bluuebunny/crossref_metadata_2025_split huggingface dataset:
Caffeine extends life span, improves healthspan, and delays age-associated pathology in Caenorhabditis elegans
Authors: Sutphin George L , Bishop Emma , Yanos Melana E , Moller Richard M , Kaeberlein Matt 
Published: December 2012

Abstract

Background
The longevity of an organism is influenced by both genetic and environmental factors. With respect to genetic factors, a significant effort is being made to identify pharmacological agents that extend life span by targeting pathways with a defined role in the aging process. On the environmental side, the molecular mechanisms responsible for the positive influence of interventions such as dietary restriction are being explored. The environment experienced by humans in modern societies already contains countless compounds that may influence longevity. Understanding the role played by common compounds that substantially affect the aging process will be critical for predicting and interpreting the outcome of introducing new interventions. Caffeine is the most widely used psychoactive drug worldwide. Prior studies in flies, worms, and mice indicate that caffeine may positively impact age-associated neurodegenerative pathology, such as that observed in Alzheimer’s disease.

Results
Here we report that caffeine is capable of extending life span and improving healthspan in Caenorhabditis elegans, a finding that is in agreement with a recently published screen looking for FDA-approved compounds capable of extending worm life span. Life span extension using caffeine displays epistatic interaction with two known longevity interventions: dietary restriction and reduced insulin signaling. Caffeine treatment also delays pathology in a nematode model of polyglutamine disease.

Conclusions
The identification of caffeine as a relevant factor in aging and healthspan in worms, combined with prior work in both humans and rodents linking caffeine consumption to reduced risk of age-associated disease, suggests that caffeine may target conserved longevity pathways. Further, it may be important to consider caffeine consumption when developing clinical interventions, particularly those designed to mimic dietary restriction or modulate insulin/IGF-1-like signaling. The positive impact of caffeine on a worm model of polyglutamine disease suggests that chronic caffeine consumption may generally enhance resistance to proteotoxic stress and may be relevant to assessing risk and developing treatments for human diseases like Alzheimer’s and Huntington’s disease. Future work addressing the relevant targets of caffeine in models of aging and healthspan will help to clarify the underlying mechanisms and potentially identify new molecular targets for disease intervention.
Mouse zygote-specific proteasome assembly chaperone important for maternal-to-zygotic transition
Authors: Shin Seung-Wook , Shimizu Natsumi , Tokoro Mikiko , Nishikawa Satoshi , Hatanaka Yuki , Anzai Masayuki , Hamazaki Jun , Kishigami Satoshi , Saeki Kazuhiro , Hosoi Yoshihiko , Iritani Akira , Murata Shigeo , Matsumoto Kazuya 
Published: December 2012

Summary
During the maternal-to-zygotic transition (MZT), maternal proteins in oocytes are degraded by the ubiquitin–proteasome system (UPS), and new proteins are synthesized from the zygotic genome. However, the specific mechanisms underlying the UPS at the MZT are not well understood. We identified a molecule named zygote-specific proteasome assembly chaperone (ZPAC) that is specifically expressed in mouse gonads, and expression of ZPAC was transiently increased at the mouse MZT. ZPAC formed a complex with Ump1 and associated with precursor forms of 20S proteasomes. Transcription of ZPAC genes was also under the control of an autoregulatory feedback mechanism for the compensation of reduced proteasome activity similar to Ump1 and 20S proteasome subunit gene expression. Knockdown of ZPAC in early embryos caused a significant reduction of proteasome activity and decrease in Ump1 and mature proteasomes, leading to accumulation of proteins that need to be degraded at the MZT and early developmental arrest. Therefore, a unique proteasome assembly pathway mediated by ZPAC is important for progression of the mouse MZT.
In vivo genetic manipulation of cortical progenitors in gyrencephalic carnivores using in utero electroporation
Authors: Kawasaki Hiroshi , Toda Tomohisa , Tanno Kaori 
Published: December 2012

