Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 41
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
Exp Cell Res ; 436(2): 113981, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38387697

RESUMO

Osteoarthritis (OA) is the most common type of joint disease and the leading cause of chronic disability among older adults. As an important component of the joint, synovium influences the inflammatory and degenerative process of OA. This study found that miRNA 182 (miR-182) in synovium-specific exosomes can modulate inflammation and apoptotic signaling. It also regulated different biological functions to promote the progression of OA. Experiments based on rat OA model and synovium samples from OA patients, we found that synovium-derived miR-182 regulates inflammatory response in the early stage of OA by regulating the expression level of forkhead box O-3 (FOXO3). However, the expression of miR-182 was significantly increased in synovial tissue of advanced OA, which was involved in the apoptotic signal of severe OA. These findings suggest that miR-182 may directly regulate OA progression by modulating FOXO3 production inflammation, and apoptosis.


Assuntos
Exossomos , MicroRNAs , Osteoartrite , Humanos , Ratos , Animais , Idoso , Líquido Sinovial/metabolismo , Exossomos/genética , Exossomos/metabolismo , Osteoartrite/genética , Osteoartrite/metabolismo , Inflamação/genética , Inflamação/metabolismo , MicroRNAs/genética , MicroRNAs/metabolismo , Condrócitos/metabolismo
2.
Am J Physiol Cell Physiol ; 327(1): C48-C64, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38708522

RESUMO

Deficiencies in mice and in humans have brought to the fore the importance of the caveolar network in key aspects of adipocyte biology. The conserved N-terminal caveolin-binding motif (CBM) of the ubiquitous Na/K-ATPase (NKA) α1 isoform, which allows NKA/caveolin-1 (Cav1) interaction, influences NKA signaling and caveolar distribution. It has been shown to be critical for animal development and ontogenesis, as well as lineage-specific differentiation of human induced pluripotent stem cells (hiPSCs). However, its role in postnatal adipogenesis has not been fully examined. Using a genetic approach to alter CBM in hiPSC-derived adipocytes (iAdi-mCBM) and in mice (mCBM), we investigated the regulatory function of NKA CBM signaling in adipogenesis. Seahorse XF cell metabolism analyses revealed impaired glycolysis and decreased ATP synthesis-coupled respiration in iAdi-mCBM. These metabolic dysfunctions were accompanied by evidence of extensive remodeling of the extracellular matrix (ECM), including increased collagen staining, overexpression of ECM marker genes, and heightened TGF-ß signaling uncovered by RNAseq analysis. Rescue of mCBM by lentiviral delivery of WT NKA α1 or treatment of mCBM hiPSCs with the TGF-ß inhibitor SB431542 normalized ECM, suggesting that NKA CBM signaling integrity is required for adequate control of TGF-ß signaling and ECM stiffness during adipogenesis. The physiological impact was revealed in mCBM male mice with reduced fat mass accompanied by histological and transcriptional evidence of elevated adipose fibrosis and decreased adipocyte size. Based on these findings, we propose that the genetic alteration of the NKA/Cav1 regulatory path uncovered in human iAdi leads to lipodystrophy in mice.NEW & NOTEWORTHY A Na/K-ATPase α1 caveolin-binding motif regulates adipogenesis. Mutation of this binding motif in the mouse leads to reduced fat with increased extracellular matrix production and inflammation. RNA-seq analysis and pharmacological interventions in human iPSC-derived adipocytes revealed that TGF-ß signal, rather than Na/K-ATPase-mediated ion transport, is a key mediator of NKA regulation of adipogenesis.


Assuntos
Adipócitos , Adipogenia , Caveolina 1 , Células-Tronco Pluripotentes Induzidas , ATPase Trocadora de Sódio-Potássio , Adipogenia/genética , Animais , Caveolina 1/metabolismo , Caveolina 1/genética , ATPase Trocadora de Sódio-Potássio/metabolismo , ATPase Trocadora de Sódio-Potássio/genética , Humanos , Camundongos , Adipócitos/metabolismo , Células-Tronco Pluripotentes Induzidas/metabolismo , Transdução de Sinais , Diferenciação Celular , Masculino , Matriz Extracelular/metabolismo , Motivos de Aminoácidos , Camundongos Endogâmicos C57BL
3.
J Biochem Mol Toxicol ; 38(1): e23601, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38069819

RESUMO

Dysregulation of osteoblastic differentiation is an important risk factor of osteoporosis, the therapy of which is challenging. Dehydrocostus lactone (DHC), a sesquiterpene isolated from medicinal plants, has displayed anti-inflammatory and antitumor properties. In this study, we investigated the effects of DHC on osteoblastic differentiation and mineralization of MC3T3-E1 cells. Interestingly, we found that DHC increased the expression of marker genes of osteoblastic differentiation, such as alkaline phosphatase (ALP), osteocalcin (OCN), and osteopontin (OPN). Additionally, DHC increased the expressions of collagen type I alpha 1 (Col1a1) and collagen type I alpha 2 (Col1a2). We also demonstrate that DHC increased ALP activity. Importantly, the Alizarin Red S staining assay revealed that DHC enhanced osteoblastic differentiation of MC3T3-E1 cells. Mechanistically, it is shown that DHC increased the expression of Runx-2, a central regulator of osteoblastic differentiation. Treatment with DHC also increased the levels of phosphorylated p38, and its blockage using its specific inhibitor SB203580 abolished the effects of DHC on runt-related transcription factor 2 (Runx-2) expression and osteoblastic differentiation, suggesting the involvement of p38. Based on these findings, we concluded that DHC might possess a capacity for the treatment of osteoporosis by promoting osteoblastic differentiation.


