Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 16 de 16
Filtrar
Más filtros












Base de datos
Intervalo de año de publicación
1.
J Phys Ther Sci ; 33(1): 69-74, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-33519078

RESUMEN

[Purpose] To compare the sensitivity to change and responsiveness of the Balance Evaluation Systems Test, Mini-Balance Evaluation Systems Test, and Brief-Balance Evaluation Systems Test in patients with subacute cerebral infarction. [Participants and Methods] Thirty patients with subacute cerebral infarction participated in this study. The Balance Evaluation Systems Test, Mini-Balance Evaluation Systems Test, Brief-Balance Evaluation Systems Test, Berg Balance Scale, and ambulatory ability were assessed on admission and discharge. Sensitivity to change was calculated using the effect size, standardized response mean, and relative efficiency. Responsiveness was analyzed by comparing the ability of the difference between the scores of the balance assessments at admission and discharge in classifying the participants' ambulatory independence. [Results] All assessments showed significant improvement from admission to discharge. The effect size of the three versions of the Balance Evaluation Systems Test ranged from 0.41 to 0.69. The standardized response mean ranged from 0.75 to 1.28. The cutoff score was 16.7% for the Balance Evaluation Systems Test, 5.5 points for the Mini-Balance Evaluation Systems Test, 1.5 points for the Brief-Balance Evaluation Systems Test, and 3.5 points for the Berg Balance Scale. [Conclusion] The sensitivity to change of the three versions of the Balance Evaluation Systems Test was high or moderate. However, the Mini-Balance Evaluation Systems Test had the highest responsiveness, as determined with the extent of ambulatory independence.

2.
Gen Comp Endocrinol ; 174(2): 80-8, 2011 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-21827760

RESUMEN

Molecular cloning of thyrotropin-releasing hormone receptors (TRHR) was performed in a teleost, the sockeye salmon (Oncorhynchus nerka). Four different TRHR cDNAs were cloned and named TRHR1, TRHR2a, TRHR2b and TRHR3 based on their similarity to known TRHR subtypes in vertebrates. Important residues for TRH binding were conserved in deduced amino acid sequences of the three TRHR subtypes except for the TRHR2b. Seven transmembrane domains were predicted for TRHR1, TRHR2a and TRHR3 proteins but only five for TRHR2b which appears to be truncated. In silico database analysis identified putative TRHR sequences including invertebrate TRHR and reptilian, avian and mammalian TRHR3. Phylogenetic analyses predicted the molecular evolution of TRHR in vertebrates: from the common ancestral TRHR (i.e. invertebrate TRHR), the TRHR2 subtype diverged first and then TRHR1 and TRHR3 diverged. Reverse transcription-polymerase chain reaction analyses revealed TRHR1 transcripts in the brain (hypothalamus), retina, pituitary gland and large intestine; TRHR2a in the brain (telencephalon and hypothalamus); and TRHR3 in the brain (olfactory bulbs) and retina.


Asunto(s)
ADN Complementario/genética , Proteínas de Peces/genética , Receptores de Hormona Liberadora de Tirotropina/genética , Salmón/genética , Secuencia de Aminoácidos , Animales , Clonación Molecular , Evolución Molecular , Proteínas de Peces/química , Proteínas de Peces/metabolismo , Expresión Génica/genética , Datos de Secuencia Molecular , Receptores de Hormona Liberadora de Tirotropina/química , Receptores de Hormona Liberadora de Tirotropina/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Análisis de Secuencia de Proteína
3.
Gen Comp Endocrinol ; 170(2): 374-80, 2011 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-20977909

