RESUMEN
AIMS: Heart failure (HF) is one of the most devastating consequences of cardiovascular diseases. Regardless of etiology, cardiac fibrosis is present and promotes the loss of heart function in HF patients. Cardiac resident fibroblasts, in response to a host of pro-fibrogenic stimuli, trans-differentiate into myofibroblasts to mediate cardiac fibrosis, the underlying mechanism of which remains incompletely understood. METHODS: Fibroblast-myofibroblast transition was induced in vitro by exposure to transforming growth factor (TGF-ß). Cardiac fibrosis was induced in mice by either transverse aortic constriction (TAC) or by chronic infusion with angiotensin II (Ang II). RESULTS: Through bioinformatic screening, we identified Kruppel-like factor 6 (KLF6) as a transcription factor preferentially up-regulated in cardiac fibroblasts from individuals with non-ischemic cardiomyopathy (NICM) compared to the healthy donors. Further analysis showed that nuclear factor kappa B (NF-κB) bound to the KLF6 promoter and mediated KLF6 trans-activation by pro-fibrogenic stimuli. KLF6 knockdown attenuated whereas KLF6 over-expression enhanced TGF-ß induced fibroblast-myofibroblast transition in vitro. More importantly, myofibroblast-specific KLF6 depletion ameliorated cardiac fibrosis and rescued heart function in mice subjected to the TAC procedure or chronic Ang II infusion. SIGNIFICANCE: In conclusion, our data support a role for KLF6 in cardiac fibrosis.
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Fibroblastos , Fibrosis , Factor 6 Similar a Kruppel , Ratones Endogámicos C57BL , Miofibroblastos , Animales , Factor 6 Similar a Kruppel/metabolismo , Factor 6 Similar a Kruppel/genética , Fibrosis/metabolismo , Ratones , Humanos , Masculino , Fibroblastos/metabolismo , Miofibroblastos/metabolismo , Miofibroblastos/patología , Angiotensina II/farmacología , Miocardio/metabolismo , Miocardio/patología , Factor de Crecimiento Transformador beta/metabolismo , FN-kappa B/metabolismo , Células Cultivadas , Factores de Transcripción de Tipo Kruppel/metabolismo , Factores de Transcripción de Tipo Kruppel/genética , Insuficiencia Cardíaca/metabolismo , Insuficiencia Cardíaca/patología , Insuficiencia Cardíaca/genéticaRESUMEN
Despite decades of research, endometriosis remains a mysterious gynecological disease with unknown etiology and pathogenesis. Krüppel-like Factor 6 (KLF6), a transcription factor, has a wide expression profile and regulates a variety of biological processes. Here, we investigated the expression and function of KLF6 and its possible regulatory mechanisms in endometriosis. To determine the function of KLF6, knockdown and overexpression experiments were performed in eutopic endometrial stromal cells (EU-ESCs) and ectopic endometrial stromal cells (EC-ESCs), respectively. Cell viability, apoptosis, migration, invasion, and angiogenesis assays were conducted in ESCs. ChIP-sequencing and mRNA-sequencing were performed to investigate the functional mechanism of KLF6 in regulating ESCs. We found that KLF6 was highly expressed in eutopic endometrium of endometriosis patients, compared with ectopic endometrium. Similarly, the same was true in EU-ESCs, which was compared with EC-ESCs. Overexpression of KLF6 significantly suppressed EC-ESC proliferation, migration and invasion and induced cell apoptosis, while knockdown of KLF6 resulted in the opposite effects on EU-ESCs. Overexpression of KLF6 significantly inhibited EC-ESC angiogenesis. Mechanistically, the results of ChIP sequencing and mRNA sequencing revealed that CTNNB1 may be a transcriptional target regulated by KLF6. Reintroduction of KLF6 reversed the effects of KLF6 knockdown on EU-ESCs. KLF6 inhibited the proliferation, migration and angiogenesis of EC-ESCs by inhibiting the expression of CTNNB1. Our findings provided a new perspective on the role of KLF6 in endometriosis progression and inspire potential targeted therapeutic strategies.
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Movimiento Celular , Endometriosis , Endometrio , Factor 6 Similar a Kruppel , Células del Estroma , beta Catenina , Humanos , Femenino , Endometriosis/metabolismo , Endometriosis/patología , Endometriosis/genética , Factor 6 Similar a Kruppel/metabolismo , Factor 6 Similar a Kruppel/genética , beta Catenina/metabolismo , Células del Estroma/metabolismo , Células del Estroma/patología , Endometrio/metabolismo , Endometrio/patología , Adulto , Apoptosis/genética , Proliferación Celular , Progresión de la EnfermedadRESUMEN
ABSTRACT: Background: Myocardial infarction (MI) is a severe condition that typically results from the ischemia and necrosis of heart muscle. Kruppel-like factor 6 (KLF6) can aggravate myocardial ischemia/reperfusion injury. This work aims to reveal its role and mechanism in hypoxia/reoxygenation (H/R)-induced cardiomyocyte injury. Methods: Human cardiomyocyte (AC16) was exposed to hypoxic treatment to mimic MI-like cell injury. mRNA expression levels of KLF6 and WT1-associated protein (WTAP) were detected by quantitative real-time polymerase chain reaction. Protein expression was detected by western blotting assay. Cell viability was assessed by CCK-8 assay. Cell apoptosis and cell cycle were investigated by flow cytometry. Enzyme-linked immunosorbent assays were conducted to detect IL-1ß, TNF-α and IL-6 levels. Fe 2+ colorimetric assay kit was used to detect Fe 2+ level. MDA Content Assay Kit was used to detect MDA level. Cellular ROS Assay kit was applied to assess ROS level. The association of KLF6 and WTAP was identified by RNA immunoprecipitation assay and dual-luciferase reporter assay. Results: KLF6 and WTAP expression at mRNA and protein levels were significantly upregulated in serum samples of MI patients and H/R-induced AC16 cells when compared with control groups. KLF6 silencing attenuated H/R-induced AC16 cell apoptosis, inflammatory response, oxidative stress, and ferroptosis. Additionally, WTAP stabilized KLF6 mRNA by regulating its m6A modification. Furthermore, WTAP knockdown rescued H/R-induced AC16 cell apoptosis, inflammatory response, oxidative stress, and ferroptosis by decreasing KLF6 expression. Conclusion: WTAP-mediated m6A modification of KLF6 aggravated hypoxia/reoxygenation-induced apoptosis, inflammatory response, oxidative stress, and ferroptosis of human cardiomyocytes, providing a therapeutic strategy for MI.