Assuntos
Colágeno Tipo I , Lactonas , Osteoporose , Sesquiterpenos , Humanos , Colágeno Tipo I/metabolismo , Transdução de Sinais , Diferenciação Celular , Fosfatase Alcalina/metabolismo , Osteogênese
4.
Stem Cells ; 40(2): 133-148, 2022 03 16.
Artigo em Inglês | MEDLINE | ID: mdl-35257186

RESUMO

The N-terminal caveolin-binding motif (CBM) in Na/K-ATPase (NKA) α1 subunit is essential for cell signaling and somitogenesis in animals. To further investigate the molecular mechanism, we have generated CBM mutant human-induced pluripotent stem cells (iPSCs) through CRISPR/Cas9 genome editing and examined their ability to differentiate into skeletal muscle (Skm) cells. Compared with the parental wild-type human iPSCs, the CBM mutant cells lost their ability of Skm differentiation, which was evidenced by the absence of spontaneous cell contraction, marker gene expression, and subcellular myofiber banding structures in the final differentiated induced Skm cells. Another NKA functional mutant, A420P, which lacks NKA/Src signaling function, did not produce a similar defect. Indeed, A420P mutant iPSCs retained intact pluripotency and ability of Skm differentiation. Mechanistically, the myogenic transcription factor MYOD was greatly suppressed by the CBM mutation. Overexpression of a mouse Myod cDNA through lentiviral delivery restored the CBM mutant cells' ability to differentiate into Skm. Upstream of MYOD, Wnt signaling was demonstrated from the TOPFlash assay to have a similar inhibition. This effect on Wnt activity was further confirmed functionally by defective induction of the presomitic mesoderm marker genes BRACHYURY (T) and MESOGENIN1 (MSGN1) by Wnt3a ligand or the GSK3 inhibitor/Wnt pathway activator CHIR. Further investigation through immunofluorescence imaging and cell fractionation revealed a shifted membrane localization of ß-catenin in CBM mutant iPSCs, revealing a novel molecular component of NKA-Wnt regulation. This study sheds light on a genetic regulation of myogenesis through the CBM of NKA and control of Wnt/ß-catenin signaling.


Assuntos
Quinase 3 da Glicogênio Sintase , beta Catenina , Animais , Caveolina 1/genética , Caveolina 1/metabolismo , Caveolina 1/farmacologia , Diferenciação Celular , Quinase 3 da Glicogênio Sintase/metabolismo , Quinase 3 da Glicogênio Sintase/farmacologia , Camundongos , Desenvolvimento Muscular/genética , ATPase Trocadora de Sódio-Potássio/genética , ATPase Trocadora de Sódio-Potássio/metabolismo , Via de Sinalização Wnt , beta Catenina/metabolismo
5.
BMC Musculoskelet Disord ; 23(1): 340, 2022 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-35397519

RESUMO

BACKGROUND: Macrophages are one of the important cells in immune system. In this article, we aim to explore the regulatory role of miR-455-3p on proliferation and osteoblast differentiation of RAW264.7 cells. METHODS: Expression levels of genes and proteins in cells were tested via qRT-PCR and western blot. The targeted correlation between miR-455-3p and PTEN was identified by luciferase analysis. MTT assay and flow cytometry were applied to detect the proliferation and apoptosis of cells. Osteoclastogenesis was completed by stimulating RAW 264.7 cells with RANKL. Tartrate-resistant acid phosphatase (TRAP) activity in different groups of cells were assessed. RESULTS: Firstly, we determined that up-regulation of miR-455-3p promoted the proliferation and inhibited apoptosis of RAW 264.7 cells. MiR-455-3p deficiency played opposite effect in RAW 264.7 cells. Additionally, osteoclastogenesis-related factors (TRAP, CTSK and NFATc1) expression levels were remarkably up-regulated in miR-455-3p-mimic group of RAW264.7 cells treated with RANKL, but decreased in inhibitor group. Luciferase assay proved that miR-455-3p targeted PTEN. We took a further step and found overexpression of PTEN significantly inhibited the increased proliferation and osteoblast differentiation of RAW264.7 cells induced by miR-455-3p. CONCLUSIONS: Our findings supported basic to explore the molecular mechanism of proliferation and osteoblast differentiation of RAW264.7 cells.


Assuntos
MicroRNAs , Osteoclastos , Osteogênese , PTEN Fosfo-Hidrolase , Animais , Proliferação de Células/genética , Camundongos , MicroRNAs/metabolismo , Osteoclastos/citologia , Osteogênese/genética , PTEN Fosfo-Hidrolase/genética , PTEN Fosfo-Hidrolase/metabolismo , Células RAW 264.7
6.
Mol Pharmacol ; 99(3): 217-225, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33495275

