Neonatal Stage Research Articles

Spatiotemporal patterns of spontaneous movement in neonates are significantly linked to risk of autism spectrum disorders at 18 months old

Infants make spontaneous movements from the prenatal period. Several studies indicate that an atypical pattern of body motion during infancy could be utilized as an early biomarker of autism spectrum disorders (ASD). However, to date, little is known about whether the body motion pattern in neonates is associated with ASD risk. The present study sought to clarify this point by examining, in a longitudinal design, the link between features of spontaneous movement at about two days after birth and ASD risk evaluated using the Modified Checklist for Autism in Toddlers by their caregivers at 18 months old. The body movement features were quantified by a recently developed markerless system of infant body motion analysis. Logistic regression analysis revealed that ASD risk at 18 months old is associated with the pattern of spontaneous movement at the neonatal stage. Further, logistic regression based on body movement features during sleep shows better performance in classifying high- and low-risk infants than during the awake state. These findings raise the possibility that early signs of ASD risk may emerge at a developmental stage far earlier than previously thought.

Calbindin Has a Potential Spatiotemporal Correlation with Proliferation and Apoptosis in the Postnatal Rat Kidney.

The protein calbindin-D28k modulates calcium reabsorption in the kidney. Here, we aimed to study the influence of proliferation and apoptosis in different compartments of the kidney on the developmental function of calbindin. Using immunohistochemistry, we investigated the postnatal development of rats' kidneys by using calbindin, proliferative cell nuclear antigen (PCNA), and apoptotic single-stranded DNA (ssDNA). In the neonatal stage (1-day and 1-week-old rats), calbindin showed a positive reaction in the distal convoluted tubule (DCT), a short nephron segment between the macula densa, collecting ducts, and tubules. Moreover, the localization of calbindin was restricted to immature nephrons and mesenchymal tissues. Furthermore, PCNA immunoreactivity was moderate in early-developed podocytes with no reactivity in other renal tubules. The ssDNA immunoreactivity was moderate in the undifferentiated nephron. Then, in the mature stage (3 and 6 weeks old), there was an intense calbindin reaction in DCT but a moderate reaction to PCNA and ssDNA in podocytes. A more intense calbindin reactivity was found in the adult stage (2- and 3-month-old rats) in DCT and collecting tubules. Therefore, in this study, calbindin localization showed an inverse relationship with PCNA and ssDNA of the nephron compartments, which might reflect the efficiency of bone-building and muscle contraction during animal development.

Determinación de la eficacia de la administración de hCG sobre el desempeño reproductivo, la placentación, el parto y los parámetros neonatales en diferentes días posteriores al apareamiento en ovejas Kangal inducidas sexualmente durante el anestro

This study aimed to determine the efficacy of post mating human Chorionic Gonadotropin (hCG) during anestrus on the formation of the accessory corpus luteum and some reproductive parameters. For this purpose. after synchronization of all the animal were divided into group 1 (n=100), group 2 (n=100), and group 3 (n=100) by applying 600 IU of hCG 6 d after sponge removal, 600 IU of hCG 8 d after sponge removal, and no hCG application (Control), respectively. The difference between groups in terms of reproductive parameters such as estrus, pregnancy, multiple pregnancy, litter size, and productivity was not statistically significant. The live birth weight of lambs was evaluated for singletons, twins, and triplets. The difference between group 1 and the control group was statistically significant in singleton lambs (P=0.04). The difference between group 1 and control (P<0.001) and between group 2 and control (P<0.001) was statistically significant for twins. In triplets, group 1 was different from both groups (P<0.001) and group 2 was different from the control group (P<0.001). In addition, when the placenta weight and the daily body weight gain of singleton lamb in the neonatal stage were examined, the values of both groups that were administered with post mating hCG were higher than the control group (P<0.001). The Progesterone (P4) level in blood samples taken on the 21st d of pregnancy was found to be different between all groups. Furthermore, P4 levels were found to be higher in group 1 compared to the other two groups (P<0.001). In the light of these findings, it was determined that hCG administration after mating contributed to placenta and offspring development by elevating P4 levels. It was concluded that hCG should be administered 6 d after the sponge will be removed (on d 5 postmating) for optimal efficacy.

