Project description:Mapttm1(EGFP)Klt/J mice (Mapt-EGFP; The Jackson Laboratory, Bar Harbor, ME, USA; stock 004779) carry a knock-in of the EGFP coding sequence in the first exon of the microtubule-associated protein tau (Mapt) gene producing a cytoplasmic EGFP fused to the first 31 amino acids of MAPT. EGFP expression marks neurons including enteric neurons regardless of their lineage, closely patterning the expression of neuron-specific beta-tubulin III (TUBB3). Mapt-EGFP ice were backcrossed to C57BL/6J (Jackson Laboratory strain #:000664) for three to five generations at Mayo Clinic. Six male and six female Mapt-EGFP mice (54-98 days of age) underwent surgical laparotomy in 3 groups (surgery #1: 1 male and 1 female, surgery #2: 3 males and 1 female, surgery #3: 2 males and 4 females) under pentobarbital (50mg/kg) anesthesia. The celiac ganglion of each mouse was injected with 3-5 μL of 25 mg/mL Alexa Fluor 647-labeled cholera toxin subunit B (CTB-AF647; Thermo Fisher Scientific, Waltham, MA, USA) with the intention of labeling the cell soma of intestinofugal neurons in the myenteric plexus of the colon. The animals were killed 3-4 days after surgery. The muscularis externa of the colon from each Mapt-EGFP mouse was pooled together between all mice of the same surgery date (2, 4, and 6 mice) and mechanically and enzymatically dissociated into single cells with a two-step process that first enriches for cells within myenteric ganglia (PMCID: PMC8114175). The pooled cells from each group of mice formed one biological replicate and subjected to FACS immediately after dissociation to generate populations of Mapt-EGFP+ neurons with or without the CTB-AF647 tracer and Mapt-EGFP− non-neuronal cells. The frequency of Mapt-EGFP+CTB-AF647+ neurons was approximately 125-fold lower than that of Mapt-EGFP+CTB-AF647− neurons and RNA from these preparations did not pass quality control. Therefore, only data from Mapt-EGFP+CTB-AF647− neurons were analyzed and referred to as Mapt-EGFP+ cells. Total RNA was isolated from Mapt-EGFP+ colonic neurons and Mapt-EGFP− myenteric cells using RNA-Bee (AMSBIO, Cambridge, MA, USA) and purified with RNeasy Mini Kit (Qiagen, Germantown, MD, USA). RNA quality was tested using Agilent Electropherogram (Agilent Technologies, Santa Clara, CA, USA) and hybridized to Affymetrix Mouse Genome 430.2 gene expression microarrays (Thermo Fisher Scientific, Waltham, MA, USA). This study utilized Affymetrix Mouse Genome 430.2 oligonucleotide microarray analysis to charaterize the transcriptome of Mapt-EGFP+ neurons and Mapt-EGFP- non-neuronal myenteric cells isolated from the colon of Mapttm1(EGFP)Klt/J mice.
Project description:Transcriptomics and phosphoproteomics were carried out in B6.Cg-Mapttm1(EGFP)Klt (mapt knockout: tau-KO) and wild-type (WT) 12-month-old mice to learn about the effects of tau ablation.
Project description:Enteric glial cells (EGCs) are the main constituent of the enteric nervous system and share similarities with astrocytes from the central nervous system including their reactivity to an inflammator microenvironment. In this study we isolated GFAP-positive myenteric glia from FVB/hGFAP-eGFP transgenic postnatal day 7 mice. Following cell sorting for the eGFP reporter, GFAP-positive EGCs were cultured for 3 weeks to generate neurosphere-like bodies. This cell culture was stimulated with LPS for 48 h and cells were employed for gene expression profiling. LPS-stimulated cell cultures were compared to untreated control cell cultures. Enriched GFAP+ EGC cultures secreted increased levels of prominent inflammatory cytokines upon LPS stimulation. Further, in vitro cultures were compared to GFAP-eGFP-positive cells directly analyzed after cell sorting of small intestinal LMMP digests (in vivo) to assess alterations in transcriptomic profiles due to the in vitro culture. In vivo data and in vitro data were collected in three independent replicates. For each replicate one litter of FVB/hGFAP-eGFP transgenic mice at postnatal day 7 was employed. GFAP-eFP-positive small intestines were digested enzymatically and from the single cell suspensions eGFP-positive GFAP-expressing cells were sorted by fluorescence-activated cell sorting. For the in vivo data the cells were directly sorted into lysis buffer and further processed . For the in vitro data GFAP-eGFP cells were seeded onto coated plastic dishes for adherent growth and cultured in DMEM/F12-medium supplemented with antibiotics, N2, B27, bFGF and EGF. In the first passage cells were divided into two uncoated six well dishes to promote spheroid growth. One well was supplemented with LPS (100 µg/ml, from E. coli O26:B6, Sigma Aldrich, potency 3 EU/ng) for 48 h, the corresponding second well was left untreated and used as respective control. After 48 h, cells were processed for total RNA isolation.