RESUMO

Recent studies have revealed that Na/K-ATPase (NKA) can transmit signals through ion-pumping-independent activation of pathways relayed by distinct intracellular protein/lipid kinases, and endocytosis challenges the traditional definition that cardiotonic steroids (CTS) are NKA inhibitors. Although additional effects of CTS have long been suspected, revealing its agonist impact through the NKA receptor could be a novel mechanism in understanding the basic biology of NKA. In this study, we tested whether different structural CTS could trigger different sets of NKA/effector interactions, resulting in biased signaling responses without compromising ion-pumping capacity. Using purified NKA, we found that ouabain, digitoxigenin, and somalin cause comparable levels of NKA inhibition. However, although endogenous ouabain stimulates both protein kinases and NKA endocytosis, digitoxigenin and somalin bias to protein kinases and endocytosis, respectively, in LLC-PK1 cells. The positive inotropic effects of CTS are traditionally regarded as NKA inhibitors. However, CTS-induced signaling occurs at concentrations at least one order of magnitude lower than that of inotropy, which eliminates their well known toxic actions on the heart. The current study adds a novel mechanism that CTS could exert its biased signaling properties through the NKA signal transducer. SIGNIFICANCE STATEMENT: Although it is now well accepted that NKA has an ion-pumping-independent signaling function, it is still debated whether direct and conformation-dependent NKA/effector interaction is a key to this function. Therefore, this investigation is significant in advancing our understanding of the basic biology of NKA-mediated signal transduction and gaining molecular insight into the structural elements that are important for cardiotonic steroid's biased action.


Assuntos
Glicosídeos Cardíacos/farmacologia , Digitoxigenina/farmacologia , Glicosídeos/farmacologia , Ouabaína/farmacologia , Transdução de Sinais/efeitos dos fármacos , Animais , Sobrevivência Celular/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Células LLC-PK1 , ATPase Trocadora de Sódio-Potássio/metabolismo , Suínos
7.
Prostate ; 81(10): 667-682, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33956349

RESUMO

The surface expression of Na/K-ATPase α1 (NKA) is significantly reduced in primary prostate tumors and further decreased in bone metastatic lesions. Here, we show that the loss of cell surface expression of NKA induces epithelial-mesenchymal transition (EMT) and promotes metastatic potential and tumor growth of prostate cancer (PCa) by decreasing the expression of E-cadherin and increasing c-Myc expression via the activation of Src/FAK pathways. Mechanistically, reduced surface expression of NKA in PCa is due to increased endocytosis through the activation of NKA/Src receptor complex. Using a high-throughput NKA ligand-screening platform, we have discovered MB5 as an inverse agonist of the NKA/Src receptor complex, capable of blocking the endocytosis of NKA. MB5 treatment increased NKA expression and E-cadherin in PCa cells, which reversed EMT and consequently decreased the invasion and growth of spheroid models and tumor xenografts. Thus, we have identified a hitherto unrecognized mechanism that regulates EMT and invasiveness of PCa and demonstrated for the first time the feasibility of identifying inverse agonists of receptor NKA/Src complex and their potential utility as anticancer drugs. We, therefore, conclude that cell surface expression of α1 NKA can be targeted for the development of new therapeutics against aggressive PCa and that MB5 may serve as a prototype for drug development against EMT in metastatic PCa.


Assuntos
Agonismo Inverso de Drogas , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Transição Epitelial-Mesenquimal/fisiologia , Neoplasias da Próstata/metabolismo , ATPase Trocadora de Sódio-Potássio/biossíntese , Animais , Linhagem Celular Tumoral , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/farmacologia , Humanos , Masculino , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Ouabaína/farmacologia , Tiamina/análogos & derivados , Tiamina/farmacologia , Tiamina/uso terapêutico , Ensaios Antitumorais Modelo de Xenoenxerto/métodos
8.
Int J Mol Sci ; 22(7)2021 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-33801629

RESUMO

The Na/K-ATPase is the specific receptor for cardiotonic steroids (CTS) such as ouabain and digoxin. At pharmacological concentrations used in the treatment of cardiac conditions, CTS inhibit the ion-pumping function of Na/K-ATPase. At much lower concentrations, in the range of those reported for endogenous CTS in the blood, they stimulate hypertrophic growth of cultured cardiac myocytes through initiation of a Na/K-ATPase-mediated and reactive oxygen species (ROS)-dependent signaling. To examine a possible effect of endogenous concentrations of CTS on cardiac structure and function in vivo, we compared mice expressing the naturally resistant Na/K-ATPase α1 and age-matched mice genetically engineered to express a mutated Na/K-ATPase α1 with high affinity for CTS. In this model, total cardiac Na/K-ATPase activity, α1, α2, and ß1 protein content remained unchanged, and the cardiac Na/K-ATPase dose-response curve to ouabain shifted to the left as expected. In males aged 3-6 months, increased α1 sensitivity to CTS resulted in a significant increase in cardiac carbonylated protein content, suggesting that ROS production was elevated. A moderate but significant increase of about 15% of the heart-weight-to-tibia-length ratio accompanied by an increase in the myocyte cross-sectional area was detected. Echocardiographic analyses did not reveal any change in cardiac function, and there was no fibrosis or re-expression of the fetal gene program. RNA sequencing analysis indicated that pathways related to energy metabolism were upregulated, while those related to extracellular matrix organization were downregulated. Consistent with a functional role of the latter, an angiotensin-II challenge that triggered fibrosis in the α1r/rα2s/s mouse failed to do so in the α1s/sα2s/s. Taken together, these results are indicative of a link between circulating CTS, Na/K-ATPase α1, ROS, and physiological cardiac hypertrophy in mice under baseline laboratory conditions.