DNA methylation in the mouse cochlea promotes maturation of supporting cells and contributes to the failure of hair cell regeneration

Mammalian hair cells do not functionally regenerate in adulthood but can regenerate at embryonic and neonatal stages in mice by direct transdifferentiation of neighboring supporting cells into new hair cells. Previous work showed loss of transdifferentiation potential of supporting cells is in part due to H3K4me1 enhancer decommissioning of the hair cell gene regulatory network during the first postnatal week. However, inhibiting this decommissioning only partially preserves transdifferentiation potential. Therefore, we explored other repressive epigenetic modifications that may be responsible for this loss of plasticity. We find supporting cells progressively accumulate DNA methylation at promoters of developmentally regulated hair cell genes. Specifically, DNA methylation overlaps with binding sites of Atoh1, a key transcription factor for hair cell fate. We further show that DNA hypermethylation replaces H3K27me3-mediated repression of hair cell genes in mature supporting cells, and is accompanied by progressive loss of chromatin accessibility, suggestive of facultative heterochromatin formation. Another subset of hair cell loci is hypermethylated in supporting cells, but not in hair cells. Ten-eleven translocation (TET) enzyme-mediated demethylation of these hypermethylated sites is necessary for neonatal supporting cells to transdifferentiate into hair cells. We also observe changes in chromatin accessibility of supporting cell subtypes at the single-cell level with increasing age: Gene programs promoting sensory epithelium development loses chromatin accessibility, in favor of gene programs that promote physiological maturation and function of the cochlea. We also find chromatin accessibility is partially recovered in a chronically deafened mouse model, which holds promise for future translational efforts in hearing restoration.

Abstract GS.09: Interleukin 13 Signaling To Macrophages Promotes Recovery After Myocardial Infarction In Mice

Introduction: There is great interest in identifying signaling pathways that promote pro-reparative macrophage phenotypes in the heart. Considering the remarkable cardiac healing potential of neonatal mice, we employ this model to identify pro-reparative mechanisms that can be applied to promote cardiac repair in adults after myocardial infarction (MI). We show that IL13/IL4Rα signaling specifically on macrophages mediates neonatal heart regeneration and activation of this pathway in adult mice promotes cardiac functional recovery in post-MI. Results: We developed IL4Rα fl/fl ;CX3CR1 Cre mice (IL4Rα MacKO ) to delete IL4Rα specifically in macrophages. Neonatal IL4Rα MacKO and control mice were subjected to MI on postnatal day 1 (P1). Following injury, IL4Rα MacKO mice had significantly larger scars at 8 days post injury (dpi) and lower ejection fraction and capillary density at 21 dpi. Thus, macrophage IL4Rα expression is critical for cardiac functional recovery following injury in neonates. Using fluorescent reporter mice, we found that IL13, a ligand for IL4Rα, is produced almost exclusively by type 2 innate lymphoid cells in the neonatal heart. Interestingly, we didn’t find any cellular source of IL13 in the adult mouse heart. Considering the decline in cardiac production of IL13 from neonatal to adult stages, we postulated that reactivation of IL4Rα in the adult heart would improve cardiac healing post MI in adults. Indeed, daily IL13 administration significantly improved cardiac function post MI in adult mice, and this improvement was mediated entirely by IL4Rα expression on macrophages as IL4Rα MacKO mice showed no functional improvement with IL13 administration. Intriguingly, while IL13 administration to control mice improved cardiac function, administration to IL4Rα MacKO mice further exacerbated post MI mortality and scar size compared to animals receiving PBS, suggesting multiple cardiac cell types respond to IL13 resulting in beneficial or detrimental outcomes. Conclusions: Our data elucidates a strongly pro-reparative role for IL13 signaling directly to macrophages. While this signaling pathway is active in neonatal stages, we demonstrate that re-activation by IL13 administration is required to promote cardiac repair in adults.

