Mandipropamid as a chemical inducer of proximity for in vivo applications.

Direct control of protein interactions by chemically induced protein proximity holds great potential for both cell and synthetic biology as well as therapeutic applications. Low toxicity, orthogonality and excellent cell permeability are important criteria for chemical inducers of proximity (CIPs), in particular for in vivo applications. Here, we present the use of the agrochemical mandipropamid (Mandi) as a highly efficient CIP in cell culture systems and living organisms. Mandi specifically induces complex formation between a sixfold mutant of the plant hormone receptor pyrabactin resistance 1 (PYR1) and abscisic acid insensitive (ABI). It is orthogonal to other plant hormone-based CIPs and rapamycin-based CIP systems. We demonstrate the applicability of the Mandi system for rapid and efficient protein translocation in mammalian cells and zebrafish embryos, protein network shuttling and manipulation of endogenous proteins.

Target-Guided Isolation of Progenitors of 1,1,6-Trimethyl-1,2-dihydronaphthalene (TDN) from Riesling Wine by High-Performance Countercurrent Chromatography.

High-performance countercurrent chromatography (HPCCC) was used for the target-guided isolation of precursors of 1,1,6-trimethyl-1,2-dihydronaphthalene (TDN) from Riesling wine. In separated HPCCC fractions of an Amberlite® XAD®-2 extract obtained from a German Riesling, TDN-generating fractions were identified by the acid-catalyzed hydrolysis of the progenitors at pH 3.0 and subsequent HS-GC-MS/MS analysis. The presence of multiple TDN-generating precursors in Riesling wine could be confirmed. From polar HPCCC fractions (11-13 and 14-16), 3,4-dihydroxy-7,8-dihydro-ß-ionone 3-O-rutinoside and 3,4-dihydroxy-7,8-dihydro-ß-ionone 3-O-ß-d-glucopyranoside were isolated as major TDN-precursors at a sufficient amount for structure elucidation by NMR spectroscopic studies. In the medium polar HPCCC factions (27-35), enzymatic hydrolysis liberated the aglycones 3-hydroxy-ß-ionone and 3-hydroxy-TDN in minor amounts. In further less polar TDN-generation fractions (36-44 and 45-50), glycosidic progenitors were absent; instead, a minor TDN formation most likely from non-conjugated constituents was observed.

The Role of Behavioral Ecotoxicology in Environmental Protection.

For decades, we have known that chemicals affect human and wildlife behavior. Moreover, due to recent technological and computational advances, scientists are now increasingly aware that a wide variety of contaminants and other environmental stressors adversely affect organismal behavior and subsequent ecological outcomes in terrestrial and aquatic ecosystems. There is also a groundswell of concern that regulatory ecotoxicology does not adequately consider behavior, primarily due to a lack of standardized toxicity methods. This has, in turn, led to the exclusion of many behavioral ecotoxicology studies from chemical risk assessments. To improve understanding of the challenges and opportunities for behavioral ecotoxicology within regulatory toxicology/risk assessment, a unique workshop with international representatives from the fields of behavioral ecology, ecotoxicology, regulatory (eco)toxicology, neurotoxicology, test standardization, and risk assessment resulted in the formation of consensus perspectives and recommendations, which promise to serve as a roadmap to advance interfaces among the basic and translational sciences, and regulatory practices.

A Bioorthogonal Click Chemistry Toolbox for Targeted Synthesis of Branched and Well-Defined Protein-Protein Conjugates.

Bioorthogonal chemistry holds great potential to generate difficult-to-access protein-protein conjugate architectures. Current applications are hampered by challenging protein expression systems, slow conjugation chemistry, use of undesirable catalysts, or often do not result in quantitative product formation. Here we present a highly efficient technology for protein functionalization with commonly used bioorthogonal motifs for Diels-Alder cycloaddition with inverse electron demand (DAinv ). With the aim of precisely generating branched protein chimeras, we systematically assessed the reactivity, stability and side product formation of various bioorthogonal chemistries directly at the protein level. We demonstrate the efficiency and versatility of our conjugation platform using different functional proteins and the therapeutic antibody trastuzumab. This technology enables fast and routine access to tailored and hitherto inaccessible protein chimeras useful for a variety of scientific disciplines. We expect our work to substantially enhance antibody applications such as immunodetection and protein toxin-based targeted cancer therapies.

