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1.
Cell ; 137(1): 73-86, 2009 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-19345188

RESUMO

Brown fat is specialized for energy expenditure, a process that is principally controlled by the transcriptional coactivator PGC-1alpha. Here, we describe a molecular network important for PGC-1alpha function and brown fat metabolism. We find that twist-1 is selectively expressed in adipose tissue, interacts with PGC-1alpha, and is recruited to the promoters of PGC-1alpha's target genes to suppress mitochondrial metabolism and uncoupling. In vivo, transgenic mice expressing twist-1 in the adipose tissue are prone to high-fat-diet-induced obesity, whereas twist-1 heterozygous knockout mice are obesity resistant. These phenotypes are attributed to their altered mitochondrial metabolism in the brown fat. Interestingly, the nuclear receptor PPARdelta not only mediates the actions of PGC-1alpha but also regulates twist-1 expression, suggesting a negative-feedback regulatory mechanism. These findings reveal an unexpected physiological role for twist-1 in the maintenance of energy homeostasis and have important implications for understanding metabolic control and metabolic diseases.


Assuntos
Tecido Adiposo Marrom/metabolismo , Proteínas Nucleares/metabolismo , Transativadores/genética , Proteína 1 Relacionada a Twist/metabolismo , Adipócitos/metabolismo , Tecido Adiposo Marrom/citologia , Animais , Metabolismo Energético , Histonas/metabolismo , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Mitocôndrias/metabolismo , Obesidade/metabolismo , PPAR delta/genética , PPAR delta/metabolismo , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo , Transativadores/metabolismo , Fatores de Transcrição
2.
Chirality ; 36(5): e23677, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38752253

RESUMO

Electrons in circular motion emit electromagnetic radiation and lose their energy and angular momentum, both of which are carried away by the radiation field. Electromagnetic radiation from such electrons is not only circularly polarized but also, in general, possessing helical phase structure, the former of which corresponds to spin angular momentum and the latter orbital angular momentum. Based on the classical electrodynamics, we show that the chiral topological property related to the orbital angular momentum arises from deformation of the electromagnetic field due to the relativistic effect.

3.
J Neurosci ; 42(23): 4607-4618, 2022 06 08.
Artigo em Inglês | MEDLINE | ID: mdl-35504726

RESUMO

Ubiquitin-specific protease 2 (USP2) participates in glucose metabolism in peripheral tissues such as the liver and skeletal muscles. However, the glucoregulatory role of USP2 in the CNS is not well known. In this study, we focus on USP2 in the ventromedial hypothalamus (VMH), which has dominant control over systemic glucose homeostasis. ISH, using a Usp2-specific probe, showed that Usp2 mRNA is present in VMH neurons, as well as other glucoregulatory nuclei, in the hypothalamus of male mice. Administration of a USP2-selective inhibitor ML364 (20 ng/head), into the VMH elicited a rapid increase in the circulating glucose level in male mice, suggesting USP2 has a suppressive role on glucose mobilization. ML364 treatment also increased serum norepinephrine concentration, whereas it negligibly affected serum levels of insulin and corticosterone. ML364 perturbated mitochondrial oxidative phosphorylation in neural SH-SY5Y cells and subsequently promoted the phosphorylation of AMP-activated protein kinase (AMPK). Consistent with these findings, hypothalamic ML364 treatment stimulated AMPKα phosphorylation in the VMH. Inhibition of hypothalamic AMPK prevented ML364 from increasing serum norepinephrine and blood glucose. Removal of ROS restored the ML364-evoked mitochondrial dysfunction in SH-SY5Y cells and impeded the ML364-induced hypothalamic AMPKα phosphorylation as well as prevented the elevation of serum norepinephrine and blood glucose levels in male mice. These results indicate hypothalamic USP2 attenuates perturbations in blood glucose levels by modifying the ROS-AMPK-sympathetic nerve axis.SIGNIFICANCE STATEMENT Under normal conditions (excluding hyperglycemia or hypoglycemia), blood glucose levels are maintained at a constant level. In this study, we used a mouse model to identify a hypothalamic protease controlling blood glucose levels. Pharmacological inhibition of USP2 in the VMH caused a deviation in blood glucose levels under a nonstressed condition, indicating that USP2 determines the set point of the blood glucose level. Modification of sympathetic nervous activity accounts for the USP2-mediated glucoregulation. Mechanistically, USP2 mitigates the accumulation of ROS in the VMH, resulting in attenuation of the phosphorylation of AMPK. Based on these findings, we uncovered a novel glucoregulatory axis consisting of hypothalamic USP2, ROS, AMPK, and the sympathetic nervous system.