Assuntos
Glicosídeos Cardíacos/química , Coração/fisiologia , Miocárdio/enzimologia , ATPase Trocadora de Sódio-Potássio/genética , Angiotensina II/farmacologia , Animais , Cardiomegalia/patologia , Modelos Animais de Doenças , Ecocardiografia , Coração/efeitos dos fármacos , Masculino , Camundongos , Mutação , Ouabaína/farmacologia , Isoformas de Proteínas , RNA-Seq , Espécies Reativas de Oxigênio , Transdução de Sinais/efeitos dos fármacos
9.
J Neuroinflammation ; 17(1): 202, 2020 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-32631435

RESUMO

BACKGROUND: Spinal cord injury (SCI) triggers the primary mechanical injury and secondary inflammation-mediated injury. Neuroinflammation-mediated insult causes secondary and extensive neurological damage after SCI. Microglia play a pivotal role in the initiation and progression of post-SCI neuroinflammation. METHODS: To elucidate the significance of LRCH1 to microglial functions, we applied lentivirus-induced LRCH1 knockdown in primary microglia culture and tested the role of LRCH1 in microglia-mediated inflammatory reaction both in vitro and in a rat SCI model. RESULTS: We found that LRCH1 was downregulated in microglia after traumatic SCI. LRCH1 knockdown increased the production of pro-inflammatory cytokines such as IL-1ß, TNF-α, and IL-6 after in vitro priming with lipopolysaccharide and adenosine triphosphate. Furthermore, LRCH1 knockdown promoted the priming-induced microglial polarization towards the pro-inflammatory inducible nitric oxide synthase (iNOS)-expressing microglia. LRCH1 knockdown also enhanced microglia-mediated N27 neuron death after priming. Further analysis revealed that LRCH1 knockdown increased priming-induced activation of p38 mitogen-activated protein kinase (MAPK) and Erk1/2 signaling, which are crucial to the inflammatory response of microglia. When LRCH1-knockdown microglia were adoptively injected into rat spinal cords, they enhanced post-SCI production of pro-inflammatory cytokines, increased SCI-induced recruitment of leukocytes, aggravated SCI-induced tissue damage and neuronal death, and worsened the locomotor function. CONCLUSION: Our study reveals for the first time that LRCH1 serves as a negative regulator of microglia-mediated neuroinflammation after SCI and provides clues for developing novel therapeutic approaches against SCI.


Assuntos
Mediadores da Inflamação/metabolismo , Proteínas dos Microfilamentos/antagonistas & inibidores , Proteínas dos Microfilamentos/metabolismo , Microglia/metabolismo , Traumatismos da Medula Espinal/metabolismo , Animais , Células Cultivadas , Inflamação/induzido quimicamente , Inflamação/metabolismo , Inflamação/patologia , Lipopolissacarídeos/toxicidade , Masculino , Microglia/efeitos dos fármacos , Microglia/patologia , Ratos , Ratos Sprague-Dawley , Traumatismos da Medula Espinal/patologia
10.
Acta Biochim Biophys Sin (Shanghai) ; 51(3): 243-253, 2019 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-30805592

RESUMO

A close relationship between cancer progression and microRNAs (miRNAs) regulation has been demonstrated. Abnormal microRNA-206 (miR-206) expression has been shown to be related to the development of malignancies. However, the role of miR-206 in hepatocellular carcinoma (HCC) remains unclear. Here, we evaluated the function of miR-206 in HCC. Results showed that miR-206 expression was decreased in 27 human HCC tissues compared with that of adjacent normal tissues. Conversely, cMET was up-regulated in human HCC cancer tissues, and cMET levels were shown to be negatively correlated with miR-206 expression. Abnormally increased miR-206 expression in three HCC cell lines (SMMC-7721, HepG2, and Huh7) attenuated cell viability, migration, and invasion. Increased apoptosis was also observed in these miR-206 expressing cells. Furthermore, we identified that miR-206 targets the 3'-UTR of the cMET gene for silencing, and restoration of cMET expression reversed the inhibitory effect of miR-206 on HCC. Tumor cells expressing miR-206 also showed delayed growth in the in vivo experiments compared with the controls. Altogether, our findings provide new insights into the molecular mechanisms of HCC oncogenesis.


Assuntos
Apoptose , Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/patologia , MicroRNAs/fisiologia , Proteínas Proto-Oncogênicas c-met/genética , Adulto , Idoso , Animais , Carcinoma Hepatocelular/etiologia , Carcinoma Hepatocelular/genética , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Humanos , Neoplasias Hepáticas/etiologia , Neoplasias Hepáticas/genética , Camundongos , MicroRNAs/análise , Pessoa de Meia-Idade , Invasividade Neoplásica
11.
Stem Cells ; 34(5): 1354-68, 2016 05.
Artigo em Inglês | MEDLINE | ID: mdl-26840832

