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1.
Appl Environ Microbiol ; 83(7)2017 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-28087537

RESUMEN

Studies on the health-promoting effects of lactic acid bacteria (LAB) are numerous, but few provide examples of the relationship between LAB function and culture conditions. We verified the effect of differences in culture conditions on Lactobacillus plantarum OLL2712 functionality; this strain exhibits anti-inflammatory activity and preventive effects against metabolic disorders. We measured interleukin-10 (IL-10) and IL-12 production in murine immune cells treated with OLL2712 cells prepared under various culture conditions. The results showed that the IL-10-inducing activities of OLL2712 cells on murine immune cells differed dramatically between OLL2712 groups at different culture phases and using different culture medium components, temperatures, and neutralizing pHs. In particular, exponential-phase cells had much more IL-10-inducing activity than stationary-phase cells. We confirmed that the Toll-like receptor 2 (TLR2) stimulation activity of OLL2712 cells depended on culture conditions in conjunction with IL-10-inducing activity. We also demonstrated functional differences by culture phases in vivo; OLL2712 cells at exponential phase had more anti-inflammatory activity and anti-metabolic-disorder effects on obese and diabetic mice than those by their stationary-phase counterparts. These results suggest that culture conditions affect the functionality of anti-inflammatory LAB.IMPORTANCE While previous studies demonstrated that culture conditions affected the immunomodulatory properties of lactic acid bacteria (LAB), few have comprehensively investigated the relationship between culture conditions and LAB functionality. In this study, we demonstrated several culture conditions of Lactobacillus plantarum OLL2712 for higher anti-inflammatory activity. We also showed that culture conditions concretely influenced the health-promoting functions of OLL2712 in vivo, particularly against metabolic disorders. Further, we characterized a novel mechanism by which changing LAB culture conditions affected immunomodulatory properties. Our results suggest that culture condition optimization is important for the production of LAB with anti-inflammatory activity.


Asunto(s)
Diabetes Mellitus Tipo 2/inmunología , Diabetes Mellitus Tipo 2/microbiología , Lactobacillus plantarum/fisiología , Obesidad/inmunología , Obesidad/microbiología , Animales , Medios de Cultivo/química , Células Dendríticas/inmunología , Concentración de Iones de Hidrógeno , Inmunomodulación , Interleucina-10/análisis , Interleucina-10/biosíntesis , Interleucina-10/inmunología , Interleucina-12/análisis , Interleucina-12/biosíntesis , Interleucina-12/inmunología , Lactobacillus plantarum/crecimiento & desarrollo , Macrófagos/inmunología , Ratones , Probióticos/uso terapéutico , Temperatura , Receptor Toll-Like 2/biosíntesis
2.
Br Poult Sci ; 58(5): 569-577, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-28548864

RESUMEN

1. The aim of this study was to investigate the effects on the rectal temperature of young chicks of the oral administration of a medium that contained both live bacteria that produce D-aspartate (D-Asp) and D-Asp. 2. In Experiment 1, chicks were subjected to chronic oral administration of either the medium (containing live bacteria and 2.46 µmol D-Asp) or water from 7 to 14 d of age. Plasma-free amino acids as well as mitochondrial biogenic gene expression in the breast muscle were analysed. In Experiment 2, 7-d-old chicks were subjected to acute oral administration of the above medium or of an equimolar amount of D-Asp to examine their effect on changes in rectal temperature. In Experiment 3, after 1 week of chronic oral administration of the medium, 14-d-old chicks were exposed to either high ambient temperature (HT; 40 ± 1°C, 3 h) or control thermoneutral temperature (CT; 30 ± 1°C, 3 h) to monitor the changes in rectal temperature. 3. Chronic, but not acute, oral administration of the medium significantly reduced rectal temperature in chicks, and a chronic effect also appeared under HT conditions. 4. Chronic oral administration of the medium significantly reduced the mRNA abundance of the avian uncoupling protein (avUCP) in the breast muscle, but led to a significant increase in avian adenine nucleotide translocator (avANT) mRNA in the same muscle. 5. (a) These results indicate that the medium can reduce body temperature through the decline in avUCP mRNA expression in the breast muscle that may be involved in reduced mitochondrial proton leaks and heat production. (b) The increase in avANT further suggests a possible enhancement of adenosine triphosphate (ATP) synthesis.


