Blockade of the mineralocorticoid receptor improves markers of human endothelial cell dysfunction and hematological indices in a mouse model of sickle cell disease.

Increased endothelin-1 (ET-1) levels in patients with sickle cell disease (SCD) and transgenic mouse models of SCD contribute to disordered hematological, vascular, and inflammatory responses. Mineralocorticoid receptor (MR) activation by aldosterone, a critical component of the Renin-Angiotensin-Aldosterone-System, modulates inflammation and vascular reactivity, partly through increased ET-1 expression. However, the role of MR in SCD remains unclear. We hypothesized that MR blockade in transgenic SCD mice would reduce ET-1 levels, improve hematological parameters, and reduce inflammation. Berkeley SCD (BERK) mice, a model of severe SCD, were randomized to either sickle standard chow or chow containing the MR antagonist (MRA), eplerenone (156 mg/Kg), for 14 days. We found that MRA treatment reduced ET-1 plasma levels (p = .04), improved red cell density gradient profile (D50 ; p < .002), and increased mean corpuscular volume in both erythrocytes (p < .02) and reticulocytes (p < .024). MRA treatment also reduced the activity of the erythroid intermediate-conductance Ca2+ -activated K+ channel - KCa 3.1 (Gardos channel, KCNN4), reduced cardiac levels of mRNAs encoding ET-1, Tumor Necrosis Factor Receptor-1, and protein disulfide isomerase (PDI) (p < .01), and decreased plasma PDI and myeloperoxidase activity. Aldosterone (10-8 M for 24 h in vitro) also increased PDI mRNA levels (p < .01) and activity (p < .003) in EA.hy926 human endothelial cells, in a manner blocked by pre-incubation with the MRA canrenoic acid (1 µM; p < .001). Our results suggest a novel role for MR activation in SCD that may exacerbate SCD pathophysiology and clinical complications.

Association of salivary alpha-amylase and salivary flow rate with working memory functioning in healthy children.

The aim of this study was to examine the association between auditory and visual working memory (WM) performance and salivary alpha-amylase (sAA) and salivary flow rate (SFR) in a sample of 63 children (38 boys). WM was assessed by means of WISC-V subtests: four auditory subtests (Digit Span and Letter-Number Sequencing) and one visual subtest (Picture Span). SAA activity, output, and SFR were measured at baseline (10 min prior to testing), one minute prior to testing, one minute after the end of the auditory WM subtests and one minute after the end of the visual WM subtest. Our statistical analyses showed an association among SAA activity, output and SFR levels and the number of recalled digits in the last attempt score in Letter-Number Sequencing subtest. Specifically, our results showed that working performance in this task was associated with a concurrent decrease in SFR (r(63) = -0.423, p < .05). This salivary measure was the best predictor of this specific index of working memory performance (ß = -0.423, p < .05). These results show that the changes in SFR, which represents changes in parasympathetic tone, could be employed in future studies as a noninvasive marker of working memory performance in child studies.

Effect of supplementation with leucine alone, with other nutrients or with physical exercise in older people with sarcopenia: a systematic review.

BACKGROUND: Older adults are at a greater risk of developing sarcopenia as a result of reduced mobility, malnutrition, dietary changes and certain diseases. There are no systematic reviews in the literature analysing the effects of supplementation with leucine alone or as part of a supplement, and with or without physical exercise in older people with sarcopenia. We aimed to systematically review the evidence in intervention studies on the effects of supplementation with leucine, either alone, combined with other supplements, or combined with other supplements and physical exercise in older people with sarcopenia. MATERIALS AND METHODS: Literature searches related to the topic were conducted in three databases (Pubmed/Medline, Cochrane and SciELO) looking for articles published prior to December 2020. This review includes intervention studies in older adults over 60 years of age with a history of sarcopenia where researchers reported on the effects of leucine supplementation, with or without physical exercise, related to the disease's treatments or outcomes. RESULTS: The systematic review identified three intervention studies examining the effect of leucine without physical exercise, one on leucine with physical exercise, seven on leucine paired with another nutrient and without physical exercise, and twelve on leucine paired with another nutrient and physical exercise. The results revealed that leucine supplementation alone and without physical exercise did not improve markers of sarcopenia, whereas interventions pairing leucine with supplements, particularly leucine-enriched protein supplements, are a promising treatment for the improvement of sarcopenic markers, whether with or without physical exercise. CONCLUSIONS: Leucine supplementation, specifically paired with protein supplements, both with and without physical exercise, was found to be an effective dietary intervention for the improvement of sarcopenia. Further dietary interventions are necessary to calculate effective dosage quantities for both leucine and nutrient supplementation as an integral part of the treatment.

