RESUMO
Impaired macroautophagy/autophagy is involved in the pathogenesis of hepatic fibrosis. However, how aberrant autophagy promotes fibrosis is far from understood. Here, we aimed to define a previously unrevealed pro-fibrotic mechanism for the stress protein TRIB3 (tribbles pseudokinase 3)-mediated autophagy dysfunction. Human fibrotic liver tissues were obtained from patients with cirrhosis who underwent an open surgical repair process. The functional implications of TRIB3 were evaluated in mouse models of hepatic fibrosis induced by bile duct ligation (BDL) or thioacetamide (TAA) injection. Human fibrotic liver tissues expressed higher levels of TRIB3 and selective autophagic receptor SQSTM1/p62 (sequestosome 1) than nonfibrotic tissues and the elevated expression of TRIB3 and SQSTM1 was positively correlated in the fibrotic tissues. Silencing Trib3 protected against experimentally induced hepatic fibrosis, accompanied by restored autophagy activity in fibrotic liver tissues. Furthermore, TRIB3 interacted with SQSTM1 and hindered its binding to MAP1LC3/LC3, which caused the accumulation of SQSTM1 aggregates and obstructed autophagic flux. The TRIB3-mediated autophagy impairment not only suppressed autophagic degradation of late endosomes but also promoted hepatocellular secretion of INHBA/Activin A-enriched exosomes which caused migration, proliferation and activation of hepatic stellate cells (HSCs), the effector cells of liver fibrosis. Disrupting the TRIB3-SQSTM1 interaction with a specific helical peptide exerted potent protective effects against hepatic fibrosis by restoring autophagic flux in hepatocytes and HSCs. Together, stress-elevated TRIB3 expression promotes hepatic fibrosis by interacting with SQSTM1 and interfering with its functions in liver-parenchymal cells and activating HSCs. Targeting this interaction is a promising strategy for treating fibroproliferative liver diseases.Abbreviations: 3-MA: 3-methyladenine; AAV: adeno-associated virus; ACTA2/α-SMA: actin, alpha 2, smooth muscle, aorta; BDL: bile duct ligation; BECN1/Beclin 1: beclin 1, autophagy related; CHX: cycloheximide; CQ: chloroquine; Edu: 5-ethynyl-2-deoxyuridine; ESCRT: endosomal sorting complexes required for transport; HSC: hepatic stellate cell; ILV: intralumenal vesicle; LAMP1: lysosomal-associated membrane protein 1; MAP1LC3/LC3: microtubule-associated protein 1 light chain 3; MVB: multivesicular body; PIK3C3: phosphatidylinositol 3-kinase, catalytic subunit type 3; PPI: protein-protein interaction; SQSTM1/p62: sequestosome 1; TAA: thioacetamide; TEM: transmission electron microscopy; TGFB1/TGFß1: transforming growth factor, beta 1; TLR2: toll-like receptor 2; TRIB3: tribbles pseudokinase 3.
Assuntos
Autofagia/fisiologia , Proteínas de Ciclo Celular/metabolismo , Cirrose Hepática/patologia , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Repressoras/metabolismo , Proteína Sequestossoma-1/metabolismo , Animais , Autofagia/genética , Proteínas de Ciclo Celular/genética , Hepatócitos/metabolismo , Humanos , Cirrose Hepática/genética , Cirrose Hepática/metabolismo , Camundongos Transgênicos , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Repressoras/genética , Proteína Sequestossoma-1/genéticaRESUMO
The existence of breast cancer stem cells (BCSCs) is a major reason underlying cancer metastasis and recurrence after chemotherapy and radiotherapy. Targeting BCSCs may ameliorate breast cancer relapse and therapy resistance. Here we report that expression of the pseudokinase Tribble 3 (TRIB3) positively associates with breast cancer stemness and progression. Elevated TRIB3 expression supports BCSCs by interacting with AKT to interfere with the FOXO1-AKT interaction and suppress FOXO1 phosphorylation, ubiquitination, and degradation by E3 ligases SKP2 and NEDD4L. The accumulated FOXO1 promotes transcriptional expression of SOX2, a transcriptional factor for cancer stemness, which in turn, activates FOXO1 transcription and forms a positive regulatory loop. Disturbing the TRIB3-AKT interaction suppresses BCSCs by accelerating FOXO1 degradation and reducing SOX2 expression in mouse models of breast cancer. Our study provides insights into breast cancer development and confers a potential therapeutic strategy against TRIB3-overexpressed breast cancer.
