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1.
EMBO Rep ; 21(5): e48901, 2020 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-32157776

RESUMO

Recent evidence has linked the lysosomal cholesterol accumulation in Niemann-Pick type C1 with anomalies associated with primary ciliogenesis. Here, we report that perturbed intracellular cholesterol distribution imposed by lysosomal cholesterol accumulation during TMEM135 depletion is closely associated with impaired ciliogenesis. TMEM135 depletion does not affect the formation of the basal body and the ciliary transition zone. TMEM135 depletion severely blunts Rab8 trafficking to the centrioles without affecting the centriolar localization of Rab11 and Rabin8, the upstream regulators of Rab8 activation. Although TMEM135 depletion prevents enhanced IFT20 localization at the centrioles, ciliary vesicle formation is not affected. Furthermore, enhanced IFT20 localization at the centrioles is dependent on Rab8 activation. Supplementation of cholesterol in complex with cyclodextrin rescues Rab8 trafficking to the centrioles and Rab8 activation, thereby recovering primary ciliogenesis in TMEM135-depleted cells. Taken together, our data suggest that TMEM135 depletion prevents ciliary vesicle elongation, a characteristic of impaired Rab8 function. Our study thus reveals a previously uncharacterized effect of erroneous intracellular cholesterol distribution on impairing Rab8 function and primary ciliogenesis.

2.
Artigo em Inglês | MEDLINE | ID: mdl-32075719

RESUMO

Peroxisomes are metabolically active oxygen demanding organelles with a high abundance of oxidases making it vulnerable to low oxygen levels such as hypoxic conditions. However, the exact mechanism of peroxisome degradation in hypoxic condition remains elusive. In order to study the mechanism of peroxisome degradation in hypoxic condition, we use Dimethyloxaloylglycine (DMOG), a cell-permeable prolyl-4-hydroxylase inhibitor, which mimics hypoxic condition by stabilizing hypoxia-inducible factors. Here we report that DMOG degraded peroxisomes by selectively activating pexophagy in a HIF-2α dependent manner involving autophagy receptor p62. Furthermore, DMOG not only increased peroxisome turnover by pexophagy but also reduced HIF-2α dependent peroxisome proliferation at the transcriptional level. Taken together, our data suggest that hypoxic condition is a negative regulator for peroxisome abundance through increasing pexophagy and decreasing peroxisome proliferation in HIF-2α dependent manner.

3.
J Cell Physiol ; 235(1): 151-165, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31187491

RESUMO

Slc25a17 is known as a peroxisomal solute carrier, but the in vivo role of the protein has not been demonstrated. We found that the zebrafish genome contains two slc25a17 genes that function redundantly, but additively. Notably, peroxisome function in slc25a17 knockdown embryos is severely compromised, resulting in an altered lipid composition. Along the defects found in peroxisome-associated phenotypic presentations, we highlighted that development of the swim bladder is also highly dependent on Slc25a17 function. As Slc25a17 showed substrate specificity towards coenzyme A (CoA), injecting CoA, but not NAD+ , rescued the defective swim bladder induced by slc25a17 knockdown. These results indicated that Slc25a17 acts as a CoA transporter, involved in the maintenance of functional peroxisomes that are essential for the development of multiple organs during zebrafish embryogenesis. Given high homology in protein sequences, the role of zebrafish Slc25a17 may also be applicable to the mammalian system.

5.
Aging Cell ; 18(5): e13016, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31353811

RESUMO

Age-related hearing loss (ARHL) is a major neurodegenerative disorder and the leading cause of communication deficit in the elderly population, which remains largely untreated. The development of ARHL is a multifactorial event that includes both intrinsic and extrinsic factors. Recent studies suggest that NAD+ /NADH ratio may play a critical role in cellular senescence by regulating sirtuins, PARP-1, and PGC-1α. Nonetheless, the beneficial effect of direct modulation of cellular NAD+ levels on aging and age-related diseases has not been studied, and the underlying mechanisms remain obscure. Herein, we investigated the effect of ß-lapachone (ß-lap), a known plant-derived metabolite that modulates cellular NAD+ by conversion of NADH to NAD+ via the enzymatic action of NADH: quinone oxidoreductase 1 (NQO1) on ARHL in C57BL/6 mice. We elucidated that the reduction of cellular NAD+ during the aging process was an important contributor for ARHL; it facilitated oxidative stress and pro-inflammatory responses in the cochlear tissue through regulating sirtuins that alter various signaling pathways, such as NF-κB, p53, and IDH2. However, augmentation of NAD+ by ß-lap effectively prevented ARHL and accompanying deleterious effects through reducing inflammation and oxidative stress, sustaining mitochondrial function, and promoting mitochondrial biogenesis in rodents. These results suggest that direct regulation of cellular NAD+ levels by pharmacological agents may be a tangible therapeutic option for treating various age-related diseases, including ARHL.

