RESUMO
BACKGROUND AIMS: As a global health threat, NASH has been confirmed to be a chronic progressive liver disease that is strongly associated with obesity. However, no approved drugs or efficient therapeutic strategies are valid, mainly because its complicated pathological processes is underestimated. APPROACH RESULTS: We identified the RING-type E3 ubiquitin transferase-tripartite motif-containing protein 31 (TRIM31), a member of the E3 ubiquitin ligases family, as an efficient endogenous inhibitor of transforming growth factor-beta-activated kinase 1 (mitogen-activated protein kinase kinase kinase 7; MAP3K7), and we further confirmed that TRIM31 is an MAP3K7-interacting protein and promotes MAP3K7 degradation by enhancing ubiquitination of K48 linkage in hepatocytes. Hepatocyte-specific Trim31 deletion blocks hepatic metabolism homeostasis, concomitant with glucose metabolic syndrome, lipid accumulation, up-regulated inflammation, and dramatically facilitates NASH progression. Inversely, transgenic overexpression, lentivirus, or adeno-associated virus-mediated Trim31 gene therapy restrain NASH in three dietary mice models. Mechanistically, in response to metabolic insults, TRIM31 interacts with MAP3K7 and conjugates K48-linked ubiquitination chains to promote MAP3K7 degradation, thus blocking MAP3K7 abundance and its downstream signaling cascade activation in hepatocytes. CONCLUSIONS: TRIM31 may serve as a promising therapeutic target for NASH treatment and associated metabolic disorders.
Assuntos
Hepatopatia Gordurosa não Alcoólica , Proteínas com Motivo Tripartido , Ubiquitina-Proteína Ligases , Animais , Camundongos , MAP Quinase Quinase Quinases/metabolismo , Hepatopatia Gordurosa não Alcoólica/metabolismo , Hepatopatia Gordurosa não Alcoólica/prevenção & controle , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitinação , Humanos , Proteínas com Motivo Tripartido/metabolismoRESUMO
BACKGROUND AND AIMS: Nonalcoholic fatty liver disease (NAFLD) has been widely recognized as a precursor to metabolic complications. Elevated inflammation levels are predictive of NAFLD-associated metabolic disorder. Inactive rhomboid-like protein 2 (iRhom2) is regarded as a key regulator in inflammation. However, the precise mechanisms by which iRhom2-regulated inflammation promotes NAFLD progression remain to be elucidated. APPROACH AND RESULTS: Here, we report that insulin resistance, hepatic steatosis, and specific macrophage inflammatory activation are significantly alleviated in iRhom2-deficient (knockout [KO]) mice, but aggravated in iRhom2 overexpressing mice. We further show that, mechanistically, in response to a high-fat diet (HFD), iRhom2 KO mice and mice with iRhom2 deficiency in myeloid cells only showed less severe hepatic steatosis and insulin resistance than controls. Inversely, transplantation of bone marrow cells from healthy mice to iRhom2 KO mice expedited the severity of insulin resistance and hepatic dyslipidemia. Of note, in response to HFD, hepatic iRhom2 binds to mitogen-activated protein kinase kinase kinase 7 (MAP3K7) to facilitate MAP3K7 phosphorylation and nuclear factor kappa B cascade activation, thereby promoting the activation of c-Jun N-terminal kinase/insulin receptor substrate 1 signaling, but disturbing AKT/glycogen synthase kinase 3ß-associated insulin signaling. The iRhom2/MAP3K7 axis is essential for iRhom2-regulated liver steatosis. CONCLUSIONS: iRhom2 may represent a therapeutic target for the treatment of HFD-induced hepatic steatosis and insulin resistance.
