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1.
Mol Psychiatry ; 29(4): 992-1004, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38216727

RESUMEN

Neuroinflammation is a hallmark of Alzheimer's disease (AD) and both positive and negative associations of individual inflammation-related markers with brain structure and cognitive function have been described. We aimed to identify inflammatory signatures of CSF immune-related markers that relate to changes of brain structure and cognition across the clinical spectrum ranging from normal aging to AD. A panel of 16 inflammatory markers, Aß42/40 and p-tau181 were measured in CSF at baseline in the DZNE DELCODE cohort (n = 295); a longitudinal observational study focusing on at-risk stages of AD. Volumetric maps of gray and white matter (GM/WM; n = 261) and white matter hyperintensities (WMHs, n = 249) were derived from baseline MRIs. Cognitive decline (n = 204) and the rate of change in GM volume was measured in subjects with at least 3 visits (n = 175). A principal component analysis on the CSF markers revealed four inflammatory components (PCs). Of these, the first component PC1 (highly loading on sTyro3, sAXL, sTREM2, YKL-40, and C1q) was associated with older age and higher p-tau levels, but with less pathological Aß when controlling for p-tau. PC2 (highly loading on CRP, IL-18, complement factor F/H and C4) was related to male gender, higher body mass index and greater vascular risk. PC1 levels, adjusted for AD markers, were related to higher GM and WM volumes, less WMHs, better baseline memory, and to slower atrophy rates in AD-related areas and less cognitive decline. In contrast, PC2 related to less GM and WM volumes and worse memory at baseline. Similar inflammatory signatures and associations were identified in the independent F.ACE cohort. Our data suggest that there are beneficial and detrimental signatures of inflammatory CSF biomarkers. While higher levels of TAM receptors (sTyro/sAXL) or sTREM2 might reflect a protective glia response to degeneration related to phagocytic clearance, other markers might rather reflect proinflammatory states that have detrimental impact on brain integrity.


Asunto(s)
Enfermedad de Alzheimer , Péptidos beta-Amiloides , Biomarcadores , Encéfalo , Cognición , Disfunción Cognitiva , Inflamación , Imagen por Resonancia Magnética , Sustancia Blanca , Proteínas tau , Humanos , Masculino , Femenino , Biomarcadores/líquido cefalorraquídeo , Anciano , Enfermedad de Alzheimer/líquido cefalorraquídeo , Enfermedad de Alzheimer/patología , Persona de Mediana Edad , Encéfalo/patología , Péptidos beta-Amiloides/líquido cefalorraquídeo , Cognición/fisiología , Inflamación/líquido cefalorraquídeo , Imagen por Resonancia Magnética/métodos , Disfunción Cognitiva/líquido cefalorraquídeo , Sustancia Blanca/patología , Proteínas tau/líquido cefalorraquídeo , Estudios Longitudinales , Sustancia Gris/patología , Estudios de Cohortes
2.
World Dev ; 135: 105064, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32834377

RESUMEN

Emerging evidence supports the intuitive link between chronic health conditions associated with air pollution and the vulnerability of individuals and communities to COVID-19. Poor air quality already imposes a highly significant public health burden in Northwest India, with pollution levels spiking to hazardous levels in November and early December when rice crop residues are burned. The urgency of curtailing the COVID-19 pandemic and mitigating a potential resurgence later in the year provides even more justification for accelerating efforts to dramatically reduce open agricultural burning in India.

3.
Clin Genet ; 89(1): 82-7, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26153062

RESUMEN

The human X chromosome contains ∼ 1600 genes, about 15% of which have been associated with a specific genetic condition, mainly affecting males. Blue cone monochromacy (BCM) is an X-linked condition caused by a loss-of-function of both the OPN1LW and OPN1MW opsin genes. The cone opsin gene cluster is composed of 2-9 paralogs with 99.8% sequence homology and is susceptible to deletions, duplications, and mutations. Current diagnostic tests employ polymerase chain reaction (PCR)-based technologies; however, alterations remain undetermined in 10% of patients. Furthermore, carrier testing in females is limited or unavailable. High-resolution X chromosome-targeted CGH microarray was applied to test for rearrangements in males with BCM and female carriers from three unrelated families. Pathogenic alterations were revealed in all probands, characterized by sequencing of the breakpoint junctions and quantitative real-time PCR. In two families, we identified a novel founder mutation that consisted of a complex 3-kb deletion that embraced the cis-regulatory locus control region and insertion of an additional aberrant OPN1MW gene. The application of high-resolution X-chromosome microarray in clinical diagnosis brings significant advantages in detection of small aberrations that are beyond the resolution of clinically available aCGH analysis and which can improve molecular diagnosis of the known conditions and unravel previously unrecognized X-linked diseases.