6.
Ann Otol Rhinol Laryngol ; 128(6_suppl): 117S-124S, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31092035

RESUMO

OBJECTIVES: Auditory neuropathy due to toxicity mechanism of pyridoxine has not yet been fully documented. Therefore, the present study explored a direct mechanism underlying the effects of pyridoxine on auditory neuropathy in organ of Corti (OC) explants ex vivo and cochlear neuroblast cell line, VOT-33 in vitro. METHODS: Primary OC explants containing spiral ganglion neurons and cultured VOT-33 cells were treated with pyridoxine. RESULTS: In nerve fiber of primary OC explants, pyridoxine decreased staining for NF200, a neuro-cytoskeletal protein. We also found that pyridoxine-induced VOT-33 apoptosis, as indicated by accumulation of the sub-G0/G1 fraction, caspase-3 activation, and PARP cleavage. In addition, pyridoxine induced reactive oxygen species (ROS) generation and alteration of mitochondrial membrane potential transition (MPT), including Bcl-2 family protein expression and consequently Ca2+ accumulation and changes of endoplasmic reticulum (ER) stress-related protein expression such as phospho-PERK, caspase-12, Grp78, and CHOP. CONCLUSION: Pyridoxine preferentially induced severe cell death on nerve fiber in primary OC explants and markedly increased apoptotic cell death via mitochondria-mediated ER stress in VOT-33 cells.


Assuntos
Estresse do Retículo Endoplasmático/efeitos dos fármacos , Perda Auditiva Central/etiologia , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Órgão Espiral/efeitos dos fármacos , Piridoxina/farmacologia , Complexo Vitamínico B/farmacologia , Animais , Apoptose/efeitos dos fármacos , Técnicas de Cultura de Células , Linhagem Celular , Camundongos , Órgão Espiral/patologia , Ratos , Ratos Sprague-Dawley
7.
Cell Death Dis ; 10(1): 5, 2018 12 18.
Artigo em Inglês | MEDLINE | ID: mdl-30584237

RESUMO

Reactive oxygen species (ROS) regulates the activation of inflammatory cascades and tissue damage in acute pancreatitis. NADPH oxidase (NOX) is upregulated in pancreatitis and is one of the major enzymes involved in ROS production using NADPH as a general rate-limiting substrate. Dunnione, a well-known substrate of NAD(P)H:quinone oxidoreductase 1 (NQO1), reduces the ratio of cellular NADPH/NADP+ through the enzymatic action of NQO1. This study assessed whether a reduction in cellular NADPH/NADP+ ratio can be used to regulate caerulein-induced pancreatic damage associated with NOX-induced ROS production in animal models. Dunnione treatment significantly reduced the cellular NADPH/NADP+ ratio and NOX activity through the enzymatic action of NQO1 in the pancreas of the caerulein-injection group. Similar to these results, total ROS production and expressions of mRNA and protein for NOX subunits Nox1, p27phox, p47phox, and p67phox also decreased in the dunnione-treated group. In addition, caerulein-induced pancreatic inflammation and acinar cell injury were significantly reduced by dunnione treatment. This study is the first to demonstrate that modulation of the cellular NADPH:NADP+ ratio by enzymatic action of NQO1 protects acute pancreatitis through the regulation of NOX activity. Furthermore, these results suggest that modulation of the NADPH:NADP+ ratio in cells by NQO1 may be a novel therapeutic strategy for acute pancreatitis.


