RESUMO
The transcription factor TFEB is a major regulator of lysosomal biogenesis and autophagy. There is growing evidence that posttranslational modifications play a crucial role in regulating TFEB activity. Here, we show that lactate molecules can covalently modify TFEB, leading to its lactylation and stabilization. Mechanically, lactylation at K91 prevents TFEB from interacting with E3 ubiquitin ligase WWP2, thereby inhibiting TFEB ubiquitination and proteasome degradation, resulting in increased TFEB activity and autophagy flux. Using a specific antibody against lactylated K91, enhanced TFEB lactylation was observed in clinical human pancreatic cancer samples. Our results suggest that lactylation is a novel mode of TFEB regulation and that lactylation of TFEB may be associated with high levels of autophagy in rapidly proliferating cells, such as cancer cells.
Assuntos
Autofagia , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos , Lisossomos , Ubiquitinação , Humanos , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/metabolismo , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/genética , Lisossomos/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitina-Proteína Ligases/genética , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patologia , Neoplasias Pancreáticas/genética , Células HEK293 , Processamento de Proteína Pós-Traducional , Estabilidade Proteica , Linhagem Celular Tumoral , Proteólise , Complexo de Endopeptidases do Proteassoma/metabolismoRESUMO
Long-chain free fatty acids (FFAs) accumulation and oxidative toxicity is a major cause for several pathological conditions. The mechanisms underlying FFA cytotoxicity remain elusive. Here we show that palmitic acid (PA), the most abundant FFA in the circulation, induces S403 phosphorylation of SQSTM1/p62 (sequestosome 1) and its aggregation, which sequesters KEAP1 and activates the non-canonical SQSTM1-KEAP1-NFE2L2 antioxidant pathway. The PA-induced SQSTM1 S403 phosphorylation and aggregation are dependent on SQSTM1 K7-D69 hydrogen bond formation and dimerization in the Phox and Bem1 (PB1) domain, which facilitates the recruitment of TBK1 that phosphorylates SQSTM1 S403. The ubiquitin E3 ligase TRIM21 ubiquitinates SQSTM1 at the K7 residue and abolishes the PB1 dimerization, S403 phosphorylation, and SQSTM1 aggregation. TRIM21 is oxidized at C92, C111, and C114 to form disulfide bonds that lead to its oligomerization and decreased E3 activity. Mutagenizing the three C residues to S (3CS) abolishes TRIM21 oligomerization and increases its E3 activity. TRIM21 ablation leads to decreased SQSTM1 K7 ubiquitination, hence elevated SQSTM1 S403 phosphorylation and aggregation, which confers protection against PA-induced oxidative stress and cytotoxicity. Therefore, TRIM21 is a negative regulator of SQSTM1 phosphorylation, aggregation, and the antioxidant sequestration function. TRIM21 is oxidized to reduce its E3 activity that helps enhance the SQSTM1-KEAP1-NFE2L2 antioxidant pathway. Inhibition of TRIM21 May be a viable strategy to protect tissues from lipotoxicity resulting from long-chain FFAs.
RESUMO
Traumatic brain injuries (TBI) and stroke are major causes of morbidity and mortality in both developing and developed countries. The complex and heterogeneous pathophysiology of TBI and cerebral ischemia-reperfusion injury (CIRI), in addition to the blood-brain barrier (BBB) resistance, is a major barrier to the advancement of diagnostics and therapeutics. Clinical data showed that the severity of TBI and stroke is positively correlated with the number of neutrophils in peripheral blood and brain injury sites. Furthermore, neutrophil extracellular traps (NETs) released by neutrophils correlate with worse TBI and stroke outcomes by impairing revascularization and vascular remodeling. Therefore, targeting neutrophils to deliver NETs inhibitors to brain injury sites and reduce the formation of NETs can be an optimal strategy for TBI and stroke therapy. Herein, the study designs and synthesizes a reactive oxygen species (ROS)-responsive neutrophil-targeting delivery system loaded with peptidyl arginine deiminase 4 (PAD4) inhibitor, GSK484, to prevent the formation of NETs in brain injury sites, which significantly inhibited neuroinflammation and improved neurological deficits, and improved the survival rate of TBI and CIRI. This strategy may provide a groundwork for the development of targeted theranostics of TBI and stroke.
