Molecularly stratified hypothalamic astrocytes are cellular foci for obesity

Astrocytes safeguard the homeostasis of the central nervous system1,2. Despite their prominent morphological plasticity under conditions that challenge the brain's adaptive capacity3-5, the classification of astrocytes, and relating their molecular make-up to spatially devolved neuronal operations that specify behavior or metabolism, remained mostly futile6,7. Although it seems unexpected in the era of single-cell biology, the lack of a major advance in stratifying astrocytes under physiological conditions rests on the incompatibility of 'neurocentric' algorithms that rely on stable developmental endpoints, lifelong transcriptional, neurotransmitter, and neuropeptide signatures for classification6-8 with the dynamic functional states, anatomic allocation, and allostatic plasticity of astrocytes1. Simplistically, therefore, astrocytes are still grouped as 'resting' vs. 'reactive', the latter referring to pathological states marked by various inducible genes3,9,10. Here, we introduced a machine learning-based feature recognition algorithm that benefits from the cumulative power of published single-cell RNA-seq data on astrocytes as a reference map to stepwise eliminate pleiotropic and inducible cellular features. For the healthy hypothalamus, this walk-back approach revealed gene regulatory networks (GRNs) that specified subsets of astrocytes, and could be used as landmarking tools for their anatomical assignment. The core molecular censuses retained by astrocyte subsets were sufficient to stratify them by allostatic competence, chiefly their signaling and metabolic interplay with neurons. Particularly, we found differentially expressed mitochondrial genes in insulin-sensing astrocytes and demonstrated their reciprocal signaling with neurons that work antagonistically within the food intake circuitry. As a proof-of-concept, we showed that disrupting Mfn2 expression in astrocytes reduced their ability to support dynamic circuit reorganization, a time-locked feature of satiety in the hypothalamus, thus leading to obesity in mice. Overall, our results suggest that astrocytes in the healthy brain are fundamentally more heterogeneous than previously thought and topologically mirror the specificity of local neurocircuits.

Socio-economic inequality and healthcare costs over the life course - A dynamic microsimulation approach

OBJECTIVES

Although there is well-established evidence for the existence of socio-economic inequalities in virtually all dimensions of health, little is known about the implications of these socio-economic disparities for healthcare costs from a cumulative life course perspective. Accounting for differentials in healthcare use patterns and mortality, we assess how lifetime costs differ between socio-economic groups.

STUDY DESIGN

This study used dynamic microsimulation modelling.

METHODS

Combining price weights for healthcare services with information on healthcare consumption from the 2014 Austrian Health Interview Survey (n = 15,771), we calculated average cost profiles by gender, age and education consistent with aggregate System of Health Accounts. A dynamic microsimulation model was used to project cumulative healthcare costs over the entire lifecycle for the 2019 birth cohort in four different scenarios to illustrate the influence of the different cost determinants on lifetime costs.

RESULTS

Before considering social inequalities in mortality, men with compulsory education have close to 66% higher lifetime costs than men with tertiary education; for women, the difference is close to 20%. Accounting for longevity differentials reduces this gap to approximately 40% for men and 10% for women. Closing the gap in healthcare use and in longevity between socio-economic groups would reduce lifetime healthcare expenditure by 4.1% in the 2019 birth cohort and by 19% in the whole population.

CONCLUSIONS

Accounting for mortality differentials between socio-economic groups has a large impact on estimated lifetime healthcare costs. Reducing social inequalities in health can contribute to containing healthcare expenditures against the backdrop of rising life expectancy.

Laterality of deep white matter hyperintensities correlates with basilar artery bending and vertebral artery dominance

Aim

Methods

Results

Conclusions

Are the Morphological Indices of the Vertebrobasilar System Heritable? A Twin Study Based on 3D Reconstructed Models

Background and Objectives: The asymmetrical vertebral artery (VA) flow and diameter are common findings, which can result in an asymmetrical blood flow in the basilar artery (BA), leading to bending of the artery over time. This study investigated whether the variation of the different vertebrobasilar morphological indices that influence flow characteristics might be inherited. Materials and Methods: We analyzed 200 cerebral magnetic resonance imaging (MRI) scans of healthy Caucasian twins (100 pairs) who underwent time-of-flight MRI. From the scans, we reconstructed the 3D mesh of the posterior circulation from the start of the V4 segment to the basilar tip and subsequently analyzed the morphology of the vertebrobasilar system. The phenotypic covariances of the different morphological parameters were decomposed into heritability (A), shared (C), and unshared (E) environmental effects. Results: 39% of the twins had left dominant VA, while 32.5% had right dominant. In addition, 28.5% were classified as equal. The vertebral artery V4 segment diameter, curvature, and tortuosity were mainly influenced by shared (C) and unshared (E) environmental factors. A moderate heritability was found for the BA length (A: 63%; 95% CI: 45.7–75.2%; E: 37%; 95% CI: 24.8–54.3%) and volume (A: 60.1%; 95% CI: 42.4–73.2%; E: 39.9%; 95% CI: 26.8–57.6%), while the torsion of both arteries showed no heritability and were only influenced by the unshared environment. Conclusions: The length and volume of the BA show a moderate genetical influence. However, most of the measured morphological indices were influenced by shared and unshared factors, which highlight the role of the ever-changing hemodynamic influences shaping the geometry of the vertebrobasilar system.

