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Sample records for receptor promotes longevity

  1. Nectarine promotes longevity in Drosophila melanogaster

    USDA-ARS?s Scientific Manuscript database

    Aging is associated with increased oxidative damage and gradual decline of physiology function with age, and is modulated by numerous genetic and environmental factors. Functional fruits are thought to be ideal candidates for promoting longevity and healthspan due to their high contents of polypheno...

  2. NECTARINE PROMOTES LONGEVITY IN DROSOPHILA MELANOGASTER

    PubMed Central

    Boyd, Olga; Weng, Peter; Sun, Xiaoping; Alberico, Thomas; Laslo, Mara; Obenland, David M.; Kern, Bradley; Zou, Sige

    2011-01-01

    Fruits containing high antioxidant capacities and other bioactivities are ideal for promoting longevity and healthspan. However, few fruits are known to improve the survival and healthspan in animals, let alone the underlying mechanisms. Here we investigate the effect of nectarine, a globally consumed fruit, on lifespan and healthspan in Drosophila melanogaster. Wild-type flies were fed the standard, dietary restriction (DR) or high fat diets supplemented with 0–4% nectarine extract. We measured lifespan, food intake, locomotor activity, fecundity, gene expression changes, and oxidative damage indicated by the level of 4-Hydroxynonenal-protein adduct in these flies. We also measured lifespan, locomotor activity and oxidative damage of sod1 mutant flies on the standard diet supplemented with 0–4% nectarine. Supplementation of 4% nectarine extended lifespan, increased fecundity and decreased expression of some metabolic genes, including a key gluconeogenesis gene PEPCK, and oxidative stress response genes, including peroxiredoxins, in female wild-type flies fed the standard, DR or high fat diet. Nectarine reduced oxidative damage in wild-type females fed the high fat diet. Moreover, nectarine improved the survival and reduced oxidative damage in female sod1 mutant flies. Together, these findings suggest that nectarine promotes longevity and healthspan partly through modulating glucose metabolism and reducing oxidative damage. PMID:21406223

  3. Induction of autophagy by spermidine promotes longevity.

    PubMed

    Eisenberg, Tobias; Knauer, Heide; Schauer, Alexandra; Büttner, Sabrina; Ruckenstuhl, Christoph; Carmona-Gutierrez, Didac; Ring, Julia; Schroeder, Sabrina; Magnes, Christoph; Antonacci, Lucia; Fussi, Heike; Deszcz, Luiza; Hartl, Regina; Schraml, Elisabeth; Criollo, Alfredo; Megalou, Evgenia; Weiskopf, Daniela; Laun, Peter; Heeren, Gino; Breitenbach, Michael; Grubeck-Loebenstein, Beatrix; Herker, Eva; Fahrenkrog, Birthe; Fröhlich, Kai-Uwe; Sinner, Frank; Tavernarakis, Nektarios; Minois, Nadege; Kroemer, Guido; Madeo, Frank

    2009-11-01

    Ageing results from complex genetically and epigenetically programmed processes that are elicited in part by noxious or stressful events that cause programmed cell death. Here, we report that administration of spermidine, a natural polyamine whose intracellular concentration declines during human ageing, markedly extended the lifespan of yeast, flies and worms, and human immune cells. In addition, spermidine administration potently inhibited oxidative stress in ageing mice. In ageing yeast, spermidine treatment triggered epigenetic deacetylation of histone H3 through inhibition of histone acetyltransferases (HAT), suppressing oxidative stress and necrosis. Conversely, depletion of endogenous polyamines led to hyperacetylation, generation of reactive oxygen species, early necrotic death and decreased lifespan. The altered acetylation status of the chromatin led to significant upregulation of various autophagy-related transcripts, triggering autophagy in yeast, flies, worms and human cells. Finally, we found that enhanced autophagy is crucial for polyamine-induced suppression of necrosis and enhanced longevity.

  4. Lithium Promotes Longevity through GSK3/NRF2-Dependent Hormesis

    PubMed Central

    Castillo-Quan, Jorge Iván; Li, Li; Kinghorn, Kerri J.; Ivanov, Dobril K.; Tain, Luke S.; Slack, Cathy; Kerr, Fiona; Nespital, Tobias; Thornton, Janet; Hardy, John; Bjedov, Ivana; Partridge, Linda

    2016-01-01

    Summary The quest to extend healthspan via pharmacological means is becoming increasingly urgent, both from a health and economic perspective. Here we show that lithium, a drug approved for human use, promotes longevity and healthspan. We demonstrate that lithium extends lifespan in female and male Drosophila, when administered throughout adulthood or only later in life. The life-extending mechanism involves the inhibition of glycogen synthase kinase-3 (GSK-3) and activation of the transcription factor nuclear factor erythroid 2-related factor (NRF-2). Combining genetic loss of the NRF-2 repressor Kelch-like ECH-associated protein 1 (Keap1) with lithium treatment revealed that high levels of NRF-2 activation conferred stress resistance, while low levels additionally promoted longevity. The discovery of GSK-3 as a therapeutic target for aging will likely lead to more effective treatments that can modulate mammalian aging and further improve health in later life. PMID:27068460

  5. Variations of the angiotensin II type 1 receptor gene are associated with extreme human longevity.

    PubMed

    Benigni, Ariela; Orisio, Silvia; Noris, Marina; Iatropoulos, Paraskevas; Castaldi, Davide; Kamide, Kei; Rakugi, Hiromi; Arai, Yasumichi; Todeschini, Marta; Ogliari, Giulia; Imai, Enyu; Gondo, Yasuyuki; Hirose, Nobuyoshi; Mari, Daniela; Remuzzi, Giuseppe

    2013-06-01

    Longevity phenotype in humans results from the influence of environmental and genetic factors. Few gene polymorphisms have been identified so far with a modest effect on lifespan leaving room for the search of other players in the longevity game. It has been recently demonstrated that targeted disruption of the mouse homolog of the human angiotensin II type 1 receptor (AT1R) gene (AGTR1) translates into marked prolongation of animal lifespan (Benigni et al., J Clin Invest 119(3):524-530, 2009). Based on the above study in mice, here we sought to search for AGTR1 variations associated to reduced AT1 receptor protein levels and to prolonged lifespan in humans. AGTR1 was sequenced in 173 Italian centenarians and 376 younger controls. A novel non-synonymous mutation was detected in a centenarian. Two polymorphisms in AGTR1 promoter, rs422858 and rs275653, in complete linkage disequilibrium, were significantly associated with the ability to attain extreme old age. We then replicated the study of rs275653 in a large independent cohort of Japanese origin (598 centenarians and semi-supercentenarians, 422 younger controls) and indeed confirmed its association with exceptional old age. In combined analyses, rs275653 was associated to extreme longevity either at recessive model (P = 0.007, odds ratio (OR) 3.57) or at genotype level (P = 0.015). Significance was maintained after correcting for confounding factors. Fluorescence activated cell sorting analysis revealed that subjects homozygous for the minor allele of rs275653 had less AT1R-positive peripheral blood polymorphonuclear cells. Moreover, rs275653 was associated to lower blood pressure in centenarians. These findings highlight the role of AGTR1 as a possible candidate among longevity-enabling genes.

  6. Hormetic efficacy of rutin to promote longevity in Drosophila melanogaster.

    PubMed

    Chattopadhyay, Debarati; Chitnis, Atith; Talekar, Aishwarya; Mulay, Prajakta; Makkar, Manyata; James, Joel; Thirumurugan, Kavitha

    2017-04-07

    Hormetins are compounds that mediate hormesis by being beneficial at low doses but detrimental at high doses. Recent studies have highlighted that many compounds that extended lifespan in model organisms did so by mediating hormesis. Rutin is a glycosylate conjugate of quercetin and rutinose and is abundant in citrus fruits and buckwheat seeds. Rutin possess ROS scavenging, anti-cancer, cardio-protective, skin-regenerative and neuro-protective properties. Drosophila melanogaster is an attractive model organism for longevity studies owing to its homology of organ and cellular-pathways with mammals. In this study, we aimed to understand the effect of rutin on extending longevity in Drosophila melanogaster. Male and female flies were administered with a range of rutin doses (100-800 µM) to analyse whether rutin mediated lifespan-extension by hormesis. Effect of rutin on physiological parameters like food intake, fecundity, climbing activity, development and resistance to various stresses was also studied. Lifespan assays showed that rutin at 200 and 400 µM significantly extended median lifespan in both male and female flies beyond which flies exhibited drastically reduced longevity. Increase in survival at 400 µM was associated with reduced food intake and fecundity. Flies exhibited improved climbing capability with both 200 and 400 µM rutin. Flies fed with 100 and 200 µM rutin exhibited enhanced survival upon exposure to oxidative stress with 400 µM rutin exhibiting no improvement in median lifespan following oxidative stress. Analysis of endogenous peroxide upon treatment with rutin (100-400 µM) with or without 5% H2O2 showed elevated levels of endogenous peroxide with 400 µM rutin whereas no increase in hydrogen peroxide level was observed with rutin at 100 and 200 µM. Finally, gene expression studies in male flies revealed that rutin treatment at 200 and/or 400 µM elevated transcript levels of dFoxO, MnSod, Cat, dTsc1, dTsc2, Thor, dAtg1, dAtg5

  7. Identification of longevity, fertility and growth-promoting properties of pomegranate in Caenorhabditis elegans

    PubMed Central

    Kılıçgün, Hasan; Arda, Nazlı; Uçar, Evren Önay

    2015-01-01

    Background: Pomegranate (Punica granatum L.) is commonly consumed as fresh fruit and fruit juice. It is also used in the production of jam, wine, food coloring agent, and flavor enhancer. Objective: The aim of this study was to identify the possible longevity, fertility and growth promoting properties of different ethanolic extract concentrations of pomegranate in Caenorhabditis elegans, which is increasingly popular and has proven to be a very useful experimental model organism for aging studies as well as for testing antioxidants and other compounds for effects on longevity. Materials and Methods: In this study, five experimental groups (20, 10, 5, 2.5 and 1.25 mg pomegranate extract/mL and one control group) were used to determine the most effective dose of pomegranate in terms of longevity, fertility and growth parameters. Results: It was seen that, pomegranate extracts up to the concentration of 5 mg/mL, had the potential to promote for the longevity, formation of new generations, fertility of new generations and growth properties of C. elegans although higher concentrations significantly reduced these parameters. Conclusion: these findings indicated that pomegranate could be used as a supplement to enhance longevity, fertility and growth rate for the other living organisms and human beings, but the dose should be carefully adjusted to avoid adverse effects. PMID:25829775

  8. Promoting longevity by maintaining metabolic and proliferative homeostasis

    PubMed Central

    Wang, Lifen; Karpac, Jason; Jasper, Heinrich

    2014-01-01

    Aging is characterized by a widespread loss of homeostasis in biological systems. An important part of this decline is caused by age-related deregulation of regulatory processes that coordinate cellular responses to changing environmental conditions, maintaining cell and tissue function. Studies in genetically accessible model organisms have made significant progress in elucidating the function of such regulatory processes and the consequences of their deregulation for tissue function and longevity. Here, we review such studies, focusing on the characterization of processes that maintain metabolic and proliferative homeostasis in the fruitfly Drosophila melanogaster. The primary regulatory axis addressed in these studies is the interaction between signaling pathways that govern the response to oxidative stress, and signaling pathways that regulate cellular metabolism and growth. The interaction between these pathways has important consequences for animal physiology, and its deregulation in the aging organism is a major cause for increased mortality. Importantly, protocols to tune such interactions genetically to improve homeostasis and extend lifespan have been established by work in flies. This includes modulation of signaling pathway activity in specific tissues, including adipose tissue and insulin-producing tissues, as well as in specific cell types, such as stem cells of the fly intestine. PMID:24353210

  9. Dietary Restriction Induced Longevity Is Mediated by Nuclear Receptor NHR-62 in Caenorhabditis elegans

    PubMed Central

    Heestand, Bree N.; Shen, Yidong; Liu, Wei; Magner, Daniel B.; Storm, Nadia; Meharg, Caroline; Habermann, Bianca; Antebi, Adam

    2013-01-01

    Dietary restriction (DR) extends lifespan in a wide variety of species, yet the underlying mechanisms are not well understood. Here we show that the Caenorhabditis elegans HNF4α-related nuclear hormone receptor NHR-62 is required for metabolic and physiologic responses associated with DR-induced longevity. nhr-62 mediates the longevity of eat-2 mutants, a genetic mimetic of dietary restriction, and blunts the longevity response of DR induced by bacterial food dilution at low nutrient levels. Metabolic changes associated with DR, including decreased Oil Red O staining, decreased triglyceride levels, and increased autophagy are partly reversed by mutation of nhr-62. Additionally, the DR fatty acid profile is altered in nhr-62 mutants. Expression profiles reveal that several hundred genes induced by DR depend on the activity of NHR-62, including a putative lipase required for the DR response. This study provides critical evidence of nuclear hormone receptor regulation of the DR longevity response, suggesting hormonal and metabolic control of life span. PMID:23935515

  10. Inhibition of telomere recombination by inactivation of KEOPS subunit Cgi121 promotes cell longevity.

    PubMed

    Peng, Jing; He, Ming-Hong; Duan, Yi-Ming; Liu, Yu-Ting; Zhou, Jin-Qiu

    2015-03-01

    DNA double strand break (DSB) is one of the major damages that cause genome instability and cellular aging. The homologous recombination (HR)-mediated repair of DSBs plays an essential role in assurance of genome stability and cell longevity. Telomeres resemble DSBs and are competent for HR. Here we show that in budding yeast Saccharomyces cerevisiae telomere recombination elicits genome instability and accelerates cellular aging. Inactivation of KEOPS subunit Cgi121 specifically inhibits telomere recombination, and significantly extends cell longevity in both telomerase-positive and pre-senescing telomerase-negative cells. Deletion of CGI121 in the short-lived yku80(tel) mutant restores lifespan to cgi121Δ level, supporting the function of Cgi121 in telomeric single-stranded DNA generation and thus in promotion of telomere recombination. Strikingly, inhibition of telomere recombination is able to further slow down the aging process in long-lived fob1Δ cells, in which rDNA recombination is restrained. Our study indicates that HR activity at telomeres interferes with telomerase to pose a negative impact on cellular longevity.

  11. Do Sirtuins Promote Mammalian Longevity?: A Critical Review on Its Relevance to the Longevity Effect Induced by Calorie Restriction

    PubMed Central

    Park, Seongjoon; Mori, Ryoichi; Shimokawa, Isao

    2013-01-01

    Sirtuins (SIRTs), a family of nicotinamide adenine dinucleotide (NAD)-dependent deacetylases, are emerging as key molecules that regulate aging and age-related diseases including cancers, metabolic disorders, and neurodegenerative diseases. Seven isoforms of SIRT (SIRT1–7) have been identified in mammals. SIRT1 and 6, mainly localized in the nucleus, regulate transcription of genes and DNA repair. SIRT3 in the mitochondria regulates mitochondrial bioenergetics. Initial studies in yeasts, nematodes, and flies indicated a strong connection of SIRT with the life-prolonging effects of calorie restriction (CR), a robust experimental intervention for longevity in a range of organisms. However, subsequent studies reported controversial findings regarding SIRT roles in the effect of CR. This review describes the functional roles of mammalian SIRTs and discusses their relevance to mechanisms underlying the longevity effect of CR. PMID:23661364

  12. Longevity-promoting effects of 4-hydroxy-E-globularinin in Caenorhabditis elegans.

    PubMed

    Shukla, Virendra; Yadav, Deepti; Phulara, Suresh C; Gupta, M M; Saikia, Shilpi K; Pandey, Rakesh

    2012-11-15

    In modern times, there has been a major increase in the use of plants or herbal constituents for the prevention of age-related disorders. 4-Hydroxy-E-globularinin (4-HEG) is an iridoid and a major component of Premna integrifolia. This investigation represents a breakthrough in geriatrics by showing the longevity-promoting activity of 4-HEG in the animal model Caenorhabditis elegans. 4-HEG (20μM) enhanced the mean life span of worms by over 18.8% under normal culture conditions and also enhanced their survival under oxidative stress. The longevity-promoting activity was associated with reduced reactive oxygen species (ROS) levels and fat accumulation in the worms. Gene-specific mutant studies verified the role of ROS detoxification pathways and simultaneous nuclear translocation of DAF-16 in the 4-HEG-mediated effects. Quantitative real-time PCR estimations and observations of transcriptional reporters indicated that 4-HEG was able to upregulate stress-inducible genes, viz., hsp-16.2 and sod-3. Thus, 4-HEG may serve as a lead compound of plant origin for the development of important nutraceuticals superseding the aging process. Copyright © 2012 Elsevier Inc. All rights reserved.

  13. RNA helicase HEL-1 promotes longevity by specifically activating DAF-16/FOXO transcription factor signaling in Caenorhabditis elegans.

    PubMed

    Seo, Mihwa; Seo, Keunhee; Hwang, Wooseon; Koo, Hee Jung; Hahm, Jeong-Hoon; Yang, Jae-Seong; Han, Seong Kyu; Hwang, Daehee; Kim, Sanguk; Jang, Sung Key; Lee, Yoontae; Nam, Hong Gil; Lee, Seung-Jae V

    2015-08-04

    The homeostatic maintenance of the genomic DNA is crucial for regulating aging processes. However, the role of RNA homeostasis in aging processes remains unknown. RNA helicases are a large family of enzymes that regulate the biogenesis and homeostasis of RNA. However, the functional significance of RNA helicases in aging has not been explored. Here, we report that a large fraction of RNA helicases regulate the lifespan of Caenorhabditis elegans. In particular, we show that a DEAD-box RNA helicase, helicase 1 (HEL-1), promotes longevity by specifically activating the DAF-16/forkhead box O (FOXO) transcription factor signaling pathway. We find that HEL-1 is required for the longevity conferred by reduced insulin/insulin-like growth factor 1 (IGF-1) signaling (IIS) and is sufficient for extending lifespan. We further show that the expression of HEL-1 in the intestine and neurons contributes to longevity. HEL-1 enhances the induction of a large fraction of DAF-16 target genes. Thus, the RNA helicase HEL-1 appears to promote longevity in response to decreased IIS as a transcription coregulator of DAF-16. Because HEL-1 and IIS are evolutionarily well conserved, a similar mechanism for longevity regulation via an RNA helicase-dependent regulation of FOXO signaling may operate in mammals, including humans.

  14. Autophagy and leucine promote chronological longevity and respiration proficiency during calorie restriction in yeast

    PubMed Central

    Aris, John P.; Alvers, Ashley L.; Ferraiuolo, Roy A.; Fishwick, Laura K.; Hanvivatpong, Amanda; Hu, Doreen; Kirlew, Christine; Leonard, Michael T.; Losin, Kyle J.; Marraffini, Michelle; Seo, Arnold Y.; Swanberg, Veronica; Westcott, Jennifer L.; Wood, Michael S.; Leeuwenburgh, Christiaan; Dunn, William A.

    2013-01-01

    We have previously shown that autophagy is required for chronological longevity in the budding yeast Saccharomyces cerevisiae. Here we examine the requirements for autophagy during extension of chronological life span (CLS) by calorie restriction (CR). We find that autophagy is upregulated by two CR interventions that extend CLS: water wash CR and low glucose CR. Autophagy is required for full extension of CLS during water wash CR under all growth conditions tested. In contrast, autophagy was not uniformly required for full extension of CLS during low glucose CR, depending on the atg allele and strain genetic background. Leucine status influenced CLS during CR. Eliminating the leucine requirement in yeast strains or adding supplemental leucine to growth media extended CLS during CR. In addition, we observed that both water wash and low glucose CR promote mitochondrial respiration proficiency during aging of autophagy-deficient yeast. In general, the extension of CLS by water wash or low glucose CR was inversely related to respiration deficiency in autophagy-deficient cells. Also, autophagy is required for full extension of CLS under non-CR conditions in buffered media, suggesting that extension of CLS during CR is not solely due to reduced medium acidity. Thus, our findings show that autophagy is: (1) induced by CR, (2) required for full extension of CLS by CR in most cases (depending on atg allele, strain, and leucine availability) and, (3) promotes mitochondrial respiration proficiency during aging under CR conditions. PMID:23337777

  15. Knockout of Vasohibin-1 Gene in Mice Results in Healthy Longevity with Reduced Expression of Insulin Receptor, Insulin Receptor Substrate 1, and Insulin Receptor Substrate 2 in Their White Adipose Tissue

    PubMed Central

    Takeda, Eichi; Suzuki, Yasuhiro; Yamada, Tetsuya; Katagiri, Hideki

    2017-01-01

    Vasohibin-1 (Vash1), originally isolated as an endothelium-derived angiogenesis inhibitor, has a characteristic of promoting stress tolerance in endothelial cells (ECs). We therefore speculated that the lack of the vash1 gene would result in a short lifespan. However, to our surprise, vash1−/− mice lived significantly longer with a milder senescence phenotype than wild-type (WT) mice. We sought the cause of this healthy longevity and found that vash1−/− mice exhibited mild insulin resistance along with reduced expression of the insulin receptor (insr), insulin receptor substrate 1 (irs-1), and insulin receptor substrate 2 (irs-2) in their white adipose tissue (WAT) but not in their liver or skeletal muscle. The expression of vash1 dominated in the WAT among those 3 organs. Importantly, vash1−/− mice did not develop diabetes even when fed a high-fat diet. These results indicate that the expression of vash1 was required for the normal insulin sensitivity of the WAT and that the target molecules for this activity were insr, irs1, and irs2. The lack of vash1 caused mild insulin resistance without the outbreak of overt diabetes and might contribute to healthy longevity. PMID:28367331

  16. What are the roles of calorie restriction and diet quality in promoting healthy longevity?

    PubMed

    Rizza, Wanda; Veronese, Nicola; Fontana, Luigi

    2014-01-01

    Epidemiological and experimental data indicate that diet plays a central role in the pathogenesis of many age-associated chronic diseases, and in the biology of aging itself. Data from several animal studies suggest that the degree and time of calorie restriction (CR) onset, the timing of food intake as well as diet composition, play major roles in promoting health and longevity, breaking the old dogma that only calorie intake is important in extending healthy lifespan. Data from human studies indicate that long-term CR with adequate intake of nutrients results in several metabolic adaptations that reduce the risk of developing type 2 diabetes, hypertension, cardiovascular disease and cancer. Moreover, CR opposes the expected age-associated alterations in myocardial stiffness, autonomic function, and gene expression in the human skeletal muscle. However, it is possible that some of the beneficial effects on metabolic health are not entirely due to CR, but to the high quality diets consumed by the CR practitioners, as suggested by data collected in individuals consuming strict vegan diets. More studies are needed to understand the interactions among single nutrient modifications (e.g. protein/aminoacid, fatty acids, vitamins, phytochemicals, and minerals), the degree of CR and the frequency of food consumption in modulating anti-aging metabolic and molecular pathways, and in the prevention of age-associated diseases.

  17. TRIPLE PLAY: PROMOTING NEUROVASCULAR LONGEVITY WITH NICOTINAMIDE, WNT, AND ERYTHROPOIETIN IN DIABETES MELLITUS

    PubMed Central

    Maiese, Kenneth

    2008-01-01

    Summary Oxidative stress is a principal pathway for the dysfunction and ultimate destruction of cells in the neuronal and vascular systems for several disease entities, non promoting the ravages of oxidative stress to any less of a degree than diabetes mellitus. Diabetes mellitus is increasing in incidence as a result of changes in human behavior that relate to diet and daily exercise and is predicted to affect almost 400 million individuals worldwide in another two decades. Furthermore, both type 1 and type 2 diabetes mellitus can lead to significant disability in the nervous and cardiovascular systems, such as cognitive loss and cardiac insufficiency. As a result, innovative strategies that directly target oxidative stress to preserve neuronal and vascular longevity could offer viable therapeutic options to diabetic patients in addition to more conventional treatments that are designed to control serum glucose levels. Here we discuss the novel application of nicotinamide, Wnt signaling, and erythropoietin that modulate cellular oxidative stress and offer significant promise for the prevention of diabetic complications in the nervous and vascular systems. Essential to this process is the precise focus upon diverse as well as common cellular pathways governed by nicotinamide, Wnt signaling, and erythropoietin to outline not only the potential benefits, but also the challenges and possible detriments of these therapies. In this way, new avenues of investigation can hopefully bypass toxic complications, or at the very least, avoid contraindications that may limit care and offer both safe and robust clinical treatment for patients. PMID:18342481

  18. Beyond Calories: An Integrated Approach to Promote Health, Longevity, and Well-Being.

    PubMed

    Bertozzi, Beatrice; Tosti, Valeria; Fontana, Luigi

    2017-01-01

    In 1948, the World Health Organization defined health as 'a state of complete physical, mental, and social well-being, and not merely the absence of disease or infirmity'. Detractors claim that this definition of health is utopian and unrealistic. However, accumulating evidence from experimental studies suggests that aging is not inevitably linked with the development of chronic diseases, and the age-associated accumulation of molecular damage can be prevented or greatly delayed by dietary and genetic manipulations that downregulate key cellular nutrient-sensing pathways. Nonetheless, to obtain a state of complete physical, mental, and social well-being, we as human beings need to go beyond nutrition or pharmacological treatments and implement a combination of interventions that enhance not only our metabolic health but also our psychological, emotional, intellectual and spiritual development, our social relationships and cultural well-being. This perspective highlights a range of scientific research-based interventions that can potentially be used to promote human health and longevity. We will also briefly address the importance of environmental health in achieving this goal.

  19. NADPH oxidase-mediated redox signaling promotes oxidative stress resistance and longevity through memo-1 in C. elegans.

    PubMed

    Ewald, Collin Yvès; Hourihan, John M; Bland, Monet S; Obieglo, Carolin; Katic, Iskra; Moronetti Mazzeo, Lorenza E; Alcedo, Joy; Blackwell, T Keith; Hynes, Nancy E

    2017-01-13

    Transient increases in mitochondrially-derived reactive oxygen species (ROS) activate an adaptive stress response to promote longevity. Nicotinamide adenine dinucleotide phosphate (NADPH) oxidases produce ROS locally in response to various stimuli, and thereby regulate many cellular processes, but their role in aging remains unexplored. Here, we identified the C. elegans orthologue of mammalian mediator of ErbB2-driven cell motility, MEMO-1, as a protein that inhibits BLI-3/NADPH oxidase. MEMO-1 is complexed with RHO-1/RhoA/GTPase and loss of memo-1 results in an enhanced interaction of RHO-1 with BLI-3/NADPH oxidase, thereby stimulating ROS production that signal via p38 MAP kinase to the transcription factor SKN-1/NRF1,2,3 to promote stress resistance and longevity. Either loss of memo-1 or increasing BLI-3/NADPH oxidase activity by overexpression is sufficient to increase lifespan. Together, these findings demonstrate that NADPH oxidase-induced redox signaling initiates a transcriptional response that protects the cell and organism, and can promote both stress resistance and longevity.

  20. NADPH oxidase-mediated redox signaling promotes oxidative stress resistance and longevity through memo-1 in C. elegans

    PubMed Central

    Ewald, Collin Yvès; Hourihan, John M; Bland, Monet S; Obieglo, Carolin; Katic, Iskra; Moronetti Mazzeo, Lorenza E; Alcedo, Joy; Blackwell, T Keith; Hynes, Nancy E

    2017-01-01

    Transient increases in mitochondrially-derived reactive oxygen species (ROS) activate an adaptive stress response to promote longevity. Nicotinamide adenine dinucleotide phosphate (NADPH) oxidases produce ROS locally in response to various stimuli, and thereby regulate many cellular processes, but their role in aging remains unexplored. Here, we identified the C. elegans orthologue of mammalian mediator of ErbB2-driven cell motility, MEMO-1, as a protein that inhibits BLI-3/NADPH oxidase. MEMO-1 is complexed with RHO-1/RhoA/GTPase and loss of memo-1 results in an enhanced interaction of RHO-1 with BLI-3/NADPH oxidase, thereby stimulating ROS production that signal via p38 MAP kinase to the transcription factor SKN-1/NRF1,2,3 to promote stress resistance and longevity. Either loss of memo-1 or increasing BLI-3/NADPH oxidase activity by overexpression is sufficient to increase lifespan. Together, these findings demonstrate that NADPH oxidase-induced redox signaling initiates a transcriptional response that protects the cell and organism, and can promote both stress resistance and longevity. DOI: http://dx.doi.org/10.7554/eLife.19493.001 PMID:28085666

  1. Mondo complexes regulate TFEB via TOR inhibition to promote longevity in response to gonadal signals

    PubMed Central

    Nakamura, Shuhei; Karalay, Özlem; Jäger, Philipp S.; Horikawa, Makoto; Klein, Corinna; Nakamura, Kayo; Latza, Christian; Templer, Sven E.; Dieterich, Christoph; Antebi, Adam

    2016-01-01

    Germline removal provokes longevity in several species and shifts resources towards survival and repair. Several Caenorhabditis elegans transcription factors regulate longevity arising from germline removal; yet, how they work together is unknown. Here we identify a Myc-like HLH transcription factor network comprised of Mondo/Max-like complex (MML-1/MXL-2) to be required for longevity induced by germline removal, as well as by reduced TOR, insulin/IGF signalling and mitochondrial function. Germline removal increases MML-1 nuclear accumulation and activity. Surprisingly, MML-1 regulates nuclear localization and activity of HLH-30/TFEB, a convergent regulator of autophagy, lysosome biogenesis and longevity, by downregulating TOR signalling via LARS-1/leucyl-transfer RNA synthase. HLH-30 also upregulates MML-1 upon germline removal. Mammalian MondoA/B and TFEB show similar mutual regulation. MML-1/MXL-2 and HLH-30 transcriptomes show both shared and preferential outputs including MDL-1/MAD-like HLH factor required for longevity. These studies reveal how an extensive interdependent HLH transcription factor network distributes responsibility and mutually enforces states geared towards reproduction or survival. PMID:27001890

  2. Mondo complexes regulate TFEB via TOR inhibition to promote longevity in response to gonadal signals.

    PubMed

    Nakamura, Shuhei; Karalay, Özlem; Jäger, Philipp S; Horikawa, Makoto; Klein, Corinna; Nakamura, Kayo; Latza, Christian; Templer, Sven E; Dieterich, Christoph; Antebi, Adam

    2016-03-22

    Germline removal provokes longevity in several species and shifts resources towards survival and repair. Several Caenorhabditis elegans transcription factors regulate longevity arising from germline removal; yet, how they work together is unknown. Here we identify a Myc-like HLH transcription factor network comprised of Mondo/Max-like complex (MML-1/MXL-2) to be required for longevity induced by germline removal, as well as by reduced TOR, insulin/IGF signalling and mitochondrial function. Germline removal increases MML-1 nuclear accumulation and activity. Surprisingly, MML-1 regulates nuclear localization and activity of HLH-30/TFEB, a convergent regulator of autophagy, lysosome biogenesis and longevity, by downregulating TOR signalling via LARS-1/leucyl-transfer RNA synthase. HLH-30 also upregulates MML-1 upon germline removal. Mammalian MondoA/B and TFEB show similar mutual regulation. MML-1/MXL-2 and HLH-30 transcriptomes show both shared and preferential outputs including MDL-1/MAD-like HLH factor required for longevity. These studies reveal how an extensive interdependent HLH transcription factor network distributes responsibility and mutually enforces states geared towards reproduction or survival.

  3. The ectoparasitic mite Tropilaelaps mercedesae reduces western honey bee, Apismellifera, longevity and emergence weight, and promotes Deformed wing virus infections.

    PubMed

    Khongphinitbunjong, Kitiphong; Neumann, Peter; Chantawannakul, Panuwan; Williams, Geoffrey R

    2016-06-01

    Historically an ectoparasite of the native Giant honey bee Apis dorsata, the mite Tropilaelaps mercedesae has switched hosts to the introduced western honey bee Apis mellifera throughout much of Asia. Few data regarding lethal and sub-lethal effects of T. mercedesae on A. mellifera exist, despite its similarity to the devastating mite Varroa destructor. Here we artificially infested worker brood of A. mellifera with T. mercedesae to investigate lethal (longevity) and sub-lethal (emergence weight, Deformed wing virus (DWV) levels and clinical symptoms of DWV) effects of the mite on its new host. The data show that T. mercedesae infestation significantly reduced host longevity and emergence weight, and promoted both DWV levels and associated clinical symptoms. Our results suggest that T. mercedesae is a potentially important parasite to the economically important A. mellifera honey bee.

  4. Drosophila Longevity Assurance Conferred by Reduced Insulin Receptor Substrate Chico Partially Requires d4eBP.

    PubMed

    Bai, Hua; Post, Stephanie; Kang, Ping; Tatar, Marc

    2015-01-01

    Mutations of the insulin/IGF signaling (IIS) pathway extend Drosophila lifespan. Based on genetic epistasis analyses, this longevity assurance is attributed to downstream effects of the FOXO transcription factor. However, as reported FOXO accounts for only a portion of the observed longevity benefit, suggesting there are additional outputs of IIS to mediate aging. One candidate is target of rapamycin complex 1 (TORC1). Reduced TORC1 activity is reported to slow aging, whereas reduced IIS is reported to repress TORC1 activity. The eukaryotic translation initiation factor 4E binding protein (4E-BP) is repressed by TORC1, and activated 4E-BP is reported to increase Drosophila lifespan. Here we use genetic epistasis analyses to test whether longevity assurance mutants of chico, the Drosophila insulin receptor substrate homolog, require Drosophila d4eBP to slow aging. In chico heterozygotes, which are robustly long-lived, d4eBP is required but not sufficient to slow aging. Remarkably, d4eBP is not required or sufficient for chico homozygotes to extend longevity. Likewise, chico heterozygote females partially require d4eBP to preserve age-dependent locomotion, and both chico genotypes require d4eBP to improve stress-resistance. Reproduction and most measures of growth affected by either chico genotype are always independent of d4eBP. In females, chico heterozygotes paradoxically produce more rather than less phosphorylated 4E-BP (p4E-BP). Altered IRS function within the IIS pathway of Drosophila appears to have partial, conditional capacity to regulate aging through an unconventional interaction with 4E-BP.

  5. Drosophila Longevity Assurance Conferred by Reduced Insulin Receptor Substrate Chico Partially Requires d4eBP

    PubMed Central

    Bai, Hua; Post, Stephanie; Kang, Ping; Tatar, Marc

    2015-01-01

    Mutations of the insulin/IGF signaling (IIS) pathway extend Drosophila lifespan. Based on genetic epistasis analyses, this longevity assurance is attributed to downstream effects of the FOXO transcription factor. However, as reported FOXO accounts for only a portion of the observed longevity benefit, suggesting there are additional outputs of IIS to mediate aging. One candidate is target of rapamycin complex 1 (TORC1). Reduced TORC1 activity is reported to slow aging, whereas reduced IIS is reported to repress TORC1 activity. The eukaryotic translation initiation factor 4E binding protein (4E-BP) is repressed by TORC1, and activated 4E-BP is reported to increase Drosophila lifespan. Here we use genetic epistasis analyses to test whether longevity assurance mutants of chico, the Drosophila insulin receptor substrate homolog, require Drosophila d4eBP to slow aging. In chico heterozygotes, which are robustly long-lived, d4eBP is required but not sufficient to slow aging. Remarkably, d4eBP is not required or sufficient for chico homozygotes to extend longevity. Likewise, chico heterozygote females partially require d4eBP to preserve age-dependent locomotion, and both chico genotypes require d4eBP to improve stress-resistance. Reproduction and most measures of growth affected by either chico genotype are always independent of d4eBP. In females, chico heterozygotes paradoxically produce more rather than less phosphorylated 4E-BP (p4E-BP). Altered IRS function within the IIS pathway of Drosophila appears to have partial, conditional capacity to regulate aging through an unconventional interaction with 4E-BP. PMID:26252766

  6. Gender specific association of genetic variation in peroxisome proliferator-activated receptor (PPAR)gamma-2 with longevity.

    PubMed

    Barbieri, Michelangela; Bonafè, Massimiliano; Rizzo, Maria Rosaria; Ragno, Emilia; Olivieri, Fabiola; Marchegiani, Francesca; Franceschi, Claudio; Paolisso, Giuseppe

    2004-07-01

    Long-lived subjects have been shown to have peculiar anthropometric features (i.e. lower body mass index (BMI)) and metabolic parameters (i.e. improved insulin sensitivity). Life style and a genetic background potentially protective against the age-related metabolic derangement might contribute to such a particular phenotype. Peroxisome proliferator-activated receptor (PPAR)gamma-2 is an important regulator of adipose tissue metabolism, insulin sensitivity and inflammatory response. Thus, the potential role of genetic variability at Pro/Ala loci of PPARG gene on longevity was studied in 222 long-lived subjects and 250 aged subjects. We found a different Pro/Ala genotype frequency distribution between long-lived and aged men subjects, long-lived men having an increased frequency of Pro/Ala genotype (20 vs 8.5%); no differences was found when allele and genotype distribution of Pro/Ala gene polymorphism were analyzed in the two age group of women. Interestingly, subjects with Pro/Ala polymorphism had significantly lower BMI than Ala/Ala and Pro/Pro polymorphism. In conclusion, our study demonstrated that paraoxonase Pro/Ala gene polyporphism is associated with human longevity. Such an effect is probably due to the effect of Pro/Ala polymorphism on body composition and appears to be gender specific.

  7. Caloric restriction and resveratrol promote longevity through the Sirtuin-1-dependent induction of autophagy.

    PubMed

    Morselli, E; Maiuri, M C; Markaki, M; Megalou, E; Pasparaki, A; Palikaras, K; Criollo, A; Galluzzi, L; Malik, S A; Vitale, I; Michaud, M; Madeo, F; Tavernarakis, N; Kroemer, G

    2010-01-01

    Caloric restriction and autophagy-inducing pharmacological agents can prolong lifespan in model organisms including mice, flies, and nematodes. In this study, we show that transgenic expression of Sirtuin-1 induces autophagy in human cells in vitro and in Caenorhabditis elegans in vivo. The knockdown or knockout of Sirtuin-1 prevented the induction of autophagy by resveratrol and by nutrient deprivation in human cells as well as by dietary restriction in C. elegans. Conversely, Sirtuin-1 was not required for the induction of autophagy by rapamycin or p53 inhibition, neither in human cells nor in C. elegans. The knockdown or pharmacological inhibition of Sirtuin-1 enhanced the vulnerability of human cells to metabolic stress, unless they were stimulated to undergo autophagy by treatment with rapamycin or p53 inhibition. Along similar lines, resveratrol and dietary restriction only prolonged the lifespan of autophagy-proficient nematodes, whereas these beneficial effects on longevity were abolished by the knockdown of the essential autophagic modulator Beclin-1. We conclude that autophagy is universally required for the lifespan-prolonging effects of caloric restriction and pharmacological Sirtuin-1 activators.

  8. Caloric restriction and resveratrol promote longevity through the Sirtuin-1-dependent induction of autophagy

    PubMed Central

    Morselli, E; Maiuri, M C; Markaki, M; Megalou, E; Pasparaki, A; Palikaras, K; Criollo, A; Galluzzi, L; Malik, S A; Vitale, I; Michaud, M; Madeo, F; Tavernarakis, N; Kroemer, G

    2010-01-01

    Caloric restriction and autophagy-inducing pharmacological agents can prolong lifespan in model organisms including mice, flies, and nematodes. In this study, we show that transgenic expression of Sirtuin-1 induces autophagy in human cells in vitro and in Caenorhabditis elegans in vivo. The knockdown or knockout of Sirtuin-1 prevented the induction of autophagy by resveratrol and by nutrient deprivation in human cells as well as by dietary restriction in C. elegans. Conversely, Sirtuin-1 was not required for the induction of autophagy by rapamycin or p53 inhibition, neither in human cells nor in C. elegans. The knockdown or pharmacological inhibition of Sirtuin-1 enhanced the vulnerability of human cells to metabolic stress, unless they were stimulated to undergo autophagy by treatment with rapamycin or p53 inhibition. Along similar lines, resveratrol and dietary restriction only prolonged the lifespan of autophagy-proficient nematodes, whereas these beneficial effects on longevity were abolished by the knockdown of the essential autophagic modulator Beclin-1. We conclude that autophagy is universally required for the lifespan-prolonging effects of caloric restriction and pharmacological Sirtuin-1 activators. PMID:21364612

  9. An in vitro study of neuroprotective properties of traditional Chinese herbal medicines thought to promote healthy ageing and longevity

    PubMed Central

    2013-01-01

    Background Age is the leading risk factor for acute and chronic neurodegenerative diseases. The Shen Nong Ben Cao Jing, the oldest known compendium of Chinese materia media, lists herbal medicines that were believed to exert neither fast acting pharmacological effects nor discernible toxicity, but to promote general health and longevity. In modern terms, these herbal medicines could be considered as complementary health care products for prevention rather than treatment of diseases. In the present study, we examined whether a selection of 13 such herbal medicines exhibited neuroprotective activity. Methods The antioxidant capacity of the herbal extracts was determined using three non-cellular assays measuring the total phenol content (FCR assay), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity and oxygen radical absorbance capacity (ORAC). Cytotoxic effects of the herbal extracts were assayed in cultured mouse cortical neurons and their neuroprotective activities were studied using staurosporine-induced apoptosis of the cultured neurons. Results Most of the herbal extracts showed negligible toxic effects at 100 μg/ml. However, Polygonum multiflorum and Rhodiola rosea exhibited some neurotoxicity at this concentration. Extracts of Ganoderma lucidum, Glycyrrhiza glabra, Schizandra chinensis, and Polygonum cuspidatum inhibited staurosporine-induced apoptosis by 30 – 50% in a dose-dependent manner. The neuroprotective effects of Polygonum cuspidatum were predominantly due to its major ingredient, resveratrol. The effective herbal extracts showed various levels of reactive oxygen species (ROS) scavenging capacity, which was significantly correlated with their neuro- protective activity. However, P. multiflorum and R. rosea extracts proved to be the exception as they exhibited a high level of antioxidant capacity, but did not exhibit neuroprotective effects in cell-based assay. Conclusions This in vitro study provides evidence for neuroprotective

  10. An in vitro study of neuroprotective properties of traditional Chinese herbal medicines thought to promote healthy ageing and longevity.

    PubMed

    Shen, Bojiang; Truong, John; Helliwell, Ray; Govindaraghavan, Suresh; Sucher, Nikolaus J

    2013-12-27

    Age is the leading risk factor for acute and chronic neurodegenerative diseases. The Shen Nong Ben Cao Jing, the oldest known compendium of Chinese materia media, lists herbal medicines that were believed to exert neither fast acting pharmacological effects nor discernible toxicity, but to promote general health and longevity. In modern terms, these herbal medicines could be considered as complementary health care products for prevention rather than treatment of diseases. In the present study, we examined whether a selection of 13 such herbal medicines exhibited neuroprotective activity. The antioxidant capacity of the herbal extracts was determined using three non-cellular assays measuring the total phenol content (FCR assay), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity and oxygen radical absorbance capacity (ORAC). Cytotoxic effects of the herbal extracts were assayed in cultured mouse cortical neurons and their neuroprotective activities were studied using staurosporine-induced apoptosis of the cultured neurons. Most of the herbal extracts showed negligible toxic effects at 100 μg/ml. However, Polygonum multiflorum and Rhodiola rosea exhibited some neurotoxicity at this concentration. Extracts of Ganoderma lucidum, Glycyrrhiza glabra, Schizandra chinensis, and Polygonum cuspidatum inhibited staurosporine-induced apoptosis by 30 - 50% in a dose-dependent manner. The neuroprotective effects of Polygonum cuspidatum were predominantly due to its major ingredient, resveratrol. The effective herbal extracts showed various levels of reactive oxygen species (ROS) scavenging capacity, which was significantly correlated with their neuro- protective activity. However, P. multiflorum and R. rosea extracts proved to be the exception as they exhibited a high level of antioxidant capacity, but did not exhibit neuroprotective effects in cell-based assay. This in vitro study provides evidence for neuroprotective activity of some Chinese herbal medicines

  11. Acarbose, lente carbohydrate, and prebiotics promote metabolic health and longevity by stimulating intestinal production of GLP-1

    PubMed Central

    McCarty, Mark F; DiNicolantonio, James J

    2015-01-01

    The α-glucosidase inhibitor acarbose, which slows carbohydrate digestion and blunts postprandial rises in plasma glucose, has long been used to treat patients with type 2 diabetes or glucose intolerance. Like metformin, acarbose tends to aid weight control, postpone onset of diabetes and decrease risk for cardiovascular events. Acarbose treatment can favourably affect blood pressure, serum lipids, platelet aggregation, progression of carotid intima-media thickness and postprandial endothelial dysfunction. In mice, lifetime acarbose feeding can increase median and maximal lifespan—an effect associated with increased plasma levels of fibroblast growth factor 21 (FGF21) and decreased levels of insulin-like growth factor-I (IGF-I). There is growing reason to suspect that an upregulation of fasting and postprandial production of glucagon-like peptide-1 (GLP-1)—stemming from increased delivery of carbohydrate to L cells in the distal intestinal tract—is largely responsible for the versatile health protection conferred by acarbose. Indeed, GLP-1 exerts protective effects on vascular endothelium, the liver, the heart, pancreatic β cells, and the brain which can rationalise many of the benefits reported with acarbose. And GLP-1 may act on the liver to modulate its production of FGF21 and IGF-I, thereby promoting longevity. The benefits of acarbose are likely mimicked by diets featuring slowly-digested ‘lente’ carbohydrate, and by certain nutraceuticals which can slow carbohydrate absorption. Prebiotics that promote colonic generation of short-chain fatty acids represent an alternative strategy for boosting intestinal GLP-1 production. The health benefits of all these measures presumably would be potentiated by concurrent use of dipeptidyl peptidase 4 inhibitors, which slow the proteolysis of GLP-1 in the blood. PMID:25685364

  12. The Critical Need to Promote Research of Aging and Aging-related Diseases to Improve Health and Longevity of the Elderly Population

    PubMed Central

    Jin, Kunlin; Simpkins, James W.; Ji, Xunming; Leis, Miriam; Stambler, Ilia

    2015-01-01

    Due to the aging of the global population and the derivative increase in aging-related non-communicable diseases and their economic burden, there is an urgent need to promote research on aging and aging-related diseases as a way to improve healthy and productive longevity for the elderly population. To accomplish this goal, we advocate the following policies: 1) Increasing funding for research and development specifically directed to ameliorate degenerative aging processes and to extend healthy and productive lifespan for the population; 2) Providing a set of incentives for commercial, academic, public and governmental organizations to foster engagement in such research and development; and 3) Establishing and expanding coordination and consultation structures, programs and institutions involved in aging-related research, development and education in academia, industry, public policy agencies and at governmental and supra-governmental levels. PMID:25657847

  13. Homocysteine and Familial Longevity: The Leiden Longevity Study

    PubMed Central

    Wijsman, Carolien A.; van Heemst, Diana; Rozing, Maarten P.; Slagboom, P. Eline; Beekman, Marian; de Craen, Anton J. M.; Maier, Andrea B.; Westendorp, Rudi G. J.; Blom, Henk J.; Mooijaart, Simon P.

    2011-01-01

    Homocysteine concentrations are a read-out of methionine metabolism and have been related to changes in lifespan in animal models. In humans, high homocysteine concentrations are an important predictor of age related disease. We aimed to explore the association of homocysteine with familial longevity by testing whether homocysteine is lower in individuals that are genetically enriched for longevity. We measured concentrations of total homocysteine in 1907 subjects from the Leiden Longevity Study consisting of 1309 offspring of nonagenarian siblings, who are enriched with familial factors promoting longevity, and 598 partners thereof as population controls. We found that homocysteine was related to age, creatinine, folate, vitamin B levels and medical history of hypertension and stroke in both groups (all p<0.001). However, levels of homocysteine did not differ between offspring enriched for longevity and their partners, and no differences in the age-related rise in homocysteine levels were found between groups (p for interaction 0.63). The results suggest that homocysteine metabolism is not likely to predict familial longevity. PMID:21408159

  14. Genes of human longevity: an endless quest?

    PubMed

    Capri, Miriam; Santoro, Aurelia; Garagnani, Paolo; Bacalini, Maria Giulia; Pirazzini, Chiara; Olivieri, Fabiola; Procopio, Antonio; Salvioli, Stefano; Franceschi, Claudio

    2014-01-01

    Human longevity is a complex trait in which genetics, epigenetics, environmental and stochasticity differently contribute. To disentangle the complexity, our studies on genetics of longevity were, at the beginning, mainly focused on the extreme phenotypes, i.e. centenarians who escaped the major age-related diseases compared with cross sectional cohorts. Recently, we implemented this model by studying centenarians' offspring and offspring of non-long lived parents. In association, during studies on many candidate genes SNPs, positively or negatively correlated with longevity have been identified. The results obtained on Insulin-like Growth Factor 1 Receptor (IGF1R) polymorphisms showed a correlation between specific genetic variants combinations and the low plasma level of IGF1 in centenarians, suggesting an impact of the IGF-I/insulin pathway on human longevity. This pathway together with mammalian target of rapamycin (mTOR) will be reviewed as being the most promising for longevity. Further, we will summarise the role of apolipoprotein E (APOE) variants in human longevity since the results of the large European project GEHA (Genetics of Healthy Aging) indicate APOE among the chromosomal loci associated with longevity. On the other hand, the identification of longevity-related genes does not explain the mechanisms of healthy aging and longevity rather pose questions on epigenetic contribution, gene regulation and the interactions with essential genomes, i.e. mitochondrial DNA and microbiota. To fully disentangle what appears to be an endless quest, all the components of the complexity of human longevity genetics are taken into account.

  15. Fatty Acid Desaturation Links Germ Cell Loss to Longevity Through NHR-80/HNF4 in C. elegans

    PubMed Central

    Goudeau, Jérôme; Bellemin, Stéphanie; Toselli-Mollereau, Esther; Shamalnasab, Mehrnaz; Chen, Yiqun; Aguilaniu, Hugo

    2011-01-01

    Background Preventing germline stem cell proliferation extends lifespan in nematodes and flies. So far, studies on germline-longevity signaling have focused on daf-16/FOXO and daf-12/VDR. Here, we report on NHR-80/HNF4, a nuclear receptor that specifically mediates longevity induced by depletion of the germ line through a mechanism that implicates fatty acid monodesaturation. Methods and Findings nhr-80/HNF4 is induced in animals lacking a germ line and is specifically required for their extended longevity. Overexpressing nhr-80/HNF4 increases the lifespan of germline-less animals. This lifespan extension can occur in the absence of daf-16/FOXO but requires the presence of the nuclear receptor DAF-12/VDR. We show that the fatty acid desaturase, FAT-6/SCD1, is a key target of NHR-80/HNF4 and promotes germline-longevity by desaturating stearic acid to oleic acid (OA). We find that NHR-80/HNF4 and OA must work in concert to promote longevity. Conclusions Taken together, our data indicate that the NHR-80 pathway participates in the mechanism of longevity extension through depletion of the germ line. We identify fat-6 and OA as essential downstream elements although other targets must also be present. Thus, NHR-80 links fatty acid desaturation to lifespan extension through germline ablation in a daf-16/FOXO independent manner. PMID:21423649

  16. Vitellogenin, juvenile hormone, insulin signaling, and queen honey bee longevity

    PubMed Central

    Corona, Miguel; Velarde, Rodrigo A.; Remolina, Silvia; Moran-Lauter, Adrienne; Wang, Ying; Hughes, Kimberly A.; Robinson, Gene E.

    2007-01-01

    In most animals, longevity is achieved at the expense of fertility, but queen honey bees do not show this tradeoff. Queens are both long-lived and fertile, whereas workers, derived from the same genome, are both relatively short-lived and normally sterile. It has been suggested, on the basis of results from workers, that vitellogenin (Vg), best known as a yolk protein synthesized in the abdominal fat body, acts as an antioxidant to promote longevity in queen bees. We explored this hypothesis, as well as related roles of insulin–IGF-1 signaling and juvenile hormone. Vg was expressed in thorax and head fat body cells in an age-dependent manner, with old queens showing much higher expression than workers. In contrast, Vg expression in worker head was much lower. Queens also were more resistant to oxidative stress than workers. These results support the hypothesis that caste-specific differences in Vg expression are involved in queen longevity. Consistent with predictions from Drosophila, old queens had lower head expression of insulin-like peptide and its putative receptors than did old workers. Juvenile hormone affected the expression of Vg and insulin–IGF-1 signaling genes in opposite directions. These results suggest that conserved and species-specific mechanisms interact to regulate queen bee longevity without sacrificing fecundity. PMID:17438290

  17. GABAA receptor-expressing neurons promote consumption in Drosophila melanogaster

    PubMed Central

    Cheung, Samantha K.

    2017-01-01

    Feeding decisions are highly plastic and bidirectionally regulated by neurons that either promote or inhibit feeding. In Drosophila melanogaster, recent studies have identified four GABAergic interneurons that act as critical brakes to prevent incessant feeding. These GABAergic neurons may inhibit target neurons that drive consumption. Here, we tested this hypothesis by examining GABA receptors and neurons that promote consumption. We find that Resistance to dieldrin (RDL), a GABAA type receptor, is required for proper control of ingestion. Knockdown of Rdl in a subset of neurons causes overconsumption of tastants. Acute activation of these neurons is sufficient to drive consumption of appetitive substances and non-appetitive substances and acute silencing of these neurons decreases consumption. Taken together, these studies identify GABAA receptor-expressing neurons that promote Drosophila ingestive behavior and provide insight into feeding regulation. PMID:28362856

  18. GABAA receptor-expressing neurons promote consumption in Drosophila melanogaster.

    PubMed

    Cheung, Samantha K; Scott, Kristin

    2017-01-01

    Feeding decisions are highly plastic and bidirectionally regulated by neurons that either promote or inhibit feeding. In Drosophila melanogaster, recent studies have identified four GABAergic interneurons that act as critical brakes to prevent incessant feeding. These GABAergic neurons may inhibit target neurons that drive consumption. Here, we tested this hypothesis by examining GABA receptors and neurons that promote consumption. We find that Resistance to dieldrin (RDL), a GABAA type receptor, is required for proper control of ingestion. Knockdown of Rdl in a subset of neurons causes overconsumption of tastants. Acute activation of these neurons is sufficient to drive consumption of appetitive substances and non-appetitive substances and acute silencing of these neurons decreases consumption. Taken together, these studies identify GABAA receptor-expressing neurons that promote Drosophila ingestive behavior and provide insight into feeding regulation.

  19. Dynamic O-GlcNAc cycling at promoters of Caenorhabditis elegans genes regulating longevity, stress, and immunity.

    PubMed

    Love, Dona C; Ghosh, Salil; Mondoux, Michelle A; Fukushige, Tetsunari; Wang, Peng; Wilson, Mark A; Iser, Wendy B; Wolkow, Catherine A; Krause, Michael W; Hanover, John A

    2010-04-20

    Nutrient-driven O-GlcNAcylation of key components of the transcription machinery may epigenetically modulate gene expression in metazoans. The global effects of GlcNAcylation on transcription can be addressed directly in C. elegans because knockouts of the O-GlcNAc cycling enzymes are viable and fertile. Using anti-O-GlcNAc ChIP-on-chip whole-genome tiling arrays on wild-type and mutant strains, we detected over 800 promoters where O-GlcNAc cycling occurs, including microRNA loci and multigene operons. Intriguingly, O-GlcNAc-marked promoters are biased toward genes associated with PIP3 signaling, hexosamine biosynthesis, and lipid/carbohydrate metabolism. These marked genes are linked to insulin-like signaling, metabolism, aging, stress, and pathogen-response pathways in C. elegans. Whole-genome transcriptional profiling of the O-GlcNAc cycling mutants confirmed dramatic deregulation of genes in these key pathways. As predicted, the O-GlcNAc cycling mutants show altered lifespan and UV stress susceptibility phenotypes. We propose that O-GlcNAc cycling at promoters participates in a molecular program impacting nutrient-responsive pathways in C. elegans, including stress, pathogen response, and adult lifespan. The observed impact of O-GlcNAc cycling on both signaling and transcription in C. elegans has important implications for human diseases of aging, including diabetes and neurodegeneration.

  20. Tor-Sch9 deficiency activates catabolism of the ketone body-like acetic acid to promote trehalose accumulation and longevity

    PubMed Central

    Hu, Jia; Wei, Min; Mirzaei, Hamed; Madia, Federica; Amparo, Mario; Chagoury, Shawna; Kennedy, Brian; Longo, Valter D

    2014-01-01

    In mammals, extended periods of fasting leads to the accumulation of blood ketone bodies including acetoacetate. Here we show that similar to the conversion of leucine to acetoacetate in fasting mammals, starvation conditions induced ketone body-like acetic acid generation from leucine in S. cerevisiae. Whereas wild-type and ras2Δ cells accumulated acetic acid, long-lived tor1Δ and sch9Δ mutants rapidly depleted it through a mitochondrial acetate CoA transferase-dependent mechanism, which was essential for lifespan extension. The sch9Δ-dependent utilization of acetic acid also required coenzyme Q biosynthetic genes and promoted the accumulation of intracellular trehalose. These results indicate that Tor-Sch9 deficiency extends longevity by switching cells to an alternative metabolic mode, in which acetic acid can be utilized for the storage of stress resistance carbon sources. These effects are reminiscent of those described for ketone bodies in fasting mammals and raise the possibility that the lifespan extension caused by Tor-S6K inhibition may also involve analogous metabolic changes in higher eukaryotes. PMID:24649827

  1. Tor-Sch9 deficiency activates catabolism of the ketone body-like acetic acid to promote trehalose accumulation and longevity.

    PubMed

    Hu, Jia; Wei, Min; Mirzaei, Hamed; Madia, Federica; Mirisola, Mario; Amparo, Camille; Chagoury, Shawna; Kennedy, Brian; Longo, Valter D

    2014-06-01

    In mammals, extended periods of fasting leads to the accumulation of blood ketone bodies including acetoacetate. Here we show that similar to the conversion of leucine to acetoacetate in fasting mammals, starvation conditions induced ketone body-like acetic acid generation from leucine in S. cerevisiae. Whereas wild-type and ras2Δ cells accumulated acetic acid, long-lived tor1Δ and sch9Δ mutants rapidly depleted it through a mitochondrial acetate CoA transferase-dependent mechanism, which was essential for lifespan extension. The sch9Δ-dependent utilization of acetic acid also required coenzyme Q biosynthetic genes and promoted the accumulation of intracellular trehalose. These results indicate that Tor-Sch9 deficiency extends longevity by switching cells to an alternative metabolic mode, in which acetic acid can be utilized for the storage of stress resistance carbon sources. These effects are reminiscent of those described for ketone bodies in fasting mammals and raise the possibility that the lifespan extension caused by Tor-S6K inhibition may also involve analogous metabolic changes in higher eukaryotes.

  2. 2,3,5,4′-Tetrahydroxystilbene-2-O-β-D-glucoside Promotes Expression of the Longevity Gene Klotho

    PubMed Central

    Duan, Ju; Ni, Rongzhen

    2016-01-01

    The longevity gene klotho has numerous physiological functions, such as regulating calcium and phosphorus levels, delaying senescence, improving cognition, reducing oxidative stress, and protecting vascular endothelial cells. This study tested whether 2,3,5,4′-Tetrahydroxystilbene-2-O-β-D-glucoside (THSG), a small molecule with antiaging effects, regulates the expression and physiological effects of klotho. Our results showed that THSG dose-dependently increased the luciferase reporter activity of the klotho gene, reversed the decrease in mRNA and protein expression of klotho which was induced by angiotensin II in NRK-52E renal tubular epithelial cells, and increased klotho mRNA expression in the cerebral cortex, hippocampus, testis, and kidney medulla of spontaneously hypertensive rats. THSG also reduced the number of senescent cells induced by angiotensin II and improved the antioxidant capacity and enhanced the bone strength in vivo. Based on klotho's role in promoting cognition, regulating bone metabolism, and improving renal function, the effect of THSG on klotho expression will be beneficial to the functional improvement or enhancement of the expressed organs or tissues. PMID:27885332

  3. Ah receptor ligands and tumor promotion: survival of neoplastic cells.

    PubMed

    Schwarz, M; Buchmann, A; Stinchcombe, S; Kalkuhl, A; Bock, K

    2000-03-15

    A number of agonists of the aryl hydrocarbon or dioxin receptor (AhR) are potent tumor promoters in rodent liver. The prototype compound is 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Tumor promotion by TCDD is likely to be AhR-mediated. Tumor promoters may affect the rate of division, terminal differentiation or death (apoptosis) of tumor precursor cells. The present paper reviews some of the effects of TCDD on liver cell homeostasis that have been observed under diverse experimental settings and discusses some of the possible underlying mechanisms.

  4. Regulation of longevity by the reproductive system.

    PubMed

    Antebi, Adam

    2013-07-01

    Pioneering work in model organisms reveals that the reproductive system is involved not only in propagation of the species but also regulates organismal metabolism and longevity. In C. elegans, prevention of germline stem cell proliferation results in a 60% extension of lifespan, termed gonadal longevity. Gonadal longevity relies on the transcriptional activities of steroid nuclear receptor DAF-12, the FOXO transcription factor homolog DAF-16, the FOXA transcription factor homolog PHA-4, and the HNF-4-like nuclear receptor NHR-80. These transcription factors work in an integrated transcriptional network to regulate fatty acid lipolysis, autophagy, stress resistance and other processes, which altogether enhance homeostasis and extend life. Because the reproductive system also regulates longevity in other species, studies in C. elegans may shed light on ancient mechanisms governing reproduction and survival.

  5. The BTB-ZF transcription factor Zbtb20 is driven by Irf4 to promote plasma cell differentiation and longevity

    PubMed Central

    Chevrier, Stéphane; Emslie, Dianne; Shi, Wei; Kratina, Tobias; Wellard, Cameron; Karnowski, Alexander; Erikci, Erdem; Smyth, Gordon K.; Chowdhury, Kamal; Tarlinton, David

    2014-01-01

    The transcriptional network regulating antibody-secreting cell (ASC) differentiation has been extensively studied, but our current understanding is limited. The mechanisms of action of known “master” regulators are still unclear, while the participation of new factors is being revealed. Here, we identify Zbtb20, a Bcl6 homologue, as a novel regulator of late B cell development. Within the B cell lineage, Zbtb20 is specifically expressed in B1 and germinal center B cells and peaks in long-lived bone marrow (BM) ASCs. Unlike Bcl6, an inhibitor of ASC differentiation, ectopic Zbtb20 expression in primary B cells facilitates terminal B cell differentiation to ASCs. In plasma cell lines, Zbtb20 induces cell survival and blocks cell cycle progression. Immunized Zbtb20-deficient mice exhibit curtailed humoral responses and accelerated loss of antigen-specific plasma cells, specifically from the BM pool. Strikingly, Zbtb20 induction does not require Blimp1 but depends directly on Irf4, acting at a newly identified Zbtb20 promoter in ASCs. These results identify Zbtb20 as an important player in late B cell differentiation and provide new insights into this complex process. PMID:24711583

  6. promotes pheromone receptor polarization and yeast chemotropism by inhibiting receptor phosphorylation

    PubMed Central

    Ismael, Amber; Tian, Wei; Waszczak, Nicholas; Wang, Xin; Cao, Youfang; Suchkov, Dmitry; Bar, Eli; Metodiev, Metodi V.; Liang, Jie; Arkowitz, Robert; Stone, David E.

    2016-01-01

    Gradient-directed cell migration (chemotaxis) and growth (chemotropism) are universal processes, which are essential to the development and life cycles of all species. Cells use surface receptors to sense the shallow chemical gradients that elicit chemotaxis and chemotropism. Slight asymmetries in receptor activation are amplified by downstream signaling systems, which ultimately induce dynamic reorganization of the cytoskeleton. During the mating response of budding yeast, a model chemotropic system, the pheromone receptor on the plasma membrane polarizes to the side of the cell closest to the stimulus. Although receptor polarization occurs before and independently of actin-cable dependent vesicle delivery (directed secretion), it requires receptor internalization. Phosphorylation of pheromone receptors by yeast casein kinase 1 or 2 (Yck1/2) stimulates their internalization. We showed that the pheromone-responsive Gβγ dimer promotes the polarization of the pheromone receptor by interacting with Yck1/2 and locally inhibiting receptor phosphorylation. We also found that receptor phosphorylation is essential for chemotropism, independent of its role in inducing receptor internalization. A mathematical model supports the idea that the interaction between Gβγ and Yck1/2 results in differential phosphorylation and internalization of the pheromone receptor and accounts for its polarization before the initiation of directed secretion. PMID:27072657

  7. promotes pheromone receptor polarization and yeast chemotropism by inhibiting receptor phosphorylation.

    PubMed

    Ismael, Amber; Tian, Wei; Waszczak, Nicholas; Wang, Xin; Cao, Youfang; Suchkov, Dmitry; Bar, Eli; Metodiev, Metodi V; Liang, Jie; Arkowitz, Robert A; Stone, David E

    2016-04-12

    Gradient-directed cell migration (chemotaxis) and growth (chemotropism) are processes that are essential to the development and life cycles of all species. Cells use surface receptors to sense the shallow chemical gradients that elicit chemotaxis and chemotropism. Slight asymmetries in receptor activation are amplified by downstream signaling systems, which ultimately induce dynamic reorganization of the cytoskeleton. During the mating response of budding yeast, a model chemotropic system, the pheromone receptors on the plasma membrane polarize to the side of the cell closest to the stimulus. Although receptor polarization occurs before and independently of actin cable-dependent delivery of vesicles to the plasma membrane (directed secretion), it requires receptor internalization. Phosphorylation of pheromone receptors by yeast casein kinase 1 or 2 (Yck1/2) stimulates their internalization. We showed that the pheromone-responsive Gβγ dimer promotes the polarization of the pheromone receptor by interacting with Yck1/2 and locally inhibiting receptor phosphorylation. We also found that receptor phosphorylation is essential for chemotropism, independently of its role in inducing receptor internalization. A mathematical model supports the idea that the interaction between Gβγ and Yck1/2 results in differential phosphorylation and internalization of the pheromone receptor and accounts for its polarization before the initiation of directed secretion.

  8. Mechanism of GABAB receptor-induced BDNF secretion and promotion of GABAA receptor membrane expression.

    PubMed

    Kuczewski, Nicola; Fuchs, Celine; Ferrand, Nadine; Jovanovic, Jasmina N; Gaiarsa, Jean-Luc; Porcher, Christophe

    2011-08-01

    Recent studies have shown that GABA(B) receptors play more than a classical inhibitory role and can function as an important synaptic maturation signal early in life. In a previous study, we reported that GABA(B) receptor activation triggers secretion of brain-derived neurotrophic factor (BDNF) and promotes the functional maturation of GABAergic synapses in the developing rat hippocampus. To identify the signalling pathway linking GABA(B) receptor activation to BDNF secretion in these cells, we have now used the phosphorylated form of the cAMP response element-binding protein as a biological sensor for endogenous BDNF release. In the present study, we show that GABA(B) receptor-induced secretion of BDNF relies on the activation of phospholipase C, followed by the formation of diacylglycerol, activation of protein kinase C, and the opening of L-type voltage-dependent Ca(2+) channels. We further show that once released by GABA(B) receptor activation, BDNF increases the membrane expression of β(2/3) -containing GABA(A) receptors in neuronal cultures. These results reveal a novel function of GABA(B) receptors in regulating the expression of GABA(A) receptor through BDNF-tropomyosin-related kinase B receptor dependent signalling pathway.

  9. 5-HT7 receptor activation promotes an increase in TrkB receptor expression and phosphorylation

    PubMed Central

    Samarajeewa, Anshula; Goldemann, Lolita; Vasefi, Maryam S.; Ahmed, Nawaz; Gondora, Nyasha; Khanderia, Chandni; Mielke, John G.; Beazely, Michael A.

    2014-01-01

    The serotonin (5-HT) type 7 receptor is expressed throughout the CNS including the cortex and hippocampus. We have previously demonstrated that the application of 5-HT7 receptor agonists to primary hippocampal neurons and SH-SY5Y cells increases platelet-derived growth factor (PDGF) receptor expression and promotes neuroprotection against N-methyl-D-aspartate-(NMDA)-induced toxicity. The tropomyosin-related kinase B (TrkB) receptor is one of the receptors for brain-derived neurotrophic factor (BDNF) and is associated with neurodevelopmental and neuroprotective effects. Application of LP 12 to primary cerebral cortical cultures, SH-SY5Y cells, as well as the retinal ganglion cell line, RGC-5, increased both the expression of full length TrkB as well as its basal phosphorylation state at tyrosine 816. The increase in TrkB expression and phosphorylation was observed as early as 30 min after 5-HT7 receptor activation. In addition to full-length TrkB, kinase domain-deficient forms may be expressed and act as dominant-negative proteins toward the full length receptor. We have identified distinct patterns of TrkB isoform expression across our cell lines and cortical cultures. Although TrkB receptor expression is regulated by cyclic AMP and Gαs-coupled GPCRs in several systems, we demonstrate that, depending on the model system, pathways downstream of both Gαs and Gα12 are involved in the regulation of TrkB expression by 5-HT7 receptors. Given the number of psychiatric and degenerative diseases associated with TrkB/BDNF deficiency and the current interest in developing 5-HT7 receptor ligands as pharmaceuticals, identifying signaling relationships between these two receptors will aid in our understanding of the potential therapeutic effects of 5-HT7 receptor ligands. PMID:25426041

  10. 5-HT7 receptor activation promotes an increase in TrkB receptor expression and phosphorylation.

    PubMed

    Samarajeewa, Anshula; Goldemann, Lolita; Vasefi, Maryam S; Ahmed, Nawaz; Gondora, Nyasha; Khanderia, Chandni; Mielke, John G; Beazely, Michael A

    2014-01-01

    The serotonin (5-HT) type 7 receptor is expressed throughout the CNS including the cortex and hippocampus. We have previously demonstrated that the application of 5-HT7 receptor agonists to primary hippocampal neurons and SH-SY5Y cells increases platelet-derived growth factor (PDGF) receptor expression and promotes neuroprotection against N-methyl-D-aspartate-(NMDA)-induced toxicity. The tropomyosin-related kinase B (TrkB) receptor is one of the receptors for brain-derived neurotrophic factor (BDNF) and is associated with neurodevelopmental and neuroprotective effects. Application of LP 12 to primary cerebral cortical cultures, SH-SY5Y cells, as well as the retinal ganglion cell line, RGC-5, increased both the expression of full length TrkB as well as its basal phosphorylation state at tyrosine 816. The increase in TrkB expression and phosphorylation was observed as early as 30 min after 5-HT7 receptor activation. In addition to full-length TrkB, kinase domain-deficient forms may be expressed and act as dominant-negative proteins toward the full length receptor. We have identified distinct patterns of TrkB isoform expression across our cell lines and cortical cultures. Although TrkB receptor expression is regulated by cyclic AMP and Gαs-coupled GPCRs in several systems, we demonstrate that, depending on the model system, pathways downstream of both Gαs and Gα12 are involved in the regulation of TrkB expression by 5-HT7 receptors. Given the number of psychiatric and degenerative diseases associated with TrkB/BDNF deficiency and the current interest in developing 5-HT7 receptor ligands as pharmaceuticals, identifying signaling relationships between these two receptors will aid in our understanding of the potential therapeutic effects of 5-HT7 receptor ligands.

  11. Life course analysis of the impact of mammary cancer and pyometra on age-anchored life expectancy in female Rottweilers: Implications for envisioning ovary conservation as a strategy to promote healthy longevity in pet dogs.

    PubMed

    Waters, D J; Kengeri, S S; Maras, A H; Suckow, C L; Chiang, E C

    2017-06-01

    %) case fatality (pyometra). These findings fail to support the notion that a strategy, such as elective ovariohysterectomy, implemented to reduce the incidence of mammary carcinoma and pyometra will beneficially impact overall longevity. It follows that future efforts to find and implement effective longevity-promoting interventions should look beyond reducing the incidence of a particular disease to considering trade-offs. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Brain endogenous liver X receptor ligands selectively promote midbrain neurogenesis.

    PubMed

    Theofilopoulos, Spyridon; Wang, Yuqin; Kitambi, Satish Srinivas; Sacchetti, Paola; Sousa, Kyle M; Bodin, Karl; Kirk, Jayne; Saltó, Carmen; Gustafsson, Magnus; Toledo, Enrique M; Karu, Kersti; Gustafsson, Jan-Åke; Steffensen, Knut R; Ernfors, Patrik; Sjövall, Jan; Griffiths, William J; Arenas, Ernest

    2013-02-01

    Liver X receptors (Lxrα and Lxrβ) are ligand-dependent nuclear receptors critical for ventral midbrain neurogenesis in vivo. However, no endogenous midbrain Lxr ligand has so far been identified. Here we used LC/MS and functional assays to identify cholic acid as a new Lxr ligand. Moreover, 24(S),25-epoxycholesterol (24,25-EC) was found to be the most potent and abundant Lxr ligand in the developing mouse midbrain. Both Lxr ligands promoted neural development in an Lxr-dependent manner in zebrafish in vivo. Notably, each ligand selectively regulated the development of distinct midbrain neuronal populations. Whereas cholic acid increased survival and neurogenesis of Brn3a-positive red nucleus neurons, 24,25-EC promoted dopaminergic neurogenesis. These results identify an entirely new class of highly selective and cell type-specific regulators of neurogenesis and neuronal survival. Moreover, 24,25-EC promoted dopaminergic differentiation of embryonic stem cells, suggesting that Lxr ligands may thus contribute to the development of cell replacement and regenerative therapies for Parkinson's disease.

  13. Birth Month Affects Longevity

    ERIC Educational Resources Information Center

    Abel, Ernest L.; Kruger, Michael L.

    2010-01-01

    The authors examined the association between birth month and longevity for major league baseball players. Players born in the month of November had the greatest longevities whereas those born in June had the shortest life spans. These differences remained after controlling for covariates such as birth year, career length, age at debut, height, and…

  14. Birth Month Affects Longevity

    ERIC Educational Resources Information Center

    Abel, Ernest L.; Kruger, Michael L.

    2010-01-01

    The authors examined the association between birth month and longevity for major league baseball players. Players born in the month of November had the greatest longevities whereas those born in June had the shortest life spans. These differences remained after controlling for covariates such as birth year, career length, age at debut, height, and…

  15. CdiA promotes receptor-independent intercellular adhesion.

    PubMed

    Ruhe, Zachary C; Townsley, Loni; Wallace, Adam B; King, Andrew; Van der Woude, Marjan W; Low, David A; Yildiz, Fitnat H; Hayes, Christopher S

    2015-10-01

    CdiB/CdiA proteins mediate inter-bacterial competition in a process termed contact-dependent growth inhibition (CDI). Filamentous CdiA exoproteins extend from CDI(+) cells and bind specific receptors to deliver toxins into susceptible target bacteria. CDI has also been implicated in auto-aggregation and biofilm formation in several species, but the contribution of CdiA-receptor interactions to these multi-cellular behaviors has not been examined. Using Escherichia coli isolate EC93 as a model, we show that cdiA and bamA receptor mutants are defective in biofilm formation, suggesting a prominent role for CdiA-BamA mediated cell-cell adhesion. However, CdiA also promotes auto-aggregation in a BamA-independent manner, indicating that the exoprotein possesses an additional adhesin activity. Cells must express CdiA in order to participate in BamA-independent aggregates, suggesting that adhesion could be mediated by homotypic CdiA-CdiA interactions. The BamA-dependent and BamA-independent interaction domains map to distinct regions within the CdiA filament. Thus, CdiA orchestrates a collective behavior that is independent of its growth-inhibition activity. This adhesion should enable 'greenbeard' discrimination, in which genetically unrelated individuals cooperate with one another based on a single shared trait. This kind-selective social behavior could provide immediate fitness benefits to bacteria that acquire the systems through horizontal gene transfer.

  16. Lipidomics of familial longevity.

    PubMed

    Gonzalez-Covarrubias, Vanessa; Beekman, Marian; Uh, Hae-Won; Dane, Adrie; Troost, Jorne; Paliukhovich, Iryna; van der Kloet, Frans M; Houwing-Duistermaat, Jeanine; Vreeken, Rob J; Hankemeier, Thomas; Slagboom, Eline P

    2013-06-01

    Middle-aged offspring of nonagenarians, as compared to their spouses (controls), show a favorable lipid metabolism marked by larger LDL particle size in men and lower total triglyceride levels in women. To investigate which specific lipids associate with familial longevity, we explore the plasma lipidome by measuring 128 lipid species using liquid chromatography coupled to mass spectrometry in 1526 offspring of nonagenarians (59 years ± 6.6) and 675 (59 years ± 7.4) controls from the Leiden Longevity Study. In men, no significant differences were observed between offspring and controls. In women, however, 19 lipid species associated with familial longevity. Female offspring showed higher levels of ether phosphocholine (PC) and sphingomyelin (SM) species (3.5-8.7%) and lower levels of phosphoethanolamine PE (38:6) and long-chain triglycerides (TG) (9.4-12.4%). The association with familial longevity of two ether PC and four SM species was independent of total triglyceride levels. In addition, the longevity-associated lipid profile was characterized by a higher ratio of monounsaturated (MUFA) over polyunsaturated (PUFA) lipid species, suggesting that female offspring have a plasma lipidome less prone to oxidative stress. Ether PC and SM species were identified as novel longevity markers in females, independent of total triglycerides levels. Several longevity-associated lipids correlated with a lower risk of hypertension and diabetes in the Leiden Longevity Study cohort. This sex-specific lipid signature marks familial longevity and may suggest a plasma lipidome with a better antioxidant capacity, lower lipid peroxidation and inflammatory precursors, and an efficient beta-oxidation function.

  17. Lipidomics of familial longevity

    PubMed Central

    Gonzalez-Covarrubias, Vanessa; Beekman, Marian; Uh, Hae-Won; Dane, Adrie; Troost, Jorne; Paliukhovich, Iryna; Kloet, Frans M; Houwing-Duistermaat, Jeanine; Vreeken, Rob J; Hankemeier, Thomas; Slagboom, Eline P

    2013-01-01

    Middle-aged offspring of nonagenarians, as compared to their spouses (controls), show a favorable lipid metabolism marked by larger LDL particle size in men and lower total triglyceride levels in women. To investigate which specific lipids associate with familial longevity, we explore the plasma lipidome by measuring 128 lipid species using liquid chromatography coupled to mass spectrometry in 1526 offspring of nonagenarians (59 years ± 6.6) and 675 (59 years ± 7.4) controls from the Leiden Longevity Study. In men, no significant differences were observed between offspring and controls. In women, however, 19 lipid species associated with familial longevity. Female offspring showed higher levels of ether phosphocholine (PC) and sphingomyelin (SM) species (3.5–8.7%) and lower levels of phosphoethanolamine PE (38:6) and long-chain triglycerides (TG) (9.4–12.4%). The association with familial longevity of two ether PC and four SM species was independent of total triglyceride levels. In addition, the longevity-associated lipid profile was characterized by a higher ratio of monounsaturated (MUFA) over polyunsaturated (PUFA) lipid species, suggesting that female offspring have a plasma lipidome less prone to oxidative stress. Ether PC and SM species were identified as novel longevity markers in females, independent of total triglycerides levels. Several longevity-associated lipids correlated with a lower risk of hypertension and diabetes in the Leiden Longevity Study cohort. This sex-specific lipid signature marks familial longevity and may suggest a plasma lipidome with a better antioxidant capacity, lower lipid peroxidation and inflammatory precursors, and an efficient beta-oxidation function. PMID:23451766

  18. Longevity health sciences and mental health as future medicine.

    PubMed

    Riga, Sorin; Riga, Dan; Mihailescu, Alexandra; Motoc, Daniela; Mos, Liana; Schneider, Francisc

    2010-06-01

    Longevity health sciences and mental health are fields of public health and of preventive and integrative medicine. The antagonism between health construction and human pathology is substantiated by two opposite fundamental pathways: the health-longevity tetrad versus the aging-disease cascade. It is necessary that the current paradigm of contemporary medicine be replaced by the advanced paradigm of future medicine. A societal cost-benefit rate is decisive for health-longevity promotion. This is why the WHO public health strategy keeps forwarding the societal medical target into the global health-longevity field.

  19. Seminal Plasma Proteins as Androgen Receptor Corregulators Promote Prostate Cancer Growth

    DTIC Science & Technology

    2016-12-01

    Award Number: W81XWH-13-1-0412 TITLE: Seminal Plasma Proteins as Androgen Receptor Corregulators Promote Prostate Cancer Growth PRINCIPAL...SUBTITLE Seminal Plasma Proteins as Androgen Receptor Corregulators Promote Prostate Cancer Growth 5a. CONTRACT NUMBER 5b. GRANT NUMBER W81XWH-13...semenogelin I (SgI) in the presence of zinc, promote prostate cancer growth via functioning as androgen receptor (AR) co-activators. Using cell lines

  20. ABA receptor PYL9 promotes drought resistance and leaf senescence

    PubMed Central

    Zhao, Yang; Chan, Zhulong; Gao, Jinghui; Xing, Lu; Cao, Minjie; Yu, Chunmei; Hu, Yuanlei; You, Jun; Shi, Haitao; Zhu, Yingfang; Gong, Yuehua; Mu, Zixin; Wang, Haiqing; Deng, Xin; Wang, Pengcheng; Bressan, Ray A.; Zhu, Jian-Kang

    2016-01-01

    Drought stress is an important environmental factor limiting plant productivity. In this study, we screened drought-resistant transgenic plants from 65 promoter-pyrabactin resistance 1-like (PYL) abscisic acid (ABA) receptor gene combinations and discovered that pRD29A::PYL9 transgenic lines showed dramatically increased drought resistance and drought-induced leaf senescence in both Arabidopsis and rice. Previous studies suggested that ABA promotes senescence by causing ethylene production. However, we found that ABA promotes leaf senescence in an ethylene-independent manner by activating sucrose nonfermenting 1-related protein kinase 2s (SnRK2s), which subsequently phosphorylate ABA-responsive element-binding factors (ABFs) and Related to ABA-Insensitive 3/VP1 (RAV1) transcription factors. The phosphorylated ABFs and RAV1 up-regulate the expression of senescence-associated genes, partly by up-regulating the expression of Oresara 1. The pyl9 and ABA-insensitive 1-1 single mutants, pyl8-1pyl9 double mutant, and snrk2.2/3/6 triple mutant showed reduced ABA-induced leaf senescence relative to the WT, whereas pRD29A::PYL9 transgenic plants showed enhanced ABA-induced leaf senescence. We found that leaf senescence may benefit drought resistance by helping to generate an osmotic potential gradient, which is increased in pRD29A::PYL9 transgenic plants and causes water to preferentially flow to developing tissues. Our results uncover the molecular mechanism of ABA-induced leaf senescence and suggest an important role of PYL9 and leaf senescence in promoting resistance to extreme drought stress. PMID:26831097

  1. ABA receptor PYL9 promotes drought resistance and leaf senescence.

    PubMed

    Zhao, Yang; Chan, Zhulong; Gao, Jinghui; Xing, Lu; Cao, Minjie; Yu, Chunmei; Hu, Yuanlei; You, Jun; Shi, Haitao; Zhu, Yingfang; Gong, Yuehua; Mu, Zixin; Wang, Haiqing; Deng, Xin; Wang, Pengcheng; Bressan, Ray A; Zhu, Jian-Kang

    2016-02-16

    Drought stress is an important environmental factor limiting plant productivity. In this study, we screened drought-resistant transgenic plants from 65 promoter-pyrabactin resistance 1-like (PYL) abscisic acid (ABA) receptor gene combinations and discovered that pRD29A::PYL9 transgenic lines showed dramatically increased drought resistance and drought-induced leaf senescence in both Arabidopsis and rice. Previous studies suggested that ABA promotes senescence by causing ethylene production. However, we found that ABA promotes leaf senescence in an ethylene-independent manner by activating sucrose nonfermenting 1-related protein kinase 2s (SnRK2s), which subsequently phosphorylate ABA-responsive element-binding factors (ABFs) and Related to ABA-Insensitive 3/VP1 (RAV1) transcription factors. The phosphorylated ABFs and RAV1 up-regulate the expression of senescence-associated genes, partly by up-regulating the expression of Oresara 1. The pyl9 and ABA-insensitive 1-1 single mutants, pyl8-1pyl9 double mutant, and snrk2.2/3/6 triple mutant showed reduced ABA-induced leaf senescence relative to the WT, whereas pRD29A::PYL9 transgenic plants showed enhanced ABA-induced leaf senescence. We found that leaf senescence may benefit drought resistance by helping to generate an osmotic potential gradient, which is increased in pRD29A::PYL9 transgenic plants and causes water to preferentially flow to developing tissues. Our results uncover the molecular mechanism of ABA-induced leaf senescence and suggest an important role of PYL9 and leaf senescence in promoting resistance to extreme drought stress.

