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1.
Ann Oncol ; 34(11): 1055-1063, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37673210

RESUMO

BACKGROUND: Relapsed or refractory peripheral T-cell lymphomas (r/r PTCLs) are a group of rare and aggressive diseases that lack effective therapies. Constitutive activation of the Janus kinase (JAK)/signal transducer and activator of transcription (STAT) pathway is reported to be associated with PTCLs. Golidocitinib is an oral, potent JAK1 selective inhibitor evaluated in a phase I/II multinational study in patients with r/r PTCLs. PATIENTS AND METHODS: Patients with r/r PTCLs were eligible. The primary objectives were to assess safety and tolerability of golidocitinib and to define its recommended phase II dose (RP2D). The secondary objectives were to evaluate its antitumor activity and pharmacokinetics (PK). RESULTS: A total of 51 patients were enrolled and received golidocitinib treatment at 150 or 250 mg once daily (QD). The median prior lines of therapies were 2 (range: 1-8). Golidocitinib was tolerated at both doses tested, while a higher incidence of serious adverse events and dose modifications at 250 mg were observed. The most common grade ≥3 drug-related treatment-emergent adverse events were neutropenia (27.5%) and thrombocytopenia (11.8%). An objective response rate of 39.2% and a complete response rate of 21.6% were observed. With median follow-up time of 14.7 and 15.9 months, the median duration of response (DoR) and progression-free survival were 8.0 and 3.3 months, respectively. Based on these data, 150 mg QD was defined as the RP2D. Golidocitinib demonstrated a favorable PK profile as an oral agent. Biomarker analysis suggested a potential correlation between JAK/STAT pathway aberrations and clinical activity of golidocitinib. CONCLUSIONS: In this phase I study, golidocitinib demonstrated an acceptable safety profile and encouraging antitumor efficacy in heavily pretreated patients with r/r PTCLs. These results support the initiation of the multinational pivotal study in patients with r/r PTCLs.


Assuntos
Linfoma de Células T Periférico , Humanos , Linfoma de Células T Periférico/tratamento farmacológico , Janus Quinases , Recidiva Local de Neoplasia/tratamento farmacológico , Fatores de Transcrição STAT , Transdução de Sinais , Janus Quinase 1
2.
Benef Microbes ; 11(4): 361-373, 2020 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-32755263

RESUMO

Excessive body fat and the related dysmetabolic diseases affect both developed and developing countries. The aim of this study was to investigate the beneficial role of a bacterial culture supernatant (hereafter: BS) of Lactobacillus and Bifidobacterium and their potential mechanisms of action on white-fat browning and lipolysis. For selection of four candidates among 55 Lactic acid producing bacteria (LAB) from human infant faeces, we evaluated by Oil Red O staining and Ucp1 mRNA quantitation in 3T3-L1 preadipocytes. The expression of browning and lipolysis markers was examined along with in vitro assays. The possible mechanism was revealed by molecular and biological experiments including inhibitor and small interfering RNA (siRNA) assays. In a mouse model, physiological, histological, and biochemical parameters and expression of some thermogenesis-related genes were compared among six experimental groups fed a high-fat diet and one normal-diet control group. The results allow us to speculate that BS treatment promotes browning and lipolysis both in vitro and in vivo. Moreover, the BS may activate thermogenic programs via a mechanism involving PKA-CREB signaling in 3T3-L1 cells. According to our data, we can propose that two LAB strains, Bifidobacterium longum DS0956 and Lactobacillus rhamnosus DS0508, may be good candidates for a dietary supplement against obesity and metabolic diseases; however, further research is required for the development as dietary supplements or drugs.