Assuntos
NAD(P)H Desidrogenase (Quinona)/metabolismo , NADP/metabolismo , Pancreatite/enzimologia , Espécies Reativas de Oxigênio/metabolismo , Animais , Ceruletídeo/toxicidade , Masculino , Camundongos , Camundongos Knockout , NAD(P)H Desidrogenase (Quinona)/genética , NADP/genética , Naftoquinonas/farmacologia , Pancreatite/induzido quimicamente , Pancreatite/tratamento farmacológico , Pancreatite/genética
8.
J Mol Cell Cardiol ; 124: 45-57, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30291911

RESUMO

BACKGROUND: Adriamycin (ADR) is a powerful chemotherapeutic agent extensively used to treat various human neoplasms. However, its clinical utility is hampered due to severe adverse side effects i.e. cardiotoxicity and heart failure. ADR-induced cardiomyopathy (AIC) has been reported to be caused by myocardial damage and dysfunction through oxidative stress, DNA damage, and inflammatory responses. Nonetheless, the remedies for AIC are even not established. Therefore, we illustrate the role of NAD+/NADH modulation by NAD(P)H quinone oxidoreductase 1 (NQO1) enzymatic action on AIC. METHODS AND RESULTS: AIC was established by intraperitoneal injection of ADR in C57BL/6 wild-type (WT) and NQO1 knockout (NQO1-/-) mice. All Mice were orally administered dunnione (named NQO1 substrate) before and after exposure to ADR. Cardiac biomarker levels in the plasma, cardiac dysfunction, oxidative biomarkers, and mRNA and protein levels of pro-inflammatory mediators were determined compared the cardiac toxicity of each experimental group. All biomarkers of Cardiac damage and oxidative stress, and mRNA levels of pro-inflammatory cytokines including cardiac dysfunction were increased in ADR-treated both WT and NQO1-/- mice. However, this increase was significantly reduced by dunnione in WT, but not in NQO1-/- mice. In addition, a decrease in SIRT1 activity due to a reduction in the NAD+/NADH ratio by PARP-1 hyperactivation was associated with AIC through increased nuclear factor (NF)-κB p65 and p53 acetylation in both WT and NQO1-/- mice. While an elevation in NAD+/NADH ratio via NQO1 enzymatic action using dunnione recovered SIRT1 activity and subsequently deacetylated NF-κB p65 and p53, however not in NQO1-/- mice, thereby attenuating AIC. CONCLUSION: Thus, modulation of NAD+/NADH by NQO1 may be a novel therapeutic approach to prevent chemotherapy-associated heart failure, including AIC.


Assuntos
Antibióticos Antineoplásicos/efeitos adversos , Doxorrubicina/efeitos adversos , Cardiopatias/etiologia , Cardiopatias/metabolismo , NADH NADPH Oxirredutases/metabolismo , NAD/metabolismo , Animais , Biópsia , Cardiotônicos/farmacologia , Citocinas/metabolismo , Modelos Animais de Doenças , Ecocardiografia , Expressão Gênica , Cardiopatias/diagnóstico , Cardiopatias/fisiopatologia , Mediadores da Inflamação/metabolismo , Camundongos , Camundongos Knockout , NADH NADPH Oxirredutases/genética , Naftoquinonas/farmacologia , Oxirredução/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Sirtuína 1/metabolismo
9.
Toxicol Appl Pharmacol ; 353: 43-54, 2018 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-29908243

RESUMO

Cisplatin is an alkylating agent that interferes with DNA replication and kills proliferating carcinogenic cells. Several studies have been conducted to attenuate the side effects of cisplatin; one such side effect in cancer patients undergoing cisplatin chemotherapy is ototoxicity. However, owing to a lack of understanding of the precise mechanism underlying cisplatin-induced side effects, management of cisplatin-induced ototoxicity remains unsolved. We investigated the protective effects of fenofibrate, a PPAR-α activator, on cisplatin-induced ototoxicity. Fenofibrate prevented cisplatin-induced loss of hair cells and improved cell viability; moreover, fenofibrate significantly attenuated the threshold of auditory brainstem responses (ABR) in cisplatin-injected mice. Fenofibrate significantly increased PPAR-α, PPAR-γ, and PGC-1α expression, which consequently resulted in increased number and functional enzyme levels of peroxisomes and mitochondria, and markedly decreased phospho-p53 (S15), activated caspase-3, cleaved-PARP, and NF-κB p65 nuclear translocation, which reduced NADPH oxidase isoform (NOX3 and NOX4) expression, thereby decreasing reactive oxygen species (ROS) production in cisplatin-treated tissues ex vivo. Taken together, these results indicate that fenofibrate rescues cisplatin-induced ototoxicity by maintaining peroxisome and mitochondria number and function, reducing inflammation, and decreasing ROS levels. Our findings suggest that fenofibrate administration might serve as an effective therapeutic agent against cisplatin-induced ototoxicity.