Assuntos
Glicemia , Neuroblastoma , Sistema Nervoso Simpático , Ubiquitina Tiolesterase , Núcleo Hipotalâmico Ventromedial , Proteínas Quinases Ativadas por AMP/metabolismo , Animais , Glicemia/metabolismo , Glucose/metabolismo , Humanos , Masculino , Camundongos , Norepinefrina/metabolismo , Fosforilação Oxidativa , Espécies Reativas de Oxigênio/metabolismo , Sistema Nervoso Simpático/enzimologia , Sistema Nervoso Simpático/metabolismo , Ubiquitina Tiolesterase/metabolismo , Núcleo Hipotalâmico Ventromedial/enzimologia , Núcleo Hipotalâmico Ventromedial/metabolismo
4.
Eur J Nucl Med Mol Imaging ; 49(3): 821-833, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34468781

RESUMO

PURPOSE: Eribulin, an inhibitor of microtubule dynamics, is known to show antitumor effects through its remodeling activity in the tumor vasculature. However, the extent to which the improvement of tumor hypoxia by eribulin affects radio-sensitivity remains unclear. We utilized 1-(2,2-dihydroxymethyl-3-18F-fluoropropyl)-2-nitroimidazole (18F-DiFA), a new PET probe for hypoxia, to investigate the effects of eribulin on tumor hypoxia and evaluate the radio-sensitivity during eribulin treatment. METHODS: Mice bearing human breast cancer MDA-MB-231 cells or human lung cancer NCI-H1975 cells were administered a single dose of eribulin. After administration, mice were injected with 18F-DiFA and pimonidazole, and tumor hypoxia regions were analyzed. For the group that received combined treatment with radiation, 18F-DiFA PET/CT imaging was performed before tumors were locally X-irradiated. Tumor size was measured every other day after irradiation. RESULTS: Eribulin significantly reduced 18F-DiFA accumulation levels in a dose-dependent manner. Furthermore, the reduction in 18F-DiFA accumulation levels by eribulin was most significant 7 days after treatment. These results were also supported by reduction of the pimonidazole-positive hypoxic region. The combined treatment showed significant retardation of tumor growth in comparison with the control, radiation-alone, and drug-alone groups. Importantly, tumor growth after irradiation was inversely correlated with 18F-DiFA accumulation. CONCLUSION: These results demonstrated that 18F-DiFA PET/CT clearly detected eribulin-induced tumor oxygenation and that eribulin efficiently enhanced the antitumor activity of radiation by improving tumor oxygenation.


Assuntos
Furanos , Cetonas , Neoplasias Pulmonares , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Hipóxia Tumoral , Animais , Linhagem Celular Tumoral , Xenoenxertos , Humanos , Neoplasias Pulmonares/diagnóstico por imagem , Neoplasias Pulmonares/patologia , Camundongos
5.
Nihon Koshu Eisei Zasshi ; 68(6): 412-424, 2021 Jun 25.
Artigo em Japonês | MEDLINE | ID: mdl-33790094