Impaired Suppression of Glucagon in Obese Subjects Parallels Decline in Insulin Sensitivity and Beta-Cell Function.

AIM: To examine the relationship between plasma glucagon levels and insulin sensitivity and insulin secretion in obese subjects. METHODS: Suppression of plasma glucagon was examined in 275 obese Hispanic Americans with varying glucose tolerance. All subjects received a 2-hour oral glucose tolerance test (OGTT) and a subset (n = 90) had euglycemic hyperinsulinemic clamp. During OGTT, we quantitated suppression of plasma glucagon concentration, Matsuda index of insulin sensitivity, and insulin secretion/insulin resistance (disposition) index. Plasma glucagon suppression was compared between quartiles of insulin sensitivity and beta-cell function. RESULTS: Fasting plasma glucagon levels were similar in obese subjects with normal glucose tolerance (NGT), prediabetes, and type 2 diabetes (T2D), but the fasting glucagon/insulin ratio decreased progressively from NGT to prediabetes to T2D (9.28 ± 0.66 vs 6.84 ± 0.44 vs 5.84 ± 0.43; P < 0.001). Fasting and 2-hour plasma glucagon levels during OGTT progressively increased and correlated positively with severity of insulin resistance (both Matsuda index and euglycemic hyperinsulinemic clamp). The fasting glucagon/insulin ratio declined with worsening insulin sensitivity and beta-cell function, and correlated with whole-body insulin sensitivity (Matsuda index, r = 0.81; P < 0.001) and beta-cell function (r = 0.35; P < 0.001). The glucagon/insulin ratio also correlated and with beta-cell function during OGTT at 60 and 120 minutes (r = -0.47; P < 0.001 and r = -0.32; P < 0.001). CONCLUSION: Insulin-mediated suppression of glucagon secretion in obese subjects is impaired with increasing severity of glucose intolerance and parallels the severity of insulin resistance and beta-cell dysfunction.

Genotype-Phenotype Features of Germline Variants of the TMEM127 Pheochromocytoma Susceptibility Gene: A 10-Year Update.

PURPOSE: This work aimed to evaluate genotype-phenotype associations in individuals carrying germline variants of transmembrane protein 127 gene (TMEM127), a poorly known gene that confers susceptibility to pheochromocytoma (PHEO) and paraganglioma (PGL). DESIGN: Data were collected from a registry of probands with TMEM127 variants, published reports, and public databases. MAIN OUTCOME ANALYSIS: Clinical, genetic, and functional associations were determined. RESULTS: The cohort comprised 110 index patients (111 variants) with a mean age of 45 years (range, 21-84 years). Females were predominant (76 vs 34, P < .001). Most patients had PHEO (n = 94; 85.5%), although PGL (n = 10; 9%) and renal cell carcinoma (RCC, n = 6; 5.4%) were also detected, either alone or in combination with PHEO. One-third of the cases had multiple tumors, and known family history was reported in 15.4%. Metastatic PHEO/PGL was rare (2.8%). Epinephrine alone, or combined with norepinephrine, accounted for 82% of the catecholamine profiles of PHEO/PGLs. Most variants (n = 63) occurred only once and 13 were recurrent (2-12 times). Although nontruncating variants were less frequent than truncating changes overall, they were predominant in non-PHEO clinical presentations (36% PHEO-only vs 69% other, P < .001) and clustered disproportionately within transmembrane regions (P < .01), underscoring the relevance of these domains for TMEM127 function. Integration of clinical and previous experimental data supported classification of variants into 4 groups based on mutation type, localization, and predicted disruption. CONCLUSIONS: Patients with TMEM127 variants often resemble sporadic nonmetastatic PHEOs. PGL and RCC may also co-occur, although their causal link requires further evaluation. We propose a new classification to predict variant pathogenicity and assist with carrier surveillance.

