Your browser doesn't support javascript.
loading
: 20 | 50 | 100
1 - 20 de 39
1.
EMBO J ; 43(6): 956-992, 2024 Mar.
Article En | MEDLINE | ID: mdl-38360995

While most glial cell types in the central nervous system (CNS) arise from neuroectodermal progenitors, some, like microglia, are mesodermally derived. To understand mesodermal glia development and function, we investigated C. elegans GLR glia, which envelop the brain neuropil and separate it from the circulatory system cavity. Transcriptome analysis shows that GLR glia combine astrocytic and endothelial characteristics, which are relegated to separate cell types in vertebrates. Combined fate acquisition is orchestrated by LET-381/FoxF, a fate-specification/maintenance transcription factor also expressed in glia and endothelia of other animals. Among LET-381/FoxF targets, the UNC-30/Pitx2 transcription factor controls GLR glia morphology and represses alternative mesodermal fates. LET-381 and UNC-30 co-expression in naive cells is sufficient for GLR glia gene expression. GLR glia inactivation by ablation or let-381 mutation disrupts locomotory behavior and promotes salt-induced paralysis, suggesting brain-neuropil activity dysregulation. Our studies uncover mechanisms of mesodermal glia development and show that like neuronal differentiation, glia differentiation requires autoregulatory terminal selector genes that define and maintain the glial fate.


Caenorhabditis elegans Proteins , Caenorhabditis elegans , Forkhead Transcription Factors , Homeodomain Proteins , Animals , Caenorhabditis elegans/metabolism , Caenorhabditis elegans Proteins/genetics , Caenorhabditis elegans Proteins/metabolism , Gene Expression Regulation , Neuroglia/metabolism , Transcription Factors/genetics , Transcription Factors/metabolism , Forkhead Transcription Factors/metabolism , Homeodomain Proteins/metabolism
2.
bioRxiv ; 2023 Oct 24.
Article En | MEDLINE | ID: mdl-37961181

While most CNS glia arise from neuroectodermal progenitors, some, like microglia, are mesodermally derived. To understand mesodermal glia development and function, we investigated C. elegans GLR glia, which ensheath the brain neuropil and separate it from the circulatory-system cavity. Transcriptome analysis suggests GLR glia merge astrocytic and endothelial characteristics relegated to separate cell types in vertebrates. Combined fate acquisition is orchestrated by LET-381/FoxF, a fate-specification/maintenance transcription factor expressed in glia and endothelia of other animals. Among LET-381/FoxF targets, UNC-30/Pitx2 transcription factor controls GLR glia morphology and represses alternative mesodermal fates. LET-381 and UNC-30 co-expression in naïve cells is sufficient for GLR glia gene expression. GLR glia inactivation by ablation or let-381 mutation disrupts locomotory behavior and induces salt hypersensitivity, suggesting brain-neuropil activity dysregulation. Our studies uncover mechanisms of mesodermal glia development and show that like neurons, glia differentiation requires autoregulatory terminal selector genes that define and maintain the glial fate.

3.
bioRxiv ; 2023 Nov 17.
Article En | MEDLINE | ID: mdl-38014226

Neurons have elaborate structures that determine their connectivity and functions. Changes in neuronal structure accompany learning and memory formation and are hallmarks of neurological disease. Here we show that glia monitor dendrite structure and respond to dendrite perturbation. In C. elegans mutants with defective sensory-organ dendrite cilia, adjacent glia accumulate extracellular matrix-laden vesicles, secrete excess matrix around cilia, alter gene expression, and change their secreted protein repertoire. Inducible cilia disruption reveals that this response is acute. DGS-1, a 7-transmembrane domain neuronal protein, and FIG-1, a multifunctional thrombospondin-domain glial protein, are required for glial detection of cilia integrity, and exhibit mutually-dependent localization to and around cilia, respectively. While inhibiting glial secretion disrupts dendritic cilia properties, hyperactivating the glial response protects against dendrite damage. Our studies uncover a homeostatic protective dendrite-glia interaction and suggest that similar signaling occurs at other sensory structures and at synapses, which resemble sensory organs in architecture and molecules.

4.
OMICS ; 26(12): 660-670, 2022 12.
Article En | MEDLINE | ID: mdl-36454164

Obesity has reached epidemic proportions in the United States, but little is known about the mechanisms of weight gain and weight loss. Integration of omics data is becoming a popular tool to increase understanding in such complex phenotypes. Biomarkers come in abundance, but small sample size remains a serious limitation in clinical trials. In the present study, we developed a strategy to screen predictors from a multiomics, high-dimensional, and longitudinal dataset from a small cohort of 10 women with obesity who were provided an identical very-low calorie diet. Our proposal explores the combinatorial space of potential predictors from transcriptomics, microbiome, metabolome, fecal bile acids, and clinical data with the application of the first-order Spearman partial correlation coefficient. Two statistics are proposed for screening predictors, the partial association score, and the persistent significance. We applied our strategy to predict rates of weight loss in our sample of participants in a hospital metabolic facility. Our method reduced an initial set of 42,000 biomarker candidates to 61 robust predictors. The results show baseline fecal bile acids and regulation in RT-polymerase chain reaction as the most predictive data sources in forecasting the rate of weight-loss. In summary, the present study proposes a strategy based on nonparametric statistics for ranking and screening predictors of weight loss from a multiomics study. The proposed biomarker screening strategy warrants further translational clinical investigation in obesity and other complex clinical phenotypes.