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Factor 6 Similar a Kruppel , Miocitos Cardíacos , Humanos , Apoptosis , Proteínas Reguladoras de la Apoptosis , Hipoxia de la Célula/fisiología , Factor 6 Similar a Kruppel/metabolismo , Factor 6 Similar a Kruppel/genética , Factores de Transcripción de Tipo Kruppel/metabolismo , Factores de Transcripción de Tipo Kruppel/genética , Proteínas de la Membrana , Daño por Reperfusión Miocárdica/metabolismo , Miocitos Cardíacos/metabolismo , Miocitos Cardíacos/patologíaRESUMEN
Intramuscular fat is a crucial determinant of carcass quality traits like tenderness and taste, which in turn is influenced by the proliferation of intramuscular preadipocytes. This study aimed to investigate the Krüppel-like factor 6 (KLF6)-mediated proliferation of bovine preadipocytes and identify underlying molecular mechanisms. Down-regulation of KLF6 by siKLF6 resulted in a significant (p < 0.01) suppression of cell cycle-related genes including CDK1, MCM6, ZNF4, PCNA, CDK2, CCNB1, and CDK6. Conversely, the expression level of p27 was significantly (p < 0.01) increased. Moreover, EdU (5-ethynyl-20-deoxyuridine) staining revealed a significant decrease in EdU-labeled cells due to KLF6 down-regulation. Collectively, these findings indicate that KLF6 down-regulation inhibits adipocyte proliferation. Furthermore, RNA sequencing of preadipocytes transfected with siKLF6 and NC, followed by differential gene expression analysis, identified 100 up-regulated and 70 down-regulated genes. Additionally, the differentially expressed genes also significantly influenced various Gene Ontology (GO) terms related to cell cycle, nuclear chromosomes, and catalytic activity on DNA. Furthermore, the top 20 pathways enriched in these DEGs included cell cycle, DNA replication, cellular senescence, and homologous recombination. These GO terms and KEGG pathways play key roles in bovine preadipocyte proliferation. In conclusion, the results of this study suggest that KLF6 positively regulates the proliferation of bovine preadipocytes.
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Adipocitos , Proliferación Celular , Factor 6 Similar a Kruppel , Animales , Bovinos/metabolismo , Bovinos/genética , Adipocitos/metabolismo , Adipocitos/citología , Factor 6 Similar a Kruppel/genética , Factor 6 Similar a Kruppel/metabolismo , Perfilación de la Expresión Génica , Transcriptoma , Ciclo Celular , Carne Roja/análisisRESUMEN
BACKGROUND: Periodontitis is a chronic osteolytic inflammatory disease, where anti-inflammatory intervention is critical for restricting periodontal damage and regenerating alveolar bone. Ropinirole, a dopamine D2 receptor agonist, has previously shown therapeutic potential for periodontitis but the underlying mechanism is still unclear. METHODS: Human gingival fibroblasts (HGFs) treated with LPS were considered to mimic periodontitis in vitro. The dosage of Ropinirole was selected through the cell viability of HGFs evaluation. The protective effects of Ropinirole on HGFs were evaluated by detecting cell viability, cell apoptosis, and pro-inflammatory factor levels. The molecular docking between NAT10 and Ropinirole was performed. The interaction relationship between NAT10 and KLF6 was verified by ac4C Acetylated RNA Immunoprecipitation followed by qPCR (acRIP-qPCR) and dual-luciferase reporter assay. RESULTS: Ropinirole alleviates LPS-induced damage of HGFs by promoting cell viability, inhibiting cell apoptosis and the levels of IL-1ß, IL-18, and TNF-α. Overexpression of NAT10 weakens the effects of Ropinirole on protecting HGFs. Meanwhile, NAT10-mediated ac4C RNA acetylation promotes KLF6 mRNA stability. Upregulation of KLF6 reversed the effects of NAT10 inhibition on HGFs. CONCLUSIONS: Taken together, Ropinirole protected HGFs through inhibiting the NAT10 ac4C RNA acetylation to decrease the KLF6 mRNA stability from LPS injury. The discovery of this pharmacological and molecular mechanism of Ropinirole further strengthens its therapeutic potential for periodontitis.