Asunto(s)
Aberraciones Cromosómicas , Cromosomas Humanos X , Defectos de la Visión Cromática/diagnóstico , Defectos de la Visión Cromática/genética , Enfermedades Genéticas Ligadas al Cromosoma X , Heterocigoto , Puntos de Rotura del Cromosoma , Deleción Cromosómica , Hibridación Genómica Comparativa , Consanguinidad , Orden Génico , Humanos , Masculino , Análisis de Secuencia por Matrices de Oligonucleótidos , Linaje
4.
Cereb Cortex ; 23(2): 305-14, 2013 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-22351647

RESUMEN

Plasticity of the human primary motor cortex (M1) has a critical role in motor control and learning. The cerebellum facilitates these functions using sensory feedback. We investigated whether cerebellar processing of sensory afferent information influences the plasticity of the primary motor cortex (M1). Theta-burst stimulation protocols (TBS), both excitatory and inhibitory, were used to modulate the excitability of the posterior cerebellar cortex and to condition an ongoing M1 plasticity. M1 plasticity was subsequently induced in 2 different ways: by paired associative stimulation (PAS) involving sensory processing and TBS that exclusively involves intracortical circuits of M1. Cerebellar excitation attenuated the PAS-induced M1 plasticity, whereas cerebellar inhibition enhanced and prolonged it. Furthermore, cerebellar inhibition abolished the topography-specific response of PAS-induced M1 plasticity, with the effects spreading to adjacent motor maps. Conversely, cerebellar excitation had no effect on the TBS-induced M1 plasticity. This demonstrates the key role of the cerebellum in priming M1 plasticity, and we propose that it is likely to occur at the thalamic or olivo-dentate nuclear level by influencing the sensory processing. We suggest that such a cerebellar priming of M1 plasticity could shape the impending motor command by favoring or inhibiting the recruitment of several muscle representations.


Asunto(s)
Mapeo Encefálico , Cerebelo/fisiología , Corteza Motora/fisiología , Plasticidad Neuronal/fisiología , Adulto , Estimulación Eléctrica , Potenciales Evocados Motores/fisiología , Potenciales Evocados Somatosensoriales/fisiología , Femenino , Humanos , Masculino , Estimulación Magnética Transcraneal
5.
J Anim Breed Genet ; 130(2): 106-17, 2013 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-23496011

RESUMEN

It is now a well-accepted notion that each new experimental design requires proper evaluation of internal control genes (ICGs) for accurate normalization of expression data. In riverine buffaloes, till date no appropriate ICG has been reported for studying transcriptional response under any of the physiological stressful condition. The objective here was to test 16 well-known reference genes from different functional categories that could serve as suitable ICG during heat stress studies in buffalo mammary tissue. Briefly, the mammary explants were exposed to 45°C for 1 h and subsequently allowed to recover at 37°C for different time points (2-24 h). Three software programs, geNorm, Normfinder and BestKeeper, were used to measure gene transcript stability. RPL22 was excluded because of weak amplification and unacceptable PCR efficiency. Except GAPDH, all other genes showed expression stability within the acceptable range (<1.5). RPL4, B2M, RPS23 and EEF1A1 genes were found to be most stably expressed while GAPDH and ACTB showed least stability. The BestKeeper analysis identified high correlation for RPL4 (r=0.953) and EEF1A1 (r=0.914) with BestKeeper index. Based on the present findings, it could be suggested that geometric average of RPL4, B2M, RPS23 and EEF1A1 would provide accurate normalization to transcriptional data of buffalo mammary explant in response to heat stress.


