Ketamine Influences CLOCK:BMAL1 Function Leading to Altered Circadian Gene Expression

Major mood disorders have been linked to abnormalities in circadian rhythms, leading to disturbances in sleep, mood, temperature, and hormonal levels. We provide evidence that ketamine, a drug with rapid antidepressant effects, influences the function of the circadian molecular machinery. Ketamine modulates CLOCK:BMAL1-mediated transcriptional activation when these regulators are ectopically expressed in NG108-15 neuronal cells. Inhibition occurs in a dose-dependent manner and is attenuated after treatment with the GSK3β antagonist SB21673. We analyzed the effect of ketamine on circadian gene expression and observed a dose-dependent reduction in the amplitude of circadian transcription of the Bmal1, Per2, and Cry1 genes. Finally, chromatin-immunoprecipitation analyses revealed that ketamine altered the recruitment of the CLOCK:BMAL1 complex on circadian promoters in a time-dependent manner. Our results reveal a yet unsuspected molecular mode of action of ketamine and thereby may suggest possible pharmacological antidepressant strategies

Ketamine Influences CLOCK:BMAL1 Function Leading to Altered Circadian Gene Expression

Major mood disorders have been linked to abnormalities in circadian rhythms, leading to disturbances in sleep, mood, temperature, and hormonal levels. We provide evidence that ketamine, a drug with rapid antidepressant effects, influences the function of the circadian molecular machinery. Ketamine modulates CLOCK:BMAL1-mediated transcriptional activation when these regulators are ectopically expressed in NG108-15 neuronal cells. Inhibition occurs in a dose-dependent manner and is attenuated after treatment with the GSK3β antagonist SB21673. We analyzed the effect of ketamine on circadian gene expression and observed a dose-dependent reduction in the amplitude of circadian transcription of the Bmal1, Per2, and Cry1 genes. Finally, chromatin-immunoprecipitation analyses revealed that ketamine altered the recruitment of the CLOCK:BMAL1 complex on circadian promoters in a time-dependent manner. Our results reveal a yet unsuspected molecular mode of action of ketamine and thereby may suggest possible pharmacological antidepressant strategies

A study of psychological pain in substance use disorder and its relationship to treatment outcome.

Substance Use Disorder (SUD) is a major public health concern affecting an estimated 22.5 million individuals in the United States. The primary aim of this study was to characterize psychological pain in a cohort of patients participating in outpatient treatment for SUD. A secondary aim was to determine the relationships between pre-treatment assessments of psychological pain, depression, anxiety and hopelessness with treatment retention time and completion rates. Data was analyzed from 289 patients enrolled in an outpatient community drug treatment clinic in Southern California, U.S. A previously determined threshold score on the Mee-Bunney Psychological Pain Assessment Scale (MBP) was utilized to group patients into high and low-moderate scoring subgroups. The higher pain group scored higher on measures of anxiety, hopelessness and depression compared to those in the low-moderate pain group. Additionally, patients scoring in the higher psychological pain group exhibited reduced retention times in treatment and more than two-fold increased odds of dropout relative to patients with lower pre-treatment levels of psychological pain. Among all assessments, the correlation between psychological pain and treatment retention time was strongest. To our knowledge, this is the first study to demonstrate that psychological pain is an important construct which correlates with relevant clinical outcomes in SUD. Furthermore, pre-treatment screening for psychological pain may help target higher-risk patients for clinical interventions aimed at improving treatment retention and completion rates