SAS CARE 2 - a randomized study of CPAP in patients with obstructive sleep disordered breathing following ischemic stroke or transient ischemic attack

Objective/background

The benefit of Continuous Positive Airway Pressure (CPAP) treatment following ischemic stroke in patients with obstructive sleep-disordered breathing (SDB) is unclear. We set out to investigate this open question in a randomized controlled trial as part of the SAS-CARE study.

Patients/methods.

Non-sleepy patients (ESS < 10) with ischemic stroke or transient ischemic attack (TIA) and obstructive SDB (AHI ≥ 20) 3 months post-stroke were randomized 1:1 to CPAP treatment (CPAP+) or standard care. Primary outcome was the occurrence of vascular events (TIA/stroke, myocardial infarction/revascularization, hospitalization for heart failure or unstable angina) or death within 24 months post-stroke. Secondary outcomes included Modified Rankin Scale (mRS) and Barthel Index.

Results

Among 238 SAS-CARE patients 41 (17%) non-sleepy obstructive SDB patients were randomized to CPAP (n = 19) or standard care (n = 22). Most patients (80%) had stroke and were males (78%), mean age was 64 ± 7 years and mean NIHSS score 0.6 ± 1.0 (range: 0–5). The primary endpoint was met by one patient in the standard care arm (a new stroke). In an intent-to treat analysis disregarding adherence, this corresponds to an absolute risk difference of 4.5% or an NNT = 22. mRS and Barthel Index were stable and similar between arms. CPAP adherence was sufficient in 60% of evaluable patients at month 24.

Conclusion

No benefit of CPAP started three months post-stroke was found in terms of new cardio- and cerebrovascular events over 2 years. This may be related to the small size of this study, the mild stoke severity, the exclusion of sleepy patients, the delayed start of treatment, and the overall low event rate.

•

No benefit of CPAP started 3 months post-stroke was found.

•

A sufficient CPAP compliance was observed over 2 years in 60% of patients.

•

Studies of CPAP in mild stroke need to be large and include long-term outcomes.

Mitofusin 2 plays a role in oocyte and follicle development, and is required to maintain ovarian follicular reserve during reproductive aging

Mitochondria change their shape through fusion and fission in order to adapt to their metabolic milieu. Mitofusin-2 (MFN2) is a key regulatory protein in this process, mediating mitochondrial fusion and interaction with endoplasmic reticulum. Targeted deletion of Mfn2 in oocytes resulted in mitochondrial dysfunction and female subfertility associated with impaired oocyte maturation and follicle development. Oocytes lacking MFN2 showed shortened telomeres and increased apoptosis, resulting in compromised oocyte quality and accelerated follicular depletion, consistent with a reproductive aging phenotype.

DisProt: intrinsic protein disorder annotation in 2020

The Database of Protein Disorder (DisProt, URL: https://disprot.org) provides manually curated annotations of intrinsically disordered proteins from the literature. Here we report recent developments with DisProt (version 8), including the doubling of protein entries, a new disorder ontology, improvements of the annotation format and a completely new website. The website includes a redesigned graphical interface, a better search engine, a clearer API for programmatic access and a new annotation interface that integrates text mining technologies. The new entry format provides a greater flexibility, simplifies maintenance and allows the capture of more information from the literature. The new disorder ontology has been formalized and made interoperable by adopting the OWL format, as well as its structure and term definitions have been improved. The new annotation interface has made the curation process faster and more effective. We recently showed that new DisProt annotations can be effectively used to train and validate disorder predictors. We believe the growth of DisProt will accelerate, contributing to the improvement of function and disorder predictors and therefore to illuminate the ‘dark’ proteome.

Does The Type of Ossicular Chain Lesion Affect Outcomes in Chronic Suppurative Otitis Media Without Cholesteatoma?

OBJECTIVES

We evaluated the pattern of ossicular chain (OC) lesion in chronic suppurative otitis media (CSOM) without cholesteatoma and its impact on outcomes in primary and revision surgeries.

MATERIALS AND METHODS

This was a retrospective chart review. Patients who underwent tympanoplasty due to CSOM with OC defect between 2010 and 2015 were included in the study.

RESULTS

OC lesions were found during 40 of 147 tympanoplasties performed due to CSOM. The preoperative air-bone gap (ABG) was greater in both discontinuity and fixation cases than in cases with CSOM with an intact OC (p<0.001). Twenty-nine patients were followed up postoperatively, after excluding four patients with stapes footplate fixation, in whom stapedotomy was not performed simultaneously. Among the 29 patients, the audiological results were similar in cases of discontinuity and fixation regarding gap change, residual ABG, and the rate of successful ossiculoplasty. Primary tympanoplasties provided better results according to postoperative ABG and the rate of successful ossiculoplasty than revision surgeries (p<0.05); however, similar patterns of OC lesions were found during primary and revision surgeries.