The spatiotemporal dynamics of spatially variable genes in developing mouse brain revealed by a novel computational scheme

To understand how brain regions form and work, it is important to explore the spatially variable genes (SVGs) enriched in specific brain regions during development. Spatial transcriptomics techniques provide opportunity to select SVGs in the high-throughput way. However, previous methods neglected the ranking order and combinatorial effect of SVGs, making them difficult to automatically select the high-priority SVGs from spatial transcriptomics data. Here, we proposed a novel computational pipeline, called SVGbit, to rank the individual and combinatorial SVGs for marker selection in various brain regions, which was tested in different kinds of public datasets for both human and mouse brains. We then generated the spatial transcriptomics and immunohistochemistry data from mouse brain at critical embryonic and neonatal stages. The results show that our ranking and clustering scheme captures the key SVGs which coincide with known anatomic regions in the developing mouse brain. More importantly, SVGbit can facilitate the identification of multiple gene combination sets in different brain regions. We identified three dynamical sub-regions which can be segregated by the staining of Sox2 and Calb2 in thalamus, and we also found that Nr4a2 expression gradually segregates the neocortex and hippocampus during the development. In summary, our work not only reveals the spatiotemporal dynamics of individual and combinatorial SVGs in developing mouse brain, but also provides a novel computational pipeline to facilitate the selection of marker genes from spatial transcriptomics data.

Outcomes after HSCT for mucolipidosis II (I-cell disease) caused by novel compound heterozygous GNPTAB mutations.

Mucolipidosis type II (MLII), or I-cell disease, is a rare lysosomal storage disease (LSD) caused by variants in the GNPTAB gene. MLII patients exhibit clinical phenotypes in the prenatal or neonatal stage, such as marked dysmorphic features, cardiac involvement, respiratory symptoms, dysostosis multiplex, severe growth abnormalities, and mental and motor developmental abnormalities. The median age at diagnosis for MLII is 0.7 years, the median survival is 5.0 years, and the median age at death is 1.8 years. No cure for MLII exists. Sanger sequencing of the GNPTAB gene identified the compound heterozygous mutations c.673C > T in exon 7 and c.1090C > T in exon 9, which were novel double heterozygous mutations first reported in China. For the first time, we describe our experience in the use of HSCT for MLII. Our patient underwent HSCT with cells from a 9/10 human leukocyte antigen (HLA)-matched unrelated donor at 12 months of age. Myeloid neutrophil and platelet engraftment occurred on Days 10 and 11, respectively. The patient's limb muscle tension was significantly reduced, and his gross and fine motor skills were improved four months after transplantation. DST(Developmental Screen Test) results showed that the patient's fine motor skills and mental development were improved compared with before HSCT. MLII is a very severe lysosomal storage disease, to date, only 3 cases have been reported on the use of HSCT to treat MLII. Our data show that HSCT is a potential way to prolong the life of patients and improve their quality of life. Due to the lack of comparable data and time, the exact benefit remains unclear in MLII patients. Longer-term follow-up and in-depth prospective studies are indispensable.

Spatiotemporal proteomic atlas of multiple brain regions across early fetal to neonatal stages in cynomolgus monkey

Fetal stages are critical periods for brain development. However, the protein molecular signature and dynamics of the human brain remain unclear due to sampling difficulty and ethical limitations. Non-human primates present similar developmental and neuropathological features to humans. This study constructed a spatiotemporal proteomic atlas of cynomolgus macaque brain development from early fetal to neonatal stages. Here we showed that (1) the variability across stages was greater than that among brain regions, and comparisons of cerebellum vs. cerebrum and cortical vs. subcortical regions revealed region-specific dynamics across early fetal to neonatal stages; (2) fluctuations in abundance of proteins associated with neural disease suggest the risk of nervous disorder at early fetal stages; (3) cross-species analysis (human, monkey, and mouse) and comparison between proteomic and transcriptomic data reveal the proteomic specificity and genes with mRNA/protein discrepancy. This study provides insight into fetal brain development in primates.