Multiomics , Weight Loss , Female , Humans , Obesity/genetics , Feces , Bile Acids and Salts
5.
Cell Rep ; 40(11): 111321, 2022 09 13.
Article En | MEDLINE | ID: mdl-36103835

Advanced non-alcoholic fatty liver disease (NAFLD) is a rapidly emerging global health problem associated with pre-disposing genetic polymorphisms, most strikingly an isoleucine to methionine substitution in patatin-like phospholipase domain-containing protein 3 (PNPLA3-I148M). Here, we study how human hepatocytes with PNPLA3 148I and 148M variants engrafted in the livers of broadly immunodeficient chimeric mice respond to hypercaloric diets. As early as four weeks, mice developed dyslipidemia, impaired glucose tolerance, and steatosis with ballooning degeneration selectively in the human graft, followed by pericellular fibrosis after eight weeks of hypercaloric feeding. Hepatocytes with the PNPLA3-148M variant, either from a homozygous 148M donor or overexpressed in a 148I donor background, developed microvesicular and severe steatosis with frequent ballooning degeneration, resulting in more active steatohepatitis than 148I hepatocytes. We conclude that PNPLA3-148M in human hepatocytes exacerbates NAFLD. These models will facilitate mechanistic studies into human genetic variant contributions to advanced fatty liver diseases.


Non-alcoholic Fatty Liver Disease , Acyltransferases , Animals , Hepatocytes/metabolism , Humans , Lipase/genetics , Lipase/metabolism , Membrane Proteins/genetics , Membrane Proteins/metabolism , Mice , Non-alcoholic Fatty Liver Disease/genetics , Phospholipases A2, Calcium-Independent
6.
Nat Commun ; 13(1): 3101, 2022 06 03.
Article En | MEDLINE | ID: mdl-35661736

The mechanisms by which commensal organisms affect human physiology remain poorly understood. Lectins are non-enzymatic carbohydrate binding proteins that all organisms employ as part of establishing a niche, evading host-defenses and protecting against pathogens. Although lectins have been extensively studied in plants, bacterial pathogens and human immune cells for their role in disease pathophysiology and as therapeutics, the role of bacterial lectins in the human microbiome is largely unexplored. Here we report on the characterization of a lectin produced by a common human associated bacterium that interacts with myeloid cells in the blood and intestine. In mouse and cell-based models, we demonstrate that this lectin induces distinct immunologic responses in peripheral and intestinal leukocytes and that these responses are specific to monocytes, macrophages and dendritic cells. Our analysis of human microbiota sequencing data reveal thousands of unique sequences that are predicted to encode lectins, many of which are highly prevalent in the human microbiome yet completely uncharacterized. Based on the varied domain architectures of these lectins we predict they will have diverse effects on the human host. The systematic investigation of lectins in the human microbiome should improve our understanding of human health and provide new therapeutic opportunities.


Lectins , Microbiota , Animals , Bacteria/metabolism , Humans , Lectins/metabolism , Mice , Plants/metabolism
7.
PLoS One ; 17(1): e0261775, 2022.
Article En | MEDLINE | ID: mdl-35051209

HIV pre-exposure prophylaxis (PrEP) is dominated by clinical therapeutic antiretroviral (ARV) drugs. Griffithsin (GRFT) is a non-ARV lectin with potent anti-HIV activity. GRFT's preclinical safety, lack of systemic absorption after vaginal administration in animal studies, and lack of cross-resistance with existing ARV drugs prompted its development for topical HIV PrEP. We investigated safety, pharmacokinetics (PK), pharmacodynamics (PD), and immunogenicity of PC-6500 (0.1% GRFT in a carrageenan (CG) gel) in healthy women after vaginal administration. This randomized, placebo-controlled, parallel group, double-blind first-in-human phase 1 study enrolled healthy, HIV-negative, non-pregnant women aged 24-45 years. In the open label period, all participants (n = 7) received single dose of PC-6500. In the randomized period, participants (n = 13) were instructed to self-administer 14 doses of PC-6500 or its matching CG placebo (PC-535) once daily for 14 days. The primary outcomes were safety and PK after single dose, and then after 14 days of dosing. Exploratory outcomes were GRFT concentrations in cervicovaginal fluids, PD, inflammatory mediators and gene expression in ectocervical biopsies. This trial is registered with ClinicalTrials.gov, number NCT02875119. No significant adverse events were recorded in clinical or laboratory results or histopathological evaluations in cervicovaginal mucosa, and no anti-drug (GRFT) antibodies were detected in serum. No cervicovaginal proinflammatory responses and no changes in the ectocervical transcriptome were evident. Decreased levels of proinflammatory chemokines (CXCL8, CCL5 and CCL20) were observed. GRFT was not detected in plasma. GRFT and GRFT/CG in cervicovaginal lavage samples inhibited HIV and HPV, respectively, in vitro in a dose-dependent fashion. These data suggest GRFT formulated in a CG gel is a safe and promising on-demand multipurpose prevention technology product that warrants further investigation.


