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1.
Animals (Basel) ; 14(6)2024 Mar 12.
Article in English | MEDLINE | ID: mdl-38539967

ABSTRACT

Ewe lambs that are heavier due to improved nutrition pre- and post-weaning achieve puberty at a younger age, are more fertile, and have a higher reproductive rate. Fatness is intimately linked to reproduction, and we hypothesised that higher body condition scores at breeding would have positive effects on the reproductive rate of ewe lambs over and above liveweight. We also expected that if only a proportion of ewe lambs were presented for breeding, then it would be more effective to select them based on both liveweight and body condition score. To test these hypotheses, we analysed data from over 17,000 records from Merino and non-Merino ewe lambs from 22 different flocks across Australia. Non-Merino ewe lambs were more fertile (69.4% vs. 48.7%) and achieved a higher reproductive rate than Merino ewe lambs (96.9% vs. 60.7%). There were significant curvilinear relationships between liveweight (p < 0.001) or body condition score (p < 0.001) prior to breeding and reproductive rate for both Merino and non-Merino ewe lambs. For both breeds, there was a significant (p < 0.001) quadratic effect of body condition score prior to breeding on reproductive rate, independent of the correlated changes in liveweight, and at the same liveweight, an extra 0.5 of a body condition score up to 3.3 improved reproductive rate by about 20%. Nevertheless, the results indicated that if only a proportion of ewe lambs were selected for breeding, then selection based on both liveweight and body condition scores may only improve the overall reproductive rate by 1 to 2% compared to selection based on liveweight alone. We conclude that liveweight is a more effective method than body condition score for selecting ewe lambs for breeding.

2.
Elife ; 112022 05 10.
Article in English | MEDLINE | ID: mdl-35535852

ABSTRACT

Pitt-Hopkins syndrome (PTHS) is a neurodevelopmental disorder caused by monoallelic mutation or deletion in the transcription factor 4 (TCF4) gene. Individuals with PTHS typically present in the first year of life with developmental delay and exhibit intellectual disability, lack of speech, and motor incoordination. There are no effective treatments available for PTHS, but the root cause of the disorder, TCF4 haploinsufficiency, suggests that it could be treated by normalizing TCF4 gene expression. Here, we performed proof-of-concept viral gene therapy experiments using a conditional Tcf4 mouse model of PTHS and found that postnatally reinstating Tcf4 expression in neurons improved anxiety-like behavior, activity levels, innate behaviors, and memory. Postnatal reinstatement also partially corrected EEG abnormalities, which we characterized here for the first time, and the expression of key TCF4-regulated genes. Our results support a genetic normalization approach as a treatment strategy for PTHS, and possibly other TCF4-linked disorders.


Subject(s)
Intellectual Disability , Transcription Factor 4/metabolism , Animals , Disease Models, Animal , Facies , Hyperventilation , Intellectual Disability/genetics , Intellectual Disability/metabolism , Mice , Phenotype , Transcription Factor 4/genetics
3.
Cells ; 9(5)2020 05 08.
Article in English | MEDLINE | ID: mdl-32397240

ABSTRACT

The replication independent (RI) histone H2A.Z is one of the more extensively studied variant members of the core histone H2A family, which consists of many replication dependent (RD) members. The protein has been shown to be indispensable for survival, and involved in multiple roles from DNA damage to chromosome segregation, replication, and transcription. However, its functional involvement in gene expression is controversial. Moreover, the variant in several groups of metazoan organisms consists of two main isoforms (H2A.Z-1 and H2A.Z-2) that differ in a few (3-6) amino acids. They comprise the main topic of this review, starting from the events that led to their identification, what is currently known about them, followed by further experimental, structural, and functional insight into their roles. Despite their structural differences, a direct correlation to their functional variability remains enigmatic. As all of this is being elucidated, it appears that a strong functional involvement of isoform variability may be connected to development.