Salivary cortisol response to a psychosocial stressor on children diagnosed with attention-deficit/hyperactivity disorder: differences between diagnostic subtypes.

The purpose of the present study was to compare the reactivity of the HPA-axis in children diagnosed with different subtypes of ADHD against a healthy control group. This study included a total of 66 children: 33 children with ADHD diagnoses (10 with prevalent inattentive symptoms, 9 with prevalent hyperactive-impulsive symptoms and 14 with the combined subtype) and 33 healthy controls. The Trier Stress Social Test for Children (TSST-C) was employed as stressor. This test included two main stressors: first, completing a story initiated by an interviewer, and second, executing a timed cognitive task. Saliva samples were then obtained at -1, and +1, +10, +20 and +30 minutes with respect to the stress-inducing task. While the repeated-measures ANOVA showed a statistically significant time effect, the expected cortisol stress-response was not observed in any group. A difference was observed in the response from the hyperactive-impulsive group that was also observed in the AUC(G) comparisons with the subgroups. The ADHD group with prevalent hyperactivity-impulsive symptoms showed more significantly reduced cortisol levels than the control group and other experimental subgroup with prevalent inattentive symptoms.

Correction: Intensive longitudinal modelling predicts diurnal activity of salivary alpha-amylase.

[This corrects the article DOI: 10.1371/journal.pone.0209475.].

Association between Salivary Alpha-Amylase and Executive Functioning in Healthy Children.

The main aim of this study was to confirm the relationship between executive performance and salivary alpha-amylase (SAA) activity in a sample of 64 healthy children (39 boys), and compare it to the association of SAA output and salivary flow rate (SFR). Executive functioning was assessed via fluency, trail-making, rings and inhibition tasks from the Batería de Evaluación Neuropsicológica de la Función Ejecutiva en Niños [Battery of Neuropsychological Assessment for Executive Function in Children] (ENFEN), merged into an ENFEN total score. SAA activity, output, and SFR were measured at baseline, one minute before, and one minute after the end of a neuropsychological testing session. Our results confirmed a direct, linear and significant association between SAA activity and executive functioning, r(64) = .351, p < .05, and extended it to SAA output, r(64) =.431, p < .05. The mean level of SAA output was the best predictor of executive functioning (ß = .431, p < .05) and explained 18.2 % of the variance in ENFEN total score. In sum, and compared to SAA activity, measuring SAA output may be a more precise and indirect marker to assess executive functioning in children.

Cognitive performance and morning levels of salivary cortisol and alpha-amylase in children reporting high vs. low daily stress perception.

The aim of the present study was to assess the effects of daily stress perception on cognitive performance and morning basal salivary cortisol and alpha-amylase levels in healthy children aged 9-12. Participants were classified by whether they had low daily perceived stress (LPS, n = 27) or a high daily perceived stress (HPS, n = 26) using the Children Daily Stress Inventory (CDSI). Salivary cortisol and alpha-amylase were measured at awakening and 30 minutes later. Cognitive performance was assessed using the Cognitive Drug Research assessment system. The HPS group exhibited significantly poorer scores on speed of memory (p < .05) and continuity of attention (p < .05) relative to the LPS group. The HPS group also showed significantly lower morning cortisol levels at awakening and at +30 minutes measures in comparison with the LPS group (p < .05), and mean morning cortisol levels were negatively correlated with speed of memory (p < .05) in the 53 participants. No significant differences were observed between both groups in alpha-amylase levels. These findings suggest that daily perceived stress in children may impoverish cognitive performance via its modulating effects on the HPA axis activity.

Autonomic reactivity in blood-injection-injury and snake phobia.

