Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 202
Filtrar
Más filtros

Banco de datos
Tipo del documento
Intervalo de año de publicación
1.
Immunity ; 57(7): 1497-1513.e6, 2024 Jul 09.
Artículo en Inglés | MEDLINE | ID: mdl-38744293

RESUMEN

RIPK1 is a multi-functional kinase that regulates cell death and inflammation and has been implicated in the pathogenesis of inflammatory diseases. RIPK1 acts in a kinase-dependent and kinase-independent manner to promote or suppress apoptosis and necroptosis, but the underlying mechanisms remain poorly understood. Here, we show that a mutation (R588E) disrupting the RIPK1 death domain (DD) caused perinatal lethality induced by ZBP1-mediated necroptosis. Additionally, these mice developed postnatal inflammatory pathology, which was mediated by necroptosis-independent TNFR1, TRADD, and TRIF signaling, partially requiring RIPK3. Our biochemical mechanistic studies revealed that ZBP1- and TRIF-mediated activation of RIPK3 required RIPK1 kinase activity in wild-type cells but not in Ripk1R588E/R588E cells, suggesting that DD-dependent oligomerization of RIPK1 and its interaction with FADD determine the mechanisms of RIPK3 activation by ZBP1 and TRIF. Collectively, these findings revealed a critical physiological role of DD-dependent RIPK1 signaling that is important for the regulation of tissue homeostasis and inflammation.


Asunto(s)
Proteínas Adaptadoras del Transporte Vesicular , Inflamación , Necroptosis , Proteínas de Unión al ARN , Proteína Serina-Treonina Quinasas de Interacción con Receptores , Transducción de Señal , Animales , Proteína Serina-Treonina Quinasas de Interacción con Receptores/metabolismo , Proteína Serina-Treonina Quinasas de Interacción con Receptores/genética , Ratones , Inflamación/metabolismo , Inflamación/inmunología , Proteínas Adaptadoras del Transporte Vesicular/metabolismo , Proteínas Adaptadoras del Transporte Vesicular/genética , Proteínas de Unión al ARN/metabolismo , Proteínas de Unión al ARN/genética , Proteína de Dominio de Muerte Asociada a Fas/metabolismo , Proteína de Dominio de Muerte Asociada a Fas/genética , Muerte Celular , Receptores Tipo I de Factores de Necrosis Tumoral/metabolismo , Receptores Tipo I de Factores de Necrosis Tumoral/genética , Dominios Proteicos , Humanos , Ratones Endogámicos C57BL , Ratones Noqueados , Apoptosis , Mutación , Proteína de Dominio de Muerte Asociada a Receptor de TNF
2.
Clin Exp Immunol ; 217(3): 291-299, 2024 Aug 09.
Artículo en Inglés | MEDLINE | ID: mdl-38916251

RESUMEN

The clinical spectrum of Down syndrome (DS) ranges from congenital malformations to premature aging and early-onset senescence. Excessive immunoreactivity and oxidative stress are thought to accelerate the pace of aging in DS patients; however, the immunological profile remains elusive. We investigated whether peripheral blood monocyte-derived dendritic cells (MoDCs) in DS patients respond to lipopolysaccharide (LPS) distinctly from non-DS control MoDCs. Eighteen DS patients (age 2-47 years, 12 males) and 22 controls (age 4-40 years, 15 males) were enrolled. CD14-positive monocytes were immunopurified and cultured for 7 days in the presence of granulocyte-macrophage colony-stimulating factor and IL-4, yielding MoDCs in vitro. After the LPS-stimulation for 48 hours from days 7 to 9, culture supernatant cytokines were measured by multiplex cytokine bead assays, and bulk-prepared RNA from the cells was used for transcriptomic analyses. MoDCs from DS patients produced cytokines/chemokines (IL-6, IL-8, TNF-α, MCP-1, and IP-10) at significantly higher levels than those from controls in response to LPS. RNA sequencing revealed that DS-derived MoDCs differentially expressed 137 genes (74 upregulated and 63 downregulated) compared with controls. A gene enrichment analysis identified 5 genes associated with Toll-like receptor signaling (KEGG: hsa04620, P = 0.00731) and oxidative phosphorylation (hsa00190, P = 0.0173) pathways. MoDCs obtained from DS patients showed higher cytokine or chemokine responses to LPS than did control MoDCs. Gene expression profiles suggest that hyperactive Toll-like receptor and mitochondrial oxidative phosphorylation pathways configure the immunoreactive signature of MoDCs in DS patients.


