John W. Denninger

Guanylate cyclase and the .NO/cGMP signaling pathway.

Signal transduction with the diatomic radical nitric oxide (NO) is involved in a number of important physiological processes, including smooth muscle relaxation and neurotransmission. Soluble guanylate cyclase (sGC), a heterodimeric enzyme that converts guanosine triphosphate to cyclic guanosine monophosphate, is a critical component of this signaling pathway. sGC is a hemoprotein; it is through the specific interaction of NO with the sGC heme that sGC is activated. Over the last decade, much has been learned about the unique heme environment of sGC and its interaction with ligands like NO and carbon monoxide. This review will focus on the role of sGC in signaling, its relationship to the other nucleotide cyclases, and on what is known about sGC genetics, heme environment and catalysis. The latest understanding in regard to sGC will be incorporated to build a model of sGC structure, activation, catalytic mechanism and deactivation.

Chronic variable stress activates hematopoietic stem cells

Exposure to psychosocial stress is a risk factor for many diseases, including atherosclerosis. Although incompletely understood, interaction between the psyche and the immune system provides one potential mechanism linking stress and disease inception and progression. Known cross-talk between the brain and immune system includes the hypothalamic-pituitary-adrenal axis, which centrally drives glucocorticoid production in the adrenal cortex, and the sympathetic-adrenal-medullary axis, which controls stress-induced catecholamine release in support of the fight-or-flight reflex. It remains unknown, however, whether chronic stress changes hematopoietic stem cell activity. Here we show that stress increases proliferation of these most primitive hematopoietic progenitors, giving rise to higher levels of disease-promoting inflammatory leukocytes. We found that chronic stress induced monocytosis and neutrophilia in humans. While investigating the source of leukocytosis in mice, we discovered that stress activates upstream hematopoietic stem cells. Under conditions of chronic variable stress in mice, sympathetic nerve fibers released surplus noradrenaline, which signaled bone marrow niche cells to decrease CXCL12 levels through the β3-adrenergic receptor. Consequently, hematopoietic stem cell proliferation was elevated, leading to an increased output of neutrophils and inflammatory monocytes. When atherosclerosis-prone Apoe−/− mice were subjected to chronic stress, accelerated hematopoiesis promoted plaque features associated with vulnerable lesions that cause myocardial infarction and stroke in humans.

Relaxation Response Induces Temporal Transcriptome Changes in Energy Metabolism, Insulin Secretion and Inflammatory Pathways

The relaxation response (RR) is the counterpart of the stress response. Millennia-old practices evoking the RR include meditation, yoga and repetitive prayer. Although RR elicitation is an effective therapeutic intervention that counteracts the adverse clinical effects of stress in disorders including hypertension, anxiety, insomnia and aging, the underlying molecular mechanisms that explain these clinical benefits remain undetermined. To assess rapid time-dependent (temporal) genomic changes during one session of RR practice among healthy practitioners with years of RR practice and also in novices before and after 8 weeks of RR training, we measured the transcriptome in peripheral blood prior to, immediately after, and 15 minutes after listening to an RR-eliciting or a health education CD. Both short-term and long-term practitioners evoked significant temporal gene expression changes with greater significance in the latter as compared to novices. RR practice enhanced expression of genes associated with energy metabolism, mitochondrial function, insulin secretion and telomere maintenance, and reduced expression of genes linked to inflammatory response and stress-related pathways. Interactive network analyses of RR-affected pathways identified mitochondrial ATP synthase and insulin (INS) as top upregulated critical molecules (focus hubs) and NF-κB pathway genes as top downregulated focus hubs. Our results for the first time indicate that RR elicitation, particularly after long-term practice, may evoke its downstream health benefits by improving mitochondrial energy production and utilization and thus promoting mitochondrial resiliency through upregulation of ATPase and insulin function. Mitochondrial resiliency might also be promoted by RR-induced downregulation of NF-κB-associated upstream and downstream targets that mitigates stress.