Avaliação reprodutiva e econômica da estimulação sexual durante o período antrópico em uma fazenda comercial com perdas neonatais de cordeiros

ABSTRACT This study was performed during the anestrous, involving 140 Akkaraman Kangal ewes whose lambs had died in the neonatal stage due to pneumonia and enteritis. Intravaginal sponge containing progesterone was placed to the animals (Group 1, n = 70) on day 0 and removed after 7 days, following which 263 µg PGF2α and 500 IU eCG were administered to the sheep. Ram introduction was performed for 7 days (days 8-14), starting from the day after the removal of the intravaginal sponge (day 8). The animals in Group 2 (n = 70) were not exposed to any treatment. Ram introduction was performed simultaneously in both the groups. To determine the reproductive response, reproductive parameters such as estrous, pregnancy, multiple pregnancy, and embryonic mortality rates, number of births, number of offspring, and fertility, as well as their economic implications, were compared between groups. Each reproductive parameter exhibited a statistical difference between groups. An economically positive trend was observed in the study group compared with the control group. It was concluded that in case of lamb losses in commercial farms that derive profit from lambing, pregnancy of ewes can be achieved via sexual stimulation without waiting for the next breeding season.

Generation of Vgll4-DreER transgenic mouse for visualizing and manipulating VGLL4-expressing cells in vivo.

Vestigial like family member 4 (VGLL4), a member of the Hippo pathway, is a transcriptional cofactor involved in many biological processes, such as tumor progression, postnatal heart growth, and muscle regeneration. However, the VGLL4 expression pattern in vivo remains unclear. To detect and trace Vgll4-expressing cells and their progeny, we generated and characterized a new tamoxifen-inducible Dre knock-in mouse line, Vgll4-DreER. This mouse line expressed DreER (Dre recombinase fused to the estrogen receptor) under the control of the endogenous Vgll4 promoter. After crossing the Vgll4-DreER mouse line with the Dre-responsive reporter H11-rRFP, Dre-mediated recombination in the tissue was monitored on the basis of red fluorescent protein (RFP) signals, which indicated the distribution of VGLL4-positive cells in vivo. Our data revealed that VGLL4 is widely expressed in various cell types at embryonic and neonatal stages. After comparison with our previously reported Vgll4-GFP mouse, we found that the RFP signal profile was wider than the green fluorescent protein (GFP) pattern, indicating that Vgll4-DreER is more sensitive for labeling VGLL4-expressing cells. We next used a dual-recombination system to simultaneously label VGLL4- and keratin 5 (KRT5)-positive cell populations, and no crosstalk was observed in the Krt5-CreER;Vgll4-DreER;R26-rGlR mice. Taken together, the Vgll4-DreER mouse line is a valuable new tool for examining the precise VGLL4 expression profile and conditional manipulating of VGLL4-expressing cells and their progeny.

257-LB: Defining the Stage-Dependent Transcriptome and Methylome in the Mouse Liver during Perinatal Metabolic Maturation