Assuntos
Proteínas de Transporte/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Fígado/metabolismo , MAP Quinase Quinase Quinases/metabolismo , Hepatopatia Gordurosa não Alcoólica/metabolismo , Ativação Metabólica , Animais , Proteínas de Transporte/biossíntese , Dieta Hiperlipídica/efeitos adversos , Modelos Animais de Doenças , Progressão da Doença , Fígado Gorduroso/etiologia , Fígado Gorduroso/metabolismo , Fígado Gorduroso/fisiopatologia , Inflamação/metabolismo , Inflamação/fisiopatologia , Resistência à Insulina/fisiologia , Peptídeos e Proteínas de Sinalização Intracelular/biossíntese , Fígado/fisiopatologia , Macrófagos/metabolismo , Camundongos Endogâmicos C57BL , Camundongos Knockout , Hepatopatia Gordurosa não Alcoólica/etiologia , Hepatopatia Gordurosa não Alcoólica/fisiopatologia , Transdução de SinaisRESUMO
Chronic alcohol exposure can lead to liver pathology relating to inflammation and oxidative stress, which are two of the major factors in the incidence of liver fibrosis and even liver cancer. The underlying molecular mechanisms regarding hepatic lesions associated with alcohol are not fully understood. Considering that the recently identified iRhom2 is a key pathogenic mediator of inflammation, we performed in vitro and in vivo experiments to explore its regulatory role in alcohol-induced liver fibrosis. We found that iRhom2 knockout significantly inhibited alcohol-induced inflammatory responses in vitro, including elevated expressions of inflammatory cytokines (IL-1ß, IL-6, IL-18, and TNF-α) and genes associated with inflammatory signaling pathways, such as TACE (tumor necrosis factor-alpha converting enzyme), TNFR1 (tumor necrosis factor receptor 1), and TNFR2, as well as the activation of NF-κB. The in vivo results confirmed that long-term alcohol exposure leads to hepatocyte damage and fibrous accumulation. In this pathological process, the expression of iRhom2 is promoted to activate the TACE/NF-κB signaling pathway, leading to inflammatory responses. Furthermore, the deletion of iRhom2 blocks the TACE/NF-κB signaling pathway and reduces liver damage and fibrosis caused by alcohol. Additionally, the activation of the JNK/Nrf2/HO-1 signaling pathway caused by alcohol exposure was also noted in vitro and in vivo. In the same way, knockout or deleting iRhom2 blocked the JNK/Nrf2/HO-1 signaling pathway to regulate the oxidative stress. Therefore, we contend that iRhom2 is a key regulator that promotes inflammatory responses and regulates oxidative stress in alcoholic liver fibrosis lesions. We posit that iRhom2 is potentially a new therapeutic target for alcoholic liver fibrosis.
Assuntos
Proteínas de Transporte , Inflamação , Peptídeos e Proteínas de Sinalização Intracelular , Cirrose Hepática Alcoólica , Estresse Oxidativo , Animais , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Humanos , Inflamação/genética , Inflamação/metabolismo , Inflamação/patologia , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Fígado/metabolismo , Fígado/patologia , Cirrose Hepática/metabolismo , Cirrose Hepática Alcoólica/genética , Cirrose Hepática Alcoólica/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Fator 2 Relacionado a NF-E2/metabolismo , NF-kappa B/metabolismo , Estresse Oxidativo/genética , Estresse Oxidativo/fisiologia , Transdução de SinaisRESUMO
BACKGROUND: The failure of proper recognition of the intricate nature of pathophysiology in colorectal cancer (CRC) has a substantial effect on the progress of developing novel medications and targeted therapy approaches. Imbalances in the processes of lipid oxidation and biosynthesis of fatty acids are significant risk factors for the development of CRC. Therapeutic intervention that specifically targets the peroxisome proliferator-activated receptor gamma (PPARγ) and its downstream response element, in response to lipid metabolism, has been found to promote the growth of tumors and has shown significant clinical advantages in cancer patients. METHODS: Clinical CRC samples and extensive in vitro and in vivo experiments were carried out to determine the role of ZDHHC6 and its downstream targets via a series of biochemical assays, molecular analysis approaches and lipid metabolomics assay, etc. RESULTS: To study the effect of ZDHHC6 on the progression of CRC and identify whether ZDHHC6 is a palmitoyltransferase that regulates fatty acid synthesis, which directly palmitoylates and stabilizes PPARγ, and this stabilization in turn activates the ACLY transcription-related metabolic pathway. In this study, we demonstrate that PPARγ undergoes palmitoylation in its DNA binding domain (DBD) section. This lipid-related modification enhances the stability of PPARγ protein by preventing its destabilization. As a result, palmitoylated PPARγ inhibits its degradation induced by the lysosome and facilitates its translocation into the nucleus. In addition, we have identified zinc finger-aspartate-histidine-cysteine 6 (ZDHHC6) as a crucial controller of fatty acid biosynthesis. ZDHHC6 directly interacts with and adds palmitoyl groups to stabilize PPARγ at the Cys-313 site within the DBD domain of PPARγ. Consequently, this palmitoylation leads to an increase in the expression of ATP citrate lyase (ACLY). Furthermore, our findings reveals that ZDHHC6 actively stimulates the production of fatty acids and plays a role in the development of colorectal cancer. However, we have observed a significant reduction in the cancer-causing effects when the expression of ZDHHC6 is inhibited in in vivo trials. Significantly, in CRC, there is a strong positive correlation between the high expression of ZDHHC6 and the expression of PPARγ. Moreover, this high expression of ZDHHC6 is connected with the severity of CRC and is indicative of a poor prognosis. CONCLUSIONS: We have discovered a mechanism in which lipid biosynthesis is controlled by ZDHHC6 and includes the signaling of PPARγ-ACLY in the advancement of CRC. This finding provides a justification for targeting lipid synthesis by blocking ZDHHC6 as a potential therapeutic approach.