Frontal EEG predictors of treatment outcome in major depressive disorder

OBJECTIVE To investigate the role of frontal EEG as predictor of clinical response to SSRIs or venlafaxine in major depressive disorder (MDD). METHOD 82 subjects (age 35.9+/-13.0; 47.6% female) meeting DSM-IV criteria for MDD entered an 8-week prospective treatment with SSRIs or venlafaxine. At baseline and week 1 we recorded serial, 4-channel EEGs (F7-Fpz, F8-Fpz, A1-Fpz, A2-Fpz). We evaluated prospectively the relative theta power as predictor of treatment outcome. We also developed an Antidepressant Treatment Response (ATR) index using EEG parameters assessed at baseline and week 1. RESULTS 45 subjects (54.9%) responded to treatment (HAM-D-17 reduction>or=50%). At baseline, frontal relative theta power (i.e., 4-8 Hz power/2-20 Hz power) was significantly (p=0.017) lower (21%) in treatment responders than in non-responders (24%). Baseline relative theta power predicted treatment response with 63% accuracy [64% sensitivity, 62% specificity, 66% area under the receiver operator curve (AUROC) (p=0.014)]. Relative theta power at week 1 predicted treatment response with 60% accuracy [62% sensitivity, 57% specificity, 61% AUROC (p=0.089)]. ATR predicted response with 70% accuracy [82% sensitivity, 54% specificity, 72% AUROC (p=0.001)]. CONCLUSION Using automated analysis of frontal EEG collected during the first week of antidepressant treatment it may be possible to facilitate prediction of SSRI or venlafaxine efficacy in MDD.

Development of a positive psychology intervention for patients with acute cardiovascular disease

The management of depression and other negative psychological states in cardiac patients has been a focus of multiple treatment trials, though such trials have not led to substantial improvements in cardiac outcomes. In contrast, there has been minimal focus on interventions to increase positive psychological states in cardiac patients, despite the fact that optimism and other positive states have been associated with superior cardiovascular outcomes. Our objective was to develop an 8-week, phone-based positive psychology intervention for patients hospitalized with acute cardiac disease (acute coronary syndrome or decompensated heart failure). Such an intervention would consist of positive psychology exercises adapted for this specific population, and it would need to be feasible for practitioners and patients in real-world settings. By adapting exercises that were previously validated in healthy individuals, we were able to generate a positive psychology telemedicine intervention for cardiac patients that focused on optimism, kindness, and gratitude. In addition, we successfully created a companion treatment manual for subjects to enhance the educational aspects of the intervention and facilitate completion of exercises. Finally, we successfully performed a small pilot trial of this intervention, and found that the positive psychology intervention appeared to be feasible and well-accepted in a cohort of patients with acute cardiac illness. Future studies should further develop this promising intervention and examine its impact on psychological and medical outcomes in this vulnerable population of cardiac patients.

Feasibility and utility of positive psychology exercises for suicidal inpatients

OBJECTIVE The objective was to assess the feasibility and acceptability of nine positive psychology exercises delivered to patients hospitalized for suicidal thoughts or behaviors, and to secondarily explore the relative impact of the exercises. METHOD Participants admitted to a psychiatric unit for suicidal ideation or behavior completed daily positive psychology exercises while hospitalized. Likert-scale ratings of efficacy (optimism, hopelessness, perceived utility) and ease of completion were consolidated and compared across exercises using mixed models accounting for age, missing data and exercise order. Overall effects of exercise on efficacy and ease were also examined using mixed models. RESULTS Fifty-two (85.3%) of 61 participants completed at least one exercise, and 189/213 (88.7%) assigned exercises were completed. There were overall effects of exercise on efficacy (χ(2)=19.39; P=.013) but not ease of completion (χ(2)=11.64; P=.17), accounting for age, order and skipped exercises. Effect (Cohens d) of exercise on both optimism and hopelessness was moderate for the majority of exercises. Exercises related to gratitude and personal strengths ranked highest. Both gratitude exercises had efficacy scores that were significantly (P=.001) greater than the lowest-ranked exercise (forgiveness). CONCLUSION In this exploratory project, positive psychology exercises delivered to suicidal inpatients were feasible and associated with short-term gains in clinically relevant outcomes.

Psychosocial functioning during the treatment of major depressive disorder with fluoxetine

Background: Major depressive disorder (MDD) is associated with significant disability, having a profound impact on psychosocial functioning. Therefore, studying the impact of treatment on psychosocial functioning in MDD could help further improve the standard of care. Methods: Two hundred twenty-two MDD outpatients were treated openly with 20 mg fluoxetine for 8 weeks. The self-report version of the Social Adjustment Scale was administered at baseline and during the final visit. We then tested for the relationships between (1) self-report version of the Social Adjustment Scale scores at baseline and clinical response, (2) nonresponse, response and remission status and overall psychosocial adjustment at end point, (3) the number/severity of residual depressive symptoms and overall psychosocial adjustment at end point in responders, and (4) the time to onset of response and overall psychosocial adjustment at end point. Results: An earlier onset of clinical response predicted better overall psychosocial functioning at end point (P = 0.0440). Responders (n = 128) demonstrated better overall psychosocial adjustment at end point than nonresponders (P = 0.0003), while remitters (n = 64) demonstrated better overall psychosocial adjustment at end point than nonremitted responders (P = 0.0031). In fact, a greater number/severity of residual symptoms predicted poorer overall psychosocial adjustment at end point in responders (P = 0.0011). Psychosocial functioning at baseline did not predict response. Conclusions: While MDD patients appear equally likely to respond to treatment with fluoxetine, regardless of their level of functioning immediately before treatment, the above results stress the importance of achieving early symptom improvement then followed by full remission of depressive symptoms with respect to restoring psychosocial functioning in MDD.