A mammalian liver serves as an extramedullary hematopoietic organ during fetus, and matures into a metabolic organ after birth, thereby adapting to the changes in nutritional environment. PPARα-dependent DNA demethylation upregulates hepatic fatty acid β-oxidation (FAO) genes in the postnatal mouse liver to produce energy from breast milk lipids. However, the detailed interaction between DNA methylation (DNAme) and gene expression in the liver through perinatal stages remain poorly understood. Here, we perform an integrative analysis of transcriptome and methylome of the mice liver at fetal, neonatal, and postweaning stages. While the level of global DNAme gradually increased from fetal to postweaning stages, we found a drastic loss of DNAme in specific regions that are associated with metabolic pathways such as FAO, gluconeogenesis, and amino acid metabolism within the neonatal stage in concordance with the activation of such metabolic processes. Moreover, in silico analysis predicted transcription factors, such as HNF4α, PPARα, NR1H2, and NR1H3, as key epigenetic regulators within lactation period. We also observed an inactivation of erythrocyte development with a concordant gain of DNAme. This analysis extends the epigenetic landscape for understanding the hepatic maturation during early life, and suggests the importance of lactation period in epigenetic regulation. Disclosure S. Yano: None. N. Sato: None. H. Araki: None. F. Miura: None. T. Ito: None. Y. Ogawa: None.

Craniogenetic studies in Sus scrofa: With emphasis on the 'orbitosphenoid' problem.

The orbitosphenoid is a skeletal element of the endocranium of extant mammals. However, it has also been described in many of their fossil ancestors. Craniogenetic studies show that it is composed of two types of bone: first, the cartilaginous ala orbitalis and parts of the trabecular plate are transformed by endochondral ossification; second, so-called 'appositional bone' ('Zuwachsknochen') arises directly from the perichondrium of the two optic pilae and spreads in all directions and overlays the remaining cartilage and the endochondral ossifications. For some time, both bone types can be distinguished microscopically, but later in craniogenesis they fuse completely to become the presphenoid sensu lato of the osteocranium. We interpret the 'appositional bone' as neomorphic mode to reinforce the endocranial bone structures, which are the ossification of the delicate cartilaginous template of the chondrocranium. We studied the ossifications of the presphenoidal skull region in a series of ontogenetic stages of the pig Sus scrofa. We applied conventional histology as well as stained and unstained μCT scans. We can show the above-mentioned modes of ossification, and we can demonstrate the contribution of 'appositional bone' well into neonatal and infantile stages. The ossifications of the presphenoid (including the orbitosphenoid) are very slender in therapsids and early mammaliaforms as previously described by other authors. In mammaliaforms, they tend to become thicker and closely connected with the frontal bone, which may be due to the contribution of neomorphic appositional bone. We assume that thereby the presphenoid sensu lato becomes an enforcement of the orbital pillars.

Predictors of Human Milk Feeding and Direct Breastfeeding for Infants with Single Ventricle Congenital Heart Disease: Machine Learning Analysis of the National Pediatric Cardiology Quality Improvement Collaborative Registry

To identify factors that support or limit human milk (HM) feeding and direct breastfeeding (BF) for infants with single ventricle congenital heart disease at neonatal stage 1 palliation (S1P) discharge and at stage 2 palliation (S2P) (∼4-6months old). Analysis of the National Pediatric Cardiology Quality Improvement Collaborative (NPC-QIC) registry (2016-2021; 67 sites). Primary outcomes were any HM, exclusive HM, and any direct BF at S1P discharge and at S2P. The main analysis involved multiple phases of elastic net logistic regression on imputed data to identify important predictors. For 1944 infants, the strongest predictor domain areas included preoperative feeding, demographics/social determinants of health, feeding route, clinical course, and site. Significant findings included: preoperative BF was associated with any HM at S1P discharge (OR=2.02, 95% CI=1.74-3.44) and any BF at S2P (OR = 2.29, 95% CI = 1.38-3.80); private/self-insurance was associated with any HM at S1P discharge (OR = 1.91, 95% CI = 1.58-2.47); and Black/African-American infants had lower odds of any HM at S1P discharge (OR = 0.54, 95% CI = 0.38-0.65) and at S2P (0.57, 0.30-0.86). Adjusted odds of HM/BF practices varied among NPC-QIC sites. Preoperative feeding practices predict later HM and BF for infants with single ventricle congenital heart disease; therefore, family-centered interventions focused on HM/BF during the S1P preoperative time are needed. These interventions should include evidence-based strategies to address implicit bias and seek to minimize disparities related to social determinants of health. Future research is needed to identify supportive practices common to high-performing NPC-QIC sites.