RESUMO

Disorders affecting smooth muscle structure/function may require technologies that can generate large scale, differentiated and contractile smooth muscle cells (SMC) suitable for cell therapy. To date no clonal precursor population that provides large numbers of differentiated SMC in culture has been identified in a rodent. Identification of such cells may also enhance insight into progenitor cell fate decisions and the relationship between smooth muscle precursors and disease states that implicate differentiated SMC. In this study, we used classic clonal expansion techniques to identify novel self-renewing Islet 1 (Isl-1) positive primitive progenitor cells (PPC) within rat bone marrow that exhibited canonical stem cell markers and preferential differentiation towards a smooth muscle-like fate. We subsequently used molecular tagging to select Isl-1 positive clonal populations from expanded and de novo marrow cell populations. We refer to these previously undescribed cells as the PPC given its stem cell marker profile, and robust self-renewal capacity. PPC could be directly converted into induced smooth muscle cells (iSMC) using single transcription factor (Kruppel-like factor 4) knockdown or transactivator (myocardin) overexpression in contrast to three control cells (HEK 293, endothelial cells and mesenchymal stem cells) where such induction was not possible. iSMC exhibited immuno- and cytoskeletal-phenotype, calcium signaling profile and contractile responses similar to bona fide SMC. Passaged iSMC could be expanded to a scale sufficient for large scale tissue replacement. PPC and reprogramed iSMC so derived may offer future opportunities to investigate molecular, structure/function and cell-based replacement therapy approaches to diverse cardiovascular, respiratory, gastrointestinal, and genitourinary diseases that have as their basis smooth muscle cell functional aberrancy or numerical loss. Stem Cells 2016;34:1354-1368.


Assuntos
Reprogramação Celular , Proteínas com Homeodomínio LIM/metabolismo , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/metabolismo , Miócitos de Músculo Liso/citologia , Fatores de Transcrição/metabolismo , Animais , Células da Medula Óssea/citologia , Diferenciação Celular , Proliferação de Células , Autorrenovação Celular , Separação Celular , Células Cultivadas , Células Clonais , Inativação Gênica , Vetores Genéticos/metabolismo , Proteínas de Fluorescência Verde/metabolismo , Células HEK293 , Humanos , Fator 4 Semelhante a Kruppel , Fatores de Transcrição Kruppel-Like/metabolismo , Miócitos de Músculo Liso/metabolismo , Proteínas Nucleares/metabolismo , Fenótipo , Ratos Endogâmicos F344 , Telomerase/metabolismo , Transativadores/metabolismo
12.
Prostate ; 75(9): 976-87, 2015 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-25808853

RESUMO

BACKGROUND: ELL-associated factor 2 (EAF2) is an androgen-regulated tumor suppressor in the prostate. However, the mechanisms underlying tumor suppressive function of EAF2 are still largely unknown. Identification of factors capable of modulating EAF2 function will help elucidate the mechanisms underlying EAF2 tumor suppressive function. METHODS: Using eaf-1(the ortholog of EAF2) mutant C. elegans model, RNAi screen was used to identify factors on the basis of their knockdown to synergistically enhance the reduced fertility phenotype of the eaf-1 mutant C. elegans. In human cells, the interaction of EAF2 with FOXA1 and the effect of EAF2 on the FOXA1 protein levels were determined by co-immunoprecipitation and protein stability assay. The effect of EAF2 and/or FOXA1 knockdown on the expression of AR-target genes was determined by real-time RT-PCR and luciferase reporter assays. The effect of EAF2 and/or FOXA1 knockdown on LNCaP human prostate cancer cell proliferation and migration was tested using BrdU assay and transwell migration assay. RESULTS: RNAi screen identified pha-4, the C. elegans ortholog of mammalian FOXA1, on the basis of its knockdown to synergistically enhance the reduced fertility phenotype of the eaf-1 mutant C. elegans causing sterility. EAF2 co-immunoprecipitated with FOXA1. EAF2 knockdown enhanced endogenous FOXA1 protein level, whereas transfected GFP-EAF2 down-regulated the FOXA1 protein. Also, EAF2 knockdown enhanced the expression of AR-target genes, cell proliferation, and migration in LNCaP cells. However, FOXA1 knockdown inhibited the effect of EAF2 knockdown on AR-target gene expression, cell proliferation, and migration in LNCaP cells, suggesting that FOXA1 can modulate EAF2 regulation of AR transcriptional activation, cell proliferation, and migration. CONCLUSIONS: These findings suggest that regulation of the AR signaling pathway, cell proliferation, and migration through FOXA1 represents an important mechanism of EAF2 suppression of prostate carcinogenesis.


Assuntos
Fator 3-alfa Nuclear de Hepatócito/metabolismo , Neoplasias da Próstata/metabolismo , Receptores Androgênicos/metabolismo , Fatores de Transcrição/metabolismo , Animais , Western Blotting , Caenorhabditis elegans , Linhagem Celular Tumoral , Proliferação de Células/fisiologia , Regulação para Baixo , Fator 3-alfa Nuclear de Hepatócito/genética , Humanos , Imunoprecipitação , Masculino , Neoplasias da Próstata/genética , Neoplasias da Próstata/patologia , Interferência de RNA/fisiologia , Receptores Androgênicos/genética , Fatores de Transcrição/genética , Ativação Transcricional , Transfecção/métodos
13.
Biochem Biophys Res Commun ; 447(2): 292-8, 2014 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-24727455