Subject(s)
Histones/metabolism , Amino Acid Sequence , Animals , Brain/metabolism , Cell Cycle , Chickens , Chromatin/metabolism , DNA Methylation , Histones/chemistry , Humans , Liver/metabolism , Male , Mice , Nucleosomes/metabolism , Osmolar Concentration , Phylogeny , Protein Isoforms/chemistry , Protein Isoforms/metabolism , Spermatogenesis
4.
Mol Ther Nucleic Acids ; 19: 1399-1412, 2020 Mar 06.
Article in English | MEDLINE | ID: mdl-32160709

ABSTRACT

Knockout of the memory suppressor gene histone deacetylase 2 (Hdac2) in mice elicits cognitive enhancement, and drugs that block HDAC2 have potential as therapeutics for disorders affecting memory. Currently available HDAC2 catalytic activity inhibitors are not fully isoform specific and have short half-lives. Antisense oligonucleotides (ASOs) are drugs that elicit extremely long-lasting, specific inhibition through base pairing with RNA targets. We utilized an ASO to reduce Hdac2 messenger RNA (mRNA) in mice and determined its longevity, specificity, and mechanism of repression. A single injection of the Hdac2-targeted ASO in the central nervous system produced persistent reduction in HDAC2 protein and Hdac2 mRNA levels for 16 weeks. It enhanced object location memory for 8 weeks. RNA sequencing (RNA-seq) analysis of brain tissues revealed that the repression was specific to Hdac2 relative to related Hdac isoforms, and Hdac2 reduction caused alterations in the expression of genes involved in extracellular signal-regulated kinase (ERK) and memory-associated immune signaling pathways. Hdac2-targeted ASOs also suppress a nonpolyadenylated Hdac2 regulatory RNA and elicit direct transcriptional suppression of the Hdac2 gene through stalling RNA polymerase II. These findings identify transcriptional suppression of the target gene as a novel mechanism of action of ASOs.

5.
Nat Neurosci ; 23(3): 375-385, 2020 03.
Article in English | MEDLINE | ID: mdl-32015540

ABSTRACT

Autism spectrum disorder (ASD) is genetically heterogeneous with convergent symptomatology, suggesting common dysregulated pathways. In this study, we analyzed brain transcriptional changes in five mouse models of Pitt-Hopkins syndrome (PTHS), a syndromic form of ASD caused by mutations in the TCF4 gene, but not the TCF7L2 gene. Analyses of differentially expressed genes (DEGs) highlighted oligodendrocyte (OL) dysregulation, which we confirmed in two additional mouse models of syndromic ASD (Ptenm3m4/m3m4 and Mecp2tm1.1Bird). The PTHS mouse models showed cell-autonomous reductions in OL numbers and myelination, functionally confirming OL transcriptional signatures. We also integrated PTHS mouse model DEGs with human idiopathic ASD postmortem brain RNA-sequencing data and found significant enrichment of overlapping DEGs and common myelination-associated pathways. Notably, DEGs from syndromic ASD mouse models and reduced deconvoluted OL numbers distinguished human idiopathic ASD cases from controls across three postmortem brain data sets. These results implicate disruptions in OL biology as a cellular mechanism in ASD pathology.


Subject(s)
Autism Spectrum Disorder/genetics , DNA Fingerprinting , Hyperventilation/genetics , Intellectual Disability/genetics , Myelin Sheath/genetics , Transcriptome/genetics , Aging , Animals , Cell Count , Facies , Gene Expression Regulation , Humans , Methyl-CpG-Binding Protein 2/genetics , Mice , Mice, Knockout , Oligodendroglia/metabolism , PTEN Phosphohydrolase/genetics , Primary Cell Culture , Signal Transduction/genetics , Transcription Factor 4/genetics
6.
ACS Med Chem Lett ; 10(2): 180-185, 2019 Feb 14.
Article in English | MEDLINE | ID: mdl-30783500

ABSTRACT

DNA methylation is known as the prima donna epigenetic mark for its critical role in regulating local gene transcription. Changes in the landscape of DNA methylation across the genome occur during cellular transition, such as differentiation and altered neuronal plasticity, and become dysregulated in disease states such as cancer. The TET family of enzymes is known to be responsible for catalyzing the reverse process that is DNA demethylation by recognizing 5-methylcytosine and oxidizing the methyl group via an Fe(II)/alpha-ketoglutarate-dependent mechanism. Here, we describe the design, synthesis, and evaluation of novel cytosine-based TET enzyme inhibitors, a class of small molecule probes previously underdeveloped but broadly desired in the field of epigenetics. We identify a promising cytosine-based lead compound, Bobcat339, that has mid-µM inhibitor activity against TET1 and TET2, but does not inhibit the DNA methyltransferase, DNMT3a. In silico modeling of the TET enzyme active site is used to rationalize the activity of Bobcat339 and other cytosine-based inhibitors. These new molecular tools will be useful to the field of epigenetics and serve as a starting point for new therapeutics that target DNA methylation and gene transcription.

