Differential impact of perfluorooctanoic acid and fluorotelomer ethoxylates on placental metabolism in mice.

Poly- and perfluoroalkyl substances (PFAS) are a group of compounds with uses in industry and many consumer products. Concerns about the potential health effects of these compounds resulted in regulation by the Stockholm Convention on the use of three of the most common PFAS, including perfluorooctanoic acid (PFOA). Thousands of PFAS remain in production that are unregulated and for which their toxicity is unknown. Our group recently identified a new class of PFAS, fluorotelomer ethoxylates (FTEOs), in indoor dust and industrial wastewater. In this study, we investigated the effect of PFAS on placental metabolism by exposing healthy, pregnant CD-1 mice to PFOA or FTEOs at one of three concentrations (0 ng/L (controls), 5 ng/L, 100 ng/L) (n = 7-8/group). While PFOA is banned and PFOA concentrations in human blood are decreasing, we hypothesize that FTEOs will cause adverse pregnancy outcomes similar to PFOA, the compounds they were meant to replace. Placental tissue samples were collected at embryonic day 17.5 and 1H solid-state magic angle spinning nuclear magnetic resonance spectroscopy was used to determine the relative concentration of placental metabolites (n = 18-20/group). At the highest concentration, the relative concentrations of glucose and threonine were increased and the relative concentration of creatine was decreased in the PFOA-exposed placentas compared to controls (p < 0.05). In contrast, the relative concentrations of asparagine and lysine were decreased and the relative concentration of creatine was increased in the FTEOs-exposed placentas compared to controls (p < 0.05). Partial least squares - discriminant analysis showed the FTEOs-exposed and control groups were significantly separated (p < 0.005) and pathway analysis found four biochemical pathways were perturbed following PFOA exposure, while one pathway was altered following FTEOs exposure. Maternal exposure to PFOA and FTEOs had a significant impact on the placental metabolome, with the effect depending on the pollutant. This work motivates further studies to determine exposure levels and evaluate associations with adverse outcomes in human pregnancies.

Intramuscular vaccination against SARS-CoV-2 transiently induces neutralizing IgG rather than IgA in the saliva.

The mucosal immunity is crucial for restricting SARS-CoV-2 at its entry site. Intramuscularly applied vaccines against SARS-CoV-2 stimulate high levels of neutralizing Abs in serum, but the impact of these intramuscular vaccinations on features of mucosal immunity is less clear. Here, we analyzed kinetic and functional properties of anti-SARS-CoV-2 Abs in the saliva after vaccination with BNT162b2. We analyzed a total of 24 healthy donors longitudinally for up to 16 months. We found that specific IgG appeared in the saliva after the second vaccination, declined thereafter and reappeared after the third vaccination. Adjusting serum and saliva for the same IgG concentration revealed a strong correlation between the reactivity in these two compartments. Reactivity to VoCs correlated strongly as seen by ELISAs against RBD variants and by live-virus neutralizing assays against replication-competent viruses. For further functional analysis, we purified IgG and IgA from serum and saliva. In vaccinated donors we found neutralizing activity towards authentic virus in the IgG, but not in the IgA fraction of the saliva. In contrast, IgA with neutralizing activity appeared in the saliva only after breakthrough infection. In serum, we found neutralizing activity in both the IgA and IgG fractions. Together, we show that intramuscular mRNA vaccination transiently induces a mucosal immunity that is mediated by IgG and thus differs from the mucosal immunity after infection. Waning of specific mucosal IgG might be linked to susceptibility for breakthrough infection.

Cellular development and evolution of the mammalian cerebellum.

The expansion of the neocortex, a hallmark of mammalian evolution1,2, was accompanied by an increase in cerebellar neuron numbers3. However, little is known about the evolution of the cellular programmes underlying the development of the cerebellum in mammals. In this study we generated single-nucleus RNA-sequencing data for around 400,000 cells to trace the development of the cerebellum from early neurogenesis to adulthood in human, mouse and the marsupial opossum. We established a consensus classification of the cellular diversity in the developing mammalian cerebellum and validated it by spatial mapping in the fetal human cerebellum. Our cross-species analyses revealed largely conserved developmental dynamics of cell-type generation, except for Purkinje cells, for which we observed an expansion of early-born subtypes in the human lineage. Global transcriptome profiles, conserved cell-state markers and gene-expression trajectories across neuronal differentiation show that cerebellar cell-type-defining programmes have been overall preserved for at least 160 million years. However, we also identified many orthologous genes that gained or lost expression in cerebellar neural cell types in one of the species or evolved new expression trajectories during neuronal differentiation, indicating widespread gene repurposing at the cell-type level. In sum, our study unveils shared and lineage-specific gene-expression programmes governing the development of cerebellar cells and expands our understanding of mammalian brain evolution.

