Enhanced Protein Homeostasis Mechanisms in Naked Mole Rats Cells

Phylogenic studies suggest that cells from long-lived species are more resistant to a variety of stressors than short-lived species. However, there is little information on the cellular mechanisms that give rise to increased resistance to stress. Our previous studies have shown that liver proteins from a long-lived species have lower levels of protein ubiquitination which is associated with increased proteasome activity, suggesting that mechanisms of protein quality control could play a critical role in assuring longevity of long-lived species. In this study, we evaluated whether autophagy and heat shock chaperones proteins (HSPs) are associated with longevity in rodents using skin fibroblasts isolated from mice and naked mole rats (NMR); two species that are similar in body size but differ almost 10 fold in longevity. Our results indicate that macroautophagy induced by serum-starvation is significantly enhanced in NMR compared to mouse which correlates with an inhibition of the mTOR pathway and increased LC3 conversion. We also found that several HSPs (e.g., Hsp90, Hsp70, Hsp40, Hsp 27) were significantly higher at both basal and after heat shock conditions. These observations suggest that NMR, a long-lived species, has increased mechanisms to ensure protein quality (autophagy and HSPs) and support the idea that protein homeostasis could play an important role in promoting longevity

Evidence from diatom-bound nitrogen isotopes for subarctic Pacific stratification during the last ice age and a link to North Pacific denitrification changes

Author Posting. © American Geophysical Union, 2007. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Paleoceanography 22 (2007): PA1215, doi:10.1029/2005PA001205.In a piston core from the central Bering Sea, diatom microfossil-bound N isotopes and the concentrations of opal, biogenic barium, calcium carbonate, and organic N are measured over the last glacial/interglacial cycle. Compared to the interglacial sections of the core, the sediments of the last ice age are characterized by 3‰ higher diatom-bound δ 15N, 70 wt % lower opal content and 1200 ppm lower biogenic barium. Taken together and with constraints on sediment accumulation rate, these results suggest a reduced supply of nitrate to the surface due to stronger stratification of the upper water column of the Bering Sea during glacial times, with more complete nitrate consumption resulting from continued iron supply through atmospheric deposition. This finding extends the body of evidence for a pervasive link between cold climates and polar ocean stratification. In addition, we hypothesize that more complete nutrient consumption in the glacial age subarctic Pacific contributed to the previously observed ice age reduction in suboxia and denitrification in the eastern tropical North Pacific by lowering the nutrient content of the intermediate-depth water formed in the subpolar North Pacific. In the deglacial interval of the Bering Sea record, two apparent peaks in export productivity are associated with maxima in diatom-bound and bulk sediment δ 15N. The high δ 15N in these intervals may have resulted from greater surface nutrient consumption during this period. However, the synchroneity of the deglacial peaks in the Bering Sea with similar bulk sediment δ 15N changes in the eastern Pacific margin and the presence of sediment lamination within the Bering Sea during the deposition of the productivity peaks raise the possibility that both regional and local denitrification worked to raise the δ 15N of the nitrate feeding Bering Sea surface waters at these times.Financial support for this work was provided by NSF grants OCE-0136449, OCE-9981479, ANT-0453680, by BP and Ford Motor Company through the Princeton Carbon Migration Initiative, and by a NDSEG fellowship to B.G.B. Work conducted aboard the USCG Healy (Healy 0202) was funded by grant OPP-9912122

Cardiovascular and neuropsychiatric safety of varenicline and bupropion compared with nicotine replacement therapy for smoking cessation:study protocol of a retrospective cohort study using the QResearch general practice database