Assuntos
Aciltransferases , Neoplasias do Colo , Reprogramação Metabólica , PPAR gama , Animais , Feminino , Humanos , Masculino , Camundongos , Aciltransferases/metabolismo , Aciltransferases/genética , Carcinogênese/genética , Carcinogênese/metabolismo , Linhagem Celular Tumoral , Neoplasias do Colo/metabolismo , Neoplasias do Colo/patologia , Neoplasias do Colo/genética , Metabolismo dos Lipídeos/genética , Lipidômica/métodos , Reprogramação Metabólica/genética , PPAR gama/metabolismoRESUMO
The treatment of wound inflammation is intricately linked to the concentration of reactive oxygen species (ROS) in the wound microenvironment. Among these ROS, H2O2 serves as a critical signaling molecule and second messenger, necessitating the urgent need for its rapid real-time quantitative detection, as well as effective clearance, in the pursuit of effective wound inflammation treatment. Here, we exploited a sophisticated 3D Cu2- x Se/GO nanostructure-based nanonzymatic H2O2 electrochemical sensor, which is further decorated with evenly distributed Pt nanoparticles (Pt NPs) through electrodeposition. The obtained Cu2- x Se/GO@Pt/SPCE sensing electrode possesses a remarkable increase in specific surface derived from the three-dimensional surface constructed by GO nanosheets. Moreover, the localized surface plasma effect of the Cu2- x Se nanospheres enhances the separation of photogenerated electron-hole pairs between the interface of the Cu2- x Se NPs and the Pt NPs. This innovation enables near-infrared light-enhanced catalysis, significantly reducing the detection limit of the Cu2- x Se/GO@Pt/SPCE sensing electrode for H2O2 (from 1.45 µM to 0.53µM) under NIR light. Furthermore, this biosensor electrode enables in-situ real-time monitoring of H2O2 released by cells. The NIR-enhanced Cu2- x Se/GO@Pt/SPCE sensing electrode provide a simple-yet-effective method to achieve a detection of ROS (H2O2ã-OH) with high sensitivity and efficiency. This innovation promises to revolutionize the field of wound inflammation treatment by providing clinicians with a powerful tool for accurate and rapid assessment of ROS levels, ultimately leading to improved patient outcomes.
Assuntos
Cobre , Peróxido de Hidrogênio , Inflamação , Nanopartículas Metálicas , Platina , Peróxido de Hidrogênio/metabolismo , Platina/química , Cobre/química , Nanopartículas Metálicas/química , Inflamação/metabolismo , Animais , Camundongos , Nanoestruturas/química , Técnicas Biossensoriais/métodos , Selênio/química , Humanos , Raios Infravermelhos , Espécies Reativas de Oxigênio/metabolismo , Células RAW 264.7RESUMO
Underestimation of the complexity of pathogenesis in nonalcoholic steatohepatitis (NASH) significantly encumbers development of new drugs and targeted therapy strategies. Inactive rhomboid protein 2 (IRHOM2) has a multifunctional role in regulating inflammation, cell survival, and immunoreaction. Although cytokines and chemokines promote IRHOM2 trafficking or cooperate with partner factors by phosphorylation or ubiquitin ligases-mediated ubiquitination to perform physiological process, it remains unknown whether other regulators induce IRHOM2 activation via different mechanisms in NASH progression. Here the authors find that IRHOM2 is post-translationally S-palmitoylated at C476 in iRhom homology domain (IRHD), which facilitates its cytomembrane translocation and stabilization. Fatty-acids challenge can directly promote IRHOM2 trafficking by increasing its palmitoylation. Additionally, the authors identify Zinc finger DHHC-type palmitoyltransferase 3 (ZDHHC3) as a key acetyltransferase required for the IRHOM2 palmitoylation. Fatty-acids administration enhances IRHOM2 palmitoylation by increasing the direct association between ZDHHC3 and IRHOM2, which is catalyzed by the DHHC (C157) domain of ZDHHC3. Meanwhile, a metabolic stresses-triggered increase of ZDHHC3 maintains palmitoylated IRHOM2 accumulation by blocking