OBJECTIVE: This research aimed to study the salivary flow and other autonomic reactions -heart rate (HR) and skin conductance response (SCR)- in blood-injection-injury (BII) phobia and snake phobia participants, under the assumption that exposure to blood-related pictures in BII phobia will provoke an increase in parasympathetic activity that, in turn, will lead to a greater saliva production than other affective contents. METHODS: We selected 18 BII phobia and 14 snake phobia participants along with 22 non-phobia individuals. All participants were exposed to 3 blocks of pictures (12 pictures per block) depicting either mutilations, snakes or neutral, household objects. Saliva samples were taken in the 2-min interval before and after each block. RESULTS: In comparison to other contents, blood-related pictures provoked an increase in salivary flow in BII phobia participants, as well as an increase in the number of SCRs. In the snake phobia group, snake pictures provoked HR acceleration, but the SCRs they elicited did not differ from the SCRs provoked by the blood-related pictures. CONCLUSION: BII phobia individuals react to their phobic object with a series of physiological changes resulting from a sympathetic-parasympathetic co-activation. This is in contrast with other specific phobias (e.g., small animal phobias) that usually show a sympathetically mediated, defensive reactivity when exposed to their disorder-relevant stimuli. These data support the use of therapeutic interventions in BII phobia that may differ in some respect from those used in other specific phobias.

Acute and subchronic effects of MDMA ("ecstasy") on anxiety in male mice tested in the elevated plus-maze.

3,4-Methylenedioxymethamphetamine (MDMA) is a compound structurally similar to methamphetamine, which has become one of the most widely used illicit substances. Animal studies investigating acute effects of MDMA on anxiety are unclear since, although an anxiogenic-like action of MDMA in different animal models of anxiety has been mainly described, there is also evidence supporting an anxiolytic-like effect for this drug. An attempt was made to clarify the possible anxiogenic-like profile of MDMA (1, 8 and 15 mg/kg i.p.) by analyzing its effect on behavior of male mice in the elevated plus-maze test. Moreover, the possible development of tolerance to the effects of MDMA on anxiety after its subchronic administration for 5 consecutive days was examined. The parameters evaluated included: (1) total time in open arms, (2) total time in closed arms, (3) total time in central area, (4) number of open arm entries, (5) number of closed arm entries and (6) number of central area entries. Acute treatment with MDMA (8 mg/kg) significantly reduced the time spent in the open arms, as well as markedly increasing the number of entries in the closed arms and in the central area, as compared with the control group, suggesting that MDMA, at this dose, has an anxiogenic-like activity. Mice subchronically treated with the drug (1 and 8 mg/kg) displayed a notable reduction in the time spent in the open arms, accompanied by an increase in the time spent in the closed arms and in the central platform. These results indicate that the anxiogenic-like effect found after acute treatment is not only maintained but also more marked after subchronic treatment. In contrast, mice treated subchronically with the highest dose of MDMA (15 mg/kg) exhibited a significant increase in the time spent in the open arms as well as a marked reduction in the time spent in the closed arms, supporting an anxiolytic-like activity of the drug. A possible dual pharmacological property of MDMA on anxiety is suggested.

Anxiogenic-like activity of 3,4-methylenedioxy-methamphetamine ("Ecstasy") in the social interaction test is accompanied by an increase of c-fos expression in mice amygdala.

3,4-Methylenedioxymethamphetamine (MDMA) is a synthetic amphetamine popularly known as "Ecstasy." Animal studies examining acute effects of MDMA on anxiety are unclear because although an anxiolytic-like action of MDMA in different animal models of anxiety has been described, there is also substantial evidence supporting an anxiogenic-like effect of this drug. To date, several studies have examined c-fos expression following MDMA administration in rats. However, there is no information about the MDMA-induced c-fos expression in mice previously tested in an animal model of anxiety. In this study, male mice were injected with MDMA (1, 8 and 15 mg/kg ip) and assessed for changes on anxiety and for the expression of the immediate early gene c-fos in the amygdala (central, basolateral and basomedial). Anxiety was evaluated by the "social interaction test." Ten behavioral categories were recorded: body care, digging, nonsocial exploration, exploration from a distance, social investigation, threat, attack, avoidance/flee, defense/submission and immobility. As compared with the control group, mice treated with MDMA (all doses) showed a decrease in mean duration and total time spent in social investigation behaviors, whereas avoidance/flee behaviors were significantly increased after treatment with this compound (8 and 15 mg/kg). Likewise, a significant increase in c-fos expression was found in the basolateral (all doses) and central (15 mg/kg) amygdala after MDMA administration. Overall, these findings indicate that MDMA exhibits an anxiogenic-like profile in the social interaction test in mice, and that central and basolateral amygdala might be involved in these anxiogenic-like effects of the drug.

Aldosterone's rapid, nongenomic effects are mediated by striatin: a modulator of aldosterone's effect on estrogen action.

The cellular responses to steroids are mediated by 2 general mechanisms: genomic and rapid/nongenomic effects. Identification of the mechanisms underlying aldosterone (ALDO)'s rapid vs their genomic actions is difficult to study, and these mechanisms are not clearly understood. Recent data suggest that striatin is a mediator of nongenomic effects of estrogen. We explored the hypothesis that striatin is an intermediary of the rapid/nongenomic effects of ALDO and that striatin serves as a novel link between the actions of the mineralocorticoid and estrogen receptors. In human and mouse endothelial cells, ALDO promoted an increase in phosphorylated extracellular signal-regulated protein kinases 1/2 (pERK) that peaked at 15 minutes. In addition, we found that striatin is a critical intermediary in this process, because reducing striatin levels with small interfering RNA (siRNA) technology prevented the rise in pERK levels. In contrast, reducing striatin did not significantly affect 2 well-characterized genomic responses to ALDO. Down-regulation of striatin with siRNA produced similar effects on estrogen's actions, reducing nongenomic, but not some genomic, actions. ALDO, but not estrogen, increased striatin levels. When endothelial cells were pretreated with ALDO, the rapid/nongenomic response to estrogen on phosphorylated endothelial nitric oxide synthase (peNOS) was enhanced and accelerated significantly. Importantly, pretreatment with estrogen did not enhance ALDO's nongenomic response on pERK. In conclusion, our results indicate that striatin is a novel mediator for both ALDO's and estrogen's rapid and nongenomic mechanisms of action on pERK and phosphorylated eNOS, respectively, thereby suggesting a unique level of interactions between the mineralocorticoid receptor and the estrogen receptor in the cardiovascular system.

Salivary alpha-amylase changes promoted by sustained exposure to affective pictures.

We studied the changes in salivary alpha-amylase (sAA) and other psychophysiological indices (heart rate, skin conductance, and corrugator supercilii activity) elicited by sustained exposure to affective pictures. Thirty-nine subjects viewed five blocks of pictures depicting mutilations, human attack, neutral scenes, sport/adventure, and erotica. Each block comprised 12 pictures of the same content. Saliva samples were collected before and after each block of pictures. The results showed that mutilation pictures promoted the greatest increase in sAA activity and output, as well as greater corrugator supercilii activity than pleasant pictures. Skin conductance response did not differ among high arousal picture contents. Changes in sAA varied with the affective valence but not with the arousal ratings of the pictures. Our results point to sAA as an index directly related to the unpleasantness elicited by sustained exposure to affective stimuli.

Activation of the mineralocorticoid receptor increases striatin levels.

BACKGROUND: Aldosterone (ALDO), a critical regulator of sodium homeostasis, mediates its effects via activation of the mineralocorticoid receptor (MR) through mechanisms that are not entirely clear. Striatin, a membrane associated protein, interacts with estrogen receptors in endothelial cells. METHODS: We studied the effects of MR activation in vitro and in vivo on striatin levels in vascular tissue. RESULTS: We observed that dietary sodium restriction was associated with increased striatin levels in mouse heart and aorta and that striatin and MR are present in the human endothelial cell line, (EA.hy926), and in mouse aortic endothelial cells (MAEC). Further, we show that MR co-precipitates with striatin in vascular tissue. Incubation of EA.hy926 cells with ALDO (10(-8) mol/l for 5-24 h) increases striatin protein and mRNA expression, an effect that was inhibited by canrenoic acid, an MR antagonist. Consistent with these observations, incubation of MAEC with ALDO increased striatin levels that were likewise blocked by canrenoic acid. To test the in vivo relevance of these findings, we studied two previously described mouse models of increased ALDO levels. Intraperitoneal ALDO administration augmented the abundance of striatin protein in mouse heart. We also observed that in a murine model of chronic ALDO-mediated cardiovascular damage following treatment with N(G)-nitro-L-arginine methyl ester plus angiotensin II an increased abundance of striatin protein in heart and kidney tissue. CONCLUSION: Our results provide evidence that increased striatin levels is a component of MR activation in the vasculature and suggest that regulation of striatin by ALDO may modulate estrogen's nongenomic effects.

Subjective Sleep Quality and hormonal modulation in long-term yoga practitioners.

Yoga represents a fascinating mind-body approach, wherein body movements (asana), breathing exercises (pranayama) and meditation are integrated into a single multidimensional practice. Numerous beneficial mental and physical effects have been classically ascribed to this holistic ancient method. The purpose of the present study has been to examine the effects of long-term yoga practice on Subjective Sleep Quality (SSQ) and on several hormonal parameters of the hypothalamus-pituitary-adrenal (HPA) axis. Twenty-six subjects (16 experimental and 10 controls) were recruited to be part of the study. Experimental subjects were regular yoga practitioners with a minimum of 3 years of practice. Blood samples for the quantification of adrenocorticotropic hormone (ACTH), cortisol and dehydroepiandrosterone sulphate (DHEA-S) were drawn from all subjects. Likewise, the Pittsburgh Sleep Quality Index (PSQI) was employed to assess SSQ. As statistical analysis, Mann-Whitney U-test was performed. The yoga group displayed lower PSQI scores and higher blood cortisol levels than control subjects. Therefore, it can be concluded that long-term yoga practice is associated with significant psycho-biological differences, including better sleep quality as well as a modulatory action on the levels of cortisol. These preliminary results suggest interesting clinical implications which should be further researched.

Biochemical changes after a qigong program: lipids, serum enzymes, urea, and creatinine in healthy subjects.

BACKGROUND: The aim of the present study was to analyze the effects of a qigong training program on blood biochemical parameters. MATERIAL/METHODS: Twenty-nine healthy subjects participated in the study of whom 16 were randomly assigned to the experimental group and 13 to the control. The experimental subjects underwent daily qigong training for one month. Blood samples for the quantification of biochemical parameters (total cholesterol, HDL, LDL, triglycerides, phospholipids, GOT, GPT, GGT, urea, creatinine) were taken before and after the training program. As statistical analysis, ANCOVA was performed. RESULTS: Statistically significant differences were found showing that the experimental group had lower serum levels of GOT (glutamic-oxaloacetic transaminase), GPT (glutamic-pyruvic transaminase), and urea and that there was a trend towards significance in GGT (gamma-glutamyltransferase). CONCLUSIONS: This study demonstrates that after practicing qigong for the short period of one month, noteworthy changes in several blood biochemical parameters were induced. While it is tempting to speculate on the relevance and implications of these biochemical variations, further investigation is needed to elucidate the scope of these findings.

The psychosocial stress-induced increase in salivary alpha-amylase is independent of saliva flow rate.

The stress response of salivary alpha-amylase (sAA) has been suggested as an index for sympathetic nervous system activation. However, concurrent inhibition of the parasympathetic nervous system is discussed as a confounder due to suppression of saliva flow rate. Here we set out to test the influence of stress-induced changes in flow rate on sAA secretion. Twenty-six subjects underwent the Trier Social Stress Test and a control condition. Saliva was sampled by passive drooling or salivettes. Saliva flow rate, sAA levels and output, salivary cortisol, and heart rate variability were measured. Flow rate increased only when sampled by passive drooling. Stress-induced increases in amylase levels were correlated with increases of amylase output but not with flow rate. Results indicate that flow rate is not a confounder of stress-induced sAA activation and suggest that valid measurements of sAA can be obtained by salivettes without the need for assessment of flow rate.