  2. The aryl hydrocarbon receptor promotes aging phenotypes across species

    PubMed Central

    Eckers, Anna; Jakob, Sascha; Heiss, Christian; Haarmann-Stemmann, Thomas; Goy, Christine; Brinkmann, Vanessa; Cortese-Krott, Miriam M.; Sansone, Roberto; Esser, Charlotte; Ale-Agha, Niloofar; Altschmied, Joachim; Ventura, Natascia; Haendeler, Judith

    2016-01-01

    The ubiquitously expressed aryl hydrocarbon receptor (AhR) induces drug metabolizing enzymes as well as regulators of cell growth, differentiation and apoptosis. Certain AhR ligands promote atherosclerosis, an age-associated vascular disease. Therefore, we investigated the role of AhR in vascular functionality and aging. We report a lower pulse wave velocity in young and old AhR-deficient mice, indicative of enhanced vessel elasticity. Moreover, endothelial nitric oxide synthase (eNOS) showed increased activity in the aortas of these animals, which was reflected in increased NO production. Ex vivo, AhR activation reduced the migratory capacity of primary human endothelial cells. AhR overexpression as well as treatment with a receptor ligand, impaired eNOS activation and reduced S-NO content. All three are signs of endothelial dysfunction. Furthermore, AhR expression in blood cells of healthy human volunteers positively correlated with vessel stiffness. In the aging model Caenorhabditis elegans, AhR-deficiency resulted in increased mean life span, motility, pharynx pumping and heat shock resistance, suggesting healthier aging. Thus, AhR seems to have a negative impact on vascular and organismal aging. Finally, our data from human subjects suggest that AhR expression levels could serve as an additional, new predictor of vessel aging. PMID:26790370

  3. The glycocalyx promotes cooperative binding and clustering of adhesion receptors.

    PubMed

    Xu, Guang-Kui; Qian, Jin; Hu, Jinglei

    2016-05-18

    Cell adhesion plays a pivotal role in various biological processes, e.g., immune responses, cancer metastasis, and stem cell differentiation. The adhesion behaviors depend subtly on the binding kinetics of receptors and ligands restricted at the cell-substrate interfaces. Although much effort has been directed toward investigating the kinetics of adhesion molecules, the role of the glycocalyx, anchored on cell surfaces as an exterior layer, is still unclear. In this paper, we propose a theoretical approach to study the collective binding kinetics of a few and a large number of binders in the presence of the glycocalyx, representing the cases of initial and mature adhesions of cells, respectively. The analytical results are validated by finding good agreement with our Monte Carlo simulations. In the force loading case, the on-rate and affinity increase as more bonds form, whereas this cooperative effect is not observed in the displacement loading case. The increased thickness and stiffness of the glycocalyx tend to decrease the affinity for a few bonds, while they have less influence on the affinity for a large number of bonds. Moreover, for a flexible membrane with thermally-excited shape fluctuations, the glycocalyx is exhibited to promote the formation of bond clusters, mainly due to the cooperative binding of binders. This study helps to understand the cooperative kinetics of adhesion receptors under physiologically relevant loading conditions and sheds light on the novel role of the glycocalyx in cell adhesion.

  4. CdiA promotes receptor-independent intercellular adhesion

    PubMed Central

    Ruhe, Zachary C.; Townsley, Loni; Wallace, Adam B.; King, Andrew; der Woude, Marjan W. Van; Low, David A.; Yildiz, Fitnat H.; Hayes, Christopher S.

    2015-01-01

    Summary CdiB/CdiA proteins mediate inter-bacterial competition in a process termed contact-dependent growth inhibition (CDI). Filamentous CdiA exoproteins extend from CDI+ cells and bind specific receptors to deliver toxins into susceptible target bacteria. CDI has also been implicated in auto-aggregation and biofilm formation in several species, but the contribution of CdiA-receptor interactions to these multi-cellular behaviors has not been examined. Using Escherichia coli isolate EC93 as a model, we show that cdiA and bamA receptor mutants are defective in biofilm formation, suggesting a prominent role for CdiA-BamA mediated cell-cell adhesion. However, CdiA also promotes auto-aggregation in a BamA-independent manner, indicating that the exoprotein possesses an additional adhesin activity. Cells must express CdiA in order to participate in BamA-independent aggregates, suggesting that adhesion could be mediated by homotypic CdiA-CdiA interactions. The BamA-dependent and BamA-independent interaction domains map to distinct regions within the CdiA filament. Thus, CdiA orchestrates a collective behavior that is independent of its growth-inhibition activity. This adhesion should enable “greenbeard” discrimination, in which genetically unrelated individuals cooperate with one another based on a single shared trait. This kind-selective social behavior could provide immediate fitness benefits to bacteria that acquire the systems through horizontal gene transfer. PMID:26135212

  5. Endoplasmic reticulum stress contributes to acetylcholine receptor degradation by promoting endocytosis in skeletal muscle cells.

    PubMed

    Du, Ailian; Huang, Shiqian; Zhao, Xiaonan; Zhang, Yun; Zhu, Lixun; Ding, Ji; Xu, Congfeng

    2016-01-15

    After binding by acetylcholine released from a motor neuron, a nicotinic acetylcholine receptor at the neuromuscular junction produces a localized end-plate potential, which leads to muscle contraction. Improper turnover and renewal of acetylcholine receptors contributes to the pathogenesis of myasthenia gravis. In the present study, we demonstrate that endoplasmic reticulum (ER) stress contributes to acetylcholine receptor degradation in C2C12 myocytes. We further show that ER stress promotes acetylcholine receptor endocytosis and lysosomal degradation, which was dampened by blocking endocytosis or treating with lysosome inhibitor. Knockdown of ER stress proteins inhibited acetylcholine receptor endocytosis and degradation, while rescue assay restored its endocytosis and degradation, confirming the effects of ER stress on promoting endocytosis-mediated degradation of junction acetylcholine receptors. Thus, our studies identify ER stress as a factor promoting acetylcholine receptor degradation through accelerating endocytosis in muscle cells. Blocking ER stress and/or endocytosis might provide a novel therapeutic approach for myasthenia gravis.

  6. Truncating Prolactin Receptor Mutations Promote Tumor Growth in Murine Estrogen Receptor-Alpha Mammary Carcinomas.

    PubMed

    Griffith, Obi L; Chan, Szeman Ruby; Griffith, Malachi; Krysiak, Kilannin; Skidmore, Zachary L; Hundal, Jasreet; Allen, Julie A; Arthur, Cora D; Runci, Daniele; Bugatti, Mattia; Miceli, Alexander P; Schmidt, Heather; Trani, Lee; Kanchi, Krishna-Latha; Miller, Christopher A; Larson, David E; Fulton, Robert S; Vermi, William; Wilson, Richard K; Schreiber, Robert D; Mardis, Elaine R

    2016-09-27

    Estrogen receptor alpha-positive (ERα+) luminal tumors are the most frequent subtype of breast cancer. Stat1(-/-) mice develop mammary tumors that closely recapitulate the biological characteristics of this cancer subtype. To identify transforming events that contribute to tumorigenesis, we performed whole genome sequencing of Stat1(-/-) primary mammary tumors and matched normal tissues. This investigation identified somatic truncating mutations affecting the prolactin receptor (PRLR) in all tumor and no normal samples. Targeted sequencing confirmed the presence of these mutations in precancerous lesions, indicating that this is an early event in tumorigenesis. Functional evaluation of these heterozygous mutations in Stat1(-/-) mouse embryonic fibroblasts showed that co-expression of truncated and wild-type PRLR led to aberrant STAT3 and STAT5 activation downstream of the receptor, cellular transformation in vitro, and tumor formation in vivo. In conclusion, truncating mutations of PRLR promote tumor growth in a model of human ERα+ breast cancer and warrant further investigation.

  7. Longevity, Genes, and Aging

    NASA Astrophysics Data System (ADS)

    Michal Jazwinski, S.

    1996-07-01

    Until recently, biogerontology was a backwater of biology, but progress in the qualitative and quantitative genetic analysis of longevity has led to a revolution in aging research. This research has revealed that extended longevity is frequently associated with enhanced metabolic capacity and response to stress. Moreover, it suggests that there are multiple mechanisms of aging. Because of its complexity, the aging process takes us into the realm of integrative biology, and thus, biogerontology should prove instrumental in deciphering the functional and regulatory circuitry of the sequenced genome.

  8. IL-36 receptor promotes resolution of intestinal damage

    PubMed Central

    Medina-Contreras, Oscar; Harusato, Akihito; Nishio, Hikaru; Flannigan, Kyle L.; Ngo, Vu; Leoni, Giovanna; Neumann, Philipp-Alexander; Geem, Duke; Lili, Loukia N.; Ramadas, Ravisankar A.; Chassaing, Benoit; Gewirtz, Andrew T.; Kohlmeier, Jacob E.; Parkos, Charles A.; Towne, Jennifer E.; Nusrat, Asma; Denning, Timothy L.

    2015-01-01

    Interleukin-1 family members are central mediators of host defense. Here we show that the novel IL-1 family member, IL-36γ, was expressed during experimental colitis and human inflammatory bowel disease (IBD). In response to dextran sodium sulfate (DSS)-induced damage, germ-free (GF) mice failed to induce IL-36γ, suggesting that gut microbiota are involved in its induction. Surprisingly, IL-36R-deficient (Il1rl2−/−) mice exhibited defective recovery following DSS-induced damage and impaired closure of colonic mucosal biopsy wounds, which coincided with impaired neutrophil accumulation in the wound bed. Failure of Il1rl2−/− mice to recover from DSS-induced damage was associated with a profound reduction in IL-22 expression, particularly by colonic neutrophils. Defective recovery of Il1rl2−/− mice could be rescued an aryl hydrocarbon receptor (AhR) agonist, which was sufficient to restore IL-22 expression and promote full recovery from DSS-induced damage. These findings implicate the IL-36/IL-36R axis in the resolution of intestinal mucosal wounds. PMID:26590314

  9. Selective Androgen Receptor Modulators (SARMs) as Function Promoting Therapies

    PubMed Central

    Bhasin, Shalender; Jasuja, Ravi

    2010-01-01

    Purpose of review The last decade has witnessed unprecedented discovery effort to develop selective androgen receptor modulators (SARMs) that improve physical function and bone health without adversely affecting the prostate and cardiovascular outcomes. This review describes the historical evolution, the rationale for SARM development, and the mechanisms of testosterone action and SARM selectivity. Recent Findings While steroidal SARMs have been around since the 1940s, a number of nonsteroidal SARMs that do not serve as substrates for CYP19 aromatase or 5α-reductase, act as full agonists in muscle and bone and as partial agonists in prostate are in development. The differing interactions of steroidal and nonsteroidal compounds with AR contribute to their unique pharmacologic actions. Ligand binding induces specific conformational changes in the ligand binding domain, which could modulate surface topology and protein-protein interactions between AR and coregulators, resulting in tissue-specific gene regulation. Preclinical studies have demonstrated the ability of SARMs to increase muscle and bone mass in preclinical rodent models with varying degree of prostate sparing. Phase I trials of SARMs in humans have reported modest increments in fat-free mass. Summary SARMs hold promise as a new class of function promoting anabolic therapies for a number of clinical indications, including functional limitations associated with aging and chronic disease, frailty, cancer cachexia, and osteoporosis. PMID:19357508

  10. Estrogen receptor subtype- and promoter-specific modulation of aryl hydrocarbon receptor-dependent transcription.

    PubMed

    Wihlén, Björn; Ahmed, Shaimaa; Inzunza, José; Matthews, Jason

    2009-06-01

    In this study, we examined the role of estrogen receptors (ER) in aryl hydrocarbon receptor (AHR)-dependent transactivation. Chromatin immunoprecipitation assays showed that AHR agonists differentially induced recruitment of ERalpha to the AHR target genes CYP1A1 and CYP1B1. Cotreatment with 17beta-estradiol significantly increased beta-naphthoflavone (BNF)- and 2,3,7,8-tetrachlorodibenzo-p-dioxin-induced recruitment of ERalpha to CYP1A1, whereas 3,3'-diindolylmethane induced promoter occupancy of ERalpha at CYP1A1 that was unaffected by cotreatment with 17beta-estradiol. Cyclical recruitment of AHR and ERalpha to CYP1A1 was only observed in cells treated with BNF. Stable and subtype-specific knockdown of ERalpha or ERbeta using shRNA showed that suppression of ERalpha significantly reduced, whereas knockdown of ERbeta significantly enhanced, AHR agonist-induced Cyp1a1 expression in HC11 mouse mammary epithelial cells. AHR agonist-induced Cyp1b1 expression was reduced by ERbeta knockdown but unaffected by ERalpha knockdown. The siRNA-mediated knockdown of ERalpha in MCF-7 human breast cancer cells did not affect 2,3,7,8-tetrachlorodibenzo-p-dioxin-dependent regulation of CYP1A1 and CYP1B1 mRNA expression. In agreement with our in vitro findings in the HC11 cells, ERalpha knockout mice exhibit reduced BNF-dependent induction of Cyp1a1 mRNA. These results establish ligand- and promoter-specific influences on the cyclical recruitment patterns for AHR and show ER species-, subtype-, and promoter-specific modulation of AHR-dependent transcription.

  11. Parental divorce and adult longevity.

    PubMed

    Larson, Kandyce; Halfon, Neal

    2013-02-01

    Life course research has established associations between adverse childhood events and later life health. We examine the relationship of experiencing parental divorce before the age of 16 and survival across 34 years of adulthood. Analysis of panel data from a USA-based survey of 6,928 adults residing in Alameda County, California in 1965. Cox regression was used to examine associations between parental divorce and longevity. Controlling for age, race/ethnicity, gender, and childhood socioeconomic position, respondents who recalled a parental divorce during childhood had increased risk of mortality compared to those with no separation. The association was stronger for premature mortality and deaths due to cardiovascular disease. Divorce in childhood was also associated with lowered adult education, fewer social network ties, more depression, and worse health practices. These factors appeared to explain the association with longevity. Parental divorce in childhood is associated with lowered well-being in adulthood and long-term survival. Early prevention and health promotion efforts may be warranted for children who experience parental divorce or discord as a means of supporting enhanced trajectories of health and well-being.

  12. Neonatal Fc Receptor Promotes Immune Complex–Mediated Glomerular Disease

    PubMed Central

    Olaru, Florina; Luo, Wentian; Suleiman, Hani; St. John, Patricia L.; Ge, Linna; Mezo, Adam R.; Shaw, Andrey S.; Abrahamson, Dale R.; Miner, Jeffrey H.

    2014-01-01

    The neonatal Fc receptor (FcRn) is a major regulator of IgG and albumin homeostasis systemically and in the kidneys. We investigated the role of FcRn in the development of immune complex–mediated glomerular disease in mice. C57Bl/6 mice immunized with the noncollagenous domain of the α3 chain of type IV collagen (α3NC1) developed albuminuria associated with granular capillary loop deposition of exogenous antigen, mouse IgG, C3 and C5b-9, and podocyte injury. High-resolution imaging showed abundant IgG deposition in the expanded glomerular basement membrane, especially in regions corresponding to subepithelial electron dense deposits. FcRn-null and -humanized mice immunized with α3NC1 developed no albuminuria and had lower levels of serum IgG anti-α3NC1 antibodies and reduced glomerular deposition of IgG, antigen, and complement. Our results show that FcRn promotes the formation of subepithelial immune complexes and subsequent glomerular pathology leading to proteinuria, potentially by maintaining higher serum levels of pathogenic IgG antibodies. Therefore, reducing pathogenic IgG levels by pharmacologic inhibition of FcRn may provide a novel approach for the treatment of immune complex–mediated glomerular diseases. As proof of concept, we showed that a peptide inhibiting the interaction between human FcRn and human IgG accelerated the degradation of human IgG anti-α3NC1 autoantibodies injected into FCRN-humanized mice as effectively as genetic ablation of FcRn, thus preventing the glomerular deposition of immune complexes containing human IgG. PMID:24357670

  13. Resilience Significantly Contributes to Exceptional Longevity

    PubMed Central

    Zeng, Yi; Shen, Ke

    2010-01-01

    Objective. We aim to investigate whether centenarians are significantly more resilient than younger elders and whether resilience significantly contributes to exceptional longevity. Data. We use a unique dataset from the Chinese Longitudinal Healthy Longevity Survey with the largest sample to date of centenarians, nonagenarians, octogenarians, and a compatible group of young old aged 65–79. Methods and Results. Logistic regressions based on the cross-sectional sample show that after controlling for various confounders, including physical health and cognitive status, centenarians are significantly more resilient than any other old-age group. Logistic regression analyses based on the longitudinal data show that nonagenarians aged 94–98 with better resilience have a 43.1% higher likelihood of becoming a centenarian compared to nonagenarians with lower resilience. Conclusions. Resilience significantly contributes to longevity at all ages, and it becomes even more profound at very advanced ages. These findings indicate that policies and programs to promote resilience would have long-term and positive effects on the well-being and longevity for senior citizens and their families. PMID:21197075

  14. Longevity in mice is promoted by probiotic-induced suppression of colonic senescence dependent on upregulation of gut bacterial polyamine production.

    PubMed

    Matsumoto, Mitsuharu; Kurihara, Shin; Kibe, Ryoko; Ashida, Hisashi; Benno, Yoshimi

    2011-01-01

    Chronic low-grade inflammation is recognized as an important factor contributing to senescence and age-related diseases. In mammals, levels of polyamines (PAs) decrease during the ageing process; PAs are known to decrease systemic inflammation by inhibiting inflammatory cytokine synthesis in macrophages. Reductions in intestinal luminal PAs levels have been associated with intestinal barrier dysfunction. The probiotic strain Bifidobacterium animalis subsp. lactis LKM512 is known to increase intestinal luminal PA concentrations. We supplemented the diet of 10-month-old Crj:CD-1 female mice with LKM512 for 11 months, while the controls received no supplementation. Survival rates were compared using Kaplan-Meier survival curves. LKM512-treated mice survived significantly longer than controls (P<0.001); moreover, skin ulcers and tumors were more common in the control mice. We then analyzed inflammatory and intestinal conditions by measuring several markers using HPLC, ELISA, reverse transcription-quantitative PCR, and histological slices. LKM512 mice showed altered 16S rRNA gene expression of several predominant intestinal bacterial groups. The fecal concentrations of PAs, but not of short-chain fatty acids, were significantly higher in LKM512-treated mice (P<0.05). Colonic mucosal function was also better in LKM512 mice, with increased mucus secretion and better maintenance of tight junctions. Changes in gene expression levels were evaluated using the NimbleGen mouse DNA microarray. LKM512 administration also downregulated the expression of ageing-associated and inflammation-associated genes and gene expression levels in 21-month-old LKM512-treated mice resembled those in 10-month-old untreated (younger) mice. Our study demonstrated increased longevity in mice following probiotic treatment with LKM512, possibly due to the suppression of chronic low-grade inflammation in the colon induced by higher PA levels. This indicates that ingestion of specific probiotics may be

  15. Longevity in Mice Is Promoted by Probiotic-Induced Suppression of Colonic Senescence Dependent on Upregulation of Gut Bacterial Polyamine Production

    PubMed Central

    Matsumoto, Mitsuharu; Kurihara, Shin; Kibe, Ryoko; Ashida, Hisashi; Benno, Yoshimi

    2011-01-01

    Background Chronic low-grade inflammation is recognized as an important factor contributing to senescence and age-related diseases. In mammals, levels of polyamines (PAs) decrease during the ageing process; PAs are known to decrease systemic inflammation by inhibiting inflammatory cytokine synthesis in macrophages. Reductions in intestinal luminal PAs levels have been associated with intestinal barrier dysfunction. The probiotic strain Bifidobacterium animalis subsp. lactis LKM512 is known to increase intestinal luminal PA concentrations. Methodology/Principal Findings We supplemented the diet of 10-month-old Crj:CD-1 female mice with LKM512 for 11 months, while the controls received no supplementation. Survival rates were compared using Kaplan–Meier survival curves. LKM512-treated mice survived significantly longer than controls (P<0.001); moreover, skin ulcers and tumors were more common in the control mice. We then analyzed inflammatory and intestinal conditions by measuring several markers using HPLC, ELISA, reverse transcription-quantitative PCR, and histological slices. LKM512 mice showed altered 16S rRNA gene expression of several predominant intestinal bacterial groups. The fecal concentrations of PAs, but not of short-chain fatty acids, were significantly higher in LKM512-treated mice (P<0.05). Colonic mucosal function was also better in LKM512 mice, with increased mucus secretion and better maintenance of tight junctions. Changes in gene expression levels were evaluated using the NimbleGen mouse DNA microarray. LKM512 administration also downregulated the expression of ageing-associated and inflammation-associated genes and gene expression levels in 21-month-old LKM512-treated mice resembled those in 10-month-old untreated (younger) mice. Conclusion/Significance Our study demonstrated increased longevity in mice following probiotic treatment with LKM512, possibly due to the suppression of chronic low-grade inflammation in the colon induced by higher PA

  16. RNA surveillance via nonsense-mediated mRNA decay is crucial for longevity in daf-2/insulin/IGF-1 mutant C. elegans

    PubMed Central

    Son, Heehwa G.; Seo, Mihwa; Ham, Seokjin; Hwang, Wooseon; Lee, Dongyeop; An, Seon Woo A.; Artan, Murat; Seo, Keunhee; Kaletsky, Rachel; Arey, Rachel N.; Ryu, Youngjae; Ha, Chang Man; Kim, Yoon Ki; Murphy, Coleen T.; Roh, Tae-Young; Nam, Hong Gil; Lee, Seung-Jae V.

    2017-01-01

    Long-lived organisms often feature more stringent protein and DNA quality control. However, whether RNA quality control mechanisms, such as nonsense-mediated mRNA decay (NMD), which degrades both abnormal as well as some normal transcripts, have a role in organismal aging remains unexplored. Here we show that NMD mediates longevity in C. elegans strains with mutations in daf-2/insulin/insulin-like growth factor 1 receptor. We find that daf-2 mutants display enhanced NMD activity and reduced levels of potentially aberrant transcripts. NMD components, including smg-2/UPF1, are required to achieve the longevity of several long-lived mutants, including daf-2 mutant worms. NMD in the nervous system of the animals is particularly important for RNA quality control to promote longevity. Furthermore, we find that downregulation of yars-2/tyrosyl-tRNA synthetase, an NMD target transcript, by daf-2 mutations contributes to longevity. We propose that NMD-mediated RNA surveillance is a crucial quality control process that contributes to longevity conferred by daf-2 mutations. PMID:28276441

  17. Endurance exercise and selective breeding for longevity extend Drosophila healthspan by overlapping mechanisms

    PubMed Central

    Sujkowski, Alyson; Bazzell, Brian; Carpenter, Kylie; Arking, Robert; Wessells, Robert J

    2015-01-01

    Endurance exercise has emerged as a powerful intervention that promotes healthy aging by maintaining the functional capacity of critical organ systems. In addition, long-term exercise reduces the incidence of age-related diseases in humans and in model organisms. Despite these evident benefits, the genetic pathways required for exercise interventions to achieve these effects are still relatively poorly understood. Here, we compare gene expression changes during endurance training in Drosophila melanogaster to gene expression changes during selective breeding for longevity. Microarrays indicate that 65% of gene expression changes found in flies selectively bred for longevity are also found in flies subjected to three weeks of exercise training. We find that both selective breeding and endurance training increase endurance, cardiac performance, running speed, flying height, and levels of autophagy in adipose tissue. Both interventions generally upregulate stress defense, folate metabolism, and lipase activity, while downregulating carbohydrate metabolism and odorant receptor expression. Several members of the methuselah-like (mthl) gene family are downregulated by both interventions. Knockdown of mthl-3 was sufficient to provide extension of negative geotaxis behavior, endurance and cardiac stress resistance. These results provide support for endurance exercise as a broadly acting anti-aging intervention and confirm that exercise training acts in part by targeting longevity assurance pathways. PMID:26298685

  18. Aging, longevity and health

    PubMed Central

    Rasmussen, Lene Juel; Sander, Miriam; Wewer, Ulla M.; Bohr, Vilhelm A.

    2016-01-01

    The IARU Congress on Aging, Longevity and Health, held on 5–7 October 2010 in Copenhagen, Denmark, was hosted by Rector Ralf Hemmingsen, University of Copenhagen and Dean Ulla Wewer, Faculty of Health Sciences, University of Copenhagen and was organized by Center for Healthy Aging (CEHA) under the leadership of CEHA Managing Director Lene Juel Rasmussen and Prof. Vilhelm Bohr, National Institute on Aging, NIH, Baltimore, USA (associated to CEHA). The Congress was attended by approximately 125 researchers interested in and/or conducting research on aging and aging-related topics. The opening Congress Session included speeches by Ralf Hemmingsen, Ulla Wewer, and Lene Juel Rasmussen and Keynote Addresses by four world renowned aging researchers: Povl Riis (The Age Forum), Bernard Jeune (University of Southern Denmark), George Martin (University of Washington, USA) and Jan Vijg (Albert Einstein School of Medicine, USA) as well as a lecture discussing the art-science interface by Thomas Söderqvist (Director, Medical Museion, University of Copenhagen). The topics of the first six Sessions of the Congress were: Neuroscience and DNA damage, Aging and Stress, Life Course, Environmental Factors and Neuroscience, Muscle and Life Span and Life Span and Mechanisms. Two additional Sessions highlighted ongoing research in the recently established Center for Healthy Aging at the University of Copenhagen. This report highlights outcomes of recent research on aging-related topics, as described at the IARU Congress on Aging, Longevity and Health. PMID:21820462

  19. Aging, longevity and health.

    PubMed

    Rasmussen, Lene Juel; Sander, Miriam; Wewer, Ulla M; Bohr, Vilhelm A

    2011-10-01

    The IARU Congress on Aging, Longevity and Health, held on 5-7 October 2010 in Copenhagen, Denmark, was hosted by Rector Ralf Hemmingsen, University of Copenhagen and Dean Ulla Wewer, Faculty of Health Sciences, University of Copenhagen and was organized by Center for Healthy Aging (CEHA) under the leadership of CEHA Managing Director Lene Juel Rasmussen and Prof. Vilhelm Bohr, National Institute on Aging, NIH, Baltimore, USA (associated to CEHA). The Congress was attended by approximately 125 researchers interested in and/or conducting research on aging and aging-related topics. The opening Congress Session included speeches by Ralf Hemmingsen, Ulla Wewer, and Lene Juel Rasmussen and Keynote Addresses by four world renowned aging researchers: Povl Riis (The Age Forum), Bernard Jeune (University of Southern Denmark), George Martin (University of Washington, USA) and Jan Vijg (Albert Einstein School of Medicine, USA) as well as a lecture discussing the art-science interface by Thomas Söderqvist (Director, Medical Museion, University of Copenhagen). The topics of the first six Sessions of the Congress were: Neuroscience and DNA damage, Aging and Stress, Life Course, Environmental Factors and Neuroscience, Muscle and Life Span and Life Span and Mechanisms. Two additional Sessions highlighted ongoing research in the recently established Center for Healthy Aging at the University of Copenhagen. This report highlights outcomes of recent research on aging-related topics, as described at the IARU Congress on Aging, Longevity and Health.

  20. Longevity Genes Revealed by Integrative Analysis of Isoform-Specific daf-16/FoxO Mutants of Caenorhabditis elegans

    PubMed Central

    Chen, Albert Tzong-Yang; Guo, Chunfang; Itani, Omar A.; Budaitis, Breane G.; Williams, Travis W.; Hopkins, Christopher E.; McEachin, Richard C.; Pande, Manjusha; Grant, Ana R.; Yoshina, Sawako; Mitani, Shohei; Hu, Patrick J.

    2015-01-01

    FoxO transcription factors promote longevity across taxa. How they do so is poorly understood. In the nematode Caenorhabditis elegans, the A- and F-isoforms of the FoxO transcription factor DAF-16 extend life span in the context of reduced DAF-2 insulin-like growth factor receptor (IGFR) signaling. To elucidate the mechanistic basis for DAF-16/FoxO-dependent life span extension, we performed an integrative analysis of isoform-specific daf-16/FoxO mutants. In contrast to previous studies suggesting that DAF-16F plays a more prominent role in life span control than DAF-16A, isoform-specific daf-16/FoxO mutant phenotypes and whole transcriptome profiling revealed a predominant role for DAF-16A over DAF-16F in life span control, stress resistance, and target gene regulation. Integration of these datasets enabled the prioritization of a subset of 92 DAF-16/FoxO target genes for functional interrogation. Among 29 genes tested, two DAF-16A-specific target genes significantly influenced longevity. A loss-of-function mutation in the conserved gene gst-20, which is induced by DAF-16A, reduced life span extension in the context of daf-2/IGFR RNAi without influencing longevity in animals subjected to control RNAi. Therefore, gst-20 promotes DAF-16/FoxO-dependent longevity. Conversely, a loss-of-function mutation in srr-4, a gene encoding a seven-transmembrane-domain receptor family member that is repressed by DAF-16A, extended life span in control animals, indicating that DAF-16/FoxO may extend life span at least in part by reducing srr-4 expression. Our discovery of new longevity genes underscores the efficacy of our integrative strategy while providing a general framework for identifying specific downstream gene regulatory events that contribute substantially to transcription factor functions. As FoxO transcription factors have conserved functions in promoting longevity and may be dysregulated in aging-related diseases, these findings promise to illuminate fundamental

  1. Longevity Genes Revealed by Integrative Analysis of Isoform-Specific daf-16/FoxO Mutants of Caenorhabditis elegans.

    PubMed

    Chen, Albert Tzong-Yang; Guo, Chunfang; Itani, Omar A; Budaitis, Breane G; Williams, Travis W; Hopkins, Christopher E; McEachin, Richard C; Pande, Manjusha; Grant, Ana R; Yoshina, Sawako; Mitani, Shohei; Hu, Patrick J

    2015-10-01

    FoxO transcription factors promote longevity across taxa. How they do so is poorly understood. In the nematode Caenorhabditis elegans, the A- and F-isoforms of the FoxO transcription factor DAF-16 extend life span in the context of reduced DAF-2 insulin-like growth factor receptor (IGFR) signaling. To elucidate the mechanistic basis for DAF-16/FoxO-dependent life span extension, we performed an integrative analysis of isoform-specific daf-16/FoxO mutants. In contrast to previous studies suggesting that DAF-16F plays a more prominent role in life span control than DAF-16A, isoform-specific daf-16/FoxO mutant phenotypes and whole transcriptome profiling revealed a predominant role for DAF-16A over DAF-16F in life span control, stress resistance, and target gene regulation. Integration of these datasets enabled the prioritization of a subset of 92 DAF-16/FoxO target genes for functional interrogation. Among 29 genes tested, two DAF-16A-specific target genes significantly influenced longevity. A loss-of-function mutation in the conserved gene gst-20, which is induced by DAF-16A, reduced life span extension in the context of daf-2/IGFR RNAi without influencing longevity in animals subjected to control RNAi. Therefore, gst-20 promotes DAF-16/FoxO-dependent longevity. Conversely, a loss-of-function mutation in srr-4, a gene encoding a seven-transmembrane-domain receptor family member that is repressed by DAF-16A, extended life span in control animals, indicating that DAF-16/FoxO may extend life span at least in part by reducing srr-4 expression. Our discovery of new longevity genes underscores the efficacy of our integrative strategy while providing a general framework for identifying specific downstream gene regulatory events that contribute substantially to transcription factor functions. As FoxO transcription factors have conserved functions in promoting longevity and may be dysregulated in aging-related diseases, these findings promise to illuminate fundamental

  2. High-throughput mapping of the promoters of the mouse olfactory receptor genes reveals a new type of mammalian promoter and provides insight into olfactory receptor gene regulation

    PubMed Central

    Clowney, E. Josephine; Magklara, Angeliki; Colquitt, Bradley M.; Pathak, Nidhi; Lane, Robert P.; Lomvardas, Stavros

    2011-01-01

    The olfactory receptor (OR) genes are the largest mammalian gene family and are expressed in a monogenic and monoallelic fashion in olfactory neurons. Using a high-throughput approach, we mapped the transcription start sites of 1085 of the 1400 murine OR genes and performed computational analysis that revealed potential transcription factor binding sites shared by the majority of these promoters. Our analysis produced a hierarchical model for OR promoter recognition in which unusually high AT content, a unique epigenetic signature, and a stereotypically positioned O/E site distinguish OR promoters from the rest of the murine promoters. Our computations revealed an intriguing correlation between promoter AT content and evolutionary plasticity, as the most AT-rich promoters regulate rapidly evolving gene families. Within the AT-rich promoter category the position of the TATA-box does not correlate with the transcription start site. Instead, a spike in GC composition might define the exact location of the TSS, introducing the concept of “genomic contrast” in transcriptional regulation. Finally, our experiments show that genomic neighborhood rather than promoter sequence correlates with the probability of different OR genes to be expressed in the same olfactory cell. PMID:21705439

  3. LPA1 receptor activation promotes renal interstitial fibrosis.

    PubMed

    Pradère, Jean-Philippe; Klein, Julie; Grès, Sandra; Guigné, Charlotte; Neau, Eric; Valet, Philippe; Calise, Denis; Chun, Jerold; Bascands, Jean-Loup; Saulnier-Blache, Jean-Sébastien; Schanstra, Joost P

    2007-12-01

    Tubulointerstitial fibrosis in chronic renal disease is strongly associated with progressive loss of renal function. We studied the potential involvement of lysophosphatidic acid (LPA), a growth factor-like phospholipid, and its receptors LPA(1-4) in the development of tubulointerstitial fibrosis (TIF). Renal fibrosis was induced in mice by unilateral ureteral obstruction (UUO) for up to 8 d, and kidney explants were prepared from the distal poles to measure LPA release into conditioned media. After obstruction, the extracellular release of LPA increased approximately 3-fold. Real-time reverse transcription PCR (RT-PCR) analysis demonstrated significant upregulation in the expression of the LPA(1) receptor subtype, downregulation of LPA3, and no change of LPA2 or LPA4. TIF was significantly attenuated in LPA1 (-/-) mice compared to wild-type littermates, as measured by expression of collagen III, alpha-smooth muscle actin (alpha-SMA), and F4/80. Furthermore, treatment of wild-type mice with the LPA1 antagonist Ki16425 similarly reduced fibrosis and significantly attenuated renal expression of the profibrotic cytokines connective tissue growth factor (CTGF) and transforming growth factor beta (TGFbeta). In vitro, LPA induced a rapid, dose-dependent increase in CTGF expression that was inhibited by Ki16425. In conclusion, LPA, likely acting through LPA1, is involved in obstruction-induced TIF. Therefore, the LPA1 receptor might be a pharmaceutical target to treat renal fibrosis.

  4. Familial Risk for Exceptional Longevity

    PubMed Central

    Sebastiani, Paola; Andersen, Stacy L.; McIntosh, Avery I.; Nussbaum, Lisa; Stevenson, Meredith D.; Pierce, Leslie; Xia, Samantha; Salance, Kelly; Perls, Thomas T.

    2015-01-01

    One of the most glaring deficiencies in the current assessment of mortality risk is the lack of information concerning the impact of familial longevity. In this work, we update estimates of sibling relative risk of living to extreme ages using data from more than 1,700 sibships, and we begin to examine the trend for heritability for different birth-year cohorts. We also build a network model that can be used to compute the increased chance for exceptional longevity of a subject, conditional on his family history of longevity. The network includes familial longevity from three generations and can be used to understand the effects of paternal and maternal longevity on an individual's chance to live to an extreme age. PMID:27041978

  5. Familial Risk for Exceptional Longevity.

    PubMed

    Sebastiani, Paola; Andersen, Stacy L; McIntosh, Avery I; Nussbaum, Lisa; Stevenson, Meredith D; Pierce, Leslie; Xia, Samantha; Salance, Kelly; Perls, Thomas T

    2016-01-01

    One of the most glaring deficiencies in the current assessment of mortality risk is the lack of information concerning the impact of familial longevity. In this work, we update estimates of sibling relative risk of living to extreme ages using data from more than 1,700 sibships, and we begin to examine the trend for heritability for different birth-year cohorts. We also build a network model that can be used to compute the increased chance for exceptional longevity of a subject, conditional on his family history of longevity. The network includes familial longevity from three generations and can be used to understand the effects of paternal and maternal longevity on an individual's chance to live to an extreme age.

  6. Metformin, the aspirin of the 21st century: its role in gestational diabetes mellitus, prevention of preeclampsia and cancer, and the promotion of longevity.

    PubMed

    Romero, Roberto; Erez, Offer; Hüttemann, Maik; Maymon, Eli; Panaitescu, Bogdan; Conde-Agudelo, Agustin; Pacora, Percy; Yoon, Bo Hyun; Grossman, Lawrence I

    2017-09-01

    Metformin is everywhere. Originally introduced in clinical practice as an antidiabetic agent, its role as a therapeutic agent is expanding to include treatment of prediabetes mellitus, gestational diabetes mellitus, and polycystic ovarian disease; more recently, experimental studies and observations in randomized clinical trials suggest that metformin could have a place in the treatment or prevention of preeclampsia. This article provides a brief overview of the history of metformin in the treatment of diabetes mellitus and reviews the results of metaanalyses of metformin in gestational diabetes mellitus as well as the treatment of obese, non-diabetic, pregnant women to prevent macrosomia. We highlight the results of a randomized clinical trial in which metformin administration in early pregnancy did not reduce the frequency of large-for-gestational-age infants (the primary endpoint) but did decrease the frequency of preeclampsia (a secondary endpoint). The mechanisms by which metformin may prevent preeclampsia include a reduction in the production of antiangiogenic factors (soluble vascular endothelial growth factor receptor-1 and soluble endoglin) and the improvement of endothelial dysfunction, probably through an effect on the mitochondria. Another potential mechanism whereby metformin may play a role in the prevention of preeclampsia is its ability to modify cellular homeostasis and energy disposition, mediated by rapamycin, a mechanistic target. Metformin has a molecular weight of 129 Daltons and therefore readily crosses the placenta. There is considerable evidence to suggest that this agent is safe during pregnancy. New literature on the role of metformin as a chemotherapeutic adjuvant in the prevention of cancer and in prolonging life and protecting against aging is reviewed briefly. Herein, we discuss the mechanisms of action and potential benefits of metformin. Published by Elsevier Inc.

  7. Gain-of-Function Mutants of the Cytokinin Receptors AHK2 and AHK3 Regulate Plant Organ Size, Flowering Time and Plant Longevity.

    PubMed

    Bartrina, Isabel; Jensen, Helen; Novák, Ondřej; Strnad, Miroslav; Werner, Tomáš; Schmülling, Thomas

    2017-03-01

    The phytohormone cytokinin is a regulator of numerous processes in plants. In Arabidopsis (Arabidopsis thaliana), the cytokinin signal is perceived by three membrane-located receptors named ARABIDOPSIS HISTIDINE KINASE2 (AHK2), AHK3, and AHK4/CRE1. How the signal is transmitted across the membrane is an entirely unknown process. The three receptors have been shown to operate mostly in a redundant fashion, and very few specific roles have been attributed to single receptors. Using a forward genetic approach, we isolated constitutively active gain-of-function variants of the AHK2 and AHK3 genes, named repressor of cytokinin deficiency2 (rock2) and rock3, respectively. It is hypothesized that the structural changes caused by these mutations in the sensory and adjacent transmembrane domains emulate the structural changes caused by cytokinin binding, resulting in domain motion propagating the signal across the membrane. Detailed analysis of lines carrying rock2 and rock3 alleles revealed how plants respond to locally enhanced cytokinin signaling. Early flowering time, a prolonged reproductive growth phase, and, thereby, increased seed yield suggest that cytokinin regulates various aspects of reproductive growth. In particular, it counteracts the global proliferative arrest, a correlative inhibition of maternal growth by seeds, an as yet unknown activity of the hormone.

  8. P2Y2 receptor promotes cell invasion and metastasis in prostate cancer cells

    PubMed Central

    Li, W-H; Qiu, Y; Zhang, H-Q; Liu, Y; You, J-F; Tian, X-X; Fang, W-G

    2013-01-01

    Background: Our previous study demonstrated that extracellular adenosine 5′-triphosphate (ATP) stimulated prostate cancer cell invasion via P2Y receptors. However, the purinergic receptor subtype(s) involved in this process remains unclear. Here we aimed to determine whether P2Y2, one subtype of P2Y receptors, was involved in the invasion and metastasis of prostate cancer cells, and elucidated the underlying mechanism. Methods: RNAi was introduced to silence the expression of P2Y2. In vitro invasion and migration assays and in vivo experiments were carried out to examine the role of P2Y2 receptor in cell invasion and metastasis. cDNA microarray was performed to identify the differentially expressed genes downstream of ATP treatment. Results: P2Y2 was significantly expressed in the prostate cancer cells. Knockdown of P2Y2 receptor suppressed cell invasion and metastasis in vitro and in vivo. Further experiments identified that ATP could promote IL-8 and Snail expression and inhibit E-cadherin and Claudin-1 expression. Knockdown of P2Y2 receptor affected the expression of these EMT/invasion-related genes in vitro and in vivo. Conclusion: P2Y2 receptor promotes cell invasion and metastasis in prostate cancer cells via some EMT/invasion-related genes. Thereby, P2Y2 receptor could be a potential therapeutic target for the treatment of prostate cancer. PMID:23969730

  9. P2Y2 receptor promotes cell invasion and metastasis in prostate cancer cells.

    PubMed

    Li, W-H; Qiu, Y; Zhang, H-Q; Liu, Y; You, J-F; Tian, X-X; Fang, W-G

    2013-09-17

    Our previous study demonstrated that extracellular adenosine 5'-triphosphate (ATP) stimulated prostate cancer cell invasion via P2Y receptors. However, the purinergic receptor subtype(s) involved in this process remains unclear. Here we aimed to determine whether P2Y2, one subtype of P2Y receptors, was involved in the invasion and metastasis of prostate cancer cells, and elucidated the underlying mechanism. RNAi was introduced to silence the expression of P2Y2. In vitro invasion and migration assays and in vivo experiments were carried out to examine the role of P2Y2 receptor in cell invasion and metastasis. cDNA microarray was performed to identify the differentially expressed genes downstream of ATP treatment. P2Y2 was significantly expressed in the prostate cancer cells. Knockdown of P2Y2 receptor suppressed cell invasion and metastasis in vitro and in vivo. Further experiments identified that ATP could promote IL-8 and Snail expression and inhibit E-cadherin and Claudin-1 expression. Knockdown of P2Y2 receptor affected the expression of these EMT/invasion-related genes in vitro and in vivo. P2Y2 receptor promotes cell invasion and metastasis in prostate cancer cells via some EMT/invasion-related genes. Thereby, P2Y2 receptor could be a potential therapeutic target for the treatment of prostate cancer.

  10. Age-related changes in the proteostasis network in the brain of the naked mole-rat: Implications promoting healthy longevity.

    PubMed

    Triplett, Judy C; Tramutola, Antonella; Swomley, Aaron; Kirk, Jessime; Grimes, Kelly; Lewis, Kaitilyn; Orr, Miranda; Rodriguez, Karl; Cai, Jian; Klein, Jon B; Perluigi, Marzia; Buffenstein, Rochelle; Butterfield, D Allan

    2015-10-01

    The naked mole-rat (NMR) is the longest-lived rodent and possesses several exceptional traits: marked cancer resistance, negligible senescence, prolonged genomic integrity, pronounced proteostasis, and a sustained health span. The underlying molecular mechanisms that contribute to these extraordinary attributes are currently under investigation to gain insights that may conceivably promote and extend human health span and lifespan. The ubiquitin-proteasome and autophagy-lysosomal systems play a vital role in eliminating cellular detritus to maintain proteostasis and have been previously shown to be more robust in NMRs when compared with shorter-lived rodents. Using a 2-D PAGE proteomics approach, differential expression and phosphorylation levels of proteins involved in proteostasis networks were evaluated in the brains of NMRs in an age-dependent manner. We identified 9 proteins with significantly altered levels and/or phosphorylation states that have key roles involved in proteostasis networks. To further investigate the possible role that autophagy may play in maintaining cellular proteostasis, we examined aspects of the PI3K/Akt/mammalian target of rapamycin (mTOR) axis as well as levels of Beclin-1, LC3-I, and LC3-II in the brain of the NMR as a function of age. Together, these results show that NMRs maintain high levels of autophagy throughout the majority of their lifespan and may contribute to the extraordinary health span of these rodents. The potential of augmenting human health span via activating the proteostasis network will require further studies.

  11. Age-related Changes in the Proteostasis Network in the Brain of the Naked Mole-Rat: Implications Promoting Healthy Longevity

    PubMed Central

    Triplett, Judy C.; Tramutola, Antonella; Swomley, Aaron; Kirk, Jessime; Grimes, Kelly; Lewis, Kaitilyn; Orr, Miranda; Rodriguez, Karl; Cai, Jian; Klein, Jon B.; Perluigi, Marzia; Buffenstein, Rochelle; Butterfield, D. Allan

    2016-01-01

    The naked mole-rat (NMR) is the longest-lived rodent and possesses several exceptional traits: marked cancer resistance, negligible senescence, prolonged genomic integrity, pronounced proteostasis, and a sustained healthspan. The underlying molecular mechanisms that contribute to these extraordinary attributes are currently under investigation to gain insights that may conceivably promote and extended human healthspan and lifespan. The ubiquitin-proteasome and autophagy-lysosomal systems play a vital role in eliminating cellular detritus to maintain proteostasis and have been previously shown to be more robust in NMRs when compared to shorter-lived rodents. Using a 2-D PAGE proteomics approach, differential expression and phosphorylation levels of proteins involved in proteostasis networks were evaluated in the brains of NMRs in an age-dependent manner. We identified 9 proteins with significantly altered levels and/or phosphorylation states that have key roles involved in proteostasis networks. To further investigate the possible role that autophagy may play in maintaining cellular proteostasis, we examined aspects of the PI3K/Akt/mammalian target of rapamycin (mTOR) axis as well as levels of Beclin-1, LC3-I, and LC3-II in the brain of the NMR as a function of age. Together, these results show that NMRs maintain high levels of autophagy throughout the majority of their lifespan. PMID:26248058

  12. The Mouse Solitary Odorant Receptor Gene Promoters as Models for the Study of Odorant Receptor Gene Choice

    PubMed Central

    Degl'Innocenti, Andrea

    2016-01-01

    Background In vertebrates, several anatomical regions located within the nasal cavity mediate olfaction. Among these, the main olfactory epithelium detects most conventional odorants. Olfactory sensory neurons, provided with cilia exposed to the air, detect volatile chemicals via an extremely large family of seven-transmembrane chemoreceptors named odorant receptors. Their genes are expressed in a monogenic and monoallelic fashion: a single allele of a single odorant receptor gene is transcribed in a given mature neuron, through a still uncharacterized molecular mechanism known as odorant receptor gene choice. Aim Odorant receptor genes are typically arranged in genomic clusters, but a few are isolated (we call them solitary) from the others within a region broader than 1 Mb upstream and downstream with respect to their transcript's coordinates. The study of clustered genes is problematic, because of redundancy and ambiguities in their regulatory elements: we propose to use the solitary genes as simplified models to understand odorant receptor gene choice. Procedures Here we define number and identity of the solitary genes in the mouse genome (C57BL/6J), and assess the conservation of the solitary status in some mammalian orthologs. Furthermore, we locate their putative promoters, predict their homeodomain binding sites (commonly present in the promoters of odorant receptor genes) and compare candidate promoter sequences with those of wild-caught mice. We also provide expression data from histological sections. Results In the mouse genome there are eight intact solitary genes: Olfr19 (M12), Olfr49, Olfr266, Olfr267, Olfr370, Olfr371, Olfr466, Olfr1402; five are conserved as solitary in rat. These genes are all expressed in the main olfactory epithelium of three-day-old mice. The C57BL/6J candidate promoter of Olfr370 has considerably varied compared to its wild-type counterpart. Within the putative promoter for Olfr266 a homeodomain binding site is predicted. As a

  13. Jewish denominations and longevity.

    PubMed

    Abel, Ernest L; Kruger, Michael L

    2012-01-01

    This study examined the relationship between affiliation with one of three denominations within Judaism representing a conservative-liberal continuum of Orthodox, Conservative, and Reform Judaism. The criterion for affiliation was burial in a cemetery maintained by these denominations. Longevities of married congregants born 1850-1910 were compared, controlling for birth year. Orthodox Jews had the shortest life spans (77 years); Conservative and Reform Jews had very similar life spans (80.7 years). Differences in years of survival of husbands after death of a spouse did not differ significantly. Reform widows survived longest (16.5 years) after death of a spouse. Conservative and Reform widows did not differ significantly from one another.

  14. Metabolism, longevity and epigenetics.

    PubMed

    Cosentino, Claudia; Mostoslavsky, Raul

    2013-05-01

    Metabolic homeostasis and interventions that influence nutrient uptake are well-established means to influence lifespan even in higher eukaryotes. Until recently, the molecular mechanisms explaining such an effect remained scantily understood. Sirtuins are a group of protein deacetylases that depend on the metabolic intermediate NAD(+) as a cofactor for their function. For this reason they sense metabolic stress and in turn function at multiple levels to exert proper metabolic adaptation. Among other things, sirtuins can perform as histone deacetylases inducing epigenetic changes to modulate transcription and DNA repair. Recent studies have indicated that beyond sirtuins, the activity of other chromatin modifiers, such as histone acetyl transferases, might also be tightly linked to the availability of their intermediate metabolite acetyl-CoA. We summarize current knowledge of the emerging concepts indicating close crosstalk between the epigenetic machineries able to sense metabolic stress, their adaptive metabolic responses and their potential role in longevity.

  15. Intestinal farnesoid X receptor signaling promotes nonalcoholic fatty liver disease.

    PubMed

    Jiang, Changtao; Xie, Cen; Li, Fei; Zhang, Limin; Nichols, Robert G; Krausz, Kristopher W; Cai, Jingwei; Qi, Yunpeng; Fang, Zhong-Ze; Takahashi, Shogo; Tanaka, Naoki; Desai, Dhimant; Amin, Shantu G; Albert, Istvan; Patterson, Andrew D; Gonzalez, Frank J

    2015-01-01

    Nonalcoholic fatty liver disease (NAFLD) is a major worldwide health problem. Recent studies suggest that the gut microbiota influences NAFLD pathogenesis. Here, a murine model of high-fat diet-induced (HFD-induced) NAFLD was used, and the effects of alterations in the gut microbiota on NAFLD were determined. Mice treated with antibiotics or tempol exhibited altered bile acid composition, with a notable increase in conjugated bile acid metabolites that inhibited intestinal farnesoid X receptor (FXR) signaling. Compared with control mice, animals with intestine-specific Fxr disruption had reduced hepatic triglyceride accumulation in response to a HFD. The decrease in hepatic triglyceride accumulation was mainly due to fewer circulating ceramides, which was in part the result of lower expression of ceramide synthesis genes. The reduction of ceramide levels in the ileum and serum in tempol- or antibiotic-treated mice fed a HFD resulted in downregulation of hepatic SREBP1C and decreased de novo lipogenesis. Administration of C16:0 ceramide to antibiotic-treated mice fed a HFD reversed hepatic steatosis. These studies demonstrate that inhibition of an intestinal FXR/ceramide axis mediates gut microbiota-associated NAFLD development, linking the microbiome, nuclear receptor signaling, and NAFLD. This work suggests that inhibition of intestinal FXR is a potential therapeutic target for NAFLD treatment.

  16. Hypoxia Selectively Enhances Integrin Receptor Expression to Promote Metastasis.

    PubMed

    Ju, Julia A; Godet, Ines; Ye, I Chae; Byun, Jungmin; Jayatilaka, Hasini; Lee, Sun Joo; Xiang, Lisha; Samanta, Debangshu; Lee, Meng Horng; Wu, Pei-Hsun; Wirtz, Denis; Semenza, Gregg L; Gilkes, Daniele M

    2017-02-17

    Metastasis is the leading cause of breast cancer (BCa)mortality. Previous studies have implicated hypoxia-induced changes in the composition and stiffness of the extracellular matrix (ECM) in the metastatic process. Therefore, the contribution of potential ECM binding receptors in this process was explored. Using a bioinformatics approach the expression of all integrin receptor subunits, in two independent BCa patient data sets, were analyzed to determine if integrin status correlates with a validated hypoxiainducible gene signature. Subsequently, a large panel of breast cancer cell lines were used to validate that hypoxia induces the expression of integrin's that bind to collagen (ITGA1, ITGA11, ITGB1) and fibronectin (ITGA5, ITGB1). Hypoxia-inducible factors (HIF-1 and HIF-2) are directly required for ITGA5 induction under hypoxic conditions, which leads to enhanced migration and invasion of single cells within a multicellular 3D tumor spheroid but did not affect migration in a 2D microenvironment. ITGB1 expression requires HIF-1alpha, but not HIF-2alpha, for hypoxic induction in breast cancer cells. ITGA5 (alpha5 subunit) is required for metastasis to lymph nodes and lungs in breast cancer models and high ITGA5 expression in clinical biopsies is associated with an increased risk of mortality.

  17. Impaired wake-promoting mechanisms in ghrelin receptor-deficient mice.

    PubMed

    Esposito, Matthew; Pellinen, Jacob; Kapás, Levente; Szentirmai, Éva

    2012-01-01

    Ghrelin receptors are expressed by key components of the arousal system. Exogenous ghrelin induces behavioral activation, promotes wakefulness and stimulates eating. We hypothesized that ghrelin-sensitive mechanisms play a role in the arousal system. To test this, we investigated the responsiveness of ghrelin receptor knockout (KO) mice to two natural wake-promoting stimuli. Additionally, we assessed the integrity of their homeostatic sleep-promoting system using sleep deprivation. There was no significant difference in the spontaneous sleep-wake activity between ghrelin receptor KO and wild-type (WT) mice. WT mice mounted robust arousal responses to a novel environment and food deprivation. Wakefulness increased for 6 h after cage change accompanied by increases in body temperature and locomotor activity. Ghrelin receptor KO mice completely lacked the wake and body temperature responses to new environment. When subjected to 48 h food deprivation, WT mice showed marked increases in their waking time during the dark periods of both days. Ghrelin receptor KO mice failed to mount an arousal response on the first night and wake increases were attenuated on the second day. The responsiveness to sleep deprivation did not differ between the two genotypes. These results indicate that the ghrelin-receptive mechanisms play an essential role in the function of the arousal system but not in homeostatic sleep-promoting mechanisms. © 2011 The Authors. European Journal of Neuroscience © 2011 Federation of European Neuroscience Societies and Blackwell Publishing Ltd.

  18. Activation of Dopamine Receptors in the Nucleus Accumbens Promotes Sucrose-Reinforced Cued Approach Behavior.

    PubMed

    du Hoffmann, Johann; Nicola, Saleem M

    2016-01-01

    Dopamine receptor activation in the nucleus accumbens (NAc) promotes vigorous environmentally-cued food-seeking in hungry rats. Rats fed ad libitum, however, respond to fewer food-predictive cues, particularly when the value of food reward is low. Here, we investigated whether this difference could be due to differences in the degree of dopamine receptor activation in the NAc. First, we observed that although rats given ad libitum access to chow in their home cages approached a food receptacle in response to reward-predictive cues, the number of such approaches declined as animals accumulated food rewards. Intriguingly, cued approach to food occurred in clusters, with several cued responses followed by successive non-responses. This pattern suggested that behavior was dictated by transitions between two states, responsive and non-responsive. Injection of D1 or D2 dopamine receptor agonists into the NAc dose-dependently increased cue responding by promoting transitions to the responsive state and by preventing transitions to the non-responsive state. In contrast, antagonists of either D1 or D2 receptors promoted long bouts of non-responding by inducing transitions to the non-responsive state and by preventing transitions to the responsive state. Moreover, locomotor behavior during the inter-trial interval was correlated with the responsive state, and was also increased by dopamine receptor agonists. These results suggest that activation of NAc dopamine receptors plays an important role in regulating the probability of approach to food under conditions of normative satiety.

  19. Activation of Dopamine Receptors in the Nucleus Accumbens Promotes Sucrose-Reinforced Cued Approach Behavior

    PubMed Central

    du Hoffmann, Johann; Nicola, Saleem M.

    2016-01-01

    Dopamine receptor activation in the nucleus accumbens (NAc) promotes vigorous environmentally-cued food-seeking in hungry rats. Rats fed ad libitum, however, respond to fewer food-predictive cues, particularly when the value of food reward is low. Here, we investigated whether this difference could be due to differences in the degree of dopamine receptor activation in the NAc. First, we observed that although rats given ad libitum access to chow in their home cages approached a food receptacle in response to reward-predictive cues, the number of such approaches declined as animals accumulated food rewards. Intriguingly, cued approach to food occurred in clusters, with several cued responses followed by successive non-responses. This pattern suggested that behavior was dictated by transitions between two states, responsive and non-responsive. Injection of D1 or D2 dopamine receptor agonists into the NAc dose-dependently increased cue responding by promoting transitions to the responsive state and by preventing transitions to the non-responsive state. In contrast, antagonists of either D1 or D2 receptors promoted long bouts of non-responding by inducing transitions to the non-responsive state and by preventing transitions to the responsive state. Moreover, locomotor behavior during the inter-trial interval was correlated with the responsive state, and was also increased by dopamine receptor agonists. These results suggest that activation of NAc dopamine receptors plays an important role in regulating the probability of approach to food under conditions of normative satiety. PMID:27471453

  20. The Nogo-B receptor promotes Ras plasma membrane localization and activation.

    PubMed

    Zhao, B; Hu, W; Kumar, S; Gonyo, P; Rana, U; Liu, Z; Wang, B; Duong, W Q; Yang, Z; Williams, C L; Miao, Q R

    2017-06-15

    The localization of prenylated Ras at the plasma membrane promotes activation of Ras by receptor tyrosine kinases and stimulates oncogenic signaling by mutant Ras. The Nogo-B receptor (NgBR) is a transmembrane receptor that contains a conserved hydrophobic pocket. Here, we demonstrate that the NgBR promotes the membrane accumulation of Ras by directly binding prenylated Ras at the plasma membrane. We show that NgBR knockdown diminishes the membrane localization of Ras in multiple cell types. NgBR overexpression in NIH-3T3 fibroblasts increases membrane-associated Ras, induces the transformed phenotype in vitro, and promotes the formation of fibrosarcoma in nude mice. NgBR knockdown in human breast cancer cells reduces Ras membrane localization, inhibits epidermal growth factor (EGF)-stimulated Ras signaling and diminishes tumorigenesis of xenografts in nude mice. Our data demonstrate that NgBR is a unique receptor that promotes accumulation of prenylated Ras at the plasma membrane and promotes EGF pathways.

  1. A comparative cellular and molecular biology of longevity database.

    PubMed

    Stuart, Jeffrey A; Liang, Ping; Luo, Xuemei; Page, Melissa M; Gallagher, Emily J; Christoff, Casey A; Robb, Ellen L

    2013-10-01

    Discovering key cellular and molecular traits that promote longevity is a major goal of aging and longevity research. One experimental strategy is to determine which traits have been selected during the evolution of longevity in naturally long-lived animal species. This comparative approach has been applied to lifespan research for nearly four decades, yielding hundreds of datasets describing aspects of cell and molecular biology hypothesized to relate to animal longevity. Here, we introduce a Comparative Cellular and Molecular Biology of Longevity Database, available at ( http://genomics.brocku.ca/ccmbl/ ), as a compendium of comparative cell and molecular data presented in the context of longevity. This open access database will facilitate the meta-analysis of amalgamated datasets using standardized maximum lifespan (MLSP) data (from AnAge). The first edition contains over 800 data records describing experimental measurements of cellular stress resistance, reactive oxygen species metabolism, membrane composition, protein homeostasis, and genome homeostasis as they relate to vertebrate species MLSP. The purpose of this review is to introduce the database and briefly demonstrate its use in the meta-analysis of combined datasets.

  2. Altered Death Receptor Signaling Promotes Epithelial-to-Mesenchymal Transition and Acquired Chemoresistance

    PubMed Central

    Antoon, James W.; Lai, Rongye; Struckhoff, Amanda P.; Nitschke, Ashley M.; Elliott, Steven; Martin, Elizabeth C.; Rhodes, Lyndsay V.; Yoon, Nam Seung; Salvo, Virgilio A.; Shan, Bin; Beckman, Barbara S.; Nephew, Kenneth P.; Burow, Matthew E.

    2012-01-01

    Altered death receptor signaling and resistance to subsequent apoptosis is an important clinical resistance mechanism. Here, we investigated the role of death receptor resistance in breast cancer progression. Resistance of the estrogen receptor alpha (ER)-positive, chemosensitive MCF7 breast cancer cell line to tumor necrosis factor (TNF) was associated with loss of ER expression and a multi-drug resistant phenotype. Changes in three major pathways were involved in this transition to a multidrug resistance phenotype: ER, Death Receptor and epithelial to mesenchymal transition (EMT). Resistant cells exhibited altered ER signaling, resulting in decreased ER target gene expression. The death receptor pathway was significantly altered, blocking extrinsic apoptosis and increasing NF-kappaB survival signaling. TNF resistance promoted EMT changes, resulting in a more aggressive phenotype. This first report identifying specific mechanisms underlying acquired resistance to TNF could lead to a better understanding of the progression of breast cancer in response to chemotherapy treatment. PMID:22844580

  3. Activation of GLP-1 Receptor Promotes Bone Marrow Stromal Cell Osteogenic Differentiation through β-Catenin.

    PubMed

    Meng, Jingru; Ma, Xue; Wang, Ning; Jia, Min; Bi, Long; Wang, Yunying; Li, Mingkai; Zhang, Huinan; Xue, Xiaoyan; Hou, Zheng; Zhou, Ying; Yu, Zhibin; He, Gonghao; Luo, Xiaoxing

    2016-04-12

    Glucagon-like peptide 1 (GLP-1) plays an important role in regulating bone remodeling, and GLP-1 receptor agonist shows a positive relationship with osteoblast activity. However, GLP-1 receptor is not found in osteoblast, and the mechanism of GLP-1 receptor agonist on regulating bone remodeling is unclear. Here, we show that the GLP-1 receptor agonist exendin-4 (Ex-4) promoted bone formation and increased bone mass and quality in a rat unloading-induced bone loss model. These functions were accompanied by an increase in osteoblast number and serum bone formation markers, while the adipocyte number was decreased. Furthermore, GLP-1 receptor was detected in bone marrow stromal cells (BMSCs), but not in osteoblast. Activation of GLP-1 receptor by Ex-4 promoted the osteogenic differentiation and inhibited BMSC adipogenic differentiation through regulating PKA/β-catenin and PKA/PI3K/AKT/GSK3β signaling. These findings reveal that GLP-1 receptor regulates BMSC osteogenic differentiation and provide a molecular basis for therapeutic potential of GLP-1 against osteoporosis.

  4. Activation of GLP-1 Receptor Promotes Bone Marrow Stromal Cell Osteogenic Differentiation through β-Catenin

    PubMed Central

    Meng, Jingru; Ma, Xue; Wang, Ning; Jia, Min; Bi, Long; Wang, Yunying; Li, Mingkai; Zhang, Huinan; Xue, Xiaoyan; Hou, Zheng; Zhou, Ying; Yu, Zhibin; He, Gonghao; Luo, Xiaoxing

    2016-01-01

    Summary Glucagon-like peptide 1 (GLP-1) plays an important role in regulating bone remodeling, and GLP-1 receptor agonist shows a positive relationship with osteoblast activity. However, GLP-1 receptor is not found in osteoblast, and the mechanism of GLP-1 receptor agonist on regulating bone remodeling is unclear. Here, we show that the GLP-1 receptor agonist exendin-4 (Ex-4) promoted bone formation and increased bone mass and quality in a rat unloading-induced bone loss model. These functions were accompanied by an increase in osteoblast number and serum bone formation markers, while the adipocyte number was decreased. Furthermore, GLP-1 receptor was detected in bone marrow stromal cells (BMSCs), but not in osteoblast. Activation of GLP-1 receptor by Ex-4 promoted the osteogenic differentiation and inhibited BMSC adipogenic differentiation through regulating PKA/β-catenin and PKA/PI3K/AKT/GSK3β signaling. These findings reveal that GLP-1 receptor regulates BMSC osteogenic differentiation and provide a molecular basis for therapeutic potential of GLP-1 against osteoporosis. PMID:26947974

  5. Tumor-promoting effects of cannabinoid receptor type 1 in human melanoma cells.

    PubMed

    Carpi, Sara; Fogli, Stefano; Polini, Beatrice; Montagnani, Valentina; Podestà, Adriano; Breschi, Maria Cristina; Romanini, Antonella; Stecca, Barbara; Nieri, Paola

    2017-04-01

    The role of endocannabinoid system in melanoma development and progression is actually not fully understood. This study was aimed at clarifying whether cannabinoid-type 1 (CB1) receptor may function as tumor-promoting or -suppressing signal in human cutaneous melanoma. CB1 receptor expression was measured in human melanoma cell lines by real-time PCR. A genetic deletion of CB1 receptors in selected melanoma cells was carried out by using three different short hairpin RNAs (shRNAs). Performance of target gene silencing was verified by real-time PCR and Western blot. The effects of CB1 receptor silencing on cell growth, clonogenicity, migration capability, cell cycle progression, and activation of mitogenic signals was tested. Lentiviral shRNAs vectors targeting different regions of the human CB1 gene led to a significant reduction in CB1 receptor mRNA and a near complete loss of CB1 receptor protein, compared to control vector (LV-c). The number of viable cells, the colony-forming ability and cell migration were significantly reduced in cells transduced with CB1 lentiviral shRNAs compared to LV-c. Cell cycle analyses showed arrest at G1/S phase. p-Akt and p-ERK expression were decreased in transduced versus control cells. Findings of this study suggest that CB1 receptor might function as tumor-promoting signal in human cutaneous melanoma. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Identification of constitutive androstane receptor and glucocorticoid receptor binding sites in the CYP2C19 promoter.

    PubMed

    Chen, Yuping; Ferguson, Stephen S; Negishi, Masahiko; Goldstein, Joyce A

    2003-08-01

    CYP2C19 is an important human drug-metabolizing enzyme that metabolizes a number of clinically used drugs including the antiulcer drug omeprazole, the anxiolytic drug diazepam, the beta-blocker propranolol, the antimalarial drug proguanil, certain antidepressants and barbiturates, and the prototype substrate S-mephenytoin. Previous studies show that compounds such as rifampicin and dexamethasone induce CYP2C19 both in vivo in humans and in vitro in human hepatocytes. This study examines the transcriptional regulation of CYP2C19. Analysis of the CYP2C19 promoter revealed a single constitutive androstane receptor (CAR) binding site (CAR-RE; -1891/-1876 bp) and a glucocorticoid-responsive element (GRE; -1750/-1736 bp). Gel-shift assays showed that CAR-RE binds CAR and pregnane X receptor (PXR). Cotransfection with hCAR, mCAR, or hPXR in HepG2 cells up-regulated transcription of CYP2C19 promoter constructs, whereas mutation of the -1891-bp CAR-RE abolished up-regulation. Expression with hCAR also up-regulated endogenous CYP2C19 mRNA content in HepG2 cells. Androstenol repressed the mCAR-mediated constitutive activation of the CYP2C19 promoter in HepG2 cells, whereas the potent mCAR ligand 1,4-bis[2-3,5-dichloropyridyloxyl)] benzene derepressed this response. Rifampicin produced a modest increase in promoter activity in cells cotransfected with hPXR. Dexamethasone activated the -2.7-kb CYP2C19 promoter constructs in HepG2 cells only in the presence of cotransfected glucocorticoid receptor (GR), whereas the GR antagonist mifepristone inhibits this response. Mutation of the GRE abolishes dexamethasone activation. This is the first study to identify nuclear receptor binding sites (CAR/PXR and GR) in the CYP2C19 promoter and to suggest that these receptors may up-regulate CYP2C19 constitutively and possibly its response to drugs.

  7. Hormone replacement therapy and longevity.

    PubMed

    Comhaire, F

    2016-02-01

    To assess whether hormone replacement therapy influences longevity, an analysis was made of published life tables allowing for the calculation of the relative benefit of hormone replacement therapy on longevity in men with late onset hypogonadism and in post-menopausal women. It was found that testosterone replacement therapy of men suffering from late onset hypogonadism increased survival rate by 9-10% in 5 years, similar to that of eugonadal, non-LOH men with normal endogenous testosterone secretion. Oestrogen replacement therapy resulted in increased survival by 2.6% in 5 years. It is concluded that hormone replacement therapy increases longevity.

  8. EPO-independent functional EPO receptor in breast cancer enhances estrogen receptor activity and promotes cell proliferation.

    PubMed

    Reinbothe, Susann; Larsson, Anna-Maria; Vaapil, Marica; Wigerup, Caroline; Sun, Jianmin; Jögi, Annika; Neumann, Drorit; Rönnstrand, Lars; Påhlman, Sven

    2014-02-28

    The main function of Erythropoietin (EPO) and its receptor (EPOR) is the stimulation of erythropoiesis. Recombinant human EPO (rhEPO) is therefore used to treat anemia in cancer patients. However, clinical trials have indicated that rhEPO treatment might promote tumor progression and has a negative effect on patient survival. In addition, EPOR expression has been detected in several cancer forms. Using a newly produced anti-EPOR antibody that reliably detects the full-length isoform of the EPOR we show that breast cancer tissue and cells express the EPOR protein. rhEPO stimulation of cultured EPOR expressing breast cancer cells did not result in increased proliferation, overt activation of EPOR (receptor phosphorylation) or a consistent activation of canonical EPOR signaling pathway mediators such as JAK2, STAT3, STAT5, or AKT. However, EPOR knockdown experiments suggested functional EPO receptors in estrogen receptor positive (ERα(+)) breast cancer cells, as reduced EPOR expression resulted in decreased proliferation. This effect on proliferation was not seen in ERα negative cells. EPOR knockdown decreased ERα activity further supports a mechanism by which EPOR affects proliferation via ERα-mediated mechanisms. We show that EPOR protein is expressed in breast cancer cells, where it appears to promote proliferation by an EPO-independent mechanism in ERα expressing breast cancer cells. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

  9. Functional receptor coupling to Gi is a mechanism of agonist-promoted desensitization of the beta2-adrenergic receptor.

    PubMed

    Tepe, N M; Liggett, S B

    2000-01-01

    The beta2-adrenergic receptor (beta2AR) couples to Gs activating adenylyl cyclase (AC) and increasing cAMP. Such signaling undergoes desensitization with continued agonist exposure. Beta2AR also couple to Gi after receptor phosphorylation by the cAMP dependent protein kinase A, but the efficiency of such coupling is not known. Given the PKA dependence of beta2AR-Gi coupling, we explored whether this may be a mechanism of agonist-promoted desensitization. HEK293 cells were transfected to express beta2AR or beta2AR and Gialpha2, and then treated with vehicle or the agonist isoproterenol to evoke agonist-promoted beta2AR desensitization. Membrane AC activities showed that Gialpha2 overexpression decreased basal levels, but the fold-stimulation of the AC over basal by agonist was not altered. However, with treatment of the cells with isoproterenol prior to membrane preparation, a marked decrease in agonist-stimulated AC was observed with the cells overexpressing Gialpha2. In the absence of such overexpression, beta2AR desensitization was 23+/-7%, while with 5-fold Gialpha2 overexpression desensitization was 58+/-5% (p<0.01, n=4). The effect of Gi on desensitization was receptor-specific, in that forskolin responses were not altered by G(i)alpha2 overexpression. Thus, acquired beta2AR coupling to Gi is an important mechanism of agonist-promoted desensitization, and pathologic conditions that increase Gi levels contribute to beta2AR dysfunction.

  10. Neurotrophin receptor TrkB promotes lung adenocarcinoma metastasis

    PubMed Central

    Sinkevicius, Kerstin W.; Kriegel, Christina; Bellaria, Kelly J.; Lee, Jaewon; Lau, Allison N.; Leeman, Kristen T.; Zhou, Pengcheng; Beede, Alexander M.; Fillmore, Christine M.; Caswell, Deborah; Barrios, Juliana; Wong, Kwok-Kin; Sholl, Lynette M.; Schlaeger, Thorsten M.; Bronson, Roderick T.; Chirieac, Lucian R.; Winslow, Monte M.; Haigis, Marcia C.; Kim, Carla F.

    2014-01-01

    Lung cancer is notorious for its ability to metastasize, but the pathways regulating lung cancer metastasis are largely unknown. An in vitro system designed to discover factors critical for lung cancer cell migration identified brain-derived neurotrophic factor, which stimulates cell migration through activation of tropomyosin-related kinase B (TrkB; also called NTRK2). Knockdown of TrkB in human lung cancer cell lines significantly decreased their migratory and metastatic ability in vitro and in vivo. In an autochthonous lung adenocarcinoma model driven by activated oncogenic Kras and p53 loss, TrkB deficiency significantly reduced metastasis. Hypoxia-inducible factor-1 directly regulated TrkB expression, and, in turn, TrkB activated Akt signaling in metastatic lung cancer cells. Finally, TrkB expression was correlated with metastasis in patient samples, and TrkB was detected more often in tumors that did not have Kras or epidermal growth factor receptor mutations. These studies demonstrate that TrkB is an important therapeutic target in metastatic lung adenocarcinoma. PMID:24982195

  11. Co-administration of delta- and mu-opioid receptor agonists promotes peripheral opioid receptor function

    PubMed Central

    Schramm, Cicely L.; Honda, Christopher N.

    2010-01-01

    Enhancement of peripheral opioid analgesia following tissue injury or inflammation in animal models is well-documented, but clinical results of peripheral opioid therapy remain inconsistent. Previous studies in the central nervous system have shown that co-administration of μ- and δ-opioid receptor agonists can enhance analgesic outcomes; however, less is known about the functional consequences of opioid receptor interactions in the periphery. The present study examines the effects of intraplantar injection of the μ- and δ-opioid receptor agonists, morphine and deltorphin, alone and in combination on behavioral tests of nociception in naïve rats and on potassium-evoked release of CGRP from sciatic nerves of naïve rats. Neither drug alone affected nociceptive behaviors or CGRP release. Two separate measures of mechanical nociceptive sensitivity remained unchanged after co-administration of the two drugs. In contrast, when deltorphin was co-injected with morphine, dose-dependent and peripherally-restricted increases in paw withdrawal latencies to radiant heat were observed. Similarly, concentration-dependent inhibition of CGRP release was observed when deltorphin and morphine were administered in sequence prior to potassium stimulation. However, no inhibition was observed when morphine was administered prior to deltorphin. All combined opioid effects were blocked by co-application of antagonists. Deltorphin exposure also enhanced the in vivo and in vitro effects of another μ-opioid receptor agonist, DAMGO. Together, these results suggest that under normal conditions, δ-opioid receptor agonists enhance the effect of μ-opioid receptor agonists in the periphery, and local co-administration of δ- and μ-opioid receptor agonists may improve results of peripheral opioid therapy for the treatment of pain. PMID:20970925

  12. Longevity of aeolian megaripples

    NASA Astrophysics Data System (ADS)

    Yizhaq, H.; Katra, I.

    2015-07-01

    Megaripples are distinguished from regular ripples by their larger dimensions and bimodal grain-size distributions. The interplay between wind, grain size and ripple morphology (height and wavelength) controls their development. Two main mechanisms limit megaripple height. The first, megaripple flattening due to winds that are above the fluid threshold of the coarse grains, destroys the armoring layer of the megaripple. The second is megaripple erosion by the impacts of fast-moving, fine saltating grains that propel the coarse grains constituting the armoring layer. For any given wind regime and grain size distribution, the potential megaripple dimensions are limited by these two mechanisms. Here we study the first mechanism and estimate the duration of strong winds (sustained above the fluid threshold) needed to flatten megaripples. Strong gusts of wind, in contrast, cannot destroy the megaripples but can cause ripple migration. Based on data from previous works on megaripples, we find a scaling law between the ripple morphology and the coarse mode of grains at the crest. Using this scaling relation allows us to calculate the wind velocity and duration needed for megaripple flattening. In general, the coarser the particles at the megaripple crest, the stronger the wind needed to flatten the megaripples. Moreover, the greater the strength of the wind required to flatten the megaripples, the lower the recurrence probability. Taken together, these findings increase the longevity of megaripples. We apply the results for a megaripple field in the southern Arava valley (Israel).

  13. Thermosensation and longevity

    PubMed Central

    Xiao, Rui; Liu, Jianfeng; Xu, X.Z. Shawn

    2015-01-01

    Temperature has profound effects on behavior and aging in both poikilotherms and homeotherms. To thrive under the ever fluctuating environmental temperatures, animals have evolved sophisticated mechanisms to sense and adapt to temperature changes. Animals sense temperature through various molecular thermosensors, such as thermosensitive TRP channels expressed in neurons, keratinocytes, and intestine. These evolutionarily conserved thermosensitive TRP channels feature distinct activation thresholds, thereby covering a wide spectrum of ambient temperature. Temperature changes trigger complex thermosensory behaviors. Due to the simplicity of the nervous system in model organisms such as C. elegans and Drosophila, the mechanisms of thermosensory behaviors in these species have been extensively studied at the circuit and molecular levels. While much is known about temperature regulation of behavior, it remains largely unclear how temperature affects aging. Recent studies in C. elegans demonstrate that temperature modulation of longevity is not simply a passive thermodynamic phenomenon as suggested by the rate-of-living theory, but rather a process that is actively regulated by genes, including those encoding thermosensitive TRP channels. In this review, we discuss our current understanding of thermosensation and its role in aging. PMID:26101089

  14. Hypocretin receptor 1 blockade preferentially reduces high effort responding for cocaine without promoting sleep

    PubMed Central

    Brodnik, Zachary D.; Bernstein, David L.; Prince, Courtney D.; España, Rodrigo A.

    2015-01-01

    Recent evidence suggests that blockade of the hypocretin receptor 1 may act as a useful pharmacotherapy for cocaine abuse. Here we investigated the extent to which various doses of a hypocretin receptor 1 antagonist, SB-334867, affect cocaine self-administration at varying doses of cocaine and across a range of effort requirements, and tested if these SB-334867 doses produce sedative effects. First, we trained animals to self-administer one of three doses of cocaine on a progressive ratio schedule, and then tested the effects of three doses of SB-334867. Responding for cocaine was then analyzed to segregate features of relatively high and low effort requirements across the progressive ratio session. In another set of experiments we tested the sleep-promoting effects of the same doses of SB-334867. Our data indicate that blockade of hypocretin receptor 1 preferentially reduces high effort responding for cocaine at levels that do not promote sedation. PMID:26049058

  15. The Proximal J Kappa Germline-Transcript Promoter Facilitates Receptor Editing through Control of Ordered Recombination

    PubMed Central

    Vettermann, Christian; Timblin, Greg A.; Lim, Vivian; Lai, Ernest C.; Schlissel, Mark S.

    2015-01-01

    V(D)J recombination creates antibody light chain diversity by joining a Vκ gene segment with one of four Jκ segments. Two Jκ germline-transcript (GT) promoters control Vκ-Jκ joining, but the mechanisms that govern Jκ choice are unclear. Here, we show in gene-targeted mice that the proximal GT promoter helps targeting rearrangements to Jκ1 by preventing premature DNA breaks at Jκ2. Consequently, cells lacking the proximal GT promoter show a biased utilization of downstream Jκ segments, resulting in a diminished potential for receptor editing. Surprisingly, the proximal—in contrast to the distal—GT promoter is transcriptionally inactive prior to Igκ recombination, indicating that its role in Jκ choice is independent of classical promoter function. Removal of the proximal GT promoter increases H3K4me3 levels at Jκ segments, suggesting that this promoter could act as a suppressor of recombination by limiting chromatin accessibility to RAG. Our findings identify the first cis-element critical for Jκ choice and demonstrate that ordered Igκ recombination facilitates receptor editing. PMID:25559567

  16. Orexin 2 Receptor Antagonism is Sufficient to Promote NREM and REM Sleep from Mouse to Man

    PubMed Central

    Gotter, Anthony L.; Forman, Mark S.; Harrell, Charles M.; Stevens, Joanne; Svetnik, Vladimir; Yee, Ka Lai; Li, Xiaodong; Roecker, Anthony J.; Fox, Steven V.; Tannenbaum, Pamela L.; Garson, Susan L.; Lepeleire, Inge De; Calder, Nicole; Rosen, Laura; Struyk, Arie; Coleman, Paul J.; Herring, W. Joseph; Renger, John J.; Winrow, Christopher J.