Activity-dependent regulation of the BAX/BCL-2 pathway protects cortical neurons from apoptotic death during early development

During early brain development, homeostatic removal of cortical neurons is crucial and requires multiple control mechanisms. We investigated in the cerebral cortex of mice whether the BAX/BCL-2 pathway, an important regulator of apoptosis, is part of this machinery and how electrical activity might serve as a set point of regulation. Activity is known to be a pro-survival factor; however, how this effect is translated into enhanced survival chances on a neuronal level is not fully understood. In this study, we show that caspase activity is highest at the neonatal stage, while developmental cell death peaks at the end of the first postnatal week. During the first postnatal week, upregulation of BAX is accompanied by downregulation of BCL-2 protein, resulting in a high BAX/BCL-2 ratio when neuronal death rates are high. In cultured neurons, pharmacological blockade of activity leads to an acute upregulation of Bax, while elevated activity results in a lasting increase of BCL-2 expression. Spontaneously active neurons not only exhibit lower Bax levels than inactive neurons but also show almost exclusively BCL-2 expression. Disinhibition of network activity prevents the death of neurons overexpressing activated CASP3. This neuroprotective effect is not the result of reduced caspase activity but is associated with a downregulation of the BAX/BCL-2 ratio. Notably, increasing neuronal activity has a similar, non-additive effect as the blockade of BAX. Conclusively, high electrical activity modulates BAX/BCL-2 expression and leads to higher tolerance to CASP3 activity, increases survival, and presumably promotes non-apoptotic CASP3 functions in developing neurons.

Differential average daily gain of pregnant Holstein × Gyr dairy heifers causes placental adaptations to support fetal growth and development

This study aimed to evaluate the effects of differential average daily gain targets of dairy heifers throughout gestation on placental hemodynamics, uterine involution, colostrum production of the heifers, and effects on newborn calf weight and immunity transfer. Fourteen Holstein × Gyr heifers with an average body weight of 446 ± 46.7 kg and age of 25 ± 3.9 mo were randomly assigned to the following treatments: moderate body weight gain (MOD, n = 7), where heifers were fed to achieve 0.50 kg/d; and high body weight gain (HIG, n = 7), where heifers were fed to achieve 0.75 kg/d. Target average daily gains were established based on common tropical dairy production systems. The heifers received a total mixed ration feed twice daily starting at 70 d of gestation. Placentome vascularization was assessed using a color Doppler ultrasound at 180, 210, and 240 d of gestation. After calving, cotyledons were counted and sampled to analyze the mRNA expression of placental angiogenesis markers. After birth, calves were weighed and fed colostrum, and transfer of passive immunity efficiency was assessed. A significant increase in cotyledons was detected for MOD placenta soon after expulsion (81.5 ± 12.91 vs. 63.6 ± 10.52). Placentome vascularization at the final third of gestation increased for MOD heifers compared with HIG. Greater mRNA expression after membrane expulsion of VEGFB and IGFR1 in cotyledons and a greater estradiol concentration in circulation 1 d before calving was found for MOD heifers compared with HIG heifers; however, uterine involution postpartum was not different between treatment groups. Greater colostrum production was observed in HIG heifers (3.9 ± 1.05 vs. 2.2 ± 1.57 L) but with lower quality (25.2 ± 0.51 vs. 29.5 ± 0.65 Brix). No differences were observed in birth weight or transfer of passive immunity efficiency between treatments; however, HIG calves had significantly greater vitality scores than MOD calves. The results of this study indicate that a moderate feeding regimen enhances placental blood flow by increasing angiogenesis, which suggests improved nutrient transfer to the fetus without major effects on its development during the neonatal stage, colostrum production, or uterine involution in the heifers.