its ubiquitination, consequently suppressing its ubiquitin-proteasome-related degradation mediated by tripartite motif containing 31 (TRIM31). High-levels of ZDHHC3 protein abundance positively correlate with the severity of NASH phenotype in patient samples. Hepatocyte-specific dysfunction of ZDHHC3 significantly inhibits palmitoylated IRHOM2 deposition, therefore suppressing the fatty-acids-mediated hepatosteatosis and inflammation in vitro, as well as NASH pathological phenotype induced by two different high-energy diets (HFHC & WTDF) in the in vivo rodent and rabbit model. Inversely, specific restoration of ZDHHC3 in hepatocytes markedly provides acceleration over the course of NASH development via increasing palmitoylation of IRHOM2 along with suppression of ubiquitin degradation. The current work uncovers that ZDHHC3-induced palmitoylation is a novel regulatory mechanism and signal that regulates IRHOM2 trafficking, which confers evidence associating the regulation of palmitoylation with NASH progression.
Assuntos
Hepatopatia Gordurosa não Alcoólica , Animais , Humanos , Coelhos , Lipoilação , Inflamação/metabolismo , Fosforilação , Ácidos Graxos , Ubiquitinas/metabolismo , Proteínas com Motivo Tripartido/metabolismo , Ubiquitina-Proteína Ligases/metabolismoRESUMO
Nowadays potential preclinical drugs for the treatment of nonalcoholic steatohepatitis (NASH) have failed to achieve expected therapeutic efficacy because the pathogenic mechanisms are underestimated. Inactive rhomboid protein 2 (IRHOM2), a promising target for treatment of inflammation-related diseases, contributes to deregulated hepatocyte metabolism-associated nonalcoholic steatohepatitis (NASH) progression. However, the molecular mechanism underlying Irhom2 regulation is still not completely understood. In this work, we identify the ubiquitin-specific protease 13 (USP13) as a critical and novel endogenous blocker of IRHOM2, and we also indicate that USP13 is an IRHOM2-interacting protein that catalyzes deubiquitination of Irhom2 in hepatocytes. Hepatocyte-specific loss of the Usp13 disrupts liver metabolic homeostasis, followed by glycometabolic disorder, lipid deposition, increased inflammation, and markedly promotes NASH development. Conversely, transgenic mice with Usp13 overexpression, lentivirus (LV)- or adeno-associated virus (AAV)-driven Usp13 gene therapeutics mitigates NASH in 3 models of rodent. Mechanistically, in response to metabolic stresses, USP13 directly interacts with IRHOM2 and removes its K63-linked ubiquitination induced by ubiquitin-conjugating enzyme E2N (UBC13), a ubiquitin E2 conjugating enzyme, and thus prevents its activation of downstream cascade pathway. USP13 is a potential treatment target for NASH therapy by targeting the Irhom2 signaling pathway.
RESUMO
Currently potential preclinical drugs for the treatment of nonalcoholic steatohepatitis (NASH) and NASH-related pathopoiesis have failed to achieve expected therapeutic efficacy due to the complexity of the pathogenic mechanisms. Here we show Tripartite motif containing 26 (TRIM26) as a critical endogenous suppressor of CCAAT/enhancer binding protein delta (C/EBPδ), and we also confirm that TRIM26 is an C/EBPδ-interacting partner protein that catalyses the ubiquitination degradation of C/EBPδ in hepatocytes. Hepatocyte-specific loss of Trim26 disrupts liver metabolic homeostasis, followed by glucose metabolic disorder, lipid accumulation, increased hepatic inflammation, and fibrosis, and dramatically facilitates NASH-related phenotype progression. Inversely, transgenic Trim26 overexpression attenuates the NASH-associated phenotype in a rodent or rabbit model. We provide mechanistic evidence that, in response to metabolic insults, TRIM26 directly interacts with C/EBPδ and promotes its ubiquitin proteasome degradation. Taken together, our present findings identify TRIM26 as a key suppressor over the course of NASH development.
