Dendritic cells (DCs) and monocytes play a central role in pathogen sensing, phagocytosis, and antigen presentation and consist of multiple specialized subtypes. However, their identities and ...interrelationships are not fully understood. Using unbiased single-cell RNA sequencing (RNA-seq) of ~2400 cells, we identified six human DCs and four monocyte subtypes in human blood. Our study reveals a new DC subset that shares properties with plasmacytoid DCs (pDCs) but potently activates T cells, thus redefining pDCs; a new subdivision within the CD1C
subset of DCs; the relationship between blastic plasmacytoid DC neoplasia cells and healthy DCs; and circulating progenitor of conventional DCs (cDCs). Our revised taxonomy will enable more accurate functional and developmental analyses as well as immune monitoring in health and disease.
Many viruses sequester the materials needed for their replication into discrete subcellular factories. For rotaviruses (RVs), these factories are called viroplasms, and they are formed in the host ...cell cytosol via the process of liquid-liquid phase separation (LLPS). The nonstructural protein 2 (NSP2) and its binding partner, nonstructural protein 5 (NSP5), are critical for viroplasm biogenesis. Yet it is not fully understood how NSP2 and NSP5 cooperate to form factories. The C-terminal region (CTR) of NSP2 (residues 291 to 317) is flexible, allowing it to participate in domain-swapping interactions that promote interoctamer interactions and, presumably, viroplasm formation. Molecular dynamics simulations showed that a lysine-to-glutamic acid change at position 294 (K294E) reduces NSP2 CTR flexibility
. To test the impact of reduced NSP2 CTR flexibility during infection, we engineered a mutant RV bearing this change (rRV-NSP2
). Single-cycle growth assays revealed a >1.2-log reduction in endpoint titers for rRV-NSP2
versus the wild-type control (rRV-WT). Using immunofluorescence assays, we found that rRV-NSP2
formed smaller, more numerous viroplasms than rRV-WT. Live-cell imaging experiments confirmed these results and revealed that rRV-NSP2
factories had delayed fusion kinetics. Moreover, NSP2
and several other CTR mutants formed fewer viroplasm-like structures in NSP5 coexpressing cells than did control NSP2
. Finally, NSP2
exhibited defects in its capacity to induce LLPS droplet formation
when incubated alongside NSP5. These results underscore the importance of NSP2 CTR flexibility in supporting the biogenesis of RV factories.
Viruses often condense the materials needed for their replication into discrete intracellular factories. For rotaviruses, agents of severe gastroenteritis in children, factory formation is mediated in part by an octameric protein called NSP2. A flexible C-terminal region of NSP2 has been proposed to link several NSP2 octamers together, a feature that might be important for factory formation. Here, we created a change in NSP2 that reduced C-terminal flexibility and analyzed the impact on rotavirus factories. We found that the change caused the formation of smaller and more numerous factories that could not readily fuse together like those of the wild-type virus. The altered NSP2 protein also had a reduced capacity to form factory-like condensates in a test tube. Together, these results add to our growing understanding of how NSP2 supports rotavirus factory formation-a key step of viral replication.
Brain-derived neurotrophic factor (BDNF) links learning, memory and cognitive decline in elderly, but evidence linking BDNF allele variation, cognition and brain structural differences is lacking.
...367 elderly Swedish men (n = 181) and women (n = 186) from Prospective Investigation of the Vasculature in Uppsala seniors (PIVUS) were genotyped and the BDNF functional rs6265 SNP was further examined in subjects who completed the Trail Making Task (TMT), verbal fluency task, and had a magnetic resonance imaging (MRI) scan. Voxel-based morphometry (VBM) examined brain structure, cognition and links with BDNF.
The functional BDNF SNP (rs6265,) predicted better working memory performance on the TMT with positive association of the Met rs6265, and was linked with greater cerebellar, precuneus, left superior frontal gyrus and bilateral hippocampal volume, and reduced brainstem and bilateral posterior cingulate volumes.
The functional BDNF polymorphism influences brain volume in regions associated with memory and regulation of sensorimotor control, with the Met rs6265 allele potentially being more beneficial to these functions in the elderly.
To generate performance predictions of borehole thermal energy storage (BTES) systems for both seasonal and short-term storage of industrial excess heat, e.g., from high to low production hours, ...models are needed that can handle the short-term effects. In this study, the first and largest industrial BTES in Sweden, applying intermittent heat injection and extraction down to half-day intervals, was modelled in the IDA ICE 4.8 environment and compared to three years of measured storage performance. The model was then used in a parametric study to investigate the change in performance of the storage from e.g., borehole spacing and storage supply flow characteristics at heat injection. For the three-year comparison, predicted and measured values for total injected and extracted energy differed by less than 1% and 3%, respectively and the mean relative difference for the storage temperatures was 4%, showing that the performance of large-scale BTES with intermittent heat injection and extraction can be predicted with high accuracy. At the actual temperature of the supply flow during heat injection, 40 °C, heat extraction would not exceed approximately 100 MWh/year for any investigated borehole spacing, 1–8 m. However, when the temperature of the supply flow was increased to 60–80 °C, 1400–3100 MWh/year, also dependent on the flow rate, could be extracted at the spacing yielding the highest heat extraction, which in all cases was 3–4 m.
DNA methylation has been proposed to play a critical role in many cellular and biological processes.
To examine the influence of Roux-en-Y gastric bypass (RYGB) surgery on genome-wide ...promoter-specific DNA methylation in obese patients. Promoters are involved in the initiation and regulation of gene transcription.
Promoter-specific DNA methylation in whole blood was measured in 11 obese patients (presurgery BMI >35 kg/m(2), 4 females), both before and 6 months after RYGB surgery, as well as once only in a control group of 16 normal-weight men. In addition, body weight and fasting plasma glucose were measured after an overnight fast.
The mean genome-wide distance between promoter-specific DNA methylation of obese patients at six months after RYGB surgery and controls was shorter, as compared to that at baseline (p<0.001). Moreover, postsurgically, the DNA methylation of 51 promoters was significantly different from corresponding values that had been measured at baseline (28 upregulated and 23 downregulated, P<0.05 for all promoters, Bonferroni corrected). Among these promoters, an enrichment for genes involved in metabolic processes was found (n = 36, P<0.05). In addition, the mean DNA methylation of these 51 promoters was more similar after surgery to that of controls, than it had been at baseline (P<0.0001). When controlling for the RYGB surgery-induced drop in weight (-24% of respective baseline value) and fasting plasma glucose concentration (-16% of respective baseline value), the DNA methylation of only one out of 51 promoters (~2%) remained significantly different between the pre-and postsurgery time points.
Epigenetic modifications are proposed to play an important role in the development of and predisposition to metabolic diseases, including type II diabetes and obesity. Thus, our findings may form the basis for further investigations to unravel the molecular effects of gastric bypass surgery.
ClinicalTrials.gov NCT01730742.
The combination of the obesity epidemic and an aging population presents growing challenges for the healthcare system. Obesity and aging are major risk factors for a diverse number of diseases and it ...is of importance to understand their interaction and the underlying molecular mechanisms. Herein the authors examined the methylation levels of 27578 CpG sites in 46 samples from adult peripheral blood. The effect of obesity and aging was ascertained with general linear models. More than one hundred probes were correlated to aging, nine of which belonged to the KEGG group map04080. Additionally, 10 CpG sites had diverse methylation profiles in obese and lean individuals, one of which was the telomerase catalytic subunit (TERT). In eight of ten cases the methylation change was reverted between obese and lean individuals. One region proved to be differentially methylated with obesity (LINC00304) independent of age. This study provides evidence that obesity influences age driven epigenetic changes, which provides a molecular link between aging and obesity. This link and the identified markers may prove to be valuable biomarkers for the understanding of the molecular basis of aging, obesity and associated diseases.
•We perform genome wide methylation analysis on 46 individuals.•We investigate the influence of age, obesity, and FTO genotype on methylation.•We found associations to age, obesity and interaction between age and obesity.
When microbes grow in foreign nutritional environments, selection may enrich mutations in unexpected pathways connecting growth and homeostasis. An evolution experiment designed to identify ...beneficial mutations in Burkholderia cenocepacia captured six independent nonsynonymous substitutions in the essential gene
, which modifies tRNA
by adding a lysine to the anticodon for faithful AUA recognition. Further, five additional mutants acquired mutations in tRNA
, which strongly suggests that disrupting the TilS-tRNA
interaction was subject to strong positive selection. Mutated TilS incurred greatly reduced enzymatic function but retained capacity for tRNA
binding. However, both mutant sets outcompeted the wild type by decreasing the lag phase duration by ~3.5 h. We hypothesized that lysine demand could underlie fitness in the experimental conditions. As predicted, supplemental lysine complemented the ancestral fitness deficit, but so did the additions of several other amino acids. Mutant fitness advantages were also specific to rapid growth on galactose using oxidative overflow metabolism that generates redox imbalance, not resources favoring more balanced metabolism. Remarkably, 13
mutations also evolved in the long-term evolution experiment with Escherichia coli, including four fixed mutations. These results suggest that TilS or unknown binding partners contribute to improved growth under conditions of rapid sugar oxidation at the predicted expense of translational accuracy.
There is growing evidence that the fundamental components of protein translation can play multiple roles in maintaining cellular homeostasis. Enzymes that interact with transfer RNAs not only ensure faithful decoding of the genetic code but also help signal the metabolic state by reacting to imbalances in essential building blocks like free amino acids and cofactors. Here, we present evidence of a secondary function for the essential enzyme TilS, whose only prior known function is to modify tRNA
to ensure accurate translation. Multiple nonsynonymous substitutions in
, as well as its cognate tRNA, were selected in evolution experiments favoring rapid, redox-imbalanced growth. These mutations alone decreased lag phase and created a competitive advantage, but at the expense of most primary enzyme function. These results imply that TilS interacts with other factors related to the timing of exponential growth and that tRNA-modifying enzymes may serve multiple roles in monitoring metabolic health.
Objective
To investigate if acute sleep deprivation affects food purchasing choices in a mock supermarket.
Design and Methods
On the morning after one night of total sleep deprivation (TSD) or after ...one night of sleep, 14 normal‐weight men were given a fixed budget (300 SEK—approximately 50 USD). They were instructed to purchase as much as they could out of a possible 40 items, including 20 high‐caloric foods (>2 kcal/g) and 20 low‐caloric foods (<2 kcal/g). The prices of the high‐caloric foods were then varied (75%, 100% (reference price), and 125%) to determine if TSD affects the flexibility of food purchasing. Before the task, participants received a standardized breakfast, thereby minimizing the potential confound produced by hunger. In addition, morning plasma concentrations of the orexigenic hormone ghrelin were measured under fasting conditions.
Results
Independent of both type of food offered and price condition, sleep‐deprived men purchased significantly more calories (+9%) and grams (+18%) of food than they did after one night of sleep (both P < 0.05). Morning plasma ghrelin concentrations were also higher after TSD (P < 0.05). However, this increase did not correlate with the effects of TSD on food purchasing.
Conclusions
This experiment demonstrates that acute sleep loss alters food purchasing behavior in men.
Spinal muscular atrophy (SMA) is a monogenic neurodegenerative disorder subdivided into four different types. Whole genome methylation analysis revealed 40 CpG sites associated with genes that are ...significantly differentially methylated between SMA patients and healthy individuals of the same age. To investigate the contribution of methylation changes to SMA severity, we compared the methylation level of found CpG sites, designed as "targets", as well as the nearest CpG sites in regulatory regions of ARHGAP22, CDK2AP1, CHML, NCOR2, SLC23A2 and RPL9 in three groups of SMA patients. Of notable interest, compared to type I SMA male patients, the methylation level of a target CpG site and one nearby CpG site belonging to the 5'UTR of SLC23A2 were significantly hypomethylated 19-22% in type III-IV patients. In contrast to type I SMA male patients, type III-IV patients demonstrated a 16% decrease in the methylation levels of a target CpG site, belonging to the 5'UTR of NCOR2. To conclude, this study validates the data of our previous study and confirms significant methylation changes in the SLC23A2 and NCOR2 regulatory regions correlates with SMA severity.
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