Asunto(s)
Proteínas Aviares/genética , Bacterias/química , Pollos/fisiología , Ácido D-Aspártico/administración & dosificación , Ácido D-Aspártico/metabolismo , Proteínas Mitocondriales/genética , Administración Oral , Crianza de Animales Domésticos , Animales , Temperatura Corporal , Pollos/crecimiento & desarrollo , Expresión Génica , Calor , Masculino , Distribución Aleatoria
3.
Ann Oncol ; 26(10): 2149-54, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-26205395

RESUMEN

BACKGROUND: Giant cell tumor of bone (GCTB) is a rare primary bone tumor, characterized by osteoclast-like giant cells that express receptor activator of nuclear factor-kappa B (RANK), and stromal cells that express RANK ligand (RANKL), a key mediator of osteoclast activation. A RANKL-specific inhibitor, denosumab, was predicted to reduce osteolysis and control disease progression in patients with GCTB. PATIENTS AND METHODS: Seventeen patients with GCTB were enrolled. Patients were treated with denosumab at 120 mg every 4 weeks, with a loading dose of 120 mg on days 8 and 15. To evaluate efficacy, objective tumor response was evaluated prospectively by an independent imaging facility on the basis of prespecified criteria. RESULTS: The proportion of patients with an objective tumor response was 88% based on best response using any tumor response criteria. The proportion of patients with an objective tumor response using individual response criteria was 35% based on the modified Response Evaluation Criteria in Solid Tumors (RECIST) criteria, 82% based on the modified European Organization for Research and Treatment of Cancer (EORTC) criteria, and 71% based on inverse Choi criteria. The median time of study treatment was 13.1 months. CONCLUSION: The findings demonstrate that denosumab has robust clinical efficacy in the treatment of GCTB.


Asunto(s)
Conservadores de la Densidad Ósea/uso terapéutico , Neoplasias Óseas/tratamiento farmacológico , Denosumab/uso terapéutico , Tumor Óseo de Células Gigantes/tratamiento farmacológico , Recurrencia Local de Neoplasia/tratamiento farmacológico , Adolescente , Adulto , Anciano , Neoplasias Óseas/patología , Femenino , Estudios de Seguimiento , Tumor Óseo de Células Gigantes/patología , Humanos , Masculino , Persona de Mediana Edad , Recurrencia Local de Neoplasia/patología , Estadificación de Neoplasias , Pronóstico , Estudios Prospectivos , Adulto Joven
5.
Artículo en Inglés | MEDLINE | ID: mdl-32954967

RESUMEN

Lactococcus lactis has been reported unable to directly incorporate mononucleotides but instead requires their external dephosphorylation by nucleotidases to the corresponding nucleosides prior to their incorporation. Although Lactobacillus gasseri PA-3 (PA-3), a strain of lactic acid bacteria, has been found to incorporate purine mononucleotides such as adenosine 5'-monophosphate (AMP), it remains unclear whether these bacteria directly incorporate these mononucleotides or incorporate them after dephosphorylation to the corresponding nucleosides. This study evaluated whether PA-3 incorporated radioactively-labeled mononucleotides in the presence or absence of the 5'-nucleotidase inhibitor α,ß-methylene ADP (APCP). PA-3 took up 14C-AMP in the presence of APCP, as well as incorporating 32P-AMP. Furthermore, radioactivity was detected in the RNA/DNA of bacterial cells cultured in the presence of 32P-AMP. Taken together, these findings indicated that PA-3 incorporated purine mononucleotides directly rather than after their dephosphorylation to purine nucleosides and that PA-3 utilizes these purine mononucleotides in the synthesis of RNA and DNA. Although additional studies are required to identify purine mononucleotide transporters in PA-3, this study is the first to show that some lactic acid bacteria directly incorporate purine mononucleotides and use them for growth.


Asunto(s)
Lactobacillus gasseri , Adenosina Monofosfato/metabolismo , Lactobacillus gasseri/metabolismo , Nucleotidasas/metabolismo , Nucleósidos de Purina/metabolismo
6.
Nucleosides Nucleotides Nucleic Acids ; 39(10-12): 1440-1448, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32397874