Assuntos
Bifidobacterium longum/metabolismo , Lacticaseibacillus rhamnosus/metabolismo , Obesidade/terapia , Termogênese/efeitos dos fármacos , Células 3T3-L1 , Adipócitos/citologia , Adipócitos/efeitos dos fármacos , Adipócitos/metabolismo , Tecido Adiposo Branco/efeitos dos fármacos , Tecido Adiposo Branco/metabolismo , Tecido Adiposo Branco/patologia , Animais , Diferenciação Celular/efeitos dos fármacos , Meios de Cultivo Condicionados/metabolismo , Meios de Cultivo Condicionados/farmacologia , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Dieta Hiperlipídica/efeitos adversos , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Lipólise/efeitos dos fármacos , Lipólise/genética , Camundongos , Camundongos Endogâmicos C57BL , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Obesidade/etiologia , Obesidade/genética , Obesidade/metabolismo , Oxirredução/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Termogênese/genética
3.
J Frailty Aging ; 9(3): 179-184, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32588034

RESUMO

BACKGROUND: Physical frailty and impaired executive function of the brain show similar pathophysiology. Both of these factors lead to dysfunction of neuromuscular and abilities in elderly. High-speed power training (HSPT) has been determined to have positive effects on neuromuscular function and gait performance, as well as executive function in the elderly. OBJECTIVES: The purpose of this study was to investigate the effects of 8-week HSPT on neuromuscular, gait and executive functions in frail elderly with mild cognitive impairment (MCI). DESIGN, SETTING AND PARTICIPANTS: We performed a randomized controlled trial of frail elderly from community and medical center in republic of Korea. Forty-two physically frail elderly with MCI were randomly allocated to control (n=22, age=74.22±4.46) and intervention groups (n=18, age=73.77±4.64). The intervention group was subjected to HSPT, 3 times weekly for 8 weeks. MEASUREMENTS: Isometric contraction of knee extension and flexion with electromyography (EMG) was measured to determine the neuromuscular function such as knee extensor strength, rate of torque development, movement time, pre-motor time, motor time, rate of EMG rise, and hamstrings antagonist co-activation. Additionally, the 4.44-meter gait and timed up-and-go (TUG) test were administered to assess gait performance. A frontal assessment battery was measured in this study. RESULTS: The 8-week HSPT regimen improved the knee extensor strength from 1.13±0.08 to 1.25±0.07 (p<0.05), the 200-ms RTD from 3.01±0.3 to 3.55±0.24 (p<0.05) and the rate of EMG rise from 166.48±13.31 to 197.94±11.51 (p<0.05), whereas the movement time and motor time were statistically decreased from 921.69±40.10 to 799.51±72.84, and 271.40±19.29 to 181.15±38.08 (p<0.05), respectively. The 4.44-m gait speed and TUG significantly decreased from 6.39±0.25 to 5.5±0.24, and 11.05±0.53 to 9.17±0.43 respectively (p<0.05). CONCLUSION: The findings of this study suggest the favorable effects of 8-week HSPT on the neuromuscular function and the gait performance in the frail elderly with MCI without increase in the executive function.


Assuntos
Disfunção Cognitiva/terapia , Função Executiva/fisiologia , Terapia por Exercício/métodos , Idoso Fragilizado/psicologia , Marcha/fisiologia , Músculo Esquelético/fisiologia , Fenômenos Fisiológicos do Sistema Nervoso , Idoso , Disfunção Cognitiva/epidemiologia , Idoso Fragilizado/estatística & dados numéricos , Humanos , República da Coreia/epidemiologia , Resultado do Tratamento
4.
Environ Pollut ; 254(Pt A): 112934, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31376601

RESUMO

Urban heat island (UHI), an iconic consequence of anthropogenic activities and climate condition, affects air pollution, energy use, and health. Therefore, better understanding of the temporal dynamics of UHI is required for sustainable urban planning to mitigate air pollution under a changing climate. Here, we present the evolution of UHI intensity (UHIi) and its controlling factors in the Seoul metropolitan area, Korea, over the last 56 years (1962-2017), which has experienced unique compressed economic growth and urban transformation under monsoon climate. The analysis demonstrated an inverted U-shape long-term variation of UHIi with the progress of urban transformation and economic climate which has not been reported in Asian cities before. Meanwhile, short-term variations in UHIi are related to both diurnal temperature range and duration after rainfall event unlike previous studies, and the UHIi was exacerbated by heat waves. Our findings suggest that the UHIi will exhibit different temporal dynamics with future changes in the monsoon climate, and heat waves in the urban area will be reinforced if current rapid urbanization continues without a shift toward sustainable and equitable development. Asian cities that are likely to face the similar urbanization trajectory and the implications are that urban (re)development strategy considers changes in rainfall magnitude and timing due to monsoon system variation under changing climate and plans to mitigate synergy between heat wave and UHI in this area.