Assuntos
Hepatopatia Gordurosa não Alcoólica , Animais , Coelhos , Hepatopatia Gordurosa não Alcoólica/genética , Hepatopatia Gordurosa não Alcoólica/prevenção & controle , Transdução de Sinais , Ubiquitinação , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismoRESUMO
Excessive fructose (Fru) consumption has been reported to favor nonalcoholic fatty liver disease (NAFLD). However, the molecular mechanism is still elusive, lacking effective therapeutic strategies. Carminic acid (CA), a glucosylated anthraquinone found in scale insects like Dactylopius coccus, exerts anti-tumor and anti-oxidant activities. Nevertheless, its regulatory role in Fru-induced NAFLD is still obscure. Here, the effects of CA on NAFLD in Fru-challenged mice and the underlying molecular mechanisms were explored. We found that Fru intake significantly led to insulin resistance and dyslipidemia in liver of mice, which were considerably attenuated by CA treatment through repressing endoplasmic reticulum (ER) stress. Additionally, inflammatory response induced by Fru was also attenuated by CA via the blockage of nuclear factor-κB (NF-κB), mitogen-activated protein kinases (MAPKs) and tumor necrosis factor α/TNF-α receptor (TNF-α/TNFRs) signaling pathways. Moreover, Fru-provoked oxidative stress in liver tissues was remarkably attenuated by CA mainly through improving the activation of nuclear factor erythroid 2-related factor 2 (Nrf-2). These anti-dyslipidemias, anti-inflammatory and anti-oxidant activities regulated by CA were confirmed in the isolated primary hepatocytes with Fru stimulation. Importantly, the in vitro experiments demonstrated that Fru-induced lipid accumulation was closely associated with inflammatory response and reactive oxygen species (ROS) production regulated by TNF-α and Nrf-2 signaling pathways, respectively. In conclusion, these results demonstrated that CA could be considered as a potential therapeutic strategy to attenuate metabolic disorder and NAFLD in Fru-challenged mice mainly through suppressing inflammatory response and oxidative stress.
Assuntos
Carmim/farmacologia , Inflamação/tratamento farmacológico , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Estresse Oxidativo/efeitos dos fármacos , Animais , Anti-Inflamatórios/farmacologia , Antioxidantes/farmacologia , Modelos Animais de Doenças , Dislipidemias/tratamento farmacológico , Frutose , Hepatócitos/efeitos dos fármacos , Hepatócitos/patologia , Inflamação/patologia , Resistência à Insulina , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Hepatopatia Gordurosa não Alcoólica/patologia , Espécies Reativas de Oxigênio/metabolismoRESUMO
Obesity is a major predictive factor for the diabetic nephropathy (DN). However, the precise mechanism and therapeutic approach still require to be investigated. Cynapanosides A (CPS-A) is a glycoside derived from the Chinese drug Cynanchum paniculatum that has numerous pharmacological activities, but its regulatory function on obesity-induced kidney disease is still obscure. In the present study, we attempted to explore the renoprotective effects of CPS-A on the established DN in high fat diet (HFD)-fed mice, and the underlying mechanisms. We initially found that CPS-A significantly ameliorated the obesity and metabolic syndrome in mice with HFD feeding. Mice with HFD-induced DN exerted renal dysfunctions, indicated by the elevated functional parameters, including up-regulated blood urea nitrogen (BUN), urine albumin and creatinine, which were significantly attenuated by CPS-A in obese mice. Moreover, histological changes including glomerular enlargement, sclerosis index and collagen deposition in kidney of obese mice were detected, while being strongly ameliorated by CPS-A. Additionally, podocyte loss induced by HFD was also markedly mitigated in mice with CPS-A supplementation. HFD feeding also led to lipid deposition and inflammatory response in renal tissues of obese mice, whereas being considerably attenuated after CPS-A consumption. Intriguingly, we found that tripartite motif-containing protein 31 (TRIM31) signaling might be a crucial mechanism for CPS-A to perform its renoprotective functions in mice with DN. The anti-inflammatory, anti-fibrotic and anti-dyslipidemia capacities of CPS-A were confirmed in the mouse podocytes under varying metabolic stresses, which were however almost abolished upon TRIM31 ablation. These data elucidated that TRIM31 expression was largely required for CPS-A to perform its renoprotective effects. Collectively, our study is the first to reveal that CPS-A may be a promising therapeutic strategy for the treatment of obesity-induced DN or associated kidney disease.