RESUMEN

Molecular cloning of thyrotropin-releasing hormone receptors (TRHR) was performed in a model teleost fish, medaka (Oryzias latipes). Four subtypes of TRHR were cloned and named them as TRHR1a, TRHR1b, TRHR2 and TRHR3 based on their similarity to known TRHR subtypes in vertebrates. TRHR1a, TRHR1b, TRHR2, and TRHR3 of medaka encode 416, 398, 451, and 386 amino acid residues, respectively. Comparison of cDNA sequences of medaka TRHR subtypes with respective genomic DNA sequences revealed gene structures: TRHR1a, TRHR1b and TRHR3genes consist of two exons while the TRH2 gene consists of five exons. Molecular phylogenetic analyses depicted the molecular evolution of TRHR in vertebrates: From the ancestral molecule, TRHR2 diverged first and then TRHR1 and TRHR3. Reverse transcription-polymerase chain reaction analyses revealed the sites of TRHR expression: Expression of TRHR1, TRHR1b and TRHR2 subtypes has been confirmed in the brain, pineal organ, retina and pituitary gland. In addition, TRHR1b is expressed in spleen, digestive tract and skin, and TRHR2 in testis, ovary and gill. TRHR3 is widely expressed in various tissues. These results indicate that in medaka, TRH might exert multiple functions mediated by different TRHR subtypes expressed in each tissue.


Asunto(s)
Evolución Molecular , Proteínas de Peces/genética , Oryzias/genética , Receptores de Hormona Liberadora de Tirotropina/genética , Secuencia de Aminoácidos , Animales , Clonación Molecular , Femenino , Proteínas de Peces/química , Proteínas de Peces/metabolismo , Masculino , Datos de Secuencia Molecular , Oryzias/metabolismo , Filogenia , Receptores de Hormona Liberadora de Tirotropina/química , Receptores de Hormona Liberadora de Tirotropina/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Alineación de Secuencia , Análisis de Secuencia de Proteína
4.
Extremophiles ; 13(3): 471-9, 2009 May.
Artículo en Inglés | MEDLINE | ID: mdl-19242651

RESUMEN

Deinococcus radiodurans possesses a DNA damage response mechanism that acts via the PprI protein to induce RecA and PprA proteins, both of which are necessary in conferring extreme radioresistance. In an effort to further delineate the nature of the DNA damage response mechanism in D. radiodurans, we set out to identify novel components of the PprI-dependent signal transduction pathway in response to radiation stress. Here we demonstrate the discovery of a novel regulatory protein, PprM (a modulator of the PprI-dependent DNA damage response), which is a homolog of cold shock protein (Csp). Disruption of the pprM gene rendered D. radiodurans significantly sensitive to gamma-rays. PprM regulates the induction of PprA but not that of RecA. PprM belongs in a distinct clade of a subfamily together with Csp homologs from D. geothermalis and Thermus thermophilus. Purified PprM is present as a homodimer under physiological conditions, as the case with Escherichia coli CspD. The pprA pprM double-disruptant strain exhibited higher sensitivity than the pprA or pprM single disruptant strains, suggesting that PprM regulates other hitherto unknown protein(s) important for radioresistance besides PprA. This study strongly suggests that PprM is involved in the radiation response mediated by PprI in D. radiodurans.


Asunto(s)
Daño del ADN , Deinococcus/genética , Dicroismo Circular , Deinococcus/química , Desnaturalización Proteica , Espectrofotometría Ultravioleta , Termodinámica
5.
Zoolog Sci ; 24(7): 686-92, 2007 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-17824776

RESUMEN

A cDNA encoding prepro-thyrotropin-relaesing hormone (ppTRH) in chicken (Gallus gallus) was isolated and the sites of expression in the brain were determined. The chicken ppTRH cDNA encodes 260 amino acids, including four TRH progenitor sequences (-Lys/Arg-Arg-Gln-His-Pro-Gly-Lys/Arg-Arg-). It is interesting to note that chicken ppTRH harbors four TRH progenitor-like sequences. According to the hydropathy profile of chicken ppTRH, not only the TRH progenitor sequences but also the TRH progenitor-like sequences are localized in hydrophilic regions. The TRH progenitor-like sequences might be related to structural conservation in the evolution of ppTRH, although they cannot be processed into TRH due to the mutation of several amino acids. According to the alignment of the deduced amino-acid sequences of known vertebrate ppTRHs and the molecular phylogenetic tree we constructed, we speculate on the molecular evolution of ppTRH in vertebrates. In situ hybridization demonstrated experession of the ppTRH gene in the nucleus preopticus periventricularis, nucleus preopticus medialis, regio lateralis hypothalami, paraventricular nucleus, nucleus periventricularis hypothalami, and nucleus ventromedialis hypothalami in the chicken brain.


