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1.
Biochem Biophys Res Commun ; 709: 149828, 2024 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-38537596

RESUMO

Long intergenic non-coding RNA 346 (LINC00346) has been reported to be involved in the development of atherosclerosis and specific cancers by affecting signaling pathways. However, its function in inflammation has not been thoroughly studied. Therefore, its expression pattern and function were determined in the human macrophage-like cell line THP-1. Lipopolysaccharide (LPS) treatment induced the expression of LINC00346. LPS-induced NF-κB activation and proinflammatory cytokine expression were suppressed or enhanced by the overexpression or knockdown of LINC00346, respectively. Analyses using dual luciferase assay and decoy RNAs that could block RNA-RNA interactions indicated that LINC00346 improves phosphatase and tensin homolog (PTEN) expression by sponging miR-25-3p. Subsequently, PTEN suppresses phosphoinositide-3 kinase (PI3K)-mediated conversion of phosphatidylinositol-4,5-bisphosphate (PIP2) into phosphatidylinositol-3,4,5-trisphosphate (PIP3) as well as consequent activation of protein kinase B (AKT) and NF-κB. Interestingly, database analysis revealed that the expression levels of LINC00346 and PTEN were simultaneously decreased in breast cancer tissues. Further analyses conducted using a breast cancer cell line, MDA-MB-231, confirmed the functional relationship among LINC00346, miR-25-3p, and PTEN in LPS-induced activation of NF-κB. These results indicate that miR-25-3p-sponging activity of LINC00346 affects the balance between PTEN and PI3K as well as the downstream activation of AKT/NF-κB pathway in inflammatory conditions.


Assuntos
Neoplasias da Mama , MicroRNAs , Feminino , Humanos , Lipopolissacarídeos/farmacologia , MicroRNAs/genética , MicroRNAs/metabolismo , NF-kappa B/metabolismo , Fosfatidilinositol 3-Quinase , Fosfatidilinositol 3-Quinases/metabolismo , Fosfatidilinositóis , Proteínas Proto-Oncogênicas c-akt/metabolismo , PTEN Fosfo-Hidrolase/genética , PTEN Fosfo-Hidrolase/metabolismo
2.
Ecotoxicol Environ Saf ; 269: 115820, 2024 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-38103469

RESUMO

Perfluorooctanesulfonate (PFOS) is a ubiquitous environmental pollutant associated with increasing health concerns and environmental hazards. Toxicological analyses of PFOS exposure are hampered by large interspecies variations and limited studies on the mechanistic details of PFOS-induced toxicity. We investigated the effects of PFOS exposure on Xenopus laevis embryos based on the reported developmental effects in zebrafish. X. laevis was selected to further our understanding of interspecies variation in response to PFOS, and we built upon previous studies by including transcriptomics and an assessment of ciliogenic effects. Midblastula-stage X. laevis embryos were exposed to PFOS using the frog embryo teratogenesis assay Xenopus (FETAX). Results showed teratogenic effects of PFOS in a time- and dose-dependent manner. The morphological abnormalities of skeleton deformities, a small head, and a miscoiled gut were associated with changes in gene expression evidenced by whole-mount in situ hybridization and transcriptomics. The transcriptomic profile of PFOS-exposed embryos indicated the perturbation in the expression of genes associated with cell death, and downregulation in adenosine triphosphate (ATP) biosynthesis. Moreover, we observed the effects of PFOS exposure on cilia development as a reduction in the number of multiciliated cells and changes in the directionality and velocity of the cilia-driven flow. Collectively, these data broaden the molecular understanding of PFOS-induced developmental effects, whereby ciliary dysfunction and disrupted ATP synthesis are implicated as the probable modes of action of embryotoxicity. Furthermore, our findings present a new challenge to understand the links between PFOS-induced developmental toxicity and vital biological processes.


Assuntos
Ácidos Alcanossulfônicos , Fluorocarbonos , Perfilação da Expressão Gênica , Peixe-Zebra , Animais , Xenopus laevis/genética , Trifosfato de Adenosina , Embrião não Mamífero , Teratogênicos/toxicidade
3.
Molecules ; 29(2)2024 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-38257395