Summary
Brain structures such as the outer subventricular zone (OSVZ) and the inner fiber layer (IFL) in the developing cerebral cortex are especially prominent in higher mammals. However, the molecular mechanisms underlying the formation of the OSVZ are still largely unknown, mainly because genetic manipulations that can be applied to the OSVZ in higher mammals had been poorly available. Here we developed and validated a rapid and efficient genetic manipulation technique for germinal zones including the OSVZ using in utero electroporation in developing gyrencephalic carnivore ferrets. We also determined the optimal conditions for using in utero electroporation to express transgenes in germinal zones. Using our electroporation procedure, the morphology of GFP-positive cells in the OSVZ was clearly visible even without immunostaining, and multiple genes were efficiently co-expressed in the same cells. Furthermore, we uncovered that fibers, which seemed to correspond to those in the IFL of monkeys, also existed in ferrets, and were derived from newly generated cortical neurons. Our technique promises to be a powerful tool for investigating the fundamental mechanisms underlying the formation and abnormalities of the cerebral cortex in higher mammals.
Capicua regulates proliferation and survival of RB-deficient cells in Drosophila
Authors: Krivy Kate , Bradley-Gill Mary-Rose , Moon Nam-Sung 
Published: December 2012

Summary
Mutations in rbf1, the Drosophila homologue of the RB tumour suppressor gene, generate defects in cell cycle control, cell death, and differentiation during development. Previous studies have established that EGFR/Ras activity is an important determinant of proliferation and survival in rbf1 mutant cells. Here, we report that Capicua (Cic), an HMG box transcription factor whose activity is regulated by the EGFR/Ras pathway, regulates both proliferation and survival of RB-deficient cells in Drosophila. We demonstrate that cic mutations allow rbf1 mutant cells to bypass developmentally controlled cell cycle arrest and apoptotic pressure. The cooperative effect between Cic and RBF1 in promoting G1 arrest is mediated, at least in part, by limiting Cyclin E expression. Surprisingly, we also found evidence to suggest that cic mutant cells have decreased levels of reactive oxygen species (ROS), and that the survival of rbf1 mutant cells is affected by changes in ROS levels. Collectively, our results elucidate the importance of the crosstalk between EGFR/Ras and RBF1 in coordinating cell cycle progression and survival.
Association of β-catenin with P-Smad3 but not LEF-1 dissociates in vitro profibrotic from anti-inflammatory effects of TGF-β1
Authors: Tian Xinrui , Zhang Jianlin , Tan Thian Kui , Lyons J. Guy , Zhao Hong , Niu Bo , Lee So Ra , Tsatralis Tania , Zhao Ye , Wang Ya , Cao Qi , Wang Changqi , Wang Yiping , Lee Vincent W. S. , Kahn Michael , Zheng Guoping , Harris David C. H. 
Published: December 2012