Assuntos
Antineoplásicos/toxicidade , Cisplatino/antagonistas & inibidores , Cisplatino/toxicidade , Otopatias/induzido quimicamente , Otopatias/prevenção & controle , Fenofibrato/uso terapêutico , Hipolipemiantes/uso terapêutico , Animais , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Cóclea/patologia , Otopatias/patologia , Potenciais Evocados Auditivos do Tronco Encefálico/efeitos dos fármacos , Células Ciliadas Auditivas/patologia , Imuno-Histoquímica , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Mitocôndrias/efeitos dos fármacos , Peroxissomos/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo
10.
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
11.
Autophagy ; 14(6): 1011-1027, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29771182

RESUMO

The primary cilia are evolutionarily conserved microtubule-based cellular organelles that perceive metabolic status and thus link the sensory system to cellular signaling pathways. Therefore, ciliogenesis is thought to be tightly linked to autophagy, which is also regulated by nutrient-sensing transcription factors, such as PPARA (peroxisome proliferator activated receptor alpha) and NR1H4/FXR (nuclear receptor subfamily 1, group H, member 4). However, the relationship between these factors and ciliogenesis has not been clearly demonstrated. Here, we present direct evidence for the involvement of macroautophagic/autophagic regulators in controlling ciliogenesis. We showed that activation of PPARA facilitated ciliogenesis independently of cellular nutritional states. Importantly, PPARA-induced ciliogenesis was mediated by controlling autophagy, since either pharmacological or genetic inactivation of autophagy significantly repressed ciliogenesis. Moreover, we showed that pharmacological activator of autophagy, rapamycin, recovered repressed ciliogenesis in ppara-/- cells. Conversely, activation of NR1H4 repressed cilia formation, while knockdown of NR1H4 enhanced ciliogenesis by inducing autophagy. The reciprocal activities of PPARA and NR1H4 in regulating ciliogenesis were highlighted in a condition where de-repressed ciliogenesis by NR1H4 knockdown was further enhanced by PPARA activation. The in vivo roles of PPARA and NR1H4 in regulating ciliogenesis were examined in greater detail in ppara-/- mice. In response to starvation, ciliogenesis was facilitated in wild-type mice via enhanced autophagy in kidney, while ppara-/- mice displayed impaired autophagy and kidney damage resembling ciliopathy. Furthermore, an NR1H4 agonist exacerbated kidney damage associated with starvation in ppara-/- mice. These findings indicate a previously unknown role for PPARA and NR1H4 in regulating the autophagy-ciliogenesis axis in vivo.


Assuntos
Autofagia/genética , Cílios/metabolismo , Organogênese , PPAR alfa/metabolismo , Receptores Citoplasmáticos e Nucleares/metabolismo , Animais , Linhagem Celular , Fibroblastos/metabolismo , Regulação da Expressão Gênica , Humanos , Rim/patologia , Ligantes , Camundongos , Organogênese/efeitos dos fármacos , PPAR alfa/deficiência
12.
Exp Mol Med ; 50(4): 4, 2018 04 06.
Artigo em Inglês | MEDLINE | ID: mdl-29622767