RESUMO

Autophagy is a pivotal biological process responsible for maintaining the homeostasis of intracellular organelles. Yet the molecular intricacies of peroxisomal autophagy (pexophagy) remain largely elusive. From a ubiquitin-related chemical library for screening, we identified several inhibitors of the Von Hippel-Lindau (VHL) E3 ligase, including VH298, thereby serving as potent inducers of pexophagy. In this study, we observed that VH298 stimulates peroxisomal degradation by ATG5 dependently and escalates the ubiquitination of the peroxisomal membrane protein ABCD3. Interestingly, the ablation of NBR1 is similar to the curtailed peroxisomal degradation in VH298-treated cells. We also found that the pexophagy induced by VH298 is impeded upon the suppression of gene expression by the translation inhibitor cycloheximide. Beyond VHL inhibition, we discovered that roxadustat, a direct inhibitor of HIF-α prolyl hydroxylase, is also a potent inducer of pexophagy. Furthermore, we found that VH298-mediated pexophagy is blocked by silencing HIF-1α. In conclusion, our findings suggest that VH298 promotes pexophagy by modulating VHL-mediated HIF-α transcriptional activity.


Assuntos
Autofagia , Ciclopropanos , Macroautofagia , Pirrolidinas , Tiazóis , Humanos , Células HeLa , Homeostase , Proteína Supressora de Tumor Von Hippel-Lindau/genética
4.
Environ Toxicol ; 38(1): 216-224, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36218123

RESUMO

Pentachloronitrobenzene (PCNB) is an organochlorine fungicide commonly used to treat seeds against seedling infections and controlling snow mold on golf courses. PCNB has been demonstrated to be toxic to living organisms, including fish and several terrestrial organisms. However, only phenotypical deformities have been studied, and the effects of PCNB on early embryogenesis, where primary organogenesis occurs, have not been completely studied. In the current study, the developmental toxicity and teratogenicity of PCNB is evaluated by using frog embryo teratogenesis assay Xenopus (FETAX). Our results confirmed the teratogenic potential of PCNB revealing the teratogenic index of 1.29 during early embryogenesis. Morphological studies revealed tiny head, bent axis, reduced inter ocular distance, hyperpigmentation, and reduced total body lengths. Whole mount in situ hybridization and reverse transcriptase polymerase chain reaction were used to identify PCNB teratogenic effects at the gene level. The gene expression analyses revealed that PCNB was embryotoxic to the liver and heart of developing embryos. Additionally, to determine the most sensitive developmental stages to PCNB, embryos were exposed to the compound at various developmental stages, demonstrating that the most sensitive developmental stage to PCNB is primary organogenesis. Taken together, we infer that PCNB's teratogenic potential affects not just the phenotype of developing embryos but also the associated genes and involving the oxidative stress as a possible mechanism of toxicity, posing a hazard to normal embryonic growth. However, the mechanisms of teratogenesis require additional extensive investigation to be defined completely.


Assuntos
Teratogênese , Animais , Xenopus laevis/genética , Embrião não Mamífero , Teratogênicos/toxicidade , Desenvolvimento Embrionário/genética , Expressão Gênica
5.
Int J Mol Sci ; 23(14)2022 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-35887370

RESUMO

Since the discovery of the small ubiquitin-like modifier (SUMO) protein in 1995, SUMOylation has been considered a crucial post-translational modification in diverse cellular functions. In neurons, SUMOylation has various roles ranging from managing synaptic transmitter release to maintaining mitochondrial integrity and determining neuronal health. It has been discovered that neuronal dysfunction is a key factor in the development of major depressive disorder (MDD). PubMed and Google Scholar databases were searched with keywords such as 'SUMO', 'neuronal plasticity', and 'depression' to obtain relevant scientific literature. Here, we provide an overview of recent studies demonstrating the role of SUMOylation in maintaining neuronal function in participants suffering from MDD.


Assuntos
Transtorno Depressivo Maior , Sumoilação , Transtorno Depressivo Maior/metabolismo , Humanos , Neurônios/metabolismo , Processamento de Proteína Pós-Traducional , Proteínas Modificadoras Pequenas Relacionadas à Ubiquitina/metabolismo
6.
Biochem Biophys Res Commun ; 545: 69-74, 2021 03 19.
Artigo em Inglês | MEDLINE | ID: mdl-33545634

RESUMO

Peroxisomes play an essential role in cellular homeostasis by regulating lipid metabolism and the conversion of reactive oxygen species (ROS). Several peroxisomal proteins, known as peroxins (PEXs), control peroxisome biogenesis and degradation. Various mutations in the PEX genes are genetic causes for the development of inheritable peroxisomal-biogenesis disorders, such as Zellweger syndrome. Among the peroxins, PEX1 defects are the most common mutations in Zellweger syndrome. PEX1 is an AAA-ATPase that regulates the recycling of PEX5, which is essential for importing peroxisome matrix proteins. However, the post-transcriptional regulation of PEX1 is largely unknown. Here, we showed that heterogeneous nuclear ribonucleoprotein A1 (HNRNPA1) controls PEX1 expression. In addition, we found that depletion of HNRNPA1 induces autophagic degradation of peroxisome, which is blocked in ATG5-knockout cells. In addition, depletion of HNRNPA1 increased peroxisomal ROS levels. Inhibition of the generation of peroxisomal ROS by treatment with NAC significantly suppressed pexophagy in HNRNPA1-deficient cells. Taken together, our results suggest that depletion of HNRNPA1 increases peroxisomal ROS and pexophagy by downregulating PEX1 expression.