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Fibroblastos , Indoles , Factor 6 Similar a Kruppel , Acetiltransferasas N-Terminal , Periodontitis , Humanos , Acetilación/efectos de los fármacos , Apoptosis/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Fibroblastos/efectos de los fármacos , Fibroblastos/metabolismo , Encía/efectos de los fármacos , Encía/metabolismo , Indoles/farmacología , Indoles/uso terapéutico , Factor 6 Similar a Kruppel/metabolismo , Lipopolisacáridos , Simulación del Acoplamiento Molecular , Periodontitis/tratamiento farmacológico , Periodontitis/metabolismo , Acetiltransferasas N-Terminal/antagonistas & inhibidoresRESUMEN
Background: The incidence of chronic obstructive pulmonary disease (COPD) is increasing year by year. Kruppel-like factor 6 (KLF6) plays an important role in inflammatory diseases. However, the regulatory role of KLF6 in COPD has not been reported so far. Methods: The viability of human bronchial epithelial cells BEAS-2B induced by cigarette smoke extract (CSE) was detected by CCK-8 assay. The protein expression of KLF6 and sirtuin 4 (SIRT4) was appraised with Western blot. RT-qPCR and Western blot were applied to examine the transfection efficacy of sh-KLF6 and Oe-KLF6. Cell apoptosis was detected using flow cytometry. The levels of inflammatory factors IL-6, TNF-α and IL-1ß were assessed with ELISA assay. DCFH-DA staining was employed for the detection of ROS activity and the levels of oxidative stress markers SOD, CAT and MDA were estimated with corresponding assay kits. The mitochondrial membrane potential (MMP), adenosine triphosphate (ATP) content and Complex I activity were evaluated with JC-1 staining, ATP colorimetric/fluorometric assay kit and Complex I enzyme activity microplate assay kit. With the application of mitochondrial permeability transition pore detection kit, mPTP opening was measured. Luciferase report assay was employed to evaluate the activity of SIRT4 promoter and chromatin immunoprecipitation (ChIP) to verify the binding ability of KLF6 and SIRT4 promoter. Results: KLF6 expression was significantly elevated in CSE-induced cells. KLF6 was confirmed to suppress SIRT4 transcription. Interference with KLF6 expression significantly inhibited cell viability damage, cell apoptosis, inflammatory response, oxidative stress and mitochondrial dysfunction in CSE-induced BEAS-2B cells, which were all reversed by SIRT4 overexpression. Conclusion: Silencing KLF6 alleviated CSE-induced mitochondrial dysfunction in bronchial epithelial cells by SIRT4 upregulation.
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Fumar Cigarrillos , Enfermedades Mitocondriales , Enfermedad Pulmonar Obstructiva Crónica , Sirtuinas , Humanos , Enfermedad Pulmonar Obstructiva Crónica/metabolismo , Regulación hacia Arriba , Línea Celular , Factor 6 Similar a Kruppel/genética , Factor 6 Similar a Kruppel/metabolismo , Fumar Cigarrillos/efectos adversos , Apoptosis , Células Epiteliales/metabolismo , Adenosina Trifosfato/efectos adversos , Adenosina Trifosfato/metabolismo , Enfermedades Mitocondriales/metabolismo , Proteínas Mitocondriales/efectos adversos , Proteínas Mitocondriales/metabolismo , Sirtuinas/genéticaRESUMEN
Acute liver failure (ALF) is a complex syndrome characterized by overactivation of innate immunity, and the recruitment and differentiation of immune cells at inflammatory sites. The present study aimed to explore the role of microRNA (miRNA/miR)21 and its potential mechanisms underlying inflammatory responses in ALF. Baseline serum miR21 was analyzed in patients with ALF and healthy controls. In addition, miR21 antagomir was injected via the tail vein into C57BL/6 mice, and lipopolysaccharide/Dgalactosamine (LPS/GalN) was injected into mice after 48 h. The expression levels of miR21, Krüppellikefactor6 (KLF6), autophagyrelated proteins and interleukin (IL)23, and hepatic pathology were then assessed in the liver tissue. Furthermore, THP1derived macrophages were transfected with a miRNA negative control, miR21 inhibitor, miR21 mimics or KLF6 overexpression plasmid, followed by treatment with or without rapamycin, and the expression levels of miR21, KLF6, autophagyrelated proteins and IL23 were evaluated. The results revealed that baseline serum miR21 levels were significantly upregulated in patients with ALF. In addition, LPS/GalNinduced ALF was attenuated in the antagomir21 mouse group. KLF6 was identified as a target of miR215p with one putative seed match site identified by TargetScan. A subsequent luciferase activity assay demonstrated a direct interaction between miR215p and the 3'UTR of KLF6 mRNA. Further experiments suggested that miR21 promoted the expression of IL23 via inhibiting KLF6, which regulated autophagy. In conclusion, in the present study, baseline serum miR21 levels were highly upregulated in patients with ALF, antagomir21 attenuated LPS/GalNinduced ALF in a mouse model, and miR21 could promote the expression of IL23 via inhibiting KLF6.