Assuntos
Lesões Encefálicas Traumáticas , Modelos Animais de Doenças , Armadilhas Extracelulares , Neutrófilos , Acidente Vascular Cerebral , Armadilhas Extracelulares/metabolismo , Neutrófilos/metabolismo , Animais , Camundongos , Proteína-Arginina Desiminase do Tipo 4/metabolismo , Humanos , Espécies Reativas de Oxigênio/metabolismo , Masculino , Nanomedicina Teranóstica/métodosRESUMO
Posttranslational modifications (PTMs) of histones are well-established contributors in a variety of biological functions, especially tumorigenesis. Histone demethylase JMJD2D (also known as KDM4D), a member of the JMJD2 subfamily, promotes gene transcription by antagonizing H3K9 methylation. JMJD2D is an epigenetic factor coordinating androgen receptor activation, DNA damage repair, DNA replication, and cell cycle regulation. Recently, the oncogenic role of JMJD2D in colorectal cancer (CRC) and hepatocellular cancer (HCC) has been recognized. JMJD2D serves as a coactivator of ß-catenin, Gli1/2, HIF1α, STAT3, IRF1, TCF4, and NICD or an antagonist of p53 to promote the progression of CRC and HCC. In this review, we summarize the molecular mechanisms of JMJD2D in promoting the progression of CRC and HCC as well as the constructive role of its targeting inhibitors in suppressing tumorigenesis and synergistically enhancing the efficacy of anti-PD-1/PD-L1 immunotherapy.
RESUMO
Overexpression of nuclear coactivator steroid receptor coactivator 1 (SRC-1) and aberrant activation of the Hedgehog (Hh) signaling pathway are associated with various tumorigenesis; however, the significance of SRC-1 in colorectal cancer (CRC) and its contribution to the activation of Hh signaling are unclear. Here, we identified a conserved Hh signaling signature positively correlated with SRC-1 expression in CRC based on TCGA database; SRC-1 deficiency significantly inhibited the proliferation, survival, migration, invasion, and tumorigenesis of both human and mouse CRC cells, and SRC-1 knockout significantly suppressed azoxymethane/dextran sodium sulfate (AOM/DSS)-induced CRC in mice. Mechanistically, SRC-1 promoted the expression of GLI family zinc finger 2 (GLI2), a major downstream transcription factor of Hh pathway, and cooperated with GLI2 to enhance multiple Hh-regulated oncogene expression, including Cyclin D1, Bcl-2, and Slug. Pharmacological blockages of SRC-1 and Hh signaling retarded CRC progression in human CRC cell xenograft mouse model. Together, our studies uncover an SRC-1/GLI2-regulated Hh signaling looping axis that promotes CRC tumorigenesis, offering an attractive strategy for CRC treatment.
Assuntos
Neoplasias Colorretais , Proteínas Hedgehog , Coativador 1 de Receptor Nuclear , Animais , Carcinogênese/genética , Proliferação de Células/genética , Neoplasias Colorretais/genética , Regulação Neoplásica da Expressão Gênica , Proteínas Hedgehog/metabolismo , Humanos , Camundongos , Proteínas Nucleares/genética , Coativador 1 de Receptor Nuclear/genética , Transdução de Sinais/fisiologia , Proteína Gli2 com Dedos de Zinco/metabolismoRESUMO
Programmed death-ligand 1 (PD-L1) is an important immunosuppressive molecule highly expressed on the surface of cancer cells. IFNγ triggered cancer cell immunosuppression against CD8+ T cell surveillance via up-regulation of PD-L1. Histone demethylase JMJD2D promotes colorectal cancer (CRC) progression; however, the role of JMJD2D in cancer immune escape is unknown. Here, we report that both PD-L1 and JMJD2D are frequently overexpressed in human CRC specimens with a significant positive correlation. Genetic ablation of JMJD2D in CRC cells attenuated the expression of PD-L1 and stalled tumor growth in mice, accompanied by the elevated number and effector function of tumor infiltrating CD8+ T cells. Mechanistically, JMJD2D coactivated SP-1 to promote the expression of IFNGR1, which elevated STAT3-IRF1 signaling and promoted PD-L1 expression. Again, JMJD2D is a major coactivator for STAT3-IRF1 axis to enhance PD-L1 transcription in a demethylation activity dependent manner. Furthermore, pharmacological inhibition of JMJD2D conduced to improve the anti-tumor efficacy of PD-L1 antibody as demonstrated by slower tumor growth and higher infiltration and function of CD8+ T cells in the combination of JMJD2D inhibitor 5-c-8HQ and PD-L1 antibody group compared with monotherapy with either agent. These results demonstrate that JMJD2D promotes CRC immune escape by enhancing PD-L1 expression to inhibit the activation and tumor infiltration of CD8+ T cells; targeting JMJD2D has the potential role in promoting the efficacy of anti-PD-1/PD-L1 immunotherapy.