Assuntos
ATPases Associadas a Diversas Atividades Celulares/metabolismo , Ribonucleoproteína Nuclear Heterogênea A1/metabolismo , Macroautofagia/fisiologia , Proteínas de Membrana/metabolismo , Peroxissomos/metabolismo , ATPases Associadas a Diversas Atividades Celulares/genética , Proteína 5 Relacionada à Autofagia/antagonistas & inibidores , Proteína 5 Relacionada à Autofagia/genética , Proteína 5 Relacionada à Autofagia/metabolismo , Células Cultivadas , Regulação para Baixo , Técnicas de Inativação de Genes , Células HCT116 , Células HeLa , Ribonucleoproteína Nuclear Heterogênea A1/deficiência , Ribonucleoproteína Nuclear Heterogênea A1/genética , Humanos , Macroautofagia/genética , Proteínas de Membrana/genética , Processamento Pós-Transcricional do RNA , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Síndrome de Zellweger/genética , Síndrome de Zellweger/metabolismo
7.
FASEB J ; 34(2): 2944-2957, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31908024

RESUMO

Mitochondrial quality control maintains mitochondrial function by regulating mitochondrial dynamics and mitophagy. Despite the identification of mitochondrial quality control factors, little is known about the crucial regulators coordinating both mitochondrial fission and mitophagy. Through a cell-based functional screening assay, FK506 binding protein 8 (FKBP8) was identified to target microtubule-associated protein 1 light chain 3 (LC3) to the mitochondria and to change mitochondrial morphology. Microscopy analysis revealed that the formation of tubular and enlarged mitochondria was observed in FKBP8 knockdown HeLa cells and the cortex of Fkbp8 heterozygote-knockout mouse embryos. Under iron depletion-induced stress, FKBP8 was recruited to the site of mitochondrial division through budding and colocalized with LC3. FKBP8 was also found to be required for mitochondrial fragmentation and mitophagy under hypoxic stress. Conversely, FKBP8 overexpression induced mitochondrial fragmentation in HeLa cells, human fibroblasts and mouse embryo fibroblasts (MEFs), and this fragmentation occurred in Drp1 knockout MEF cells, FIP200 knockout HeLa cells and BNIP3/NIX double knockout HeLa cells, but not in Opa1 knockout MEFs. Interestingly, we found an LIR motif-like sequence (LIRL), as well as an LIR motif, at the N-terminus of FKBP8 and LIRL was essential for both inducing mitochondrial fragmentation and binding of FKBP8 to OPA1. Together, we suggest that FKBP8 plays an essential role in mitochondrial fragmentation through LIRL during mitophagy and this activity of FKBP8 together with LIR is required for mitophagy under stress conditions.


Assuntos
Fibroblastos/metabolismo , Mitocôndrias/metabolismo , Dinâmica Mitocondrial , Estresse Fisiológico , Proteínas de Ligação a Tacrolimo/metabolismo , Animais , Células HEK293 , Células HeLa , Humanos , Camundongos , Camundongos Knockout , Proteínas Associadas aos Microtúbulos/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Mitocôndrias/genética , Proteínas de Ligação a Tacrolimo/genética
8.
J Surg Oncol ; 124(7): 1136-1145, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34351649

RESUMO

BACKGROUND: Because of the heterogeneity of metastatic colorectal cancer (mCRC), a genome-wide analysis was performed to characterize the tumor immune microenvironment (TIME). METHODS: RNA-seq analysis of 62 primary CRCs without and 63 with systemic metastasis (SM- and SM+ groups) was conducted, and the data were used in a training set after adjustment by propensity score matching. Samples were further subdivided into those with hepatic metastasis (CHM subgroup), pulmonary metastasis (CPM subgroup), or concurrent CHM and CPM (concurrent group). Validation was done by quantitative reverse-transcription polymerase chain reaction using another 40 primary CRC samples. RESULTS: Compared with the CHM or CPM subgroups, the concurrent group showed upregulated in inflammatory or immune processes, cytokine secretion, and myeloid leukocyte migration. Nine candidate genes were selected: SM-specific IDO1, JAM3, and PDE2A; CHM- or CPM-specific BIRC7; CPM-specific HISI1H2BK, and both SM-specific and CHM- or CPM-specific EPHB6, LPL, THBD, and PPBP. In a validation set of primary CRCs, JAM3 and IDO1 (p = 0.044 and p = 0.036, respectively) were confirmed to show significant upregulation and downregulation, respectively, in the SM+ group, whereas HIST1H2BK (p = 0.017) was significantly upregulated in the CPM subgroup. CONCLUSIONS: Our findings indicate that a host-suppressive TIME is established in the primary tumor of mCRC and identify immune-related site-specific markers of mCRC.