Maternal exposure to polystyrene nanoplastics alters fetal brain metabolism in mice.

INTRODUCTION: Plastics used in everyday materials accumulate as waste in the environment and degrade over time. The impacts of the resulting particulate micro- and nanoplastics on human health remain largely unknown. In pregnant mice, we recently demonstrated that exposure to nanoplastics throughout gestation and during lactation resulted in changes in brain structure detected on MRI. One possible explanation for this abnormal postnatal brain development is altered fetal brain metabolism. OBJECTIVES: To determine the effect of maternal exposure to nanoplastics on fetal brain metabolism. METHODS: Healthy pregnant CD-1 mice were exposed to 50 nm polystyrene nanoplastics at a concentration of 106 ng/L through drinking water during gestation. Fetal brain samples were collected at embryonic day 17.5 (n = 18-21 per group per sex) and snap-frozen in liquid nitrogen. Magic angle spinning nuclear magnetic resonance was used to determine metabolite profiles and their relative concentrations in the fetal brain. RESULTS: The relative concentrations of gamma-aminobutyric acid (GABA), creatine and glucose were found to decrease by 40%, 21% and 30% respectively following maternal nanoplastic exposure when compared to the controls (p < 0.05). The change in relative concentration of asparagine with nanoplastic exposure was dependent on fetal sex (p < 0.005). CONCLUSION: Maternal exposure to polystyrene nanoplastics caused abnormal fetal brain metabolism in mice. The present study demonstrates the potential impacts of nanoplastic exposure during fetal development and motivates further studies to evaluate the risk to human pregnancies.

A lamprey neural cell type atlas illuminates the origins of the vertebrate brain.

The vertebrate brain emerged more than ~500 million years ago in common evolutionary ancestors. To systematically trace its cellular and molecular origins, we established a spatially resolved cell type atlas of the entire brain of the sea lamprey-a jawless species whose phylogenetic position affords the reconstruction of ancestral vertebrate traits-based on extensive single-cell RNA-seq and in situ sequencing data. Comparisons of this atlas to neural data from the mouse and other jawed vertebrates unveiled various shared features that enabled the reconstruction of cell types, tissue structures and gene expression programs of the ancestral vertebrate brain. However, our analyses also revealed key tissues and cell types that arose later in evolution. For example, the ancestral brain was probably devoid of cerebellar cell types and oligodendrocytes (myelinating cells); our data suggest that the latter emerged from astrocyte-like evolutionary precursors in the jawed vertebrate lineage. Altogether, our work illuminates the cellular and molecular architecture of the ancestral vertebrate brain and provides a foundation for exploring its diversification during evolution.

Change-of-Direction Speed Assessments and Testing Procedures in Tennis: A Systematic Review.

ABSTRACT: Schneider, C, Rothschild, J, and Uthoff, A. Change-of-direction speed assessments and testing procedures in tennis: a systematic review. J Strength Cond Res 37(9): 1888-1895, 2023-Change-of-direction speed (CODS) plays an essential role in tennis match play, and CODS performance is, therefore, commonly assessed and monitored in tennis players. Thus, the aim of this systematic review was to describe test characteristics, performance metrics, test-retest reliability, construct validity, and test outcomes of tests that are used to assess CODS in tennis players. A literature search conducted on PubMed and SPORTDiscus yielded 563 results. After applying the eligibility criteria, a total of 27 studies were included in the present review. Ten unique CODS tests were identified. 505 test variations were most frequently used across all studies, and total time required to complete the test was the predominant performance metric investigated. Intrasession test-retest reliability ranged from "moderate" to "excellent." Intersession test-retest reliability as well as the effects of tennis performance, sex, and age on CODS performance were unclear given the subject demographics and the limited number of studies that investigated these aspects. In conclusion, most studies included CODS tests that exhibit longer COD entry and total distances but similar COD angles to those seen during tennis match play. All CODS tests have at least "moderate" intrasession test-retest reliability. However, to improve CODS assessment methods and to increase our current understanding of CODS performance in tennis players, there is a need to conduct more research on the intersession test-retest reliability, construct validity, and the effects of sex, age, and tennis performance and to investigate other performance metrics that might provide additional insights into CODS (e.g., phase-specific performance variables).