Asunto(s)
Pollos/fisiología , Evolución Molecular , Expresión Génica/fisiología , Precursores de Proteínas/biosíntesis , Precursores de Proteínas/genética , Hormona Liberadora de Tirotropina/biosíntesis , Hormona Liberadora de Tirotropina/genética , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Encéfalo/fisiología , Pollos/genética , Femenino , Perfilación de la Expresión Génica/veterinaria , Datos de Secuencia Molecular , Precursores de Proteínas/química , Alineación de Secuencia , Hormona Liberadora de Tirotropina/química
6.
Gen Comp Endocrinol ; 154(1-3): 91-7, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-17681505

RESUMEN

In many teleost species, the photoreceptive pineal organ harbors the circadian clock that regulates melatonin release in the pineal organ itself. However, the pineal organ of three salmonids (rainbow trout Oncorhynchus mykiss, masu salmon Oncorhynchus masou, and sockeye salmon Oncorhynchus nerka) did not exhibit circadian rhythms in melatonin release when maintained under constant darkness (DD) in vitro, suggesting that the pineal organs of all salmonids lack the circadian regulation of melatonin production. To test this hypothesis, the pineal organ of seven salmonids (common whitefish Coregonus lavaretus, grayling Thymallus thymallus, Japanese huchen Hucho perryi, Japanese charr Salvelius leucomaenis pluvius, brook trout Salvelius fontinalis, brown trout Salmo trutta and chum salmon Oncorhynchus keta) and closely related osmerids (ayu Plecoglossus altivelis altivelis and Japanese smelt Hypomesus nipponensis) were individually maintained in flow-through culture at 15 degrees C under several light conditions. Under light-dark cycles, the pineal organ of all species showed a rhythmic melatonin release with high rates during the dark phase. Under DD, the osmerid pineal organs exhibited circadian rhythms in melatonin release with high rates only during the subjective-night but the salmonid pineal organs constantly released melatonin at high rates. Under constant light, melatonin release was suppressed in all species. The pineal organ of rainbow trout maintained at different temperature (15, 20 or 25 degrees C) under DD released melatonin with high rates but the amount of melatonin released was temperature-sensitive (highest at 20 degrees C). Thus, melatonin release from the pineal organ of osmerids is regulated by both light and circadian clock but the circadian regulation is lacking in salmonids. These results indicate that ancestral salmonids lost the circadian regulation of melatonin production after the divergence from osmerid teleosts.


Asunto(s)
Ritmo Circadiano/fisiología , Melatonina/metabolismo , Glándula Pineal/metabolismo , Salmonidae/metabolismo , Animales , Técnicas In Vitro , Oncorhynchus mykiss/metabolismo , Osmeriformes/metabolismo , Flujo Pulsátil
7.
Gen Comp Endocrinol ; 150(2): 364-70, 2007 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-17098236

RESUMEN

The cDNA encoding prepro-thyrotropin-releasing hormone (ppTRH) in a teleost, medaka (Oryzias latipes) was isolated and characterized. The medaka ppTRH cDNA codes for 270 amino acid residues including eight TRH progenitor sequences (-Lys/Arg-Arg-Gln-His-Pro-Gly-Lys/Arg-Arg-). In silico analyses of the medaka genome database predicted that the structure of the medaka ppTRH gene is similar to the ppTRH genes of the other vertebrate species studied to date; consisting of three exons and two introns. Identity of the medaka ppTRH with the other vertebrates is rather low except the sockeye salmon. A molecular phylogenic tree showed that the ppTRH sequences reflected the predicted pattern of species classification. RT-PCR analysis demonstrated ppTRH gene expression in the brain and retina. These results gave some insight into the molecular evolution of ppTRH and physiological functions of TRH in vertebrates.