Assuntos
Poluição do Ar/análise , Mudança Climática , Clima , Urbanização , Planejamento de Cidades , Desenvolvimento Econômico , Temperatura Alta , Chuva , República da Coreia , Seul
5.
Sci Rep ; 9(1): 677, 2019 01 24.
Artigo em Inglês | MEDLINE | ID: mdl-30679656

RESUMO

Large-scale landslides at volcanic islands are one of the most dangerous geological phenomena, able to generate tsunamis whose effects can propagate far from the source. However, related deposits are scarcely preserved on-land in the geologic records, and are often difficult to be interpreted. Here we show the discovery of three unprecedented well-preserved tsunami deposits related to repeated flank collapses of the volcanic island of Stromboli (Southern Italy) occurred during the Late Middle Ages. Based on carbon datings, on stratigraphic, volcanological and archaeological evidence, we link the oldest, highest-magnitude investigated tsunami to the following rapid abandonment of the island which was inhabited at that time, contrary than previously thought. The destructive power of this event is also possibly related to a huge marine storm that devastated the ports of Naples in 1343 (200 km north of Stromboli) described by the famous writer Petrarch. The portrayed devastation can be potentially attributed to the arrival of multiple tsunami waves generated by a major landslide in Stromboli island, confirming the hypothetical hazard of these phenomena at a regional scale.

6.
Risk Anal ; 39(4): 859-870, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30286528

RESUMO

Increasing concern for climate change adaptation and disaster risk reduction is driving the need for more accurate and sophisticated tools of analysis to protect populations. Standards of analysis that can normalize measurements under various contexts are particularly valuable in the global arena of disaster management. One concern that may benefit from normalizing is the analysis of disaster loss trends. Previous studies have used a combination of inflation, wealth, and societal factors in their normalization of disaster loss methodologies. This study examines the various normalization methods in previous research and applies a selection of eight formulae to 50 years of disaster data in South Korea. The results show both decreasing and increasing trends in disaster damage losses based on the methods, but there are curious biases under the results that may be artifacts of Korea's unique experiences in economic development. The conclusion discusses how the case of Korea may help to clarify the optimal normalization methodology for other countries.

7.
J Nutr Health Aging ; 22(8): 944-951, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30272098

RESUMO

BACKGROUND: Cognitive frailty is defined as the presence of both physical frailty and cognitive impairment (clinical dementia rating score = 0.5), in the absence of dementia. It is characterized by concurrent physical frailty and potentially reversible cognitive impairment. In this study, we sought to elucidate the effects of high-speed resistance exercise training on cognitive function and physical performance in older adults with cognitive frailty. METHODS: We conducted a parallel-group, randomized controlled trial involving community-living older adults with cognitive frailty. The participants' mean age was 73.9 (± 4.3 SD) years, and 69.8% (n=30) were female. Two different 4-month interventions included high-speed resistance exercise training group (n=22) and a control group (balance and band stretching, n=23). Frailty score, cognitive function (memory, processing speed, cognitive flexibility, working memory, executive function), physical function (SPPB, TUG, gait speed), and muscle strength (grip strength, knee extension strength) were assessed at baseline, 8 weeks, and 16 weeks. RESULTS: Statistical analysis showed that exercise improved performance significantly in the tests for cognitive function (processing speed and executive function, both p < 0.05), physical function (SPPB, TUG, gait speed, both p < 0.05), and muscle strength (grip strength, knee extension strength, both p < 0.05). However, no significant changes in frailty score were observed between intervention and either control group (p < 0.05). CONCLUSION: In conclusion, our findings indicate that high-speed resistance exercise training approaches are effective in improving cognitive function and physical performance in older adults with cognitive frailty. This study shows that it is feasible to identify older adults with cognitive frailty in the community and primary care setting for effective intervention to reduce their level of frailty and cognitive impairment.