RESUMEN

Although most lactic acid bacteria do not directly incorporate purine nucleotides, the strain Lactobacillus gasseri PA-3 was found to incorporate purine mononucleotides. To determine whether the direct uptake of purine mononucleotides is dependent on the species or strain of lactic acid bacteria, incorporation of purine mononucleotides was assessed in L. gasseri, Lactcoccus lactis sbsp. lactis, Streptococcus thermophilus and other species of lactic acid bacteria. Each bacterial strain was incubated with 32P-AMP or 14C-adenosine and the incorporation of each purine was evaluated by measuring their radioactivity. All investigated strains of L. gasseri incorporated 32P-AMP, whereas strains of S. thermophilus and most strains of L. lactis did not. Incorporation of 32P-AMP into strains of Pediococcus was dependent on the strain or species of that genus of bacteria. All investigated strains, except for one strain of L. gasseri, incorporated 14C-adenosine, with S. thermophilus, L. lactis and Pediococcus generally displaying greater incorporation of 14C-adenosine than L. gasseri. Although most lactic acid bacteria such as S. thermophiles and L. lactis do not incorporate purine mononucleotides, some species such as L. gasseri directly incorporate purine mononucleotides. These findings indicate that the preferential incorporation of purine mononucleotides or nucleosides by lactic acid bacteria is dependent on the species or strain.


Asunto(s)
Adenosina Monofosfato/metabolismo , Adenosina/metabolismo , Bacterias/metabolismo , Ácido Láctico/biosíntesis , Transporte Biológico , Especificidad de la Especie
8.
Artículo en Inglés | MEDLINE | ID: mdl-29842848

RESUMEN

Lactobacillus gasseri PA-3 (PA-3) is a bacterial strain with a strong ability to degrade purine nucleosides. We previously showed that PA-3 incorporates purines in vitro and that oral administration of PA-3 and purines to rats attenuated their absorption of purines. It remains unclear whether these effects of PA-3 depend on bacterial strains. This study therefore compared the abilities of PA-3 and another bacterial strain of L. gasseri, OLL2996, which has shown decreased ability to degrade purine nucleosides in vitro, to incorporate purine nucleosides and to inhibit the absorption of purines fed to rats. Each bacterial strain was incubated in the presence of 14C-adenosine or 14C-inosine and the incorporation of each purine was evaluated by measuring their radioactivity. In vivo, rats were fed 14C-labeled purines along with PA-3 or OLL2996 and the absorption of these 14C-labeled purines was evaluated by analyzing radioactivity of blood samples. PA-3 incorporated about twice as much 14C-adenosine and 14C-inosine as OLL2996. The elevation of radioactivity levels in blood was 10-20% lower in rats treated with PA-3 than in control rats, after feeding with both 14C-adenosine and 14C-inosine as purines. In contrast, treatment with OLL2996 did not have statistically significant effects on radioactivity compared with the control group. These results indicate that the magnitude of bacterial inhibition of purine absorption is dependent on bacterial strain, correlating at least partly with the ability to incorporate and degrade purines.


Asunto(s)
Lactobacillus gasseri/metabolismo , Nucleósidos de Purina/metabolismo , Adenina/metabolismo , Adenosina/metabolismo , Animales , Radioisótopos de Carbono , Absorción Gástrica , Inosina/metabolismo , Masculino , Purinas/metabolismo , Ratas Wistar , Especificidad de la Especie
9.
Artículo en Inglés | MEDLINE | ID: mdl-29723107

RESUMEN

Excessive intake of purine-rich foods elevates serum uric acid levels, making it a risk factor for hyperuricemia. We hypothesized that lactic acid bacteria ingested with food might utilize purines and contribute to their decreased absorption in the intestines, thereby preventing hyperuricemia. We previously reported that Lactobacillus gasseri PA-3 (PA-3) incorporates adenosine/inosine and related purines and that oral ingestion of PA-3 reduced the absorption of these purines in rats. However, it is unclear whether PA-3 also decreases the absorption of other purines, such as guanosine 5'-monophosphate (GMP) and guanosine. This study investigated whether PA-3 incorporates GMP and guanosine and reduces their absorption in rats. PA-3 incorporated both purines, with 14C-GMP uptake being greater than that of 14C-guanosine. Radioactivity in rat blood was significantly lower 30, 45, and 60 minutes after administration of 14C-GMP plus PA-3 than after administration of 14C-GMP alone and was significantly lower 15 minutes after administration of 14C-guanosine plus PA-3 than after administration of 14C-guanosine alone. PA-3 incorporates GMP and guanosine in vitro. Oral administration of PA-3 with GMP and guanosine reduces the intestinal absorption of these purines in vivo. These findings, together with those of previous studies, indicate that PA-3 reduces the absorption of major purines contained in foods. PA-3 may also attenuate the excessive absorption of dietary purines in humans, protecting these individuals against hyperuricemia.