Somatic symptoms in treatment-resistant depression

The purpose of this work was to study the prevalence of somatic symptoms in patients with treatment-resistant depression (TRD) and their impact on the response to antidepressant treatment. Somatic symptoms were assessed during the screen visit with the Symptom Questionnaire (SQ) somatic symptom (SQ-SS) and somatic well-being sub-scales (SQ-SWB) in 40 patients with TRD enrolled in a 6-week open trial of nortriptyline. A logistic regression was used to test whether SQ-SS or SQ-SWB scores predicted clinical response to nortriptyline. Ninety-five percent of patients reported at least one somatic symptom. Higher SQ-SS scores during the screen visit predicted poorer response to nortriptyline. There was a trend for lower SQ-SWB scores to predict poor response to nortriptyline. None of the patients with SQ-SS scores above the mean for the sample responded to nortriptyline. The overwhelming majority of patients with TRD presented with somatic symptoms. In addition, a greater number of somatic symptoms during the screen visit placed patients at risk for further treatment resistance.

Relaxation Response–Based Yoga Improves Functioning in Young Children with Autism: A Pilot Study

OBJECTIVES The study objectives were to develop and objectively assess the therapeutic effect of a novel movement-based complementary and alternative medicine approach for children with an autism-spectrum disorder (ASD). DESIGN A within-subject analysis comparing pre- to post-treatment scores on two standard measures of childhood behavioral problems was used. SETTINGS AND LOCATION: The intervention and data analysis occurred at a tertiary care, medical school teaching hospital. SUBJECTS Twenty-four (24) children aged 3-16 years with a diagnosis of an ASD comprised the study group. INTERVENTION The efficacy of an 8-week multimodal yoga, dance, and music therapy program based on the relaxation response (RR) was developed and examined. OUTCOME MEASURES The study outcome was measured using The Behavioral Assessment System for Children, Second Edition (BASC-2) and the Aberrant Behavioral Checklist (ABC). RESULTS Robust changes were found on the BASC-2, primarily for 5-12-year-old children. Unexpectedly, the post-treatment scores on the Atypicality scale of the BASC-2, which measures some of the core features of autism, changed significantly (p=0.003). CONCLUSIONS A movement-based, modified RR program, involving yoga and dance, showed efficacy in treating behavioral and some core features of autism, particularly for latency-age children.

Relaxation Response and Resiliency Training and Its Effect on Healthcare Resource Utilization.

Background Poor psychological and physical resilience in response to stress drives a great deal of health care utilization. Mind-body interventions can reduce stress and build resiliency. The rationale for this study is therefore to estimate the effect of mind-body interventions on healthcare utilization. Objective Estimate the effect of mind body training, specifically, the Relaxation Response Resiliency Program (3RP) on healthcare utilization. Design Retrospective controlled cohort observational study. Setting: Major US Academic Health Network. Sample: All patients receiving 3RP at the MGH Benson-Henry Institute from 1/12/2006 to 7/1/2014 (n = 4452), controls (n = 13149) followed for a median of 4.2 years (.85–8.4 yrs). Measurements: Utilization as measured by billable encounters/year (be/yr) stratified by encounter type: clinical, imaging, laboratory and procedural, by class of chief complaint: e.g., Cardiovascular, and by site of care delivery, e.g., Emergency Department. Subgroup analysis by propensity score matched pre-intervention utilization rate. Results At one year, total utilization for the intervention group decreased by 43% [53.5 to 30.5 be/yr] (p <0.0001). Clinical encounters decreased by 41.9% [40 to 23.2 be/yr], imaging by 50.3% [11.5 to 5.7 be/yr], lab encounters by 43.5% [9.8 to 5.6], and procedures by 21.4% [2.2 to 1.7 be/yr], all p < 0.01. The intervention group’s Emergency department (ED) visits decreased from 3.6 to 1.7/year (p<0.0001) and Hospital and Urgent care visits converged with the controls. Subgroup analysis (identically matched initial utilization rates—Intervention group: high utilizing controls) showed the intervention group significantly reduced utilization relative to the control group by: 18.3% across all functional categories, 24.7% across all site categories and 25.3% across all clinical categories. Conclusion Mind body interventions such as 3RP have the potential to substantially reduce healthcare utilization at relatively low cost and thus can serve as key components in any population health and health care delivery system.