Assuntos
Adenocarcinoma/patologia , Neoplasias Colorretais/patologia , Neoplasias Hepáticas/secundário , Neoplasias Pulmonares/secundário , Microambiente Tumoral/genética , Estudos de Casos e Controles , Moléculas de Adesão Celular/genética , Moléculas de Adesão Celular/metabolismo , Regulação para Baixo , Feminino , Estudo de Associação Genômica Ampla , Histonas/genética , Histonas/metabolismo , Humanos , Indolamina-Pirrol 2,3,-Dioxigenase/genética , Indolamina-Pirrol 2,3,-Dioxigenase/metabolismo , Masculino , Pessoa de Meia-Idade , RNA Mensageiro/metabolismo , Regulação para Cima
9.
Int J Mol Sci ; 22(20)2021 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-34681602

RESUMO

Particulate matters (PMs) increase oxidative stress and inflammatory response in different tissues. PMs disrupt the formation of primary cilia in various skin cells, including keratinocytes and melanocytes. In this study, we found that 2-isopropylmalic acid (2-IPMA) promoted primary ciliogenesis and restored the PM2.5-induced dysgenesis of primary cilia in dermal fibroblasts. Moreover, 2-IPMA inhibited the generation of excessive reactive oxygen species and the activation of stress kinase in PM2.5-treated dermal fibroblasts. Further, 2-IPMA inhibited the production of pro-inflammatory cytokines, including IL-6 and TNF-α, which were upregulated by PM2.5. However, the inhibition of primary ciliogenesis by IFT88 depletion reversed the downregulated cytokines by 2-IPMA. Moreover, we found that PM2.5 treatment increased the MMP-1 expression in dermal fibroblasts and a human 3-D-skin model. The reduced MMP-1 expression by 2-IPMA was further reversed by IFT88 depletion in PM2.5-treated dermal fibroblasts. These findings suggest that 2-IPMA ameliorates PM2.5-induced inflammation by promoting primary ciliogenesis in dermal fibroblasts.


Assuntos
Citocinas/metabolismo , Ativação Enzimática/efeitos dos fármacos , Malatos/farmacologia , Metaloproteinase 1 da Matriz/metabolismo , Técnicas de Cultura de Células , Linhagem Celular , Cílios/metabolismo , Cílios/patologia , Fibroblastos/citologia , Fibroblastos/metabolismo , Humanos , Interleucina-6/metabolismo , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Metaloproteinase 1 da Matriz/genética , Modelos Biológicos , Estresse Oxidativo/efeitos dos fármacos , Material Particulado/toxicidade , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Proteínas Supressoras de Tumor/antagonistas & inibidores , Proteínas Supressoras de Tumor/genética , Proteínas Supressoras de Tumor/metabolismo , Regulação para Cima/efeitos dos fármacos
10.
Molecules ; 26(17)2021 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-34500843

RESUMO

Primary cilia mediate the interactions between cells and external stresses. Thus, dysregulation of primary cilia is implicated in various ciliopathies, e.g., degeneration of the retina caused by dysregulation of the photoreceptor primary cilium. Particulate matter (PM) can cause epithelium injury and endothelial dysfunction by increasing oxidative stress and inflammatory responses. Previously, we showed that PM disrupts the formation of primary cilia in retinal pigment epithelium (RPE) cells. In the present study, we identified 2-isopropylmalic acid (2-IPMA) as a novel inducer of primary ciliogenesis from a metabolite library screening. Both ciliated cells and primary cilium length were increased in 2-IPMA-treated RPE cells. Notably, 2-IPMA strongly promoted primary ciliogenesis and restored PM2.5-induced dysgenesis of primary cilia in RPE cells. Both excessive reactive oxygen species (ROS) generation and activation of a stress kinase, JNK, by PM2.5 were reduced by 2-IPMA. Moreover, 2-IPMA inhibited proinflammatory cytokine production, i.e., IL-6 and TNF-α, induced by PM2.5 in RPE cells. Taken together, our data suggest that 2-IPMA ameliorates PM2.5-induced inflammation by promoting primary ciliogenesis in RPE cells.