Asunto(s)
Guanosina Monofosfato/metabolismo , Absorción Intestinal/efectos de los fármacos , Lactobacillus gasseri/metabolismo , Purinas/farmacocinética , Animales , Alimentos , Masculino , Purinas/metabolismo , Ratas , Ratas Wistar , Ácido Úrico/sangre
10.
Nucleosides Nucleotides Nucleic Acids ; 35(10-12): 670-676, 2016 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-27906630

RESUMEN

It is well accepted that frequent and heavy intake of purine-rich foods causes elevation of serum uric acid levels, which is a risk factor of hyperuricemia. Reducing intestinal absorption of dietary purines may attenuate the elevation of serum uric acid levels and exacerbation of hyperuricemia. This reduction may be achieved by the ingestion of lactic acid bacteria that take up purines in the intestine. In this study, we investigated the degree of uptake and utilization of purines of three lactobacilli strains. Among them, Lactobacillus gasseri PA-3 (PA-3) showed the greatest incorporation of 14C-adenine. PA-3 also incorporated 14C-adenosine and 14C-AMP. Additionally, using defined growth medium, PA-3 demonstrated greater proliferation in the presence of these purines than in their absence. Although further investigation is required, ingestion of PA-3 may lower serum uric acid levels by reducing intestinal absorption of purines in humans.


Asunto(s)
Adenina/metabolismo , Adenosina Monofosfato/metabolismo , Adenosina/metabolismo , Lactobacillus gasseri/metabolismo , Dieta , Alimentos , Humanos , Absorción Intestinal , Lactobacillus gasseri/crecimiento & desarrollo
11.
J Am Coll Cardiol ; 35(1): 164-8, 2000 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-10636275

RESUMEN

OBJECTIVES: The study evaluated the value of coronary flow velocity measurement by transthoracic color Doppler echocardiography (TTCDE) for the noninvasive diagnosis of restenosis after percutaneous transluminal coronary angioplasty (PTCA) for left anterior descending coronary artery (LAD) lesions. BACKGROUND: Recent advances in TTCDE provide coronary flow velocity measurements in the LAD under the guidance of color flow mapping. METHODS: We studied 53 patients who underwent successful PTCA for LAD lesions and follow-up coronary angiography (18 patients with restenosis [Group-R], 35 patients without restenosis [Group-N]). We searched localized color aliasing corresponding to local flow acceleration to obtain coronary flow velocity at PTCA sites in the LAD. When localized aliasing was detected, we measured coronary flow velocity at the aliasing (stenotic site) and the prestenotic site. RESULTS: Using TTCDE, it was possible to measure mean diastolic velocity (MDV) in the LAD in 41 (77%) of 53 patients (14 of 18 patients in Group-R; 27 of 35 patients in Group-N). Localized aliasing was displayed by color flow mapping in 14 (100%) of 14 patients in Group-R, and 15 (56%) of 27 patients in Group-N. Stenotic MDV in Group-R was significantly higher than that in Group-N (60.3 +/- 21.1 vs. 35.1 +/- 7.6 cm/s, p < 0.01), although prestenotic MDV did not differ between Group-R and Group-N (20.2 +/- 3.0 vs. 19.6 +/- 2.3 cm/s). There were significant differences in the prestenotic to stenotic MDV ratio between Group-R and Group-N (0.36 +/- 0.10 vs. 0.57 +/- 0.09, p < 0.001). Localized aliasing with the prestenotic to stenotic MDV ratio <0.45 as the optimal cutoff value had a sensitivity of 86% and a specificity of 93% for the presence of restenosis in LAD lesions. CONCLUSIONS: Detection of localized color aliasing and measurement of the prestenotic to stenotic MDV ratio in the LAD by TTCDE are useful in the noninvasive diagnosis of restenosis after PTCA for LAD lesions.


