Dopamine adjusts the circadian gene expression of Per2 and Per3 in human dermal fibroblasts from ADHD patients

Relationship between Traumatic Experiences, Circadian Preference and ADHD Symptoms in Adolescents with ADHD Residing in Institutional Care: A Controlled Study

Circadian preference, describes biological and behavioural characteristics that influence the ability to plan daily activities according to optimal waking times. It is divided into three main categories: morning, evening and intermediate. In particular, the evening chronotype is associated with conditions such as Attention Deficit Hyperactivity Disorder (ADHD) and Post Traumatic Stress Disorder (PTSD). This study was conducted in three groups aged 14-18 years: The first group consisted of 34 adolescents diagnosed with ADHD who had been in institutional care for at least two years and had not used medication in the last six months. The second group included 29 adolescents with ADHD living with their families who had not used medication in the last six months. The third control group consisted of 32 healthy adolescents. The study utilized sociodemographic data forms, the Turgay DSM-IV Disruptive Behavior Disorders Rating Scale (T-DSM-IV-S) to measure ADHD symptoms, the Childhood Chronotype Questionnaire (CCQ), and the Childhood Trauma Questionnaire (CTQ). In institutionalized adolescents with diagnosed ADHD, ADHD and disruptive behavior symptoms were more severe. Increased trauma scores were associated with higher ADHD and disruptive behaviour symptom severity and evening chronotype. In the conducted mediation analysis, evening chronotype was identified as a full mediator in the relationship between trauma symptoms and ADHD symptoms, while it was determined as a partial mediator in the relationship between trauma symptoms and PTSD symptoms. In conclusion, traumatic experiences in institutionalized adolescents with diagnosed ADHD may exacerbate ADHD and disruptive behavior symptoms. Evening chronotype is associated with ADHD and disruptive behavior symptoms, and therefore, the chronotypes of these adolescents should be assessed. Chronotherapeutic interventions may assist in reducing inattention, hyperactivity, and behavioral problems.

Chronobiology of Parkinson's disease: Past, present and future

Parkinson's disease is a neurodegenerative disorder predominately affecting midbrain dopaminergic neurons that results in a broad range of motor and non-motor symptoms. Sleep complaints are among the most common non-motor symptoms, even in the prodromal period. Sleep alterations in Parkinson's disease patients may be associated with dysregulation of circadian rhythms, intrinsic 24-h cycles that control essential physiological functions, or with side effects from levodopa medication and physical and mental health challenges. The impact of circadian dysregulation on sleep disturbances in Parkinson's disease is not fully understood; as such, we review the systems, cellular and molecular mechanisms that may underlie circadian perturbations in Parkinson's disease. We also discuss the potential benefits of chronobiology-based personalized medicine in the management of Parkinson's disease both in terms of behavioural and pharmacological interventions. We propose that a fuller understanding of circadian clock function may shed important new light on the aetiology and symptomatology of the disease and may allow for improvements in the quality of life for the millions of people with Parkinson's disease.

Evaluation of the Regulatory Role of Circadian Rhythm Related Long Non-Coding RNAs in ADHD Etiogenesis

OBJECTIVE

ADHD is associated with increased sleep problems and circadian rhythm disturbances. This study aimed to examine ADHD patients and healthy controls in terms of chronotypic features and expression levels of CLOCK, PER1, lncRNA HULC, lncRNA UCA1.

METHOD

Eighty-three children were included (43 ADHD). Conner's Parent Rating Scale-Revised Short Form, Childhood Chronotype Questionnaire, Children's Sleep Disorders Scale were administered. Gene expression levels were studied from peripheral blood.

RESULTS

Evening chronotype, sleep initiation/maintenance disorder, sleep-wake transition disorder, excessive sleepiness disorder were higher in the ADHD group compared to the controls in the scales reported by the parents. Expression levels of all examined genes were statistically significantly higher in the ADHD group. There was no significant relationship between genes and sleep parameters in the ADHD group.

CONCLUSION

Our study provides the first evidence that lncRNA HULC and lncRNA UCA1 might have a role in the etiology of ADHD.

The light response in chickens divergently selected for feather pecking behavior reveals mechanistic insights towards psychiatric disorders

Background

Feather pecking is a serious behavioral disorder in chickens that has a considerable impact on animal welfare and poses an economic burden for poultry farming. To study the underlying genetics of feather pecking animals were divergently selected for feather pecking over 15 generations based on estimated breeding values for the behavior.

Methods and results

By characterizing the transcriptomes of whole brains isolated from high and low feather pecking chickens in response to light stimulation we discovered a putative dysregulation of micro RNA processing caused by a lack of Dicer1. This results in a prominent downregulation of the GABRB2 gene and other GABA receptor transcripts, which might cause a constant high level of excitation in the brains of high feather pecking chickens. Moreover, our results point towards an increase in immune system-related transcripts that may be caused by higher interferon concentrations due to Dicer1 downregulation.

Conclusion

Based on our results, we conclude that feather pecking in chickens and schizophrenia in humans have numerous common features. For instance, a Dicer1 dependent disruption of miRNA biogenesis and the lack of GABRB2 expression have been linked to schizophrenia pathogenesis. Furthermore, disturbed circadian rhythms and dysregulation of genes involved in the immune system are common features of both conditions.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11033-021-07111-4.