Assuntos
Inflamação/metabolismo , Material Particulado/metabolismo , Epitélio Pigmentado da Retina/metabolismo , Cílios/metabolismo , Cílios/ultraestrutura , Citocinas/metabolismo , Ativação Enzimática , Técnicas de Silenciamento de Genes , Humanos , MAP Quinase Quinase 4/metabolismo , Malatos/metabolismo , Estresse Oxidativo , Espécies Reativas de Oxigênio/metabolismo , Retina
11.
Anal Chem ; 92(6): 4371-4378, 2020 03 17.
Artigo em Inglês | MEDLINE | ID: mdl-32088959

RESUMO

Vicinal dithiol-containing proteins (VDPs) play an important role in maintaining the structures and functions of proteins mainly through the conversion between dithiols and disulfide bonds. The content of VDPs also reflects the redox status of an organism. To specifically and expediently detect VDPs, we developed a turn-on monoarsenical fluorescent probe (NEP) based on the intramolecular charge transfer mechanism. Naphthalimide was chosen as a fluorophore and linked with the receptor moiety (cyclic dithiarsolane) via carbamate segment. In the presence of VDPs, NEP displays a strong green fluorescence signal produced by the cyclic dithiarsolane cleavage and subsequent intramolecular cyclization to liberate the fluorophore. Furthermore, NEP exhibits high selectivity toward VDPs over other protein thiols and low molecular weight thiols. The favorable properties of NEP enable it readily to detect VDPs in live cells and in vivo. In addition, a remarkable decrease of VDPs in parkinsonism was disclosed for the first time, highlighting that regulating VDPs level has a therapeutic potential for parkinsonism.


Assuntos
Corantes Fluorescentes/química , Naftalimidas/química , Proteínas de Neoplasias/metabolismo , Transtornos Parkinsonianos/metabolismo , Compostos de Sulfidrila/metabolismo , Animais , Corantes Fluorescentes/síntese química , Células Hep G2 , Humanos , Estrutura Molecular , Naftalimidas/síntese química , Proteínas de Neoplasias/análise , Imagem Óptica , Células PC12 , Ratos , Espectrofotometria , Compostos de Sulfidrila/análise , Peixe-Zebra
12.
Biochem Biophys Res Commun ; 531(2): 209-214, 2020 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-32792197

RESUMO

Melanosomes are specialized membrane-bound organelles that are involved in melanin synthesis. Unlike melanosome biogenesis, the melanosome degradation pathway is poorly understood. Among the cellular processes, autophagy controls degradation of intracellular components by cooperating with lysosomes. In this study, we showed that ursolic acid inhibits skin pigmentation by promoting melanosomal autophagy, or melanophagy, in melanocytes. We found that B16F1 cells treated with ursolic acid suppressed alpha-melanocyte stimulating hormone (α-MSH) stimulated increase in melanin content and activated autophagy. In addition, we found that treatment with ursolic acid promotes melanosomal degradation, and bafilomycin A1 inhibition of autophagosome-lysosome fusion blocked the removal of melanosomes in α-MSH-stimulated B16F1 cells. Furthermore, depletion of the autophagy-related gene 5 (ATG5) resulted in significant suppression of ursolic acid-mediated anti-pigmentation activity and autophagy in α-MSH-treated B16F1 cells. Taken together, our results suggest that ursolic acid inhibits skin pigmentation by increasing melanosomal degradation in melanocytes.


Assuntos
Autofagia/efeitos dos fármacos , Melanoma Experimental/patologia , Melanossomas/patologia , Pigmentação da Pele/efeitos dos fármacos , Triterpenos/farmacologia , Animais , Linhagem Celular Tumoral , Melaninas/biossíntese , Melanossomas/efeitos dos fármacos , Camundongos , Triterpenos/química , alfa-MSH/farmacologia , Ácido Ursólico
13.
Biochem Biophys Res Commun ; 518(4): 746-751, 2019 10 22.
Artigo em Inglês | MEDLINE | ID: mdl-31472964

RESUMO

Autophagy is a catabolic cellular response to stress that has been liked to various human diseases. However, the precise involvement of autophagy in health and disease remains unclear. To explore the molecular mechanisms of autophagy, we investigated the effect of TMP21. We found that the down-regulation of TMP21 induced autophagy in SH-SY5Y cells. In addition, the enhanced autophagy observed upon TMP21 depletion was almost completely blocked in ATG5 knockout (KO) or ATG7-KO HeLa cells. Silencing of TMP21 in SH-SY5Y cells also increased the production of cellular reactive oxygen species (ROS). Accordingly, treatment with the ROS scavenger NAC suppressed autophagy activation as well as ROS production in TMP21-depleted cells. In addition, the inhibition of mTOR by treatment with Torin1 was mitigated in TMP21 overexpressing cells compared with that in control cells. Taken together, these results indicated that TMP21 could regulate autophagy by modulating ROS production and mTOR activation.


