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1.
Proc Natl Acad Sci U S A ; 114(41): E8711-E8720, 2017 10 10.
Artigo em Inglês | MEDLINE | ID: mdl-28973896

RESUMO

Mycobacterium tuberculosis' success as a pathogen comes from its ability to evade degradation by macrophages. Normally macrophages clear microorganisms that activate pathogen-recognition receptors (PRRs) through a lysosomal-trafficking pathway called "LC3-associated phagocytosis" (LAP). Although Mtuberculosis activates numerous PRRs, for reasons that are poorly understood LAP does not substantially contribute to Mtuberculosis control. LAP depends upon reactive oxygen species (ROS) generated by NADPH oxidase, but Mtuberculosis fails to generate a robust oxidative response. Here, we show that CpsA, a LytR-CpsA-Psr (LCP) domain-containing protein, is required for Mtuberculosis to evade killing by NADPH oxidase and LAP. Unlike phagosomes containing wild-type bacilli, phagosomes containing the ΔcpsA mutant recruited NADPH oxidase, produced ROS, associated with LC3, and matured into antibacterial lysosomes. Moreover, CpsA was sufficient to impair NADPH oxidase recruitment to fungal particles that are normally cleared by LAP. Intracellular survival of the ΔcpsA mutant was largely restored in macrophages missing LAP components (Nox2, Rubicon, Beclin, Atg5, Atg7, or Atg16L1) but not in macrophages defective in a related, canonical autophagy pathway (Atg14, Ulk1, or cGAS). The ΔcpsA mutant was highly impaired in vivo, and its growth was partially restored in mice deficient in NADPH oxidase, Atg5, or Atg7, demonstrating that CpsA makes a significant contribution to the resistance of Mtuberculosis to NADPH oxidase and LC3 trafficking in vivo. Overall, our findings reveal an essential role of CpsA in innate immune evasion and suggest that LCP proteins have functions beyond their previously known role in cell-wall metabolism.


Assuntos
Proteínas de Bactérias/metabolismo , Macrófagos/imunologia , Proteínas Associadas aos Microtúbulos/fisiologia , NADPH Oxidase 2/fisiologia , Fagocitose/fisiologia , Tuberculose/prevenção & controle , Animais , Autofagia , Proteínas de Bactérias/genética , Feminino , Interações Hospedeiro-Patógeno , Macrófagos/microbiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos SCID , Mycobacterium tuberculosis/patogenicidade , Óxido Nítrico Sintase Tipo II/fisiologia , Fagossomos , Espécies Reativas de Oxigênio/metabolismo , Tuberculose/imunologia , Tuberculose/microbiologia
2.
Environ Sci Pollut Res Int ; 31(40): 53156-53176, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39174829

RESUMO

Machine tools constitute the backbone of the industrial sector, representing the largest global inventory of equipment. The carbon emissions resulting from the production of each machine tool merit attention. Effective management of carbon emissions in the machine tool manufacturing process is crucial. This paper introduces a novel method for early carbon emission warnings in the machine tool manufacturing process, utilizing an adaptive dynamic exponentially weighted moving average (EWMA) approach. This method addresses the challenges in identifying and monitoring abnormal carbon emissions, emerging from uncertainties and dynamic correlations. Utilizing dynamic sampling techniques and adaptive principles, this method constructs an adaptive dynamic EWMA control chart. The EWMA control chart incorporates a multi-objective optimization design model, concentrating on carbon emissions in the machine tool manufacturing process, and incorporates statistical, economic, and environmental objectives. To mitigate slow convergence rates and enhance optimization accuracy in complex control chart multi-objective optimization algorithms, this study proposes an enhanced Harris hawks optimization (HHO) algorithm as the solving algorithm. Finally, the application of this method is demonstrated through the monitoring of carbon emissions in the manufacturing process of a five-axis machine tool (EOC), as a case study. The results validate the method's rapid responsiveness to abnormal carbon emissions, providing alerts. This further confirms the efficacy and feasibility of the proposed approach. Ultimately, this approach offers a viable strategy for fostering environmentally conscious and high-quality growth in the machine tool industry.


