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1.
EMBO Rep ; 22(3): e51063, 2021 03 03.
Artículo en Inglés | MEDLINE | ID: mdl-33470040

RESUMEN

Metazoans use protein homeostasis (proteostasis) pathways to respond to adverse physiological conditions, changing environment, and aging. The nervous system regulates proteostasis in different tissues, but the mechanism is not understood. Here, we show that Caenorhabditis elegans employs biogenic amine neurotransmitters to regulate ubiquitin proteasome system (UPS) proteostasis in epithelia. Mutants for biogenic amine synthesis show decreased poly-ubiquitination and turnover of a GFP-based UPS substrate. Using RNA-seq and mass spectrometry, we found that biogenic amines promote eicosanoid production from poly-unsaturated fats (PUFAs) by regulating expression of cytochrome P450 monooxygenases. Mutants for one of these P450s share the same UPS phenotype observed in biogenic amine mutants. The production of n-6 eicosanoids is required for UPS substrate turnover, whereas accumulation of n-6 eicosanoids accelerates turnover. Our results suggest that sensory neurons secrete biogenic amines to modulate lipid signaling, which in turn activates stress response pathways to maintain UPS proteostasis.


Asunto(s)
Proteínas de Caenorhabditis elegans , Proteostasis , Animales , Aminas Biogénicas , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Neurotransmisores
2.
Cell Commun Signal ; 19(1): 97, 2021 09 25.
Artículo en Inglés | MEDLINE | ID: mdl-34563224

RESUMEN

BACKGROUND: Recent studies have shown that bone morphogenetic protein receptor 2 (BMPR2) regulates cell survival signaling events in cancer cells independent of the BMP type 1 receptor (BMPR1) or the Smad-1/5 transcription factor. Mutations in BMPR2 trafficking proteins leads to overactive BMP signaling, which leads to neurological diseases caused by BMPR2 stabilization of the microtubules. It is not known whether BMPR2 regulates the microtubules in cancer cells and what effect this has on cell survival. It is also not known whether alterations in BMPR2 trafficking effects activity and response to BMPR2 inhibitors. METHODS: We utilized BMPR2 siRNA and the BMP receptor inhibitors JL5 and Ym155, which decrease BMPR2 signaling and cause its mislocalization to the cytoplasm. Using the JL5 resistant MDA-MD-468 cell line and sensitive lung cancer cell lines, we examined the effects of BMPR2 inhibition on BMPR2 mislocalization to the cytoplasm, microtubule destabilization, lysosome activation and cell survival. RESULTS: We show that the inhibition of BMPR2 destabilizes the microtubules. Destabilization of the microtubules leads to the activation of the lysosomes. Activated lysosomes further decreases BMPR2 signaling by causing it to mislocalizated to the cytoplasm and/or lysosome for degradation. Inhibition of the lysosomes with chloroquine attenuates BMPR2 trafficking to the lysosome and cell death induced by BMPR2 inhibitors. Furthermore, in MDA-MD-468 cells that are resistant to JL5 induced cell death, BMPR2 was predominately located in the cytoplasm. BMPR2 failed to localize to the cytoplasm and/or lysosome following treatment with JL5 and did not destabilize the microtubules or activate the lysosomes. CONCLUSIONS: These studies reveal that the inhibition of BMPR2 destabilizes the microtubules promoting cell death of cancer cells that involves the activation of the lysosomes. Resistance to small molecules targeting BMPR2 may occur if the BMPR2 is localized predominantly to the cytoplasm and/or fails to localize to the lysosome for degradation. Video Abstract.


Asunto(s)
Receptores de Proteínas Morfogenéticas Óseas de Tipo II/genética , Muerte Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Neoplasias Pulmonares/tratamiento farmacológico , Receptores de Proteínas Morfogenéticas Óseas de Tipo 1/genética , Receptores de Proteínas Morfogenéticas Óseas de Tipo II/antagonistas & inhibidores , Muerte Celular/genética , Supervivencia Celular/efectos de los fármacos , Humanos , Imidazoles/farmacología , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patología , Lisosomas/efectos de los fármacos , Lisosomas/genética , Microtúbulos/efectos de los fármacos , Microtúbulos/genética , Naftoquinonas/farmacología , Pirazoles/farmacología , Pirimidinas/farmacología , Quinolonas/farmacología , ARN Interferente Pequeño/farmacología , Transducción de Señal/efectos de los fármacos
3.
PLoS Genet ; 9(8): e1003737, 2013 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-24009527

RESUMEN

Caloric/dietary restriction (CR/DR) can promote longevity and protect against age-associated disease across species. The molecular mechanisms coordinating food intake with health-promoting metabolism are thus of significant medical interest. We report that conserved Caenorhabditis elegans microRNA-80 (mir-80) is a major regulator of the DR state. mir-80 deletion confers system-wide healthy aging, including maintained cardiac-like and skeletal muscle-like function at advanced age, reduced accumulation of lipofuscin, and extended lifespan, coincident with induction of physiological features of DR. mir-80 expression is generally high under ad lib feeding and low under food limitation, with most striking food-sensitive expression changes in posterior intestine. The acetyltransferase transcription co-factor cbp-1 and interacting transcription factors daf-16/FOXO and heat shock factor-1 hsf-1 are essential for mir-80(Δ) benefits. Candidate miR-80 target sequences within the cbp-1 transcript may confer food-dependent regulation. Under food limitation, lowered miR-80 levels directly or indirectly increase CBP-1 protein levels to engage metabolic loops that promote DR.