Assuntos
Autofagia/genética , Proteínas de Membrana/genética , Espécies Reativas de Oxigênio/metabolismo , Serina-Treonina Quinases TOR/genética , Acetilcisteína/farmacologia , Proteína 5 Relacionada à Autofagia/genética , Proteína 5 Relacionada à Autofagia/metabolismo , Proteína 7 Relacionada à Autofagia/genética , Proteína 7 Relacionada à Autofagia/metabolismo , Linhagem Celular Tumoral , Ativação Enzimática/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Técnicas de Inativação de Genes , Células HeLa , Humanos , Proteínas de Membrana/metabolismo , Naftiridinas/farmacologia , Proteínas de Transporte Nucleocitoplasmático , Interferência de RNA , Espécies Reativas de Oxigênio/antagonistas & inibidores , Serina-Treonina Quinases TOR/antagonistas & inibidores , Serina-Treonina Quinases TOR/metabolismo
14.
Biochem Biophys Res Commun ; 516(3): 713-718, 2019 08 27.
Artigo em Inglês | MEDLINE | ID: mdl-31253394

RESUMO

Mitochondria are essential for providing the energy necessary for neuronal function. Dysregulation of mitochondrial dynamics has been linked with the pathogenesis of many neurodegenerative diseases. Dynamin related protein 1 (Drp1) participates in fission activity in the mitochondria, and post-translational modifications to Drp1 modulate complex mitochondrial dynamics. However, the regulation of Drp1 at the post-transcriptional level remains poorly understood. In this study, we found that the RNA-binding protein Hu antigen R (HuR) post-transcriptionally regulates Drp1 expression. HuR interacts with Drp1 mRNA at its 3' untranslated region. Depletion of HuR reduces Drp1 expression, which leads to mitochondrial elongation in SH-SY5Y neuroblastoma cells. In contrast, ectopic expression of HuR enhances Drp1 expression, which promotes mitochondrial fragmentation in response to treatment with the mitochondrial complex 1 inhibitor MPP+. In addition, depletion of HuR suppressed the generation of mitochondrial ROS and cytotoxicity in MPP+ treated cells. Taken together, these findings suggest that HuR controls mitochondrial morphology via regulation of Drp1.


Assuntos
Dinaminas/genética , Proteína Semelhante a ELAV 1/genética , Regulação Neoplásica da Expressão Gênica , Mitocôndrias/genética , Dinâmica Mitocondrial/genética , Proteínas de Ligação a RNA/genética , 1-Metil-4-fenilpiridínio/farmacologia , Regiões 3' não Traduzidas/genética , Linhagem Celular Tumoral , Dinaminas/metabolismo , Proteína Semelhante a ELAV 1/metabolismo , Herbicidas/farmacologia , Humanos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Dinâmica Mitocondrial/efeitos dos fármacos , Ligação Proteica , Interferência de RNA , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Proteínas de Ligação a RNA/metabolismo
15.
J Neurosci ; 37(20): 5099-5110, 2017 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-28432138

RESUMO

Excessive mitochondrial fission is a prominent early event and contributes to mitochondrial dysfunction, synaptic failure, and neuronal cell death in the progression of Alzheimer's disease (AD). However, it remains to be determined whether inhibition of excessive mitochondrial fission is beneficial in mammal models of AD. To determine whether dynamin-related protein 1 (Drp1), a key regulator of mitochondrial fragmentation, can be a disease-modifying therapeutic target for AD, we examined the effects of Drp1 inhibitor on mitochondrial and synaptic dysfunctions induced by oligomeric amyloid-ß (Aß) in neurons and neuropathology and cognitive functions in Aß precursor protein/presenilin 1 double-transgenic AD mice. Inhibition of Drp1 alleviates mitochondrial fragmentation, loss of mitochondrial membrane potential, reactive oxygen species production, ATP reduction, and synaptic depression in Aß-treated neurons. Furthermore, Drp1 inhibition significantly improves learning and memory and prevents mitochondrial fragmentation, lipid peroxidation, BACE1 expression, and Aß deposition in the brain in the AD model. These results provide evidence that Drp1 plays an important role in Aß-mediated and AD-related neuropathology and in cognitive decline in an AD animal model. Therefore, inhibiting excessive Drp1-mediated mitochondrial fission may be an efficient therapeutic avenue for AD.SIGNIFICANCE STATEMENT Mitochondrial fission relies on the evolutionary conserved dynamin-related protein 1 (Drp1). Drp1 activity and mitochondria fragmentation are significantly elevated in the brains of sporadic Alzheimer's disease (AD) cases. In the present study, we first demonstrated that the inhibition of Drp1 restored amyloid-ß (Aß)-mediated mitochondrial dysfunctions and synaptic depression in neurons and significantly reduced lipid peroxidation, BACE1 expression, and Aß deposition in the brain of AD mice. As a result, memory deficits in AD mice were rescued by Drp1 inhibition. These results suggest that neuropathology and combined cognitive decline can be attributed to hyperactivation of Drp1 in the pathogenesis of AD. Therefore, inhibitors of excessive mitochondrial fission, such as Drp1 inhibitors, may be a new strategy for AD.


