Negative Regulation of mTOR Signaling Restricts Cell Proliferation in the Floor Plate

Weighted single-step genome-wide association study to reveal new candidate genes for productive traits of Landrace pig in Korea

The objective of this study was to identify genomic regions and candidate genes associated with productive traits using a total of 37,099 productive records and 6,683 single nucleotide polymorphism (SNP) data obtained from five Great-Grand-Parents (GGP) farms in Landrace. The estimated of heritabilities for days to 105 kg (AGE), average daily gain (ADG), backfat thickness (BF), and eye muscle area (EMA) were 0.49, 0.49, 0.56, and 0.23, respectively. We identified a genetic window that explained 2.05%-2.34% for each trait of the total genetic variance. We observed a clear partitioning of the four traits into two groups, and the most significant genomic region for AGE and ADG were located on the Sus scrofa chromosome (SSC) 1, while BF and EMA were located on SSC 2. We conducted Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG), which revealed results in three biological processes, four cellular component, three molecular function, and six KEGG pathway. Significant SNPs can be used as markers for quantitative trait loci (QTL) investigation and genomic selection (GS) for productive traits in Landrace pig.

Regulation of progenitor cell survival by a novel chromatin remodeling factor during neural tube development

During development, progenitor cell survival is essential for proper tissue functions, but the underlying mechanisms are not fully understood. Here we show that ERCC6L2, a member of the Snf2 family of helicase-like proteins, plays an essential role in the survival of developing chick neural cells. ERCC6L2 expression is induced by the Sonic Hedgehog (Shh) signaling molecule by a mechanism similar to that of the known Shh target genes Ptch1 and Gli1. ERCC6L2 blocks programmed cell death induced by Shh inhibition and this inhibition is independent of neural tube patterning. ERCC6L2 knockdown by siRNA resulted in the aberrant appearance of apoptotic cells. Furthermore, ERCC6L2 cooperates with the Shh signal and plays an essential role in the induction of the anti-apoptotic factor Bcl-2. Taken together, ERCC6L2 acts as a key factor in ensuring the survival of neural progenitor cells.

Sorafenib inhibits invasion of multicellular organoids that mimic Lymphangioleiomyomatosis nodules

Lymphangioleiomyomatosis (LAM) is a debilitating, progressive lung disease with few therapeutic options, largely due to a paucity of mechanistic knowledge of disease pathogenesis. Lymphatic endothelial cells (LECs) are known to envelope and invade clusters of LAM-cells, comprising of smooth muscle α-actin and/or HMB-45 positive "smooth muscle-like cells" however the role of LECs in LAM pathogenesis is still unknown. To address this critical knowledge gap, we investigated wether LECs interact with LAM-cells to augment their metastatic behaviour of LAM-cells. We performed in situ spatialomics and identified a core of transcriptomically related cells within the LAM nodules. Pathway analysis highlights wound and pulmonary healing, VEGF signaling, extracellular matrix/actin cytoskeletal regulating and the HOTAIR regulatory pathway enriched in the LAM Core cells. We developed an organoid co-culture model combining primary LAM-cells with LECs and applied this to evaluate invasion, migration, and the impact of Sorafenib, a multi-kinase inhibitor. LAM-LEC organoids had significantly higher extracellular matrix invasion, decreased solidity and a greater perimeter, reflecting increased invasion compared to non-LAM control smooth muscle cells. Sorafenib significantly inhibited this invasion in both LAM spheroids and LAM-LEC organoids compared to their respective controls. We identified TGFβ1ι1, a molecular adapter coordinating protein-protein interactions at the focal adhesion complex and known to regulate VEGF, TGFβ and Wnt signalling, as a Sorafenib-regulated kinase in LAM-cells. In conclusion we have developed a novel 3D co-culture LAM model and have demonstrated the effectiveness of Sorafenib to inhibit LAM-cell invasion, identifying new avenues for therapeutic intervention.