RESUMO

The tumor suppressor EAF2 is regulated by androgen signaling and associated with prostate cancer. While EAF2 and its partner ELL have been shown to be members of protein complexes involved in RNA polymerase II transcriptional elongation, the biologic roles for EAF2 especially with regards to the development of cancer remains poorly understood. We have previously identified the eaf-1 gene in Caenorhabditiselegans as the ortholog of EAF2, and shown that eaf-1 interacts with the ELL ortholog ell-1 to control development and fertility in worms. To identify genetic pathways that interact with eaf-1, we screened RNAi libraries consisting of transcription factors, phosphatases, and chromatin-modifying factors to identify genes which enhance the effects of eaf-1(tm3976) on fertility. From this screen, we identified lin-53, hmg-1.2, pha-4, ruvb-2 and set-6 as hits. LIN-53 is the C. elegans ortholog of human retinoblastoma binding protein 4/7 (RBBP 4/7), which binds to the retinoblastoma protein and inhibits the Ras signaling pathway. We find that lin-53 showed a synthetic interaction with eaf-1(tm3976) where knockdown of lin-53 in an eaf-1(tm3976) mutant resulted in sterile worms. This phenotype may be due to cell death as the treated worms contain degenerated embryos with increased expression of the ced-1:GFP cell death marker. Further we find that the interaction between eaf-1 and lin-53/RBBP4/7 also exists in vertebrates, which is reflected by the formation of a protein complex between EAF2 and RBBP4/7. Finally, overexpression of either human EAF2 or RBBP4 in LNCaP cells induced the cell death while knockdown of EAF2 in LNCaP enhanced cell proliferation, indicating an important role of EAF2 in controlling the growth and survival of prostate cancer cells. Together these findings identify a novel physical and functional interaction between EAF2 and the Rb pathway.


Assuntos
Proteínas de Caenorhabditis elegans/genética , Caenorhabditis elegans/genética , Neoplasias da Próstata/genética , Proteínas Repressoras/genética , Proteína do Retinoblastoma/genética , Fatores de Transcrição/genética , Proteínas Supressoras de Tumor/genética , Animais , Apoptose , Proteínas de Caenorhabditis elegans/metabolismo , Linhagem Celular Tumoral , Técnicas de Silenciamento de Genes , Humanos , Masculino , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologia , Interferência de RNA , Proteínas Repressoras/metabolismo , Proteína do Retinoblastoma/metabolismo , Proteína 4 de Ligação ao Retinoblastoma/genética , Proteína 4 de Ligação ao Retinoblastoma/metabolismo , Transdução de Sinais , Fatores de Transcrição/metabolismo , Proteínas Supressoras de Tumor/metabolismo
14.
J Bone Oncol ; 45: 100593, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38495379

RESUMO

Background and objective: Pelvic bone tumors represent a harmful orthopedic condition, encompassing both benign and malignant forms. Addressing the issue of limited accuracy in current machine learning algorithms for bone tumor image segmentation, we have developed an enhanced bone tumor image segmentation algorithm. This algorithm is built upon an improved full convolutional neural network, incorporating both the fully convolutional neural network (FCNN-4s) and a conditional random field (CRF) to achieve more precise segmentation. Methodology: The enhanced fully convolutional neural network (FCNN-4s) was employed to conduct initial segmentation on preprocessed images. Following each convolutional layer, batch normalization layers were introduced to expedite network training convergence and enhance the accuracy of the trained model. Subsequently, a fully connected conditional random field (CRF) was integrated to fine-tune the segmentation results, refining the boundaries of pelvic bone tumors and achieving high-quality segmentation. Results: The experimental outcomes demonstrate a significant enhancement in segmentation accuracy and stability when compared to the conventional convolutional neural network bone tumor image segmentation algorithm. The algorithm achieves an average Dice coefficient of 93.31 %, indicating superior performance in real-time operations. Conclusion: In contrast to the conventional convolutional neural network segmentation algorithm, the algorithm presented in this paper boasts a more intricate structure, proficiently addressing issues of over-segmentation and under-segmentation in pelvic bone tumor segmentation. This segmentation model exhibits superior real-time performance, robust stability, and is capable of achieving heightened segmentation accuracy.

15.
Front Biosci (Elite Ed) ; 16(1): 6, 2024 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-38538524

RESUMO

BACKGROUND: This research explores the significance of miR-215-5p and vasculogenic mimicry (VM) in forecasting the prognosis for hepatocellular carcinoma (HCC). METHODS: We analyzed HCC-associated miRNA expression profiles using data from The Cancer Genome Atlas (TCGA) and the Gene Expression Omnibus (GEO). Samples included tissue and blood from 80 early-stage HCC patients and serum from 120 healthy individuals. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was employed to measure miR-215-5p and zinc finger E-box binding homeobox 2 (ZEB2) gene expressions. Hematoxylin and eosin (H&E) and CD34/Periodic Acid-Schiff (PAS) double staining assessed VM presence in HCC tissue sections. Bioinformatics tools predicted interactions between miR-215-5p and ZEB2, confirmed through luciferase reporter assays. We also examined the impact of miR-215-5p or ZEB2 overexpression on HCC cell invasion, migration, and VM formation using scratch, Transwell invasion assays, and Matrigel 3D cultures. RESULTS: Bioinformatics analysis indicated that miR-215-5p was under-expressed in HCC, particularly in cases with vascular invasion, which correlated with worse patient outcomes. In contrast, ZEB2, targeted by miR-215-5p, was overexpressed in HCC. RT-qPCR validated these expression patterns in HCC tissues. Among the HCC patients, 38 were VM positive and 42 VM negative. Logistic regression highlighted a negative correlation between miR-215-5p levels and VM positivity in HCC tissues and a positive correlation for ZEB2 with VM positivity and tumor vascular invasion. Lower miR-215-5p levels were linked to increased HCC recurrence and metastasis. Both bioinformatics analysis and luciferase assays demonstrated a direct interaction between miR-215-5p and ZEB2. Enhancing miR-215-5p levels reduced ZEB2 expression, consequently diminishing invasion, migration, and VM formation of the HCC cells in vitro. CONCLUSIONS: miR-215-5p expression inversely correlates with VM occurrence in HCC tissues, while ZEB2 expression shows a direct correlation. By targeting ZEB2, miR-215-5p may hinder VM in HCC tissues, helping to prevent vascular invasion and HCC recurrence. Thus, miR-215-5p emerges as a vital prognostic indicator for predicting vascular invasion and recurrence in HCC.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , MicroRNAs , Humanos , Carcinoma Hepatocelular/genética , Neoplasias Hepáticas/genética , MicroRNAs/genética , MicroRNAs/metabolismo , Linhagem Celular Tumoral , Luciferases/genética , Luciferases/metabolismo , Proliferação de Células , Regulação Neoplásica da Expressão Gênica , Movimento Celular/genética
16.
J Bone Oncol ; 42: 100502, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37736418