Assuntos
Cognição/fisiologia , Disfunção Cognitiva/prevenção & controle , Terapia por Exercício , Fragilidade/prevenção & controle , Fragilidade/psicologia , Treinamento Resistido , Idoso , Idoso de 80 Anos ou mais , Disfunção Cognitiva/psicologia , Demência/psicologia , Função Executiva/fisiologia , Feminino , Humanos , Masculino , Memória , Força Muscular/fisiologia , Desempenho Físico Funcional
8.
Rev Sci Instrum ; 89(4): 046101, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29716319

RESUMO

We present a compact nuclear magnetic resonance (NMR) probe which is compatible with a magnet of a commercial superconducting quantum interference device magnetometer and demonstrate its application to the study of a quantum magnet. We employ trimmer chip capacitors to construct an NMR tank circuit for low temperature measurements. Using a magnetic insulator MoOPO4 with S = 1/2 (Mo5+) as an example, we show that the T-dependence of the circuit is weak enough to allow the ligand-ion NMR study of magnetic systems. Our 31P NMR results are compatible with previous bulk susceptibility and neutron scattering experiments and furthermore reveal unconventional spin dynamics.

9.
Nat Commun ; 9(1): 308, 2018 01 22.
Artigo em Inglês | MEDLINE | ID: mdl-29358728

RESUMO

The equilibrium optical phonons of graphene are well characterized in terms of anharmonicity and electron-phonon interactions; however, their non-equilibrium properties in the presence of hot charge carriers are still not fully explored. Here we study the Raman spectrum of graphene under ultrafast laser excitation with 3 ps pulses, which trade off between impulsive stimulation and spectral resolution. We localize energy into hot carriers, generating non-equilibrium temperatures in the ~1700-3100 K range, far exceeding that of the phonon bath, while simultaneously detecting the Raman response. The linewidths of both G and 2D peaks show an increase as function of the electronic temperature. We explain this as a result of the Dirac cones' broadening and electron-phonon scattering in the highly excited transient regime, important for the emerging field of graphene-based photonics and optoelectronics.

10.
J Fish Dis ; 41(1): 105-116, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28914452

RESUMO

Members of the Iridoviridae family have been considered as aetiological agents of iridovirus diseases, causing fish mortalities and economic losses all over the world. Virus identification based on candidate gene sequencing is faster, more accurate and more reliable than other traditional phenotype methodologies. Iridoviridae viruses are covered by a protein shell (capsid) encoded by the important candidate gene, major capsid protein (MCP). In this study, we investigated the potential of the MCP gene for use in the diagnosis and identification of infections caused Megalocytivirus of the Iridoviridae family. We selected data of 66 Iridoviridae family isolates (53 strains of Megalocytivirus, eight strains of iridoviruses and five strains of Ranavirus) infecting various species of fish distributed all over the world. A total of 53 strains of Megalocytivirus were used for designing the complete primer sets for identifying the most hypervariable region of the MCP gene. Further, our in silico analysis of 102 sequences of related and unrelated viruses reconfirms that primer sets could identify strains more specifically and offers a useful and fast alternative for routine clinical laboratory testing. Our findings suggest that phenotype observation along with diagnosis using universal primer sets can help detect infection or carriers at an early stage.


Assuntos
Infecções por Vírus de DNA/diagnóstico , Infecções por Vírus de DNA/veterinária , Doenças dos Peixes/diagnóstico , Iridoviridae/genética , Animais , Proteínas do Capsídeo/genética , Infecções por Vírus de DNA/genética , Doenças dos Peixes/virologia , Peixes/virologia , Iridovirus/genética , Filogenia , Ranavirus/genética , Análise de Sequência de DNA
12.
AJNR Am J Neuroradiol ; 39(1): 151-155, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29122761

RESUMO

BACKGROUND AND PURPOSE: The image quality of neck CT is frequently disturbed by streak artifact from the shoulder girdles. Our aim was to determine the effects of an arm traction device on image quality and radiation exposure in neck CT. MATERIALS AND METHODS: Patients with lymphoma with complete remission who were scheduled to undergo 2 consecutive follow-up neck CT scans for surveillance within a 1-year interval were enrolled in this prospective study. They underwent 2 consecutive neck CT scans (intervention protocol: patients with an arm traction device; standard protocol: no positioning optimization) on the same CT system. The primary outcome measures were image noise in the lower neck and dose-length product. Secondary outcomes were streak artifacts in the supraclavicular fossa, volume CT dose index, and the extent of the biacromial line shift. RESULTS: Seventy-three patients were enrolled and underwent 2 consecutive CT scans with a mean interval of 155 days. In the intervention protocol, a mean noise reduction in the lower neck of 25.2%-28.5% (P < .001) was achieved, and a significant decrease in dose-length product (413 versus 397, P < .001) was observed. The intervention protocol significantly decreased streak artifacts (P < .001) and volume CT dose index (13.9 versus 13.4, P < .001) and could lower the biacromial line an average of 2.1 cm. CONCLUSIONS: An arm traction device can improve image quality and reduce radiation exposure during neck CT. The device can be simply applied in cooperative patients with suspected lower neck lesions, and the approach offers distinct advantages over the conventional imaging protocol.