Assuntos
Doença de Alzheimer/fisiopatologia , Peptídeos beta-Amiloides/metabolismo , Transtornos Cognitivos/fisiopatologia , Dinaminas/metabolismo , Depressão Sináptica de Longo Prazo , Mitocôndrias/metabolismo , Neurônios/metabolismo , Doença de Alzheimer/complicações , Animais , Encéfalo/fisiopatologia , Transtornos Cognitivos/complicações , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Inibição Neural
16.
J Cell Sci ; 129(16): 3059-66, 2016 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-27528206

RESUMO

Macroautophagy, hereafter referred to as autophagy, is a catabolic process that results in the lysosomal degradation of cytoplasmic contents ranging from abnormal proteins to damaged cell organelles. It is activated  under diverse conditions, including nutrient deprivation and hypoxia. During autophagy, members of the core autophagy-related (ATG) family of proteins mediate membrane rearrangements, which lead to the engulfment and degradation of cytoplasmic cargo. Recently, the nuclear regulation of autophagy, especially by transcription factors and histone modifiers, has gained increased attention. These factors are not only involved in rapid responses to autophagic stimuli, but also regulate the long-term outcome of autophagy. Now there are more than 20 transcription factors that have been shown to be linked to the autophagic process. However, their interplay and timing appear enigmatic as several have been individually shown to act as major regulators of autophagy. This Cell Science at a Glance article and the accompanying poster highlights the main cellular regulators of transcription involved in mammalian autophagy and their target genes.


Assuntos
Autofagia/genética , Regulação da Expressão Gênica , Mamíferos/genética , Transcrição Gênica , Animais , Hipóxia Celular/genética , Humanos , Transdução de Sinais/genética , Fatores de Transcrição/metabolismo
17.
Biochem Biophys Res Commun ; 501(3): 696-702, 2018 06 27.
Artigo em Inglês | MEDLINE | ID: mdl-29753736

RESUMO

Peroxisomes are dynamic and multifunctional organelles involved in various cellular metabolic processes, and their numbers are tightly regulated by pexophagy, a selective degradation of peroxisomes through autophagy to maintain peroxisome homeostasis in cells. Catalase, a major peroxisome protein, plays a critical role in removing peroxisome-generated reactive oxygen species (ROS) produced by peroxisome enzymes, but the contribution of catalase to pexophagy has not been reported. Here, we investigated the role of catalase in peroxisome degradation during nutrient deprivation. Both short interfering RNA-mediated silencing of catalase and pharmacological inhibition by 3-aminotriazole (3AT) decreased the number of peroxisomes and resulted in the downregulation of peroxisomal proteins, such as PMP70 and PEX14 under serum starvation. In addition, treatment with 3AT induced NBR1-dependent autophagy and PEX5 ubiquitination in the absence of serum, which was accompanied by accumulation of ROS. Co-treatment with antioxidant agent N-acetyl-l-cysteine (NAC) prevented ROS accumulation and pexophagy by modulating peroxisome protein levels and the association of NBR1, a pexophagy receptor with peroxisomes. Taken together, these findings demonstrate that catalase plays an important role in pexophagy during nutrient deprivation.