RESUMO

Objective This study aimed to determine the factors associated with mental health based on the type of stress related to high school admissions for correspondence courses.Methods The targeted participants were 3,888 students belonging to 11 campuses of a high school providing correspondence courses. During the homeroom, the teachers in charge distributed and collected questionnaires directly. The questionnaire was designed to collect data concerning demographic characteristics, stresses, mental health, and life skills. Concerning stress, the questions inquired about stress before admission and after admission. Further, they asked about stress related to entry regarding the study, friendship, relationship with teachers, club activities, school events, home environment, health, and work. Kessler 6 was used as an index of mental health.Results Questionnaires were returned by 2,424 students (response rate of 62.3%). Regarding the change in stress before and after admission, students showed decreases in anxiety after admission in other areas, excluding work. Because of the k-means clustering analysis, based on the scores of the eight areas of stress related to admission, six groups were extracted. Factors related to mental health were extracted from each group. Health stress was strongly associated with the K6 score in all groups. For the study stress group, friendship stress group, family environment, and health stress group, stress related to admission were associated with the K6 score. Furthermore, for the complex school-related stress group, friendship and family environment stress were associated with the K6 score. In the high-stress group, the K6 score was significantly associated with study stress. As for life skills, stress management and decision-making skills were associated with higher mental health.Conclusions These findings indicate that it is important to understand students' needs and support them in coping with stress and improving their life skills according to their stress type. Support should be developed for high school students enrolled in correspondence courses.


Assuntos
Educação a Distância , Saúde Mental , Humanos , Japão/epidemiologia , Instituições Acadêmicas , Estudantes , Inquéritos e Questionários
6.
Biochem Biophys Res Commun ; 522(1): 144-150, 2020 01 29.
Artigo em Inglês | MEDLINE | ID: mdl-31757415

RESUMO

Mitochondrial dynamics are crucial for cellular survival in response to various stresses. Previously, we reported that Drp1 promoted mitochondrial fission after x-irradiation and its inhibition resulted in reduced cellular radiosensitivity and mitotic catastrophe. However, the mechanisms of radiation-induced mitotic catastrophe related to mitochondrial fission remain unclear. In this study, we investigated the involvement of cellular ATP production, ROS generation, and Ca2+ levels in mitotic catastrophe in EMT6 cells. Knockdown of Drp1 and Fis1, which are mitochondrial fission regulators, resulted in elongated mitochondria and significantly attenuated cellular radiosensitivity. Reduced mitochondrial fission mainly decreased mitotic catastrophe rather than necrosis and apoptosis after irradiation. Cellular ATP contents in Drp1 and Fis1 knockdown cells were similar to those in control cells. N-acetylcysteine and 2-glucopyranoside ascorbic acid have no effect on mitotic catastrophe after irradiation. The cellular [Ca2+]i level increased after irradiation, which was completely suppressed by Drp1 and Fis1 inhibition. Furthermore, BAPTA-AM significantly reduced radiation-induced mitotic catastrophe, indicating that cellular Ca2+ is a key mediator of mitotic catastrophe induction after irradiation. These results suggest that mitochondrial fission is associated with radiation-induced mitotic catastrophe via cytosolic Ca2+ regulation.


Assuntos
Neoplasias da Mama/metabolismo , Cálcio/metabolismo , Dinâmica Mitocondrial , Trifosfato de Adenosina/metabolismo , Animais , Neoplasias da Mama/patologia , Neoplasias da Mama/radioterapia , Linhagem Celular Tumoral , Feminino , Camundongos , Dinâmica Mitocondrial/efeitos da radiação , Mitose/efeitos da radiação , Tolerância a Radiação , Espécies Reativas de Oxigênio/metabolismo , Raios X
7.
J Clin Biochem Nutr ; 67(3): 240-247, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33293764

RESUMO

Mitotic catastrophe is a form of cell death linked to aberrant mitosis caused by improper or uncoordinated mitotic progression. Abnormal centrosome amplification and mitotic catastrophe occur simultaneously, and some cells with amplified centrosomes enter aberrant mitosis, but it is not clear whether abnormal centrosome amplification triggers mitotic catastrophe. Here, to investigate whether radiation-induced abnormal centrosome amplification is essential for induction of radiation-induced mitotic catastrophe, centrinone-B, a highly selective inhibitor of polo-like kinase 4, was utilized to inhibit centrosome amplification, since polo-like kinase 4 is an essential kinase in centrosome duplication. When human cervical tumor HeLa cells and murine mammary tumor EMT6 cells were irradiated with 2.5 Gy of X-rays, cells with morphological features of mitotic catastrophe and the number of cells having >2 centrosomes increased in both cell lines. Although centrinone-B significantly inhibited radiation-induced abnormal centrosome amplification in both cell lines, such treatment did not change cell growth and significantly enhanced mitotic catastrophe in HeLa cells exposed to X-rays. In contrast, inhibition of centrosome amplification reduced cell growth and mitotic catastrophe in EMT6 cells exposed to X-rays. These results indicated that the role of radiation-induced abnormal centrosome amplification in radiation-induced mitotic catastrophe changes, depending on the cell type.