Assuntos
Antígeno B7-H1 , Neoplasias Colorretais , Histona Desmetilases com o Domínio Jumonji/metabolismo , Animais , Linfócitos T CD8-Positivos , Linhagem Celular Tumoral , Neoplasias Colorretais/patologia , Humanos , Fator Regulador 1 de Interferon/metabolismo , Camundongos , Receptores de Interferon/metabolismo , Fator de Transcrição STAT3/metabolismo , Transdução de Sinais/genética , Receptor de Interferon gamaRESUMO
BACKGROUND AND AIMS: TRIM21 is a ubiquitin E3 ligase that is implicated in numerous biological processes including immune response, cell metabolism, redox homeostasis, and cancer development. We recently reported that TRIM21 can negatively regulate the p62-Keap1-Nrf2 antioxidant pathway by ubiquitylating p62 and prevents its oligomerization and protein sequestration function. As redox homeostasis plays a pivotal role in many cancers including liver cancer, we sought to determine the role of TRIM21 in hepatocarcinogenesis. METHODS: We examined the correlation between TRIM21 expression and the disease using publicly available data sets and 49 cases of HCC clinical samples. We used TRIM21 genetic knockout mice to determine how TRIM21 ablation impact HCC induced by the carcinogen DEN plus phenobarbital (PB). We explored the mechanism that loss of TRIM21 protects cells from DEN-induced oxidative damage and cell death. RESULTS: There is a positive correlation between TRIM21 expression and HCC. Consistently, TRIM21-knockout mice are resistant to DEN-induced hepatocarcinogenesis. This is accompanied by decreased cell death and tissue damage upon DEN treatment, hence reduced hepatic tissue repair response and compensatory proliferation. Cells deficient in TRIM21 display enhanced p62 sequestration of Keap1 and are protected from DEN-induced ROS induction and cell death. Reconstitution of wild-type but not the E3 ligase-dead and the p62 binding-deficient mutant TRIM21 impedes the protection from DEN-induced oxidative damage and cell death in TRIM21-deficient cells. CONCLUSIONS: Increased TRIM21 expression is associated with human HCC. Genetic ablation of TRIM21 leads to protection against oxidative hepatic damage and decreased hepatocarcinogenesis, suggesting TRIM21 as a preventive and therapeutic target.
Assuntos
Biomarcadores Tumorais/metabolismo , Carcinogênese/patologia , Carcinoma Hepatocelular/patologia , Regulação Neoplásica da Expressão Gênica , Neoplasias Hepáticas/patologia , Ribonucleoproteínas/metabolismo , Animais , Apoptose , Biomarcadores Tumorais/genética , Carcinogênese/genética , Carcinogênese/metabolismo , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/metabolismo , Proliferação de Células , Humanos , Proteína 1 Associada a ECH Semelhante a Kelch/genética , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fator 2 Relacionado a NF-E2/genética , Fator 2 Relacionado a NF-E2/metabolismo , Prognóstico , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Ribonucleoproteínas/genética , Taxa de Sobrevida , Células Tumorais CultivadasRESUMO
Hypoxia-inducible factor 1 (HIF1) signaling pathway plays a key role in cancer progression by enhancing glycolysis through activating the transcription of glycolytic genes. JMJD2D, a histone demethylase that specifically demethylates H3K9me2/3, can promote colorectal cancer (CRC) progression. However, it is unknown whether JMJD2D could promote CRC progression by enhancing glycolysis through activating HIF1 signaling pathway. In this study, we found that downregulation of JMJD2D inhibited the glycolysis in CRC cells through suppressing HIF1 signaling pathway to downregulate glycolytic gene expression. Restoring HIF1 signaling by enforced expression of HIF1α in JMJD2D-knockdown CRC cells partially recovered CRC cell glycolysis, proliferation, migration, invasion, xenograft growth, and metastasis, suggesting that JMJD2D promotes CRC progression by enhancing glycolysis through activating HIF1 signaling pathway. JMJD2D activated HIF1 signaling pathway through three different mechanisms: JMJD2D cooperated with the transcription factor SOX9 to enhance mTOR expression and then to promote HIF1α translation; JMJD2D cooperated with the transcription factor c-Fos to enhance HIF1ß transcription; JMJD2D interacted and cooperated with HIF1α to enhance the expression of glycolytic gene. The demethylase-defective mutant of JMJD2D could not induce the expression of mTOR, HIF1α, HIF1ß, and glycolytic genes, suggesting that the demethylase activity of JMJD2D is important for glycolysis through activating HIF1 signaling. Clinically, a highly positive correlation between the expression of JMJD2D and mTOR, HIF1ß, and several glycolytic genes in human CRC specimens was identified. Collectively, our study reveals an important role of JMJD2D in CRC progression by enhancing glycolysis through activating HIF1 signaling pathway.