7.
Mol Vis ; 24: 153-164, 2018.
Article in English | MEDLINE | ID: mdl-29463953

ABSTRACT

Purpose: Epigenetic and transcriptional mechanisms have been shown to contribute to long-lasting functional changes in adult neurons. The purpose of this study was to identify any such modifications in diseased retinal tissues from a mouse model of rhodopsin mutation-associated autosomal dominant retinitis pigmentosa (ADRP), Q344X, relative to age-matched wild-type (WT) controls. Methods: We performed RNA sequencing (RNA-seq) at poly(A) selected RNA to profile the transcriptional patterns in 3-week-old ADRP mouse model rhodopsin Q344X compared to WT controls. Differentially expressed genes were determined by DESeq2 using the Benjamini & Hochberg p value adjustment and an absolute log2 fold change cutoff. Quantitative western blots were conducted to evaluate protein expression levels of histone H3 phosphorylated at serine 10 and histone H4. qRT-PCR was performed to validate the expression patterns of differentially expressed genes. Results: We observed significant differential expression in 2151 genes in the retina of Q344X mice compared to WT controls, including downregulation in the potassium channel gene, Kcnv2, and differential expression of histone genes, including the H1 family histone member, H1foo; the H3 histone family 3B, H3f3b; and the histone deacetylase 9, Hdac9. Quantitative western blots revealed statistically significant decreased protein expression of both histone H3 phosphorylated at serine 10 and histone H4 in 3-week-old Q344X retinas. Furthermore, qRT-PCR performed on select differentially expressed genes based on our RNA-seq results revealed matched expression patterns of up or downregulation. Conclusions: These findings provide evidence that transcriptomic alterations occur in the ADRP mouse model rhodopsin Q344X retina and that these processes may contribute to the dysfunction and neurodegeneration seen in this animal model.


Subject(s)
Amino Acid Substitution , Chromatin/metabolism , Chromosome Disorders/genetics , Retinitis Pigmentosa/genetics , Rhodopsin/genetics , Transcription, Genetic , Animals , Chromatin/chemistry , Chromosome Disorders/metabolism , Chromosome Disorders/pathology , Female , Gene Expression Profiling , Gene Knock-In Techniques , Genes, Dominant , Histone Deacetylases/genetics , Histone Deacetylases/metabolism , Histones/genetics , Histones/metabolism , Humans , Male , Mice , Mice, Transgenic , Mutation , Potassium Channels, Voltage-Gated/genetics , Potassium Channels, Voltage-Gated/metabolism , Protein Isoforms/genetics , Protein Isoforms/metabolism , Repressor Proteins/genetics , Repressor Proteins/metabolism , Retinitis Pigmentosa/metabolism , Retinitis Pigmentosa/pathology , Rhodopsin/metabolism
8.
Cell Rep ; 22(5): 1124-1131, 2018 01 30.
Article in English | MEDLINE | ID: mdl-29386101

ABSTRACT

Histone variants were recently discovered to regulate neural plasticity, with H2A.Z emerging as a memory suppressor. Using whole-genome sequencing of the mouse hippocampus, we show that basal H2A.Z occupancy is positively associated with steady-state transcription, whereas learning-induced H2A.Z removal is associated with learning-induced gene expression. AAV-mediated H2A.Z depletion enhanced fear memory and resulted in gene-specific alterations of learning-induced transcription, reinforcing the role of H2A.Z as a memory suppressor. H2A.Z accumulated with age, although it remained sensitive to learning-induced eviction. Learning-related H2A.Z removal occurred at largely distinct genes in young versus aged mice, suggesting that H2A.Z is subject to regulatory shifts in the aged brain despite similar memory performance. When combined with prior evidence of H3.3 accumulation in neurons, our data suggest that nucleosome composition in the brain is reorganized with age.