Assuntos
Artefatos , Linfoma/diagnóstico por imagem , Exposição à Radiação , Tomografia Computadorizada por Raios X/instrumentação , Tração/instrumentação , Adulto , Idoso , Braço , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pescoço/diagnóstico por imagem , Estudos Prospectivos , Doses de Radiação , Tomografia Computadorizada por Raios X/métodos , Tração/métodos
13.
Ann Oncol ; 28(9): 2199-2205, 2017 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-28911074

RESUMO

BACKGROUND: Current standard treatment, including non-anthracycline-based chemotherapy and optimal combining of radiotherapy, has dramatically improved outcomes of patients with extranodal natural killer/T-cell lymphoma (ENKTL) during the last decade. This study was conducted to investigate the clinical outcome of ENKTL patients with relapsed or progressive disease after initial current standard therapy. PATIENTS AND METHODS: We retrospectively reviewed patients diagnosed with ENKTL at six centers in four countries (China, France, Singapore, and South Korea) from 1997 to 2015 and analyzed 179 patients who had relapsed or progressed after initial current standard therapy. RESULTS: After a median follow-up of 58.6 months (range 27.9-89.2), the median second progression-free survival (PFS) was 4.1 months [95% confidence interval (CI) 3.04-5.16] and overall survival (OS) was 6.4 months (95% CI 4.36-8.51). Multivariate Cox-regression analysis revealed that elevated lactate dehydrogenase, multiple extranodal sites (≥2), and presence of B symptoms were associated with inferior OS (P < 0.05). OS and PFS were significantly different according to both prognostic index of natural killer lymphoma (PINK) and PINK-E (Epstein-Barr virus) models. Salvage chemotherapy with l-asparaginase (l-Asp)-based regimens showed a significantly better clinical benefit to response rate and PFS, although it did not lead to OS improvement. First use of l-Asp in the salvage setting and l-Asp rechallenge at least 6 months after initial treatment were the best candidates for salvage l-Asp containing chemotherapy. CONCLUSIONS: Most patients with relapsed or refractory ENKTL had poor prognosis with short survival. Further studies are warranted to determine the optimal treatment of patients with relapsed or refractory ENKTL.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Linfoma Extranodal de Células T-NK/tratamento farmacológico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Antraciclinas/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Progressão da Doença , Feminino , Humanos , Linfoma Extranodal de Células T-NK/patologia , Masculino , Pessoa de Meia-Idade , Recidiva , Terapia de Salvação , Resultado do Tratamento , Adulto Jovem
14.
Ultraschall Med ; 38(3): 311-317, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28511228

RESUMO

Purpose The number of citations that an article has received reflects its impact on a particular research area. The aim of this study was to identify the 100 most-cited articles focused on ultrasound (US) imaging and to analyze the characteristics of these articles. Methods We determined the 100 most-cited articles on US imaging via the Web of Science database, using the search term. The following parameters were used to analyze the characteristics of the 100 most-cited articles: publication year, journal, journal impact factor, number of citations and annual citations, authors, department, institution, country, type of article, and topic. Results The number of citations for the 100 most-cited articles ranged from 1849 to 341 (median: 442.0) and the number of annual citations ranged from 108.0 to 8.1 (median: 22.1). The majority of articles were published in 1990 - 1999 (39 %), published in radiology journals (20 %), originated in the United States (45 %), were clinical observation studies (67 %), and dealt with the vessels (35 %). The Department of Internal Medicine at the University of California and the Research Institute of Public Health at the University of Kuopio (n = 4 each) were the leading institutions and Salonen JT and Salonen R (n = 4 each) were the most prolific authors. Conclusion Our study presents a detailed list and analysis of the 100 most-cited US articles, which provides a unique insight into the historical development in this field.