Asunto(s)
Proteínas de Caenorhabditis elegans/genética , Caenorhabditis elegans/genética , Restricción Calórica , Longevidad/genética , MicroARNs/genética , Animales , Caenorhabditis elegans/fisiología , Proteínas de Caenorhabditis elegans/metabolismo , Factores de Transcripción Forkhead , Regulación de la Expresión Génica , Histona Acetiltransferasas/genética , Histona Acetiltransferasas/metabolismo , Eliminación de Secuencia , Transducción de Señal , Factores de Transcripción/genética , Factores de Transcripción/metabolismo
4.
PLoS Comput Biol ; 10(7): e1003702, 2014 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-25033081

RESUMEN

In the effort to define genes and specific neuronal circuits that control behavior and plasticity, the capacity for high-precision automated analysis of behavior is essential. We report on comprehensive computer vision software for analysis of swimming locomotion of C. elegans, a simple animal model initially developed to facilitate elaboration of genetic influences on behavior. C. elegans swim test software CeleST tracks swimming of multiple animals, measures 10 novel parameters of swim behavior that can fully report dynamic changes in posture and speed, and generates data in several analysis formats, complete with statistics. Our measures of swim locomotion utilize a deformable model approach and a novel mathematical analysis of curvature maps that enable even irregular patterns and dynamic changes to be scored without need for thresholding or dropping outlier swimmers from study. Operation of CeleST is mostly automated and only requires minimal investigator interventions, such as the selection of videotaped swim trials and choice of data output format. Data can be analyzed from the level of the single animal to populations of thousands. We document how the CeleST program reveals unexpected preferences for specific swim "gaits" in wild-type C. elegans, uncovers previously unknown mutant phenotypes, efficiently tracks changes in aging populations, and distinguishes "graceful" from poor aging. The sensitivity, dynamic range, and comprehensive nature of CeleST measures elevate swim locomotion analysis to a new level of ease, economy, and detail that enables behavioral plasticity resulting from genetic, cellular, or experience manipulation to be analyzed in ways not previously possible.


Asunto(s)
Biología Computacional/métodos , Programas Informáticos , Natación/fisiología , Animales , Caenorhabditis elegans , Bases de Datos Factuales , Modelos Biológicos , Fenotipo
5.
J Virol ; 87(14): 7837-52, 2013 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-23658454

RESUMEN

The interferon-induced transmembrane protein 3 (IFITM3) gene is an interferon-stimulated gene that inhibits the replication of multiple pathogenic viruses in vitro and in vivo. IFITM3 is a member of a large protein superfamily, whose members share a functionally undefined area of high amino acid conservation, the CD225 domain. We performed mutational analyses of IFITM3 and identified multiple residues within the CD225 domain, consisting of the first intramembrane domain (intramembrane domain 1 [IM1]) and a conserved intracellular loop (CIL), that are required for restriction of both influenza A virus (IAV) and dengue virus (DENV) infection in vitro. Two phenylalanines within IM1 (F75 and F78) also mediate a physical association between IFITM proteins, and the loss of this interaction decreases IFITM3-mediated restriction. By extension, similar IM1-mediated associations may contribute to the functions of additional members of the CD225 domain family. IFITM3's distal N-terminal domain is also needed for full antiviral activity, including a tyrosine (Y20), whose alteration results in mislocalization of a portion of IFITM3 to the cell periphery and surface. Comparative analyses demonstrate that similar molecular determinants are needed for IFITM3's restriction of both IAV and DENV. However, a portion of the CIL including Y99 and R87 is preferentially needed for inhibition of the orthomyxovirus. Several IFITM3 proteins engineered with rare single-nucleotide polymorphisms demonstrated reduced expression or mislocalization, and these events were associated with enhanced viral replication in vitro, suggesting that possessing such alleles may impact an individual's risk for viral infection. On the basis of this and other data, we propose a model for IFITM3-mediated restriction.