Asunto(s)
Citocinas , Células Dendríticas , Síndrome de Down , Lipopolisacáridos , Monocitos , Humanos , Síndrome de Down/inmunología , Células Dendríticas/inmunología , Células Dendríticas/metabolismo , Masculino , Femenino , Adolescente , Adulto , Niño , Lipopolisacáridos/inmunología , Lipopolisacáridos/farmacología , Monocitos/inmunología , Monocitos/metabolismo , Preescolar , Persona de Mediana Edad , Citocinas/metabolismo , Adulto Joven , Células Cultivadas
3.
Phys Rev Lett ; 128(15): 157202, 2022 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-35499891

RESUMEN

We use ^{79}Br nuclear quadrupole resonance (NQR) to demonstrate that ultraslow lattice dynamics set in below the temperature scale set by the Cu-Cu superexchange interaction J (≃160 K) in the kagome lattice Heisenberg antiferromagnet Zn-barlowite. The lattice completely freezes below 50 K, and ^{79}Br NQR line shapes become twice broader due to increased lattice distortions. Moreover, the frozen lattice exhibits an oscillatory component in the transverse spin echo decay, a typical signature of pairing of nuclear spins by indirect nuclear spin-spin interaction. This indicates that some Br sites form structural dimers via a pair of kagome Cu sites prior to the gradual emergence of spin singlets below ∼30 K. Our findings underscore the significant roles played by subtle structural distortions in determining the nature of the disordered magnetic ground state of the kagome lattice.

4.
Proc Natl Acad Sci U S A ; 115(45): E10662-E10671, 2018 11 06.
Artículo en Inglés | MEDLINE | ID: mdl-30352847

RESUMEN

Group A Streptococcus (GAS) is a Gram-positive bacterial pathogen that causes a range of diseases, including fatal invasive infections. However, the mechanisms by which the innate immune system recognizes GAS are not well understood. We herein report that the C-type lectin receptor macrophage inducible C-type lectin (Mincle) recognizes GAS and initiates antibacterial immunity. Gene expression analysis of myeloid cells upon GAS stimulation revealed the contribution of the caspase recruitment domain-containing protein 9 (CARD9) pathway to the antibacterial responses. Among receptors signaling through CARD9, Mincle induced the production of inflammatory cytokines, inducible nitric oxide synthase, and reactive oxygen species upon recognition of the anchor of lipoteichoic acid, monoglucosyldiacylglycerol (MGDG), produced by GAS. Upon GAS infection, Mincle-deficient mice exhibited impaired production of proinflammatory cytokines, severe bacteremia, and rapid lethality. GAS also possesses another Mincle ligand, diglucosyldiacylglycerol; however, this glycolipid interfered with MGDG-induced activation. These results indicate that Mincle plays a central role in protective immunity against acute GAS infection.


Asunto(s)
Lectinas Tipo C/metabolismo , Lipopolisacáridos/metabolismo , Proteínas de la Membrana/metabolismo , Infecciones Estreptocócicas/inmunología , Streptococcus pyogenes/patogenicidad , Ácidos Teicoicos/metabolismo , Animales , Proteínas Adaptadoras de Señalización CARD/genética , Células HEK293 , Humanos , Ratones , Ratones Endogámicos C57BL , Monocitos/metabolismo , Infecciones Estreptocócicas/microbiología
5.
Parasite Immunol ; 42(9): e12700, 2020 09.
Artículo en Inglés | MEDLINE | ID: mdl-32027755

RESUMEN

Intestinal helminthes induce immunosuppressive responses as well as type 2 immunity. Their suppressive properties are intended to regulate inflammatory diseases such as allergies and autoimmune diseases. This study evaluated whether helminthic infections suppress obesity, a chronic inflammatory state, using an intestinal nematode, Heligmosomoides polygyrus (Hp). Infection with Hp at the same time as feeding a high-fat diet (HFD) prevented weight gain, dyslipidaemia and glucose intolerance observed in uninfected obese mice. Immunologically, Hp infection skewed M1 macrophages to M2 macrophages and induced type 2 innate lymphoid cells in adipose tissues. The expression of interleukin (IL)-33, a potent initiator of type 2 responses, was also increased in association with uncoupled protein 1 (UCP1). To further investigate the anti-obesity effects of IL-33 in mice infected with Hp, IL-33-deficient mice were fed the HFD and infected with Hp. These mutant mice rapidly gained weight compared with wild-type mice, indicating the anti-obesity effect of IL-33. In the absence of IL-33, the rapid increase in weight was not prevented, and type 2 responses and UCP1 expression were not observed even during Hp infection. These results suggested that the suppression of obesity by Hp is dependent on IL-33.