RESUMO

Defects in the PEX5 gene impair the import of peroxisomal matrix proteins, leading to nonfunctional peroxisomes and other associated pathological defects such as Zellweger syndrome. Although PEX5 regulates autophagy process in a stress condition, the mechanisms controlling autophagy by PEX5 under nutrient deprivation are largely unknown. Herein, we show a novel function of PEX5 in the regulation of autophagy via Transcription Factor EB (TFEB). Under serum-starved conditions, when PEX5 is depleted, the mammalian target of rapamycin (mTORC1) inhibitor TSC2 is downregulated, which results in increased phosphorylation of the mTORC1 substrates, including 70S6K, S6K, and 4E-BP-1. mTORC1 activation further suppresses the nuclear localization of TFEB, as indicated by decreased mRNA levels of TFEB, LIPA, and LAMP1. Interestingly, peroxisomal mRNA and protein levels are also reduced by TFEB inactivation, indicating that TFEB might control peroxisome biogenesis at a transcriptional level. Conversely, pharmacological inhibition of mTOR resulting from PEX5 depletion during nutrient starvation activates TFEB by promoting nuclear localization of the protein. In addition, mTORC1 inhibition recovers the damaged-peroxisome biogenesis. These data suggest that PEX5 may be a critical regulator of lysosomal gene expression and autophagy through the mTOR-TFEB-autophagy axis under nutrient deprivation.


Assuntos
Autofagia , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/metabolismo , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Receptor 1 de Sinal de Orientação para Peroxissomos/metabolismo , Autofagia/genética , Linhagem Celular Tumoral , Metabolismo Energético , Regulação da Expressão Gênica , Humanos , Lisossomos/metabolismo , Receptor 1 de Sinal de Orientação para Peroxissomos/genética , Peroxissomos/metabolismo , Transporte Proteico
13.
Biochem Biophys Res Commun ; 500(2): 242-248, 2018 06 02.
Artigo em Inglês | MEDLINE | ID: mdl-29649478

RESUMO

Primary cilium is a microtubule structure that emanates from the surface of most human cells. Primary cilia assemble during the resting stage (G0 phase) and disassemble with cell cycle progression. Defects associated with the control of the assembly or disassembly of the primary cilium have been implicated in various human diseases, including ciliopathy and cancer. Although studies have suggested the interplay between activation of autophagy and ciliogenesis, any direct mechanism between autophagy abatement and disassembly of primary cilium remains elusive. In this study, we found that the gradual abatement in autophagy during serum-restimulation was a dynamic process and significantly correlated with the disassembly of primary cilium in human retinal pigmented epithelial (RPE1) cells. Although autophagy activity was gradually decreased during serum-restimulation, the alteration in autophagy under the same condition prevented the disassembly of the primary cilium. Autophagy inhibitors such as chloroquine, U18666A and 3-methyladenine (3-MA) retained both the number of ciliated cells and cilium length. In contrast, rapamycin treatment during serum-restimulation maintained the number of ciliated cells with shortened cilia. Taken together, alteration in autophagy during serum-restimulation prevent the disassembly of the primary cilium, and autophagy modulators may serve as useful compounds for studying mechanistic details related to the disassembly of the primary cilium and ciliopathy.


Assuntos
Autofagia , Cílios/metabolismo , Epitélio Pigmentado da Retina/citologia , Autofagia/efeitos dos fármacos , Linhagem Celular , Cílios/efeitos dos fármacos , Humanos , Soro/metabolismo , Sirolimo/farmacologia
14.
Front Pharmacol ; 8: 654, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29033835

RESUMO

Brown adipocytes dissipate energy as heat and hence have an important therapeutic capacity for obesity. Development of brown-like adipocytes (also called beige) is also another attractive target for obesity treatment. Here, we investigated the effect of farnesol, an isoprenoid, on adipogenesis in adipocytes and on the browning of white adipose tissue (WAT) as well as on the weight gain of high-fat diet (HFD)-induced obese mice. Farnesol inhibited adipogenesis and the related key regulators including peroxisome proliferator-activated receptor γ (PPARγ) and CCAAT/enhancer binding protein α through the up-regulation of AMP-activated protein kinase in 3T3-L1 murine adipocytes and human adipose tissue-derived mesenchymal stem cells (hAMSCs). Farnesol markedly increased the expression of uncoupling protein 1 and PPARγ coactivator 1 α in differentiated hAMSCs. In addition, farnesol limited the weight gain in HFD obese mice and induced the development of beige adipocytes in both inguinal and epididymal WAT. These results suggest that farnesol could be a potential therapeutic agent for obesity treatment.