Assuntos
Diabetes Mellitus , Nefropatias Diabéticas , Podócitos , Camundongos , Animais , Nefropatias Diabéticas/tratamento farmacológico , Nefropatias Diabéticas/metabolismo , Camundongos Obesos , Fibrose , Inflamação/metabolismo , Obesidade/complicações , Obesidade/tratamento farmacológico , Obesidade/metabolismo , Lipídeos/uso terapêutico , Camundongos Endogâmicos C57BL , Diabetes Mellitus/patologiaRESUMO
Nonalcoholic steatohepatitis (NASH), a common clinical disease, is becoming a leading cause of hepatocellular carcinoma (HCC). Dual specificity phosphatase 22 (DUSP22, also known as JKAP or JSP-1) expressed in numerous tissues plays essential biological functions in immune responses and tumor growth. However, the effects of DUSP22 on NASH still remain unknown. Here, we find a significant decrease of DUSP22 expression in human and murine fatty liver, which is mediated by reactive oxygen species (ROS) generation. Hepatic-specific DUSP22 deletion particularly exacerbates lipid deposition, inflammatory response and fibrosis in liver, facilitating NASH and non-alcoholic fatty liver disease (NAFLD)-associated HCC progression. In contrast, transgenic over-expression, lentivirus or adeno-associated virus (AAV)-mediated DUSP22 gene therapy substantially inhibit NASH-related phenotypes and HCC development in mice. We provide mechanistic evidence that DUSP22 directly interacts with focal adhesion kinase (FAK) and restrains its phosphorylation at Tyr397 (Y397) and Y576 + Y577 residues, subsequently prohibiting downstream activation of extracellular signal-regulated kinase 1/2 (ERK1/2) and nuclear factor-κB (NF-κB) cascades. The binding of DUSP22 to FAK and the dephosphorylation of FAK are indispensable for DUSP22-meliorated NASH progression. Collectively, our findings identify DUSP22 as a key suppressor of NASH-HCC, and underscore the DUSP22-FAK axis as a promising therapeutic target for treatment of the disease.
Assuntos
Carcinoma Hepatocelular , Fosfatases de Especificidade Dupla/metabolismo , Neoplasias Hepáticas , Hepatopatia Gordurosa não Alcoólica , Animais , Carcinoma Hepatocelular/metabolismo , Progressão da Doença , Fosfatases de Especificidade Dupla/genética , Proteína-Tirosina Quinases de Adesão Focal/genética , Proteína-Tirosina Quinases de Adesão Focal/metabolismo , Hepatócitos/metabolismo , Humanos , Lipídeos , Fígado/metabolismo , Neoplasias Hepáticas/metabolismo , Camundongos , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Fosfatases da Proteína Quinase Ativada por Mitógeno/genética , Fosfatases da Proteína Quinase Ativada por Mitógeno/metabolismo , NF-kappa B/metabolismo , Hepatopatia Gordurosa não Alcoólica/metabolismo , Espécies Reativas de Oxigênio/metabolismoRESUMO
Mulberrin (Mul) is a key component of the traditional Chinese medicine Romulus Mori with various biological functions. However, the effects of Mul on liver fibrosis have not been addressed, and thus were investigated in our present study, as well as the underlying mechanisms. Here, we found that Mul administration significantly ameliorated carbon tetrachloride (CCl4)-induced liver injury and dysfunction in mice. Furthermore, CCl4-triggerd collagen deposition and liver fibrosis were remarkably attenuated in mice with Mul supplementation through suppressing transforming growth factor ß1 (TGF-ß1)/SMAD2/3 signaling pathway. Additionally, Mul treatments strongly restrained the hepatic inflammation in CCl4-challenged mice via blocking nuclear factor-κB (NF-κB) signaling. Importantly, we found that Mul markedly increased liver TRIM31 expression in CCl4-treated mice, accompanied with the inactivation of NOD-like receptor protein 3 (NLRP3) inflammasome. CCl4-triggered hepatic oxidative stress was also efficiently mitigated by Mul consumption via improving nuclear factor E2-related factor 2 (Nrf2) activation. Our in vitro studies confirmed that Mul reduced the activation of human and mouse primary hepatic stellate cells (HSCs) stimulated by TGF-ß1. Consistently, Mul remarkably retarded the inflammatory response and reactive oxygen species (ROS) accumulation both in human and murine hepatocytes. More importantly, by using hepatocyte-specific TRIM31 knockout mice (TRIM31Hep-cKO) and mouse primary hepatocytes with Nrf2-knockout (Nrf2KO), we identified that the anti-fibrotic and hepatic protective effects of Mul were TRIM31/Nrf2 signaling-dependent, relieving HSCs activation and liver fibrosis. Therefore, Mul-ameliorated hepatocyte injury contributed to the suppression of HSCs activation by improving TRIM31/Nrf2 axis, thus providing a novel therapeutic strategy for hepatic fibrosis treatment.
