scholarly journals Untangling a Web: Basic Mechanisms of the Complex Interactions Between Sleep, Circadian Rhythms, and Epilepsy

2021 ◽  
pp. 153575972198967
Author(s):  
Rama K. Maganti ◽  
Mathew V. Jones

Seizures have sleep–wake and circadian patterns in various epilepsies and, in turn, disrupt sleep and circadian rhythms. The resultant sleep deprivation (SD) is an exacerbating factor for seizures that sets up a vicious cycle that can potentially lead to disease progression and even to epilepsy-related mortality. A variety of cellular or network electrophysiological changes and changes in expression of clock-controlled genes or other transcription factors underlie sleep–wake and circadian distribution of seizures, as well as the disruptions seen in both. A broad understanding of these mechanisms may help in designing better treatments to prevent SD-induced seizure exacerbation, disrupt the vicious cycle of disease progression, and reduce epilepsy-related mortality.

2021 ◽  
Author(s):  
Ivanna C. Castro-Pascual ◽  
Mariana L. Ferramola ◽  
Fernando G. Altamirano ◽  
Ethelina Cargnelutti ◽  
Cristina M. Devia ◽  
...  

Author(s):  
Arjun Bhattacharya ◽  
Yun Li ◽  
Michael I. Love

ABSTRACTTraditional predictive models for transcriptome-wide association studies (TWAS) consider only single nucleotide polymorphisms (SNPs) local to genes of interest and perform parameter shrinkage with a regularization process. These approaches ignore the effect of distal-SNPs or other molecular effects underlying the SNP-gene association. Here, we outline multi-omics strategies for transcriptome imputation from germline genetics to allow more powerful testing of gene-trait associations by prioritizing distal-SNPs to the gene of interest. In one extension, we identify mediating biomarkers (CpG sites, microRNAs, and transcription factors) highly associated with gene expression and train predictive models for these mediators using their local SNPs. Imputed values for mediators are then incorporated into the final predictive model of gene expression, along with local SNPs. In the second extension, we assess distal-eQTLs (SNPs associated with genes not in a local window around it) for their mediation effect through mediating biomarkers local to these distal-eSNPs. Distal-eSNPs with large indirect mediation effects are then included in the transcriptomic prediction model with the local SNPs around the gene of interest. Using simulations and real data from ROS/MAP brain tissue and TCGA breast tumors, we show considerable gains of percent variance explained (1-2% additive increase) of gene expression and TWAS power to detect gene-trait associations. This integrative approach to transcriptome-wide imputation and association studies aids in identifying the complex interactions underlying genetic regulation within a tissue and important risk genes for various traits and disorders.AUTHOR SUMMARYTranscriptome-wide association studies (TWAS) are a powerful strategy to study gene-trait associations by integrating genome-wide association studies (GWAS) with gene expression datasets. TWAS increases study power and interpretability by mapping genetic variants to genes. However, traditional TWAS consider only variants that are close to a gene and thus ignores important variants far away from the gene that may be involved in complex regulatory mechanisms. Here, we present MOSTWAS (Multi-Omic Strategies for TWAS), a suite of tools that extends the TWAS framework to include these distal variants. MOSTWAS leverages multi-omic data of regulatory biomarkers (transcription factors, microRNAs, epigenetics) and borrows from techniques in mediation analysis to prioritize distal variants that are around these regulatory biomarkers. Using simulations and real public data from brain tissue and breast tumors, we show that MOSTWAS improves upon traditional TWAS in both predictive performance and power to detect gene-trait associations. MOSTWAS also aids in identifying possible mechanisms for gene regulation using a novel added-last test that assesses the added information gained from the distal variants beyond the local association. In conclusion, our method aids in detecting important risk genes for traits and disorders and the possible complex interactions underlying genetic regulation within a tissue.


Cell Division ◽  
2019 ◽  
Vol 14 (1) ◽  
Author(s):  
Choogon Lee

Abstract Cryptochromes (CRYs) are UVA and blue light photoreceptors present in all major evolutionary lineages ranging from cyanobacteria to plants and animals, including mammals. In plants, blue light activates CRYs to induce photomorphogenesis by inhibiting the CRL4Cop1 E3 ligase complex which regulates the degradation of critical transcription factors involved in plant development and growth. However, in mammals, CRYs do not physically interact with Cop1, and of course mammals are not photomorphogenic, leading to the belief that the CRY–Cop1 axis is not conserved in mammals. This belief was recently overturned by Rizzini et al., who showed that although mammalian CRYs do not inhibit Cop1 activity in a light-dependent manner, they antagonize Cop1 activity by displacing Cop1 from CRL4 E3 ligase complex. Because CRYs oscillate, they act in a circadian manner resulting in daily oscillations in Cop1 substrates and the downstream pathways that they regulate. The conserved antagonism of Cop1 by CRY indicates that the CRY–Cop1 axis has an ancient origin, and was repurposed by evolution to regulate photomorphogenesis in plants and circadian rhythms in mammals.


1981 ◽  
Vol 5 (1) ◽  
pp. 67-76 ◽  
Author(s):  
Anna Wirz-Justice ◽  
Irene Tobler ◽  
Marian S. Kafka ◽  
Dieter Naber ◽  
Paul J. Marangos ◽  
...  