Asunto(s)
Angina de Pecho/terapia , Angioplastia Coronaria con Balón , Circulación Coronaria/fisiología , Enfermedad Coronaria/terapia , Ecocardiografía Doppler en Color , Hemodinámica/fisiología , Infarto del Miocardio/terapia , Anciano , Angina de Pecho/diagnóstico por imagen , Angina de Pecho/fisiopatología , Velocidad del Flujo Sanguíneo/fisiología , Enfermedad Coronaria/diagnóstico por imagen , Enfermedad Coronaria/fisiopatología , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Infarto del Miocardio/diagnóstico por imagen , Infarto del Miocardio/fisiopatología , Recurrencia
12.
J Am Coll Cardiol ; 32(5): 1251-9, 1998 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-9809933

RESUMEN

OBJECTIVES: The purpose of this study was to evaluate whether transthoracic Doppler echocardiography (TTDE) can reliably measure coronary flow velocity (CFV) and coronary flow velocity reserve (CFVR) in the left anterior descending coronary artery (LAD) in the clinical setting. BACKGROUND: Coronary flow velocity measurement has provided useful clinical and physiologic information. Advancement in TTDE provides noninvasive measurement of CFV and CFVR in the distal LAD. METHODS: In 23 patients, CFV in the distal LAD was measured by TTDE (5 or 3.5 MHz) under the guidance of color Doppler flow mapping at the time of Doppler guide wire (DGW) examination. Coronary flow velocity in the distal LAD were measured at baseline and hyperemic conditions (intravenous administration of adenosine 0.14 mg/kg/min) by both TTDE and DGW techniques. Coronary flow velocity reserve was defined as the ratio of peak hyperemic to basal averaged peak velocity in the distal LAD. RESULTS: Clear envelopes of basal and hyperemic CFV in the distal LAD were obtained in 18 (78%) of 23 study patients by TTDE. There were excellent correlations between TTDE and DGW methods for the measurements of CFV (averaged peak velocity: r=0.97, y=0.94x + 0.40; averaged diastolic peak velocity: r=0.97, y=0.94x + 0.69; systolic peak velocities: r=0.97, y=0.91x + 0.87; diastolic peak velocity: r=0.98, y=0.95x + 1.10). Coronary flow velocity reserve from TTDE correlated highly with those from DGW examinations (r=0.94, y=0.95x + 0.21). CONCLUSIONS: Noninvasive measurement of CFV and CFVR in the distal LAD using TTDE accurately reflects invasive measurement of CFV and CFVR by DGW method.


Asunto(s)
Circulación Coronaria , Vasos Coronarios/diagnóstico por imagen , Vasos Coronarios/fisiopatología , Ecocardiografía Doppler/métodos , Cardiopatías/fisiopatología , Adenosina/administración & dosificación , Velocidad del Flujo Sanguíneo , Vasos Coronarios/efectos de los fármacos , Femenino , Cardiopatías/diagnóstico por imagen , Humanos , Infusiones Intravenosas , Masculino , Persona de Mediana Edad , Variaciones Dependientes del Observador , Reproducibilidad de los Resultados , Vasodilatadores/administración & dosificación
13.
Genetics ; 158(1): 29-39, 2001 May.
Artículo en Inglés | MEDLINE | ID: mdl-11333216

RESUMEN

We studied the role of DNA ligase in illegitimate recombination in Escherichia coli. A temperature-sensitive mutation in the lig gene reduced the frequency with which lambdabio-transducing phages were generated to 10-14% of that of wild type under UV irradiation. Reintroduction of the lig gene into this mutant restored the frequency of recombinant phage generation to that of wild type. Furthermore, overexpression of DNA ligase enhanced illegitimate recombination by 10-fold with or without UV irradiation. In addition, when DNA ligase was present in only limited amounts, UV-induced or spontaneous illegitimate recombination occurred exclusively at hotspot sites that have relatively long sequences of homology (9 or 13 bp). However, when DNA ligase was overexpressed, most of the illegitimate recombination took place at non-hotspot sites having only short sequences of homology (<4 bp). Thus, the level of ligase activity affects the frequency of illegitimate recombination, the length of sequence homology at the recombination sites, and the preference for recombination at hotspots, at least after UV irradiation. These observations support our hypothesis that the illegitimate recombination that generates lambdabio-transducing phages is mediated by the DNA break-and-join mechanism.