Carrageenan/administration & dosage , HIV Infections/prevention & control , Papillomavirus Infections/prevention & control , Plant Lectins/administration & dosage , Pre-Exposure Prophylaxis , Vaginal Creams, Foams, and Jellies/administration & dosage , Administration, Intravaginal , Adolescent , Adult , Double-Blind Method , Female , HIV-1 , Humans , Middle Aged , Papillomaviridae
8.
Cell Rep ; 37(13): 110166, 2021 12 28.
Article En | MEDLINE | ID: mdl-34965433

Animals encounter microorganisms in their habitats, adapting physiology and behavior accordingly. The nematode Caenorhabditis elegans is found in microbe-rich environments; however, its responses to fungi are not extensively studied. Here, we describe interactions of C. elegans and Penicillium brevicompactum, an ecologically relevant mold. Transcriptome studies reveal that co-culture upregulates stress response genes, including xenobiotic-metabolizing enzymes (XMEs), in C. elegans intestine and AMsh glial cells. The nuclear hormone receptors (NHRs) NHR-45 and NHR-156 are induction regulators, and mutants that cannot induce XMEs in the intestine when exposed to P. brevicompactum experience mitochondrial stress and exhibit developmental defects. Different C. elegans wild isolates harbor sequence polymorphisms in nhr-156, resulting in phenotypic diversity in AMsh glia responses to microbe exposure. We propose that P. brevicompactum mitochondria-targeting mycotoxins are deactivated by intestinal detoxification, allowing tolerance to moldy environments. Our studies support the idea that C. elegans NHRs may be regulated by environmental cues.


Caenorhabditis elegans Proteins/metabolism , Caenorhabditis elegans/drug effects , Gastrointestinal Tract/enzymology , Mitochondria/enzymology , Neuroglia/enzymology , Penicillium/physiology , Receptors, Cytoplasmic and Nuclear/metabolism , Animals , Caenorhabditis elegans/enzymology , Caenorhabditis elegans/microbiology , Caenorhabditis elegans Proteins/genetics , Enzyme Induction , Gastrointestinal Tract/drug effects , Gastrointestinal Tract/microbiology , Gene Expression Regulation, Developmental , Mitochondria/drug effects , Mitochondria/microbiology , Neuroglia/drug effects , Neuroglia/microbiology
9.
Neurosci Lett ; 760: 136092, 2021 08 24.
Article En | MEDLINE | ID: mdl-34197905

Though it is well known that G protein-coupled receptor kinase 2 [GRK2] is involved in regulation of mu opioid receptor [MOR] desensitization and morphine-related behaviors, the potential role of GRK2 in regulation of kappa opioid receptor [KOR] functions in vivo has not been established yet. A couple of recent studies have found that GRK2 activity desensitizes KOR functions via decreasing G protein-coupled signaling with sensitizing arrestin-coupled signaling. Nalfurafine, a G protein-biased KOR full agonist, produces an inhibitory effect on alcohol intake in mice, with fewer side effects (sedation, aversion, or anxiety/depression-like behaviors). Using RNA sequencing (RNA-seq) analysis, we first identified that nuclear transcript level of grk2 [adrbk1] (but not other grks) was significantly up-regulated in mouse nucleus accumbens shell (NAcs) after chronic excessive alcohol drinking, suggesting alcohol specifically increased NAcs grk2 expression. We then tested whether selective GRK2/3 inhibitor CMPD101 could alter alcohol intake and found that CMPD101 alone had no effect on alcohol drinking. Therefore, we hypothesized that the grk2 increase in the NAcs could modulate the nalfurafine effect on alcohol intake via interacting with the G protein-mediated KOR signaling. Nalfurafine decreased alcohol drinking in a dose-related manner, and pretreatment with CMPD101 enhanced the reduction in alcohol intake induced by nalfurafine, indicating an involvement of GRK2/3 blockade in modulating G protein-biased KOR agonism of nalfurafine. Together, our study provides initial evidence relevant to the transcriptional change of grk2 gene in the NAc shell after excessive alcohol drinking. Pharmacological GRK2/3 blockade enhanced nalfurafine's efficacy, suggesting a GRK2/3-mediated mechanism, probably through the G protein-mediated KOR signaling.