RESUMO

Background and objective: Bone tumor is a kind of harmful orthopedic disease, there are benign and malignant points. Aiming at the problem that the accuracy of the existing machine learning algorithm for bone tumor image segmentation is not high, a bone tumor image segmentation algorithm based on improved full convolutional neural network which consists fully convolutional neural network (FCNN-4s) and conditional random field (CRF). Methodology: The improved fully convolutional neural network (FCNN-4s) was used to perform coarse segmentation on preprocessed images. Batch normalization layers were added after each convolutional layer to accelerate the convergence speed of network training and improve the accuracy of the trained model. Then, a fully connected conditional random field (CRF) was fused to refine the bone tumor boundary in the coarse segmentation results, achieving the fine segmentation effect. Results: The experimental results show that compared with the traditional convolutional neural network bone tumor image segmentation algorithm, the algorithm has a great improvement in segmentation accuracy and stability, the average Dice can reach 91.56%, the real-time performance is better. Conclusion: Compared with the traditional convolutional neural network segmentation algorithm, the algorithm in this paper has a more refined structure, which can effectively solve the problem of over-segmentation and under-segmentation of bone tumors. The segmentation prediction has better real-time performance, strong stability, and can achieve higher segmentation accuracy.

17.
Biomedicines ; 11(12)2023 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-38137428

RESUMO

Na/K-ATPase (NKA)-mediated regulation of Src kinase, which involves defined amino acid sequences of the NKA α1 polypeptide, has emerged as a novel regulatory mechanism of mitochondrial function in metazoans. Mitochondrial metabolism ensures adequate myocardial performance and adaptation to physiological demand. It is also a critical cellular determinant of cardiac repair and remodeling. To assess the impact of the proposed NKA/Src regulatory axis on cardiac mitochondrial metabolic function, we used a gene targeting approach in human cardiac myocytes. Human induced pluripotent stem cells (hiPSC) expressing an Src-signaling null mutant (A420P) form of the NKA α1 polypeptide were generated using CRISPR/Cas9-mediated genome editing. Total cellular Na/K-ATPase activity remained unchanged in A420P compared to the wild type (WT) hiPSC, but baseline phosphorylation levels of Src and ERK1/2 were drastically reduced. Both WT and A420P mutant hiPSC readily differentiated into cardiac myocytes (iCM), as evidenced by marker gene expression, spontaneous cell contraction, and subcellular striations. Total NKA α1-3 protein expression was comparable in WT and A420P iCM. However, live cell metabolism assessed functionally by Seahorse extracellular flux analysis revealed significant reductions in both basal and maximal rates of mitochondrial respiration, spare respiratory capacity, ATP production, and coupling efficiency. A significant reduction in ROS production was detected by fluorescence imaging in live cells, and confirmed by decreased cellular protein carbonylation levels in A420P iCM. Taken together, these data provide genetic evidence for a role of NKA α1/Src in the tonic stimulation of basal mitochondrial metabolism and ROS production in human cardiac myocytes. This signaling axis in cardiac myocytes may provide a new approach to counteract mitochondrial dysfunction in cardiometabolic diseases.

18.
J Biol Chem ; 286(41): 35915-35921, 2011 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-21880729

RESUMO

EAF2, an androgen-regulated protein, interacts with members of the ELL (eleven-nineteen lysine-rich leukemia) transcription factor family and also acts as a tumor suppressor. Although these proteins control transcriptional elongation and perhaps modulate the effects of other transcription factors, the mechanisms of their actions remain largely unknown. To gain new insights into the biology of the EAF2 and ELL family proteins, we used Caenorhabditis elegans as a model to explore the in vivo roles of their worm orthologs. Through the use of transgenic worms, RNAi, and an eaf-1 mutant, we found that both genes are expressed in multiple cell types throughout the worm life cycle and that they play important roles in fertility, survival, and body size regulation. ELL-1 and EAF-1 likely contribute to these activities in part through modulating cuticle synthesis, given that we observed a disrupted cuticle structure in ell-1 RNAi-treated or eaf-1 mutant worms. Consistent with disruption of cuticle structure, loss of either ELL-1 or EAF-1 suppressed the rol phenotype of specific collagen mutants, possibly through the control of dpy-3, dpy-13, and sqt-3 collagen gene expression. Furthermore, we also noted the regulation of collagen expression by ELL overexpression in PC3 human prostate cancer cells. Together, these results reveal important roles for the eaf-1 and ell-1 genes in the regulation of extracellular matrix components.