Asunto(s)
Dieta Alta en Grasa , Interleucina-33/fisiología , Parasitosis Intestinales/inmunología , Nematospiroides dubius , Obesidad/prevención & control , Infecciones por Strongylida/inmunología , Tejido Adiposo/inmunología , Animales , Inmunidad Innata , Parasitosis Intestinales/complicaciones , Linfocitos/inmunología , Macrófagos/inmunología , Masculino , Ratones , Ratones Endogámicos C57BL , Nematospiroides dubius/inmunología , Obesidad/inmunología , Terapia con Helmintos
6.
Pediatr Nephrol ; 35(10): 1977-1984, 2020 10.
Artículo en Inglés | MEDLINE | ID: mdl-32488669

RESUMEN

BACKGROUND: Acute kidney injury (AKI) often occurs in pediatric patients who received allogeneic hematopoietic cell transplantation (HCT). We evaluated the risk and effect of HCT-related AKI in pediatric patients. METHODS: We retrospectively studied the survival and renal outcome of 69 children 100 days and 1-year posttransplant in our institution in 2004-2016. Stage-3 AKI developed in 34 patients (49%) until 100 days posttransplant. RESULTS: The 100-day overall survival (OS) rates of patients with stage-3 AKI were lower than those without it (76.5% vs. 94.3%, P = 0.035). The 1-year OS rates did not differ markedly between 21 post-100-day survivors with stage-3 AKI and 29 without it (80.8% vs. 87.9%, P = 0.444). The causes of 19 deaths included the relapse of underlying disease or graft failure (n = 11), treatment-related events (4), and second HCT-related events (4). Underlying disease of malignancy (crude hazard ratio (HR) 5.7; 95% confidence interval (CI), 2.20 to 14.96), > 1000 ng/mL ferritinemia (crude HR 4.29; 95% CI, 2.11 to 8.71), stem cell source of peripheral (crude HR 2.96; 95% CI, 1.22 to 7.20) or cord blood (crude HR 2.29; 95% CI, 1.03 to 5.06), and myeloablative regimen (crude HR 2.56; 95% CI, 1.24 to 5.26), were identified as risk factors for stage-3 AKI until 100 days posttransplant. Hyperferritinemia alone was significant (adjusted HR 5.52; 95% CI, 2.21 to 13.76) on multivariable analyses. CONCLUSIONS: Hyperferritinemia was associated with stage-3 AKI and early mortality posttransplant. Pretransplant iron control may protect the kidney of pediatric HCT survivors.


Asunto(s)
Lesión Renal Aguda/epidemiología , Neoplasias Hematológicas/cirugía , Trasplante de Células Madre Hematopoyéticas/efectos adversos , Hiperferritinemia/epidemiología , Complicaciones Posoperatorias/epidemiología , Lesión Renal Aguda/diagnóstico , Lesión Renal Aguda/etiología , Adolescente , Niño , Preescolar , Femenino , Ferritinas/sangre , Estudios de Seguimiento , Neoplasias Hematológicas/mortalidad , Humanos , Hiperferritinemia/diagnóstico , Hiperferritinemia/etiología , Estimación de Kaplan-Meier , Masculino , Complicaciones Posoperatorias/etiología , Modelos de Riesgos Proporcionales , Estudios Retrospectivos , Medición de Riesgo/estadística & datos numéricos , Factores de Riesgo , Índice de Severidad de la Enfermedad , Tasa de Supervivencia , Trasplante Homólogo/efectos adversos
7.
Int J Mol Sci ; 21(8)2020 Apr 18.
Artículo en Inglés | MEDLINE | ID: mdl-32325684

RESUMEN

The establishment of cancer cell lines, which have different metastatic abilities compared with the parental cell, is considered as an effective approach to investigate mechanisms of metastasis. A highly metastatic potential mouse colon cancer cell subline, Colon-26MGS, was derived from the parental cell line Colon-26 by in vivo selection using continuous subcutaneous implanting to immunocompetent mice. To clarify the mechanisms involved in the enhancement of metastasis, morphological characteristics, cell proliferation, and gene expression profiles were compared between Colon-26MGS and the parental cell. Colon-26MGS showed over 10 times higher metastatic ability compared with the parental cell, but there were no differences in morphological characteristics and in vitro proliferation rates. In addition, the Colon-26MGS-bearing mice exhibited no marked change of splenocyte population and lung pre-metastatic niche with tumor-free mice, but there were significant differences compared to Colon-26-bearing mice. RNA-seq analyses indicated that immune costimulatory molecules were significantly up-regulated in Colon-26MGS. These results suggest that Colon-26MGS showed not only higher metastatic activity, but also less induction property of host immune response compared to parental Colon-26. Colon-26MGS has proven to be a novel useful tool for studying multiple mechanisms involving metastasis enhancement.