15.
Front Cell Neurosci ; 11: 314, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29056901

RESUMO

Inflammatory reaction plays a crucial role in the pathophysiology of acquired hearing loss such as ototoxicity and labyrinthitis. In our earlier work, we showed the pivotal role of otic fibrocytes in cochlear inflammation and the critical involvement of proinflammatory cytokines in cisplatin ototoxicity. We also demonstrated that otic fibrocytes inhibit monocyte chemoattractant protein 1 (CCL2) upregulation in response to interleukin-10 (IL-10) via heme oxygenase 1 (HMOX1) signaling, resulting in suppression of cochlear inflammation. However, it is still unclear how IL-10 affects inflammation-mediated cochlear injury. Here we aim to determine how hypochlorous acid, a model inflammation mediator affects cochlear cell viability and how IL-10 affects hypochlorous acid-mediated cochlear cell injury. NaOCl, a sodium salt of hypochlorous acid (HOCl) was found to induce cytotoxicity of HEI-OC1 cells in a dose-dependent manner. Combination of hydrogen peroxide and myeloperoxidase augmented cisplatin cytotoxicity, and this synergism was inhibited by N-Acetyl-L-cysteine and ML-171. The rat spiral ligament cell line (RSL) appeared to upregulate the antioxidant response element (ARE) activities upon exposure to IL-10. RSL cells upregulated the expression of NRF2 (an ARE ligand) and NR0B2 in response to CoPP (a HMOX1 inducer), but not to ZnPP (a HMOX1 inhibitor). Adenovirus-mediated overexpression of NR0B2 was found to suppress CCL2 upregulation. IL-10-positive cells appeared in the mouse stria vascularis 1 day after intraperitoneal injection of lipopolysaccharide (LPS). Five days after injection, IL-10-positive cells were observed in the spiral ligament, spiral limbus, spiral ganglia, and suprastrial area, but not in the stria vascularis. IL-10R1 appeared to be expressed in the mouse organ of Corti as well as HEI-OC1 cells. HEI-OC1 cells upregulated Bcl-xL expression in response to IL-10, and IL-10 was shown to attenuate NaOCl-induced cytotoxicity. In addition, HEI-OC1 cells upregulated IL-22RA upon exposure to cisplatin, and NaOCl cytotoxicity was inhibited by IL-22. Taken together, our findings suggest that hypochlorous acid is involved in cochlear injury and that IL-10 potentially reduces cochlear injury through not only inhibition of inflammation but also enhancement of cochlear cell viability. Further studies are needed to determine immunological characteristics of intracochlear IL-10-positive cells and elucidate molecular mechanisms involved in the otoprotective activity of IL-10.

16.
Metabolism ; 73: 85-99, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-28732574

RESUMO

OBJECTIVE: Brown adipose tissue (BAT) activation has been identified as a possible target to treat obesity and to protect against metabolic diseases by increasing energy consumption. We explored whether albiflorin (AF), a natural compound, could contribute to lowering the high risk of obesity with BAT and primary brown preadipocytes in vivo and in vitro. MATERIALS/METHODS: Human adipose tissue-derived mesenchymal stem cells (hAMSCs) were cultured with adipogenic differentiation media with or without AF. Male C57BL/6J mice (n=5 per group) were fed a high-fat diet (HFD) for six weeks with or without AF. Brown preadipocytes from the interscapular BAT of mice were cultured with or without AF. RESULTS: In white adipogenic differentiation of hAMSCs, AF treatment significantly reduced the formation of lipid droplets and the expression of adipogenesis-related genes. In HFD-induced obese C57BL/6J mice, AF treatment significantly reduced body weight gain as well as the weights of the white adipose tissue, liver and spleen. Furthermore, AF induced the expression of genes involved in thermogenic function in BAT. In primary brown adipocytes, AF effectively stimulated the expressions of thermogenic genes and markedly up-regulated the AMP-activated protein kinase (AMPK) signaling pathway. Pretreatment with phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002 nullified the induction of the thermogenic genes by AF in primary brown adipocytes. Moreover, AF activated beige cell marker genes induced by the pharmacological activation of peroxisome proliferator-activated receptor γ in hAMSCs. CONCLUSION: This study shows that AF prevents the development of obesity in hAMSCs and mice fed an HFD and that it is also capable of stimulating the differentiation of brown adipocytes through the modulation of thermogenic genes by AMPK and PI3K/AKT.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Hidrocarbonetos Aromáticos com Pontes/farmacologia , Células-Tronco Mesenquimais/citologia , Obesidade/tratamento farmacológico , Proteína Oncogênica v-akt/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Termogênese/genética , Adipócitos Marrons/efeitos dos fármacos , Tecido Adiposo/citologia , Tecido Adiposo Branco/efeitos dos fármacos , Animais , Hidrocarbonetos Aromáticos com Pontes/uso terapêutico , Diferenciação Celular , Células Cultivadas , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Ativação Transcricional
17.
Sci Rep ; 7(1): 3006, 2017 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-28592850