Alcoholism/drug therapy , G-Protein-Coupled Receptor Kinase 2/metabolism , Morphinans/pharmacology , Nucleus Accumbens/drug effects , Receptors, Opioid, kappa/agonists , Spiro Compounds/pharmacology , Animals , Benzamides/pharmacology , Benzamides/therapeutic use , Disease Models, Animal , Drug Synergism , Drug Therapy, Combination , Ethanol/administration & dosage , Ethanol/adverse effects , G-Protein-Coupled Receptor Kinase 2/antagonists & inhibitors , G-Protein-Coupled Receptor Kinase 3/antagonists & inhibitors , G-Protein-Coupled Receptor Kinase 3/metabolism , Humans , Male , Mice , Morphinans/therapeutic use , Nucleus Accumbens/metabolism , Pyridines/pharmacology , Pyridines/therapeutic use , Receptors, Opioid, kappa/metabolism , Spiro Compounds/therapeutic use , Triazoles/pharmacology , Triazoles/therapeutic use
10.
Pharmacol Biochem Behav ; 195: 172954, 2020 08.
Article En | MEDLINE | ID: mdl-32470351

KOP-r agonist U50,488H produces strong aversion and anxiety/depression-like behaviors that enhance alcohol intake and promote alcohol seeking and relapse-like drinking in rodents. Mammalian target of rapamycin complex 1 (mTORC1) pathway in mouse striatum is highly involved in excessive alcohol intake and seeking, and in the U50,488H-induced conditioned place aversion. Therefore, we hypothesized that KOP-r activation increases alcohol consumption through the mTORC1 activation. This study focuses on: (1) how chronic excessive alcohol drinking (4-day drinking-in-the-dark paradigm followed by 3-week chronic intermittent access drinking paradigm [two-bottle choice, 24-h access every other day]) affected nuclear transcript levels of the mTORC1 pathway genes in mouse nucleus accumbens shell (NAcs), using transcriptome-wide RNA sequencing analysis; and (2) whether selective mTORC1 inhibitor rapamycin could alter excessive alcohol drinking and prevent U50,488H-promoted alcohol intake. Thirteen nuclear transcripts of mTORC1 pathway genes showed significant up-regulation in the NAcs, with two genes down-regulated, after excessive alcohol drinking, suggesting the mTORC1 pathway was profoundly disrupted. Single administration of rapamycin decreased alcohol drinking in a dose-dependent manner. U50,488H increased alcohol drinking, and pretreatment with rapamycin, at a dose lower than effective doses, blocked the U50,488H-promoted alcohol intake in a dose-dependent manner, indicating a mTORC1-mediated mechanism. Our results provide supportive and direct evidence relevant to the transcriptional profiling of the critical mTORC1 genes in mouse NAc shell: with functional and pharmacological effects of rapamycin, altered nuclear transcripts in the mTORC1 signaling pathway after excessive alcohol drinking may contribute to increased alcohol intake triggered by KOP-r activation.


Binge Drinking/metabolism , Mechanistic Target of Rapamycin Complex 1/metabolism , Receptors, Opioid, kappa/metabolism , 3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer/administration & dosage , Animals , Binge Drinking/drug therapy , Binge Drinking/prevention & control , Central Nervous System Depressants/administration & dosage , Disease Models, Animal , Ethanol/administration & dosage , Gene Expression/drug effects , Male , Mechanistic Target of Rapamycin Complex 1/genetics , Mice , Mice, Inbred C57BL , Nucleus Accumbens/drug effects , Nucleus Accumbens/metabolism , Receptors, Opioid, kappa/agonists , Signal Transduction/drug effects , Sirolimus/administration & dosage , Transcriptome
11.
Cancer Cell ; 37(4): 584-598.e11, 2020 04 13.
Article En | MEDLINE | ID: mdl-32220301

Metastatic prostate cancer is characterized by recurrent genomic copy number alterations that are presumed to contribute to resistance to hormone therapy. We identified CHD1 loss as a cause of antiandrogen resistance in an in vivo small hairpin RNA (shRNA) screen of 730 genes deleted in prostate cancer. ATAC-seq and RNA-seq analyses showed that CHD1 loss resulted in global changes in open and closed chromatin with associated transcriptomic changes. Integrative analysis of this data, together with CRISPR-based functional screening, identified four transcription factors (NR3C1, POU3F2, NR2F1, and TBX2) that contribute to antiandrogen resistance, with associated activation of non-luminal lineage programs. Thus, CHD1 loss results in chromatin dysregulation, thereby establishing a state of transcriptional plasticity that enables the emergence of antiandrogen resistance through heterogeneous mechanisms.