Asunto(s)
Carcinoma/metabolismo , Carcinoma/secundario , Línea Celular Tumoral , Movimiento Celular/genética , Proliferación Celular/genética , Neoplasias del Colon/metabolismo , Neoplasias Pulmonares/metabolismo , Animales , Carcinoma/genética , Carcinoma/patología , Neoplasias del Colon/genética , Neoplasias del Colon/patología , Femenino , Regulación Neoplásica de la Expresión Génica/genética , Inmunohistoquímica , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patología , Ratones , Ratones Endogámicos BALB C , RNA-Seq
8.
Carcinogenesis ; 40(2): 216-224, 2019 04 29.
Artículo en Inglés | MEDLINE | ID: mdl-30721949

RESUMEN

Biallelic germline mutations in the DNA mismatch repair gene MLH1 lead to constitutional mismatch repair-deficiency syndrome and an increased risk for childhood hematopoietic malignancies, including lymphoma and leukemia. To examine how Mlh1 dysfunction promotes lymphoma as well as the influence of ionizing radiation (IR) exposure, we used an Mlh1-/- mouse model and whole-exome sequencing to assess genomic alterations in 23 T-cell lymphomas, including 8 spontaneous and 15 IR-associated lymphomas. Exposure to IR accelerated T-cell lymphoma induction in the Mlh1-/- mice, and whole-exome sequencing revealed that IR exposure neither increased the number of mutations nor altered the mutation spectrum of the lymphomas. Frequent mutations were evident in genes encoding transcription factors (e.g. Ikzf1, Trp53, Bcl11b), epigenetic regulators (e.g. Suv420h1, Ep300, Kmt2d), transporters (e.g. Rangap1, Kcnj16), extracellular matrix (e.g. Megf6, Lrig1), cell motility (e.g. Argef19, Dnah17), protein kinase cascade (e.g. Ptpro, Marcks) and in genes involved in NOTCH (e.g. Notch1), and PI3K/AKT (e.g. Pten, Akt2) signaling pathways in both spontaneous and IR-associated lymphomas. Frameshift mutations in mononucleotide repeat sequences within the genes Trp53, Ep300, Kmt2d, Notch1, Pten and Marcks were newly identified in the lymphomas. The lymphomas also exhibited a few chromosomal abnormalities. The results establish a landscape of genomic alterations in spontaneous and IR-associated lymphomas that occur in the context of mismatch repair dysfunction and suggest potential targets for cancer treatment.


Asunto(s)
Reparación de la Incompatibilidad de ADN/genética , Mutación del Sistema de Lectura/genética , Mutación de Línea Germinal/genética , Linfoma de Células T/genética , Homólogo 1 de la Proteína MutL/genética , Animales , Epigénesis Genética/genética , Proteínas de Transporte de Membrana/genética , Ratones , Ratones Endogámicos C57BL , Radiación Ionizante , Transducción de Señal/genética , Factores de Transcripción/genética
9.
Infect Immun ; 87(6)2019 06.
Artículo en Inglés | MEDLINE | ID: mdl-30962398

RESUMEN

Obesity is increasingly causing lifestyle diseases in developed countries where helminthic infections are rarely seen. Here, we investigated whether an intestinal nematode, Heligmosomoides polygyrus, has a suppressive role in diet-induced obesity in mice. Infection with H. polygyrus suppressed weight gain in obese mice, which was associated with increased uncoupling protein 1 (UCP1) expression in adipocytes and a higher serum norepinephrine (NE) concentration. Blocking interactions of NE with its receptor on adipocytes resulted in the failure to prevent weight gain and to enhance UCP1 expression in obese mice infected with H. polygyrus, indicating that NE is responsible for the protective effects of H. polygyrus on obesity. In addition to sympathetic nerve-derived NE, the intestinal microbiota was involved in the increase in NE. Infection with H. polygyrus altered the composition of intestinal bacteria, and antibiotic treatment to reduce intestinal bacteria reversed the higher NE concentration, UCP1 expression, and prevention of the weight gain observed after H. polygyrus infection. Our data indicate that H. polygyrus exerts suppressive roles on obesity through modulation of microbiota that produce NE.


Asunto(s)
Terapia Biológica , Microbioma Gastrointestinal , Nematospiroides dubius/fisiología , Obesidad/microbiología , Obesidad/terapia , Adipocitos/metabolismo , Animales , Humanos , Intestinos/microbiología , Intestinos/parasitología , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Obesos , Norepinefrina/metabolismo , Obesidad/metabolismo , Obesidad/parasitología , Proteína Desacopladora 1/genética , Proteína Desacopladora 1/metabolismo
10.
J Am Chem Soc ; 141(49): 19397-19403, 2019 Dec 11.
Artículo en Inglés | MEDLINE | ID: mdl-31738059

RESUMEN

Negative thermal expansion (NTE) induced by simultaneous mechanisms, that is, charge transfer and polar-nonpolar transitions, was observed for the first time in BiNi1-xFexO3 (0.25 ≤ x ≤ 0.5). The low-temperature phase was found to have a polar structure (space group of R3c) with a Bi3+0.5(1+x)Bi5+0.5(1-x)Ni2+1-xFe3+xO3 charge distribution and short-range ordering of Bi3+ and Bi5+. The volume reduction upon heating that was induced by charge transfer between Bi5+ and Ni2+ decreased with increasing x because of the reduction in the amount of Ni2+. Simultaneous polar-nonpolar transition also contributed to NTE, and a composition-independent enhanced volume reduction of ∼2% was observed.

