROUND: Graft-infiltrated dendritic cells (DCs) and CD8+ T lymphocytes are closely related with immune regulation after liver transplantation (LT). An additional factor which appears to play an important role with regard to transplantation immunity are exosomes, which are membrane-derived small vesicles released by various cells. However, the regulation of CD80+ DCs derived exosomes on CD8+ T cells in response to LT remains unclear. METHODS: Ten LT patients and two donors were included in this study. Multiple immunofluorescencewas performed to identify infiltratedCD8+ Tcells and DCs in human liver samples. The expression of NLRP3 and Ki-67 were measured usingimmunohistochemistry and immunofluorescence staining.Changes in CD80+ DCs and CD8+ T cells within the liver and blood of a mouse model of LT were detected with flow cytometry. After coculture with CD80+ DCs derived exosomes, the proliferation, adhesion, and transmigration ofCD8+ T cells were determined with the use of CCK-8, Adhesion and Transmigration assay in vitro.CD8+ T cells related cytokines were measured using Western blot, qRT-PCR and ELISA. RESULTS: In human liver samples, there was an increase in intrahepatic CD8+ T cell infiltration in the acute LT rejection group, an effect which was accompanied by high expressions of NLRP3 and Ki-67 index and a decrease in DCs. Similarly, lower levels of CD80+ DCs were observed with acute rejection in an LT mouse model, along with increased numbers of CD8+ T cells in the liver and blood. In vitro, CD80+ DCs derived exosomes modulated the secretion of CD8+ T cells from cytokines by down-regulating NLRP3 expression, combined with a synchronous inhibition in the adhesion, invasion, and proliferation of CD8+ T cells. CONCLUSION: CD80+ DCs derived exosomes negatively regulate CD8+ T cells via inhibition of NLRP3 expression, a series of events which are essential to attenuate acute LT rejection. These results reveal a new role for CD80+ DCs exosomes as related to tolerance induction in LT.
Assuntos
Exossomos , Transplante de Fígado , Animais , Antígeno B7-1/metabolismo , Linfócitos T CD8-Positivos , Citocinas/metabolismo , Células Dendríticas , Exossomos/metabolismo , Humanos , Antígeno Ki-67/metabolismo , Camundongos , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismoRESUMO
It remains unclear as to whether there are differences that exist in the types and functional status of immune cells within different areas of the liver lobules after rejection of liver transplantation. The composition of infiltrating T cells in liver allografts during liver transplantation rejection is indistinct and difficult to visualize within the same biopsy slide. In an attempt to rectify this problem, we applied multiplex immunofluorescent assays to assess the spatial distribution of various types of infiltrating T cells in different areas of the liver lobules after liver transplantation. In identical areas of the hepatic lobules, the percentage of CD4+ T, CD8+ T, and regulatory T (Treg) cells in the rejection group was greater than that observed in the non-rejection and normal groups. Within all three groups, the percentage of CD4+ T, CD8+ T, and Treg cells from the periportal to perivenous zones initially increased and then decreased. In the rejection group, the percentage of CD8+ T cells gradually increased from the periportal to perivenous zones, with maximal levels in the perivenous as compared with that in the transitional and periportal zones. In conclusion, levels of CD8+ T cells within different regions of liver lobules are closely related to levels of rejection after liver transplantation. Liver transplantation rejection may be linked with increases in CD8+ T cells within the perivenous zone. Although the regional percent of increase in CD4+ T cells may not reflect level of the rejection, the overall numbers of both of CD4+ and CD8+ T cells within different regions were closely related to rejection levels.
Assuntos
Rejeição de Enxerto , Transplante de Fígado , Linfócitos T CD8-Positivos , Imunofluorescência , Fígado/patologia , Transplante de Fígado/efeitos adversosRESUMO
Liver ischemia-reperfusion injury (IRI) can severely compromise the prognosis of patients receiving liver surgery. While inflammation contributes to the damage resulting from IRI, only a limited number of inflammation biomarkers have been identified as being associated with the different stages of hepatic IRI. As an approach to identify some of these inflammatory cytokines and the molecular mechanisms involved within different stages of hepatic IRI, we used an advanced antibody array assay to detect multiple proteins. With this technology, we observed specific differences in the content of inflammatory cytokines between ischemic and sham controls, as well as a function of the different reperfusion stages in a hepatic IRI mouse model. For example, while liver tissue content of IL-12p40/p70 was significantly increased in the ischemic stage, it was significantly decreased in the reperfusion stage as compared with that of the sham group. For other inflammatory cytokines, no changes were obtained between the ischemic and reperfusion stages with levels of IL-17, Eotaxin-2, Eotaxin, and sTNF RII all being consistently increased, while those of TIMP-1, TIMP-2, BLC, and MCSF consistently decreased as compared with that of the sham group at all reperfusion stages examined. Results from protein function annotation Gene Ontology and the KEGG pathway revealed that inflammatory cytokines are enriched in a network associated with activation of inflammatory response signaling pathways such as TLR, TNF, and IL-17 when comparing responses of the IR versus sham groups. The identification of cytokines along with their roles at specific stages of IRI may reveal important new biological markers for the diagnosis and prognosis of hepatic IRI.