Asunto(s)
Búfalos/metabolismo , Regulación de la Expresión Génica/fisiología , Calor , Glándulas Mamarias Animales/fisiología , Técnicas de Cultivo de Tejidos/veterinaria , Animales , ADN Complementario/genética , ADN Complementario/metabolismo , Femenino , Reacción en Cadena de la Polimerasa/veterinaria , ARN/genética , ARN/metabolismo , Reproducibilidad de los Resultados , Técnicas de Cultivo de Tejidos/métodos
6.
J Anim Physiol Anim Nutr (Berl) ; 97(6): 1132-41, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23363300

RESUMEN

Gene expression analysis unravels the complex changes or relations at transcriptomic level. To nullify all type of errors that can be incorporated during any stage of RNA extraction into cDNA synthesis and for reliable results, the data obtained from qPCR have to be normalized using the appropriate/suitable housekeeping genes (HKGs). Unfortunately, till date, no such HKG has been reported for bubaline mammary gland. The objective of the present study was thus to identify and validate the potential HKGs for the gene expression studies in buffalo mammary gland. Mammary tissues from twelve buffaloes during different physiological stages: pre-pubertal (heifer), lactation and involution were obtained for the present study. A total of 16 potential HKGs (GAPDH, ß-actin, UXT, ß2M, A2M, RPl4, RPS9, RPS15A, RPS18, RPS23, HMBS, HPRT1, GTP, EEF1A1, UB1 and RPL22) from different functional classes were evaluated. The analysis revealed that the expression of EEF1A1, RPl4, ß2M and RPS15A was most consistent across different physiological stages of buffalo mammary gland. On the other hand, ß-actin, A2M, RPL22 and GAPDH were the least stable genes making them unsuitable as HKGs. Based on our analysis, we recommend the use of EEF1A1, RPl4, ß2M and RPS15A genes as suitable HKGs for accurate normalization of gene expression data in bubaline mammary gland.


Asunto(s)
Búfalos/metabolismo , Regulación de la Expresión Génica/fisiología , Lactancia/fisiología , Reacción en Cadena en Tiempo Real de la Polimerasa/veterinaria , Animales , Femenino , Datos de Secuencia Molecular , Transcriptoma
7.
Cancer Metab ; 11(1): 5, 2023 Apr 21.
Artículo en Inglés | MEDLINE | ID: mdl-37085901

RESUMEN

BACKGROUND: Glycogen storage disease type 1a (GSD Ia) is an inborn error of metabolism caused by a defect in glucose-6-phosphatase (G6PC1) activity, which induces severe hepatomegaly and increases the risk for liver cancer. Hepatic GSD Ia is characterized by constitutive activation of Carbohydrate Response Element Binding Protein (ChREBP), a glucose-sensitive transcription factor. Previously, we showed that ChREBP activation limits non-alcoholic fatty liver disease (NAFLD) in hepatic GSD Ia. As ChREBP has been proposed as a pro-oncogenic molecular switch that supports tumour progression, we hypothesized that ChREBP normalization protects against liver disease progression in hepatic GSD Ia. METHODS: Hepatocyte-specific G6pc knockout (L-G6pc-/-) mice were treated with AAV-shChREBP to normalize hepatic ChREBP activity. RESULTS: Hepatic ChREBP normalization in GSD Ia mice induced dysplastic liver growth, massively increased hepatocyte size, and was associated with increased hepatic inflammation. Furthermore, nuclear levels of the oncoprotein Yes Associated Protein (YAP) were increased and its transcriptional targets were induced in ChREBP-normalized GSD Ia mice. Hepatic ChREBP normalization furthermore induced DNA damage and mitotic activity in GSD Ia mice, while gene signatures of chromosomal instability, the cytosolic DNA-sensing cGAS-STING pathway, senescence, and hepatocyte dedifferentiation emerged. CONCLUSIONS: In conclusion, our findings indicate that ChREBP activity limits hepatomegaly while decelerating liver disease progression and protecting against chromosomal instability in hepatic GSD Ia. These results disqualify ChREBP as a therapeutic target for treatment of liver disease in GSD Ia. In addition, they underline the importance of establishing the context-specific roles of hepatic ChREBP to define its therapeutic potential to prevent or treat advanced liver disease.