Subject(s)
Aging/metabolism , Hippocampus/metabolism , Histones/metabolism , Learning/physiology , Animals , Gene Expression Regulation , Male , Mice , Mice, Inbred C57BL , Nucleosomes/metabolism
9.
Front Aging Neurosci ; 9: 383, 2017.
Article in English | MEDLINE | ID: mdl-29276487

ABSTRACT

The current study employed next-generation RNA sequencing to examine gene expression differences related to brain aging, cognitive decline, and hippocampal subfields. Young and aged rats were trained on a spatial episodic memory task. Hippocampal regions CA1, CA3, and the dentate gyrus were isolated. Poly-A mRNA was examined using two different sequencing platforms, Illumina, and Ion Proton. The Illumina platform was used to generate seed lists of genes that were statistically differentially expressed across regions, ages, or in association with cognitive function. The gene lists were then retested using the data from the Ion Proton platform. The results indicate hippocampal subfield differences in gene expression and point to regional differences in vulnerability to aging. Aging was associated with increased expression of immune response-related genes, particularly in the dentate gyrus. For the memory task, impaired performance of aged animals was linked to the regulation of Ca2+ and synaptic function in region CA1. Finally, we provide a transcriptomic characterization of the three subfields regardless of age or cognitive status, highlighting and confirming a correspondence between cytoarchitectural boundaries and molecular profiling.

10.
Learn Mem ; 24(7): 278-288, 2017 07.
Article in English | MEDLINE | ID: mdl-28620075

ABSTRACT

Using a hippocampus-dependent contextual threat learning and memory task, we report widespread, coordinated DNA methylation changes in CA1 hippocampus of Sprague-Dawley rats specific to threat learning at genes involved in synaptic transmission. Experience-dependent alternations in gene expression and DNA methylation were observed as early as 1 h following memory acquisition and became more pronounced after 24 h. Gene ontology analysis revealed significant enrichment of functional categories related to synaptic transmission in genes that were hypomethylated at 24 h following threat learning. Integration of these data sets with previously characterized epigenetic and transcriptional changes in brain disease states suggested significant overlap between genes regulated by memory formation and genes altered in memory-related neurological and neuropsychiatric diseases. These findings provide a comprehensive resource to aid in the identification of memory-relevant therapeutic targets. Our results shed new light on the gene expression and DNA methylation changes involved in memory formation, confirming that these processes are dynamic and experience-dependent. Finally, this work provides a roadmap for future studies to identify linkage of memory-associated genes to altered disease states.


Subject(s)
Conditioning, Classical/physiology , Epigenomics/methods , Gene Expression Regulation/physiology , Hippocampus/metabolism , Memory/physiology , Animals , CpG Islands/physiology , DNA Methylation/physiology , Gene Ontology , Male , Maze Learning , Models, Molecular , RNA, Messenger/metabolism , Rats , Rats, Sprague-Dawley , Synaptic Transmission/genetics , Time Factors
11.
Cell Rep ; 16(10): 2666-2685, 2016 09 06.
Article in English | MEDLINE | ID: mdl-27568567

ABSTRACT

Human haploinsufficiency of the transcription factor Tcf4 leads to a rare autism spectrum disorder called Pitt-Hopkins syndrome (PTHS), which is associated with severe language impairment and development delay. Here, we demonstrate that Tcf4 haploinsufficient mice have deficits in social interaction, ultrasonic vocalization, prepulse inhibition, and spatial and associative learning and memory. Despite learning deficits, Tcf4(+/-) mice have enhanced long-term potentiation in the CA1 area of the hippocampus. In translationally oriented studies, we found that small-molecule HDAC inhibitors normalized hippocampal LTP and memory recall. A comprehensive set of next-generation sequencing experiments of hippocampal mRNA and methylated DNA isolated from Tcf4-deficient and WT mice before or shortly after experiential learning, with or without administration of vorinostat, identified "memory-associated" genes modulated by HDAC inhibition and dysregulated by Tcf4 haploinsufficiency. Finally, we observed that Hdac2 isoform-selective knockdown was sufficient to rescue memory deficits in Tcf4(+/-) mice.