Androgen Antagonists/pharmacology , Chromatin/genetics , DNA Helicases/antagonists & inhibitors , DNA-Binding Proteins/antagonists & inhibitors , Drug Resistance, Neoplasm/genetics , Prostatic Neoplasms, Castration-Resistant/drug therapy , RNA, Small Interfering/genetics , Receptors, Androgen/chemistry , Animals , Apoptosis , Biomarkers, Tumor/genetics , Cell Proliferation , Chromatin/metabolism , DNA Helicases/genetics , DNA-Binding Proteins/genetics , DNA-Binding Proteins/metabolism , Gene Expression Regulation, Neoplastic , High-Throughput Screening Assays , Humans , Male , Mice , Prostatic Neoplasms, Castration-Resistant/genetics , Prostatic Neoplasms, Castration-Resistant/pathology , Receptors, Androgen/genetics , Transcription Factors/metabolism , Tumor Cells, Cultured , Xenograft Model Antitumor Assays
12.
Res Pract Thromb Haemost ; 4(1): 92-99, 2020 Jan.
Article En | MEDLINE | ID: mdl-31989089

BACKGROUND: Bleeding assessment is part of the diagnostic workup of von Willebrand disease (VWD). Bleeding assessment tools (BATs) have standardized obtaining this information but have been criticized because they are time consuming. OBJECTIVE: To use our legacy data to determine which questions from BATs are the strongest predictors of a VWD diagnosis. PATIENTS/METHODS: Bleeding score data from 3 different BATs were used. Patients aged <12 years were excluded. Questions on BATs relate to different bleeding symptoms, and each symptom is scored by severity. Scores for each symptom were sorted based on whether they indicated clinically significant bleeding, and nonsignificant scores were set as the reference category. Multivariable logistic regression was used to determine the symptoms that were the strongest predictors of a laboratory-confirmed VWD diagnosis. RESULTS: A total of 927 participants were included; 144 (16%) were patients with VWD, and 783 (84%) were healthy controls. The top 3 symptoms for which a clinically significant positive response increased the likelihood of VWD were hemarthrosis (odds ratio [OR], 19.2; 95% confidence interval [CI], 3.7-100.4), postsurgical bleeding (OR, 15.2; 95% CI, 5.9-38.9), and menorrhagia (OR, 10.3; 95% CI, 4.9-21.9). With each increase in number of bleeding symptom categories with clinically significant scores, subjects had a stepwise increase in odds of a VWD diagnosis. CONCLUSIONS: Our results suggest that most of the bleeding symptoms on BATs are significant predictors of VWD, and there is value in assessing multiple bleeding symptoms when eliciting a bleeding history. Certain bleeding symptoms are more useful predictors than others. Future BAT revisions may consider adding a relative weighting to each symptom.

13.
Genes Brain Behav ; 18(8): e12600, 2019 11.
Article En | MEDLINE | ID: mdl-31339663

Persistent alterations of proopiomelanocortin (Pomc) and mu-opioid receptor (Oprm1) activity and stress responses after alcohol are critically involved in vulnerability to alcohol dependency. Gene transcriptional regulation altered by alcohol may play important roles. Mice with genome-wide deletion of neuronal Pomc enhancer1 (nPE1-/- ), had hypothalamic-specific partial reductions of beta-endorphin and displayed lower alcohol consumption, compared to wildtype littermates (nPE1+/+ ). We used RNA-Seq to measure steady-state nuclear mRNA transcripts of opioid and stress genes in hypothalamus of nPE1+/+ and nPE1-/- mice after 1-day acute withdrawal from chronic excessive alcohol drinking or after water. nPE1-/- had lower basal Pomc and Pdyn (prodynorphin) levels compared to nPE1+/+ , coupled with increased basal Oprm1 and Oprk1 (kappa-opioid receptor) levels, and low alcohol drinking increased Pomc and Pdyn to the basal levels of nPE1+/+ in the water group, without significant effects on Oprm1 and Oprk1. In nPE1+/+ , excessive alcohol intake increased Pomc and Oprm1, with no effect on Pdyn or Oprk1. For stress genes, nPE1-/- had lowered basal Oxt (oxytocin) and Avp (arginine vasopressin) that were restored by low alcohol intake to basal levels of nPE1+/+ . In nPE1+/+ , excessive alcohol intake decreased Oxt and Avpi1 (AVP-induced protein1). Functionally examining the effect of pharmacological blockade of mu-opioid receptor, we found that naltrexone reduced excessive alcohol intake in nPE1+/+ , but not nPE1-/- . Our results provide evidence relevant to the transcriptional profiling of the critical genes in mouse hypothalamus: enhanced opioid and reduced stress gene transcripts after acute withdrawal from excessive alcohol may contribute to altered reward and stress responses.


Binge Drinking/genetics , Enhancer Elements, Genetic/genetics , Hypothalamus/metabolism , Pro-Opiomelanocortin/genetics , Animals , Arginine Vasopressin/metabolism , Binge Drinking/metabolism , Enkephalins/genetics , Enkephalins/metabolism , Ethanol/pharmacology , Hypothalamus/drug effects , Male , Mice , Mice, Inbred C57BL , Oxytocin/metabolism , Pro-Opiomelanocortin/metabolism , Protein Precursors/genetics , Protein Precursors/metabolism , Receptors, Opioid, mu/genetics , Receptors, Opioid, mu/metabolism , Transcriptome
14.
Nat Commun ; 10(1): 1882, 2019 04 23.
Article En | MEDLINE | ID: mdl-31015396

