ADNP (Activity Dependent Neuroprotective Protein) is a neuroprotective protein whose aberrant expression has been frequently linked to neural developmental disorders, including the Helsmoortel-Van der Aa syndrome (also called the ADNP syndrome). However, its role in neural development and pathology remains unclear. Here, we show that ADNP is required for neural induction and differentiation by enhancing Wnt signaling. Mechanistically, ADNP functions to stabilize β-Catenin through binding to its armadillo domain which prevents its association with key components of the degradation complex: Axin and APC. Loss of ADNP promotes the formation of the degradation complex and β-Catenin degradation via ubiquitin-proteasome pathway, resulting in down-regulation of key neuroectoderm developmental genes. In addition, adnp gene disruption in zebrafish leads to defective neurogenesis and reduced Wnt signaling. Our work provides important insights into the role of ADNP in neural development and the pathology of the Helsmoortel-Van der Aa syndrome caused by ADNP gene mutation.

ADNP (Activity Dependent Neuroprotective Protein) is proposed as a neuroprotective protein whose aberrant expression has been frequently linked to rare neural developmental disorders and cancers, including the recently described neurodevelopmental Helsmoortel-Van der Aa syndrome. Recent studies have suggested that ADNP functions as an important chromatin regulator. However, how ADNP-regulated chromatin mechanisms control gene expression and stem cell fate commitment remains unclear. Here we show that ADNP interacts with two chromatin remodelers, BRG1 and CHD4. ADNP is required for proper establishment of chromatin accessibility, nucleosome configuration, and bivalent histone modifications of developmental genes. Loss of ADNP leads to enhancer over-activation and increased ratio of H3K4me3/H3K27me3 at key primitive endoderm (PrE) gene promoters, resulting in prominent up-regulation of these genes and priming ES cell differentiation toward endodermal cell types. Thus, our work revealed a key role of ADNP in the establishment of local chromatin landscape and structure of developmental genes by association with BRG1 and CHD4. These findings provide further insights into the role of ADNP in the pathology of the Helsmoortel-Van der Aa syndrome.

The cardiac valvular endothelial cells (VECs) are an ideal cell source that could be used for making the valve organoids. However, few studies have been focused on the derivation of this important cell type. Here we describe a two-step chemically defined xeno-free method for generating VEC-like cells from human pluripotent stem cells (hPSCs). HPSCs were specified to KDR⁺/ISL1⁺multipotent cardiac progenitors (CPCs), followed by differentiation into valve endothelial-like cells (VELs) via an intermediate endocardial cushion cell (ECC) type. Mechanistically, administration of TGFb1 and BMP4 may specify VEC fate by activating the NOTCH/WNT signaling pathways and previously unidentified targets such as ATF3 and KLF family of transcription factors. When seeded onto the surface of the de-cellularized porcine aortic valve (DCV) matrix scaffolds, hPSC-derived VELs exhibit superior proliferative and clonogenic potential than the primary VECs and human aortic endothelial cells (HAEC). Our results show that hPSC-derived valvular cells could be efficiently generated from hPSCs, which might be used as seed cells for construction of valve organoids or next generation tissue engineered heart valves.

The POGZ gene has been found frequently mutated in neurodevelopmental disorders (NDDs) such as autism spectrum disorder (ASD) and intellectual disability (ID). We have recently shown that POGZ maintains mouse embryonic stem cells (ESCs). However, the exact mechanisms remain unclear. Here, we show that POGZ plays an important role in the maintenance of ESCs by silencing Dux and endogenous retroviruses (ERVs). POGZ maintains a silent chromatin state at Dux and ERVs by associating with and recruiting TRIM28 and SETDB1, and its loss leads to decreased levels of H3K9me3/H4K20me3, resulting in up-regulation of 2C transcripts and ESC transition to a 2C-like state. POGZ suppresses different classes of ERVs through direct (IAPEy, the intracisternal A-type particle elements) and indirect regulation (MERVL). Activation of POGZ-bound ERVs is associated with up-regulation of nearby neural disease genes such as Serpina3m. Our findings provide important insights into understanding the disease mechanism caused by POGZ dysfunction.

Germline stem cells (GSCs) are a group of unique adult stem cells in gonads that act as important transmitters for genetic information. Donor GSCs have been used to produce offspring by transplantation in fisheries. In this study, we successfully isolated and enriched GSCs from the ovary, ovotestis, and testis of Monopterus albus, one of the most important breeding freshwater fishes in China. Transcriptome comparison assay suggests that a distinct molecular signature exists in each type of GSC, and that different signaling activities are required for the maintenance of distinct GSCs. Functional analysis shows that fGSCs can successfully colonize and contribute to the germline cell lineage of a host zebrafish gonad after transplantation. Finally, we describe a simple feeder-free method for the isolation and enrichment of GSCs that can contribute to the germline cell lineage of zebrafish embryos and generate the germline chimeras after transplantation.

Background: The POGZ gene has been found frequently mutated in neurodevelopmental disorders (NDDs), particularly autism spectrum disorder (ASD) and intellectual disability (ID). However, little is known about its roles in embryonic stem cells (ESCs), neural development and diseases. Methods: We generated Pogz−/− ESCs and directed ESC differentiation toward a neural fate. We performed biochemistry, ChIP-seq, ATAC-seq, and bioinformatics analyses to understand the role of POGZ. Results: We show that POGZ is required for the maintenance of ESC identity and the up-regulation of neural genes during ESC differentiation toward a neural fate. Genome-wide binding analysis shows that POGZ is primarily localized to gene promoter and enhancer regions. POGZ functions as both a transcriptional activator and repressor, and its loss leads to deregulation of differentiation genes, including neural genes. POGZ physically associates with the SWI-SNF (esBAF) chromatin remodeler complex, and together they modulate enhancer activities via epigenetic modifications such as chromatin remodeling and histone modification. During ESC neural induction, POGZ-mediated recruitment of esBAF/BRG1 and H3K27ac are important for proper expression of neural progenitor genes. Limitations: The genotype and allele relevant to human neurodevelopmental disorders is heterozygous loss of function. This work is designed to study the effects of loss of POGZ function on ESCs and during ESC neural induction. Also, this work lacks of in vivo validation using animal models. Conclusions: The data suggest that POGZ is both a transcription factor and a genome regulator, and its loss leads to defects in neural induction and neurogenesis.