Project description:This study was undertaken to define the molecular subtypes of myenteric plexus glial cells in mice, and to understand the molecular basis for glial cells’ capacity to become neurons. Methods: We performed single-cell RNA sequencing and single-nucleus ATAC sequencing of enteric neurons from small intestine at the adolescent mice (on or near postnatal day of life 14). We also performed both single-cell RNA sequencing and single-nucleus ATAC sequencing on 3-dimensional neurosphere cultures. Results: We identify numerous distinct transcriptional subgroups of myenteric plexus glial cells, including cells expressing genes associated with neuronal differentiation. Epigenetic analysis shows distinct chromatin accessibility profiles that correlate with gene expression patterns. Glial cells maintain open chromatin at gene loci associated with neuronal fate. 3-dimensional cultures provide a niche for active neurogenesis. Chromatin closes at glial-associate loci during neurogenesis. Conclusion: Utilizing single-cell RNA sequencing and single-nucleus ATAC sequencing, we identify myenteric glial cell subtypes and uncover a molecular basis for a glial-to-neuronal fate transition.
Project description:Enteric glial cells (EGCs) are the main constituent of the enteric nervous system and share similarities with astrocytes from the central nervous system including their reactivity to an inflammator microenvironment. In this study we isolated GFAP-positive myenteric glia from FVB/hGFAP-eGFP transgenic postnatal day 7 mice. Following cell sorting for the eGFP reporter, GFAP-positive EGCs were cultured for 3 weeks to generate neurosphere-like bodies. This cell culture was stimulated with LPS for 48 h and cells were employed for gene expression profiling. LPS-stimulated cell cultures were compared to untreated control cell cultures. Enriched GFAP+ EGC cultures secreted increased levels of prominent inflammatory cytokines upon LPS stimulation. Further, in vitro cultures were compared to GFAP-eGFP-positive cells directly analyzed after cell sorting of small intestinal LMMP digests (in vivo) to assess alterations in transcriptomic profiles due to the in vitro culture.
Project description:Tau (MAPT) is a microtubule-associated protein causing frequent neurodegenerative diseases or inherited frontotemporal lobar degenerations. Emerging evidence for non-canonical functions of Tau in DNA protection and P53 regulation suggests its involvement in cancer. Indeed, Tau expression correlates with cancer-specific survival or response to microtubule therapeutics. These data may imply common molecular pathways involved in the pathogenesis of neurodegenerative disorders and cancer. To bring new evidence that Tau represents a key protein in cancer, we present an in silico pan-cancer analysis of MAPT transcriptomic profile in over 11000 clinical samples and over 1300 pre-clinical samples provided by the TCGA and the DEPMAP datasets respectively. We completed this analysis by exploring a possible interplay of MAPT with wild-type or mutated P53. Then, we calculated the impact of MAPT expression on clinical outcome and drug response. Overall, the results support a relevant role of the MAPT gene in several cancer types, although the contribution of Tau to cancer appears to very much depend on the cellular context.
Project description:The aim of this experiment was to assess the on- and off-target effects of MAPT-AS1 expression, and whether mutations/deletions to MAPT-AS1 alter these effects. SHSY5Y cells stably expressing variants of MAPT-AS1 were analyzed by Riboseq and Quantseq.
Project description:Samples of dissociated mouse small intestinal longitudinal muscle-myenteric plexus were prepared from post natal day 10 (P10), P20, and P60, each with two biological replicates. Samples were run through the 10x Chromium 3' Single Cell Gene Expression platform v3.1