Asunto(s)
Colifagos/fisiología , ADN Ligasas/fisiología , Escherichia coli/virología , Recombinación Genética/fisiología , Transducción Genética , Secuencia de Bases , Colifagos/genética , Daño del ADN , Reparación del ADN , ADN Viral , Escherichia coli/enzimología , Datos de Secuencia Molecular , Homología de Secuencia de Ácido Nucleico , Rayos Ultravioleta
14.
Atherosclerosis ; 146(2): 237-42, 1999 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-10532679

RESUMEN

The hypocholesterolemic and anti-atherosclerotic effect of TS-962, a specific ACAT inhibitor, was investigated in a hamster model fed a high fat diet containing 10% coconut oil and 0.05% cholesterol. Lipid accumulated atherosclerotic lesions were detected by using oil red O staining in the lesion-prone aortic arch. A high dose, estimated to be 15 mg/kg, of TS-962 decreased serum cholesterol to normal levels with reduction of liver cholesterol contents below normal levels, and as a consequence, entirely inhibited the lipid accumulation in the aortic arch. Furthermore, a low dose, estimated to be 1.5 mg/kg, of TS-962 remarkably inhibited aortic lipid accumulation by 73% compared with the control group, without changing either serum cholesterol level or liver cholesterol content. These findings suggest that TS-962 is effective in the primary prevention of atherosclerosis by directly suppressing the formation of foam cells in arteries.


Asunto(s)
Acetamidas/farmacología , Arteriosclerosis/prevención & control , Grasas de la Dieta/toxicidad , Inhibidores Enzimáticos/farmacología , Hiperlipidemias/complicaciones , Metabolismo de los Lípidos , Esterol O-Aciltransferasa/antagonistas & inhibidores , Animales , Aorta Torácica/patología , Arteriosclerosis/etiología , Arteriosclerosis/metabolismo , Arteriosclerosis/patología , Peso Corporal , Cricetinae , Modelos Animales de Enfermedad , Hiperlipidemias/inducido químicamente , Hiperlipidemias/metabolismo , Hiperlipidemias/patología , Hígado/metabolismo , Masculino
15.
Atherosclerosis ; 146(2): 281-90, 1999 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-10532684

RESUMEN

Stimulatory effects of a novel isobenzofranone, MD-700, on low density lipoprotein (LDL) receptor activity were investigated in vitro and in vivo. MD-700 at 0.03 microg/ml elevated the expression of LDL receptor in HepG2 cells within 4 h. Corresponding to this, uptake of fluorescent labeled-LDL (3,3'-dioctadecylindocarbocyanine-LDL) by the cells increased linearly in time- and dose-dependent manner by MD-700 for up to 12 h. In the experiment using HepG2 cells transiently transfected with promoter-luciferase gene constructs, MD-700 increased luciferase activity in a dose-dependent manner from 0.03 to 0.1 microg/ml. In contrast, luciferase activity was not stimulated by MD-700 in construct with a deleted sterol regulatory element (SRE)-1, suggesting importance of SRE-1 in stimulation of the LDL receptor gene promoter by MD-700. Binding experiments on liver membranes from MD-700-treated hamsters showed about a 60% increase in 125I-labeled LDL binding. A Scatchard plot revealed that MD-700 increased the maximal binding without affecting binding affinity. In contrast to findings with an inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A reductase, pravastatin, MD-700 had no effect on the sterol synthesis in hamster liver homogenates. These results suggest that MD-700 stimulates the expression of LDL receptor, presumably in a manner independent of change in sterol metabolism, and thereby promotes LDL clearance. Hypocholesterolemic actions of MD-700 in hamsters were then examined. MD-700 lowered serum cholesterol levels in hamsters fed normal chow or a high-fat diet. Fractionation of serum lipoproteins demonstrated that MD-700 selectively decreased LDL and very low density lipoprotein cholesterol. Dose-dependent decrease in serum cholesterol was also seen in hypercholesterolemic rats. Thus, the hypocholesterolemic action of MD-700 may be attributed to up-regulation of the LDL receptor, based on stimulation of the transcription of the LDL receptor gene. Although pravastatin stimulates LDL uptake and lowers serum cholesterol in a manner similar to that seen with MD-700, the mechanism responsible for hypocholesterolemic action appears to differ.