Asunto(s)
Virus del Dengue/fisiología , Virus de la Influenza A/fisiología , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Proteínas de Unión al ARN/genética , Proteínas de Unión al ARN/metabolismo , Replicación Viral/fisiología , Secuencia de Aminoácidos , Animales , Técnicas de Cultivo de Célula , Clonación Molecular , Secuencia Conservada/genética , Análisis Mutacional de ADN , ADN Complementario/genética , Perros , Células HEK293 , Células HeLa , Humanos , Immunoblotting , Inmunoprecipitación , Células de Riñón Canino Madin Darby , Espectrometría de Masas , Microscopía Confocal , Modelos Biológicos , Datos de Secuencia Molecular , Polimorfismo de Nucleótido Simple/genética , Estructura Terciaria de Proteína/genética , Replicación Viral/genética
6.
Cell Commun Signal ; 17(1): 150, 2019 11 19.
Artículo en Inglés | MEDLINE | ID: mdl-31744505
7.
bioRxiv ; 2024 Jun 06.
Artículo en Inglés | MEDLINE | ID: mdl-38895257

RESUMEN

Smads and their transcription factor partners mediate the transcriptional responses of target cells to secreted ligands of the Transforming Growth Factor-ß (TGF-ß) family, including those of the conserved bone morphogenetic protein (BMP) family, yet only a small number of direct target genes have been well characterized. In C. elegans, the BMP2/4 ortholog DBL-1 regulates multiple biological functions, including body size, via a canonical receptor-Smad signaling cascade. Here, we identify functional binding sites for SMA-3/Smad and its transcriptional partner SMA-9/Schnurri based on ChIP-seq peaks (identified by modEncode) and expression differences of nearby genes identified from RNA-seq analysis of corresponding mutants. We found that SMA-3 and SMA-9 have both overlapping and unique target genes. At a genome-wide scale, SMA-3/Smad acts as a transcriptional activator, whereas SMA-9/Schnurri direct targets include both activated and repressed genes. Mutations in sma-9 partially suppress the small body size phenotype of sma-3, suggesting some level of antagonism between these factors and challenging the prevailing model for Schnurri function. A functional analysis of target genes revealed a novel role in body size for genes involved in one-carbon metabolism and in the endoplasmic reticulum (ER) secretory pathway, including the disulfide reductase dpy-11. Our findings indicate that Smads and SMA-9/Schnurri have previously unappreciated complex genetic and genomic regulatory interactions that in turn regulate the secretion of extracellular components like collagen into the cuticle to mediate body size regulation.

8.
Nat Commun ; 13(1): 6168, 2022 10 18.
Artículo en Inglés | MEDLINE | ID: mdl-36257965

RESUMEN

Actively dividing cells, including some cancers, rely on aerobic glycolysis rather than oxidative phosphorylation to generate energy, a phenomenon termed the Warburg effect. Constitutive activation of the Hypoxia Inducible Factor (HIF-1), a transcription factor known for mediating an adaptive response to oxygen deprivation (hypoxia), is a hallmark of the Warburg effect. HIF-1 is thought to promote glycolysis and suppress oxidative phosphorylation. Here, we instead show that HIF-1 can promote gluconeogenesis. Using a multiomics approach, we reveal the genomic, transcriptomic, and metabolomic landscapes regulated by constitutively active HIF-1 in C. elegans. We use RNA-seq and ChIP-seq under aerobic conditions to analyze mutants lacking EGL-9, a key negative regulator of HIF-1. We integrate these approaches to identify over two hundred genes directly and functionally upregulated by HIF-1, including the PEP carboxykinase PCK-1, a rate-limiting mediator of gluconeogenesis. This activation of PCK-1 by HIF-1 promotes survival in response to both oxidative and hypoxic stress. Our work identifies functional direct targets of HIF-1 in vivo, comprehensively describing the metabolome induced by HIF-1 activation in an organism.


Asunto(s)
Caenorhabditis elegans , Gluconeogénesis , Animales , Caenorhabditis elegans/genética , Gluconeogénesis/genética , Factores de Transcripción/genética , Hipoxia de la Célula , Hipoxia/genética , Oxígeno , Subunidad alfa del Factor 1 Inducible por Hipoxia/genética
9.
Cell Biosci ; 12(1): 76, 2022 May 31.
Artículo en Inglés | MEDLINE | ID: mdl-35641992