Assuntos
Citocinas/metabolismo , Inflamação/metabolismo , Traumatismo por Reperfusão/metabolismo , Animais , Biomarcadores/metabolismo , Fígado/lesões , Camundongos , Prognóstico , Índice de Gravidade de DoençaRESUMO
Mitochondrial dysfunction plays a central role in hepatic ischemia-reperfusion injury (IRI). The significance of mitophagy in hepatic IRI remains poorly understood. The mechanisms that cause IRI are complex, and many factors are involved in the injury formation process. The miR-330-3p mediates cell proliferation, cell death, and metabolism in various organisms. In this study, the levels of miR-330-3p were significantly downregulated in hepatic IRI, and the number of autophagosomes was increased in response to IRI as obtained under both in vivo and in vitro conditions. These results demonstrate that a reduction in miR-330-3p expression represents an important factor involved with promoting hepatic IRI. Moreover, we found that miR-330-3p interacted with phosphoglycerate mutase family member 5 (PGAM5) to regulate mitophagy. In specific, an overexpression of miR-330-3p diminished PGAM5 levels, which promoted mitophagy in response to IRI. In contrast, a downregulation of miR-330-3p was associated with increased PGAM5 levels leading to increased mitophagy. In conclusion, miR-330-3p suppresses PGAM5-induced mitophagy to alleviate hepatic IRI. Such findings not only reveal some of the mechanistic basis for this microRNA in liver injury, but also provide a foundation for new therapeutic approaches in the treatment of this condition.
Assuntos
Fígado/lesões , MicroRNAs/metabolismo , Mitofagia , Fosfoproteínas Fosfatases/metabolismo , Traumatismo por Reperfusão/metabolismo , Animais , Linhagem Celular , Modelos Animais de Doenças , Hepatócitos/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , MicroRNAs/genética , TransfecçãoRESUMO
Ischemia-reperfusion (I/R) injury causes cellular dysfunction and a series of immune or apoptotic reactions. Bach1 is a mammalian transcription factor that represses Hmox1, which encodes heme oxygenase-1 (HO-1) that can degrade heme into free iron, carbon monoxide, and biliverdin, to play an important role in antioxidant, anti-inflammatory, and antiapoptotic activities. MicroRNAs (miRNAs) can be found in a variety of eukaryotic cells and viruses, a class of noncoding small RNAs that are encoded by endogenous genes. The aims of this study were to determine whether miR-27a-5p targets Bach1 and regulates cellular death; the dual-luciferase reporter assay was used to detect this and the results showed that miR-27a-5p significantly decreased the luciferase activity of the Bach1 3'-untranslated region. MiR-27a-5p was increased in mice during hepatic I/R and Bach1 was decreased. By transfecting the AML12 cells with the mimic, inhibitor miR-27a-5p in hypoxia/reoxygenation (H/R) models showed that overexpression of miR-27a-5p decreased Bach1 messenger RNA, upregulated HO-1 expression, and promoted antiapoptotic Bcl-2 and downregulated proapoptotic caspase-3 gene expression. In contrast, the miR-27a-5p inhibitor yielded the opposite results. Meanwhile, transfection with Bach1 small interference RNA obviously upregulated the protein levels of HO-1 and resulted in an increase in Bcl-2 and a decrease in caspase-3 protein levels. Thus, we can conclude that miR-27a-5p is relevant to liver I/R injury and overexpression of miR-27a-5p may alleviate apoptosis in H/R injury by targeting Bach1 in vitro.
