94 research outputs found

    Interplay between Polo kinase, LKB1-activated NUAK1 kinase, PP1β<sup>MYPT1 </sup>phosphatase complex and the SCF<sup>βTrCP</sup> E3 ubiquitin ligase

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    NUAK1 (NUAK family SnF1-like kinase-1) and NUAK2 protein kinases are activated by the LKB1 tumour suppressor and have been implicated in regulating multiple processes such as cell survival, senescence, adhesion and polarity. In the present paper we present evidence that expression of NUAK1 is controlled by CDK (cyclin-dependent kinase), PLK (Polo kinase) and the SCF(βTrCP) (Skp, Cullin and F-box(βTrCP)) E3 ubiquitin ligase complex. Our data indicate that CDK phosphorylates NUAK1 at Ser(445), triggering binding to PLK, which subsequently phosphorylates NUAK1 at two conserved non-catalytic serine residues (Ser(476) and Ser(480)). This induces binding of NUAK1 to βTrCP, the substrate-recognition subunit of the SCF(βTrCP) E3 ligase, resulting in NUAK1 becoming ubiquitylated and degraded. We also show that NUAK1 and PLK1 are reciprocally controlled in the cell cycle. In G(2)–M-phase, when PLK1 is most active, NUAK1 levels are low and vice versa in S-phase, when PLK1 expression is low, NUAK1 is more highly expressed. Moreover, NUAK1 inhibitors (WZ4003 or HTH-01-015) suppress proliferation by reducing the population of cells in S-phase and mitosis, an effect that can be rescued by overexpression of a NUAK1 mutant in which Ser(476) and Ser(480) are mutated to alanine. Finally, previous work has suggested that NUAK1 phosphorylates and inhibits PP1β(MYPT1) (where PP1 is protein phosphatase 1) and that a major role for the PP1β(MYPT1) complex is to inhibit PLK1 by dephosphorylating its T-loop (Thr(210)). We demonstrate that activation of NUAK1 leads to a striking increase in phosphorylation of PLK1 at Thr(210), an effect that is suppressed by NUAK1 inhibitors. Our data link NUAK1 to important cell-cycle signalling components (CDK, PLK and SCF(βTrCP)) and suggest that NUAK1 plays a role in stimulating S-phase, as well as PLK1 activity via its ability to regulate the PP1β(MYPT1) phosphatase

    EMDR Effects on Pursuit Eye Movements

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    This study aimed to objectivize the quality of smooth pursuit eye movements in a standard laboratory task before and after an Eye Movement Desensitization and Reprocessing (EMDR) session run on seven healthy volunteers. EMDR was applied on autobiographic worries causing moderate distress. The EMDR session was complete in 5 out of the 7 cases; distress measured by SUDS (Subjective Units of Discomfort Scale) decreased to a near zero value. Smooth pursuit eye movements were recorded by an Eyelink II video system before and after EMDR. For the five complete sessions, pursuit eye movement improved after their EMDR session. Notably, the number of saccade intrusions—catch-up saccades (CUS)—decreased and, reciprocally, there was an increase in the smooth components of the pursuit. Such an increase in the smoothness of the pursuit presumably reflects an improvement in the use of visual attention needed to follow the target accurately. Perhaps EMDR reduces distress thereby activating a cholinergic effect known to improve ocular pursuit

    Y-chromosome descent clusters and male differential reproductive success: young lineage expansions dominate Asian pastoral nomadic populations

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    International audienceHigh-frequency microsatellite haplotypes of the male-specific Y-chromosome can signal past episodes of high reproductive success of particular men and their patrilineal descendants. Previously, two examples of such successful Y-lineages have been described in Asia, both associated with Altaic-speaking pastoral nomadic societies, and putatively linked to dynasties descending, respectively, from Genghis Khan and Giocangga. Here we surveyed a total of 5321 Y-chromosomes from 127 Asian populations, including novel Y-SNP and microsatellite data on 461 Central Asian males, to ask whether additional lineage expansions could be identified. Based on the most frequent eight-microsatellite haplotypes, we objectively defined 11 descent clusters (DCs), each within a specific haplogroup, that represent likely past instances of high male reproductive success, including the two previously identified cases. Analysis of the geographical patterns and ages of these DCs and their associated cultural characteristics showed that the most successful lineages are found both among sedentary agriculturalists and pastoral nomads, and expanded between 2100 BCE and 1100 CE. However, those with recent origins in the historical period are almost exclusively found in Altaic-speaking pastoral nomadic populations, which may reflect a shift in political organisation in pastoralist economies and a greater ease of transmission of Y-chromosomes through time and space facilitated by the use of horses