Asunto(s)
Oryzias/genética , Precursores de Proteínas/genética , Hormona Liberadora de Tirotropina/genética , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Encéfalo/fisiología , Clonación Molecular , ADN Complementario/genética , ADN Complementario/aislamiento & purificación , Datos de Secuencia Molecular , Filogenia , Retina/fisiología , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/veterinaria , Alineación de Secuencia
8.
Biochem Biophys Res Commun ; 351(4): 1072-7, 2006 Dec 29.
Artículo en Inglés | MEDLINE | ID: mdl-17097613

RESUMEN

To elucidate the roles of DEC1 and DEC2, basic helix-loop-helix transcription factors, in the circadian clock of photosensitive zebrafish peripheral cells, zebrafish Dec1 and Dec2 (zDec1 and zDec2) were cloned and their functions and expression patterns were examined in BRF41, a zebrafish cell line. zDEC1 and zDEC2 have high sequence similarity to mammalian counterparts and the molecular phylogenetic analysis of the zDEC1 and zDEC2 sequences reflected the predicted pattern of species classification. zDEC1 and zDEC2 inhibited zCLOCK1:zBMAL3 mediated transcription as CRY1a. zDec1 and zDec2 mRNA showed robust circadian oscillation in BRF41 cells. However, zDec1 and zDec2 mRNA was not strongly induced by exposure to light. These results indicate that zDec1 and zDec2 are involved in the circadian clock mechanism in photosensitive zebrafish peripheral cells by suppressing CLOCK/BMAL-induced gene expression and that the feedback loops of zDEC1 and zDEC2 may be interlocked with the PER/CRY core circadian feedback loops.


Asunto(s)
Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/fisiología , Ritmo Circadiano/genética , Regulación de la Expresión Génica , Proteínas de Pez Cebra/fisiología , Pez Cebra/fisiología , Animales , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/genética , Proteínas CLOCK , Ritmo Circadiano/efectos de la radiación , Clonación Molecular , Luz , Filogenia , Supresión Genética , Transactivadores/genética , Transcripción Genética/efectos de la radiación , Pez Cebra/genética , Proteínas de Pez Cebra/genética
9.
J Nat Prod ; 69(6): 975-7, 2006 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-16792423

RESUMEN

Two novel limonoids, musidunin (1) and musiduol (2), were isolated from a methanol extract of Croton jatrophoides by bioassay-guided fractionation. Their structures were established by extensive NMR experiments. Interestingly, A,B-seco limonoid 1 contains a unique acetal annulation of A, A', and B' rings. Both limonoids exhibited antifeedant activities against two pests, Pectinophora gossypiella and Spodoptera frugiperda.


Asunto(s)
Croton/química , Conducta Alimentaria/efectos de los fármacos , Lepidópteros/efectos de los fármacos , Limoninas/aislamiento & purificación , Plantas Medicinales/química , Animales , Kenia , Larva/efectos de los fármacos , Limoninas/química , Limoninas/farmacología , Estructura Molecular , Control Biológico de Vectores
10.
Endocrinology ; 147(3): 1067-73, 2006 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-16293658

RESUMEN

The photoperiodic response of the gonads requires T3, which is generated photoperiodically from T4 by type 2 iodothyronine deiodinase in the hypothalamus. Although thyroid hormones were long thought to traverse the plasma membrane by passive diffusion due to their lipophilic nature, it is now known that several organic anion transporting polypeptides (Oatp) transport thyroid hormones into target cells. In this study, we have used database searches to isolate DNA sequences encoding members of the chicken Oatp family and constructed a molecular phylogenetic tree. Comprehensive expression analyses using in situ hybridization revealed strong expression of cOatp1c1 and weak expression of cOatp1b1 in the ventro-lateral walls of basal tuberal hypothalamus, whereas expression of four genes (cOatp1a1, cOatp1b1, cOatp1c1, and cOatp3a2) was observed in the choroid plexus. Expression levels of all these genes in both regions were not different between short-day and long-day conditions. Functional expression of cOatp1c1 in Chinese hamster ovary cells revealed that cOatp1c1 is a highly specific transporter for T4 with an apparent Km of 6.8 nm and a Vmax of 1.50 pmol per milligram of protein per minute. These results suggest that cOatp1c1 could be involved in the thyroxine transport necessary for the avian photoperiodic response of the gonads.


