Biology subjects

Hildebrandt, T.

Publications and source records attributed to Hildebrandt, T..

5 recordsLinked to original sources

bioRxiv2025

Altered Brain Network Topology during Successful Response Inhibition in Children with Binge Eating

AimAlthough a risk factor for the later development of eating disorders, few studies examine the neural underpinnings of binge eating (BE) in children. Preliminary evidence suggests a role of the corticostriatal system; the purpose of this study was to evaluate the role of the inhibitory control brain network for risk of BE in children. MethodsData from 65 children with BE (57% girls) and 84 matched controls (52% girls) from the 4.0 baseline release of the Adolescent Brain Cognitive Development (ABCD) Study were included. Stop Signal Task-based fMRI data were analyzed using graph theoretic techniques. Global and nodal network properties (e.g. efficiency, betweenness-centrality) were compared for between-group differences and sex-by-group interactions. ResultsDespite comparable behavioral performance, children with BE showed significantly increased nodal efficiency of the right postcentral gyrus and left middle frontal gyrus (MFG), and increased connectedness of the right postcentral gyrus compared to control children. Children with BE showed distinct network hubs including the right MFG and left insula, while controls had distinct hubs in the right orbitofrontal and left fusiform gyri. Group-specific sex differences were found in the functioning of insular and frontal cortices. ConclusionIncreased efficiency and connectedness in frontal and parietal nodes of the inhibitory control network functioning in children with BE may represent a vulnerability for overeating. Distinct sex differences in functioning in children with BE compared to control children may reflect specific vulnerabilities to BE in the inhibitory control system in boys and girls that may contribute to sex differences in prevalence.

neuroscience↗

bioRxiv2023

Elephants develop wrinkles through both form & function

The trunks of elephants have prominent wrinkles from their base to the very tip. But neither the obvious differences in wrinkles between elephant species nor their development have been studied before. Asian elephants have more dorsal major, meaning deep and wide, trunk wrinkles (~126 {+/-} 25 SD) than African elephants (~83 {+/-} 13 SD). Both species have more dorsal than ventral major trunk wrinkles and a closer wrinkle spacing distally than proximally. In Asian elephants wrinkle density is high in the trunk wrapping zone. Wrinkle numbers on the left and right sides of the distal trunk differed as a function of trunk lateralization, with frequent bending in one direction causing wrinkle formation. MicroCT-imaging and microscopy of newborn elephants trunks revealed a constant thickness of the putative epidermis, whereas the putative dermis shrinks in the wrinkle troughs. During fetal development wrinkle numbers double every 20 days in an early exponential phase. Later wrinkles are added slowly, but at a faster rate in Asian than African elephants. We characterize the lifelong development of trunk wrinkles in Asian and African elephants and discuss the relation of species differences in trunk wrinkle distribution and number with behavioral, environmental, genetic, and biomechanical factors.

physiology↗

bioRxiv2022

Mouse primary T cell phosphotyrosine proteomics enabled by BOOST

The Broad Spectrum Optimization of Selective Triggering (BOOST) approach was recently developed to increase the quantitative depth of the tyrosine phosphoproteome by mass spectrometry-based proteomics. While BOOST has been demonstrated in the Jurkat T cell line, it has not been demonstrated in scarce mice primary T cells. Here, we show the first phosphotyrosine proteomics experiment performed in mice primary T cells using BOOST. We identify and precisely quantify more than 2,000 unique pTyr sites from more than 3,000 unique pTyr peptide PSMs using only 1 mg of protein from T cell receptor-stimulated primary T cells from mice. We further reveal the importance of the phase-constrained spectrum deconvolution method ({Phi}SDM) parameter on Orbitrap instruments that, when disabled, enhances quantitation depth, accuracy, and precision in low-abundance samples. Using samples with contrived ratios, we find that disabling {Phi}SDM allows for up to a two-fold increase in the number of statistically significant intensity ratios detected while enabling {Phi}SDM degrades quantitation, especially in low-abundance samples. TOC Graphic O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=111 SRC="FIGDIR/small/491817v1_ufig1.gif" ALT="Figure 1"> View larger version (27K): org.highwire.dtl.DTLVardef@4a2742org.highwire.dtl.DTLVardef@57645borg.highwire.dtl.DTLVardef@17dbfacorg.highwire.dtl.DTLVardef@b2df00_HPS_FORMAT_FIGEXP M_FIG C_FIG

biochemistry↗

bioRxiv2017

Species comparison of liver proteomes reveals enhanced lipid metabolism, reduced mitochondrial respiration and enhanced expression of detoxifying enzymes in the long-lived naked mole-rat.

Mammals display wide range of variation in their lifespan. Investigating the molecular networks that distinguish long-from short-lived species has proven useful to identify determinants of longevity. Here, we compared the liver of long-lived naked mole-rats (NMRs) and the phylogenetically closely related, shorter-lived, guinea pigs using an integrated omic approach. We found that NMRs livers display a unique expression pattern of mitochondrial proteins that result in distinct metabolic features of their mitochondria. For instance, we observed a generally reduced respiration rate associated with lower protein levels of respiratory chain components, particularly complex I, and increased capacity to utilize fatty acids. Interestingly, we show that the same molecular networks are affected during aging in both NMR and humans, supporting a direct link to the extraordinary longevity of both species. Finally, we identified a novel longevity pathway and validated it experimentally in the nematode C. elegans.

systems biology↗

bioRxiv2017

Long-lived rodents reveal signatures of positive selection in genes associated with lifespan and eusociality

The genetic mechanisms that determine lifespan are poorly understood. Most research has been done on short lived animals and it is unclear if these insights can be transferred to long-lived mammals like humans. Some African mole-rats (Bathyergidae) have life expectancies that are multiple times higher than similar sized and phylogenetically closely related rodents. We obtained genomic and transcriptomic data from 17 rodent species and systematically scanned eleven lineages associated with the evolution of longevity and eusociality for positively selected genes (PSGs). The set of 319 PSGs contains regulators of mTOR and is enriched in functional terms associated with (i) processes that are regulated by the mTOR pathway, e.g. translation, autophagy and mitochondrial biogenesis, (ii) the immune system and (iii) antioxidant defense. Analyzing gene expression of PSGs during aging in the long-lived naked mole-rat and up-regulation in the short-lived rat, we found a pattern fitting the antagonistic pleiotropy theory of aging.

evolutionary biology↗