Subject(s)
DNA Methylation/genetics , Memory , Neuronal Plasticity/genetics , Transcription Factor 7-Like 2 Protein/metabolism , Animals , Autistic Disorder/complications , Autistic Disorder/pathology , Autistic Disorder/physiopathology , CpG Islands/genetics , DNA Methylation/drug effects , Disease Models, Animal , Facies , Gene Expression Profiling , Gene Knockdown Techniques , Hippocampus/metabolism , Histone Deacetylase 2/metabolism , Histone Deacetylase Inhibitors/pharmacology , Hydroxamic Acids/pharmacology , Hyperventilation/complications , Hyperventilation/genetics , Hyperventilation/pathology , Hyperventilation/physiopathology , Intellectual Disability/complications , Intellectual Disability/genetics , Intellectual Disability/pathology , Intellectual Disability/physiopathology , Long-Term Potentiation/drug effects , Male , Memory/drug effects , Mice , Motor Activity/drug effects , Neuronal Plasticity/drug effects , Prepulse Inhibition/drug effects , Transcription Factor 7-Like 2 Protein/genetics , Transcription, Genetic/drug effects , Vorinostat
12.
ACS Med Chem Lett ; 7(5): 487-92, 2016 May 12.
Article in English | MEDLINE | ID: mdl-27190598

ABSTRACT

Sphingosine 1-phosphate (S1P) is a potent growth-signaling lipid that has been implicated in cancer progression, inflammation, sickle cell disease, and fibrosis. Two sphingosine kinases (SphK1 and 2) are the source of S1P; thus, inhibitors of the SphKs have potential as targeted cancer therapies and will help to clarify the roles of S1P and the SphKs in other hyperproliferative diseases. Recently, we reported a series of amidine-based inhibitors with high selectivity for SphK1 and potency in the nanomolar range. However, these inhibitors display a short half-life. With the goal of increasing metabolic stability and maintaining efficacy, we designed an analogous series of molecules containing oxadiazole moieties. Generation of a library of molecules resulted in the identification of the most selective inhibitor of SphK1 reported to date (705-fold selectivity over SphK2), and we found that potency and selectivity vary significantly depending on the particular oxadiazole isomer employed. The best inhibitors were subjected to in silico molecular dynamics docking analysis, which revealed key insights into the binding of amidine-based inhibitors by SphK1. Herein, the design, synthesis, biological evaluation, and docking analysis of these molecules are described.

13.
Antimicrob Agents Chemother ; 60(7): 3980-7, 2016 07.
Article in English | MEDLINE | ID: mdl-27090174

ABSTRACT

Amixicile is a promising derivative of nitazoxanide (an antiparasitic therapeutic) developed to treat systemic infections caused by anaerobic bacteria, anaerobic parasites, and members of the Epsilonproteobacteria (Campylobacter and Helicobacter). Amixicile selectively inhibits pyruvate-ferredoxin oxidoreductase (PFOR) and related enzymes by inhibiting the function of the vitamin B1 cofactor (thiamine pyrophosphate) by a novel mechanism. Here, we interrogate the amixicile scaffold, guided by docking simulations, direct PFOR inhibition assays, and MIC tests against Clostridium difficile, Campylobacter jejuni, and Helicobacter pylori Docking simulations revealed that the nitro group present in nitazoxanide interacts with the protonated N4'-aminopyrimidine of thiamine pyrophosphate (TPP). The ortho-propylamine on the benzene ring formed an electrostatic interaction with an aspartic acid moiety (B456) of PFOR that correlated with improved PFOR-inhibitory activity and potency by MIC tests. Aryl substitution with electron-withdrawing groups and substitutions of the propylamine with other alkyl amines or nitrogen-containing heterocycles both improved PFOR inhibition and, in many cases, biological activity against C. difficile Docking simulation results correlate well with mechanistic enzymology and nuclear magnetic resonance (NMR) studies that show members of this class of antimicrobials to be specific inhibitors of vitamin B1 function by proton abstraction, which is both novel and likely to limit mutation-based drug resistance.