Enzymatic and Site-Specific Ligation of Minimal-Size Tetrazines and Triazines to Proteins for Bioconjugation and Live-Cell Imaging.

Diels-Alder reactions with inverse electron demand (DAinv) have emerged as an indispensable tool for bioorthogonal labeling and the manipulation of biomolecules. In this context, reactions between tetrazines and strained dienophiles have received attention because of high reaction rates. Current methods for the DAinv-mediated functionalization of proteins suffer from slow reactivity, impaired stability, isomerization, or elimination of the incorporated strained dienophiles. We report here a versatile platform for the posttranslational, highly selective, and quantitative modification of proteins with stable dienes. New synthetic access to minimal size tetrazine and triazine derivatives enabled us to synthesize tailored diene substrates for the lipoic acid protein ligase A (LplA) from Escherichia coli, which we employ for the rapid, mild, and quantitative bioconjugation of proteins by DAinv. The presented method benefits from the minimal tag size for LplA recognition and can be applied to proteins from any source organism. We demonstrate its broad suitability by site-specific in vitro protein labeling and live cell labeling for fluorescence microscopy. With this work we expand the scope of DAinv bioorthogonal chemistry for site-specific protein labeling, providing additional experimental flexibility for preparing well-defined bioconjugates and addressing biological questions in complex biological environments.

The Relationship Between Circulating Interleukin-6 Levels and Future Health Service Use in Dementia Caregivers.

OBJECTIVE: Older adults are among the most frequent users of emergency departments (EDs). Nonspecific symptoms, such as fatigue and widespread pain, are among the most common symptoms in patients admitted at the ED. Interleukin 6 (IL-6) and tumor necrosis factor α (TNF-α) are inflammation biomarkers associated with chronic stress (i.e., dementia caregiving) and nonspecific symptoms. This study aimed to determine whether IL-6 and TNF-α were prospectively associated with ED risk in dementia caregivers (CGs). METHODS: Participants were 85 dementia CGs, who reported during three assessments (3, 9, and 15 months after enrollment) if they had visited an ED for any reason. Cox proportional hazards models were used to examine the relations between resting circulating levels of IL-6 and TNF-α obtained at enrollment and subsequent risk for an ED visit, adjusting for age, sex, use of ED 1 month before enrollment, physical and mental health well-being, body mass index, and CG demands. RESULTS: (log) IL-6 significantly predicted ED visits during the 15-month follow-up (B = 1.96, SE = 0.82, p = .017). For every (log) picogram per milliliter increase in IL-6, the risk of visiting an ED was 7.10 times greater. TNF-α was not associated with subsequent ED visits. Exploratory analyses suggested that CGs with levels of IL-6 above the 80th percentile and experiencing high CG demands were at highest risk of an ED visit. CONCLUSIONS: IL-6 levels and CG demands may be useful for predicting vulnerability for future ED visits. Although further studies should be conducted to replicate and extend these findings, interventions that successfully modify inflammation markers, including the underlying pathophysiology related to stress and/or comorbid illnesses, may be useful in preventing costly and detrimental outcomes in this population.

Refining caregiver vulnerability for clinical practice: determinants of self-rated health in spousal dementia caregivers.

BACKGROUND: Caregivers of a family member with a chronic disability or illness such as dementia are at increased risk for chronic disease. There are many factors that contribute to dementia caregiver vulnerability and these factors can be challenging to assess in clinical settings. Self-rated health (SRH) is an independent measure of survival and physical health in the elderly. As an inclusive measure of health, SRH has been proposed as a reliable way to assess a patient's general health in primary care. Therefore, we sought to identify determinants of poor/fair SRH versus categories of at least good SRH in informal caregivers. METHODS: In a cross-sectional study, we examined 134 elderly (≥55 years) providing in-home care for a spouse with dementia who rated their own health with a single-item question: "In general, would you say your health is excellent, very good, good, fair or poor?". In a multivariable model, we compared caregivers with poor/fair SRH to those with good, very good, or excellent SRH on demographics, health characteristics (health behaviors, physical health indicators, psychosocial factors) and caregiving-specific stress (a composite index/total of four caregiving-specific stressors: years of caregiving, dementia severity, care recipient functional impairment and perceived caregiver burden). RESULTS: Compared with caregivers who rated their own health as either good (31.3%), very good (38.8%) or excellent (14.2%), caregivers with poor/fair SRH (15.7%) were more likely to have lower physical function and total greater caregiving-specific stress. More years of caregiving, severe dementia and care recipient functional impairment, but not perceived caregiver burden, were also more likely among caregivers with poor/fair SRH. Additionally, high negative affect and low positive affect were more likely in caregivers with poor/fair vs. good or excellent and very good or excellent SRH, respectively. CONCLUSIONS: Caregivers with poor/fair SRH were characterized by higher levels of medical comorbidity, low physical function, high negative, but low positive affect and longer duration of caregiving, as well as more severe dementia and greater functional impairment of the care recipient. These findings suggest that caregivers need to be more closely evaluated and targeted for preventive interventions in clinical practice. TRIAL REGISTRATION: ClinicalTrials.gov registration number: NCT02317523 .

Sympathetic nerves and hypertension in stress, sleep apnea, and caregiving.

PURPOSE OF REVIEW: The sympathetic nervous system (SNS) mediates short-term increases in blood pressure. Evidence that psychosocial stress leads to chronic hypertension is mixed. The SNS activation found in obstructive sleep apnea (OSA), caregiving for a severely demented spouse, and obesity more specifically address whether SNS activation might lead to the metabolic syndrome and hypertension. RECENT FINDINGS: Obesity is associated with both increased SNS electrical activity and plasma norepinephrine. This is partly because of frequent OSA among the obese, but OSA does not fully explain SNS activation in obesity. Large stresses activate adrenal epinephrine release, but both animal and human studies indicate that epinephrine decreases aspects of the metabolic syndrome. On the other hand, norepinephrine is chronically elevated in OSA and among markedly stressed caregivers, and they have an increased incidence of hypertension. This is most striking in OSA, which causes a nocturnal diuresis. Hypertensive patients with OSA are resistant to the antihypertensive effects of diuretics, but respond to drugs that block SNS activity and the effects of renin. SUMMARY: The SNS may mediate chronic blood pressure increases in response to specific stresses and alter responses to therapy. Evidence linking psychosocial stress to hypertension is mixed.

Engagement in Pleasant Leisure Activities and Blood Pressure: A 5-Year Longitudinal Study in Alzheimer Caregivers.

OBJECTIVE: Elevated blood pressure is a significant public health concern, particularly given its association with cardiovascular disease risk, including stroke. Caring for a loved one with Alzheimer disease has been associated with physical health morbidity, including higher blood pressure. Engagement in adaptive coping strategies may help prevent blood pressure elevation in this population. This 5-year longitudinal study examined whether greater participation in pleasant leisure activities was associated with reduced blood pressure in caregivers. METHODS: Participants were 126 in-home spousal Alzheimer's caregivers (M [SD] age = 74.2 [7.9] years) that completed five yearly assessments. Linear mixed-effects models analysis was used to examine the longitudinal relationship between pleasant leisure activities and caregivers' blood pressure, after adjusting for demographic and health characteristics. RESULTS: Greater engagement in pleasant leisure activities was associated with reduced mean arterial blood pressure (B = -0.08, SE = 0.04, p = .040). Follow-up analyses indicated that engagement in activities was significantly associated with reduced diastolic (B = -0.07, SE = 0.03, p = .030) but not systolic blood pressure (B = -0.10, SE = 0.06, p = .114). In addition, mean arterial blood pressure was significantly reduced when caregiving duties ended because of placement of care recipients in nursing homes (B = -3.10, SE = 1.11, p = .005) or death of the care recipient (B = -2.64, SE = 1.14, p = .021). CONCLUSIONS: Greater engagement in pleasant leisure activities was associated with lowered caregivers' blood pressure over time. Participation in pleasant leisure activities may have cardiovascular health benefits for Alzheimer's caregivers.

Effect of obstructive sleep apnea on the response to hypertension therapy.

Obstructive sleep apnea (OSA) often precedes cardiovascular disease, partly due to treatment resistant hypertension. The nocturnal apneas of OSA trigger increased sympathetic nervous discharge during both sleep and wakefulness. Apneas also trigger cardiac release of the endogenous diuretic atrial natriuretic peptide. We hypothesized that treatment of the excess sympathetic nervous activity of OSA with a ß1 blocker would lower 24 h blood pressure (BP) more than diuretic therapy. Subjects with OSA associated hypertension received 2 weeks of placebo followed by the ß1 blocker nebivolol or hydrochlorothiazide (HCTZ) for 6 weeks in a blinded crossover study. BP, baroreflex sensitivity (BRS), heart rate variability (HRV), arterial reactivity, and stiffness were measured after placebo and each treatment. The ß1 blocker lowered clinic BP by -11/-8 mmHg, more than the -3/-1 effect of HCTZ (P < 0.01). The ß1 blocker lowered 24 h diastolic blood pressure (DBP) more than HCTZ. Although given at bedtime, neither drug increased BP dipping. Nebivolol increased HRV in the high-frequency band. Nebivolol did not alter BRS while HCTZ significantly diminished BRS compared to nebivolol (P < 0.01). Nebivolol increased flow-mediated brachial artery dilation when compared to HCTZ and slowed pulse wave velocity, indicating a decrease in arterial stiffness. Diuretic therapy failed to lower BP in OSA subjects and this might account for the frequent association of OSA with treatment resistant hypertension. However, blockade of the excess sympathetic nervous activity of OSA with a ß1 blocker lowered both clinic and 24 h DBP.

Genome of the pathogen Porphyromonas gingivalis recovered from a biofilm in a hospital sink using a high-throughput single-cell genomics platform.

Although biofilms have been shown to be reservoirs of pathogens, our knowledge of the microbial diversity in biofilms within critical areas, such as health care facilities, is limited. Available methods for pathogen identification and strain typing have some inherent restrictions. In particular, culturing will yield only a fraction of the species present, PCR of virulence or marker genes is mainly focused on a handful of known species, and shotgun metagenomics is limited in the ability to detect strain variations. In this study, we present a single-cell genome sequencing approach to address these limitations and demonstrate it by specifically targeting bacterial cells within a complex biofilm from a hospital bathroom sink drain. A newly developed, automated platform was used to generate genomic DNA by the multiple displacement amplification (MDA) technique from hundreds of single cells in parallel. MDA reactions were screened and classified by 16S rRNA gene PCR sequence, which revealed a broad range of bacteria covering 25 different genera representing environmental species, human commensals, and opportunistic human pathogens. Here we focus on the recovery of a nearly complete genome representing a novel strain of the periodontal pathogen Porphyromonas gingivalis (P. gingivalis JCVI SC001) using the single-cell assembly tool SPAdes. Single-cell genomics is becoming an accepted method to capture novel genomes, primarily in the marine and soil environments. Here we show for the first time that it also enables comparative genomic analysis of strain variation in a pathogen captured from complex biofilm samples in a healthcare facility.

Profiles of secreted neuropeptides and catecholamines illustrate similarities and differences in response to stimulation by distinct secretagogues.

The goal of this study was to define profiles of secreted neuropeptide and catecholamine neurotransmitters that undergo co-release from sympathoadrenal chromaffin cells upon stimulation by distinct secretagogues. Chromaffin cells of the adrenal medulla participate in the dynamic responses to stress, especially that of 'fight and flight', and, thus, analyses of the co-release of multiple neurotransmitters is necessary to gain knowledge of how the stress response regulates cell-cell communication among physiological systems. Results of this study demonstrated that six different secretagogues stimulated the co-release of the neuropeptides Met-enkephalin, galanin, NPY, and VIP with the catecholamines dopamine, norepinephrine, and epinephrine. Importantly, the quantitative profiles of the secreted neurotransmitters showed similarities and differences upon stimulation by the different secretagogues evaluated, composed of KCl depolarization, nicotine, carbachol, PACAP, bradykinin, and histamine. The rank-orders of the secreted profiles of the neurotransmitters were generally similar among these secretagogues, but differences in the secreted amounts of each neurotransmitter occurred with different secretagogues. Epinephrine among the catecholamines showed the highest level of secretion. (Met)enkephalin showed the largest levels of secretion compared to the other neuropeptides examined. Levels of secreted catecholamines were greater than that of the neuropeptides. These data support the hypothesis that profiles of secreted neuropeptide and catecholamine neurotransmitters show similarities and differences upon stimulation by distinct secretagogues. These results illustrate the co-release of concerted neurotransmitter profiles that participate in the stress response of the sympathoadrenal nervous system.

Candidate phylum TM6 genome recovered from a hospital sink biofilm provides genomic insights into this uncultivated phylum.

The "dark matter of life" describes microbes and even entire divisions of bacterial phyla that have evaded cultivation and have yet to be sequenced. We present a genome from the globally distributed but elusive candidate phylum TM6 and uncover its metabolic potential. TM6 was detected in a biofilm from a sink drain within a hospital restroom by analyzing cells using a highly automated single-cell genomics platform. We developed an approach for increasing throughput and effectively improving the likelihood of sampling rare events based on forming small random pools of single-flow-sorted cells, amplifying their DNA by multiple displacement amplification and sequencing all cells in the pool, creating a "mini-metagenome." A recently developed single-cell assembler, SPAdes, in combination with contig binning methods, allowed the reconstruction of genomes from these mini-metagenomes. A total of 1.07 Mb was recovered in seven contigs for this member of TM6 (JCVI TM6SC1), estimated to represent 90% of its genome. High nucleotide identity between a total of three TM6 genome drafts generated from pools that were independently captured, amplified, and assembled provided strong confirmation of a correct genomic sequence. TM6 is likely a Gram-negative organism and possibly a symbiont of an unknown host (nonfree living) in part based on its small genome, low-GC content, and lack of biosynthesis pathways for most amino acids and vitamins. Phylogenomic analysis of conserved single-copy genes confirms that TM6SC1 is a deeply branching phylum.

MicroRNA-22 and promoter motif polymorphisms at the Chga locus in genetic hypertension: functional and therapeutic implications for gene expression and the pathogenesis of hypertension.

Hypertension is a common hereditary syndrome with unclear pathogenesis. Chromogranin A (Chga), which catalyzes formation and cargo storage of regulated secretory granules in neuroendocrine cells, contributes to blood pressure homeostasis centrally and peripherally. Elevated Chga occurs in spontaneously hypertensive rat (SHR) adrenal glands and plasma, but central expression is unexplored. In this report, we measured SHR and Wistar-Kyoto rat (control) Chga expression in central and peripheral nervous systems, and found Chga protein to be decreased in the SHR brainstem, yet increased in the adrenal and the plasma. By re-sequencing, we systematically identified five promoter, two coding and one 3'-untranslated region (3'-UTR) polymorphism at the SHR (versus WKY or BN) Chga locus. Using HXB/BXH recombinant inbred (RI) strain linkage and correlations, we demonstrated genetic determination of Chga expression in SHR, including a cis-quantitative trait loci (QTLs) (i.e. at the Chga locus), and such expression influenced biochemical determinants of blood pressure, including a cascade of catecholamine biosynthetic enzymes, catecholamines themselves and steroids. Luciferase reporter assays demonstrated that the 3'-UTR polymorphism (which disrupts a microRNA miR-22 motif) and promoter polymorphisms altered gene expression consistent with the decline in SHR central Chga expression. Coding region polymorphisms did not account for changes in Chga expression or function. Thus, we hypothesized that the 3'-UTR and promoter mutations lead to dysregulation (diminution) of Chga in brainstem cardiovascular control nuclei, ultimately contributing to the pathogenesis of hypertension in SHR. Accordingly, we demonstrated that in vivo administration of miR-22 antagomir to SHR causes substantial (∼18 mmHg) reductions in blood pressure, opening a novel therapeutic avenue for hypertension.

Beta-adrenergic receptor mediated inflammation control by monocytes is associated with blood pressure and risk factors for cardiovascular disease.

Overwhelming data indicate that individuals with even mildly elevated blood pressure (BP) are at great risk for developing clinical hypertension and future cardiovascular disease (CVD). There remains a lack of consensus regarding treatment strategies for mildly elevated BP, termed prehypertension, and the knowledge of pathophysiology and mechanisms of its clinical outcomes remains limited. Our primary aim was to investigate ßAR-mediated inflammation control (BARIC) responses of blood monocytes to isoproterenol (Iso) in relation to BP and CVD risk factors, including obesity, depressive mood, fasting glucose, triglycerides, and cholesterol levels in the 64 prehypertensive compared to 84 individuals with normal BP. BARIC was determined by measuring the degree of inhibition in lipopolysaccharides-stimulated monocytic intracellular TNF production by ex vivo Iso treatment (10(-8)M). Depressive mood was assessed by Beck Depression Inventory (BDI). Fasting metabolic and lipid panels were assessed, and plasma levels of inflammatory cytokines TNF, IL-1ß, IL-6 were measured in a subset to confirm proinflammatory state of prehypertensive participants. Prehypertensive participants were older, heavier, included more men, and presented higher levels of fasting glucose, triglycerides, cholesterol, and plasma TNF compared to normotensive participants (p's<.05). BARIC was significantly attenuated in the prehypertensive compared to normotensive group (p<.05). BARIC was negatively associated with systolic BP, diastolic BP, age, BMI, fasting glucose, triglycerides, total and low density cholesterol levels, and somatic depressive symptoms in all participants (p's<.0001 to .05). However, among the prehypertensive individuals BARIC was positively associated with SBP even after controlling for the covariates (age, gender, race, BMI, glucose and lipid panel, somatic BDI scores) (p<.05). This differing nature of the BARIC-SBP relationship between the two BP groups may be attributed to moderating factors such as cardiorespiratory fitness or depressive symptoms that could not be clearly deciphered in this current study. Nonetheless, our findings indicate the associations between inflammation dysregulation mediated by sympathoadrenal activation and BP that is observable even among individuals with normal to mildly elevated BP. BARIC may be a useful and sensitive indicator of elevated risk for vascular inflammatory disease that can be detected even at lower BP levels, especially given its associations with traditional CVD risk factors and the critical role of monocytes in atherogenic processes.

Leukocyte ß-adrenergic receptor sensitivity and depression severity in patients with heart failure.

OBJECTIVES: Clinical outcomes are worse for patients with heart failure (HF) and elevated depression symptoms. Depression-related sympathoimmune dysregulation may be one mechanism leading to poorer HF prognosis. Sympathetically mediated adrenergic activity is known to regulate immune activity via ß-adrenergic receptors (ß-ARs). However, studies show conflicting relationships between leukocyte ß-AR sensitivity and depression symptoms. The aim of this study was to determine in patients with HF the relationship of leukocyte ß-AR sensitivity with two diverse measures of depression, self-report questionnaire versus clinical diagnostic interview. METHODS: Patients with HF (N = 73, mean [standard deviation] age = 56.3 [13.0]) completed the Beck Depression Inventory-1A and a modified Structured Clinical Interview for the DSM-IV. Leukocyte ß-AR sensitivity was determined from isoproterenol-stimulated cyclic adenosine monophosphate levels; plasma norepinephrine and epinephrine were also assessed. RESULTS: Patients with major depression determined by Structured Clinical Interview for the DSM-IV had significantly higher ß-AR sensitivity than did nondepressed patients (F(6,72) = 9.27, p = .003, η = 0.12). The Beck Depression Inventory-1A revealed a more complex relationship. Minimal, mild, and moderate-to-severe depression symptom groups had significant differences in ß-AR sensitivity (F(7,72) = 7.03, p = .002, η = 0.18); mild symptoms were associated with reduced ß-AR sensitivity and moderate-to-severe symptoms with higher ß-AR sensitivity compared with patients with minimal depressive symptoms. CONCLUSIONS: Clinical depression was associated with elevated ß-AR sensitivity in patients with HF. By deconstructing depression measurements, a greater depth of information may be garnered to potentially reveal subtypes of depression symptoms and their relation to ß-AR sensitivity.

Endothelial function and sleep: associations of flow-mediated dilation with perceived sleep quality and rapid eye movement (REM) sleep.

Endothelial function typically precedes clinical manifestations of cardiovascular disease and provides a potential mechanism for the associations observed between cardiovascular disease and sleep quality. This study examined how subjective and objective indicators of sleep quality relate to endothelial function, as measured by brachial artery flow-mediated dilation (FMD). In a clinical research centre, 100 non-shift working adults (mean age: 36 years) completed FMD testing and the Pittsburgh Sleep Quality Index, along with a polysomnography assessment to obtain the following measures: slow wave sleep, percentage rapid eye movement (REM) sleep, REM sleep latency, total arousal index, total sleep time, wake after sleep onset, sleep efficiency and apnea-hypopnea index. Bivariate correlations and follow-up multiple regressions examined how FMD related to subjective (i.e., Pittsburgh Sleep Quality Index scores) and objective (i.e., polysomnography-derived) indicators of sleep quality. After FMD showed bivariate correlations with Pittsburgh Sleep Quality Index scores, percentage REM sleep and REM latency, further examination with separate regression models indicated that these associations remained significant after adjustments for sex, age, race, hypertension, body mass index, apnea-hypopnea index, smoking and income (Ps < 0.05). Specifically, as FMD decreased, scores on the Pittsburgh Sleep Quality Index increased (indicating decreased subjective sleep quality) and percentage REM sleep decreased, while REM sleep latency increased (Ps < 0.05). Poorer subjective sleep quality and adverse changes in REM sleep were associated with diminished vasodilation, which could link sleep disturbances to cardiovascular disease.