Assuntos
Neoplasias Colorretais/genética , Regulação Neoplásica da Expressão Gênica , Glicólise/genética , Fator 1 Induzível por Hipóxia/metabolismo , Histona Desmetilases com o Domínio Jumonji/metabolismo , Animais , Proliferação de Células/genética , Neoplasias Colorretais/patologia , Desmetilação do DNA , Progressão da Doença , Técnicas de Silenciamento de Genes , Células HCT116 , Células HEK293 , Humanos , Fator 1 Induzível por Hipóxia/genética , Histona Desmetilases com o Domínio Jumonji/genética , Masculino , Camundongos , Mutação , Transdução de Sinais/genéticaRESUMO
Histone demethylase JMJD2D can promote gene expression by specifically demethylating H3K9me2/3. The role of JMJD2D in colitis and colitis-associated colorectal cancer (CRC) progression remains unclear. Here, we show that colonic JMJD2D is induced by TNFα during dextran sulfate sodium-induced colitis. JMJD2D-deficient mice exhibit more severe colon damage and defective colon regeneration due to impaired Hedgehog signaling activation after colitis. JMJD2D knockdown in CRC cells suppresses Hedgehog signaling, resulting in reduced CRC growth and metastasis. Mechanistically, JMJD2D promotes Hedgehog target gene expression through interacting with Gli2 to reduce H3K9me3 levels at the promoter. Clinically, JMJD2D expression is upregulated and positively correlated with Gli2 expression in human inflammatory bowel disease specimens and CRC specimens. The JMJD2D inhibitor 5-c-8HQ or aspirin synergizes with Hedgehog inhibitor vismodegib to inhibit CRC cell proliferation and tumorigenesis. Collectively, our findings unveil an essential role of JMJD2D in activating the processes of colonic protection, regeneration, and tumorigenesis.
Assuntos
Colite/tratamento farmacológico , Neoplasias Colorretais/tratamento farmacológico , Inflamação/tratamento farmacológico , Histona Desmetilases com o Domínio Jumonji/genética , Anilidas/farmacologia , Animais , Aspirina/farmacologia , Carcinogênese/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Colite/genética , Colite/patologia , Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Modelos Animais de Doenças , Sinergismo Farmacológico , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Técnicas de Silenciamento de Genes , Proteínas Hedgehog/antagonistas & inibidores , Proteínas Hedgehog/genética , Humanos , Inflamação/genética , Inflamação/patologia , Histona Desmetilases com o Domínio Jumonji/antagonistas & inibidores , Camundongos , Piridinas/farmacologia , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genéticaRESUMO
BACKGROUND & AIMS: Wnt signaling contributes to the development of colorectal cancer (CRC). We studied interactions between lysine demethylase 4D (KDM4D or JMJD2D) and ß-catenin, a mediator of Wnt signaling, in CRC cell lines and the effects on tumor formation in mice. METHODS: We obtained colorectal tumor specimens and surrounding nontumor colon tissues (controls) from patients undergoing surgery in China; levels of JMJD2D were measured by immunohistochemical or immunoblot analysis. JMJD2D expression was knocked down in CRC (CT26, HCT116, and SW480 cells) using small hairpin RNAs, and cells were analyzed with viability, flow cytometry, colony formation, and transwell migration and invasion assays. Cells were also grown as tumor xenografts in nude mice or injected into tail veins or spleens of mice, and metastases were measured. We performed promoter activity, co-immunoprecipitation, and chromatin immunoprecipitation assays. We also performed studies with Apcmin/+ and JMJD2D-knockout mice; these mice were crossed, and colorectal tumor formation in offspring (Apcmin/+Jmjd2d+/+ and Apcmin/+Jmjd2d-/-) was analyzed. JMJD2D-knockout and wild-type (control) mice were given azoxymethane followed by dextran sodium sulfate to induce colitis-associated CRC; some mice were given the JMJD2D inhibitor 5-chloro-8-hydroxyquinoline (5-c-8HQ) or vehicle to examine the effects of 5-c-8HQ on intestinal tumor formation. RESULTS: Levels of JMJD2D were significantly higher in human colorectal tumors than in control tissues and correlated with levels of proliferating cell nuclear antigen. JMJD2D knockdown reduced CRC cell proliferation, migration, and invasion, as well as growth of xenograft tumors and formation of metastases in mice. JMJD2D was required for expression of ß-catenin in CRC cell lines; ectopic expression of JMJD2D increased the promoter activities of genes regulated by ß-catenin (MYC, CCND1, MMP2, and MMP9). We found that JMJD2D and ß-catenin interacted physically and that JMJD2D demethylated H3K9me3 at promoters of ß-catenin target genes. JMJD2D-knockout mice developed fewer colitis-associated colorectal tumors than control mice, and their tumor tissues had lower levels of ß-catenin, MYC, cyclin D1, and proliferating cell nuclear antigen than tumors from control mice. Apcmin/+Jmjd2d-/- mice developed fewer and smaller colon tumors than Apcmin/+ mice. Mice given 5-c-8HQ developed smaller and fewer colitis-associated tumors, with lower levels of cell proliferation, than mice given vehicle. Apcmin/+ mice given 5-c-8HQ also developed fewer tumors in intestines and colons than mice given vehicle. CONCLUSIONS: Levels of the histone demethylase JMJD2D are increased in human colorectal tumors compared with nontumor colon tissues. JMJD2D interacts with ß-catenin to activate transcription of its target genes and promote CRC cell proliferation, migration, and invasion, as well as formation of colorectal tumors in mice.