RESUMEN

BACKGROUND: Bone morphogenetic protein (BMP) is a phylogenetically conserved signaling pathway required for development that is aberrantly expressed in several age-related diseases including cancer, Alzheimer's disease, obesity, and cardiovascular disease. Aberrant BMP signaling in mice leads to obesity, suggesting it may alter normal metabolism. The role of BMP signaling regulating cancer metabolism is not known. METHODS: To examine BMP regulation of metabolism, C. elegans harboring BMP gain-of-function (gof) and loss-of-function (lof) mutations were examined for changes in activity of catabolic and anabolic metabolism utilizing Western blot analysis and fluorescent reporters. AMP activated kinase (AMPK) gof and lof mutants were used to examine AMPK regulation of BMP signaling. H1299 (LKB1 wild-type), A549 (LKB1 lof), and A549-LKB1 (LKB1 restored) lung cancer cell lines were used to study BMP regulation of catabolic and anabolic metabolism. Studies were done using recombinant BMP ligands to activate BMP signaling, and BMP receptor specific inhibitors and siRNA to inhibit signaling. RESULTS: BMP signaling in both C. elegans and cancer cells is responsive to nutrient conditions. In both C. elegans and lung cancer cell lines BMP suppressed AMPK, the master regulator of catabolism, while activating PI3K, a regulator of anabolism. In lung cancer cells, inhibition of BMP signaling by siRNA or small molecules increased AMPK activity, and this increase was mediated by activation of LKB1. BMP2 ligand suppressed AMPK activation during starvation. BMP2 ligand decreased expression of TCA cycle intermediates and non-essential amino acids in H1299 cells. Furthermore, we show that BMP activation of PI3K is mediated through BMP type II receptor. We also observed feedback signaling, as AMPK suppressed BMP signaling, whereas PI3K increased BMP signaling. CONCLUSION: These studies show that BMP signaling suppresses catabolic metabolism and stimulates anabolic metabolism. We identified feedback mechanisms where catabolic induced signaling mediated by AMPK negatively regulates BMP signaling, whereas anabolic signaling produces a positive feedback regulation of BMP signing through Akt. These mechanisms were conserved in both lung cancer cells and C. elegans. These studies suggest that aberrant BMP signaling causes dysregulation of metabolism that is a potential mechanism by which BMP promotes survival of cancer cells.

10.
PLoS One ; 14(5): e0216628, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31071172

RESUMEN

The transforming growth factor-ß (TGFß) family plays an important role in many developmental processes and when mutated often contributes to various diseases. Marfan syndrome is a genetic disease with an occurrence of approximately 1 in 5,000. The disease is caused by mutations in fibrillin, which lead to an increase in TGFß ligand activity, resulting in abnormalities of connective tissues which can be life-threatening. Mutations in other components of TGFß signaling (receptors, Smads, Schnurri) lead to similar diseases with attenuated phenotypes relative to Marfan syndrome. In particular, mutations in TGFß receptors, most of which are clustered at the C-terminal end, result in Marfan-like (MFS-like) syndromes. Even though it was assumed that many of these receptor mutations would reduce or eliminate signaling, in many cases signaling is active. From our previous studies on receptor trafficking in C. elegans, we noticed that many of these receptor mutations that lead to Marfan-like syndromes overlap with mutations that cause mis-trafficking of the receptor, suggesting a link between Marfan-like syndromes and TGFß receptor trafficking. To test this hypothesis, we introduced three of these key MFS and MFS-like mutations into the C. elegans TGFß receptor and asked if receptor trafficking is altered. We find that in every case studied, mutated receptors mislocalize to the apical surface rather than basolateral surface of the polarized intestinal cells. Further, we find that these mutations result in longer animals, a phenotype due to over-stimulation of the nematode TGFß pathway and, importantly, indicating that function of the receptor is not abrogated in these mutants. Our nematode models of Marfan syndrome suggest that MFS and MFS-like mutations in the type II receptor lead to mis-trafficking of the receptor and possibly provides an explanation for the disease, a phenomenon which might also occur in some cancers that possess the same mutations within the type II receptor (e.g. colon cancer).


Asunto(s)
Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Síndrome de Marfan/genética , Síndrome de Marfan/metabolismo , Mutación Missense , Receptor Tipo II de Factor de Crecimiento Transformador beta/genética , Receptor Tipo II de Factor de Crecimiento Transformador beta/metabolismo , Receptores de Factores de Crecimiento Transformadores beta/genética , Receptores de Factores de Crecimiento Transformadores beta/metabolismo , Secuencia de Aminoácidos , Sustitución de Aminoácidos , Animales , Animales Modificados Genéticamente , Proteínas de Caenorhabditis elegans/química , Modelos Animales de Enfermedad , Humanos , Dominios Proteicos , Receptor Tipo II de Factor de Crecimiento Transformador beta/química , Receptores de Superficie Celular/genética , Receptores de Superficie Celular/metabolismo , Receptores de Factores de Crecimiento Transformadores beta/química , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Homología de Secuencia de Aminoácido , Especificidad de la Especie
11.
Mol Biol Cell ; 30(26): 3151-3160, 2019 12 15.
Artículo en Inglés | MEDLINE | ID: mdl-31693440

RESUMEN

Bone morphogenetic protein (BMP) signaling pathways control many developmental and homeostatic processes, including cell size and extracellular matrix remodeling. An understanding of how this pathway itself is controlled remains incomplete. To identify novel regulators of BMP signaling, we performed a forward genetic screen in Caenorhabditis elegans for genes involved in body size regulation, a trait under the control of BMP member DBL-1. We isolated mutations that suppress the long phenotype of lon-2, a gene that encodes a negative regulator that sequesters DBL-1. This screen was effective because we isolated alleles of several core components of the DBL-1 pathway, demonstrating the efficacy of the screen. We found additional alleles of previously identified but uncloned body size genes. Our screen also identified widespread involvement of extracellular matrix proteins in DBL-1 regulation of body size. We characterized interactions between the DBL-1 pathway and extracellular matrix and other genes that affect body morphology. We discovered that loss of some of these genes affects the DBL-1 pathway, and we provide evidence that DBL-1 signaling affects many molecular and cellular processes associated with body size. We propose a model in which multiple body size factors are controlled by signaling through the DBL-1 pathway and by DBL-1-independent processes.