Subject(s)
Anti-Bacterial Agents/chemical synthesis , Anti-Bacterial Agents/pharmacology , Bacteria, Anaerobic/drug effects , Benzamides/chemical synthesis , Benzamides/pharmacology , Enzyme Inhibitors/pharmacology , Epsilonproteobacteria/drug effects , Ferredoxins/metabolism , Oxidoreductases/antagonists & inhibitors , Pyruvic Acid/metabolism , Thiazoles/chemical synthesis , Thiazoles/pharmacology , Anti-Bacterial Agents/chemistry , Bacteria, Anaerobic/metabolism , Benzamides/chemistry , Campylobacter jejuni/drug effects , Campylobacter jejuni/metabolism , Clostridioides difficile/drug effects , Clostridioides difficile/metabolism , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/chemistry , Epsilonproteobacteria/metabolism , Helicobacter pylori/drug effects , Helicobacter pylori/metabolism , Oxidoreductases/metabolism , Thiazoles/chemistry
14.
Crit Rev Biochem Mol Biol ; 51(3): 185-94, 2016.
Article in English | MEDLINE | ID: mdl-26915423

ABSTRACT

Over the past decade, since epigenetic mechanisms were first implicated in memory formation and synaptic plasticity, dynamic DNA methylation reactions have been identified as integral to long-term memory formation, maintenance, and recall. This review incorporates various new findings that DNA methylation mechanisms are important regulators of non-Hebbian plasticity mechanisms, suggesting that these epigenetic mechanisms are a fundamental link between synaptic plasticity and metaplasticity. Because the field of neuroepigenetics is so young and the biochemical tools necessary to probe gene-specific questions are just now being developed and used, this review also speculates about the direction and potential of therapeutics that target epigenetic mechanisms in the central nervous system and the unique pharmacokinetic and pharmacodynamic properties that epigenetic therapies may possess. Mapping the dynamics of the epigenome in response to experiential learning, even a single epigenetic mark in isolation, remains a significant technical and bioinformatic hurdle facing the field, but will be necessary to identify changes to the methylome that govern memory-associated gene expression and effectively drug the epigenome.


Subject(s)
DNA Methylation , Epigenesis, Genetic , Memory , Animals , DNA Methylation/drug effects , Drug Discovery , Epigenesis, Genetic/drug effects , Genomics , Humans , Memory/drug effects , Neuronal Plasticity/drug effects
15.
Lab Invest ; 95(11): 1319-30, 2015 Nov.
Article in English | MEDLINE | ID: mdl-26237272

ABSTRACT

Barrett's esophagus (BE) is a precursor of esophageal adenocarcinoma (EAC). Both low-grade dysplasia (LGD) and high-grade dysplasia (HGD) are associated with an increased risk of progression to EAC. However, histological interpretation and grading of dysplasia (particularly LGD) is subjective and poorly reproducible. This study has combined whole slide imaging with DNA image cytometry to provide a novel method for the detection of abnormal DNA content through image analysis of tissue sections. A total of 20 cases were evaluated, including 8 negative for dysplasia (NFD), 6 LGD, and 6 HGD. Feulgen-stained esophageal sections were scanned in their entirety. Barrett's mucosa was interactively chosen for automatic nuclei segmentation where irrelevant cell types were ignored. The combined DNA content histogram for all nuclei within selected image regions was then obtained. In addition, three histogram measurements were computed, including xER-5C, 2cDI, and DNA-MG. Visual evaluation suggested the shape of DNA content histograms from NFD, LGD, and HGD cases exhibiting identifiable differences. The histogram measurements, xER-5C, 2cDI, and DNA-MG, were shown to be effective in differentiating metaplastic from dysplastic cases with statistical significance. Moreover, they also successfully separated NFD, LGD, and HGD patients with statistical significance. Whole slide image cytometry is a novel and effective method for the detection of abnormal DNA content in BE. Compared with histological review, it is more objective. Compared with flow cytometry and cytology-preparation image cytometry, it is low cost, simple to use, only requires a single 1 µm section, and facilitates selection of tissue and topographical correlation. Whole slide image cytometry can detect differences in DNA content between NFD, LGD, and HGD patients in this cross-sectional study. Abnormal DNA content detection by whole slide image cytometry is a promising biomarker of progression that could affect future diagnostics in BE.