8.
Cutan Ocul Toxicol ; 31(1): 26-32, 2012 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-21830917

RESUMEN

CONTEXT: In light of the increased use of zinc oxide nanoparticles in cosumer products such as sunscreens, there is a need for screening the potential dermal toxicity of these nanoparticles. OBJECTIVE: The aim of this study is to identify the risk associated with the nano zinc oxide at realistic exposure levels through dermal route. This study is to understand the toxic potential of nano zinc oxide through repeated dermal exposure for a period of 28 days. MATERIALS AND METHODS: Six- to 8-week-old Sprague-Dawley rats were applied with three different doses (75, 180, and 360 mg/kg body weight) of nano zinc oxide (20 nm) at 5 days/week basis for a period of 28 days. The dose levels were calculated taking into consideration the percentage of nanomaterial in the sunscreen, number of application times, and average weight of the consumer in order to assess the realistic risk related to it. Control group animals were applied with distilled water alone. The collagen content was estimated in skin and tail of all the treated and control animals. RESULTS: The content was significantly decreased in all the nano zinc oxide-treated groups with an inverse dose relationship. DISCUSSION AND CONCLUSION: The percentage collagen loss was high in skin when compared with tail. This may be due to the site of application where in the nano zinc oxide may be passed through skin due to their small size and may induce oxidative stress. Hence, we suggest that regulators and industry need to address the toxicity of nanomaterials with a realistic exposure assessment rather following conventional dose measurements following existing protocols.


Asunto(s)
Nanopartículas/toxicidad , Óxido de Zinc/toxicidad , Administración Cutánea , Animales , Colágeno/metabolismo , Femenino , Masculino , Nanopartículas/administración & dosificación , Ratas , Ratas Sprague-Dawley , Piel/efectos de los fármacos , Piel/metabolismo , Absorción Cutánea , Pruebas de Toxicidad Subaguda , Óxido de Zinc/administración & dosificación
9.
Mol Genet Metab Rep ; 31: 100872, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35782606

RESUMEN

Glycogen storage disease type 1a (GSD Ia) is an inborn error of carbohydrate metabolism. Despite severe hyperlipidemia, GSD Ia patients show limited atherogenesis compared to age-and-gender matched controls. Employing a GSD Ia mouse model that resembles the severe hyperlipidemia in patients, we here found increased atherogenesis in GSD Ia. These data provide a rationale for investigating atherogenesis in GSD Ia in a larger patient cohort.

10.
J Biol Chem ; 285(10): 7143-52, 2010 Mar 05.
Artículo en Inglés | MEDLINE | ID: mdl-20022955

RESUMEN

Methylation of the arginine residues of histones by methyltransferases has important consequences for chromatin structure and gene regulation; however, the molecular mechanism(s) of methyltransferase regulation is still unclear, as is the biological significance of methylation at particular arginine residues. Here, we report a novel specific inhibitor of coactivator-associated arginine methyltransferase 1 (CARM1; also known as PRMT4) that selectively inhibits methylation at arginine 17 of histone H3 (H3R17). Remarkably, this plant-derived inhibitor, called TBBD (ellagic acid), binds to the substrate (histone) preferentially at the signature motif, "KAPRK," where the proline residue (Pro-16) plays a critical role for interaction and subsequent enzyme inhibition. In a promoter-specific context, inhibition of H3R17 methylation represses expression of p21, a p53-responsive gene, thus implicating a possible role for H3 Arg-17 methylation in tumor suppressor function. These data establish TBBD as a novel specific inhibitor of arginine methylation and demonstrate substrate sequence-directed inhibition of enzyme activity by a small molecule and its physiological consequence.