Asunto(s)
Tamaño Corporal/genética , Proteínas Morfogenéticas Óseas/metabolismo , Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/fisiología , Neuropéptidos/metabolismo , Factor de Crecimiento Transformador beta/metabolismo , Animales , Proteínas de Caenorhabditis elegans/genética , Matriz Extracelular/metabolismo , Proteínas de la Matriz Extracelular/metabolismo , Glipicanos/genética , Transducción de Señal
12.
Fly (Austin) ; 12(2): 105-117, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30015555

RESUMEN

Decapentaplegic (Dpp), the Drosophila homolog of the vertebrate bone morphogenetic protein (BMP2/4), is crucial for patterning and growth in many developmental contexts. The Dpp pathway is regulated at many different levels to exquisitely control its activity. We show that bantam (ban), a microRNA, modulates Dpp signaling activity. Over expression of ban decreases phosphorylated Mothers against decapentaplegic (Mad) levels and negatively affects Dpp pathway transcriptional target genes, while null mutant clones of ban upregulate the pathway. We provide evidence that dpp upregulates ban in the wing imaginal disc, and attenuation of Dpp signaling results in a reduction of ban expression, showing that they function in a feedback loop. Furthermore, we show that this feedback loop is important for maintaining anterior-posterior compartment boundary stability in the wing disc through regulation of optomotor blind (omb), a known target of the pathway. Our results support a model that ban functions with dpp in a negative feedback loop.


Asunto(s)
Proteínas de Drosophila/metabolismo , Drosophila melanogaster/genética , Retroalimentación Fisiológica , MicroARNs/genética , Alas de Animales/crecimiento & desarrollo , Animales , Proteínas de Drosophila/genética , Drosophila melanogaster/crecimiento & desarrollo , Drosophila melanogaster/metabolismo , Regulación del Desarrollo de la Expresión Génica , Transducción de Señal , Alas de Animales/metabolismo
14.
Biosens Bioelectron ; 22(11): 2643-9, 2007 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-17169547

RESUMEN

This work proposes the use of amperometric signals generated by a 96-well multi-array dissolved oxygen multi-electrode sensor (DOX) coupled with principal component analysis for continuous monitoring, identification and differentiation of bacteria. Two types of differentiation mechanisms were tested: (1) direct monitoring of respiratory activity via oxygen consumption and (2) quantification of the effect of three broad-spectrum antibiotics on bacteria growth and respiration over time. Five species of bacteria were examined including: Escherichia coli, Escherichia adecarboxylata, Comamonas acidovorans, Corynebacterium glutamicum and Staphylococcus epidermidis. The addition of small concentrations of antibiotics to the growth medium alters the oxygen consumption of the cells and a unique fingerprint is created for a specific cell. This fingerprint is shown to evolve over a specific concentration range that is dependant of instrumental constraints of the DOX system. The application of principal component analysis (PCA) to classify the data was also examined. It was shown that bacteria could be classified simply by their oxygen consumption rates over a varying concentration range. Discrimination between species can also be increased by the effects of the antibiotics on the oxygen consumption of varying concentrations of cells. The proposed DOX-PCA system illustrates a generic template that can be tailored to meet specific research goals by the selection of specific cell/antibiotic combinations and concentrations.


Asunto(s)
Antibacterianos/administración & dosificación , Bacterias/aislamiento & purificación , Bacterias/metabolismo , Técnicas Biosensibles/instrumentación , Electroquímica/instrumentación , Pruebas de Sensibilidad Microbiana/instrumentación , Reconocimiento de Normas Patrones Automatizadas/métodos , Algoritmos , Inteligencia Artificial , Bacterias/clasificación , Bacterias/efectos de los fármacos , Técnicas Biosensibles/métodos , Técnicas de Cultivo de Célula/instrumentación , Técnicas de Cultivo de Célula/métodos , Electroquímica/métodos , Diseño de Equipo , Análisis de Falla de Equipo , Análisis de Inyección de Flujo/instrumentación , Análisis de Inyección de Flujo/métodos , Pruebas de Sensibilidad Microbiana/métodos , Consumo de Oxígeno/fisiología , Robótica/instrumentación , Robótica/métodos
15.
G3 (Bethesda) ; 7(1): 87-93, 2017 01 05.
Artículo en Inglés | MEDLINE | ID: mdl-27793971