Subject(s)
Barrett Esophagus/genetics , Barrett Esophagus/pathology , DNA/analysis , Humans , Reproducibility of Results
16.
Autism Res ; 8(5): 629-33, 2015 Oct.
Article in English | MEDLINE | ID: mdl-25728630

ABSTRACT

Pitt-Hopkins syndrome (PTHS) is a neurodevelopmental disorder, classified as an autism spectrum disorder that is caused by the haploinsufficiency of Transcription Factor 4 (TCF4). The most common non-neurological symptoms in PTHS patients are gastrointestinal (GI) disturbances, mainly gastroesophageal reflux and severe constipation (in about 30 and 75% of PTHS patients, respectively). We hypothesized that the recently recognized mouse model of PTHS will exhibit problems with their gut function. We conducted series of in vivo tests on 15- to 19- week old male mice, heterozygous for the TCF4 functional deletion, mimicking the TCF4 haploinsufficiency in PTHS patients, and their wild type littermates. Data collection and initial analysis were performed blindly, that is, the genotyping key was received after the mean values were calculated for each individual animal, and then mean/median of each group was subsequently calculated. Body weight, fecal pellet output, and fluid content were similar between the groups, indicating normal gross growth of PTHS mice and their overall physiological GI motility and intestinal secretion/absorption. There were no significant differences in gut length and gross appearance pointing out that PTHS mice have normal gut in gross anatomical terms. However, the assessment of gut transit indicates that, while whole-gut transit velocity was similar between the groups, the upper GI and distal colon transit velocities were significantly reduced in the PTHS mice. This is the first evidence of specific gut related problems in the PTHS mice. Our study also validates the TCF4 functional knockout mice as an animal model to study PTHS-associated GI disturbances.


Subject(s)
Gastrointestinal Transit/physiology , Hyperventilation/physiopathology , Intellectual Disability/physiopathology , Animals , Disease Models, Animal , Facies , Male , Mice , Mice, Knockout
17.
Annu Rev Pharmacol Toxicol ; 55: 591-611, 2015.
Article in English | MEDLINE | ID: mdl-25340930

ABSTRACT

In this review, we discuss the potential pharmacological targeting of a set of powerful epigenetic mechanisms: DNA methylation control systems in the central nervous system (CNS). Specifically, we focus on the possible use of these targets for novel future treatments for learning and memory disorders. We first describe several unique pharmacological attributes of epigenetic mechanisms, especially DNA cytosine methylation, as potential drug targets. We then present an overview of the existing literature regarding DNA methylation control pathways and enzymes in the nervous system, particularly as related to synaptic function, plasticity, learning and memory. Lastly, we speculate upon potential categories of CNS cognitive disorders that might be amenable to methylomic targeting.


Subject(s)
Central Nervous System Agents/therapeutic use , DNA Methylation/drug effects , Drug Discovery/methods , Epigenesis, Genetic/drug effects , Mental Disorders/drug therapy , Molecular Targeted Therapy/methods , Animals , Cognition/drug effects , DNA Modification Methylases/antagonists & inhibitors , DNA Modification Methylases/chemistry , DNA Modification Methylases/metabolism , Enzyme Inhibitors/therapeutic use , Gene Silencing/drug effects , Humans , Memory/drug effects , Mental Disorders/genetics , Mental Disorders/psychology , Nucleic Acid Conformation , Protein Conformation , Structure-Activity Relationship
18.
Med Res Rev ; 34(1): 45-76, 2014 Jan.
Article in English | MEDLINE | ID: mdl-23239102

ABSTRACT

Natural killer T (NKT) cells serve as a bridge between the innate and adaptive immune systems, and manipulating their effector functions can have therapeutic significances in the treatment of autoimmunity, transplant biology, infectious disease, and cancer. NKT cells are a subset of T cells that express cell-surface markers characteristic of both natural killer cells and T cells. These unique immunologic cells have been demonstrated to serve as a link between the innate and adaptive immune systems through their potent cytokine production following the recognition of a range of lipid antigens, mediated through presentation of the major histocompatibility complex (MHC) class I like CD1d molecule, in addition to the NKT cell's cytotoxic capabilities upon activation. Although a number of glycolipid antigens have been shown to complex with CD1d molecules, most notably the marine sponge derived glycolipid alpha-galactosylceramide (α-GalCer), there has been debate as to the identity of the endogenous activating lipid presented to the T-cell receptor (TCR) via the CD1d molecule on antigen-presenting cells (APCs). This review aims to survey the use of pharmacological agents and subsequent structure-activity relationships (SAR) that have given insight into the binding interaction of glycolipids with both the CD1d molecules as well as the TCR and the subsequent immunologic response of NKT cells. These studies not only elucidate basic binding interactions but also pave the way for future pharmacological modulation of NKT cell responses.