Asunto(s)
Arginina/metabolismo , Ácido Elágico/metabolismo , Histonas/metabolismo , Proteína-Arginina N-Metiltransferasas/antagonistas & inhibidores , Proteína-Arginina N-Metiltransferasas/metabolismo , Secuencia de Aminoácidos , Animales , Línea Celular , Ácido Elágico/química , Regulación de la Expresión Génica , Histonas/química , Histonas/genética , Humanos , Lythraceae/química , Metilación , Modelos Moleculares , Datos de Secuencia Molecular , Estructura Molecular , Mutagénesis Sitio-Dirigida , Prolina/metabolismo , Estructura Terciaria de Proteína , Proteína-Arginina N-Metiltransferasas/química , Proteína-Arginina N-Metiltransferasas/genética , Termodinámica , Proteína p53 Supresora de Tumor/genética , Proteína p53 Supresora de Tumor/metabolismo , Xenopus laevis
11.
Biochemistry ; 49(7): 1355-7, 2010 Feb 23.
Artículo en Inglés | MEDLINE | ID: mdl-20073534

RESUMEN

The chromatin is comprised of repeating subunits that make up the nucleosome which is composed of an octamer of histones: H3, H4, H2A, and H2B. The replication-dependent and -independent nucleosome assembly occurs in an ordered fashion and is aided by cellular proteins such as histone chaperones and chromatin remodelers. Previously, we found that the histone chaperone NPM1 activates transcription from the chromatin template. Here we report that NPM3, a member of the nucleophosmin/nucleoplasmin family, lacks intrinsic histone chaperone activity, inhibits histone assembly activity of NPM1 in vitro, and dramatically enhances transcription in a cellular system.


Asunto(s)
Familia de Multigenes/fisiología , Nucleoplasminas/fisiología , Transactivadores/fisiología , Transcripción Genética , Línea Celular , Células HeLa , Histonas/antagonistas & inhibidores , Histonas/metabolismo , Humanos , Proteínas Nucleares/antagonistas & inhibidores , Proteínas Nucleares/química , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Proteínas Nucleares/fisiología , Nucleofosmina , Nucleoplasminas/química , Nucleoplasminas/genética , Nucleosomas/química , Nucleosomas/genética , Nucleosomas/fisiología , Transactivadores/química , Transactivadores/genética , Regulación hacia Arriba/genética
12.
J Complement Integr Med ; 17(1)2019 Sep 18.
Artículo en Inglés | MEDLINE | ID: mdl-31536034

RESUMEN

Background Virgin coconut oil (VCO), a cold processed form of coconut oil, is traditionally consumed in Asian countries owing to its nutritional and medicinal properties. The aim of this study was to investigate whether the health benefits of VCO involve alterations in immune responses that are regulated by intracellular signaling molecules in the spleens of rats. Methods Young male Wistar rats were fed with three doses of VCO in diet for 30 days. At the end of the treatment period, spleens were isolated and in vitro effects on immune responses (Concanavalin A [Con A]-induced lymphoproliferation and cytokine production), and direct effects of VCO treatment on intracellular signaling molecules and antioxidant status were examined. Serum was collected to measure glucose, lipid levels, and leptin. Results VCO supplementation in diet enhanced Con A-induced splenocyte proliferation and Th1 cytokine production while it suppressed the proinflammatory cytokine production. VCO increased the expression of mechanistic target of rapamycin (p-mTOR), sirtuin1 (SIRT1), liver kinase B1 (p-LKB1) p-ERK, and p-CREB in spleen. Similarly, VCO increased the activities of antioxidant enzymes while it suppressed lipid peroxidation in the spleen. VCO diet had hypolipidemic effects on the rats: an increase in high density lipoprotein cholesterol (HDL-C) levels while lowering triacylglycerol (TAG) levels. Conclusion The health benefits of VCO may be mediated through enhanced Th1 immunity through the upregulation of survival signaling pathways and inhibition of free radical generation in the spleen besides its capacity to induce hypolipidemia.


Asunto(s)
Antioxidantes/metabolismo , Aceite de Coco/administración & dosificación , Suplementos Dietéticos , Peroxidación de Lípido , Bazo/inmunología , Animales , Citocinas/inmunología , Cromatografía de Gases y Espectrometría de Masas , Inmunidad Celular , Masculino , Ratas , Ratas Wistar , Transducción de Señal
13.
J Med Chem ; 51(4): 792-7, 2008 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-18215015