Asunto(s)
Proteínas de la Membrana/biosíntesis , Proteínas de la Membrana/fisiología , Transportadores de Anión Orgánico/biosíntesis , Transportadores de Anión Orgánico/fisiología , Animales , Transporte Biológico , Aves , Encéfalo/metabolismo , Células CHO , Pollos , Clonación Molecular , Biología Computacional , Coturnix , Cricetinae , ADN/metabolismo , Cartilla de ADN/química , Bases de Datos Genéticas , Gónadas/metabolismo , Hipotálamo/metabolismo , Hibridación in Situ , Cinética , Luz , Masculino , Modelos Biológicos , Fotoperiodo , Filogenia , Hormonas Tiroideas/metabolismo , Tiroxina/metabolismo , Factores de Tiempo
11.
Gene ; 363: 133-41, 2005 Dec 19.
Artículo en Inglés | MEDLINE | ID: mdl-16203111

RESUMEN

In a previous study, we identified a novel radiation-inducible protein PprA that plays a critical role in the radiation resistance of Deinococcus radiodurans [Narumi, I., Satoh, K., Cui, S., Funayama, T., Kitayama, S., Watanabe, H., 2004. PprA: a novel protein from Deinococcus radiodurans that stimulates DNA ligation. Mol. Microbiol. 54, 278-285.]. Despite the interest in mechanisms underlying radiation responses in D. radiodurans, little is known about the radiation responsive promoter for radiation-inducible proteins. In this study, three transcriptional start points for pprA mRNA were identified by primer extension analysis, located at positions -156, -154 and -22 upstream from the pprA translation initiation site. The amount of the three extended products increased in cells exposed to 2 kGy followed by a 0.5-h post-incubation. This suggested the existence of at least two radiation responsive promoters for pprA expression. Functional characterization of the upstream region of the pprA gene using a luciferase reporter assay revealed that the distal promoter is located between positions -208 and -156 from the translation initiation site, while the proximal promoter is located between positions -57 and -22. The region located between positions -57 and -38 was indispensable for proximal promoter activity. Site-directed mutagenesis of a thymine positioned at -33 resulted in severe impairment of promoter activity, and suggested that the thymine functions as a master base for the proximal radiation responsive promoter. The product of the D. radiodurans pprI gene is thought to be a general switch in the radiation response [Hua, Y., Narumi, I., Gao, G., Tian, B., Satoh, K., Kitayama, S., Shen, B., 2003. PprI: a general switch responsible for extreme radioresistance of Deinococcus radiodurans. Biochem. Biophys. Res. Commun. 306, 354-360.]. We examined the effect of pprI disruption on pprA promoter activity. The results suggested that up-regulation of pprA expression by the pprI gene product is triggered at the promoter level.


Asunto(s)
Proteínas Bacterianas/genética , Deinococcus/efectos de la radiación , Regiones Promotoras Genéticas/efectos de la radiación , Secuencia de Bases , Cartilla de ADN , Deinococcus/genética , Tolerancia a Radiación/genética , Transcripción Genética
12.
Gen Comp Endocrinol ; 141(1): 84-92, 2005 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-15707606

RESUMEN

To expand our knowledge on the evolution of prepro-thyrotropin-releasing hormone (ppTRH) from fish to tetrapods, sequences of ppTRH cDNAs from two cyprinid teleosts, the common carp Cyprinus carpio and goldfish Carassius auratus, were determined. Degenerate primers were designed based on the conserved regions between the zebrafish ppTRH sequence identified from the zebrafish EST database and the sockeye salmon ppTRH sequence, and PCR amplification was performed. Full-length ppTRHs were confirmed from ppTRH cDNAs obtained by 5'- and 3'-rapid amplification of cDNA ends. The common carp ppTRH cDNA encodes 187 amino acids including 6 copies of the TRH progenitor sequence (Lys/Arg-Arg-Gln-His-Pro-Gly-Lys/Arg-Arg), whereas the goldfish ppTRH cDNA encodes 231 amino acids including 8 copies of the TRH progenitor sequence. The molecular phylogenetic analysis of the ppTRH sequences reflected the predicted pattern of species classification. The common carp, goldfish, and zebrafish ppTRHs have some unique characteristics. The common carp and zebrafish ppTRHs are smaller than that of the goldfish mainly due to the absence of 29 and 17 consecutive amino acids, respectively. The deleted region includes one or two TRH progenitor sequences flanked by some glutamate residues, similar to the glutamate-rich regions of human ppTRH. Hydropathy profiles showed that the presence of a TRH progenitor sequence in the C-terminal hydrophilic region is a characteristic of teleosts and human ppTRHs. These observations may provide clues to a better understanding of the molecular evolution of ppTRH.