Assuntos
Neoplasias da Mama/genética , Proteínas de Ciclo Celular/metabolismo , Proteína Forkhead Box O1/metabolismo , Células-Tronco Neoplásicas/patologia , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Repressoras/metabolismo , Fatores de Transcrição SOXB1/genética , Animais , Mama/patologia , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Progressão da Doença , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Camundongos , Pessoa de Meia-Idade , Ligação Proteica , Proteínas Serina-Treonina Quinases/metabolismo , Proteólise , Proteínas Proto-Oncogênicas c-akt/metabolismo , Análise Serial de Tecidos , Transcrição Gênica , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Although recent progress provides mechanistic insights into the pathogenesis of pulmonary fibrosis (PF), rare anti-PF therapeutics show definitive promise for treating this disease. Repeated lung epithelial injury results in injury-repairing response and inflammation, which drive the development of PF. Here, we report that chronic lung injury inactivated the ubiquitin-editing enzyme A20, causing progressive accumulation of the transcription factor C/EBPß in alveolar macrophages (AMs) from PF patients and mice, which upregulated a number of immunosuppressive and profibrotic factors promoting PF development. In response to chronic lung injury, elevated glycogen synthase kinase-3ß (GSK-3ß) interacted with and phosphorylated A20 to suppress C/EBPß degradation. Ectopic expression of A20 or pharmacological restoration of A20 activity by disturbing the A20-GSK-3ß interaction accelerated C/EBPß degradation and showed potent therapeutic efficacy against experimental PF. Our study indicates that a regulatory mechanism of the GSK-3ß-A20-C/EBPß axis in AMs may be a potential target for treating PF and fibroproliferative lung diseases.
Assuntos
Proteína beta Intensificadora de Ligação a CCAAT/metabolismo , Macrófagos/metabolismo , Fibrose Pulmonar/metabolismo , Fatores de Transcrição/metabolismo , Ubiquitina/metabolismo , Animais , Linhagem Celular , Glicogênio Sintase Quinase 3 beta/metabolismo , Células HEK293 , Humanos , Inflamação/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Fosforilação/fisiologia , Transdução de Sinais/fisiologia , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitinação/fisiologia , Regulação para Cima/fisiologiaRESUMO
Objective To evaluate the safety and effectiveness of oral midazolam sedation combined nitrous oxide sedation for reducing dental fear in children.Methods Totally 77 children with a Frankl's Behavior Rating Scale score of 1 were included in this study,among whom 41 received a total of 78 person-times of oral midazolam sedation (0.50-0.75 mg·kg -1) (midazolam group) and 36 children were treated with the combination of 0.4 mg/kg oral midazolam with 30%-40% nitrous oxide (totally 73 person-times)(combination group). At each visit,heart rate,arterial oxygen saturation,and treatments were recorded. The behaviors of children during the treatment were assessed by Frankl's Behavior Rating Scale,the completion of treatment was assessed by Houpt Scale,and the sedation status was assessed by Ramsay Scale. Telephone follow-up was performed to record the side effects 24 hours after treatment. Results The vital signs were stable among all the 77 subjects,with a Ramsay score of 2 or 3. In the midazolam group, the behaviors were cooperative in 52 person-times (66.7%) and not cooperative in 26 person-times (33.3%);the planned treatments were completed in 62 person-times (79.5%) and partially completed in 16 person-times(20.5%). In the combination group,the behaviors were cooperative in 56 person-times (76.7%) and not cooperative in 17 person-times (23.3%);64 person-times (87.7%) completed the planned treatments and 9 person-times (12.3%) partially completed the treatments. The success rates of sedation (χ 2=1.87,P= 0.17) and treatment (χ 2=1.83,P= 0.18) were not significantly different between these two groups. The median Frankl scale score was significantly higher in the combination group [3 (3,4)] than in the midazolam group [3 (2,4)] (Z=2.647,P=0.008]. The median score of Houpt scale in the combination group [5(4,6)] was also significantly higher than in midazolam group [5(3,5)] (Z=2.236,P=0.026]. In midazolam group,there were 7 person-times of dysphoria,3 person-times of diplopia,and 2 person-times of hiccough among 78 person-times;in the combination group,there were 5 person-times of dysphoria,5 person-times of diplopia,1 person-time of hiccough,and 2 person-times of vomit among 73 person-times of treatment. Thus,there was no significant difference in the incidence of side effects (15.4% vs.17.8%,χ 2=0.160,P=0.689). Logistic regression analysis showed that the success rate of treatment was not associated with sex (OR=1.704,P=0.174),dose (OR=1.289,P=0.516),and treatment types (OR=0.555,P=0.143). Children over 3 years old had a significantly high success rate than those under 3 years old (OR=3.372,P=0.011). Conclusions Oral midazolam is safe and effective for reducing dental fear in children. The combination of oral midazolam with 30%-40% nitrous oxide can improve the behaviors of children during the dental treatment,especially in children over 3 years old.