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Fallo Hepático Agudo , MicroARNs , Animales , Humanos , Ratones , Antagomirs , Autofagia/genética , Proteínas Relacionadas con la Autofagia , Interleucina-23/genética , Interleucina-23/metabolismo , Factor 6 Similar a Kruppel/genética , Factor 6 Similar a Kruppel/metabolismo , Lipopolisacáridos/toxicidad , Fallo Hepático Agudo/inducido químicamente , Fallo Hepático Agudo/genética , Fallo Hepático Agudo/metabolismo , Ratones Endogámicos C57BL , MicroARNs/genética , MicroARNs/metabolismo , Transducción de SeñalRESUMEN
Resistance to immunity is associated with the selection of cancer cells with superior capacities to survive inflammatory reactions. Here, we tailored an ex vivo immune selection model for acute myeloid leukemia (AML) and isolated the residual subpopulations as "immune-experienced" AML (ieAML) cells. We confirmed that upon surviving the immune reactions, the malignant blasts frequently decelerated proliferation, displayed features of myeloid differentiation and activation, and lost immunogenicity. Transcriptomic analyses revealed a limited number of commonly altered pathways and differentially expressed genes in all ieAML cells derived from distinct parental cell lines. Molecular signatures predominantly associated with interferon and inflammatory cytokine signaling were enriched in the AML cells resisting the T-cell-mediated immune reactions. Moreover, the expression and nuclear localization of the transcription factors c-MYB and KLF6 were noted as the putative markers for immune resistance and identified in subpopulations of AML blasts in the patients' bone marrow aspirates. The immune modulatory capacities of ieAML cells lasted for a restricted period when the immune selection pressure was omitted. In conclusion, myeloid leukemia cells harbor subpopulations that can adapt to the harsh conditions established by immune reactions, and a previous "immune experience" is marked with IFN signature and may pave the way for susceptibility to immune intervention therapies.
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Interferones , Factor 6 Similar a Kruppel , Leucemia Mieloide Aguda , Proteínas Proto-Oncogénicas c-myb , Humanos , Factor 6 Similar a Kruppel/genética , Factor 6 Similar a Kruppel/inmunología , Factor 6 Similar a Kruppel/metabolismo , Proteínas Proto-Oncogénicas c-myb/genética , Proteínas Proto-Oncogénicas c-myb/inmunología , Proteínas Proto-Oncogénicas c-myb/metabolismo , Leucemia Mieloide Aguda/inmunología , Leucemia Mieloide Aguda/genética , Interferones/inmunología , Interferones/metabolismo , Interferones/genética , Femenino , Masculino , Persona de Mediana Edad , Anciano , Línea Celular Tumoral , Adulto , TranscriptomaRESUMEN
OBJECTIVE: We aim to accurately distinguish ubiquitin-specific proteases (USPs) from other members within the deubiquitinating enzyme families based on protein sequences. Additionally, we seek to elucidate the specific regulatory mechanisms through which USP26 modulates Krüppel-like factor 6 (KLF6) and assess the subsequent effects of this regulation on both the proliferation and migration of cervical cancer cells. METHODS: All the deubiquitinase (DUB) sequences were classified into USPs and non-USPs. Feature vectors, including 188D, n-gram, and 400D dimensions, were extracted from these sequences and subjected to binary classification via the Weka software. Next, thirty human USPs were also analyzed to identify conserved motifs and ascertained evolutionary relationships. Experimentally, more than 90 unique DUB-encoding plasmids were transfected into HeLa cell lines to assess alterations in KLF6 protein levels and to isolate a specific DUB involved in KLF6 regulation. Subsequent experiments utilized both wild-type (WT) USP26 overexpression and shRNA-mediated USP26 knockdown to examine changes in KLF6 protein levels. The half-life experiment was performed to assess the influence of USP26 on KLF6 protein stability. Immunoprecipitation was applied to confirm the USP26-KLF6 interaction, and ubiquitination assays to explore the role of USP26 in KLF6 deubiquitination. Additional cellular assays were conducted to evaluate the effects of USP26 on HeLa cell proliferation and migration. RESULTS: 1. Among the extracted feature vectors of 188D, 400D, and n-gram, all 12 classifiers demonstrated excellent performance. The RandomForest classifier demonstrated superior performance in this assessment. Phylogenetic analysis of 30 human USPs revealed the presence of nine unique motifs, comprising zinc finger and ubiquitin-specific protease domains. 2. Through a systematic screening of the deubiquitinase library, USP26 was identified as the sole DUB associated with KLF6. 3. USP26 positively regulated the protein level of KLF6, as evidenced by the decrease in KLF6 protein expression upon shUSP26 knockdown in both 293T and Hela cell lines. Additionally, half-life experiments demonstrated that USP26 prolonged the stability of KLF6. 4. Immunoprecipitation experiments revealed a strong interaction between USP26 and KLF6. Notably, the functional interaction domain was mapped to amino acids 285-913 of USP26, as opposed to the 1-295 region. 5. WT USP26 was found to attenuate the ubiquitination levels of KLF6. However, the mutant USP26 abrogated its deubiquitination activity. 6. Functional biological assays demonstrated that overexpression of USP26 inhibited both proliferation and migration of HeLa cells. Conversely, knockdown of USP26 was shown to promote these oncogenic properties. CONCLUSIONS: 1. At the protein sequence level, members of the USP family can be effectively differentiated from non-USP proteins. Furthermore, specific functional motifs have been identified within the sequences of human USPs. 2. The deubiquitinating enzyme USP26 has been shown to target KLF6 for deubiquitination, thereby modulating its stability. Importantly, USP26 plays a pivotal role in the modulation of proliferation and migration in cervical cancer cells.