    2016-01-01

    Orexin neuropeptides regulate sleep/wake through orexin receptors (OX1R, OX2R); OX2R is the predominant mediator of arousal promotion. The potential for single OX2R antagonism to effectively promote sleep has yet to be demonstrated in humans. MK-1064 is an OX2R-single antagonist. Preclinically, MK-1064 promotes sleep and increases both rapid eye movement (REM) and non-REM (NREM) sleep in rats at OX2R occupancies higher than the range observed for dual orexin receptor antagonists. Similar to dual antagonists, MK-1064 increases NREM and REM sleep in dogs without inducing cataplexy. Two Phase I studies in healthy human subjects evaluated safety, tolerability, pharmacokinetics and sleep-promoting effects of MK-1064, and demonstrated dose-dependent increases in subjective somnolence (via Karolinska Sleepiness Scale and Visual Analogue Scale measures) and sleep (via polysomnography), including increased REM and NREM sleep. Thus, selective OX2R antagonism is sufficient to promote REM and NREM sleep across species, similarly to that seen with dual orexin receptor antagonism. PMID:27256922

  17. Hypermethylated promoter region of DR3, the death receptor 3 gene, in rheumatoid arthritis synovial cells.

    PubMed

    Takami, Nozomi; Osawa, Kayo; Miura, Yasushi; Komai, Koichiro; Taniguchi, Mariko; Shiraishi, Masahiko; Sato, Keizo; Iguchi, Tetsuhiro; Shiozawa, Kazuko; Hashiramoto, Akira; Shiozawa, Shunichi

    2006-03-01

    To examine the promoter activity and protein expression of the death receptor 3 gene DR3, a member of the apoptosis-inducing Fas gene family, with particular reference to the methylation status of its promoter region in rheumatoid arthritis (RA). Genomic DNA was prepared from peripheral blood mononuclear cells obtained from healthy individuals and from patients with RA and synovial cells obtained from patients with RA and osteoarthritis. The methylation status of the DR3 promoter was analyzed by bisulfite genomic sequencing and methylation-specific polymerase chain reaction techniques. Gene promoter activity and protein expression were examined using the luciferase reporter and Western blotting techniques. The promoter region of the DR3 gene contained many CpG motifs, including one CpG island that was specifically hypermethylated in synovial cells from patients with RA. Promoter assays showed that the promoter CpG island was essential for the transactivation of the DR3 gene and that forced hypermethylation of the CpG island with the bacterial methylase Sss I in vitro resulted in inhibition of the DR3 gene expression. Furthermore, the expression of DR-3 protein was down-modulated in association with methylation of the promoter CpG island in RA synovial cells. The CpG island in the DR3 gene promoter was specifically methylated to down-modulate the expression of DR-3 protein in rheumatoid synovial cells, which may provide resistance to apoptosis in RA synovial cells.

  18. Chemokines and chemokine receptors as promoters of prostate cancer growth and progression.

    PubMed

    Salazar, Nicole; Castellan, Miguel; Shirodkar, Samir S; Lokeshwar, Bal L

    2013-01-01

    Prostate cancer (CaP) is estimated to be first in incidence among cancers, with more than 240,000 new cases in 2012 in the United States. Chemokines and their receptors provide survival, proliferation, and invasion characteristics to CaP cells in both primary sites of cancer and metastatic locations. The emerging data demonstrate that many chemokines and their receptors are involved in the multistep process of CaP, leading to metastasis, and, further, that these factors act cooperatively to enhance other mechanisms of tumor cell survival, growth, and metastasis. Changes of chemokine receptor cohorts may be necessary to activate tumor-promoting signals. Chemokine receptors can activate downstream effectors, such as mitogen-activated protein kinases, by complex mechanisms of ligand-dependent activation of cryptic growth factors; guanosine triphosphate-binding, protein-coupled activation of survival kinases; or transactivation of other receptors such as ErbB family members. We describe vanguard research in which more than the classic view of chemokine receptor biology was clarified. Control of chemokines and inhibition of their receptor activation may add critical tools to reduce tumor growth, especially in chemo-hormonal refractory CaP that is both currently incurable and the most aggressive form of the disease, accounting for most of the more than 28,000 annual deaths.

  19. RAGE is a nucleic acid receptor that promotes inflammatory responses to DNA

    PubMed Central

    Sirois, Cherilyn M.; Jin, Tengchuan; Miller, Allison L.; Bertheloot, Damien; Nakamura, Hirotaka; Horvath, Gabor L.; Mian, Abubakar; Jiang, Jiansheng; Schrum, Jacob; Bossaller, Lukas; Pelka, Karin; Garbi, Natalio; Brewah, Yambasu; Tian, Jane; Chang, ChewShun; Chowdhury, Partha S.; Sims, Gary P.; Kolbeck, Roland; Coyle, Anthony J.; Humbles, Alison A.

    2013-01-01

    Recognition of DNA and RNA molecules derived from pathogens or self-antigen is one way the mammalian immune system senses infection and tissue damage. Activation of immune signaling receptors by nucleic acids is controlled by limiting the access of DNA and RNA to intracellular receptors, but the mechanisms by which endosome-resident receptors encounter nucleic acids from the extracellular space are largely undefined. In this study, we show that the receptor for advanced glycation end-products (RAGE) promoted DNA uptake into endosomes and lowered the immune recognition threshold for the activation of Toll-like receptor 9, the principal DNA-recognizing transmembrane signaling receptor. Structural analysis of RAGE–DNA complexes indicated that DNA interacted with dimers of the outermost RAGE extracellular domains, and could induce formation of higher-order receptor complexes. Furthermore, mice deficient in RAGE were unable to mount a typical inflammatory response to DNA in the lung, indicating that RAGE is important for the detection of nucleic acids in vivo. PMID:24081950

  20. Particulate Matter Promotes In Vitro Receptor-Recognizable Low-Density Lipoprotein Oxidation and Dysfunction of Lipid Receptors

    PubMed Central

    Manzano-León, Natalia; Mas-Oliva, Jaime; Sevilla-Tapia, Laura; Morales-Bárcenas, Rocío; Serrano, Jesús; O’Neill, Marie S.; García-Cuellar, Claudia M.; Quintana, Raúl; Vázquez-López, Inés

    2015-01-01

    Particulate matter may promote cardiovascular disease, possibly as a consequence of its oxidative potential. Studies using susceptible animals indicate that particulate matter aggravates atherosclerosis by increasing lipid/macrophage content in plaques. Macrophage lipid uptake requires oxidized low-density lipoprotein and scavenger receptors; same receptors are involved in particulate matter uptake. We studied in vitro particulate matter potential to oxidize low-density lipoproteins and subsequent cell uptake through scavenger receptors. Particulate matter-induced low-density lipoproteins oxidation was evaluated by the thiobarbituric acid assay. Binding/internalization was tested in wild type and scavenger receptor–transfected Chinese hamster ovary cells, and in RAW264.7 cells using fluorescently labeled low-density lipoproteins. Dose-dependent binding/internalization only occurred in scavenger receptor–transfected Chinese hamster ovary cells and RAW264.7 cells. Competition binding/internalization using particles showed that particulate matter induced decreased binding (~50%) and internalization (~70%) of particle-oxidized low-density lipoproteins and native low-density lipoproteins. Results indicate that particulate matter was capable of oxidizing low-density lipoproteins, favoring macrophage internalization, and also altered scavenger and low-density lipoproteins receptor function. PMID:23297186

  1. Bradykinin promotes Toll like receptor-4 expression in human gingival fibroblasts.

    PubMed

    Gutiérrez-Venegas, Gloria; Arreguín-Cano, Juan Antonio; Hernández-Bermúdez, Cristina

    2012-12-01

    Bacterial infections are a potent mechanism for enzymatic generation of kinins such as bradykinin (BK), a universal mediator for inducing inflammatory reaction by associating with the B2 receptor and stimulating liberation of arachidonic acid and synthesis of prostaglandin E2 (PGE2). In this study we evaluate the role of bradykinin in regulating the expression of TLR4 receptor in human gingival fibroblasts. We examine the ability of bradykinin to modulate inflammatory response of human gingival fibroblasts to Gram-negative components and evaluated the role of Toll-like receptors (TLR)-4 in the co-operation between bradykinin and bacterial pathogens. We show that treatment with bradykinin promotes TLR4 receptor expression in human gingival fibroblasts (HGF) and amplifies inflammatory responses to the bacterial components of Gram-negative bacteria. The TLR4 expression induced by bradykinin was blocked with Hoe 140, a B2R antagonist. When HGF cells were incubated with BK resulted of an increased in cyclooxygenase-2 (COX-2) expression and prostaglandin E2 synthesis. Bradykinin and lipopolysaccharide, a specific TLR4 ligand stimulated COX-2 expression. In other series of experiments we found that ERK, phosphatidylinositol-3 kinase, protein kinase C and NFkB are involved in BK promoted-increased in TLR4 expression. The results demonstrate that bradykinin up-regulates the expression of TLR4 and promotes an additive increase in inflammatory responses to lipopolysaccharides.

  2. Perceptions of Longevity and Successful Aging in Very Old Adults

    PubMed Central

    Cherry, Katie E.; Marks, Loren D.; Benedetto, Tim; Sullivan, Marisa C.; Barker, Alyse

    2013-01-01

    We examined perceptions of longevity and successful aging in young-old (60 to 74 years), old-old (75 to 89 years), and oldest-old (90 + years) adults drawn from the Louisiana Healthy Aging Study (LHAS). Participants’ responses to three open-ended questions that assessed their attributions for longevity, what they look forward to, and advice for younger persons today were compared. Content analyses yielded three emergent themes: maintaining physical, mental, and relational well-being; living a healthy life; and living a faithful life. Implications of these findings for current views on successful aging and insights for promoting a long and healthy life are considered. PMID:24353480

  3. EPO-independent functional EPO receptor in breast cancer enhances estrogen receptor activity and promotes cell proliferation

    SciTech Connect

    Reinbothe, Susann; Larsson, Anna-Maria; Vaapil, Marica; Wigerup, Caroline; Sun, Jianmin; Jögi, Annika; Neumann, Drorit; Rönnstrand, Lars; Påhlman, Sven

    2014-02-28

    Highlights: • New anti-human EPOR antibody confirms full-length EPOR expression in breast cancer cells. • Proliferation of breast cancer cells is not affected by rhEPO treatment in vitro. • EPOR knockdown impairs proliferation of ERa positive breast cancer cells. • EPOR knockdown reduces AKT phosphorylation and ERa activity. - Abstract: The main function of Erythropoietin (EPO) and its receptor (EPOR) is the stimulation of erythropoiesis. Recombinant human EPO (rhEPO) is therefore used to treat anemia in cancer patients. However, clinical trials have indicated that rhEPO treatment might promote tumor progression and has a negative effect on patient survival. In addition, EPOR expression has been detected in several cancer forms. Using a newly produced anti-EPOR antibody that reliably detects the full-length isoform of the EPOR we show that breast cancer tissue and cells express the EPOR protein. rhEPO stimulation of cultured EPOR expressing breast cancer cells did not result in increased proliferation, overt activation of EPOR (receptor phosphorylation) or a consistent activation of canonical EPOR signaling pathway mediators such as JAK2, STAT3, STAT5, or AKT. However, EPOR knockdown experiments suggested functional EPO receptors in estrogen receptor positive (ERα{sup +}) breast cancer cells, as reduced EPOR expression resulted in decreased proliferation. This effect on proliferation was not seen in ERα negative cells. EPOR knockdown decreased ERα activity further supports a mechanism by which EPOR affects proliferation via ERα-mediated mechanisms. We show that EPOR protein is expressed in breast cancer cells, where it appears to promote proliferation by an EPO-independent mechanism in ERα expressing breast cancer cells.

  4. The NMDA receptor functions independently and as an LRP1 co-receptor to promote Schwann cell survival and migration

    PubMed Central

    Mantuano, Elisabetta; Lam, Michael S.; Shibayama, Masataka; Campana, W. Marie; Gonias, Steven L.

    2015-01-01

    ABSTRACT NMDA receptors (NMDA-Rs) are ionotropic glutamate receptors, which associate with LDL-receptor-related protein-1 (LRP1) to trigger cell signaling in response to protein ligands in neurons. Here, we demonstrate for the first time that the NMDA-R is expressed by rat Schwann cells and functions independently and with LRP1 to regulate Schwann cell physiology. The NR1 (encoded by GRIN1) and NR2b (encoded by GRIN2B) NMDA-R subunits were expressed by cultured Schwann cells and upregulated in sciatic nerves following crush injury. The ability of LRP1 ligands to activate ERK1/2 (also known as MAPK3 and MAPK1, respectively) and promote Schwann cell migration required the NMDA-R. NR1 gene silencing compromised Schwann cell survival. Injection of the LRP1 ligands tissue-type plasminogen activator (tPA, also known as PLAT) or MMP9-PEX into crush-injured sciatic nerves activated ERK1/2 in Schwann cells in vivo, and the response was blocked by systemic treatment with the NMDA-R inhibitor MK801. tPA was unique among the LRP1 ligands examined because tPA activated cell signaling and promoted Schwann cell migration by interacting with the NMDA-R independently of LRP1, albeit with delayed kinetics. These results define the NMDA-R as a Schwann cell signaling receptor for protein ligands and a major regulator of Schwann cell physiology, which may be particularly important in peripheral nervous system (PNS) injury. PMID:26272917

  5. Characterizing exons 11 and 1 promoters of the mu opioid receptor (Oprm) gene in transgenic mice

    PubMed Central

    Xu, Jin; Xu, Mingming; Pan, Ying-Xian

    2006-01-01

    Background The complexity of the mouse mu opioid receptor (Oprm) gene was demonstrated by the identification of multiple alternatively spliced variants and promoters. Our previous studies have identified a novel promoter, exon 11 (E11) promoter, in the mouse Oprm gene. The E11 promoter is located ~10 kb upstream of the exon 1 (E1) promoter. The E11 promoter controls the expression of nine splice variants in the mouse Oprm gene. Distinguished from the TATA-less E1 promoter, the E11 promoter resembles a typical TATA-containing eukaryote class II promoter. The aim of this study is to further characterize the E11 and E1 promoters in vivo using a transgenic mouse model. Results We constructed a ~20 kb transgenic construct in which a 3.7 kb E11 promoter region and an 8.9 kb E1 promoter region controlled expression of tau/LacZ and tau/GFP reporters, respectively. The construct was used to establish a transgenic mouse line. The expression of the reporter mRNAs, determined by a RT-PCR approach, in the transgenic mice during embryonic development displayed a temporal pattern similar to that of the endogenous promoters. X-gal staining for tau/LacZ reporter and GFP imaging for tau/GFP reporter showed that the transgenic E11 and E1 promoters were widely expressed in various regions of the central nervous system (CNS). The distribution of tau/GFP reporter in the CNS was similar to that of MOR-1-like immunoreactivity using an exon 4-specific antibody. However, differential expression of both promoters was observed in some CNS regions such as the hippocampus and substantia nigra, suggesting that the E11 and E1 promoters were regulated differently in these regions. Conclusion We have generated a transgenic mouse line to study the E11 and E1 promoters in vivo using tau/LacZ and tau/GFP reporters. The reasonable relevance of the transgenic model was demonstrated by the temporal and spatial expression of the transgenes as compared to those of the endogenous transcripts. We believe

  6. Characterization of the angiotensin (AT1b) receptor promoter and its regulation by glucocorticoids

    PubMed Central

    Bogdarina, Irina G; King, Peter J; Clark, Adrian J L

    2009-01-01

    Angiotensin II acts through two pharmacologically distinct receptors known as AT1 and AT2. Duplication of the AT1 receptor in rodents into At1a and b subtypes allows tissue-specific expression of the AT1b in adrenal and pituitary tissue. Adrenal expression of this receptor is increased in the offspring of rat mothers exposed to a low-protein diet and this is associated with the undermethylation of its promoter. This phenomenon is blocked by the inhibition of maternal glucocorticoid synthesis by metyrapone. We have mapped the transcriptional start site of the promoter and demonstrated that a 1·2 kbp fragment upsteam of this site is effective in driving luciferase expression in mouse Y1 cells. A combination of bioinformatic analysis, electrophoretic mobility shift analysis (EMSA), and mutagenesis studies demonstrates: i) the presence of a putative TATA box and CAAT box; ii) the presence of three Sp1 response elements, capable of binding SP1; mutation of any pair of these sites effectively disables this promoter; iii) the presence of four potential glucocorticoid response elements which each bind glucocorticoid receptor in EMSA, although only two confer dexamethasone inhibition on the promoter; iv) the presence of two AP1 sites. Mutagenesis of the distal AP1 site greatly diminishes promoter function but this is also associated with the loss of dexamethasone inhibition. These studies will facilitate an understanding of the mechanisms by which fetal programming leads to long term alterations in gene expression and the development of adult disease. PMID:19411305

  7. Role of TATA-element in transcription from glucocorticoid receptor-responsive model promoters.

    PubMed Central

    Wieland, S; Schatt, M D; Rusconi, S

    1990-01-01

    Transcription activation properties of the rat glucocorticoid receptor (GR) on minimal, TATA-box containing or depleted promoters have been tested. We show that a cluster of Glucocorticoid Responsive Elements (GRE), upon activation by the GR, is sufficient to mediate abundant RNA-polymerase II transcription. We find that in absence of a bona fide TATA-element transcription initiates at a distance of 45-55bp from the activated GRE cluster with a marked preference for sequences homologous to the initiator element (Inr). Analyzing defined, bi-directional transcription units we demonstrate that the apparent reduction of specific transcription in strong, TATA-depleted promoters, is mainly due to loss of short-range promoter polarization. The implications for long-range promoter/enhancer communication mechanisms are also discussed. Images PMID:2402438

  8. Glycine Transporter-1 Inhibition Promotes Striatal Axon Sprouting via NMDA Receptors in Dopamine Neurons

    PubMed Central

    Castagna, Candace; Mrejeru, Ana; Lizardi-Ortiz, José E.; Klein, Zoe; Lindsley, Craig W.

    2013-01-01

    NMDA receptor activity is involved in shaping synaptic connections throughout development and adulthood. We recently reported that brief activation of NMDA receptors on cultured ventral midbrain dopamine neurons enhanced their axon growth rate and induced axonal branching. To test whether this mechanism was relevant to axon regrowth in adult animals, we examined the reinnervation of dorsal striatum following nigral dopamine neuron loss induced by unilateral intrastriatal injections of the toxin 6-hydroxydopamine. We used a pharmacological approach to enhance NMDA receptor-dependent signaling by treatment with an inhibitor of glycine transporter-1 that elevates levels of extracellular glycine, a coagonist required for NMDA receptor activation. All mice displayed sprouting of dopaminergic axons from spared fibers in the ventral striatum to the denervated dorsal striatum at 7 weeks post-lesion, but the reinnervation in mice treated for 4 weeks with glycine uptake inhibitor was approximately twice as dense as in untreated mice. The treated mice also displayed higher levels of striatal dopamine and a complete recovery from lateralization in a test of sensorimotor behavior. We confirmed that the actions of glycine uptake inhibition on reinnervation and behavioral recovery required NMDA receptors in dopamine neurons using targeted deletion of the NR1 NMDA receptor subunit in dopamine neurons. Glycine transport inhibitors promote functionally relevant sprouting of surviving dopamine axons and could provide clinical treatment for disorders such as Parkinson's disease. PMID:24133278

  9. AFR1 acts in conjunction with the alpha-factor receptor to promote morphogenesis and adaptation.

    PubMed Central

    Konopka, J B

    1993-01-01

    Mating pheromone receptors activate a G-protein signaling pathway that induces changes in transcription, cell division, and morphogenesis needed for the conjunction of Saccharomyces cerevisiae. The C terminus of the alpha-factor pheromone receptor functions in two complex processes, adaptation and morphogenesis. Adaptation to alpha-factor may occur through receptor desensitization, and alpha-factor-induced morphogenesis forms the conjugation bridge between mating cells. A plasmid overexpression strategy was used to isolate a new gene, AFR1, which acts together with the receptor C terminus to promote adaptation. The expression of AFR1 was highly induced by alpha-factor. Unexpectedly, cells lacking AFR1 showed a defect in alpha-factor-stimulated morphogenesis that was similar to the morphogenesis defect observed in cells producing C-terminally truncated alpha-factor receptors. In contrast, AFR1 overexpression resulted in longer projections of morphogenesis, which suggests that this gene may directly stimulate morphogenesis. These results indicate that AFR1 encodes a developmentally regulated function that coordinates both the regulation of receptor signaling and the induction of morphogenesis during conjugation. Images PMID:8413281

  10. A receptor model for tumor promoters: rational superposition of teleocidins and phorbol esters.

    PubMed Central

    Itai, A; Kato, Y; Tomioka, N; Iitaka, Y; Endo, Y; Hasegawa, M; Shudo, K; Fujiki, H; Sakai, S

    1988-01-01

    Four 12-O-tetradecanoyl-13-O-acetylphorbol-type tumor promoters--teleocidin, phorbol ester, aplysiatoxin, and ingenol ester--are superposed in an attempt to understand their common biological activity on the assumption that they may bind to the same receptor site. A method using three-dimensional computer graphics was applied for superposing molecules and receptor mapping. The main feature of the method is that molecules are superposed in terms of spatial arrangement of physical and chemical properties but not in terms of the atomic positions as in conventional methods. This led to successful extraction of common structural features required for potent tumor-promoting activity: two hydrogen donors, a hydrogen acceptor, and a large lipophilic group. Their mutual spatial arrangements are most important for biological activity. Images PMID:3131760

  11. M1-muscarinic receptors promote fear memory consolidation via phospholipase C and the M-current.

    PubMed

    Young, Matthew B; Thomas, Steven A

    2014-01-29

    Neuromodulators released during and after a fearful experience promote the consolidation of long-term memory for that experience. Because overconsolidation may contribute to the recurrent and intrusive memories of post-traumatic stress disorder, neuromodulatory receptors provide a potential pharmacological target for prevention. Stimulation of muscarinic receptors promotes memory consolidation in several conditioning paradigms, an effect primarily associated with the M1 receptor (M1R). However, neither inhibiting nor genetically disrupting M1R impairs the consolidation of cued fear memory. Using the M1R agonist cevimeline and antagonist telenzepine, as well as M1R knock-out mice, we show here that M1R, along with β2-adrenergic (β2AR) and D5-dopaminergic (D5R) receptors, regulates the consolidation of cued fear memory by redundantly activating phospholipase C (PLC) in the basolateral amygdala (BLA). We also demonstrate that fear memory consolidation in the BLA is mediated in part by neuromodulatory inhibition of the M-current, which is conducted by KCNQ channels and is known to be inhibited by muscarinic receptors. Manipulating the M-current by administering the KCNQ channel blocker XE991 or the KCNQ channel opener retigabine reverses the effects on consolidation caused by manipulating β2AR, D5R, M1R, and PLC. Finally, we show that cAMP and protein kinase A (cAMP/PKA) signaling relevant to this stage of consolidation is upstream of these neuromodulators and PLC, suggesting an important presynaptic role for cAMP/PKA in consolidation. These results support the idea that neuromodulatory regulation of ion channel activity and neuronal excitability is a critical mechanism for promoting consolidation well after acquisition has occurred.

  12. Crosstalk between dopamine D₂ receptors and cannabinoid CB₁ receptors regulates CNR1 promoter activity via ERK1/2 signaling.

    PubMed

    Chiang, Yao-Chang; Lo, Yan-Ni; Chen, Jin-Chung

    2013-10-01

    Previously, we found that chronic methamphetamine treatment altered cannabinoid type 1 receptor (CB₁R)-dependent cAMP/PKA/dopamine and cAMP-regulated phosphoprotein of Mr 32,000 (DARPP-32)/T34/PP2B signaling and decreased levels of CB₁R protein and mRNA in the nucleus accumbens. These findings suggested the existence of signaling interplay between mesolimbic dopamine and CB₁R. In this study, we further investigate interactions between CB₁R and dopamine D2 receptor (D₂R) signaling. Activation of either CB₁R or D₂R increased extracellular signal-regulated kinases 1 and 2 (ERK1/2) phosphorylation, while co-stimulation of CB₁R and D2 R evoked an additive effect on the phospho-ERK1/2 signal. This effect was mediated through a pertussis toxin-sensitive Gαi/o pathway in primary striatal cells. Furthermore, the mRNA level of CB₁R was increased via dopamine D2 receptor short form (D(2S)R) by treatment with D₂R agonist quinpirole in D(2S)R/C6 glioma cells. This effect could be suppressed by co-treatment with the ERK1/2 inhibitor U0126. To test if D(2S)R could transcriptionally regulate CB₁R, the 5'-untranslated region (5'-UTR) of the cannabinoid receptor 1 (CNR1) gene was sequenced from rat brain. Results showed that the CNR1 gene includes two exons, which contain 375 bp of 5'-UTR and are separated by a 17-kb intron. A luciferase reporter assay showed that the maximal D(2S)R-responsive promoter activity is located in the -1 to -222 region of CNR1 promoter. Overall, we demonstrate previously unidentified crosstalk between D₂R and CB₁R via ERK1/2 signaling that enhances the expression of CB₁R by modulating its promoter activity. © 2013 International Society for Neurochemistry.

  13. Class A scavenger receptor promotes osteoclast differentiation via the enhanced expression of receptor activator of NF-{kappa}B (RANK)

    SciTech Connect

    Takemura, Kenichi; Sakashita, Naomi; Fujiwara, Yukio; Komohara, Yoshihiro; Lei, XiaoFeng; Ohnishi, Koji; Suzuki, Hiroshi; Kodama, Tatsuhiko; Mizuta, Hiroshi; Takeya, Motohiro

    2010-01-22

    Osteoclasts originate from bone marrow monocyte/macrophage lineage cells, and their differentiation depends on macrophage colony-stimulating factor (M-CSF) and receptor activator nuclear factor kappa B (RANK) ligand. Class A scavenger receptor (SR-A) is one of the principal functional molecules of macrophages, and its level of expression declines during osteoclast differentiation. To investigate the role of SR-A in osteoclastogenesis, we examined pathological changes in femoral bone and the expression levels of osteoclastogenesis-related molecules in SR-A{sup -/-} mice. The femoral osseous density of SR-A{sup -/-} mice was higher than that of SR-A{sup +/+} mice, and the number of multinucleated osteoclasts was significantly decreased. An in vitro differentiation assay revealed that the differentiation of multinucleated osteoclasts from bone marrow-derived progenitor cells is impaired in SR-A{sup -/-} mice. Elimination of SR-A did not alter the expression level of the M-CSF receptor, c-fms; however, the expression levels of RANK and RANK-related osteoclast-differentiation molecules such as nuclear factor of activated T-cells, cytoplasmic, calcineurin-dependent 1 (NFATc1) and microphthalmia-associated transcription factor (MITF) significantly decreased. Furthermore, acetylated low-density lipoprotein (AcLDL), an SR-A ligand, significantly increased the expression level of RANK and MITF during osteoclast differentiation. These data indicate that SR-A promotes osteoclastogenesis via augmentation of the expression level of RANK and its related molecules.

  14. α(2A) adrenergic receptor promotes amyloidogenesis through disrupting APP-SorLA interaction.

    PubMed

    Chen, Yunjia; Peng, Yin; Che, Pulin; Gannon, Mary; Liu, Yin; Li, Ling; Bu, Guojun; van Groen, Thomas; Jiao, Kai; Wang, Qin

    2014-12-02

    Accumulation of amyloid β (Aβ) peptides in the brain is the key pathogenic factor driving Alzheimer's disease (AD). Endocytic sorting of amyloid precursor protein (APP) mediated by the vacuolar protein sorting (Vps10) family of receptors plays a decisive role in controlling the outcome of APP proteolytic processing and Aβ generation. Here we report for the first time to our knowledge that this process is regulated by a G protein-coupled receptor, the α(2A) adrenergic receptor (α(2A)AR). Genetic deficiency of the α(2A)AR significantly reduces, whereas stimulation of this receptor enhances, Aβ generation and AD-related pathology. Activation of α(2A)AR signaling disrupts APP interaction with a Vps10 family receptor, sorting-related receptor with A repeat (SorLA), in cells and in the mouse brain. As a consequence, activation of α(2A)AR reduces Golgi localization of APP and concurrently promotes APP distribution in endosomes and cleavage by β secretase. The α(2A)AR is a key component of the brain noradrenergic system. Profound noradrenergic dysfunction occurs consistently in patients at the early stages of AD. α(2A)AR-promoted Aβ generation provides a novel mechanism underlying the connection between noradrenergic dysfunction and AD. Our study also suggests α(2A)AR as a previously unappreciated therapeutic target for AD. Significantly, pharmacological blockade of the α(2A)AR by a clinically used antagonist reduces AD-related pathology and ameliorates cognitive deficits in an AD transgenic model, suggesting that repurposing clinical α(2A)R antagonists would be an effective therapeutic strategy for AD.

  15. α2A adrenergic receptor promotes amyloidogenesis through disrupting APP-SorLA interaction

    PubMed Central

    Chen, Yunjia; Peng, Yin; Che, Pulin; Gannon, Mary; Liu, Yin; Li, Ling; Bu, Guojun; van Groen, Thomas; Jiao, Kai; Wang, Qin

    2014-01-01

    Accumulation of amyloid β (Aβ) peptides in the brain is the key pathogenic factor driving Alzheimer’s disease (AD). Endocytic sorting of amyloid precursor protein (APP) mediated by the vacuolar protein sorting (Vps10) family of receptors plays a decisive role in controlling the outcome of APP proteolytic processing and Aβ generation. Here we report for the first time to our knowledge that this process is regulated by a G protein-coupled receptor, the α2A adrenergic receptor (α2AAR). Genetic deficiency of the α2AAR significantly reduces, whereas stimulation of this receptor enhances, Aβ generation and AD-related pathology. Activation of α2AAR signaling disrupts APP interaction with a Vps10 family receptor, sorting-related receptor with A repeat (SorLA), in cells and in the mouse brain. As a consequence, activation of α2AAR reduces Golgi localization of APP and concurrently promotes APP distribution in endosomes and cleavage by β secretase. The α2AAR is a key component of the brain noradrenergic system. Profound noradrenergic dysfunction occurs consistently in patients at the early stages of AD. α2AAR-promoted Aβ generation provides a novel mechanism underlying the connection between noradrenergic dysfunction and AD. Our study also suggests α2AAR as a previously unappreciated therapeutic target for AD. Significantly, pharmacological blockade of the α2AAR by a clinically used antagonist reduces AD-related pathology and ameliorates cognitive deficits in an AD transgenic model, suggesting that repurposing clinical α2AR antagonists would be an effective therapeutic strategy for AD. PMID:25404298

  16. Sigma-1 Receptor Agonism Promotes Mechanical Allodynia After Priming the Nociceptive System with Capsaicin.

    PubMed

    Entrena, J M; Sánchez-Fernández, C; Nieto, F R; González-Cano, R; Yeste, S; Cobos, E J; Baeyens, J M

    2016-11-25

    Sigma-1 receptor antagonists promote antinociception in several models of pain, but the effects of sigma-1 agonists on nociception (particularly when the nociceptive system is primed) are not so well characterized; therefore we evaluated the effects of sigma-1 agonists on pain under different experimental conditions. The systemic administration of the selective sigma-1 agonists (+)-pentazocine and PRE-084, as well as the nonselective sigma-1 agonist carbetapentane (used clinically as an antitussive drug), did not alter sensitivity to mechanical stimulation under baseline conditions. However, they greatly promoted secondary mechanical allodynia after priming the nociceptive system with capsaicin. These effects of sigma-1 agonists were consistent in terms potency with the affinities of these drugs for sigma-1 receptors, were reversed by sigma-1 antagonists, and were not observed in sigma-1 knockout mice, indicating that they are sigma-1-mediated. Repeated systemic treatment with PRE-084 induced proallodynic effects even 24 h after treatment completion, but only after the nociceptive system was primed. However, neither the presence of this drug in the organism nor changes in sigma-1 receptor expression in areas involved in pain processing explains its long-term effects, suggesting that sustained sigma-1 agonism induces plastic changes in the nociceptive system that promote nociception.

  17. Galanin and its receptor system promote the repair of injured sciatic nerves in diabetic rats.

    PubMed

    Xu, Xiao-Feng; Zhang, Dan-Dan; Liao, Jin-Chi; Xiao, Li; Wang, Qing; Qiu, Wei

    2016-09-01

    Various studies have reported that galanin can promote axonal regeneration of dorsal root ganglion neurons in vitro and inhibit neuropathic pain. However, little is known about its effects on diabetic peripheral neuropathy, and in vivo experimental data are lacking. We hypothesized that repeated applications of exogenous galanin over an extended time frame may also repair nerve damage in diabetic peripheral neuropathy, and relieve pain in vivo. We found that neuropathic pain occurred in streptozotocin-induced diabetic rats and was more severe after sciatic nerve pinch injury at 14 and 28 days than in diabetic sham-operated rats. Treatment with exogenous galanin alleviated the neuropathic pain and promoted sciatic nerve regeneration more effectively in diabetic rats than in non-diabetic rats after sciatic nerve pinch injury. This was accompanied by changes in the levels of endogenous galanin, and its receptors galanin receptor 1 and galanin receptor 2 in the dorsal root ganglia and the spinal dorsal horn when compared with nerve pinch normal rats. Our results show that application of exogenous galanin daily for 28 days can promote the regeneration of injured sciatic nerves, and alleviate neuropathic pain in diabetic rats.

  18. Sigma-1 Receptor Agonism Promotes Mechanical Allodynia After Priming the Nociceptive System with Capsaicin

    PubMed Central

    Entrena, J. M.; Sánchez-Fernández, C.; Nieto, F. R.; González-Cano, R.; Yeste, S.; Cobos, E. J.; Baeyens, J. M.

    2016-01-01

    Sigma-1 receptor antagonists promote antinociception in several models of pain, but the effects of sigma-1 agonists on nociception (particularly when the nociceptive system is primed) are not so well characterized; therefore we evaluated the effects of sigma-1 agonists on pain under different experimental conditions. The systemic administration of the selective sigma-1 agonists (+)-pentazocine and PRE-084, as well as the nonselective sigma-1 agonist carbetapentane (used clinically as an antitussive drug), did not alter sensitivity to mechanical stimulation under baseline conditions. However, they greatly promoted secondary mechanical allodynia after priming the nociceptive system with capsaicin. These effects of sigma-1 agonists were consistent in terms potency with the affinities of these drugs for sigma-1 receptors, were reversed by sigma-1 antagonists, and were not observed in sigma-1 knockout mice, indicating that they are sigma-1-mediated. Repeated systemic treatment with PRE-084 induced proallodynic effects even 24 h after treatment completion, but only after the nociceptive system was primed. However, neither the presence of this drug in the organism nor changes in sigma-1 receptor expression in areas involved in pain processing explains its long-term effects, suggesting that sustained sigma-1 agonism induces plastic changes in the nociceptive system that promote nociception. PMID:27886264

  19. Soluble forms of VEGF receptor-1 and -2 promote vascular maturation via mural cell recruitment.

    PubMed

    Lorquet, Sophie; Berndt, Sarah; Blacher, Silvia; Gengoux, Emily; Peulen, Olivier; Maquoi, Erik; Noël, Agnès; Foidart, Jean-Michel; Munaut, Carine; Péqueux, Christel

    2010-10-01

    Two soluble forms of vascular endothelial growth factor (VEGF) receptors, sVEGFR-1 and sVEGFR-2, are physiologically released and overproduced in some pathologies. They are known to act as anti-VEGF agents. Here we report that these soluble receptors contribute to vessel maturation by mediating a dialogue between endothelial cells (ECs) and mural cells that leads to blood vessel stabilization. Through a multidisciplinary approach, we provide evidence that these soluble VEGF receptors promote mural cell migration through a paracrine mechanism involving interplay in ECs between VEGF/VEGFR-2 and sphingosine-1-phosphate type-1 (S1P)/S1P1 pathways that leads to endothelial nitric oxyde synthase (eNOS) activation. This new paradigm is supported by the finding that sVEGFR-1 and -2 perform the following actions: 1) induce an eNOS-dependent outgrowth of a mural cell network in an ex vivo model of angiogenesis, 2) increase the mural cell coverage of neovessels in vitro and in vivo, 3) promote mural cell migration toward ECs, and 4) stimulate endothelial S1P1 overproduction and eNOS activation that promote the migration and the recruitment of neighboring mural cells. These findings provide new insights into mechanisms regulating physiological and pathological angiogenesis and vessel stabilization.

  20. Galanin and its receptor system promote the repair of injured sciatic nerves in diabetic rats

    PubMed Central

    Xu, Xiao-feng; Zhang, Dan-dan; Liao, Jin-chi; Xiao, Li; Wang, Qing; Qiu, Wei

    2016-01-01

    Various studies have reported that galanin can promote axonal regeneration of dorsal root ganglion neurons in vitro and inhibit neuropathic pain. However, little is known about its effects on diabetic peripheral neuropathy, and in vivo experimental data are lacking. We hypothesized that repeated applications of exogenous galanin over an extended time frame may also repair nerve damage in diabetic peripheral neuropathy, and relieve pain in vivo. We found that neuropathic pain occurred in streptozotocin-induced diabetic rats and was more severe after sciatic nerve pinch injury at 14 and 28 days than in diabetic sham-operated rats. Treatment with exogenous galanin alleviated the neuropathic pain and promoted sciatic nerve regeneration more effectively in diabetic rats than in non-diabetic rats after sciatic nerve pinch injury. This was accompanied by changes in the levels of endogenous galanin, and its receptors galanin receptor 1 and galanin receptor 2 in the dorsal root ganglia and the spinal dorsal horn when compared with nerve pinch normal rats. Our results show that application of exogenous galanin daily for 28 days can promote the regeneration of injured sciatic nerves, and alleviate neuropathic pain in diabetic rats. PMID:27857760

  1. Isolation and characterization of the chicken vitamin D receptor gene and its promoter.

    PubMed

    Lu, Z; Jehan, F; Zierold, C; DeLuca, H F

    2000-02-01

    The sequences from several independent cDNA clones encoding the chicken vitamin D receptor as well as primer extension assay have clearly delineated the 5' terminus and the transcriptional start site. Screening a chicken genomic library produced genomic clones containing vitamin D receptor (VDR) gene fragments. Restriction map of clone 8 showed that the 18.6-kb chicken VDR fragment has exons 1 and 2, intron 1, part of intron 2, and 7-kb 5' flanking region. Exons 1, 2, and 3 found in the chicken VDR gene shares low homology with its mammalian counterparts (i.e., E1A, E1B, and E1C in human). By contrast, the fourth exon and following exons for the coding region of VDR gene are highly conserved between avian and mammalian species. While the fourth exon bears the ATG sites for translation initiation in mammals, the third exon in birds has two extra ATG sites for leaky translation as determined previously. Thus, the avian VDR has more N-terminal sequence than the mammalian VDR and is found in two distinct forms. The 5' flanking region from genomic clone 8 shares considerable homology in several regions with the human and mouse VDR promoters. Moreover, the 5' flanking region of chicken VDR gene possesses promoter activity, as shown by its ability to drive the luciferase reporter gene in cell transfection assays. Like other steroid receptor promoters, the chicken VDR promoter contains no TATA box but possesses several GC boxes or SP1 sites. A series of deletional promoter constructs established that the proximal GC boxes are the major drivers of gene transcription, while the more upstream sequences have repressive elements. Copyright 2000 Wiley-Liss, Inc.

  2. Promoter DNA methylation of farnesoid X receptor and pregnane X receptor modulates the intrahepatic cholestasis of pregnancy phenotype.

    PubMed

    Cabrerizo, Romina; Castaño, Gustavo O; Burgueño, Adriana L; Fernández Gianotti, Tomas; Gonzalez Lopez Ledesma, María Mora; Flichman, Diego; Pirola, Carlos J; Sookoian, Silvia

    2014-01-01

    The intrahepatic cholestasis of pregnancy (ICP) is a multifactorial liver disorder which pathogenesis involves the interplay among abnormal bile acid (BA) levels, sex hormones, environmental factors, and genetic susceptibility. The dynamic nature of ICP that usually resolves soon after delivery suggests the possibility that its pathobiology is under epigenetic modulation. We explored the status of white blood peripheral cells-DNA methylation of CpG-enriched sites at the promoter of targeted genes (FXR/NR1H4, PXR/NR1I2, NR1I3, ESR1, and ABCC2) in a sample of 88 ICP patients and 173 healthy pregnant women in the third trimester of their pregnancies. CpG dinucleotides at the gene promoter of nuclear receptors subfamily 1 members and ABCC2 transporter were highly methylated during healthy pregnancy. We observed significant differences at the distal (-1890) and proximal promoter (-358) CpG sites of the FXR/NR1H4 and at the distal PXR/NR1I2 (-1224) promoter, which were consistently less methylated in ICP cases when compared with controls. In addition, we observed that methylation at FXR/NR1H4-1890 and PXR/NR1I2-1224 promoter sites was highly and positively correlated with BA profiling, particularly, conjugated BAs. Conversely, methylation level at the proximal FXR/NR1H4-358 CpG site was significantly and negatively correlated with the primary cholic and secondary deoxycholic acid. In vitro exploration showed that epiallopregnanolone sulfate, a reported FXR inhibitor, regulates the transcriptional activity of FXR/NR1H4 but seems to be not involved in the methylation changes. In conclusion, the identification of epigenetic marks in target genes provides a basis for the understanding of adverse liver-related pregnancy outcomes, including ICP.

  3. Promoter DNA Methylation of Farnesoid X Receptor and Pregnane X Receptor Modulates the Intrahepatic Cholestasis of Pregnancy Phenotype

    PubMed Central

    Cabrerizo, Romina; Castaño, Gustavo O.; Burgueño, Adriana L.; Fernández Gianotti, Tomas; Gonzalez Lopez Ledesma, María Mora; Flichman, Diego; Pirola, Carlos J.; Sookoian, Silvia

    2014-01-01

    The intrahepatic cholestasis of pregnancy (ICP) is a multifactorial liver disorder which pathogenesis involves the interplay among abnormal bile acid (BA) levels, sex hormones, environmental factors, and genetic susceptibility. The dynamic nature of ICP that usually resolves soon after delivery suggests the possibility that its pathobiology is under epigenetic modulation. We explored the status of white blood peripheral cells-DNA methylation of CpG-enriched sites at the promoter of targeted genes (FXR/NR1H4, PXR/NR1I2, NR1I3, ESR1, and ABCC2) in a sample of 88 ICP patients and 173 healthy pregnant women in the third trimester of their pregnancies. CpG dinucleotides at the gene promoter of nuclear receptors subfamily 1 members and ABCC2 transporter were highly methylated during healthy pregnancy. We observed significant differences at the distal (−1890) and proximal promoter (−358) CpG sites of the FXR/NR1H4 and at the distal PXR/NR1I2 (−1224) promoter, which were consistently less methylated in ICP cases when compared with controls. In addition, we observed that methylation at FXR/NR1H4-1890 and PXR/NR1I2-1224 promoter sites was highly and positively correlated with BA profiling, particularly, conjugated BAs. Conversely, methylation level at the proximal FXR/NR1H4-358 CpG site was significantly and negatively correlated with the primary cholic and secondary deoxycholic acid. In vitro exploration showed that epiallopregnanolone sulfate, a reported FXR inhibitor, regulates the transcriptional activity of FXR/NR1H4 but seems to be not involved in the methylation changes. In conclusion, the identification of epigenetic marks in target genes provides a basis for the understanding of adverse liver-related pregnancy outcomes, including ICP. PMID:24498169

  4. Human pregnane X receptor compromises the function of p53 and promotes malignant transformation

    PubMed Central

    Robbins, D; Cherian, M; Wu, J; Chen, T

    2016-01-01

    The pregnane X receptor (PXR) is well established as a nuclear receptor that has a central role in xenobiotic metabolism and disposition. However, emerging evidence suggests that PXR is also a regulator of apoptosis, promoting a malignant phenotype both in vitro and in vivo. The tumor suppressor p53 can be activated in the presence of DNA damage and induce cell cycle arrest to allow for DNA repair or, ultimately, apoptosis to suppress tumor formation. We previously identified p53 as a novel PXR-associated protein by using a mass spectrometric approach. In the current study, we identified a novel inhibitory effect of PXR on p53, revealing an anti-apoptotic function of PXR in colon carcinogenesis. PXR expression reduced p53 transactivation and the expression of its downstream target genes involved in cell cycle arrest and apoptosis by decreasing p53 recruitment to the promoter regions of these genes. Consistent with the inhibitory effect of PXR on p53, elevated PXR levels decreased doxorubicin- or nutlin-3a-mediated toxicity and promoted malignant transformation in colon cancer cells. Our findings show for the first time that PXR expression modulates p53 target gene promoter binding and contributes to the downregulation of p53 function in human colon cancer cells. These results define the functional significance of PXR expression in modulating p53-mediated mechanisms of tumor suppression. PMID:27547448

  5. Transactivation of the proximal promoter of human oxytocin gene by TR4 orphan receptor

    SciTech Connect

    Wang, C.-P.; Lee, Y.-F.; Chang, C.; Lee, H.-J. . E-mail: hjlee@mail.ndhu.edu.tw

    2006-12-08

    The human testicular receptor 4 (TR4) shares structural homology with members of the nuclear receptor superfamily. Some other members of this superfamily were able to regulate the transcriptional activity of the human oxytocin (OXT) promoter by binding to the first DR0 regulatory site. However, little investigation was conducted systematically in the study of the second dDR4 site of OXT proximal promoter, and the relationship between the first and the second sites of OXT promoter. Here, we demonstrated for the first time that TR4 could increase the proximal promoter activity of the human OXT gene via DR0, dDR4, and OXT (both DR0 and dDR4) elements, respectively. TR4 might induce OXT gene expression through the OXT element in a dose-dependent manner. However, there is no synergistic effect between DR0 and dDR4 elements during TR4 transactivation. Taken together, these results suggested that TR4 should be one of important regulators of OXT gene expression.

  6. Sustained neurotensin exposure promotes cell surface recruitment of NTS2 receptors

    SciTech Connect

    Perron, Amelie; Sharif, Nadder; Gendron, Louis; Lavallee, Mariette; Stroh, Thomas; Mazella, Jean; Beaudet, Alain . E-mail: abeaudet@frsq.gouv.qc.ca

    2006-05-12

    In this study, we investigated whether persistent agonist stimulation of NTS2 receptors gives rise to down-regulation, in light of reports that their activation induced long-lasting effects. To address this issue, we incubated COS-7 cells expressing the rat NTS2 with neurotensin (NT) for up to 24 h and measured resultant cell surface [{sup 125}I]-NT binding. We found that NTS2-expressing cells retained the same surface receptor density despite efficient internalization mechanisms. This preservation was neither due to NTS2 neosynthesis nor recycling since it was not blocked by cycloheximide or monensin. However, it appeared to involve translocation of spare receptors from internal stores, as NT induced NTS2 migration from trans-Golgi network to endosome-like structures. This stimulation-induced regulation of cell surface NTS2 receptors was even more striking in rat spinal cord neurons. Taken together, these results suggest that sustained NTS2 activation promotes recruitment of intracellular receptors to the cell surface, thereby preventing functional desensitization.

  7. Endotoxin promotes neutrophil hierarchical chemotaxis via the p38-membrane receptor pathway

    PubMed Central

    Wang, Xu; Qin, Weiting; Zhang, Yisen; Zhang, Huafeng; Sun, Bingwei

    2016-01-01

    Neutrophils are the most abundant leukocytes in peripheral blood and play critical a role in bacterial infection, tumor immunity and wound repair. Clarifying the process of neutrophil chemotaxis to target sites of immune activity has been a focus of increased interest within the past decade. In bacterial infectious foci, neutrophils migrate toward the bacterial-derived chemoattractant N-formyl-Met-Leu-Phe (fMLP) and ignore other intermediary chemoattractants to arrive at the area of infection. Using an under agarose chemotaxis assay, we observed that the bacterial fMLP-induced neutrophil chemotaxis signal overrode interleukin 8 (IL-8)- and leukotriene B4 (LTB4)-induced chemotaxis signals. Moreover, in the presence of bacterial lipopolysaccharide (LPS), the fMLP-induced hierarchical chemotaxis signal was enhanced. Further studies revealed that LPS increased the membrane expression of the fMLP receptor, formyl peptide receptor 1 (FPR1). However, expression levels of the membrane receptors for IL-8 and LTB4 were decreased by LPS administration. A human Phospho-mitogen-activated protein kinase (MAPK) proteome array showed that the p38 pathway was significantly activated by LPS stimulation. Moreover, p38 was responsible for the altered expression of neutrophil membrane chemoattractant receptors. Inhibition of neutrophil p38 restored LPS-improved hierarchical chemotaxis. Taken together, these data indicate that endotoxin promotes neutrophil hierarchical chemotaxis via the p38-membrane receptor pathway. PMID:27655676

  8. Longevity and diet. Myth or pragmatism?

    PubMed

    Chrysohoou, Christina; Stefanadis, Christodoulos

    2013-12-01

    Longevity is a very complex phenomenon, because many environmental, behavioral, socio-demographic and dietary factors influence the physiological pathways of aging and life-expectancy. Nutrition has been recognized to have an important impact on overall mortality and morbidity; and its role in extending life expectancy has been the object of extensive scientific research. This paper reviews the pathophysiological mechanisms that potentially link aging with diet and the scientific evidence supporting the anti-aging effect of the traditional Mediterranean diet, as well as of some specific foods. The diet and several of its components have additionally been shown to have beneficial effects on the co-morbidities typical of elderly populations. Furthermore, the epigenetic effects of diet on the aging process - through calorie restriction and the consumption of foods like red wine, orange juice, probiotics and prebiotics - have attracted scientific interest. Some, such as dark chocolate, red wine, nuts, beans, avocados are being promoted as anti-aging foods, due to their anti-oxidative and anti-inflammatory properties. Finally, an important moderator in the relationship between diet, longevity and human health remains the socio-economic status of individual, as a healthy diet, due to its higher cost, is closely related to higher financial and educational status.

  9. Longevity of Native Wildflower Seeds

    USDA-ARS?s Scientific Manuscript database

    Wildflowers and forbs used for production, plantings and restoration generally exhibit ‘orthodox’ storage behavior, meaning that longevity can be adjusted by balancing storage relative humidity and temperature. An RH of about 20 to 30% at the storage temperature provides optimum moisture condition...

  10. Typologies of Extreme Longevity Myths

    PubMed Central

    Young, Robert D.; Desjardins, Bertrand; McLaughlin, Kirsten; Poulain, Michel; Perls, Thomas T.

    2010-01-01

    Purpose. Political, national, religious, and other motivations have led the media and even scientists to errantly accept extreme longevity claims prima facie. We describe various causes of false claims of extraordinary longevity. Design and Methods. American Social Security Death Index files for the period 1980–2009 were queried for individuals with birth and death dates yielding ages 110+ years of age. Frequency was compared to a list of age-validated supercentenarians maintained by the Gerontology Research Group who died during the same time period. Age claims of 110+ years and the age validation experiences of the authors facilitated a list of typologies of false age claims. Results. Invalid age claim rates increase with age from 65% at age 110-111 to 98% by age 115 to 100% for 120+ years. Eleven typologies of false claims were: Religious Authority Myth, Village Elder Myth, Fountain of Youth Myth (substance), Shangri-La Myth (geographic), Nationalist Pride, Spiritual Practice, Familial Longevity, Individual and/or Family Notoriety, Military Service, Administrative Entry Error, and Pension-Social Entitlement Fraud. Conclusions. Understanding various causes of false extreme age claims is important for placing current, past, and future extreme longevity claims in context and for providing a necessary level of skepticism. PMID:21461047

  11. Typologies of extreme longevity myths.

    PubMed

    Young, Robert D; Desjardins, Bertrand; McLaughlin, Kirsten; Poulain, Michel; Perls, Thomas T

    2010-01-01

    Purpose. Political, national, religious, and other motivations have led the media and even scientists to errantly accept extreme longevity claims prima facie. We describe various causes of false claims of extraordinary longevity. Design and Methods. American Social Security Death Index files for the period 1980-2009 were queried for individuals with birth and death dates yielding ages 110+ years of age. Frequency was compared to a list of age-validated supercentenarians maintained by the Gerontology Research Group who died during the same time period. Age claims of 110+ years and the age validation experiences of the authors facilitated a list of typologies of false age claims. Results. Invalid age claim rates increase with age from 65% at age 110-111 to 98% by age 115 to 100% for 120+ years. Eleven typologies of false claims were: Religious Authority Myth, Village Elder Myth, Fountain of Youth Myth (substance), Shangri-La Myth (geographic), Nationalist Pride, Spiritual Practice, Familial Longevity, Individual and/or Family Notoriety, Military Service, Administrative Entry Error, and Pension-Social Entitlement Fraud. Conclusions. Understanding various causes of false extreme age claims is important for placing current, past, and future extreme longevity claims in context and for providing a necessary level of skepticism.

  12. Loco signaling pathway in longevity.

    PubMed

    Lin, Yuh-Ru; Parikh, Hardik; Park, Yongkyu

    2011-05-01

    Despite the various roles of regulator of G protein signaling (RGS) protein in the G protein signaling pathway that have been defined, the function of RGS has not been characterized in longevity signaling pathways. We found that reduced expression of Loco, a Drosophila RGS protein, resulted in a longer lifespan of flies with stronger resistance to stress, higher MnSOD activity and increased fat content. In contrast, overexpression of the loco gene shortened the fly lifespan significantly, lowered stress resistance and reduced fat content, also indicating that the RGS domain containing GTPase-activating protein (GAP) activity is related to the regulation of longevity. Interestingly, expressional changes of yeast RGS2 and rat RGS14, homologs to the fly Loco, also affected oxidative stress resistance and longevity in the respective species. It is known that Loco inactivates inhibitory Gαi•GTP protein to reduce activity of adenylate cyclase (AC) and RGS14 interacts with activated H-Ras and Raf-1 kinases, which subsequently inhibits ERK phosphorylation. We propose that Loco/RGS14 protein may regulate stress resistance and longevity as an activator in AC-cAMP-PKA pathway and/or as a molecular scaffold that sequesters active Ras and Raf from Ras•GTP-Raf-MEK-ERK signaling pathway. Consistently, our data showed that downregulation of Loco significantly diminishes cAMP amounts and increases p-ERK levels with higher resistance to the oxidative stress.

  13. Female Superintendent Longevity in California

    ERIC Educational Resources Information Center

    Rohlfing, Tracy

    2011-01-01

    The purpose of this study was to investigate, through narrative inquiry (Clandinin & Connelly, 2000), the leadership evolution of five female superintendents in California with longevity of 5 or more years in their current school district positions. The research question addressed was, "How do California female superintendents evolve to…

  14. Longevity Of Dry Film Lubricants

    NASA Technical Reports Server (NTRS)

    Kannel, J. W.; Stockwell, R. D.

    1993-01-01

    Report describes evaluation of dry film lubricants candidate for use in rotary joints of proposed Space Station. Study included experiments and theoretical analyses focused on longevity of sputtered molybdenum disulfide films and ion-plated lead films under conditions partially simulating rolling contact.

  15. A Novel 3-Hydroxysteroid Dehydrogenase That Regulates Reproductive Development and Longevity

    PubMed Central

    Wollam, Joshua; Magner, Daniel B.; Magomedova, Lilia; Rass, Elisabeth; Shen, Yidong; Rottiers, Veerle; Habermann, Bianca; Cummins, Carolyn L.; Antebi, Adam

    2012-01-01

    Endogenous small molecule metabolites that regulate animal longevity are emerging as a novel means to influence health and life span. In C. elegans, bile acid-like steroids called the dafachronic acids (DAs) regulate developmental timing and longevity through the conserved nuclear hormone receptor DAF-12, a homolog of mammalian sterol-regulated receptors LXR and FXR. Using metabolic genetics, mass spectrometry, and biochemical approaches, we identify new activities in DA biosynthesis and characterize an evolutionarily conserved short chain dehydrogenase, DHS-16, as a novel 3-hydroxysteroid dehydrogenase. Through regulation of DA production, DHS-16 controls DAF-12 activity governing longevity in response to signals from the gonad. Our elucidation of C. elegans bile acid biosynthetic pathways reveals the possibility of novel ligands as well as striking biochemical conservation to other animals, which could illuminate new targets for manipulating longevity in metazoans. PMID:22505847

  16. C-type lectin-like receptor LOX-1 promotes dendritic cell-mediated class-switched B cell responses.

    PubMed

    Joo, HyeMee; Li, Dapeng; Dullaers, Melissa; Kim, Tae-Whan; Duluc, Dorothee; Upchurch, Katherine; Xue, Yaming; Zurawski, Sandy; Le Grand, Roger; Liu, Yong-Jun; Kuroda, Marcelo; Zurawski, Gerard; Oh, SangKon

    2014-10-16

    Lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) is a pattern-recognition receptor for a variety of endogenous and exogenous ligands. However, LOX-1 function in the host immune response is not fully understood. Here, we report that LOX-1 expressed on dendritic cells (DCs) and B cells promotes humoral responses. On B cells LOX-1 signaling upregulated CCR7, promoting cellular migration toward lymphoid tissues. LOX-1 signaling on DCs licensed the cells to promote B cell differentiation into class-switched plasmablasts and led to downregulation of chemokine receptor CXCR5 and upregulation of chemokine receptor CCR10 on plasmablasts, enabling their exit from germinal centers and migration toward local mucosa and skin. Finally, we found that targeting influenza hemagglutinin 1 (HA1) subunit to LOX-1 elicited HA1-specific protective antibody responses in rhesus macaques. Thus, LOX-1 expressed on B cells and DC cells has complementary functions to promote humoral immune responses.

  17. Fat chance for longevity

    PubMed Central

    Kniazeva, Marina; Han, Min

    2013-01-01

    The health benefits of specific fatty acids and physiological roles of fat metabolism are important subjects that are still poorly understood. In this issue of Genes & Development, O'Rourke and colleagues (pp. 429–440) uncovered a role for lipase-generated ω-6 fatty acids in promoting autophagy and, consequently, life span extension under both fed and fasting conditions. The impact of this finding is discussed with regard to the nutritional value of ω-6 fatty acids and regulatory functions of fat metabolism beyond its well-known role in energy storage. PMID:23431052

  18. P2X7R suppression promotes glioma growth through epidermal growth factor receptor signal pathway.

    PubMed

    Fang, Jingqin; Chen, Xiao; Zhang, Letian; Chen, Jinhua; Liang, Yi; Li, Xue; Xiang, Jianbo; Wang, Lili; Guo, Guangkuo; Zhang, Bo; Zhang, Weiguo

    2013-06-01

    P2X7 receptor (P2X7R) has been shown to mediate an anticancer effect via apoptosis in different types of cancer. However, whether P2X7R exerts a promoting or suppressive effect on brain glioma is still a controversial issue and its underlying mechanism remains unknown. We showed here that P2X7R suppression exerted a pro-growth effect on glioma through directly promoting cells proliferation and pro-angiogenesis, which was associated with epidermal growth factor receptor (EGFR) signaling. The P2X7R was markedly downregulated by cells exposure to the P2X7R antagonist, brilliant blue G (BBG), moreover, the cells proliferation was enhanced in a dose-dependent manner and the expression of EGFR or p-EGFR protein was significantly upregulated. By constructing C6 cells with reduced expression of P2X7R using shRNA, we also demonstrated strong upregulation in cells proliferation and EGFR/p-EGFR expression. However, this effect of BBG was reversed in the presence of gefitinib or suramin. Magnetic resonance imaging and computed tomography perfusion showed that the BBG or P2X7R shRNA promoted the tumor growth by about 40% and 50%, respectively, and significantly increased angiogenesis. Nissl and Ki-67 staining also confirmed that BBG or P2X7R shRNA notably increased the tumor growth. More importantly, either BBG or P2X7R shRNA could markedly upregulated the expression of EGFR, p-EGFR, HIF-1α and VEGF in glioma cells. In conclusion, P2X7R suppression exerts a promoting effect on glioma growth, which is likely to be related to upregulated EGFR, HIF-1α and VEGF expression. These findings provide important clues to the molecular basis of anticancer effect of targeting purinergic receptors. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Structure and Activity of the Human Growth Hormone Receptor (hGHR) Gene V2 Promoter

    PubMed Central

    Wei, Yuhong; Puzhko, Svetlana; Wabitsch, Martin; Goodyer, Cynthia Gates

    2009-01-01

    Human GH (hGH) has important effects on growth as well as carbohydrate, fat, and protein metabolism. These actions require the presence of normal levels of a functional hGH receptor (hGHR) on the surface of target cells. hGHR gene expression is characterized by the use of several 5′-noncoding exons and alternative splicing, resulting in the generation of multiple mRNA isoforms. The hGHR V2 transcript is predominant in most tissues, including human fat. However, factors regulating its ubiquitous expression have remained unidentified. The present study was aimed at characterizing the mechanisms regulating hGHR V2 transcription. Two major V2 transcriptional start sites were identified by primer extension assays. The V2 proximal promoter is TATA-less, with several characteristics of a housekeeping gene promoter. Transient transfection analyses of 2.6 kb of the 5′-flanking region of V2 confirmed its promoter activity in multiple primate cell lines. Similar promoter activity patterns were observed in human SGBS preadipocytes and mature adipocytes but with much higher V2 promoter activity in mature adipocytes, suggesting that changes in the availability of specific factors during adipocyte differentiation play a role in V2 promoter regulation. Serial deletion and mutation analyses revealed that transcription of hGHR V2 in different cell types, including adipocytes, is determined by a core promoter and distinct inhibitory and activation domains in the 5′-promoter region as well as within the V2 exon. Our data suggest that V2 transcription is the result of a complex interplay involving multiple factors, to ensure appropriate expression of hGHR in different hGH target cells. PMID:19116246

  20. Promotion of Cancer Cell Invasiveness and Metastasis Emergence Caused by Olfactory Receptor Stimulation

    PubMed Central

    Sanz, Guenhaël; Leray, Isabelle; Dewaele, Aurélie; Sobilo, Julien; Lerondel, Stéphanie; Bouet, Stéphan; Grébert, Denise; Monnerie, Régine; Pajot-Augy, Edith; Mir, Lluis M.

    2014-01-01

    Olfactory receptors (ORs) are expressed in the olfactory epithelium, where they detect odorants, but also in other tissues with additional functions. Some ORs are even overexpressed in tumor cells. In this study, we identified ORs expressed in enterochromaffin tumor cells by RT-PCR, showing that single cells can co-express several ORs. Some of the receptors identified were already reported in other tumors, but they are orphan (without known ligand), as it is the case for most of the hundreds of human ORs. Thus, genes coding for human ORs with known ligands were transfected into these cells, expressing functional heterologous ORs. The in vitro stimulation of these cells by the corresponding OR odorant agonists promoted cell invasion of collagen gels. Using LNCaP prostate cancer cells, the stimulation of the PSGR (Prostate Specific G protein-coupled Receptor), an endogenously overexpressed OR, by β-ionone, its odorant agonist, resulted in the same phenotypic change. We also showed the involvement of a PI3 kinase γ dependent signaling pathway in this promotion of tumor cell invasiveness triggered by OR stimulation. Finally, after subcutaneous inoculation of LNCaP cells into NSG immunodeficient mice, the in vivo stimulation of these cells by the PSGR agonist β-ionone significantly enhanced metastasis emergence and spreading. PMID:24416348

  1. Tumour-cell-induced endothelial cell necroptosis via death receptor 6 promotes metastasis.

    PubMed

    Strilic, Boris; Yang, Lida; Albarrán-Juárez, Julián; Wachsmuth, Laurens; Han, Kang; Müller, Ulrike C; Pasparakis, Manolis; Offermanns, Stefan

    2016-08-11

    Metastasis is the leading cause of cancer-related death in humans. It is a complex multistep process during which individual tumour cells spread primarily through the circulatory system to colonize distant organs. Once in the circulation, tumour cells remain vulnerable, and their metastatic potential largely depends on a rapid and efficient way to escape from the blood stream by passing the endothelial barrier. Evidence has been provided that tumour cell extravasation resembles leukocyte transendothelial migration. However, it remains unclear how tumour cells interact with endothelial cells during extravasation and how these processes are regulated on a molecular level. Here we show that human and murine tumour cells induce programmed necrosis (necroptosis) of endothelial cells, which promotes tumour cell extravasation and metastasis. Treatment of mice with the receptor-interacting serine/threonine-protein kinase 1 (RIPK1)-inhibitor necrostatin-1 or endothelial-cell-specific deletion of RIPK3 reduced tumour-cell-induced endothelial necroptosis, tumour cell extravasation and metastasis. In contrast, pharmacological caspase inhibition or endothelial-cell-specific loss of caspase-8 promoted these processes. We furthermore show in vitro and in vivo that tumour-cell-induced endothelial necroptosis leading to extravasation and metastasis requires amyloid precursor protein expressed by tumour cells and its receptor, death receptor 6 (DR6), on endothelial cells as the primary mediators of these effects. Our data identify a new mechanism underlying tumour cell extravasation and metastasis, and suggest endothelial DR6-mediated necroptotic signalling pathways as targets for anti-metastatic therapies.

  2. Promotion of cancer cell invasiveness and metastasis emergence caused by olfactory receptor stimulation.

    PubMed

    Sanz, Guenhaël; Leray, Isabelle; Dewaele, Aurélie; Sobilo, Julien; Lerondel, Stéphanie; Bouet, Stéphan; Grébert, Denise; Monnerie, Régine; Pajot-Augy, Edith; Mir, Lluis M

    2014-01-01

    Olfactory receptors (ORs) are expressed in the olfactory epithelium, where they detect odorants, but also in other tissues with additional functions. Some ORs are even overexpressed in tumor cells. In this study, we identified ORs expressed in enterochromaffin tumor cells by RT-PCR, showing that single cells can co-express several ORs. Some of the receptors identified were already reported in other tumors, but they are orphan (without known ligand), as it is the case for most of the hundreds of human ORs. Thus, genes coding for human ORs with known ligands were transfected into these cells, expressing functional heterologous ORs. The in vitro stimulation of these cells by the corresponding OR odorant agonists promoted cell invasion of collagen gels. Using LNCaP prostate cancer cells, the stimulation of the PSGR (Prostate Specific G protein-coupled Receptor), an endogenously overexpressed OR, by β-ionone, its odorant agonist, resulted in the same phenotypic change. We also showed the involvement of a PI3 kinase γ dependent signaling pathway in this promotion of tumor cell invasiveness triggered by OR stimulation. Finally, after subcutaneous inoculation of LNCaP cells into NSG immunodeficient mice, the in vivo stimulation of these cells by the PSGR agonist β-ionone significantly enhanced metastasis emergence and spreading.

  3. AMPA-Kainate Receptor Inhibition Promotes Neurologic Recovery in Premature Rabbits with Intraventricular Hemorrhage

    PubMed Central

    Dohare, Preeti; Zia, Muhammad T.; Ahmed, Ehsan; Ahmed, Asad; Yadala, Vivek; Schober, Alexandra L.; Ortega, Juan Alberto; Kayton, Robert; Ungvari, Zoltan; Mongin, Alexander A.

    2016-01-01

    of survivors with IVH develop cerebral palsy and cognitive deficits. The development of IVH leads to inflammation of the periventricular white matter, apoptosis and arrested maturation of oligodendrocyte precursor cells, and hypomyelination. Here, we show that AMPA-kainate receptor inhibition by NBQX suppresses inflammation, attenuates apoptosis of oligodendrocyte precursor cells, and promotes myelination as well as clinical recovery in preterm rabbits with IVH. Importantly, AMPA-specific inhibition by the FDA-approved perampanel, which unlike NBQX has a low side-effect profile, also enhances myelination and neurological recovery in rabbits with IVH. Hence, the present study highlights the role of AMPA-kainate receptor in IVH-induced white matter injury and identifies a novel strategy of neuroprotection, which might improve the neurological outcome for premature infants with IVH. PMID:26985043

  4. AMPA-Kainate Receptor Inhibition Promotes Neurologic Recovery in Premature Rabbits with Intraventricular Hemorrhage.

    PubMed

    Dohare, Preeti; Zia, Muhammad T; Ahmed, Ehsan; Ahmed, Asad; Yadala, Vivek; Schober, Alexandra L; Ortega, Juan Alberto; Kayton, Robert; Ungvari, Zoltan; Mongin, Alexander A; Ballabh, Praveen

    2016-03-16

    IVH develop cerebral palsy and cognitive deficits. The development of IVH leads to inflammation of the periventricular white matter, apoptosis and arrested maturation of oligodendrocyte precursor cells, and hypomyelination. Here, we show that AMPA-kainate receptor inhibition by NBQX suppresses inflammation, attenuates apoptosis of oligodendrocyte precursor cells, and promotes myelination as well as clinical recovery in preterm rabbits with IVH. Importantly, AMPA-specific inhibition by the FDA-approved perampanel, which unlike NBQX has a low side-effect profile, also enhances myelination and neurological recovery in rabbits with IVH. Hence, the present study highlights the role of AMPA-kainate receptor in IVH-induced white matter injury and identifies a novel strategy of neuroprotection, which might improve the neurological outcome for premature infants with IVH. Copyright © 2016 the authors 0270-6474/16/363364-15$15.00/0.

  5. AT2 receptor non-peptide agonist C21 promotes natriuresis in obese Zucker rats.

    PubMed

    Ali, Quaisar; Hussain, Tahir

    2012-06-01

    Previously, we demonstrated that angiotensin II type 2 (AT(2)) receptors have a role in natriuresis in obese Zucker rats (OZR). In the present study, we investigated the role of a novel, non-peptide agonist, C21, in natriuresis via AT(2) receptor activation in OZR. Infusion of C21 (1 and 5 μg kg(-1) min(-1)) into rats under anesthesia caused a dose-dependent increase in urine flow (UF) and urinary Na volume (U(Na)V). These effects of C21 were blocked by pre-infusion of the AT(2) receptor antagonist, PD123319, (50 μg kg(-1) min(-1)), suggesting involvement of the AT(2) receptor. Infusion of C21 (5 μg kg(-1) min(-1)) significantly increased the fractional excretion of sodium without changing the glomerular filtration rate or blood pressure, suggesting a tubular effect. Similarly, C21 infusion increased the fractional excretion of lithium, suggesting a proximal tubular effect. Furthermore, we tested the effect of C21 on natriuresis after blocking two main, distal-nephron Na transporters, the epithelial Na channels (ENaC), with amiloride (AM, 3 mg kg(-1) body wt), and the NaCl cotransporters (NCC), with bendroflumethiazide (BFTZ, 7 mg kg(-1) body wt). Infusion of AM + BFTZ caused significant increases in both diuresis and natriuresis, which were further increased by infusion of C21 (5 μg kg(-1) min(-1)). Natriuresis in response to C21 was associated with increases in urinary NO and cGMP levels. The data indicate that the AT(2) receptor agonist, C21, promotes natriuresis via AT(2) receptor activation and that this effect is potentially based in the proximal tubules and linked to the nitric oxide/cyclic guanosine monophosphate pathway. The natriuretic response to C21 may have therapeutic significance by improving kidney function in obesity.

  6. Glycone-rich Soy Isoflavone Extracts Promote Estrogen Receptor Positive Breast Cancer Cell Growth.

    PubMed

    Johnson, Kailee A; Vemuri, Sravan; Alsahafi, Sameerh; Castillo, Rudy; Cheriyath, Venugopalan

    2016-01-01

    Due to the association of hormone replacement therapy (HRT) with breast cancer risk, estrogenically active soy isoflavones are considered as an HRT alternative to alleviate menopausal symptoms. However, several recent reports challenged the health benefits of soy isoflavones and associated them with breast cancer promotion. While glyconic isoflavones are the major constituents of soybean seeds, due to their low cell permeability, they are considered to be biologically inactive. The glyconic isoflavones may exert their effects on membrane-bound estrogen receptors or could be converted to aglycones by extracellular β-glucosidases. Therefore, we hypothesized that despite their low cell permeability, soybean cultivars with high glyconic isoflavones may promote breast cancer cell growth. To test this, composition and estrogenic activity of isoflavones from 54 commercial soybean cultivars were determined. Soybean seeds produced in identical climate and growth conditions were used to minimize the effects of extraneous factors on isoflavone profile and concentrations. The glyconic daidzin concentration negatively correlated with genistin and with other aglycones. Relative to control, isoflavone extracts from 51 cultivars were estrogenic and promoted the growth of estrogen receptor positive (ER+) breast cancer cell line MCF-7 from 1.14 to 4.59 folds and other three cultivars slightly reduced the growth. Among these, extracts from three cultivars were highly estrogenic and promoted MCF-7 cell growth by 2.59-4.64 folds (P<0.005). Among six isoflavones, daidzin was positively associated with MCF-7 cell growth (P<0.005, r = 0.13966), whereas the negative correlation between genistin and MCF-7 cell growth was nearly significant (P≤0.0562, r = -0.026141). Furthermore, in drug interaction studies daidzin-rich isoflavone extracts antagonized tamoxifen, an ER inhibitor. Taken together, our results suggest that the glyconic daidzin-rich soy isoflavone extracts may exert estrogenic

  7. Phosphorylation of histone H3 is functionally linked to retinoic acid receptor β promoter activation

    PubMed Central

    Lefebvre, Bruno; Ozato, Keiko; Lefebvre, Philippe

    2002-01-01

    Ligand-dependent transcriptional activation of retinoic acid receptors (RARs) is a multistep process culminating in the formation of a multimeric co-activator complex on regulated promoters. Several co-activator complexes harbor an acetyl transferase activity, which is required for retinoid-induced transcription of reporter genes. Using murine P19 embryonal carcinoma cells, we examined the relationship between histone post-translational modifications and activation of the endogenous RARβ2 promoter, which is under the control of a canonical retinoic acid response element and rapidly induced upon retinoid treatment. While histones H3 and H4 were constitutively acetylated at this promoter, retinoid agonists induced a rapid phosphorylation at Ser10 of histone H3. A retinoid antagonist, whose activity was independent of co-repressor binding to RAR, could oppose this agonist-induced H3 phosphorylation. Since such post-translational modifications were not observed at several other promoters, we conclude that histone H3 phosphorylation may be a molecular signature of the activated, retinoid-controlled mRARβ2 gene promoter. PMID:11897660

  8. Nonmyogenic factors bind nicotinic acetylcholine receptor promoter elements required for response to denervation.

    PubMed

    Bessereau, J L; Laudenbach, V; Le Poupon, C; Changeux, J P

    1998-05-22

    Nicotinic acetylcholine receptors (AChRs) belong to a class of muscle proteins whose expression is regulated by muscle electrical activity. In innervated muscle fiber, AChR genes are transcriptionally repressed outside of the synapse, while after denervation they become reexpressed throughout the fiber. The myogenic determination factors (MDFs) of the MyoD family have been shown to play a central role in this innervation-dependent regulation. In the chicken AChR alpha-subunit gene promoter, two E-boxes that bind MDFs are necessary to achieve the enhancement of transcription following muscle denervation. However, the deletion of promoter sequences located upstream to these E-boxes greatly impairs the response to denervation (Bessereau, J. L., Stratford- Perricaudet, L. D., Piette, J., Le Poupon, C. and Changeux, J. P. (1994) Proc. Natl. Acad. Sci. U. S. A. 91, 1304-1308). Here we identified two additional cis-regulatory elements of the alpha-subunit gene promoter that cooperate with the E-boxes in the denervation response. One region binds the Sp1 and Sp3 zinc finger transcription factors. The second region binds at least three distinct factors, among which we identified an upstream stimulatory factor, a b-ZIP-HLH transcription factor. We propose that among MDF-responsive muscle promoters, a specific combination between myogenic and nonmyogenic factors specify innervation-dependent versus innervation-independent promoters.

  9. Goat activin receptor type IIB knockdown by muscle specific promoter driven artificial microRNAs.

    PubMed

    Patel, Amrutlal K; Shah, Ravi K; Patel, Utsav A; Tripathi, Ajai K; Joshi, Chaitanya G

    2014-10-10

    Activin receptor type IIB (ACVR2B) is a transmembrane receptor which mediates signaling of TGF beta superfamily ligands known to function in regulation of muscle mass, embryonic development and reproduction. ACVR2B antagonism has shown to enhance the muscle growth in several disease and transgenic models. Here, we show ACVR2B knockdown by RNA interference using muscle creatine kinase (MCK) promoter driven artificial microRNAs (amiRNAs). Among the various promoter elements tested, the ∼1.26 kb MCK promoter region showed maximum transcriptional activity in goat myoblasts cells. We observed up to 20% silencing in non-myogenic 293T cells and up to 32% silencing in myogenic goat myoblasts by MCK directed amiRNAs by transient transfection. Goat myoblasts stably integrated with MCK directed amiRNAs showed merely 8% silencing in proliferating myoblasts which was increased to 34% upon induction of differentiation at transcript level whereas up to 57% silencing at protein level. Knockdown of ACVR2B by 5'-UTR derived amiRNAs resulted in decreased SMAD2/3 signaling, increased expression of myogenic regulatory factors (MRFs) and enhanced proliferation and differentiation of myoblasts. Unexpectedly, knockdown of ACVR2B by 3'-UTR derived amiRNAs resulted in increased SMAD2/3 signaling, reduced expression of MRFs and suppression of myogenesis. Our study offers muscle specific knockdown of ACVR2B as a potential strategy to enhance muscle mass in the farm animal species.

  10. Characterization of the promoter of human CRTh2, a prostaglandin D{sub 2} receptor

    SciTech Connect

    Quapp, Russell; Madsen, Norman; Cameron, Lisa

    2007-11-30

    Chemoattractant-receptor homologous molecule expressed on Th2 cells (CRTh2) is a receptor for prostaglandin (PG)D{sub 2}, a lipid mediator involved in allergic inflammation. CRTh2 is expressed by Th2 cells, eosinophils and basophils and PDG{sub 2}-CRTh2 signaling induces calcium mobilization, cell migration and expression of the Th2 cytokines IL-4, IL-5, and IL-13. Despite the role of CRTh2 in allergic inflammation, transcriptional regulation of this gene has not been studied. Here, we demonstrated that a reporter construct of the CRTh2 promoter was induced following T cell stimulation. This activity could be further enhanced by over-expression of GATA-3, but not NFAT2 or STAT6. Electromobility shift assay demonstrated GATA-3 binding to a probe from the CRTh2 promoter. This study provides the first detailed analysis of transcriptional regulation of the human CRTh2 promoter. These findings may help identify strategies to attenuate expression of this gene and influence the maintenance and proliferation of Th2 cells in allergic inflammation.

  11. Functional diversity of Robo receptor immunoglobulin domains promotes distinct axon guidance decisions.

    PubMed

    Evans, Timothy A; Bashaw, Greg J

    2010-03-23

    Recognition molecules of the immunoglobulin (Ig) superfamily control axon guidance in the developing nervous system. Ig-like domains are among the most widely represented protein domains in the human genome, and the number of Ig superfamily proteins is strongly correlated with cellular complexity. In Drosophila, three Roundabout (Robo) Ig superfamily receptors respond to their common Slit ligand to regulate axon guidance at the midline: Robo and Robo2 mediate midline repulsion, Robo2 and Robo3 control longitudinal pathway selection, and Robo2 can promote midline crossing. How these closely related receptors mediate distinct guidance functions is not understood. We report that the differential functions of Robo2 and Robo3 are specified by their ectodomains and do not reflect differences in cytoplasmic signaling. Functional modularity of Robo2's ectodomain facilitates multiple guidance decisions: Ig1 and Ig3 of Robo2 confer lateral positioning activity, whereas Ig2 confers promidline crossing activity. Robo2's distinct functions are not dependent on greater Slit affinity but are instead due in part to differences in multimerization and receptor-ligand stoichiometry conferred by Robo2's Ig domains. Together, our findings suggest that diverse responses to the Slit guidance cue are imparted by intrinsic structural differences encoded in the extracellular Ig domains of the Robo receptors.

  12. A novel fibroblast growth factor receptor family member promotes neuronal outgrowth and synaptic plasticity in aplysia.

    PubMed

    Pollak, Daniela D; Minh, Bui Quang; Cicvaric, Ana; Monje, Francisco J

    2014-11-01

    Fibroblast Growth Factor (FGF) Receptors (FGFRs) regulate essential biological processes, including embryogenesis, angiogenesis, cellular growth and memory-related long-term synaptic plasticity. Whereas canonical FGFRs depend exclusively on extracellular Immunoglobulin (Ig)-like domains for ligand binding, other receptor types, including members of the tropomyosin-receptor-kinase (Trk) family, use either Ig-like or Leucine-Rich Repeat (LRR) motifs, or both. Little is known, however, about the evolutionary events leading to the differential incorporation of LRR domains into Ig-containing tyrosine kinase receptors. Moreover, although FGFRs have been identified in many vertebrate species, few reports describe their existence in invertebrates. Information about the biological relevance of invertebrate FGFRs and evolutionary divergences between them and their vertebrate counterparts is therefore limited. Here, we characterized ApLRRTK, a neuronal cell-surface protein recently identified in Aplysia. We unveiled ApLRRTK as the first member of the FGFRs family deprived of Ig-like domains that instead contains extracellular LRR domains. We describe that ApLRRTK exhibits properties typical of canonical vertebrate FGFRs, including promotion of FGF activity, enhancement of neuritic outgrowth and signaling via MAPK and the transcription factor CREB. ApLRRTK also enhanced the synaptic efficiency of neurons known to mediate in vivo memory-related defensive behaviors. These data reveal a novel molecular regulator of neuronal function in invertebrates, provide the first evolutionary linkage between LRR proteins and FGFRs and unveil an unprecedented mechanism of FGFR gene diversification in primeval central nervous systems.