Introduction: Cigarette smoking continues to be the leading cause of preventable death and is the main risk factor of major diseases such as chronic obstructive pulmonary disease (COPD). The best treatment to help smokers quit is a combination of behavioural support with pharmacotherapy. Varenicline is the newest drug on the market and has been shown to be effective in the general smoking population and in smokers with COPD. The safety profile of varenicline was initially established using standard approaches to pharmacovigilance, but postmarketing reports have raised concerns about a possible association between the use of varenicline and cardiovascular and neuropsychiatric events. Although recent studies have not confirmed such an association, further research is needed given the large number of smokers who are being prescribed varenicline, including important subgroups such as smokers with COPD who may be particularly vulnerable to side effects of drugs. The aim of this study is to assess the cardiovascular and neuropsychiatric safety of varenicline using data from the QResearch general practice (GP) database. Methods and analysis We will conduct a retrospective cohort study in the QResearch GP database. Patients will be categorised into three exposure groups: prescription of (1) varenicline, (2) bupropion or (3) nicotine replacement therapy (NRT Rx; =reference group). We will separately consider major incident neuropsychiatric and cardiovascular outcomes that occur during 6 months of follow-up using Cox proportional hazards models, adjusted for confounders. Furthermore, propensity score analysis will be used as an analytical approach to account for potential confounding by indication. Ethics and dissemination This work involves analysis of anonymised, routinely collected data. The protocol has been independently peer-reviewed by the QResearch Scientific Board and meets the requirements of the Trent research ethics committee. We plan to disseminate the results from this study via articles in international peer-reviewed journals and presentations at relevant national and international health conferences

DOH-2013-Harrison.pptx

Phylogenic studies suggest that cells from long-lived species are more resistant to a variety of stressors than short-lived species. However, there is little information on the cellular mechanisms that give rise to increased resistance to stress. Our previous studies have shown that liver proteins from a long-lived species have lower levels of protein ubiquitination which is associated with increased proteasome activity, suggesting that mechanisms of protein quality control could play a critical role in assuring longevity of long-lived species. In this study, we evaluated whether autophagy and heat shock chaperones proteins (HSPs) are associated with longevity in rodents using skin fibroblasts isolated from mice and naked mole rats (NMR); two species that are similar in body size but differ almost 10 fold in longevity. Our results indicate that macroautophagy induced by serum-starvation is significantly enhanced in NMR compared to mouse which correlates with an inhibition of the mTOR pathway and increased LC3 conversion. We also found that several HSPs (e.g., Hsp90, Hsp70, Hsp40, Hsp 27) were significantly higher at both basal and after heat shock conditions. These observations suggest that NMR, a long-lived species, has increased mechanisms to ensure protein quality (autophagy and HSPs) and support the idea that protein homeostasis could play an important role in promoting longevity.Keywords: Longevity, Autophagy, Aging, Naked Mole Rats, Protein Homeostasis, Heat Shock Protein

Social skills and autism spectrum disorder symptoms in children with neurofibromatosis type 1: evidence for clinical trial outcomes.

AIM: We examined key features of two outcome measures for social dysfunction and autism spectrum disorder traits, the Social Responsiveness Scale, Second Edition (SRS-2) and the Social Skills Improvement System - Rating Scales (SSIS-RS), in children with neurofibromatosis type 1 (NF1). The aim of the study was to provide objective evidence as to which behavioural endpoint should be used in clinical trials. METHOD: Cross-sectional behavioural and demographic data were pooled from four paediatric NF1 tertiary referral centres in Australia and the United States (N=122; 65 males, 57 females; mean age [SD] 9y 2mo [3y], range 3-15y). RESULTS: Distributions of SRS-2 and SSIS-RS scores were unimodal and both yielded deficits, with a higher proportion of severely impaired scores on the SRS-2 (16.4%) compared to the SSIS-RS (8.2%). Pearson's product-moment correlations revealed that both questionnaires were highly related to each other (r=-0.72, p<0.001) and to measures of adaptive social functioning (both p<0.001). Both questionnaires were significantly related to attention-deficit/hyperactivity disorder symptoms, but only very weakly associated with intelligence. INTERPRETATION: The SRS-2 and SSIS-RS capture social dysfunction associated with NF1, suggesting both may be suitable choices for assessing social outcomes in this population in a clinical trial. However, careful thought needs to be given to the nature of the intervention when selecting either as a primary endpoint. WHAT THIS PAPER ADDS: The Social Responsiveness Scale, Second Edition yielded a large deficit relative to population norms. The Social Skills Improvement System - Rating Scales yielded a moderate deficit relative to population norms. Both scales were highly correlated, suggesting that they are measuring a unitary construct