Assuntos
Fatores de Transcrição de Zíper de Leucina Básica/genética , Fígado/metabolismo , MicroRNAs/genética , Traumatismo por Reperfusão/genética , Animais , Apoptose/genética , Caspase 3/genética , Hipóxia Celular/genética , Regulação da Expressão Gênica/genética , Heme Oxigenase-1/genética , Humanos , Fígado/patologia , Proteínas de Membrana/genética , Camundongos , Proteínas Proto-Oncogênicas c-bcl-2/genética , Traumatismo por Reperfusão/patologia , TransfecçãoRESUMO
We retrospectively analyzed 252 patients with end-stage liver disease who had undergone LDLT from January 2009 to September 2015. Of these, 25 had a GRWR of <2.0% (Group A), 204 had a GRWR of ≥2.0% or <4.0% (Group B), and 23 had a GRWR ≥4.0% (Group C). The three GRWR groups demonstrated similar characteristics, except for recipient age and recipient BMI. The overall 1-, 2-, and 3-year graft survival rates were 95.1%, 93.5%, and 93.5%, respectively. However, among the three groups, graft survival rates at 1 year, 2 years, and 3 years were significantly different (P = .0009). Hepatic artery stenosis/thrombosis was more frequently observed in Group C than in Groups A and B (P = .001). Wound infection was also more frequently observed in Group C than in Group A and B (P = .002). However, intestinal fistula/bile leakage/biliary-enteric anastomotic fistula was more frequently observed in Group A than in Groups B and C (P = .001). In addition, reoperation more frequently occurred in Group A and C than in Group B (P = .001). Recipients with a GRWR between 2.0% and 4.0% had significantly better graft survival rates.
Assuntos
Doença Hepática Terminal/cirurgia , Sobrevivência de Enxerto , Transplante de Fígado/métodos , Fígado/anatomia & histologia , Doadores Vivos , Adulto , Feminino , Seguimentos , Humanos , Fígado/cirurgia , Masculino , Pessoa de Meia-Idade , Tamanho do Órgão , Prognóstico , Estudos Retrospectivos , Adulto JovemRESUMO
In performing our experiment, impaired autophagy increased hepatocellular damage during the reperfusion period. It was demonstrated by the effect of blocking autophagy using bafilomycin A1 or knocking Atg5 gene out reduces the anti-apoptotic effect of Stat3. Here we focus on the role of signal transducer and activator of transcription 3 (Stat3) in regulating autophagy to alleviate hepatic IRI. We found that Stat3 was up-regulated during hepatic IRI and was associated with an activation of the autophagic signaling pathway. This increased Stat3 expression, which was allied with high autophagic activity, alleviated liver damage to IR, an effect which was abrogated by Stat3 epletion as demonstrated in both in vivo and in vitro methods. The levels of Atg5 protein were decreased when Stat3 was inhibited by HO 3867 or siStat3. We conclude that Stat3 appeared to exert a pivotal role in hepatic IRI, by activating autophagy to alleviate hepatic IRI, and Atg5 was required for this process. The identification of this novel pathway, that links expression levels of Stat3 with Atg5-mediated autophagy, may provide new insights for the generation of novel protective therapies directed against hepatic IRI.
Assuntos
Proteína 5 Relacionada à Autofagia/metabolismo , Autofagia/fisiologia , Fígado/metabolismo , Fígado/patologia , Fator de Transcrição STAT3/metabolismo , Animais , Apoptose/genética , Apoptose/fisiologia , Autofagia/genética , Western Blotting , Linhagem Celular , Sobrevivência Celular/genética , Sobrevivência Celular/fisiologia , Modelos Animais de Doenças , Imuno-Histoquímica , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Microscopia Confocal , Microscopia Eletrônica de Transmissão , Traumatismo por Reperfusão/genética , Traumatismo por Reperfusão/metabolismo , Transdução de Sinais/genética , Transdução de Sinais/fisiologiaRESUMO
Vitexin, a flavonoids compound, is known to exhibit broad anti-oxidative, anti-inflammatory, analgesic, and antitumor activity in many cancer xenograft models and cell lines. The purpose of this study was to investigate the antitumor effects and underlying mechanisms of vitexin on hepatocellular carcinoma. In this study, we found that vitexin suppressed the viability of HCC cell lines (SK-Hep1 and Hepa1-6 cells) significantly. Vitexin showed cytotoxic effects against HCC cell lines in vitro by inducing apoptosis and inhibiting autophagy. Vitexin induced apoptosis in a concentration-dependent manner, and caused up-regulations of Caspase-3, Cleave Caspase-3, and a down-regulation of Bcl-2. The expression of autophagy-related protein LC3 II was significantly decreased after vitexin treatment. Moreover, western blot analysis presented that vitexin markedly up-regulated the levels of p-JNK and down-regulated the levels of p-Erk1/2 in SK-Hep1 cells and Hepa1-6 cells. Cotreatment with JNK inhibitor SP600125, we demonstrated that apoptosis induced by vitexin was suppressed, while the inhibition of autophagy by vitexin was reversed. The results of colony formation assay and mouse model confirmed the growth inhibition role of vitexin on HCC in vitro and in vivo. In conclusion, vitexin inhibits HCC growth by way of apoptosis induction and autophagy suppression, both of which are through JNK MAPK pathway. Therefore, vitexin could be regarded as a potent therapeutic agent for the treatment of HCC.