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Neoplasias del Cuello Uterino , Femenino , Humanos , Factor 6 Similar a Kruppel/genética , Células HeLa , Neoplasias del Cuello Uterino/genética , Filogenia , Proteasas Ubiquitina-Específicas/genética , Proteasas Ubiquitina-Específicas/metabolismo , Proliferación Celular , Cisteína EndopeptidasasRESUMEN
Prolidase (PEPD) is the only hydrolase that cleaves the dipeptides containing C-terminal proline or hydroxyproline-the rate-limiting step in collagen biosynthesis. However, the molecular regulation of prolidase expression remains largely unknown. In this study, we have identified overlapping binding sites for the transcription factors Krüppel-like factor 6 (KLF6) and Specificity protein 1 (Sp1) in the PEPD promoter and demonstrate that KLF6/Sp1 transcriptionally regulate prolidase expression. By cloning the PEPD promoter into a luciferase reporter and through site-directed deletion, we pinpointed the minimal sequences required for KLF6 and Sp1-mediated PEPD promoter-driven transcription. Interestingly, Sp1 inhibition abrogated KLF6-mediated PEPD promoter activity, suggesting that Sp1 is required for the basal expression of prolidase. We further studied the regulation of PEPD by KLF6 and Sp1 during transforming growth factor ß1 (TGF-ß1) signaling, since both KLF6 and Sp1 are key players in TGF-ß1 mediated collagen biosynthesis. Mouse and human fibroblasts exposed to TGF-ß1 resulted in the induction of PEPD transcription and prolidase expression. Inhibition of TGF-ß1 signaling abrogated PEPD promoter-driven transcriptional activity of KLF6 and Sp1. Knock-down of KLF6 as well as Sp1 inhibition also reduced prolidase expression. Chromatin immunoprecipitation assay supported direct binding of KLF6 and Sp1 to the PEPD promoter and this binding was enriched by TGF-ß1 treatment. Finally, immunofluorescence studies showed that KLF6 co-operates with Sp1 in the nucleus to activate prolidase expression and enhance collagen biosynthesis. Collectively, our results identify functional elements of the PEPD promoter for KLF6 and Sp1-mediated transcriptional activation and describe the molecular mechanism of prolidase expression.
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Dipeptidasas , Factor 6 Similar a Kruppel , Transducción de Señal , Factor de Transcripción Sp1 , Animales , Humanos , Ratones , Colágeno/metabolismo , Factor 6 Similar a Kruppel/genética , Factor de Transcripción Sp1/genética , Factor de Transcripción Sp1/metabolismo , Factores de Transcripción/metabolismo , Factor de Crecimiento Transformador beta/metabolismo , Factor de Crecimiento Transformador beta1/genética , Factor de Crecimiento Transformador beta1/metabolismoRESUMEN
The pathogenesis of rheumatoid arthritis (RA) is heavily impacted by the inflammation and activation of fibroblast-like synoviocytes (FLS). The objective of this investigation is to clarify the involvement of exosomes derived from FLS stimulated by tumour necrosis factor α (TNF-α) in angiogenesis and the underlying mechanisms. FLS cells were obtained from synovial fluid of RA patients and exosomes were obtained from FLS cell supernatant with TNF-α stimulation by ultracentrifugation. Exosomes were subsequently analysed using transmission electron microscopy, nanoparticle tracking analysis, and western blotting. The functional effects of exosomes with TNF-α stimulation on human umbilical vein endothelial cells (HUVEC) migration, invasion, and angiogenesis was evaluated using wound scratch healing test, transwell invasion assay, and tube formation assay. DNA nanoball-seq (DNBSEQ) sequencing platform was utilised to analysis different expression miRNA from exosomes, miRNA and mRNA from HUVEC. The expression level of miR-200a-3p was determined through quantitative real-time polymerase chain reaction (qRT-PCR). The quantification of KLF6 and VEGFA expression levels were performed by qRT-PCR and western blot analysis. The validation of the association between miR-200a-3p and KLF6 was established through a fluorescence enzyme reporting assay. In comparison to exosome induced by PBS, exosome induced by TNF-α exhibited a substantial exacerbation of invasion, migration, and angiogenesis in HUVEC. 4 miRNAs in exosomes and HUVEC cells, namely miR-1246, miR-200a-3p, miR-30a-3p, and miR-99b-3p was obtained. MiR-200a-3p maintained high consistency with the sequencing results. We obtained 5 gene symbols, and KLF6 was chose for further investigation. The expression of miR-200a-3p in exosomes induced by TNF-α and in HUVEC treated with these exosomes demonstrated a significantly increase. Additionally, HUVEC cells displayed a notable decrease in KLF6 expression and a significant elevation in VEGFA expression. This was further confirmed by the fluorescence enzyme report assay, which provided evidence of the direct targeting of KLF6 by miR-200a-3p. Exosomes induced by TNF-α have the ability to enhance the migration, invasion, and angiogenesis of HUVEC cells via the miR-200a-3p/KLF6/VEGFA axis.