Assuntos
Catalase/metabolismo , Peroxissomos/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Soro/metabolismo , Autofagia , Catalase/antagonistas & inibidores , Linhagem Celular , Células Hep G2 , Humanos , Ubiquitinação
18.
Biochem Biophys Res Commun ; 503(1): 309-315, 2018 09 03.
Artigo em Inglês | MEDLINE | ID: mdl-29890139

RESUMO

Skin pigmentation involves multiple processes, including melanin synthesis, transport, and melanosome release. Melanin content determines skin color and protects against UV radiation-induced damage. Autophagy is a cooperative process between autophagosomes and lysosomes that degrades cellular components and organelles. In the present study, B16F1 cells were treated with Rhizoma Arisaematis extract (RA) and assessed for pigmentation and autophagy regulation. RA treatment suppressed the α-MSH-stimulated increase of melanogenesis and down-regulated the expression of tyrosinase and TRP1 proteins in B16F1 cells. In addition, autophagy was activated in RA-treated cells. Inhibition of autophagy reduced the anti-melanogenic activity of RA in α-MSH-treated B16F1 cells. We identified schaftoside as an effector molecule by LC-MS analysis of RA. Consistently, treatment of schaftoside showed anti-melanogenic effect and induced autophagy activation in B16F1 cells. Inhibition of autophagy by 3 MA treatment reduced the anti-melanogenic effect of the schaftoside and recovered expression level of melanogenesis regulators in α-MSH-treated B16F1 cells. Taken together, our results suggest that schaftoside from RA inhibits skin pigmentation through modulation of autophagy.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Autofagia/efeitos dos fármacos , Glicosídeos/farmacologia , Melaninas/metabolismo , Melanoma/tratamento farmacológico , Animais , Arisaema/química , Linhagem Celular Tumoral , Feminino , Humanos , Melanoma/metabolismo , Camundongos , Pessoa de Meia-Idade , alfa-MSH/metabolismo
19.
Biol Proced Online ; 20: 18, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30275774

RESUMO

Several methods for the quantification of human anti-HBs, an antibody to hepatitis B surface antigen (HBsAg), have been developed based on enzyme reaction, chemiluminescence, fluorescence, and radioactivity for application to human serum or plasma. Commercial anti-HBs immunoassay kits use a sandwich method in which a bridge is formed by the anti-HBs between a HBsAg immobilized solid matrix and the labeled HBsAg. However, this direct sandwich enzyme-linked immunosorbent assay (ELISA) is insufficient to accurately evaluate the activity of the human monoclonal anti-HBs, GC1102. As an alternative, we developed an indirect anti-HBs ELISA (anti-HBs qELISA_v.1) that improved detection of anti-HBs. In this current study, we further optimized this indirect method to minimize nonspecific binding of human serum, by employing incubation buffers containing animal serum, Tween 20, skim milk, and a low pH washing buffer. This new and improved method, termed anti-HBs qELISA_v.2, showed accurate quantification of plasma-derived hepatitis B immune globulin (HBIG) and was comparable to results obtained with commercial ELISA (r = 0.93) and RIA (r = 0.85) kits. Further, the GC1102 in human serum could be precisely measured using the anti-HBs qELISA_v.2 without limitations of nonspecific binding.

20.
Biochem Biophys Res Commun ; 489(2): 193-199, 2017 07 22.
Artigo em Inglês | MEDLINE | ID: mdl-28552528

RESUMO

Peroxiredoxins (Prxs) are highly conserved antioxidant enzymes and are implicated in multiple biological processes; however, their function in oocyte meiosis has not been studied. Here we show that inhibition of Prx I and II results in spindle defects, chromosome disorganization, and impaired polarization in mouse oocytes. Prx I was specifically localized at the spindle, whereas Prx II was enriched at the oocyte cortex and chromosomes. Inhibition of Prx activity with conoidin A disturbed assembly of the microtubule organizing center (MTOC) through Aurora A regulation, leading to defects in spindle formation. Moreover, conoidin A impaired actin filament and cortical granule (CG) distribution, disrupting actin cap and CG formation, respectively. Conoidin A also increased DNA damage without significantly increasing reactive oxygen species (ROS) levels, suggesting that the effects of conoidin A on meiotic maturation are not likely associated with ROS scavenging pathways. Therefore, our data suggest that Prxs are required for spindle assembly, chromosome organization, and polarization during meiotic maturation.


Assuntos
Polaridade Celular/efeitos dos fármacos , Cromossomos de Mamíferos/efeitos dos fármacos , Oócitos/efeitos dos fármacos , Peroxirredoxinas/farmacologia , Fuso Acromático/efeitos dos fármacos , Animais , Células Cultivadas , Cromossomos de Mamíferos/metabolismo , Relação Dose-Resposta a Droga , Feminino , Meiose/efeitos dos fármacos , Camundongos , Oócitos/metabolismo , Peroxirredoxinas/genética , Quinoxalinas/farmacologia , Fuso Acromático/metabolismo , Relação Estrutura-Atividade
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