Assuntos
Carbono , Monitoramento Ambiental , Carbono/química , Monitoramento Ambiental/métodos , Algoritmos , Poluentes Atmosféricos/análise
3.
Nat Microbiol ; 2024 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-39242815

RESUMO

Mycobacterium tuberculosis (Mtb) infects several lung macrophage populations, which have distinct abilities to restrict Mtb. What enables Mtb survival in certain macrophage populations is not well understood. Here we used transposon sequencing analysis of Mtb in wild-type and autophagy-deficient mouse macrophages lacking ATG5 or ATG7, and found that Mtb genes involved in phthiocerol dimycocerosate (PDIM) virulence lipid synthesis confer resistance to autophagy. Using ppsD mutant Mtb, we found that PDIM inhibits LC3-associated phagocytosis (LAP) by inhibiting phagosome recruitment of NADPH oxidase. In mice, PDIM protected Mtb from LAP and classical autophagy. During acute infection, PDIM was dispensable for Mtb survival in alveolar macrophages but required for survival in non-alveolar macrophages in an autophagy-dependent manner. During chronic infection, autophagy-deficient mice succumbed to infection with PDIM-deficient Mtb, with impairments in B-cell accumulation in lymphoid follicles. These findings demonstrate that PDIM contributes to Mtb virulence and immune evasion, revealing a contributory role for autophagy in B-cell responses.

4.
Proc Natl Acad Sci U S A ; 107(19): 8782-7, 2010 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-20421485

RESUMO

We report that adrenocorticotropic hormone (ACTH) protects against osteonecrosis of the femoral head induced by depot methylprednisolone acetate (depomedrol). This therapeutic response likely arises from enhanced osteoblastic support and the stimulation of VEGF by ACTH; the latter is largely responsible for maintaining the fine vascular network that surrounds highly remodeling bone. We suggest examining the efficacy of ACTH in preventing human osteonecrosis, a devastating complication of glucocorticoid therapy.


Assuntos
Hormônio Adrenocorticotrópico/uso terapêutico , Fêmur/patologia , Glucocorticoides/efeitos adversos , Osteonecrose/induzido quimicamente , Osteonecrose/tratamento farmacológico , Substâncias Protetoras/uso terapêutico , Células 3T3 , Hormônio Adrenocorticotrópico/farmacologia , Animais , Apoptose/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Citoproteção/efeitos dos fármacos , Feminino , Fêmur/efeitos dos fármacos , Humanos , Camundongos , Osteoblastos/efeitos dos fármacos , Osteoblastos/metabolismo , Osteoblastos/patologia , Osteoclastos/efeitos dos fármacos , Osteoclastos/metabolismo , Osteoclastos/patologia , Osteonecrose/prevenção & controle , Substâncias Protetoras/farmacologia , Coelhos , Fator A de Crescimento do Endotélio Vascular/biossíntese
5.
Artigo em Inglês | MEDLINE | ID: mdl-35000184

RESUMO

Due to the strong coating properties, laser cladding is widely used in the remanufacturing of scrap metal parts. Nevertheless, the risk of cladding quality assurance is increased by the complex cladding formation pattern of multiple multilayers and the unpredictable cross-sectional morphology. In this study, the coupling law of laser power, scanning speed, and powder feeding speed on the geometry of cladding layer is deeply analyzed, and the process-dimension model of single-track melting layers is established. The complex process of laser cladding and the intrinsic laws of process parameters and cladding morphology are revealed by the model. Furthermore, based on the characteristics of the cross-sectional morphology of the cladding layer, a parabolic fitting model of the cross-sectional profile of a single-track cladding layer and an analytical model of the influence of the planar lap of multiple cladding trajectories on the melting width are proposed. Finally, the cross-sectional profile curves of the multilayer cladding were derived and the prediction of the multilayer cladding geometry was achieved. Validation experimental data for laser cladding with 304 powder showed that the average relative errors of melting height and width between the predicted results and the experimental samples were 5.18% and 1.53%, respectively, indicating that the proposed model can accurately predict the cross-sectional shape of the multilayered laser cladding. This study provides experimental data and theoretical prediction methods for the laser remanufacturing of coating profiles on used parts.

6.
Comput Intell Neurosci ; 2022: 9181865, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36619813

RESUMO

To cope with the problems of frequent mold changes, long production cycles and serious logistics crossings in workshop of aerospace enterprise. First, a manufacturing cell layout planning method based on the feature bit code domain method and K-Means++ is proposed to realize the accurate division of manufacturing cells. Then, a multiobjective optimization method of dynamic reconstruction layout based on improved fruit fly optimization algorithm (IFOA) is proposed to solve the reconstruction layout optimization of the production workshop problem with the optimization objectives of logistics cost, reconstruction cost, loss cost, and cell integrated area. Finally, plant simulation software is applied to simulate the workshop layout before and after optimization. The simulation results show that the logistics cost of the workshop cell layout after optimization is reduced by 8.7%, the utilization rate of the workshop area is improved by 5.2%, and the value-added rate of products is increased by 6.6%, which verifies the effectiveness and feasibility of the proposed model and method.