Asunto(s)
Carpas/genética , ADN Complementario/genética , Carpa Dorada/genética , Precursores de Proteínas/genética , Hormona Liberadora de Tirotropina/genética , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Clonación Molecular , Evolución Molecular , Datos de Secuencia Molecular , Reacción en Cadena de la Polimerasa , Análisis de Secuencia de ADN
13.
Genes Genet Syst ; 78(5): 319-27, 2003 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-14676423

RESUMEN

The insertion sequence element IS8301 isolated from the radiation resistant bacterium Deinococcus radiodurans strain KD8301 was characterized. IS8301 is comprised of 1,736-bp, lacks terminal inverted repeats and does not duplicate target DNA upon its insertion. The amino acid sequence homology of two open reading frames encoded in IS8301 indicates that this insertion sequence element belongs to the IS200/IS605 group. There were seven loci completely identical with the IS8301 sequence in the published D. radiodurans R(1) genome sequence. The genome distribution profiles of IS8301 in strain KD8301 as well as in the three different laboratory isolates (KR(1), MR(1), and R(1)) of wild-type D. radiodurans were investigated using genomic hybridization analysis. At least 21 strong hybridization signals were detected in strain KD8301 while only one hybridization signal was detected in strain KR(1), the parent strain of KD8301. In strain MR1, a different wild-type isolate, six strong hybridization signals were detected. In spite of the identification of seven copies of IS8301 in the published D. radiodurans R(1) genome sequence, only one hybridization signal was detected in strain R(1) purchased from American Type Culture Collection. Using inverse PCR and sequencing analyses, total 13 different insertion loci of IS8301 in the D. radiodurans genome were identified. Sequence comparison of the flanking region of insertion sites indicated that the sequence 5'-TTGAT-3' preceded the left end of IS8301 in all cases.


Asunto(s)
Elementos Transponibles de ADN/genética , Deinococcus/genética , Genoma Bacteriano , Tolerancia a Radiación/genética , Secuencia de Aminoácidos , Secuencia de Bases , ADN Bacteriano , Deinococcus/efectos de la radiación , Genes Bacterianos , Datos de Secuencia Molecular , Hibridación de Ácido Nucleico , Sistemas de Lectura Abierta , Reacción en Cadena de la Polimerasa , Alineación de Secuencia , Secuencias Repetidas Terminales/genética
14.
J Pharmacol Exp Ther ; 303(1): 104-9, 2002 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-12235239

RESUMEN

Interleukin (IL)-6 is a key mediator in the regulation and coordination of the immune response and participates in pathogenesis of cancer cachexia, autoimmune disease, and postmenopausal osteoporosis. In the course of a screening program aimed at IL-6 inhibitor from natural products, we isolated 20S,21-epoxy-resibufogenin-3-formate (ERBF) from bufadienolide and examined the effect of ERBF on activities of various cytokines. ERBF dose dependently suppressed IL-6 activity and caused a parallel rightward shift of dose-response curves to IL-6 at concentrations of 0.03 to 10 ng/ml. Analysis of data yields a pA(2) of 5.12 and a slope of 0.99. Selectivity of ERBF on activity of cytokines was examined using cytokine-dependent cell lines. ERBF did not affect IL-2-dependent growth of CTLL-2 cells, IL-3-dependent growth of Baf3 cells, or tumor necrosis factor (TNF)alpha-induced growth suppression in TNFalpha-sensitive L929 cells. ERBF also did not affect IL-4-stimulated expression of FcepsilonR II receptor (CD23) in U-937 cells, the IL-8-induced chemotaxis of human neutrophils, or nerve growth factor-stimulated neuronal differentiation in PC-12 cells. In contrast, ERBF dose dependently suppressed IL-6-induced neuronal differentiation in PC-12 cells. Furthermore, ERBF suppressed only IL-6-induced osteoclast formation without affecting osteoclast formation induced by IL-11, leukemia inhibitory factor, and 1alpha,25-dihydroxyvitamin D(3). In receptor binding assay, unbound (free) IL-6 was increased in a dose-dependent manner by pretreatment with ERBF on IL-6 receptor (IL-6R), suggesting that ERBF suppresses binding of IL-6 to IL-6R. These results clearly indicate that ERBF is a novel specific small molecule to show IL-6 receptor antagonist activity.