Summary
Transforming growth factor β1 (TGF-β1) is known to be both anti-inflammatory and profibrotic. Cross-talk between TGF-β/Smad and Wnt/β-catenin pathways in epithelial–mesenchymal transition (EMT) suggests a specific role for β-catenin in profibrotic effects of TGF-β1. However, no such mechanistic role has been demonstrated for β-catenin in the anti-inflammatory effects of TGF-β1. In the present study, we explored the role of β-catenin in the profibrotic and anti-inflammatory effects of TGF-β1 by using a cytosolic, but not membrane, β-catenin knockdown chimera (F-TrCP-Ecad) and the β-catenin/CBP inhibitor ICG-001. TGF-β1 induced nuclear Smad3/β-catenin complex, but not β-catenin/LEF-1 complex or TOP-flash activity, during EMT of C1.1 (renal tubular epithelial) cells. F-TrCP-Ecad selectively degraded TGF-β1-induced cytoplasmic β-catenin and blocked EMT of C1.1 cells. Both F-TrCP-Ecad and ICG-001 blocked TGF-β1-induced Smad3/β-catenin and Smad reporter activity in C1.1 cells, suggesting that TGF-β1-induced EMT depends on β-catenin binding to Smad3, but not LEF-1 downstream of Smad3, through canonical Wnt. In contrast, in J774 macrophages, the β-catenin level was low and was not changed by interferon-γ (IFN-γ) or lipopolysaccharide (LPS) with or without TGF-β1. TGF-β1 inhibition of LPS-induced TNF-α and IFN-γ-stimulated inducible NO synthase (iNOS) expression was not affected by F-TrCP-Ecad, ICG-001 or by overexpression of wild-type β-catenin in J774 cells. Inhibition of β-catenin by either F-TrCP-Ecad or ICG-001 abolished LiCl-induced TOP-flash, but not TGF-β1-induced Smad reporter, activity in J774 cells. These results demonstrate for the first time that β-catenin is required as a co-factor of Smad in TGF-β1-induced EMT of C1.1 epithelial cells, but not in TGF-β1 inhibition of macrophage activation. Targeting β-catenin may dissociate the TGF-β1 profibrotic and anti-inflammatory effects.
A non-catalytic role for inositol 1,3,4,5,6-pentakisphosphate 2-kinase in the synthesis of ribosomal RNA
Authors: Brehm Maria A. , Wundenberg Torsten , Williams Jason , Mayr Georg W. , Shears Stephen B. 
Published: December 2012

Summary
Fundamental to the life and destiny of every cell is the regulation of protein synthesis through ribosome biogenesis, which begins in the nucleolus with the production of ribosomal RNA (rRNA). Nucleolar organization is a highly dynamic and tightly regulated process; the structural factors that direct nucleolar assembly and disassembly are just as important in controlling rRNA synthesis as are the catalytic activities that synthesize rRNA. Here, we report that a signaling enzyme, inositol 1,3,4,5,6-pentakisphosphate 2-kinase (IP5K) is also a structural component in the nucleolus. We demonstrate that IP5K has functionally significant interactions with three proteins that regulate rRNA synthesis: protein kinase CK2, TCOF1 and upstream-binding-factor (UBF). Through molecular modeling and mutagenic studies, we identified an Arg-Lys-Lys tripeptide located on the surface of IP5K that mediates its association with UBF. Nucleolar IP5K spatial dynamics were sensitive to experimental procedures (serum starvation or addition of actinomycin D) that inhibited rRNA production. We show that IP5K makes stoichiometrically sensitive contributions to the architecture of the nucleoli in intact cells, thereby influencing the degree of rRNA synthesis. Our study adds significantly to the biological significance of IP5K; previously, it was the kinase activity of this protein that had attracted attention. Our demonstration that IP5K ‘moonlights’ as a molecular scaffold offers an unexpected new example of how the biological sophistication of higher organisms can arise from gene products acquiring multiple functions, rather than by an increase in gene number.
The transcriptional co-regulator Jab1 is crucial for chondrocyte differentiation in vivo
Authors: Chen Dongxing , Bashur Lindsay A. , Liang Bojian , Panattoni Martina , Tamai Keiko , Pardi Ruggero , Zhou Guang 
Published: December 2012