Assuntos
Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/patologia , Histonas/genética , Histona Desmetilases com o Domínio Jumonji/metabolismo , beta Catenina/metabolismo , Animais , Movimento Celular/genética , Proliferação de Células , Sobrevivência Celular/genética , Cloroquinolinóis/farmacologia , Neoplasias Colorretais/induzido quimicamente , Neoplasias Colorretais/genética , Ciclina D1/genética , Feminino , Regulação Neoplásica da Expressão Gênica , Técnicas de Silenciamento de Genes , Células HCT116 , Histonas/metabolismo , Humanos , Histona Desmetilases com o Domínio Jumonji/antagonistas & inibidores , Histona Desmetilases com o Domínio Jumonji/genética , Metaloproteinase 2 da Matriz/genética , Metaloproteinase 9 da Matriz/genética , Metilação , Camundongos , Camundongos Knockout , Camundongos Nus , Metástase Neoplásica , Transplante de Neoplasias , Antígeno Nuclear de Célula em Proliferação/metabolismo , Proteínas Proto-Oncogênicas c-myc/genética , Transcrição Gênica , Ensaio Tumoral de Célula-Tronco , Via de Sinalização Wnt , beta Catenina/genéticaRESUMO
The histone demethylase Jumonji domain containing 1A (JMJD1A) is overexpressed in multiple tumors and promotes cancer progression. JMJD1A has been shown to promote colorectal cancer (CRC) progression, but its molecular role in CRC is unclear. Here, we report that JMJD1A is overexpressed in CRC specimens and that its expression is positively correlated with that of proliferating cell nuclear antigen (PCNA). JMJD1A knockdown decreased the expression of proliferative genes such as c-Myc, cyclin D1, and PCNA, suppressed CRC cell proliferation, arrested cell cycle progression, and reduced xenograft tumorigenesis. Furthermore, JMJD1A knockdown inhibited CRC cell migration, invasion, and lung metastasis by decreasing matrix metallopeptidase 9 (MMP9) expression and enzymatic activity. Moreover, bioinformatics analysis of GEO profile datasets revealed that JMJD1A expression in human CRC specimens is positively correlated with the expression of Wnt/ß-catenin target genes, including c-Myc, cyclin D1, and MMP9. Mechanistically, JMJD1A enhanced Wnt/ß-catenin signaling by promoting ß-catenin expression and interacting with ß-catenin to enhance its transactivation. JMJD1A removed the methyl groups of H3K9me2 at the promoters of c-Myc and MMP9 genes. In contrast, the JMJD1AH1120Y variant, which lacked demethylase activity, did not demethylate H3K9me2 at these promoters, failed to assist ß-catenin to induce the expression of Wnt/ß-catenin target genes, and failed to promote CRC progression. These findings suggest that JMJD1A's demethylase activity is required for Wnt/ß-catenin activation. Of note, high JMJD1A levels in CRC specimens predicted poor cancer outcomes. In summary, JMJD1A promotes CRC progression by enhancing Wnt/ß-catenin signaling, implicating JMJD1A as a potential molecular target for CRC management.
Assuntos
Movimento Celular , Proliferação de Células , Neoplasias Colorretais/patologia , Histona Desmetilases com o Domínio Jumonji/metabolismo , Neoplasias Pulmonares/secundário , Proteínas Wnt/metabolismo , beta Catenina/metabolismo , Animais , Apoptose , Carcinogênese , Ciclo Celular , Neoplasias Colorretais/genética , Neoplasias Colorretais/metabolismo , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Histona Desmetilases com o Domínio Jumonji/genética , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Nus , Antígeno Nuclear de Célula em Proliferação/genética , Antígeno Nuclear de Célula em Proliferação/metabolismo , Células Tumorais Cultivadas , Proteínas Wnt/genética , Ensaios Antitumorais Modelo de Xenoenxerto , beta Catenina/genéticaRESUMO
Bile duct obstruction is a potent stimulus for cholangiocyte proliferation, especially for large cholangiocytes. Our previous studies reported that conjugated bile acids (CBAs) activate the protein kinase B (AKT) and extracellular signal-regulated kinase 1 and 2 (ERK1/2) signaling pathways through sphingosine 1-phosphate receptor (S1PR) 2 in hepatocytes and cholangiocarcinoma cells. It also has been reported that taurocholate (TCA) promotes large cholangiocyte proliferation and protects cholangiocytes from bile duct ligation (BDL)-induced apoptosis. However, the role of S1PR2 in bile-acid-mediated cholangiocyte proliferation and cholestatic liver injury has not been elucidated. Here, we report that S1PR2 is the predominant S1PR expressed in cholangiocytes. Both TCA- and sphingosine-1-phosphate (S1P)-induced activation of ERK1/2 and AKT were inhibited by JTE-013, a specific antagonist of S1PR2, in cholangiocytes. In addition, TCA- and S1P-induced cell proliferation and migration were inhibited by JTE-013 and a specific short hairpin RNA of S1PR2, as well as chemical inhibitors of ERK1/2 and AKT in mouse cholangiocytes. In BDL mice, expression of S1PR2 was up-regulated in whole liver and cholangiocytes. S1PR2 deficiency significantly reduced BDL-induced cholangiocyte proliferation and cholestatic injury, as indicated by significant reductions in inflammation and liver fibrosis in S1PR2 knockout mice. Treatment of BDL mice with JTE-013 significantly reduced total bile acid levels in serum and cholestatic liver injury. CONCLUSION: This study suggests that CBA-induced activation of S1PR2-mediated signaling pathways plays a critical role in obstructive cholestasis and may represent a novel therapeutic target for cholestatic liver diseases. (Hepatology 2017;65:2005-2018).