Assuntos
Algoritmos , Software , Simulação por Computador , Indústrias , Comércio
7.
Proc Natl Acad Sci U S A ; 105(11): 4289-94, 2008 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-18332426

RESUMO

We recently described the direct effects of thyroid-stimulating hormone (TSH) on bone and suggested that the bone loss in hyperthyroidism, hitherto attributed solely to elevated thyroid hormone levels, could at least in part arise from accompanying decrements in serum TSH. Recent studies on both mice and human subjects provide compelling evidence that thyroid hormones and TSH have the opposite effects on the skeleton. Here, we show that TSH, when injected intermittently into rodents, even at intervals of 2 weeks, displays a powerful antiresorptive action in vivo. By virtue of this action, together with the possible anabolic effects shown earlier, TSH both prevents bone loss and restores the lost bone after ovariectomy. Importantly, the osteoclast inhibitory action of TSH persists ex vivo even after therapy is stopped for 4 weeks. This profound and lasting antiresorptive action of TSH is mimicked in cells that genetically overexpress the constitutively active ligand-independent TSH receptor (TSHR). In contrast, loss of function of a mutant TSHR (Pro --> Leu at 556) in congenital hypothyroid mice activates osteoclast differentiation, confirming once again our premise that TSHRs have a critical role in regulating bone remodeling.


Assuntos
Osteoporose/prevenção & controle , Ovariectomia , Tireotropina/administração & dosagem , Animais , Densidade Óssea , Diferenciação Celular/efeitos dos fármacos , Células Cultivadas , Feminino , Humanos , Injeções , Camundongos , Osteoclastos/metabolismo , Osteoporose/metabolismo , Ratos , Receptores da Tireotropina/metabolismo , Proteínas Recombinantes/administração & dosagem , Estresse Mecânico , Tiroxina/sangue
8.
mBio ; 11(4)2020 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-32636249

RESUMO

Macrophage activation involves metabolic reprogramming to support antimicrobial cellular functions. How these metabolic shifts influence the outcome of infection by intracellular pathogens remains incompletely understood. Mycobacterium tuberculosis (Mtb) modulates host metabolic pathways and utilizes host nutrients, including cholesterol and fatty acids, to survive within macrophages. We found that intracellular growth of Mtb depends on host fatty acid catabolism: when host fatty acid ß-oxidation (FAO) was blocked chemically with trimetazidine, a compound in clinical use, or genetically by deletion of the mitochondrial fatty acid transporter carnitine palmitoyltransferase 2 (CPT2), Mtb failed to grow in macrophages, and its growth was attenuated in mice. Mechanistic studies support a model in which inhibition of FAO generates mitochondrial reactive oxygen species, which enhance macrophage NADPH oxidase and xenophagy activity to better control Mtb infection. Thus, FAO inhibition promotes key antimicrobial functions of macrophages and overcomes immune evasion mechanisms of Mtb.IMPORTANCEMycobacterium tuberculosis (Mtb) is the leading infectious disease killer worldwide. We discovered that intracellular Mtb fails to grow in macrophages in which fatty acid ß-oxidation (FAO) is blocked. Macrophages treated with FAO inhibitors rapidly generate a burst of mitochondria-derived reactive oxygen species, which promotes NADPH oxidase recruitment and autophagy to limit the growth of Mtb. Furthermore, we demonstrate the ability of trimetazidine to reduce pathogen burden in mice infected with Mtb. These studies will add to the knowledge of how host metabolism modulates Mtb infection outcomes.