The molecular evolution of spermatogenesis across mammals.

The testis produces gametes through spermatogenesis and evolves rapidly at both the morphological and molecular level in mammals1-6, probably owing to the evolutionary pressure on males to be reproductively successful7. However, the molecular evolution of individual spermatogenic cell types across mammals remains largely uncharacterized. Here we report evolutionary analyses of single-nucleus transcriptome data for testes from 11 species that cover the three main mammalian lineages (eutherians, marsupials and monotremes) and birds (the evolutionary outgroup), and include seven primates. We find that the rapid evolution of the testis was driven by accelerated fixation rates of gene expression changes, amino acid substitutions and new genes in late spermatogenic stages, probably facilitated by reduced pleiotropic constraints, haploid selection and transcriptionally permissive chromatin. We identify temporal expression changes of individual genes across species and conserved expression programs controlling ancestral spermatogenic processes. Genes predominantly expressed in spermatogonia (germ cells fuelling spermatogenesis) and Sertoli (somatic support) cells accumulated on X chromosomes during evolution, presumably owing to male-beneficial selective forces. Further work identified transcriptomal differences between X- and Y-bearing spermatids and uncovered that meiotic sex-chromosome inactivation (MSCI) also occurs in monotremes and hence is common to mammalian sex-chromosome systems. Thus, the mechanism of meiotic silencing of unsynapsed chromatin, which underlies MSCI, is an ancestral mammalian feature. Our study illuminates the molecular evolution of spermatogenesis and associated selective forces, and provides a resource for investigating the biology of the testis across mammals.

Maternal exposure to polystyrene microplastics alters placental metabolism in mice.

INTRODUCTION: The rapid growth in the worldwide use of plastics has resulted in a vast accumulation of microplastics in the air, soil and water. The impact of these microplastics on pregnancy and fetal development remains largely unknown. In pregnant mice, we recently demonstrated that exposure to micro- and nanoplastics throughout gestation resulted in significant fetal growth restriction. One possible explanation for reduced fetal growth is abnormal placental metabolism. OBJECTIVES: To evaluate the effect of maternal exposure to microplastics on placental metabolism. METHODS: In the present study, CD-1 pregnant mice were exposed to 5 µm polystyrene microplastics in filtered drinking water at one of four concentrations (0 ng/L (controls), 102 ng/L, 104 ng/L, 106 ng/L) throughout gestation (n = 7-11/group). At embryonic day 17.5, placental tissue samples were collected (n = 28-44/group). Metabolite profiles were determined using 1 H high-resolution magic angle spinning magnetic resonance spectroscopy. RESULTS: The relative concentration of lysine (p = 0.003) and glucose (p < 0.0001) in the placenta were found to decrease with increasing microplastic concentrations, with a significant reduction at the highest exposure concentration. Multivariate analysis identified shifts in the metabolic profile with MP exposure and pathway analysis identified perturbations in the biotin metabolism, lysine degradation, and glycolysis/gluconeogenesis pathways. CONCLUSION: Maternal exposure to microplastics resulted in significant alterations in placental metabolism. This study highlights the potential impact of microplastic exposure on pregnancy outcomes and that efforts should be made to minimize exposure to plastics, particularly during pregnancy.

Endothelial nitric oxide deficiency results in abnormal placental metabolism.

Placental metabolism determines the amount of nutrients available to the fetus and may be altered in pregnancies complicated by fetal growth restriction (FGR). To study which metabolites are associated with FGR, we performed 1H high-resolution magic angle spinning magnetic resonance spectroscopy of placental tissue from endothelial nitric oxide synthase knockout (eNOS KO) mice, a model of FGR, and C57BL/6J controls at embryonic day 17.5 (n = 24/genotype). The relative concentration of glucose was increased in the placentas of eNOS KO mice compared to controls (p = 0.006). This study highlights the potential for glucose as a biomarker of abnormal placental metabolism that leads to FGR.