Assuntos
Colangiocarcinoma/patologia , Colangite Esclerosante/patologia , Colestase/patologia , Cirrose Hepática/patologia , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Receptores de Lisoesfingolipídeo/metabolismo , Análise de Variância , Animais , Ácidos e Sais Biliares/farmacologia , Neoplasias dos Ductos Biliares/metabolismo , Neoplasias dos Ductos Biliares/patologia , Ductos Biliares/cirurgia , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/fisiologia , Colangiocarcinoma/metabolismo , Colangite Esclerosante/metabolismo , Colestase/complicações , Modelos Animais de Doenças , Ligadura , Fígado/lesões , Fígado/patologia , Cirrose Hepática/metabolismo , Lisofosfolipídeos/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos CBA , Camundongos Knockout , Distribuição Aleatória , Papel (figurativo) , Transdução de Sinais , Esfingosina/análogos & derivados , Esfingosina/metabolismo , Receptores de Esfingosina-1-Fosfato , Regulação para CimaRESUMO
Glucocorticoids are used to treat a number of human diseases but often lead to insulin resistance and metabolic syndrome. 11ß-hydroxysteroid dehydrogenase type 1 (11ß-HSD1) is a key enzyme that catalyzes the intracellular conversion of cortisone to physiologically active cortisol. Despite the known role of 11ß-HSD1 and active glucocorticoid in causing insulin resistance, the molecular mechanisms by which insulin resistance is induced remain elusive. The aim of this study is to identify these mechanisms in high fat diet (HFD) experimental models. Mice on a HFD were treated with 11ß-HSD1 inhibitor as well as a JNK inhibitor. We then treated 3T3-L1-derived adipocytes with prednisone, a synthetic glucocorticoid, and cells with 11ß-HSD1 overexpression to study insulin resistance. Our results show that 11ß-HSD1 and JNK inhibition mitigated insulin resistance in HFD mice. Prednisone stimulation or overexpression of 11ß-HSD1 also caused JNK activation in cultured adipocytes. Inhibition of 11ß-HSD1 blocked the activation of JNK in adipose tissue of HFD mice as well as in cultured adipocytes. Furthermore, prednisone significantly impaired the insulin signaling pathway, and these effects were reversed by 11ß-HSD1 and JNK inhibition. Our study demonstrates that glucocorticoid-induced insulin resistance was dependent on 11ß-HSD1, resulting in the critical activation of JNK signaling in adipocytes.
Assuntos
11-beta-Hidroxiesteroide Desidrogenase Tipo 1/metabolismo , Adipócitos/enzimologia , Resistência à Insulina , Prednisona/farmacologia , Transdução de Sinais , Células 3T3-L1 , Adipócitos/patologia , Animais , Ativação Enzimática/efeitos dos fármacos , MAP Quinase Quinase 4/antagonistas & inibidores , MAP Quinase Quinase 4/metabolismo , Masculino , CamundongosRESUMO
BACKGROUND: General control non-depressible 5 (GCN5) is a crucial catalytic component of a transcriptional regulatory complex that plays important roles in cellular functions from cell cycle regulation to DNA damage repair. Although GCN5 has recently been implicated in certain oncogenic roles, its role in liver cancer progression remains vague. RESULTS: In this study, we report that GCN5 was overexpressed in 17 (54.8 %) of 31 human hepatocellular carcinoma (HCC) specimens. Down-regulation of GCN5 inhibited HCC cell proliferation and xenograft tumor formation. GCN5 knockdown decreased the protein levels of the proliferation marker proliferating cell nuclear antigen (PCNA) and amplified in breast cancer 1 (AIB1), but increased the protein levels of cell cycle inhibitor p21(Cip1/Waf1) in HepG2 cells. GCN5 regulated AIB1 expression, at least in part, by cooperating with E2F1 to enhance AIB1 transcription. Consistently, GCN5 expression was positively correlated with AIB1 expression in human HCC specimens in two GEO profile datasets. CONCLUSION: Since AIB1 plays a promoting role in HCC progression, our results propose that GCN5 promotes HCC progression at least partially by regulating AIB1 expression. This study implicates that GCN5 might be a potential molecular target for HCC diagnosis and treatment.