8.
J Synchrotron Radiat ; 24(Pt 5): 934-938, 2017 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-28862615

RESUMO

The observation of an optical vortex beam at 60 nm wavelength, produced as the second-harmonic radiation from a helical undulator, is reported. The helical wavefront of the optical vortex beam was verified by measuring the interference pattern between the vortex beam from a helical undulator and a normal beam from another undulator. Although the interference patterns were slightly blurred owing to the relatively large electron beam emittance, it was possible to observe the interference features thanks to the helical wavefront of the vortex beam. The experimental results were well reproduced by simulation.

9.
Chem Senses ; 42(4): 295-302, 2017 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-28431091

RESUMO

An oral sweet taste sensation (OSTS) exaggerates digestive activation transiently, but whether it has a role after swallowing a meal is not known. Gymnema sylvestre (GS) can inhibit the OSTS in humans. We explored the effect of the OSTS of glucose intake on gastrointestinal blood flow, gastric emptying, blood-glucose, and plasma-insulin responses during the postprandial phase. Eight participants ingested 200 g (50 g × 4 times) of 15% glucose solution containing 100 mg of 13C-sodium acetate after rinsing with 25 mL of 2.5% roasted green tea (control) or 2.5% GS solution. During each protocol, gastrointestinal blood flow and gastric emptying were measured by ultrasonography and 13C-sodium acetate breath test, respectively. Decreased subjective sweet taste intensity was observed in all participants in the GS group. The time to attain a peak value of blood flow in the celiac artery and gastric emptying were delayed in the GS group compared with the control group. At the initial phase after glucose intake, blood-glucose and plasma-insulin responses were lower in the GS group than those for the control group. These results suggest that the OSTS itself has a substantial role in controlling postprandial gastrointestinal activities, which may affect subsequent glycemic metabolism.


Assuntos
Esvaziamento Gástrico , Trato Gastrointestinal/irrigação sanguínea , Período Pós-Prandial , Paladar/fisiologia , Adulto , Feminino , Glucose/farmacologia , Gymnema sylvestre , Humanos , Masculino
10.
Radiat Res ; 2024 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-38779845

RESUMO

Radioresistant cancer cells are risk factors for recurrence and are occasionally detected in recurrent tumors after radiotherapy. Intratumor heterogeneity is believed to be a potential cause of treatment resistance. Heterogeneity in DNA content has also been reported in human colorectal cancer; however, little is known about how such heterogeneity changes with radiotherapy or how it affects cancer radioresistance. In the present study, we established radioresistant clone SW480RR cells after fractionated X-ray irradiation of human colorectal cancer-derived SW480.hu cells, which are composed of two cell populations with different chromosome numbers, and examined how cellular radioresistance changed with fractionated radiotherapy. Compared with the parental cell population, which mostly comprised cells with higher ploidy, the radioresistant clones showed lower ploidy and less initial DNA damage. The lower ploidy cells in the parental cell population were identified as having radioresistance prior to irradiation; thus, SW480RR cells were considered intrinsically radioresistant cells selected from the parental population through fractionated irradiation. This study presents a practical example of the emergence of radioresistant cells from a cell population with ploidy heterogeneity after irradiation. The most likely mechanism is the selection of an intrinsically radioresistant population after fractionated X-ray irradiation, with a background in which lower ploidy cells exhibit lower initial DNA damage.