CONCLUSION

Both OC discontinuity and fixation occur in CSOM in a similar distribution in primary tympanoplasties and revision surgeries. The type of OC lesion does not affect outcomes. Primary surgeries provide better results, but that is not due to a difference in the character of the OC lesion.

Mitofusin 1 is required for female fertility and to maintain ovarian follicular reserve

Mitochondria are dynamic organelles that continually adapt their structure through fusion and fission in response to changes in their bioenergetic environment. Targeted deletion of mitochondrial fusion protein mitofusin1 (MFN1) in oocytes resulted in female infertility associated with failure to achieve oocyte maturation. Oocyte-granulosa cell communication was impaired, and cadherins and connexins were downregulated, resulting in follicle developmental arrest at the secondary follicle stage. Deletion of MFN1 in oocytes resulted in mitochondrial dysfunction and altered mitochondrial dynamics, as well as accumulation of ceramide, which contributed to increased apoptosis and a reproductive phenotype that was partially rescued by treatment with ceramide synthesis inhibitor myriocin. Absence of MFN1 and resulting apoptotic cell loss also caused depletion of ovarian follicular reserve, and a phenotype consistent with accelerated female reproductive aging.

Intrinsically Disordered Linkers Impart Processivity on Enzymes by Spatial Confinement of Binding Domains

(1) Background: Processivity is common among enzymes and mechanochemical motors that synthesize, degrade, modify or move along polymeric substrates, such as DNA, RNA, polysaccharides or proteins. Processive enzymes can make multiple rounds of modification without releasing the substrate/partner, making their operation extremely effective and economical. The molecular mechanism of processivity is rather well understood in cases when the enzyme structurally confines the substrate, such as the DNA replication factor PCNA, and also when ATP energy is used to confine the succession of molecular events, such as with mechanochemical motors. Processivity may also result from the kinetic bias of binding imposed by spatial confinement of two binding elements connected by an intrinsically disordered (ID) linker. (2) Method: By statistical physical modeling, we show that this arrangement results in processive systems, in which the linker ensures an optimized effective concentration around novel binding site(s), favoring rebinding over full release of the polymeric partner. (3) Results: By analyzing 12 such proteins, such as cellulase, and RNAse-H, we illustrate that in these proteins linker length and flexibility, and the kinetic parameters of binding elements, are fine-tuned for optimizing processivity. We also report a conservation of structural disorder, special amino acid composition of linkers, and the correlation of their length with step size. (4) Conclusion: These observations suggest a unique type of entropic chain function of ID proteins, that may impart functional advantages on diverse enzymes in a variety of biological contexts.

SUN-097 AgRP Neurons Determine Survival in Activity-Based Anorexia Model

Anorexia Nervosa (AN) is an eating disorder characterized by severe hypophagia, high levels of physical activity, harsh weight loss and an intense fear of weight gain. It has the highest mortality rate among psychiatric illnesses and, due to the unknown underlying neurobiology, it is challenging to treat. Agouti-related protein (AgRP) neurons, which are localized in the arcuate nucleus in the hypothalamus, are both necessary and sufficient or feeding in adult animals.To uncover new neural circuits that may contribute towards vulnerability to AN or might be affected by AN, we employed the specific diphtheria toxin receptor-expressing mice (AgRP-DTR) which, by the selective ablation of AgRP neurons, allow to test the impact of an impaired AgRP circuit function under the activity-based anorexia (ABA) paradigm. ABA is a bio-behavioral phenomenon described in rodents and refers to the weight loss, hypophagia and paradoxical hyperactivity that develops in rodents exposed to running wheels and restricted food access, and provides a model for the key symptoms of AN. Mice that express DTR only in AgRP neurons and subcutaneously injected with diphtheria toxin (DTX) at postnatal day 3 lost more than 50% of AgRP neurons on postnatal day 7 compared to control. The same percentage of neuronal loss was detected in 8 weeks old mice. In addition, the neonatal animals developed normally after AgRP ablation, did not show any phenotypic effects and maintained normal food intake and weight when fed ad libitum. On postnatal day 36 (P36), males and females animals were housed with access on a running wheel and fed ad libitum for 4 days (acclimation phase). On P40, for 72 hours animals were fed for only two hours daily. Following the fasting phase, free access to food was returned and the running wheel was removed. Continuous multi-day analysis of running wheel activity showed that both controls and AgRP-DTR mice kept constant weight and food intake during acclimation. In contrast, although mice became hyperactive within the 24 hours following the onset of food restriction (FR), we noted a 10% mortality on day 2 and 70% mortality at day 4 among the AgRP DTR mice. Moreover, the survived AgRP-DTR mice failed to return to normal food intake and weight even when ad libitum food was provided. Overall, AgRP neurons showed to be crucial for the full development of ABA symptoms. The results suggest that our new experimental setting is able to correlate particular neurons populationto vulnerability, onset and progression of anorexia nervosa.

