Lift-out cryo-FIBSEM and cryo-ET reveal the ultrastructural landscape of extracellular matrix

The extracellular matrix (ECM) serves as a scaffold for cells and plays an essential role in regulating numerous cellular processes, including cell migration and proliferation. Due to limitations in specimen preparation for conventional room-temperature electron microscopy, we lack structural knowledge on how ECM components are secreted, remodeled, and interact with surrounding cells. We have developed a 3D-ECM platform compatible with sample thinning by cryo-focused ion beam milling, the lift-out extraction procedure, and cryo-electron tomography. Our workflow implements cell-derived matrices (CDMs) grown on EM grids, resulting in a versatile tool closely mimicking ECM environments. This allows us to visualize ECM for the first time in its hydrated, native context. Our data reveal an intricate network of extracellular fibers, their positioning relative to matrix-secreting cells, and previously unresolved structural entities. Our workflow and results add to the structural atlas of the ECM, providing novel insights into its secretion and assembly.

Developmental dyslexia susceptibility genes DNAAF4, DCDC2, and NRSN1 are associated with brain function in fluently reading adolescents and young adults

Reading skills and developmental dyslexia, characterized by difficulties in developing reading skills, have been associated with brain anomalies within the language network. Genetic factors contribute to developmental dyslexia risk, but the mechanisms by which these genes influence reading skills remain unclear. In this preregistered study (https://osf.io/7sehx), we explored if developmental dyslexia susceptibility genes DNAAF4, DCDC2, NRSN1, and KIAA0319 are associated with brain function in fluently reading adolescents and young adults. Functional MRI and task performance data were collected during tasks involving written and spoken sentence processing, and DNA sequence variants of developmental dyslexia susceptibility genes previously associated with brain structure anomalies were genotyped. The results revealed that variation in DNAAF4, DCDC2, and NRSN1 is associated with brain activity in key language regions: the left inferior frontal gyrus, middle temporal gyrus, and intraparietal sulcus. Furthermore, NRSN1 was associated with task performance, but KIAA0319 did not yield any significant associations. Our findings suggest that individuals with a genetic predisposition to developmental dyslexia may partly employ compensatory neural and behavioral mechanisms to maintain typical task performance. Our study highlights the relevance of these developmental dyslexia susceptibility genes in language-related brain function, even in individuals without developmental dyslexia, providing valuable insights into the genetic factors influencing language processing.

Chromosomal Inversions and the Demography of Speciation in Drosophila montana and Drosophila flavomontana

Chromosomal inversions may play a central role in speciation given their ability to locally reduce recombination and therefore genetic exchange between diverging populations. We analyzed long- and short-read whole-genome data from sympatric and allopatric populations of 2 Drosophila virilis group species, Drosophila montana and Drosophila flavomontana, to understand if inversions have contributed to their divergence. We identified 3 large alternatively fixed inversions on the X chromosome and one on each of the autosomes 4 and 5. A comparison of demographic models estimated for inverted and noninverted (colinear) chromosomal regions suggests that these inversions arose before the time of the species split. We detected a low rate of interspecific gene flow (introgression) from D. montana to D. flavomontana, which was further reduced inside inversions and was lower in allopatric than in sympatric populations. Together, these results suggest that the inversions were already present in the common ancestral population and that gene exchange between the sister taxa was reduced within inversions both before and after the onset of species divergence. Such ancestrally polymorphic inversions may foster speciation by allowing the accumulation of genetic divergence in loci involved in adaptation and reproductive isolation inside inversions early in the speciation process, while gene exchange at colinear regions continues until the evolving reproductive barriers complete speciation. The overlapping X inversions are particularly good candidates for driving the speciation process of D. montana and D. flavomontana, since they harbor strong genetic incompatibilities that were detected in a recent study of experimental introgression.

Longitudinal Mediating Effect of Fat Mass and Lipids on Sedentary Time, Light PA, and MVPA with Inflammation in Youth

CONTEXT

Inflammation has been associated with atherosclerosis and metabolic disorders in youth. Preventing inflammation through exposure to different accelerometer-based movement behaviors has not been longitudinally examined.

OBJECTIVE

This work aimed to examine the mediating role of fat mass, lipids, and insulin resistance on the associations of cumulative sedentary time (ST), light physical activity (LPA), and moderate-to-vigorous physical activity (MVPA) with inflammation.

METHODS

From the Avon Longitudinal Study of Parents and Children, United Kingdom, 792 children with data on at least 2 time-point measures of accelerometer-based ST, LPA, and MVPA during age 11, 15, and 24 years follow-up clinic visits with complete high-sensitivity C-reactive protein (hsCRP) measures at age 15, 17, and 24 years were studied. Mediating associations were examined using structural equation models. When the magnitude of the association between the exposure and outcome is increased after including a third variable, suppression occurred but mediation if decreased.

RESULTS

Among 792 (58% female; mean [SD] age at baseline, 11.7 [0.2] years), ST increased, LPA decreased, and MVPA had a U-shaped increase while hsCRP increased during 13-year follow-up. Insulin resistance partly suppressed (23.5% suppression) the positive associations of ST with hsCRP among participants who were overweight/obese. Fat mass partly mediated (30% mediation) the negative associations of LPA with hsCRP. Fat mass had a 77% mediation effect on the negative associations of MVPA with hsCRP.

CONCLUSION

ST worsens inflammation, but increased LPA had a 2-fold inflammatory-lowering effect and was more resistant to the attenuating effect of fat mass compared with MVPA, and hence should be targeted in future interventions.

Attention biases for emotional facial expressions during a free viewing task increase between 2.5 and 5 years of age

The normative, developmental changes in affect-biased attention during the preschool years are largely unknown. To investigate the attention bias for emotional versus neutral faces, an eye-tracking measurement and free viewing of paired pictures of facial expressions (i.e., happy, fearful, sad, or angry faces) and nonface pictures with neutral faces were conducted with 367 children participating in a Finnish cohort study at the age of 2.5 years and with 477 children at the age of 5 years, 216 of which having follow-up measurements. We found an attention-orienting bias for happy and fearful faces versus neutral faces at both age points. An attention-orienting bias for sad faces emerged between 2.5 and 5 years. In addition, there were significant biases in sustained attention toward happy, fearful, sad, and angry faces versus neutral faces, with a bias in sustained attention for fearful faces being the strongest. All biases in sustained attention increased between 2.5 and 5 years of age. Moderate correlations in saccadic latencies were found between 2.5 and 5 years. In conclusion, attention biases for emotional facial expressions seem to be age-specific and specific for the attentional subcomponent. This implies that future studies on affect-biased attention during the preschool years should use small age ranges and cover multiple subcomponents of attention. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

A scalable school-based intervention to increase early adolescents' motor competence and health-related fitness

Schools are key settings for the promotion of students' physical activity, fitness, and motor competence. The purpose of our study was to investigate the efficacy of a 5-month-long intervention program that aimed to increase students' motor competence and health-related fitness during school days. We conducted a quasi-experimental study with 325 Finnish Grade 5 (Mage  = 11.26, SD = 0.33) students from five schools. Two schools were allocated to the intervention group and three schools to the control group. The intervention consisted of three components: (a) weekly 20 min session during regular PE lessons, (b) weekly 20 min session during recess, and (c) daily 5-minute-long classroom activity breaks. All activities were designed to systematically develop different elements of motor competence and fitness. The following assessments were conducted at baseline and 5-months: cardiorespiratory fitness levels were measured by 20-meter shuttle run test, muscular fitness by curl-up and push-up tests, and motor competence by 5-leaps and throwing-catching combination tests. We analyzed the data using a multi-group latent change score modeling. Results showed that students in the intervention group developed significantly better in 20-meter shuttle run test (β = 0.269, p = 0.000, 95% CI [0.141, 0.397]; +5.0 laps), push-up (β = 0.442, p = 0.000, 95% CI [0.267, 0.617]; +6.5 repetitions), curl-up (β = 0.353, p = 0.001, 95% CI [0.154, 0.552]; +7.8 repetitions), and throwing-catching combination tests (β = 0.195, p = 0.019, 95% CI [0.033, 0.356]; +1.1 repetitions) than students in the control group. The intervention program appeared to be feasible and effective in increasing students' cardiorespiratory fitness, muscular fitness, and object control skills. This indicates that guided school-based physical activity programs can be influential in promoting physical fitness and motor competence among early adolescent students.

Socio-economic factors, mood, primary care utilization, and quality of life as predictors of intervention cessation and chronic stress in a type 2 diabetes prevention intervention (PREVIEW Study)

BACKGROUND

Sedentary lifestyle and unhealthy diet combined with overweight are risk factors for type 2 diabetes (T2D). Lifestyle interventions with weight-loss are effective in T2D-prevention, but unsuccessful completion and chronic stress may hinder efficacy. Determinants of chronic stress and premature cessation at the start of the 3-year PREVIEW study were examined.

METHODS

Baseline Quality of Life (QoL), social support, primary care utilization, and mood were examined as predictors of intervention cessation and chronic stress for participants aged 25 to 70 with prediabetes (n = 2,220). Moderating effects of sex and socio-economic status (SES) and independence of predictor variables of BMI were tested.

RESULTS

Participants with children, women, and higher SES quitted intervention earlier than those without children, lower SES, and men. Lower QoL, lack of family support, and primary care utilization were associated with cessation. Lower QoL and higher mood disturbances were associated with chronic stress. Predictor variables were independent (p ≤ .001) from BMI, but moderated by sex and SES.

CONCLUSIONS

Policy-based strategy in public health should consider how preventive interventions may better accommodate different individual states and life situations, which could influence intervention completion. Intervention designs should enable in-built flexibility in delivery enabling response to individual needs.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01777893.

Lack of freedom predicted poor self-reported health among family caregivers of children with disabilities during the COVID-19 pandemic in Europe

AIM

We aim to assess the effects of the COVID-19 pandemic on self-reported health and quality of life among family caregivers of children with disabilities across Europe.

DESIGN

Cross-sectional study.

METHODS

Data from the survey by the Eurocarers and IRCCS-INRCA were used. The data were collected between November 2020 and March 2021 from 16 European countries. Data analysis was done using regression analysis to identify family caregivers' self-reported health and well-being predictors.

RESULTS

This study included 289 caregivers. The mean age of children was 12 years. Their family caregiver's mean age was 44, and they were mainly women. Experience of lack of freedom predicted family caregivers' poor self-reported health and quality of life. Children's interrupted health and social services also predicted family caregivers' poor self-reported mental well-being. Longitudinal evidence on the pandemic's effects and a diverse view of family caregivers of children with disabilities are needed to plan effective post-pandemic health services and nursing practice. No Patient or Public Contribution.

Longitudinal left ventricular mass indexing for DEXA-measured lean mass and fat mass: novel normative reference centiles in postpubertal adolescents and young adults

Left ventricular (LV) hypertrophy derived from LV mass (LVM) cut point is a marker of cardiovascular events in adults and target organ damage in pediatric research. Inadequate LVM indexing for body size due to scarcity of dual-energy X-ray absorptiometry (DEXA)-measured lean mass may lead to misclassification in the pediatric population. The only LVM indexed for DEXA-measured lean mass reference in children, mean age 11.6 yr, is 3-decades old and accurate LVM indexing in postpubertal adolescents and young adults is nonexistent. We generate new sex-specific LVM indexed for lean mass percentiles in healthy adolescence and young adulthood and correlated them with surrogates for normalizing body size. From the Avon Longitudinal Study of Parents and Children UK birth cohort, 868 adolescents (531 females) aged 17 yr were followed up for 7 yr. Lean mass was measured by DEXA at both time points. Echocardiography M-mode, two-dimensional (2-D), and three-dimensional (3-D) echo data for estimating LVM were collected at baseline and follow-up. Over 7 years, LVM increased in males (177.1 g) and females (133.5 g) at 17 yr to 199.9 g (males) and 145 g (females) at 24 yr. LVM/height3 and LVM/height2.7 provided the most consistent cross-sectional and longitudinal intraclass correlation coefficients with LVM/lean mass in both sexes (0.90-0.93). Indexing LVM by lean mass eliminated the sex difference only at age 24 yr but not at 17 yr. LVM/height2.7 85th percentiles for males and females at age 17 yr were 45.1 g/m2.7 and 41.4 g/m2.7, respectively, and at age 24 yr the 75th percentiles were 45.5 g/m2.7 and 41.7 g/m2.7, respectively. The 95th percentiles for males and females at age 17 yr were 49.5 g/m2.7 and 46.8 g/m2.7, respectively, and at age 24 yr were 57.1 g/m2.7 and 50.2 g/m2.7, respectively. These new reference percentile cut points were higher than the currently used 95th percentile pediatric reference of 38.6 g/m2.7. Future studies are warranted in youth with clinical diseases to examine whether these new cut points provide a more accurate stratification of cardiovascular risk.NEW & NOTEWORTHY Current left ventricular mass cut points for pediatric left ventricular hypertrophy are inaccurate. The inaccuracies are due, in part, to the average age of participants (11.6 yr) evaluated and also due to the lack of Echo and DEXA-measured body composition in postpubertal youth. Novel sex-based cut points are proposed for postpubertal youths at 17 and 24 yr. The new 95th percentile cut points are 15-20 g/m2.7 higher than the current cut point.

Distinct healthy and atopic canine gut microbiota is influenced by diet and antibiotics

The rising trend in non-communicable chronic inflammatory diseases coincides with changes in Western lifestyle. While changes in the human microbiota may play a central role in the development of chronic diseases, estimating the contribution of associated lifestyle factors remains challenging. We studied the influence of lifestyle-diet, antibiotic use, and residential environment with housing and family-on the gut microbiota of healthy and owner-reported atopic pet dogs, searching for associations between the lifestyle factors, atopy and microbiota. The results showed that atopic and healthy dogs had contrasting gut microbial composition. The gut microbiota also differed between two breeds, Labrador Retriever and Finnish Lapphund, selected for our study. Among all lifestyle factors studied, diet was most significantly associated with gut microbiota but only weakly with atopic symptoms. Thus, diet- and atopy-associated changes in the microbiota were not interrelated. Instead, the severity of symptoms was positively associated with the usage of antibiotics, which in turn was associated with the microbiota composition. Urban lifestyle was significantly associated with the increased prevalence of allergies but not with the gut microbiota. Our results from pet dogs supported previous evidence from humans, demonstrating that antibiotics, gut microbiota and atopic manifestation are interrelated. This congruence suggests that canine atopy might be a promising model for understanding the aetiology of human allergy.

The complex structure of Fomes fomentarius represents an architectural design for high-performance ultralightweight materials

High strength, hardness, and fracture toughness are mechanical properties that are not commonly associated with the fleshy body of a fungus. Here, we show with detailed structural, chemical, and mechanical characterization that Fomes fomentarius is an exception, and its architectural design is a source of inspiration for an emerging class of ultralightweight high-performance materials. Our findings reveal that F. fomentarius is a functionally graded material with three distinct layers that undergo multiscale hierarchical self-assembly. Mycelium is the primary component in all layers. However, in each layer, mycelium exhibits a very distinct microstructure with unique preferential orientation, aspect ratio, density, and branch length. We also show that an extracellular matrix acts as a reinforcing adhesive that differs in each layer in terms of quantity, polymeric content, and interconnectivity. These findings demonstrate how the synergistic interplay of the aforementioned features results in distinct mechanical properties for each layer.

Critical Role of Iodous Acid in Neutral Iodine Oxoacid Nucleation

Nucleation of neutral iodine particles has recently been found to involve both iodic acid (HIO₃) and iodous acid (HIO₂). However, the precise role of HIO₂ in iodine oxoacid nucleation remains unclear. Herein, we probe such a role by investigating the cluster formation mechanisms and kinetics of (HIO₃)_m(HIO₂)_n (m = 0-4, n = 0-4) clusters with quantum chemical calculations and atmospheric cluster dynamics modeling. When compared with HIO₃, we find that HIO₂ binds more strongly with HIO₃ and also more strongly with HIO₂. After accounting for ambient vapor concentrations, the fastest nucleation rate is predicted for mixed HIO₃-HIO₂ clusters rather than for pure HIO₃ or HIO₂ ones. Our calculations reveal that the strong binding results from HIO₂ exhibiting a base behavior (accepting a proton from HIO₃) and forming stronger halogen bonds. Moreover, the binding energies of (HIO₃)_m(HIO₂)_n clusters show a far more tolerant choice of growth paths when compared with the strict stoichiometry required for sulfuric acid-base nucleation. Our predicted cluster formation rates and dimer concentrations are acceptably consistent with those measured by the Cosmic Leaving Outdoor Droplets (CLOUD) experiment. This study suggests that HIO₂ could facilitate the nucleation of other acids beyond HIO₃ in regions where base vapors such as ammonia or amines are scarce.

Signaled night awakening and its association with social information processing and socio-emotional development across the first two years

STUDY OBJECTIVES

Night awakening is common in infancy, and some infants continue to have signaled night awakenings throughout early childhood. However, the influence of signaled night awakening on children's social development is less explored. In the present study, longitudinal associations between signaled night awakening, social information processing, and socio-emotional development were measured within the CHILD-SLEEP birth cohort in two groups formed based on parent-reported night awakenings.

METHODS

At 8 months, there were 77 infants in the waking group (≥3 awakenings) and 69 infants in the nonwaking group (≤1 awakening). At 8 and 24 months, social information processing was measured as children's attention to neutral and emotional faces, and at 24 months, parent-reported socio-emotional behavior was measured with the Brief Infant-Toddler Social and Emotional Assessment (BITSEA) questionnaire.

RESULTS

The two groups showed different patterns of attention to emotional faces. The waking group had a more pronounced attentional bias to fearful versus happy faces, whereas in the nonwaking group, attention to fearful and happy faces did not differ. In addition, at 24 months, the waking group had more dysregulation problems and lower social competence than the nonwaking group, but no clear differences in internalizing or externalizing problems were found.

CONCLUSIONS

Our results contribute to the literature by showing that during the first 2 years of life, signaled night awakening is associated with social information processing and socio-emotional behavior.

Faster maturation of selective attention in musically trained children and adolescents: Converging behavioral and event-related potential evidence

Previous work suggests that musical training in childhood is associated with enhanced executive functions. However, it is unknown whether this advantage extends to selective attention-another central aspect of executive control. We recorded a well-established event-related potential (ERP) marker of distraction, the P3a, during an audio-visual task to investigate the maturation of selective attention in musically trained children and adolescents aged 10-17 years and a control group of untrained peers. The task required categorization of visual stimuli, while a sequence of standard sounds and distracting novel sounds were presented in the background. The music group outperformed the control group in the categorization task and the younger children in the music group showed a smaller P3a to the distracting novel sounds than their peers in the control group. Also, a negative response elicited by the novel sounds in the N1/MMN time range (~150-200 ms) was smaller in the music group. These results indicate that the music group was less easily distracted by the task-irrelevant sound stimulation and gated the neural processing of the novel sounds more efficiently than the control group. Furthermore, we replicated our previous finding that, relative to the control group, the musically trained children and adolescents performed faster in standardized tests for inhibition and set shifting. These results provide novel converging behavioral and electrophysiological evidence from a cross-modal paradigm for accelerated maturation of selective attention in musically trained children and adolescents and corroborate the association between musical training and enhanced inhibition and set shifting.

The Impacts of Fish Oil and/or Probiotic Intervention on Low-Grade Inflammation, IGFBP-1 and MMP-8 in Pregnancy: A Randomized, Placebo-Controlled, Double-Blind Clinical Trial

Background: We investigated the impact of fish oil and/or probiotics on serum and vaginal inflammatory and metabolic proteins and their relation to the onset of gestational diabetes mellitus (GDM). Methods: Overweight/obese pregnant women received fish oil + placebo, probiotics + placebo, fish oil + probiotics or placebo + placebo from early pregnancy until six months postpartum (fish oil: 1.9 g docosahexaenoic acid and 0.22 g eicosapentaenoic acid; probiotics: Lactobacillus rhamnosus HN001 and Bifidobacterium animalis ssp. lactis 420, 10¹⁰ colony-forming units each). Serum high sensitivity C-reactive protein (hsCRP) and serum/vaginal (s/v) phosphorylated insulin-like growth factor binding-protein-1 (phIGFBP-1), IGFBP-1 and matrix metalloproteinase 8 (MMP-8) were analyzed. GDM was diagnosed according to 2 h 75 g OGTT. Results: The intervention had no impact on the change in proteins during pregnancy. Nevertheless, s-MMP-8 decreased and s-IGFBP-1 increased more in obese than in overweight women in the fish oil + probiotics group, while a decrease in s-MMP-8 was seen in obese women and an increase was seen in overweight women in the probiotics + placebo group. The late pregnancy s-phIGFBP-1 was higher in women who developed GDM in fish oil + probiotics-group compared to fish oil + placebo-group. The concentrations of s-phIGFBP-1 (635.9 ± 315.3 ng/mL vs. 753.2 ± 335.1 ng/mL, p = 0.005) and s-IGFBP-1 (3.78 ± 0.72 ng/mL vs. 3.96 ± 0.69 ng/mL, p = 0.042) were lower in early pregnancy in women who developed GDM than in women remaining healthy. Conclusions: The intervention per se had no impact on the proteins, but obesity and GDM may modify the effect. IGFBPs may affect the development of GDM.

TCP and MADS-Box Transcription Factor Networks Regulate Heteromorphic Flower Type Identity in Gerbera hybrida

The large sunflower family, Asteraceae, is characterized by compressed, flower-like inflorescences that may bear phenotypically distinct flower types. The CYCLOIDEA (CYC)/TEOSINTE BRANCHED1-like transcription factors (TFs) belonging to the TEOSINTE BRANCHED1/CYCLOIDEA/PROLIFERATING CELL FACTOR (TCP) protein family are known to regulate bilateral symmetry in single flowers. In Asteraceae, they function at the inflorescence level, and were recruited to define differential flower type identities. Here, we identified upstream regulators of GhCYC3, a gene that specifies ray flower identity at the flower head margin in the model plant Gerbera hybrida We discovered a previously unidentified expression domain and functional role for the paralogous CINCINNATA-like TCP proteins. They function upstream of GhCYC3 and affect the developmental delay of marginal ray primordia during their early ontogeny. At the level of single flowers, the Asteraceae CYC genes show a unique function in regulating the elongation of showy ventral ligules that play a major role in pollinator attraction. We discovered that during ligule development, the E class MADS-box TF GRCD5 activates GhCYC3 expression. We propose that the C class MADS-box TF GAGA1 contributes to stamen development upstream of GhCYC3 Our data demonstrate how interactions among and between the conserved floral regulators, TCP and MADS-box TFs, contribute to the evolution of the elaborate inflorescence architecture of Asteraceae.

Nonsense variant in COL7A1 causes recessive dystrophic epidermolysis bullosa in Central Asian Shepherd dogs

A rare hereditary mechanobullous disorder called epidermolysis bullosa (EB) causes blistering in the skin and the mucosal membranes. To date, nineteen EB-related genes have been discovered in human and other species. We describe here a novel EB variant in dogs. Two newborn littermates of Central Asian Shepherd dogs with severe signs of skin blistering were brought to a veterinary clinic and euthanized due to poor prognosis. In post-mortem examination, the puppies were shown to have findings in the skin and the mucosal membranes characteristic of EB. A whole-genome sequencing of one of the affected puppies was performed to identify the genetic cause. The resequencing data were filtered under a recessive model against variants from 31 other dog genomes, revealing a homozygous case-specific nonsense variant in one of the known EB-causing genes, COL7A1 (c.4579C>T, p.R1527*). The variant results in a premature stop codon and likely absence of the functional protein in the basement membrane of the skin in the affected dogs. This was confirmed by immunohistochemistry using a COL7A1 antibody. Additional screening of the variant indicated full penetrance and breed specificity at ~28% carrier frequency. In summary, this study reveals a novel COL7A1 variant causing recessive dystrophic EB and provides a genetic test for the eradication of the disease from the breed.