Glutamate is a major excitatory neurotransmitter, and impaired glutamate clearance following synaptic release promotes spillover, inducing extra-synaptic signaling. The effects of glutamate spillover on animal behavior and its neural correlates are poorly understood. We developed a glutamate spillover model in Caenorhabditis elegans by inactivating the conserved glial glutamate transporter GLT-1. GLT-1 loss drives aberrant repetitive locomotory reversal behavior through uncontrolled oscillatory release of glutamate onto AVA, a major interneuron governing reversals. Repetitive glutamate release and reversal behavior require the glutamate receptor MGL-2/mGluR5, expressed in RIM and other interneurons presynaptic to AVA. mgl-2 loss blocks oscillations and repetitive behavior; while RIM activation is sufficient to induce repetitive reversals in glt-1 mutants. Repetitive AVA firing and reversals require EGL-30/Gαq, an mGluR5 effector. Our studies reveal that cyclic autocrine presynaptic activation drives repetitive reversals following glutamate spillover. That mammalian GLT1 and mGluR5 are implicated in pathological motor repetition suggests a common mechanism controlling repetitive behaviors.


Behavior, Animal/physiology , Caenorhabditis elegans Proteins/metabolism , Caenorhabditis elegans/physiology , Glutamic Acid/metabolism , Presynaptic Terminals/physiology , Receptors, Metabotropic Glutamate/metabolism , Animals , Animals, Genetically Modified , Datasets as Topic , Excitatory Amino Acid Transporter 2/metabolism , Gene Expression Profiling , Interneurons/metabolism , Locomotion/physiology , Models, Animal , Receptor, Metabotropic Glutamate 5 , Receptors, Metabotropic Glutamate/genetics
15.
J Clin Transl Res ; 4(2): 122-135, 2019 Jan 10.
Article En | MEDLINE | ID: mdl-30873501

BACKGROUND AND AIM: The metabolic syndrome (MetS) is a pathological condition comprised of abdominal obesity, insulin resistance, hypertension, and hyperlipidemia. It has become a major threat globally, resulting in rapidly increasing rates of diabetes, coronary heart disease, and stroke. The polyphenol resveratrol (RES) is believed to improve glucose homeostasis and insulin resistance by activating sirtuin, which acetylates and coactivates downstream targets and affects glucose and lipid homeostasis in the liver, insulin secretion in the pancreas, and glucose uptake in skeletal muscle. We studied the effects of RES on insulin resistance, glucose homeostasis, and concomitant effects on adipose tissue metabolism and fecal microbiota in insulin-resistant subjects with the MetS. METHODS: A total of 28 obese men with the MetS were studied during a 35-day stay in the Rockefeller University Hospital metabolic unit. Subjects were randomized to receive RES 1 g orally twice daily or placebo while kept weight stable and consuming a western-style diet. At baseline, and after 30 days of RES or placebo administration, subjects underwent testing that included a euglycemic, hyperinsulinemic clamp, 2-h oral glucose tolerance test (GTT), resting energy expenditure, daily blood pressure monitoring, abdominal adipose tissue biopsy, and fecal and blood collections. RESULTS: RES induced no changes in insulin resistance but reduced the 120-min time point and the area under the curve for glucose concentration in the 2-h GTT. In post-hoc analysis, Caucasian subjects showed a significant improvement in insulin sensitivity and glucose homeostasis after GTT, whereas non-Caucasians showed no similar effects. Levels of fasting plasma RES and its primary metabolite dihydroresveratrol were variable and did not explain the racial differences in glucose homeostasis. RES administration to Caucasian subjects leads to an increase in several taxa including Akkermansia muciniphila. CONCLUSIONS: RES 2 g administered orally to obese men with MetS and insulin resistance marginally altered glucose homeostasis. However, in a small group of Caucasians, insulin resistance and glucose homeostasis improved. No concomitant changes in adipose tissue metabolism occurred, but fecal microbiota showed RES-induced changes. RELEVANCE FOR PATIENTS: The MetS increases the risk of diabetes, heart disease, and stroke. A major component of the syndrome is insulin resistance, resulting in systemic inflammation and hyperinsulinemia. The primary treatment consists of lifestyle changes, improved diet, and increased physical activity. This is often unsuccessful. In this study, RES was well tolerated. In Caucasian men, it significantly improved insulin sensitivity and glucose homeostasis. Similar results were found in studies that consisted exclusively of Caucasian men. However, RES presents a novel addition to the current treatment of the MetS and its sequelae.