  13. Neuronal receptor activity-modifying protein 1 promotes energy expenditure in mice.

    PubMed

    Zhang, Zhongming; Liu, Xuebo; Morgan, Donald A; Kuburas, Adisa; Thedens, Daniel R; Russo, Andrew F; Rahmouni, Kamal

    2011-04-01

    Receptor activity-modifying proteins (RAMPs) 1, 2, and 3 are unusual accessory proteins that dictate the binding specificity of two G protein-coupled receptors involved in energy homeostasis: calcitonin gene-related peptide (CGRP) and amylin receptors. These proteins are expressed throughout the central nervous system (CNS), including in the brain regions involved in the regulation of energy homeostasis, but the significance of CNS RAMPs in the control of energy balance remains unknown. To examine the functional significance of modulating neuronal RAMP1, we assessed the effect of overexpressing human RAMP1 (hRAMP1) in the CNS on body energy balance. Nestin/hRAMP1 transgenic mice have a remarkably decreased body weight associated with reduced fat mass and circulating leptin levels. The transgenic mice exhibited higher energy expenditure as indicated by increased oxygen consumption, body temperature, and sympathetic tone subserving brown adipose tissue (BAT). Consistent with this, the nestin/hRAMP1 transgenic mice had elevated BAT mRNA levels of peroxisome proliferator-activated receptor γ coactivator 1α and uncoupling protein 1 and 3, and these changes can be reversed by chronic blockade of sympathetic nervous system signaling. Furthermore, metabolic response to amylin was enhanced in the nestin/hRAMP1 mice whereas the response to CGRP was blunted, possibly the result of higher expression of CGRP in the CNS. These data demonstrate that CNS RAMP1 plays a pivotal role in the regulation of energy homeostasis by promoting energy expenditure.

  14. Site-specific ubiquitination exposes a linear motif to promote interferon-α receptor endocytosis

    PubMed Central

    Kumar, K.G. Suresh; Barriere, Hervé; Carbone, Christopher J.; Liu, Jianghuai; Swaminathan, Gayathri; Xu, Ping; Li, Ying; Baker, Darren P.; Peng, Junmin; Lukacs, Gergely L.; Fuchs, Serge Y.

    2007-01-01

    Ligand-induced endocytosis and lysosomal degradation of cognate receptors regulate the extent of cell signaling. Along with linear endocytic motifs that recruit the adaptin protein complex 2 (AP2)–clathrin molecules, monoubiquitination of receptors has emerged as a major endocytic signal. By investigating ubiquitin-dependent lysosomal degradation of the interferon (IFN)-α/β receptor 1 (IFNAR1) subunit of the type I IFN receptor, we reveal that IFNAR1 is polyubiquitinated via both Lys48- and Lys63-linked chains. The SCFβTrcp (Skp1–Cullin1–F-box complex) E3 ubiquitin ligase that mediates IFNAR1 ubiquitination and degradation in cells can conjugate both types of chains in vitro. Although either polyubiquitin linkage suffices for postinternalization sorting, both types of chains are necessary but not sufficient for robust IFNAR1 turnover and internalization. These processes also depend on the proximity of ubiquitin-acceptor lysines to a linear endocytic motif and on its integrity. Furthermore, ubiquitination of IFNAR1 promotes its interaction with the AP2 adaptin complex that is required for the robust internalization of IFNAR1, implicating cooperation between site-specific ubiquitination and the linear endocytic motif in regulating this process. PMID:18056411

  15. Endogenous central amygdala mu-opioid receptor signaling promotes sodium appetite in mice

    PubMed Central

    Smith, Craig M.; Walker, Lesley L.; Leeboonngam, Tanawan; McKinley, Michael J.; Denton, Derek A.; Lawrence, Andrew J.

    2016-01-01

    Due to the importance of dietary sodium and its paucity within many inland environments, terrestrial animals have evolved an instinctive sodium appetite that is commensurate with sodium deficiency. Despite a well-established role for central opioid signaling in sodium appetite, the endogenous influence of specific opioid receptor subtypes within distinct brain regions remains to be elucidated. Using selective pharmacological antagonists of opioid receptor subtypes, we reveal that endogenous mu-opioid receptor (MOR) signaling strongly drives sodium appetite in sodium-depleted mice, whereas a role for kappa (KOR) and delta (DOR) opioid receptor signaling was not detected, at least in sodium-depleted mice. Fos immunohistochemistry revealed discrete regions of the mouse brain displaying an increased number of activated neurons during sodium gratification: the rostral portion of the nucleus of the solitary tract (rNTS), the lateral parabrachial nucleus (LPB), and the central amygdala (CeA). The CeA was subsequently targeted with bilateral infusions of the MOR antagonist naloxonazine, which significantly reduced sodium appetite in mice. The CeA is therefore identified as a key node in the circuit that contributes to sodium appetite. Moreover, endogenous opioids, acting via MOR, within the CeA promote this form of appetitive behavior. PMID:27849613

  16. Nuclear Receptor Nr4a2 Promotes Alternative Polarization of Macrophages and Confers Protection in Sepsis.

    PubMed

    Mahajan, Sahil; Saini, Ankita; Chandra, Vemika; Nanduri, Ravikanth; Kalra, Rashi; Bhagyaraj, Ella; Khatri, Neeraj; Gupta, Pawan

    2015-07-24

    The orphan nuclear receptor Nr4a2 is known to modulate both inflammatory and metabolic processes, but the mechanism by which it regulates innate inflammatory homeostasis has not been adequately addressed. This study shows that exposure to ligands for Toll-like receptors (TLRs) robustly induces Nr4a2 and that this induction is tightly regulated by the PI3K-Akt signaling axis. Interestingly, exogenous expression of Nr4a2 in macrophages leads to their alternative phenotype with induction of genes that are prototypical M2 markers. Moreover, Nr4a2 transcriptionally activates arginase 1 expression by directly binding to its promoter. Adoptive transfer experiments revealed that increased survival of animals in endotoxin-induced sepsis is Nr4a2-dependent. Thus our data identify a previously unknown role for Nr4a2 in the regulation of macrophage polarization. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  17. Epigenetic regulation of the glucocorticoid receptor promoter 1(7) in adult rats.

    PubMed

    Witzmann, Simone R; Turner, Jonathan D; Mériaux, Sophie B; Meijer, Onno C; Muller, Claude P

    2012-11-01

    Regulation of glucocorticoid receptor (GR) levels is an important stress adaptation mechanism. Transcription factor Nfgi-a and environmentally induced Gr promoter 1 7 methylation have been implicated in fine-tuning the expression of Gr 1 7 transcripts. Here, we investigated Gr promoter 1 7 methylation and Gr 1 7 expression in adult rats exposed to either acute or chronic stress paradigms. A strong negative correlation was observed between the sum of promoter-wide methylation levels and Gr 1 7 transcript levels, independent of the stressor. Methylation of individual sites did not, however, correlate with transcript levels. This suggested that promoter 1 7 was directly regulated by promoter-wide DNA methylation. Although acute stress increased Ngfi-a expression in the hypothalamic paraventricular nucleus (PVN), Gr 1 7 transcript levels remained unaffected despite low methylation levels. Acute stress had little effect on these low methylation levels, except at four hippocampal CpGs. Chronic stress altered the corticosterone response to an acute stressor. In the adrenal and pituitary glands, but not in the brain, this was accompanied by an increase in methylation levels in orchestrated clusters rather than individual CpGs. PVN methylation levels, unaffected by acute or chronic stress, were significantly more variable within- than between-groups, suggesting that they were instated probably during the perinatal period and represent a pre-established trait. Thus, in addition to the known perinatal programming, the Gr 1 7 promoter is epigenetically regulated by chronic stress in adulthood, and retains promoter-wide tissue-specific plasticity. Differences in methylation susceptibility between the PVN in the perinatal period and the peripheral HPA axis tissues in adulthood may represent an important "trait" vs. "state" regulation of the Gr gene.

  18. Exceptional longevity in female Rottweiler dogs is not encumbered by investment in reproduction.

    PubMed

    Kengeri, S S; Maras, A H; Suckow, C L; Chiang, E C; Waters, D J

    2013-12-01

    To better understand the potential trade-off between female reproductive investment and longevity in an emerging model of human healthspan, we studied pet dogs to determine whether intensity of reproduction (total number of offspring) encumbered the likelihood of exceptional longevity. This hypothesis was tested by collecting and analyzing lifetime medical histories, including complete reproductive histories, for a cohort of canine "centenarians"--exceptionally long-lived Rottweiler dogs that lived more than 30% longer than the breed's average life expectancy. Reproductive intensity (number of litters, total number of pups) and tempo of reproductive effort (age at first reproduction, mean interbirth interval, age at last reproduction) in 78 exceptionally long-lived female Rottweilers (>13 years old) were compared to a cohort of 97 female Rottweilers that had usual longevity (age at death 8.0-10.75 years). We found no evidence that a mother's physiological investment in offspring was associated with disadvantaged longevity. Instead, similar to some studies in women, our data showed an inverted U-shaped trend, suggesting that moderate investment in reproduction may promote longevity. Late reproductive success, a much-studied surrogate of maternal fitness in women, was not a strong predictor of longevity in this canine cohort. Instead, independent of reproductive investment, the duration of lifetime ovary exposure was significantly associated with highly successful aging. Our results from exceptionally long-lived pet dogs provide rationale for further investigative efforts to understand the ovary-sensitive biological factors that promote healthy longevity in women and pet dogs.

  19. Longevity and ageing: appraising the evolutionary consequences of growing old

    PubMed Central

    Bonsall, Michael B

    2005-01-01

    Senescence or ageing is an increase in mortality and/or decline in fertility with increasing age. Evolutionary theories predict that ageing or longevity evolves in response to patterns of extrinsic mortality or intrinsic damage. If ageing is viewed as the outcome of the processes of behaviour, growth and reproduction then it should be possible to predict mortality rate. Recent developments have shown that it is now possible to integrate these ecological and physiological processes and predict the shape of mortality trajectories. By drawing on the key exciting developments in the cellular, physiological and ecological process of longevity the evolutionary consequences of ageing are reviewed. In presenting these ideas an evolutionary demographic framework is used to argue how trade-offs in life-history strategies are important in the maintenance of variation in longevity within and between species. Evolutionary processes associated with longevity have an important role in explaining levels of biological diversity and speciation. In particular, the effects of life-history trait trade-offs in maintaining and promoting species diversity are explored. Such trade-offs can alleviate the effects of intense competition between species and promote species coexistence and diversification. These results have important implications for understanding a number of core ecological processes such as how species are divided among niches, how closely related species co-occur and the rules by which species assemble into food-webs. Theoretical work reveals that the proximate physiological processes are as important as the ecological factors in explaining the variation in the evolution of longevity. Possible future research challenges integrating work on the evolution and mechanisms of growing old are briefly discussed. PMID:16553312

  20. Indy Mutations and Drosophila Longevity

    PubMed Central

    Rogina, Blanka; Helfand, Stephen L.

    2013-01-01

    Decreased expression of the fly and worm Indy genes extends longevity. The fly Indy gene and its mammalian homolog are transporters of Krebs cycle intermediates, with the highest rate of uptake for citrate. Cytosolic citrate has a role in energy regulation by affecting fatty acid synthesis and glycolysis. Fly, worm, and mice Indy gene homologs are predominantly expressed in places important for intermediary metabolism. Consequently, decreased expression of Indy in fly and worm, and the removal of mIndy in mice exhibit changes associated with calorie restriction, such as decreased levels of lipids, changes in carbohydrate metabolism and increased mitochondrial biogenesis. Here we report that several Indy alleles in a diverse array of genetic backgrounds confer increased longevity. PMID:23580130

  1. Longevity of silicate ceramic restorations.

    PubMed

    Beier, Ulrike Stephanie; Dumfahrt, Herbert

    2014-09-01

    The demand for esthetic restorations has resulted in an increased use of dental ceramics as a biocompatible and functionally sufficient alternative to conventional restorative materials. Silicate ceramic restorations are widely used for veneers, inlays, onlays, and crowns in dentistry. Long-term data are of crucial importance to optimize clinical practice. The purpose of the present article is to summarize data of the Innsbruck ceramic evaluation up to 261 months with the focus on longevity and failure characteristics.

  2. Kappa opioid receptor activation alleviates experimental autoimmune encephalomyelitis and promotes oligodendrocyte-mediated remyelination.

    PubMed

    Du, Changsheng; Duan, Yanhui; Wei, Wei; Cai, Yingying; Chai, Hui; Lv, Jie; Du, Xiling; Zhu, Jian; Xie, Xin

    2016-04-04

    Multiple sclerosis (MS) is characterized by autoimmune damage to the central nervous system. All the current drugs for MS target the immune system. Although effective in reducing new lesions, they have limited effects in preventing the progression of disability. Promoting oligodendrocyte-mediated remyelination and recovery of neurons are the new directions of MS therapy. The endogenous opioid system, consisting of MOR, DOR, KOR and their ligands, has been suggested to participate in the pathogenesis of MS. However, the exact receptor and mechanism remain elusive. Here we show that genetic deletion of KOR exacerbates experimental autoimmune encephalomyelitis, whereas activating KOR with agonists alleviates the symptoms. KOR does not affect immune cell differentiation and function. Instead, it promotes oligodendrocyte differentiation and myelination both in vitro and in vivo. Our study suggests that targeting KOR might be an intriguing way to develop new MS therapies that may complement the existing immunosuppressive approaches.

  3. Kappa opioid receptor activation alleviates experimental autoimmune encephalomyelitis and promotes oligodendrocyte-mediated remyelination

    PubMed Central

    Du, Changsheng; Duan, Yanhui; Wei, Wei; Cai, Yingying; Chai, Hui; Lv, Jie; Du, Xiling; Zhu, Jian; Xie, Xin

    2016-01-01

    Multiple sclerosis (MS) is characterized by autoimmune damage to the central nervous system. All the current drugs for MS target the immune system. Although effective in reducing new lesions, they have limited effects in preventing the progression of disability. Promoting oligodendrocyte-mediated remyelination and recovery of neurons are the new directions of MS therapy. The endogenous opioid system, consisting of MOR, DOR, KOR and their ligands, has been suggested to participate in the pathogenesis of MS. However, the exact receptor and mechanism remain elusive. Here we show that genetic deletion of KOR exacerbates experimental autoimmune encephalomyelitis, whereas activating KOR with agonists alleviates the symptoms. KOR does not affect immune cell differentiation and function. Instead, it promotes oligodendrocyte differentiation and myelination both in vitro and in vivo. Our study suggests that targeting KOR might be an intriguing way to develop new MS therapies that may complement the existing immunosuppressive approaches. PMID:27040771

  4. The Shh receptor Boc promotes progression of early medulloblastoma to advanced tumors.

    PubMed

    Mille, Frédéric; Tamayo-Orrego, Lukas; Lévesque, Martin; Remke, Marc; Korshunov, Andrey; Cardin, Julie; Bouchard, Nicolas; Izzi, Luisa; Kool, Marcel; Northcott, Paul A; Taylor, Michael D; Pfister, Stefan M; Charron, Frédéric

    2014-10-13

    During cerebellar development, Sonic hedgehog (Shh) signaling drives the proliferation of granule cell precursors (GCPs). Aberrant activation of Shh signaling causes overproliferation of GCPs, leading to medulloblastoma. Although the Shh-binding protein Boc associates with the Shh receptor Ptch1 to mediate Shh signaling, whether Boc plays a role in medulloblastoma is unknown. Here, we show that BOC is upregulated in medulloblastomas and induces GCP proliferation. Conversely, Boc inactivation reduces proliferation and progression of early medulloblastomas to advanced tumors. Mechanistically, we find that Boc, through elevated Shh signaling, promotes high levels of DNA damage, an effect mediated by CyclinD1. High DNA damage in the presence of Boc increases the incidence of Ptch1 loss of heterozygosity, an important event in the progression from early to advanced medulloblastoma. Together, our results indicate that DNA damage promoted by Boc leads to the demise of its own coreceptor, Ptch1, and consequently medulloblastoma progression. Copyright © 2014 Elsevier Inc. All rights reserved.

  5. The Aryl Hydrocarbon Receptor Relays Metabolic Signals to Promote Cellular Regeneration

    PubMed Central

    2016-01-01

    While sensing the cell environment, the aryl hydrocarbon receptor (AHR) interacts with different pathways involved in cellular homeostasis. This review summarizes evidence suggesting that cellular regeneration in the context of aging and diseases can be modulated by AHR signaling on stem cells. New insights connect orphaned observations into AHR interactions with critical signaling pathways such as WNT to propose a role of this ligand-activated transcription factor in the modulation of cellular regeneration by altering pathways that nurture cellular expansion such as changes in the metabolic efficiency rather than by directly altering cell cycling, proliferation, or cell death. Targeting the AHR to promote regeneration might prove to be a useful strategy to avoid unbalanced disruptions of homeostasis that may promote disease and also provide biological rationale for potential regenerative medicine approaches. PMID:27563312

  6. Statistical laws for career longevity

    NASA Astrophysics Data System (ADS)

    Petersen, Alexander; Jung, Woo-Sung; Yang, Jae-Suk; Stanley, H. Eugene

    2009-03-01

    Career length distinguishes successful long tenures from unsuccessful short stints, and partially reflects the contributions of an employee to the goals of the employer. In some professions, there are well-defined metrics that quantify career longevity, prowess, and productivity, which together contribute to the overall success rating for an individual employee. In this talk, I motivate a stochastic model for career development that relies on two key ingredients, random progress within the career and random stopping times terminating the career. This model is exactly solvable, predicting the probability density function (pdf) of career longevity, characterized by two parameters, α and xc. The parameter α quantifies the power-law scaling of the pdf, which is terminated by an exponential cutoff after a crossover value xc, representing the mean career lifetime. We test the model with the large quantity of empirical data available for several professional sports leagues, American baseball, Korean baseball, American basketball, and English soccer, finding excellent agreement with the model's predictions. In all, the generality of the model suggests that there may be common stochastic forces that underly progress, success, and longevity in various professions.

  7. The Dual Hypocretin Receptor Antagonist Almorexant is Permissive for Activation of Wake-Promoting Systems

    PubMed Central

    Parks, Gregory S; Warrier, Deepti R; Dittrich, Lars; Schwartz, Michael D; Palmerston, Jeremiah B; Neylan, Thomas C; Morairty, Stephen R; Kilduff, Thomas S

    2016-01-01

    The dual hypocretin receptor (HcrtR) antagonist almorexant (ALM) may promote sleep through selective disfacilitation of wake-promoting systems, whereas benzodiazepine receptor agonists (BzRAs) such as zolpidem (ZOL) induce sleep through general inhibition of neural activity. Previous studies have indicated that HcrtR antagonists cause less-functional impairment than BzRAs. To gain insight into the mechanisms underlying these differential profiles, we compared the effects of ALM and ZOL on functional activation of wake-promoting systems at doses equipotent for sleep induction. Sprague-Dawley rats, implanted for EEG/EMG recording, were orally administered vehicle (VEH), 100 mg/kg ALM, or 100 mg/kg ZOL during their active phase and either left undisturbed or kept awake for 90 min after which their brains were collected. ZOL-treated rats required more stimulation to maintain wakefulness than VEH- or ALM-treated rats. We measured Fos co-expression with markers for wake-promoting cell groups in the lateral hypothalamus (Hcrt), tuberomammillary nuclei (histamine; HA), basal forebrain (acetylcholine; ACh), dorsal raphe (serotonin; 5HT), and singly labeled Fos+ cells in the locus coeruleus (LC). Following SD, Fos co-expression in Hcrt, HA, and ACh neurons (but not in 5HT neurons) was consistently elevated in VEH- and ALM-treated rats, whereas Fos expression in these neuronal groups was unaffected by SD in ZOL-treated rats. Surprisingly, Fos expression in the LC was elevated in ZOL- but not in VEH- or ALM-treated SD animals. These results indicate that Hcrt signaling is unnecessary for the activation of Hcrt, HA, or ACh wake-active neurons, which may underlie the milder cognitive impairment produced by HcrtR antagonists compared to ZOL. PMID:26289145

  8. Prostaglandin E2 promotes proliferation of skeletal muscle myoblasts via EP4 receptor activation

    PubMed Central

    Mo, Chenglin; Zhao, Ruonan; Vallejo, Julian; Igwe, Orisa; Bonewald, Lynda; Wetmore, Lori; Brotto, Marco

    2015-01-01

    We recently demonstrated that conditioned media (CM) from osteocytes enhances myogenic differentiation of myoblasts, suggesting that signaling from bone may be important for skeletal muscle myogenesis. The effect of CM was closely mimicked by prostaglandin E2 (PGE2), a bioactive lipid mediator in various physiological or pathological conditions. PGE2 is secreted at high levels by osteocytes and such secretion is further enhanced under loading conditions. Although four types of receptors, EP1 to EP4, mediate PGE2 signaling, it is unknown whether these receptors play a role in myogenesis. Therefore, in this study, the expression of EPs in mouse primary myoblasts was characterized, followed by examination of their roles in myoblast proliferation by treating myoblasts with PGE2 or specific agonists. All four PGE2 receptor mRNAs were detectable by quantitative real-time PCR (qPCR), but only PGE2 and EP4 agonist CAY 10598 significantly enhance myoblast proliferation. EP1/EP3 agonist 17-phenyl trinor PGE2 (17-PT PGE2) and EP2 agonist butaprost did not have any significant effects. Moreover, treatment with EP4 antagonist L161,982 dose-dependently inhibited myoblast proliferation. These results were confirmed by cell cycle analysis and the gene expression of cell cycle regulators. Concomitant with the inhibition of myoblast proliferation, treatment with L161,982 significantly increased intracellular reactive oxygen species (ROS) levels. Cotreatment with antioxidant N-acetyl cysteine (NAC) or sodium ascorbate (SA) successfully reversed the inhibition of myoblast proliferation and ROS overproduction caused by L161,982. Therefore, PGE2 signaling via the EP4 receptor regulates myogenesis by promoting myoblast proliferation and blocking this receptor results in increased ROS production in myoblasts. PMID:25785867

  9. Methylation Status of Vitamin D Receptor Gene Promoter in Benign and Malignant Adrenal Tumors

    PubMed Central

    Pilon, Catia; Rebellato, Andrea; Urbanet, Riccardo; Guzzardo, Vincenza; Cappellesso, Rocco; Sasano, Hironobu; Fassina, Ambrogio

    2015-01-01

    We previously showed a decreased expression of vitamin D receptor (VDR) mRNA/protein in a small group of adrenocortical carcinoma (ACC) tissues, suggesting the loss of a protective role of VDR against malignant cell growth in this cancer type. Downregulation of VDR gene expression may result from epigenetics events, that is, methylation of cytosine nucleotide of CpG islands in VDR gene promoter. We analyzed methylation of CpG sites in the VDR gene promoter in normal adrenals and adrenocortical tumor samples. Methylation of CpG-rich 5′ regions was assessed by bisulfite sequencing PCR using bisulfite-treated DNA from archival microdissected paraffin-embedded adrenocortical tissues. Three normal adrenals and 23 various adrenocortical tumor samples (15 adenomas and 8 carcinomas) were studied. Methylation in the promoter region of VDR gene was found in 3/8 ACCs, while no VDR gene methylation was observed in normal adrenals and adrenocortical adenomas. VDR mRNA and protein levels were lower in ACCs than in benign tumors, and VDR immunostaining was weak or negative in ACCs, including all 3 methylated tissue samples. The association between VDR gene promoter methylation and reduced VDR gene expression is not a rare event in ACC, suggesting that VDR epigenetic inactivation may have a role in adrenocortical carcinogenesis. PMID:26843863

  10. Aryl hydrocarbon receptor protects against bacterial infection by promoting macrophage survival and reactive oxygen species production.

    PubMed

    Kimura, Akihiro; Abe, Hiromi; Tsuruta, Sanae; Chiba, Sayuri; Fujii-Kuriyama, Yoshiaki; Sekiya, Takashi; Morita, Rimpei; Yoshimura, Akihiko

    2014-04-01

    Aryl hydrocarbon receptor (AhR) is crucial for various immune responses. The relationship between AhR and infection with the intracellular bacteria Listeria monocytogenes (LM) is poorly understood. Here, we show that in response to LM infection, AhR is required for bacterial clearance by promoting macrophage survival and reactive oxygen species (ROS) production. AhR-deficient mice were more susceptible to listeriosis, and AhR deficiency enhances bacterial growth in vivo and in vitro. On the other hand, pro-inflammatory cytokines were increased in AhR-deficient macrophages infected with LM despite enhanced susceptibility to LM infection in AhR-deficient mice. Subsequent studies demonstrate that AhR protects against macrophage cell death induced by LM infection through the induction of the antiapoptotic factor, the apoptosis inhibitor of macrophages, which promotes macrophage survival in the setting of LM infection. Furthermore, AhR promotes ROS production for bacterial clearance. Our results demonstrate that AhR is essential to the resistance against LM infection as it promotes macrophage survival and ROS production. This suggests that the activation of AhR by its ligands may be an effective strategy against listeriosis.

  11. AP-2{alpha} suppresses skeletal myoblast proliferation and represses fibroblast growth factor receptor 1 promoter activity

    SciTech Connect

    Mitchell, Darrion L.; DiMario, Joseph X.

    2010-01-15

    Skeletal muscle development is partly characterized by myoblast proliferation and subsequent differentiation into postmitotic muscle fibers. Developmental regulation of expression of the fibroblast growth factor receptor 1 (FGFR1) gene is required for normal myoblast proliferation and muscle formation. As a result, FGFR1 promoter activity is controlled by multiple transcriptional regulatory proteins during both proliferation and differentiation of myogenic cells. The transcription factor AP-2{alpha} is present in nuclei of skeletal muscle cells and suppresses myoblast proliferation in vitro. Since FGFR1 gene expression is tightly linked to myoblast proliferation versus differentiation, the FGFR1 promoter was examined for candidate AP-2{alpha} binding sites. Mutagenesis studies indicated that a candidate binding site located at - 1035 bp functioned as a repressor cis-regulatory element. Furthermore, mutation of this site alleviated AP-2{alpha}-mediated repression of FGFR1 promoter activity. Chromatin immunoprecipitation studies demonstrated that AP-2{alpha} interacted with the FGFR1 promoter in both proliferating myoblasts and differentiated myotubes. In total, these results indicate that AP-2{alpha} is a transcriptional repressor of FGFR1 gene expression during skeletal myogenesis.

  12. Renal angiotensin II AT2 receptors promote natriuresis in streptozotocin-induced diabetic rats.

    PubMed

    Hakam, Amer C; Siddiqui, Athar H; Hussain, Tahir

    2006-02-01

    Angiotensin II AT2 receptors have been implicated to play a role in the regulation of renal/cardiovascular functions under pathological conditions. The present study is designed to investigate the function of the AT2 receptors on renal sodium excretion and AT(2) receptor expression in the cortical membranes of streptozotocin (STZ)-induced diabetic rats. The STZ treatment led to a significant weight loss, hyperglycemia, and decrease in plasma insulin levels compared with control rats. STZ-induced diabetic rats had significantly elevated basal urine flow, urinary sodium excretion rate (U(Na)V), urinary fractional sodium excretion, and urinary cGMP compared with control rats. Infusion of PD-123319, an AT2 receptor antagonist, caused a significant decrease in U(Na)V (mumol/min) in STZ-induced diabetic rats (1 +/- 0.09 vs. 0.45 +/- 0.1) but not in control rats (0.35 +/- 0.05 vs. 0.4 +/- 0.07). The decrease in U(Na)V was associated with a significant decrease in urinary cGMP levels (pmol/min) in STZ-induced diabetic rats (21 +/- 2 vs. 10 +/- 0.8) but not in control rats (11.75 +/- 3 vs. 12.6 +/- 2). The infusion of PD-123319 did not alter glomerular filtration rate (STZ: 0.3 +/- 0.02 vs. 0.25 +/- 0.03; control: 1.4 +/- 0.05 vs. 1.5 +/- 0.09 ml/min) or mean arterial pressure (STZ: 82 +/- 3 vs. 79 +/- 3.5; control: 90 +/- 4 vs. 89 +/- 4 mmHg), suggesting a tubular effect of the drug. Western blot analysis using an AT2 receptor antibody revealed a significantly enhanced expression of the AT2 receptor protein ( approximately 45 kDa) in brush-border ( approximately 50-fold) and basolateral membranes ( approximately 80-fold) of STZ-induced diabetic compared with control rats. In conclusion, our data suggest that the tubular AT2 receptors in diabetic rats are profoundly enhanced and possibly via a cGMP pathway promote sodium excretion in this model of diabetes.

  13. Abluminal Stimulation of Sphingosine 1-Phosphate Receptors 1 and 3 Promotes and Stabilizes Endothelial Sprout Formation

    PubMed Central

    Lenz, Steven M.; Awojoodu, Anthony O.

    2015-01-01

    Local delivery of lipid mediators has become a promising new approach for therapeutic angiogenesis and regenerative medicine. In this study, we investigated how gradient stimulation (either abluminal/distal or luminal/proximal) of engineered microvessels with sphingosine 1-phosphate (S1P) receptor-subtype-targeted molecules affects endothelial sprout growth using a microfluidic device. Our studies show that distal stimulation of microvessels with FTY720, an S1P1/3 selective agonist, promotes both arterial and venular sprout growth, whereas proximal stimulation does not. Using novel pharmacological antagonists of S1P receptor subtypes, we further show that S1P3 functionality is necessary for VEGF-induced sprouting, and confirmed these findings ex vivo using a murine aortic ring assay from S1P3-deficient mice. S1P3 agonist stimulation enhanced vascular stability in both cell types via upregulation of the interendothelial junction protein VE-cadherin. Lastly, S1P3 activation under flow promoted endothelial sprouting and branching while decreasing migratory cell fate in the microfluidic device. We used an in vivo murine dorsal skinfold window chamber model to confirm S1P3's role in neovascular branching. Together, these data suggest that a distal transendothelial gradient of S1P1/3-targeted drugs is an effective technique for both enhancing and stabilizing capillary morphogenesis in angiogenic applications. PMID:25315888

  14. Impaired SUMOylation of nuclear receptor LRH-1 promotes nonalcoholic fatty liver disease.

    PubMed

    Stein, Sokrates; Lemos, Vera; Xu, Pan; Demagny, Hadrien; Wang, Xu; Ryu, Dongryeol; Jimenez, Veronica; Bosch, Fatima; Lüscher, Thomas F; Oosterveer, Maaike H; Schoonjans, Kristina

    2017-02-01

    Hepatic steatosis is caused by metabolic imbalances that could be explained in part by an increase in de novo lipogenesis that results from increased sterol element binding protein 1 (SREBP-1) activity. The nuclear receptor liver receptor homolog 1 (LRH-1) is an important regulator of intermediary metabolism in the liver, but its role in regulating lipogenesis is not well understood. Here, we have assessed the contribution of LRH-1 SUMOylation to the development of nonalcoholic fatty liver disease (NAFLD). Mice expressing a SUMOylation-defective mutant of LRH-1 (LRH-1 K289R mice) developed NAFLD and early signs of nonalcoholic steatohepatitis (NASH) when challenged with a lipogenic, high-fat, high-sucrose diet. Moreover, we observed that the LRH-1 K289R mutation induced the expression of oxysterol binding protein-like 3 (OSBPL3), enhanced SREBP-1 processing, and promoted de novo lipogenesis. Mechanistically, we demonstrated that ectopic expression of OSBPL3 facilitates SREBP-1 processing in WT mice, while silencing hepatic Osbpl3 reverses the lipogenic phenotype of LRH-1 K289R mice. These findings suggest that compromised SUMOylation of LRH-1 promotes the development of NAFLD under lipogenic conditions through regulation of OSBPL3.

  15. Abluminal stimulation of sphingosine 1-phosphate receptors 1 and 3 promotes and stabilizes endothelial sprout formation.

    PubMed

    Das, Anusuya; Lenz, Steven M; Awojoodu, Anthony O; Botchwey, Edward A

    2015-01-01

    Local delivery of lipid mediators has become a promising new approach for therapeutic angiogenesis and regenerative medicine. In this study, we investigated how gradient stimulation (either abluminal/distal or luminal/proximal) of engineered microvessels with sphingosine 1-phosphate (S1P) receptor-subtype-targeted molecules affects endothelial sprout growth using a microfluidic device. Our studies show that distal stimulation of microvessels with FTY720, an S1P1/3 selective agonist, promotes both arterial and venular sprout growth, whereas proximal stimulation does not. Using novel pharmacological antagonists of S1P receptor subtypes, we further show that S1P3 functionality is necessary for VEGF-induced sprouting, and confirmed these findings ex vivo using a murine aortic ring assay from S1P3-deficient mice. S1P3 agonist stimulation enhanced vascular stability in both cell types via upregulation of the interendothelial junction protein VE-cadherin. Lastly, S1P3 activation under flow promoted endothelial sprouting and branching while decreasing migratory cell fate in the microfluidic device. We used an in vivo murine dorsal skinfold window chamber model to confirm S1P3's role in neovascular branching. Together, these data suggest that a distal transendothelial gradient of S1P1/3-targeted drugs is an effective technique for both enhancing and stabilizing capillary morphogenesis in angiogenic applications.

  16. Structure of the gene for human. beta. /sub 2/-adrenergic receptor: expression and promoter characterization

    SciTech Connect

    Emorine, L.J.; Marullo, S.; Delavier-Klutchko, C.; Kaveri, S.V.; Durieu-Trautmann, O.; Strosberg, A.D.

    1987-10-01

    The genomic gene coding for the human ..beta../sub 2/-adrenergic receptor (..beta../sub 2/AR) from A431 epidermoid cells has been isolated. Transfection of the gene into eukaryotic cells restores a fully active receptor/GTP-binding protein/adenylate cyclase complex with ..beta../sub 2/AR properties. Southern blot analyses with ..beta../sub 2/AR-specific probes show that a single ..beta../sub 2/AR gene is common to various human tissues and that its flanking sequences are highly conserved among humans and between man and rabbit, mouse, and hamster. Functional significance of these regions is supported by the presence of a promoter region (including mRNA cap sites, two TATA boxes, a CAAT box, and three G + C-rich regions that resemble binding sites for transcription factor Sp1) 200-300 base pairs 5' to the translation initiation codon. In the 3' flanking region, sequences homologous to glucocorticoid-response elements might be responsible for the increased expression of the ..beta../sub 2/AR gene observed after treatment of the transfected cells with hydrocortisone. In addition, 5' to the promoter region, an open reading frame encodes a 251-residue polypeptide that displays striking homologies with protein kinases and other nucleotide-binding proteins.

  17. Impaired SUMOylation of nuclear receptor LRH-1 promotes nonalcoholic fatty liver disease

    PubMed Central

    Lemos, Vera; Xu, Pan; Jimenez, Veronica; Bosch, Fatima; Lüscher, Thomas F.; Oosterveer, Maaike H.

    2017-01-01

    Hepatic steatosis is caused by metabolic imbalances that could be explained in part by an increase in de novo lipogenesis that results from increased sterol element binding protein 1 (SREBP-1) activity. The nuclear receptor liver receptor homolog 1 (LRH-1) is an important regulator of intermediary metabolism in the liver, but its role in regulating lipogenesis is not well understood. Here, we have assessed the contribution of LRH-1 SUMOylation to the development of nonalcoholic fatty liver disease (NAFLD). Mice expressing a SUMOylation-defective mutant of LRH-1 (LRH-1 K289R mice) developed NAFLD and early signs of nonalcoholic steatohepatitis (NASH) when challenged with a lipogenic, high-fat, high-sucrose diet. Moreover, we observed that the LRH-1 K289R mutation induced the expression of oxysterol binding protein-like 3 (OSBPL3), enhanced SREBP-1 processing, and promoted de novo lipogenesis. Mechanistically, we demonstrated that ectopic expression of OSBPL3 facilitates SREBP-1 processing in WT mice, while silencing hepatic Osbpl3 reverses the lipogenic phenotype of LRH-1 K289R mice. These findings suggest that compromised SUMOylation of LRH-1 promotes the development of NAFLD under lipogenic conditions through regulation of OSBPL3. PMID:28094767

  18. Progesterone receptor B promoter hypermethylation in human placenta after labor onset.

    PubMed

    Zhuang, Yanyan; Cui, Hong; Liu, Sishi; Zheng, Dongming; Liu, Caixia

    2015-03-01

    To determine the methylation status of progesterone receptor B (PR-B) promoter and how PR-B regulates progesterone action in placenta during human pregnancy. Placentas were obtained from the pregnancy women at term who underwent cesarean delivery and vaginal delivery. The methylation status of the PR-B promoter was analyzed using the methylation-specific polymerase chain reaction (PCR) and bisulfite sequencing PCR. And the messenger RNA (mRNA) and protein expression of the PR-B and DNA methyltransferases (DNMTs) were determined by quantitative real-time PCR and Western blot. Compared with the cesarean group, the placentas of vaginal delivery group had greater levels of PR-B DNA methylation, and the PR-B, DNMT1, DNMT3a, and DNMT3b mRNA and protein expression were significantly decreased. Progesterone receptor B methylation occurs with high frequency after labor onset and may play an important epigenetic mechanism of labor-related PR-B negative expression, thereby mediating the biological process of functional progesterone withdrawal at term for parturition. © The Author(s) 2014.

  19. Leptin promotes proliferation and metastasis of human gallbladder cancer through OB-Rb leptin receptor.

    PubMed

    Zou, Hao; Liu, Yunxia; Wei, Dong; Wang, Tao; Wang, Kun; Huang, Songquan; Liu, Lixin; Li, Yuehua; Ge, Jiayun; Li, Xiao; Zhu, Hong; Wang, Lianmin; Zhao, Songling; Zhang, Xiaowen; Wang, Lin

    2016-07-01

    Emerging evidence has shown that leptin, an adipocyte-derived cytokine that is closely associated with obesity, play a significant role in carcinogenesis and tumorigenesis. However, its impact on gallbladder cancer (GBC) remains unclear. In this study, we firstly found that leptin and its functional receptor OB-Rb were significantly co-expressed in human GBC tissues and cell lines, the content of which were higher than those in normal human gallbladder tissues. Treatment with leptin promoted the proliferation, migration and invasion of GBC cells, which were attenuated by OB-Rb shRNA. Blocking in the G2/M period of cell cycle, increasing of MMP3 and MMP9, increasing of VEGF-C/D, activation of SOCS3/JAK2/p-STAT3 pathway was demonstrated after treatment with leptin. All of these positive responses were attenuated by OB-Rb receptor shRNA. Taken together, our findings suggest that leptin promoted the proliferation, migration and invasion of GBC cells by increasing OB-Rb expression through the SOCS3/JAK2/p-STAT3 signal pathway. Targeting the leptin/OB-Rb axis could be an attractive therapeutic strategy for treatment of GBC.

  20. Estrogen-related receptor gamma promotes mesenchymal-to-epithelial transition and suppresses breast tumor growth.

    PubMed

    Tiraby, Claire; Hazen, Bethany C; Gantner, Marin L; Kralli, Anastasia

    2011-04-01

    Estrogen-related receptors (ERR), ERR alpha (ERRα) and ERR gamma (ERRγ), are orphan nuclear receptors implicated in breast cancer that function similarly in the regulation of oxidative metabolism genes. Paradoxically, in clinical studies, high levels of ERRα are associated with poor outcomes whereas high levels of ERRγ are associated with a favorable course. Recent studies suggest that ERRα may indeed promote breast tumor growth. The roles of ERRγ in breast cancer progression and how ERRα and ERRγ may differentially affect cancer growth are unclear. In mammary carcinoma cells that do not express endogenous ERRγ, we found that ectopic expression of ERRγ enhanced oxidative metabolism in vitro and inhibited the growth of tumor xenografts in vivo. In contrast, ectopic expression of the ERRα coactivator PGC-1α enhanced oxidative metabolism but did not affect tumor growth. Notably, ERRγ activated expression of a genetic program characteristic of mesenchymal-to-epithelial transition (MET). This program was apparent by changes in cellular morphology, upregulation of epithelial cell markers, downregulation of mesenchymal markers, and decreased cellular invasiveness. We determined that this program was also associated with upregulation of E-cadherin, which is activated directly by ERRγ. In contrast, PGC-1α activated only a subset of genes characteristic of the MET program and, unlike ERRγ, did not upregulate E-cadherin. In conclusion, these results show that ERRγ induces E-cadherin, promotes MET, and suppresses breast cancer growth. Our findings suggest that ERRγ agonists may have applications in the treatment of breast cancer.

  1. Macropinocytosis of the PDGF β-receptor promotes fibroblast transformation by H-RasG12V

    PubMed Central

    Schmees, C.; Villaseñor, R.; Zheng, W.; Ma, H.; Zerial, M.; Heldin, C.-H.; Hellberg, C.

    2012-01-01

    Receptor tyrosine kinase (RTK) signaling is frequently increased in tumor cells, sometimes as a result of decreased receptor down-regulation. The extent to which the endocytic trafficking routes can contribute to such RTK hyperactivation is unclear. Here, we show for the first time that fibroblast transformation by H-RasG12V induces the internalization of platelet-derived growth factor β-receptor (PDGFRβ) by macropinocytosis, enhancing its signaling activity and increasing anchorage-independent proliferation. H-RasG12V transformation and PDGFRβ activation were synergistic in stimulating phosphatidylinositol (PI) 3-kinase activity, leading to receptor macropinocytosis. PDGFRβ macropinocytosis was both necessary and sufficient for enhanced receptor activation. Blocking macropinocytosis by inhibition of PI 3-kinase prevented the increase in receptor activity in transformed cells. Conversely, increasing macropinocytosis by Rabankyrin-5 overexpression was sufficient to enhance PDGFRβ activation in nontransformed cells. Simultaneous stimulation with PDGF-BB and epidermal growth factor promoted macropinocytosis of both receptors and increased their activation in nontransformed cells. We propose that H-Ras transformation promotes tumor progression by enhancing growth factor receptor signaling as a result of increased receptor macropinocytosis. PMID:22573884

  2. Paeoniflorin Promotes Non-rapid Eye Movement Sleep via Adenosine A1 Receptors.

    PubMed

    Chen, Chang-Rui; Sun, Yu; Luo, Yan-Jia; Zhao, Xin; Chen, Jiang-Fan; Yanagawa, Yuchio; Qu, Wei-Min; Huang, Zhi-Li

    2016-01-01

    Paeoniflorin (PF, C23H28O11), one of the principal active ingredients of Paeonia Radix, exerts depressant effects on the central nervous system. We determined whether PF could modulate sleep behaviors and the mechanisms involved. Electroencephalogram and electromyogram recordings in mice showed that intraperitoneal PF administered at a dose of 25 or 50 mg/kg significantly shortened the sleep latency and increased the amount of non-rapid eye movement (NREM). Immunohistochemical study revealed that PF decreased c-fos expression in the histaminergic tuberomammillary nucleus (TMN). The sleep-promoting effects and changes in c-fos induced by PF were reversed by 8-cyclopentyl-1,3-dimethylxanthine (CPT), an adenosine A1 receptor antagonist, and PF-induced sleep was not observed in adenosine A1 receptor knockout mice. Whole-cell patch clamping in mouse brain slices showed that PF significantly decreased the firing frequency of histaminergic neurons in TMN, which could be completely blocked by CPT. These results indicate that PF increased NREM sleep by inhibiting the histaminergic system via A1 receptors.

  3. G-protein coupled receptor BAI3 promotes myoblast fusion in vertebrates

    PubMed Central

    Hamoud, Noumeira; Tran, Viviane; Croteau, Louis-Philippe; Kania, Artur; Côté, Jean-François

    2014-01-01

    Muscle fibers form as a result of myoblast fusion, yet the cell surface receptors regulating this process are unknown in vertebrates. In Drosophila, myoblast fusion involves the activation of the Rac pathway by the guanine nucleotide exchange factor Myoblast City and its scaffolding protein ELMO, downstream of cell-surface cell-adhesion receptors. We previously showed that the mammalian ortholog of Myoblast City, DOCK1, functions in an evolutionarily conserved manner to promote myoblast fusion in mice. In search for regulators of myoblast fusion, we identified the G-protein coupled receptor brain-specific angiogenesis inhibitor (BAI3) as a cell surface protein that interacts with ELMO. In cultured cells, BAI3 or ELMO1/2 loss of function severely impaired myoblast fusion without affecting differentiation and cannot be rescued by reexpression of BAI3 mutants deficient in ELMO binding. The related BAI protein family member, BAI1, is functionally distinct from BAI3, because it cannot rescue the myoblast fusion defects caused by the loss of BAI3 function. Finally, embryonic muscle precursor expression of a BAI3 mutant unable to bind ELMO was sufficient to block myoblast fusion in vivo. Collectively, our findings provide a role for BAI3 in the relay of extracellular fusion signals to their intracellular effectors, identifying it as an essential transmembrane protein for embryonic vertebrate myoblast fusion. PMID:24567399

  4. Gangliosides stimulate bradykinin B2 receptors to promote calmodulin kinase II-mediated neuronal differentiation.

    PubMed

    Kanatsu, Yoshinori; Chen, Nai Hong; Mitoma, Junya; Nakagawa, Tetsuto; Hirabayashi, Yoshio; Higashi, Hideyoshi

    2012-07-01

    Gangliosides mediate neuronal differentiation and maturation and are indispensable for the maintenance of brain function and survival. As part of our ongoing efforts to understand signaling pathways related to ganglioside function, we recently demonstrated that neuronal cells react to exogenous gangliosides GT1b and GD1b. Both of these gangliosides are enriched in the synapse-forming area of the brain and induce Ca(2+) release from intracellular stores, activation of Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) and activation of cdc42 to promote reorganization of cytoskeletal actin and dendritic differentiation. Here, we show that bradykinin B2 receptors transduce these reactions as a mediator for ganglioside glycan signals. The B2 antagonist Hoe140 inhibited ganglioside-induced CaMKII activation, actin reorganization and early development of axon- and dendrite-like processes of primary cultured hippocampal neurons. Furthermore, we confirmed by yeast reporter assay that major b-series gangliosides, GT1b, GD1b and GD3, stimulated B2 bradykinin receptors. We hypothesize that this B2 receptor-mediated ganglioside signal transduction pathway is one mechanism that modulates neuronal differentiation and maturation.

  5. Renal function in familial longevity: the Leiden Longevity Study.

    PubMed

    de Goeij, Moniek C M; Halbesma, Nynke; Dekker, Friedo W; Wijsman, Carolien A; van Heemst, Diana; Maier, Andrea B; Mooijaart, Simon P; Slagboom, P Eline; Westendorp, Rudi G J; de Craen, Anton J M

    2014-03-01

    Studying renal function in subjects with a familial propensity for longevity may provide insight in (un)known mechanisms that determine the age-related decline in renal function of normal subjects. In the Leiden Longevity Study, middle-aged offspring of non-agenarian siblings and their partners as environmentally matched controls were included. Information was collected on lifestyle, medical history, medication use, and a non-fasting blood sample was drawn. Renal function (estimated glomerular filtration rate, eGFR) was assessed with the Chronic Kidney Disease epidemiology collaboration (CKD-EPI) formula. Linear mixed models were used to account for familial dependencies within the offspring and all analyses were stratified by sex. eGFR was similar between female offspring and female controls (0.44ml/min/1.73m(2) (SE 0.72) difference, p=0.54, age-adjusted). Male offspring had a higher eGFR compared to male controls (1.78ml/min/1.73m(2) (SE 0.78) difference, p=0.022, age-adjusted), and further adjustments for various characteristics did not materially change this difference. Among men with a history of hypertension, or myocardial infarction and/or stroke, offspring had a higher eGFR compared to controls (4.74ml/min/1.73m(2) (SE 1.53) difference, p=0.002, age-adjusted, and 6.21ml/min/1.73m(2) (SE 2.85) difference, p=0.033, age-adjusted, respectively). Middle-aged men, but not women, with a propensity for longevity have better renal function compared to environmentally matched controls, especially among those with a history of cardiovascular disease.

  6. Hyperphagia in male melanocortin 4 receptor deficient mice promotes growth independently of growth hormone.

    PubMed

    Tan, H Y; Steyn, F J; Huang, L; Cowley, M; Veldhuis, J D; Chen, C

    2016-12-15

    Loss of function of the melanocortin 4 receptor (MC4R) results in hyperphagia, obesity and increased growth. Despite knowing that MC4Rs control food intake, we are yet to understand why defects in the function of the MC4R receptor contribute to rapid linear growth. We show that hyperphagia following germline loss of MC4R in male mice promotes growth while suppressing the growth hormone-insulin-like growth factor-1 (GH-IGF-1) axis. We propose that hyperinsulinaemia promotes growth while suppressing the GH-IGF-1 axis. It is argued that physiological responses essential to maintain energy flux override conventional mechanisms of pubertal growth to promote the storage of excess energy while ensuring growth. Defects in melanocortin-4-receptor (MC4R) signalling result in hyperphagia, obesity and increased growth. Clinical observations suggest that loss of MC4R function may enhance growth hormone (GH)-mediated growth, although this remains untested. Using male mice with germline loss of the MC4R, we assessed pulsatile GH release and insulin-like growth factor-1 (IGF-1) production and/or release relative to pubertal growth. We demonstrate early-onset suppression of GH release in rapidly growing MC4R deficient (MC4RKO) mice, confirming that increased linear growth in MC4RKO mice does not occur in response to enhanced activation of the GH-IGF-1 axis. The progressive suppression of GH release in MC4RKO mice occurred alongside increased adiposity and the progressive worsening of hyperphagia-associated hyperinsulinaemia. We next prevented hyperphagia in MC4RKO mice through restricting calorie intake in these mice to match that of wild-type (WT) littermates. Pair feeding of MC4RKO mice did not prevent increased adiposity, but attenuated hyperinsulinaemia, recovered GH release, and normalized linear growth rate to that seen in pair-fed WT littermate controls. We conclude that the suppression of GH release in MC4RKO mice occurs independently of increased adipose mass, and is a

  7. Adenosine A2B Receptor Deficiency Promotes Host Defenses against Gram-Negative Bacterial Pneumonia

    PubMed Central

    Barletta, Kathryn E.; Cagnina, R. Elaine; Burdick, Marie D.; Linden, Joel

    2012-01-01

    Rationale: Activation of the adenosine A2B receptor (A2BR) promotes antiinflammatory effects in diverse biological settings, but the role of this receptor in antimicrobial host defense in the lung has not been established. Gram-negative bacillary pneumonia is a common and serious illness associated with high morbidity and mortality, the treatment of which is complicated by increasing rates of antibiotic resistance. Objectives: To test the hypothesis that absence of adenosine A2B receptor signaling promotes host defense against bacterial pneumonia. Methods: We used a model of Klebsiella pneumoniae pneumonia in wild-type mice and mice with targeted deletion of the A2BR. Host responses were compared in vivo and leukocyte responses to the bacteria were examined in vitro. Measurements and Main Results: A2BR–/– mice demonstrated enhanced bacterial clearance from the lung and improved survival after infection with K. pneumoniae compared with wild-type controls, an effect that was mediated by bone marrow–derived cells. Leukocyte recruitment to the lungs and expression of inflammatory cytokines did not differ between A2BR–/– and wild-type mice, but A2BR–/– neutrophils exhibited sixfold greater bactericidal activity and enhanced production of neutrophil extracellular traps compared with wild-type neutrophils when incubated with K. pneumoniae. Consistent with this finding, bronchoalveolar lavage fluid from A2BR–/– mice with Klebsiella pneumonia contained more extracellular DNA compared with wild-type mice with pneumonia. Conclusions: These data suggest that the absence of A2BR signaling enhances antimicrobial activity in gram-negative bacterial pneumonia. PMID:22997203

  8. Cancer cell-selective promoter recognition accompanies antitumor effect by glucocorticoid receptor-targeted gold nanoparticle

    NASA Astrophysics Data System (ADS)

    Sau, Samaresh; Agarwalla, Pritha; Mukherjee, Sudip; Bag, Indira; Sreedhar, Bojja; Pal-Bhadra, Manika; Patra, Chitta Ranjan; Banerjee, Rajkumar

    2014-05-01

    Nanoparticles, such as gold nanoparticles (GNP), upon convenient modifications perform multi tasks catering to many biomedical applications. However, GNP or any other type of nanoparticles is yet to achieve the feat of intracellular regulation of endogenous genes of choice such as through manipulation of a gene-promoter in a chromosome. As for gene modulation and delivery, GNP (or other nanoparticles) showed only limited gene therapy potential, which relied on the delivery of `exogenous' genes invoking gene knockdown or replacement. Practically, there are no instances for the nanoparticle-mediated promoter regulation of `endogenous' genes, more so, as a cancer selective phenomenon. In this regard, we report the development of a simple, easily modifiable GNP-formulation, which promoted/up-regulated the expression of a specific category of `endogenous' genes, the glucocorticoid responsive genes. This genetic up-regulation was induced in only cancer cells by modified GNP-mediated transcriptional activation of its cytoplasmic receptor, glucocorticoid receptor (GR). Normal cells and their GR remained primarily unperturbed by this GNP-formulation. The most potent gene up-regulating GNP-formulation down-regulated a cancer-specific proliferative signal, phospho-Akt in cancer cells, which accompanied retardation of tumor growth in the murine melanoma model. We show that GR-targeted GNPs may find potential use in the targeting and modulation of genetic information in cancer towards developing novel anticancer therapeutics.Nanoparticles, such as gold nanoparticles (GNP), upon convenient modifications perform multi tasks catering to many biomedical applications. However, GNP or any other type of nanoparticles is yet to achieve the feat of intracellular regulation of endogenous genes of choice such as through manipulation of a gene-promoter in a chromosome. As for gene modulation and delivery, GNP (or other nanoparticles) showed only limited gene therapy potential, which relied

  9. Ageing, longevity, exceptional longevity and related genetic and non genetics markers: panel statement.

    PubMed

    Avery, Peter; Barzilai, Nir; Benetos, Athanase; Bilianou, Helen; Capri, Miriam; Caruso, Calogero; Franceschi, Claudio; Katsiki, Niki; Mikhailidis, Dimitri P; Panotopoulos, George; Sikora, Ewa; Tzanetakou, Irene P; Kolovou, Genovefa

    2014-01-01

    In May 2012, a group of scientists and clinicians met in Athens (Greece) to consider the relevance of ageing, longevity, exceptional longevity and related genetic and non genetic markers. During this meeting, we firstly reviewed recent epidemiological and clinical studies on ageing, longevity and exceptional longevity, briefly analyzed the ageing theories and discussed successful and unsuccessful ageing also taking into account the evolutionary perspective. Secondly, we considered the three phenotypes based on the definition of ageing, longevity and exceptional longevity and the associated biomarkers. Third, we discussed proposed treatments suitable to counteract or slow down ageing. Finally, this panel produced a consensus statement to highlight the importance of ageing, longevity and exceptional longevity, since this is a rapidly increasing phenotype worldwide. We acknowledge that not all experts in this field may completely agree with this statement.

  10. Selective 5HT2A and 5HT6 Receptor Antagonists Promote Sleep in Rats

    PubMed Central

    Morairty, Stephen R.; Hedley, Linda; Flores, Judith; Martin, Renee; Kilduff, Thomas S.

    2008-01-01

    Study Objectives: Serotonin (5-HT) has long been implicated in the control of sleep and wakefulness. This study evaluated the hypnotic efficacy of the 5-HT6 antagonist RO4368554 (RO) and the 5-HT2A receptor antagonist MDL100907 (MDL) relative to zolpidem. Design: A randomized, repeated-measures design was utilized in which Wistar rats received intraperitoneal injections of RO (1.0, 3.0, and 10 mg/kg), MDL (0.1, 1.0 and 3.0 mg/kg), zolpidem (10 mg/kg), or vehicle in the middle of the dark (active) period. Electroencephalogram, electromyogram, body temperature (Tb) and locomotor activity were analyzed for 6 hours after injection. Measurements and Results: RO, MDL, and zolpidem all produced significant increases in sleep and decreases in waking, compared with vehicle control. All 3 doses of MDL produced more consolidated sleep, increased non-rapid eye movement sleep (NREM) sleep, and increased electroencephalographic delta power during NREM sleep. The highest dose of RO (10.0 mg/kg) produced significant increases in sleep and decreases in waking during hour 2 following dosing. These increases in sleep duration were associated with greater delta power during NREM sleep. ZO Zolpidem induced sleep with the shortest latency and significantly increased NREM sleep and delta power but also suppressed rapid eye movement sleep sleep; in contrast, neither RO nor MDL affected rapid eye movement sleep. Whereas RO did not affect Tb, both zolpidem and MDL reduced Tb relative to vehicle-injected controls. Conclusions: These results support a role for 5-HT2A receptor modulation in NREM sleep and suggest a previously unrecognized role for 5-HT6 receptors in sleep-wake regulation. Citation: Morairty SR; Hedley L; Flores J; Martin R; Kilduff TS. Selective 5HT2A and 5HT6 receptor antagonists promote sleep in rats. SLEEP 2008;31(1):34-44. PMID:18220076

  11. Rarity of DNA sequence alterations in the promoter region of the human androgen receptor gene.

    PubMed

    Cabral, D F; Santos, A; Ribeiro, M L; Mesquita, J C; Carvalho-Salles, A B; Hackel, C

    2004-12-01

    The human androgen receptor (AR) gene promoter lies in a GC-rich region containing two principal sites of transcription initiation and a putative Sp1 protein-binding site, without typical "TATA" and "CAAT" boxes. It has been suggested that mutations within the 5'untranslated region (5'UTR) may contribute to the development of prostate cancer by changing the rates of gene transcription and/or translation. In order to investigate this question, the aim of the present study was to search for the presence of mutations or polymorphisms at the AR-5'UTR in 92 prostate cancer patients, where histological diagnosis of adenocarcinoma was established in specimens obtained from transurethral resection or after prostatectomy. The AR-5'UTR was amplified by PCR from genomic DNA samples of the patients and of 100 healthy male blood donors, included as controls. Conformation-sensitive gel electrophoresis was used for DNA sequence alteration screening. Only one band shift was detected in one individual from the blood donor group. Sequencing revealed a new single nucleotide deletion (T) in the most conserved portion of the promoter region at position +36 downstream from the transcription initiation site I. Although the effect of this specific mutation remains unknown, its rarity reveals the high degree of sequence conservation of the human androgen promoter region. Moreover, the absence of detectable variation within the critical 5'UTR in prostate cancer patients indicates a low probability of its involvement in prostate cancer etiology.

  12. Thrombomodulin promotes diabetic wound healing by regulating toll-like receptor 4 expression.

    PubMed

    Cheng, Tsung-Lin; Lai, Chao-Han; Chen, Po-Ku; Cho, Chia-Fong; Hsu, Yun-Yan; Wang, Kuan-Chieh; Lin, Wei-Ling; Chang, Bi-Ing; Liu, Shi-Kai; Wu, Yu-Ting; Hsu, Chao-Kai; Shi, Guey-Yueh; Wu, Hua-Lin

    2015-06-01

    Keratinocyte-expressed thrombomodulin (TM) and the released soluble TM (sTM) have been demonstrated to promote wound healing. However, the effects of high glucose on TM expression in keratinocytes and the role of TM in diabetic ulcer remain unclear. In this study, we demonstrated that expressions of TM and Toll-like receptor 4 (TLR4) were both downregulated in high-glucose cultured human keratinocytes and in skin keratinocytes of diabetic patients. In addition, the wound-triggered upregulation of TM and sTM production was abolished in both high-glucose cultured human keratinocytes and streptozotocin-induced diabetic mouse skin. Furthermore, supplementation of recombinant sTM could increase TLR4 expression and promote cutaneous wound healing in both high-glucose cultured human keratinocytes and diabetic mice. However, in Tlr4-deleted mice, which exhibited delayed wound healing, the therapeutic benefit of recombinant sTM was abrogated. Moreover, our results showed that tumor necrosis factor-α (TNF-α) expression in keratinocytes was dose-dependently upregulated by glucose, and TNF-α treatment downregulated the expression of TM and TLR4. Taken together, high-glucose environment reduces the expression of TM and TLR4 in keratinocytes possibly through the action of TNF-α, and recombinant sTM can increase the TLR4 expression and promote wound healing under diabetic condition.

  13. Gut Microbiota and Extreme Longevity.

    PubMed

    Biagi, Elena; Franceschi, Claudio; Rampelli, Simone; Severgnini, Marco; Ostan, Rita; Turroni, Silvia; Consolandi, Clarissa; Quercia, Sara; Scurti, Maria; Monti, Daniela; Capri, Miriam; Brigidi, Patrizia; Candela, Marco

    2016-06-06

    The study of the extreme limits of human lifespan may allow a better understanding of how human beings can escape, delay, or survive the most frequent age-related causes of morbidity, a peculiarity shown by long-living individuals. Longevity is a complex trait in which genetics, environment, and stochasticity concur to determine the chance to reach 100 or more years of age [1]. Because of its impact on human metabolism and immunology, the gut microbiome has been proposed as a possible determinant of healthy aging [2, 3]. Indeed, the preservation of host-microbes homeostasis can counteract inflammaging [4], intestinal permeability [5], and decline in bone and cognitive health [6, 7]. Aiming at deepening our knowledge on the relationship between the gut microbiota and a long-living host, we provide for the first time the phylogenetic microbiota analysis of semi-supercentenarians, i.e., 105-109 years old, in comparison to adults, elderly, and centenarians, thus reconstructing the longest available human microbiota trajectory along aging. We highlighted the presence of a core microbiota of highly occurring, symbiotic bacterial taxa (mostly belonging to the dominant Ruminococcaceae, Lachnospiraceae, and Bacteroidaceae families), with a cumulative abundance decreasing along with age. Aging is characterized by an increasing abundance of subdominant species, as well as a rearrangement in their co-occurrence network. These features are maintained in longevity and extreme longevity, but peculiarities emerged, especially in semi-supercentenarians, describing changes that, even accommodating opportunistic and allochthonous bacteria, might possibly support health maintenance during aging, such as an enrichment and/or higher prevalence of health-associated groups (e.g., Akkermansia, Bifidobacterium, and Christensenellaceae).

  14. Liver Tumor Promotion by 2,3,7,8-Tetrachlorodibenzo-p-dioxin Is Dependent on the Aryl Hydrocarbon Receptor and TNF/IL-1 Receptors

    PubMed Central

    Kennedy, Gregory D.; Nukaya, Manabu; Moran, Susan M.; Glover, Edward; Weinberg, Samuel; Balbo, Silvia; Hecht, Stephen S.; Pitot, Henry C.; Drinkwater, Norman R.; Bradfield, Christopher A.

    2014-01-01

    We set out to better understand the signal transduction pathways that mediate liver tumor promotion by 2,3,7,8-tetrachlorodibenzo-p-dioxn (“dioxin”). To this end, we first employed congenic mice homozygous for either the Ahrb1 or Ahrd alleles (encoding an aryl hydrocarbon receptor (AHR) with high or low binding affinity for dioxin, respectively) and demonstrated that hepatocellular tumor promotion in response to dioxin segregated with the Ahr locus. Once we had genetic evidence for the importance of AHR signaling, we then asked if tumor promotion by dioxin was influenced by “interleukin-1 (IL-1)-like” inflammatory cytokines. The importance of this question arose from our earlier observation that aspects of the acute hepatocellular toxicity of dioxin are dependent upon IL1-like cytokine signaling. To address this issue, we employed a triple knock-out (TKO) mouse model with null alleles at the loci encoding the three relevant receptors for tumor necrosis factors α and β and IL-1α and IL-1β (i.e., null alleles at the Tnfrsf1a, Tnfrsf1b, and Il-1r1 loci). The observation that TKO mice were resistant to the tumor promoting effects of dioxin in liver suggests that inflammatory cytokines play an important step in dioxin mediated liver tumor promotion in the mouse. Collectively, these data support the idea that the mechanism of dioxin acute hepatotoxicity and its activity as a promoter in a mouse two stage liver cancer model may be similar, i.e., tumor promotion by dioxin, like acute hepatotoxicity, are mediated by the linked action of two receptor systems, the AHR and the receptors for the “IL-1-like” cytokines. PMID:24718703

  15. Thyroid Hormone Receptor Binds to a Site in the Rat Growth Hormone Promoter Required for Induction by Thyroid Hormone

    NASA Astrophysics Data System (ADS)

    Koenig, Ronald J.; Brent, Gregory A.; Warne, Robert L.; Reed Larsen, P.; Moore, David D.

    1987-08-01

    Transcription of the rat growth hormone (rGH) gene in pituitary cells is increased by addition of thyroid hormone (T3). This induction is dependent on the presence of specific sequences just upstream of the rGH promoter. We have partially purified T3 receptor from rat liver and examined its interaction with these rGH sequences. We show here that T3 receptor binds specifically to a site just upstream of the basal rGH promoter. This binding site includes two copies of a 7-base-pair direct repeat, the centers of which are separated by 10 base pairs. Deletions that specifically remove the T3 receptor binding site drastically reduce response to T3 in transient transfection experiments. These results demonstrate that T3 receptor can recognize specific DNA sequences and suggest that it can act directly as a positive transcriptional regulatory factor.

  16. Craniopharyngioma cell growth is promoted by growth hormone (GH) and is inhibited by tamoxifen: involvement of growth hormone receptor (GHR) and IGF-1 receptor (IGF-1R).

    PubMed

    Li, Qiang; You, Chao; Liu, Liang; Rao, Zhengxi; Sima, Xiutian; Zhou, Liangxue; Xu, Jianguo

    2013-01-01

    Hormone receptors are related to the biological behavior and recurrence of craniopharyngioma (CP). The effect of therapeutic growth hormone (GH) replacement on CP growth remains largely unclear. We intended to study expression patterns of GH-related receptors in CP, and to study the effect of GH and its mediator, insulin-like growth factor-1 (IGF-1), as well as tamoxifen, on primary CP cell cultures. Primary cell cultures were established from fresh tumor specimens. The expression of GH receptor (GHR) and IGF-1 receptor (IGF-1R) in tumor specimens was studied using immunohistochemistry. Cell cultures were treated with various concentrations of recombinant GH, IGF-1 and tamoxifen. Cell growth promotion or inhibition was assayed using the Trypan blue dye exclusion test of cell viability. Expression of GHR, IGF-1R, phosphorylated-Akt and Akt after treatment was studied using Western blot assay. Twenty-nine primary cultures from 36 patients were established. GHR and IGF-1R were expressed in tumor tissue. The promotion of cell growth by GH compared to control was most prominent at 100 ng/mL, while inhibition by tamoxifen was concentration dependent. IGF-1 was more effective in promoting growth in CP cell cultures with high IGF-1R expression, and it increased phosphorylation of Akt protein. Primary cell cultures can be established in more than 80% of fresh CP specimens. GH and its endogenous mediator, IGF-1, promotes CP cell growth in vitro, while tamoxifen inhibits growth. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. Cannabinoid receptor 1 promotes hepatocellular carcinoma initiation and progression through multiple mechanisms.

    PubMed

    Mukhopadhyay, Bani; Schuebel, Kornel; Mukhopadhyay, Partha; Cinar, Resat; Godlewski, Grzegorz; Xiong, Keming; Mackie, Ken; Lizak, Martin; Yuan, Qiaoping; Goldman, David; Kunos, George

    2015-05-01

    Hepatocellular carcinoma (HCC) has high mortality and no adequate treatment. Endocannabinoids interact with hepatic cannabinoid 1 receptors (CB1Rs) to promote hepatocyte proliferation in liver regeneration by inducing cell cycle proteins involved in mitotic progression, including Forkhead Box M1. Because this protein is highly expressed in HCC and contributes to its genesis and progression, we analyzed the involvement of the endocannabinoid/CB1R system in murine and human HCC. Postnatal diethylnitrosamine treatment induced HCC within 8 months in wild-type mice but fewer and smaller tumors in CB1R(-/-) mice or in wild-type mice treated with the peripheral CB1R antagonist JD5037, as monitored in vivo by serial magnetic resonance imaging. Genome-wide transcriptome analysis revealed CB1R-dependent, tumor-induced up-regulation of the hepatic expression of CB1R, its endogenous ligand anandamide, and a number of tumor-promoting genes, including the GRB2 interactome as well as Forkhead Box M1 and its downstream target, the tryptophan-catalyzing enzyme indoleamine 2,3-dioxygenase. Increased indoleamine 2,3-dioxygenase activity and consequent induction of immunosuppressive T-regulatory cells in tumor tissue promote immune tolerance. The endocannabinoid/CB1R system is up-regulated in chemically induced HCC, resulting in the induction of various tumor-promoting genes, including indoleamine 2,3-dioxygenase; and attenuation of these changes by blockade or genetic ablation of CB1R suppresses the growth of HCC and highlights the therapeutic potential of peripheral CB1R blockade. © 2015 by the American Association for the Study of Liver Diseases. This article has been contributed to by U.S. Government employees, and their work is in the public domain in the U.S.A.

  18. Cannabinoid Receptor 1 Promotes Hepatocellular Carcinoma Initiation and Progression via Multiple Mechanisms

    PubMed Central

    Mukhopadhyay, Bani; Schuebel, Kornel; Mukhopadhyay, Partha; Cinar, Resat; Godlewski, Grzegorz; Xiong, Keming; Mackie, Ken; Lizak, Martin; Yuan, Qiaoping; Goldman, David; Kunos, George

    2015-01-01

    Hepatocellular carcinoma (HCC) has high mortality and no adequate treatment. Endocannabinoids interact with hepatic CB1 receptors (CB1R) to promote hepatocyte proliferation in liver regeneration via inducing cell-cycle proteins involved in mitotic progression, including Forkhead Box M1 (FOXM1). Because FOXM1 is highly expressed in HCC and contributes to its genesis and progression, we analyzed the involvement of the endocannabinoid/CB1R system in murine and human HCC. Postnatal diethylnitrosamine (DEN) treatment induced HCC within 8 months in wild-type mice, but fewer and smaller tumors in CB1R−/− mice or in wild-type mice treated with the peripheral CB1R antagonist JD5037, as monitored in vivo by serial magnetic resonance imaging. Genome-wide transcriptome analysis revealed CB1R-dependent, tumor-induced upregulation of the hepatic expression of CB1R, its endogenous ligand anandamide, and a number of tumor promoting genes, including the GRB2 interactome as well as FOXM1 and its downstream target the tryptophan-catalyzing enzyme indoleamine 2,3-dioxygenase (IDO2). Increased IDO2 activity and consequent induction of immunosuppressive Treg cells in tumor tissue promote immune tolerance. Conclusion The endocannabinoid/CB1R system is upregulated in chemically induced HCC resulting in the induction of various tumor promoting genes, including IDO2, and attenuation of these changes by blockade or genetic ablation of CB1R suppresses the growth of HCC and highlights the therapeutic potential of peripheral CB1R blockade. PMID:25580584

  19. Promoter hypermethylation of progesterone receptor isoform B (PR-B) in endometriosis.

    PubMed

    Wu, Yan; Strawn, Estil; Basir, Zainab; Halverson, Gloria; Guo, Sun-Wei

    2006-01-01

    The physiological effects of progesterone (P) are mediated by two isoforms of progesterone receptors (PRs): PR-A and PR-B. Progestins have long been used in the treatment of endometriosis but unfortunately the relief of pain is relatively short-term. In addition, about nine percent of women with endometriosis simply do not respond to progestin therapy due to unknown reasons. In fact, a general tendency for relative progesterone resistance within eutopic and ectopic endometrium of women with endometriosis and also the downregulation of PR-B, but not PR-A, in endometriosis have been noted. Since promoter hypermethylation is well-documented to be associated with transcriptional silencing, we sought to determine the methylation status of the PR-A and PR-B promoter regions in the epithelial component of endometriotic implants using a combination of laser capture microdissection (LCM), methylation specific PCR, and bisulfite sequencing. We found that the promoter region of PR-B, but not PR-A, is hypermethylated in endometriosis as compared with controls. In addition, the PR-B expression was significantly reduced in the ectopic endometrium. Our finding suggests that progesterone resistance in endometriosis in general and the down regulation of PR-B, but not PR-A, in particular, are a result of promoter hypermethylation of PR-B, but not PR-A. This, in conjunction with our reported aberrant methylation of HOXA10 in the eutopic endometrium of women with endometriosis, strongly suggests that endometriosis is an epigenetic disease. This perspective should potentially open up new avenues for the delineation of pathogenesis of endometriosis, and might also lead to novel ways to treat the disease through reversing aberrant methylation via pharmacological means.

  20. Histone Deacetylase 7 Promotes Toll-like Receptor 4-dependent Proinflammatory Gene Expression in Macrophages*

    PubMed Central

    Shakespear, Melanie R.; Hohenhaus, Daniel M.; Kelly, Greg M.; Kamal, Nabilah A.; Gupta, Praveer; Labzin, Larisa I.; Schroder, Kate; Garceau, Valerie; Barbero, Sheila; Iyer, Abishek; Hume, David A.; Reid, Robert C.; Irvine, Katharine M.; Fairlie, David P.; Sweet, Matthew J.

    2013-01-01

    Broad-spectrum inhibitors of histone deacetylases (HDACs) constrain Toll-like receptor (TLR)-inducible production of key proinflammatory mediators. Here we investigated HDAC-dependent inflammatory responses in mouse macrophages. Of the classical Hdacs, Hdac7 was expressed at elevated levels in inflammatory macrophages (thioglycollate-elicited peritoneal macrophages) as compared with bone marrow-derived macrophages and the RAW264 cell line. Overexpression of a specific, alternatively spliced isoform of Hdac7 lacking the N-terminal 22 amino acids (Hdac7-u), but not the Refseq Hdac7 (Hdac7-s), promoted LPS-inducible expression of Hdac-dependent genes (Edn1, Il-12p40, and Il-6) in RAW264 cells. A novel class IIa-selective HDAC inhibitor reduced recombinant human HDAC7 enzyme activity as well as TLR-induced production of inflammatory mediators in thioglycollate-elicited peritoneal macrophages. Both LPS and Hdac7-u up-regulated the activity of the Edn1 promoter in an HDAC-dependent fashion in RAW264 cells. A hypoxia-inducible factor (HIF) 1 binding site in this promoter was required for HDAC-dependent TLR-inducible promoter activity and for Hdac7- and HIF-1α-mediated trans-activation. Coimmunoprecipitation assays showed that both Hdac7-u and Hdac7-s interacted with HIF-1α, whereas only Hdac7-s interacted with the transcriptional repressor CtBP1. Thus, Hdac7-u positively regulates HIF-1α-dependent TLR signaling in macrophages, whereas an interaction with CtBP1 likely prevents Hdac7-s from exerting this effect. Hdac7 may represent a potential inflammatory disease target. PMID:23853092

  1. Histone deacetylase 7 promotes Toll-like receptor 4-dependent proinflammatory gene expression in macrophages.

    PubMed

    Shakespear, Melanie R; Hohenhaus, Daniel M; Kelly, Greg M; Kamal, Nabilah A; Gupta, Praveer; Labzin, Larisa I; Schroder, Kate; Garceau, Valerie; Barbero, Sheila; Iyer, Abishek; Hume, David A; Reid, Robert C; Irvine, Katharine M; Fairlie, David P; Sweet, Matthew J

    2013-08-30

    Broad-spectrum inhibitors of histone deacetylases (HDACs) constrain Toll-like receptor (TLR)-inducible production of key proinflammatory mediators. Here we investigated HDAC-dependent inflammatory responses in mouse macrophages. Of the classical Hdacs, Hdac7 was expressed at elevated levels in inflammatory macrophages (thioglycollate-elicited peritoneal macrophages) as compared with bone marrow-derived macrophages and the RAW264 cell line. Overexpression of a specific, alternatively spliced isoform of Hdac7 lacking the N-terminal 22 amino acids (Hdac7-u), but not the Refseq Hdac7 (Hdac7-s), promoted LPS-inducible expression of Hdac-dependent genes (Edn1, Il-12p40, and Il-6) in RAW264 cells. A novel class IIa-selective HDAC inhibitor reduced recombinant human HDAC7 enzyme activity as well as TLR-induced production of inflammatory mediators in thioglycollate-elicited peritoneal macrophages. Both LPS and Hdac7-u up-regulated the activity of the Edn1 promoter in an HDAC-dependent fashion in RAW264 cells. A hypoxia-inducible factor (HIF) 1 binding site in this promoter was required for HDAC-dependent TLR-inducible promoter activity and for Hdac7- and HIF-1α-mediated trans-activation. Coimmunoprecipitation assays showed that both Hdac7-u and Hdac7-s interacted with HIF-1α, whereas only Hdac7-s interacted with the transcriptional repressor CtBP1. Thus, Hdac7-u positively regulates HIF-1α-dependent TLR signaling in macrophages, whereas an interaction with CtBP1 likely prevents Hdac7-s from exerting this effect. Hdac7 may represent a potential inflammatory disease target.

  2. Receptor for hyaluronan mediated motility (RHAMM/HMMR) is a novel target for promoting subcutaneous adipogenesis.

    PubMed

    Bahrami, S B; Tolg, C; Peart, T; Symonette, C; Veiseh, M; Umoh, J U; Holdsworth, D W; McCarthy, J B; Luyt, L G; Bissell, M J; Yazdani, A; Turley, E A

    2017-03-01

    Hyaluronan, CD44 and the Receptor for Hyaluronan-Mediated Motility (RHAMM, gene name HMMR) regulate stem cell differentiation including mesenchymal progenitor differentiation. Here, we show that CD44 expression is required for subcutaneous adipogenesis, whereas RHAMM expression suppresses this process. We designed RHAMM function blocking peptides to promote subcutaneous adipogenesis as a clinical and tissue engineering tool. Adipogenic RHAMM peptides were identified by screening for their ability to promote adipogenesis in culture assays using rat bone marrow mesenchymal stem cells, mouse pre-adipocyte cell lines and primary human subcutaneous pre-adipocytes. Oil red O uptake into fat droplets and adiponectin production were used as biomarkers of adipogenesis. Positive peptides were formulated in either collagen I or hyaluronan (Orthovisc) gels then assessed for their adipogenic potential in vivo following injection into dorsal rat skin and mammary fat pads. Fat content was quantified and characterized using micro CT imaging, morphometry, histology, RT-PCR and ELISA analyses of adipogenic gene expression. Injection of screened peptides increased dorsal back subcutaneous fat pad area (208.3 ± 10.4 mm(2)versus control 84.11 ± 4.2 mm(2); p < 0.05) and mammary fat pad size (45 ± 11 mg above control background, p = 0.002) in female rats. This effect lasted >5 weeks as detected by micro CT imaging and perilipin 1 mRNA expression. RHAMM expression suppresses while blocking peptides promote expression of PPARγ, C/EBP and their target genes. Blocking RHAMM function by peptide injection or topical application is a novel and minimally invasive method for potentially promoting subcutaneous adipogenesis in lipodystrophic diseases and a complementary tool to subcutaneous fat augmentation techniques.

  3. Neural regulation of muscle acetylcholine receptor epsilon- and alpha- subunit gene promoters in transgenic mice

    PubMed Central

    1993-01-01

    The effects of denervation were investigated in mice with transgenes containing promoter elements from the muscle acetylcholine receptor epsilon- and alpha-subunit genes. The promoter sequences were coupled to a nuclear localization signal-beta-galactosidase fusion gene (nlacZ) as a reporter. While many postsynaptic specializations form in the embryo, expression of the epsilon subunit is induced during the first two postnatal weeks. When muscles were denervated at birth, before the onset of epsilon expression, epsilon nlacZ still appeared at the former synaptic sites on schedule. This result suggests that the nerve leaves a localized "trace" in the muscle that can continue to regulate transcription. An additional finding was that epsilon nlacZ expression was much stronger in denervated than in intact muscles. This suggests that the epsilon promoter is similar to the other subunits in containing elements that are activated on cessation of neural activity. However, even after denervation, epsilon nlacZ expression was always confined to the synaptic region whereas alpha nlacZ expression increased in nuclei along the entire length of the fiber. This suggests that while the epsilon gene is similar in its activity dependence to other subunit genes, it is unique in that local nerve-derived signals are essential for its expression. Consequently, inactivity enhances epsilon expression only in synaptic nuclei where such signals are present, but enhances expression throughout the muscle fiber. Truncations and an internal deletion of the epsilon promoter indicate that cis-elements essential for the response to synaptic signals are contained within 280 bp of the transcription start site. In contrast to these results in young animals, denervation in older animals leads to an unexpected reduction in nlacZ activity. However, mRNA measurements indicated that transgene expression was increased in these animals. This discordance between nlacZ mRNA and enzyme activity, demonstrates a

  4. Decreased DNA Methylations at the Progesterone Receptor Promoter A Induce Functional Progesterone Withdrawal in Human Parturition.

    PubMed

    Li, Xia; Chen, Cheng; Luo, Hui; van Velkinburgh, Jennifer C; Ni, Bing; Chang, Qing

    2014-07-01

    The functional interaction of progesterone receptor (PR) isoforms PRA and PRB regulates myometrial transition from the resting state to excitation-contraction to initiate parturition. However, the regulatory mechanisms responsible for maintenance and functional alteration of the PRA and PRB expression levels during human pregnancy and term labor, respectively, remain unknown. Therefore, this study was designed to investigate whether and how epigenetic DNA modifications, specifically methylations, at the PRs' promoter regions contribute to the differential expression of PRA and PRB in laboring term myometrium of humans. Comparative analysis of PRA and PRB messenger RNA (mRNA) expression levels and accompanying changes in their promoters' methylation status was carried out using human myometrial samples from women undergoing singleton, term deliveries by cesarean section, either in the absence of labor (designated as NIL for not-in-labor) or in active labor (designated as IL for in labor). The PRA gene expression was shown to be elevated significantly during labor, while PRB gene expression was unaltered, and this differential expression was accompanied by decreased DNA methylation at the PRA promoter and not at the PRB promoter. In addition, labor-related decreased mRNA expression of the DNA methyltransferase (DNMT) family members DNMT1 and DNMT3a was found, however whether the increased expression of DNMTs directly supports the functional withdrawal of progesterone needs further investigation. Collectively, these data indicate that DNA methylation might represent an important epigenetic mechanism of labor-related differential expression of PRs, thereby mediating the biological process of functional PR withdrawal at term for parturition. © The Author(s) 2013.