Assuntos
Bibliometria , Fator de Impacto de Revistas , Publicações Periódicas como Assunto , Ultrassonografia , Alemanha , Humanos
15.
Lab Chip ; 17(8): 1481-1486, 2017 04 11.
Artigo em Inglês | MEDLINE | ID: mdl-28301613

RESUMO

This paper presents the formation of complex cross-sectional microfibers using three-dimensional microfluidic devices. The compartments and shapes of core and shell layers in the microfibers were independently controlled via three-dimensional fluidic channels fabricated by the combination of sheath units. The number of layers is easily expanded by the stacking of these units. Therefore, the highly heterogeneous microfibers of alginate hydrogel are obtained in polydimethylsiloxane structures. This widely expandable method has great potential for the development of functional and complex fiber-shaped materials.

17.
Nat Commun ; 8: 14024, 2017 01 19.
Artigo em Inglês | MEDLINE | ID: mdl-28102222

RESUMO

Electron pairing in the vast majority of superconductors follows the Bardeen-Cooper-Schrieffer theory of superconductivity, which describes the condensation of electrons into pairs with antiparallel spins in a singlet state with an s-wave symmetry. Unconventional superconductivity was predicted in single-layer graphene (SLG), with the electrons pairing with a p-wave or chiral d-wave symmetry, depending on the position of the Fermi energy with respect to the Dirac point. By placing SLG on an electron-doped (non-chiral) d-wave superconductor and performing local scanning tunnelling microscopy and spectroscopy, here we show evidence for a p-wave triggered superconducting density of states in SLG. The realization of unconventional superconductivity in SLG offers an exciting new route for the development of p-wave superconductivity using two-dimensional materials with transition temperatures above 4.2 K.

18.
Osteoarthritis Cartilage ; 24(12): 2153-2161, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27421775

RESUMO

OBJECTIVE: SIRT1 has anti-inflammatory as well as protective effects in chondrocytes. The object of this study was to investigate whether microRNA-449a regulates expression of SIRT1, which inhibits expression of catabolic genes in IL-1ß-induced cartilage destruction. MATERIALS AND METHODS: MicroRNA-449a expression was determined in OA chondrocytes and IL-1ß-induced chondrocytes by real-time PCR. MicroRNA-449a binding sites on the 3'-UTR of SIRT1 mRNA and binding site conservation were examined using microRNA target prediction tools. SIRT1-overexpressing or knockdown chondrocytes were transfected with microRNA-449a or anti-microRNA-449a mimic and stimulated by IL-1ß. Expression of catabolic and anabolic genes was examined by real-time PCR and western blotting. Finally, positive effects of anti-microRNA-449a on expression of these genes were confirmed by western analysis of OA chondrocytes. RESULTS: Expression of microRNA-449a was increased in OA chondrocytes and IL-1ß-induced chondrocytes. MMP-13 expression was enhanced, whereas type II collagen and SIRT1 expression were decreased in IL-1ß-induced chondrocytes. SIRT1 overexpression resulted in decreased expression of catabolic genes such as MMPs and ADAMTSs in response to IL-1ß, but these effects were moderated by microRNA-449a. Suppression of microRNA-449a by anti-microRNA-449a inhibited expression of catabolic genes despite IL-1ß stimulation, but these effects were abolished in SIRT1 knockdown chondrocytes. Furthermore, expression of catabolic genes was decreased and expression of type II collagen as well as SIRT1 was restored by anti-microRNA-449a in OA chondrocytes as well as in IL-1ß-induced chondrocytes. CONCLUSION: Silencing of microRNA-449a had a protective effect, inhibiting catabolic gene expression and restoring anabolic gene expression, by targeting SIRT1 in IL-1ß-induced cartilage destruction.