Placental metabolite profiles in late gestation for healthy mice.

INTRODUCTION: During pregnancy, appropriate placental metabolism is essential for fetuses to reach their growth potential. However, metabolic mechanisms during pregnancy remain poorly understood. Determination of the levels of placental metabolites in healthy pregnancy and how they change throughout gestation is critical for understanding placental function. OBJECTIVE: To determine the effects of gestational age on placental metabolites using healthy pregnant mice. METHODS: In the present study, we collected placental tissue samples from healthy pregnant mice at three timepoints in late gestation (n = 16 placentas per gestational age). Metabolite profiles were determined using 1H high-resolution magic angle spinning magnetic resonance spectroscopy (HRMAS MRS). RESULTS: Using HRMAS MRS, we identified 14 metabolites in murine placental tissue samples. The relative concentration of 12 of the 14 metabolites remains unchanged throughout late gestation. Lysine was found to decrease significantly (p = 0.04) and glucose showed an inverted U-shape relationship (p = 0.03) with gestational age. CONCLUSION: This study demonstrated the feasibility of HRMAS MRS to determine relative metabolite concentrations in murine placental tissue. These findings establish baseline levels of placental tissue metabolite profiles and will serve as reference ranges for future studies using mouse models of fetal distress.

Persistence of functional memory B cells recognizing SARS-CoV-2 variants despite loss of specific IgG.

Although some COVID-19 patients maintain SARS-CoV-2-specific serum immunoglobulin G (IgG) for more than 6 months postinfection, others eventually lose IgG levels. We assessed the persistence of SARS-CoV-2-specific B cells in 17 patients, 5 of whom had lost specific IgGs after 5-8 months. Differentiation of blood-derived B cells in vitro revealed persistent SARS-CoV-2-specific IgG B cells in all patients, whereas IgA B cells were maintained in 11. Antibodies derived from cultured B cells blocked binding of viral receptor-binding domain (RBD) to the cellular receptor ACE-2, had neutralizing activity to authentic virus, and recognized the RBD of the variant of concern Alpha similarly to the wild type, whereas reactivity to Beta and Gamma were decreased. Thus, differentiation of memory B cells could be more sensitive for detecting previous infection than measuring serum antibodies. Understanding the persistence of SARS-CoV-2-specific B cells even in the absence of specific serum IgG will help to promote long-term immunity.

Use of micro-climatic monitoring to assess potential stone weathering on a monument: example of the Saint-Remi Basilica (Reims, France).

Temperature and humidity variations influence various weathering processes of historical building stones. The aim of this study is to define the possible micro-climates on a monument in order to identify the recurring stress events, allowing to assess the potential stone weathering. For this purpose, a sensor network was set up on the two towers of the Saint-Remi Basilica of Reims: fourteen i-Buttons recorded temperature and relative humidity for 2 years with a time step of 1 h or 2 min for short measurement campaigns. Two micro-climates were identified: the sunny micro-climate (areas oriented South and West) presenting higher temperatures and lower relative humidity than the shadowed micro-climate (areas oriented North, East, and other shadowed zones). On the micro-climates, three typical days (Sunny, Rainy, and Frost days) were determined and allowed to fragment 1 year in a succession of these days. Short temperature variations (1 ∘C/min) due to cloud cover were also identified during the sunny days, thanks to the shorter time step of 2 min. The stress generated during the typical days could then be estimated. Depending on the repartition of typical days for each micro-climate, some weathering processes could be favored: concentration of stress near the surface on the sunny micro-climate, development of biological colonization, and harsher frost events for the shadowed micro-climate. Taking into account the properties of the main limestones present on the basilica, the weathering on-site could be explained.

Demystifying and unravelling the molecular structure of the biopolymer sporopollenin.