RESUMEN

Aurora kinases are essential for chromosomal segregation and cell division and thereby important for maintaining the proper genomic integrity. There are three classes of aurora kinases in humans: A, B, and C. Aurora kinase A is frequently overexpressed in various cancers. The link of the overexpression and tumorigenesis is yet to be understood. By employing virtual screening, we have found that anacardic acid, a pentadecane aliphatic chain containing hydroxylcarboxylic acid, from cashew nut shell liquid could be docked in Aurora kinases A and B. Remarkably, we found that anacardic acid could potently activate the Aurora kinase A mediated phosphorylation of histone H3, but at a similar concentration the activity of aurora kinase B remained unaffected in vitro. Mechanistically, anacardic acid induces the structural changes and also the autophosphorylation of the aurora kinase A to enhance the enzyme activity. This data thus indicate anacardic acid as the first small-molecule activator of Aurora kinase, which could be highly useful for probing the function of hyperactive (overexpressed) Aurora kinase A.


Asunto(s)
Ácidos Anacárdicos/química , Activadores de Enzimas/química , Proteínas Serina-Treonina Quinasas/química , Ácidos Anacárdicos/aislamiento & purificación , Anacardium , Aurora Quinasa A , Aurora Quinasa B , Aurora Quinasas , Línea Celular , Clonación Molecular , Cristalografía por Rayos X , Activadores de Enzimas/aislamiento & purificación , Histonas/química , Humanos , Cinética , Modelos Moleculares , Estructura Molecular , Fosforilación , Proteínas Serina-Treonina Quinasas/genética , Espectrometría de Fluorescencia
14.
Chem Biol ; 14(6): 645-57, 2007 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-17584612

RESUMEN

Reversible acetylation of histone and nonhistone proteins plays pivotal role in cellular homeostasis. Dysfunction of histone acetyltransferases (HATs) leads to several diseases including cancer, neurodegenaration, asthma, diabetes, AIDS, and cardiac hypertrophy. We describe the synthesis and characterization of a set of p300-HAT-specific small-molecule inhibitors from a natural nonspecific HAT inhibitor, garcinol, which is highly toxic to cells. We show that the specific inhibitor selectively represses the p300-mediated acetylation of p53 in vivo. Furthermore, inhibition of p300-HAT down regulates several genes but significantly a few important genes are also upregulated. Remarkably, these inhibitors were found to be nontoxic to T cells, inhibit histone acetylation of HIV infected cells, and consequently inhibit the multiplication of HIV.


Asunto(s)
Fármacos Anti-VIH , Proteínas de Ciclo Celular/antagonistas & inhibidores , Inhibidores Enzimáticos , Expresión Génica/efectos de los fármacos , VIH-1 , Histona Acetiltransferasas/antagonistas & inhibidores , Terpenos , Factores de Transcripción/antagonistas & inhibidores , Replicación Viral/efectos de los fármacos , Acetilación , Animales , Fármacos Anti-VIH/síntesis química , Fármacos Anti-VIH/química , Fármacos Anti-VIH/farmacología , Proteínas de Ciclo Celular/genética , Supervivencia Celular/efectos de los fármacos , Cromatina/genética , Regulación hacia Abajo , Inhibidores Enzimáticos/síntesis química , Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/farmacología , VIH-1/efectos de los fármacos , VIH-1/genética , VIH-1/fisiología , Células HeLa , Histona Acetiltransferasas/genética , Histonas/genética , Humanos , Modelos Moleculares , Estructura Molecular , Linfocitos T/virología , Terpenos/síntesis química , Terpenos/química , Terpenos/farmacología , Factores de Transcripción/genética , Transcripción Genética , Proteína p53 Supresora de Tumor/metabolismo , Regulación hacia Arriba , Factores de Transcripción p300-CBP
15.
J Phys Chem B ; 112(21): 6703-7, 2008 May 29.
Artículo en Inglés | MEDLINE | ID: mdl-18461904

RESUMEN

We report, for the first time, the surface-enhanced Raman spectra of an important enzyme, coactivator-associated arginine methyltransferase 1 (CARM1), involved in various biological activities such as tumor suppressor function and stem cell differentiation. We have employed surface-enhanced Raman scattering (SERS) to obtain insight into the structural details of CARM1 by adsorbing it to silver (Ag) nanoparticles. The enzyme retains its activity even after its adsorption onto Ag nanoparticles. We observe strong SERS modes arising from amide vibrations and aromatic ring amino acids. The SERS spectra revealed amide I bands at 1637 cm(-1) and 1666 cm(-1), which arise as a result of the alpha helix of the protein and the polypeptide backbone vibration of a random coil, respectively. In order to confirm the amide vibrations, we have performed SERS on deuterated CARM1, which exhibits a clear red shift in amide band positions. The SERS spectra may provide useful information, which could be harnessed to study the functional interactions of CARM1 with small molecule modulators.