  5. Disruption of Retinoic Acid Receptor Alpha Reveals the Growth Promoter Face of Retinoic Acid

    PubMed Central

    Ren, MingQiang; Ghidoni, Riccardo; Sacchi, Nicoletta

    2007-01-01

    Background Retinoic acid (RA), the bioactive derivative of Vitamin A, by epigenetically controlling transcription through the RA-receptors (RARs), exerts a potent antiproliferative effect on human cells. However, a number of studies show that RA can also promote cell survival and growth. In the course of one of our studies we observed that disruption of RA-receptor alpha, RARα, abrogates the RA-mediated growth-inhibitory effects and unmasks the growth-promoting face of RA (Ren et al., Mol. Cell. Biol., 2005, 25:10591). The objective of this study was to investigate whether RA can differentially govern cell growth, in the presence and absence of RARα, through differential regulation of the “rheostat” comprising ceramide (CER), the sphingolipid with growth-inhibitory activity, and sphingosine-1-phosphate (S1P), the sphingolipid with prosurvival activity. Methodology/Principal Findings We found that functional inhibition of endogenous RARα in breast cancer cells by using either RARα specific antagonists or a dominant negative RARα mutant hampers on one hand the RA-induced upregulation of neutral sphingomyelinase (nSMase)-mediated CER synthesis, and on the other hand the RA-induced downregulation of sphingosine kinase 1, SK1, pivotal for S1P synthesis. In association with RA inability to regulate the sphingolipid rheostat, cells not only survive, but also grow more in response to RA both in vitro and in vivo. By combining genetic, pharmacological and biochemical approaches, we mechanistically demonstrated that RA-induced growth is, at least in part, due to non-RAR-mediated activation of the SK1-S1P signaling. Conclusions/Significance In the presence of functional RARα, RA inhibits cell growth by concertedly, and inversely, modulating the CER and S1P synthetic pathways. In the absence of a functional RARα, RA–in a non-RAR-mediated fashion–promotes cell growth by activating the prosurvival S1P signaling. These two distinct, yet integrated processes

  6. The G protein-coupled receptor GPR31 promotes membrane association of KRAS.

    PubMed

    Fehrenbacher, Nicole; Tojal da Silva, Israel; Ramirez, Craig; Zhou, Yong; Cho, Kwang-Jin; Kuchay, Shafi; Shi, Jie; Thomas, Susan; Pagano, Michele; Hancock, John F; Bar-Sagi, Dafna; Philips, Mark R

    2017-08-07

    The product of the KRAS oncogene, KRAS4B, promotes tumor growth when associated with the plasma membrane (PM). PM association is mediated, in part, by farnesylation of KRAS4B, but trafficking of nascent KRAS4B to the PM is incompletely understood. We performed a genome-wide screen to identify genes required for KRAS4B membrane association and identified a G protein-coupled receptor, GPR31. GPR31 associated with KRAS4B on cellular membranes in a farnesylation-dependent fashion, and retention of GPR31 on the endoplasmic reticulum inhibited delivery of KRAS4B to the PM. Silencing of GPR31 expression partially mislocalized KRAS4B, slowed the growth of KRAS-dependent tumor cells, and blocked KRAS-stimulated macropinocytosis. Our data suggest that GPR31 acts as a secretory pathway chaperone for KRAS4B. © 2017 Fehrenbacher et al.

  7. Increased longevity evolves from grandmothering.

    PubMed

    Kim, Peter S; Coxworth, James E; Hawkes, Kristen

    2012-12-22

    Postmenopausal longevity may have evolved in our lineage when ancestral grandmothers subsidized their daughters' fertility by provisioning grandchildren, but the verbal hypothesis has lacked mathematical support until now. Here, we present a formal simulation in which life spans similar to those of modern chimpanzees lengthen into the modern human range as a consequence of grandmother effects. Greater longevity raises the chance of living through the fertile years but is opposed by costs that differ for the sexes. Our grandmother assumptions are restrictive. Only females who are no longer fertile themselves are eligible, and female fertility extends to age 45 years. Initially, there are very few eligible grandmothers and effects are small. Grandmothers can support only one dependent at a time and do not care selectively for their daughters' offspring. They must take the oldest juveniles still relying on mothers; and infants under the age of 2 years are never eligible for subsidy. Our model includes no assumptions about brains, learning or pair bonds. Grandmother effects alone are sufficient to propel the doubling of life spans in less than sixty thousand years.

  8. Increased longevity evolves from grandmothering

    PubMed Central

    Kim, Peter S.; Coxworth, James E.; Hawkes, Kristen

    2012-01-01

    Postmenopausal longevity may have evolved in our lineage when ancestral grandmothers subsidized their daughters' fertility by provisioning grandchildren, but the verbal hypothesis has lacked mathematical support until now. Here, we present a formal simulation in which life spans similar to those of modern chimpanzees lengthen into the modern human range as a consequence of grandmother effects. Greater longevity raises the chance of living through the fertile years but is opposed by costs that differ for the sexes. Our grandmother assumptions are restrictive. Only females who are no longer fertile themselves are eligible, and female fertility extends to age 45 years. Initially, there are very few eligible grandmothers and effects are small. Grandmothers can support only one dependent at a time and do not care selectively for their daughters' offspring. They must take the oldest juveniles still relying on mothers; and infants under the age of 2 years are never eligible for subsidy. Our model includes no assumptions about brains, learning or pair bonds. Grandmother effects alone are sufficient to propel the doubling of life spans in less than sixty thousand years. PMID:23097518

  9. Mitochondria and mitochondria-induced signalling molecules as longevity determinants.

    PubMed

    Rose, Giuseppina; Santoro, Aurelia; Salvioli, Stefano

    2017-07-01

    An intense cross talk between mitochondria and nucleus continuously informs the cell about the functional state of these crucial organelles and elicits an effective stress response that strenghtens the cell, promoting its survival. Interestingly, this effect can spread also in a non-cell autonomous fashion to distal tissues by means of soluble factors. This stress response is responsible of a consistent lifespan increase in many animal models, while in humans there is still a lack of knowledge. This review summarises the available data on the involvement of mitochondria in longevity focusing in particular on this signalling activity and the consequent stress response that is elicited, and proposes the idea that, similarly to animal models, humans may benefit from this response in terms of delayed aging and longevity. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  10. Glucocorticoids promote hepatic cholestasis in mice by inhibiting the transcriptional activity of the farnesoid X receptor.

    PubMed

    Lu, Yan; Zhang, Zhijian; Xiong, Xuelian; Wang, Xiaolin; Li, Jin; Shi, Guojun; Yang, Jian; Zhang, Xianfeng; Zhang, Huijie; Hong, Jie; Xia, Xuefeng; Ning, Guang; Li, Xiaoying

    2012-12-01

    Glucocorticoids have potent anti-inflammatory effects, but also can cause insulin resistance, osteoporosis, and muscle wasting, preventing their long-term use. Glucocorticoids also have been associated with the development of hepatic cholestasis and gallstone disease, but little is known about their pathogenic mechanisms. We analyzed levels of bile acids (BAs) and glucocorticoids in serum samples from patients with Cushing disease and obese individuals (body mass index, >30). C57BL/6 mice were injected with dexamethasone and db/db obese mice were injected with glucocorticoid receptor (GR) antagonists or small hairpin RNAs. We analyzed farnesoid X receptor (FXR) signaling in HepG2 cells and cells from mice using immunoprecipitation, luciferase reporter, and glutathione-s-transferase and chromatin immunoprecipitation assays. We analyzed BA metabolism in FXR-/- mice and mice with reduced levels of the transcription factor C-terminal binding protein (CtBP). Serum levels of BAs were higher in patients with Cushing disease or obesity than in individuals with normal levels of glucocorticoids. Administration of dexamethasone promoted cholestasis and overproduction of BAs in C57BL/6 mice, but not in FXR-/- mice. GR antagonists, or injection of an adenoviral small hairpin RNA against GR, reduced features of hepatic cholestasis in db/db mice. The GR interacted with FXR to reduce its transcriptional activity by recruiting CtBP co-repressor complexes. Mice with reduced levels of CtBP were resistant to induction of hepatic cholestasis by dexamethasone. Glucocorticoids promote hepatic cholestasis in mice by recruiting CtBP co-repressor complexes to FXR and thereby blocking the transcriptional activity. Copyright © 2012 AGA Institute. Published by Elsevier Inc. All rights reserved.

  11. Aryl Hydrocarbon Receptor Downregulates MYCN Expression and Promotes Cell Differentiation of Neuroblastoma

    PubMed Central

    Wu, Pei-Yi; Liao, Yung-Feng; Juan, Hsueh-Fen; Huang, Hsuan-Cheng; Wang, Bo-Jeng; Lu, Yen-Lin; Yu, I-Shing; Shih, Yu-Yin; Jeng, Yung-Ming; Hsu, Wen-Ming; Lee, Hsinyu

    2014-01-01

    Neuroblastoma (NB) is the most common malignant disease of infancy. MYCN amplification is a prognostic factor for NB and is a sign of highly malignant disease and poor patient prognosis. In this study, we aimed to investigate novel MYCN-related genes and assess how they affect NB cell behavior. The different gene expression found in 10 MYCN amplification NB tumors and 10 tumors with normal MYCN copy number were analyzed using tissue oligonucleotide microarrays. Ingenuity Pathway Analysis was subsequently performed to identify the potential genes involved in MYCN regulation pathways. Aryl hydrocarbon receptor (AHR), a receptor for dioxin-like compounds, was found to be inversely correlated with MYCN expression in NB tissues. This correlation was confirmed in a further 14 human NB samples. Moreover, AHR expression in NB tumors was found to correlate highly with histological grade of differentiation. In vitro studies revealed that AHR overexpression in NB cells induced spontaneous cell differentiation. In addition, it was found that ectopic expression of AHR suppressed MYCN promoter activity resulting in downregulation of MYCN expression. The suppression effect of AHR on the transcription of MYCN was compensated for by E2F1 overexpression, indicating that E2F1 is involved in the AHR-regulating MYCN pathway. Furthermore, AHR shRNA promotes the expression of E2F1 and MYCN in NB cells. These findings suggest that AHR is one of the upstream regulators of MYCN. Through the modulation of E2F1, AHR regulates MYCN gene expression, which may in turn affect NB differentiation. PMID:24586395

  12. Ischemic insults promote epigenetic reprogramming of μ opioid receptor expression in hippocampal neurons

    PubMed Central

    Formisano, Luigi; Noh, Kyung-Min; Miyawaki, Takahiro; Mashiko, Toshihiro; Bennett, Michael V. L.; Zukin, R. Suzanne

    2007-01-01

    Transient global ischemia is a neuronal insult that induces delayed, selective death of hippocampal CA1 pyramidal neurons. A mechanism underlying ischemia-induced cell death is activation of the gene silencing transcription factor REST (repressor element-1 silencing transcription factor)/NRSF (neuron-restrictive silencing factor) and REST-dependent suppression of the AMPA receptor subunit GluR2 in CA1 neurons destined to die. Here we show that REST regulates an additional gene target, OPRM1 (μ opioid receptor 1 or MOR-1). MORs are abundantly expressed by basket cells and other inhibitory interneurons of CA1. Global ischemia induces a marked decrease in MOR-1 mRNA and protein expression that is specific to the selectively vulnerable area CA1, as assessed by quantitative real-time RT-PCR, Western blotting, and ChIP. We further show that OPRM1 gene silencing is REST-dependent and occurs via epigenetic modifications. Ischemia promotes deacetylation of core histone proteins H3 and H4 and dimethylation of histone H3 at lysine-9 (H3-K9) over the MOR-1 promoter, an signature of epigenetic gene silencing. Acute knockdown of MOR-1 gene expression by administration of antisense oligodeoxynucleotides to hippocampal slices in vitro or injection of the MOR antagonist naloxone to rats in vivo affords protection against ischemia-induced death of CA1 pyramidal neurons. These findings implicate MORs in ischemia-induced death of CA1 pyramidal neurons and document epigenetic remodeling of expression of OPRM1 in CA1 inhibitory interneurons. PMID:17360495

  13. The NMDA Receptor Promotes Sleep in the Fruit Fly, Drosophila melanogaster

    PubMed Central

    Tomita, Jun; Ueno, Taro; Mitsuyoshi, Madoka; Kume, Shoen; Kume, Kazuhiko

    2015-01-01

    Considerable evidence indicates that sleep is essential for learning and memory. Drosophila melanogaster has emerged as a novel model for studying sleep. We previously found a short sleeper mutant, fumin (fmn), and identified its mutation in the dopamine transporter gene. We reported similarities in the molecular basis of sleep and arousal regulation between mammals and Drosophila. In aversive olfactory learning tasks, fmn mutants demonstrate defective memory retention, which suggests an association between sleep and memory. In an attempt to discover additional sleep related genes in Drosophila, we carried out a microarray analysis comparing mRNA expression in heads of fmn and control flies and found that 563 genes are differentially expressed. Next, using the pan-neuronal Gal4 driver elav-Gal4 and UAS-RNA interference (RNAi) to knockdown individual genes, we performed a functional screen. We found that knockdown of the NMDA type glutamate receptor channel gene (Nmdar1) (also known as dNR1) reduced sleep. The NMDA receptor (NMDAR) plays an important role in learning and memory both in Drosophila and mammals. The application of the NMDAR antagonist, MK-801, reduced sleep in control flies, but not in fmn. These results suggest that NMDAR promotes sleep regulation in Drosophila. PMID:26023770

  14. Chemokine Receptor Ccr6 Deficiency Alters Hepatic Inflammatory Cell Recruitment and Promotes Liver Inflammation and Fibrosis

    PubMed Central

    Blaya, Delia; Morales-Ibanez, Oriol; Coll, Mar; Millán, Cristina; Altamirano, José; Arroyo, Vicente; Caballería, Joan; Bataller, Ramón; Ginès, Pere; Sancho-Bru, Pau

    2015-01-01

    Chronic liver diseases are characterized by a sustained inflammatory response in which chemokines and chemokine-receptors orchestrate inflammatory cell recruitment. In this study we investigated the role of the chemokine receptor CCR6 in acute and chronic liver injury. In the absence of liver injury Ccr6-/- mice presented a higher number of hepatic macrophages and increased expression of pro-inflammatory cytokines and M1 markers Tnf-α, Il6 and Mcp1. Inflammation and cell recruitment were increased after carbon tetrachloride-induced acute liver injury in Ccr6-/- mice. Moreover, chronic liver injury by carbon tetrachloride in Ccr6-/- mice was associated with enhanced inflammation and fibrosis, altered macrophage recruitment, enhanced CD4+ cells and a reduction in Th17 (CD4+IL17+) and mature dendritic (MHCII+CD11c+) cells recruitment. Clodronate depletion of macrophages in Ccr6-/- mice resulted in a reduction of hepatic pro-inflammatory and pro-fibrogenic markers in the absence and after liver injury. Finally, increased CCR6 hepatic expression in patients with alcoholic hepatitis was found to correlate with liver expression of CCL20 and severity of liver disease. In conclusion, CCR6 deficiency affects hepatic inflammatory cell recruitment resulting in the promotion of hepatic inflammation and fibrosis. PMID:26691857

  15. Chemokine Receptor Ccr6 Deficiency Alters Hepatic Inflammatory Cell Recruitment and Promotes Liver Inflammation and Fibrosis.

    PubMed

    Affò, Silvia; Rodrigo-Torres, Daniel; Blaya, Delia; Morales-Ibanez, Oriol; Coll, Mar; Millán, Cristina; Altamirano, José; Arroyo, Vicente; Caballería, Joan; Bataller, Ramón; Ginès, Pere; Sancho-Bru, Pau

    2015-01-01

    Chronic liver diseases are characterized by a sustained inflammatory response in which chemokines and chemokine-receptors orchestrate inflammatory cell recruitment. In this study we investigated the role of the chemokine receptor CCR6 in acute and chronic liver injury. In the absence of liver injury Ccr6-/- mice presented a higher number of hepatic macrophages and increased expression of pro-inflammatory cytokines and M1 markers Tnf-α, Il6 and Mcp1. Inflammation and cell recruitment were increased after carbon tetrachloride-induced acute liver injury in Ccr6-/- mice. Moreover, chronic liver injury by carbon tetrachloride in Ccr6-/- mice was associated with enhanced inflammation and fibrosis, altered macrophage recruitment, enhanced CD4+ cells and a reduction in Th17 (CD4+IL17+) and mature dendritic (MHCII+CD11c+) cells recruitment. Clodronate depletion of macrophages in Ccr6-/- mice resulted in a reduction of hepatic pro-inflammatory and pro-fibrogenic markers in the absence and after liver injury. Finally, increased CCR6 hepatic expression in patients with alcoholic hepatitis was found to correlate with liver expression of CCL20 and severity of liver disease. In conclusion, CCR6 deficiency affects hepatic inflammatory cell recruitment resulting in the promotion of hepatic inflammation and fibrosis.

  16. The chemokine receptor CCR7 promotes mammary tumorigenesis through amplification of stem-like cells.

    PubMed

    Boyle, S T; Ingman, W V; Poltavets, V; Faulkner, J W; Whitfield, R J; McColl, S R; Kochetkova, M

    2016-01-07

    The chemokine receptor CCR7 is widely implicated in breast cancer pathobiology. Although recent reports correlated high CCR7 levels with more advanced tumor grade and poor prognosis, limited in vivo data are available regarding its specific function in mammary gland neoplasia and the underlying mechanisms involved. To address these questions we generated a bigenic mouse model of breast cancer combined with CCR7 deletion, which revealed that CCR7 ablation results in a considerable delay in tumor onset as well as significantly reduced tumor burden. Importantly, CCR7 was found to exert its function by regulating mammary cancer stem-like cells in both murine and human tumors. In vivo experiments showed that loss of CCR7 activity either through deletion or pharmacological antagonism significantly decreased functional pools of stem-like cells in mouse primary mammary tumors, providing a mechanistic explanation for the tumor-promoting role of this chemokine receptor. These data characterize the oncogenic properties of CCR7 in mammary epithelial neoplasia and point to a new route for therapeutic intervention to target evasive cancer stem cells.

  17. Influence of a critical single nucleotide polymorphism on nuclear receptor PXR-promoter function.

    PubMed

    Rana, Manjul; Coshic, Poonam; Goswami, Ravinder; Tyagi, Rakesh K

    2017-02-15

    The Pregnane and Xenobiotic Receptor (PXR; NR1I2) is a ligand-modulated transcription factor that belongs to the nuclear receptor superfamily. It is expressed at higher levels primarily in liver and intestine as compared to the levels in several other organs. It is activated by a broad spectrum of xenobiotics and endobiotics. The primary function of PXR is to regulate the expression of drug metabolizing enzymes and transporters and prevent the accumulation of toxic chemicals in the body, thereby maintaining body's homeostasis. In this study, we identified a C/T single nucleotide polymorphism at position -831 from the transcriptional start site of the PXR gene promoter and examined the functional significance of this variant using both the luciferase reporter gene assays and electrophoretic mobility shift assays (EMSA). Transient transfection experiments showed that the T-allele was associated with significantly greater transcriptional activity than the C-allele of SNP rs3814055. These results indicate that the -831C/T polymorphism has a direct effect on transcriptional regulation of PXR gene. This allelic variation may be a potential genetic marker that can help identify individuals at higher risk for Inflammatory Bowel Disease (IBD).

  18. Histamine-HisCl1 Receptor Axis Regulates Wake-Promoting Signals in Drosophila melanogaster

    PubMed Central

    Oh, Yangkyun; Jang, Donghoon; Sonn, Jun Young; Choe, Joonho

    2013-01-01

    Histamine and its two receptors, histamine-gated chloride channel subunit 1 (HisCl1) and ora transientless (Ort), are known to control photoreception and temperature sensing in Drosophila. However, histamine signaling in the context of neural circuitry for sleep-wake behaviors has not yet been examined in detail. Here, we obtained mutant flies with compromised or enhanced histamine signaling and tested their baseline sleep. Hypomorphic mutations in histidine decarboxylase (HDC), an enzyme catalyzing the conversion from histidine to histamine, caused an increase in sleep duration. Interestingly, hisCl1 mutants but not ort mutants showed long-sleep phenotypes similar to those in hdc mutants. Increased sleep duration in hisCl1 mutants was rescued by overexpressing hisCl1 in circadian pacemaker neurons expressing a neuropeptide pigment dispersing factor (PDF). Consistently, RNA interference (RNAi)-mediated depletion of hisCl1 in PDF neurons was sufficient to mimic hisCl1 mutant phenotypes, suggesting that PDF neurons are crucial for sleep regulation by the histamine-HisCl1 signaling. Finally, either hisCl1 mutation or genetic ablation of PDF neurons dampened wake-promoting effects of elevated histamine signaling via direct histamine administration. Taken together, these data clearly demonstrate that the histamine-HisCl1 receptor axis can activate and maintain the wake state in Drosophila and that wake-activating signals may travel via the PDF neurons. PMID:23844178

  19. Estrogen and estrogen receptor alpha promotes malignancy and osteoblastic tumorigenesis in prostate cancer.

    PubMed

    Mishra, Sweta; Tai, Qin; Gu, Xiang; Schmitz, James; Poullard, Ashley; Fajardo, Roberto J; Mahalingam, Devalingam; Chen, Xiaodong; Zhu, Xueqiong; Sun, Lu-Zhe

    2015-12-29

    The role of estrogen signaling in regulating prostate tumorigenesis is relatively underexplored. Although, an increasing body of evidence has linked estrogen receptor beta (ERß) to prostate cancer, the function of estrogen receptor alpha (ERα) in prostate cancer is not very well studied. We have discovered a novel role of ERα in the pathogenesis of prostate tumors. Here, we show that prostate cancer cells express ERα and estrogen induces oncogenic properties in prostate cancer cells through ERα. Importantly, ERα knockdown in the human prostate cancer PacMetUT1 cells as well as pharmacological inhibition of ERα with ICI 182,780 inhibited osteoblastic lesion formation and lung metastasis in vivo. Co-culture of pre-osteoblasts with cancer cells showed a significant induction of osteogenic markers in the pre-osteoblasts, which was attenuated by knockdown of ERα in cancer cells suggesting that estrogen/ERα signaling promotes crosstalk between cancer and osteoblastic progenitors to stimulate osteoblastic tumorigenesis. These results suggest that ERα expression in prostate cancer cells is essential for osteoblastic lesion formation and lung metastasis. Thus, inhibition of ERα signaling in prostate cancer cells may be a novel therapeutic strategy to inhibit the osteoblastic lesion development as well as lung metastasis in patients with advanced prostate cancer.

  20. Aryl hydrocarbon receptor degradation-promoting factor (ADPF) and the control of the xenobiotic response.

    PubMed

    Ma, Qiang

    2007-06-01

    The study of xenobiotic metabolism has long been a core activity in pharmacology. The diverse chemical transformations of xenobiotics in vivo are elegant in themselves, depending as they do on a battery of enzymes that include the cytochomes P450 (CYPs), and their reaction mechanisms have been elucidated by a great many pioneering pharmacologists who helped to launch the discipline. Today, researchers are finding surprising and subtle intricacies in the molecular control that underpins the xenobiotic response. For example, the inducible expression of CYP-encoding genes above normal basal output is controlled by specialized xenobiotic activated receptors (XARs), which include the aryl hydrocarbon receptor (AhR). But because CYP activities can be double-edged, supporting a multiplicity of chemical transformations, their expression levels must be tightly regulated over time and biological space. Indeed, the kinetics of xenobiotic-induced CYP expression suggest multiple checks and balances at both transcriptional and post-translational levels. Recent research points to the regulated degradation of AhR as one aspect of control. A key participant in directing AhR degradation has been identified-the AhR degradation promoting factor (ADPF)-which appears to serve as an E3 ubiquitin ligase. The biological machinery that controls the xenobiotic response thus encompasses an elegance deep beneath the traditional recognition of CYPs as catalysts of xenobiotic degradation.

  1. GABA A receptor π subunit promotes apoptosis of HTR-8/SVneo trophoblastic cells: Implications in preeclampsia.

    PubMed

    Lu, Junjie; Zhang, Qian; Tan, Dongmei; Luo, Wenping; Zhao, Hai; Ma, Jing; Liang, Hao; Tan, Yi

    2016-07-01

    Gamma-aminobutyric acid (GABA) functions primarily as an inhibitory neurotransmitter through its receptors in the mature central nervous system. The GABA type A receptor π subunit (GABRP) has been identified in the tissues of the reproductive system, particularly in the uterus. In addition, we have previously detected GABRP expression in both human and mouse placentas. To examine the role of GABRP in trophoblastic cell invasion, we constructed a pIRES2-GABRP-EGFP plasmid which was used for the transfection of a human placental cell line derived from first trimester extravillous trophoblasts (HTR-8/SVneo). The number of invaded cells was decreased by GABRP overexpression. Notably, the decrease in the invasive cell number may be due to the increased apoptosis of the HTR-8/SVneo cells following GABRP transfection, which was further confirmed by flow cytometry, reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and western blot analysis. Based on the increased apoptosis of trophoblastic cells in pregnancies complicated by preeclampsia (PE) and the fact that GABRP promotes the apoptosis of trophoblastic cells, we hypothesized that GABRP expression is increased in the placental tissues from patients with PE compared with that in the normal groups and this hypothesis was confirmed by RT-qPCR and immunohistochemical analysis. Taken together, these findings imply that GABRP plays an important role in placentation and this pathway may be a promising molecular target for the development of novel therapeutic strategies for PE.

  2. Toll-like receptor 2 ligands promote microglial cell death by inducing autophagy

    PubMed Central

    Arroyo, Daniela S.; Soria, Javier A.; Gaviglio, Emilia A.; Garcia-Keller, Constanza; Cancela, Liliana M.; Rodriguez-Galan, Maria C.; Wang, Ji Ming; Iribarren, Pablo

    2013-01-01

    Microglial cells are phagocytes in the central nervous system (CNS) and become activated in pathological conditions, resulting in microgliosis, manifested by increased cell numbers and inflammation in the affected regions. Thus, controlling microgliosis is important to prevent pathological damage to the brain. Here, we evaluated the contribution of Toll-like receptor 2 (TLR2) to microglial survival. We observed that activation of microglial cells with peptidoglycan (PGN) from Staphylococcus aureus and other TLR2 ligands results in cell activation followed by the induction of autophagy and autophagy-dependent cell death. In C57BL/6J mice, intracerebral injection of PGN increased the autophagy of microglial cells and reduced the microglial/macrophage cell number in brain parenchyma. Our results demonstrate a novel role of TLRs in the regulation of microglial cell activation and survival, which are important for the control of microgliosis and associated inflammatory responses in the CNS.—Arroyo, D. S., Soria, J. A., Gaviglio, E. A., Garcia-Keller, C., Cancela, L. M., Rodriguez-Galan, M. C., Wang, J. M., Iribarren, P. Toll-like receptor 2 ligands promote microglial cell death by inducing autophagy. PMID:23073832

  3. Phase transitions of multivalent proteins can promote clustering of membrane receptors

    PubMed Central

    Banjade, Sudeep; Rosen, Michael K

    2014-01-01

    Clustering of proteins into micrometer-sized structures at membranes is observed in many signaling pathways. Most models of clustering are specific to particular systems, and relationships between physical properties of the clusters and their molecular components are not well understood. We report biochemical reconstitution on supported lipid bilayers of protein clusters containing the adhesion receptor Nephrin and its cytoplasmic partners, Nck and N-WASP. With Nephrin attached to the bilayer, multivalent interactions enable these proteins to polymerize on the membrane surface and undergo two-dimensional phase separation, producing micrometer-sized clusters. Dynamics and thermodynamics of the clusters are modulated by the valencies and affinities of the interacting species. In the presence of the Arp2/3 complex, the clusters assemble actin filaments, suggesting that clustering of regulatory factors could promote local actin assembly at membranes. Interactions between multivalent proteins could be a general mechanism for cytoplasmic adaptor proteins to organize membrane receptors into micrometer-scale signaling zones. DOI: http://dx.doi.org/10.7554/eLife.04123.001 PMID:25321392

  4. Estrogen Promotes Luteolysis by Redistributing Prostaglandin F2α Receptors Within Primate Luteal Cells*

    PubMed Central

    Kim, Soon Ok; Markosyan, Nune; Pepe, Gerald J.; Duffy, Diane M.

    2015-01-01

    Prostaglandin F2α (PGF2α) has been proposed as a functional luteolysin in primates. However, administration of PGF2α or prostaglandin synthesis inhibitors in vivo both initiate luteolysis. These contradictory findings may reflect changes in PGF2α receptors (PTGFR) or responsiveness to PGF2α at a critical point during the life span of the corpus luteum. The current study addressed this question using ovarian cells and tissues from female cynomolgus monkeys and luteinizing granulosa cells from healthy women undergoing follicle aspiration. PTGFRs were present in the cytoplasm of monkey granulosa cells, while PTGFRs were localized to the perinuclear region of large, granulosa-derived monkey luteal cells by mid-late luteal phase. A PTGFR agonist decreased progesterone production by luteal cells obtained at mid-late and late luteal phases but did not decrease progesterone production by granulosa or luteal cells from younger corpora lutea. These findings are consistent with a role for perinuclear PTGFRs in functional luteolysis. This concept was explored using human luteinizing granulosa cells maintained in vitro as a model for luteal cell differentiation. In these cells, PTGFRs relocated from the cytoplasm to the perinuclear area in an estrogen- and estrogen receptor-dependent manner. Similar to our findings with monkey luteal cells, human luteinizing granulosa cells with perinuclear PTGFRs responded to a PTGFR agonist with decreased progesterone production. These data support the concept that PTGFR stimulation promotes functional luteolysis only when PTGFRs are located in the perinuclear region. Estrogen receptor-mediated relocation of PTGFRs within luteal cells may be a necessary step in the initiation of luteolysis in primates. PMID:25687410

  5. 3-methylcholanthrene induces differential recruitment of aryl hydrocarbon receptor to human promoters.

    PubMed

    Pansoy, Andrea; Ahmed, Shaimaa; Valen, Eivind; Sandelin, Albin; Matthews, Jason

    2010-09-01

    The aryl hydrocarbon receptor (AHR) is a ligand-activated protein that mediates the toxic actions of polycyclic aromatic and halogenated compounds. Identifying genes directly regulated by AHR is important in understanding the pathways regulated by this receptor. Here we used the techniques of chromatin immunoprecipitation and DNA microarrays (ChIP-chip) to detect AHR-bound genomic regions after 3-methylcholanthrene (3MC) treatment of T-47D human breast cancer cells. We identified 241 AHR-3MC-bound regions, and transcription factor-binding site analysis revealed a strong overrepresentation of the AHR-responsive element. Conventional ChIP confirmed recruitment of AHR to 26 regions with target gene responses to 3MC varying from activation to inhibition to having no effect. A comparison of identified AHR-3MC-bound regions with AHR-2,3,7,8-tetrchlorodibenzo-p-dioxin (TCDD)-bound regions from our previous study (Ahmed, S., Valen, E., Sandelin, A., and Matthews, J. (2009). Toxicol. Sci. 111, 254-266) revealed that 127 regions were common between the data sets. Time course ChIPs for six of the regions showed that 3MC induced gene-specific changes in histone H3 acetylation and methylation and induced differential oscillatory binding of AHR, with a periodicity between 1.5 and 2 h. Re-treatment of cells with 3MC failed to alter the oscillatory binding profiles of AHR or aryl hydrocarbon receptor nuclear translocator. Cells became responsive to 3MC but not TCDD after 24 h of exposure to 3MC, highlighting important differences in AHR responsiveness between the two ligands. Our results reveal a number of novel AHR-bound promoter regions and target genes that exhibit differential kinetic binding profiles and regulation by AHR.

  6. Ritonavir binds to and downregulates estrogen receptors: Molecular mechanism of promoting early atherosclerosis

    SciTech Connect

    Xiang, Jin; Wang, Ying; Su, Ke; Liu, Min; Hu, Peng-Chao; Ma, Tian; Li, Jia-Xi; Wei, Lei; Zheng, Zhongliang; Yang, Fang

    2014-10-01

    Estrogenic actions are closely related to cardiovascular disease. Ritonavir (RTV), a human immunodeficiency virus (HIV) protease inhibitor, induces atherosclerosis in an estrogen-related manner. However, how RTV induce pathological phenotypes through estrogen pathway remains unclear. In this study, we found that RTV increases thickness of coronary artery walls of Sprague Dawley rats and plasma free fatty acids (FFA) levels. In addition, RTV could induce foam cell formation, downregulate both estrogen receptor α (ERα) and ERβ expression, upregulate G protein-coupled estrogen receptor (GPER) expression, and all of them could be partially blocked by 17β-estradiol (E2), suggesting RTV acts as an antagonist for E2. Computational modeling shows a similar interaction with ERα between RTV and 2-aryl indoles, which are highly subtype-selective ligands for ERα. We also found that RTV directly bound to ERα and selectively inhibited the nuclear localization of ERα, and residue Leu536 in the hydrophobic core of ligand binding domain (LBD) was essential for the interaction with RTV. In addition, RTV did not change the secondary structure of ERα-LBD like E2, which explained how ERα lost the capacity of nuclear translocation under the treatment of RTV. All of the evidences suggest that ritonavir acts as an antagonist for 17β-estradiol in regulating α subtype estrogen receptor function and early events of atherosclerosis. - Graphical abstract: RTV directly binds to ERα and Leu536 in the hydrophobic core of ligand binding domain is essential for the interaction. - Highlights: • RTV increases the thickness of rat coronary artery wall and foam cell formation. • RTV downregulates the expression of ERα and ERβ. • RTV inhibits ERα promoter activity. • RTV directly binds to ERα and the key amino acid is Leu536. • RTV inhibits the nuclear translocation of ERα and GPER.

  7. CD97 amplifies LPA receptor signaling and promotes thyroid cancer progression in a mouse model.

    PubMed

    Ward, Y; Lake, R; Martin, P L; Killian, K; Salerno, P; Wang, T; Meltzer, P; Merino, M; Cheng, S-y; Santoro, M; Garcia-Rostan, G; Kelly, K

    2013-05-30

    CD97, a member of the adhesion family of G-protein-coupled receptors (GPCRs), complexes with and potentiates lysophosphatidic acid (LPA) receptor signaling to the downstream effector RHOA. We show here that CD97 was expressed in a majority of thyroid cancers but not normal thyroid epithelium and that the level of CD97 expression was further elevated with progression to poorly differentiated and undifferentiated carcinoma. Intratumoral progression also showed that CD97 expression correlates with invasiveness and dedifferentiation. To determine the functional role of CD97, we produced a transgenic model of thyroglobulin promoter-driven CD97 expression. Transgenic CD97 in combination with Thrb(PV), an established mouse model of thyroid follicular cell carcinogenesis, significantly increased the occurrence of vascular invasion and lung metastasis. Expression of transgenic CD97 in thyroid epithelium led to elevated ERK phosphorylation and increased numbers of Ki67+ cells in developing tumors. In addition, tumor cell cultures derived from CD97 transgenic as compared with non-transgenic mice demonstrated enhanced, constitutive and LPA-stimulated ERK activation. In human thyroid cancer cell lines, CD97 depletion reduced RHO-GTP and decreased LPA-stimulated invasion but not EGF-stimulated invasion, further suggesting that CD97 influences an LPA-associated mechanism of progression. Consistent with the above, CD97 expression in human thyroid cancers correlated with LPA receptor and markers of aggressiveness including Ki67 and pAKT. This study shows an autonomous effect of CD97 on thyroid cancer progression and supports the investigation of this GPCR as a therapeutic target for these cancers.

  8. Nitrosylcobalamin Promotes Cell Death via S Nitrosylation of Apo2L/TRAIL Receptor DR4

    PubMed Central

    Tang, Zhuo; Bauer, Joseph A.; Morrison, Bei; Lindner, Daniel J.

    2006-01-01

    We have previously demonstrated that nitrosylcobalamin (NO-Cbl), an analogue of vitamin B12 that delivers nitric oxide (NO), had potent antiproliferative activity against several human cancer cell lines. NO-Cbl induced apoptosis via a death receptor/caspase-8 pathway. In this study, we demonstrate that a functional Apo2L/TRAIL receptor was necessary for the induction of cell death by NO-Cbl. Furthermore, the Apo2L/TRAIL death receptor DR4 (TRAIL R1) was S nitrosylated following NO-Cbl treatment. Human melanoma (A375), renal carcinoma (ACHN), and ovarian carcinoma (NIH-OVCAR-3) cells were treated with NO-Cbl and subjected to the biotin switch assay; S-nitrosylated DR4 was detected in all three cell lines. NO-Cbl treatment did not cause S nitrosylation of DR5. The seven cysteine residues located in the cytoplasmic domain of DR4 were individually point mutated to alanines. NIH-OVCAR-3 cells expressing the DR4 C336A mutation lacked S nitrosylation following NO-Cbl treatment. Overexpression of wild-type DR4 sensitized cells to growth inhibition by NO-Cbl. Cells expressing the DR4 C336A mutant were more resistant to NO-Cbl and Apo2L/TRAIL than were the other six C-A mutations or wild-type cells. The C336A mutant also displayed blunted caspase-8 enzymatic activity following NO-Cbl treatment compared to the other mutants. Thus, DR4 residue C336 becomes S nitrosylated and promotes apoptosis following NO-Cbl treatment. PMID:16847314

  9. The small-molecule iron transport inhibitor ferristatin/NSC306711 promotes degradation of the transferrin receptor.

    PubMed

    Horonchik, Lior; Wessling-Resnick, Marianne

    2008-07-21

    Iron delivery by transferrin (Tf) is accomplished through clathrin-mediated endocytosis of Tf receptors. The small molecule NSC306711 inhibits iron uptake from the Tf-TfR pathway. Here we show that the drug's mechanism of action is to induce internalization and degradation of unoccupied Tf receptors through an unexpected endocytic pathway. Unlike classical clathrin-mediated Tf receptor endocytosis, internalization promoted by NSC306711 is independent of clathrin and dynamin, and is sensitive to the cholesterol-depleting agents filipin and nystatin. The finding of this cholesterol-dependent Tf receptor internalization pathway through use of the small-molecule inhibitor sheds light on the pleiotropic nature of membrane trafficking dynamics and adds a complex dimension to our understanding of receptor regulation. Because of its unusual properties to inhibit iron uptake, we refer to NSC306711 as "ferristatin."

  10. Tumor-promoting phorbol diesters cause the phosphorylation of epidermal growth factor receptors in normal human fibroblasts at threonine-654.

    PubMed Central

    Davis, R J; Czech, M P

    1985-01-01

    The effect of tumor-promoting phorbol diesters to potentiate the action of epidermal growth factor (EGF) on cell proliferation is associated with phosphorylation of EGF receptors, acute depression of EGF binding, and inhibition of EGF receptor tyrosine kinase activity. In the present studies, normal human fibroblasts and A431 carcinoma cells were labeled with [32P]phosphate and treated with and without 10 nM 4 beta-phorbol 12 beta-myristate 13 alpha-acetate (PMA). The EGF receptors then were isolated by immunoprecipitation and digested with trypsin. Analysis of the labeled receptor phosphopeptides by reversed-phase HPLC revealed that PMA induces the phosphorylation of a unique phosphopeptide containing [32P]phosphothreonine. Comparison of several chemical and physical properties of the 32P-labeled phosphopeptide with the primary structure of the EGF receptor suggested the identify Lys-Arg-Thr(P)-Leu-Arg. This was confirmed by direct demonstration that a synthetic peptide of this structure comigrates during HPLC and electrophoresis with the 32P-labeled phosphopeptide isolated from the EGF receptors of normal human fibroblasts. The phosphorylated site on the peptide corresponds to threonine-654 of the EGF receptor, which is located on the cytoplasmic side of the plasma membrane nine residues distant from the transmembrane domain. These data indicate that phosphorylation of the EGF receptor in human fibroblasts and A431 cells at threonine-654 may regulate the EGF receptor tyrosine kinase activity and the binding of EGF. Images PMID:2984676

  11. Longevity of the Human Spaceflight Program

    NASA Astrophysics Data System (ADS)

    Gott, J. Richard

    2007-02-01

    The longevity of the human spaceflight program is important to our survival prospects. On May 27, 1993 I proposed a method for estimating future longevity, based on past observed longevity using the Copernican Principle: if your observation point is not special the 95% confidence level prediction of future longevity is between (1/39)th and 39 times the past longevity. The prediction for the future longevity of the human spaceflight program (then 32 years old) was greater than 10 months but less than 1248 years. We have already passed the lower limit. This Copernican formula has been tested a number of times, correctly predicting, among other things, future longevities of Broadway plays and musicals, and the Conservative Government in the United Kingdom. Recently, a study of future longevities of the 313 world leaders in power on May 27, 1993 has been completed. Assuming none still in office serve past age 100, the success rate of the 95% Copernican Formula is currently 94.55% with only one case (out of 313) left to be decided. The human spaceflight program has not been around long and so there is the danger its future will not be long enough to allow us to colonize off the earth. Policy implications are discussed. A smart plan would be to try to establish a self-supporting colony on Mars in the next 45 years. This should not require sending any more tons of material into space in the next 45 years than we have in the last 45 years.

  12. Genetics, lifestyle and longevity: Lessons from centenarians

    PubMed Central

    Govindaraju, Diddahally; Atzmon, Gil; Barzilai, Nir

    2015-01-01

    Longevity as a complex life-history trait shares an ontogenetic relationship with other quantitative traits and varies among individuals, families and populations. Heritability estimates of longevity suggest that about a third of the phenotypic variation associated with the trait is attributable to genetic factors, and the rest is influenced by epigenetic and environmental factors. Individuals react differently to the environments that they are a part of, as well as to the environments they construct for their survival and reproduction; the latter phenomenon is known as niche construction. Lifestyle influences longevity at all the stages of development and levels of human diversity. Hence, lifestyle may be viewed as a component of niche construction. Here, we: a) interpret longevity using a combination of genotype-epigenetic-phenotype (GEP) map approach and niche-construction theory, and b) discuss the plausible influence of genetic and epigenetic factors in the distribution and maintenance of longevity among individuals with normal life span on the one hand, and centenarians on the other. Although similar genetic and environmental factors appear to be common to both of these groups, exceptional longevity may be influenced by polymorphisms in specific genes, coupled with superior genomic stability and homeostatic mechanisms, maintained by negative frequency-dependent selection. We suggest that a comparative analysis of longevity between individuals with normal life span and centenarians, along with insights from population ecology and evolutionary biology, would not only advance our knowledge of biological mechanisms underlying human longevity, but also provide deeper insights into extending healthy life span. PMID:26937346

  13. 28 CFR 345.55 - Longevity pay.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 28 Judicial Administration 2 2014-07-01 2014-07-01 false Longevity pay. 345.55 Section 345.55 Judicial Administration FEDERAL PRISON INDUSTRIES, INC., DEPARTMENT OF JUSTICE FEDERAL PRISON INDUSTRIES (FPI) INMATE WORK PROGRAMS Inmate Pay and Benefits § 345.55 Longevity pay. (a) Except as provided in...

  14. 28 CFR 345.55 - Longevity pay.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 28 Judicial Administration 2 2013-07-01 2013-07-01 false Longevity pay. 345.55 Section 345.55 Judicial Administration FEDERAL PRISON INDUSTRIES, INC., DEPARTMENT OF JUSTICE FEDERAL PRISON INDUSTRIES (FPI) INMATE WORK PROGRAMS Inmate Pay and Benefits § 345.55 Longevity pay. (a) Except as provided in...

  15. 28 CFR 345.55 - Longevity pay.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 28 Judicial Administration 2 2011-07-01 2011-07-01 false Longevity pay. 345.55 Section 345.55 Judicial Administration FEDERAL PRISON INDUSTRIES, INC., DEPARTMENT OF JUSTICE FEDERAL PRISON INDUSTRIES (FPI) INMATE WORK PROGRAMS Inmate Pay and Benefits § 345.55 Longevity pay. (a) Except as provided in...

  16. 28 CFR 345.55 - Longevity pay.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Longevity pay. 345.55 Section 345.55 Judicial Administration FEDERAL PRISON INDUSTRIES, INC., DEPARTMENT OF JUSTICE FEDERAL PRISON INDUSTRIES (FPI) INMATE WORK PROGRAMS Inmate Pay and Benefits § 345.55 Longevity pay. (a) Except as provided in...

  17. 28 CFR 345.55 - Longevity pay.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 28 Judicial Administration 2 2012-07-01 2012-07-01 false Longevity pay. 345.55 Section 345.55 Judicial Administration FEDERAL PRISON INDUSTRIES, INC., DEPARTMENT OF JUSTICE FEDERAL PRISON INDUSTRIES (FPI) INMATE WORK PROGRAMS Inmate Pay and Benefits § 345.55 Longevity pay. (a) Except as provided in...

  18. Stage dependent nutritional regulation of transgenerational longevity

    PubMed Central

    Roussou, Ilianna G.; Savakis, Charalambos; Tavernarakis, Nektarios; Metaxakis, Athanasios

    2016-01-01

    BACKGROUND: Statistical analyses in human populations have associated limited food availability during development with increased longevity of next generations. In support, recent findings in Caenorhabditis elegans revealed nutritional effects on transgenerational longevity. OBJECTIVES: In this study we tested the effect of nutrition on longevity of future generations in Drosophila and whether this is sex-specific. METHODS: We reared male larvae and adults of Drosophila under different food conditions and performed lifespan analyses in F2 generation. RESULTS: Grandsons of males which experienced starvation through larval stages were long-lived and grandsons of well fed larvae were short lived, in two Drosophila strains. In one strain, the nutritional effect on transgenerational longevity was transmitted through male line. Interestingly, we find that dietary restriction in adult males is the main nutritional condition affecting lifespan of grandsons. CONCLUSIONS: Our findings suggest that nutritional regulation of transgenerational longevity is evolutionarily conserved and developmental stage – dependent in Drosophila. PMID:28035341

  19. Reduced activin receptor-like kinase 1 activity promotes cardiac fibrosis in heart failure.

    PubMed

    Morine, Kevin J; Qiao, Xiaoying; Paruchuri, Vikram; Aronovitz, Mark J; Mackey, Emily E; Buiten, Lyanne; Levine, Jonathan; Ughreja, Keshan; Nepali, Prerna; Blanton, Robert M; Oh, S Paul; Karas, Richard H; Kapur, Navin K

    2017-07-18

    Activin receptor-like kinase 1 (ALK1) mediates signaling via the transforming growth factor beta-1 (TGFβ1), a pro-fibrogenic cytokine. No studies have defined a role for ALK1 in heart failure. We tested the hypothesis that reduced ALK1 expression promotes maladaptive cardiac remodeling in heart failure. In patients with advanced heart failure referred for left ventricular (LV) assist device implantation, LV Alk1 mRNA and protein levels were lower than control LV obtained from patients without heart failure. To investigate the role of ALK1 in heart failure, Alk1 haploinsufficient (Alk1(+/-)) and wild-type (WT) mice were studied 2 weeks after severe transverse aortic constriction (TAC). LV and lung weights were higher in Alk1(+/-) mice after TAC. Cardiomyocyte area and LV mRNA levels of brain natriuretic peptide and β-myosin heavy chain were increased similarly in Alk1(+/-) and WT mice after TAC. Alk-1 mice exhibited reduced Smad 1 phosphorylation and signaling compared to WT mice after TAC. Compared to WT, LV fibrosis and Type 1 collagen mRNA and protein levels were higher in Alk1(+/-) mice. LV fractional shortening was lower in Alk1(+/-) mice after TAC. Reduced expression of ALK1 promotes cardiac fibrosis and impaired LV function in a murine model of heart failure. Further studies examining the role of ALK1 and ALK1 inhibitors on cardiac remodeling are required. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. 3-methylcholanthrene induces differential recruitment of aryl hydrocarbon receptor to human promoters.

    PubMed

    Safe, Stephen

    2010-09-01

    The paper by Pansoy and coworkers investigates the effects of the aryl hydrocarbon receptor (AHR) ligand 3-methylcholanthrene (3MC) on recruitment of the AHR complex to human promoters in T47D breast cancer cells. The results are particularly important because they can be compared with a prior study using the potent AHR ligand 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in the same cell line. The chromatin immunoprecipitation and promoter-focused microarrays (ChIP-chip) demonstrated that after treatment of T47D cells with 1microM 3MC, there were 241 AHR-3MC bound regions and many of these contained AHR-responsive elements. However, they also observed interactions with regions that do not contain these responsive elements, and subsequent analysis of selected target genes show that 3MC-dependent AHR binding did not necessarily predict Ah-responsiveness because induction, repression, and no effects were observed. A prior study with TCDD demonstrated that both 3MC and TCDD induced AHR binding to 127 common regions; however, there were significant differences in ligand (3MC vs. TCDD)-dependent AHR bound regions. The results illustrate the complexity of AHR signaling and also demonstrate that compared with TCDD as a reference ligand, 3MC is a selective AHR modulator.

  1. Variants in the Dopamine-4-Receptor Gene Promoter Are Not Associated with Sensation Seeking in Skiers

    PubMed Central

    Thomson, Cynthia J.; Rajala, Amelia K.; Carlson, Scott R.; Rupert, Jim L.

    2014-01-01

    Sensation seeking is a personality trait that has been associated with disinhibited behaviours including substance use and gambling, but also with high-risk sport practices including skydiving, paragliding, and downhill skiing. Twin studies have shown that sensation seeking is moderately heritable, and candidate genes encoding components involved in dopaminergic transmission have been investigated as contributing to this type of behaviour. To determine whether variants in the regulatory regions of the dopamine-4-receptor gene (DRD4) influenced sport-specific sensation seeking, we analyzed five polymorphisms (−1106T/C, −906T/C, −809G/A, −291C/T, 120-bp duplication) in the promoter region of the gene in a cohort of skiers and snowboarders (n = 599) that represented a broad range of sensation seeking behaviours. We grouped subjects by genotype at each of the five loci and compared impulsive sensation seeking and domain-specific (skiing) sensation seeking between groups. There were no significant associations between genotype(s) and general or domain-specific sensation seeking in the skiers and snowboarders, suggesting that while DRD4 has previously been implicated in sensation seeking, the promoter variants investigated in this study do not contribute to sensation seeking in this athlete population. PMID:24691022

  2. Variants in the dopamine-4-receptor gene promoter are not associated with sensation seeking in skiers.

    PubMed

    Thomson, Cynthia J; Rajala, Amelia K; Carlson, Scott R; Rupert, Jim L

    2014-01-01

    Sensation seeking is a personality trait that has been associated with disinhibited behaviours including substance use and gambling, but also with high-risk sport practices including skydiving, paragliding, and downhill skiing. Twin studies have shown that sensation seeking is moderately heritable, and candidate genes encoding components involved in dopaminergic transmission have been investigated as contributing to this type of behaviour. To determine whether variants in the regulatory regions of the dopamine-4-receptor gene (DRD4) influenced sport-specific sensation seeking, we analyzed five polymorphisms (-1106T/C, -906T/C, -809G/A, -291C/T, 120-bp duplication) in the promoter region of the gene in a cohort of skiers and snowboarders (n = 599) that represented a broad range of sensation seeking behaviours. We grouped subjects by genotype at each of the five loci and compared impulsive sensation seeking and domain-specific (skiing) sensation seeking between groups. There were no significant associations between genotype(s) and general or domain-specific sensation seeking in the skiers and snowboarders, suggesting that while DRD4 has previously been implicated in sensation seeking, the promoter variants investigated in this study do not contribute to sensation seeking in this athlete population.

  3. Proteolytic activation of receptor-bound anthrax protective antigen on macrophages promotes its internalization.

    PubMed

    Beauregard, K E; Collier, R J; Swanson, J A

    2000-06-01

    Immunofluorescence and other methods have been used to probe the self-assembly and internalization of the binary toxin, anthrax lethal toxin (LeTx), in primary murine macrophages. Proteolytic activation of protective antigen (PA; 83 kDa, the B moiety of the toxin) by furin was the rate-limiting step in internalization of LeTx and promoted clearance of PA from the cell surface. A furin-resistant form of PA remained at the cell surface for at least 90 min. Oligomerization of receptor-bound PA63, the 63 kDa active fragment of PA, was manifested by its conversion to a pronase-resistant state, characteristic of the heptameric prepore form in solution. That oligomerization of PA63 triggers toxin internalization is supported by the observation that PA20, the complementary 20 kDa fragment of PA, inhibited clearance of nicked PA. The PA63 prepore, with or without lethal factor (LF), cleared slowly from the cell surface. These studies show that proteolytic cleavage of PA, in addition to permitting oligomerization and LF binding, also promotes internalization of the protein. The relatively long period of activation and internalization of PA at the cell surface may reflect adaptation of this binary toxin that maximizes self-assembly.

  4. The VLDL receptor promotes lipotoxicity and increases mortality in mice following an acute myocardial infarction

    PubMed Central

    Perman, Jeanna C.; Boström, Pontus; Lindbom, Malin; Lidberg, Ulf; StÅhlman, Marcus; Hägg, Daniel; Lindskog, Henrik; Scharin Täng, Margareta; Omerovic, Elmir; Mattsson Hultén, Lillemor; Jeppsson, Anders; Petursson, Petur; Herlitz, Johan; Olivecrona, Gunilla; Strickland, Dudley K.; Ekroos, Kim; Olofsson, Sven-Olof; Borén, Jan

    2011-01-01

    Impaired cardiac function is associated with myocardial triglyceride accumulation, but it is not clear how the lipids accumulate or whether this accumulation is detrimental. Here we show that hypoxia/ischemia-induced accumulation of lipids in HL-1 cardiomyocytes and mouse hearts is dependent on expression of the VLDL receptor (VLDLR). Hypoxia-induced VLDLR expression in HL-1 cells was dependent on HIF-1α through its interaction with a hypoxia-responsive element in the Vldlr promoter, and VLDLR promoted the endocytosis of lipoproteins. Furthermore, VLDLR expression was higher in ischemic compared with nonischemic left ventricles from human hearts and was correlated with the total lipid droplet area in the cardiomyocytes. Importantly, Vldlr–/– mice showed improved survival and decreased infarct area following an induced myocardial infarction. ER stress, which leads to apoptosis, is known to be involved in ischemic heart disease. We found that ischemia-induced ER stress and apoptosis in mouse hearts were reduced in Vldlr–/– mice and in mice treated with antibodies specific for VLDLR. These findings suggest that VLDLR-induced lipid accumulation in the ischemic heart worsens survival by increasing ER stress and apoptosis. PMID:21670500

  5. NR2D-containing NMDA receptors mediate tissue plasminogen activator-promoted neuronal excitotoxicity.

    PubMed

    Baron, A; Montagne, A; Cassé, F; Launay, S; Maubert, E; Ali, C; Vivien, D

    2010-05-01

    Although the molecular bases of its actions remain debated, tissue-type plasminogen activator (tPA) is a paradoxical brain protease, as it favours some learning/memory processes, but increases excitotoxic neuronal death. Here, we show that, in cultured cortical neurons, tPA selectively promotes NR2D-containing N-methyl-D-aspartate receptor (NMDAR)-dependent activation. We show that tPA-mediated signalling and neurotoxicity through the NMDAR are blocked by co-application of an NR2D antagonist (phenanthrene derivative (2S(*), 3R(*))-1-(phenanthrene-2-carbonyl)piperazine-2,3-dicarboxylic acid, PPDA) or knockdown of neuronal NR2D expression. In sharp contrast with cortical neurons, hippocampal neurons do not exhibit NR2D both in vitro and in vivo and are consequently resistant to tPA-promoted NMDAR-mediated neurotoxicity. Moreover, we have shown that activation of synaptic NMDAR prevents further tPA-dependent NMDAR-mediated neurotoxicity and sensitivity to PPDA. This study shows that the earlier described pro-neurotoxic effect of tPA is mediated by NR2D-containing NMDAR-dependent extracellular signal-regulated kinase activation, a deleterious effect prevented by synaptic pre-activation.

  6. Hepatic scavenger receptor BI protects against polymicrobial-induced sepsis through promoting LPS clearance in mice.

    PubMed

    Guo, Ling; Zheng, Zhong; Ai, Junting; Huang, Bin; Li, Xiang-An

    2014-05-23

    Recent studies revealed that scavenger receptor BI (SR-BI or Scarb1) plays a critical protective role in sepsis. However, the mechanisms underlying this protection remain largely unknown. In this study, using Scarb1(I179N) mice, a mouse model specifically deficient in hepatic SR-BI, we report that hepatic SR-BI protects against cecal ligation and puncture (CLP)-induced sepsis as shown by 75% fatality in Scarb1(I179N) mice, but only 21% fatality in C57BL/6J control mice. The increase in fatality in Scarb1(I179N) mice was associated with an exacerbated inflammatory cytokine production. Further study demonstrated that hepatic SR-BI exerts its protection against sepsis through its role in promoting LPS clearance without affecting the inflammatory response in macrophages, the glucocorticoid production in adrenal glands, the leukocyte recruitment to peritoneum or the bacterial clearance in liver. Our findings reveal hepatic SR-BI as a critical protective factor in sepsis and point out that promoting hepatic SR-BI-mediated LPS clearance may provide a therapeutic approach for sepsis.

  7. Advanced glycation end products (AGEs) promote melanogenesis through receptor for AGEs

    PubMed Central

    Lee, Eun Jung; Kim, Ji Young; Oh, Sang Ho

    2016-01-01

    Accumulation of advanced glycation end products (AGEs) is linked with development or aggravation of many degenerative processes or disorders, including aging and atherosclerosis. AGEs production in skin cells is known to promote stiffness and loss of elasticity through their buildup in connective tissue. However, the impact of AGEs has yet to be fully explored in melanocytes. In this study, we confirmed the existence of receptor for AGE (RAGE) in melanocytes in western blot and immunofluorescence along with increased melanin production in ex vivo skin organ culture and in vitro melanocyte culture following AGEs treatment. Cyclic AMP response element-binding protein (CREB) and extracellular signal-regulated kinases (ERK) 1/2 are considered as key regulatory proteins in AGEs-induced melanogenesis. In addition, blockage experiment using anti-RAGE blocking antibody has indicated that RAGE plays a pivotal role in AGE-mediated melanogenesis. Therefore, it is apparent that AGEs, known markers of aging, promote melanogenesis via RAGE. In addition, AGEs could be implicated in pigmentation associated with photoaging according to the results of increased secretion of AGEs from keratinocytes following UV irradiation. AGE-mediated melanogenesis may thus hold promise as a novel mean of altering skin pigmentation. PMID:27293210

  8. Formononetin promotes angiogenesis through the estrogen receptor alpha-enhanced ROCK pathway

    PubMed Central

    Li, Shang; Dang, Yuanye; Zhou, Xuelin; Huang, Bin; Huang, Xiaohui; Zhang, Zherui; Kwan, Yiu Wa; Chan, Shun Wan; Leung, George Pak Heng; Lee, Simon Ming Yuen; Hoi, Maggie Pui Man

    2015-01-01

    Formononetin is an isoflavone that has been shown to display estrogenic properties and induce angiogenesis activities. However, the interrelationship between the estrogenic properties and angiogenesis activities of formononetin are not well defined. In the present study, docking and enzymatic assay demonstrated that formononetin displayed direct binding to the ligand-binding domain (LBD) of estrogen receptor alpha (ERα) with an agonistic property. Results from Human Umbilical Vein Endothelial Cells (HUVEC) by using real-time migration xCELLigence system, immunofluorescence and western blotting provided strong evidences of formononetin induced endothelial cell migration and dramatic actin cytoskeleton spatial modification through ERα-enhanced-ROCK-II/MMP2/9 signaling pathways. In addition, results from co-immunoprecipitation suggested formononetin induced cell migration via recruiting of ERα/ROCK-II activated complex formation. More interestingly, in zebrafish embryo we observed that formononetin significantly promoted angiogenic sproutings in the subintestinal vessels (SIVs) that could be completely abolished by ROCK inhibitor. In this study, we elucidated the underlying mechanisms that formononetin produced proangiogenesis effects through an ERα-enhanced ROCK-II signaling pathways. Results from the present study also expand our knowledge about the enigmatic underlying mechanisms of phytoestrogenic compounds in the promotion of angiogenesis in relation to ERα and ROCK interaction in endothelial cells and their relationship with actin assembly and cell migration. PMID:26568398

  9. Promoting MPhi transepithelial migration by stimulating the epithelial cell P2Y(2) receptor.

    PubMed

    Langlois, Christine; Gendron, Fernand-Pierre

    2009-10-01

    In intestine, neutrophils are recruited in response to bacterial infiltration and their anti-cellular activities contribute to inflammatory bowel diseases. In contrast, little is known regarding the recruitment of MPhi to the intestinal epithelium. Extracellular adenosine and uridine 5'-triphosphate (ATP and UTP) can function as leukocyte chemoattractants. We investigated the effects of these nucleotides on the ability of intestinal epithelial cells (IEC) to promote MPhi transepithelial migration and adhesion. ATP and UTP promoted the migration of neutrophil-like PLB-985 cells and MPhi across a Caco-2 monolayer. The MPhi-like U-937 cells adhered to nucleotide-stimulated IEC monolayers. In mice with intestinal inflammation, there were infiltrating CD68(+) MPhi in the colonic epithelium and CD68(+) MPhi present at the apical surface of colonocytes. We determined that ATP and UTP activated the P2Y(2) receptor P (P2Y(2)R) to increase ICAM-1 expression, which mediated the adhesion of MPhi to the apical surface of IEC. Intriguingly, stimulation of IEC with nucleotides did not increase the adhesion of neutrophils. However, in the presence of adherent MPhi, there was adhesion of neutrophils, suggesting that MPhi may serve as anchors for neutrophil adhesion. These studies provide insight into the inflammatory mechanisms that contribute to inflammatory bowel diseases and identify potential therapeutic targets for the treatment of gastrointestinal disorders.

  10. The atypical antipsychotics clozapine and olanzapine promote down-regulation and display functional selectivity at human 5-HT7 receptors

    PubMed Central

    Andressen, K W; Manfra, O; Brevik, C H; Ulsund, A H; Vanhoenacker, P; Levy, F O; Krobert, K A

    2015-01-01

    Background and Purpose Classically, ligands of GPCRs have been classified primarily upon their affinity and efficacy to activate a signal transduction pathway. Recent reports indicate that the efficacy of a particular ligand can vary depending on the receptor-mediated response measured (e.g. activating G proteins, other downstream responses, internalization). Previously, we reported that inverse agonists induce both homo- and heterologous desensitization, similar to agonist stimulation, at the Gs-coupled 5-HT7 receptor. The primary objective of this study was to determine whether different inverse agonists at the 5-HT7 receptor also induce internalization and/or degradation of 5-HT7 receptors. Experimental Approach HEK293 cells expressing 5-HT7(a, b or d) receptors were pre-incubated with 5-HT, clozapine, olanzapine, mesulergine or SB269970 and their effects upon receptor density, AC activity, internalization, recruitment of β-arrestins and lysosomal trafficking were measured. Key Results The agonist 5-HT and three out of four inverse agonists tested increased internalization independently of β-arrestin recruitment. Among these, only the atypical antipsychotics clozapine and olanzapine promoted lysosomal sorting and reduced 5-HT7 receptor density (∼60% reduction within 24 h). Inhibition of lysosomal degradation with chloroquine blocked the clozapine- and olanzapine-induced down-regulation of 5-HT7 receptors. Incubation with SB269970 decreased both 5-HT7(b) constitutive internalization and receptor density but increased 5-HT7(d) receptor density, indicating differential ligand regulation among the 5-HT7 splice variants. Conclusions and Implications Taken together, we found that various ligands differentially activate regulatory processes governing receptor internalization and degradation in addition to signal transduction. Thus, these data extend our understanding of functional selectivity at the 5-HT7 receptor. PMID:25884989

  11. Autophagy-mediated longevity is modulated by lipoprotein biogenesis

    PubMed Central

    Seah, Nicole E.; de Magalhaes Filho, C. Daniel; Petrashen, Anna P.; Henderson, Hope R.; Laguer, Jade; Gonzalez, Julissa; Dillin, Andrew; Hansen, Malene; Lapierre, Louis R.

    2016-01-01

    ABSTRACT Autophagy-dependent longevity models in C. elegans display altered lipid storage profiles, but the contribution of lipid distribution to life-span extension is not fully understood. Here we report that lipoprotein production, autophagy and lysosomal lipolysis are linked to modulate life span in a conserved fashion. We find that overexpression of the yolk lipoprotein VIT/vitellogenin reduces the life span of long-lived animals by impairing the induction of autophagy-related and lysosomal genes necessary for longevity. Accordingly, reducing vitellogenesis increases life span via induction of autophagy and lysosomal lipolysis. Life-span extension due to reduced vitellogenesis or enhanced lysosomal lipolysis requires nuclear hormone receptors (NHRs) NHR-49 and NHR-80, highlighting novel roles for these NHRs in lysosomal lipid signaling. In dietary-restricted worms and mice, expression of VIT and hepatic APOB (apolipoprotein B), respectively, are significantly reduced, suggesting a conserved longevity mechanism. Altogether, our study demonstrates that lipoprotein biogenesis is an important mechanism that modulates aging by impairing autophagy and lysosomal lipolysis. PMID:26671266

  12. DRD4 genotype predicts longevity in mouse and human.

    PubMed

    Grady, Deborah L; Thanos, Panayotis K; Corrada, Maria M; Barnett, Jeffrey C; Ciobanu, Valentina; Shustarovich, Diana; Napoli, Anthony; Moyzis, Alexandra G; Grandy, David; Rubinstein, Marcelo; Wang, Gene-Jack; Kawas, Claudia H; Chen, Chuansheng; Dong, Qi; Wang, Eric; Volkow, Nora D; Moyzis, Robert K

    2013-01-02

    Longevity is influenced by genetic and environmental factors. The brain's dopamine system may be particularly relevant, since it modulates traits (e.g., sensitivity to reward, incentive motivation, sustained effort) that impact behavioral responses to the environment. In particular, the dopamine D4 receptor (DRD4) has been shown to moderate the impact of environments on behavior and health. We tested the hypothesis that the DRD4 gene influences longevity and that its impact is mediated through environmental effects. Surviving participants of a 30-year-old population-based health survey (N = 310; age range, 90-109 years; the 90+ Study) were genotyped/resequenced at the DRD4 gene and compared with a European ancestry-matched younger population (N = 2902; age range, 7-45 years). We found that the oldest-old population had a 66% increase in individuals carrying the DRD4 7R allele relative to the younger sample (p = 3.5 × 10(-9)), and that this genotype was strongly correlated with increased levels of physical activity. Consistent with these results, DRD4 knock-out mice, when compared with wild-type and heterozygous mice, displayed a 7-9.7% decrease in lifespan, reduced spontaneous locomotor activity, and no lifespan increase when reared in an enriched environment. These results support the hypothesis that DRD4 gene variants contribute to longevity in humans and in mice, and suggest that this effect is mediated by shaping behavioral responses to the environment.

  13. Dopamine D3 receptor inhibits the ubiquitin-specific peptidase 48 to promote NHE3 degradation

    PubMed Central

    Armando, Ines; Villar, Van Anthony M.; Jones, John E.; Lee, Hewang; Wang, Xiaoyan; Asico, Laureano D.; Yu, Peiying; Yang, Jian; Escano, Crisanto S.; Pascua-Crusan, Annabelle M.; Felder, Robin A.; Jose, Pedro A.

    2014-01-01

    The dopamine D3 receptor (D3R) is crucial in the regulation of blood pressure and sodium balance, in that Drd3 gene ablation in mice results in hypertension and failure to excrete a dietary salt load. The mechanism responsible for the renal sodium retention in these mice is largely unknown. We now offer and describe a novel mechanism by which D3R decreases sodium transport in the long term by inhibiting the deubiquitinylating activity of ubiquitin-specific peptidase 48 (USP48), thereby promoting Na+-H+ exchanger (NHE)-3 degradation. We found that stimulation with the D3R-specific agonist PD128907 (1 μM, 30 min) promoted the interaction and colocalization among D3R, NHE3, and USP48; inhibited USP48 activity (−35±6%, vs. vehicle), resulting in increased ubiquitinylated NHE3 (+140±10%); and decreased NHE3 expression (−50±9%) in human renal proximal tubule cells (hRPTCs). USP48 silencing decreased NHE3's half-life (USP48 siRNA t1/2=6.1 h vs. vehicle t1/2=12.9 h), whereas overexpression of USP48 increased NHE3 half-life (t1/2=21.8 h), indicating that USP48 protects NHE3 from degradation via deubiquitinylation. USP48 accounted for ∼30% of the total deubiquitinylating activity in these cells. Extending our studies in vivo, we found that pharmacologic blockade of D3R via the D3R-specific antagonist GR103691 (1 μg/kg/min, 4 d) in C57Bl/6J mice increased renal NHE3 expression (+310±15%, vs. vehicle), whereas an innovative kidney-restricted Usp48 silencing via siRNA (3 μg/d, 7 d) increased ubiquitinylated NHE3 (+250±30%, vs. controls), decreased total NHE3 (−23±2%), and lowered blood pressure (−24±2 mm Hg), compared with that in control mice that received either the vehicle or nonsilencing siRNA. Our data demonstrate a crucial role for the dynamic interaction between D3R and USP48 in the regulation of NHE3 expression and function.—Armando, I., Villar, V. A. M., Jones J. E., Lee, H., Wang, X., Asico L. D., Yu, P., Yang, J., Escano, C. S. Jr., Pascua

  14. Conjugated bile acids promote cholangiocarcinoma cell invasive growth through activation of sphingosine 1-phosphate receptor 2

    PubMed Central

    Liu, Runping; Zhao, Renping; Zhou, Xiqiao; Liang, Xiuyin; Campbell, Deanna JW; Zhang, Xiaoxuan; Zhang, Luyong; Shi, Ruihua; Wang, Guangji; Pandak, William M; Sirica, Alphonse E; Hylemon, Phillip B; Zhou, Huiping

    2014-01-01

    Cholangiocarcinoma (CCA) is an often fatal primary malignancy of the intra- and extrahepatic biliary tract that is commonly associated with chronic cholestasis and significantly elevated levels of primary and conjugated bile acids (CBAs), which are correlated with bile duct obstruction (BDO). BDO has also recently been shown to promote CCA progression. However, whereas there is increasing evidence linking chronic cholestasis and abnormal bile acid profiles to CCA development and progression, the specific mechanisms by which bile acids may be acting to promote cholangiocarcinogenesis and invasive biliary tumor growth have not been fully established. Recent studies have shown that CBAs, but not free bile acids, stimulate CCA cell growth, and that an imbalance in the ratio of free to CBAs may play an important role in the tumorigenesis of CCA. Also, CBAs are able to activate extracellular signal-regulated kinase (ERK)1/2- and phosphatidylinositol-3-kinase/protein kinase B (AKT)-signaling pathways through sphingosine 1-phosphate receptor 2 (S1PR2) in rodent hepatocytes. In the current study, we demonstrate S1PR2 to be highly expressed in rat and human CCA cells, as well as in human CCA tissues. We further show that CBAs activate the ERK1/2- and AKT-signaling pathways and significantly stimulate CCA cell growth and invasion in vitro. Taurocholate (TCA)-mediated CCA cell proliferation, migration, and invasion were significantly inhibited by JTE-013, a chemical antagonist of S1PR2, or by lentiviral short hairpin RNA silencing of S1PR2. In a novel organotypic rat CCA coculture model, TCA was further found to significantly increase the growth of CCA cell spheroidal/“duct-like” structures, which was blocked by treatment with JTE-013. Conclusion: Our collective data support the hypothesis that CBAs promote CCA cell-invasive growth through S1PR2. PMID:24700501

  15. Ligand structural motifs can decouple glucocorticoid receptor transcriptional activation from target promoter occupancy.

    PubMed

    Blind, Raymond D; Pineda-Torra, Inés; Xu, Yong; Xu, H Eric; Garabedian, Michael J

    2012-04-20

    Glucocorticoid (GC) induction of the tyrosine aminotransferase (TAT) gene by the glucocorticoid receptor (GR) is a classic model used to investigate steroid-regulated gene expression. Classic studies analyzing GC-induction of the TAT gene demonstrated that despite having very high affinity for GR, some steroids cannot induce maximal TAT enzyme activity, but the molecular basis for this phenomenon is unknown. Here, we used RT-PCR and chromatin immunoprecipitation to determine TAT mRNA accumulation and GR recruitment to the TAT promoter (TAT-GRE) in rat hepatoma cells induced by seven GR ligands: dexamethasone (DEX), cortisol (CRT), corticosterone (CCS), 11-deoxycorticosterone (DOC), aldosterone (ALD), progesterone (PRG) and 17-hydroxyprogesterone (17P). As expected, DEX, CRT, CCS and ALD all induced both TAT mRNA and GR recruitment to the TAT-GRE, while PRG and 17P did not. However, while DOC could not induce significant TAT mRNA, it did induce robust GR occupancy of the TAT-GRE. DOC also induced recruitment of the histone acetyltransferase p300 to the TAT-GRE as efficiently as DEX. These DOC-induced effects recapitulated at another GR target gene (sulfonyltransferase 1A1), and DOC also failed to promote the multiple changes in gene expression required for glucocorticoid-dependent 3T3-L1 adipocyte differentiation. Structural simulations and protease sensitivity assays suggest that DOC and DEX induce different conformations in GR. Thus, although steroids that bind GR with high affinity can induce GR and p300 occupancy of target promoters, they may not induce a conformation of GR capable of activating transcription.

  16. Promoter methylation of glucocorticoid receptor gene is associated with subclinical atherosclerosis: A monozygotic twin study.

    PubMed

    Zhao, Jinying; An, Qiang; Goldberg, Jack; Quyyumi, Arshed A; Vaccarino, Viola

    2015-09-01

    Endothelial dysfunction assessed by brachial artery flow-mediated dilation (FMD) is a marker of early atherosclerosis. Glucocorticoid receptor gene (NR3C1) regulates many biological processes, including stress response, behavioral, cardiometabolic and immunologic functions. Genetic variants in NR3C1 have been associated with atherosclerosis and related risk factors. This study investigated the association of NR3C1 promoter methylation with FMD, independent of genetic and family-level environmental factors. We studied 84 middle-aged, male-male monozygotic twin pairs recruited from the Vietnam Era Twin Registry. Brachial artery FMD was measured by ultrasound. DNA methylation levels at 22 CpG residues in the NR3C1 exon 1F promoter region were quantified by bisulfite pyrosequencing in genomic DNA isolated from peripheral blood leukocytes. Co-twin control analyses were conducted to examine the association of methylation variation with FMD, adjusting for smoking, physical activity, body mass index, lipids, blood pressure, fasting glucose, and depressive symptoms. Multiple testing was corrected using the false discovery rate. Mean methylation level across the 22 studied CpG sites was 2.02%. Methylation alterations at 12 out of the 22 CpG residues were significantly associated with FMD. On average, a 1% increase in the intra-pair difference in mean DNA methylation was associated with 2.83% increase in the intra-pair difference in FMD (95% CI: 1.46-4.20; P < 0.0001) after adjusting for risk factors and multiple testing. Methylation variation in NR3C1 exon 1F promoter significantly influences subclinical atherosclerosis, independent of genetic, early family environmental and other risk factors. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  17. The emergence of longevous populations

    PubMed Central

    Colchero, Fernando; Rau, Roland; Barthold, Julia A.; Conde, Dalia A.; Lenart, Adam; Nemeth, Laszlo; Scheuerlein, Alexander; Schoeley, Jonas; Torres, Catalina; Zarulli, Virginia; Altmann, Jeanne; Brockman, Diane K.; Bronikowski, Anne M.; Fedigan, Linda M.; Pusey, Anne E.; Stoinski, Tara S.; Strier, Karen B.; Baudisch, Annette; Alberts, Susan C.; Vaupel, James W.

    2016-01-01

    The human lifespan has traversed a long evolutionary and historical path, from short-lived primate ancestors to contemporary Japan, Sweden, and other longevity frontrunners. Analyzing this trajectory is crucial for understanding biological and sociocultural processes that determine the span of life. Here we reveal a fundamental regularity. Two straight lines describe the joint rise of life expectancy and lifespan equality: one for primates and the second one over the full range of human experience from average lifespans as low as 2 y during mortality crises to more than 87 y for Japanese women today. Across the primate order and across human populations, the lives of females tend to be longer and less variable than the lives of males, suggesting deep evolutionary roots to the male disadvantage. Our findings cast fresh light on primate evolution and human history, opening directions for research on inequality, sociality, and aging. PMID:27872299

  18. Modulation of epidermal growth factor receptor proto-oncogene transcription by a promoter site sensitive to S1 nuclease.

    PubMed Central

    Johnson, A C; Jinno, Y; Merlino, G T

    1988-01-01

    The epidermal growth factor (EGF) receptor is the functional target of the mitogen EGF and the cellular homolog of the avian erythroblastosis virus erbB oncogene product. Regulation of expression of the proto-oncogene encoding the EGF receptor can be elucidated by studying the structure and function of the gene promoter outside the confines of the cell. Previously, we reported the isolation of the human EGF receptor gene promoter. The promoter is highly GC rich, contains no TATA or CAAT box, and has multiple transcription start sites. An S1 nuclease-sensitive site has now been found 80 to 110 base pairs (bp) upstream from the major in vivo transcription initiation site. Two sets of direct repeat sequences were found in this area; both conform to the motif TCCTCCTCC. When deletion mutations were made in this region of the promoter by using either Bal 31 exonuclease or S1 nuclease, we found that in vivo activity dropped three- to fivefold, on the basis of transient-transfection analysis. Examination of nuclear protein binding to normal and mutated promoter DNAs by gel retardation analysis and DNase I footprinting revealed that two specific factors bind to the direct repeat region but cannot bind to the S1 nuclease-mutated promoter. One of the specific factors is the transcription factor Sp1. The results suggest that these nuclear trans-acting factors interact with the S1 nuclease-sensitive region of the EGF receptor gene promoter and either directly or indirectly stimulate transcription. Images PMID:2847030

  19. The nuclear orphan receptors COUP-TFII and Ear-2 act as silencers of the human oxytocin gene promoter.

    PubMed

    Chu, K; Zingg, H H

    1997-10-01

    We have previously shown that COUP-TFII and Ear-2, two members of the nuclear orphan receptor family, are able to repress oestrogen-stimulated transcriptional activity of the human oxytocin (OT) gene promoter by binding to a site that overlaps with the oestrogen response element (ERE) present in the 5' flanking region of the gene. Although most nuclear receptor-mediated transcriptional repression conforms with the paradigm of passive repression and involves competitive binding to an activator site, active repression, i.e. silencing of basal promoter activity, has been observed in a limited number of cases. Here we show by co-transfection experiments using COUP-TFII and Ear-2 expression vectors and reporter constructs containing OT gene promoter fragments linked to the chloramphenicol acetyltransferase gene that both COUP-TFII and Ear-2 are capable of silencing basal OT gene promoter activity by 54 and 75% respectively. 5' Deletion and footprint analyses revealed two areas of functionally important interaction sites: (1) a direct TGACC(T/C) repeat overlapping the ERE and (2) a more promoter-proximal area centred at - 90 containing three imperfect direct repeats (R1-R3) spaced by four nucleotides each. Mutagenesis of reporter constructs as well as electrophoretic mobility-shift assays demonstrated that each of the three proximal repeats R1-R3 contributed to orphan receptor binding and the silencing effect. Inasmuch as the orphan receptor-binding sites are not involved in mediating basal transcriptional activity of the OT gene promoter, the observed effects are best interpreted as active repression or promoter silencing. Moreover, since COUP-TFII and Ear-2 are both co-expressed in OT-expressing uterine epithelial cells, the novel transcriptional effects described here are likely to be of functional importance in the fine-tuning of uterine OT gene expression in vivo.

  20. Thyroid hormone receptors bind to the promoter of the mouse histone H10 gene and modulate its transcription.

    PubMed Central

    Bauer-Hofmann, R; Alonso, A

    1995-01-01

    It has been shown that the mouse histone H10 promoter contains a DNA element, composed of a direct repeat of the sequence GGTGACC separated by 7 nt, which is able to bind retinoic acid receptors and to modulate transcription of reporter genes following treatment with retinoic acid. We have now investigated whether this DNA motif is also responsive to thyroid hormone. We co-transfected CV-1 monkey kidney cells with chloramphenicol acetyltransferase (CAT) expression plasmids containing either 740 bp of the H10 wild-type promoter or five copies of the repeat element cloned in front of the thymidine kinase promoter and expression vectors for human thyroid hormone receptors (TRs) alpha or beta and retinoid X receptor alpha (RXR alpha). Treatment of transfected cells with triiodothyronine led to a dose-dependent increase in CAT activity. Transfection experiments with increasing amounts of expression vectors for either TR alpha or RXR alpha resulted in up to 6-fold enhancement of CAT transcription. Furthermore, point mutations within the half-sites of the response element of the H10 promoter, as well as deletions within the interspace region, lowered CAT activity to 60-80% of that of the wild-type control. Electrophoretic mobility shift assays showed that the repeat element was able to form retarded complexes with TR alpha homodimers, as well as with TR alpha-RXR alpha heterodimers. Our results suggest that thyroid hormone receptors are involved in the regulation of mouse histone H10 expression. Images PMID:8559662

  1. Energetics and longevity in birds

    PubMed Central

    Furness, L. J.

    2008-01-01

    The links between energy expenditure and ageing are different at different levels of enquiry. When studies have examined the relationships between different species within a given class the association is generally negative—animals with greater metabolism per gram of tissue live shorter lives. Within species, or between classes (e.g. between birds and mammals) the association is the opposite—animals with higher metabolic rates live longer. We have previously shown in mammals that the negative association between lifespan and metabolic rate is in fact an artefact of using resting rather than daily energy expenditure, and of failing to adequately take into account the confounding effects of body size and the lack of phylogenetic independence of species data. When these factors are accounted for, across species of mammals, the ones with higher metabolism also have the largest lifetime expenditures of energy—consistent with the inter-class and intra-specific data. A previous analysis in birds did not yield the same pattern, but this may have been due to a lack of sufficient power in the analysis. Here we present an analysis of a much enlarged data set (>300 species) for metabolic and longevity traits in birds. These data show very similar patterns to those in mammals. Larger individuals have longer lives and lower per-gram resting and daily energy expenditures, hence there is a strong negative relationship between longevity and mass-specific metabolism. This relationship disappears when the confounding effects of body mass and phylogeny are accounted for. Across species of birds, lifetime expenditure of energy per gram of tissue based on both daily and resting energy expenditure is positively related to metabolic intensity, mirroring these statistical relationships in mammals and synergising with the positive associations of metabolism with lifespan within species and between vertebrate classes. PMID:19424858

  2. Angiotensin II receptor blockade promotes repair of skeletal muscle through down-regulation of aging-promoting C1q expression

    PubMed Central

    Yabumoto, Chizuru; Akazawa, Hiroshi; Yamamoto, Rie; Yano, Masamichi; Kudo-Sakamoto, Yoko; Sumida, Tomokazu; Kamo, Takehiro; Yagi, Hiroki; Shimizu, Yu; Saga-Kamo, Akiko; Naito, Atsuhiko T.; Oka, Toru; Lee, Jong-Kook; Suzuki, Jun-ichi; Sakata, Yasushi; Uejima, Etsuko; Komuro, Issei

    2015-01-01

    Disruption of angiotensin II type 1 (AT1) receptor prolonged life span in mice. Since aging-related decline in skeletal muscle function was retarded in Atgr1a−/− mice, we examined the role of AT1 receptor in muscle regeneration after injury. Administration of AT1 receptor blocker irbesartan increased the size of regenerating myofibers, decreased fibrosis, and enhanced functional muscle recovery after cryoinjury. We recently reported that complement C1q, secreted by macrophages, activated Wnt/β-catenin signaling and promoted aging-related decline in regenerative capacity of skeletal muscle. Notably, irbesartan induced M2 polarization of macrophages, but reduced C1q expression in cryoinjured muscles and in cultured macrophage cells. Irbesartan inhibited up-regulation of Axin2, a downstream gene of Wnt/β-catenin pathway, in cryoinjured muscles. In addition, topical administration of C1q reversed beneficial effects of irbesartan on skeletal muscle regeneration after injury. These results suggest that AT1 receptor blockade improves muscle repair and regeneration through down-regulation of the aging-promoting C1q-Wnt/β-catenin signaling pathway. PMID:26571361

  3. Promotion

    PubMed Central

    Alam, Hasan B.