Assessment of psychological pain in suicidal veterans

<div><p>Psychological pain is a relatively understudied and potentially important construct in the evaluation of suicidal risk. Psychological pain also referred to as ‘mental pain’ or ‘psychache’ can be defined as an adverse emotional reaction to a severe trauma (e.g., the loss of a child) or may be associated with an illness such as depression. When psychological pain levels reach intolerable levels, some individuals may view suicide as the only and final means of escape. To better understand psychological pain, we previously developed and validated a brief self-rating 10-item scale, Mee-Bunney Psychological Pain Assessment Scale [MBP] in depressed patients and non-psychiatric controls. Our results showed a significant increase in psychological pain in the depressed patients compared to controls. We also observed a significant linear correlation between psychological pain and suicidality in the depressed patient cohort. The current investigation extends our study of psychological pain to a diagnostically heterogeneous population of 57 US Veterans enrolled in a suicide prevention program. In addition to the MBP, we administered the Columbia Suicide Severity Rating Scale (C-SSRS), Beck Depression Inventory (BDI-II), Beck Hopelessness Scale (BHS), and the Barratt Impulsiveness Scale (BIS-11). Suicidal patients scoring above a predetermined threshold for high psychological pain also had significantly elevated scores on all the other assessments. Among all of the evaluations, psychological pain accounted for the most shared variance for suicidality (C-SSRS). Stepwise regression analyses showed that impulsiveness (BIS) and psychological pain (MBP) contributed more to suicidality than any of the other combined assessments. We followed patients for 15 months and identified a subgroup (24/57) with serious suicide events. Within this subgroup, 29% (7/24) had a serious suicidal event (determined by the lethality subscale of the C-SSRS), including one completed suicide. Our results build upon our earlier findings and recent literature supporting psychological pain as a potentially important construct. Systematically evaluating psychological pain along with additional measures of suicidality could improve risk assessment and more effectively guide clinical resource allocation toward prevention.</p></div

Simple linear regression of psychological pain (MBP), impulsiveness (BIS), depression (BDI) and hopelessness (BHS) on suicidality (C-SSRS).

<p>Simple linear regression of psychological pain (MBP), impulsiveness (BIS), depression (BDI) and hopelessness (BHS) on suicidality (C-SSRS).</p

Altered circadian expression of clock genes and CCGs after ketamine treatment.

<p><i>Per2</i>, <i>Dbp</i>, <i>Bmal1</i> and <i>Cry1</i> mRNA expression profiles in WT MEFs, untreated or treated for 1 h with ketamine (10 mM and 1 mM) at circadian times CT11–12, CT17–18, CT 23–24, CT29–30 after serum shock, were analyzed by quantitative PCR. The values are relative to those of 18S mRNA levels at each CT (circadian time). Time 12 (CT12) value in untreated cells was set to 1. All values are the mean +/− SD (n = 3); (*) <i>p</i><0.05, (**) <i>p</i><0.01, (***) p<0.001.</p

Cumulative distribution graph of MBP scores for suicidal patients (N = 57).

<p>Suicidal patients were ranked according to MBP scores from highest to lowest.</p

Ketamine treatment represses CLOCK:BMAL1 transactivation potential on the <i>mPer1</i> gene promoter.

<p>(A) Effect of ketamine on CLOCK:BMAL1 dependent transcription. Vectors expressing CLOCK:BMAL1 (C:B, 25 ng each) were cotransfected with a construct containing the <i>mPer1</i> promoter (pGL3-mPer1-Luc, 50 ng) in NG108-15 cells. The total DNA amount was kept constant by adding carrier plasmid DNA. After 6 hs of transfection, cells were treated with increasing amounts of ketamine (K, 18 h, + as 10 mM and ++ as 1 mM). After normalization for transfection efficiency using β-galactosidase activity, reporter gene activities were expressed relative to those of a control transfected only with non-expressing plasmids. All the values are the mean +/− SD (n = 3); (**) p<0.01. (B) The E box promoter element mediates ketamine repression of CLOCK:BMAL1. Experimental conditions were as in A except that reporter constructs containing three copies of the E box consensus sequence (pGL3 promoter (E box) X3 LUC) or its mutated form (pGL3 promoter (Emut) X3 LUC) were used. All values are the mean +/− SD (n = 3); (*) <i>p</i><0.05, (**) <i>p</i><0.01. (C) Ketamine repression of CLOCK:BMAL1 involves activation of GSK3β. Experimental conditions were as in B except that the kinase inhibitors UO126 (ERK kinase inhibitor), SB216763 (GSK3β kinase inhibitor) and GF109203 (PKC kinase inhibitor) were applied to cells together with ketamine treatment (K, ++ as 1 mM). % of repression of CLOCK:BMAL1 transactivation with ketamine alone or ketamine with different kinase inhibitors is shown. All values are the mean +/− SD (n = 3); (*) <i>p</i><0.05.</p