RATIONALE: We report the unsolved molecular structure of the complex biopolymer sporopollenin exine extracted from Lycopodium clavatum pollen grains. METHODS: TOF-SIMS and CID-MS/MS, MALDI-TOF-MS and CID-TOF/TOF-MS/MS were used for the analysis of this complex biopolymer sporopollenin exine extracted from Lycopodium clavatum pollen grains. Solid-state 1 H- and 13 C-NMR, 2D 1 H-1 H NOESY, Rotor-synchronized 13 C{1 H} HSQC, and 13 C{1 H} multi CP-MAS NMR experiments were used to confirm the structural assigments revealed by MS and MS/MS studies. Finally, high-resolution XPS was used to check for the presence of aromatic components in sporopollenin. RESULTS: The combined MS and NMR analyses showed that sporopollenin contained poly(hydroxy acid) dendrimer-like networks with glycerol as a core unit, which accounted for the sporopollenin empirical formula. In addition, these analyses showed that the hydroxy acid monomers forming this network contained a ß-diketone moiety. Moreover, MALDI-TOF-MS and MS/MS allowed us to identify a unique macrocyclic oligomeric unit composed of polyhydroxylated tetraketide-like monomers. Lastly, high-resolution X-ray photoelectron spectroscopy (HR-XPS) showed the absence of aromaticity in sporopollenin. CONCLUSIONS: We report for the first time the two main building units that form the Lycopodium clavatum sporopollenin exine. The first building unit is a macrocyclic oligomer and/or polymer composed of polyhydroxylated tetraketide-like monomeric units, which represents the main rigid backbone of the sporopollenin biopolymer. The second building unit is the poly(hydroxy acid) network in which the hydroxyl end groups can be covalently attached by ether links to the hydroxylated macrocyclic backbone to form the sporopollenin biopolymer, a spherical dendrimer. Such spherical dendrimers are a typical type of microcapsule that have been used for drug delivery applications. Finally, HR-XPS indicated the total absence of aromaticity in the sporopollenin exine.

Collagen-Based Medical Device as a Stem Cell Carrier for Regenerative Medicine.

Maintenance of mesenchymal stem cells (MSCs) requires a tissue-specific microenvironment (i.e., niche), which is poorly represented by the typical plastic substrate used for two-dimensional growth of MSCs in a tissue culture flask. The objective of this study was to address the potential use of collagen-based medical devices (HEMOCOLLAGENE®, Saint-Maur-des-Fossés, France) as mimetic niche for MSCs with the ability to preserve human MSC stemness in vitro. With a chemical composition similar to type I collagen, HEMOCOLLAGENE® foam presented a porous and interconnected structure (>90%) and a relative low elastic modulus of around 60 kPa. Biological studies revealed an apparently inert microenvironment of HEMOCOLLAGENE® foam, where 80% of cultured human MSCs remained viable, adopted a flattened morphology, and maintained their undifferentiated state with basal secretory activity. Thus, three-dimensional HEMOCOLLAGENE® foams present an in vitro model that mimics the MSC niche with the capacity to support viable and quiescent MSCs within a low stiffness collagen I scaffold simulating Wharton's jelly. These results suggest that haemostatic foam may be a useful and versatile carrier for MSC transplantation for regenerative medicine applications.

Ring-opening polymerization of cyclic esters with lithium amine-bis(phenolate) complexes.

Lithium compounds of tetradentate amino-bis(phenolato)-tetrahydrofuranyl ligands, Li(2)[L1] (1) and Li(2)[L2] (2) (where [L1] = 2-tetrahydrofuranyl-N,N-bis(2-methylene-4-methyl-6-tert-butylphenolate), and [L2] = 2-tetrahydrofuranyl-N,N-bis(2-methylene-4,6-tert-butylphenolate)) were characterized by multinuclear solution NMR and solid-state (6)Li and (7)Li NMR spectroscopy. The proligands, n-propylamino-N,N-bis(2-methylene-4-methyl-6-tert-butylphenol), (H(2)[L3]) and benzylamino-N,N-bis(2-methylene-4,6-di-tert-amylphenol), H(2)[L4] were reacted with n-butyllithium in THF to give the related dilithium compounds Li(2)[L3] (4) and Li(2)[L4] (5), respectively. The pyridine adduct of 1, (py)(2)Li(2)[L1] (3) and complexes 4 and 5 have been structurally characterized by single-crystal X-ray diffraction and NMR spectroscopy. The reactivity of these complexes for the ring-opening polymerization of rac-lactide, as well as the influences of monomer concentration, monomer/Li molar ratio, polymerization temperature and time, were studied.

Plasma advanced glycation endproduct, methylglyoxal-derived hydroimidazolone is elevated in young, complication-free patients with Type 1 diabetes.