11.
J Neurol Neurosurg Psychiatry ; 90(4): 451-457, 2019 04.
Artículo en Inglés | MEDLINE | ID: mdl-30636701

RESUMEN

OBJECTIVE: To evaluate the efficacy and safety of intramuscular ultra-high-dose methylcobalamin in patients with amyotrophic lateral sclerosis (ALS). METHODS: 373 patients with ALS (El Escorial definite or probable; laboratory-supported probable; duration ≤36 months) were randomly assigned to placebo, 25 mg or 50 mg of methylcobalamin groups. The primary endpoints were the time interval to primary events (death or full ventilation support) and changes in the Revised ALS Functional Rating Scale (ALSFRS-R) score from baseline to week 182. Efficacy was also evaluated using post-hoc analyses in patients diagnosed early (entered ≤12 months after symptom onset). RESULTS: No significant differences were detected in either primary endpoint (minimal p value=0.087). However, post-hoc analyses of methylcobalamin-treated patients diagnosed and entered early (≤12 months' duration) showed longer time intervals to the primary event (p<0.025) and less decreases in the ALSFRS-R score (p<0.025) than the placebo group. The incidence of treatment-related adverse events was similar and low in all groups. CONCLUSION: Although ultra-high-dose methylcobalamin did not show significant efficacy in the whole cohort, this treatment may prolong survival and retard symptomatic progression without major side effects if started early. TRIAL REGISTRATION NUMBER: NCT00444613.


Asunto(s)
Esclerosis Amiotrófica Lateral/tratamiento farmacológico , Vitamina B 12/análogos & derivados , Anciano , Método Doble Ciego , Femenino , Humanos , Inyecciones Intramusculares , Masculino , Persona de Mediana Edad , Respiración Artificial , Tasa de Supervivencia , Vitamina B 12/administración & dosificación , Vitamina B 12/uso terapéutico
12.
J Biol Chem ; 292(41): 16933-16941, 2017 10 13.
Artículo en Inglés | MEDLINE | ID: mdl-28848046

RESUMEN

C-type lectin receptors (CLRs) comprise a large family of immunoreceptors that recognize polysaccharide ligands exposed on pathogen surfaces and are conserved among mammals. However, interspecies differences in their ligand spectrums are not fully understood. Dectin-1 is a well-characterized CLR that recognizes ß-glucan. We report here that seaweed-derived fucan activates cells expressing human Dectin-1 but not mouse Dectin-1. Low-valency ß-glucan components within fucan appeared to be responsible for this activation, as the ligand activity was eliminated by ß-glucanase treatment. The low-valency ß-glucan laminarin also acted as an agonist for human Dectin-1 but not for mouse Dectin-1, whereas the high-valency ß-glucan curdlan activated both human and mouse Dectin-1. Reciprocal mutagenesis analysis revealed that the ligand-binding domain of human Dectin-1 does not determine its unique sensitivity to low-valency ß-glucan. Rather, we found that its intracellular domain renders human Dectin-1 reactive to low-valency ß-glucan ligand. Substitution with two amino acids, Glu2 and Pro5, located in the human Dectin-1 intracellular domain was sufficient to confer sensitivity to low-valency ß-glucan in mouse Dectin-1. Conversely, the introduction of mouse-specific amino acids, Lys2 and Ser5, to human Dectin-1 reduced the reactivity to low-valency ß-glucan. Indeed, low-valency ligands induced a set of proinflammatory genes in human but not mouse dendritic cells. These results suggest that the intracellular domain, not ligand-binding domain, of Dectin-1 determines the species-specific ligand profile.


Asunto(s)
Glucanos/metabolismo , Lectinas Tipo C/metabolismo , Polisacáridos/metabolismo , beta-Glucanos/metabolismo , Sustitución de Aminoácidos , Animales , Línea Celular , Humanos , Lectinas Tipo C/genética , Ratones , Mutagénesis , Mutación Missense , Dominios Proteicos , Especificidad de la Especie , Especificidad por Sustrato/fisiología
13.
Malar J ; 17(1): 288, 2018 Aug 09.
Artículo en Inglés | MEDLINE | ID: mdl-30092798