Subject(s)
Killer Cells, Natural/drug effects , Th1 Cells/drug effects , Th2 Cells/drug effects , Animals , Carbohydrate Sequence , Galactosylceramides/chemistry , Galactosylceramides/pharmacology , Glycolipids/immunology , Humans , Killer Cells, Natural/immunology , Molecular Sequence Data , Structure-Activity Relationship , Th1 Cells/immunology , Th2 Cells/immunology
19.
Histopathology ; 62(5): 752-63, 2013 Apr.
Article in English | MEDLINE | ID: mdl-23530586

ABSTRACT

AIMS: Involved circumferential resection margin (CRM) (R1) in oesophageal carcinoma (OC) has conflicting definitions. This study aimed to compare two such definitions applied to a cohort of OC resection specimens and also evaluated a novel three-tier CRM stratification. METHODS AND RESULTS: OC patients with pT3 disease were classified as R0 or R1 on the basis of Royal College of Pathologists (UK) (RCPath) and College of American Pathologists (CAP) criteria and group survivals were compared. Patients were then stratified into three groups on the basis of tumour distance from the CRM (>1 mm, 0.1-1 mm, 0 mm). A total of 195 patients were included. According to RCPath criteria, 50 resections were R0 and 145 R1; median survival was 72.0 and 18.1 months. Using CAP criteria, 137 resections were R0 and 58 R1; median survival was 30.1 and 12.6 months. Using three-tier stratification, tumour was clear by >1 mm (R0) in 50 cases, 0.1-1 mm from CRM (RCPath R1; CAP R0) in 87 cases and 0 mm (R1) in 58 cases; median survival was 72.0, 24.6 and 12.6 months, respectively. Survival difference was statistically significant using each binary system and also the three-tier system. CONCLUSIONS: Both RCPath and CAP criteria to define CRM have similar prognostic value. A novel three-tier classification of CRM status provides more detailed prognostication.


Subject(s)
Adenocarcinoma/secondary , Carcinoma, Squamous Cell/secondary , Esophageal Neoplasms/pathology , Adenocarcinoma/mortality , Adenocarcinoma/surgery , Aged , Carcinoma, Squamous Cell/mortality , Carcinoma, Squamous Cell/surgery , Cohort Studies , Esophageal Neoplasms/mortality , Esophageal Neoplasms/surgery , Female , Humans , Lymph Nodes/pathology , Lymphatic Metastasis , Male , Middle Aged , Neoplasm Invasiveness , Prognosis , Survival Rate , United Kingdom/epidemiology
20.
J Med Chem ; 54(10): 3524-48, 2011 May 26.
Article in English | MEDLINE | ID: mdl-21495716

ABSTRACT

Sphingosine 1-phosphate (S1P) is a bioactive lipid that has been identified as an accelerant of cancer progression. The sphingosine kinases (SphKs) are the sole producers of S1P, and thus, SphK inhibitors may prove effective in cancer mitigation and chemosensitization. Of the two SphKs, SphK1 overexpression has been observed in a myriad of cancer cell lines and tissues and has been recognized as the presumptive target over that of the poorly characterized SphK2. Herein, we present the design and synthesis of amidine-based nanomolar SphK1 subtype-selective inhibitors. A homology model of SphK1, trained with this library of amidine inhibitors, was then used to predict the activity of additional, more potent, inhibitors. Lastly, select amidine inhibitors were validated in human leukemia U937 cells, where they significantly reduced endogenous S1P levels at nanomolar concentrations.


Subject(s)
Amidines/chemistry , Antineoplastic Agents/pharmacology , Gene Expression Regulation, Leukemic , Leukemia/drug therapy , Lysophospholipids/antagonists & inhibitors , Phosphotransferases (Alcohol Group Acceptor)/antagonists & inhibitors , Sphingosine/analogs & derivatives , Cell Line, Tumor , Chemistry, Pharmaceutical/methods , Drug Design , Enzyme Inhibitors/pharmacology , Humans , Kinetics , Models, Chemical , Models, Molecular , Sphingosine/antagonists & inhibitors , U937 Cells
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