Asunto(s)
Metiltransferasas/química , Espectrometría Raman/métodos , Adsorción , Células HeLa , Humanos , Péptidos y Proteínas de Señalización Intracelular , Nanopartículas , Proteína-Arginina N-Metiltransferasas , Proteínas Recombinantes/química
16.
Mol Cell Biol ; 25(17): 7534-45, 2005 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-16107701

RESUMEN

Histone chaperones are a group of proteins that aid in the dynamic chromatin organization during different cellular processes. Here, we report that the human histone chaperone nucleophosmin interacts with the core histones H3, H2B, and H4 but that this histone interaction is not sufficient to confer the chaperone activity. Significantly, nucleophosmin enhances the acetylation-dependent chromatin transcription and it becomes acetylated both in vitro and in vivo. Acetylation of nucleophosmin and the core histones was found to be essential for the enhancement of chromatin transcription. The acetylated NPM1 not only shows an increased affinity toward acetylated histones but also shows enhanced histone transfer ability. Presumably, nucleophosmin disrupts the nucleosomal structure in an acetylation-dependent manner, resulting in the transcriptional activation. These results establish nucleophosmin (NPM1) as a human histone chaperone that becomes acetylated, resulting in the enhancement of chromatin transcription.


Asunto(s)
Cromatina/genética , Regulación de la Expresión Génica , Histonas/metabolismo , Chaperonas Moleculares/metabolismo , Proteínas Nucleares/metabolismo , Transcripción Genética/genética , Acetilación , Secuencia de Aminoácidos , Animales , Células HeLa , Humanos , Datos de Secuencia Molecular , Proteínas Nucleares/química , Proteínas Nucleares/genética , Nucleofosmina , Unión Proteica , Proteína p53 Supresora de Tumor/metabolismo , Xenopus laevis
17.
Biochem J ; 406(3): 437-44, 2007 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-17555406

RESUMEN

The tumour suppressor protein p53 regulates the expression of several genes that mediate cell cycle arrest, apoptosis, DNA repair and other cellular responses. Recently, we have shown that human transcriptional co-activator PC4 is a unique activator of p53 function. In the present study, we report that PC4 is a p53-inducible gene. Bioinformatics analysis reveals multiple p53-binding sites in the PC4 promoter. We have found that indeed p53 binds to all the identified sites in vitro and in vivo with varying affinities. p53 acts as an activator of PC4 transcription. Both PC4 mRNA and protein levels increase in response to stimuli that result in p53 induction. Furthermore, PC4 enhances p53 recruitment to the PC4 promoter. Our results thus establish the first report of a positively regulated feedback loop to control p53 function.


Asunto(s)
Proteínas de Unión al ADN/genética , Regulación de la Expresión Génica , Factores de Transcripción/genética , Activación Transcripcional , Proteína p53 Supresora de Tumor/metabolismo , Células Cultivadas , Inmunoprecipitación de Cromatina , Biología Computacional , Proteínas de Unión al ADN/metabolismo , Ensayo de Cambio de Movilidad Electroforética , Genes Reguladores , Humanos , Regiones Promotoras Genéticas , Factores de Transcripción/metabolismo , Transcripción Genética , Transfección
18.
Int J Toxicol ; 27(6): 449-53, 2008 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-19482824

RESUMEN

As an alternative to the standard Draize eye irritation test, the potential irritancy of compounds was evaluated by observing adverse changes that occur in chorioallantoic membrane CAM) of the hen egg (HECAM) after exposure to a test chemical placed directly on the CAM. The occurrence of hemorrhage, coagulation, and lysis in response to a test compound is the basis for employing this technique to evaluate its potential for in vivo damage to mucous membrane, in particular the eye. Irritancy is scored according to the severity and speed at which damage occurs. In the present study, five different classes of pesticides were screened for irritation potential. There was good correlation between the HECAM assay and the in vivo Draize eye irritation test. The proposed HECAM assay, which reduces the requirement for laboratory animals, could be a painless alternative to the Draize test.


