Regulation of corticotropin-releasing hormone (CRH) activity is critical for the animal's adaptation to stressful challenges, and its dysregulation is associated with psychiatric disorders in humans. ...However, the molecular mechanism underlying this transcriptional response to stress is not well understood. Using various stress paradigms in mouse and zebrafish, we show that the hypothalamic transcription factor Orthopedia modulates the expression of CRH as well as the splicing factor Ataxin 2-Binding Protein-1 (A2BP1/Rbfox-1). We further show that the G protein coupled receptor PAC1, which is a known A2BP1/Rbfox-1 splicing target and an important mediator of CRH activity, is alternatively spliced in response to a stressful challenge. The generation of PAC1-hop messenger RNA isoform by alternative splicing is required for termination of CRH transcription, normal activation of the hypothalamic-pituitary-adrenal axis and adaptive anxiety-like behavior. Our study identifies an evolutionarily conserved biochemical pathway that modulates the neuronal adaptation to stress through transcriptional activation and alternative splicing.
► The homeodomain protein Otp is required for molecular and behavioral stress responses ► Otp regulates the stress hormone CRH and the activity-dependent splicing factor A2BP1 ► The PAC1 receptor, a known A2BP1 target, is alternatively spliced following stress ► Activity-dependent splicing of PAC1 terminates the physiological stress response
Amir-Zilberstein et al. studied the regulation of corticotropin-releasing hormone (CRH), which mediates adaptation to stressful challenges. They revealed that stress response is modulated by the transcription factor Otp and the transmembrane neuropeptide receptor PAC1 and involves activity-dependent alternative splicing of PAC1.
Zebrafish are a valuable model organism in biomedical research. Their rapid development, ability to model human diseases, utility for testing genetic variants identified from next-generation ...sequencing, amenity to CRISPR mutagenesis, and potential for therapeutic compound screening, has led to their wide-spread adoption in diverse fields of study. However, their power for large-scale screens is limited by the absence of automated genotyping tools for live animals. This constrains potential drug screen options, limits analysis of embryonic and larval phenotypes, and requires raising additional animals to adulthood to ensure obtaining an animal of the desired genotype. Our objective was to develop an automated system that would rapidly obtain cells and DNA from zebrafish embryos and larvae for genotyping, and that would keep the animals alive. We describe the development, testing, and validation of a zebrafish embryonic genotyping device, termed "ZEG" (Zebrafish Embryo Genotyper). Using microfluidic harmonic oscillation of the animal on a roughened glass surface, the ZEG is able to obtain genetic material (cells and DNA) for use in genotyping, from 24 embryos or larvae simultaneously in less than 10 minutes. Loading and unloading of the ZEG is performed manually with a standard pipette tip or transfer pipette. The obtained genetic material is amplified by PCR and can be used for subsequent analysis including sequencing, gel electrophoresis, or high-resolution melt-analysis. Sensitivity of genotyping and survival of animals are both greater than 90%. There are no apparent effects on body morphology, development, or motor behavior tests. In summary, the ZEG device enables rapid genotyping of live zebrafish embryos and larvae, and animals are available for downstream applications, testing, or raising.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Neurological manifestations are commonly reported in patients with celiac disease (CD). We aimed to characterize epilepsy features in a pediatric population with CD and the effect of a gluten-free ...diet (GFD) on seizure burden.
A retrospective chart review was performed on pediatric patients treated at the University of Utah and Primary Children's Hospital in Salt Lake City, Utah, with both epilepsy and CD and compared with a control group with epilepsy only.
We identified 56 patients with epilepsy and biopsy-confirmed CD (n = 36, 64%) or elevated tissue transglutaminase antibodies (tTG-Ab) without biopsy-confirmed CD (n = 20, 36%). Age- and gender-matched controls were selected from patients with epilepsy only (n = 168). Patients with biopsy-proven CD or positive tTG-Ab had high percentage of drug-resistant epilepsy (DRE) compared with the control group (P < 0.05). Age at seizure onset preceded the diagnosis of CD on average by 5.9 years for patients with DRE (P < 0.01) compared with 2.2 years for those with drug-responsive epilepsy. Adhering to a GFD reduced seizure frequency or resulted in weaning dosage or weaning off of one or more antiseizure medications in a majority of patients with DRE.
DRE was more prevalent in pediatric patients with biopsy-confirmed CD and positive tTG-Ab compared with the control group (which included childhood epilepsy syndromes), but comparable with the prevalence of DRE in the general population. Adherence to a GFD in combination with antiseizure medications appears to reduce seizure burden for those with CD and DRE.
The developing nervous system depends upon precise regulation of oxygen levels. Hypoxia, the condition of low oxygen concentration, can interrupt developmental sequences and cause a range of ...molecular, cellular and neuronal changes and injuries. The roles and effects of hypoxia on the central nervous system (CNS) are poorly characterized, even though hypoxia is simultaneously a normal component of development, a potentially abnormal environmental stressor in some settings, and a clinically important complication, for example of prematurity. Work over the past decade has revealed that hypoxia causes specific disruptions in the development of CNS connectivity, altering axon pathfinding and synapse development. The goals of this article are to review hypoxia's effects on the development of CNS connectivity, including its genetic and molecular mediators, and the changes it causes in CNS circuitry and function due to regulated as well as unintended mechanisms. The transcription factor HIF1α is the central mediator of the CNS response to hypoxia (as it is elsewhere in the body), but hypoxia also causes a dysregulation of gene expression. Animals appear to have evolved genetic and molecular responses to hypoxia that result in functional behavioral alterations to adapt to the changes in oxygen concentration during CNS development. Understanding the molecular pathways underlying both the normal and abnormal effects of hypoxia on CNS connectivity may reveal novel insights into common neurodevelopmental disorders. In addition, this Review explores the current gaps in knowledge, and suggests important areas for future studies.