RESUMEN

Genome editing using the Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) and associated nuclease (Cas9) enables specific genetic modifications, including deletions, insertions, and substitutions in numerous organisms, such as the fruit fly Drosophila melanogaster One challenge of the CRISPR/Cas9 system can be the laborious and time-consuming screening required to find CRISPR-induced modifications due to a lack of an obvious phenotype and low frequency after editing. Here we apply the successful co-CRISPR technique in Drosophila to simultaneously target a gene of interest and a marker gene, ebony, which is a recessive gene that produces dark body color and has the further advantage of not being a commonly used transgenic marker. We found that Drosophila broods containing higher numbers of CRISPR-induced ebony mutations ("jackpot" lines) are significantly enriched for indel events in a separate gene of interest, while broods with few or no ebony offspring showed few mutations in the gene of interest. Using two different PAM sites in our gene of interest, we report that ∼61% (52-70%) of flies from the ebony-enriched broods had an indel in DNA near either PAM site. Furthermore, this marker mutation system may be useful in detecting the less frequent homology-directed repair events, all of which occurred in the ebony-enriched broods. By focusing on the broods with a significant number of ebony flies, successful identification of CRISPR-induced events is much faster and more efficient. The co-CRISPR technique we present significantly improves the screening efficiency in identification of genome-editing events in Drosophila.


Asunto(s)
Sistemas CRISPR-Cas/genética , Proteínas de Unión al ADN/genética , Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Edición Génica/métodos , Animales , Animales Modificados Genéticamente , Marcación de Gen/métodos , Mutación INDEL/genética , Fenotipo
16.
PLoS One ; 12(7): e0180681, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28704415

RESUMEN

Signal transduction of the conserved transforming growth factor-ß (TGFß) family signaling pathway functions through two distinct serine/threonine transmembrane receptors, the type I and type II receptors. Endocytosis orchestrates the assembly of signaling complexes by coordinating the entry of receptors with their downstream signaling mediators. Recently, we showed that the C. elegans type I bone morphogenetic protein (BMP) receptor SMA-6, part of the TGFß family, is recycled through the retromer complex while the type II receptor, DAF-4 is recycled in a retromer-independent, ARF-6 dependent manner. From genetic screens in C. elegans aimed at identifying new modifiers of BMP signaling, we reported on SMA-10, a conserved LRIG (leucine-rich and immunoglobulin-like domains) transmembrane protein. It is a positive regulator of BMP signaling that binds to the SMA-6 receptor. Here we show that the loss of sma-10 leads to aberrant endocytic trafficking of SMA-6, resulting in its accumulation in distinct intracellular endosomes including the early endosome, multivesicular bodies (MVB), and the late endosome with a reduction in signaling strength. Our studies show that trafficking defects caused by the loss of sma-10 are not universal, but affect only a limited set of receptors. Likewise, in Drosophila, we find that the fly homolog of sma-10, lambik (lbk), reduces signaling strength of the BMP pathway, consistent with its function in C. elegans and suggesting evolutionary conservation of function. Loss of sma-10 results in reduced ubiquitination of the type I receptor SMA-6, suggesting a possible mechanism for its regulation of BMP signaling.


Asunto(s)
Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/metabolismo , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/metabolismo , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Receptores de Superficie Celular/metabolismo , Animales , Caenorhabditis elegans/genética , Endocitosis , Endosomas/metabolismo , Regulación del Desarrollo de la Expresión Génica , Mutación , Transporte de Proteínas , Transducción de Señal
17.
J Chromatogr A ; 1096(1-2): 69-75, 2005 Nov 25.
Artículo en Inglés | MEDLINE | ID: mdl-16301070

RESUMEN

Gas chromatography and pattern recognition methods were used to develop a potential method for differentiating European honeybees from Africanized honeybees. The test data consisted of 237 gas chromatograms of hydrocarbon extracts obtained from the wax glands, cuticle, and exocrine glands of European and Africanized honeybees. Each gas chromatogram contained 65 peaks corresponding to a set of standardized retention time windows. A genetic algorithm (GA) for pattern recognition was used to identify features in the gas chromatograms characteristic of the genotype. The pattern recognition GA searched for features in the chromatograms that optimized the separation of the European and Africanized honeybees in a plot of the two or three largest principal components of the data. Because the largest principal components capture the bulk of the variance in the data, the peaks identified by the pattern recognition GA primarily contained information about differences between gas chromatograms of European and Africanized honeybees. The principal component analysis routine embedded in the fitness function of the pattern recognition GA acted as an information filter, significantly reducing the size of the search space since it restricted the search to feature sets whose principal component plots showed clustering on the basis of the bees' genotype. In addition, the algorithm focused on those classes and/or samples that were difficult to classify as it trained using a form of boosting. Samples that consistently classify correctly are not as heavily weighted as samples that are difficult to classify. Over time, the algorithm learns its optimal parameters in a manner similar to a neural network. The pattern recognition GA integrates aspects of artificial intelligence and evolutionary computations to yield a "smart" one-pass procedure for feature selection and classification.