    2013-01-01

    This article gives an overview of the promotion process in an academic medical center. A description of different promotional tracks, tenure and endowed chairs, and the process of submitting an application is provided. Finally, some practical advice about developing skills and attributes that can help with academic growth and promotion is dispensed. PMID:24436683

  4. Potential role of marine algae on female health, beauty, and longevity.

    PubMed

    Kim, Se-Kwon; Pangestuti, Ratih

    2011-01-01

    Marine environment has been known as a rich source of chemical structures with numerous health benefit effects. Among marine organisms, marine algae have been identified as an underexploited plant resource although they have long been recognized as valuable sources of structurally diverse bioactive compounds. Presently, several lines of studies have provided insight into biological activities of marine algae in promoting female health, beauty, and longevity. Hence, marine algae have a great potential to be used as a part of pharmaceuticals, nutraceuticals, and functional foods. This contribution presents an overview of marine algal potential effect in promoting female health, beauty, and longevity. Copyright © 2011 Elsevier Inc. All rights reserved.

  5. Lipidomics in longevity and healthy aging.

    PubMed

    Gonzalez-Covarrubias, Vanessa

    2013-12-01

    The role of classical lipids in aging diseases and human longevity has been widely acknowledged. Triglyceride and cholesterol concentrations are clinically assessed to infer the risk of cardiovascular disease while larger lipoprotein particle size and low triglyceride levels have been identified as markers of human longevity. The rise of lipidomics as a branch of metabolomics has provided an additional layer of accuracy to pinpoint specific lipids and its association with aging diseases and longevity. The molecular composition and concentration of lipid species determine their cellular localization, metabolism, and consequently, their impact in disease and health. For example, low density lipoproteins are the main carriers of sphingomyelins and ceramides, while high density lipoproteins are mostly loaded with ether phosphocholines, partly explaining their opposing roles in atherogenesis. Moreover, the identification of specific lipid species in aging diseases and longevity would aid to clarify how these lipids alter health and influence longevity. For instance, ether phosphocholines PC (O-34:1) and PC (O-34:3) have been positively associated with longevity and negatively with diabetes, and hypertension, but other species of phosphocholines show no effect or an opposite association with these traits confirming the relevance of the identification of molecular lipid species to tackle our understanding of healthy aging and disease. Up-to-date, a minor fraction of the human plasma lipidome has been associated to healthy aging and longevity, further research would pinpoint toward specific lipidomic profiles as potential markers of healthy aging and metabolic diseases.

  6. Burial increases seed longevity of two Artemisia tridentata (Asteraceae) subspecies

    USGS Publications Warehouse

    Wijayratne, Upekala C.; Pyke, David A.

    2012-01-01

    Premise of the study: Seed longevity and persistence in soil seed banks may be especially important for population persistence in ecosystems where opportunities for seedling establishment and disturbance are unpredictable. The fire regime, an important driver of population dynamics in sagebrush steppe ecosystems, has been altered by exotic annual grass invasion. Soil seed banks may play an active role in postfire recovery of the foundation shrub Artemisia tridentata, yet conditions under which seeds persist are largely unknown. Methods: We investigated seed longevity of two Artemisia tridentata subspecies in situ by retrieving seed bags that were placed at varying depths over a 2 yr period. We also sampled naturally dispersed seeds in litter and soil immediately after seed dispersal and before flowering in subsequent seasons to estimate seed persistence. Key results: After 24 mo, seeds buried at least 3 cm below the soil surface retained 30–40% viability whereas viability of seeds on the surface and under litter declined to 0 and Artemisia tridentata has the potential to form a short-term soil seed bank that persists longer than has been commonly assumed, and that burial is necessary for seed longevity. Use of seeding techniques that promote burial of some seeds to aid in formation of a soil seed bank may increase restoration potential.

  7. Burial increases seed longevity of two Artemisia tridentata (Asteraceae) subspecies.

    PubMed

    Wijayratne, Upekala C; Pyke, David A

    2012-03-01

    Seed longevity and persistence in soil seed banks may be especially important for population persistence in ecosystems where opportunities for seedling establishment and disturbance are unpredictable. The fire regime, an important driver of population dynamics in sagebrush steppe ecosystems, has been altered by exotic annual grass invasion. Soil seed banks may play an active role in postfire recovery of the foundation shrub Artemisia tridentata, yet conditions under which seeds persist are largely unknown. We investigated seed longevity of two Artemisia tridentata subspecies in situ by retrieving seed bags that were placed at varying depths over a 2 yr period. We also sampled naturally dispersed seeds in litter and soil immediately after seed dispersal and before flowering in subsequent seasons to estimate seed persistence. After 24 mo, seeds buried at least 3 cm below the soil surface retained 30-40% viability whereas viability of seeds on the surface and under litter declined to 0 and < 11%, respectively. The density of naturally dispersed seeds in the seed bank was highly heterogeneous both spatially and temporally, and attrition varied significantly by region. Our study suggests that Artemisia tridentata has the potential to form a short-term soil seed bank that persists longer than has been commonly assumed, and that burial is necessary for seed longevity. Use of seeding techniques that promote burial of some seeds to aid in formation of a soil seed bank may increase restoration potential.

  8. Human longevity: Genetics or Lifestyle? It takes two to tango.

    PubMed

    Passarino, Giuseppe; De Rango, Francesco; Montesanto, Alberto

    2016-01-01

    Healthy aging and longevity in humans are modulated by a lucky combination of genetic and non-genetic factors. Family studies demonstrated that about 25 % of the variation in human longevity is due to genetic factors. The search for genetic and molecular basis of aging has led to the identification of genes correlated with the maintenance of the cell and of its basic metabolism as the main genetic factors affecting the individual variation of the aging phenotype. In addition, studies on calorie restriction and on the variability of genes associated with nutrient-sensing signaling, have shown that ipocaloric diet and/or a genetically efficient metabolism of nutrients, can modulate lifespan by promoting an efficient maintenance of the cell and of the organism. Recently, epigenetic studies have shown that epigenetic modifications, modulated by both genetic background and lifestyle, are very sensitive to the aging process and can either be a biomarker of the quality of aging or influence the rate and the quality of aging. On the whole, current studies are showing that interventions modulating the interaction between genetic background and environment is essential to determine the individual chance to attain longevity.

  9. Reproduction-longevity trade-offs reflect diet, not adaptation.

    PubMed

    Attisano, A; Moore, A J; Moore, P J

    2012-05-01

    A tenet of life history evolution is that allocation of limited resources results in trade-offs, such as that between reproduction and lifespan. Reproduction and lifespan are also influenced proximately by differences in the availability of specific nutrients. What is unknown is how the evolution of the ability to use a nutritionally novel diet is reflected in this fundamental trade-off. Does the evolution of the ability to use a nutritionally novel food maintain the trade-off in reproduction and longevity, or do the proximate effects of nutrition alter the adapted trade-off? We tested this by measuring trade-offs in male milkweed bugs, Oncopeltus fasciatus, fed either an adapted diet of sunflower or the ancestral diet of milkweed. Sunflower-fed males lived longer but invested less in reproduction, both in mating and fertility. Milkweed-fed males invested in both mating and fertility at the expense of survival. The evolution of an expanded diet was not constrained by the existing trade-off, but instead was accompanied by a different trade-off between reproduction and longevity. We suggest that this occurs because diets differ in promoting germ line development or longevity.

  10. Gene expression patterns associated with queen honey bee longevity.

    PubMed

    Corona, Miguel; Hughes, Kimberly A; Weaver, Daniel B; Robinson, Gene E

    2005-11-01

    The oxidative stress theory of aging proposes that accumulation of oxidative damage is the main proximate cause of aging and that lifespan is determined by the rate at which this damage occurs. Two predictions from this theory are that long-lived organisms produce fewer ROS or have increased antioxidant production. Based in these predictions, molecular mechanisms to promote longevity could include either changes in the regulation of mitochondrial genes that affect ROS production or elevated expression of antioxidant genes. We explored these possibilities in the honey bee, a good model for the study of aging because it has a caste system in which the same genome produces both a long-lived queen and a short-lived worker. We measured mRNA levels for genes encoding eight of the most prominent antioxidant enzymes and five mitochondrial proteins involved in respiration. The expression of antioxidant genes generally decreased with age in queens, but not in workers. Expression of most mitochondrial genes, in particular CytC, was higher in young queens, but these genes showed a faster age-related decline relative to workers. One exception to this trend was COX-I in thorax. This resulted in higher COX-I/CytC ratios in old queens compared to old workers, which suggests caste-specific differences in mitochondrial function that might be related to the caste-specific differences in longevity. Queen honey bee longevity appears to have evolved via mechanisms other than increased antioxidant gene expression.

  11. Oxidative Stress Promotes Ligand-independent and Enhanced Ligand-dependent Tumor Necrosis Factor Receptor Signaling*

    PubMed Central

    Ozsoy, Hatice Z.; Sivasubramanian, Natarajan; Wieder, Eric D.; Pedersen, Steen; Mann, Douglas L.

    2008-01-01

    Tumor necrosis factor (TNF) receptor 1 (TNFR1, p55) and 2 (TNFR2, p75) are characterized by several cysteine-rich modules in the extracellular domain, raising the possibility that redox-induced modifications of these cysteine residues might alter TNFR function. To test this possibility, we examined fluorescence resonance energy transfer (FRET) in 293T cells transfected with CFP- and YFP-tagged TNFRs exposed to the thiol oxidant diamide. Treatment with high concentrations of diamide (1 mm) resulted in an increase in the FRET signal that was sensitive to inhibition with the reducing agent dithiothreitol, suggesting that oxidative stress resulted in TNFR self-association. Treatment of cells with low concentrations of diamide (1 μm) that was not sufficient to provoke TNFR self-association resulted in increased TNF-induced FRET signals relative to the untreated cells, suggesting that oxidative stress enhanced ligand-dependent TNFR signaling. Similar findings were obtained when the TNFR1- and TNFR2-transfected cells were pretreated with a cell-impermeable oxidase, DsbA, that catalyzes disulfide bond formation between thiol groups on cysteine residues. The changes in TNFR self-association were functionally significant, because pretreating the HeLa cells and 293T cells resulted in increased TNF-induced NF-κB activation and TNF-induced expression of IκB and syndecan-4 mRNA levels. Although pretreatment with DsbA did not result in an increase in TNF binding to TNFRs, it resulted in increased TNF-induced activation of NF-κB, consistent with an allosteric modification of the TNFRs. Taken together, these results suggest that oxidative stress promotes TNFR receptor self-interaction and ligand-independent and enhanced ligand-dependent TNF signaling. PMID:18544535

  12. GLUTAMATERGIC SYNAPSE FORMATION IS PROMOTED BY α7-CONTAINING NICOTINIC ACETYLCHOLINE RECEPTORS

    PubMed Central

    Lozada, Adrian F.; Wang, Xulong; Gounko, Natalia V.; Massey, Kerri A.; Duan, Jingjing; Liu, Zhaoping; Berg, Darwin K.

    2012-01-01

    Glutamate is the primary excitatory transmitter in adult brain, acting through synapses on dendritic spines and shafts. Early in development, however, when glutamatergic synapses are only beginning to form, nicotinic cholinergic excitation is already widespread; it is mediated by acetylcholine activating nicotinic acetylcholine receptors (nAChRs) that generate waves of activity across brain regions. A major class of nAChRs contributing at this time is a species containing α7 subunits (α7-nAChRs). These receptors are highly permeable to calcium, influence a variety of calcium-dependent events, and are diversely distributed throughout the developing CNS. Here we show that α7-nAChRs unexpectedly promote formation of glutamatergic synapses during development. The dependence on α7-nAChRs becomes clear when comparing wild-type mice with mice constitutively lacking the α7-nAChR gene. Ultrastructural analysis, immunostaining, and patch-clamp recording all reveal synaptic deficits when α7-nAChR input is absent. Similarly, nicotinic activation of α7-nAChRs in wild-type organotypic culture, as well as cell culture, increases the number of glutamatergic synapses. RNA interference demonstrates that the α7-nAChRs must be expressed in the neuron being innervated for normal innervation to occur. Moreover the deficits persist throughout the developmental period of major de novo synapse formation and are still fully apparent in the adult. GABAergic synapses, in contrast, are undiminished in number under such conditions. As a result, mice lacking α7-nAChRs have an altered balance in the excitatory/inhibitory input they receive. This ratio represents a fundamental feature of neural networks and shows for the first time that endogenous nicotinic cholinergic signaling plays a key role in network construction. PMID:22649244

  13. Upregulation of orexin receptor in paraventricular nucleus promotes sympathetic outflow in obese Zucker rats.

    PubMed

    Zhou, Jing-Jing; Yuan, Fang; Zhang, Yi; Li, De-Pei

    2015-12-01

    Sympathetic vasomotor tone is elevated in obesity-related hypertension. Orexin importantly regulates energy metabolism and autonomic function. We hypothesized that alteration of orexin receptor in the paraventricular nucleus (PVN) of the hypothalamus leads to elevated sympathetic vasomotor tone in obesity. We used in vivo measurement of sympathetic vasomotor tone and microinjection into brain nucleus, whole-cell patch clamp recording in brain slices, and immunocytochemical staining in obese Zucker rats (OZRs) and lean Zucker rats (LZRs). Microinjection of orexin 1 receptor (OX1R) antagonist SB334867 into the PVN reduced basal arterial blood pressure (ABP) and renal sympathetic nerve activity (RSNA) in anesthetized OZRs but not in LZRs. Microinjection of orexin A into the PVN produced greater increases in ABP and RSNA in OZRs than in LZRs. Western blot analysis revealed that OX1R expression levels in the PVN were significantly increased in OZRs compared with LZRs. OX1R immunoreactivity was positive in retrogradely labeled PVN-spinal neurons. The basal firing rate of labeled PVN-spinal neurons was higher in OZRs than in LZRs. SB334867 decreased the basal firing activity of PVN-spinal neurons in OZRs but had no effect in LZRs. Orexin A induced a greater increase in the firing rate of PVN-spinal neurons in OZRs than in LZRs. In addition, orexin A induced larger currents in PVN-spinal neurons in OZRs than in LZRs. These data suggest that upregulation of OX1R in the PVN promotes hyperactivity of PVN presympathetic neurons and elevated sympathetic outflow in obesity.

  14. Erythropoietin Receptor-Mediated Molecular Crosstalk Promotes T Cell Immunoregulation and Transplant Survival.

    PubMed

    Purroy, Carolina; Fairchild, Robert L; Tanaka, Toshiaki; Baldwin, William M; Manrique, Joaquin; Madsen, Joren C; Colvin, Robert B; Alessandrini, Alessandro; Blazar, Bruce R; Fribourg, Miguel; Donadei, Chiara; Maggiore, Umberto; Heeger, Peter S; Cravedi, Paolo

    2017-08-01

    Although spontaneous kidney transplant acceptance/tolerance occurs in mice and occasionally in humans, mechanisms remain unclear. Herein we test the hypothesis that EPO, a hormone predominantly produced by the adult kidney, has immunomodulating properties that are required for spontaneous kidney graft acceptance. In vitro, in a manner dependent on the EPO receptor and CD131 on antigen-presenting cells, EPO induced the secretion of active TGFβ by antigen-presenting cells, which in turn converted naïve CD4(+) T cells into functional Foxp3(+) regulatory T cells (Treg). In murine transplant models, pharmacologic downregulation of kidney-derived EPO prevented spontaneous Treg generation. In a controlled, prospective cohort clinical study, EPO administration at doses used to correct anemia augmented the frequency of peripheral CD4(+)CD25(+)CD127(lo) T cells in humans with CKD. Furthermore, EPO directly inhibited conventional T cell proliferation in vitro via tyrosine phosphatase SHP-1-dependent uncoupling of IL-2Rβ signaling. Conversely, EPO-initiated signals facilitated Treg proliferation by augmenting IL-2Rγ signaling and maintaining constitutively quenched IL-2Rβ signaling. In additional murine transplant models, recombinant EPO administration prolonged heart allograft survival, whereas pharmacologic downregulation of kidney-derived EPO reduced the expression of TGFβ mRNA and abrogated kidney allograft acceptance. Together, our findings delineate the protolerogenic properties of EPO in inhibiting conventional T cells while simultaneously promoting Treg induction, and suggest that manipulating the EPO/EPO receptor signaling axis could be exploited to prevent and/or treat T cell-mediated pathologies, including transplant rejection. Copyright © 2017 by the American Society of Nephrology.

  15. Platelet-derived nucleotides promote tumor-cell transendothelial migration and metastasis via P2Y2 receptor.

    PubMed

    Schumacher, Dagmar; Strilic, Boris; Sivaraj, Kishor Kumar; Wettschureck, Nina; Offermanns, Stefan

    2013-07-08

    Tumor cells can activate platelets, which in turn facilitate tumor cell survival and dissemination. The exact mechanisms by which platelets promote metastasis have remained unclear. Here, we show that adenine nucleotides released from tumor cell-activated platelets induce opening of the endothelial barrier to allow transendothelial migration of tumor cells and thereby promote cancer cell extravasation. We identified the endothelial P2Y2 receptor, which is activated by ATP, as the primary mediator of this effect. Mice deficient in P2Y2 or lacking ATP secretion from platelets show strongly reduced tumor cell metastasis. These findings demonstrate a mechanism by which platelets promote cancer cell metastasis and suggest the P2Y2 receptor and its endothelial downstream signaling mechanisms as a target for antimetastatic therapies. Copyright © 2013 Elsevier Inc. All rights reserved.

  16. Sensitization of epithelial growth factor receptors by nicotine exposure to promote breast cancer cell growth

    PubMed Central

    2011-01-01

    Introduction Tobacco smoke is known to be the main cause of lung, head and neck tumors. Recently, evidence for an increasing breast cancer risk associated with tobacco smoke exposure has been emerging. We and other groups have shown that nicotine, as a non-conventional carcinogen, has the potential to facilitate cancer genesis and progression. However, the underlying mechanisms by which the smoke affects the breast, rather than the lung, remain unclear. Here, we examine possible downstream signaling pathways of the nicotinic acetylcholine receptor (nAChR) and their role in breast cancer promotion. Methods Using human benign MCF10A and malignant MDA-MB-231 breast cells and specific inhibitors of possible downstream kinases, we identified nAChR effectors that were activated by treatment with nicotine. We further tested the effects of these effector pathways on the regulation of E2F1 activation, cell cycle progression and on Bcl-2 expression and long-term cell survival. Results In this study, we demonstrated a novel signaling mechanism by which nicotine exposure activated Src to sensitize epidermal growth factor receptor (EGFR)-mediated pathways for breast cancer cell growth promotion. After the ligation of nAChR with nicotine, EGFR was shown to be activated and then internalized in both MCF10A and MDA-MB-231 breast cancer cells. Subsequently, Src, Akt and ERK1/2 were phosphorylated at different time points following nicotine treatment. We further demonstrated that through Src, the ligation of nicotine with nAChR stimulated the EGFR/ERK1/2 pathway for the activation of E2F1 and further cell progression. Our data also showed that Akt functioned directly downstream of Src and was responsible for the increase of Bcl-2 expression and long-term cell survival. Conclusions Our study reveals the existence of a potential, regulatory network governed by the interaction of nicotine and nAChR that integrates the conventional, mitogenic Src and EGFR signals for breast cancer

  17. Sensitization of epithelial growth factor receptors by nicotine exposure to promote breast cancer cell growth.

    PubMed

    Nishioka, Takashi; Kim, Hyun-Seok; Luo, Ling-Yu; Huang, Yi; Guo, Jinjin; Chen, Chang Yan

    2011-01-01

    Tobacco smoke is known to be the main cause of lung, head and neck tumors. Recently, evidence for an increasing breast cancer risk associated with tobacco smoke exposure has been emerging. We and other groups have shown that nicotine, as a non-conventional carcinogen, has the potential to facilitate cancer genesis and progression. However, the underlying mechanisms by which the smoke affects the breast, rather than the lung, remain unclear. Here, we examine possible downstream signaling pathways of the nicotinic acetylcholine receptor (nAChR) and their role in breast cancer promotion. Using human benign MCF10A and malignant MDA-MB-231 breast cells and specific inhibitors of possible downstream kinases, we identified nAChR effectors that were activated by treatment with nicotine. We further tested the effects of these effector pathways on the regulation of E2F1 activation, cell cycle progression and on Bcl-2 expression and long-term cell survival. In this study, we demonstrated a novel signaling mechanism by which nicotine exposure activated Src to sensitize epidermal growth factor receptor (EGFR)-mediated pathways for breast cancer cell growth promotion. After the ligation of nAChR with nicotine, EGFR was shown to be activated and then internalized in both MCF10A and MDA-MB-231 breast cancer cells. Subsequently, Src, Akt and ERK1/2 were phosphorylated at different time points following nicotine treatment. We further demonstrated that through Src, the ligation of nicotine with nAChR stimulated the EGFR/ERK1/2 pathway for the activation of E2F1 and further cell progression. Our data also showed that Akt functioned directly downstream of Src and was responsible for the increase of Bcl-2 expression and long-term cell survival. Our study reveals the existence of a potential, regulatory network governed by the interaction of nicotine and nAChR that integrates the conventional, mitogenic Src and EGFR signals for breast cancer development.

  18. Evolution of an adaptive behavior and its sensory receptors promotes eye regression in blind cavefish.

    PubMed

    Yoshizawa, Masato; Yamamoto, Yoshiyuki; O'Quin, Kelly E; Jeffery, William R

    2012-12-27

    How and why animals lose eyesight during adaptation to the dark and food-limited cave environment has puzzled biologists since the time of Darwin. More recently, several different adaptive hypotheses have been proposed to explain eye degeneration based on studies in the teleost Astyanax mexicanus, which consists of blind cave-dwelling (cavefish) and sighted surface-dwelling (surface fish) forms. One of these hypotheses is that eye regression is the result of indirect selection for constructive characters that are negatively linked to eye development through the pleiotropic effects of Sonic Hedgehog (SHH) signaling. However, subsequent genetic analyses suggested that other mechanisms also contribute to eye regression in Astyanax cavefish. Here, we introduce a new approach to this problem by investigating the phenotypic and genetic relationships between a suite of non-visual constructive traits and eye regression. Using quantitative genetic analysis of crosses between surface fish, the Pachón cavefish population and their hybrid progeny, we show that the adaptive vibration attraction behavior (VAB) and its sensory receptors, superficial neuromasts (SN) specifically found within the cavefish eye orbit (EO), are genetically correlated with reduced eye size. The quantitative trait loci (QTL) for these three traits form two clusters of congruent or overlapping QTL on Astyanax linkage groups (LG) 2 and 17, but not at the shh locus on LG 13. Ablation of EO SN in cavefish demonstrated a major role for these sensory receptors in VAB expression. Furthermore, experimental induction of eye regression in surface fish via shh overexpression showed that the absence of eyes was insufficient to promote the appearance of VAB or EO SN. We conclude that natural selection for the enhancement of VAB and EO SN indirectly promotes eye regression in the Pachón cavefish population through an antagonistic relationship involving genetic linkage or pleiotropy among the genetic factors

  19. Evolution of an adaptive behavior and its sensory receptors promotes eye regression in blind cavefish

    PubMed Central

    2012-01-01

    Background How and why animals lose eyesight during adaptation to the dark and food-limited cave environment has puzzled biologists since the time of Darwin. More recently, several different adaptive hypotheses have been proposed to explain eye degeneration based on studies in the teleost Astyanax mexicanus, which consists of blind cave-dwelling (cavefish) and sighted surface-dwelling (surface fish) forms. One of these hypotheses is that eye regression is the result of indirect selection for constructive characters that are negatively linked to eye development through the pleiotropic effects of Sonic Hedgehog (SHH) signaling. However, subsequent genetic analyses suggested that other mechanisms also contribute to eye regression in Astyanax cavefish. Here, we introduce a new approach to this problem by investigating the phenotypic and genetic relationships between a suite of non-visual constructive traits and eye regression. Results Using quantitative genetic analysis of crosses between surface fish, the Pachón cavefish population and their hybrid progeny, we show that the adaptive vibration attraction behavior (VAB) and its sensory receptors, superficial neuromasts (SN) specifically found within the cavefish eye orbit (EO), are genetically correlated with reduced eye size. The quantitative trait loci (QTL) for these three traits form two clusters of congruent or overlapping QTL on Astyanax linkage groups (LG) 2 and 17, but not at the shh locus on LG 13. Ablation of EO SN in cavefish demonstrated a major role for these sensory receptors in VAB expression. Furthermore, experimental induction of eye regression in surface fish via shh overexpression showed that the absence of eyes was insufficient to promote the appearance of VAB or EO SN. Conclusions We conclude that natural selection for the enhancement of VAB and EO SN indirectly promotes eye regression in the Pachón cavefish population through an antagonistic relationship involving genetic linkage or pleiotropy

  20. Sperm Epidermal Growth Factor Receptor (EGFR) Mediates α7 Acetylcholine Receptor (AChR) Activation to Promote Fertilization

    PubMed Central

    Jaldety, Yael; Glick, Yair; Orr-Urtreger, Avi; Ickowicz, Debby; Gerber, Doron; Breitbart, Haim

    2012-01-01

    To attain fertilization the spermatozoon binds to the egg zona pellucida (ZP) via sperm receptor(s) and undergoes an acrosome reaction (AR). Several sperm receptors have been described in the literature; however, the identity of this receptor is not yet certain. In this study, we suggest that the α7 nicotinic acetylcholine receptor (α7nAChR) might be a sperm receptor activated by ZP to induce epidermal growth factor receptor (EGFR)-mediated AR. We found that isolated ZP or α7 agonists induced the AR in sperm from WT but not α7-null spermatozoa, and the induced AR was inhibited by α7 or EGFR antagonists. Moreover, α7-null sperm showed very little binding to the egg, and microfluidic affinity in vitro assay clearly showed that α7nAChR, as well as EGFR, interacted with ZP3. Induction of EGFR activation and the AR by an α7 agonist was inhibited by a Src family kinase (SFK) inhibitor. In conclusion we suggest that activation of α7 by ZP leads to SFK-dependent EGFR activation, Ca2+ influx, and the acrosome reaction. PMID:22577141

  1. Mutant p53 amplifies Epidermal Growth Factor Receptor family signaling to promote mammary tumorigenesis

    PubMed Central

    Yallowitz, Alisha; Li, Dun; Lobko, Antony; Nemajerova, Alice; Marchenko, Natalia

    2016-01-01

    The epidermal growth factor receptor family (ErbB2/Her2 and EGFR/ErbB1/Her1) often modulates the transcriptional program involved in promoting mammary tumorigenesis. In humans, more than 70% of ErbB2-positive sporadic breast cancers harbor p53 mutations, which correlate with poor prognosis. Also, the extremely high incidence of ErbB2-positive breast cancer in women with p53 germ-line mutations (Li-Fraumeni Syndrome) suggests the key role of mutant p53 specifically in ErbB2-mediated mammary tumorigenesis. To examine the role of mutant p53 during ErbB2-mediated mammary tumorigenesis we introduced a mutant p53 R172H allele into a (MMTV)-ErbB2/Neu mouse model. We show in heterozygous p53 mice that mutp53 R172H is a more potent activator of ErbB2-mediated mammary tumorigenesis than simple loss of p53. The more aggressive disease in mutant p53 animals was reflected by earlier tumor onset, increased mammary tumor multiplicity, and shorter survival. We provide molecular evidence that mutant p53 amplifies ErbB2 and EGFR signaling to promote the expansion of mammary stem cells and induce cancer cell proliferation. This study therefore identifies mutant p53 as an essential player in ErbB2 and EGFR-mediated breast cancer and indicates the potential translational importance of targeting mutant p53 in this subset of breast cancer patients. PMID:25573952

  2. Purinergic P2Y2 receptors promote hepatocyte resistance to hypoxia.

    PubMed

    Carini, Rita; Alchera, Elisa; De Cesaris, Maria Grazia; Splendore, Roberta; Piranda, Daniela; Baldanzi, Gianluca; Albano, Emanuele

    2006-08-01

    ATP stimulation of purinergic P2 receptors (P2YR and P2XR) regulates several hepatic functions. Here we report the involvement of ATP-mediated signals in enhancing hepatocyte tolerance to lethal stress. The protection given by purinergic agonists was investigated in rat hepatocytes exposed to hypoxia. ATP released after hypotonic stress (200 mOsm/L) as well as P2YR agonists prevented hepatocyte killing by hypoxia with efficiency ranking UTP > ATPgammaS > ADPbetaS, whereas the P2XR agonist, methylene-adenosine-5'-triphosphate, was ineffective. Adenosine-5'-O-3-thiotriphosphate (ATPgammaS; 100 micromol/L) also prevented Na+ -overload in hypoxic cells by inhibiting the Na+/H+ exchanger, without interfering with hypoxic acidosis. ATPgammaS activated Src and promoted a Src-dependent stimulation of both ERK1/2 and p38MAPK. Blocking p38MAPK with SB203580 reverted the protection given by ATPgammaS on both cell viability and Na+ accumulation, whereas ERK1/2 inhibition with PD98058 was ineffective. An increased phosphorylation of ERK1/2 was also evident in untreated hypoxic hepatocytes. PD98058 ameliorated Na+ accumulation and cell death caused by hypoxia. Hepatocyte pre-treatment with ATPgammaS reverted ERK1/2 activation in hypoxic cells. SB203580 blocked the effects of ATPgammaS on both ERK1/2 and Na+/H+ exchanger. The activation of p38MAPK by P2Y2R increases hepatocyte resistance to hypoxia by down-modulating ERK1/2-mediated signals that promote Na+ influx through the Na+/H+ exchanger.

  3. Pregnane X receptor activation and silencing promote steatosis of human hepatic cells by distinct lipogenic mechanisms.

    PubMed

    Bitter, Andreas; Rümmele, Petra; Klein, Kathrin; Kandel, Benjamin A; Rieger, Jessica K; Nüssler, Andreas K; Zanger, Ulrich M; Trauner, Michael; Schwab, Matthias; Burk, Oliver

    2015-11-01

    In addition to its well-characterized role in the regulation of drug metabolism and transport by xenobiotics, pregnane X receptor (PXR) critically impacts on lipid homeostasis. In mice, both ligand-dependent activation and knockout of PXR were previously shown to promote hepatic steatosis. To elucidate the respective pathways in human liver, we generated clones of human hepatoma HepG2 cells exhibiting different PXR protein levels, and analyzed effects of PXR activation and knockdown on steatosis and expression of lipogenic genes. Ligand-dependent activation as well as knockdown of PXR resulted in increased steatosis in HepG2 cells. Activation of PXR induced the sterol regulatory element-binding protein (SREBP) 1-dependent lipogenic pathway via PXR-dependent induction of SREBP1a, which was confirmed in primary human hepatocytes. Inhibiting SREBP1 activity by blocking the cleavage-dependent maturation of SREBP1 protein impaired the induction of lipogenic SREBP1 target genes and triglyceride accumulation by PXR activation. On the other hand, PXR knockdown resulted in up-regulation of aldo-keto reductase (AKR) 1B10, which enhanced the acetyl-CoA carboxylase (ACC)-catalyzed reaction step of de novo lipogenesis. In a cohort of human liver samples histologically classified for non-alcoholic fatty liver disease, AKR1B10, SREBP1a and SREBP1 lipogenic target genes proved to be up-regulated in steatohepatitis, while PXR protein was reduced. In summary, our data suggest that activation and knockdown of PXR in human hepatic cells promote de novo lipogenesis and steatosis by induction of the SREBP1 pathway and AKR1B10-mediated increase of ACC activity, respectively, thus providing mechanistic explanations for a putative dual role of PXR in the pathogenesis of steatohepatitis.

  4. Sox2 Is an Androgen Receptor-Repressed Gene That Promotes Castration-Resistant Prostate Cancer

    PubMed Central

    Kregel, Steven; Kiriluk, Kyle J.; Rosen, Alex M.; Cai, Yi; Reyes, Edwin E.; Otto, Kristen B.; Tom, Westin; Paner, Gladell P.; Szmulewitz, Russell Z.; Vander Griend, Donald J.

    2013-01-01

    Despite advances in detection and therapy, castration-resistant prostate cancer continues to be a major clinical problem. The aberrant activity of stem cell pathways, and their regulation by the Androgen Receptor (AR), has the potential to provide insight into novel mechanisms and pathways to prevent and treat advanced, castrate-resistant prostate cancers. To this end, we investigated the role of the embryonic stem cell regulator Sox2 [SRY (sex determining region Y)-box 2] in normal and malignant prostate epithelial cells. In the normal prostate, Sox2 is expressed in a portion of basal epithelial cells. Prostate tumors were either Sox2-positive or Sox2-negative, with the percentage of Sox2-positive tumors increasing with Gleason Score and metastases. In the castration-resistant prostate cancer cell line CWR-R1, endogenous expression of Sox2 was repressed by AR signaling, and AR chromatin-IP shows that AR binds the enhancer element within the Sox2 promoter. Likewise, in normal prostate epithelial cells and human embryonic stem cells, increased AR signaling also decreases Sox2 expression. Resistance to the anti-androgen MDV3100 results in a marked increase in Sox2 expression within three prostate cancer cell lines, and in the castration-sensitive LAPC-4 prostate cancer cell line ectopic expression of Sox2 was sufficient to promote castration-resistant tumor formation. Loss of Sox2 expression in the castration-resistant CWR-R1 prostate cancer cell line inhibited cell growth. Up-regulation of Sox2 was not associated with increased CD133 expression but was associated with increased FGF5 (Fibroblast Growth Factor 5) expression. These data propose a model of elevated Sox2 expression due to loss of AR-mediated repression during castration, and consequent castration-resistance via mechanisms not involving induction of canonical embryonic stem cell pathways. PMID:23326489

  5. Trait-associated sequence variation in the bovine growth hormone receptor 1A promoter does not affect promoter activity in vitro.

    PubMed

    Zhou, Y; Jiang, H

    2005-04-01

    Growth hormone (GH) plays a central role in growth and metabolism in cattle by binding to growth hormone receptor (GHR) and stimulating production of insulin-like growth factor 1 (IGF1). Two sequence variations in the promoter transcribing a major GHR mRNA variant, GHR 1A mRNA, have been reported to be associated with quantitative differences in growth rate or blood concentration of IGF1 in cattle. One such variation is in the length of a TG-repeat, being 11 or 16-20; the other variation is in the nucleotide 155 bp upstream from the transcription start site, being G or A. In this study, we determined whether these sequence variations would affect the activity of GHR 1A promoter. We cloned GHR 1A promoters bearing different sequence variations and linked each of them to a reporter gene. Transient transfection analyses revealed that these promoter-reporter constructs did not differ in reporter gene expression. Cotransfection analyses demonstrated that they also did not differ in activation by hepatocyte nuclear factor 4alpha, hepatocyte nuclear factor 4gamma and nuclear receptor subfamily 2 group F member 2, known transcription factors for bovine GHR 1A promoter. These in vitro results, together with a previous observation that neither the nucleotide 155 bp upstream from the transcription start site nor the TG-repeat was part of the GHR 1A promoter region interacting with nuclear proteins from bovine liver, do not support a cause-effect relationship between the reported sequence variations and the associated changes in growth rate or blood IGF1 concentration in cattle.

  6. Activation of the prolactin receptor gene by promoter insertion in a Moloney murine leukemia virus-induced rat thymoma.

    PubMed Central

    Barker, C S; Bear, S E; Keler, T; Copeland, N G; Gilbert, D J; Jenkins, N A; Yeung, R S; Tsichlis, P N

    1992-01-01

    The prolactin receptor (Prlr) and growth hormone receptor (Ghr) genes and the Moloney murine leukemia virus integration-2 (Mlvi-2) locus were mapped to mouse chromosome 15 and human chromosome 5 bands p12-p14. To examine the potential relationship between Mlvi-2 and the genes encoding the growth hormone receptor and the prolactin receptor, we determined the chromosomal location of all three loci in the rat, using a panel of rat-mouse somatic cell hybrids, and in the mouse, using a panel of (C57BL/6J x Mus spretus)F1 x C57BL/6J interspecific backcross mice. These analyses revealed that Ghr, Prlr, and Mlvi-2 map to chromosome 2 in the rat and to chromosome 15 in the mouse, in close proximity with each other. Pulsed-field gel electrophoresis of rat genomic DNA showed no overlaps between the gene encoding the prolactin receptor and the remaining loci. Moreover, expression of the prolactin receptor was not affected by provirus insertion in Mlvi-2. During these studies, however, we detected one T-cell lymphoma line (2779) in which the prolactin receptor gene was activated by provirus integration. Sequence analysis of polymerase chain reaction-derived cDNA clones showed that the prolactin receptor RNA message initiates at the 5' long terminal repeat and utilizes the splice donor site 5' of the gag gene to splice the viral sequences onto exon 1 of the prolactin receptor. This message is predicted to encode the intact prolactin receptor protein product. Exposure of the T-cell lymphoma line 2779 to prolactin promoted cellular proliferation. Images PMID:1404614

  7. Supersensitive Kappa Opioid Receptors Promotes Ethanol Withdrawal-Related Behaviors and Reduce Dopamine Signaling in the Nucleus Accumbens

    PubMed Central

    Rose, Jamie H.; Karkhanis, Anushree N.; Chen, Rong; Gioia, Dominic; Lopez, Marcelo F.; Becker, Howard C.; McCool, Brian A.

    2016-01-01

    Background: Chronic ethanol exposure reduces dopamine transmission in the nucleus accumbens, which may contribute to the negative affective symptoms associated with ethanol withdrawal. Kappa opioid receptors have been implicated in withdrawal-induced excessive drinking and anxiety-like behaviors and are known to inhibit dopamine release in the nucleus accumbens. The effects of chronic ethanol exposure on kappa opioid receptor-mediated changes in dopamine transmission at the level of the dopamine terminal and withdrawal-related behaviors were examined. Methods: Five weeks of chronic intermittent ethanol exposure in male C57BL/6 mice were used to examine the role of kappa opioid receptors in chronic ethanol-induced increases in ethanol intake and marble burying, a measure of anxiety/compulsive-like behavior. Drinking and marble burying were evaluated before and after chronic intermittent ethanol exposure, with and without kappa opioid receptor blockade by nor-binaltorphimine (10mg/kg i.p.). Functional alterations in kappa opioid receptors were assessed using fast scan cyclic voltammetry in brain slices containing the nucleus accumbens. Results: Chronic intermittent ethanol-exposed mice showed increased ethanol drinking and marble burying compared with controls, which was attenuated with kappa opioid receptor blockade. Chronic intermittent ethanol-induced increases in behavior were replicated with kappa opioid receptor activation in naïve mice. Fast scan cyclic voltammetry revealed that chronic intermittent ethanol reduced accumbal dopamine release and increased uptake rates, promoting a hypodopaminergic state of this region. Kappa opioid receptor activation with U50,488H concentration-dependently decreased dopamine release in both groups; however, this effect was greater in chronic intermittent ethanol-treated mice, indicating kappa opioid receptor supersensitivity in this group. Conclusions: These data suggest that the chronic intermittent ethanol-induced increase

  8. Downstream promoter sequences facilitate the formation of a specific transcription factor IID-promoter complex topology required for efficient transcription from the megalin/low density lipoprotein receptor-related protein 2 promoter.

    PubMed

    Knutson, A; Castaño, E; Oelgeschläger, T; Roeder, R G; Westin, G

    2000-05-12

    Megalin/low density lipoprotein receptor-related protein 2 (LRP-2) is an endocytic receptor expressed in highly specialized cell types such as parathyroid cells and epithelia of the kidney. Previous experiments identified a nonconsensus TATA element, with the sequence TAGAAAA, as crucial for accurate and efficient transcription from the LRP-2 promoter. Here we show that, in addition to the TAGA element, promoter sequences downstream of the transcription start site contribute significantly to transcription both in vitro and in transfected cells. Deletion and point mutational analyses reveal that the promoter region located between positions +5 and +11 (sequence TTTTGGC) is of particular importance. Complementation experiments in nuclear extracts lacking transcription factor IID (TFIID) activity show that TATA-binding protein-associated factors of TFIID are essential for the function of LRP-2 downstream promoter sequences. Interestingly, DNase I footprinting studies show that the downstream region between positions +5 and +11 does not significantly affect overall TFIID affinity to the promoter but that it profoundly affects the topology of the TFIID x promoter complex not only downstream of the transcription start site, but in particular in the TATA box region. Our observations suggest a model for a novel downstream sequence function, in which TATA-binding protein-associated factor-promoter interactions downstream of the transcription start site modulate TFIID-DNA interactions in the TATA box region.

  9. Constitutively active transforming growth factor β receptor 1 in the mouse ovary promotes tumorigenesis

    PubMed Central

    Gao, Yang; Vincent, David F.; Davis, Anna Jane; Sansom, Owen J.; Bartholin, Laurent; Li, Qinglei

    2016-01-01

    Despite the well-established tumor suppressive role of TGFβ proteins, depletion of key TGFβ signaling components in the mouse ovary does not induce a growth advantage. To define the role of TGFβ signaling in ovarian tumorigenesis, we created a mouse model expressing a constitutively active TGFβ receptor 1 (TGFBR1) in ovarian somatic cells using conditional gain-of-function approach. Remarkably, these mice developed ovarian sex cord-stromal tumors with complete penetrance, leading to reproductive failure and mortality. The tumors expressed multiple granulosa cell markers and caused elevated serum inhibin and estradiol levels, reminiscent of granulosa cell tumors. Consistent with the tumorigenic effect, overactivation of TGFBR1 altered tumor microenvironment by promoting angiogenesis and enhanced ovarian cell proliferation, accompanied by impaired cell differentiation and dysregulated expression of critical genes in ovarian function. By further exploiting complementary genetic models, we substantiated our finding that constitutively active TGFBR1 is a potent oncogenic switch in mouse granulosa cells. In summary, overactivation of TGFBR1 drives gonadal tumor development. The TGFBR1 constitutively active mouse model phenocopies a number of morphological, hormonal, and molecular features of human granulosa cell tumors and are potentially valuable for preclinical testing of targeted therapies to treat granulosa cell tumors, a class of poorly defined ovarian malignancies. PMID:27344183

  10. Dmp1 Promoter-Driven Diphtheria Toxin Receptor Transgene Expression Directs Unforeseen Effects in Multiple Tissues

    PubMed Central

    Al-Jazzar, Ahmed; Javaheri, Behzad; Prideaux, Matt; Boyde, Alan; Scudamore, Cheryl L.; Cherifi, Chahrazad; Hay, Eric; Hopkinson, Mark; Boyd, Michael; Cohen-Solal, Martine; Farquharson, Colin; Pitsillides, Andrew A.

    2016-01-01

    Mice harbouring a dentin matrix protein 1 (Dmp1) promoter-driven human diphtheria toxin (DT) receptor (HDTR) transgene (Tg) have recently been used to attain targeted ablation of osteocytes by diphtheria toxin (DT) treatment in order to define osteocyte function. Use of these Tg mice has asserted mechano- and novel paracrine regulatory osteocyte functions. To explore osteocyte roles fully, we sought to confirm the selectivity of DT effects in these transgenic mice. However, our findings revealed incomplete DT-induced osteocyte ablation, prevalent HDTR misexpression, as well as more prominent histopathological DT-induced changes in multiple organs in Tg than in wild-type (WT) littermate mice. Mechanistic evidence for DT action, via prominent regulation of phosphorylation status of elongation factor-2 (EF-2), was also found in many non-skeletal tissues in Tg mice; indicative of direct “off-target” DT action. Finally, very rapid deterioration in health and welfare status in response to DT treatment was observed in these Tg when compared to WT control mice. Together, these data lead us to conclude that alternative models for osteocyte ablation should be sought and caution be exercised when drawing conclusions from experiments using these Tg mice alone. PMID:28035954

  11. The aryl hydrocarbon receptor controls cyclin O to promote epithelial multiciliogenesis

    PubMed Central

    Villa, Matteo; Crotta, Stefania; Dingwell, Kevin S.; Hirst, Elizabeth M. A.; Gialitakis, Manolis; Ahlfors, Helena; Smith, James C.; Stockinger, Brigitta; Wack, Andreas

    2016-01-01

    Epithelia function as barriers against environmental insults and express the transcription factor aryl hydrocarbon receptor (AhR). However, AhR function in these tissues is unknown. Here we show that AhR regulates multiciliogenesis in both murine airway epithelia and in Xenopus laevis epidermis. In air-exposed airway epithelia, induction of factors required for multiciliogenesis, including cyclin O (Ccno) and Multicilin (Mcidas), is AhR dependent, and air exposure induces AhR binding to the Ccno promoter. Submersion and hypoxic conditions impede AhR-dependent Ccno induction. This is mediated by the persistence of Notch signalling, as Notch blockade renders multiciliogenesis and Ccno induction by AhR independent from air exposure. In contrast to Ccno induction, air exposure does not induce the canonical AhR target cytochrome P450 1a1 (Cyp1a1). Inversely, exposure to AhR ligands induces Cyp1a1 but not Ccno and impeded ciliogenesis. These data indicate that AhR involvement in detoxification of environmental pollutants may impede its physiological role, resulting in respiratory pathology. PMID:27554288

  12. Mineralocorticoid receptor degradation is promoted by Hsp90 inhibition and the ubiquitin-protein ligase CHIP.

    PubMed

    Faresse, Nourdine; Ruffieux-Daidie, Dorothée; Salamin, Mélanie; Gomez-Sanchez, Celso E; Staub, Olivier

    2010-12-01

    The mineralocorticoid receptor (MR) plays a crucial role in the regulation of Na(+) balance and blood pressure, as evidenced by gain of function mutations in the MR of hypertensive families. In the kidney, aldosterone binds to the MR, induces its nuclear translocation, and promotes a transcriptional program leading to increased transepithelial Na(+) transport via the epithelial Na(+) channel. In the unliganded state, MR is localized in the cytosol and part of a multiprotein complex, including heat shock protein 90 (Hsp90), which keeps it ligand-binding competent. 17-Allylamino-17-demethoxygeldanamycin (17-AAG) is a benzoquinone ansamycin antibiotic that binds to Hsp90 and alters its function. We investigated whether 17-AAG affects the stability and transcriptional activity of MR and consequently Na(+) reabsorption by renal cells. 17-AAG treatment lead to reduction of MR protein level in epithelial cells in vitro and in vivo, thereby interfering with aldosterone-dependent transcription. Moreover, 17-AAG inhibited aldosterone-induced Na(+) transport, possibly by interfering with MR availability for the ligand. Finally, we identified the ubiquitin-protein ligase, COOH terminus of Hsp70-interacting protein, as a novel partner of the cytosolic MR, which is responsible for its polyubiquitylation and proteasomal degradation in presence of 17-AAG. In conclusion, 17-AAG may represent a novel pharmacological tool to interfere with Na(+) reabsorption and hypertension.

  13. The GABA(A) receptor RDL acts in peptidergic PDF neurons to promote sleep in Drosophila.

    PubMed

    Chung, Brian Y; Kilman, Valerie L; Keath, J Russel; Pitman, Jena L; Allada, Ravi

    2009-03-10

    Sleep is regulated by a circadian clock that times sleep and wake to specific times of day and a homeostat that drives sleep as a function of prior wakefulness. To analyze the role of the circadian clock, we have used the fruit fly Drosophila. Flies display the core behavioral features of sleep, including relative immobility, elevated arousal thresholds, and homeostatic regulation. We assessed sleep-wake modulation by a core set of circadian pacemaker neurons that express the neuropeptide PDF. We find that disruption of PDF function increases sleep during the late night in light:dark and the first subjective day of constant darkness. Flies deploy genetic and neurotransmitter pathways to regulate sleep that are similar to those of their mammalian counterparts, including GABA. We find that RNA interference-mediated knockdown of the GABA(A) receptor gene, Resistant to dieldrin (Rdl), in PDF neurons reduces sleep, consistent with a role for GABA in inhibiting PDF neuron function. Patch-clamp electrophysiology reveals GABA-activated picrotoxin-sensitive chloride currents on PDF+ neurons. In addition, RDL is detectable most strongly on the large subset of PDF+ pacemaker neurons. These results suggest that GABAergic inhibition of arousal-promoting PDF neurons is an important mode of sleep-wake regulation in vivo.

  14. Promotion of adipogenesis by an EP2 receptor agonist via stimulation of angiogenesis in pulmonary emphysema.

    PubMed

    Tsuji, Takao; Yamaguchi, Kazuhiro; Kikuchi, Ryota; Itoh, Masayuki; Nakamura, Hiroyuki; Nagai, Atsushi; Aoshiba, Kazutetsu

    2014-08-01

    Body weight loss is a common manifestation in patients with chronic obstructive pulmonary disease (COPD), particularly those with severe emphysema. Adipose angiogenesis is a key mediator of adipogenesis and use of pro-angiogenic agents may serve as a therapeutic option for lean COPD patients. Since angiogenesis is stimulated by PGE2, we examined whether ONO-AE1-259, a selective E-prostanoid (EP) 2 receptor agonist, might promote adipose angiogenesis and adipogenesis in a murine model of elastase-induced pulmonary emphysema (EIE mice). Mice were intratracheally instilled with elastase or saline, followed after 4 weeks by intraperitoneal administration of ONO-AE1-259 for 4 weeks. The subcutaneous adipose tissue (SAT) weight decreased in the EIE mice, whereas in the EIE mice treated with ONO-AE1-259, the SAT weight was largely restored, which was associated with significant increases in SAT adipogenesis, angiogenesis, and VEGF protein production. In contrast, ONO-AE1-259 administration induced no alteration in the weight of the visceral adipose tissue. These results suggest that in EIE mice, ONO-AE1-259 stimulated adipose angiogenesis possibly via VEGF production, and thence, adipogenesis. Our data pave the way for the development of therapeutic interventions for weight loss in emphysema patients, e.g., use of pro-angiogenic agents targeting the adipose tissue vascular component.

  15. Receptor-interacting protein kinase 3 promotes platelet activation and thrombosis.

    PubMed

    Zhang, Yiwen; Zhang, Jian; Yan, Rong; Tian, Jingluan; Zhang, Yang; Zhang, Jie; Chen, Mengxing; Cui, Qingya; Zhao, Lili; Hu, Renping; Jiang, Miao; Li, Zhenyu; Ruan, Changgeng; He, Sudan; Dai, Kesheng

    2017-03-14

    Previous studies have shown that receptor-interacting protein kinase 3 (RIP3) is involved in many important biological processes, including necroptosis, apoptosis, and inflammation. Here we show that RIP3 plays a critical role in regulating platelet functions and in vivo thrombosis and hemostasis. Tail bleeding times were significantly longer in RIP3-knockout (RIP3(-/-)) mice compared with their wild-type (WT) littermates. In an in vivo model of arteriole thrombosis, mice lacking RIP3 exhibited prolonged occlusion times. WT mice repopulated with RIP3(-/-) bone marrow-derived cells had longer occlusion times than RIP3(-/-) mice repopulated with WT bone marrow-derived cells, suggesting a role for RIP3-deficient platelets in arterial thrombosis. Consistent with these findings, we observed that RIP3 was expressed in both human and mice platelets. Deletion of RIP3 in mouse platelets caused a marked defect in aggregation and attenuated dense granule secretion in response to low doses of thrombin or a thromboxane A2 analog, U46619. Phosphorylation of Akt induced by U46619 or thrombin was diminished in RIP3(-/-) platelets. Moreover, RIP3 interacted with Gα13 Platelet spreading on fibrinogen and clot retraction were impaired in the absence of RIP3. RIP3 inhibitor dose-dependently inhibited platelet aggregation in vitro and prevented arterial thrombus formation in vivo. These data demonstrate a role for RIP3 in promoting in vivo thrombosis and hemostasis by amplifying platelet activation. RIP3 may represent a novel promising therapeutic target for thrombotic diseases.

  16. IQGAP1 promotes CXCR4 chemokine receptor function and trafficking via EEA-1+ endosomes

    PubMed Central

    Bamidele, Adebowale O.; Kremer, Kimberly N.; Hirsova, Petra; Clift, Ian C.; Gores, Gregory J.; Billadeau, Daniel D.

    2015-01-01

    IQ motif–containing GTPase-activating protein 1 (IQGAP1) is a cytoskeleton-interacting scaffold protein. CXCR4 is a chemokine receptor that binds stromal cell–derived factor-1 (SDF-1; also known as CXCL12). Both IQGAP1 and CXCR4 are overexpressed in cancer cell types, yet it was unclear whether these molecules functionally interact. Here, we show that depleting IQGAP1 in Jurkat T leukemic cells reduced CXCR4 expression, disrupted trafficking of endocytosed CXCR4 via EEA-1+ endosomes, and decreased efficiency of CXCR4 recycling. SDF-1–induced cell migration and activation of extracellular signal-regulated kinases 1 and 2 (ERK) MAPK were strongly inhibited, even when forced overexpression restored CXCR4 levels. Similar results were seen in KMBC and HEK293 cells. Exploring the mechanism, we found that SDF-1 treatment induced IQGAP1 binding to α-tubulin and localization to CXCR4-containing endosomes and that CXCR4-containing EEA-1+ endosomes were abnormally located distal from the microtubule (MT)-organizing center (MTOC) in IQGAP1-deficient cells. Thus, IQGAP1 critically mediates CXCR4 cell surface expression and signaling, evidently by regulating EEA-1+ endosome interactions with MTs during CXCR4 trafficking and recycling. IQGAP1 may similarly promote CXCR4 functions in other cancer cell types. PMID:26195666

  17. Toll-like receptor agonists promote prolonged triglyceride storage in macrophages.

    PubMed

    Huang, Ying-ling; Morales-Rosado, Joel; Ray, Jessica; Myers, Timothy G; Kho, Terry; Lu, Mingfang; Munford, Robert S

    2014-01-31

    Macrophages in infected tissues may sense microbial molecules that significantly alter their metabolism. In a seeming paradox, these critical host defense cells often respond by increasing glucose catabolism while simultaneously storing fatty acids (FA) as triglycerides (TAG) in lipid droplets. We used a load-chase strategy to study the mechanisms that promote long term retention of TAG in murine and human macrophages. Toll-like receptor (TLR)1/2, TLR3, and TLR4 agonists all induced the cells to retain TAG for ≥3 days. Prolonged TAG retention was accompanied by the following: (a) enhanced FA uptake and FA incorporation into TAG, with long lasting increases in acyl-CoA synthetase long 1 (ACSL1) and diacylglycerol acyltransferase-2 (DGAT2), and (b) decreases in lipolysis and FA β-oxidation that paralleled a prolonged drop in adipose triglyceride lipase (ATGL). TLR agonist-induced TAG storage is a multifaceted process that persists long after most early pro-inflammatory responses have subsided and may contribute to the formation of "lipid-laden" macrophages in infected tissues.

  18. Alu retrotransposons promote differentiation of human carcinoma cells through the aryl hydrocarbon receptor.

    PubMed

    Morales-Hernández, Antonio; González-Rico, Francisco J; Román, Angel C; Rico-Leo, Eva; Alvarez-Barrientos, Alberto; Sánchez, Laura; Macia, Ángela; Heras, Sara R; García-Pérez, José L; Merino, Jaime M; Fernández-Salguero, Pedro M

    2016-06-02

    Cell differentiation is a central process in development and in cancer growth and dissemination. OCT4 (POU5F1) and NANOG are essential for cell stemness and pluripotency; yet, the mechanisms that regulate their expression remain largely unknown. Repetitive elements account for almost half of the Human Genome; still, their role in gene regulation is poorly understood. Here, we show that the dioxin receptor (AHR) leads to differentiation of human carcinoma cells through the transcriptional upregulation of Alu retrotransposons, whose RNA transcripts can repress pluripotency genes. Despite the genome-wide presence of Alu elements, we provide evidences that those located at the NANOG and OCT4 promoters bind AHR, are transcribed by RNA polymerase-III and repress NANOG and OCT4 in differentiated cells. OCT4 and NANOG repression likely involves processing of Alu-derived transcripts through the miRNA machinery involving the Microprocessor and RISC. Consistently, stable AHR knockdown led to basal undifferentiation, impaired Alus transcription and blockade of OCT4 and NANOG repression. We suggest that transcripts produced from AHR-regulated Alu retrotransposons may control the expression of stemness genes OCT4 and NANOG during differentiation of carcinoma cells. The control of discrete Alu elements by specific transcription factors may have a dynamic role in genome regulation under physiological and diseased conditions. © The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.

  19. Alu retrotransposons promote differentiation of human carcinoma cells through the aryl hydrocarbon receptor

    PubMed Central

    Morales-Hernández, Antonio; González-Rico, Francisco J.; Román, Angel C.; Rico-Leo, Eva; Alvarez-Barrientos, Alberto; Sánchez, Laura; Macia, Ángela; Heras, Sara R.; García-Pérez, José L.; Merino, Jaime M.; Fernández-Salguero, Pedro M.

    2016-01-01

    Abstract Cell differentiation is a central process in development and in cancer growth and dissemination. OCT4 (POU5F1) and NANOG are essential for cell stemness and pluripotency; yet, the mechanisms that regulate their expression remain largely unknown. Repetitive elements account for almost half of the Human Genome; still, their role in gene regulation is poorly understood. Here, we show that the dioxin receptor (AHR) leads to differentiation of human carcinoma cells through the transcriptional upregulation of Alu retrotransposons, whose RNA transcripts can repress pluripotency genes. Despite the genome-wide presence of Alu elements, we provide evidences that those located at the NANOG and OCT4 promoters bind AHR, are transcribed by RNA polymerase-III and repress NANOG and OCT4 in differentiated cells. OCT4 and NANOG repression likely involves processing of Alu-derived transcripts through the miRNA machinery involving the Microprocessor and RISC. Consistently, stable AHR knockdown led to basal undifferentiation, impaired Alus transcription and blockade of OCT4 and NANOG repression. We suggest that transcripts produced from AHR-regulated Alu retrotransposons may control the expression of stemness genes OCT4 and NANOG during differentiation of carcinoma cells. The control of discrete Alu elements by specific transcription factors may have a dynamic role in genome regulation under physiological and diseased conditions. PMID:26883630

  20. Cardiac Ryanodine Receptor (Ryr2)-mediated Calcium Signals Specifically Promote Glucose Oxidation via Pyruvate Dehydrogenase.

    PubMed

    Bround, Michael J; Wambolt, Rich; Cen, Haoning; Asghari, Parisa; Albu, Razvan F; Han, Jun; McAfee, Donald; Pourrier, Marc; Scott, Nichollas E; Bohunek, Lubos; Kulpa, Jerzy E; Chen, S R Wayne; Fedida, David; Brownsey, Roger W; Borchers, Christoph H; Foster, Leonard J; Mayor, Thibault; Moore, Edwin D W; Allard, Michael F; Johnson, James D

    2016-11-04

    Cardiac ryanodine receptor (Ryr2) Ca(2+) release channels and cellular metabolism are both disrupted in heart disease. Recently, we demonstrated that total loss of Ryr2 leads to cardiomyocyte contractile dysfunction, arrhythmia, and reduced heart rate. Acute total Ryr2 ablation also impaired metabolism, but it was not clear whether this was a cause or consequence of heart failure. Previous in vitro studies revealed that Ca(2+) flux into the mitochondria helps pace oxidative metabolism, but there is limited in vivo evidence supporting this concept. Here, we studied heart-specific, inducible Ryr2 haploinsufficient (cRyr2Δ50) mice with a stable 50% reduction in Ryr2 protein. This manipulation decreased the amplitude and frequency of cytosolic and mitochondrial Ca(2+) signals in isolated cardiomyocytes, without changes in cardiomyocyte contraction. Remarkably, in the context of well preserved contractile function in perfused hearts, we observed decreased glucose oxidation, but not fat oxidation, with increased glycolysis. cRyr2Δ50 hearts exhibited hyperphosphorylation and inhibition of pyruvate dehydrogenase, the key Ca(2+)-sensitive gatekeeper to glucose oxidation. Metabolomic, proteomic, and transcriptomic analyses revealed additional functional networks associated with altered metabolism in this model. These results demonstrate that Ryr2 controls mitochondrial Ca(2+) dynamics and plays a specific, critical role in promoting glucose oxidation in cardiomyocytes. Our findings indicate that partial RYR2 loss is sufficient to cause metabolic abnormalities seen in heart disease.

  1. Urokinase Receptor Promotes Skin Tumor Formation by Preventing Epithelial Cell Activation of Notch1.

    PubMed

    Mazzieri, Roberta; Pietrogrande, Giovanni; Gerasi, Laura; Gandelli, Alessandro; Colombo, Piergiuseppe; Moi, Davide; Brombin, Chiara; Ambrosi, Alessandro; Danese, Silvio; Mignatti, Paolo; Blasi, Francesco; D'Alessio, Silvia

    2015-11-15

    The urokinase-type plasminogen activator receptor (uPAR) has a well-established role in cancer progression, but it has been little studied at earlier stages of cancer initiation. Here, we show that uPAR deficiency in the mouse dramatically reduces susceptibility to the classical two-stage protocol of inflammatory skin carcinogenesis. uPAR genetic deficiency decreased papilloma formation and accelerated keratinocyte differentiation, effects mediated by Notch1 hyperactivation. Notably, Notch1 inhibition in uPAR-deficient mice rescued their susceptibility to skin carcinogenesis. Clinically, we found that human differentiated keratoacanthomas expressed low levels of uPAR and high levels of activated Notch1, with opposite effects in proliferating tumors, confirming the relevance of the observations in mice. Furthermore, we found that TACE-dependent activation of Notch1 in basal kerantinocytes was modulated by uPAR. Mechanistically, uPAR sequestered TACE within lipid rafts to prevent Notch1 activation, thereby promoting cell proliferation and tumor formation. Given that uPAR signaling is nonessential for normal epidermal homeostasis, our results argue that uPAR may present a promising disease-specific target for preventing skin cancer development.

  2. IL-7 receptor blockade following T cell depletion promotes long-term allograft survival

    PubMed Central

    Mai, Hoa-Le; Boeffard, Françoise; Longis, Julie; Danger, Richard; Martinet, Bernard; Haspot, Fabienne; Vanhove, Bernard; Brouard, Sophie; Soulillou, Jean-Paul

    2014-01-01

    T cell depletion is commonly used in organ transplantation for immunosuppression; however, a restoration of T cell homeostasis following depletion leads to increased memory T cells, which may promote transplant rejection. The cytokine IL-7 is important for controlling lymphopoiesis under both normal and lymphopenic conditions. Here, we investigated whether blocking IL-7 signaling with a mAb that targets IL-7 receptor α (IL-7Rα) alone or following T cell depletion confers an advantage for allograft survival in murine transplant models. We found that IL-7R blockade alone induced indefinite pancreatic islet allograft survival if anti–IL-7R treatment was started 3 weeks before graft. IL-7R blockade following anti-CD4– and anti-CD8–mediated T cell depletion markedly prolonged skin allograft survival. Furthermore, IL-7 inhibition in combination with T cell depletion synergized with either CTLA-4Ig administration or suboptimal doses of tacrolimus to induce long-term skin graft acceptance in this stringent transplant model. Together, these therapies inhibited T cell reconstitution, decreased memory T cell numbers, increased the relative frequency of Tregs, and abrogated both cellular and humoral alloimmune responses. Our data suggest that IL-7R blockade following T cell depletion has potential as a robust, immunosuppressive therapy in transplantation. PMID:24569454

  3. Sigma 1 receptor regulates ERK activation and promotes survival of optic nerve head astrocytes

    PubMed Central

    Zhao, Jing; Mysona, Barbara A.; Wang, Jing; Gonsalvez, Graydon B.; Smith, Sylvia B.; Bollinger, Kathryn E.

    2017-01-01

    The sigma 1 receptor (S1R) is a unique transmembrane protein that has been shown to regulate neuronal differentiation and cellular survival. It is expressed within several cell types throughout the nervous system and visceral organs, including neurons and glia within the eye. S1R ligands are therapeutic targets for diseases ranging from neurodegenerative conditions to neoplastic disorders. However, effects of S1R activation and inhibition within glia cells are not well characterized. Within the eye, the astrocytes at the optic nerve head are crucial to the health and survival of the neurons that send visual information to the brain. In this study, we used the S1R-specific agonist, (+)-pentazocine, to evaluate S1R activation within optic nerve head-derived astrocytes (ONHAs). Treatment of ONHAs with (+)-pentazocine attenuated the level and duration of stress-induced ERK phosphorylation following oxidative stress exposure and promoted survival of ONHAs. These effects were specific to S1R activation because they were not observed in ONHAs that were depleted of S1R using siRNA-mediated knockdown. Collectively, our results suggest that S1R activation suppresses ERK1/2 phosphorylation and protects ONHAs from oxidative stress-induced death. PMID:28898265

  4. Structural Basis of Natural Promoter Recognition by a Unique Nuclear Receptor, HNF4[alpha

    SciTech Connect

    Lu, Peng; Rha, Geun Bae; Melikishvili, Manana; Wu, Guangteng; Adkins, Brandon C.; Fried, Michael G.; Chi, Young-In

    2010-11-09

    HNF4{alpha} (hepatocyte nuclear factor 4{alpha}) plays an essential role in the development and function of vertebrate organs, including hepatocytes and pancreatic {beta}-cells by regulating expression of multiple genes involved in organ development, nutrient transport, and diverse metabolic pathways. As such, HNF4{alpha} is a culprit gene product for a monogenic and dominantly inherited form of diabetes, known as maturity onset diabetes of the young (MODY). As a unique member of the nuclear receptor superfamily, HNF4{alpha} recognizes target genes containing two hexanucleotide direct repeat DNA-response elements separated by one base pair (DR1) by exclusively forming a cooperative homodimer. We describe here the 2.0 {angstrom} crystal structure of human HNF4{alpha} DNA binding domain in complex with a high affinity promoter element of another MODY gene, HNF1{alpha}, which reveals the molecular basis of unique target gene selection/recognition, DNA binding cooperativity, and dysfunction caused by diabetes-causing mutations. The predicted effects of MODY mutations have been tested by a set of biochemical and functional studies, which show that, in contrast to other MODY gene products, the subtle disruption of HNF4{alpha} molecular function can cause significant effects in afflicted MODY patients.

  5. G Protein-Coupled Receptor Kinase 2 Promotes Flaviviridae Entry and Replication

    PubMed Central

    Le Sommer, Caroline; Barrows, Nicholas J.; Bradrick, Shelton S.; Pearson, James L.; Garcia-Blanco, Mariano A.

    2012-01-01

    Flaviviruses cause a wide range of severe diseases ranging from encephalitis to hemorrhagic fever. Discovery of host factors that regulate the fate of flaviviruses in infected cells could provide insight into the molecular mechanisms of infection and therefore facilitate the development of anti-flaviviral drugs. We performed genome-scale siRNA screens to discover human host factors required for yellow fever virus (YFV) propagation. Using a 2×2 siRNA pool screening format and a duplicate of the screen, we identified a high confidence list of YFV host factors. To find commonalities between flaviviruses, these candidates were compared to host factors previously identified for West Nile virus (WNV) and dengue virus (DENV). This comparison highlighted a potential requirement for the G protein-coupled receptor kinase family, GRKs, for flaviviral infection. The YFV host candidate GRK2 (also known as ADRBK1) was validated both in siRNA-mediated knockdown HuH-7 cells and in GRK−/− mouse embryonic fibroblasts. Additionally, we showed that GRK2 was required for efficient propagation of DENV and Hepatitis C virus (HCV) indicating that GRK2 requirement is conserved throughout the Flaviviridae. Finally, we found that GRK2 participates in multiple distinct steps of the flavivirus life cycle by promoting both entry and RNA synthesis. Together, our findings identified GRK2 as a novel regulator of flavivirus infection and suggest that inhibition of GRK2 function may constitute a new approach for treatment of flavivirus associated diseases. PMID:23029581

  6. An endogenous tumour-promoting ligand of the human aryl hydrocarbon receptor.

    PubMed

    Opitz, Christiane A; Litzenburger, Ulrike M; Sahm, Felix; Ott, Martina; Tritschler, Isabel; Trump, Saskia; Schumacher, Theresa; Jestaedt, Leonie; Schrenk, Dieter; Weller, Michael; Jugold, Manfred; Guillemin, Gilles J; Miller, Christine L; Lutz, Christian; Radlwimmer, Bernhard; Lehmann, Irina; von Deimling, Andreas; Wick, Wolfgang; Platten, Michael

    2011-10-05

    Activation of the aryl hydrocarbon receptor (AHR) by environmental xenobiotic toxic chemicals, for instance 2,3,7,8-tetrachlorodibenzo-p-dioxin (dioxin), has been implicated in a variety of cellular processes such as embryogenesis, transformation, tumorigenesis and inflammation. But the identity of an endogenous ligand activating the AHR under physiological conditions in the absence of environmental toxic chemicals is still unknown. Here we identify the tryptophan (Trp) catabolite kynurenine (Kyn) as an endogenous ligand of the human AHR that is constitutively generated by human tumour cells via tryptophan-2,3-dioxygenase (TDO), a liver- and neuron-derived Trp-degrading enzyme not yet implicated in cancer biology. TDO-derived Kyn suppresses antitumour immune responses and promotes tumour-cell survival and motility through the AHR in an autocrine/paracrine fashion. The TDO-AHR pathway is active in human brain tumours and is associated with malignant progression and poor survival. Because Kyn is produced during cancer progression and inflammation in the local microenvironment in amounts sufficient for activating the human AHR, these results provide evidence for a previously unidentified pathophysiological function of the AHR with profound implications for cancer and immune biology.

  7. Elevated luteinizing hormone induces expression of its receptor and promotes steroidogenesis in the adrenal cortex

    PubMed Central

    Kero, Jukka; Poutanen, Matti; Zhang, Fu-Ping; Rahman, Nafis; McNicol, Anne Marie; Nilson, John H.; Keri, Ruth A.; Huhtaniemi, Ilpo T.

    2000-01-01

    Transgenic (TG) female mice expressing bLHβ-CTP (a chimeric protein derived from the β-subunit of bovine luteinizing hormone [LH] and a fragment of the β-subunit of human chorionic gonadotropin [hCG]) exhibit elevated serum LH, infertility, polycystic ovaries, and ovarian tumors. In humans, increased LH secretion also occurs in infertility and polycystic ovarian syndrome, often concomitant with adrenocortical dysfunction. We therefore investigated adrenal function in LH overexpressing bLHβ-CTP female mice. The size of their adrenals was increased by 80% with histological signs of cortical stimulation. Furthermore, adrenal steroid production was increased, with up to 14-fold elevated serum corticosterone. Primary adrenal cells from TG and control females responded similarly to ACTH stimulation, but, surprisingly, the TG adrenals responded to hCG with significantly increased cAMP, progesterone, and corticosterone production. LH receptor (LHR) expression and activity were also elevated in adrenals from female TG mice, but gonadectomized TG females showed no increase in corticosterone, suggesting that the dysfunctional ovaries of the intact TG females promote adrenocortical hyperfunction. We suggest that, in intact TG females, enhanced ovarian estrogen synthesis causes increased secretion of prolactin (PRL), which elevates LHR expression. Chronically elevated serum LH, augmented by enhanced PRL production, induces functional LHR expression in mouse adrenal cortex, leading to elevated, LH-dependent, corticosterone production. Thus, besides polycystic ovaries, the bLHβ-CTP mice provide a useful model for studying human disorders related to elevated LH secretion and adrenocortical hyperfunction. PMID:10712435

  8. Elevated luteinizing hormone induces expression of its receptor and promotes steroidogenesis in the adrenal cortex.

    PubMed

    Kero, J; Poutanen, M; Zhang, F P; Rahman, N; McNicol, A M; Nilson, J H; Keri, R A; Huhtaniemi, I T

    2000-03-01

    Transgenic (TG) female mice expressing bLHbeta-CTP (a chimeric protein derived from the beta-subunit of bovine luteinizing hormone [LH] and a fragment of the beta-subunit of human chorionic gonadotropin [hCG]) exhibit elevated serum LH, infertility, polycystic ovaries, and ovarian tumors. In humans, increased LH secretion also occurs in infertility and polycystic ovarian syndrome, often concomitant with adrenocortical dysfunction. We therefore investigated adrenal function in LH overexpressing bLHbeta-CTP female mice. The size of their adrenals was increased by 80% with histological signs of cortical stimulation. Furthermore, adrenal steroid production was increased, with up to 14-fold elevated serum corticosterone. Primary adrenal cells from TG and control females responded similarly to ACTH stimulation, but, surprisingly, the TG adrenals responded to hCG with significantly increased cAMP, progesterone, and corticosterone production. LH receptor (LHR) expression and activity were also elevated in adrenals from female TG mice, but gonadectomized TG females showed no increase in corticosterone, suggesting that the dysfunctional ovaries of the intact TG females promote adrenocortical hyperfunction. We suggest that, in intact TG females, enhanced ovarian estrogen synthesis causes increased secretion of prolactin (PRL), which elevates LHR expression. Chronically elevated serum LH, augmented by enhanced PRL production, induces functional LHR expression in mouse adrenal cortex, leading to elevated, LH-dependent, corticosterone production. Thus, besides polycystic ovaries, the bLHbeta-CTP mice provide a useful model for studying human disorders related to elevated LH secretion and adrenocortical hyperfunction.

  9. Activation of platelet-activating factor receptor exacerbates renal inflammation and promotes fibrosis.

    PubMed

    Correa-Costa, Matheus; Andrade-Oliveira, Vinicius; Braga, Tarcio T; Castoldi, Angela; Aguiar, Cristhiane F; Origassa, Clarice S T; Rodas, Andrea C D; Hiyane, Meire I; Malheiros, Denise M A C; Rios, Francisco J O; Jancar, Sonia; Câmara, Niels O S

    2014-04-01

    Platelet-activating factor (PAF) is a lipid mediator with important pro-inflammatory effects, being synthesized by several cell types including kidney cells. Although there is evidence of its involvement in acute renal dysfunction, its role in progressive kidney injury is not completely known. In the present study, we investigated the role of PAF receptor (PAFR) in an experimental model of chronic renal disease. Wild-type (WT) and PAFR knockout (KO) mice underwent unilateral ureter obstruction (UUO), and at kill time, urine and kidney tissue was collected. PAFR KO animals compared with WT mice present: (a) less renal dysfunction, evaluated by urine protein/creatinine ratio; (b) less fibrosis evaluated by collagen deposition, type I collagen, Lysyl Oxidase-1 (LOX-1) and transforming growth factor β (TGF-β) gene expression, and higher expression of bone morphogenetic protein 7 (BMP-7) (3.3-fold lower TGF-β/BMP-7 ratio); (c) downregulation of extracellular matrix (ECM) and adhesion molecule-related machinery genes; and (d) lower levels of pro-inflammatory cytokines. These indicate that PAFR engagement by PAF or PAF-like molecules generated during UUO potentiates renal dysfunction and fibrosis and might promote epithelial-to-mesenchymal transition (EMT). Also, early blockade of PAFR after UUO leads to a protective effect, with less fibrosis deposition. In conclusion, PAFR signaling contributes to a pro-inflammatory environment in the model of obstructive nephropathy, favoring the fibrotic process, which lately will generate renal dysfunction and progressive organ failure.

  10. Acetylation of androgen receptor by ARD1 promotes dissociation from HSP90 complex and prostate tumorigenesis

    PubMed Central

    Zhang, Guanyi; Qian, Chiping; Zhang, Haitao; Zabaleta, Jovanny; Liu, Wanguo

    2016-01-01

    Prostate cancer is an androgen receptor (AR)-driven disease and post-translational modification of AR is critical for AR activation. We previously reported that Arrest-defective protein 1 (ARD1) is an oncoprotein in prostate cancer. It acetylates and activates AR to promote prostate tumorigenesis. However, the ARD1-targeted residue within AR and the mechanisms of the acetylation event in prostate tumorigenesis remained unknown. In this study, we show that ARD1 acetylates AR at lysine 618 (K618) in vitro and in vivo. An AR construct with the charged lysine substitution by arginine (AR-618R) reduces RNA Pol II binding, AR transcriptional activity, prostate cancer cell growth, and xenograft tumor formation due to attenuation of AR nuclear translocation, whereas, construct mimicking neutral polar substitution acetylation at K618 by glutamine (AR-618Q) enhanced these effects beyond that of the wild-type AR. Mechanistically, ARD1 forms a ternary complex with AR and HSP90 in vitro and in vivo. Expression of ARD1 increases levels of AR acetylation and AR-HSP90 dissociation in a dose dependent manner. Moreover, the AR acetylation defective K618R mutant is unable to dissociate from HSP90 while the HSP90-dissociated AR is acetylated following ligand exposure. This work identifies a new mechanism for ligand-induced AR-HSP90 dissociation and AR activation. Targeting ARD1-mediated AR acetylation may be a potent intervention for AR-dependent prostate cancer therapy. PMID:27659526

  11. Sleep-promoting action of IIK7, a selective MT2 melatonin receptor agonist in the rat

    PubMed Central

    Fisher, Simon P.; Sugden, David

    2009-01-01

    Several novel melatonin receptor agonists, in addition to various formulations of melatonin itself, are either available or in development for the treatment of insomnia. Melatonin is thought to exert its effects principally through two high affinity, G-protein coupled receptors, MT1 and MT2, though it is not known which subtype is responsible for the sleep-promoting action. The present study used radiotelemetry to record EEG and EMG in un-restrained freely moving rats to monitor the sleep-wake behaviour and examined the acute sleep-promoting activity of an MT2 receptor subtype selective melatonin analog, IIK7. IIK7 is a full agonist at the MT2 receptor subtype but a partial agonist at the MT1 receptor and has ∼90-fold higher affinity for MT2 than MT1. Like melatonin, IIK7 (10 mg/kg i.p.) significantly reduced NREM sleep onset latency and transiently increased the time spent in NREM sleep, but did not alter REM sleep latency or the amount of REM sleep. An analysis of the EEG power spectrum showed no change in delta (1–4 Hz) or theta activity (5–8 Hz) following IIK7 administration. Core body temperature was slightly decreased (∼0.3 °C) by IIK7 compared to vehicle-treated rats. The acute and transient changes in the sleep-wake cycle mimic the changes seen with melatonin and suggest that its sleep-promoting activity is mediated by activation of the MT2 receptor subtype. PMID:19429170

  12. Sleep-promoting action of IIK7, a selective MT2 melatonin receptor agonist in the rat.

    PubMed

    Fisher, Simon P; Sugden, David

    2009-06-26

    Several novel melatonin receptor agonists, in addition to various formulations of melatonin itself, are either available or in development for the treatment of insomnia. Melatonin is thought to exert its effects principally through two high affinity, G-protein coupled receptors, MT1 and MT2, though it is not known which subtype is responsible for the sleep-promoting action. The present study used radiotelemetry to record EEG and EMG in un-restrained freely moving rats to monitor the sleep-wake behaviour and examined the acute sleep-promoting activity of an MT2 receptor subtype selective melatonin analog, IIK7. IIK7 is a full agonist at the MT2 receptor subtype but a partial agonist at the MT1 receptor and has approximately 90-fold higher affinity for MT2 than MT1. Like melatonin, IIK7 (10mg/kg i.p.) significantly reduced NREM sleep onset latency and transiently increased the time spent in NREM sleep, but did not alter REM sleep latency or the amount of REM sleep. An analysis of the EEG power spectrum showed no change in delta (1-4 Hz) or theta activity (5-8 Hz) following IIK7 administration. Core body temperature was slightly decreased ( approximately 0.3 degrees C) by IIK7 compared to vehicle-treated rats. The acute and transient changes in the sleep-wake cycle mimic the changes seen with melatonin and suggest that its sleep-promoting activity is mediated by activation of the MT2 receptor subtype.

  13. Considerations on Temperature, Longevity and Aging

    PubMed Central

    Conti, Bruno

    2008-01-01

    A modest reduction in body temperature prolongs longevity and possibly retards aging in both poikilotherm and homeotherm animals. Some of the possible mechanisms mediating these effects are considered here with respect to major aging models and theories. PMID:18425417

  14. Considerations on temperature, longevity and aging.

    PubMed

    Conti, B

    2008-06-01

    A modest reduction in body temperature prolongs longevity and may retard aging in both poikilotherm and homeotherm animals. Some of the possible mechanisms mediating these effects are considered here with respect to major aging models and theories.

  15. Prediction of C. elegans Longevity Genes by Human and Worm Longevity Networks

    PubMed Central

    de Magalhães, João Pedro; Ruvkun, Gary; Fraifeld, Vadim E.; Curran, Sean P.

    2012-01-01

    Intricate and interconnected pathways modulate longevity, but screens to identify the components of these pathways have not been saturating. Because biological processes are often executed by protein complexes and fine-tuned by regulatory factors, the first-order protein-protein interactors of known longevity genes are likely to participate in the regulation of longevity. Data-rich maps of protein interactions have been established for many cardinal organisms such as yeast, worms, and humans. We propose that these interaction maps could be mined for the identification of new putative regulators of longevity. For this purpose, we have constructed longevity networks in both humans and worms. We reasoned that the essential first-order interactors of known longevity-associated genes in these networks are more likely to have longevity phenotypes than randomly chosen genes. We have used C. elegans to determine whether post-developmental inactivation of these essential genes modulates lifespan. Our results suggest that the worm and human longevity networks are functionally relevant and possess a high predictive power for identifying new longevity regulators. PMID:23144747

  16. Body weight, health, and longevity.

    PubMed

    Simopoulos, A P; Van Itallie, T B

    1984-02-01

    In the United States, the weight associated with the greatest longevity tends to below the average weight of the population under consideration, if such weights are not associated with a history of significant medical impairment. Overweight persons tend to die sooner than average-weight persons, especially those who are overweight at younger ages. The effect of being overweight on mortality is delayed and may not be seen in short-term studies. Cigarette smoking is a potential confounder of the relationship between obesity and mortality. Studies on body weight, morbidity, and mortality must be interpreted with careful attention to the definitions of obesity or relative weight used, preexisting morbid conditions, the length of follow-up, and confounders in the analysis. The terminology of body weight standards should be defined more precisely and cited appropriately. An appropriate database relating body weight by sex, age, and possibly frame size to morbidity and mortality should be developed to permit the preparation of reference tables for defining the desirable range of body weight based on morbidity and mortality statistics.