Assuntos
Ácidos Graxos/metabolismo , Interações Hospedeiro-Patógeno/efeitos dos fármacos , Macrófagos/microbiologia , Mycobacterium tuberculosis/imunologia , Oxirredução/efeitos dos fármacos , Animais , Antituberculosos/farmacologia , Células Cultivadas , Citocinas/análise , Feminino , Metabolismo dos Lipídeos/efeitos dos fármacos , Ativação de Macrófagos , Macrófagos/efeitos dos fármacos , Redes e Vias Metabólicas , Camundongos , Camundongos Endogâmicos C57BL , Espécies Reativas de Oxigênio/metabolismo , Trimetazidina/farmacologia , Tuberculose/microbiologia
9.
Biochem Biophys Res Commun ; 371(4): 912-6, 2008 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-18384744

RESUMO

We have shown in two accompanying papers that TNF induces oscillations in (1) approximately 13% of the genome, and (2) the activation of MAP kinase and NF-kappaB signaling pathways. Here we aim to bridge oscillations in signal transduction activation to oscillations in genetic output. Specifically, we sought to study how these oscillations can combine in a ligand-specific manner at the level of the promoter to initiate gene transcription. We utilize the late onset gene CD38 as a model gene since it has previously been shown that TNF, but not the related cytokine RANK-L, induces its expression. We find that TNF-induced oscillations in p65 and p50 recruitment to the CD38 promoter correlated with recruitment of MAPK-induced AP-1 recruitment, as analyzed by quantitative ChIP analysis. Through re-ChIP analysis we show that a unique transcriptional complex is seen on the promoter at 3h post-TNF addition, corresponding to the onset of CD38 transcription, which is not seen in the basal state. Moreover, we show that RANK-L was unable to combinatorially recruit AP-1 and NF-kappaB transcription factors to the CD38 promoter, despite inducing the activation of both signaling pathways. These results, in sum with the two accompanying papers, constitute a new paradigm through which cells dynamically orchestrate signaling molecules to coordinate time-resolved gene transcription by the formation of novel time-specific transcriptional complexes.


Assuntos
ADP-Ribosil Ciclase 1/genética , Subunidade p50 de NF-kappa B/metabolismo , Fator de Transcrição AP-1/metabolismo , Fator de Transcrição RelA/metabolismo , Ativação Transcricional , Fator de Necrose Tumoral alfa/fisiologia , Animais , Células Cultivadas , Imunoprecipitação da Cromatina , Camundongos , Camundongos Endogâmicos C57BL , Quinases de Proteína Quinase Ativadas por Mitógeno/metabolismo , Regiões Promotoras Genéticas/efeitos dos fármacos , Ligante RANK/farmacologia , Ligante RANK/fisiologia , Transdução de Sinais , Transcrição Gênica/efeitos dos fármacos , Fator de Necrose Tumoral alfa/farmacologia
10.
Biochem Biophys Res Commun ; 371(4): 900-5, 2008 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-18384746

RESUMO

With only few exceptions that include Hes-1 p53, and IkappaB, the expression of genes has never been shown to be oscillatory. Here, we show that the inflammatory cytokine TNF triggers oscillations in >5000 genes. We utilize microarrays at 30-min intervals to analyze the pattern of global gene expression in murine macrophages. We find that 15% of genes in the genome underwent a significant >3-fold increase in expression, with 89% of these displaying oscillations at frequencies as low as every 50min. We analyze further two sub-clusters of genes that either began oscillating early or after a lag phase. Through the use of quantitative PCR, we confirm the oscillations and show that the oscillations are continuous. Moreover, we show that these continuous oscillations are not unique to TNF, but that related cytokines such as RANK-L produces oscillations with a unique induction profile. In the two papers accompanying this one, we analyze the mechanism of these oscillations and find that TNF also triggers oscillations in the phosphorylation of MAP kinases, and that these oscillations combine to recruit transcription factors to promoters in a cyclical fashion. The results presented here suggest that gene transcription is a highly dynamic processes, with thousands of genes displaying rapid (<60min) oscillations over time. Considering this dynamism, time-resolved measurements of gene transcription should become the experimental norm.


Assuntos
Regulação da Expressão Gênica , RNA Mensageiro/biossíntese , Fator de Necrose Tumoral alfa/fisiologia , Animais , Células Cultivadas , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Análise de Sequência com Séries de Oligonucleotídeos , Ligante RANK/farmacologia , Ligante RANK/fisiologia , Fatores de Tempo , Fator de Necrose Tumoral alfa/farmacologia
11.
Biochem Biophys Res Commun ; 366(2): 352-9, 2008 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-18060857

RESUMO

We describe for the first time functional clusters of genes that are modulated during the differentiation of osteoclasts. Pathway analysis was applied to gene array data generated from affymetrix chips hybridized to RNA isolated from RAW264.7 cells exposed to RANK-ligand (RANK-L) for 5 days. This analysis revealed major functional gene clusters that were either up- or down-regulated during osteoclastogenesis. Some of the genes within the clusters have known functions, while others do not. We discuss herein the relevance of these functional gene clusters and their modulation to biological processes underlying the formation, function, and fate of osteoclasts.