Asunto(s)
Abejas/química , Abejas/clasificación , Cromatografía de Gases/métodos , Reconocimiento de Normas Patrones Automatizadas/métodos , Animales , Glándulas Exocrinas/química , Masculino , Análisis de Componente Principal
18.
J Clin Endocrinol Metab ; 97(9): 3333-41, 2012 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-22745245

RESUMEN

CONTEXT: Sitagliptin is an inhibitor of the enzyme dipeptidyl peptidase-IV (DPP-IV), which degrades the incretins, glucagon-like peptide-1 and glucose-dependent insulinotropic polypeptide, and thus, sitagliptin increases their bioavailability. The stimulation of insulin and the suppression of glucagon secretion that follow exert a glucose lowering effect and hence its use as an antidiabetic drug. Because DPP-IV is expressed as CD26 on cell membranes and because CD26 mediates proinflammatory signals, we hypothesized that sitagliptin may exert an antiinflammatory effect. PATIENTS AND METHODS: Twenty-two patients with type 2 diabetes were randomized to receive either 100 mg daily of sitagliptin or placebo for 12 wk. Fasting blood samples were obtained at baseline and at 2, 4, and 6 hours after a single dose of sitagliptin and at 2, 4, 8, and 12 wk of treatment. RESULTS: Glycosylated hemoglobin fell significantly from 7.6 ± 0.4 to 6.9 ± 3% in patients treated with sitagliptin. Fasting glucagon-like peptide-1 concentrations increased significantly, whereas the mRNA expression in mononuclear cell of CD26, the proinflammatory cytokine, TNFα, the receptor for endotoxin, Toll-like receptor (TLR)-4, TLR-2, and proinflammatory kinases, c-Jun N-terminal kinase-1 and inhibitory-κB kinase (IKKß), and that of the chemokine receptor CCR-2 fell significantly after 12 wk of sitagliptin. TLR-2, IKKß, CCR-2, and CD26 expression and nuclear factor-κB binding also fell after a single dose of sitagliptin. There was a fall in protein expression of c-Jun N-terminal kinase-1, IKKß, and TLR-4 and in plasma concentrations of C-reactive protein, IL-6, and free fatty acids after 12 wk of sitagliptin. CONCLUSIONS: These effects are consistent with a potent and rapid antiinflammatory effect of sitagliptin and may potentially contribute to the inhibition of atherosclerosis. The suppression of CD26 expression suggests that sitagliptin may inhibit the synthesis of DPP-IV in addition to inhibiting its action.


Asunto(s)
Antiinflamatorios no Esteroideos , Inhibidores de la Dipeptidil-Peptidasa IV/farmacología , Pirazinas/farmacología , Triazoles/farmacología , Adulto , Anciano , Glucemia/análisis , Glucemia/metabolismo , Western Blotting , Proteína C-Reactiva/análisis , Proteína C-Reactiva/metabolismo , Separación Celular , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Diabetes Mellitus Tipo 2/fisiopatología , Dipeptidil Peptidasa 4/análisis , Dipeptidil Peptidasa 4/metabolismo , Método Doble Ciego , Femenino , Péptido 1 Similar al Glucagón/análisis , Péptido 1 Similar al Glucagón/metabolismo , Hemoglobina Glucada/análisis , Humanos , Quinasa I-kappa B/análisis , Quinasa I-kappa B/metabolismo , Interleucina-6/análisis , Interleucina-6/metabolismo , MAP Quinasa Quinasa 4/análisis , MAP Quinasa Quinasa 4/metabolismo , Masculino , Persona de Mediana Edad , Monocitos/efectos de los fármacos , Monocitos/metabolismo , Estudios Prospectivos , Receptores CCR2/análisis , Receptores CCR2/metabolismo , Fosfato de Sitagliptina , Receptor Toll-Like 2/análisis , Receptor Toll-Like 2/metabolismo , Receptor Toll-Like 4/análisis , Receptor Toll-Like 4/metabolismo , Factor de Necrosis Tumoral alfa/análisis , Factor de Necrosis Tumoral alfa/metabolismo
19.
J Clin Endocrinol Metab ; 97(1): 198-207, 2012 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-22013105

