Project description:Autism spectrum disorders (ASDs) are a neurodevelopmental disorder characterized by impairments in social interactions and stereotyped behaviors. While ASD has a strong genetic background, environmental factors including toxins, pesticides, infection and drugs are also known to confer autism susceptibility, likely by inducing epigenetic changes. Exposure to Valproic acid (VPA), a drug for epilepsy and bipolar disorders, during pregnancy is highly associated with the risk of ASD children. In rodents, in utero VPA exposure can precipitate behavioral phenotypes related to ASD in the offspring. Since VPA is an inhibitor of histone deacethytransferase (HDAC) activity, it thought to cause ASD with epigenetic modification. However, the core mechanism by which prenatal VPA exposure causes onset of ASD is still not fully uncovered. Here we revealed that prenatal VPA exposure strongly influences development of vasoactive intestinal peptide (VIP) - positive neurons, a subtype of cortical GABAergic interneurons. The number of VIP+ interneurons was severely reduced in somatosensory area of VPA-exposed ASD animals. We then found that the reduction in VIP+ interneurons is caused by the inhibition of HDAC3 activity upon prenatal VPA exposure. Importantly, prenatal HDAC3 inhibition caused not only the selective reduction in VIP+ interneurons but also the ASD-like behaviors in mice. We then demonstrated that the HDAC3 inhibition aberrantly activates Notch signaling, which influences the cell fate determination of VIP+ interneuron progenitors in caudal ganglionic eminence. Thus, this study uncovers the mechanism by which specific HDAC inhibition during development influences a specific type of GABAergic interneurons in the ASD model. The findings provide a novel insight into the understanding of ASD pathophysiology.
Project description:Accumulation of excess nutrients hampers proper liver function and is linked to non-alcoholic fatty liver disease (NAFLD) in obesity. However, the signals responsible for an impaired adaptation of hepatocytes to obesogenic dietary cues remain still largely unknown. Post-translational modification by the Small Ubiquitin-like Modifier (SUMO), allows for adynamic regulation of numerous processes including transcriptional reprograming. We demonstrate that specific SUMOylation of transcription factor Prox1 represents a nutrient-sensitive determinant of hepatic fasting metabolism. Prox1 was highly SUMOylated on lysine 556 in the liver of ad libitum and re-fed mice, while this modification was abolished upon fasting. In the context of diet-induced obesity, Prox1 SUMOylation became less sensitive to fasting cues. The hepatocyte-selective knock-in of a SUMOylation-deficient Prox1 mutant into mice fed a high-fat/high-fructose diet led to a reduction of systemic cholesterol levels, associated with the induction of liver bile acid detoxifying pathways during fasting. The generation of tools to maintain the nutrient-sensitive SUMO-switch on Prox1 may thus contribute to the development of “fasting-based” approaches for the preservation of metabolic health.
Project description:Analysis of CGTH-W-1 follicular thyroid carcinoma cells transcriptome following 48 hrs siRNA-mediated depletion of PROX1. PROX1 is a homeobox transcription factor. PROX1 depletion decreases migratory ability, motility and invasivness and induces profound cytoskeleton changes of CGTH-W-1 cells. Results provide insight into the role of PROX1 in the thyroid cancer. Three biological replicates for a given condition
Project description:Identification of the Early Vasoactive Intestinal Peptide (VIP) Transriptome and its Associated Interactome in Activated Murine CD4 T Cells In an attempt to understand the biological role of this neuropeptide in the immune system, we choose CD4 T cells as a cellular system for identifying a VIP-induced transcriptome. Murine CD4 T cells were isolated and used to identify changes in gene expression in the presence of PMA/ionomycin (activated) for five hours with and without 10-7 M VIP. Balanced-block design, 6 biological replicates. PMA/ionomycin (activated) mouse CD4 T spleenocytes with VIP ligand (sample) vs. PMA/ionomycin (activated) mouse CD4 T spleenocytes without VIP ligand (control), dye-swaps.