Single-cell transcriptomic dissection of the toxic impact of di(2-ethylhexyl) phthalate on immature testicular development at the neonatal stage.

Di(2-ethylhexyl) phthalate (DEHP) early exposure leads to immature testicular injury, and we aimed to utilize single-cell RNA (scRNA) sequencing to comprehensively assess the toxic effect of DEHP on testicular development. Therefore, we gavaged pregnant C57BL/6 mice with 750mg/kg body weight DEHP from gestational day 13.5 to delivery and performed scRNA sequencing of neonatal testes at postnatal day 5.5. The results revealed the gene expression dynamics in testicular cells. DEHP disrupted the developmental trajectory of germ cells and the balance between the self-renewal and differentiation of spermatogonial stem cells. Additionally, DEHP caused an abnormal developmental trajectory, cytoskeletal damage and cell cycle arrest in Sertoli cells; disrupted the metabolism of testosterone in Leydig cells; and disturbed the developmental trajectory in peritubular myoid cells. Elevated oxidative stress and excessive apoptosis mediated by p53 were observed in almost all testicular cells. The intercellular interactions among four cell types were altered, and biological processes related to glial cell line-derived neurotrophic factor (GDNF), transforming growth factor-β (TGF-β), NOTCH, platelet-derived growth factor (PDGF) and WNT signaling pathways were enriched after DEHP treatment. These findings systematically describe the damaging effects of DEHP on the immature testes and provide substantial novel insights into the reproductive toxicity of DEHP.

Current progress on in vitro differentiation of ovarian follicles from pluripotent stem cells.

Mammalian female reproduction requires a functional ovary. Competence of the ovary is determined by the quality of its basic unit-ovarian follicles. A normal follicle consists of an oocyte enclosed within ovarian follicular cells. In humans and mice, the ovarian follicles are formed at the foetal and the early neonatal stage respectively, and their renewal at the adult stage is controversial. Extensive research emerges recently to produce ovarian follicles in-vitro from different species. Previous reports demonstrated the differentiation of mouse and human pluripotent stem cells into germline cells, termed primordial germ cell-like cells (PGCLCs). The germ cell-specific gene expressions and epigenetic features including global DNA demethylation and histone modifications of the pluripotent stem cells-derived PGCLCs were extensively characterized. The PGCLCs hold potential for forming ovarian follicles or organoids upon cocultured with ovarian somatic cells. Intriguingly, the oocytes isolated from the organoids could be fertilized in-vitro. Based on the knowledge of in-vivo derived pre-granulosa cells, the generation of these cells from pluripotent stem cells termed foetal ovarian somatic cell-like cells was also reported recently. Despite successful in-vitro folliculogenesis from pluripotent stem cells, the efficiency remains low, mainly due to the lack of information on the interaction between PGCLCs and pre-granulosa cells. The establishment of in-vitro pluripotent stem cell-based models paves the way for understanding the critical signalling pathways and molecules during folliculogenesis. This article aims to review the developmental events during in-vivo follicular development and discuss the current progress of generation of PGCLCs, pre-granulosa and theca cells in-vitro.

Comprehensive volumetric phenotyping of the neonatal brain in Down syndrome.

Down syndrome (DS) is the most common genetic cause of intellectual disability with a wide range of neurodevelopmental outcomes. To date, there have been very few in vivo neuroimaging studies of the neonatal brain in DS. In this study we used a cross-sectional sample of 493 preterm- to term-born control neonates from the developing Human Connectome Project to perform normative modeling of regional brain tissue volumes from 32 to 46weeks postmenstrual age, accounting for sex and age variables. Deviation from the normative mean was quantified in 25 neonates with DS with postnatally confirmed karyotypes from the Early Brain Imaging in DS study. Here, we provide the first comprehensive volumetric phenotyping of the neonatal brain in DS, which is characterized by significantly reduced whole brain, cerebral white matter, and cerebellar volumes; reduced relative frontal and occipital lobar volumes, in contrast with enlarged relative temporal and parietal lobar volumes; enlarged relative deep gray matter volume (particularly the lentiform nuclei); and enlargement of the lateral ventricles, amongst other features. In future, the ability to assess phenotypic severity at the neonatal stage may help guide early interventions and, ultimately, help improve neurodevelopmental outcomes in children with DS.