Summary
The evolutionarily conserved transcriptional cofactor Jab1 plays critical roles in cell differentiation, proliferation, and apoptosis by modulating the activity of diverse factors and regulating the output of various signaling pathways. Although Jab1 can interact with the bone morphogenetic protein (BMP) downstream effector Smad5 to repress BMP signaling in vitro, the role of Jab1 in BMP-mediated skeletogenesis in vivo is still poorly understood. As a key regulator of skeletogenesis, BMP signaling regulates the critical Ihh-Pthrp feedback loop to promote chondrocyte hypertrophy. In this study, we utilized the loxP/Cre system to delineate the specific role of Jab1 in cartilage formation. Strikingly, Jab1 chondrocyte-specific knockout Jab1flox/flox; Col2a1-Cre (cKO) mutants exhibited neonatal lethal chondrodysplasia with severe dwarfism. In the mutant embryos, all the skeletal elements developed via endochondral ossification were extremely small with severely disorganized chondrocyte columns. Jab1 cKO chondrocytes exhibited increased apoptosis, G2 phase cell cycle arrest, and increased expression of hypertrophic chondrocyte markers Col10a1 and Runx2. Jab1 can also inhibit the transcriptional activity of Runx2, a key regulator of chondrocyte hypertrophy. Notably, our study reveals that Jab1 is likely a novel inhibitor of BMP signaling in chondrocytes in vivo. In Jab1 cKO chondrocytes, there was heightened expression of BMP signaling components including Gdf10/Bmp3b and of BMP targets during chondrocyte hypertrophy such as Ihh. Furthermore, Jab1 cKO chondrocytes exhibited an enhanced response to exogenous BMP treatment. Together, our study demonstrates that Jab1 represses chondrocyte hypertrophy in vivo, likely in part by downregulating BMP signaling and Runx2 activity.
Cooperativity between calmodulin-binding sites in Kv7.2 channels
Authors: Alaimo Alessandro , Alberdi Araitz , Gomis-Perez Carolina , Fernández-Orth Juncal , Gómez-Posada Juan Camilo , Areso Pilar , Villarroel Alvaro 
Published: December 2012

Summary
Among the multiple roles assigned to calmodulin (CaM), controlling the surface expression of Kv7.2 channels by binding to two discontinuous sites is a unique property of this Ca2+ binding protein. Mutations that interfere with CaM binding or the sequestering of CaM prevent this M-channel component from exiting the endoplasmic reticulum (ER), which reduces M-current density in hippocampal neurons, enhancing excitability and offering a rational mechanism to explain some forms of benign familial neonatal convulsions (BFNC). Previously, we identified a mutation (S511D) that impedes CaM binding while allowing the channel to exit the ER, hinting that CaM binding may not be strictly required for Kv7.2 channel trafficking to the plasma membrane. Alternatively, this interaction with CaM might escape detection and, indeed, we now show that the S511D mutant contains functional CaM-binding sites that are not detected by classical biochemical techniques. Surface expression and function is rescued by CaM, suggesting that free CaM in HEK293 cells is limiting and reinforcing the hypothesis that CaM binding is required for ER exit. Within the CaM-binding domain formed by two sites (helix A and helix B), we show that CaM binds to helix B with higher apparent affinity than helix A, both in the presence and absence of Ca2+, and that the two sites cooperate. Hence, CaM can bridge two binding domains, anchoring helix A of one subunit to helix B of another subunit, in this way influencing the function of Kv7.2 channels.
BMP9-regulated angiogenic signaling plays an important role in the osteogenic differentiation of mesenchymal progenitor cells
Authors: Hu Ning , Jiang Dianming , Huang Enyi , Liu Xing , Li Ruidong , Liang Xi , Kim Stephanie H. , Chen Xiang , Gao Jian-Li , Zhang Hongyu , Zhang Wenwen , Kong Yu-Han , Zhang Jiye , Wang Jinhua , Shui Wei , Luo Xiaoji , Liu Bo , Cui Jing , Rogers Mary Rose , Shen Jikun , Zhao Chen , Wang Ning , Wu Ningning , Luu Hue H. , Haydon Rex C. , He Tong-Chuan , Huang Wei 
Published: December 2012

Summary
Mesenchymal stromal progenitor cells (MSCs) are multipotent progenitors that can be isolated from numerous tissues. MSCs can undergo osteogenic differentiation under proper stimuli. We have recently demonstrated that bone morphogenetic protein 9 (BMP9) is one of the most osteogenic BMPs. As one of the least studied BMPs, BMP9 has been shown to regulate angiogenesis in endothelial cells. However, it is unclear whether BMP9-regulated angiogenic signaling plays any important role in the BMP9-initiated osteogenic pathway in MSCs. Here, we investigate the functional role of hypoxia-inducible factor 1α (HIF1α)-mediated angiogenic signaling in BMP9-regulated osteogenic differentiation of MSCs. We find that BMP9 induces HIF1α expression in MSCs through Smad1/5/8 signaling. Exogenous expression of HIF1α potentiates BMP9-induced osteogenic differentiation of MSCs both in vitro and in vivo. siRNA-mediated silencing of HIF1α or HIF1α inhibitor CAY10585 profoundly blunts BMP9-induced osteogenic signaling in MSCs. HIF1α expression regulated by cobalt-induced hypoxia also recapitulates the synergistic effect between HIF1α and BMP9 in osteogenic differentiation. Mechanistically, HIF1α is shown to exert its synergistic effect with BMP9 by inducing both angiogenic signaling and osteogenic signaling in MSCs. Thus, our findings should not only expand our understanding of the molecular basis behind BMP9-regulated osteoblastic lineage-specific differentiation, but also provide an opportunity to harness the BMP9-induced synergy between osteogenic and angiogenic signaling pathways in regenerative medicine.
Ezh2 maintains a key phase of muscle satellite cell expansion but does not regulate terminal differentiation
Authors: Woodhouse Samuel , Pugazhendhi Dhamayanthi , Brien Patrick , Pell Jennifer M. 
Published: December 2012

Summary
Tissue generation and repair requires a stepwise process of cell fate restriction to ensure that adult stem cells differentiate in a timely and appropriate manner. A crucial role has been implicated for Polycomb-group (PcG) proteins and the H3K27me3 repressive histone mark in coordinating the transcriptional programmes necessary for this process, but the targets and developmental timing for this repression remain unclear. To address these questions, we generated novel genome-wide maps of H3K27me3 and H3K4me3 in freshly isolated muscle stem cells. These data, together with the analysis of two conditional Ezh2-null mouse strains, identified a critical proliferation phase in which Ezh2 activity is essential. Mice lacking Ezh2 in satellite cells exhibited decreased muscle growth, severely impaired regeneration and reduced stem cell number, due to a profound failure of the proliferative progenitor population to expand. Surprisingly, deletion of Ezh2 after the onset of terminal differentiation did not impede muscle repair or homeostasis. Using these knockout models and the RNA-Seq and ChIP-Seq datasets, we show that Ezh2 does not regulate the muscle differentiation process in vivo. These results emphasise the lineage and cell-type-specific functions of Ezh2 and Polycomb repressive complex 2.
Impairment of TRPC1–STIM1 channel assembly and AQP5 translocation compromise agonist-stimulated fluid secretion in mice lacking caveolin1
Authors: Pani Biswaranjan , Liu Xibao , Bollimuntha Sunitha , Cheng Kwong Tai , Niesman Ingrid R. , Zheng Changyu , Achen Virginia R. , Patel Hemal H. , Ambudkar Indu S. , Singh Brij B. 
Published: December 2012

Summary
Neurotransmitter regulation of salivary fluid secretion is mediated by activation of Ca2+ influx. The Ca2+-permeable transient receptor potential canonical 1 (TRPC1) channel is crucial for fluid secretion. However, the mechanism(s) involved in channel assembly and regulation are not completely understood. We report that Caveolin1 (Cav1) is essential for the assembly of functional TRPC1 channels in salivary glands (SG) in vivo and thus regulates fluid secretion. In Cav1−/− mouse SG, agonist-stimulated Ca2+ entry and fluid secretion are significantly reduced. Microdomain localization of TRPC1 and interaction with its regulatory protein, STIM1, are disrupted in Cav1−/− SG acinar cells, whereas Orai1–STIM1 interaction is not affected. Furthermore, localization of aquaporin 5 (AQP5), but not that of inositol (1,4,5)-trisphosphate receptor 3 or Ca2+-activated K+ channel (IK) in the apical region of acinar cell was altered in Cav1−/− SG. In addition, agonist-stimulated increase in surface expression of AQP5 required Ca2+ influx via TRPC1 channels and was inhibited in Cav1−/− SG. Importantly, adenovirus-mediated expression of Cav1 in Cav1−/− SG restored interaction of STIM1 with TRPC1 and channel activation, apical targeting and regulated trafficking of AQP5, and neurotransmitter stimulated fluid-secretion. Together these findings demonstrate that, by directing cellular localization of TRPC1 and AQP5 channels and by selectively regulating the functional assembly TRPC1–STIM1 channels, Cav1 is a crucial determinant of SG fluid secretion.
Efficient Lentiviral Transduction of Human Mesenchymal Stem Cells That Preserves Proliferation and Differentiation Capabilities
Authors: Lin Paul , Lin Yuan , Lennon Donald P. , Correa Diego , Schluchter Mark , Caplan Arnold I. 
Published: December 2012

Abstract
Long-term lentiviral transduction of human mesenchymal stem cells (hMSCs) greatly enhances the usefulness of these cells. However, such transduction currently requires the use of polybrene, which severely inhibits hMSC proliferation. In contrast, protamine sulfate at 100 μg/ml doubled transduction efficiencies without affecting proliferation or differentiation potential. Expression levels improved 2.2-fold with the addition of a woodchuck hepatitis post-transcriptional regulatory element. Further improvements in transduction efficiencies could be obtained by a modest increase in viral concentrations through increased viral titers or decreased transduction volumes without changing multiplicity of infection, by transducing over multiple days, or by culturing the cells in fibroblast growth factor-2. Centrifugation improved expression but had no effect on efficiency. Transgene expression was stable over 6 weeks in vitro and in vivo. Donor-to-donor and intradonor variability were observed in primary passage through passage 2 cultures, but not at passage 3. These results provide a better optimized approach for expanded use of hMSCs through genetic manipulation.
Atomic Force Microscopy Study of new Sensing Platforms: Cucurbit[n]uril (n=6, 7) on Gold
Authors: Blanco Elías , Quintana Carmen , Hernández Lucas , Hernández Pedro 
Published: December 2012

AbstractThis work presents the comparative study of the spontaneous adsorption of cucurbit[6]uril and cucurbit[7]uril on gold by means of atomic force microscopy. A faster cucurbit[6]uril adsorption was not achieved by the use of a cucurbit[6]uril solution with sodium salts to increment its solubility than by the treatment with a saturated one in water. However, sodium ions promoted the cucurbit[6]uril polymerization on the previously adsorbed layer. The electrode reaction of hydroquinone became irreversible when a cucurbit[6]uril modified gold electrode was used. Cucurbit[7]uril adsorption was faster than for the smaller homologue and multilayers were generated too with high adsorption times.
Highly Selective Optical‐Electrochemical Zn2+ Detection Based on Tetrathiafulvalene
Authors: Xiao Xunwen , He Yanjun , Wang Guannan , Shen Liangjun , Guo Yuping , Fang Jianghua , Yang Jianping 
Published: December 2012

ABSTRACTEthylenedioxytetrathiafulvalene substituted with a pyridinyl (Py) group (1) shows remarkable sensing and coordinating properties only to Zn2+ ion, not to the other metal ions. Addition of a micromolar concentration of Zn2+ ion to the solution of 1, a dramatic change is observed in the UV–vis absorption spectrum and redox property, and the discrimination is readily possible even by “the naked eye.” Comparison of the recognition ability between 1 and its reference compound (ethynylpyridinyltetrathiafulvalene) 2 suggests that the nature of the space linking tetrathiafulvalene and acceptor moiety plays an important role in the intramolecular charge‐transfer state. © 2012 Wiley Periodicals, Inc. Heteroatom Chem 24:72–76, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/hc.21066