11.
Sci Rep ; 13(1): 22962, 2023 Dec 27.
Artigo em Inglês | MEDLINE | ID: mdl-38151492

RESUMO

Young's double-slit interference experiments with undulator vortex radiation were conducted, focusing on photon-counting regime. To isolate the second harmonic radiation in the ultraviolet range emitted from the helical undulator and achieve successful counting measurements, an ultranarrow bandpass filter was utilized under an extremely low-current mode of the electron storage ring. It was observed that the photon spots on the detector, after passing through the double slits, appeared to be randomly distributed. However, upon integrating these photon spots, it was confirmed that interference fringes with characteristic features of optical vortices, such as dark and broken/distorted stripes in the center, were formed. The reproducibility of these interference fringes was confirmed by calculating the optical path difference for the optical vortex reaching the double slits, as well as the optical path difference resulting from normal double-slit interference. Consequently, these findings indicate that even in the state of a single photon, the radiation emitted spontaneously by a high-energy electron in spiral motion possesses the nature of an optical vortex, characterized by a spiral wavefront.

12.
Life Sci Space Res (Amst) ; 36: 27-35, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36682826

RESUMO

Planetary protection guidance for martian exploration has become a notable point of discussion over the last decade. This is due to increased scientific interest in the habitability of the red planet with updated techniques, missions becoming more attainable by smaller space agencies, and both the private sector and governments engaging in activities to facilitate commercial opportunities and human-crewed missions. The international standards for planetary protection have been developed through consultation with the scientific community and the space agencies by the Committee on Space Research's (COSPAR) Panel on Planetary Protection, which provides guidance for compliance with the Outer Space Treaty of 1967. In 2021, the Panel evaluated recent scientific data and literature regarding the planetary protection requirements for Mars and the implications of this on the guidelines. In this paper, we discuss the COSPAR Planetary Protection Policy for Mars, review the new scientific findings and discuss the next steps required to enable the next generation of robotic missions to Mars.


Assuntos
Marte , Procedimentos Cirúrgicos Robóticos , Voo Espacial , Humanos , Planetas , Meio Ambiente Extraterreno , Astronave , Exobiologia/métodos , Contenção de Riscos Biológicos , Política Pública
13.
Life Sci Space Res (Amst) ; 37: 18-24, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37087175

RESUMO

The Committee on Space Research's (COSPAR) Planetary Protection Policy states that all types of missions to Venus are classified as Category II, as the planet has significant research interest relative to the processes of chemical evolution and the origin of life, but there is only a remote chance that terrestrial contamination can proliferate and compromise future investigations. "Remote chance" essentially implies the absence of environments where terrestrial organisms could survive and replicate. Hence, Category II missions only require simplified planetary protection documentation, including a planetary protection plan that outlines the intended or potential impact targets, brief Pre- and Post-launch analyses detailing impact strategies, and a Post-encounter and End-of-Mission Report. These requirements were applied in previous missions and are foreseen for the numerous new international missions planned for the exploration of Venus, which include NASA's VERITAS and DAVINCI missions, and ESA's EnVision mission. There are also several proposed missions including India's Shukrayaan-1, and Russia's Venera-D. These multiple plans for spacecraft coincide with a recent interest within the scientific community regarding the cloud layers of Venus, which have been suggested by some to be habitable environments. The proposed, privately funded, MIT/Rocket Lab Venus Life Finder mission is specifically designed to assess the habitability of the Venusian clouds and to search for signs of life. It includes up to three atmospheric probes, the first one targeting a launch in 2023. The COSPAR Panel on Planetary Protection evaluated scientific data that underpins the planetary protection requirements for Venus and the implications of this on the current policy. The Panel has done a thorough review of the current knowledge of the planet's conditions prevailing in the clouds. Based on the existing literature, we conclude that the environmental conditions within the Venusian clouds are orders of magnitude drier and more acidic than the tolerated survival limits of any known terrestrial extremophile organism. Because of this future orbital, landed or entry probe missions to Venus do not require extra planetary protection measures. This recommendation may be revised in the future if new observations or reanalysis of past data show any significant increment, of orders of magnitude, in the water content and the pH of the cloud layer.