  17. [Preventing dependency: the longevity challenge].

    PubMed

    Forette, Françoise

    2009-02-01

    Longevity can only be considered a privilege if the majority of the elderly population is active and in good health. In contrast to certain statistical interpretations, the HID study gives cause for optimism. It showed that only 7% of subjects aged 60 years and over suffer from dependency and, therefore, that 93% of the population remains independent. Of course, the rate of dependency increases with age, particularly in women and after 90 years of age. Dependency is mostly due to age-related diseases. The second cause is "frailty" and the third is inactivity, or more generally, lifestyle. All age-related diseases have modifiable risk factors and are thus accessible to prevention. Prevention must be started as soon as possible. It has been demonstrated that a mother's educational level influences her children's health in adulthood. It is never too late. The Hyvet study recently showed that the treatment of hypertension after 80 years of age is still able to significantly reduce the risk of death, stroke, heart failure and other cardiovascular complications. Inadequate disease management may also lead to avoidable dependency. This is the case of congestive heart failure and osteoporosis, which are not always treated in very old patients according to evidence-based principles. Another means of prevention is the detection and management of the frailty syndrome, which carries a measurable risk of loss of independence. In addition to these medical approaches, occupational activity involving strong cognitive stimulation has been shown to postpone the onset of cognitive impairment.

  18. Obesity, longevity, quality of life

    PubMed Central

    2010-01-01

    Previous investigations demonstrated that optimization of murine immunological reactivity in tissue culture required a sulfhydryl compound; the most effective being 2-mercaptoethanol (2-Me). Since these reports, 2-Me was found beneficial for both growth/function of other cell-types in vitro, including those of other species, and when fed orally, it impeded and/or reversed some in situ physiological changes associated with aging. More recently, thiol-containing compounds possessing oxidation-reduction potentials weaker than 2-Me were found to impart beneficial effects for many other, including human, diseases. Based on these effects, the research herein addressed the question: What consequences might dietary 2-Me impart on health and disease of mice other than those associated with aging? The main parameters monitored over the lifetime of individual animals exposed to dietary 10−3 M 2-Me in their drinking water were: quality of life (obesity and development of recumbent, emaciated and/or cachectic health, longevity, and appearance of tumors. Instead of anticipated toxic attributes, the following unique benefits were found: mean survival of a moderately-lived strain (A/J) was increased 40.8%, high-fat-diet obesity was curtailed in C57BL/10 mice, and a goal of aging intervention protocols, namely preventing loss of quality of life during aging (recumbent, emaciated and/or cachectic) was achieved. Various mechanisms are discussed as they pertain to these findings. PMID:21178502

  19. IRAF: Lessons for Project Longevity

    NASA Astrophysics Data System (ADS)

    Fitzpatrick, M.

    2012-09-01

    Although sometimes derided as a product of the 80's (or more generously, as a legacy system), the fact that IRAF remains a productive work environment for many astronomers today is a testament to one of its core design principles, portability. This idea has meaning beyond a survey of platforms in use at the peak of a project's active development; for true longevity, a project must be able to weather completely unimagined OS, hardware, data, staffing and political environments. A lack of attention to the broader issues of portability, or the true lifespan of a software system (e.g. archival science may extend for years beyond a given mission, upgraded or similar instruments may be developed that require the same reduction/analysis techniques, etc) might require costly new software development instead of simple code re-use. Additionally, one under-appreciated benefit to having a long history in the community is the trust that users have established in the science results produced by a particular system. However a software system evolves architecturally, preserving this trust (and by implication, the applications themselves) is the key to continued success. In this paper, we will discuss how the system architecture has allowed IRAF to navigate the many changes in computing since it was first released. It is hoped that the lessons learned can be adopted by software systems being built today so that they too can survive long enough to one day earn the distinction of being called a legacy system.

  20. MIF interacts with CXCR7 to promote receptor internalization, ERK1/2 and ZAP-70 signaling, and lymphocyte chemotaxis.

    PubMed

    Alampour-Rajabi, Setareh; El Bounkari, Omar; Rot, Antal; Müller-Newen, Gerhard; Bachelerie, Françoise; Gawaz, Meinrad; Weber, Christian; Schober, Andreas; Bernhagen, Jürgen

    2015-11-01

    Macrophage migration-inhibitory factor (MIF) is a pleiotropic cytokine with chemokine-like functions and is a mediator in numerous inflammatory conditions. Depending on the context, MIF signals through 1 or more of its receptors cluster of differentiation (CD)74, CXC-motif chemokine receptor (CXCR)2, and CXCR4. In addition, heteromeric receptor complexes have been identified. We characterized the atypical chemokine receptor CXCR7 as a novel receptor for MIF. MIF promoted human CXCR7 internalization up to 40%, peaking at 50-400 nM and 30 min, but CXCR7 internalization by MIF was not dependent on CXCR4. Yet, by coimmunoprecipitation, fluorescence microscopy, and a proximity ligation assay, CXCR7 was found to engage in MIF receptor complexes with CXCR4 and CD74, both after ectopic overexpression and in endogenous conditions in a human B-cell line. Receptor competition binding and coimmunoprecipitation studies combined with sulfo-SBED-biotin-transfer provided evidence for a direct interaction between MIF and CXCR7. Finally, we demonstrated MIF/CXCR7-mediated functional responses. Blockade of CXCR7 suppressed MIF-mediated ERK- and zeta-chain-associated protein kinase (ZAP)-70 activation (from 2.1- to 1.2-fold and from 2.5- to 1.6-fold, respectively) and fully abrogated primary murine B-cell chemotaxis triggered by MIF, but not by CXCL12. B cells from Cxcr7(-/-) mice exhibited an ablated transmigration response to MIF, indicating that CXCR7 is essential for MIF-promoted B-cell migration. Our findings provide biochemical and functional evidence that MIF is an alternative ligand of CXCR7 and suggest a functional role of the MIF-CXCR7 axis in B-lymphocyte migration.

  1. P2Y2 Receptor and EGFR Cooperate to Promote Prostate Cancer Cell Invasion via ERK1/2 Pathway

    PubMed Central

    Li, Wei-Hua; Qiu, Ying; Zhang, Hong-Quan; Tian, Xin-Xia; Fang, Wei-Gang

    2015-01-01

    As one member of G protein-coupled P2Y receptors, P2Y2 receptor can be equally activated by extracellular ATP and UTP. Our previous studies have proved that activation of P2Y2 receptor by extracellular ATP could promote prostate cancer cell invasion and metastasis in vitro and in vivo via regulating the expressions of some epithelial-mesenchymal transition/invasion-related genes (including IL-8, E-cadherin, Snail and Claudin-1), and the most significant change in expression of IL-8 was observed after P2Y2 receptor activation. However, the signaling pathway downstream of P2Y2 receptor and the role of IL-8 in P2Y2-mediated prostate cancer cell invasion remain unclear. Here, we found that extracellular ATP/UTP induced activation of EGFR and ERK1/2. After knockdown of P2Y2 receptor, the ATP -stimulated phosphorylation of EGFR and ERK1/2 was significantly suppressed. Further experiments showed that inactivation of EGFR and ERK1/2 attenuated ATP-induced invasion and migration, and suppressed ATP-mediated IL-8 production. In addition, knockdown of IL-8 inhibited ATP-mediated invasion and migration of prostate cancer cells. These findings suggest that P2Y2 receptor and EGFR cooperate to upregulate IL-8 production via ERK1/2 pathway, thereby promoting prostate cancer cell invasion and migration. Thus blocking of the P2Y2-EGFR-ERK1/2 pathway may provide effective therapeutic interventions for prostate cancer. PMID:26182292

  2. P2Y2 Receptor and EGFR Cooperate to Promote Prostate Cancer Cell Invasion via ERK1/2 Pathway.

    PubMed

    Li, Wei-Hua; Qiu, Ying; Zhang, Hong-Quan; Tian, Xin-Xia; Fang, Wei-Gang

    2015-01-01

    As one member of G protein-coupled P2Y receptors, P2Y2 receptor can be equally activated by extracellular ATP and UTP. Our previous studies have proved that activation of P2Y2 receptor by extracellular ATP could promote prostate cancer cell invasion and metastasis in vitro and in vivo via regulating the expressions of some epithelial-mesenchymal transition/invasion-related genes (including IL-8, E-cadherin, Snail and Claudin-1), and the most significant change in expression of IL-8 was observed after P2Y2 receptor activation. However, the signaling pathway downstream of P2Y2 receptor and the role of IL-8 in P2Y2-mediated prostate cancer cell invasion remain unclear. Here, we found that extracellular ATP/UTP induced activation of EGFR and ERK1/2. After knockdown of P2Y2 receptor, the ATP -stimulated phosphorylation of EGFR and ERK1/2 was significantly suppressed. Further experiments showed that inactivation of EGFR and ERK1/2 attenuated ATP-induced invasion and migration, and suppressed ATP-mediated IL-8 production. In addition, knockdown of IL-8 inhibited ATP-mediated invasion and migration of prostate cancer cells. These findings suggest that P2Y2 receptor and EGFR cooperate to upregulate IL-8 production via ERK1/2 pathway, thereby promoting prostate cancer cell invasion and migration. Thus blocking of the P2Y2-EGFR-ERK1/2 pathway may provide effective therapeutic interventions for prostate cancer.

  3. Deletion of G-protein-coupled receptor 55 promotes obesity by reducing physical activity

    USDA-ARS?s Scientific Manuscript database

    Cannabinoid receptor 1 (CB1) is the best-characterized cannabinoid receptor, and CB1 antagonists are used in clinical trials to treat obesity. Because of the wide range of CB1 functions, the side effects of CB1 antagonists pose serious concerns. G-protein-coupled receptor 55 (GPR55) is an atypical c...

  4. SynDIG1 promotes excitatory synaptogenesis independent of AMPA receptor trafficking and biophysical regulation.

    PubMed

    Lovero, Kathryn L; Blankenship, Sabine M; Shi, Yun; Nicoll, Roger A

    2013-01-01

    AMPA receptors-mediators of fast, excitatory transmission and synaptic plasticity in the brain-achieve great functional diversity through interaction with different auxiliary subunits, which alter both the trafficking and biophysical properties of these receptors. In the past several years an abundance of new AMPA receptor auxiliary subunits have been identified, adding astounding variety to the proteins known to directly bind and modulate AMPA receptors. SynDIG1 was recently identified as a novel AMPA receptor interacting protein that directly binds to the AMPA receptor subunit GluA2 in heterologous cells. Functionally, SynDIG1 was found to regulate the strength and density of AMPA receptor containing synapses in hippocampal neurons, though the way in which SynDIG1 exerts these effects remains unknown. Here, we aimed to determine if SynDIG1 acts as a traditional auxiliary subunit, directly regulating the function and localization of AMPA receptors in the rat hippocampus. We find that, unlike any of the previously characterized AMPA receptor auxiliary subunits, SynDIG1 expression does not impact AMPA receptor gating, pharmacology, or surface trafficking. Rather, we show that SynDIG1 regulates the number of functional excitatory synapses, altering both AMPA and NMDA receptor mediated transmission. Our findings suggest that SynDIG1 is not a typical auxiliary subunit to AMPA receptors, but instead is a protein critical to excitatory synaptogenesis.

  5. Associations between STR autosomal markers and longevity.

    PubMed

    Bediaga, N G; Aznar, J M; Elcoroaristizabal, X; Albóniga, O; Gómez-Busto, F; Artaza Artabe, I; Rocandio, Ana; de Pancorbo, M M

    2015-10-01

    Life span is a complex and multifactorial trait, which is shaped by genetic, epigenetic, environmental, and stochastic factors. The possibility that highly hypervariable short tandem repeats (STRs) associated with longevity has been largely explored by comparing the genotypic pools of long lived and younger individuals, but results so far have been contradictory. In view of these contradictory findings, the present study aims to investigate whether HUMTHO1 and HUMCSF1PO STRs, previously associated with longevity, exert a role as a modulator of life expectancy, as well as to assess the extent to which other autosomal STR markers are associated with human longevity in population from northern Spain. To that end, 21 autosomal microsatellite markers have been studied in 304 nonagenarian individuals (more than 90 years old) and 516 younger controls of European descent. Our results do not confirm the association found in previous studies between longevity and THO1 and CSF1PO loci. However, significant association between longevity and autosomal STR markers D12S391, D22S1045, and DS441 was observed. Even more, when we compared allelic frequency distribution of the 21 STR markers between cases and controls, we found that 6 out of the 21 STRs studied showed different allelic frequencies, thus suggesting that the genomic portrait of the human longevity is far complex and probably shaped by a high number of genomic loci.

  6. Histone H4 Lys 20 methyltransferase SET8 promotes androgen receptor-mediated transcription activation in prostate cancer

    SciTech Connect

    Yao, Lushuai; Li, Yanyan; Du, Fengxia; Han, Xiao; Li, Xiaohua; Niu, Yuanjie; Ren, Shancheng; Sun, Yingli

    2014-07-18

    Highlights: • Dihydrotestosterone stimulates H4K20me1 enrichment at the PSA promoter. • SET8 promotes AR-mediated transcription activation. • SET8 interacts with AR and promotes cell proliferation. - Abstract: Histone methylation status in different lysine residues has an important role in transcription regulation. The effect of H4K20 monomethylation (H4K20me1) on androgen receptor (AR)-mediated gene transcription remains unclear. Here we show that AR agonist stimulates the enrichment of H4K20me1 and SET8 at the promoter of AR target gene PSA in an AR dependent manner. Furthermore, SET8 is crucial for the transcription activation of PSA. Co-immunoprecipitation analyses demonstrate that SET8 interacts with AR. Therefore, we conclude that SET8 is involved in AR-mediated transcription activation, possibly through its interaction with AR and H4K20me1 modification.

  7. A novel signaling pathway of tissue kallikrein in promoting keratinocyte migration: Activation of proteinase-activated receptor 1 and epidermal growth factor receptor

    SciTech Connect

    Gao, Lin; Chao, Lee; Chao, Julie

    2010-02-01

    Biological functions of tissue kallikrein (TK, KLK1) are mainly mediated by kinin generation and subsequent kinin B2 receptor activation. In this study, we investigated the potential role of TK and its signaling pathways in cultured human keratinocyte migration and in a rat skin wound healing model. Herein, we show that TK promoted cell migration and proliferation in a concentration- and time-dependent manner. Inactive TK or kinin had no significant effect on cell migration. Interestingly, cell migration induced by active TK was not blocked by icatibant or L-NAME, indicating an event independent of kinin B2 receptor and nitric oxide formation. TK's stimulatory effect on cell migration was inhibited by small interfering RNA for proteinase-activated receptor 1 (PAR{sub 1}), and by PAR{sub 1} inhibitor. TK-induced migration was associated with increased phosphorylation of epidermal growth factor receptor (EGFR) and extracellular signal-regulated kinase (ERK), which was blocked by inhibition of protein kinase C (PKC), Src, EGFR and ERK. TK-induced cell migration and EGFR phosphorylation were blocked by metalloproteinase (MMP) inhibitor, heparin, and antibodies against EGFR external domain, heparin-binding EGF-like growth factor (HB-EGF) and amphiregulin (AR). Local application of TK promoted skin wound healing in rats, whereas icatibant and EGFR inhibitor blocked TK's effect. Skin wound healing was further delayed by aprotinin and neutralizing TK antibody. This study demonstrates a novel role of TK in skin wound healing and uncovers new signaling pathways mediated by TK in promoting keratinocyte migration through activation of the PAR{sub 1}-PKC-Src-MMP pathway and HB-EGF/AR shedding-dependent EGFR transactivation.

  8. PPAR-α and glucocorticoid receptor synergize to promote erythroid progenitor self-renewal.

    PubMed

    Lee, Hsiang-Ying; Gao, Xiaofei; Barrasa, M Inmaculada; Li, Hu; Elmes, Russell R; Peters, Luanne L; Lodish, Harvey F

    2015-06-25

    Many acute and chronic anaemias, including haemolysis, sepsis and genetic bone marrow failure diseases such as Diamond-Blackfan anaemia, are not treatable with erythropoietin (Epo), because the colony-forming unit erythroid progenitors (CFU-Es) that respond to Epo are either too few in number or are not sensitive enough to Epo to maintain sufficient red blood cell production. Treatment of these anaemias requires a drug that acts at an earlier stage of red cell formation and enhances the formation of Epo-sensitive CFU-E progenitors. Recently, we showed that glucocorticoids specifically stimulate self-renewal of an early erythroid progenitor, burst-forming unit erythroid (BFU-E), and increase the production of terminally differentiated erythroid cells. Here we show that activation of the peroxisome proliferator-activated receptor α (PPAR-α) by the PPAR-α agonists GW7647 and fenofibrate synergizes with the glucocorticoid receptor (GR) to promote BFU-E self-renewal. Over time these agonists greatly increase production of mature red blood cells in cultures of both mouse fetal liver BFU-Es and mobilized human adult CD34(+) peripheral blood progenitors, with a new and effective culture system being used for the human cells that generates normal enucleated reticulocytes. Although Ppara(-/-) mice show no haematological difference from wild-type mice in both normal and phenylhydrazine (PHZ)-induced stress erythropoiesis, PPAR-α agonists facilitate recovery of wild-type but not Ppara(-/-) mice from PHZ-induced acute haemolytic anaemia. We also show that PPAR-α alleviates anaemia in a mouse model of chronic anaemia. Finally, both in control and corticosteroid-treated BFU-E cells, PPAR-α co-occupies many chromatin sites with GR; when activated by PPAR-α agonists, additional PPAR-α is recruited to GR-adjacent sites and presumably facilitates GR-dependent BFU-E self-renewal. Our discovery of the role of PPAR-α agonists in stimulating self-renewal of early erythroid

  9. Progesterone receptor membrane component 1 deficiency attenuates growth while promoting chemosensitivity of human endometrial xenograft tumors

    PubMed Central

    Friel, Anne M.; Zhang, Ling; Pru, Cindy A.; Clark, Nicole C.; McCallum, Melissa L.; Blok, Leen J.; Shioda, Toshi; Peluso, John J.; Rueda, Bo R.; Pru, James K.

    2014-01-01

    Endometrial cancer is the leading gynecologic cancer in women in the United States with 52,630 women predicted to be diagnosed with the disease in 2014. The objective of this study was to determine if progesterone (P4) receptor membrane component 1 (PGRMC1) influenced endometrial cancer cell viability in response to chemotherapy in vitro and in vivo. A Jentiviral-based shRNA knockdown approach was used to generate stable PGRMC1-intact and PGRMC1-deplete Ishikawa endometrial cancer cell lines that also lacked expression of the classical progesterone receptor (PGR). Progesterone treatment inhibited mitosis of PGRMC1-intact, but not PGRMC1-deplete cells, suggesting that PGRMC1 mediates the anti-mitotic actions of P4.To test the hypothesis that PGRMC1 attenuates chemotherapy-induced apoptosis, PGRMC1-intact and PGRMC1-deplete cells were treated in vitro with vehicle, P4 (1 μM), doxorubicin (Dox. 2 μg/ml). or P4 + Dox for 48 h. Doxorubicin treatment of PGRMC1-intact cells resulted in a significant increase in cell death; however, co-treatment with P4 significantly attenuated Dex-induced cell death. This response to P4 was lost in PGRMC1-deplete cells. To extend these observations in vivo, a xenograft model was employed where PGRMC1-intact and PGRMC1-deplete endometrial tumors were generated following subcutaneous and intraperitonea l inoculation of immunocompromised NOD/SCIO and nude mice, respectively. Tumors derived from PGRMC1-deplete cells grew slower than tumors from PGRMC1-intact cells. Mice harboring endometrial tumors were then given three treatments of vehicle (1:1 cremophor EL: ethanol + 0.9% saline) or chemotherapy [Paclitaxel (15 mg/kg, i.p.) followed after an interval of 30 minutes by CARBOplatin (SO mg/kg)] at five day intervals. In response to chemotherapy, tumor volume decreased approximately four-fold more in PGRMC1-deplete tumors when compared with PGRMC1 intact control tumors, suggesting that PGRMC1 promotes tumor cell viability during

  10. PPARα and glucocorticoid receptor synergize to promote erythroid progenitor self-renewal

    PubMed Central

    Lee, Hsiang-Ying; Gao, Xiaofei; Barrasa, M. Inmaculada; Li, Hu; Elmes, Russell R.; Peters, Luanne L.; Lodish, Harvey F.

    2015-01-01

    Summary Many acute and chronic anemias, including hemolysis, sepsis, and genetic bone marrow failure diseases such as Diamond-Blackfan Anemia (DBA), are not treatable with erythropoietin (Epo), because the colony-forming unit erythroid progenitors (CFU-Es) that respond to Epo are either too few in number or are not sensitive enough to Epo to maintain sufficient red blood cell production 1,2,3–5,6,7,8,9. Treatment of these anemias requires a drug that acts at an earlier stage of red cell formation and enhances the formation of Epo-sensitive CFU-E progenitors. Recently we showed that glucocorticoids specifically stimulate self-renewal of the early erythroid progenitor, the burst-forming unit erythroid (BFU-E), and increase the production of terminally differentiated erythroid cells 10,11. Here we demonstrate that activation of the peroxisome proliferator-activated receptor alpha (PPARα) by PPARα agonists, GW7647 and fenofibrate, synergizes with glucocorticoid receptor (GR) to promote BFU-E self-renewal. Over time these agonists greatly increase production of mature red blood cells in cultures both of mouse fetal liver BFU-Es and of mobilized human adult CD34+ peripheral blood progenitors, the latter employing a new and effective culture system that generates normal enucleated reticulocytes. While PPARα−/− mice show no hematological difference from wild-type mice in both normal and phenylhydrazine (PHZ)-induced stress erythropoiesis, PPARα agonists facilitate recovery of wild-type mice, but not PPARα−/− mice, from PHZ-induced acute hemolytic anemia. We also showed that PPARα alleviates anemia in a mouse model of chronic anemia. Finally, both in control and corticosteroid-treated BFU-E cells PPARα co-occupies many chromatin sites with GR; when activated by PPARα agonists, additional PPARα is recruited to GR-adjacent sites and presumably facilitates GR-dependent BFU-E self-renewal. Our discovery of the role of PPARα agonists in stimulating self

  11. The lifespan-promoting effect of acetic acid and Reishi polysaccharide.

    PubMed

    Chuang, Ming-Hong; Chiou, Shyh-Horng; Huang, Chun-Hao; Yang, Wen-Bin; Wong, Chi-Huey

    2009-11-15

    Using Caenorhabditis elegans as a model organism, various natural substances and commercial health-food supplements were screened to evaluate their effects on longevity. Among the substances tested, acetic acid and Reishi polysaccharide fraction 3 (RF3) were shown to increase the expression of the lifespan and longevity-related transcription factor DAF-16 in C. elegans. We have shown that RF3 activates DAF-16 expression via TIR-1 receptor and MAPK pathway whereas acetic acid inhibits the trans-membrane receptor DAF-2 of the insulin/IGF-1 pathway to indirectly activate DAF-16 expression. In addition, a mixture of acetic acid and RF3 possesses a combined effect 30-40% greater than either substance used alone. A proteomic analysis of C. elegans using 2-DE and LC-MS/MS was then carried out, and 15 differentially expressed proteins involved in the lifespan-promoting activity were identified.

  12. Lin28 promotes growth of prostate cancer cells and activates the androgen receptor.

    PubMed

    Tummala, Ramakumar; Nadiminty, Nagalakshmi; Lou, Wei; Zhu, Yezi; Gandour-Edwards, Regina; Chen, Hong-Wu; Evans, Christopher P; Gao, Allen C

    2013-07-01

    Prostate cancer (CaP) progresses to a castration-resistant state assisted by multifold molecular changes, most of which involve activation of the androgen receptor (AR). Having previously demonstrated the importance of the Lin28/let-7/Myc axis in CaP, we tested the hypothesis that Lin28 is overexpressed in CaP and that it activates AR and promotes growth of CaP cells. We analyzed human clinical CaP samples for the expression of Lin28 by quantitative real-time RT-PCR, Western blot analysis, and IHC. Growth characteristics of CaP cell lines transiently and stably expressing Lin28 were examined. The clonogenic ability of CaP cells expressing Lin28 was determined by colony formation and soft agar assays. Increase in expression of AR and subsequent increase in transcription of AR-target genes were analyzed by quantitative real-time RT-PCR, luciferase assays, and ELISA. LNCaP cells stably expressing Lin28 were injected into nude mice, and tumorigenesis was monitored. We found that Lin28 is overexpressed in clinical CaP compared to benign prostates. Overexpression of Lin28 enhanced, while down-regulation reduced, growth of CaP cells. Lin28 enhanced the ability of CaP cells to form colonies in anchorage-dependent and anchorage-independent conditions. LNCaP cells stably expressing Lin28 exhibited significantly higher tumorigenic ability in vivo. Lin28 induced expression of the AR and its target genes such as PSA and NKX3.1. Collectively, our findings demonstrate a novel role for Lin28 in CaP development and activation of the AR axis. Copyright © 2013 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

  13. Lin28 Promotes Growth of Prostate Cancer Cells and Activates the Androgen Receptor

    PubMed Central

    Tummala, Ramakumar; Nadiminty, Nagalakshmi; Lou, Wei; Zhu, Yezi; Gandour-Edwards, Regina; Chen, Hong-Wu; Evans, Christopher P.; Gao, Allen C.

    2014-01-01

    Prostate cancer (CaP) progresses to a castration-resistant state assisted by multifold molecular changes, most of which involve activation of the androgen receptor (AR). Having previously demonstrated the importance of the Lin28/let-7/Myc axis in CaP, we tested the hypothesis that Lin28 is overexpressed in CaP and that it activates AR and promotes growth of CaP cells. We analyzed human clinical CaP samples for the expression of Lin28 by quantitative real-time RT-PCR, Western blot analysis, and IHC. Growth characteristics of CaP cell lines transiently and stably expressing Lin28 were examined. The clonogenic ability of CaP cells expressing Lin28 was determined by colony formation and soft agar assays. Increase in expression of AR and subsequent increase in transcription of AR-target genes were analyzed by quantitative real-time RT-PCR, luciferase assays, and ELISA. LNCaP cells stably expressing Lin28 were injected into nude mice, and tumorigenesis was monitored. We found that Lin28 is overexpressed in clinical CaP compared to benign prostates. Overexpression of Lin28 enhanced, while down-regulation reduced, growth of CaP cells. Lin28 enhanced the ability of CaP cells to form colonies in anchorage-dependent and anchorage-independent conditions. LNCaP cells stably expressing Lin28 exhibited significantly higher tumorigenic ability in vivo. Lin28 induced expression of the AR and its target genes such as PSA and NKX3.1. Collectively, our findings demonstrate a novel role for Lin28 in CaP development and activation of the AR axis. PMID:23790802

  14. Toll-like receptor 4 promotes fibrosis in bleomycin-induced lung injury in mice.

    PubMed

    Li, X X; Jiang, D Y; Huang, X X; Guo, S L; Yuan, W; Dai, H P

    2015-12-21

    The specific role of Toll-like receptor 4 (TLR4) in bleomycin-induced lung fibrosis of mice, a model of human idiopathic pulmonary fibrosis, has not been characterized. We injected bleomycin intratracheally into TLR4 knockout (TLR4(-/-)) and wild-type (WT) mice. Twenty-one days after injection, mice were sacrificed and their lungs were harvested for pathological, hydroxyproline, mRNA expression, and collagen I analyses. Body weight changes and mortality were observed. Light microscopy showed that lung fibrosis was minimal in TLR4(-/-) compared to that in WT mice on day 21 after bleomycin instillation. The Ashcroft score was significantly lower in TLR4(-/-) than in WT mice (3.667 ± 0.730 vs 4.945 ± 0.880, P < 0.05). Hydroxyproline content was significantly lower in TLR4(-/-) than in WT mice on day 21 after bleomycin injection (0.281 ± 0.022 vs 0.371 ± 0.047, P < 0.05). Compared to WT mice, bleomycin-treated TLR4(-/-) mice expressed significantly lower type I collagen mRNA levels (mesenchymal marker; 11.069 ± 2.627 vs 4.589 ± 1.440, P < 0.05). Collagen I was significantly lower in TLR4(-/-) than in WT mice (0.838 ± 0.352 vs 2.427 ± 0.551, P < 0.05). Bleomycin-treated TLR4(-/-) mice had a significantly lower mortality rate on day 21 than WT mice (33 vs 75%, P < 0.05). Body weight reduction was lower in TLR4(-/-) mice than in WT mice; this difference was not statistically significant (-3.735 ± 5.276 vs -6.698 ± 3.218, P > 0.05). Thus, bleomycin-induced pulmonary fibrosis is TLR4-dependent and TLR4 promoted fibrosis in bleomycin-challenged mice.

  15. The p75 neurotrophin receptor promotes Aβ-induced neuritic dystrophy in vitro and in vivo

    PubMed Central

    Knowles, Juliet; Rajadas, Jayakumar; Nguyen, Thuy-Vi V.; Yang, Tao; LeMieux, Melburne C.; Griend, Lilith Vander; Ishikawa, Chihiro; Massa, Stephen M.; Wyss-Coray, Tony; Longo, Frank M.

    2009-01-01

    Oligomeric forms of amyloid-β(1–42) (Aβ) are thought to play a causal role in Alzheimer’s disease (AD) and the p75 neurotrophin receptor (p75NTR) has been implicated in Aβ-induced neurodegeneration. To further define the functions of p75NTR in AD, we examined the interaction of oligomeric Aβ with p75NTR, and the effects of that interaction on neurite integrity in neuron cultures and in a chronic AD mouse model. Atomic force microscopy was used to ascertain the aggregated state of Aβ, and fluorescence resonance energy transfer (FRET) analysis revealed that Aβ oligomers interact with the extracellular domain of p75NTR. In vitro studies of Aβ-induced death in neuron cultures isolated from wildtype and p75NTR −/− mice, in which the p75NTR extracellular domain is deleted, showed reduced sensitivity of mutant cells to Aβ-induced cell death. Interestingly, Aβ-induced neuritic dystrophy and activation of c-Jun, a known mediator of Aβ-induced deleterious signaling, were completely prevented in p75NTR −/− neuron cultures. Thy1-hAPPLond/Swe X p75NTR−/− mice exhibited significantly diminished hippocampal neuritic dystrophy and complete reversal of basal forebrain cholinergic neurite degeneration relative to those expressing wild type p75NTR. Aβ levels were not affected, suggesting that removal of p75NTR extracellular domain reduced the ability of excess Aβ to promote neuritic degeneration. These findings indicate that while p75NTR likely does not mediate all Aβ effects, it does play a significant role in enabling Aβ-induced neurodegeneration in vitro and in vivo, establishing p75NTR as an important therapeutic target for AD. PMID:19710315

  16. Functional Mineralocorticoid Receptors in Human Vascular Endothelial Cells Regulate ICAM-1 Expression and Promote Leukocyte Adhesion

    PubMed Central

    Caprio, Massimiliano; Newfell, Brenna G.; la Sala, Andrea; Baur, Wendy; Fabbri, Andrea; Rosano, Giuseppe; Mendelsohn, Michael E.; Jaffe, Iris Z.

    2008-01-01

    In clinical trials, aldosterone antagonists decrease cardiovascular mortality and ischemia by unknown mechanisms. The steroid hormone aldosterone acts by binding to the mineralocorticoid receptor (MR), a ligand-activated transcription factor. In humans, aldosterone causes MR-dependent endothelial cell (EC) dysfunction and in animal models, aldosterone increases vascular macrophage infiltration and atherosclerosis. MR antagonists inhibit these effects without changing blood pressure, suggesting a direct role for vascular MR in EC function and atherosclerosis. Whether human vascular EC express functional MR is not known. Here we show that human coronary artery and aortic EC express MR mRNA and protein and that EC MR mediates aldosterone-dependent gene transcription. Human EC also express the enzyme 11-beta hydroxysteroid dehydrogenase-2(11βHSD2) and inhibition of 11βHSD2 in aortic EC enhances gene transactivation by cortisol, supporting that EC 11βHSD2 is functional. Furthermore, aldosterone stimulates transcription of the proatherogenic leukocyte-EC adhesion molecule Intercellular Adhesion Molecule-1(ICAM1) gene and protein expression on human coronary artery EC, an effect inhibited by the MR antagonist spironolactone and by MR knock-down with siRNA. Cell adhesion assays demonstrate that aldosterone promotes leukocyte-EC adhesion, an effect that is inhibited by spironolactone and ICAM1 blocking antibody, supporting that aldosterone induction of EC ICAM1 surface expression via MR mediates leukocyte-EC adhesion. These data show that aldosterone activates endogenous EC MR and proatherogenic gene expression in clinically important human EC. These studies describe a novel mechanism by which aldosterone may influence ischemic cardiovascular events and support a new explanation for the decrease in ischemic events in patients treated with aldosterone antagonists. PMID:18467630

  17. Enkephalin release promotes homeostatic increases in constitutively active mu opioid receptors during morphine withdrawal.

    PubMed

    Shoblock, J R; Maidment, N T

    2007-11-09

    We previously demonstrated that naloxone administration produces a robust conditioned place aversion (CPA) in opiate-naive rodents by blocking the action of enkephalins at mu opioid receptors (MORs). The aversive response to naloxone is potentiated by prior exposure to morphine. Morphine-induced MOR constitutive activity is hypothesized to underlie this enhanced effect of naloxone, an inverse agonist at the MOR. We sought additional evidence for the role of constitutively active MORs in this morphine-induced enhancement using the pro-enkephalin knockout (pENK(-)/(-)) mouse, which is devoid of naloxone CPA in the morphine-naive state. Naloxone, but not the neutral antagonist, 6-beta-naloxol, produced CPA and physical withdrawal signs in pENK(-)/(-) mice when administered 2 h, but not 20 h, after morphine administration. Naloxone-precipitated physical withdrawal signs were attenuated in the pENK(-)/(-) mice relative to wild-type (WT) animals. In both WT and pENK(-)/(-) mice, naloxone-precipitated withdrawal jumping was greatest when naloxone was administered 2 h after morphine treatment and diminished at 3 h, in agreement with previous estimates of the time course for morphine-induced MOR constitutive activity in vitro. However, naloxone regained an ability to precipitate physical withdrawal in the WT, but not the pENK(-)/(-) mice when administered 4.5 h after morphine administration. Taken together, the data suggest that a compensatory increase in enkephalin release during spontaneous morphine withdrawal promotes a second period of MOR constitutive activity in WT mice that is responsible for the enhanced naloxone aversion observed in such animals even when naloxone is administered 20 h after morphine. The endogenous enkephalin system and MOR constitutive activity may therefore play vital roles in hedonic homeostatic dysregulation following chronic opiate administration.

  18. Promoter-dependent activity on androgen receptor N-terminal domain mutations in androgen insensitivity syndrome.

    PubMed

    Tadokoro-Cuccaro, Rieko; Davies, John; Mongan, Nigel P; Bunch, Trevor; Brown, Rosalind S; Audi, Laura; Watt, Kate; McEwan, Iain J; Hughes, Ieuan A

    2014-01-01

    Androgen receptor (AR) mutations are associated with androgen insensitivity syndrome (AIS). Missense mutations identified in the AR-N-terminal domain (AR-NTD) are rare, and clinical phenotypes are typically mild. We investigated 7 missense mutations and 2 insertion/deletions located in the AR-NTD. This study aimed to elucidate the pathogenic role of AR-NTD mutants in AIS and to use this knowledge to further define AR-NTD function. AR-NTD mutations (Q120E, A159T, G216R, N235K, G248V, L272F, and P380R) were introduced into AR-expression plasmids. Stably expressing cell lines were established for del57L and ins58L. Transactivation was measured using luciferase reporter constructs under the control of GRE and Pem promoters. Intrinsic fluorescence spectroscopy and partial proteolysis studies were performed for mutations which showed reduced activities by using a purified AR-AF1 protein. Pem-luciferase reporter activation was reduced for A159T, N235K, and G248V but not the GRE-luciferase reporter. Protein structure analysis detected no significant change in the AR-AF1 region for these mutations. Reduced cellular expression and transactivation activity were observed for ins58L. The mutations Q120E, G216R, L272F, P380R, and del57L showed small or no detectable changes in function. Thus, clinical and experimental analyses have identified novel AR-signalling defects associated with mutations in the structurally disordered AR-NTD domain in patients with AIS. © 2014 S. Karger AG, Basel.

  19. Vascular Endothelial Growth Factor Receptor-2 Promotes the Development of the Lymphatic Vasculature

    PubMed Central

    Dellinger, Michael T.; Meadows, Stryder M.; Wynne, Katherine; Cleaver, Ondine; Brekken, Rolf A.

    2013-01-01

    Vascular endothelial growth factor receptor 2 (VEGFR2) is highly expressed by lymphatic endothelial cells and has been shown to stimulate lymphangiogenesis in adult mice. However, the role VEGFR2 serves in the development of the lymphatic vascular system has not been defined. Here we use the Cre-lox system to show that the proper development of the lymphatic vasculature requires VEGFR2 expression by lymphatic endothelium. We show that Lyve-1wt/Cre;Vegfr2flox/flox mice possess significantly fewer dermal lymphatic vessels than Vegfr2flox/flox mice. Although Lyve-1wt/Cre;Vegfr2flox/flox mice exhibit lymphatic hypoplasia, the lymphatic network is functional and contains all of the key features of a normal lymphatic network (initial lymphatic vessels and valved collecting vessels surrounded by smooth muscle cells (SMCs)). We also show that Lyve-1Cre mice display robust Cre activity in macrophages and in blood vessels in the yolk sac, liver and lung. This activity dramatically impairs the development of blood vessels in these tissues in Lyve-1wt/Cre;Vegfr2flox/flox embryos, most of which die after embryonic day14.5. Lastly, we show that inactivation of Vegfr2 in the myeloid lineage does not affect the development of the lymphatic vasculature. Therefore, the abnormal lymphatic phenotype of Lyve-1wt/Cre;Vegfr2flox/flox mice is due to the deletion of Vegfr2 in the lymphatic vasculature not macrophages. Together, this work demonstrates that VEGFR2 directly promotes the expansion of the lymphatic network and further defines the molecular mechanisms controlling the development of the lymphatic vascular system. PMID:24023956

  20. Shear stress causes nuclear localization of endothelial glucocorticoid receptor and expression from the GRE promoter.

    PubMed

    Ji, Julie Y; Jing, Huiyan; Diamond, Scott L

    2003-02-21

    We tested the hypothesis that steady laminar shear stress activates the glucocorticoid receptor (GR) and its transcriptional signaling pathway in an effort to investigate the potential involvement of GR in shear stress-induced antiatherosclerosis actions in the vasculature. In both bovine aortic endothelial cells (BAECs) and NIH3T3 cells expressing GFP-GR chimeric protein, wall shear stress of 10 or 25 dynes/cm2 caused a marked nuclear localization of GFP-GR within 1 hour to an extent comparable to induction with 25 micromol/L dexamethasone. The shear mediated nuclear localization of GFP-GR was significantly reduced by 25 micromol/L of the MEK1 inhibitor (PD098059) or the PI 3-kinase inhibitor (LY294002). Also, Western blots demonstrated translocation of endogenous GR into nucleus of sheared BAECs. Promoter construct studies using glucocorticoid response element (GRE)-driven expression of secreted alkaline phosphatase (SEAP) indicated that BAECs exposed to shear stress of 10 and 25 dynes/cm2 for 8 hours produced >9-fold more SEAP (n=6; P<0.005) than control cells, a level comparable to that observed with dexamethasone. Shear stress enhanced SEAP expression at 6 hours was reduced 50% (n=5; P<0.005) by MEK1/2 or PI 3-kinase inhibitors, but not by the NO inhibitor, L-NAME. Finally, in human internal mammary artery, endothelial GR is found to be highly nuclear localized. We report a new shear responsive transcriptional element, GRE. The finding that hemodynamic forces can be as potent as high dose glucocorticoid steroid in activating GR and GRE-regulated expression correlates with the atheroprotective responses of endothelial cells to unidirectional arterial shear stress.

  1. Aryl hydrocarbon receptor inhibition promotes hematolymphoid development from human pluripotent stem cells.

    PubMed

    Angelos, Mathew G; Ruh, Paige N; Webber, Beau R; Blum, Robert H; Ryan, Caitlin D; Bendzick, Laura; Shim, Seonhui; Yingst, Ashley M; Tufa, Dejene M; Verneris, Michael R; Kaufman, Dan S

    2017-06-29

    The aryl hydrocarbon receptor (AHR) plays an important physiological role in hematopoiesis. AHR is highly expressed in hematopoietic stem and progenitor cells (HSPCs) and inhibition of AHR results in a marked expansion of human umbilical cord blood-derived HSPCs following cytokine stimulation. It is unknown whether AHR also contributes earlier in human hematopoietic development. To model hematopoiesis, human embryonic stem cells (hESCs) were allowed to differentiate in defined conditions in the presence of the AHR antagonist StemReginin-1 (SR-1) or the AHR agonist 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). We demonstrate a significant increase in CD34(+)CD31(+) hematoendothelial cells in SR-1-treated hESCs, as well as a twofold expansion of CD34(+)CD45(+) hematopoietic progenitor cells. Hematopoietic progenitor cells were also significantly increased by SR-1 as quantified by standard hematopoietic colony-forming assays. Using a clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9)-engineered hESC-RUNX1c-tdTomato reporter cell line with AHR deletion, we further demonstrate a marked enhancement of hematopoietic differentiation relative to wild-type hESCs. We also evaluated whether AHR antagonism could promote innate lymphoid cell differentiation from hESCs. SR-1 increased conventional natural killer (cNK) cell differentiation, whereas TCDD treatment blocked cNK development and supported group 3 innate lymphoid cell (ILC3) differentiation. Collectively, these results demonstrate that AHR regulates early human hematolymphoid cell development and may be targeted to enhance production of specific cell populations derived from human pluripotent stem cells. © 2017 by The American Society of Hematology.

  2. Androgen Receptor Promotes Ligand-Independent Prostate Cancer Progression through c-Myc Upregulation

    PubMed Central

    Gao, Lina; Schwartzman, Jacob; Gibbs, Angela; Lisac, Robert; Kleinschmidt, Richard; Wilmot, Beth; Bottomly, Daniel; Coleman, Ilsa; Nelson, Peter; McWeeney, Shannon; Alumkal, Joshi

    2013-01-01

    The androgen receptor (AR) is the principal therapeutic target in prostate cancer. For the past 70 years, androgen deprivation therapy (ADT) has been the major therapeutic focus. However, some patients do not benefit, and those tumors that do initially respond to ADT eventually progress. One recently described mechanism of such an effect is growth and survival-promoting effects of the AR that are exerted independently of the AR ligands, testosterone and dihydrotestosterone. However, specific ligand-independent AR target genes that account for this effect were not well characterized. We show here that c-Myc, which is a key mediator of ligand-independent prostate cancer growth, is a key ligand-independent AR target gene. Using microarray analysis, we found that c-Myc and AR expression levels strongly correlated with each other in tumors from patients with castration-resistant prostate cancer (CRPC) progressing despite ADT. We confirmed that AR directly regulates c-Myc transcription in a ligand-independent manner, that AR and c-Myc suppression reduces ligand-independent prostate cancer cell growth, and that ectopic expression of c-Myc attenuates the anti-growth effects of AR suppression. Importantly, treatment with the bromodomain inhibitor JQ1 suppressed c-Myc function and suppressed ligand-independent prostate cancer cell survival. Our results define a new link between two critical proteins in prostate cancer – AR and c-Myc – and demonstrate the potential of AR and c-Myc-directed therapies to improve prostate cancer control. PMID:23704919

  3. Neural protein gamma-synuclein interacting with androgen receptor promotes human prostate cancer progression

    PubMed Central

    2012-01-01

    Background Gamma-synuclein (SNCG) has previously been demonstrated to be significantly correlated with metastatic malignancies; however, in-depth investigation of SNCG in prostate cancer is still lacking. In the present study, we evaluated the role of SNCG in prostate cancer progression and explored the underlying mechanisms. Methods First, alteration of SNCG expression in LNCaP cell line to test the ability of SNCG on cellular properties in vitro and vivo whenever exposing with androgen or not. Subsequently, the Dual-luciferase reporter assays were performed to evaluate whether the role of SNCG in LNCaP is through AR signaling. Last, the association between SNCG and prostate cancer progression was assessed immunohistochemically using a series of human prostate tissues. Results Silencing SNCG by siRNA in LNCaP cells contributes to the inhibition of cellular proliferation, the induction of cell-cycle arrest at the G1 phase, the suppression of cellular migration and invasion in vitro, as well as the decrease of tumor growth in vivo with the notable exception of castrated mice. Subsequently, mechanistic studies indicated that SNCG is a novel androgen receptor (AR) coactivator. It interacts with AR and promotes prostate cancer cellular growth and proliferation by activating AR transcription in an androgen-dependent manner. Finally, immunohistochemical analysis revealed that SNCG was almost undetectable in benign or androgen-independent tissues prostate lesions. The high expression of SNCG is correlated with peripheral and lymph node invasion. Conclusions Our data suggest that SNCG may serve as a biomarker for predicting human prostate cancer progression and metastasis. It also may become as a novel target for biomedical therapy in advanced prostate cancer. PMID:23231703

  4. Insulin Receptor Substrate-4 Binds to Slingshot-1 Phosphatase and Promotes Cofilin Dephosphorylation*

    PubMed Central

    Homma, Yuta; Kanno, Shin-ichiro; Sasaki, Kazutaka; Nishita, Michiru; Yasui, Akira; Asano, Tomoichiro; Ohashi, Kazumasa; Mizuno, Kensaku

    2014-01-01

    Cofilin plays an essential role in cell migration and morphogenesis by enhancing actin filament dynamics via its actin filament-severing activity. Slingshot-1 (SSH1) is a protein phosphatase that plays a crucial role in regulating actin dynamics by dephosphorylating and reactivating cofilin. In this study, we identified insulin receptor substrate (IRS)-4 as a novel SSH1-binding protein. Co-precipitation assays revealed the direct endogenous binding of IRS4 to SSH1. IRS4, but not IRS1 or IRS2, was bound to SSH1. IRS4 was bound to SSH1 mainly through the unique region (amino acids 335–400) adjacent to the C terminus of the phosphotyrosine-binding domain of IRS4. The N-terminal A, B, and phosphatase domains of SSH1 were bound to IRS4 independently. Whereas in vitro phosphatase assays revealed that IRS4 does not directly affect the cofilin phosphatase activity of SSH1, knockdown of IRS4 increased cofilin phosphorylation in cultured cells. Knockdown of IRS4 decreased phosphatidylinositol 3-kinase (PI3K) activity, and treatment with an inhibitor of PI3K increased cofilin phosphorylation. Akt preferentially phosphorylated SSH1 at Thr-826, but expression of a non-phosphorylatable T826A mutant of SSH1 did not affect insulin-induced cofilin dephosphorylation, and an inhibitor of Akt did not increase cofilin phosphorylation. These results suggest that IRS4 promotes cofilin dephosphorylation through sequential activation of PI3K and SSH1 but not through Akt. In addition, IRS4 co-localized with SSH1 in F-actin-rich membrane protrusions in insulin-stimulated cells, which suggests that the association of IRS4 with SSH1 contributes to localized activation of cofilin in membrane protrusions. PMID:25100728

  5. Vascular endothelial growth factor receptor-2 promotes the development of the lymphatic vasculature.

    PubMed

    Dellinger, Michael T; Meadows, Stryder M; Wynne, Katherine; Cleaver, Ondine; Brekken, Rolf A

    2013-01-01

    Vascular endothelial growth factor receptor 2 (VEGFR2) is highly expressed by lymphatic endothelial cells and has been shown to stimulate lymphangiogenesis in adult mice. However, the role VEGFR2 serves in the development of the lymphatic vascular system has not been defined. Here we use the Cre-lox system to show that the proper development of the lymphatic vasculature requires VEGFR2 expression by lymphatic endothelium. We show that Lyve-1(wt/Cre);Vegfr2(flox/flox) mice possess significantly fewer dermal lymphatic vessels than Vegfr2(flox/flox) mice. Although Lyve-1(wt/Cre);Vegfr2(flox/flox) mice exhibit lymphatic hypoplasia, the lymphatic network is functional and contains all of the key features of a normal lymphatic network (initial lymphatic vessels and valved collecting vessels surrounded by smooth muscle cells (SMCs)). We also show that Lyve-1(Cre) mice display robust Cre activity in macrophages and in blood vessels in the yolk sac, liver and lung. This activity dramatically impairs the development of blood vessels in these tissues in Lyve-1(wt/Cre);Vegfr2(flox/flox) embryos, most of which die after embryonic day14.5. Lastly, we show that inactivation of Vegfr2 in the myeloid lineage does not affect the development of the lymphatic vasculature. Therefore, the abnormal lymphatic phenotype of Lyve-1(wt/Cre);Vegfr2(flox/flox) mice is due to the deletion of Vegfr2 in the lymphatic vasculature not macrophages. Together, this work demonstrates that VEGFR2 directly promotes the expansion of the lymphatic network and further defines the molecular mechanisms controlling the development of the lymphatic vascular system.

  6. Chemokine receptor CXCR6-dependent hepatic NK T Cell accumulation promotes inflammation and liver fibrosis.

    PubMed

    Wehr, Alexander; Baeck, Christer; Heymann, Felix; Niemietz, Patricia Maria; Hammerich, Linda; Martin, Christian; Zimmermann, Henning W; Pack, Oliver; Gassler, Nikolaus; Hittatiya, Kanishka; Ludwig, Andreas; Luedde, Tom; Trautwein, Christian; Tacke, Frank

    2013-05-15

    Chronic liver injury characteristically results in hepatic inflammation, which represents a prerequisite for organ fibrosis. Although NKT cells are abundantly present in liver and involved in hepatic inflammation, molecular mechanisms of their recruitment in liver fibrosis remained elusive. We hypothesized that chemokine receptor CXCR6 and its ligand CXCL16 control NKT cell migration and functionality in liver fibrosis. In patients with chronic liver diseases (n = 58), CXCR6 and CXCL16 expression was intrahepatically upregulated compared with controls. In murine liver, Cxcl16 was strongly expressed by endothelium and macrophages, whereas lymphocyte populations (NKT, NK, CD4 T, CD8 T cells) expressed CXCR6. Intravital two-photon microscopy imaging of Cxcr6(+/gfp) and Cxcr6(gfp/gfp) mice and chemotaxis studies in vitro revealed that CXCR6 specifically controls hepatic NKT cell accumulation during the early response upon experimental liver damage. Hepatic invariant NKT cells expressed distinct proinflammatory cytokines including IFN-γ and IL-4 upon injury. CXCR6-deficient mice were protected from liver fibrosis progression in two independent experimental models. Macrophage infiltration and protein levels of inflammatory cytokines IFN-γ, TNF-α, and IL-4 were also reduced in fibrotic livers of Cxcr6(-/-) mice, corroborating that hepatic NKT cells provide essential cytokine signals perpetuating hepatic inflammation and fibrogenesis. Adoptive transfer of NKT cells, but not CD4 T cells, isolated from wild type livers restored hepatic fibrosis in Cxcr6(-/-) mice upon experimental steatohepatitis. Our results demonstrate that hepatic NKT cells accumulate CXCR6-dependent early upon injury, thereby accentuating the inflammatory response in the liver and promoting hepatic fibrogenesis. Interfering with CXCR6/CXCL16 might therefore bear therapeutic potential in liver fibrosis.

  7. MicroRNA-297 promotes cardiomyocyte hypertrophy via targeting sigma-1 receptor.

    PubMed

    Bao, Qinxue; Zhao, Mingyue; Chen, Li; Wang, Yu; Wu, Siyuan; Wu, Wenchao; Liu, Xiaojing

    2017-04-15

    Sigma-1 receptor (Sig-1R) is a ligand-regulated endoplasmic reticulum (ER) chaperone involved in cardiac hypertrophy, but it is not known whether Sig-1R is regulated by microRNAs (miRNAs). According to bioinformatic analysis, miR-297 was suggested as a potential target miRNA for Sig-1R. Therefore, we verified whether miR-297 could target Sig-1R and investigated the possible mechanisms underlying the role of miR-297 in cardiac hypertrophy. Bioinformatic analysis combined with laboratory experiments, including quantitative RT-PCR, Western blotting, and luciferase assay, were performed to identify the target miRNA of Sig-1R. Transverse aortic constriction (TAC) model and neonatal rat cardiomyocytes (NCMs) stimulated with angiotensin II (AngII) were used to explore the relationship between miR-297 and Sig-1R. Additionally, the function of miR-297 in cardiomyocyte hypertrophy and ER stress/unfolded protein response (UPR) signaling pathway was investigated by transfecting miR-297 mimics/inhibitor. miR-297 levels were increased in both TAC-induced hypertrophic heart tissue and AngII-induced cardiomyocyte hypertrophy. Up-regulation of miR-297 by specific mimics exacerbated AngII-induced cardiomyocyte hypertrophy, whereas inhibition of miR-297 suppressed the process. During cardiomyocyte hypertrophy, Sig-1R expression, which was negatively regulated by miR-297 by directly targeting its 3'untranslated region (UTR), was decreased. Furthermore, attenuation of miR-297 inhibited the activation of X-box binding protein 1 (Xbp1) and activating transcriptional factor 4 (ATF4) signaling pathways in NCMs. Our data demonstrate that miR-297 promotes cardiomyocyte hypertrophy by inhibiting the expression of Sig-1R and activation of ER stress signaling, which provides a novel interpretation for cardiac hypertrophy. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Fibroblast growth factor receptor 4 promotes progression and correlates to poor prognosis in cholangiocarcinoma

    SciTech Connect

    Xu, Yun-Fei; Yang, Xiao-Qing; Lu, Xiao-Fei; Guo, Sen; Liu, Yi; Iqbal, Mohammad; Ning, Shang-Lei; Yang, Hui; Suo, Ning; Chen, Yu-Xin

    2014-03-28

    Highlights: • FGFR4 is significantly related with N stage in IHCC, with T stage and TNM stage in PHCC. • FGFR4 is an independent prognostic factor in IHCC and PHCC. • FGFR4 promotes proliferation, invasion and EMT in cholangiocarinoma cell lines. • Inhibitor AP24354 can decrease proliferation, invasion and induce apoptosis of CCA. - Abstract: Fibroblast growth factor receptor 4 (FGFR4) is related to poor prognosis of several cancers, but the correlation between FGFR4 expression and cholangiocarcinoma (CCA) has not been well elucidated. We investigated the expression of FGFR4 in 83 intrahepatic cholangiocarcinomas (IHCCs), 75 perihilar cholangiocarcinomas (PHCCs) and 41 distal cholangiocarcinomas (DCCs) by immunohistochemistry (IHC), and subsequently evaluated association of FGFR4 with clinicopathologic parameters and survival rate. The rate of FGFR4 higher expression was 61.4% (51/83) in IHCCs, 53.3% (40/75) in PHCCs and 56.1% (23/41) in DCCs. FGFR4 expression was significantly related to poor prognosis of IHCC (P = 0.002) and PHCC (P = 0.019) with univariate analysis, and also identified as an independent prognostic factor in IHCC (P = 0.045) and PHCC (P = 0.049) with multivariate analysis. Additionally, with functional assays in vitro, we found FGFR4 can induce proliferation, invasion and epithelial–mesenchymal transition (EMT) of CCA cell lines with FGF19 stimulation. Moreover, FGFR4 inhibitor AP24354 can suppress proliferation, invasion and induce apoptosis of CCA cells. In conclusion, FGFR4 expression can be identified as a significant independent prognostic biomarker of IHCC and PHCC. FGFR4 played a pivotal role in proliferation, invasion and EMT of CCA. FGFR4 inhibitor can suppress proliferation, invasion and induce apoptosis of CCA, indicating that FGFR4 may act as a potential therapeutic target.

  9. Specific epidermal growth factor receptor autophosphorylation sites promote mouse colon epithelial cell chemotaxis and restitution.

    PubMed

    Yamaoka, Toshimitsu; Frey, Mark R; Dise, Rebecca S; Bernard, Jessica K; Polk, D Brent

    2011-08-01

    Upon ligand binding, epidermal growth factor (EGF) receptor (R) autophosphorylates on COOH-terminal tyrosines, generating docking sites for signaling partners that stimulate proliferation, restitution, and chemotaxis. Specificity for individual EGFR tyrosines in cellular responses has been hypothesized but not well documented. Here we tested the requirement for particular tyrosines, and associated downstream pathways, in mouse colon epithelial cell chemotactic migration. We compared these requirements to those for the phenotypically distinct restitution (wound healing) migration. Wild-type, Y992/1173F, Y1045F, Y1068F, and Y1086F EGFR constructs were expressed in EGFR(-/-) cells; EGF-induced chemotaxis or restitution were determined by Boyden chamber or modified scratch wound assay, respectively. Pharmacological inhibitors of p38, phospholipase C (PLC), Src, MEK, JNK/SAPK, phosphatidylinositol 3-kinase (PI 3-kinase), and protein kinase C (PKC) were used to block EGF-stimulated signaling. Pathway activation was determined by immunoblot analysis. Unlike wild-type EGFR, Y992/1173F and Y1086F EGFR did not stimulate colon epithelial cell chemotaxis toward EGF; Y1045F and Y1068F EGFR partially stimulated chemotaxis. Only wild-type EGFR promoted colonocyte restitution. Inhibition of p38, PLC, and Src, or Grb2 knockdown, blocked chemotaxis; JNK, PI 3-kinase, and PKC inhibitors or c-Cbl knockdown blocked restitution but not chemotaxis. All four EGFR mutants stimulated downstream signaling in response to EGF, but Y992/1173F EGFR was partially defective in PLCγ activation whereas both Y1068F and Y1086F EGFR failed to activate Src. We conclude that specific EGFR tyrosines play key roles in determining cellular responses to ligand. Chemotaxis and restitution, which have different migration phenotypes and physiological consequences, have overlapping but not identical EGFR signaling requirements.

  10. The HIV coat protein gp120 promotes forward trafficking and surface clustering of NMDA receptors in membrane microdomains

    PubMed Central

    Xu, Hangxiu; Bae, Mihyun; Tovar-y-Romo, Luis B.; Patel, Neha; Bandaru, Veera Venkata Ratnam; Pomerantz, Daniel; Steiner, Joseph; Haughey, Norman J.

    2011-01-01

    Infection by the Human immunodeficiency virus (HIV) can result in debilitating neurological syndromes collectively known as HIV associated neurocognitive disorders (HAND). While the HIV coat protein gp120 has been identified as a potent neurotoxin that enhances NMDA receptor function, the exact mechanisms for effect are not known. Here we provide evidence that gp120 activates two separate signaling pathways that converge to enhance NMDA-evoked calcium flux by clustering NMDA receptors in modified membrane microdomains. HIV gp120 enlarged, and stabilized the structure of lipid rafts on neuronal dendrites by mechanisms that involved a redox-regulated translocation of a sphingomyelin hydrolase (neutral sphingomyelinase-2; nSMase2) to the plasma membrane. A concurrent pathway was activated that enhanced the forward traffic of NMDA receptors by promoting a PKA-dependent phopshorylation of the NR1 C-terminal serine 897 (that masks an ER retention signal), followed by a PKC-dependent phosphorylation of serine 896 (important for surface expression). NMDA receptors were preferentially targeted to synapses, and clustered in modified membrane microdomains. In these conditions, NMDA receptors were unable to laterally disperse, and did not internalize, even in response to strong agonist induction. Focal NMDA-evoked calcium bursts were enhanced three-fold in these regions. Inhibiting membrane modification or NR1 phosphorylation prevented gp120 from enhancing the surface localization and clustering of NMDA receptors, while disrupting the structure of membrane microdomains restored the ability of NMDA receptors to disperse and internalize following gp120. These findings demonstrate that gp120 contributes to synaptic dysfunction in the setting of HIV-infection by interfering with the traffic of NMDA receptors. PMID:22114277

  11. Cross-talk between lysophosphatidic acid receptor 1 and tropomyosin receptor kinase A promotes lung epithelial cell migration.

    PubMed

    Nan, Ling; Wei, Jianxin; Jacko, Anastasia M; Culley, Miranda K; Zhao, Jing; Natarajan, Viswanathan; Ma, Haichun; Zhao, Yutong

    2016-02-01

    Lysophosphatidic acid (LPA) is a bioactive lysophospholipid, which plays a crucial role in the regulation of cell proliferation, migration, and differentiation. LPA exerts its biological effects mainly through binding to cell-surface LPA receptors (LPA1-6), which belong to the G protein-coupled receptor (GPCR) family. Recent studies suggest that cross-talk between receptor tyrosine kinases (RTKs) and GPCRs modulates GPCRs-mediated signaling. Tropomyosin receptor kinase A (TrkA) is a RTK, which mediates nerve growth factor (NGF)-induced biological functions including cell migration in neuronal and non-neuronal cells. Here, we show LPA1 transactivation of TrkA in murine lung epithelial cells (MLE12). LPA induced tyrosine phosphorylation of TrkA in both time- and dose-dependent manners. Down-regulation of LPA1 by siRNA transfection attenuated LPA-induced phosphorylation of TrkA, suggesting a cross-talk between LPA1 and TrkA. To investigate the molecular regulation of the cross-talk, we focused on the interaction between LPA1 and TrkA. We found that LPA induced interaction between LPA1 and TrkA. The LPA1/TrkA complex was localized on the plasma membrane and in the cytoplasm. The C-terminus of LPA1 was identified as the binding site for TrkA. Inhibition of TrkA attenuated LPA-induced phosphorylation of TrkA and LPA1 internalization, as well as lung epithelial cell migration. These studies provide a molecular mechanism for the transactivation of TrkA by LPA, and suggest that the cross-talk between LPA1 and TrkA regulates LPA-induced receptor internalization and lung epithelial cell migration. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. The Kronos longevity research institute.

    PubMed

    Harman, S Mitchell

    2003-05-01

    The Kronos Longevity Research Institute (KLRI), founded in Jan., 2000, is a Phoenix-based not-for-profit institution conducting clinical translational research aimed at early detection and prevention of age-related diseases and slowing or reversing the aging process. KLRI also provides education in biomedical gerontology for regional and national professional and lay communities. KLRI is privately funded, mainly by the Aurora Foundation. S. Mitchell Harman, M.D., Ph.D., founding Director and President is board-certified in internal medicine and endocrinology and a former section chief and acting clinical director of the National Institute on Aging, NIH, with an international reputation as a leader in the field of hormones and aging. Other professional staff are: a Clinical Director, Director of Exercise Sciences, Senior Scientist, and Clinical Study Coordinator. KLRI's facility includes a clinical study center (CSC), an exercise study center (ESC), and a molecular laboratory. Current research focuses on relationships among aging, endocrine function, oxidative stress, and sarcopenia. All research projects are pre-reviewed by KLRI's Scientific Advisory Board, a distinguished group of biomedical investigators. KLRI sponsors a series of bimonthly seminars in Phoenix and an annual two-day national symposium, with talks on biomedical gerontology presented by world-renowned experts. The institute has plans to double faculty, staff, and research activities by 2006, which will require new sources of funding. The aging demography of the first half of the century will make KLRI's research increasingly relevant to the population of the U.S. and the world.

  13. Cargo binding promotes KDEL receptor clustering at the mammalian cell surface

    PubMed Central

    Becker, Björn; Shaebani, M. Reza; Rammo, Domenik; Bubel, Tobias; Santen, Ludger; Schmitt, Manfred J.

    2016-01-01

    Transmembrane receptor clustering is a ubiquitous phenomenon in pro- and eukaryotic cells to physically sense receptor/ligand interactions and subsequently translate an exogenous signal into a cellular response. Despite that receptor cluster formation has been described for a wide variety of receptors, ranging from chemotactic receptors in bacteria to growth factor and neurotransmitter receptors in mammalian cells, a mechanistic understanding of the underlying molecular processes is still puzzling. In an attempt to fill this gap we followed a combined experimental and theoretical approach by dissecting and modulating cargo binding, internalization and cellular response mediated by KDEL receptors (KDELRs) at the mammalian cell surface after interaction with a model cargo/ligand. Using a fluorescent variant of ricin toxin A chain as KDELR-ligand (eGFP-RTAH/KDEL), we demonstrate that cargo binding induces dose-dependent receptor cluster formation at and subsequent internalization from the membrane which is associated and counteracted by anterograde and microtubule-assisted receptor transport to preferred docking sites at the plasma membrane. By means of analytical arguments and extensive numerical simulations we show that cargo-synchronized receptor transport from and to the membrane is causative for KDELR/cargo cluster formation at the mammalian cell surface. PMID:27353000

  14. Pirenzepine Promotes the Dimerization of Muscarinic M1 Receptors through a Three-step Binding Process*

    PubMed Central

    Ilien, Brigitte; Glasser, Nicole; Clamme, Jean-Pierre; Didier, Pascal; Piemont, Etienne; Chinnappan, Raja; Daval, Sandrine B.; Galzi, Jean-Luc; Mely, Yves

    2009-01-01

    Ligand binding to G protein-coupled receptors is a complex process that involves sequential receptor conformational changes, ligand translocation, and possibly ligand-induced receptor oligomerization. Binding events at muscarinic acetylcholine receptors are usually interpreted from radioligand binding studies in terms of two-step ligand-induced receptor isomerization. We report here, using a combination of fluorescence approaches, on the molecular mechanisms for Bodipy-pirenzepine binding to enhanced green fluorescent protein (EGFP)-fused muscarinic M1 receptors in living cells. Real time monitoring, under steady-state conditions, of the strong fluorescence energy transfer signal elicited by this interaction permitted a fine kinetic description of the binding process. Time-resolved fluorescence measurements allowed us to identify discrete EGFP lifetime species and to follow their redistribution upon ligand binding. Fluorescence correlation spectroscopy, with EGFP brightness analysis, showed that EGFP-fused muscarinic M1 receptors predominate as monomers in the absence of ligand and dimerize upon pirenzepine binding. Finally, all these experimental data could be quantitatively reconciled into a three-step mechanism, with four identified receptor conformational states. Fast ligand binding to a peripheral receptor site initiates a sequence of conformational changes that allows the ligand to access to inner regions of the protein and drives ligand-receptor complexes toward a high affinity dimeric state. PMID:19451648

  15. Pirenzepine promotes the dimerization of muscarinic M1 receptors through a three-step binding process.

    PubMed

    Ilien, Brigitte; Glasser, Nicole; Clamme, Jean-Pierre; Didier, Pascal; Piemont, Etienne; Chinnappan, Raja; Daval, Sandrine B; Galzi, Jean-Luc; Mely, Yves

    2009-07-17

    Ligand binding to G protein-coupled receptors is a complex process that involves sequential receptor conformational changes, ligand translocation, and possibly ligand-induced receptor oligomerization. Binding events at muscarinic acetylcholine receptors are usually interpreted from radioligand binding studies in terms of two-step ligand-induced receptor isomerization. We report here, using a combination of fluorescence approaches, on the molecular mechanisms for Bodipy-pirenzepine binding to enhanced green fluorescent protein (EGFP)-fused muscarinic M1 receptors in living cells. Real time monitoring, under steady-state conditions, of the strong fluorescence energy transfer signal elicited by this interaction permitted a fine kinetic description of the binding process. Time-resolved fluorescence measurements allowed us to identify discrete EGFP lifetime species and to follow their redistribution upon ligand binding. Fluorescence correlation spectroscopy, with EGFP brightness analysis, showed that EGFP-fused muscarinic M1 receptors predominate as monomers in the absence of ligand and dimerize upon pirenzepine binding. Finally, all these experimental data could be quantitatively reconciled into a three-step mechanism, with four identified receptor conformational states. Fast ligand binding to a peripheral receptor site initiates a sequence of conformational changes that allows the ligand to access to inner regions of the protein and drives ligand-receptor complexes toward a high affinity dimeric state.

  16. Cargo binding promotes KDEL receptor clustering at the mammalian cell surface

    NASA Astrophysics Data System (ADS)

    Becker, Björn; Shaebani, M. Reza; Rammo, Domenik; Bubel, Tobias; Santen, Ludger; Schmitt, Manfred J.

    2016-06-01

    Transmembrane receptor clustering is a ubiquitous phenomenon in pro- and eukaryotic cells to physically sense receptor/ligand interactions and subsequently translate an exogenous signal into a cellular response. Despite that receptor cluster formation has been described for a wide variety of receptors, ranging from chemotactic receptors in bacteria to growth factor and neurotransmitter receptors in mammalian cells, a mechanistic understanding of the underlying molecular processes is still puzzling. In an attempt to fill this gap we followed a combined experimental and theoretical approach by dissecting and modulating cargo binding, internalization and cellular response mediated by KDEL receptors (KDELRs) at the mammalian cell surface after interaction with a model cargo/ligand. Using a fluorescent variant of ricin toxin A chain as KDELR-ligand (eGFP-RTAH/KDEL), we demonstrate that cargo binding induces dose-dependent receptor cluster formation at and subsequent internalization from the membrane which is associated and counteracted by anterograde and microtubule-assisted receptor transport to preferred docking sites at the plasma membrane. By means of analytical arguments and extensive numerical simulations we show that cargo-synchronized receptor transport from and to the membrane is causative for KDELR/cargo cluster formation at the mammalian cell surface.

  17. Cloning the promoter for transforming growth factor-beta type III receptor. Basal and conditional expression in fetal rat osteoblasts

    NASA Technical Reports Server (NTRS)

    Ji, C.; Chen, Y.; McCarthy, T. L.; Centrella, M.

    1999-01-01

    Transforming growth factor-beta binds to three high affinity cell surface molecules that directly or indirectly regulate its biological effects. The type III receptor (TRIII) is a proteoglycan that lacks significant intracellular signaling or enzymatic motifs but may facilitate transforming growth factor-beta binding to other receptors, stabilize multimeric receptor complexes, or segregate growth factor from activating receptors. Because various agents or events that regulate osteoblast function rapidly modulate TRIII expression, we cloned the 5' region of the rat TRIII gene to assess possible control elements. DNA fragments from this region directed high reporter gene expression in osteoblasts. Sequencing showed no consensus TATA or CCAAT boxes, whereas several nuclear factors binding sequences within the 3' region of the promoter co-mapped with multiple transcription initiation sites, DNase I footprints, gel mobility shift analysis, or loss of activity by deletion or mutation. An upstream enhancer was evident 5' proximal to nucleotide -979, and a silencer region occurred between nucleotides -2014 and -2194. Glucocorticoid sensitivity mapped between nucleotides -687 and -253, whereas bone morphogenetic protein 2 sensitivity co-mapped within the silencer region. Thus, the TRIII promoter contains cooperative basal elements and dispersed growth factor- and hormone-sensitive regulatory regions that can control TRIII expression by osteoblasts.

  18. B cell IFN-γ receptor signaling promotes autoimmune germinal centers via cell-intrinsic induction of BCL-6

    PubMed Central

    Jackson, Shaun W.; Jacobs, Holly M.; Arkatkar, Tanvi; Dam, Elizabeth M.; Scharping, Nicole E.; Kolhatkar, Nikita S.; Hou, Baidong; Buckner, Jane H.

    2016-01-01

    Dysregulated germinal center (GC) responses are implicated in the pathogenesis of human autoimmune diseases, including systemic lupus erythematosus (SLE). Although both type 1 and type 2 interferons (IFNs) are involved in lupus pathogenesis, their respective impacts on the establishment of autoimmune GCs has not been addressed. In this study, using a chimeric model of B cell-driven autoimmunity, we demonstrate that B cell type 1 IFN receptor signals accelerate, but are not required for, lupus development. In contrast, B cells functioning as antigen-presenting cells initiate CD4+ T cell activation and IFN-γ production, and strikingly, B cell–intrinsic deletion of the IFN-γ receptor (IFN-γR) abrogates autoimmune GCs, class-switched autoantibodies (auto-Abs), and systemic autoimmunity. Mechanistically, although IFN-γR signals increase B cell T-bet expression, B cell–intrinsic deletion of T-bet exerts an isolated impact on class-switch recombination to pathogenic auto-Ab subclasses without impacting GC development. Rather, in both mouse and human B cells, IFN-γ synergized with B cell receptor, toll-like receptor, and/or CD40 activation signals to promote cell-intrinsic expression of the GC master transcription factor, B cell lymphoma 6 protein. Our combined findings identify a novel B cell–intrinsic mechanism whereby IFN signals promote lupus pathogenesis, implicating this pathway as a potential therapeutic target in SLE. PMID:27069113

  19. Cloning the promoter for transforming growth factor-beta type III receptor. Basal and conditional expression in fetal rat osteoblasts

    NASA Technical Reports Server (NTRS)

    Ji, C.; Chen, Y.; McCarthy, T. L.; Centrella, M.

    1999-01-01

    Transforming growth factor-beta binds to three high affinity cell surface molecules that directly or indirectly regulate its biological effects. The type III receptor (TRIII) is a proteoglycan that lacks significant intracellular signaling or enzymatic motifs but may facilitate transforming growth factor-beta binding to other receptors, stabilize multimeric receptor complexes, or segregate growth factor from activating receptors. Because various agents or events that regulate osteoblast function rapidly modulate TRIII expression, we cloned the 5' region of the rat TRIII gene to assess possible control elements. DNA fragments from this region directed high reporter gene expression in osteoblasts. Sequencing showed no consensus TATA or CCAAT boxes, whereas several nuclear factors binding sequences within the 3' region of the promoter co-mapped with multiple transcription initiation sites, DNase I footprints, gel mobility shift analysis, or loss of activity by deletion or mutation. An upstream enhancer was evident 5' proximal to nucleotide -979, and a silencer region occurred between nucleotides -2014 and -2194. Glucocorticoid sensitivity mapped between nucleotides -687 and -253, whereas bone morphogenetic protein 2 sensitivity co-mapped within the silencer region. Thus, the TRIII promoter contains cooperative basal elements and dispersed growth factor- and hormone-sensitive regulatory regions that can control TRIII expression by osteoblasts.

  20. Mitochondrial genomes and exceptional longevity in a Chinese population: the Rugao longevity study.

    PubMed

    Li, Lei; Zheng, Hong-Xiang; Liu, Zuyun; Qin, Zhendong; Chen, Fei; Qian, Degui; Xu, Jun; Jin, Li; Wang, Xiaofeng

    2015-02-01

    Genetic variants of whole mitochondrial DNA (mtDNA) that predispose to exceptional longevity need to be systematically identified and appraised. Here, we conducted a case-control study with 237 exceptional longevity subjects (aged 95-107) and 444 control subjects (aged 40-69) randomly recruited from a "longevity town"-the city of Rugao in China-to investigate the effects of mtDNA variants on exceptional longevity. We sequenced the entire mtDNA genomes of the 681 subjects using a next-generation platform and employed a complete mtDNA phylogenetic analytical strategy. We identified T3394C as a candidate that counteracts longevity, and we observed a higher load of private nonsynonymous mutations in the COX1 gene predisposing to female longevity. Additionally, for the first time, we identified several variants and new subhaplogroups related to exceptional longevity. Our results provide new clues for genetic mechanisms of longevity and shed light on strategies for evaluating rare mitochondrial variants that underlie complex traits.

  1. Migration-promoting role of VEGF-C and VEGF-C binding receptors in human breast cancer cells

    PubMed Central

    Timoshenko, A V; Rastogi, S; Lala, P K

    2007-01-01

    Vascular endothelial growth factor C (VEGF-C) is a lymphangiogenic factor over-expressed in highly metastatic, cyclooxygenase (COX)-2 expressing breast cancer cells. We tested the hypothesis that tumour-derived VEGF-C may play an autocrine role in metastasis by promoting cellular motility through one or more VEGF-C-binding receptors VEGFR-2, VEGFR-3, neuropilin (NRP)-1, NRP-2, and integrin α9β1. We investigated the expression of these receptors in several breast cancer cell lines (MDA-MB-231, Hs578T, SK-BR-3, T-47D, and MCF7) and their possible requirement in migration of two VEGF-C-secreting, highly metastatic lines MDA-MB-231 and Hs578T. While cell lines varied significantly in their expression of above VEGF-C receptors, migratory activity of MDA-MB-231 and Hs578T cells was linked to one or more of these receptors. Depletion of endogenous VEGF-C by treatments with a neutralising antibody, VEGF-C siRNA or inhibitors of Src, EGFR/Her2/neu and p38 MAP kinases which inhibited VEGF-C production, inhibited cellular migration, indicating the requirement of VEGF-C for migratory function. Migration was differentially attenuated by blocking or downregulation of different VEGF-C receptors, for example treatment with a VEGFR-2 tyrosine kinase inhibitor, NRP-1 and NRP-2 siRNA or α9β1 integrin antibody, indicating the participation of one or more of the receptors in cell motility. This novel role of tumour-derived VEGF-C indicates that breast cancer metastasis can be promoted by coordinated stimulation of lymphangiogenesis and enhanced migratory activity of breast cancer cells. PMID:17912247

  2. Activation of purinergic receptors (P2) in the renal medulla promotes endothelin-dependent natriuresis in male rats.

    PubMed

    Gohar, Eman Y; Speed, Joshua S; Kasztan, Malgorzata; Jin, Chunhua; Pollock, David M

    2016-08-01

    Renal endothelin-1 (ET-1) and purinergic signaling systems regulate Na(+) reabsorption in the renal medulla. A link between the renal ET-1 and purinergic systems was demonstrated in vitro, however, the in vivo interaction between these systems has not been defined. To test whether renal medullary activation of purinergic (P2) receptors promotes ET-dependent natriuresis, we determined the effect of increased medullary NaCl loading on Na(+) excretion and inner medullary ET-1 mRNA expression in anesthetized adult male Sprague-Dawley rats in the presence and absence of purinergic receptor antagonism. Isosmotic saline (NaCl; 284 mosmol/kgH2O) was infused into the medullary interstitium (500 μl/h) during a 30-min baseline urine collection period, followed by isosmotic or hyperosmotic saline (1,800 mosmol/kgH2O) for two further 30-min urine collection periods. Na(+) excretion was significantly increased during intramedullary infusion of hyperosmotic saline. Compared with isosmotic saline, hyperosmotic saline infused into the renal medulla caused significant increases in inner medullary ET-1 mRNA expression. Renal intramedullary infusion of the P2 receptor antagonist suramin inhibited the increase in Na(+) excretion and inner medullary ET-1 mRNA expression induced by NaCl loading in the renal medulla. Activation of medullary P2Y2/4 receptors by infusion of UTP increased urinary Na(+) excretion. Combined ETA and ETB receptor blockade abolished the natriuretic response to intramedullary infusion of UTP. These data demonstrate that activation of medullary P2 receptors promotes ET-dependent natriuresis in male rats, suggesting that the renal ET-1 and purinergic signaling systems interact to efficiently facilitate excretion of a NaCl load.

  3. The Sleep-Promoting and Hypothermic Effects of Glycine are Mediated by NMDA Receptors in the Suprachiasmatic Nucleus

    PubMed Central

    Kawai, Nobuhiro; Sakai, Noriaki; Okuro, Masashi; Karakawa, Sachie; Tsuneyoshi, Yosuke; Kawasaki, Noriko; Takeda, Tomoko; Bannai, Makoto; Nishino, Seiji

    2015-01-01

    The use of glycine as a therapeutic option for improving sleep quality is a novel and safe approach. However, despite clinical evidence of its efficacy, the details of its mechanism remain poorly understood. In this study, we investigated the site of action and sleep-promoting mechanisms of glycine in rats. In acute sleep disturbance, oral administration of glycine-induced non-rapid eye movement (REM) sleep and shortened NREM sleep latency with a simultaneous decrease in core temperature. Oral and intracerebroventricular injection of glycine elevated cutaneous blood flow (CBF) at the plantar surface in a dose-dependent manner, resulting in heat loss. Pretreatment with N-methyl-D-aspartate (NMDA) receptor antagonists AP5 and CGP78608 but not the glycine receptor antagonist strychnine inhibited the CBF increase caused by glycine injection into the brain. Induction of c-Fos expression was observed in the hypothalamic nuclei, including the medial preoptic area (MPO) and the suprachiasmatic nucleus (SCN) shell after glycine administration. Bilateral microinjection of glycine into the SCN elevated CBF in a dose-dependent manner, whereas no effect was observed when glycine was injected into the MPO and dorsal subparaventricular zone. In addition, microinjection of D-serine into the SCN also increased CBF, whereas these effects were blocked in the presence of L-701324. SCN ablation completely abolished the sleep-promoting and hypothermic effects of glycine. These data suggest that exogenous glycine promotes sleep via peripheral vasodilatation through the activation of NMDA receptors in the SCN shell. PMID:25533534

  4. Profiling neurotransmitter receptor expression in mouse gonadotropin-releasing hormone neurons using green fluorescent protein-promoter transgenics and microarrays.

    PubMed

    Todman, M G; Han, S-K; Herbison, A E

    2005-01-01

    The definition of neurotransmitter receptors expressed by individual neuronal phenotypes is essential for our understanding of integrated neural regulation. We report here a single-neuron strategy using green fluorescent protein (GFP)-promoter transgenic mice and oligonucleotide microarrays that has enabled us to provide a qualitative profile of the neurotransmitter receptors expressed by the gonadotropin- releasing hormone (GnRH) neurons, critical for the neural regulation of fertility. Acute brain slices were prepared from adult female GnRH-GFP transgenic mice and single GnRH neurons identified and patched. The contents of GnRH neurons underwent reverse transcription and cDNA amplification using the switch mechanism at the 5' end of RNA templates system, and hybridization to mouse gene oligonucleotide arrays. Fifty different neurotransmitter receptor subunit mRNAs were detected in GnRH neurons. Many of the classical amino acid and aminergic receptors were present in addition to 14 distinct, and in most cases novel, neuropeptidergic receptor signaling families. Four of the latter were selected for functional validation with gramicidin-perforated patch-clamp electrophysiology. Galanin, GnRH and neuromedin B were all found to exert direct depolarizing actions upon GnRH neurons whereas somatostatin induced a potent hyperpolarizing response. These studies demonstrate a relatively straightforward approach for transcriptome profiling of specific neuronal phenotypes. The stimulatory actions of GnRH and galanin upon GnRH neurons found here indicate that positive ultrashort feedback loops exist among the GnRH neuronal population.