Assuntos
Família Multigênica/fisiologia , Osteoclastos/citologia , Osteoclastos/metabolismo , Proteoma/metabolismo , Animais , Diferenciação Celular , Linhagem Celular , Camundongos , Análise de Sequência com Séries de Oligonucleotídeos
12.
FASEB J ; 21(7): 1367-75, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17307840

RESUMO

The collapsing glomerulopathy of HIV-associated nephropathy (HIVAN) is characterized by podocyte dedifferentiation and proliferation. In affected glomeruli, proliferating podocytes adhere in aggregates to form glomerular pseudocrescents and fill an enlarged Bowman's space. Previously, we reported that sidekick-1 (sdk-1), an adhesion molecule of the immunoglobulin superfamily, was highly up-regulated in HIV-1 transgenic podocytes. In the current work, we explore how sdk-1 overexpression contributes to HIVAN pathogenesis. Murine podocytes infected with HIV-1 virus expressed significantly more sdk-1 than control-infected cells. Podocytes stably transfected with an sdk-1 expression construct grew in large aggregates with a simplified morphology characterized by a disorganized actin cytoskeleton, changes similar to podocytes in HIVAN. In contrast to controls, HIV-1 infected podocytes adhered to stably transfected sdk-1 podocyte aggregates in mixing studies. Furthermore, substrate-released cell sheets of wild-type podocytes were readily dissociated by mechanical stress, whereas HIV-1 podocytes remained in aggregates. The number of HIV-1 podocyte aggregates was significantly reduced in cells expressing a short hairpin RNA (shRNA) construct specific for sdk-1 compared with cells expressing control shRNA. Finally, in a HIVAN mouse model, sdk-1 protein was detected in podocytes in collapsed glomerular tufts and in glomerular pseudocrescents. These findings suggest that sdk-1 is an important mediator of cellular adhesion in HIV-infected podocytes and may contribute to podocyte clustering that is characteristic of pseudocrescent formation in HIVAN.


Assuntos
Nefropatia Associada a AIDS/metabolismo , Imunoglobulina G/fisiologia , Proteínas de Membrana/fisiologia , Podócitos/citologia , Nefropatia Associada a AIDS/patologia , Animais , Sequência de Bases , Northern Blotting , Western Blotting , Adesão Celular , Linhagem Celular Transformada , Primers do DNA , HIV-1 , Imunoglobulina G/genética , Proteínas de Membrana/genética , Camundongos , Camundongos Transgênicos , Inclusão em Parafina , Plasmídeos
13.
Ann N Y Acad Sci ; 1116: 216-26, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17872390

RESUMO

Here we briefly review our studies that have unraveled an important role for the calcium- and calmodulin-sensitive enzyme calcineurin (CN) in bone remodeling. We find that the genetic deletion of the calcineurin Aalpha isoform results in osteoporosis, which is recapitulated in humans following calcineurin inhibitor therapy widely used after solid organ transplantation. Mechanistically, however, while both calcineurin inhibitors cyclosporine and tacrolimus initially stimulate osteoclastic bone resorption in humans, the predominant feature in the CNAalpha null mouse is a profound reduction in bone formation. We speculate that the so-called "calcineurin inhibitors" may interact with molecules other than calcineurin. The clinical relevance of these observations is explored.


Assuntos
Calcineurina/genética , Deleção de Genes , Remodelação Óssea , Calcineurina/metabolismo , Inibidores de Calcineurina , Ciclosporina/farmacologia , Homozigoto , Humanos , Imunossupressores/farmacologia , Osteoblastos/metabolismo , Tacrolimo/farmacologia
14.
J Clin Invest ; 124(4): 1757-69, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24642466