Asunto(s)
Alantoides/efectos de los fármacos , Alternativas a las Pruebas en Animales , Corion/efectos de los fármacos , Ojo/efectos de los fármacos , Irritantes/toxicidad , Plaguicidas/toxicidad , Animales , Bioensayo , Embrión de Pollo
19.
Sci Rep ; 8(1): 2263, 2018 02 02.
Artículo en Inglés | MEDLINE | ID: mdl-29396401

RESUMEN

The cerebellum can influence the responsiveness of the primary motor cortex (M1) to undergo spike timing-dependent plastic changes through a complex mechanism involving multiple relays in the cerebello-thalamo-cortical pathway. Previous TMS studies showed that cerebellar cortex excitation can block the increase in M1 excitability induced by a paired-associative stimulation (PAS), while cerebellar cortex inhibition would enhance it. Since cerebellum is known to be affected in many types of dystonia, this bidirectional modulation was assessed in 22 patients with cervical dystonia and 23 healthy controls. Exactly opposite effects were found in patients: cerebellar inhibition suppressed the effects of PAS, while cerebellar excitation enhanced them. Another experiment comparing healthy subjects maintaining the head straight with subjects maintaining the head turned as the patients found that turning the head is enough to invert the cerebellar modulation of M1 plasticity. A third control experiment in healthy subjects showed that proprioceptive perturbation of the sterno-cleido-mastoid muscle had the same effects as turning the head. We discuss these finding in the light of the recent model of a mesencephalic head integrator. We also suggest that abnormal cerebellar processing of the neck proprioceptive information drives dysfunctions of the integrator in cervical dystonia.


Asunto(s)
Trastornos Somatosensoriales/patología , Tortícolis/fisiopatología , Adulto , Anciano , Cerebelo/efectos de la radiación , Estimulación Eléctrica , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estimulación Magnética Transcraneal , Adulto Joven
20.
J Phys Chem B ; 111(17): 4527-34, 2007 May 03.
Artículo en Inglés | MEDLINE | ID: mdl-17417897

RESUMEN

Reversible acetylation of nucleosomal histones and nonhistone proteins play pivotal roles in the regulation of all the DNA templated phenomenon. Dysfunction of the enzymes involved in the acetylation/deacetylation leads to several diseases. Therefore, these enzymes are the targets for new generation therapeutics. Here, we report the synthesis of trifluoromethyl phenyl benzamides and their effect on histone acetyltransferase (HAT) activity of p300. One of these benzamides, CTPB (N-(4-chloro-3-trifluoromethyl-phenyl)-2-ethoxy-6-pentadecyl-benzamide), was discovered as a potent activator of the p300 HAT activity. We have found that pentadecyl hydrocarbon chain of CTPB is required to activate the HAT only under certain context. Furthermore, our results show that the relative position of -CF3 and -Cl in CTB (N-(4-chloro-3-trifluoromethyl-phenyl)-2-ethoxy-benzamide) is also very critical for the activation. Surface-enhanced Raman spectroscopy (SERS) of p300 and the HAT activator complexes evidently suggest that the activation of HAT activity is achieved by the alteration of p300 structure. Therefore, apart from elucidating the chemical basis for small molecule mediated activation of p300, this report also describes, for the first time, Raman spectroscopic analysis of the complexes of histone-modifying enzymes and their modulators, which may be highly useful for therapeutic applications.


Asunto(s)
Proteínas de Ciclo Celular/química , Proteínas de Ciclo Celular/metabolismo , Histona Acetiltransferasas/química , Histona Acetiltransferasas/metabolismo , Factores de Transcripción/química , Factores de Transcripción/metabolismo , Ácidos Anacárdicos/química , Benzamidas/química , Benzamidas/farmacología , Activación Enzimática/efectos de los fármacos , Células HeLa , Humanos , Hidrocarburos/química , Cinética , Estructura Molecular , Ácido Salicílico/química , Espectrometría Raman , Factores de Transcripción p300-CBP
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