Asunto(s)
Benzofuranos/farmacología , Hipercolesterolemia/metabolismo , Receptores de LDL/metabolismo , Regulación hacia Arriba , Animales , Northern Blotting , Carbocianinas/metabolismo , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patología , Membrana Celular/metabolismo , Colesterol/biosíntesis , Cricetinae , Cartilla de ADN/química , Modelos Animales de Enfermedad , Colorantes Fluorescentes/metabolismo , Humanos , Hipercolesterolemia/genética , Hipercolesterolemia/patología , Lipoproteínas LDL/efectos de los fármacos , Lipoproteínas LDL/metabolismo , Lipoproteínas VLDL/efectos de los fármacos , Lipoproteínas VLDL/metabolismo , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patología , Masculino , Regiones Promotoras Genéticas/efectos de los fármacos , ARN Mensajero/genética , ARN Neoplásico/genética , Ratas , Ratas Wistar , Receptores de LDL/genética , Esteroles/metabolismo , Transcripción Genética/efectos de los fármacos , Células Tumorales Cultivadas
16.
J Biochem ; 103(1): 61-71, 1988 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-3360762

RESUMEN

We examined the function of beta-actinin as a pointed end capping protein of thin filaments in skeletal muscle. An improvement in preparing beta-actinin yielded purified beta-actinin which retained its activity for more than a week. Two-dimensional gel electrophoresis showed that the two subunits, beta I and beta II, of beta-actinin are, respectively, split into two to three components (isoforms) with different isoelectric points. Polyclonal antibody was raised by injecting such purified and undenatured chicken breast muscle beta-actinin composed of several components into a rabbit. Immuno-gold labeling examination with electron microscopy of an F-actin-beta-actinin complex decorated with HMM showed that 85% of bound gold particles was on the pointed end of actin filaments, while the remaining 15% was on the barbed end. This suggests that in beta-actinin preparation pointed end and barbed end capping proteins inevitably coexist. Immunofluorescence and immunoelectron microscopy directly showed that beta-actinin is located at the pointed end of thin filaments in myofibrils; it was also suggested that a capping protein having common antigenic determinants to beta-actinin is located at Z-line. Thus, the physiological function of beta-actinin as a pointed end capping protein was examined as follows: When beta-actinin was dissociated from the pointed end of thin filaments in an I-Z-I brush by using a high salt solution, thin filaments could be disassembled at the pointed ends at concentrations of exogenous actin lower than a critical value. At a physiological ionic strength, these salt-washed thin filaments gradually shortened at a constant rate of about 45 nm/h. Both the association and dissociation of monomeric actin at the pointed end were suppressed by the rebinding of exogenous beta-actinin. The main physiological role of beta-actinin is therefore to stabilize thin filaments in the sarcomere by preventing addition and removal of actin monomers at the pointed filament end.


Asunto(s)
Citoesqueleto de Actina/metabolismo , Actinina/metabolismo , Citoesqueleto/metabolismo , Músculos/metabolismo , Miofibrillas/metabolismo , Citoesqueleto de Actina/ultraestructura , Actinas/metabolismo , Animales , Pollos , Cinética , Miofibrillas/ultraestructura , Miosinas/metabolismo , Conejos , Viscosidad
17.
J Biochem ; 103(1): 72-5, 1988 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-3360763

RESUMEN

We examined by means of the immunoblotting technique the transition of beta-actinin isoforms during the development of the chicken from 5 day embryo to adult. As an antigen, beta-actinin was prepared from adult chicken breast muscle (pectoralis major) and polyclonal antibody was obtained by injecting undenatured beta-actinin into a rabbit. Immunoblotting examination of breast muscle at several stages of development (except 5 day embryo, in which the whole body minus the head and limbs was examined) showed that the species of beta-actinin subunits change during development: 1) beta I is already present in 5 day embryo, whereas beta II appears only after 9 days. 2) In 5 day embryo, we found, instead of beta II, a new subunit (designated beta III) that cross-reacts with the antibody, has the apparent molecular weight of 30,000 daltons and has a slightly alkaline isoelectric point compared with beta I. The content of beta III gradually decreased and beta III completely disappeared a week after hatching. Such a type of transition of the isoforms in beta-actinin subunits is similar to that observed in other muscle proteins. The transition of beta-actinin isoforms may correlate to the organization of an I-Z-I brush, especially to the length determination of thin filaments, because the developmental stage at which beta III disappears coincides with that at which the length of thin filaments is strictly determined.