    The Natural Statistics of Audiovisual Speech

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    Humans, like other animals, are exposed to a continuous stream of signals, which are dynamic, multimodal, extended, and time varying in nature. This complex input space must be transduced and sampled by our sensory systems and transmitted to the brain where it can guide the selection of appropriate actions. To simplify this process, it's been suggested that the brain exploits statistical regularities in the stimulus space. Tests of this idea have largely been confined to unimodal signals and natural scenes. One important class of multisensory signals for which a quantitative input space characterization is unavailable is human speech. We do not understand what signals our brain has to actively piece together from an audiovisual speech stream to arrive at a percept versus what is already embedded in the signal structure of the stream itself. In essence, we do not have a clear understanding of the natural statistics of audiovisual speech. In the present study, we identified the following major statistical features of audiovisual speech. First, we observed robust correlations and close temporal correspondence between the area of the mouth opening and the acoustic envelope. Second, we found the strongest correlation between the area of the mouth opening and vocal tract resonances. Third, we observed that both area of the mouth opening and the voice envelope are temporally modulated in the 2–7 Hz frequency range. Finally, we show that the timing of mouth movements relative to the onset of the voice is consistently between 100 and 300 ms. We interpret these data in the context of recent neural theories of speech which suggest that speech communication is a reciprocally coupled, multisensory event, whereby the outputs of the signaler are matched to the neural processes of the receiver

    Inhaled furosemide for relief of air hunger versus sense of breathing effort: a randomized controlled trial

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    Background. Inhaled furosemide offers a potentially novel treatment for dyspnoea, which may reflect modulation of pulmonary stretch receptor feedback to the brain. Specificity of relief is unclear because different neural pathways may account for different components of clinical dyspnoea. Our objective was to evaluate if inhaled furosemide relieves the air hunger component (uncomfortable urge to breathe) but not the sense of breathing work/effort of dyspnoea. Methods. A randomised, double blind, placebo-controlled crossover trial in 16 healthy volunteers studied in a university research laboratory. Each participant received 3 mist inhalations (either 40 mg furosemide or 4 ml saline) separated by 30–60 min on 2 test days. Each participant was randomised to mist order ‘furosemide-saline-furosemide’ (n- = 8) or ‘saline-furosemide-saline’ (n = 8) on both days. One day involved hypercapnic air hunger tests (mean ± SD PCO2 = 50 ± 3.7 mmHg; constrained ventilation = 9 ± 1.5 L/min), the other involved work/effort tests with targeted ventilation (17 ± 3.1 L/min) and external resistive load (20cmH2O/L/s). Primary outcome was ratings of air hunger or work/effort every 15 s on a visual analogue scale. During saline inhalations, 1.5 mg furosemide was infused intravenously to match the expected systemic absorption from the lungs when furosemide is inhaled. Corresponding infusions of saline during furosemide inhalations maintained procedural blinding. Average visual analogue scale ratings (%full scale) during the last minute of air hunger or work/effort stimuli were analysed using Linear Mixed Methods. Results. Data from all 16 participants were analysed. Inhaled furosemide relative to inhaled saline significantly improved visual analogues scale ratings of air hunger (Least Squares Mean ± SE − 9.7 ± 2%; p = 0.0015) but not work/effort (+ 1.6 ± 2%; p = 0.903). There were no significant adverse events. Conclusions. Inhaled furosemide was effective at relieving laboratory induced air hunger but not work/effort in healthy adults; this is consistent with the notion that modulation of pulmonary stretch receptor feedback by inhaled furosemide leads to dyspnoea relief that is specific to air hunger, the most unpleasant quality of dyspnoea

    Respiratory Muscles, Exercise Performance and Health in Overweight and Obese Subjects

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    PURPOSE:: Overweight and obese subjects often perceive increased breathlessness during minor exertion and therefore avoid exercise. Respiratory muscle endurance training (RMET) can reduce the perception of breathlessness. We hypothesized that RMET one month prior to and during a 6-month (3months supervised + 3months unsupervised) exercise and nutrition counseling program (EN) would improve the benefits of EN. METHODS:: 26 overweight and obese subjects with significant perception of breathlessness during exercise (age: 33+/-9y; body mass index [BMI]: 31.3+/-4.9kg.m) were randomized to RMET+EN (R+EN) or EN alone. R+EN performed 30min of normocapnic hyperpnea 5wk prior to and 2wkduring EN. EN consisted of two strength and three endurance training sessions per week, as well as prescribed nutritional composition and a 2.1kJ (=500kcal) energy deficit per day. Both groups had an equal number of lab visits during the 7 months. Before, and after 4 and 7 months, subjects performed a 12-min time trial (TT; 6+6min, 2min pause) and an incremental cycling test (ICT) to exhaustion and blood lipids were assessed. RESULTS:: Weight loss was significant and similar in both groups (-4.2 vs -3.7kg; both p<0.05). During the first 4 months, distance covered in 12min improved more (p<0.05) with R+EN (1678 vs 1824m; p<0.001) than with EN alone (1638 vs 1698m; p<0.05), while after R+EN, breathlessness during the ICT was reduced. Blood lipids of the pooled group improved in those subjects with pathologic values before the study. Despite reduced training compliance during the unsupervised period, subjects of both groups maintained the benefits attained during the supervised period. CONCLUSION:: R+EN improved TT-performance more than EN alone, despite similar weight loss, possibly due to reduced perception of breathlessness

    Echocardiographic assessment of a normal adult aging population.

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