RESUMO
Chronic activation of renin-angiotensin system (RAS) greatly contributes to renal fibrosis through the over expression of angiotensin (Ang) II, ultimately leading to chronic kidney disease (CKD). As the main peptide in the RAS, Ang II is a key regulator of nephrotic inflammation, fibrogenic destruction and hypertensive nephropathy. Controlled by growth factors such as TGF-ß, Ang II is thought to be affected by other such growth factors including epidermal growth factor (EGF) due to its ability to stimulate growth, regulate angiogenesis, and desensitize cells from apoptotic stimuli. Here we show that epidermal growth factor receptor (EGFR) plays a key role in Ang II induced renal fibrosis and its inhibition for the use as an effective treatment of CKD. 453, an AG1478 analog, was used to block the EGF-EGFR interaction in vivo in 4-week old mice treated with Ang II and 453. Along with the inhibition of EGFR and its downstream signaling pathways (AKT and ERK), 453 also prevented the activation of fibrotic (collagen, CFGF, TGF-ß), inflammatory (COX2, IL-6, IL-1ß, TNF-α), apoptosis and oxidative stress pathways. These findings suggest the use of 453 as a novel EGFR-inhibitor for therapeutic use in CKD kidney dysfunction.
Assuntos
Angiotensina II/farmacologia , Receptores ErbB/antagonistas & inibidores , Rim/efeitos dos fármacos , Rim/patologia , Inibidores de Proteínas Quinases/farmacologia , Quinazolinas/farmacologia , Tirfostinas/farmacologia , Animais , Apoptose/efeitos dos fármacos , Receptores ErbB/metabolismo , Fibrose , Rim/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Estresse Oxidativo/efeitos dos fármacosRESUMO
Inflammation and oxidative stress plays an important role in the development of obesity-related complications and cardiovascular disease. Benzimidazole and imidazopyridine compounds are a class of compounds with a variety of activities, including anti-inflammatory, antioxidant and anti-cancer. X22 is an imidazopyridine derivative we synthesized and evaluated previously for anti-inflammatory activity in lipopolysaccharide-stimulated macrophages. However, its ability to alleviate obesity-induced heart injury via its anti-inflammatory actions was unclear. This study was designed to evaluate the cardioprotective effects of X22 using cell culture studies and a high-fat diet rat model. We observed that palmitic acid treatment in cardiac-derived H9c2 cells induced a significant increase in reactive oxygen species, inflammation, apoptosis, fibrosis and hypertrophy. All of these changes were inhibited by treatment with X22. Furthermore, oral administration of X22 suppressed high-fat diet-induced oxidative stress, inflammation, apoptosis, hypertrophy and fibrosis in rat heart tissues and decreased serum lipid concentration. We also found that the anti-inflammatory and anti-oxidative actions of X22 were associated with Nrf2 activation and nuclear factor-kappaB (NF-κB) inhibition, respectively, both in vitro and in vivo. The results of this study indicate that X22 may be a promising cardioprotective agent and that Nrf2 and NF-κB may be important therapeutic targets for obesity-related complications.
Assuntos
Traumatismos Cardíacos/tratamento farmacológico , Traumatismos Cardíacos/prevenção & controle , Imidazóis/farmacologia , Imidazóis/uso terapêutico , Inflamação/tratamento farmacológico , Obesidade/complicações , Estresse Oxidativo/efeitos dos fármacos , Piridinas/farmacologia , Piridinas/uso terapêutico , Animais , Apoptose/efeitos dos fármacos , Glicemia/metabolismo , Cardiomegalia/metabolismo , Cardiomegalia/patologia , Linhagem Celular , Dieta Hiperlipídica , Fibrose , Traumatismos Cardíacos/complicações , Traumatismos Cardíacos/patologia , Imidazóis/administração & dosagem , Imidazóis/química , Inflamação/complicações , Lipídeos/sangue , Masculino , Miocárdio/patologia , NF-kappa B/metabolismo , Obesidade/sangue , Obesidade/patologia , Ácido Palmítico , Piridinas/administração & dosagem , Piridinas/química , Ratos Wistar , Espécies Reativas de Oxigênio/metabolismoRESUMO
Cardiac hypertrophy is an important risk factor for heart failure. Epidermal growth factor receptor (EGFR) has been found to play a role in the pathogenesis of various cardiovascular diseases. The aim of this current study was to examine the role of EGFR in angiotensin II (Ang II)-induced cardiac hypertrophy and identify the underlying molecular mechanisms. In this study, we observed that both Ang II and EGF could increase the phospohorylation of EGFR and protein kinase B (AKT)/extracellular signal-regulated kinase (ERK), and then induce cell hypertrophy in H9c2 cells. Both pharmacological inhibitors and genetic silencing significantly reduced Ang II-induced EGFR signalling pathway activation, hypertrophic marker overexpression, and cell hypertrophy. In addition, our results showed that Ang II-induced EGFR activation is mediated by c-Src phosphorylation. In vivo, Ang II treatment significantly led to cardiac remodelling including cardiac hypertrophy, disorganization and fibrosis, accompanied by the activation of EGFR signalling pathway in the heart tissues, while all these molecular and pathological alterations were attenuated by the oral administration with EGFR inhibitors. In conclusion, the c-Src-dependent EGFR activation may play an important role in Ang II-induced cardiac hypertrophy, and inhibition of EGFR by specific molecules may be an effective strategy for the treatment of Ang II-associated cardiac diseases.