RESUMEN

BACKGROUND: Rodent malaria parasites where the gene encoding circumsporozoite protein (CSP) has been replaced with csp genes from the human malaria parasites, Plasmodium falciparum or Plasmodium vivax, are used as pre-clinical tools to evaluate CSP vaccines in vivo. These chimeric rodent parasites produce sporozoites in Anopheles stephensi mosquitoes that are capable of infecting rodent and human hepatocytes. The availability of chimeric P. falciparum parasites where the pfcsp gene has been replaced by the pvcsp would open up possibilities to test P. vivax CSP vaccines in small scale clinical trials using controlled human malaria infection studies. METHODS: Using CRISPR/Cas9 gene editing two chimeric P. falciparum parasites, were generated, where the pfcsp gene has been replaced by either one of the two major pvcsp alleles, VK210 or VK247. In addition, a P. falciparum parasite line that lacks CSP expression was also generated. These parasite lines have been analysed for sporozoite production in An. stephensi mosquitoes. RESULTS: The two chimeric Pf-PvCSP lines exhibit normal asexual and sexual blood stage development in vitro and produce sporozoite-containing oocysts in An. stephensi mosquitoes. Expression of the corresponding PvCSP was confirmed in oocyst-derived Pf-PvCSP sporozoites. However, most oocysts degenerate before sporozoite formation and sporozoites were not found in either the mosquito haemocoel or salivary glands. Unlike the chimeric Pf-PvCSP parasites, oocysts of P. falciparum parasites lacking CSP expression do not produce sporozoites. CONCLUSIONS: Chimeric P. falciparum parasites expressing P. vivax circumsporozoite protein fail to produce salivary gland sporozoites. Combined, these studies show that while PvCSP can partially complement the function of PfCSP, species-specific features of CSP govern full sporozoite maturation and development in the two human malaria parasites.


Asunto(s)
Anopheles/parasitología , Quimera/genética , Plasmodium falciparum/genética , Proteínas Protozoarias/genética , Esporozoítos/fisiología , Animales , Expresión Génica , Plasmodium vivax/genética , Proteínas Protozoarias/metabolismo , Glándulas Salivales/parasitología
14.
Angew Chem Int Ed Engl ; 57(27): 8170-8173, 2018 07 02.
Artículo en Inglés | MEDLINE | ID: mdl-29749074

RESUMEN

Colossal negative thermal expansion (NTE) with a volume contraction of about 8 %, the largest value reported so far for NTE materials, was observed in an electron-doped giant tetragonal perovskite compound Pb1-x Bix VO3 (x=0.2 and 0.3). A polar tetragonal (P4mm) to non-polar cubic structural transition took place upon heating. The coefficient of thermal expansion (CTE) and the working temperature could be tuned by changing the Bi content, and La substitution decreased the transition temperature to room temperature. Pb0.76 La0.04 Bi0.20 VO3 exhibited a unit cell volume contraction of 6.7 % from 200 K to 420 K. Interestingly, further gigantic NTE of about 8.5 % was observed in a dilametric measurement of a Pb0.76 La0.04 Bi0.20 VO3 polycrystalline sample. The pronounced NTE in the sintered body should be attributed to an anisotropic lattice parameter change.

15.
Cancer Sci ; 108(5): 961-971, 2017 May.
Artículo en Inglés | MEDLINE | ID: mdl-28256041

RESUMEN

We previously reported that about 0.4% of cells in the cultured human pancreatic cancer cell line, PANC-1, can invade matrigel during the transwell invasion assay, suggesting that these invaded PANC-1 cells may have specific characteristics to keep their invasive potential. To identify the metabolic characterization specific in the invaded PANC-1 cells, metabolome analysis of the invaded PANC-1 compared with the whole cultured PANC-1 was performed using CE-TOFMS, and concentrations of 110 metabolites were measured. In contrast to the whole cultured cells, the invaded PANC-1 was characterized as a population with reduced levels of amino acids and TCA cycle intermediates, and decreased and increased intermediates in glycolysis and nucleic acid metabolism. In particular, the ratio of both adenosine and guanosine energy charge was reduced in the invaded cells, revealing that the consumption of ATP and GTP was high in the invaded cells, and thus suggesting that ATP- or GTP-generating pathways are stimulated. In addition, the GSH/GSSG ratio was low in the invaded cells, but these cells had a higher surviving fraction after exposure to hydrogen peroxide. Thus, the invaded cells were the population resistant to oxidative stress. Furthermore, reduction in intracellular GSH content inhibited PANC-1 invasiveness, indicated that GSH has an important role in PANC-1 invasiveness. Overall, we propose the invaded cells have several unique metabolic profiles.


Asunto(s)
Invasividad Neoplásica/patología , Neoplasias Pancreáticas/metabolismo , Línea Celular Tumoral , Movimiento Celular/fisiología , Glutatión/metabolismo , Glucólisis/fisiología , Humanos , Metaboloma/fisiología , Ácidos Nucleicos/metabolismo , Estrés Oxidativo/fisiología , Neoplasias Pancreáticas/patología
16.
Cancer Sci ; 108(10): 2004-2010, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-28718972