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 2135-2135
Author(s):  
Paolo Anderlini ◽  
Rima Saliba ◽  
Michele Donato ◽  
Sergio Giralt ◽  
Borje Andersson ◽  
...  

Abstract Forty patients with relapsed or refractory Hodgkin’s disease (HD) underwent allogeneic stem cell transplantation (allo-SCT) following a fludarabine-based conditioning regimen from an HLA-identical sibling (n=20) or a matched unrelated donor (n=20). The median age was 31 years (range 18-58). The median number of chemotherapy regimens received prior to allo-SCT was five (range 2-9). Thirty (75%) and thirty (75%) patients had received prior radiotherapy or a prior autologous SCT, respectively. The median time to progression after autologous SCT was nine months (3–52). Disease status at SCT was refractory relapse (n=14) or sensitive relapse (n=26). The conditioning regimens employed were fludarabine (25 mg/m sq IV x 5 days)-cyclophosphamide (1 g/m sq IV x 3 days) ± antithymocyte globulin (30 mg/kg IV x 3 days) (FC±ATG) (n=14), a less intensive regimen, and fludarabine (25 mg/m sq IV x 5 days) -melphalan (70 mg/m sq IV x 2 days) (FM) (n=26), a more intensive one. The two groups had similar demographics and prognostic factors. Chimerism studies indicated 100% donor-derived engraftment in 26/26 (100%) FM patients and in 9/13 (69%) evaluable FC±ATG patients. Day 100 and cumulative (18-month) transplant-related mortality (TRM) were 5 % and 22%, respectively for the whole group. There was a nonsignificant trend towards a lower cumulative TRM in the FM group (18% vs. 30% at 18 months, p=0.2). The cumulative incidence of acute (grade II-IV) GVHD was 38%. The cumulative incidence of chronic GVHD at 18 months was 69%. There was a trend for a lower relapse rate after the occurrence of GVHD, however, this was not statistically significant (hazard ratio 0.8; p= 0.6). Progression rates were similar in the FM and FC patients (53% vs. 57% respectively at 18 months, p=0.4). However, disease progression occurred later in FM patients (range 2–34 months) than in FC patients (range 0.7–13 months). In addition, with comparable follow-up time after progression, the FM group experienced a lower death rate after progression. Twenty-four patients (60%) are alive (fourteen in complete remission) with a median follow-up of 13 months (4–78). Sixteen patients expired (TRM n=8, disease progression n=8). FM patients had significantly better overall survival (73% vs. 39% at 18 months; p=0.03), and a trend towards better progression-free survival (37% vs. 21% at 18 months; p=0.2). We conclude that allo-SCT with fludarabine-based, less intensive conditioning from matched related and unrelated donors are feasible in high-risk HD patients with a low TRM. The intensity of the preparative regimen affects survival.


1994 ◽  
Vol 130 (5) ◽  
pp. 472-477 ◽  
Author(s):  
Björn Lemmer ◽  
Thomas Brühl ◽  
Klaus Witte ◽  
Burkhard Pflug ◽  
Wilfried Köhler ◽  
...  

Lemmer B, Brühl T, Witte K, Pflug B, Köhler W, Touitou Y. Effects of bright light on circadian patterns of cyclic adenosine monophosphate, melatonin and cortisol in healthy subjects. Eur J Endocrinol 1994; 130:472–7. ISSN 0804–4643 Bright light is known as a strong zeitgeber on human circadian rhythms and influences several endocrine and neuroendocrine functions. In the present study we examined the influence of a 3-h bright light stimulus, given at different times during the day (morning or evening), on circadian patterns of cyclic adenosine monophosphate (cAMP), melatonin and cortisol. Two groups of synchronized healthy volunteers (lights on: 05.00–23.00 h) were exposed to bright light (2500 lux) for 3 h over 6 days either in the morning (05.00–08.00 h) or in the evening (18.00–21.00 h). The results showed a significant phase advance in the circadian rhythms of melatonin and cortisol when bright light was given in the morning but not when given in the evening. Rhythm in plasma cAMP basically was not affected by either light treatment. Björn Lemmer, Zentrum der Pharmakologie, JW Goethe Universität, Theodor-Stern-Kai 7, D-60590 Frankfurt/M, Germany


1989 ◽  
Vol 33 (10) ◽  
pp. 625-629
Author(s):  
Mary L. Rankin ◽  
Georgia Latham ◽  
Robert D. Peters ◽  
David M. Penetar

Previous research regarding the effects of sleep deprivation (SD) on human physiology and mood has yielded conflicting results. These findings may in part be due to the use of small sample sizes and the failure to separate out the pure effects of SD from those of circadian rhythms during data analysis. One purpose of this study was to clearly identify the effects of 48 hours of SD on blood pressure, temperature, heart rate, and mood by overcoming the limitations of previous research. A second purpose was to evaluate the effects of SD on recognition memory. A repeated measures design was employed to collect physiological, mood, and memory data over a 48 hour period. While strong circadian rhythms were observed for most of the physiological and mood variables, recognition memory was unaffected by 48 hours of SD.


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