16.
Proc Natl Acad Sci U S A ; 116(16): 7957-7962, 2019 04 16.
Article En | MEDLINE | ID: mdl-30923116

Diffuse intrinsic pontine glioma (DIPG) remains an incurable childhood brain tumor for which novel therapeutic approaches are desperately needed. Previous studies have shown that the menin inhibitor MI-2 exhibits promising activity in preclinical DIPG and adult glioma models, although the mechanism underlying this activity is unknown. Here, using an integrated approach, we show that MI-2 exerts its antitumor activity in glioma largely independent of its ability to target menin. Instead, we demonstrate that MI-2 activity in glioma is mediated by disruption of cholesterol homeostasis, with suppression of cholesterol synthesis and generation of the endogenous liver X receptor ligand, 24,25-epoxycholesterol, resulting in cholesterol depletion and cell death. Notably, this mechanism is responsible for MI-2 activity in both DIPG and adult glioma cells. Metabolomic and biochemical analyses identify lanosterol synthase as the direct molecular target of MI-2, revealing this metabolic enzyme as a vulnerability in glioma and further implicating cholesterol homeostasis as an attractive pathway to target in this malignancy.


Antineoplastic Agents/pharmacology , Brain Stem Neoplasms , Glioma , Intramolecular Transferases/metabolism , Proto-Oncogene Proteins/antagonists & inhibitors , Brain Stem Neoplasms/enzymology , Brain Stem Neoplasms/metabolism , Cholesterol/metabolism , Glioma/enzymology , Glioma/metabolism , Humans , Metabolic Networks and Pathways/drug effects , Proto-Oncogene Proteins/metabolism
17.
J Clin Invest ; 129(2): 583-597, 2019 02 01.
Article En | MEDLINE | ID: mdl-30422821

X-linked dominant incontinentia pigmenti (IP) and X-linked recessive anhidrotic ectodermal dysplasia with immunodeficiency (EDA-ID) are caused by loss-of-function and hypomorphic IKBKG (also known as NEMO) mutations, respectively. We describe a European mother with mild IP and a Japanese mother without IP, whose 3 boys with EDA-ID died from ID. We identify the same private variant in an intron of IKBKG, IVS4+866 C>T, which was inherited from and occurred de novo in the European mother and Japanese mother, respectively. This mutation creates a new splicing donor site, giving rise to a 44-nucleotide pseudoexon (PE) generating a frameshift. Its leakiness accounts for NF-κB activation being impaired but not abolished in the boys' cells. However, aberrant splicing rates differ between cell types, with WT NEMO mRNA and protein levels ranging from barely detectable in leukocytes to residual amounts in induced pluripotent stem cell-derived (iPSC-derived) macrophages, and higher levels in fibroblasts and iPSC-derived neuronal precursor cells. Finally, SRSF6 binds to the PE, facilitating its inclusion. Moreover, SRSF6 knockdown or CLK inhibition restores WT NEMO expression and function in mutant cells. A recurrent deep intronic splicing mutation in IKBKG underlies a purely quantitative NEMO defect in males that is most severe in leukocytes and can be rescued by the inhibition of SRSF6 or CLK.


Ectodermal Dysplasia , Frameshift Mutation , I-kappa B Kinase , Incontinentia Pigmenti , Introns , Ectodermal Dysplasia/genetics , Ectodermal Dysplasia/metabolism , Ectodermal Dysplasia/pathology , Female , Fibroblasts/metabolism , Fibroblasts/pathology , Humans , I-kappa B Kinase/deficiency , I-kappa B Kinase/metabolism , Immunologic Deficiency Syndromes/genetics , Immunologic Deficiency Syndromes/metabolism , Immunologic Deficiency Syndromes/pathology , Incontinentia Pigmenti/genetics , Incontinentia Pigmenti/metabolism , Incontinentia Pigmenti/pathology , Macrophages/metabolism , Macrophages/pathology , Male
18.
J Transl Med ; 16(1): 244, 2018 09 03.
Article En | MEDLINE | ID: mdl-30176893

BACKGROUND: Microbiota and bile acids in the gastrointestinal tract profoundly alter systemic metabolic processes. In obese subjects, gradual weight loss ameliorates adipose tissue inflammation and related systemic changes. We assessed how rapid weight loss due to a very low calorie diet (VLCD) affects the fecal microbiome and fecal bile acid composition, and their interactions with the plasma metabolome and subcutaneous adipose tissue inflammation in obesity. METHODS: We performed a prospective cohort study of VLCD-induced weight loss of 10% in ten grades 2-3 obese postmenopausal women in a metabolic unit. Baseline and post weight loss evaluation included fasting plasma analyzed by mass spectrometry, adipose tissue transcription by RNA sequencing, stool 16S rRNA sequencing for fecal microbiota, fecal bile acids by mass spectrometry, and urinary metabolic phenotyping by 1H-NMR spectroscopy. Outcome measures included mixed model correlations between changes in fecal microbiota and bile acid composition with changes in plasma metabolite and adipose tissue gene expression pathways. RESULTS: Alterations in the urinary metabolic phenotype following VLCD-induced weight loss were consistent with starvation ketosis, protein sparing, and disruptions to the functional status of the gut microbiota. We show that the core microbiome was preserved during VLCD-induced weight loss, but with changes in several groups of bacterial taxa with functional implications. UniFrac analysis showed overall parallel shifts in community structure, corresponding to reduced abundance of the genus Roseburia and increased Christensenellaceae;g__ (unknown genus). Imputed microbial functions showed changes in fat and carbohydrate metabolism. A significant fall in fecal total bile acid concentration and reduced deconjugation and 7-α-dihydroxylation were accompanied by significant changes in several bacterial taxa. Individual bile acids in feces correlated with amino acid, purine, and lipid metabolic pathways in plasma. Furthermore, several fecal bile acids and bacterial species correlated with altered gene expression pathways in adipose tissue. CONCLUSIONS: VLCD dietary intervention in obese women changed the composition of several fecal microbial populations while preserving the core fecal microbiome. Changes in individual microbial taxa and their functions correlated with variations in the plasma metabolome, fecal bile acid composition, and adipose tissue transcriptome. Trial Registration ClinicalTrials.gov NCT01699906, 4-Oct-2012, Retrospectively registered. URL- https://clinicaltrials.gov/ct2/show/NCT01699906.