Assuntos
Cardiomegalia/tratamento farmacológico , Cardiotônicos/farmacologia , Receptores ErbB/antagonistas & inibidores , Quinazolinas/farmacologia , Tirfostinas/farmacologia , Angiotensina II , Animais , Cardiomegalia/induzido quimicamente , Cardiotônicos/uso terapêutico , Linhagem Celular , Avaliação Pré-Clínica de Medicamentos , Fator de Crescimento Epidérmico/fisiologia , Receptores ErbB/genética , Receptores ErbB/metabolismo , Técnicas de Silenciamento de Genes , Camundongos Endogâmicos C57BL , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/fisiologia , Quinazolinas/uso terapêutico , Ratos , Tirfostinas/uso terapêuticoRESUMO
Chronic activation of renin-angiotensin system (RAS) greatly contributes to renal fibrosis and accelerates the progression of chronic kidney disease; however, the underlying molecular mechanism is poorly understood. Angiotensin II (Ang II), the central component of RAS, is a key regulator of renal fibrogenic destruction. Here we show that epidermal growth factor receptor (EGFR) plays an important role in Ang II-induced renal fibrosis. Inhibition of EGFR activation by novel small molecules or by short hairpin RNA knockdown in Ang II-treated SV40 mesangial cells in vitro suppresses protein kinase B and extracellular signal-related kinase signaling pathways and transforming growth factor-ß/Sma- and Mad-related protein activation, and abolishes the accumulation of fibrotic markers such as connective tissue growth factor, collagen IV. The transactivation of EGFR by Ang II in SV40 cells depends on the phosphorylation of proto-oncogene tyrosine-protein kinase Src (c-Src) kinase. Further validation in vivo demonstrates that EGFR small molecule inhibitor successfully attenuates renal fibrosis and kidney dysfunction in a mouse model induced by Ang II infusion. These findings indicate a crucial role of EGFR in Ang II-dependent renal deterioration, and reveal EGFR inhibition as a new therapeutic strategy for preventing progression of chronic renal diseases.
Assuntos
Angiotensina II/toxicidade , Receptores ErbB/antagonistas & inibidores , Nefropatias/patologia , Nefropatias/prevenção & controle , Actinas/efeitos dos fármacos , Animais , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/efeitos dos fármacos , Células Cultivadas , Colágeno Tipo IV/metabolismo , Receptores ErbB/genética , MAP Quinases Reguladas por Sinal Extracelular/antagonistas & inibidores , Fibrose , Técnicas de Silenciamento de Genes , Nefropatias/induzido quimicamente , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Células Mesangiais/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos C57BL , Proteínas Proto-Oncogênicas c-akt/metabolismo , RNA Interferente Pequeno/farmacologia , Ratos , Sistema Renina-Angiotensina/efeitos dos fármacos , Proteínas Repressoras/efeitos dos fármacos , Fator de Crescimento Transformador beta/efeitos dos fármacos , Quinases da Família src/antagonistas & inibidores , Quinases da Família src/metabolismoRESUMO
11ß-hydroxysteroid dehydrogenase type 1 (11ß-HSD1) controls the production of active glucocorticoid (GC) and has been proposed as a new target for the treatment of type 2 diabetes. We have previously reported that a natural product, curcumin, exhibited moderate inhibition and selectivity on 11ß-HSD1. By analyzing the models of protein, microsome, cells and GCs-induced mice in vitro and in vivo, this study presented a novel curcumin analog, LG13, as a potent selective 11ß-HSD1 inhibitor. In vivo, Type 2 diabetic mice were treated with LG13 for 42 days to assess the pharmacological benefits of 11ß-HSD1 inhibitor on hepatic glucose metabolism. In vitro studies revealed that LG13 selectively inhibited 11ß-HSD1 with IC50 values at nanomolar level and high selectivity over 11ß-HSD2. Targeting 11ß-HSD1, LG13 could inhibit prednisone-induced adverse changes in mice, but had no effects on dexamethasone-induced ones. Further, the 11ß-HSD1 inhibitors also suppressed 11ß-HSD1 and GR expression, indicating a possible positive feedback system in the 11ß-HSD1/GR cycle. In type 2 diabetic mice induced by high fat diet plus low-dosage STZ injection, oral administration with LG13 for 6 weeks significantly decreased fasting blood glucose, hepatic glucose metabolism, structural disorders, and lipid deposits. LG13 exhibited better pharmacological effects in vivo than insulin sensitizer pioglitazone and potential 11ß-HSD1 inhibitor PF-915275. These pharmacological and mechanistic insights on LG13 also provide us novel agents, leading structures, and strategy for the development of 11ß-HSD1 inhibitors treating metabolic syndromes.