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Artritis Reumatoide , Exosomas , MicroARNs , Sinoviocitos , Humanos , Artritis Reumatoide/metabolismo , Proliferación Celular , Exosomas/genética , Exosomas/metabolismo , Exosomas/patología , Fibroblastos/metabolismo , Células Endoteliales de la Vena Umbilical Humana/metabolismo , Células Endoteliales de la Vena Umbilical Humana/patología , Factor 6 Similar a Kruppel/metabolismo , Factor 6 Similar a Kruppel/farmacología , MicroARNs/genética , MicroARNs/metabolismo , Sinoviocitos/metabolismo , Factor de Necrosis Tumoral alfa/farmacología , Factor de Necrosis Tumoral alfa/metabolismo , Factor A de Crecimiento Endotelial Vascular/genética , Factor A de Crecimiento Endotelial Vascular/metabolismo , Factor A de Crecimiento Endotelial Vascular/farmacologíaRESUMEN
Cutaneous carcinoma is one of the most common neoplasm tumors in the West. Its incidence rate is one of the fastest growing tumors in China. The Krüppel-like factor 6 (KLF6) is a latent tumor suppressor. Decreased KLF6 is related to the occurrence and progression of many cancers in human. Our previous studies have demonstrated that KLF6 was down-regulation in cutaneous malignant melanoma (CMM), and was significant correlated with ulcer, lymph node metastasis and clinical stage, suggesting that KLF6 loss is expected to become a biological indicator of poor prognosis in CMM patients. In this research, we would further study the features of KLF6 in the malignant progression of CMM. The expression of KLF6 was up-regulated by lentivirus infection containing KLF6, and short hairpin RNA (shRNA) was used for knockdown of KLF6 in CMM cells. Western blot, RT-qpcr, CCK8 assay, transwell migration assays, wound healing assay and flow cytometry were used to test the role of KLF6 in the CMM. We found that reduced expression of KLF6 significantly enhanced proliferation, migration and invasion. Moreover, KLF6 induced CMM cell apoptosis and G1 cycle arrest. The decreased KLF6 expression is expected to be a biological indicator of poor prognosis in CMM patients.
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Biomarcadores Ambientales , Melanoma , Humanos , Línea Celular Tumoral , Proliferación Celular/genética , Regulación Neoplásica de la Expresión Génica , Factor 6 Similar a Kruppel/genética , Factor 6 Similar a Kruppel/metabolismo , Factores de Transcripción de Tipo Kruppel/genética , Factores de Transcripción de Tipo Kruppel/metabolismo , Melanoma/genética , Melanoma/patología , Melanoma Cutáneo MalignoRESUMEN
Skin color, one of the most diverse human traits, is determined by the quantity, type, and distribution of melanin. In this study, we leveraged the light-scattering properties of melanin to conduct a genome-wide screen for regulators of melanogenesis. We identified 169 functionally diverse genes that converge on melanosome biogenesis, endosomal transport, and gene regulation, of which 135 represented previously unknown associations with pigmentation. In agreement with their melanin-promoting function, the majority of screen hits were up-regulated in melanocytes from darkly pigmented individuals. We further unraveled functions of KLF6 as a transcription factor that regulates melanosome maturation and pigmentation in vivo, and of the endosomal trafficking protein COMMD3 in modulating melanosomal pH. Our study reveals a plethora of melanin-promoting genes, with broad implications for human variation, cell biology, and medicine.
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Proteínas Adaptadoras Transductoras de Señales , Factor 6 Similar a Kruppel , Melaninas , Melanocitos , Melanosomas , Pigmentación de la Piel , Humanos , Melaninas/biosíntesis , Melaninas/genética , Melanocitos/metabolismo , Melanosomas/metabolismo , Pigmentación de la Piel/genética , Estudio de Asociación del Genoma Completo , Proteínas Adaptadoras Transductoras de Señales/genética , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Factor 6 Similar a Kruppel/genética , Factor 6 Similar a Kruppel/metabolismo , Endosomas/metabolismo , Animales , Ratones , Línea Celular TumoralRESUMEN
BACKGROUND: MicroRNAs (miRNAs) exert certain functions in the development of several cancers and can be a potential hallmark for cancer diagnosis and prognosis. MiR-191-5p has been proven to have high expression in breast cancer (BC), while its biological role and potential regulatory mechanisms in BC remain an open issue. OBJECTIVE: Bioinformatics was utilized to assay miR-191-5p level in BC tissues and predict its downstream target gene as well as the enriched signaling pathways of the target gene. METHODS: qRT-PCR was carried out to assay miR-191-5p and KLF6 levels in BC cells as well as miR-191-5p level in blood-derived exosomes from BC patients. Western blot was to examine the expression of proteins linked with cell adhesion, epithelial-mesenchymal transition (EMT), and exosome markers. A dual luciferase reporter assay was utilized to verify the interaction between miR-191-5p and KLF6. Abilities of cell phenotypes of BC cells were detected by CCK8, Transwell, and cell adhesion assay, separately. RESULTS: Upregulated miR-191-5p expression and downregulated KLF6 expression were observed in BC cells. There was a targeting relationship between miR-191-5p and KLF6. MiR-191-5p negatively regulated KLF6 to promote EMT and malignant progression of BC cells. Additionally, we described a dramatically high level of miR-191-5p in the blood exosomes of BC patients. CONCLUSION: MiR-191-5p advances the EMT of BC by targeting KLF6, indicating that miR-191-5p and KLF6 may be new biomarkers for BC.