Assuntos
Apigenina/farmacologia , Apoptose/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Carcinoma Hepatocelular/tratamento farmacológico , Neoplasias Hepáticas/tratamento farmacológico , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Animais , Proteínas Relacionadas à Autofagia/metabolismo , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patologia , Caspase 3/metabolismo , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Humanos , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas Experimentais/tratamento farmacológico , Neoplasias Hepáticas Experimentais/metabolismo , Neoplasias Hepáticas Experimentais/patologia , Masculino , Camundongos Endogâmicos C57BL , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Highly upregulated in liver cancer (HULC), a lncRNA that is considered a key molecule in human liver cancer, has recently been revealed to be involved in hepatocellular carcinoma (HCC) development and progression [1, 2]. It has been reported that HULC can promote tumor invasion and metastasis of HCC, but its function and mechanism of action in HCC have not been elucidated. In this study, we found that HULC was aberrantly up-regulated in HCC tissues and associated with TNM stage, intrahepatic metastases, HCC recurrence, and postoperative survival. HULC depletion inhibited the growth and metastasis of HCC cell lines in vitro and in vivo. Moreover, HULC contributes to ZEB1-induced epithelial-mesenchymal transition (EMT), a requirement for tumor invasion and metastasis that plays a key role in cancer progression. This effect of ZEB1 was inhibited by HULC siRNA. We conclude that the HULC functioned as a competing endogenous RNA (ceRNA) to mediate EMT via up-regulating ZEB1. In this way, it sequesters the miR-200a-3p signaling pathway to facilitate HCC metastasis. HULC comes into play as an oncogene in HCC, acting mechanistically by inducing HCC cells to activate EMT. Such an effect promotes tumor progression and metastasis through the miR-200a-3p/ZEB1 signaling pathway. The identification of this novel pathway that links high expression levels of HULC with EMT in HCC cells may serve as the foundation for the development of novel anti-tumor therapeutics.
Assuntos
Carcinogênese , Carcinoma Hepatocelular/metabolismo , Transição Epitelial-Mesenquimal , Neoplasias Hepáticas/metabolismo , MicroRNAs/metabolismo , RNA Longo não Codificante/metabolismo , Homeobox 1 de Ligação a E-box em Dedo de Zinco/metabolismo , Acetilcisteína/metabolismo , Idoso , Animais , Apoptose , Carcinoma Hepatocelular/genética , Proliferação de Células , Transformação Celular Neoplásica/genética , Progressão da Doença , Feminino , Humanos , Lentivirus/genética , Fígado/metabolismo , Neoplasias Hepáticas/genética , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , MicroRNAs/genética , Pessoa de Meia-Idade , Metástase Neoplásica , Transplante de Neoplasias , RNA Interferente Pequeno/metabolismo , Transdução de Sinais , Homeobox 1 de Ligação a E-box em Dedo de Zinco/genéticaRESUMO
The prognostic values of IRF-1 and Ki-67 for liver transplantation (LT) of hepatocellular carcinoma (HCC) were investigated, as well as the mechanisms of IRF-1 in tumor suppression. Adult orthotropic liver transplantation cases (N = 127) were involved in the analysis. A significant decreased recurrence free survival (RFS) was found in the Ki-67 positive groups. Ki-67, tumor microemboli, the Milan and UCSF criteria were found to be independent risk factors for RFS. In LT for HCC beyond the Milan criteria, a significant decrease in RFS was found in the IRF-1 negative groups. In SK-Hep1 cells, an increase in apoptosis and decrease in autophagy were observed after IFN-γ stimulation, which was accompanied with increasing IRF-1 levels. When IRF-1 siRNA or a caspase inhibitor were used, reductions in LC3-II were diminished or disappeared after IFN-γ stimulation, suggesting that IFN-γ inhibited autophagy via IRF-1 expression and caspase activation. However, after IRF-1 siRNA was introduced, a reduction in LC3-II was found. Thus basic expression of IRF-1 was also necessary for autophagy. IRF-1 may be used as a potential target for HCC treatment based on its capacity to affect apoptosis and autophagy. Ki-67 shows great promise for the prediction of HCC recurrence in LT and can be used as an aid in the selection of LT candidates.