OBJECTIVES: Elevated advanced glycation endproducts (AGEs) are implicated in diabetic complications. Methylglyoxal-derived hydroimidazolone (MG-H) is one of the most abundant AGEs in vivo. Our objective was to develop a time-saving, specific method to measure free MG-H in plasma and determine its levels in complication-free young individuals with Type 1 diabetes (T1DM). The relationship of plasma free MG-H to hemoglobin A1C (A1C) and plasma methylglyoxal levels was also determined. DESIGN AND METHODS: A solid phase extraction and liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed, and free plasma MG-H levels were measured in 40 T1DM patients (DM group), aged 6-21 years, and 11 non-diabetics (ND group), 6-22 years. Methylglyoxal was measured using LC-MS/MS and A1C by a Tosoh G7 high-performance liquid chromatograph. RESULTS: Our method showed high recovery, sensitivity and short run-time. Plasma free MG-H (nmol/L) was higher (p<0.001) in the DM group (1318+/-569; mean+/-standard deviation) as compared to the ND group (583+/-419). Within the DM group, plasma free MG-H did not correlate with plasma methylglyoxal or A1C. CONCLUSIONS: Our LC-MS/MS method to measure free MG-H in plasma may be useful for future clinical application. The increased levels of free MG-H observed in individuals with TIDM are not merely the result of short term changes in glucose or methylglyoxal, but may reflect long-term alterations to tissue proteins.

Phosphorus copies of PPV: pi-conjugated polymers and molecules composed of alternating phenylene and phosphaalkene moieties.

A new class of pi-conjugated macromolecule, poly(p-phenylenephosphaalkene) (PPP), is reported. PPPs are phosphorus analogues of the important electronic material poly(p-phenylenevinylene) (PPV) where P=C rather than C=C bonds space phenylene moieties. Specifically, PPPs [-C(6)R(4)-P=C(OSiMe(3))-C(6)R'(4)-C(OSiMe(3))=P-](n)() (1: R = H, R' = Me; 11: R = Me, R' = H) were synthesized by utilizing the Becker reaction of a bifunctional silylphosphine, 1,4-C(6)R(4)[P(SiMe(3))(2)](2), and diacid chloride 1,4-C(6)R'(4)[COCl](2). Several model compounds for PPP are reported. Namely, mono(phosphaalkene)s R-P=C(OSiMe(3))-R' (4: R = Ph, R' = Mes; 7: R = Mes, R' = Ph), C-centered bis(phosphaalkene)s R-P=C(OSiMe(3))-C(6)R'(4)-C(OSiMe(3))=P-R (5: R = Ph, R' = Me; 8: R = Mes, R' = H), and P-centered bis(phosphaalkene)s R-C(OSiMe(3))=P-C(6)R'(4)-P=C(OSiMe(3))-R (6: R = Mes, R' = H; 10: R = Ph, R' = Me). Remarkably, selective Z-isomer formation (i.e., trans arylene moieties) is observed for PPPs when bulky P-substituents are employed while E/Z-mixtures are otherwise obtained. X-ray crystal structures of Z-7, Z,Z-8, and Z,Z-10 suggest moderate pi-conjugation. The twist angles between the P=C plane and unsubstituted arenes are 16 degrees -26 degrees , while those between the P=C plane and methyl-substituted arenes are 59 degrees -67 degrees . The colored PPPs and their model compounds were studied by UV/vis spectroscopy, and the results are consistent with extended pi-conjugation. Specifically, weakly emissive polymer E/Z-1 (lambda(max) = 338 nm) shows a red shift in its absorbance from model E/Z-4 (lambda(max) = 310 nm), while a much larger red shift is observed for Z-11 (lambda(max) = 394 nm) over Z-7 (lambda(max) = 324 nm).

Zeolite nanoclusters coated onto the mesopore walls of SBA-15.

Ultrahigh-field 27Al MAS and MQMAS NMR and 129Xe NMR were used to characterize the zeolite-coated SBA-15 materials. This study shows evidence that zeolite nanoclusters are coated on the mesopore surface of SBA-15. These techniques are useful for the detection of zeolite nanoclusters and different aluminum environments in zeolite/aluminosilicate composites, which are difficult or even impossible to detect by conventional techniques.