Assuntos
Marte , Voo Espacial , Vênus , Planetas , Meio Ambiente Extraterreno , Contenção de Riscos Biológicos , Exobiologia
14.
Nihon Ronen Igakkai Zasshi ; 49(5): 617-21, 2012.
Artigo em Japonês | MEDLINE | ID: mdl-23459654

RESUMO

CASE: We report a 67-year-old man in whom pseudoaldosteronism developed following consumption of the health food Shin-Gojoshin. The patient began consuming Shin-Gojoshin in February 2007. His serum potassium level, which was within the normal range until he began consumption, gradually decreased to 3.0 mEq/L. The administration of potassium supplements and spironolactone was initiated. However, his hypokalemia persisted, and in December 2009, he was referred to our hospital for further examination. Laboratory data revealed hypokalemia, metabolic alkalosis, urinary potassium wasting, low plasma renin activity, and a low plasma aldosterone concentration. Pseudoaldosteronism was suspected and he was admitted. Although he reported no history of consumption of other traditional herbal medicines at the initial medical outpatient examination, he reported the consumption of Shin-Gojoshin in a medical interview taken on admission. Discontinuation of Shin-Gojoshin and potassium supplementation on admission successfully normalized his electrolyte imbalance. CONCLUSION: The present case describes the occurrence of pseudoaldosteronism induced by consumption of Shin-Gojoshin. A history of consumption of traditional herbal medicines and other health foods should be obtained, particularly in elderly individuals presenting with symptoms of pseudoaldosteronism.


Assuntos
Alimentos Orgânicos/efeitos adversos , Síndrome de Liddle/induzido quimicamente , Idoso , Humanos , Masculino
15.
J Vet Med Sci ; 84(4): 507-510, 2022 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-35228407

RESUMO

The Cre-loxP system is widely used to investigate the cell-type specific roles of genes of interest. Cre-driver mice are required for cell-type specific knockout during the Cre-loxP reaction. To maintain Cre-driver mouse strains, Polymerase chain reaction (PCR)-oriented genotyping targeting the Cre gene cassette is usually conducted. In this study, we instead applied a colorimetric loop-mediated isothermal amplification (LAMP) method for Cre-genotyping. Among four sets of primers designed by the in silico program, one set effectively amplified the Cre cassette of three Cre-driver strains, but not of C57BL/6 mice. This LAMP-oriented method reduces assay time by less than half compared to the PCR-based method, and can be carried out using a conventional isothermal incubator. Applying this LAMP method may accelerate genotyping of Cre-driver mice.


Assuntos
Colorimetria , Técnicas de Amplificação de Ácido Nucleico , Animais , Colorimetria/veterinária , Genótipo , Integrases , Camundongos , Camundongos Endogâmicos C57BL , Técnicas de Diagnóstico Molecular , Técnicas de Amplificação de Ácido Nucleico/métodos , Técnicas de Amplificação de Ácido Nucleico/veterinária , Sensibilidade e Especificidade
16.
Transl Oncol ; 21: 101431, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35452996

RESUMO

Glutamine metabolism, known as glutaminolysis, is abnormally activated in many cancer cells with KRAS or BRAF mutations or active c-MYC. Glutaminolysis plays an important role in the proliferation of cancer cells with oncogenic mutations. In this study, we characterized radiation-induced cell death, which was enhanced by glutaminolysis inhibition in non-small cell lung cancer A549 and H460 cell lines with KRAS mutation. A clonogenic survival assay revealed that treatment with a glutaminase inhibitor, CB839, enhanced radiosensitivity. X-irradiation increased glutamate production, mitochondrial oxygen consumption, and ATP production, whereas CB839 treatment suppressed these effects. The data suggest that the enhancement of glutaminolysis-dependent energy metabolism for ATP production is important for survival after X-irradiation. Evaluation of the cell death phenotype revealed that glutaminolysis inhibitory treatment with CB839 or a low-glutamine medium significantly promoted the proliferation of ß-galactosidase-positive and IL-6/IL-8 secretory cells among X-irradiated tumor cells, corresponding to an increase in the senescent cell population. Furthermore, treatment with ABT263, a Bcl-2 family inhibitor, transformed senescent cells into apoptotic cells. The findings suggest that combination treatment with a glutaminolysis inhibitor and a senolytic drug is useful for efficient radiotherapy.