Asunto(s)
Actinina/genética , Músculos/embriología , Biosíntesis de Proteínas , Actinina/aislamiento & purificación , Animales , Embrión de Pollo , Músculos/metabolismo , Miofibrillas/metabolismo , Miofibrillas/ultraestructura
18.
J Biochem ; 103(1): 76-80, 1988 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-3360764

RESUMEN

We found that beta-actinin isoforms are present in various types of tissues in adult chicken by using immunoblotting after two dimensional gel electrophoresis; for this purpose, an antibody was raised against beta-actinin purified from adult chicken breast muscle (pectoralis major). One of the beta-actinin subunits, beta I, was present in all tissues we examined, i.e. skeletal (pectoralis major, semitendinosus, and anterior latissimus dorsi), cardiac, and smooth (gizzard) muscles, non-muscle (brain, liver, and kidney) tissues and blood, whereas another subunit, beta II, was present only in muscle tissues. A new subunit (designated beta III) that was found in the embryonic stages of skeletal muscle (Asami, Funatsu & Ishiwata (1988) J. Biochem. 103, 72-75) was present instead of beta II in non-muscle tissues and blood. In cardiac and smooth muscles, beta III coexisted with beta I and beta II. The antibody of beta-actinin did not cross-react to cytoplasmic beta-actinin (molecular weight, 80,000 daltons) found in kidney. It was suggested that the combination of beta I and beta III present in non-muscle tissues and blood is identical to the barbed end capping protein isolated from brain by Killiman and Isenberg (EMBO J. 1, 889-894 (1982)). It is likely that beta-actinin forms a genetic family whose constituents have an ability to cap either the pointed or barbed end of actin filaments.


Asunto(s)
Actinina/análisis , Músculos/análisis , Animales , Huesos/análisis , Química Encefálica , Pollos , Riñón/análisis , Músculo Liso/análisis , Miocardio/análisis
19.
J Biochem ; 128(5): 823-6, 2000 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11056395

RESUMEN

Human midkine is expressed and secreted in the medium under the control of an AOX1 gene promoter in Pichia pastoris using its own secretion signal. The midkine precursor is properly processed to yield the correct amino-terminus of mature midkine. However, more than half of the product receives yeast specific mannosylations. The sites for the mannosylations were determined to be the three threonine residues in the carboxy-terminal region of human midkine. In order to obtain non-mannosylated midkine, alanine residues were substituted for the three threonine residues by site specific mutagenesis. HPLC and mass spectrometry confirmed that the mutant midkine contained almost no mannose residues. Despite the amino acid substitutions in the carboxy-terminal region, mutant human midkine, promoted CHO cell proliferation as well as normal midkine.


Asunto(s)
Proteínas Portadoras/genética , Citocinas/genética , Manosa/química , Factores de Crecimiento Nervioso/genética , Pichia/metabolismo , Secuencia de Aminoácidos , Animales , Células COS , Proteínas Portadoras/química , Citocinas/química , Humanos , Midkina , Datos de Secuencia Molecular , Mutagénesis Sitio-Dirigida , Factores de Crecimiento Nervioso/química , Polímeros/química , Mapeo Restrictivo
20.
J Biochem ; 92(1): 283-93, 1982 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-7118871

RESUMEN

Human fibrinogen contains four asparagine-linked sugar chains in one molecule. All B beta and gamma subunits obtained from both normal fibrinogen and abnormal fibrinogen Nagoya contain 1 mol each of an asparagine-linked sugar chain. The sugar chains were quantitatively liberated as radioactive oligosaccharides from the polypeptide portion by hydrazinolysis followed by N-acetylation and NaB3H4 reduction. By the combination of sequential exoglycosidase digestion and methylation analysis, the structures of the sugar chains of human fibrinogen were elucidated to be NeuAc alpha 2 leads to 6Gal beta 1 leads to 4GlcNAc beta 1 leads to 2Man alpha 1 leads to 6(NeuAc alpha 2 leads to 6Gal beta 1 leads to 4GlcNac beta 1 leads to 2Man alpha 1 leads to 3)Man beta 1 leads to 4GlcNAc beta 1 leads to 4GlcNAc and Gal beta 1 leads to 4GlcNAc beta 1 leads to 2Man alpha 1 leads to 6(NeuAc alpha 2 leads to 6Gal beta 1 leads to 4GlcNAc beta 1 leads to 2Man alpha 1 leads to 3)Man beta 1 leads to 4GlcNAc beta 1 leads to 4GlcNAc. Neither quantitative nor qualitative differences were found between the sugar chain moieties of normal fibrinogen and fibrinogen Nagoya, indicating that the molecular basis of the abnormality in the latter may reside in its polypeptide moieties.


Asunto(s)
Fibrinógeno , Fibrinógenos Anormales , Asparagina , Conformación de Carbohidratos , Secuencia de Carbohidratos , Disulfuros , Humanos , Sustancias Macromoleculares , Oligosacáridos/análisis
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