  5. The deubiquitinating enzyme USP8 promotes trafficking and degradation of the chemokine receptor 4 at the sorting endosome.

    PubMed

    Berlin, Ilana; Higginbotham, Katherine M; Dise, Rebecca S; Sierra, Maria I; Nash, Piers D

    2010-11-26

    Reversible ubiquitination orchestrated by the opposition of ubiquitin ligases and deubiquitinating enzymes mediates endocytic trafficking of cell surface receptors for lysosomal degradation. Ubiquitin-specific protease 8 (USP8) has previously been implicated in endocytosis of several receptors by virtue of their deubiquitination. The present study explores an indirect role for USP8 in cargo trafficking through its regulation of the chemokine receptor 4 (CXCR4). Contrary to the effects of USP8 loss on enhanced green fluorescent protein, we find that USP8 depletion stabilizes CXCR4 on the cell surface and attenuates receptor degradation without affecting its ubiquitination status. In the presence of ligand, diminished CXCR4 turnover is accompanied by receptor accumulation on enlarged early endosomes and leads to enhancement of phospho-ERK signaling. Perturbation in CXCR4 trafficking, resulting from USP8 inactivation, occurs at the ESCRT-0 checkpoint, and catalytic mutation of USP8 specifically targeted to the ESCRT-0 complex impairs the spatial and temporal organization of the sorting endosome. USP8 functionally opposes the ubiquitin ligase AIP4 with respect to ESCRT-0 ubiquitination, thereby promoting trafficking of CXCR4. Collectively, our findings demonstrate a functional cooperation between USP8, AIP4, and the ESCRT-0 machinery at the early sorting phase of CXCR4 and underscore the versatility of USP8 in shaping trafficking events at the early-to-late endosome transition.

  6. Activation of islet 5-HT4 receptor regulates glycemic control through promoting insulin secretion.

    PubMed

    Chen, Hui; Hong, Feng; Chen, Ye; Li, Ji; Yao, Yuan-Sheng; Zhang, Yue; Zheng, Li-Fei; Zhu, Jin-Xia

    2016-10-15

    Mosapride, a gastrointestinal prokinetic drug, is an agonist of 5-hydroxytryptamine (5-HT) receptor 4 that also reduces blood glucose. Whether 5-HT4 receptor is distributed in pancreatic islets and whether mosapride can directly stimulate insulin secretion is unclear. In the present study, the protein expression and cellular location of 5-HT4 receptor in pancreas was detected through western blotting and immunofluorescence. The acute effects of 5-HT4 receptor agonists, mosapride and prucalopride, on insulin secretion were investigated in vivo and in vitro in normal and alloxan-induced diabetes rats. The results indicated that 5-HT4 receptor immunoreactivity was co-existed in the islets insulin-immunoreactive cells of rat, mouse, pig and human. However the immunoreactive cells of insulin and 5-HT4 receptor and the protein expression of 5-HT4 receptor were significantly decreased in the pancreas of alloxan-induced diabetes rats. In normal rats, mosapride and prucalopride decreased blood glucose and increased insulin secretion during glucose tolerance test, in association with an increase in glucose-stimulated insulin secretion, which was abolished by the 5-HT4 receptor antagonist GR113808. In diabetes rats, mosapride and prucalopride failed to improve blood glucose and insulin levels in the group of 180mg/kg alloxan, but increased glucose-stimulated insulin secretion in the group of 120mg/kg alloxan in vitro. We conclude that 5-HT4 receptor is distributed in the islet β cell. Activation of 5-HT4 receptor is able to stimulate insulin secretion directly, thereby reduce blood glucose. The study provides important experimental evidences for the 5-HT4 receptor regulating insulin secretion and acting as a potential drug target in diabetes treatment. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Galactinol as marker for seed longevity.

    PubMed

    de Souza Vidigal, Deborah; Willems, Leo; van Arkel, Jeroen; Dekkers, Bas J W; Hilhorst, Henk W M; Bentsink, Leónie

    2016-05-01

    Reduced seed longevity or storability is a major problem in seed storage and contributes to increased costs in crop production. Here we investigated whether seed galactinol contents could be predictive for seed storability behavior in Arabidopsis, cabbage and tomato. The analyses revealed a positive correlation between galactinol content and seed longevity in the three species tested, which indicates that this correlation is conserved in the Brassicaceae and beyond. Quantitative trait loci (QTL) mapping in tomato revealed a co-locating QTL for galactinol content and seed longevity on chromosome 2. A candidate for this QTL is the GALACTINOL SYNTHASE gene (Solyc02g084980.2.1) that is located in the QTL interval. GALACTINOL SYNTHASE is a key enzyme of the raffinose family oligosaccharide (RFO) pathway. To investigate the role of enzymes in the RFO pathway in more detail, we applied a reverse genetics approach using T-DNA knock-out lines in genes encoding enzymes of this pathway (GALACTINOL SYNTHASE 1, GALACTINOL SYNTHASE 2, RAFFINOSE SYNTHASE, STACHYOSE SYNTHASE and ALPHA-GALACTOSIDASE) and overexpressors of the cucumber GALACTINOL SYNTHASE 2 gene in Arabidopsis. The galactinol synthase 2 mutant and the galactinol synthase 1 galactinol synthase 2 double mutant contained the lowest seed galactinol content which coincided with lower seed longevity. These results show that galactinol content of mature dry seed can be used as a biomarker for seed longevity in Brassicaceae and tomato.

  8. Genome size and longevity in fish.

    PubMed

    Griffith, O L; Moodie, G E E; Civetta, A

    2003-03-01

    The wide variety of genome sizes (measured as C-value) observed across taxa is not related to organismal complexity or number of coding genes. Partial answers to this C-value enigma have been found by establishing associations between C-value and particular phenotypic characteristics. One such controversial association has been recently suggested between genome size and longevity in birds. In order to determine whether genome size is a general predictor of longevity, we have extended the analysis to the Actinoptergyian fish, a widely divergent group in terms of both longevity and genome size. We collected data on genome size, longevity and body mass for species covering fourteen orders of bony fish. Analysis of covariance using order as a cofactor shows a significant effect of genome size on longevity (corrected for body mass), with lifespan increasing as a function of genome size. Analysis of phylogenetically independent contrasts for orders with a large number of species with a well resolved phylogenetic relationship (Acipenseriformes, Cypriniformes, and Salmoniformes) found the same trend of longer lifespan with increases in genome size but the relationship was not significant. Our results consistently show an increase in lifespan for fish with larger genomes.

  9. Amplification and analysis of promoter region of insulin receptor gene in a patient with leprechaunism associated with severe insulin resistance.

    PubMed

    Haruta, T; Imamura, T; Iwanishi, M; Egawa, K; Goji, K; Kobayashi, M

    1995-04-01

    A patient with leprechaunism associated with severe insulin resistance was studied to identify the molecular and genetic basis for insulin resistance. Insulin binding and surface labeling of transformed lymphocytes prepared from the patient showed a significantly decreased insulin receptor number on the cell surface. Southern blot analysis of the insulin receptor gene showed no evidence of large insertions or deletions. Furthermore, direct sequencing of all 22 exons and exon-intron junctions of the insulin receptor gene failed to show any missense mutations, nonsense mutations, or mutations at exon-intron junctions. However, Northern blot analysis indicated significantly decreased insulin receptor mRNA expression in the patient's cells. Moreover, restriction endonuclease digestion of the amplified cDNA suggested that the expression levels of one allele were less efficient than the other. These findings suggested that the regulatory region of the insulin receptor gene might have abnormalities. Therefore, we examined the 5' flanking region of the insulin receptor gene. Southern blot analysis showed no major deletions or insertions between positions -1,823 and -2 relative to the translation initiation site. A 5' flanking region of the insulin receptor gene spanning positions -881 approximately +7 was amplified by polymerase chain reaction (PCR) and introduced into a reporter plasmid carrying the human growth hormone (hGH) gene. The nucleotide sequence of the amplified fragment showed two polymorphic sites at positions -603 and -500 in the patient, as well as in normal subjects. No other abnormal sequence was found in the patient. Promoter activity measured by hGH expression in transfected mouse L cells was not influenced by the polymorphism at position -603 located in a cluster of GC boxes.(ABSTRACT TRUNCATED AT 250 WORDS)

  10. Pharmacological activation of cannabinoid 2 receptor attenuates inflammation, fibrogenesis, and promotes re-epithelialization during skin wound healing.

    PubMed

    Wang, Lin-Lin; Zhao, Rui; Li, Jiao-Yong; Li, Shan-Shan; Liu, Min; Wang, Meng; Zhang, Meng-Zhou; Dong, Wen-Wen; Jiang, Shu-Kun; Zhang, Miao; Tian, Zhi-Ling; Liu, Chang-Sheng; Guan, Da-Wei

    2016-09-05

    Previous studies showed that cannabinoid 2 (CB2) receptor is expressed in multiple effector cells during skin wound healing. Meanwhile, its functional involvement in inflammation, fibrosis, and cell proliferation in other organs and skin diseases implied CB2 receptor might also regulate skin wound healing. To verify this hypothesis, mice excisional wounds were created and treated with highly selective CB2 receptor agonist GP1a (1-(2,4-dichlorophenyl)-6-methyl- N-piperidin-1-yl-4H-indeno[1,2-c]pyrazole-3-carboxamide) and antagonist AM630 ([6-iodo-2- methyl-1-(2-morpholin-4-ylethyl)indol-3-yl]-(4-methoxyphenyl)methanone) respectively. The inflammatory infiltration, cytokine expression, fibrogenesis, and wound re-epithelialization were analyzed. After CB2 receptor activation, neutrophil and macrophage infiltrations were reduced, and expressions of monocyte chemotactic protein (MCP)-1, stromal cell-derived factor (SDF)-1, Interleukin (IL)-6, IL-1β, tumor necrosis factor (TNF)-α, transforming growth factor (TGF)-β1 and vascular endothelial growth factor (VEGF)-A were decreased. Keratinocyte proliferation and migration were enhanced. Wound re-epithelialization was accelerated. Fibroblast accumulation and fibroblast-to-myofibroblast transformation were attenuated, and expression of pro-collagen I was decreased. Furthermore, HaCaT cells in vitro were treated with GP1a or AM630, which revealed that CB2 receptor activation promoted keratinocyte migration by inducing the epithelial to mesenchymal transition. These results, taken together, indicate that activating CB2 receptor could ameliorate wound healing by reducing inflammation, accelerating re-epithelialization, and attenuating scar formation. Thus, CB2 receptor agonist might be a novel perspective for skin wound therapy.

  11. Dietary homocysteine promotes atherosclerosis in apoE-deficient mice by inducing scavenger receptors expression

    USDA-ARS?s Scientific Manuscript database

    Elevated plasma homocysteine (Hcy) levels have been recognized as an independent risk factor for cardiovascular and cerebrovascular diseases. However, the causative mechanisms have not been delineated. Scavenger receptors such as scavenger receptor-AI/II (SR-A), CD36, and lectin-like oxidized LDL ...

  12. The longevity effect of echinacoside in Caenorhabditis elegans mediated through daf-16.

    PubMed

    Wang, Xue; Zhang, Jiaolong; Lu, Lulu; Zhou, Lijun

    2015-01-01

    Echinacoside (ECH), a natural polyphenolic compound, has been reported to possess important pharmacological activities. However, very little is known about whether or how ECH affects longevity in vivo. We have examined the effects of ECH on the life span and stress tolerance in Caenorhabditis elegans. Our studies demonstrate that the life span of wild-type worms could be extended in the presence of ECH. Furthermore, ECH was found to increase tolerance of worms to heat shock and oxidative stress, while not exerting any influence on pharyngeal pumping rate and progeny production. Our mechanistic studies indicate that supplementation of ECH increases the transcript level of daf-16. ECH treatment also modulates the nuclear localization and transcriptional activities of daf-16, thus fine tunes the expression of daf-16 target genes to promote longevity and increases stress response in C. elegans. Overall, this work reveals the longevity effect of ECH and elucidates the underpinning mechanisms.

  13. Impact of genetic background and experimental reproducibility on identifying chemical compounds with robust longevity effects

    PubMed Central

    Lucanic, Mark; Plummer, W. Todd; Chen, Esteban; Harke, Jailynn; Foulger, Anna C.; Onken, Brian; Coleman-Hulbert, Anna L.; Dumas, Kathleen J.; Guo, Suzhen; Johnson, Erik; Bhaumik, Dipa; Xue, Jian; Crist, Anna B.; Presley, Michael P.; Harinath, Girish; Sedore, Christine A.; Chamoli, Manish; Kamat, Shaunak; Chen, Michelle K.; Angeli, Suzanne; Chang, Christina; Willis, John H.; Edgar, Daniel; Royal, Mary Anne; Chao, Elizabeth A.; Patel, Shobhna; Garrett, Theo; Ibanez-Ventoso, Carolina; Hope, June; Kish, Jason L; Guo, Max; Lithgow, Gordon J.; Driscoll, Monica; Phillips, Patrick C.

    2017-01-01

    Limiting the debilitating consequences of ageing is a major medical challenge of our time. Robust pharmacological interventions that promote healthy ageing across diverse genetic backgrounds may engage conserved longevity pathways. Here we report results from the Caenorhabditis Intervention Testing Program in assessing longevity variation across 22 Caenorhabditis strains spanning 3 species, using multiple replicates collected across three independent laboratories. Reproducibility between test sites is high, whereas individual trial reproducibility is relatively low. Of ten pro-longevity chemicals tested, six significantly extend lifespan in at least one strain. Three reported dietary restriction mimetics are mainly effective across C. elegans strains, indicating species and strain-specific responses. In contrast, the amyloid dye ThioflavinT is both potent and robust across the strains. Our results highlight promising pharmacological leads and demonstrate the importance of assessing lifespans of discrete cohorts across repeat studies to capture biological variation in the search for reproducible ageing interventions. PMID:28220799

  14. Promotion of Wound Healing by an Agonist of Adenosine A2A Receptor Is Dependent on Tissue Plasminogen Activator.

    PubMed

    Montesinos, M Carmen; Desai-Merchant, Avani; Cronstein, Bruce N

    2015-12-01

    Impaired wound healing, as it occurs in diabetes mellitus or long-term corticoid treatment, is commonly associated with disability, diminished quality of life, and high economic costs. Selective agonists of the A2A receptor subtype of adenosine, an endogenous regulator of inflammation, promote tissue repair in animal models, both healthy and with impaired healing. Plasmin-mediated proteolysis of fibrin and other matrix proteins is essential for cell migration at sites of injury. Since adenosine A2A receptor activation increases plasminogen activator release from macrophages and mast cells, we studied the effect of a selective agonist, CGS-21680, on full-thickness excisional wound closure in wild-type, urokinase plasminogen activator (uPA)-deficient, and tissue plasminogen activator (tPA)-deficient mice. Wound closure was impaired in tPA- and uPA-deficient mice as compared with wild-type mice, and topical application of CGS-21680 significantly increased the rate at which wounds closed in wild-type mice and uPA-deficient mice, but not in tPA-deficient mice. Immunostaining of tissue sections showed that tPA was present in endothelial cells and histiocytes by day 3 post-wound and also by day 6. In contrast, uPA was more prominent in these cell types only by day 6 post-wound. Our results confirm that plasminogen activation contributes to wound repair and are consistent with the hypothesis that adenosine A2A receptor activation promotes wound closure by a mechanism that depends upon tPA, but not uPA. Moreover, our results suggest that topical adenosine A2A receptor agonists may be useful in promotion of wound closure in patients with impaired wound healing.

  15. Wnt5a promotes cancer cell invasion and proliferation by receptor-mediated endocytosis-dependent and -independent mechanisms, respectively

    PubMed Central

    Shojima, Kensaku; Sato, Akira; Hanaki, Hideaki; Tsujimoto, Ikuko; Nakamura, Masahiro; Hattori, Kazunari; Sato, Yuji; Dohi, Keiji; Hirata, Michinari; Yamamoto, Hideki; Kikuchi, Akira

    2015-01-01

    Wnt5a activates the Wnt/β-catenin-independent pathway and its overexpression is associated with tumor aggressiveness enhancing invasive activity. For this action, Wnt5a-induced receptor endocytosis with clathrin is required. Wnt5a expression was previously believed to be associated with cancer cell motility but not proliferation. Recently, it was reported that Wnt5a is also implicated in cancer cell proliferation, but the mechanism was not clear. In this study, we generated a neutralizing anti-Wnt5a monoclonal antibody (mAb5A16) to investigate the mechanism by which Wnt5a regulates cancer cell proliferation. Wnt5a stimulated both invasion and proliferation of certain types of cancer cells, including HeLaS3 cervical cancer cells and A549 lung cancer cells although Wnt5a promoted invasion but not proliferation in other cancer cells such as KKLS gastric cancer cells. mAb5A16 did not affect the binding of Wnt5a to its receptor, but it suppressed Wnt5a-induced receptor-mediated endocytosis. mAb5A16 inhibited invasion but not proliferation of HeLaS3 and A549 cells. Wnt5a activated Src family kinases (SFKs) and Wnt5a-dependent cancer cell proliferation was dependent on SFKs, yet blockade of receptor-mediated endocytosis did not affect cancer cell proliferation and SFK activity. These results suggest that Wnt5a promotes invasion and proliferation of certain types of cancer cells through receptor-mediated endocytosis-dependent and -independent mechanisms, respectively. PMID:25622531

  16. Evidence for multiple promoters of the human IL-5 receptor alpha subunit gene: a novel 6-base pair element determines cell-specific promoter function.

    PubMed

    Zhang, J; Kuvelkar, R; Cheewatrakoolpong, B; Williams, S; Egan, R W; Billah, M M

    1997-12-01

    In addition to a previously characterized promoter (P1), we now show the existence of a second promoter for the human IL-5Ralpha gene. Initially, a genomic region (P2) 5' upstream of human IL-5Ralpha exon 2 was cloned by an inverted PCR. The transcriptional start site was then mapped to a deoxycytidine (C) residue within P2 by analyzing cellular mRNA with both the 5' rapid amplification of cDNA end-PCR and S1 nuclease protection assays. Transfection of eosinophilic HL-60 cells with reporter gene constructs in which either P1 or P2 was linked to the bacterial chloramphenicol acetyltransferase (CAT) gene resulted in CAT expression; little or no CAT expression occurred in other myeloid and nonmyeloid cell lines. Deletion studies showed that a 66-bp region, ranging from -31 to +35, was sufficient to promote CAT expression in eosinophilic HL-60 cells. Analysis of linker-scanning mutants identified a novel 6-bp element (5' CTAATT 3') spanning -19 to -14 that was essential for P2 promoter activity. In electrophoretic mobility shift assays, a P2 region from -31 to +1 containing the unique 6-bp element, when used as a probe, formed a complex with a protein(s) that was found only in the eosinophilic cell line. This binding activity was lost upon replacement of the 6-bp element with a 6-bp linker, suggesting that this element likely serves as the binding site for an eosinophilic HL-60 cell-specific transcription factor(s). Together, these data suggest an important role for P2 promoter in the regulation of eosinophil-specific expression of the human IL-5 receptor alpha gene.

  17. MIF promotes B cell chemotaxis through the receptors CXCR4 and CD74 and ZAP-70 signaling.

    PubMed

    Klasen, Christina; Ohl, Kim; Sternkopf, Marieke; Shachar, Idit; Schmitz, Corinna; Heussen, Nicole; Hobeika, Elias; Levit-Zerdoun, Ella; Tenbrock, Klaus; Reth, Michael; Bernhagen, Jürgen; El Bounkari, Omar

    2014-06-01

    Macrophage migration inhibitory factor (MIF) is a proinflammatory cytokine with chemokine-like functions that plays a pivotal role in the pathogenesis of inflammatory diseases by promoting leukocyte recruitment. We showed that MIF promotes the atherogenic recruitment of monocytes and T cells through its receptors CXCR2 and CXCR4. Effects of MIF on B cell recruitment have not been addressed. In this study, we tested the involvement of MIF in B cell chemotaxis and studied the underlying mechanism. We show that MIF promotes primary murine B cell chemotaxis in a dose-dependent manner, comparable to the B cell chemokines CXCL13 and CXCL12. Splenic B cells express CXCR4 and the receptor CD74 but not CXCR2. Inhibition of CXCR4 or CD74 or a genetic deficiency of Cd74 in primary B cells fully abrogated MIF-mediated B cell migration, implying cooperative involvement of both receptors. MIF stimulation of B cells resulted in a rapid increase in intracellular Ca(2+) mobilization and F-actin polymerization. Intriguingly, the tyrosine kinase ZAP-70 was activated upon MIF and CXCL12 treatment in a CXCR4- and CD74-dependent manner. Pharmacological inhibition of ZAP-70 resulted in abrogation of primary B cell migration. Functional involvement of ZAP-70 was confirmed by small interfering RNA-mediated knockdown in Ramos B cell migration. Finally, primary B cells from ZAP-70 gene-deficient mice exhibited ablated transmigration in response to MIF or CXCL12. We conclude that MIF promotes the migration of B cells through a ZAP-70-dependent pathway mediated by cooperative engagement of CXCR4 and CD74. The data also suggest that MIF may contribute to B cell recruitment in vivo (e.g., in B cell-related immune disorders).

  18. X-linked Ectodermal Dysplasia Receptor (XEDAR) is Down-regulated in Breast Cancer via Promoter Methylation

    PubMed Central

    Punj, Vasu; Matta, Hittu; Chaudhary, Preet M.

    2009-01-01

    Purpose The X-linked ectodermal dysplasia receptor (XEDAR) is a novel receptor of the Tumor Necrosis Factor Receptor Family that binds to ectodysplasin-A2 (EDA-A2) and induces cell death. The purpose of this study was to determine the tumor-suppressive potential of XEDAR in the development of breast cancer. Experimental Design We analyzed the expression of XEDAR in breast cancer cell lines and tumor samples using quantitative real-time RT-PCR analysis and immunoblotting. We analyzed the human XEDAR gene promoter for the presence of any CpG island and examined its methylation status using methylation-specific real-time PCR. We examined the effect of 5-aza-2′-deoxycytidine (5-Aza-dC) on the expression of XEDAR and sensitivity to EDA-A2-induced apoptosis in breast cancer cell lines. Results Expression of XEDAR, but not EDA-A2, was downregulated in most tumorigenic breast cancer cell lines and tumor samples. Loss of XEDAR expression correlated with the hypermethylation of its promoter. Ectopic expression of XEDAR in MDA-MB-231 cells resulted in significant induction of apoptosis and reduction in colony formation. Treatment with 5-Aza-dC restored XEDAR expression in breast cancer cell lines with methylated XEDAR promoter and sensitized them to EDA-A2-induced cell death. Conclusions Our results suggest that XEDAR expression is down-regulated in most breast cancers via promoter methylation, which may contribute to accelerated tumor development by blocking EDA-A2-induced cell death. XEDAR may represent a novel breast tumor suppressor gene and restoration of its expression by treatment with DNA demethylating agents may represent an attractive approach for the treatment of breast cancer. PMID:20145163

  19. The Epidemiology of Longevity and Exceptional Survival

    PubMed Central

    Newman, Anne B.; Murabito, Joanne M.

    2013-01-01

    The field of the “epidemiology of longevity” has been expanding rapidly in recent years. Several long-term cohort studies have followed older adults long enough to identify the most long-lived and to define many factors that lead to a long life span. Very long-lived people such as centenarians have been examined using case-control study designs. Both cohort and case-control studies have been the subject of genome-wide association studies that have identified genetic variants associated with longevity. With growing recognition of the importance of rare variations, family studies of longevity will be useful. Most recently, exome and whole-genome sequencing, gene expression, and epigenetic studies have been undertaken to better define functional variation and regulation of the genome. In this review, we consider how these studies are leading to a deeper understanding of the underlying biologic pathways to longevity. PMID:23372024

  20. Longevity and aging. Mechanisms and perspectives.

    PubMed

    Labat-Robert, J; Robert, L

    2015-12-01

    Longevity can mostly be determined with relative accuracy from birth and death registers when available. Aging is a multifactorial process, much more difficult to quantitate. Every measurable physiological function declines with specific speeds over a wide range. The mechanisms involved are also different, genetic factors are of importance for longevity determinations. The best-known genes involved are the Sirtuins, active at the genetic and epigenetic level. Aging is multifactorial, not "coded" in the genome. There are, however, a number of well-studied physical and biological parameters involved in aging, which can be determined and quantitated. We shall try to identify parameters affecting longevity as well as aging and suggest some reasonable predictions for the future.

  1. The A2B adenosine receptor promotes Th17 differentiation via stimulation of dendritic cell IL-6.

    PubMed

    Wilson, Jeffrey M; Kurtz, Courtney C; Black, Steven G; Ross, William G; Alam, Mohammed S; Linden, Joel; Ernst, Peter B

    2011-06-15

    Adenosine is an endogenous metabolite produced during hypoxia or inflammation. Previously implicated as an anti-inflammatory mediator in CD4(+) T cell regulation, we report that adenosine acts via dendritic cell (DC) A(2B) adenosine receptor (A(2B)AR) to promote the development of Th17 cells. Mouse naive CD4(+) T cells cocultured with DCs in the presence of adenosine or the stable adenosine mimetic 5'-(N-ethylcarboximado) adenosine resulted in the differentiation of IL-17- and IL-22-secreting cells and elevation of mRNA that encode signature Th17-associated molecules, such as IL-23R and RORγt. The observed response was similar when DCs were generated from bone marrow or isolated from small intestine lamina propria. Experiments using adenosine receptor antagonists and cells from A(2B)AR(-/-) or A(2A)AR(-/-)/A(2B)AR(-/-) mice indicated that the DC A(2B)AR promoted the effect. IL-6, stimulated in a cAMP-independent manner, is an important mediator in this pathway. Hence, in addition to previously noted direct effects of adenosine receptors on regulatory T cell development and function, these data indicated that adenosine also acts indirectly to modulate CD4(+) T cell differentiation and suggested a mechanism for putative proinflammatory effects of A(2B)AR.

  2. [Adiponectin receptor-targeted therapy for lifestyle-related diseases].

    PubMed

    Iwabu, Masato; Yamauchi, Toshimasa; Okada-Iwabu, Miki; Kadowaki, Takashi

    2016-03-01

    Given that appropriate control of responses of the body to nutritional status is assumed to modulate the pace of aging, thus prolonging lifespan and maintaining youth in humans, expectations are mounting worldwide for modalities targeting the pathways in metabolic regulation for healthy longevity. Of these, this review focuses attention on adiponectin-targeted therapy and discusses milestones in this approach, which include the discovery of the ability of adiponectin to protect against lifestyle-related diseases, identification of its receptors (AdipoRs), elucidation of AdipoR-mediated signaling pathways that promote healthy longevity and acquisition of small-molecule AdipoR agonist, and explores future prospects on adiponectin-targeted therapy.

  3. Suppression of transient receptor potential melastatin 4 expression promotes conversion of endothelial cells into fibroblasts via transforming growth factor/activin receptor-like kinase 5 pathway.

    PubMed

    Echeverría, Cesar; Montorfano, Ignacio; Cabello-Verrugio, Claudio; Armisén, Ricardo; Varela, Diego; Simon, Felipe

    2015-05-01

    To study whether transient receptor potential melastatin 4 (TRPM4) participates in endothelial fibrosis and to investigate the underlying mechanism. Primary human endothelial cells were used and pharmacological and short interfering RNA-based approaches were used to test the transforming growth factor beta (TGF-β)/activin receptor-like kinase 5 (ALK5) pathway participation and contribution of TRPM7 ion channel. Suppression of TRPM4 expression leads to decreased endothelial protein expression and increased expression of fibrotic and extracellular matrix markers. Furthermore, TRPM4 downregulation increases intracellular Ca levels as a potential condition for fibrosis. The underlying mechanism of endothelial fibrosis shows that inhibition of TRPM4 expression induces TGF-β1 and TGF-β2 expression, which act through their receptor, ALK5, and the nuclear translocation of the profibrotic transcription factor smad4. TRPM4 acts to maintain endothelial features and its loss promotes fibrotic conversion via TGF-β production. The regulation of TRPM4 levels could be a target for preserving endothelial function during inflammatory diseases.

  4. Plasmin and plasminogen activator inhibitor type 1 promote cellular motility by regulating the interaction between the urokinase receptor and vitronectin.

    PubMed Central

    Waltz, D A; Natkin, L R; Fujita, R M; Wei, Y; Chapman, H A

    1997-01-01

    The urokinase receptor (uPAR) coordinates plasmin-mediated cell-surface proteolysis and promotes cellular adhesion via a binding site for vitronectin on uPAR. Because vitronectin also binds plasminogen activator inhibitor type 1 (PAI-1), and plasmin cleavage of vitronectin reduces PAI-1 binding, we explored the effects of plasmin and PAI-1 on the interaction between uPAR and vitronectin. PAI-1 blocked cellular binding of and adhesion to vitronectin by over 80% (IC50 approximately 5 nM), promoted detachment of uPAR-bearing cells from vitronectin, and increased cellular migration on vitronectin. Limited cleavage of vitronectin by plasmin also abolished cellular binding and adhesion and induced cellular detachment. A series of peptides surrounding a plasmin cleavage site (arginine 361) near the carboxy-terminal end of vitronectin were synthesized. Two peptides spanning res 364-380 blocked binding of uPAR to vitronectin (IC50 approximately 8-25 microM) identifying this region as an important site of uPAR-vitronectin interaction. These data illuminate a complex regulatory scheme for uPAR-dependent cellular adhesion to vitronectin: Active urokinase promotes adhesion and also subsequent detachment through activation of plasmin or complex formation with PAI-1. Excess PAI-1 may also promote migration by blocking cellular adhesion and/or promoting detachment, possibly accounting in part for the strong correlation between PAI-1 expression and tumor cell metastasis. PMID:9202057

  5. Taste receptors in the gut - A new target for health promoting properties in diet.

    PubMed

    Ekstrand, Bo; Young, Jette Feveile; Rasmussen, Martin Krøyer

    2017-10-01

    In this review we describe a new target for food functionality, the taste receptors in the gastrointestinal tract. These receptors are involved in an intricate signalling network for monitoring of taste and nutrient intake, homeostasis and energy metabolism, and they are also an early warning system for toxic substances in our diet. Especially the receptors for bitter taste provide a new possibility to activate a number of health related signalling pathways, already at low concentrations of the active substance, without requiring uptake into the body and transport via the circulation. When ligands bind to these receptors, signalling is induced either via peptide hormones into the circulation to other organs in the body, or via nerve fibers directly to the brain. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. CB2 cannabinoid receptor activation promotes colon cancer progression via AKT/GSK3β signaling pathway

    PubMed Central

    Martínez-Martínez, Esther; Martín-Ruiz, Asunción; Martín, Paloma; Calvo, Virginia; Provencio, Mariano; García, José M.

    2016-01-01

    The pharmacological activation of the cannabinoid receptor type 2, CB2, has been shown to elicit anti-tumoral mechanisms in different cancer types. However, little is known about its endogenous role in tumor pathophysiology, and different studies have attributed pro-tumorigenic properties to this receptor. In a previous work, we showed that CB2 expression is a poor prognostic factor in colon cancer patients. Here we report that activation of CB2 with low doses of specific agonists induce cell proliferation and favor the acquisition of aggressive molecular features in colon cancer cells. We show that sub-micromolar concentrations of CB2-specific agonists, JWH-133 and HU-308, promote an increase in cell proliferation rate through the activation of AKT/PKB pathway in colon cancer in vitro and in vivo. AKT activation promotes GSK3β inhibition and thus, a more aggressive cell phenotype with the subsequent elevation of SNAIL levels, E-cadherin degradation and β-catenin delocalization from cell membrane. Taken together, our data show that CB2 activation with sub-micromolar doses of agonists, which could be more similar to endogenous levels of cannabinoids, promote colon cancer progression, implicating that CB2 could have a pro-tumorigenic endogenous role in colon cancer. PMID:27634891

  7. Environmental Endocrine Disruptors Promote Adipogenesis in the 3T3-L1 Cell Line through Glucocorticoid Receptor Activation

    PubMed Central

    Sargis, Robert M.; Johnson, Daniel N.; Choudhury, Rashikh A.; Brady, Matthew J.

    2014-01-01

    The burgeoning obesity and diabetes epidemics threaten health worldwide, yet the molecular mechanisms underlying these phenomena are incompletely understood. Recently, attention has focused on the potential contributions of environmental pollutants that act as endocrine disrupting chemicals (EDCs) in the pathogenesis of metabolic diseases. Because glucocorticoid signaling is central to adipocyte differentiation, the ability of EDCs to stimulate the glucocorticoid receptor (GR) and drive adipogenesis was assessed in the 3T3-L1 cell line. Various EDCs were screened for glucocorticoid-like activity using a luciferase reporter construct, and four (bisphenol A (BPA), dicyclohexyl phthalate (DCHP), endrin, and tolylfluanid (TF)) were shown to significantly stimulate GR without significant activation of the peroxisome proliferator-activated receptor-γ. 3T3-L1 preadipocytes were then treated with EDCs and a weak differentiation cocktail containing dehydrocorticosterone (DHC) in place of the synthetic dexamethasone. The capacity of these compounds to promote adipogenesis was assessed by quantitative oil red O staining and immunoblotting for adipocyte-specific proteins. The four EDCs increased lipid accumulation in the differentiating adipocytes and also upregulated the expression of adipocytic proteins. Interestingly, proadipogenic effects were observed at picomolar concentrations for several of the EDCs. Because there was no detectable adipogenesis when the preadipocytes were treated with compounds alone, the EDCs are likely promoting adipocyte differentiation by synergizing with agents present in the differentiation cocktail. Thus, EDCs are able to promote adipogenesis through the activation of the GR, further implicating these compounds in the rising rates of obesity and diabetes. PMID:19927138

  8. Aryl hydrocarbon receptor is activated by glucose and regulates the thrombospondin-1 gene promoter in endothelial cells.

    PubMed

    Dabir, Pankaj; Marinic, Tina E; Krukovets, Irene; Stenina, Olga I

    2008-06-20

    Hyperglycemia is an independent risk factor for development of diabetic vascular complications. The molecular mechanisms that are activated by glucose in vascular cells and could explain the development of vascular complications are still poorly understood. A putative binding site for the transcription factor aryl hydrocarbon receptor (AhR) was identified in the glucose-responsive fragment of the promoter of thrombospondin-1, a potent antiangiogenic and proatherogenic protein involved in development of diabetic vascular complications. AhR was expressed in aortic endothelial cells (ECs), activated, and bound to the promoter in response to high glucose stimulation of ECs. The constitutively active form of AhR induced activation of the thrombospondin-1 gene promoter. In response to high glucose stimulation, AhR was found in complex with Egr-1 and activator protein-2, which are 2 other nuclear transcription factors activated by glucose in ECs that have not been previously detected in complex with AhR. The activity of the DNA-binding complex was regulated by glucose through the activation of hexosamine pathway and intracellular glycosylation. This is the first report of activation of AhR (a receptor for xenobiotic compounds) by a physiological stimulus. This report links the activation of AhR to the pathological effects of hyperglycemia in the vasculature.

  9. Aryl Hydrocarbon Receptor (AhR) is Activated by Glucose and Regulates the Thrombospondin-1 Gene Promoter in Endothelial Cells

    PubMed Central

    Dabir, Pankaj; Marinic, Tina E.; Krukovets, Irene; Stenina, Olga I.

    2009-01-01

    Hyperglycemia is an independent risk-factor for development of diabetic vascular complications. The molecular mechanisms that are activated by glucose in vascular cells and could explain the development of vascular complications are still poorly understood. A putative binding site for the transcription factor Aryl Hydrocarbon Receptor (AhR) was identified in the glucose-responsive fragment of the promoter of thrombospondin-1 (TSP-1), a potent anti-angiogenic and pro-atherogenic protein involved in development of diabetic vascular complications. AhR was expressed in aortic endothelial cells (EC), activated and bound to the promoter in response to high glucose stimulation of EC. The constitutively active form of AhR induced activation of the TSP-1 gene promoter. In response to high glucose stimulation, AhR was found in complex with Egr-1 and AP-2, two other nuclear transcription factors activated by glucose in EC that have not been previously detected in complex with AhR. The activity of the DNA-binding complex was regulated by glucose through the activation of hexosamine pathway and intracellular glycosylation. This is the first report of activation of AhR (a receptor for xenobiotic compounds) by a physiological stimulus. This report links the activation of AhR to the pathological effects of hyperglycemia in the vasculature. PMID:18515748

  10. mTORC2 promotes type I insulin-like growth factor receptor and insulin receptor activation through the tyrosine kinase activity of mTOR

    PubMed Central

    Yin, Yancun; Hua, Hui; Li, Minjing; Liu, Shu; Kong, Qingbin; Shao, Ting; Wang, Jiao; Luo, Yuanming; Wang, Qian; Luo, Ting; Jiang, Yangfu

    2016-01-01

    Mammalian target of rapamycin (mTOR) is a core component of raptor-mTOR (mTORC1) and rictor-mTOR (mTORC2) complexes that control diverse cellular processes. Both mTORC1 and mTORC2 regulate several elements downstream of type I insulin-like growth factor receptor (IGF-IR) and insulin receptor (InsR). However, it is unknown whether and how mTOR regulates IGF-IR and InsR themselves. Here we show that mTOR possesses unexpected tyrosine kinase activity and activates IGF-IR/InsR. Rapamycin induces the tyrosine phosphorylation and activation of IGF-IR/InsR, which is largely dependent on rictor and mTOR. Moreover, mTORC2 promotes ligand-induced activation of IGF-IR/InsR. IGF- and insulin-induced IGF-IR/InsR phosphorylation is significantly compromised in rictor-null cells. Insulin receptor substrate (IRS) directly interacts with SIN1 thereby recruiting mTORC2 to IGF-IR/InsR and promoting rapamycin- or ligand-induced phosphorylation of IGF-IR/InsR. mTOR exhibits tyrosine kinase activity towards the general tyrosine kinase substrate poly(Glu-Tyr) and IGF-IR/InsR. Both recombinant mTOR and immunoprecipitated mTORC2 phosphorylate IGF-IR and InsR on Tyr1131/1136 and Tyr1146/1151, respectively. These effects are independent of the intrinsic kinase activity of IGF-IR/InsR, as determined by assays on kinase-dead IGF-IR/InsR mutants. While both rictor and mTOR immunoprecitates from rictor+/+ MCF-10A cells exhibit tyrosine kinase activity towards IGF-IR and InsR, mTOR immunoprecipitates from rictor−/− MCF-10A cells do not induce IGF-IR and InsR phosphorylation. Phosphorylation-deficient mutation of residue Tyr1131 in IGF-IR or Tyr1146 in InsR abrogates the activation of IGF-IR/InsR by mTOR. Finally, overexpression of rictor promotes IGF-induced cell proliferation. Our work identifies mTOR as a dual-specificity kinase and clarifies how mTORC2 promotes IGF-IR/InsR activation. PMID:26584640

  11. Very low density lipoprotein receptor promotes adipocyte differentiation and mediates the proadipogenic effect of peroxisome proliferator-activated receptor gamma agonists.

    PubMed

    Tao, Huan; Hajri, Tahar

    2011-12-15

    Very low density lipoprotein receptor (VLDLR) is a member of the low density receptor family, expressed mostly in adipose tissue, heart, and skeletal muscles. VLDLR binds apolipoprotein-E-triglyceride-rich lipoproteins and plays a key role in lipid metabolism. In adipocytes, VLDLR expression increases with differentiation but it is not known whether it plays a role in the adipogenesis. Here we report that VLDLR expression in 3T3-L1 adipocytes is upregulated by PPARγ agonist 15-deoxy-delta(12,14)-prostaglandin J(2) (15d-PGJ(2)) in dose- and time-dependant manners. Knockdown of peroxisome proliferator-activated receptor-γ (PPARγ) with siRNA abolished pioglitazone- and 15d-PGJ(2)-induced VLDLR expression and simultaneously reduced VLDL uptake in adipocytes. In addition, PPARγ-agonist treatment of control mouse adipocytes (vldlr(+/+)) enhanced adipogenesis and VLDL uptake concurrently with the induction of VLDLR expression. However, vldlr deficiency (vldlr(-/-)) significantly blunted the proadipogenic effects of PPARγ agonists. Sequence analysis revealed the presence of a putative PPARγ responsive sequence (PPRE) within the vldlr promoter, which is responsive to natural (15d-PGJ(2)) and synthetic (pioglitazone) PPARγ agonists. Reporter gene assays using serial deletion of the 5'-flanking region showed that this putative PPRE site induced promoter transactivation, while a site-targeted mutation abolished transactivation. Moreover, electrophoresis mobility shift assay (EMSA) and chromatic immunoprecipitation (ChIP) assays showed the specific binding of PPARγ to the PPRE sequence. Together, these results support a crucial function for VLDLR in adipocyte differentiation and mediation of the proadipogenic effect of PPARγ. Copyright © 2011 Elsevier Inc. All rights reserved.

  12. Plasma long-chain free fatty acids predict mammalian longevity.

    PubMed

    Jové, Mariona; Naudí, Alba; Aledo, Juan Carlos; Cabré, Rosanna; Ayala, Victoria; Portero-Otin, Manuel; Barja, Gustavo; Pamplona, Reinald

    2013-11-28

    Membrane lipid composition is an important correlate of the rate of aging of animals and, therefore, the determination of their longevity. In the present work, the use of high-throughput technologies allowed us to determine the plasma lipidomic profile of 11 mammalian species ranging in maximum longevity from 3.5 to 120 years. The non-targeted approach revealed a specie-specific lipidomic profile that accurately predicts the animal longevity. The regression analysis between lipid species and longevity demonstrated that the longer the longevity of a species, the lower is its plasma long-chain free fatty acid (LC-FFA) concentrations, peroxidizability index, and lipid peroxidation-derived products content. The inverse association between longevity and LC-FFA persisted after correction for body mass and phylogenetic interdependence. These results indicate that the lipidomic signature is an optimized feature associated with animal longevity, emerging LC-FFA as a potential biomarker of longevity.

  13. Cannabinoid 1 receptor promotes cardiac dysfunction, oxidative stress, inflammation, and fibrosis in diabetic cardiomyopathy.

    PubMed

    Rajesh, Mohanraj; Bátkai, Sándor; Kechrid, Malek; Mukhopadhyay, Partha; Lee, Wen-Shin; Horváth, Béla; Holovac, Eileen; Cinar, Resat; Liaudet, Lucas; Mackie, Ken; Haskó, György; Pacher, Pál

    2012-03-01

    Endocannabinoids and cannabinoid 1 (CB(1)) receptors have been implicated in cardiac dysfunction, inflammation, and cell death associated with various forms of shock, heart failure, and atherosclerosis, in addition to their recognized role in the development of various cardiovascular risk factors in obesity/metabolic syndrome and diabetes. In this study, we explored the role of CB(1) receptors in myocardial dysfunction, inflammation, oxidative/nitrative stress, cell death, and interrelated signaling pathways, using a mouse model of type 1 diabetic cardiomyopathy. Diabetic cardiomyopathy was characterized by increased myocardial endocannabinoid anandamide levels, oxidative/nitrative stress, activation of p38/Jun NH(2)-terminal kinase (JNK) mitogen-activated protein kinases (MAPKs), enhanced inflammation (tumor necrosis factor-α, interleukin-1β, cyclooxygenase 2, intracellular adhesion molecule 1, and vascular cell adhesion molecule 1), increased expression of CB(1), advanced glycation end product (AGE) and angiotensin II type 1 receptors (receptor for advanced glycation end product [RAGE], angiotensin II receptor type 1 [AT(1)R]), p47(phox) NADPH oxidase subunit, β-myosin heavy chain isozyme switch, accumulation of AGE, fibrosis, and decreased expression of sarcoplasmic/endoplasmic reticulum Ca(2+)-ATPase (SERCA2a). Pharmacological inhibition or genetic deletion of CB(1) receptors attenuated the diabetes-induced cardiac dysfunction and the above-mentioned pathological alterations. Activation of CB(1) receptors by endocannabinoids may play an important role in the pathogenesis of diabetic cardiomyopathy by facilitating MAPK activation, AT(1)R expression/signaling, AGE accumulation, oxidative/nitrative stress, inflammation, and fibrosis. Conversely, CB(1) receptor inhibition may be beneficial in the treatment of diabetic cardiovascular complications.

  14. Innate immunity mediated longevity and longevity induced by germ cell removal converge on the C-type lectin domain protein IRG-7

    PubMed Central

    Yunger, Elad; Safra, Modi; Levi-Ferber, Mor; Haviv-Chesner, Anat

    2017-01-01

    In C. elegans, removal of the germline triggers molecular events in the neighboring intestine, which sends an anti-aging signal to the rest of the animal. In this study, we identified an innate immunity related gene, named irg-7, as a novel mediator of longevity in germlineless animals. We consider irg-7 to be an integral downstream component of the germline longevity pathway because its expression increases upon germ cell removal and its depletion interferes with the activation of the longevity-promoting transcription factors DAF-16 and DAF-12 in germlineless animals. Furthermore, irg-7 activation by itself sensitizes the animals' innate immune response and extends the lifespan of animals exposed to live bacteria. This lifespan-extending pathogen resistance relies on the somatic gonad as well as on many genes previously associated with the reproductive longevity pathway. This suggests that these genes are also relevant in animals with an intact gonad, and can affect their resistance to pathogens. Altogether, this study demonstrates the tight association between germline homeostasis and the immune response of animals, and raises the possibility that the reproductive system can act as a signaling center to divert resources towards defending against putative pathogen attacks. PMID:28196094

  15. Lack of nucleotide-promoted second messenger signaling responses in 1321N1 cells expressing the proposed P2Y receptor, p2y7.

    PubMed

    Herold, C L; Li, Q; Schachter, J B; Harden, T K; Nicholas, R A

    1997-06-27

    A recently cloned G protein-coupled receptor (named the p2y7 receptor) with relatively low sequence identity to previously cloned P2Y receptors was proposed to be a member of this family of receptors on the basis of both a radioligand binding assay with [35S]dATP alphaS and an inositol phosphate response to ATP in COS-7 cells transiently transfected with receptor cDNA. Previous work in our laboratory has shown that [35S]dATP alphaS is not a general radioligand for the identification of P2Y receptors and that COS-7 cells express an endogenous P2Y receptor (P2Y2) that complicates the analysis of nucleotide-promoted inositol phosphate responses. Thus, data supporting inclusion of the p2y7 receptor in the P2Y family of receptors are equivocal. To determine unambiguously whether the p2y7 receptor is a P2Y receptor subtype, a p2y7 receptor bearing an epitope-tag at its NH2-terminus was expressed in 1321N1 cells and cell surface expression of the receptor was demonstrated by an intact cell-based ELISA. Cells shown to express epitope-tagged p2y7 receptors by ELISA were examined for their second messenger signaling properties in response to a range of nucleotides. ATP, UTP, ADP, UDP, and dATP alphaS had no effect on phospholipase C or adenylyl cyclase activities in cells expressing the p2y7 receptor. Experimental controls utilizing expression of other G protein-coupled receptors showed that 1321N1 cells displayed robust responses for each of these signaling pathways. These data, together with the low sequence identity of the p2y7 receptor to other P2Y receptors, indicate that the p2y7 is not a member of the P2Y family of signaling molecules.

  16. PGE2 Promotes Apoptosis Induced by Cytokine Deprivation through EP3 Receptor and Induces Bim in Mouse Mast Cells

    PubMed Central

    Kovarova, Martina; Koller, Beverly H.

    2014-01-01

    Increased mast cell numbers are observed at sites of allergic inflammation and restoration of normal mast cell numbers is critical to the resolution of these responses. Early studies showed that cytokines protect mast cells from apoptosis, suggesting a simple model in which diminished cytokine levels during resolution leads to cell death. The report that prostaglandins can contribute both to recruitment and to the resolution of inflammation together with the demonstration that mast cells express all four PGE2 receptors raises the question of whether a single PGE2 receptor mediates the ability of PGE2 to regulate mast cell survival and apoptosis. We report here that PGE2 through the EP3 receptor promotes cell death of mast cells initiated by cytokine withdrawal. Furthermore, the ability of PGE2 to limit reconstitution of tissues with cultured mast cells is lost in cell lacking the EP3 receptor. Apoptosis is accompanied by higher dissipation of mitochondrial potential (ΔΨm), increased caspase-3 activation, chromatin condensation, and low molecular weight DNA cleavage. PGE2 augmented cell death is dependent on an increase in intracellular calcium release, calmodulin dependent kinase II and MAPK activation. Synergy between the EP3 pathway and the intrinsic mitochondrial apoptotic pathway results in increased Bim expression and higher sensitivity of mast cells to cytokine deprivation. This supports a model in which PGE2 can contribute to the resolution of inflammation in part by augmenting the removal of inflammatory cells in this case, mast cells. PMID:25054560

  17. P2X7 receptor promotes intestinal inflammation in chemically induced colitis and triggers death of mucosal regulatory T cells.

    PubMed

    Figliuolo, Vanessa R; Savio, Luiz Eduardo Baggio; Safya, Hanaa; Nanini, Hayandra; Bernardazzi, Cláudio; Abalo, Alessandra; de Souza, Heitor S P; Kanellopoulos, Jean; Bobé, Pierre; Coutinho, Cláudia M L M; Coutinho-Silva, Robson

    2017-03-07

    P2X7 receptor activation contributes to inflammation development in different pathologies. We previously reported that the P2X7 receptor is over-expressed in the gut mucosa of patients with inflammatory bowel disease, and that P2X7 inhibition protects against chemically induced colitis. Here, we investigated in detail the role of the P2X7 receptor in inflammatory bowel disease development, by treating P2X7 knockout (KO) and WT mice with two different (and established) colitis inductors. P2X7 KO mice were protected against gut inflammation induced by 2,4,6-trinitrobenzenesulfonic acid or oxazolone, with no weight loss or gut histological alterations after treatment. P2X7 receptor knockout induced regulatory T cell accumulation in the colon, as evaluated by qRT-PCR for FoxP3 expression and immunostaining for CD90/CD45RB(low). Flow cytometry analysis of mesenteric lymph node cells showed that P2X7 activation (by ATP) triggered regulatory T cell death. In addition, such cells from P2X7 KO mice expressed more CD103, suggesting increased migration of regulatory T cells to the colon (relative to the WT). Our results show that the P2X7 has a key role during inflammation development in inflammatory bowel disease, by triggering the death and retention in the mesenteric lymph nodes of regulatory T cells that would otherwise promote immune system tolerance in the gut.

  18. The C. elegans NR4A nuclear receptor gene nhr-6 promotes cell cycle progression in the spermatheca lineage.

    PubMed

    Praslicka, Brandon; Gissendanner, Chris R

    2015-03-01

    NR4A nuclear receptors are a conserved, functionally diverse group of nuclear receptors that regulate multiple cellular processes including proliferation and differentiation. The gene nhr-6 encodes the sole Caenorhabditis elegans NR4A nuclear receptor homolog with an essential role in reproduction by regulating morphogenesis of the spermatheca, a somatic gonad organ involved in ovulation and fertilization. Here, we identify the spermatheca cell lineage defects that occur in nhr-6 mutants. Utilizing cell marker analysis, we find that nhr-6 is required for cell cycle progression and that the cell proliferation phenotype is not due to premature cell cycle exit. We also show that loss of the negative cell cycle regulators fzr-1 and lin-35 suppresses the cell proliferation defects. We further demonstrate that NHR-6 activity intersects with Eph receptor signaling during spermatheca cell proliferation. NHR-6 has an essential function in promoting cell cycle progression during G1 phase in a specific spermatheca cell lineage. Genetic suppression of the proliferation phenotype does not affect the differentiation phenotypes observed in nhr-6 mutants, indicating a dualistic role for nhr-6 in regulating cell proliferation and cell differentiation during spermatheca organogenesis. © 2014 Wiley Periodicals, Inc.

  19. CDK11{sup p58} represses vitamin D receptor-mediated transcriptional activation through promoting its ubiquitin-proteasome degradation

    SciTech Connect

    Chi, Yayun; Hong, Yi; Zong, Hongliang; Wang, Yanlin; Zou, Weiying; Yang, Junwu; Kong, Xiangfei; Yun, Xiaojing; Gu, Jianxin

    2009-08-28

    Vitamin D receptor (VDR) is a member of the nuclear receptor superfamily and regulates transcription of target genes. In this study, we identified CDK11{sup p58} as a novel protein involved in the regulation of VDR. CDK11{sup p58}, a member of the large family of p34cdc2-related kinases, is associated with cell cycle progression, tumorigenesis, and apoptotic signaling. Our study demonstrated that CDK11{sup p58} interacted with VDR and repressed VDR-dependent transcriptional activation. Furthermore, overexpression of CDK11{sup p58} decreased the stability of VDR through promoting its ubiquitin-proteasome-mediated degradation. Taken together, these results suggest that CDK11{sup p58} is involved in the negative regulation of VDR.

  20. Neonatal Fc receptor promoter gene polymorphism does not predict pharmacokinetics of IVIg or the clinical course of GBS.

    PubMed

    Fokkink, Willem-Jan R; Haarman, Annechien E G; Tio-Gillen, Anne P; van Rijs, Wouter; Huizinga, Ruth; van Doorn, Pieter A; Jacobs, Bart C

    2016-07-01

    Treatment of Guillain-Barré syndrome with a standard course of high-dose intravenous immunoglobulin (IVIg) results in a variable clinical recovery which is associated with changes in serum IgG levels after treatment. The neonatal Fc-receptor protects IgG from degradation, and a genetic polymorphism in its promoter region that influences the expression of Fc-receptor, may in part explain the variation in IgG levels and outcome. This polymorphism was determined by polymerase chain reaction in a cohort of 257 patients with Guillain-Barré syndrome treated with IVIg. We could not demonstrate a relation between this polymorphism, the pharmacokinetics of IVIg, or the clinical course and outcome.

  1. Ah receptor- and TCDD-mediated liver tumor promotion: clonal selection and expansion of cells evading growth arrest and apoptosis.

    PubMed

    Bock, Karl Walter; Köhle, Christoph

    2005-05-15

    The Ah receptor (AhR) has been characterized as a ligand-activated transcription factor which belongs to the bHLH/PAS (basic helix-loop-helix/Per-Arnt-Sim) family of chemosensors. Transgenic mouse models revealed adaptive and developmental functions of the AhR in the absence of exogenous ligands. Use of persistent agonists such as dioxins including 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and related compounds demonstrated that the AhR mediates a plethora of species- and tissue-dependent toxicities, including chloracne, wasting, teratogenicity, immunotoxicity, liver tumor promotion and carcinogenicity. However, molecular mechanisms underlying most aspects of these toxic responses as well as biological functions of the AhR are currently unknown. Previous studies of liver tumor promotion in the two-stage hepatocarcinogenesis model indicated that TCDD mediates clonal expansion of 'initiated' preneoplastic hepatocytes, identified as enzyme-altered foci (EAF) by inhibiting apoptosis and bypassing AhR-mediated growth arrest. In contrast, the Ah receptor has been shown in cell models to stimulate growth arrest and apoptosis. Possible underlying mechanisms of these AhR responses are discussed, including enhanced metabolism of retinoic acid which attenuates TGFbeta-mediated apoptosis and interaction of the Ah receptor with the hypophosphorylated retinoblastoma tumor suppressor protein. The discrepancy between in vivo findings in EAF and AhR functions may be solved by hypothesizing that sustained activation of the Ah receptor generates a strong selective pressure in liver treated with genotoxic carcinogens leading to selection and expansion of clones evading growth arrest and apoptosis. Models are discussed which may facilitate verification of this hypothesis.

  2. Agonist-promoted desensitization and phosphorylation of. cap alpha. /sub 1/-adrenergic receptors coupled to stimulation of phosphatidylinositol metabolism

    SciTech Connect

    Leeb-Lundberg, L.M.F.; Cotecchia, S.; Caron, M.G.; Lefkowitz, R.J.

    1986-03-05

    In the DDT/sub 1/ MF-2 hamster vas deferens smooth muscle cell line the ..cap alpha../sub 1/-adrenergic receptor (..cap alpha../sub 1/-AR) agonist norepinephrine (NE) promotes rapid attenuation of ..cap alpha../sub 1/-AR-mediated phosphatidylinositol (PI) metabolism which is paralleled by rapid phosphorylation of the ..cap alpha../sub 1/-AR. Cells were labeled by incubation with /sup 32/P/sub i/. Coincubation with NE (100 ..mu..M) significantly increases the rate of /sup 32/P-labeling of both PI and phosphatidic acid. Pretreatment of cells with 100 ..mu..M NE (in the presence of 1 ..mu..M propranolol to prevent ..beta..-AR interactions) results in a drastic attenuation of the NE response on PI metabolism. ..cap alpha../sub 1/-AR from labeled cells can be solubilized and purified by affinity chromatography on Affigel-A55414 and wheat germ agglutinin agarose chromatography. SDS-PAGE of purified ..cap alpha../sub 1/-AR shows a NE-promoted increase in phosphorylation of the M/sub r/ 80K ligand binding peptide. Stoichiometry of phosphorylation increases from approx. 1 mol phosphate/mol ..cap alpha../sub 1/-AR in the basal condition to approx. 2.5 after NE treatment. Both desensitization and phosphorylation are rapid being maximal within 10-20 min of agonist exposure. These results together with previous findings that phorbol esters promote rapid ..cap alpha../sub 1/-AR uncoupling and phosphorylation suggest that receptor phosphorylation is an important mechanism of regulation of ..cap alpha../sub 1/-AR receptor responsiveness.

  3. Mutation of C. elegans demethylase spr-5 extends transgenerational longevity

    PubMed Central

    Greer, Eric Lieberman; Becker, Ben; Latza, Christian; Antebi, Adam; Shi, Yang

    2016-01-01

    Complex organismal properties such as longevity can be transmitted across generations by non-genetic factors. Here we demonstrate that deletion of the C. elegans histone H3 lysine 4 dimethyl (H3K4me2) demethylase, spr-5, causes a trans-generational increase in lifespan. We identify a chromatin-modifying network, which regulates this lifespan extension. We further show that this trans-generational lifespan extension is dependent on a hormonal signaling pathway involving the steroid dafachronic acid, an activator of the nuclear receptor DAF-12. These findings suggest that loss of the demethylase SPR-5 causes H3K4me2 mis-regulation and activation of a known lifespan-regulating signaling pathway, leading to trans-generational lifespan extension. PMID:26691751

  4. Genetics and gene-environment interactions on longevity and lifespan

    USDA-ARS?s Scientific Manuscript database

    Longevity is a complex trait and highly associated with healthspan – lifespan without major diseases. In human populations there is a large amount of variation in longevity, which can be attributed to genetics, environment, and interactions between them. The genetic contribution to longevity is abou...

  5. Longevity and Mortality in Down's Syndrome.

    ERIC Educational Resources Information Center

    Thase, M. E.

    1982-01-01

    Research on the longevity of Down's Syndrome persons is reviewed, and the life span is noted to have increased, although the overall mortality rate is still five times greater than that for the general population. Statistics on causes of mortality (such as immunological abnormalities, congenital heart disease, and malignancy) are summarized. (CL)

  6. Longevity and Education: Survey Results, 2002.

    ERIC Educational Resources Information Center

    Silverman, Barbara; Lange, Mary Sue

    In order to better serve the needs of people in midlife and beyond, Mt. San Antonio College (Mt. SAC), California, is considering the establishment of a Center for Longevity and Education (CLE). The CLE mission would be to foster a supportive environment for lifelong learning and life transitions for midlife and beyond, while channeling the…

  7. Longevity and Depreciation of Audiovisual Equipment.

    ERIC Educational Resources Information Center

    Post, Richard

    1987-01-01

    Describes results of survey of media service directors at public universities in Ohio to determine the expected longevity of audiovisual equipment. Use of the Delphi technique for estimates is explained, results are compared with an earlier survey done in 1977, and use of spreadsheet software to calculate depreciation is discussed. (LRW)

  8. Translational genomics for improving sow reproductive longevity

    USDA-ARS?s Scientific Manuscript database

    Sow reproductive longevity is a composite trait that is expressed throughout life that depends on the potential of females to resume ovarian cyclicity, re-breed, and farrow multiple parities. Approximately 50% of sows are culled annually with more than one third due to poor fertility. Age at puberty...

  9. Longevity and Depreciation of Audiovisual Equipment.

    ERIC Educational Resources Information Center

    Post, Richard

    1987-01-01

    Describes results of survey of media service directors at public universities in Ohio to determine the expected longevity of audiovisual equipment. Use of the Delphi technique for estimates is explained, results are compared with an earlier survey done in 1977, and use of spreadsheet software to calculate depreciation is discussed. (LRW)

  10. Longevity and Patau syndrome: what determines survival?

    PubMed

    Peroos, Sherina; Forsythe, Elizabeth; Pugh, Jennifer Harriet; Arthur-Farraj, Peter; Hodes, Deborah

    2012-12-06

    The authors report of an 8-year-old girl with non-mosaic Patau syndrome. The median life expectancy of Patau syndrome is 7-10 days, and 90% die in the first year of life. Survival is often attributed to mosaicism and the severity of associated malformations. We delineate the developing phenotype and review the literature discussing potential contributory factors to longevity.

  11. Snag longevity in managed northern hardwoods

    Treesearch

    Mariko Yamasaki; William B. Leak

    2006-01-01

    Little information on standing snag and coarse woody debris longevity exists for New England forest types. Forest managers thus lack the information on changes over time of the habitat components influenced by the decay process. We examined the fate of 568 snags that occurred on a long-term hardwood growth study on the Bartlett Experimental Forest, NH. Approximately...

  12. Mitochondrial membrane lipidome defines yeast longevity

    PubMed Central

    Burstein, Michelle T.; Bourque, Simon D.; Koupaki, Olivia; Juneau, Mylène; Feldman, Rachel; Iouk, Tatiana; Titorenko, Vladimir I.

    2013-01-01

    Our studies revealed that lithocholic acid (LCA), a bile acid, is a potent anti-aging natural compound that in yeast cultured under longevity-extending caloric restriction (CR) conditions acts in synergy with CR to enable a significant further increase in chronological lifespan. Here, we investigate a mechanism underlying this robust longevity-extending effect of LCA under CR. We found that exogenously added LCA enters yeast cells, is sorted to mitochondria, resides mainly in the inner mitochondrial membrane, and also associates with the outer mitochondrial membrane. LCA elicits an age-related remodeling of glycerophospholipid synthesis and movement within both mitochondrial membranes, thereby causing substantial changes in mitochondrial membrane lipidome and triggering major changes in mitochondrial size, number and morphology. In synergy, these changes in the membrane lipidome and morphology of mitochondria alter the age-related chronology of mitochondrial respiration, membrane potential, ATP synthesis and reactive oxygen species homeostasis. The LCA-driven alterations in the age-related dynamics of these vital mitochondrial processes extend yeast longevity. In sum, our findings suggest a mechanism underlying the ability of LCA to delay chronological aging in yeast by accumulating in both mitochondrial membranes and altering their glycerophospholipid compositions. We concluded that mitochondrial membrane lipidome plays an essential role in defining yeast longevity. PMID:23924582

  13. DDR2 receptor promotes MMP-2-mediated proliferation and invasion by hepatic stellate cells.

    PubMed

    Olaso, E; Ikeda, K; Eng, F J; Xu, L; Wang, L H; Lin, H C; Friedman, S L

    2001-11-01

    Type I collagen provokes activation of hepatic stellate cells during liver injury through mechanisms that have been unclear. Here, we tested the role of the discoidin domain tyrosine kinase receptor 2 (DDR2), which signals in response to type I collagen, in this pathway. DDR2 mRNA and protein are induced in stellate cells activated by primary culture or in vivo during liver injury. The receptor becomes tyrosine phosphorylated in response to either endogenous or exogenous type I collagen, whereas its expression is downregulated during cellular quiescence induced by growth on Matrigel. We developed stellate cell lines stably overexpressing either wild-type DDR2, a constitutively active chimeric DDR2 receptor (Fc-DDR2), a truncated receptor expressing the extracellular domain, or a kinase-dead DDR2 Cells overexpressing DDR2 showed enhanced proliferation and invasion through Matrigel, activities that were directly related to increased expression of active matrix metalloproteinase 2 (MMP-2). These data show that DDR2 is induced during stellate cell activation and implicate the phosphorylated receptor as a mediator of MMP-2 release and growth stimulation in response to type I collagen. Moreover, type I collagen-dependent upregulation of DDR2 expression establishes a positive feedback loop in activated stellate cells, leading to further proliferation and enhanced invasive activity.

  14. Down-modulation of receptors for phorbol ester tumor promoter in primary epidermal cells

    SciTech Connect

    Solanki, V.; Slaga, T.J.

    1982-01-01

    The specific (20-/sup 3/H)phorbol 12,13-dibutyrate ((/sup 3/H)PDBu) binding to intact epidermal cells displayed the phenomenon of down-modulation, i.e., the specific binding of (/sup 3/H)PDBu to its receptors on primary epidermal cells reached a maximum within 1 h and steadily declined thereafter. The apparent down-modulation of radiolabel resulted from a partial loss in the total number of receptors; the affinity of receptors for the ligand was essentially unchanged. A number of agents such as chloroquine, methylamine, or arginine which are known to prevent clustering, down-modulation, and/or internalization of several hormone receptors did not affect the down-modulation of phorbol ester receptors. Furthermore, cycloheximide had no effect either on down-modulation or on the binding capacity of cells. The surface binding capacity of down-modulated cells following a 90-min incubation with unlabeled ligand was almost returned to normal within 1 h. The effect of the antidepressant drug chlorpromazine, which is known to interact with calmodulin, on (/sup 3/H)PDBu binding was also investigated. Our data indicate that the effect of chlorpromazine on (/sup 3/H)PDBu binding is probably unrelated to its calmodulin-binding activity.

  15. Amisulpride promotes cognitive flexibility in rats: the role of 5-HT7 receptors.

    PubMed

    Nikiforuk, Agnieszka; Popik, Piotr

    2013-07-01

    The antagonism of 5-HT7 receptors may contribute to the antidepressant and procognitive actions of the atypical antipsychotic drug, amisulpride. It has been previously demonstrated that the selective 5-HT7 receptor antagonist reversed restraint stress-induced cognitive impairments in a rat model of frontal-dependent attentional set-shifting task (ASST). Therefore, the first aim of the present study was to assess the effectiveness of amisulpride against stress-evoked cognitive inflexibility. The second goal was to elucidate whether the pro-cognitive effect of amisulpride could be due to the compound's action at 5-HT7 receptors. Rats repeatedly exposed (1 h daily for 7 days) to restraint stress demonstrated impaired performance on the extra-dimensional (ED) set-shifting stage of the ASST. Amisulpride (3 mg/kg) given to stressed rats 30 min before testing reversed this restraint-induced cognitive inflexibility and improved ED performance of the unstressed control group. The 5-HT7 receptor agonist, AS19 (10 mg/kg), abolished the pro-cognitive efficacy of amisulpride (3 mg/kg). The present study suggests that the antagonism of 5-HT7 receptors may contribute to the mechanisms underlining the pro-cognitive action of amisulpride. These results may have therapeutic implications in frontal-like deficits associated with stress-related disorders.

  16. Differential and Interactive Effects of Ligand-Bound Progesterone Receptor A and B Isoforms on Tyrosine Hydroxylase Promoter Activity

    PubMed Central

    Jensik, Philip J.; Arbogast, Lydia A.

    2013-01-01

    The classical progesterone receptors (PRs) are expressed in some hypothalamic dopaminergic and brainstem noradrenergic neurons. Progesterone influences prolactin and luteinising hormone release from the anterior pituitary gland, in part by regulating the activity of these catecholaminergic neurons. The aim of this study was to determine the effects of PRs on tyrosine hydroxylase (TH) promoter activity. When CAD, SK-N-SH and CV-1 cells were transfected with TH promoter constructs and PR-A or PR-B expression vectors, progesterone treatment caused three- to six-fold increases in TH-9.0kb promoter activity in PR-B expressing cells, but a modest increase or no change in PR-A expressing cells. Using CAD cells, deletional analysis mapped the site of PR action to the −1403 to −1304 bp region of the TH promoter. Mutational analysis of putative regulatory sequences in this region indicated multiple DNA elements are required for complete PR-B transactivation. Electrophoretic mobility shift assays were unable to demonstrate direct PR-B binding to TH promoter DNA sequences. However, chromatin immunoprecipitation (ChIP) analysis indicated PR-B was recruited to the TH promoter. Two different PR-B DNA binding domain mutants had opposite effects on PR-B mediated TH promoter activation. A GS to AA mutation located in the p-box of the first zinc finger of PR-B inhibited progesterone transactivation of the TH promoter, whereas a C to A mutation in the zinc finger increased transactivation. PR-A was able to inhibit PR-B transactivation in a dose-dependent manner, although the degree of PR-A inhibition was dependent on the TH promoter deletion construct. These data indicate that ligand-bound PR-B is recruited to DNA elements in the TH promoter and acts as a transcriptional activator of the TH gene and that changes in the ratio of PR-A to PR-B may affect the ability of progesterone to increase TH expression. PMID:21815951

  17. Adrenergic receptor β2 activation by stress promotes breast cancer progression through macrophages M2 polarization in tumor microenvironment.

    PubMed

    Qin, Jun-fang; Jin, Feng-jiao; Li, Ning; Guan, Hai-tao; Lan, Lan; Ni, Hong; Wang, Yue

    2015-05-01

    Stress and its related hormones epinephrine (E) and norepinephrine (NE) play a crucial role in tumor progression. Macrophages in the tumor microenvironment (TME) polarized to M2 is also a vital pathway for tumor deterioration. Here, we explore the underlying role of macrophages in the effect of stress and E promoting breast cancer growth. It was found that the weight and volume of tumor in tumor bearing mice were increased, and dramatically accompanied with the rising E level after chronic stress using social isolation. What is most noteworthy, the number of M2 macrophages inside tumor was up-regulated with it. The effects of E treatment appear to be directly related to the change of M2 phenotype is reproduced in vitro. Moreover, E receptor ADRβ2 involved in E promoting M2 polarization was comprehended simultaneously. Our results imply psychological stress is influential on specific immune system, more essential for the comprehensive treatment against tumors.

  18. Promoter analysis of human corticotropin-releasing factor (CRF) type 1 receptor and regulation by CRF and urocortin.

    PubMed

    Parham, Kelly L; Zervou, Sevasti; Karteris, Emmanouil; Catalano, Rob D; Old, Robert W; Hillhouse, Edward W

    2004-08-01

    We report the full genomic organization of the human gene for the corticotropin-releasing factor (CRF) receptor type 1 (CRFR1), with complete mapping of exons 1-14. The 5' flanking region (2.4 kb) of the gene encoding for human CRFR1 was isolated, sequenced, and characterized. Two major transcriptional start sites were determined at -265 and -238, relative to the ATG start site (+1). Transient expression of constructs containing sequentially deleted 5'-flanking sequences of CRFR1 fused to luciferase, revealed the minimal promoter sequence 370 bp in size, as shown by assays in neuroblastoma (SH-5YSY), teratocarcinoma (NT2), and adenocarcinoma (MCF 7) cell lines. CRF and UCN markedly increased promoter activity during transient CRFR1 expression studies. Similarly, CRF and UCN up-regulate the endogenous CRFR1 at the mRNA level in NT2 and MCF 7 cells. To dissect further the mechanisms involved, we have used primary myometrial cells transfected with the CRFR1 promoter. CRF and UCN increased the promoter activity, an effect blocked by protein kinase (PK)A and PKC inhibitors. Both CRF and UCN cause a positive feedback effect in primary cultures of human pregnant myometrial cells, by increasing mRNA expression of CRFR1. This effect appears to be dependent on activation of both PKA and PKC by CRF, whereas UCN's effect was mediated solely via PKC activation. Collectively, our data suggest that the CRFR1 gene is under the influence of both CRF and UCN, acting via distinct signaling pathways to create a positive feedback loop and regulate further the transcription of the receptor.

  19. The liver X-receptor gene promoter is hypermethylated in a mouse model of prenatal protein restriction.

    PubMed

    van Straten, Esther M E; Bloks, Vincent W; Huijkman, Nicolette C A; Baller, Julius F W; van Meer, Hester; Lütjohann, Dieter; Kuipers, Folkert; Plösch, Torsten

    2010-02-01

    Prenatal nutrition as influenced by the nutritional status of the mother has been identified as a determinant of adult disease. Feeding low-protein diets during pregnancy in rodents is a well-established model to induce programming events in offspring. We hypothesized that protein restriction would influence fetal lipid metabolism by inducing epigenetic adaptations. Pregnant C57BL/6J mice were exposed to a protein-restriction protocol (9% vs. 18% casein). Shortly before birth, dams and fetuses were killed. To identify putative epigenetic changes, CG-dinucleotide-rich region in the promoter of a gene (CpG island) methylation microarrays were performed on DNA isolated from fetal livers. Two hundred four gene promoter regions were differentially methylated upon protein restriction. The liver X-receptor (Lxr) alpha promoter was hypermethylated in protein-restricted pups. Lxr alpha is a nuclear receptor critically involved in control of cholesterol and fatty acid metabolism. The mRNA level of Lxra was reduced by 32% in fetal liver upon maternal protein restriction, whereas expression of the Lxr target genes Abcg5/Abcg8 was reduced by 56% and 51%, respectively, measured by real-time quantitative PCR. The same effect, although less pronounced, was observed in the fetal intestine. In vitro methylation of a mouse Lxra-promoter/luciferase expression cassette resulted in a 24-fold transcriptional repression. Our study demonstrates that, in mice, protein restriction during pregnancy interferes with DNA methylation in fetal liver. Lxra is a target of differential methylation, and Lxra transcription is dependent on DNA methylation. It is tempting to speculate that perinatal nutrition may influence adult lipid metabolism by DNA methylation, which may contribute to the epidemiological relation between perinatal/neonatal nutrition and adult disease.

  20. Targeting peripheral opioid receptors to promote analgesic and anti-inflammatory actions

    PubMed Central

    Iwaszkiewicz, Katerina S.; Schneider, Jennifer J.; Hua, Susan

    2013-01-01

    Mechanisms of endogenous pain control are significant. Increasing studies have clearly produced evidence for the clinical usefulness of opioids in peripheral analgesia. The immune system uses mechanisms of cell migration not only to fight pathogens but also to control pain and inflammation within injured tissue. It has been demonstrated that peripheral inflammatory pain can be effectively controlled by an interaction of immune cell-derived opioid peptides with opioid receptors on peripheral sensory nerve terminals. Experimental and clinical studies have clearly shown that activation of peripheral opioid receptors with exogenous opioid agonists and endogenous opioid peptides are able to produce significant analgesic and anti-inflammatory effects, without central opioid mediated side effects (e.g., respiratory depression, sedation, tolerance, dependence). This article will focus on the role of opioids in peripheral inflammatory conditions and the clinical implications of targeting peripheral opioid receptors. PMID:24167491

  1. Optimal Retirement with Increasing Longevity*

    PubMed Central

    Bloom, David E.; Canning, David; Moore, Michael

    2014-01-01

    We develop an optimizing life-cycle model of retirement with perfect capital markets. We show that longer healthy life expectancy usually leads to later retirement, but with an elasticity less than unity. We calibrate our model using data from the US and find that, over the last century, the effect of rising incomes, which promote early retirement, has dominated the effect of rising lifespans. Our model predicts continuing declines in the optimal retirement age, despite rising life expectancy, provided the rate of real wage growth remains as high as in the last century. PMID:24954970

  2. Novel NFAT sites that mediate activation of the interleukin-2 promoter in response to T-cell receptor stimulation.

    PubMed Central

    Rooney, J W; Sun, Y L; Glimcher, L H; Hoey, T

    1995-01-01

    The transcription factors NFAT and AP-1 have been shown to be essential for inducible interleukin-2 (IL-2) expression in activated T cells. NFAT has been previously reported to bind to two sites in the IL-2 promoter: in association with AP-1 at the distal antigen response element at -280 and at -135. On the basis of DNase I footprinting with recombinant NFAT and AP-1 proteins, gel shift assays, and transfection experiments, we have identified three additional NFAT sites in the IL-2 promoter. Strikingly, all five NFAT sites are essential for the full induction of promoter activity in response to T-cell receptor stimulation. Four of the five NFAT sites are part of composite elements able to bind AP-1 in association with NFAT. These sites display a diverse range of cooperativity and interdependency on NFAT and AP-1 proteins for binding. One of the NFAT sites directly overlaps the CD28-responsive element. We present evidence that CD28 inducibility is conferred by the AP-1 component in NFAT-AP-1 composite elements. These findings provide further insight into the mechanisms involved in the regulation of the IL-2 promoter. PMID:7565783

  3. Antenatal Hypoxia Induces Epigenetic Repression of Glucocorticoid Receptor and Promotes Ischemic-Sensitive Phenotype in the Developing Heart

    PubMed Central

    Xiong, Fuxia; Lin, Thant; Song, Minwoo; Ma, Qingyi; Martinez, Shannalee R.; Lv, Juanxiu; MataGreenwood, Eugenia; Xiao, Daliao; Xu, Zhice; Zhang, Lubo

    2016-01-01

    Large studies in humans and animals have demonstrated a clear association of an adverse intrauterine environment with an increased risk of cardiovascular disease later in life. Yet mechanisms remain largely elusive. The present study tested the hypothesis that gestational hypoxia leads to promoter hypermethylation and epigenetic repression of the glucocorticoid receptor (GR) gene in the developing heart, resulting in increased heart susceptibility to ischemia and reperfusion injury in offspring. Hypoxic treatment of pregnant rats from day 15 to 21 of gestation resulted in a significant decrease of GR exon 14, 15, 16, and 17 transcripts, leading to down-regulation of GR mRNA and protein in the fetal heart. Functional cAMP-response elements (CREs) at −4408 and −3896 and Sp1 binding sites at −3425 and −3034 were identified at GR untranslated exon 1 promoters. Hypoxia significantly increased CpG methylation at the CREs and Sp1 binding sites and decreased transcription factor binding to GR exon 1 promoter, accounting for the repression of the GR gene in the developing heart. Of importance, treatment of newborn pups with 5-aza-2’-deoxycytidine reversed hypoxia-induced promoter methylation, restored GR expression and prevented hypoxia-mediated increase in ischemia and reperfusion injury of the heart in offspring. The findings demonstrate a novel mechanism of epigenetic repression of the GR gene in fetal stress-mediated programming of ischemic-sensitive phenotype in the heart. PMID:26779948

  4. Antenatal hypoxia induces epigenetic repression of glucocorticoid receptor and promotes ischemic-sensitive phenotype in the developing heart.

    PubMed

    Xiong, Fuxia; Lin, Thant; Song, Minwoo; Ma, Qingyi; Martinez, Shannalee R; Lv, Juanxiu; MataGreenwood, Eugenia; Xiao, Daliao; Xu, Zhice; Zhang, Lubo

    2016-02-01

    Large studies in humans and animals have demonstrated a clear association of an adverse intrauterine environment with an increased risk of cardiovascular disease later in life. Yet mechanisms remain largely elusive. The present study tested the hypothesis that gestational hypoxia leads to promoter hypermethylation and epigenetic repression of the glucocorticoid receptor (GR) gene in the developing heart, resulting in increased heart susceptibility to ischemia and reperfusion injury in offspring. Hypoxic treatment of pregnant rats from day 15 to 21 of gestation resulted in a significant decrease of GR exon 14, 15, 16, and 17 transcripts, leading to down-regulation of GR mRNA and protein in the fetal heart. Functional cAMP-response elements (CREs) at -4408 and -3896 and Sp1 binding sites at -3425 and -3034 were identified at GR untranslated exon 1 promoters. Hypoxia significantly increased CpG methylation at the CREs and Sp1 binding sites and decreased transcription factor binding to GR exon 1 promoter, accounting for the repression of the GR gene in the developing heart. Of importance, treatment of newborn pups with 5-aza-2'-deoxycytidine reversed hypoxia-induced promoter methylation, restored GR expression and prevented hypoxia-mediated increase in ischemia and reperfusion injury of the heart in offspring. The findings demonstrate a novel mechanism of epigenetic repression of the GR gene in fetal stress-mediated programming of ischemic-sensitive phenotype in the heart.

  5. Glucocorticoid-induced glucocorticoid-receptor expression and promoter usage is not linked to glucocorticoid resistance in childhood ALL.

    PubMed

    Tissing, Wim J E; Meijerink, Jules P P; Brinkhof, Bas; Broekhuis, Mathilde J C; Menezes, Renee X; den Boer, Monique L; Pieters, Rob

    2006-08-01

    Glucocorticoid (GC) resistance is an adverse prognostic factor in childhood acute lymphoblastic leukemia (ALL), but little is known about causes of GC resistance. Up-regulation of the glucocorticoid receptor (GR) has been suggested as an essential step to the induction of apoptosis in leukemic cells. In this study we investigated whether baseline mRNA expression levels of the 5 different GR promoter transcripts (1A1, 1A2, 1A3, 1B, and 1C) or differences in the degree of regulation of the GR or GR promoter transcripts upon GC exposure are related to GC resistance. Therefore, mRNA levels of the 5 GR promoter transcripts and of the GR were measured by quantitative real-time reverse transcriptase-polymerase chain reaction (RT-PCR; Taqman) technology in primary ALL cells prior to and after 3, 8, and 24 hours of prednisolone exposure. GR expression is induced upon GC exposure in primary ALL patient samples, which is opposite to what is found in tissues in which GCs do not induce apoptosis. GC resistance in childhood ALL cannot be attributed to an inability of resistant cells to up-regulate the expression of the GR upon GC exposure, nor to differences in GR promoter usage (at baseline and upon GC exposure).

  6. Lower methylation of glucocorticoid receptor gene promoter 1F in peripheral blood of veterans with posttraumatic stress disorder.

    PubMed

    Yehuda, Rachel; Flory, Janine D; Bierer, Linda M; Henn-Haase, Clare; Lehrner, Amy; Desarnaud, Frank; Makotkine, Iouri; Daskalakis, Nikolaos P; Marmar, Charles R; Meaney, Michael J

    2015-02-15

    Enhanced glucocorticoid receptor (GR) sensitivity is present in people with posttraumatic stress disorder (PTSD), but the molecular mechanisms of GR sensitivity are not understood. Epigenetic factors have emerged as one potential mechanism that account for how trauma