Roles of Transcription Factors in the Development and Reprogramming of the Dopaminergic Neurons

The meso-diencephalic dopaminergic (mdDA) neurons regulate various critical processes in the mammalian nervous system, including voluntary movement and a wide range of behaviors such as mood, reward, addiction, and stress. mdDA neuronal loss is linked with one of the most prominent human movement neurological disorders, Parkinson’s disease (PD). How these cells die and regenerate are two of the most hotly debated PD research topics. As for the latter, it has been long known that a series of transcription factors (TFs) involves the development of mdDA neurons, specifying cell types and controlling developmental patterns. In vitro and in vivo, TFs regulate the expression of tyrosine hydroxylase, a dopamine transporter, vesicular monoamine transporter 2, and L-aromatic amino acid decarboxylase, all of which are critical for dopamine synthesis and transport in dopaminergic neurons (DA neurons). In this review, we encapsulate the molecular mechanism of TFs underlying embryonic growth and maturation of mdDA neurons and update achievements on dopaminergic cell therapy dependent on knowledge of TFs in mdDA neuronal development. We believe that a deeper understanding of the extrinsic and intrinsic factors that influence DA neurons’ fate and development in the midbrain could lead to a better strategy for PD cell therapy.

Sox14 is essential for initiation of neuronal differentiation in the chick spinal cord

BACKGROUND

The neural tube comprises several different types of progenitors and postmitotic neurons that co-ordinately act with each other to play integrated functions. Its development consists of two phases: proliferation of progenitor cells and differentiation into postmitotic neurons. How progenitor cells differentiate into each corresponding neuron is an important question for understanding the mechanisms of neuronal development.

RESULTS

Here we introduce one of the Sox transcription factors, Sox14, which plays an essential role in the promotion of neuronal differentiation. Sox14 belongs to the SoxB2 subclass and its expression starts in the progenitor regions before neuronal differentiation is initiated at the trunk level of the neural tube. After neuronal differentiation is initiated, Sox14 expression gradually becomes confined to the V2a region of the neural tube, where Chx10 is co-expressed. Overexpression of Sox14 restricts progenitor cell proliferation. Conversely, the blockade of Sox14 expression by the RNAi strategy inhibits V2a neuron differentiation and causes expansion of the progenitor domain. We further found that Sox14 acted as a transcriptional activator.

CONCLUSIONS

Sox14 acts as a modulator of cell proliferation and is essential for initiation of neuronal differentiation in the chick neural tube.

Vitamin E Deficiency Disrupts Gene Expression Networks during Zebrafish Development

Vitamin E (VitE) is essential for vertebrate embryogenesis, but the mechanisms involved remain unknown. To study embryonic development, we fed zebrafish adults (>55 days) either VitE sufficient (E+) or deficient (E–) diets for >80 days, then the fish were spawned to generate E+ and E– embryos. To evaluate the transcriptional basis of the metabolic and phenotypic outcomes, E+ and E– embryos at 12, 18 and 24 h post-fertilization (hpf) were subjected to gene expression profiling by RNASeq. Hierarchical clustering, over-representation analyses and gene set enrichment analyses were performed with differentially expressed genes. E– embryos experienced overall disruption to gene expression associated with gene transcription, carbohydrate and energy metabolism, intracellular signaling and the formation of embryonic structures. mTOR was apparently a major controller of these changes. Thus, embryonic VitE deficiency results in genetic and transcriptional dysregulation as early as 12 hpf, leading to metabolic dysfunction and ultimately lethal outcomes.

The Role of Tissue-Specific Ubiquitin Ligases, RNF183, RNF186, RNF182 and RNF152, in Disease and Biological Function

Ubiquitylation plays multiple roles not only in proteasome-mediated protein degradation but also in various other cellular processes including DNA repair, signal transduction, and endocytosis. Ubiquitylation is mediated by ubiquitin ligases, which are predicted to be encoded by more than 600 genes in humans. RING finger (RNF) proteins form the majority of these ubiquitin ligases. It has also been predicted that there are 49 RNF proteins containing transmembrane regions in humans, several of which are specifically localized to membrane compartments in the secretory and endocytic pathways. Of these, RNF183, RNF186, RNF182, and RNF152 are closely related genes with high homology. These genes share a unique common feature of exhibiting tissue-specific expression patterns, such as in the kidney, nervous system, and colon. The products of these genes are also reported to be involved in various diseases such as cancers, inflammatory bowel disease, Alzheimer's disease, and chronic kidney disease, and in various biological functions such as apoptosis, endoplasmic reticulum stress, osmotic stress, nuclear factor-kappa B (NF-κB), mammalian target of rapamycin (mTOR), and Notch signaling. This review summarizes the current knowledge of these tissue-specific ubiquitin ligases, focusing on their physiological roles and significance in diseases.