Assuntos
Fator 2 Relacionado a NF-E2 , Fator de Crescimento Transformador beta1 , Animais , Derivados de Benzeno , Tetracloreto de Carbono/toxicidade , Células Estreladas do Fígado/metabolismo , Fígado/metabolismo , Cirrose Hepática/induzido quimicamente , Cirrose Hepática/tratamento farmacológico , Cirrose Hepática/prevenção & controle , Camundongos , Fator 2 Relacionado a NF-E2/genética , Fator 2 Relacionado a NF-E2/metabolismo , Transdução de Sinais , Fator de Crescimento Transformador beta1/genética , Fator de Crescimento Transformador beta1/farmacologiaRESUMO
Systemic metabolic syndrome significantly increases the risk of morbidity and mortality in patients with non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH). However, no effective therapeutic strategies are available, practically because our understanding of its complicated pathogenesis is poor. Here we identify the tripartite motif-containing protein 31 (Trim31) as an endogenous inhibitor of rhomboid 5 homolog 2 (Rhbdf2), and we further determine that Trim31 directly binds to Rhbdf2 and facilitates its proteasomal degradation. Hepatocyte-specific Trim31 ablation facilitates NAFLD-associated phenotypes in mice. Inversely, transgenic or ex vivo gene therapy-mediated Trim31 gain-of-function in mice with NAFLD phenotypes virtually alleviates severe deterioration and progression of steatohepatitis. The current findings suggest that Trim31 is an endogenous inhibitor of Rhbdf2 and downstream cascades in the pathogenic process of steatohepatitis and that it may serve as a feasible therapeutical target for the treatment of NAFLD/NASH and associated metabolic disorders.
Assuntos
Peptídeos e Proteínas de Sinalização Intracelular , Hepatopatia Gordurosa não Alcoólica , Proteínas com Motivo Tripartido , Ubiquitina-Proteína Ligases , Animais , Proteínas de Transporte/metabolismo , Hepatócitos/metabolismo , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Fígado/metabolismo , Camundongos , Hepatopatia Gordurosa não Alcoólica/metabolismo , Proteínas com Motivo Tripartido/metabolismo , Ubiquitina-Proteína Ligases/metabolismoRESUMO
Obesity is an important factor implicated in chronic kidney disease (CKD). Juglanin (Jug) is a natural compound extracted from the crude Polygonumaviculare, showing anti-inflammatory and anti-diabetic effects. However, whether Jug has protective effects against obesity-induced renal injury, little has been investigated. Herein, we attempted to explore the potential of Jug in mediating obesity-induced kidney disease in high fat diet (HFD)-challenged mice. Our results suggested that chronic HFD feeding markedly increased the body weights of mice compared to the ones fed with normal chow diet (NCD), along with significant glucose intolerance and insulin resistance. However, these metabolic disorders induced by HFD were effectively alleviated by Jug treatments in a dose-dependent manner. Moreover, HFD-challenged mice showed apparent histopathological changes in renal tissues with significant collagen accumulation, which were attenuated by Jug supplementation. In addition, Jug treatment decreased the expression levels of kidney injury molecule-1 (KIM-1), while increased nephrin and podocin expression levels in kidney of HFD-challenged mice, improving the renal dysfunction. Furthermore, HFD led to lipid deposition in kidney samples of mice by enhancing abnormal lipid metabolism. In addition, HFD promoted the releases of circulating pro-inflammatory cytokines, and enhanced the renal inflammation by activating nuclear factor-kappa B/histone deacetylase 3 (NF-κB/HDAC3) signaling. HFD-induced dyslipidemia and inflammation were considerably abrogated by Jug administration in mice. The protective effects of Jug against renal injury were confirmed in palmitate (PA)-stimulated HK2 cells in vitro mainly through suppressing the nuclear translocation of NF-κB and HDAC3, repressing inflammation and lipid accumulation eventually. Hence, Jug could ameliorate HFD-induced kidney injury mainly through blocking the NF-κB/HDAC3 nuclear translocation.