Cardiac dysautonomia in depression - heart rate variability biofeedback as a potential add-on therapy

Depressive disorders are among the most important health problems and are predicted to constitute the leading cause of disease burden by the year 2030. Aside significant impact on quality of life, psychosocial well-being and socioeconomic status of affected patients, depression is associated with impaired cardiovascular health and increased mortality. The link between affective and cardiovascular disease has largely been attributed to dysregulation of the autonomic nervous system resulting in a chronic shift toward increased sympathetic and decreased parasympathetic activity and, consecutively, cardiac dysautonomia. Among proposed surrogate parameters to capture and quantitatively analyze this shift, heart rate variability (HRV) and baroreflex sensitivity have emerged as reliable tools. Attenuation of these parameters is frequently seen in patients suffering from depression and is closely linked to cardiovascular morbidity and mortality. Therefore, diagnostic and therapeutic strategies were designed to assess and counteract cardiac dysautonomia. While psychopharmacological treatment can effectively improve affective symptoms of depression, its effect on cardiac dysautonomia is limited. HRV biofeedback is a non-invasive technique which is based on a metronomic breathing technique to increase parasympathetic tone. While some small studies observed beneficial effects of HRV biofeedback on dysautonomia in patients with depressive disorders, larger confirmatory trials are lacking. We reviewed the current literature on cardiac dysautonomia in patients suffering from depression with a focus on the underlying pathophysiology as well as diagnostic workup and treatment.

Mitochondrial unfolded protein response gene Clpp is required to maintain ovarian follicular reserve during aging, for oocyte competence, and development of pre-implantation embryos

Caseinolytic peptidase P mediates degradation of unfolded mitochondrial proteins and activates mitochondrial unfolded protein response (mtUPR) to maintain protein homeostasis. Clpp^−/− female mice generate a lower number of mature oocytes and two‐cell embryos, and no blastocysts. Clpp^−/− oocytes have smaller mitochondria, with lower aspect ratio (length/width), and decreased expression of genes that promote fusion. A 4‐fold increase in atretic follicles at 3 months, and reduced number of primordial follicles at 6–12 months are observed in Clpp^−/− ovaries. This is associated with upregulation of p‐S6, p‐S6K, p‐4EBP1 and p‐AKT473, p‐mTOR2481 consistent with mTORC1 and mTORC2 activation, respectively, and Clpp^−/− oocyte competence is partially rescued by mTOR inhibitor rapamycin. Our findings demonstrate that CLPP is required for oocyte and embryo development and oocyte mitochondrial function and dynamics. Absence of CLPP results in mTOR pathway activation, and accelerated depletion of ovarian follicular reserve.

Twins Lead to the Prevention of Atherosclerosis: Preliminary Findings of International Twin Study 2009

Introduction

Atherosclerosis is an inflammatory process in which the artery wall thickens as a result of plaque deposition, but this process may be preceded by increased arterial stiffness. We sought to evaluate the influence of genetics and shared and unshared environmental components on the onset of atherosclerosis.

Methods

A total of 135 monozygotic (MZ) and 70 dizygotic (DZ) twin pairs (mean age 49 ± 16 years) underwent carotid intima media thickness (IMT; carotid analyzer) and arterial stiffness (augmentation index on brachial artery [ Aixbra], pulse wave velocity on aorta [ PWVao]; TensioMed Arteriograph) measurements.

Results

Age-adjusted intraclass correlations were greater in MZ than in DZ pairs for proximal right common carotid artery (CCA; MZ = 0.19, DZ = 0.06), proximal and distal left CCA (MZ = 0.27, DZ = 0.06; MZ = 0.27, DZ = 0.13, respectively), and proximal left internal carotid artery (ICA; MZ = 0.39, DZ = −0.54), suggesting a moderate genetic effect. Heritability was estimated to be 18% (95% confidence interval [CI] = 3–33) for proximal right CCA, 26% and 27% for proximal and distal left CCA, respectively, and 38% (95% CI = 26–49) for proximal left ICA. Regarding distal right CCA and proximal right ICA, no genetic effects were detected. Age-adjusted intraclass correlation of Aixbra and PWVao were 0.65 (95% CI = 0.55–0.72) and 0.46 (95% CI = 0.33–0.57) in MZ, 0.42 (95% CI = 0.24–0.57) and 0.28 (95% CI = 0.08–0.47) in DZ pairs; heritability 45% (95% CI = 12–71%) and 42% (95% CI = 2–57%) adjusted by age, respectively.

Conclusions

The investigated parameters appeared to be only moderately influenced by genetic factors. Environmental factors of relevance for these measures appeared not to be shared within family but related to individual experience (e.g., smoking habits, diet, and physical activity). Atherosclerosis detection at an early stage is necessary for treatment to prevent serious complications such as stroke and heart attack.

Elevated O-GlcNAcylation promotes gastric cancer cells proliferation by modulating cell cycle related proteins and ERK 1/2 signaling

O-GlcNAc transferase (OGT) is the only enzyme in mammals that catalyzes the attachment of β-D-N-acetylglucosamine (GlcNAc) to serine or threonine residues of target proteins. Hyper-O-GlcNAcylation is becoming increasingly realized as a general feature of cancer and contributes to rapid proliferation of cancer cells. In this study, we demonstrated that O-GlcNAc and OGT levels were increased in all six gastric cancer (GC) cell lines as compared with immortal gastric epithelial cells. Downregulation of the O-GlcNAcylation level by silencing OGT inhibited cell viability and growth rate via the cdk-2, cyclin D1 and ERK 1/2 pathways. In vivo xenograft assays also demonstrated that the hyper-O-GlcNAc level markedly promoted the proliferation of tumors. Moreover, compared with noncancerous tissues, the O-GlcNAcylation level was increased in cancerous tissues. GC patients with higher levels of O-GlcNAcylation exhibited large tumor sizes (≥5 cm), deep tumor invasion (T3 and T4), high AJCC stages (stage III and IV), more lymph node metastases and lower overall survival. Notably, the phosphorylation level of ERK 1/2 was increased progressively with the increase of O-GlcNAcylation in both SGC 7901 and AGS cells. Consistently, human GC tissue arrays also revealed that ERK 1/2 signaling was positively correlated to O-GlcNAcylation (r = 0.348; P = 0.015). Taken together, here we reported that hyper-O-GlcNAcylation significantly promotes GC cells proliferation by modulating cell cycle related proteins and ERK 1/2 signaling, suggesting that inhibition of OGT may be a potential novel therapeutic target of GC.

Vertebral Artery Diameter and Flow: Nature or Nurture

BACKGROUND AND PURPOSE

In contrast with the carotid arteries, the vertebral arteries (VAs) show considerable variation in length, caliber, and vessel course. This study investigated whether the variation in diameter and flow characteristics of the VAs might be inherited.

METHODS

A total of 172 Italian twins from Padua, Perugia, and Terni (54 monozygotic, 32 dizygotic) recruited from the Italian Twin Registry underwent B-mode and pulsed-wave Doppler ultrasound assessment of their VAs. VA diameters, peak systolic velocity (PSV) and end diastolic velocity (EDV) were assessed at the level of a horizontal V2 segment. Univariate quantitative genetic modeling was performed.

RESULTS

Fourteen percent of the sample had VA hypoplasia. Within pair correlation in monozygotic twins was higher than in dizygotics (.552 vs. .229) for VA diameter. Age- and sex-adjusted genetic effect, under the most parsimonious model, accounted for 54.7% (95% CI: 42.2-69.1%) of the variance of VA diameter, and unshared environmental effect for 45.3% (95% CI: 30.9-57.8%). No heritability was found for the PSV of VA, but shared (34.1%; 95% CI: 16.7-53.7%) and unshared (65.9%; 95% CI: 45.9-83.1%) environmental factors determined the variance. EDV of VA is moderately genetically influenced (42.4%; 95% CI: 16.1-64.9%) and also determined by the unshared environment (57.6%; 95% CI: 34.7-83.7%).

CONCLUSIONS

The diameter of the VAs is moderately genetically determined. Different factors influence the PSV and EDV of VAs, which may highlight the complex hemodynamic background of VA flow and help to understand the vertebral flow anomalies found by ultrasound.

Reproductive aging is associated with changes in oocyte mitochondrial dynamics, function, and mtDNA quantity

Mitochondria affect numerous aspects of mammalian reproduction. We investigated whether the decrease in oocyte quality associated with aging is related to altered mitochondria. Oocytes from old (12 months) and young (9 weeks) C57BL/6J mice were compared in relation to: mitochondria morphology and dynamics (mitochondria density, coverage, size and shape) throughout folliculogenesis; levels of mitochondrial DNA (mtDNA); mitochondrial stress reflected in the expression of mitochondrial unfolded protein response (mt-UPR) genes; and levels of reactive oxygen species (ROS) under baseline conditions and following H2O2 treatment. In old mice, mitochondria of primary follicle-enclosed oocytes were smaller, with lower mitochondria coverage (total mitochondria μm2/μm2 cytosol area) (p<0.05). Other follicular stages showed a similar trend, but the changes were not significant. Mature oocytes (Metaphase II-MII) from old mice had significantly less mtDNA (p<0.01), and elevated mt-UPR gene Hspd1 expression (p<0.05), compared with those from young mice. ROS levels in aged MII oocytes were also higher following pretreatment with H2O2 (p<0.05). Aging is associated with altered mitochondrial morphological parameters and decreased mtDNA levels in oocytes, as well as an increase in ROS under stressful conditions and elevated expression of mitochondrial stress response gene Hspd1. Delineation of the mechanisms underlying mitochondrial changes associated with ageing may help in the development of diagnostic and therapeutic tools in reproductive medicine.

Discrimination Learning with Rhythmic and Nonrhythmic Background Music

Groups of rats learned a discrimination problem in a four-choice apparatus while exposed to one of six auditory stimulus conditions. The stimuli were: a selection of Mozart, an amelodic version of this piece, a selection of Schoenberg, an amelodic version of this piece, white noise, and quiet. None of the groups acquired the discrimination more quickly than quiet controls. Ss exposed to the Schoenberg music, the amelodic version of it, and to white noise performed more poorly than the controls. Presence of nonrhythmic auditory stimulation is detrimental to performance on a discrimination task.

Some Attractiveness Parameters from Birth to Four Years

Facial drawings of infants from 2 wk. to 4 yr. varying in eye height, pupil size, and mouth shape were rated for attractiveness by 181 female and 82 male undergraduates. Stimulus age was the most influential determinant of attractiveness. None of the facial variables showed a consistent effect at all ages though eye height was influential at 1 yr. and older. Judged in the context of a substantial age range the very young seem less attractive in absolute terms and possibly less susceptible to discriminations of attractiveness.

CD301b(+) Mononuclear Phagocytes Maintain Positive Energy Balance through Secretion of Resistin-like Molecule Alpha

Mononuclear phagocytes (MNPs) are a highly heterogeneous group of cells that play important roles in maintaining the body's homeostasis. Here, we found CD301b (also known as MGL2), a lectin commonly used as a marker for alternatively activated macrophages, was selectively expressed by a subset of CD11b(+)CD11c(+)MHCII(+) MNPs in multiple organs including adipose tissues. Depleting CD301b(+) MNPs in vivo led to a significant weight loss with increased insulin sensitivity and a marked reduction in serum Resistin-like molecule (RELM) α, a multifunctional cytokine produced by MNPs. Reconstituting RELMα in CD301b(+) MNP-depleted animals restored body weight and normoglycemia. Thus, CD301b(+) MNPs play crucial roles in maintaining glucose metabolism and net energy balance.

Intrinsic protein disorder in histone lysine methylation

Histone lysine methyltransferases (HKMTs), catalyze mono-, di- and trimethylation of lysine residues, resulting in a regulatory pattern that controls gene expression. Their involvement in many different cellular processes and diseases makes HKMTs an intensively studied protein group, but scientific interest so far has been concentrated mostly on their catalytic domains. In this work we set out to analyze the structural heterogeneity of human HKMTs and found that many contain long intrinsically disordered regions (IDRs) that are conserved through vertebrate species. Our predictions show that these IDRs contain several linear motifs and conserved putative binding sites that harbor cancer-related SNPs. Although there are only limited data available in the literature, some of the predicted binding regions overlap with interacting segments identified experimentally. The importance of a disordered binding site is illustrated through the example of the ternary complex between MLL1, menin and LEDGF/p75. Our suggestion is that intrinsic protein disorder plays an as yet unrecognized role in epigenetic regulation, which needs to be further elucidated through structural and functional studies aimed specifically at the disordered regions of HKMTs.

Reviewers: This article was reviewed by Arne Elofsson and Piotr Zielenkiewicz.

Ghrelin

BACKGROUND

The gastrointestinal peptide hormone ghrelin was discovered in 1999 as the endogenous ligand of the growth hormone secretagogue receptor. Increasing evidence supports more complicated and nuanced roles for the hormone, which go beyond the regulation of systemic energy metabolism.

SCOPE OF REVIEW

In this review, we discuss the diverse biological functions of ghrelin, the regulation of its secretion, and address questions that still remain 15 years after its discovery.

MAJOR CONCLUSIONS

In recent years, ghrelin has been found to have a plethora of central and peripheral actions in distinct areas including learning and memory, gut motility and gastric acid secretion, sleep/wake rhythm, reward seeking behavior, taste sensation and glucose metabolism.

Function and dysfunction of hypocretin/orexin: an energetics point of view

The basic elements of animal behavior that are critical to survival include energy, arousal, and motivation: Energy intake and expenditure are fundamental to all organisms for the performance of any type of function; according to the Yerkes-Dodson law, an optimal level of arousal is required for animals to perform normal functions; and motivation is critical to goal-oriented behaviors in higher animals. The brain is the primary organ that controls these elements and, through evolution, has developed specialized structures to accomplish this task. The orexin/hypocretin system in the perifornical/lateral hypothalamus, which was discovered 15 years ago, is one such specialized area. This review summarizes a fast-growing body of evidence discerning how the orexin/hypocretin system integrates internal and external cues to regulate energy intake that can then be used to generate sufficient arousal for animals to perform innate and goal-oriented behaviors.

Helping our patients take HIV pre-exposure prophylaxis (PrEP): a systematic review of adherence interventions

OBJECTIVES

Adherence is critical for maximizing the effectiveness of pre-exposure prophylaxis (PrEP) in preventing HIV infection. Strategies for promoting adherence to HIV treatment, and their potential application to PrEP adherence, have received considerable attention. However, adherence promotion strategies for prevention medications have not been well characterized and may be more applicable to PrEP. We aimed to identify adherence support interventions that have been effective in other prevention fields and could be applied in the HIV prevention context to support pill taking among PrEP users.

METHODS

To identify adherence support interventions that could be evaluated and applied in the PrEP context, we conducted a systematic review across the following prevention fields: hypertension, latent tuberculosis infection, hyperlipidaemia, oral contraceptives, osteoporosis, malaria prophylaxis, and post-exposure prophylaxis for HIV infection. We included randomized controlled trials that evaluated the efficacy of interventions to improve adherence to daily oral medications prescribed for primary prevention in healthy individuals or for secondary prevention in asymptomatic individuals.

RESULTS

Our searches identified 585 studies, of which 48 studies met the eligibility criteria and were included in the review; nine evaluated multiple strategies, yielding 64 separately tested interventions. Interventions with the strongest evidence for improving adherence included complex, resource-intensive interventions, which combined multiple adherence support approaches, and low-cost, low-intensity interventions that provided education or telephone calls for adherence support.

CONCLUSIONS

Our review identified adherence interventions with strong evidence of efficacy across prevention fields and provides recommendations for evaluating these interventions in upcoming PrEP studies.

Lack of heritability of exhaled volatile compound pattern: an electronic nose twin study

Electronic noses can distinguish various disorders by analyzing exhaled volatile organic compound (VOC) pattern; however it is unclear how hereditary and environmental backgrounds affect the exhaled VOC pattern. A twin study enrolling monozygotic (MZ) and dizygotic (DZ) twins is an ideal tool to separate the influence of these factors on the exhaled breath pattern. Exhaled breath samples were collected in duplicates from 28 never smoking twin pairs (in total 112 samples) without lung diseases and processed with an electronic nose (Cyranose 320). Univariate quantitative hereditary modeling (ACE analysis) adjusted for age and gender was performed to decompose the phenotypic variance of the exhaled volatile compound pattern (assessing principal components (PCs) derived from electronic nose data) into hereditary (A), shared (C), and unshared (E) environmental effects. Exhaled VOC pattern showed good intra-subject reproducibility as assessed with the Bland-Altman plot. Significant correlations were found between exhaled VOC patterns of both MZ and DZ twins. The hereditary background did not influence the VOC pattern. The shared environmental effect on PC 1, 2 and 3 was estimated to be 93%, 94% and 54%, respectively. The unshared (unique) environmental influence explained a smaller variance (7%, 6% and 46%). For the first time using the twin design, we have shown that the environmental background largely affects the exhaled volatile compound pattern in never smoking volunteers without respiratory disorders. Further studies should identify these environmental factors and also assess their influence on exhaled breath patterns in patients with lung diseases.

Bird's-eye view on noise-based logic

Noise-based logic is a practically deterministic logic scheme inspired by the randomness of neural spikes and uses a system of uncorrelated stochastic processes and their superposition to represent the logic state. We briefly discuss various questions such as (i) What does practical determinism mean? (ii) Is noise-based logic a Turing machine? (iii) Is there hope to beat (the dreams of) quantum computation by a classical physical noise-based processor, and what are the minimum hardware requirements for that? Finally, (iv) we address the problem of random number generators and show that the common belief that quantum number generators are superior to classical (thermal) noise-based generators is nothing but a myth.

Genetic influence on the relation between exhaled nitric oxide and pulse wave reflection

Nitric oxide has an important role in the development of the structure and function of the airways and vessel walls. Fractional exhaled nitric oxide (FE(NO)) is inversely related to the markers and risk factors of atherosclerosis. We aimed to estimate the relative contribution of genes and shared and non-shared environmental influences to variations and covariation of FE(NO) levels and the marker of elasticity function of arteries. Adult Caucasian twin pairs (n = 117) were recruited in Hungary, Italy and in the United States (83 monozygotic and 34 dizygotic pairs; age: 48 ± 16 SD years). FE(NO) was measured by an electrochemical sensor-based device. Pulse wave reflection (aortic augmentation index, Aix(ao)) was determined by an oscillometric method (Arteriograph). A bivariate Cholesky decomposition model was applied to investigate whether the heritabilities of FE(NO) and Aix(ao) were linked. Genetic effects accounted for 58% (95% confidence interval (CI): 42%, 71%) of the variation in FE(NO) with the remaining 42% (95%CI: 29%, 58%) due to non-shared environmental influences. A modest negative correlation was observed between FE(NO) and Aix(ao) (r = -0.17; 95%CI:-0.32,-0.02). FE(NO) showed a significant negative genetic correlation with Aix(ao) (r(g) = -0.25; 95%CI:-0.46,-0.02). Thus in humans, variations in FE(NO) are explained both by genetic and non-shared environmental effects. Covariance between FE(NO) and Aix(ao) is explained entirely by shared genetic factors. This is consistent with an overlap among the sets of genes involved in the expression of these phenotypes and provides a basis for further genetic studies on cardiovascular and respiratory diseases.

Evidence for a strong genetic influence on carotid plaque characteristics: an international twin study

BACKGROUND AND PURPOSE

Few family studies reported moderate genetic impact on the presence and scores of carotid plaques. However, the heritability of carotid plaque characteristics remains still unclear. Twin studies more reliably estimate the relative contribution of genes to these traits in contrast to family study design.

METHODS

One hundred ninety-two monozygotic and 83 dizygotic adult twin pairs (age 49±15 years) from Italy, Hungary, and the United States underwent B-mode and color Doppler ultrasound of bilateral common, internal, and external carotid arteries.

RESULTS

Age-, sex-, and country-adjusted heritability was 78% for the presence of carotid plaque (95% CI, 55%-90%), 74% for plaque echogenicity (hypoechoic, hyperechoic, or mixed; 95% CI, 38%-87%), 69% for plaque size (area in mm2 in longitudinal plane; <or>50 percentile; 95% CI, 16%-86%), 74% for plaque sidedness (unilateral or bilateral; 95% CI, 25%-90%), 74% for plaque numerosity (95% CI, 26%-86%), 68% (95% CI, 40%-84%), and 66% (95% CI, 32%-90%) for the presence of plaque in carotid bulbs and proximal internal carotid arteries. No role of shared environmental factors was found. Unique environmental factors were responsible for the remaining variance (22%-34%). Controlling for relevant covariates did not change the results significantly.

CONCLUSIONS

The heritability of ultrasound characteristics of carotid plaque is high. Unshared environmental effects account for a modest portion of the variance. Our findings should stimulate the search for genes responsible for these traits.

Relationship between heart rate variability and endothelial function in healthy subjects

In various diseased states reduced cardiac vagal activity is accompanied by impaired endothelial function. Evidence from animal studies indicates interaction between the two systems, but such data from human studies is limited. The aim of this study was to test the hypothesis that cardiac vagal activity and endothelial function are related in healthy individuals. 46 young males were studied. From 10 minute long ECG recordings mean RR-interval and time and frequency domain vagal heart rate variability indices (RMSSD; pNN50 and HF, respectively) were determined. Heart rate variability indices were used to define cardiac vagal activity. Endothelial function was assessed by measuring brachial artery flow mediated dilation. Hyperemic, diastolic shear rate was used to normalize flow mediated dilation. All three vagal heart rate variability indices correlated significantly and positively with flow mediated dilation across subjects, with r values within the range of 0.43-0.52, p<0.01 for all relations. After adjusting for potential confounders, vagal heart rate variability indices remained significantly associated with normalized flow mediated dilation. RR-interval was related to most heart rate variability indices, but was not related to flow mediated dilation. Our data demonstrate that vagal heart rate variability indices are related to flow mediated dilation across healthy male subjects. The results cannot serve as evidence of a causal relationship, but are of interest and render for further investigation into underlying mechanisms.

Differential acute and chronic effects of leptin on hypothalamic astrocyte morphology and synaptic protein levels

Astrocytes participate in neuroendocrine functions partially through modulation of synaptic input density in the hypothalamus. Indeed, glial ensheathing of neurons is modified by specific hormones, thus determining the availability of neuronal membrane space for synaptic inputs, with the loss of this plasticity possibly being involved in pathological processes. Leptin modulates synaptic inputs in the hypothalamus, but whether astrocytes participate in this action is unknown. Here we report that astrocyte structural proteins, such as glial fibrillary acidic protein (GFAP) and vimentin, are induced and astrocyte morphology modified by chronic leptin administration (intracerebroventricular, 2 wk), with these changes being inversely related to modifications in synaptic protein densities. Similar changes in glial structural proteins were observed in adult male rats that had increased body weight and circulating leptin levels due to neonatal overnutrition (overnutrition: four pups/litter vs. control: 12 pups/litter). However, acute leptin treatment reduced hypothalamic GFAP levels and induced synaptic protein levels 1 h after administration, with no effect on vimentin. In primary hypothalamic astrocyte cultures leptin also reduced GFAP levels at 1 h, with an induction at 24 h, indicating a possible direct effect of leptin. Hence, one mechanism by which leptin may affect metabolism is by modifying hypothalamic astrocyte morphology, which in turn could alter synaptic inputs to hypothalamic neurons. Furthermore, the responses to acute and chronic leptin exposure are inverse, raising the possibility that increased glial activation in response to chronic leptin exposure could be involved in central leptin resistance.

Reversible autonomic dysfunction during antiviral treatment in patients with chronic hepatitis C virus infection: Anti-HCV therapy and autonomic function

BACKGROUND

The first clinical sign of chronic hepatitis C virus (HCV) infection can be one of the various extrahepatic manifestations. During antiviral treatment, symptoms of HCV-associated neuropathies usually improve, but can also worsen and lead to discontinuation of anti-HCV therapy. Recently, we have reported autonomic dysfunction in patients with HCV infection.

OBJECTIVES

In the present prospective study, we analyzed the changes of autonomic function during anti-HCV treatment.

PATIENTS AND METHODS

Cardiovagal autonomic function was assessed in 22 HCV RNA-positive, treatment-naive patients by determining heart rate variability (HRV) and baroreflex sensitivity (BRS), at the beginning of treatment and 12, 24 and 48 weeks of antiviral therapy. interferon alfa-2 and ribavirin were given according to the guidelines.

RESULTS

Both HRV and BRS time and frequency domain indices decreased after 12 weeks of therapy compared to the pre-treatment values; then the mean±SD values increased significantly by week 24 and continued to improve by week 48 of therapy-253.0±156.1 ms before therapy vs 111.6±81.9 at week 12, and 183.4±169.6 at week 24 vs 211.6±149.1 ms at week 48 for low-frequency HRV index; p<0.05 for all comparisons). These changes were independent from the presence of cryoglobulins and from virologic response.

CONCLUSIONS

The first rise followed by reversible autonomic dysfunction during antiviral therapy may be caused by the immunomodulatory actions of interferon alfa-2.