A Carboxy-terminal Smarcb1 Point Mutation Induces Hydrocephalus Formation and Affects AP-1 and Neuronal Signalling Pathways in Mice

The BAF (BRG1/BRM-associated factor) chromatin remodelling complex is essential for the regulation of DNA accessibility and gene expression during neuronal differentiation. Mutations of its core subunit SMARCB1 result in a broad spectrum of pathologies, including aggressive rhabdoid tumours or neurodevelopmental disorders. Other mouse models have addressed the influence of a homo- or heterozygous loss of Smarcb1, yet the impact of specific non-truncating mutations remains poorly understood. Here, we have established a new mouse model for the carboxy-terminal Smarcb1 c.1148del point mutation, which leads to the synthesis of elongated SMARCB1 proteins. We have investigated its impact on brain development in mice using magnetic resonance imaging, histology, and single-cell RNA sequencing. During adolescence, Smarcb11148del/1148del mice demonstrated rather slow weight gain and frequently developed hydrocephalus including enlarged lateral ventricles. In embryonic and neonatal stages, mutant brains did not differ anatomically and histologically from wild-type controls. Single-cell RNA sequencing of brains from newborn mutant mice revealed that a complete brain including all cell types of a physiologic mouse brain is formed despite the SMARCB1 mutation. However, neuronal signalling appeared disturbed in newborn mice, since genes of the AP-1 transcription factor family and neurite outgrowth-related transcripts were downregulated. These findings support the important role of SMARCB1 in neurodevelopment and extend the knowledge of different Smarcb1 mutations and their associated phenotypes.

Prevalence of neonatal near miss in Africa: a systematic review and meta-analysis.

Neonatal near miss (NNM) applies to cases where newborns almost died during the first 28d of life but survived life-threatening conditions following birth. The most vulnerable time for infant survival is the neonatal stage, corresponding to almost 50% of deaths occurring at <5y of age. No study indicates the overall pooled prevalence of NNM in Africa. Thus this review aimed to estimate the overall pooled prevalence of NNMs in Africa. Articles were retrieved through a comprehensive search strategy using PubMed/MEDLINE, Embase, Health InterNetwork Access to Research Initiative, Cochrane Library and Google Search. Data extraction was done independently by all authors. Forest plots and tables were used to represent the original data. The statistical heterogeneity was evaluated using I2 statistics. There was heterogeneity between the included articles. Therefore the authors used a meta-analysis of random effects to estimate the aggregate pooled prevalence of NNM in Africa. Funnel plot and Egger regression test methods were used to assess possible publication bias. R software version 3.5.3 and R studio version 1.2.5003 were used to analyse the data. The guideline of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses was used to publish this article. The review was registered on the International Prospective Register of Systematic Reviews (registration ID: CRD42021290223). Through an exhaustive search, we found 835 articles. However, we considered only eight full-text articles to be included in this meta-analysis. The analysis of included studies showed that the overall pooled prevalence of NNM in Africa was 30% (95% confidence interval [CI] 16 to 44). The subgroup analysis by study year showed that the prevalence of NNM from 2012-2015 and 2018-2019 was 36% (95% CI 23 to 49) and 20% (95% CI 1 to 39), respectively. This finding suggests that the pooled prevalence of NNM is high in Africa as compared with other studies. Therefore the government and other stakeholders working on maternal and child health should assist in the design of interventions and strategies for improving the quality of neonatal care.