Assuntos
Anti-Inflamatórios/uso terapêutico , Dislipidemias/tratamento farmacológico , Glicosídeos/uso terapêutico , Hipolipemiantes/uso terapêutico , Quempferóis/uso terapêutico , Nefropatias/tratamento farmacológico , Síndrome Metabólica/tratamento farmacológico , Animais , Anti-Inflamatórios/farmacologia , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Dieta Hiperlipídica , Dislipidemias/metabolismo , Dislipidemias/patologia , Glicosídeos/farmacologia , Histona Desacetilases/genética , Histona Desacetilases/metabolismo , Humanos , Hipolipemiantes/farmacologia , Resistência à Insulina , Quempferóis/farmacologia , Rim/efeitos dos fármacos , Rim/metabolismo , Nefropatias/metabolismo , Nefropatias/patologia , Metabolismo dos Lipídeos/efeitos dos fármacos , Masculino , Síndrome Metabólica/metabolismo , Síndrome Metabólica/patologia , Camundongos Endogâmicos C57BL , NF-kappa B/metabolismo , Transdução de Sinais/efeitos dos fármacosRESUMO
Ambient particulate matter (PM2.5)-induced metabolic syndromes is a critical contributor to the pathological processes of neurological diseases, but the underlying molecular mechanisms remain poorly understood. The rhomboid 5 homolog 2 (Rhbdf2), an essential regulator in the production of TNF-α, has recently been confirmed to exhibit a key role in regulating inï¬ammation-associated diseases. Thus, we examined whether Rhbdf2 contributes to hypothalamic inflammation via NF-κB associated inflammation activation in long-term PM2.5-exposed mice. Specifically, proopiomelanocortin-specific Rhbdf2 deficiency (Rhbdf2Pomc) and corresponding littermates control mice were used for the current study. After 24 weeks of PM2.5 inhalation, systemic-metabolism disorder was confirmed in WT mice in terms of impaired glucose tolerance, increased insulin resistance, and high blood pressure. Markedly, PM2.5-treated Rhbdf2Pomc mice displayed a significantly opposite trend in these parameters compared with those of the controls group. We next confirmed hypothalamic injury accompanied by abnormal POMC neurons loss, as indicated by increased inflammatory cytokines, chemokines, and oxidative-stress levels and decreased antioxidant activity. These results were further supported by blood routine examination. In summary, our findings suggest that Rhbdf2 plays an important role in exacerbating PM2.5-stimulated POMC neurons loss associated hypothalamic injury, thus providing a possible target for blocking pathological development of air pollution-associated diseases.
Assuntos
Poluentes Atmosféricos , Material Particulado , Poluentes Atmosféricos/toxicidade , Animais , Inflamação/induzido quimicamente , Inflamação/genética , Camundongos , Neurônios , Estresse Oxidativo , Material Particulado/toxicidade , Pró-OpiomelanocortinaRESUMO
Excess high-fat diet (HFD) intake predisposes the occurrence of obesity-associated heart injury, but the mechanism is elusive. Fisetin (FIS), as a natural flavonoid, has potential activities to alleviate obesity-induced metabolic syndrome. However, the underlying molecular mechanisms of FIS against HFD-induced cardiac injury remain unclear. The present study was to explore the protective effects of FIS on cardiac dysfunction in HFD-fed mice. We found that FIS alleviated HFD-triggered metabolic disorder by reducing body weight, fasting blood glucose and insulin levels, and insulin resistance. Moreover, FIS supplements significantly alleviated dyslipidemia in both mouse hearts and cardiomyocytes stimulated by metabolic stress. FIS treatment abolished HFD-induced inflammatory response in heart tissues through suppressing TNF receptor-1/TNF receptor-associated factor-2 (Tnfr-1/Traf-2) signaling. Furthermore, FIS induced a strong reduction in the expression of fibrosis-related genes, contributing to the inhibition of fibrosis by inactivating transforming growth factor (Tgf)-ß1/Smads/Erk1/2 signaling. Collectively, these results demonstrated that FIS could be a promising therapeutic strategy for the treatment of obesity-associated cardiac injury.