Assuntos
Cartilagem , Células Cultivadas , Condrócitos , Humanos , Interleucina-1beta , MicroRNAs
19.
Cell Death Dis ; 7: e2208, 2016 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-27124582

RESUMO

Concanavalin A (Con A)-induced hepatitis model is well-established experimental T cell-mediated liver disease. Reactive oxygen species (ROS) is associated with T-cell activation and proliferation, but continued ROS exposure induces T-cell hyporesponsiveness. Because glutathione peroxidase 1 (Gpx1) is an antioxidant enzyme and is involved in T-cell development, we investigated the role of Gpx1 during Con A-induced liver injury in Gpx1 knockout (KO) mice. Male wild-type (WT) mice and Gpx1 KO mice were intravenously injected with Con A (10 mg/kg), and then killed after 8 h after Con A injection. Serum levels of aspartate transaminase and alanine transaminase were measured to assess hepatic injury. To identify that Gpx1 affects T cell-mediated inflammation, we pretreated Gpx1 inhibitor to Human Jurkat T cells then treated Con A. Con A-induced massive liver damage in WT mice but its damage was attenuated in Gpx1 KO mice. Con A-induced Th1 cytokines such as tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ) and interleukin (IL)-2 were also decreased in the liver and spleen of Gpx1 KO mice compared with WT mice. In Jurkat T cells, Con A-induced mRNA levels of IL-2, IFN-γ and TNF-α were downregulated by pretreatment of Gpx inhibitor, mercaptosuccinic acid. We also observed that Gpx1 KO mice showed increasing oxidative stress in the liver and spleen compared with WT mice. These results suggest that Gpx1 deficiency attenuates Con A-induced liver injury by induction of T-cell hyporesponsiveness through chronic ROS exposure.


Assuntos
Concanavalina A/toxicidade , Glutationa Peroxidase/metabolismo , Ativação Linfocitária/efeitos dos fármacos , Alanina Transaminase/sangue , Animais , Aspartato Aminotransferases/sangue , Regulação para Baixo/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Glutationa Peroxidase/antagonistas & inibidores , Glutationa Peroxidase/genética , Humanos , Interferon gama/genética , Interferon gama/metabolismo , Interleucina-2/genética , Interleucina-2/metabolismo , Células Jurkat , Fígado/lesões , Fígado/metabolismo , Fígado/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Estresse Oxidativo/efeitos dos fármacos , Fosforilação/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Baço/metabolismo , Linfócitos T/citologia , Linfócitos T/metabolismo , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/metabolismo , Glutationa Peroxidase GPX1
20.
Cell Death Dis ; 7: e2093, 2016 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-26866273

RESUMO

NRF2 (nuclear factor erythroid-derived 2-like 2) plays an important role in defense against oxidative stress at the cellular level. Recently, the roles of NRF2 in embryonic and adult stem cells have been reported, but its role in maintaining self-renewal and differentiation potential remains unknown. We studied the mechanisms of NRF2 action in mesenchymal stem cells (MSCs) derived from human bone marrow. We found that the cellular localization of NRF2 changed during prolonged cell passage and osteogenic differentiation. Blocking the nuclear import of NRF2 using ochratoxin A (OTA) induced the loss of the self-renewal and osteogenic potential of early-passage (EP) MSCs. Conversely, reinforcing the nuclear import of NRF2 using tert-butylhydroquinone (t-BHQ) improved the self-renewal capacity and maintained the differentiation potential in the osteogenic lineage of EP MSCs. Real-time quantitative PCR and western blot analysis showed that NRF2 positively regulates sirtuin 1 (SIRT1) at the mRNA and protein levels via the negative regulation of p53. The self-renewal and osteogenic potential suppressed in OTA-treated or NRF2-targeting small hairpin RNA (shRNA)-infected EP MSCs were rescued by introducing small interfering RNA (siRNA) targeting p53. t-BHQ treatment in late-passage (LP) MSCs, which lost their self-renewal and osteogenic potential, reversed these effects. In LP MSCs treated with t-BHQ for ∼7 days, the phosphorylation and nuclear localization of NRF2 improved and SIRT1 protein level increased, whereas p53 protein levels decreased. Therefore, our results suggest that NRF2 plays an important role in regulating p53 and SIRT1 to maintain MSC stemness. This study is the first to establish a functional link between NRF2 and SIRT1 expression in the maintenance of MSC self-renewal and differentiation potential.


Assuntos
Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Sirtuína 1/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Adulto , Diferenciação Celular/fisiologia , Proliferação de Células/fisiologia , Células Cultivadas , Células HEK293 , Humanos , Osteogênese/efeitos dos fármacos , Osteogênese/fisiologia , Fosforilação
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