RESUMO

Acute pancreatitis (AP) is a complicated disease without specific drug therapy. The cofactor nicotinamide adenine dinucleotide (NAD+) is an important regulator of cellular metabolism and homeostasis. However, it remains unclear whether modulation of NAD+ levels has an impact on caerulein-induced AP. Therefore, in this study, we investigated the effect of increased cellular NAD+ levels on caerulein-induced AP. We demonstrated for the first time that the activities and expression of SIRT1 were suppressed by reduction of intracellular NAD+ levels and the p53-microRNA-34a pathway in caerulein-induced AP. Moreover, we confirmed that the increase of cellular NAD+ by NQO1 enzymatic action using the substrate ß-Lapachone suppressed caerulein-induced AP with down-regulating TLR4-mediated inflammasome signalling, and thereby reducing the inflammatory responses and pancreatic cell death. These results suggest that pharmacological stimulation of NQO1 could be a promising therapeutic strategy to protect against pathological tissue damage in AP.


Assuntos
Inflamassomos/metabolismo , NAD/metabolismo , Pancreatite Necrosante Aguda/patologia , Transdução de Sinais , Animais , Ceruletídeo/toxicidade , Camundongos Endogâmicos C57BL , MicroRNAs/metabolismo , NAD(P)H Desidrogenase (Quinona)/metabolismo , Pancreatite Necrosante Aguda/induzido quimicamente , Sirtuína 1/metabolismo , Proteína Supressora de Tumor p53/metabolismo
18.
Tohoku J Exp Med ; 242(2): 137-142, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28626164

RESUMO

Malignancy and tuberculosis are common causes of lymphocytic exudative pleural effusion. However, it is occasionally difficult to differentiate malignant pleural effusion from tuberculous pleural effusion. Vascular endothelial growth factor (VEGF) is a critical cytokine in the pathogenesis of malignant pleural effusion. Endocan is a dermatan sulfate proteoglycan that is secreted by endothelial cells. Importantly, endocan mediates the vascular growth-promoting action of VEGF. The aim of this study was to evaluate the diagnostic significance of VEGF and endocan in pleural effusion. We thus measured the levels of VEGF and endocan in the pleural effusion and serum samples of patients with lung cancer (n = 59) and those with tuberculosis (n = 32) by enzyme-linked immunosorbent assay. Lung cancer included 40 cases of adenocarcinoma, 13 of squamous cell carcinoma, and 6 of small cell carcinoma. Pleural effusion VEGF levels were significantly higher in the malignant group than in the tuberculosis group (2,091.47 ± 1,624.80 pg/mL vs. 1,291.05 ± 1,100.53 pg/mL, P < 0.05), whereas pleural effusion endocan levels were similar between the two groups (1.22 ± 0.74 ng/mL vs. 0.87 ± 0.53 ng/mL). The areas under the curve of VEGF and endocan were 0.73 and 0.52, respectively. Notably, the VEGF levels were similar in malignant pleural effusion, irrespective of the histological type of lung cancer. Moreover, no significant difference was found in the serum VEGF and endocan levels between patients with lung cancer and those with tuberculosis. In conclusion, high VEGF levels in pleural effusion are suggestive of malignant pleural effusion.