17.
Biochem Biophys Res Commun ; 407(1): 68-73, 2011 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-21356196

RESUMO

We aimed at elucidating the roles of transforming growth factor (TGF)-ß and Smad3 signaling in adipocyte differentiation (adipogenesis) and in the pathogenesis of obesity. TGF-ß/Smad3 signaling in white adipose tissue (WAT) was determined in genetically obese (ob/ob) mice. The effect of TGF-ß on adipogenesis was evaluated in mouse embryonic fibroblasts (MEF) isolated both from WT controls and Smad3 KO mice by Oil red-O staining and gene expression analysis. Phenotypic analyses of high-fat diet (HFD)-induced obesity in Smad3 KO mice compared to WT controls were performed. TGF-ß/Smad3 signaling was elevated in WAT from ob/ob mice compared to the controls. TGF-ß significantly inhibited adipogenesis in MEF, but the inhibitory effects of TGF-ß on adipogenesis were partially abolished in MEF from Smad3 KO mice. TGF-ß inhibited adipogenesis independent from the Wnt and ß-catenin pathway. Smad3 KO mice were protected against HFD-induced insulin resistance. The size of adipocytes from Smad3 KO mice on the HFD was significantly smaller compared to the controls. In conclusion, the TGF-ß/Smad3 signaling pathway plays key roles not only in adipogenesis but also in development of insulin resistance.


Assuntos
Adipócitos Brancos/fisiologia , Adipogenia , Obesidade/metabolismo , Proteína Smad3/metabolismo , Fator de Crescimento Transformador beta/metabolismo , Adipócitos Brancos/efeitos dos fármacos , Adipócitos Brancos/metabolismo , Tecido Adiposo Branco/metabolismo , Animais , Insulina/farmacologia , Resistência à Insulina/fisiologia , Masculino , Camundongos , Camundongos Knockout , Proteína Smad3/genética
18.
Arterioscler Thromb Vasc Biol ; 30(4): 675-82, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20139355

RESUMO

OBJECTIVE: CCN3 belongs to the CCN family, which constitutes multifunctional secreted proteins that act as matrix cellular regulators. We investigated the pathophysiological roles of CCN3 in the vessels. METHODS AND RESULTS: We examined the effects of CCN3 on the proliferation and migration of rat vascular smooth muscle cells (VSMC). CCN3 knockout mice were created, and vascular phenotypes and neointimal hyperplasia induced by photochemically induced thrombosis were investigated. CCN3 suppressed the VSMC proliferation induced by fetal bovine serum. The neutralizing antibody for transforming growth factor-beta did not affect the growth inhibitory effect of CCN3. Moreover, CCN3 enhanced the mRNA expression of cyclin-dependent kinase inhibitors, p21 and p15. Gamma secretase inhibitor, an inhibitor of Notch signaling, partially inhibited the enhanced expression of p21 induced by CCN3. CCN3 also inhibited the VSMC migration. Finally, the histopathologic evaluation of the arteries 21 days after the endothelial injury revealed a 6-fold enhancement of neointimal thickening in the null mice compared with the wild-type mice. CONCLUSIONS: CCN3 suppresses neointimal thickening through the inhibition of VSMC migration and proliferation. Our findings indicate the involvement of CCN3 in vascular homeostasis, especially on injury, and the potential usefulness of this molecule in the modulation of atherosclerotic vascular disease.


Assuntos
Movimento Celular , Proliferação de Células , Angiopatias Diabéticas/metabolismo , Músculo Liso Vascular/metabolismo , Miócitos de Músculo Liso/metabolismo , Proteína Sobre-Expressa em Nefroblastoma/metabolismo , Trombose/metabolismo , Secretases da Proteína Precursora do Amiloide/antagonistas & inibidores , Secretases da Proteína Precursora do Amiloide/metabolismo , Animais , Aorta/metabolismo , Aorta/patologia , Ciclo Celular , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Inibidor de Quinase Dependente de Ciclina p15/metabolismo , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/patologia , Angiopatias Diabéticas/patologia , Angiopatias Diabéticas/prevenção & controle , Artéria Femoral/metabolismo , Artéria Femoral/patologia , Genótipo , Hiperplasia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Músculo Liso Vascular/efeitos dos fármacos , Músculo Liso Vascular/patologia , Miócitos de Músculo Liso/efeitos dos fármacos , Miócitos de Músculo Liso/patologia , Proteína Sobre-Expressa em Nefroblastoma/deficiência , Proteína Sobre-Expressa em Nefroblastoma/genética , Fenótipo , Inibidores de Proteases/farmacologia , Ratos , Ratos Wistar , Receptores Notch/metabolismo , Proteínas Recombinantes/metabolismo , Transdução de Sinais , Trombose/patologia , Trombose/prevenção & controle , Fatores de Tempo , Transfecção , Fator de Crescimento Transformador beta/metabolismo
19.
Biochem Biophys Res Commun ; 379(2): 411-6, 2009 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-19114027