Project description:Identification of the Early Vasoactive Intestinal Peptide (VIP) Transriptome and its Associated Interactome in Resting Murine CD4 T Cells In an attempt to understand the biological role of this neuropeptide in the immune system, we choose CD4 T cells as a cellular system for identifying a VIP-induced transcriptome. Murine CD4 T cells were isolated and used to identify changes in gene expression in the absence of PMA/ionomycin (resting) with and without 10-7 M VIP. Balanced-block design, 6 biological replicates. Naïve mouse CD4 T spleenocytes with VIP ligand (sample) vs. naïve mouse CD4 T spleenocytes without VIP ligand (control), dye-swaps.
Project description:Analysis of CGTH-W-1 follicular thyroid carcinoma cells transcriptome following 48 hrs siRNA-mediated depletion of PROX1. PROX1 is a homeobox transcription factor. PROX1 depletion decreases migratory ability, motility and invasivness and induces profound cytoskeleton changes of CGTH-W-1 cells. Results provide insight into the role of PROX1 in the thyroid cancer.
Project description:During central nervous system (CNS) development, proper and timely induction of axon elongation is critical for generating functional, mature neurons and neuronal networks. Despite the wealth of information on the action of extracellular cues, little is known about the intrinsic gene regulatory factors that control this developmental decision. Here we report the identification of Prox1, a homeobox transcription factor, as a key player in inhibiting axon elongation. Although Prox1 promotes acquisition of early neuronal identity and is expressed in nascent post-mitotic neurons, it is heavily down-regulated in the majority of terminally differentiated neurons, indicating a regulatory role in delaying axon outgrowth in newly formed neurons. Consistently, we show that Prox1 is sufficient to inhibit neurite extension in neuroblastoma cell lines. Furthermore, shRNA-mediated knock-down of Prox1 in Neuro2A cells induces the extension of neurites. More importantly, Prox1 overexpression suppresses axon elongation in primary neuronal cultures as well as in the developing mouse brain, while Prox1 knock-down promotes axon outgrowth. Mechanistically, RNA-Seq analysis reveals that Prox1 affects critical pathways for neuronal maturation and neurite extension. Interestingly, Prox1 strongly inhibits many components of Ca2+ signaling pathway, an important mediator of axon extension and neuronal maturation. In accordance, Prox1 represses Ca2+ entry upon KCl-mediated depolarization and reduce CREB phosphorylation. These observations suggest that Prox1 acts as a potent suppressor of axon elongation by inhibiting Ca2+ signaling pathway. This action may provide the appropriate time window for nascent neurons to find the correct position in the CNS prior to initiation of axon elongation.
Project description:Homeobox genes are a family of transcription factors that play a pivotal role in embryogenesis. Altered expression of Prospero-related homeobox gene 1 (PROX1) was recently associated with cancer, including oral squamous cell carcinoma (OSCC). This study aimed to investigate the functional role of PROX1 in oral carcinogenesis. PROX1 mRNA and protein expression levels were first investigated in 40 samples of OSCC and non-tumour margins. Methylation and amplification analysis was also performed to assess the epigenetic mechanisms involved in controlling PROX1 expression. OSCC cell line SCC9 was also transfected to stably express the PROX1 gene. Next, SCC9-PROX1-overexpressing cells and controls were then subjected to proliferation, differentiation, apoptosis, and microarray assays in vitro. OSCC samples had reduced PROX1 expression levels compared to non-tumour margins. PROX1 amplification was associated with better overall survival. PROX1 overexpression reduces cell proliferation by down-regulating cyclin D1 and up-regulating p21. PROX1-overexpressing cells also exhibited significantly reduced K18 and K19 expression.
Project description:Identification of the Early Vasoactive Intestinal Peptide (VIP) Transriptome and its Associated Interactome in Resting Murine CD4 T Cells In an attempt to understand the biological role of this neuropeptide in the immune system, we choose CD4 T cells as a cellular system for identifying a VIP-induced transcriptome. Murine CD4 T cells were isolated and used to identify changes in gene expression in the absence of PMA/ionomycin (resting) with and without 10-7 M VIP.