Assuntos
Derrame Pleural Maligno/diagnóstico , Tuberculose Pleural/diagnóstico , Fator A de Crescimento do Endotélio Vascular/metabolismo , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Diagnóstico Diferencial , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Proteínas de Neoplasias/sangue , Derrame Pleural Maligno/sangue , Proteoglicanas/sangue , Curva ROC , Tuberculose Pleural/sangue , Fator A de Crescimento do Endotélio Vascular/sangue , Adulto Jovem
19.
PLoS One ; 12(5): e0176937, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28481901

RESUMO

ß-Lapachone is a natural quinone compound from Lapacho trees, which has various pharmacological effects such as anti-bacterial, anti-fungal, anti-viral, and anti-inflammatory activities. However, the effect of ß-lapachone on metastasis of melanoma cells is unclear. In this study, ß-lapachone reduced cell viability of metastatic melanoma cancer cell lines B16F10 and B16BL6 through induction of apoptosis via the mitogen-activated protein kinase (MAPK) pathway. Additionally, flow cytometry results showed that ß-lapachone increased DNA content in the G0/G1 phase of the cell cycle. Analysis of the mechanisms of these events indicated that ß-lapachone regulated the expression of Bcl-2, Bcl-xL, and Bax, resulting in the activation of caspase-3, -8, -9, and poly-ADP-ribose polymerase (PARP). Moreover, the ß-lapachone-administered group showed significantly decreased lung metastasis in the experimental mouse model. In conclusion, our study demonstrates the inhibitory effect of ß-lapachone on lung metastasis of melanoma cells and provides a new insight into the role of ß-lapachone as a potential antitumor agent.


Assuntos
Neoplasias Pulmonares/prevenção & controle , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Melanoma/patologia , Naftoquinonas/farmacologia , Metástase Neoplásica/prevenção & controle , Animais , Feminino , Humanos , Neoplasias Pulmonares/enzimologia , Neoplasias Pulmonares/secundário , Camundongos , Camundongos Endogâmicos C57BL
20.
Int J Mol Med ; 39(4): 960-968, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28290603

RESUMO

Fenofibrate, an activator of peroxisome proliferator-activated receptors (PPARs), has been shown to protect the kidneys and brain cells from oxidative stress; however, its role in preventing hearing loss has not been reported to date, at least to the best of our knowledge. In this study, we demonstrated the protective effects of fenofibrate against gentamicin (GM)-induced ototoxicity. We found that the auditory brainstem response threshold which was increased by GM was significantly reduced by pre-treatment with fenofibrate in rats. In cochlear explants, the disruption of hair cell layers by GM was also markedly attenuated by pre-treatment with fenofibrate. In addition, fenofibrate almost completely abolished GM-induced reactive oxygen species generation, which seemed to be mediated at least in part by the restoration of the expression of PPAR­α­dependent antioxidant enzymes, including catalase and superoxide dismutase (SOD)-1. Of note, fenofibrate markedly increased the expression of heme oxygenase-1 (HO-1) which was also induced to a certain degree by GM alone. The induced expression of HO-1 by fenofibrate appeared to be essential for mediating the protective effects of fenofibrate, as the inhibition of HO-1 activity significantly diminished the protective effects of fenofibrate against the GM-mediated death of sensory hair cells in cochlea explant culture, as well as in zebrafish neuromasts. These results suggest that fenofibrate protects sensory hair cells from GM-induced toxicity by upregulating PPAR­α-dependent antioxidant enzymes, including HO-1. Our results provide insight into the preventive therapy for hearing loss caused by aminoglycoside antibiotics.


Assuntos
Antioxidantes/metabolismo , Catalase/metabolismo , Fenofibrato/farmacologia , Gentamicinas/efeitos adversos , Células Ciliadas Auditivas/enzimologia , Heme Oxigenase (Desciclizante)/metabolismo , Superóxido Dismutase-1/metabolismo , Proteínas de Peixe-Zebra/metabolismo , Peixe-Zebra/metabolismo , Animais , Morte Celular , Ativação Enzimática/efeitos dos fármacos , Feminino , Gentamicinas/farmacologia , Células Ciliadas Auditivas/patologia , Masculino , PPAR alfa/metabolismo , Ratos , Ratos Sprague-Dawley
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