Abstract Background In 2014-2015, several regions of the United States experienced an outbreak of acute flaccid myelitis in pediatric patients. A common, unique feature was disease localization to ...the gray matter of the spinal cord. Methods We report 11 children, ages 13 months to 14 years (median 9 years), in the Intermountain West who presented with extremity weakness (n = 10) or cranial neuropathy (n = 1) of varying severity without an apparent etiology. Results All children experienced acute paralysis, and 10 had symptoms or signs that localized to the spinal cord. Maximum paralysis occurred within 4 days of onset in all patients. All had spinal gray matter lesions consistent with acute myelitis detected by magnetic resonance imaging; no single infectious cause was identified. Despite therapy with intravenous immunoglobulin, corticosteroids, or plasma exchange, nine of 10 (90%) children had motor deficits at follow-up. Conclusions Recognition of this disorder enables clinicians to obtain appropriate imaging and laboratory testing, initiate treatment, and provide families with accurate prognostic information. In contrast to other causes of acute flaccid paralysis in childhood, most children with acute flaccid myelitis have residual neurological deficits.
To examine disparities in the diagnosis of leukodystrophies including geographic factors and access to specialty centers.
Retrospective cohort study of pediatric patients admitted to Pediatric Health ...Information System hospitals. Patients with leukodystrophy were identified with International Classification of Diseases, Tenth Revision, Clinical Modification diagnostic codes for any of 4 leukodystrophies (X-linked adrenoleukodystrophy, Hurler disease, Krabbe disease, and metachromatic leukodystrophy). We used 3-level hierarchical generalized logistic modeling to predict diagnosis of a leukodystrophy based on distance traveled for hospital, neighborhood composition, urban/rural context, and access to specialty center.
We identified 501 patients with leukodystrophy. Patients seen at a leukodystrophy center of excellence hospital were 1.73 times more likely to be diagnosed than patients at non-center of excellence hospitals. Patients who traveled farther were more likely to be diagnosed than those who traveled shorter. Patients living in a Health Professionals Shortage Area zip code were 0.86 times less likely to be diagnosed than those living in a non-Health Professionals Shortage Area zip code.
Geographic factors affect the diagnosis of leukodystrophies in pediatric patients, particularly in regard to access to a center with expertise in leukodystrophies. Our findings suggest a need for improving access to pediatric specialists and possibly deploying specialists or diagnostic testing more broadly.
X-linked adrenoleukodystrophy (ALD) is a progressive neurodegenerative disease caused by mutations in ABCD1, the peroxisomal very long-chain fatty acid (VLCFA) transporter. ABCD1 deficiency results ...in accumulation of saturated VLCFAs. A drug screen using a phenotypic motor assay in a zebrafish ALD model identified chloroquine as the top hit. Chloroquine increased expression of stearoyl-CoA desaturase-1 (scd1), the enzyme mediating fatty acid saturation status, suggesting that a shift toward monounsaturated fatty acids relieved toxicity. In human ALD fibroblasts, chloroquine also increased SCD1 levels and reduced saturated VLCFAs. Conversely, pharmacological inhibition of SCD1 expression led to an increase in saturated VLCFAs, and CRISPR knockout of scd1 in zebrafish mimicked the motor phenotype of ALD zebrafish. Importantly, saturated VLCFAs caused ER stress in ALD fibroblasts, whereas monounsaturated VLCFA did not. In parallel, we used liver X receptor (LXR) agonists to increase SCD1 expression, causing a shift from saturated toward monounsaturated VLCFA and normalizing phospholipid profiles. Finally, Abcd1-/y mice receiving LXR agonist in their diet had VLCFA reductions in ALD-relevant tissues. These results suggest that metabolic rerouting of saturated to monounsaturated VLCFAs may alleviate lipid toxicity, a strategy that may be beneficial in ALD and other peroxisomal diseases in which VLCFAs play a key role.
Shedding light on the leukodystrophies Bonkowsky, Joshua L
Developmental medicine and child neurology,
July 2016, 2016-07-00, 20160701, Letnik:
58, Številka:
7
Journal Article
Recenzirano
Odprti dostop
This commentary is on the original article by Stellitano et al. on pages 680–689 of this issue.
AIMPrevious work has shown that children of Hispanic ethnicity have reduced likelihood to achieve seizure remission, but it was unknown why. The purpose of this study was to evaluate antiseizure ...medicine (ASM) refill characteristics, comparing Hispanic and non-Hispanic White pediatric patients. METHODSThis was a retrospective population-based study in children between ages 6 months and 15 years. Epilepsy outcome was categorized as seizure free, treatment failure, or undetermined. ASM refill characteristics were determined from an insurance provider. RESULTS247 patients were identified: 52 (21 %) were treatment failure; 181 (73 %) were seizure free; and 14 (5.7 %) were undetermined. ASM refill rates were similar in Hispanic and White patients (38.2, 32.1, respectively). Hispanic and White patients had similar numbers of different ASMs prescribed (2.1 and 2.4). There was not a significant difference in proportion of days covered between Hispanic and White patients (0.99 and 0.95). INTERPRETATIONWe found no differences between pediatric Hispanic and White epilepsy patients, for number of ASM refills, the number of ASMs prescribed, the choice of ASMs, the proportion of days covered, or the lateness of refills. Our findings suggest that the observation of reduced likelihood to achieve seizure remission in pediatric Hispanic patients is not associated with ASM refill patterns.
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