In vivo ß-adrenergic receptor responsiveness: ethnic differences in the relationship with symptoms of depression and fatigue.

BACKGROUND: Depressive symptoms and fatigue frequently overlap in clinical samples and the general population. The link of depressive symptoms and fatigue with increased risk of cardiovascular disease has been partly explained by shared biological mechanisms including sympathetic overactivity. Prolonged sympathetic overactivity downregulates the responsiveness of the ß-adrenergic receptor (ß-AR), a receptor that mediates several end-organ sympathetic responses. PURPOSE: The authors studied whether depression and fatigue are related to reduced ß-AR responsiveness within the human body (in vivo) in an ethnically diverse sample of African and Caucasian Americans. METHODS: The chronotropic25 dose (CD25) was used to determine in vivo ß-AR responsiveness in 93 healthy participants. Psychometric measures included the Center of Epidemiological Studies-Depression Scale and the Multidimensional Fatigue Symptom Inventory. RESULTS: Hierarchical regression analyses (adjusted for age, gender, body mass index, blood pressure, smoking, and ethnicity) revealed that mental fatigue was significantly related to reduced ß-AR responsiveness (i.e., higher CD25 values) in the whole sample. Moderation analyses indicated significant ethnicity × depression/fatigue interactions. Depressive symptoms, total fatigue, emotional fatigue, mental fatigue, and physical fatigue were related to reduced ß-AR responsiveness in Caucasian American but not in African Americans. CONCLUSIONS: Our findings suggest that symptoms of depression and fatigue are related to decreased in vivo ß-AR responsiveness in Caucasian Americans. The lack of this association in African Americans highlights the importance for considering ethnicity as a potential moderator in research focusing on associations between psychological variables and cardiovascular function.

Pyroglutamate-amyloid-ß and glutaminyl cyclase are colocalized with amyloid-ß in secretory vesicles and undergo activity-dependent, regulated secretion.

BACKGROUND AND AIMS: N-truncated pyroglutamate (pGlu)-amyloid-ß [Aß(3-40/42)] peptides are key components that promote Aß peptide accumulation, leading to neurodegeneration and memory loss in Alzheimer's disease. Because Aß deposition in the brain occurs in an activity-dependent manner, it is important to define the subcellular organelle for pGlu-Aß(3-40/42) production by glutaminyl cyclase (QC) and their colocalization with full-length Aß(1-40/42) peptides for activity-dependent, regulated secretion. Therefore, the objective of this study was to investigate the hypothesis that pGlu-Aß and QC are colocalized with Aß in dense-core secretory vesicles (DCSV) for activity-dependent secretion with neurotransmitters. METHODS: Purified DCSV were assessed for pGlu-Aß(3-40/42), Aß(1-40/42), QC, and neurotransmitter secretion. Neuron-like chromaffin cells were analyzed for cosecretion of pGlu-Aß, QC, Aß, and neuropeptides. The cells were treated with a QC inhibitor, and pGlu-Aß production was measured. Human neuroblastoma cells were also examined for pGlu-Aß and QC secretion. RESULTS: Isolated DCSV contain pGlu-Aß(3-40/42), QC, and Aß(1-40/42) with neuropeptide and catecholamine neurotransmitters. Cellular pGlu-Aß and QC undergo activity-dependent cosecretion with Aß and enkephalin and galanin neurotransmitters. The QC inhibitor decreased the level of secreted pGlu-Aß. The human neuroblastoma cells displayed regulated secretion of pGlu-Aß that was colocalized with QC. CONCLUSIONS: pGlu-Aß and QC are present with Aß in DCSV and undergo activity-dependent, regulated cosecretion with neurotransmitters.