Norepinephrine influences the circadian clock in human dermal fibroblasts from study participants with a diagnosis of attention-deficit hyperactivity disorder

Attention-deficit hyperactivity disorder (ADHD) is characterized by changes to the circadian process. Many medications used to treat the condition, influence norepinephrine levels. Several studies have, in addition, reported that norepinephrine itself has an effect on circadian function. The aim of this study was to investigate the circadian gene expression in primary human-derived dermal fibroblast cultures (HDF) after norepinephrine exposure. We analyzed circadian preference, behavioral circadian and sleep parameters as well as the circadian gene expression in a cohort of healthy controls and participants with an ADHD diagnosis. Circadian preference was evaluated with German Morningness–Eveningness Questionnaire (D-MEQ) and rhythms of sleep/wake behavior were assessed via actigraphy. After ex vivo exposure to different norepinephrine concentrations in HDF cultures, the rhythmicity of circadian gene expression was analyzed via qRT-PCR. The exposure of 1 µM norepinephrine to confluent cultures of human dermal fibroblasts from participants with a diagnosis of ADHD, was shown to dampen Per1 rhythmicity. The expression of Bmal1, Per1 and Per3 in control subjects was also influenced by incubation with 1 µM norepinephrine. Cultures from the ADHD group revealed no statistically significant overall differences in circadian gene expression, between cultures with and without norepinephrine incubation. Per3 expression showed a significant ZT × group interaction via mixed ANOVA. Per3 expression at ZT4 was significant higher in the group of control samples incubated with 1 µM norepinephrine, compared to the control group without norepinephrine. This effect was also shown in the control samples incubated with 1 µM norepinephrine and cultures from subjects with ADHD without norepinephrine incubation. Per3 expression differed between the healthy control group and the ADHD group without norepinephrine incubation at ZT28. The results of the present study illustrate that norepinephrine impacts on circadian function. In both groups, control group and cultures taken from subjects with ADHD, the expression of the periodic genes (Per1–3) was significantly influenced by incubation with norepinephrine.

Atomoxetine and circadian gene expression in human dermal fibroblasts from study participants with a diagnosis of attention-deficit hyperactivity disorder

Atomoxetine (ATO) is a second line medication for attention-deficit hyperactivity disorder (ADHD). We proposed that part of the therapeutic profile of ATO may be through circadian rhythm modulation. Thus, the aim of this study was to investigate the circadian gene expression in primary human-derived dermal fibroblast cultures (HDF) after ATO exposure. We analyzed circadian preference, behavioral circadian and sleep parameters as well as the circadian gene expression in a cohort of healthy controls and participants with a diagnosis of ADHD. Circadian preference was evaluated with German Morningness-Eveningness-Questionnaire (D-MEQ) and rhythms of sleep/wake behavior were assessed via actigraphy. After ex vivo exposure to different ATO concentrations in HDF cultures, the rhythmicity of circadian gene expression was analyzed via qRT-PCR. No statistical significant effect of both groups (healthy controls, ADHD group) for mid-sleep on weekend days, mid-sleep on weekdays, social jetlag, sleep WASO and total number of wake bouts was observed. D-MEQ scores indicated that healthy controls had no evening preference, whereas subjects with ADHD displayed both definitive and moderate evening preferences. ATO induced the rhythmicity of Clock in the ADHD group. This effect, however, was not observed in HDF cultures of healthy controls. Bmal1 and Per2 expression showed a significant ZT × group interaction via mixed ANOVA. Strong positive correlations for chronotype and circadian genes were observed for Bmal1, Cry1 and Per3 among the study participants. Statistical significant different Clock, Bmal1 and Per3 expressions were observed in HDFs exposed to ATO collected from ADHD participants exhibiting neutral and moderate evening preference, as well as healthy participants with morning preferences. The results of the present study illustrate that ATO impacts on circadian function, particularly on Clock, Bmal1 and Per2 gene expression.

Remdesivir shifts circadian rhythmicity to eveningness; similar to the most prevalent chronotype in ADHD

Circadian clocks control immunity and virus replication, as well as pharmacokinetics and efficacy therapeutics. The aim of this study was to investigate the extent of these relationships by measuring circadian gene expression in primary human-derived dermal fibroblast cultures (HDF) after remdesivir exposure. In the current study, we analysed circadian gene expression in a cohort of participants without a neuropsychiatric diagnosis. After ex vivo exposure to remdesivir to human dermal fibroblast (HDF) cultures and dexamethasone synchronization, the rhythmicity of circadian gene expression (Clock, Bmal1, Per1-3, Cry1) was analysed via qRT-PCR. In this study, D-MEQ scores indicated that participants without a neuropsychiatric diagnosis had no evening preference. Remdesivir leads to a slight phase-shift in Clock, Per1 and Per2. Significant different expressions of Bmal1 and Per3 were detected after remdesivir exposure: Bmal1 at ZT8 (t(22) = 3.26, p = 0.004), ZT24 (t(22) = − 2.66, p = 0.015), ZT28 (t(20) = − 2.14, p = 0.045) and Per3 at ZT8 (t(22) = − 4.27, p < 0.001) and ZT12 (t(22) = − 2.61, p = 0.016). A significant difference between chronotype and circadian gene expression for Bmal1, Cry1 and Per3 was observed. The present study shows that remdesivir has an impact on circadian function. It is well known that the circadian rhythm effects sleep and, moreover, sleep quality. The results suggest that remdesivir medication may alter sleep quality in participants without a neuropsychiatric diagnosis and shifts chronotype to eveningness; similar as prevalent in ADHD.