Assuntos
Animais Geneticamente Modificados/metabolismo , Proteínas de Caenorhabditis elegans/biossíntese , Caenorhabditis elegans/metabolismo , Colágeno/biossíntese , Matriz Extracelular/metabolismo , Regulação da Expressão Gênica , Animais , Animais Geneticamente Modificados/genética , Caenorhabditis elegans/citologia , Caenorhabditis elegans/genética , Linhagem Celular Tumoral , Matriz Extracelular/genética , Humanos , Mutação , Interferência de RNA , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Fatores de Elongação da Transcrição/genética , Fatores de Elongação da Transcrição/metabolismo
19.
Bioengineered ; 13(5): 13680-13688, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35706414

RESUMO

Long non-coding RNA (lncRNA) plasmacytoma variant translocation 1 (PVT1) and growth arrest specific 5 (GAS5) have opposite functions in the apoptosis of chondrocytes, which are involved in the pathogenesis of osteoarthritis (OA). The opposite roles of PVT1 and GAS5 in OA may indicate the existence of crosstalk between them in OA. This study aimed to explore the possible interaction between PVT1 and GAS5 in OA. Accumulation of PVT1 and GAS5 in OA and control synovial fluid samples was measured by RT-qPCR. The interaction between PVT1 and GAS5 in chondrocytes was explored by overexpression experiments. Dual-luciferase reporter assay was performed to analyze the binding of PVT1 and GAS5 to each other's promoter regions. Regulatory roles of PVT1 and GAS5 in the apoptosis of chondrocytes were studied with cell apoptosis assay. PVT1 was upregulated in OA, and GAS5 was downregulated in OA. An inverse correlation between PVT1 and GAS5 was observed across OA samples. Under lipopolysaccharides (LPS) treatment, PVT1 was upregulated and GAS5 was downregulated. Interestingly, PVT1 and GAS5 overexpression downregulated each other in chondrocytes. Cell apoptosis analysis showed that PVT1 overexpression promoted cell apoptosis, while GAS5 overexpression suppressed cell apoptosis induced by LPS. Co-transfection of PVT1 and GAS5 failed to significantly affect cell apoptosis. PVT1 and GAS5 directly bound to each other's promoter regions. Our study characterized the interaction between PVT1 and GAS5 in OA. Their interaction regulated the apoptosis of chondrocytes, which play a critical role in OA. PVT1 and GAS5 may form a negative feedback loop in OA.


Assuntos
MicroRNAs , Osteoartrite , Plasmocitoma , RNA Longo não Codificante , Apoptose/genética , Condrócitos/metabolismo , Humanos , Lipopolissacarídeos/metabolismo , MicroRNAs/metabolismo , Osteoartrite/genética , Osteoartrite/metabolismo , Plasmocitoma/complicações , Plasmocitoma/metabolismo , Plasmocitoma/patologia , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo
20.
Comput Methods Programs Biomed ; 226: 107110, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36167001

RESUMO

OBJECTIVE: The femur is a typical human long bone with an irregular spatial structure. Femoral fractures are the most common occurrence in middle-aged and older adults. The structure of human bone tissue is very complex, and there are significant differences between individuals. Segmenting bone tissue is a challenging task and of great practical significance. METHODS: Our research is based on segmenting and the three-dimensional reconstruction of femoral images using X-ray imaging. The currently commonly used two-dimensional fully convolutional network Unet has the problem of ignoring spatial position information and losing too much feature information. The commonly used three-dimensional fully convolutional network 3D Unet has the problem of ignoring spatial position information and losing too much feature information. For the problem of many model parameters, we proposes a two-stage network segmentation model composed of 3D-DMFNet and 3D-ResUnet networks and trains the network in stages to segment the femur. One stage is used to detect the coarse segmentation of the femur range, and one stage is used for the fine segmentation of the femur so that the training speed is fast and the segmentation accuracy is moderate, which is suitable for detecting the femur range. RESULTS: The experimental dataset used in this paper is from The Second Affiliated Hospital of Fujian Medical University, which consists of 30 sets of femur X-ray images. The experiment compares the accuracy and loss value of Unet and the two-stage convolutional network. The image shows that the two-stage convolutional network has higher accuracy. At the same time, this paper shows the effect of the two-stage coarse segmentation and fine segmentation of medical images. Subsequently, this paper applies the model to practice and obtains the model's Dice, Sensitivity, Specificity and Pixel Accuracy values. After comparative analysis, the experimental results show that the two-stage network segmentation model composed of 3D-DMFNet and 3D-ResUnet network designed in this paper has higher accuracy, intuitiveness, and more application value than traditional image segmentation algorithms. CONCLUSION: With the continuous application of X-ray images in clinical diagnosis using femoral images, the method in this paper is expected to become a diagnostic tool that can effectively improve the accuracy and loss of femoral image segmentation and the three-dimensional reconstruction.


Assuntos
Processamento de Imagem Assistida por Computador , Redes Neurais de Computação , Pessoa de Meia-Idade , Humanos , Idoso , Processamento de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/métodos , Algoritmos , Fêmur/diagnóstico por imagem
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA