Specific Defects Research Articles

Imaging flow cytometry-based cellular screening elucidates pathophysiology in individuals with Variants of Uncertain Significance

BackgroundDeciphering variants of uncertain significance (VUS) represents a major diagnostic challenge, partially due to the lack of easy-to-use and versatile cellular readouts that aid the interpretation of pathogenicity and pathophysiology. To address this challenge, we propose a high-throughput screening of cellular functionality through an imaging flow cytometry (IFC)-based platform.MethodsSix assays to evaluate autophagic-, lysosomal-, Golgi- health, mitochondrial function, ER stress, and NF-κβ activity were developed in fibroblasts. Assay sensitivity was verified with compounds (N = 5) and positive control patients (N = 6). Eight healthy controls and 20 individuals with VUS were screened.ResultsAll molecular compounds and positive controls showed significant changes on their cognate assays, confirming assay sensitivity. Simultaneous screening of positive control patients on all six assays revealed distinct phenotypic profiles. In addition, individuals with VUS(es) in well-known disease genes showed distinct – but similar—phenotypic profiles compared to patients with pathogenic variants in the same gene.. For all individuals with VUSes in Genes of Uncertain Significance (GUS), we found one or more of six assays were significantly altered. Broadening the screening to an untargeted approach led to the identification of two clusters that allowed for the recognition of altered cell cycle dynamics and DNA damage repair defects. Experimental follow-up of the ‘DNA damage repair defect cluster’ led to the discovery of highly specific defects in top2cc release from double-strand DNA breaks in one of these individuals, harboring a VUS in the RAD54L2 gene.ConclusionsOur high-throughput IFC-based platform simplifies the process of identifying VUS pathogenicity through six assays and allows for the recognition of useful pathophysiological markers that structure follow-up experiments, thereby representing a novel valuable tool for precise functional diagnostics in genomics.

Circulating Extracellular Vesicles in Alcoholic Liver Disease Affect Skeletal Muscle Homeostasis and Differentiation.

The mechanisms underlying muscle alteration associated to alcoholic liver disease (ALD) are not fully understood and the physiopathologic mediators of the liver-muscle interplay remains elusive. We investigated the role of circulating extracellular vesicles (EVs) in ALD as potential mediators of muscle atrophy. We established a mouse model of sarcopenia associated to ALD, by feeding mice with an alcoholic diet for 8 weeks. We investigated the effects of hepatic and circulating EVs isolated from these mice (EtOH mice; n = 7 females) on muscle cell cultures, comparing them with EVs from mice fed with a standard diet (CD mice; n = 6 females). Additionally, we examined the impact of circulating EVs from patients with alcohol-related cirrhosis (7 males and 2 females, mean age 55.4 years) on primary human muscle cells, comparing them with EVs from age-matched healthy subjects (6 males and 3 females). We analysed the miRNA profile of the EVs to identify potential mediators of ALD-associated sarcopenia. We demonstrated that circulating EVs were internalized by muscle cells and that EVs from ALD mice and cirrhotic patients caused alteration in the myogenic program. Molecular analysis revealed that serum EVs from ALD mice reduced protein synthesis in C2C12 cells, decreasing levels of p-AKT/AKT (-54.6%; p < 0.05), p-mTOR/mTOR (-54.5%; p < 0.05) and p-GSK3(Ser9)/GSK3 (-30.63%). Similarly, hepatic EVs induced defects in muscle differentiation, with reduced levels of p-AKT/AKT (-39.1%; p < 0.05), p-mTOR/mTOR (-30.1%; p < 0.05) and p-GSK3(Ser9)/GSK3 (-40%). C2C12 cells treated with either serum or hepatic EtOH-EVs exhibited upregulated expression of muscle-specific atrophy markers Atrogin-1 (+61.2% and +189.5%, respectively; p < 0.05) and MuRF1 (+260.4% and +112.5%, respectively; p < 0.05), along with an increased LC3-II/-I ratio (+131.5% and +40.2%, respectively; p < 0.05), indicating enhanced autophagy. MiRNA analysis revealed that both circulating and hepatic EVs from ALD mice showed elevated expression of miR-21, miR-155, miR-223 and miR-122 (+230% and +292%, respectively; p < 0.01) suggesting their potential role in sarcopenia. Human muscle cells exposed to EVs from cirrhotic patients exhibited reduced protein synthesis and upregulated Atrogin-1 (+113%; p < 0.05) and MuRF1 (+86.3%; p < 0.05), indicating proteasome activation. Circulating EVs of alcoholic patients showed upregulation of the same miRNAs observed in EtOH mice, including the liver-specific miR-122 (+260%; p < 0.05) suggesting, also in human liver disease, a hepatic origin of circulating EVs. Our study highlights the critical role of ALD-derived circulating EVs in affecting muscle homeostasis and myogenic program, suggesting potential therapeutic targets for mitigating muscle loss in ALD.

Advanced Reconstructive Techniques Following Orbital Exenteration: The Role of LCFA Free Flaps

BackgroundOrbital exenteration is a severe and disabling surgical procedure that involves the removal of all orbital contents. Effective reconstruction is crucial to managing the resulting defects. This study aims to propose a reconstructive algorithm utilizing free flaps derived from the lateral circumflex femoral artery (LCFA) system for orbital exenteration defects, based on our clinical experience. Patients and MethodsBetween January 2013 and January 2022, patients who underwent orbital exenteration and subsequent reconstruction using LCFA-based free flaps were included in this study. ResultsA total of 44 patients underwent orbital exenteration followed by LCFA free flap reconstruction. The choice of reconstructive technique varied according to defect type and dura mater exposure, adhering to the proposed algorithm. The procedures included 20 standard ALT flaps, 13 chimeric ALT flaps, 1 SALT chimeric flap with skin grafting, 7 SALT flaps with skin grafting, and 3 buried SALT flaps. Complications were recorded in 10 cases at the recipient site and in 2 cases at the donor site. ConclusionOrbital exenteration presents significant challenges both surgically and reconstructively, with a high risk of local recurrence and postoperative mortality. The reconstruction algorithm using LCFA-based free flaps, as proposed in this study, may guide surgeons in selecting the most appropriate technique, tailored to the specific defect and considering postoperative treatments such as adjuvant radiotherapy.

P-1823. Development of a Nocardia Reporter Strain to Study Cell-type Specific Phagocytosis and Killing in vivo

Abstract Background Nocardia infections are associated with substantial morbidity and mortality. Little is known about how the immune system defends against Nocardia. Methods Nocardia was transformed to contain a genomic copy of mScarlet. The cell wall was then labelled with AlexaFluor633 (AF633) to generate dually labelled (mScarlet+ AF633+) Nocardia. Cybb knockout (KO) mice (chronic granulomatous disease or CGD) and wildtype (WT) controls were inoculated with 5-10 million colony forming units (CFU) via oropharyngeal aspiration. High-dimensional flow cytometry (HDFC) and bacterial burden were determined in lung and bronchoalveolar lavage (BAL) fluid obtained 24 hours post-infection. Phagocytic index (PI) was defined as % of cells that are AF633+ cells. Killing capacity (KI) was defined as % of AF633+ cells that are mScarlet–. Results Live cultures of dually labelled Nocardia were positive for both mScarlet and AF633. mScarlet but not AF633 fluorescence decreased to undetectable levels upon killing of Nocardia. HDFC demonstrated that alveolar macrophages (AM), interstitial macrophages (IM), neutrophils, monocytes, and type 2 dendritic cells (cDC2) are the primary cell types that interact with Nocardia in vivo. PI was highest in AM and IM. PI was greater in cells from BAL versus lung (P&amp;lt; 0.01) while the opposite was true for other cell types. KI was lower in neutrophils versus other cell types (P&amp;lt; 0.05). Mortality and bacterial burden in lung were higher in CGD mice compared to WT controls (P&amp;lt; 0.01 for both comparisons). CGD mice demonstrated reduced PI in neutrophils, AM, IM (P&amp;lt; 0.05 for both). KI was impaired in AM and neutrophils. Conclusion Use of a dually labelled Nocardia reporter strain demonstrated cell-type specific defects in both phagocytosis and killing of Nocardia in CGD mice. This might explain the underlying predisposition to nocardiosis seen in humans with CGD. Ongoing studies aim to elucidate the molecular basis for the susceptibility to nocardiosis in humans and mice with CGD. Disclosures All Authors: No reported disclosures

Sphingolipid metabolism orchestrates establishment of the hair follicle stem cell compartment.

Sphingolipids serve as building blocks of membranes to ensure subcellular compartmentalization and facilitate intercellular communication. How cell type-specific lipid compositions are achieved and what is their functional significance in tissue morphogenesis and maintenance has remained unclear. Here, we identify a stem cell-specific role for ceramide synthase 4 (CerS4) in orchestrating fate decisions in skin epidermis. Deletion of CerS4 prevents the proper development of the adult hair follicle bulge stem cell (HFSC) compartment due to altered differentiation trajectories. Mechanistically, HFSC differentiation defects arise from an imbalance of key ceramides and their derivate sphingolipids, resulting in hyperactivation of noncanonical Wnt signaling. This impaired HFSC compartment establishment leads to disruption of hair follicle architecture and skin barrier function, ultimately triggering a T helper cell 2-dominated immune infiltration resembling human atopic dermatitis. This work uncovers a fundamental role for a cell state-specific sphingolipid profile in stem cell homeostasis and in maintaining an intact skin barrier.

Epigenetic dysregulation of metabolic programs mediates liposarcoma cell plasticity.

Sarcomas are rare connective tissue cancers thought to arise from aberrant mesenchymal stem cell (MSC) differentiation. Liposarcoma (LPS) holds valuable insights into dysfunctional differentiation given its well- and dedifferentiated histologic subtypes (WDLPS, DDLPS). Despite well-established differences in histology and clinical behavior, the molecular pathways underlying each subtype are poorly understood. Here, we performed single-nucleus multiome sequencing and spatial profiling on carefully curated human LPS samples and found defects in adipocyte-specific differentiation within LPS. Loss of insulin-like growth factor 1 (IGF1) and gain of cellular programs related to early mesenchymal development and glucagon-like peptide-1 (GLP-1)-induced insulin secretion are primary features of DDLPS. IGF1 loss was associated with worse overall survival in LPS patients. Through in vitro stimulation of the IGF1 pathway, we identified that DDLPS cells are deficient in the adipose-specific PPARG isoform 2 (PPARG2). Defects in IGF1/PPARG2 signaling in DDLPS led to a block in differentiation that could not be fully overcome with the addition of exogenous IGF1 or the pro-adipogenic agonists to PPARG and GLP-1. However, we noted upregulation of the IGF1 receptor (IGF1R) in the setting of IGF1 deficiency, which promoted sensitivity to an IGF1R-targeted antibody-drug conjugate that may serve as a novel therapeutic strategy in LPS. In summary, lineage-specific defects in adipogenesis drive dedifferentiation in LPS and may translate into selective therapeutic targeting in this disease.

Intrinsic Mechanical Effects on the Activation of Carbon Catalysts.

The mechanical effects on carbon-based metal-free catalysts (C-MFCs) have rarely been explored, despite the global interest in C-MFCs as substitutes for noble metal catalysts. Stress is ubiquitous, whereas its dedicated study is severely restricted due to its frequent entanglement with other structural variables, such as dopants, defects, and interfaces in catalysis. Herein, we report a proof-of-concept study by establishing a platform to continuously apply strain to a highly oriented pyrolytic graphite (HOPG) lamina, simultaneously collecting electrochemical signals. Notably, we establish, for the first time, the correlation between the surface strain of graphitic carbon and its activation effect on the oxygen reduction reaction (ORR). Our results indicate that while in-plane and edge carbon sites in HOPG could not be further activated by applying tensile strain, a strong and repeatable dependence of catalytic activity on tensile strain was observed when the structure incorporated in-plane defects, leading to a significant ∼35.0% improvement in ORR current density with the application of ∼0.6% tensile strain. Density functional theory (DFT) simulations reveal that appropriate strain on specific defects can optimize the adsorption of reaction intermediates, and the Stone-Wales defect on graphene is correlated with the observed mechanical effect. This work elucidates fundamental principles of strain effects on the catalytic activity of graphitic carbon toward ORR and may lay the groundwork for the development of carbon-based mechano-electrocatalysis.

Nonlinear Airy beam propagation in defected photonic lattices.

This work theoretically investigates the interplay of nonlinear Airy beams (AB) propagation and optically induced waveguide arrays in a photorefractive (PR) crystal. By introducing defect guides within the photonic lattice, we control the trajectory and self-bending properties and mostly the complex photoinduced waveguiding structures of these unconventional beams. Positive defects within the lattice induce the formation of solitary-like waves, while negative defects result in strong repulsion effects. In the nonlinear regime, these phenomena are further enhanced, with higher solitonic wave intensity in the case of a positive defect. Our simulations further demonstrate that at a lattice period of 20 µm, a specific defect guide modulation depth, and proper nonlinearity strength, a single laser beam injected in a negatively defected waveguide splits into up to seven distinct output channels. By judiciously adjusting the parameters, we can generate output channels that are spatially separated by up to 19 times the beam waist, thereby offering precise control over both the position and intensity of the output channels.

The widely used Ucp1-Cre transgene elicits complex developmental and metabolic phenotypes

Bacterial artificial chromosome transgenic models, including most Cre-recombinases, enable potent interrogation of gene function in vivo but require rigorous validation as limitations emerge. Due to its high relevance to metabolic studies, we perform comprehensive analysis of the Ucp1-CreEvdr line which is widely used for brown fat research. Hemizygotes exhibit major brown and white fat transcriptomic dysregulation, indicating potential altered tissue function. Ucp1-CreEvdr homozygotes also show high mortality, tissue specific growth defects, and craniofacial abnormalities. Mapping the transgene insertion site reveals insertion in chromosome 1 accompanied by large genomic alterations disrupting several genes expressed in a range of tissues. Notably, Ucp1-CreEvdr transgene retains an extra Ucp1 gene copy that may be highly expressed under high thermogenic burden. Our multi-faceted analysis highlights a complex phenotype arising from the presence of the Ucp1-CreEvdr transgene independently of intended genetic manipulations. Overall, comprehensive validation of transgenic mice is imperative to maximize discovery while mitigating unexpected, off-target effects.

Hydrolethalus Syndrome: A Case of a Rare Congenital Disorder.

This is a fatal case of multiple complicated congenital anomalies displaying several symptoms consistent with hydrolethalus syndrome. The newborn's phenotype is characterized by a combination of serious anatomical abnormalities such as open-book cerebral hemispheres, defective lobulation of the lungs (one lobe on the left, two on the right), a smaller right kidney, a smooth cerebral surface, and a specific keyhole-shaped defect in the skull base, primarily associated with hydrocephalus.

A truncated variant of the ribosome-associated trigger factor specifically contributes to plant chloroplast ribosome biogenesis

Molecular chaperones are essential throughout a protein’s life and act already during protein synthesis. Bacteria and chloroplasts of plant cells share the ribosome-associated chaperone trigger factor (Tig1 in plastids), facilitating maturation of emerging nascent polypeptides. While typical trigger factor chaperones employ three domains for their task, the here described truncated form, Tig2, contains just the ribosome binding domain. Tig2 is widely present in green plants and appears to have acquired an entirely different task than co-translational nascent polypeptide folding. Tig2 deletion results in remarkable leaf developmental defects of cold-exposed Arabidopsis thaliana plants and specific defects in plastidic ribosomes. Our data indicate that Tig2 functions during ribosome biogenesis by promoting the maturation of the large subunit. We hypothesize that Tig2 binding to the ribosomal tunnel-exit surface aids protecting this sensitive surface during assembly. Tig2 illustrates a fascinating concept of how a chaperone domain evolved individually, serving a completely different molecular task.

Targeting the CD74 signaling axis suppresses inflammation and rescues defective hematopoiesis in RUNX1-familial platelet disorder.

Familial platelet disorder (FPD) is associated with germline RUNX1 mutations, establishing a preleukemic state and increasing the risk of developing leukemia. Currently, there are no intervention strategies to prevent leukemia progression. Single-cell RNA sequencing (n = 10) combined with functional analysis of samples from patients with RUNX1-FPD (n > 75) revealed that FPD hematopoietic stem and progenitor cells (HSPCs) displayed increased myeloid differentiation and suppressed megakaryopoiesis because of increased activation of prosurvival and inflammatory pathways. Bone marrow from patients with RUNX1-FPD contained an elevated cytokine milieu, exerting chronic inflammatory stress on HSPCs. RUNX1-FPD HSPCs were myeloid biased, had increased self-renewal, and were resistant to inflammation-mediated exhaustion. The bone marrow from patients with RUNX1-FPD showed high transcript and protein expression of CD74 at the preleukemic stage compared with that of healthy controls, which remained high upon patient transformation into leukemia. Further, CD74-mediated signaling was exaggerated in RUNX1-FPD HSPCs compared with healthy controls, leading to the activation of mTOR and JAK/STAT pathways with increased cytokine production. Genetic and pharmacological targeting of CD74 with ISO-1 and its downstream targets JAK1/2 and mTOR reversed RUNX1-FPD differentiation defects in vitro and in vivo and reduced inflammation. Our results highlight that inflammation is an early event in RUNX1-FPD pathogenesis, and CD74 signaling is one of the drivers of this inflammation. The repurposing of JAK1/2i (ruxolitinib) and mTORi (sirolimus) and promoting the advancement of CD74 inhibitors in clinical settings as an early intervention strategy would be beneficial to improve the phenotype of patients with RUNX1-FPD and prevent myeloid progression.

Three-dimensional analysis of facial morphology in nine-year-old children with different unilateral orofacial clefts compared to normative data.

To compare three-dimensional (3D) facial morphology of various unilateral cleft subphenotypes at 9-years of age to normative data using a general face template and automatic landmarking. The secondary objective is to compare facial morphology of 9-year-old children with unilateral fusion to differentiation defects. 3D facial stereophotogrammetric images of 9-year-old unilateral cleft patients were imported into 3DMedX® for processing. All images of patients with a right sided cleft were mirrored. A regionalized general facial template was used for standardization. This template was pre-aligned to each face using five automatically determined landmarks and fitted using MeshMonk. All cleft patients were compared to an age-and gender matched normative face using distance maps and inter-surface distances (mm). Average faces were created for five groups (unilateral cleft lip, alveolus, and/or palate (UCL/A/P), fusion and differentiation defects). The selected regions for the evaluation of facial morphology were: complete face, nose, upper lip, lower lip, chin, forehead, and cheeks. A total of 86 consecutive 3D-stereophotogrammetry images were acquired for examination. No statistically significant differences were observed among the UCL, UCLA, and UCLP groups for the complete face, cheeks, chin, forehead, lower lip, and nose. However, in the upper lip region a significant difference was observed between the UCLP and UCL groups (P = 0.004, CI [-2.93 to -0.48]). Further visual examination of the distance maps indicated that more severe clefts corresponded to increased retrusion in the midface and the tip of the nose, though these differences were not statistically significant across groups. For fusion vs differentiation defects, no statistically significant differences were observed, neither for the complete face nor for any of the individual regions. The findings demonstrate statistically significant differences in the upper lip region between children with UCL and those with UCLP, particularly with greater upper lip retrusion in the UCLP group. The use of color-coded distance maps revealed local variations and a trend of asymmetry in the nasal region, with increasing retrusion of the nose tip, upper lip, and cheeks correlating with the severity of the cleft. Although these trends were not statistically significant, they suggest a progressive facial retrusion pattern as cleft severity increases. For the secondary objective, no statistical differences were found between the facial morphology of children with fusion and differentiation defects, although a similar progression of maxillary retrusion was observed in the distance maps.

Zebrafish Cyp1b1 knockout alters eye and brain metabolomic profiles, affecting ocular and neurobehavioral function.

Cytochrome P450 1B1 (CYP1B1) metabolizes endogenous and xenobiotic substrates, including steroids and fatty acids. It is implicated in the metabolism of compounds essential for eye development and is a causative gene in primary congenital glaucoma (PCG). However, CYP1B1's role in PCG and related eye disorders and neurobehavioral function is poorly understood. To investigate the role of Cyp1b1 this study used a novel CRISPR-Cas9 generated Cyp1b1 mutant zebrafish (Danio rerio) line. Behavioral, metabolomic, and transcriptomic analyses were performed to determine the molecular and behavioral consequences of the mutant Cyp1b1. Further we aimed to distinguish a visual defect from other neurological effects. Larval mutant zebrafish were hyperactive during the vision-based larval photomotor response assay but behaved normally in the sound-based larval startle response assay. Adult mutants exhibited normal locomotion but altered interactions with other fish. In vision and hearing-based assays, mutant fish showed altered behavior to visual stimuli and reduced auditory responses. Mass spectrometry-based metabolomics analysis revealed 26 differentially abundant metabolites in the eye and 49 in the brain between the genotypes, with perturbed KEGG pathways related to lipid, nucleotide, and amino acid metabolism. RNA sequencing identified 95 differentially expressed genes in the eye and 45 in the brain. Changes in arachidonic and retinoic acid abundance were observed and potentially modulated by altered expression of CYP 1, 2, and 3 family enzymes. While these findings could not point to specific ocular defects over other neurobehavioral phenotypes, behavioral assays and omics analyses highlighted the role of Cyp1b1 in maintaining metabolic homeostasis and the behavioral consequences due to its loss.

Assessment of The Impact of Apremilast on Levels of IL-17, IL-23, and Lipids in Obese Psoriatic Patient

Background: Psoriasis is an immune-mediated inflammatory disease with unknown aetiology that may be associated with the defect in proliferation and differentiation of the keratinocytes related to inflammatory cell infiltration. According to published reports, it is universal in occurrence; its prevalence in different populations varies from 0.1% to 11.8%. Receiving Apremilast resulted in a strong reduction in interleukin 17 and interleukin 23, as well as reduced expression of other inflammatory cytokines and improvement of psoriatic lesions. Objectives: This study aimed to assess the impact of Apremilast on levels of IL-17, IL-23, and lipids in obese psoriatic patients. Methods: Thirty obese patients with psoriasis were included in this prospective interventional study to measure serum levels of lipid profile, IL-17, and IL-23, before and after receiving Apremilast treatment. A t-test was used to compare between means. Results: The mean age of the participants was 38 years. The most common age group was 30–40 years. The levels of IL-17 before the administration of Apremilast were 225.55 ± 7.70 pg/mL. After six months of treatment with Apremilast, a statistically significant reduction was seen, with the value decreasing to 183.41 ±2.33 pg/ml. IL-22 levels before the administration of Apremilast were measured to be 76.42 ± 4.03 pg/mL. After six months of treatment with Apremilast, these levels exhibited a non-significant decrease to 67.15 ± 5.40 pg/ml. Modest alterations were noted in the lipid profile. Conclusion: The use of Apremilast is effective in decreasing IL-17 levels, which have pro-inflammatory effects; this leads to improvement in psoriatic lesions. Moreover, receiving Apremilast in obese psoriatic individuals led to a reduction in TG levels and an elevation in HDL-C levels. Additionally, a rise in TC levels and LDL-C was seen.

Native Point Defects Controlling Piezoelectric Voltage in Strained ZnO Microwires.

Piezovoltages generated by ZnO nano/microwire bending and strain enable electronic biogenerators that harvest human body movement to power-implanted biomedical devices. Currently, low voltages generated by these biogenerators limit their use to replace today's biomedical batteries. Electrically charged native point defects inside ZnO microwires can control these macroscopic piezo voltages, generating transverse electric fields that couple with strained wires' lengthwise piezoelectric fields so they redistribute spatially and change voltage output. Cathodoluminescence spectroscopy inside a scanning electron microscope correlates tip voltages directly with native point defect distributions of individual ZnO microwires in three dimensions. Spatial distributions of common CuZn antisites in ZnO extending throughout their length correlate this defect's acceptor nature and distribution directly with piezoelectric potential, revealing how they can control the tip piezovoltage of ZnO microwire-based nanogenerators, identifying specific defects to increase device output, and suggesting growth and processing treatments to create these defects.

Fetal Tracheal Occlusion Corelates with Normalized YAP Expression and Alveolar Epithelial Differentiation in CDH.

Congenital diaphragmatic hernia (CDH) is characterized by incomplete closure of the diaphragm. While the ensuing compression to the fetal lung causes lung hypoplasia, specific cellular phenotypes and developmental signaling defects in the alveolar epithelium in CDH are not fully understood. Employing lung samples from human CDH, a surgical lamb model and a nitrogen rat model, we investigate whether lung compression impairs alveolar epithelial differentiation and Yes-associated protein (YAP)-mediated mechanosensing. We showed that CDH in humans and lambs caused defective alveolar epithelial differentiation manifested by more abundant ATII cells, fewer ATI cells, and the emergence of cells expressing both ATI and ATII markers. Associated with the alveolar epithelial defects, we found a decrease in the level and nuclear localization of YAP. Reduced nuclear YAP and abnormal distal lung development were evident as early as 21 weeks in gestation in human CDH. In addition, rat fetuses with CDH also showed diminished nuclear YAP and mor abundant ATII cells. In contrast, the littermates without the hernia had no such alveolar phenotypes. Furthermore, fetal tracheal occlusion (TO) in the surgical lamb model of CDH fully normalized nuclear YAP and rescued alveolar epithelial defects in a gestational age-dependent manner. Taken together, our findings across species indicate that lung compression in CDH is sufficient to disrupt alveolar epithelial differentiation and impair YAP signaling. TO can restore nuclear YAP and rescue the alveolar defects in CDH, depending on the timing and the duration of this prenatal surgical intervention. This article is open access and distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives License 4.0 (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Influence of planar defects on the mechanical behaviors of spherical metallic nanoparticles

Abstract In present study, we adopt molecular dynamics simulations to investigate the influences of typical planar defects, including twin boundaries (TBs), stacking faults (SFs) and grain boundaries (GBs), on the mechanical properties of fcc copper nanoparticles. Groups of nanoparticle samples, including defect-free single crystal and those with specific defects, are examined for elastic modulus, yield strength, and deformation mechanisms. Detailed results reveal that the elastic behavior of nanoparticles can be well described by a modified theoretical model regardless the type of defects. While the planar defects have negligible influence on the elastic modulus, they significantly enhance the yield strength of nanoparticles. Notably, nanoparticles containing fivefold TBs exhibit the highest yield stress, i.e. ∼17.0 GPa, even surpassing that of the defect-free counterparts, i.e. ∼10.0 GP. Analysis of atomic deformation unravels that the distinct yielding behaviors are attributed to the activation of different slip systems and the nucleation of dislocations at specific preferential sites. These findings highlight the potential of fabricating planar defects to tailor the mechanical properties of metallic nanoparticles for targeted applications in nanotechnology and materials science.

Anion Doping as a “Trigger” to Modulate Defect‐Tailored Dielectric Coupling for Ultrathin Microwave Absorber

AbstractAnion doping engineering is recognized as a prospective strategy to adjust the electronic configuration and transport capacity of carbon‐based magnetoelectric hybrids and to optimize defects for the modulation of electromagnetic (EM) properties. This study effectively accomplishes an overwhelming enhancement in the dielectric coupling between conduction and polarization for the CuCo bimetallic/carbon system by employing in situ (N, O)/ex situ (S, Se) doping and defect modulation strategies. The well‐designed lattice distortions are facilitated by the large atomic radii (Se) intercalated carbon skeleton and the bimetallic CuCo, which activate the reinforcement of the dipole polarization in the high‐frequency region. Interestingly, an appropriate number of vacancies acts as “electron traps” to accelerate the local charge redistribution, endowing the system with extremely strong electronic interactions and interface‐induced polarization. It is remarkable that the ultra‐thin feature (1.8 mm) is able to achieve an extraordinary microwave attenuation (‒56.1 dB). Additionally, specific defect upgrading of anionic Se doping beneficially hinders the development of phonon transmission, conferring Cu2Se/CoSe2/NC‐Se aerogel outstanding infrared stealth capabilities along with inheriting the advantages of traditional carbon‐based hybrids (lightness, compressive/structural stability, and hydrophobicity/anti‐corrosive properties). This research offers distinctive perspectives on the advanced design of multifunctional absorbers in complex environments.

Vascular FLRT2 regulates venous-mediated angiogenic expansion and CNS barriergenesis

Veins have emerged as the origin of all other endothelial cell subtypes needed to expand vascular networks during developmental and pathological neoangiogenesis. Here, we uncover the role of the angioneurin Fibronectin Leucine Rich Transmembrane protein (FLRT) 2 in central nervous system (CNS) vascular development in the mouse. Early postnatal FLRT2 deletion reveals specific defects in retinal veins, impacting endothelial cell proliferation, sprouting and polarity that result in reduced tip cells at the vascular front. FLRT2 interacts with VE-cadherin and together with the endocytic adaptor protein Numb contribute to the modulation of adherens junction morphology in both retina and cerebral cortex in vivo. Utilizing expansion microscopy, we visualize the altered dynamic distribution of VE-cadherin in tissue of FLRT2 endothelial mutants. Additionally, FLRT2 in cortical vessels regulates the crosstalk between adherens and tight junctions, influencing blood-brain barrier development. Our findings position FLRT2 as a vein-specific regulator of CNS vascular development.