RESUMO

Transforming growth factor-beta (TGF-beta) is known to promote the accumulation of extracellular matrix (ECM) and the development of diabetic nephropathy. Halofuginone, an analog of febrifugine, has been shown to block TGF-beta(1) signaling and subsequent type I collagen production. Here, the inhibitory effect of halofuginone on diabetic nephropathy was examined. Halofuginone suppressed Smad2 phosphorylation induced by TGF-beta(1) in cultured mesangial cells. In addition, the expression of TGF-beta type 2 receptor decreased by halofuginone. Halofuginone showed an inhibitory effect on type I collagen and fibronectin expression promoted by TGF-beta(1). An in vivo experiment using db/db mice confirmed the ability of halofuginone to suppress mesangial expansion and fibronectin overexpression in the kidneys. Moreover, an analysis of urinary 8-OHdG level and dihydroethidium fluorescence revealed that halofuginone reduced oxidative stress in the glomerulus of db/db mice. These data indicate that halofuginone prevents ECM deposition and decreases oxidative stress, thereby suppressing the progression of diabetic nephropathy.


Assuntos
Nefropatias Diabéticas/metabolismo , Nefropatias Diabéticas/patologia , Matriz Extracelular/efeitos dos fármacos , Matriz Extracelular/patologia , Piperidinas/farmacologia , Quinazolinonas/farmacologia , Animais , Colágeno Tipo I/antagonistas & inibidores , Colágeno Tipo I/metabolismo , Fibronectinas/antagonistas & inibidores , Fibronectinas/metabolismo , Células Mesangiais/efeitos dos fármacos , Células Mesangiais/metabolismo , Células Mesangiais/patologia , Camundongos , Camundongos Endogâmicos , Estresse Oxidativo/efeitos dos fármacos , Ratos , Proteína Smad2/metabolismo , Fator de Crescimento Transformador beta/antagonistas & inibidores
20.
Dent Traumatol ; 25(2): 194-7, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19290899

RESUMO

AIM: The purpose of this study was to investigate the demographics, the type of impact, the site and the treatment of maxillofacial fractures sustained during baseball and softball to develop an effective preventive strategy. PATIENTS AND METHODS: Data of 82 patients treated for baseball- and softball-related maxillofacial fractures at the Department of Oral and Maxillofacial Surgery, Nara Medical University between 1982 and 2007 were retrospectively analyzed. RESULTS: Injuries were found in 64 men in baseball and 16 men and two women in softball with average ages of 19.6 and 30.0 years, respectively. Fractures were caused by being hit by the ball in 61 patients followed by collision in 16 patients. Fractures of the mandible and the mid-face were found in 44 and 38 patients, respectively. The mental and angle region of the mandible and zygoma and alveolar bone of the maxilla were frequently involved. Treatment was mostly conservative. Open reduction and internal fixation were performed only in 15 patients. CONCLUSIONS: Most maxillofacial fractures in these sports were ball-related. Therefore, effective preventive means should be considered to protect against such injuries.


Assuntos
Traumatismos em Atletas/epidemiologia , Beisebol/lesões , Fraturas Mandibulares/epidemiologia , Traumatismos Maxilofaciais/epidemiologia , Adolescente , Adulto , Distribuição por Idade , Beisebol/estatística & dados numéricos , Criança , Feminino , Humanos , Japão/epidemiologia , Masculino , Fraturas Mandibulares/terapia , Traumatismos Maxilofaciais/terapia , Pessoa de Meia-Idade , Distribuição por Sexo , Adulto Jovem
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