RESUMEN

Our aim was to evaluate whether repetition of C-ion (carbon ion beam) irradiation induces radioresistance as well as repeated X-ray irradiation in cancer cell lines, and to find the key molecular pathway for radioresistance by comparing radioresistant cancer cells with their parental cells. A mouse squamous cell carcinoma cell line, NR-S1, and radioresistant cancer cells, NR-S1-C30 (C30) and NR-S1-X60 (X60), established by repetition of C-ion and X-ray irradiation, respectively, were used. X-ray and C-ion sensitivity, changes in lysosome, mitochondria, intracellular ATP and reactive oxygen species (ROS) level, and mechanistic target of rapamycin (mTOR) signaling were evaluated. Moreover, the effect of rapamycin on radioresistance was also assessed. X-ray and C-ion resistance of C30 cells was moderate, and the resistance of X60 cells was the highest in this study. In X60 cells, the amount of lysosome, mitochondria, intracellular ATP and ROS level were significantly increased, and mTOR and p70S6K (ribosomal protein S6 kinase p70) phosphorylation were enhanced compared with C30 and NR-S1 cells. The inhibition of mTOR signaling was effective for X-ray and C-ion radiosensitization in both cell lines, especially in X60 cells in which X-ray and C-ion resistance was decreased to the same level as that in NR-S1 cells. Our results indicated that the contribution to generate X-ray and C-ion resistance was less for repeated C-ion irradiations compared with repeated X-ray irradiation. Moreover, we found that activated mTOR signaling contributes to X-ray and C-ion resistance in the X60 cancer cells.


Asunto(s)
Carcinoma de Células Escamosas/metabolismo , Tolerancia a Radiación , Especies Reactivas de Oxígeno/metabolismo , Sirolimus/farmacología , Serina-Treonina Quinasas TOR/metabolismo , Adenosina Trifosfato/metabolismo , Animales , Carcinoma de Células Escamosas/tratamiento farmacológico , Carcinoma de Células Escamosas/radioterapia , Línea Celular Tumoral , Radioterapia de Iones Pesados , Ratones , Mitocondrias/metabolismo , Mitocondrias/efectos de la radiación , Fosforilación/efectos de la radiación , Transducción de Señal , Terapia por Rayos X , Ensayos Antitumor por Modelo de Xenoinjerto
17.
PLoS Comput Biol ; 12(5): e1004950, 2016 05.
Artículo en Inglés | MEDLINE | ID: mdl-27203839

RESUMEN

Humans and animals control their walking rhythms to maintain motion in a variable environment. The neural mechanism for controlling rhythm has been investigated in many studies using mechanical and electrical stimulation. However, quantitative evaluation of rhythm variation in response to perturbation at various timings has rarely been investigated. Such a characteristic of rhythm is described by the phase response curve (PRC). Dynamical simulations of human skeletal models with changing walking rhythms (phase reset) described a relation between the effective phase reset on stability and PRC, and phase reset around touch-down was shown to improve stability. A PRC of human walking was estimated by pulling the swing leg, but such perturbations hardly influenced the stance leg, so the relation between the PRC and walking events was difficult to discuss. This research thus examines human response to variations in floor velocity. Such perturbation yields another problem, in that the swing leg is indirectly (and weakly) perturbed, so the precision of PRC decreases. To solve this problem, this research adopts the weighted spike-triggered average (WSTA) method. In the WSTA method, a sequential pulsed perturbation is used for stimulation. This is in contrast with the conventional impulse method, which applies an intermittent impulsive perturbation. The WSTA method can be used to analyze responses to a large number of perturbations for each sequence. In the experiment, perturbations are applied to walking subjects by rapidly accelerating and decelerating a treadmill belt, and measured data are analyzed by the WSTA and impulse methods. The PRC obtained by the WSTA method had clear and stable waveforms with a higher temporal resolution than those obtained by the impulse method. By investigation of the rhythm transition for each phase of walking using the obtained PRC, a rhythm change that extends the touch-down and mid-single support phases is found to occur.


Asunto(s)
Modelos Biológicos , Caminata/fisiología , Aceleración , Fenómenos Biomecánicos , Biología Computacional , Marcha/fisiología , Humanos , Pierna , Masculino , Músculo Esquelético/fisiología , Periodicidad , Adulto Joven
18.
Semin Cancer Biol ; 35: 45-52, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26410035

RESUMEN

Cancer patients without metastasis are generally considered as candidates for curative localized radiation therapy. However, while the benefits of localized radiation have been demonstrated by many clinical studies, recurrences or distant metastases that develop after local treatment remain a major therapeutic challenge. Several in vitro and in vivo studies have reported that irradiation may subsequently alter tumor aggression by reducing or promoting the invasiveness of the remaining cancer cells after radiation, which appears to differ depending on the form of radiation, as well as the investigated cell lines. Cell lines recapitulate cancer heterogeneity based on the characteristics reflected in their genetic abnormalities, and thus can be used as a tool to investigate the genetic basis of cancer aggression. Importantly, molecular insights into this process would allow us to tailor drug treatments for use in combination with local radiation treatment. This review summarizes the diverse responses of cancer cell invasiveness induced by radiation, and discusses the possible molecular pathways and the genetic variations that may affect radiation-altered invasion.