RESUMEN

OBJECTIVE: Our objective was to determine whether exenatide exerts an antiinflammatory effect. RESEARCH DESIGN AND METHODS: Twenty-four patients were prospectively randomized to be injected sc with either exenatide 10 µg twice daily [n = 12; mean age = 56 ± 3 yr; mean body mass index = 39.8 ± 2 kg/m(2); mean glycosylated hemoglobin (HbA1c) = 8.6 ± 0.4%] or placebo twice daily (n = 12; mean age = 54 ± 4 yr; mean body mass index = 39.1 ± 1.6 kg/m(2); mean HbA1c = 8.5 ± 0.3%) for 12 wk. Fasting blood samples were obtained at 0, 3, 6, and 12 wk. Blood samples were also collected for up to 6 h after a single dose of exenatide (5 µg) or placebo. RESULTS: Fasting blood glucose fell from 139 ± 17 to 110 ± 9 mg/dl, HbA1c from 8.6 ± 0.4 to 7.4 ± 0.5% (P < 0.05), and free fatty acids by 21 ± 5% from baseline (P < 0.05) with exenatide. There was no weight loss. There was a significant reduction in reactive oxygen species generation and nuclear factor-κB binding by 22 ± 9 and 26 ± 7%, respectively, and the mRNA expression of TNFα, IL-1ß, JNK-1, TLR-2, TLR-4, and SOCS-3 in mononuclear cells by 31 ± 12, 22 ± 10, 20 ± 11, 22 ± 9, 16 ± 7, and 31 ± 10%, respectively (P < 0.05 for all) after 12 wk of exenatide. After a single injection of exenatide, there was a reduction by 20 ± 7% in free fatty acids, 19 ± 7% in reactive oxygen species generation, 39 ± 11% in nuclear factor-κB binding, 18 ± 9% in TNFα expression, 26 ± 7% in IL-1ß expression, 18 ± 7% in JNK-1 expression, 24 ± 12% in TLR-4 expression, and 23 ± 11% in SOCS-3 expression (P < 0.05 for all). The plasma concentrations of monocyte chemoattractant protein-1, matrix metalloproteinase-9, serum amyloid A, and IL-6 were suppressed after 12 wk exenatide treatment by 15 ± 7, 20 ± 11, 16 ± 7, and 22 ± 12%, respectively (P < 0.05 for all). CONCLUSIONS: Exenatide exerts a rapid antiinflammatory effect at the cellular and molecular level. This may contribute to a potentially beneficial antiatherogenic effect. This effect was independent of weight loss.


Asunto(s)
Antiinflamatorios/farmacología , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Obesidad/tratamiento farmacológico , Péptidos/administración & dosificación , Péptidos/farmacología , Ponzoñas/administración & dosificación , Ponzoñas/farmacología , Antiinflamatorios/administración & dosificación , Glucemia/efectos de los fármacos , Glucemia/metabolismo , Diabetes Mellitus Tipo 2/sangre , Diabetes Mellitus Tipo 2/complicaciones , Diabetes Mellitus Tipo 2/inmunología , Esquema de Medicación , Exenatida , Ácidos Grasos no Esterificados/sangre , Humanos , Hipoglucemiantes/administración & dosificación , Hipoglucemiantes/farmacología , Insulina/sangre , Persona de Mediana Edad , Obesidad/sangre , Obesidad/complicaciones , Obesidad/inmunología , Placebos , Especies Reactivas de Oxígeno/sangre , Método Simple Ciego , Factores de Tiempo , Resultado del Tratamiento
20.
Diabetes Care ; 34(8): 1854-9, 2011 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-21715518

RESUMEN

OBJECTIVE: It has been suggested that the high prevalence of subnormal free testosterone concentrations, along with low or inappropriately normal gonadotropins in men with type 2 diabetes, may be the result of an increase in plasma estradiol concentrations secondary to an increase in aromatase activity in the adipose tissue that leads to the suppression of the hypothalamo-hypophyseal-gonadal axis. RESEARCH DESIGN AND METHODS: To investigate this hypothesis, plasma estradiol, testosterone, leutinizing hormone, follicle-stimulating hormone, and sex hormone-binding globulin (SHBG) concentrations were measured in fasting blood samples of 240 men with type 2 diabetes. Free estradiol concentrations were either calculated (n = 198) using total estradiol and SHBG measured by immunoassay or directly measured by liquid chromatography tandem mass spectrometry (LC-MS/MS) and equilibrium dialysis (n = 102). RESULTS: The calculated free estradiol concentration in men with subnormal free testosterone concentrations was lower than that in men with normal free testosterone concentrations (median 0.047 vs. 0.063 ng/dL, P < 0.001). Directly measured (LC-MS/MS) free estradiol concentrations were also lower in men with subnormal free testosterone concentrations (median 0.025 vs. 0.045 ng/dL, P = 0.008). Free estradiol concentrations were directly related to free testosterone but not to BMI or age. CONCLUSIONS: These data show that the suppression of the hypothalamo-hypophyseal-gonadal axis in patients with subnormal free testosterone concentrations and type 2 diabetes is not associated with increased estradiol concentrations. The pathogenesis of subnormal free testosterone concentrations in type 2 diabetes needs to be investigated further.


Asunto(s)
Diabetes Mellitus Tipo 2/sangre , Estradiol/sangre , Testosterona/sangre , Adulto , Anciano , Cromatografía Liquida , Femenino , Hormona Folículo Estimulante/sangre , Humanos , Hormona Luteinizante/sangre , Masculino , Persona de Mediana Edad , Globulina de Unión a Hormona Sexual/metabolismo , Espectrometría de Masas en Tándem
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