Asunto(s)
Bufanólidos/farmacología , Quimiotaxis de Leucocito/efectos de los fármacos , Receptores de Interleucina-6/antagonistas & inhibidores , Animales , Células de la Médula Ósea/citología , Células de la Médula Ósea/efectos de los fármacos , Diferenciación Celular , División Celular/efectos de los fármacos , Línea Celular , Técnicas de Cocultivo , Citocinas/farmacología , Humanos , Ratones , Estructura Molecular , Neuronas/citología , Neuronas/efectos de los fármacos , Osteoclastos/citología , Osteoclastos/efectos de los fármacos , Células PC12 , Feocromocitoma , Ratas , Proteínas Recombinantes/antagonistas & inhibidores , Células U937
15.
J Biochem ; 131(1): 121-9, 2002 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-11754743

RESUMEN

RecA protein is considered to be the most important participant in the radiation resistance of Deinococcus radiodurans. However, it is still unclear how RecA contributes to the resistance. In this study, we identified a new recA mutation (recA424) in the DNA-repair deficient mutant strain KI696, the phenotype of which is remarkably different from mutant strain rec30 carrying recA670. The properties of the gene products from the recA mutants were compared. recA424 could not complement the deficiency in Escherichia coli RecA, as found for recA670. In vitro, neither RecA424 nor RecA670 could promote DNA strand exchange under conditions in which wild-type RecA promoted the reaction, indicating that both RecA424 and Rec670 are defective in recombination activity. RecA424 promoted the autocleavage reaction of LexA in vitro, whereas RecA670 did not. The intracellular LexA level in KI696 was decreased following gamma-irradiation. However, the LexA level in strain rec30 was constant irrespective of irradiation. These results indicate that RecA424 retains co-protease activity, whereas RecA670 does not. While strain rec30 is extremely radiation sensitive, strain KI696 is only slightly sensitive. Together, these observations suggest that the co-protease activity rather than the recombination activity of RecA contributes to radiation resistance in D. radiodurans.


Asunto(s)
Proteínas Bacterianas/metabolismo , Reparación del ADN/fisiología , Tolerancia a Radiación , Rec A Recombinasas/genética , Recombinación Genética , Serina Endopeptidasas/metabolismo , Bacterias/enzimología , Rayos gamma , Prueba de Complementación Genética , Mutación , Péptido Hidrolasas/metabolismo , Rec A Recombinasas/aislamiento & purificación , Rec A Recombinasas/metabolismo , Transformación Genética
16.
Biosci Biotechnol Biochem ; 61(5): 864-869, 1997 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-28862568

RESUMEN

Three-day-old rice seedlings treated with ethylene showed elongation of the 2nd and 3rd leaves. This ethylene-stimulated elongation was not observed in the presence of uniconazole-P or prohexadione, both gibberellin (GA) biosynthesis inhibitors, suggesting that GA was involved in the response. An analysis of endogenous GAs by GC-MS revealed that the GA1 level was reduced in the 3rd leaf in response to ethylene. Dose-response experiments showed that the responsiveness to GA1 was enhanced by ethylene. Feeding experiments of 14C-GA1 with ethylene-treated seedlings showed that ethylene may increase the conversion of GA1 to GA8. These results suggest that, in young seedlings of rice, ethylene stimulates leaf elongation by increasing the responsiveness to GA1 and the turnover of GA1.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...