Asunto(s)
Neoplasias/metabolismo , Neoplasias/patología , Radiación , Animales , Línea Celular Tumoral , Movimiento Celular/genética , Movimiento Celular/efectos de la radiación , Matriz Extracelular/metabolismo , Matriz Extracelular/efectos de la radiación , Humanos , Invasividad Neoplásica , Neoplasias/etiología , Neoplasias/radioterapia , Radiación/clasificación , Transducción de Señal/efectos de la radiación , Microambiente Tumoral/genética , Microambiente Tumoral/efectos de la radiación
19.
J Neurol Neurosurg Psychiatry ; 87(8): 851-8, 2016 08.
Artículo en Inglés | MEDLINE | ID: mdl-26746183

RESUMEN

OBJECTIVE: To classify the patterns of functional decline in patients with sporadic amyotrophic lateral sclerosis (ALS) and explore the genetic backgrounds that modified these patterns. METHODS: We included 465 patients with sporadic ALS in the analysis and clustered the longitudinal functional scores in the registered patients, using a mixture approach of a non-linear mixed-effects model. We conducted a genome-wide analysis of 572 983 single nucleotide polymorphisms (SNPs). We then assessed the association between the clusters of longitudinal functional scores and SNPs. RESULTS: We identified the following four clusters of longitudinal functional decline in the cases: a rapid decline cluster, an intermediate decline cluster, a sigmoidal decline cluster and a moderate decline cluster. We identified seven SNPs associated with the rapid decline cluster, using a recessive model (p=3.47-8.34×10(-8)). The OR for the probabilities of the rapid decline cluster ranged from 5.5 to 5.84. Homozygosity for the minor alleles in the seven SNPs, which constituted a linkage disequilibrium (LD) block, was associated with decreased expression of TTN (encoding Titin, a large sarcomere protein) in the expression quantitative trait loci database of a large-scale Japanese genetic variation database (p=8.6×10(-10)-1.1×10(-7)). TTN expression in immortalised lymphocyte lines was decreased in patients who were homozygous for the minor alleles compared with those who were homozygous for the major alleles (n=19 in each group, p=0.002). CONCLUSIONS: We detected an LD block associated with a rapid functional decline in patients with sporadic ALS, which is linked to decreased expression of TTN.


Asunto(s)
Esclerosis Amiotrófica Lateral/diagnóstico , Esclerosis Amiotrófica Lateral/genética , Conectina/genética , Predisposición Genética a la Enfermedad/genética , Alelos , Femenino , Estudio de Asociación del Genoma Completo , Humanos , Desequilibrio de Ligamiento , Masculino , Polimorfismo de Nucleótido Simple/genética , Pronóstico
20.
Gan To Kagaku Ryoho ; 42(2): 154-8, 2015 Feb.
Artículo en Japonés | MEDLINE | ID: mdl-25743134

RESUMEN

The clinical application of carbon ions generated by the heavy ion medical accelerator in Chiba (HIMAC) reached its 20th anniversary in 2014. More than 9,000 cancer patients have been treated at the National Institute of Radiological Sciences (NIRS). Carbon-ion radiotherapy has been applied for treating various types of tumors that were considered difficult to control with existing modalities. Our experience to date has indicated that carbon-ion radiotherapy is advantageous for head and neck cancer, non-small cell lung cancer, pancreatic cancer, prostate cancer, bone/soft tissue sarcomas of the pelvis, uterine cervix adenocarcinomas, and other cancers. However, some cancer types (such as those in close proximity to radiosensitive normal organs) require additional treatments to sensitize the target cancer because of limitation of the irradiation dose. Furthermore, systemic combined therapy is also utilized to suppress possible metastasis. Currently, some anticancer agents are utilized with carbon-ion radiotherapy, including dacarbazine, nimustine hydrochloride, vincristine (DAV), gemcitabine, cisplatin, and 5-fluorouracil. Interesting reagents such as PARP and HSP90 inhibitors have been proposed as cancer cell- specific sensitizers for carbon-ion irradiation during basic biological studies, especially those from the Research Project with Heavy Ions at NIRS-HIMAC. In our laboratory, we have focused our studies on the suppression of metastasis. We have proposed the concurrent use of reagents to inhibit the invasive potential of cancer cells under carbon-ion irradiation. Recently, we have also shown that combining carbon-ion radiotherapy with the local injection of dendritic cells inhibits lung metastases in an in vivo murine model.


Asunto(s)
Radioterapia de Iones Pesados/métodos , Neoplasias/radioterapia , Animales , Ensayos Clínicos como Asunto , Femenino , Humanos , Masculino , Ratones , Invasividad Neoplásica/prevención & control , Metástasis de la Neoplasia/prevención & control
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA