482 research outputs found
Temporal and causal reasoning in deaf and hearing novice readers
Temporal and causal information in text are crucial in helping the reader form a coherent representation of a narrative. Deaf novice readers are generally poor at processing linguistic markers of causal/temporal information (i.e., connectives), but what is unclear is whether this is indicative of a more general deficit in reasoning about temporal/causal information. In Study 1, 10 deaf and 63 hearing children, matched for comprehension ability and age, were compared on a range of tasks tapping temporal/causal reasoning skills. In Study 2, 20 deaf and 32 hearing children, matched for age but not reading comprehension ability, were compared on revised versions of the tasks. The pattern of performance of the deaf was different from that of the hearing; they had difficulties when temporal and causal reasoning was text-based, but not when it was nonverbal, indicating that their global temporal/causal reasoning skills are comparable with those of their hearing counterparts
1,2,6-thiadiazinones as novel narrow spectrum calcium/calmodulin-dependent protein kinase kinase 2 (CaMKK2) inhibitors
We demonstrate for the first time that 4H-1,2,6-thiadiazin-4-one (TDZ) can function as a chemotype for the design of ATP-competitive kinase inhibitors. Using insights from a co-crystal structure of a 3,5-bis(arylamino)-4H-1,2,6-thiadiazin-4-one bound to calcium/calmodulin-dependent protein kinase kinase 2 (CaMKK2), several analogues were identified with micromolar activity through targeted displacement of bound water molecules in the active site. Since the TDZ analogues showed reduced promiscuity compared to their 2,4-dianilinopyrimidine counter parts, they represent starting points for development of highly selective kinase inhibitors
AMP Is a True Physiological Regulator of AMP-Activated Protein Kinase by Both Allosteric Activation and Enhancing Net Phosphorylation
SummaryWhile allosteric activation of AMPK is triggered only by AMP, binding of both ADP and AMP has been reported to promote phosphorylation and inhibit dephosphorylation at Thr172. Because cellular concentrations of ADP and ATP are higher than AMP, it has been proposed that ADP is the physiological signal that promotes phosphorylation and that allosteric activation is not significant in vivo. However, we report that: AMP is 10-fold more potent than ADP in inhibiting Thr172 dephosphorylation; only AMP enhances LKB1-induced Thr172 phosphorylation; and AMP can cause >10-fold allosteric activation even at concentrations 1–2 orders of magnitude lower than ATP. We also provide evidence that allosteric activation by AMP can cause increased phosphorylation of acetyl-CoA carboxylase in intact cells under conditions in which there is no change in Thr172 phosphorylation. Thus, AMP is a true physiological regulator of AMPK, and allosteric regulation is an important component of the overall activation mechanism
Establishing Foundation Archives: A Reader and Guide to First Steps
This publication is an anthology of papers presented at a conference held at the Rockefeller Archive Center in January 1990, and sponsored by the Council on Foundations. This collaboration of the Archive Center and the Council provided a rare opponunity for foundations to learn both why preserving documents is imponant and how several foundations have approached finding a repository or setting up and managing an archives. Participants in the conference had the added privilege of conferring with experts and seeing an operating archive as they toured the Rockefeller Archive Center.Foundations are institutions that are shaping private initiatives for the public good, so documenting this aspect of American society falls uniquely under the stewardship of the organizations themselves. Foundation documents often provide the only surviving records of the important contributions of nonprofits and foundations to civic life. These records will help to inform future judgments and ensure that the history of the field is not lost. The publication of this volume was intended to make the information shared at the conference more widely available and to provide an entry point and a primer for foundations as they begin their records and archives journey
AMP-activated protein kinase complexes containing the β2 regulatory subunit are upregulated during and contribute to adipogenesis
AMP-activated protein kinase (AMPK) is a heterotrimer of α catalytic and β and γ regulatory subunits that acts to regulate cellular and whole-body nutrient metabolism. The key role of AMPK in sensing energy status has led to significant interest in AMPK as a therapeutic target for dysfunctional metabolism in type 2 diabetes, insulin resistance and obesity. Despite the actions of AMPK in liver and skeletal muscle being extensively studied, the role of AMPK in adipose tissue and adipocytes remains less well characterised. Small molecules that selectively influence AMPK heterotrimers containing specific AMPKβ subunit isoforms have been developed, including MT47-100, which selectively inhibits complexes containing AMPKβ2. AMPKβ1 and AMPKβ2 are the principal AMPKβ subunit isoforms in rodent liver and skeletal muscle respectively, yet the contribution of specific AMPKβ isoforms to adipose tissue function, however, remains largely unknown. This study therefore sought to determine the contribution of AMPKβ subunit isoforms to adipocyte biology, focussing on adipogenesis. AMPKβ2 was the principal AMPKβ isoform in 3T3-L1 adipocytes, isolated rodent adipocytes and human subcutaneous adipose tissue, as assessed by the contribution to total cellular AMPK activity. Downregulation of AMPKβ2 with siRNA inhibited lipid accumulation, cellular adiponectin levels and adiponectin secretion during 3T3-L1 adipogenesis, whereas downregulation of AMPKβ1 had no effect. Incubation of 3T3-L1 cells with MT47-100 selectively inhibited AMPK complexes containing AMPKβ2 whilst simultaneously inhibiting cellular lipid accumulation as well as cellular levels and secretion of adiponectin. Taken together, these data indicate that increased expression of AMPKβ2 is an important feature of efficient adipogenesis
Systemic ablation of Camkk2 impairs metastatic colonization and improves insulin sensitivity in TRAMP mice : Evidence for cancer cell-extrinsic CAMKK2 functions in prostate cancer
Despite early studies linking calcium-calmodulin protein kinase kinase 2 (CAMKK2) to prostate cancer cell migration and invasion, the role of CAMKK2 in metastasis in vivo remains unclear. Moreover, while CAMKK2 is known to regulate systemic metabolism, whether CAMKK2’s effects on whole-body metabolism would impact prostate cancer progression and/or related comorbidities is not known. Here, we demonstrate that germline ablation of Camkk2 slows, but does not stop, primary prostate tumorigenesis in the TRansgenic Adenocarcinoma Mouse Prostate (TRAMP) genetic mouse model. Consistent with prior epidemiological reports supporting a link between obesity and prostate cancer aggressiveness, TRAMP mice fed a high-fat diet exhibited a pronounced increase in the colonization of lung metastases. We demonstrated that this effect on the metastatic spread was dependent on CAMKK2. Notably, diet-induced lung metastases exhibited a highly aggressive neuroendocrine phenotype. Concurrently, Camkk2 deletion improved insulin sensitivity in the same mice. Histological analyses revealed that cancer cells were smaller in the TRAMP;Camkk2−/− mice compared to TRAMP;Camkk2+/+ controls. Given the differences in circulating insulin levels, a known regulator of cell growth, we hypothesized that systemic CAMKK2 could promote prostate cancer cell growth and disease progression in part through cancer cell-extrinsic mechanisms. Accordingly, host deletion of Camkk2 impaired the growth of syngeneic murine prostate tumors in vivo, confirming nonautonomous roles for CAMKK2 in prostate cancer. Cancer cell size and mTOR signaling was diminished in tumors propagated in Camkk2-null mice. Together, these data indicate that, in addition to cancer cell-intrinsic roles, CAMKK2 mediates prostate cancer progression via tumor-extrinsic mechanisms. Further, we propose that CAMKK2 inhibition may also help combat common metabolic comorbidities in men with advanced prostate cancer
Thienopyridone Drugs Are Selective Activators of AMP-Activated Protein Kinase β1-Containing Complexes
SummaryThe AMP-activated protein kinase (AMPK) is an αβγ heterotrimer that plays a pivotal role in regulating cellular and whole-body metabolism. Activation of AMPK reverses many of the metabolic defects associated with obesity and type 2 diabetes, and therefore AMPK is considered a promising target for drugs to treat these diseases. Recently, the thienopyridone A769662 has been reported to directly activate AMPK by an unexpected mechanism. Here we show that A769662 activates AMPK by a mechanism involving the β subunit carbohydrate-binding module and residues from the γ subunit but not the AMP-binding sites. Furthermore, A769662 exclusively activates AMPK heterotrimers containing the β1 subunit. Our findings highlight the regulatory role played by the β subunit in modulating AMPK activity and the possibility of developing isoform specific therapeutic activators of this important metabolic regulator
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Associated reading skills in children with a history of Specific Language Impairment (SLI)
A large cohort of 200 eleven-year-old children with Specific Language Impairment (SLI) were assessed on basic reading accuracy and on reading comprehension as well as language tasks. Reading skills were examined descriptively and in relation to early language and literacy factors. Using stepwise regression analyses in which age and nonverbal IQ were controlled for, it was found that a single word reading measure taken at 7 years was unsurprisingly a strong predictor of the two different types of reading ability. However, even with this measure included, a receptive syntax task (TROG) entered when reading accuracy score was the DV. Furthermore, a test of expressive syntax/narrative and a receptive syntax task completed at 7 years entered into the model for word reading accuracy. When early reading accuracy was excluded from the analyses, early phonological skills also entered as a predictor of both reading accuracy and comprehension at 11 years. The group of children with a history of SLI were then divided into those with no literacy difficulties at 11 and those with some persisting literacy impairment. Using stepwise logistic regression, and again controlling for IQ and age, 7 years receptive syntax score (but not tests of phonology, expressive vocabulary or expressive syntax/narrative) entered as a positive predictor of membership of the ‘no literacy problems’ group regardless of whether early reading accuracy was controlled for in step one. The findings are discussed in relation to the overlap of SLI and dyslexia and the long term sequelae of language impairment
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