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Neoplasias de la Mama , MicroARNs , Humanos , Femenino , Neoplasias de la Mama/genética , Neoplasias de la Mama/patología , Línea Celular Tumoral , Transición Epitelial-Mesenquimal/genética , MicroARNs/genética , MicroARNs/metabolismo , Movimiento Celular , Proliferación Celular/genética , Factor 6 Similar a Kruppel/genéticaRESUMEN
Nicotine contributes to the causation of atherosclerosis, which the prominent cellular components are macrophages. Long non-coding RNAs (lncRNAs) play an important role in regulating cell functions such as cell proliferation, differentiation and programmed death. However, the function and mechanism of lncRNAs in nicotine-induced macrophage pyroptosis has not been reported. We screened the deferentially expressed lncRNAs of human carotid artery plaque (GSE97210) and verified them in nicotine-induced pyroptosis of macrophages. Results showed only LINC01272 was up-regulated in a dose-dependent manner in macrophages. The immunofluorescence staining result confirmed that interfering LINC01272 inhibited nicotine-induced macrophage pyroptosis. Through bioinformatics analysis, dual luciferase reporter gene assay and qPCR, we identified miR-515 was significantly negatively correlated with the expression of LINC01272, and KLF6 is the target gene of miR-515. Furthermore, our results demonstrated that LINC01272/miR-515/KLF6 axis meditated nicotine-induced macrophage pyroptosis. In addition, in human peripheral blood mononuclear cells of smoking populations, the expression of GSDMD-N, NLRP3, LINC01272 and KLF6 was significantly increased, while the level of miR-515 was reduced. This study confirmed that nicotine increases the expression of LINC01272 to competitively bind with miR-515 in macrophages, reducing the inhibitory effect of miR-515 on its target gene KLF6, which ultimately induces macrophage pyroptosis.
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MicroARNs , ARN Largo no Codificante , Humanos , MicroARNs/genética , MicroARNs/metabolismo , Piroptosis/genética , Nicotina/toxicidad , ARN Largo no Codificante/genética , ARN Largo no Codificante/metabolismo , Leucocitos Mononucleares , Macrófagos/metabolismo , Factor 6 Similar a Kruppel/genética , Factor 6 Similar a Kruppel/metabolismoRESUMEN
The transcription factor SREBP2 is the main regulator of cholesterol homeostasis and is central to the mechanism of action of lipid-lowering drugs, such as statins, which are responsible for the largest overall reduction in cardiovascular risk and mortality in humans with atherosclerotic disease. Recently, SREBP2 has been implicated in leukocyte innate and adaptive immune responses by upregulation of cholesterol flux or direct transcriptional activation of pro-inflammatory genes. Here, we investigate the role of SREBP2 in endothelial cells (ECs), since ECs are at the interface of circulating lipids with tissues and crucial to the pathogenesis of cardiovascular disease. Loss of SREBF2 inhibits the production of pro-inflammatory chemokines but amplifies type I interferon response genes in response to inflammatory stimulus. Furthermore, SREBP2 regulates chemokine expression not through enhancement of endogenous cholesterol synthesis or lipoprotein uptake but partially through direct transcriptional activation. Chromatin immunoprecipitation sequencing of endogenous SREBP2 reveals that SREBP2 bound to the promoter regions of two nonclassical sterol responsive genes involved in immune modulation, BHLHE40 and KLF6. SREBP2 upregulation of KLF6 was responsible for the downstream amplification of chemokine expression, highlighting a novel relationship between cholesterol homeostasis and inflammatory phenotypes in ECs.
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Citocinas , Células Endoteliales , Humanos , Activación Transcripcional , Células Endoteliales/metabolismo , Citocinas/metabolismo , Colesterol/metabolismo , Factores de Transcripción/metabolismo , Proteína 2 de Unión a Elementos Reguladores de Esteroles/genética , Proteína 2 de Unión a Elementos Reguladores de Esteroles/metabolismo , Factor 6 Similar a Kruppel/genética , Factor 6 Similar a Kruppel/metabolismoRESUMEN
Hepatic ischemia-reperfusion (I/R) injury, a common clinical complication of liver transplantation, gravely affects patient prognosis. Krüppel-like factors (KLFs) constitute a family of C2/H2 zinc finger DNA-binding proteins. KLF6, a member of the KLF protein family, plays crucial roles in proliferation, metabolism, inflammation, and injury responses; however, its role in HIR is largely remains unknown. After I/R injury, we found that KLF6 expression in mice and hepatocytes was significantly upregulated. Mice were then subjected to I/R following injection of shKLF6- and KLF6-overexpressing adenovirus through the tail vein. KLF6 deficiency markedly exacerbated liver damage, cell apoptosis, and activation of hepatic inflammatory responses, whereas hepatic overexpression of KLF6 in mice produced the opposite results. In addition, we knocked out or overexpressed KLF6 in AML12 cells before exposing them to a hypoxia-reoxygenation challenge. KLF6 knockout decreased cell viability and increased hepatocyte inflammation, apoptosis, and ROS, whereas KLF6 overexpression had the opposite effects. Mechanistically, KLF6 inhibited the overactivation of autophagy at the initial stage, and the regulatory effect of KLF6 on I/R injury was autophagy-dependent. CHIP-qPCR and luciferase reporter gene assays confirmed that KLF6 bound to the promoter region of Beclin1 and inhibited its transcription. Additionally, KLF6 activated the mTOR/ULK1 pathway. Finally, we performed a retrospective analysis of the clinical data of liver transplantation patients and identified significant associations between KLF6 expression and liver function following liver transplantation. In conclusion, KLF6 inhibited the overactivation of autophagy via transcriptional regulation of Beclin1 and activation of the mTOR/ULK1 pathway, thereby protecting the liver from I/R injury. KLF6 is expected to serve as a biomarker for estimating the severity of I/R injury following liver transplantation.
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Inflamación , Factor 6 Similar a Kruppel , Hígado , Animales , Ratones , Autofagia/genética , Beclina-1 , Estudios RetrospectivosRESUMEN
Members of the Krüppel-like family of transcription factors are widely expressed, including in the kidney. Expression of some KLFs changes in acute kidney injury, and this may be adaptive or maladaptive, and result in effects on various cellular pathways. This mini-review will highlight the roles of KLF6 and KLF15 in control of proximal tubular cell metabolism.