RESUMO

Injury to the specialized epithelial cells of the glomerulus (podocytes) underlies the pathogenesis of all forms of proteinuric kidney disease; however, the specific genetic changes that mediate podocyte dysfunction after injury are not fully understood. Here, we performed a large-scale insertional mutagenic screen of injury-resistant podocytes isolated from mice and found that increased expression of the gene Rap1gap, encoding a RAP1 activation inhibitor, ameliorated podocyte injury resistance. Furthermore, injured podocytes in murine models of disease and kidney biopsies from glomerulosclerosis patients exhibited increased RAP1GAP, resulting in diminished glomerular RAP1 activation. In mouse models, podocyte-specific inactivation of Rap1a and Rap1b induced massive glomerulosclerosis and premature death. Podocyte-specific Rap1a and Rap1b haploinsufficiency also resulted in severe podocyte damage, including features of podocyte detachment. Over-expression of RAP1GAP in cultured podocytes induced loss of activated ß1 integrin, which was similarly observed in kidney biopsies from patients. Furthermore, preventing elevation of RAP1GAP levels in injured podocytes maintained ß1 integrin-mediated adhesion and prevented cellular detachment. Taken together, our findings suggest that increased podocyte expression of RAP1GAP contributes directly to podocyte dysfunction by a mechanism that involves loss of RAP1-mediated activation of ß1 integrin.


Assuntos
Proteínas Ativadoras de GTPase/metabolismo , Glomerulosclerose Segmentar e Focal/metabolismo , Podócitos/metabolismo , Animais , Proteínas Ativadoras de GTPase/genética , Glomerulosclerose Segmentar e Focal/genética , Glomerulosclerose Segmentar e Focal/patologia , Haploinsuficiência , Humanos , Integrina beta1/metabolismo , Glomérulos Renais/lesões , Glomérulos Renais/metabolismo , Glomérulos Renais/patologia , Camundongos , Camundongos Knockout , Camundongos Transgênicos , Podócitos/patologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Proteínas rap de Ligação ao GTP/deficiência , Proteínas rap de Ligação ao GTP/genética , Proteínas rap de Ligação ao GTP/metabolismo , Proteínas rap1 de Ligação ao GTP/deficiência , Proteínas rap1 de Ligação ao GTP/genética , Proteínas rap1 de Ligação ao GTP/metabolismo
15.
Biochem Biophys Res Commun ; 361(4): 910-5, 2007 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-17681281

RESUMO

We have shown recently that FSH stimulates osteoclast formation and function by a direct action on a G(i)-coupled FSH receptor (FSHR). Here, we report properties of the mouse FSH receptor promoter in the context of its activation in RAW-C3 osteoclast precursor macrophages. Basal promoter activity was low, but was significantly stimulated by receptor activator for NF-kappaB-ligand (RANK-L), a critical osteoclastogenic and pro-resorptive cytokine. In contrast, FSH dampened FSHR promoter activation, while estrogen had no effect. We surmise that the FSHR expression is regulated distinctly in the osteoclast, and differently from other cells, such as the ovarian follicular and Leydig cells.


Assuntos
Osteoclastos/metabolismo , Regiões Promotoras Genéticas , Receptores do FSH/genética , Ativação Transcricional , Animais , Sequência de Bases , Linhagem Celular , Sequência Consenso , Genes Reporter , Luciferases/análise , Luciferases/genética , Camundongos , Dados de Sequência Molecular , Células-Tronco/metabolismo
16.
Immunity ; 24(4): 393-403, 2006 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16618598

RESUMO

Somatic hypermutation (SHM) and class switch recombination (CSR) are initiated by activation-induced cytidine deaminase (AID), which preferentially deaminates deoxycytidines at WRC (W = A/T, R = A/G) motifs in vitro. The mechanisms responsible for targeting AID and for organizing the queue of enzymes involved in vivo have been elusive. Here, we examined point mutant knockin Msh6 mice (Msh6(TD/TD)), which lack the second phase of SHM but retain all the proteins involved, and found that AID was frequently targeted to non-WRC motifs. Unexpectedly, by comparing SHM and CSR in wild-type, Msh6(TD/TD), and age-matched Msh6(-/-) mice, we discovered that the presence of Msh6 protein influenced the AID targeting in phase one of SHM and mediated the proper targeting of recombination sites in CSR in vivo. Our data suggest that Msh6 plays a scaffolding role in the first phase of SHM, in addition to its enzymatic role in the second phase of SHM.


Assuntos
Citosina Desaminase/metabolismo , Proteínas de Ligação a DNA/genética , Genes de Imunoglobulinas/genética , Switching de Imunoglobulina/genética , Hipermutação Somática de Imunoglobulina , Animais , Sequência de Bases , Citosina Desaminase/imunologia , Análise Mutacional de DNA , Proteínas de Ligação a DNA/imunologia , Proteínas de Ligação a DNA/metabolismo , Camundongos , Camundongos Mutantes , Dados de Sequência Molecular , Mutação
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