Adipose Tissue/metabolism , Bile Acids and Salts/chemistry , Diet, Reducing , Feces/microbiology , Obesity/therapy , Postmenopause , Weight Loss , Adult , Aged , Caloric Restriction , Carbohydrate Metabolism , Female , Gene Expression Profiling , Gene Expression Regulation , Humans , Inflammation , Ketosis/urine , Metabolomics , Middle Aged , Obesity/microbiology , Phenotype , Prospective Studies , RNA, Ribosomal, 16S/metabolism , Sequence Analysis, RNA
19.
Neuroscience ; 393: 333-349, 2018 11 21.
Article En | MEDLINE | ID: mdl-30059705

Prescription opioid abuse, for example of oxycodone, is a pressing public health issue. This study focuses on how chronic oxycodone self-administration (SA) affects the reward pathways in the mouse brain. In this study, we tested the hypothesis that the expression of reward-related genes in the ventral and dorsal striatum, areas involved in different aspects of opioid addiction models, was altered within 1 h after chronic oxycodone SA, using transcriptome-wide sequencing (RNA-seq). Based on results from earlier human genetic and rodent preclinical studies, we focused on a set of genes that may be associated with the development of addictive diseases and the rewarding effect of drugs of abuse, primarily in the opioid, stress response and classical neurotransmitter systems. We found that 32 transcripts in the ventral striatum, and 7 in the dorsal striatum, were altered significantly in adult mice that had self-administered oxycodone (n = 5) for 14 consecutive days (4 h/day) compared with yoked saline controls (n = 5). The following 5 genes in the ventral striatum showed experiment-wise significant changes: proopiomelanocortin (Pomc) and serotonin 5-HT-2A receptor (Htr2a) were upregulated; serotonin receptor 7 (Htr7), galanin receptor1 (Galr1) and glycine receptor 1 (Glra1) were downregulated. Some genes detected by RNA-seq were confirmed by quantitative polymerase chain reaction (qPCR). Conclusion: A RNA-seq study shows that chronic oxycodone SA alters the expression of several reward-related genes in the dorsal and ventral striatum. These results suggest potential mechanisms underlying neuronal adaptation to chronic oxycodone self-exposure, of relevance to our mechanistic understanding of prescription opioid abuse.


Analgesics, Opioid/pharmacology , Oxycodone/pharmacology , Reward , Ventral Striatum/drug effects , Analgesics, Opioid/administration & dosage , Animals , Behavior, Addictive/drug therapy , Gene Expression/drug effects , Male , Mice, Inbred C57BL , Opioid-Related Disorders/metabolism , Oxycodone/administration & dosage , Self Administration/methods , Sequence Analysis, RNA/methods , Ventral Striatum/metabolism
20.
Proc Natl Acad Sci U S A ; 115(29): E6900-E6909, 2018 07 17.
Article En | MEDLINE | ID: mdl-29967172

Neurons of the medullary reticular nucleus gigantocellularis (NGC) and their targets have recently been a focus of research on mechanisms supporting generalized CNS arousal (GA) required for proper cognitive functions. Using the retro-TRAP method, we characterized transcripts enriched in NGC neurons which have projections to the thalamus. The unique expression and activation of the endothelial nitric oxide (eNOS) signaling pathway in these cells and their intimate connections with blood vessels indicate that these neurons exert direct neurovascular coupling. Production of nitric oxide (NO) within eNOS-positive NGC neurons increases after environmental perturbations, indicating a role for eNOS/NO in modulating environmentally appropriate levels of GA. Inhibition of NO production causes dysregulated behavioral arousal after exposure to environmental perturbation. Further, our findings suggest interpretations for associations between psychiatric disorders and mutations in the eNOS locus.


Arousal/physiology , Brain , Cerebrovascular Circulation/physiology , Neurons/metabolism , Nitric Oxide Synthase Type III , Signal Transduction/physiology , Animals , Brain/blood supply , Brain/cytology , Brain/metabolism , Genetic Loci , Mice , Mice, Transgenic , Neurons/cytology , Nitric Oxide Synthase Type III/biosynthesis , Nitric Oxide Synthase Type III/genetics
...