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Factores de Transcripción de Tipo Kruppel , Factores de Transcripción , Humanos , Factores de Transcripción de Tipo Kruppel/genética , Factores de Transcripción de Tipo Kruppel/metabolismo , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Riñón/metabolismo , Células Epiteliales/metabolismo , Factor 6 Similar a Kruppel/genética , Factor 6 Similar a Kruppel/metabolismoRESUMEN
Purpose: The purpose of this study was to identify novel abnormally expressed microRNAs (miRNAs) and their downstream target in diabetic cataract (DC). Methods: General feature, fasting blood glucose, glycosylated hemoglobin, and type A1c (HbA1c) expression level of patients were collected. DC capsular tissues were obtained from patients and the lens cells (HLE-B3) exposed to different concentrations of glucose were used to simulate the model in vitro. Both mimic and inhibitor of miR-22-3p were transferred into HLE-B3 to up- and downregulate miR-22-3p expression, respectively. The cellular apoptosis was evaluated by quantitative real-time polymerase chain reaction (qRT-PCR), Western blot, and immunofluorescence. The downstream target gene of miR-22-3p was identified by dual luciferase reporter. Results: In DC capsules and HLE-B3 under hyperglycemia, miR-22-3p showed a significant downward trend. The expression of BAX was upregulated and the BCL-2 was downregulated following high glucose. The expression of BAX was significantly down- or upregulated in HLE-B3 cells following transfection of mimic or inhibitor of miR-22-3p, respectively. Conversely, BCL-2 was significantly increased or decreased. Dual luciferase reporter assay showed that miR-22-3p directly targeted Krüppel Like Factor 6 (KLF6) to regulate cell apoptosis. In addition, the expression of KLF6 were significantly up- or downregulated following transfection of inhibitor or mimic of miR-22-3p. Conclusions: This study suggested that miR-22-3p could inhibit lens apoptosis by targeting KLF6 directly under high glucose condition. The miR-22-3p/KLF6 signal axis may provide novel insights into the pathogenesis of DC. Translational Relevance: Differential expression of miR-22-3p may account for the pathogenesis of DC and lead to a new therapeutic strategy for DC.
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Catarata , Diabetes Mellitus , MicroARNs , Humanos , Factor 6 Similar a Kruppel/genética , Proteína X Asociada a bcl-2 , Apoptosis/genética , Células Epiteliales , Catarata/genética , Proteínas Proto-Oncogénicas c-bcl-2 , MicroARNs/genética , Glucosa/toxicidad , Diabetes Mellitus/genéticaRESUMEN
Objective To explore the effect of microRNA-22-3p (miR-22-3p) regulating the expression of Kruppel-like factor 6 (KLF6) on the cardiomyocyte-like differentiation of bone marrow mesenchymal stem cell (BMSC). Methods Rat BMSC was isolated and cultured,and the third-generation BMSC was divided into a control group,a 5-azacytidine(5-AZA)group,a mimics-NC group,a miR-22-3p mimics group,a miR-22-3p mimics+pcDNA group,and a miR-22-3p mimics+pcDNA-KLF6 group.Real-time fluorescent quantitative PCR (qRT-PCR) was carried out to determine the expression of miR-22-3p and KLF6 in cells.Immunofluorescence staining was employed to detect the expression of Desmin,cardiac troponin T (cTnT),and connexin 43 (Cx43).Western blotting was employed to determine the protein levels of cTnT,Cx43,Desmin,and KLF6,and flow cytometry to detect the apoptosis of BMSC.The targeting relationship between miR-22-3p and KLF6 was analyzed by dual luciferase reporter gene assay. Results Compared with the control group,5-AZA up-regulated the expression of miR-22-3p (q=7.971,P<0.001),Desmin (q=7.876,P<0.001),cTnT (q=10.272,P<0.001),and Cx43 (q=6.256,P<0.001),increased the apoptosis rate of BMSC (q=12.708,P<0.001),and down-regulated the mRNA (q=20.850,P<0.001) and protein (q=11.080,P<0.001) levels of KLF6.Compared with the 5-AZA group and the mimics-NC group,miR-22-3p mimics up-regulated the expression of miR-22-3p (q=3.591,P<0.001;q=11.650,P<0.001),Desmin (q=5.975,P<0.001;q=13.579,P<0.001),cTnT (q=7.133,P<0.001;q=17.548,P<0.001),and Cx43 (q=4.571,P=0.037;q=11.068,P<0.001),and down-regulated the mRNA (q=7.384,P<0.001;q=28.234,P<0.001) and protein (q=4.594,P=0.036;q=15.945,P<0.001) levels of KLF6.The apoptosis rate of miR-22-3p mimics group was lower than that of 5-AZA group (q=8.216,P<0.001).Compared with the miR-22-3p mimics+pcDNA group,miR-22-3p mimics+pcDNA-KLF6 up-regulated the mRNA(q=23.891,P<0.001) and protein(q=13.378,P<0.001)levels of KLF6,down-regulated the expression of Desmin (q=9.505,P<0.001),cTnT (q=10.985,P<0.001),and Cx43 (q=8.301,P<0.001),and increased the apoptosis rate (q=4.713,P=0.029).The dual luciferase reporter gene experiment demonstrated that KLF6 was a potential target gene of miR-22-3p. Conclusion MiR-22-3p promotes cardiomyocyte-like differentiation of BMSC by inhibiting the expression of KLF6.