bluuebunny/crossref_metadata_2025 huggingface dataset:
Acute influence of oral vitamin C on the vasoconstrictor responses to local cooling and tyramine in human skin
Authors: Yamazaki Fumio
Published: June 2021

It has been reported that orally ingesting vitamin C (Asc) enhanced the cutaneous vasoconstrictor response to local cooling (LC). In this study, we examined whether the increased vasoconstrictor response caused by oral Asc is due to the adrenergic system. The release of neurotransmitters from adrenergic nerves in forearm skin was blocked locally by iontophoresis of bretylium tosylate (BT). Skin blood flow (SkBF) was measured by laser‐Doppler flowmetry at BT‐treated and untreated sites. The skin sites were locally cooled from 34 to 24°C at −1°C/min and maintained at 24°C for 10 min before (Pre) and 1.5 h after (Post) oral Asc (2g single dose) supplementation. Cutaneous vascular conductance (CVC) was calculated as the ratio of SkBF to blood pressure and expressed relative to the baseline value before LC. Oral Asc enhanced (P<0.05) the reductions in CVC at untreated sites but did not change the responses at BT‐treated sites during LC. To further examine whether adrenergically mediated vasoconstriction is enhanced by oral Asc, 0.1mM tyramine was administered using intradermal microdialysis in the forearm skin at 34°C in the Pre and Post periods. Oral Asc increased (P<0.05) the tyramine‐induced reduction in CVC. These findings suggest that oral Asc acutely enhances the cutaneous vasoconstrictor responses to LC through the modification of adrenergic sympathetic mechanisms.
Norepinephrine, but not neuropeptide Y, is involved in the cutaneous vasodilator response in young human females
Authors: Collins Ann B , Carter Stephen J , Del Pozzi Andrew T , Hodges Gary J
Published: June 2021

Previously, our laboratory reported that sedentary young males required neuropeptide Y (NPY) for a complete cutaneous vasodilator response to local skin heating. Animal work has shown no role for NPY in vascular control in females. We investigated the contribution of cutaneous noradrenergic sympathetic neurotransmitters norepinephrine (NE) and NPY between endurance trained and sedentary young females. Participant forearms were instrumented with mircodialysis fibers, local skin heaters, and laser‐Doppler probes. Treatments were as follows: untreated control (CT), propranolol and yohimbine (YP) to antagonize α‐ and β‐receptors, BIBP3226 administration to antagonize Y1‐receptors, and bretylium tosylate (BT) to presynaptically block the release of sympathetic neurotransmitters. Skin sites were locally heated from 33 to 42 ºC. YP treatment resulted in a reduction of the vasodilator response compared to CT (P<0.05) in both the endurance trained and sedentary young females; by contrast, BIBP3226 treatment had no effect (P>0.05) in either group. These data indicate that NE, but not NPY, plays a role in the vasodilator response to local skin heating in young females. Supported by The University of Alabama.
Role of MAP kinases in stress modulation of choline transport in cadmium (Cd) treated primary cultures of choroid plexus
Authors: Zarate Sara M , Stuart Samantha D Francis , Young Robin K , Villalobos Alice R
Published: June 2021

Our objective is to use primary cultures of rat choroid plexus to elucidate the up‐regulation of apical choline uptake in the context of the cellular response induced by low concentrations of Cd, i.e., 250–500 nM. The roles of MAP kinases were examined in preliminary experiments. In Cd‐treated cells, ERK1/2 was activated; inhibition of ERK1/2 activation with PD98059 resulted in greater accumulation of reactive oxygen species. However, inhibition of ERK1/2 activation abated stimulation of apical 3H‐choline uptake in Cd‐treated cells. Treatment with SP600125 to inhibit JNK activation markedly increased cytotoxicity in Cd‐treated cells as indicated by large increases in LDH release. Nevertheless, inhibition of JNK activation did not attenuate stimulation of choline uptake in Cd‐treated cells, but elicited even greater stimulation of uptake. Treatment with SB203580 to inhibit p38 MAP kinase induced a modest increase in cytotoxicity in Cd‐treated cells, but did not alter stimulation of choline uptake. These preliminary data suggest in cultured choroid plexus multiple MAP kinase pathways are activated by Cd, but stimulation of choline uptake is mediated by ERK1/2 specifically. Supported by NSF‐IOS# 1052654
Modulation of gastric nesfatin by rapamycin
Authors: Li Ziru , xu geyang , Li yin , Zhao Jin , zhang weizhen
Published: June 2021

Nesfatin‐1, an 82 amino acid peptide mainly found in the hypothalamus and stomach, is a novel satiety hormone acting through a leptin‐independent mechanism in the hypothalamus. Mechanism by which production of nesfatin‐1 is regulated remains unknown. Here we showed the co‐localization of pS6K, the downstream target of the mammalian target of rapamycin (mTOR) in the gastric X/A like cells. Reciprocal relationship of gastric mTOR signaling and nesfatin‐1 was observed during changes in energy status. Both mTOR activity and gastric nesfatin‐1 were down‐regulated by fasting, and returned to near basal level by re‐feeding. In high fat diet induced obese mice, gastric mTOR signaling and nesfatin‐1 were enhanced. Inhibition of the gastric mTOR signaling by rapamycin attenuated the expression of gastric nesfatin‐1 mRNA and protein in both lean and obese mice. Attenuation of mTOR activity by rapamycin or over‐expression of TSC1 or TSC2 reduced the expression of nesfatin in Min‐6 cells, suggesting a direct effect of mTOR signaling. In conclusion, gastric mTOR is a gastric sensor whose activity is linked to the regulation of gastric nesfatin‐1.
Liver heme oxygenase‐1 (HO‐1) protein expression in inbred rat strains divergent in survival to severe hemorrhage
Authors: Calderon Mariam Lee , Klemcke Harold G
Published: June 2021

We have previously identified inbred rat strains that are different in survival time to severe controlled hemorrhage (Brown Norway/Medical College of Wisconsin < Fawn Hooded Hypertensive = Dark Agouti; Klemcke et al., Physiol Genomics 43: 758, 2011). In efforts to identify cellular mechanisms associated with enhanced survival, we measured protein expression of liver HO‐1, an inducible, cytoprotective, anti‐inflammatory, and anti‐apoptotic protein. Inbred rats from these three strains were randomly assigned to one of three treatment groups (n = 4– 5/group): non‐operated controls, surgically catheterized rats, or catheterized rats bled (~ 46% of blood volume) 24 h post‐surgery. Rats were euthanized 30 min after handling or after initiation of a 26 min hemorrhage. Western blot analyses were conducted using a primary antibody specific for HO‐1. β‐actin, a “housekeeping” protein that was unaffected by strain or treatment, was used for normalization of HO‐1 expression. At the time intervals measured, liver HO‐1 protein expression did not differ among inbred rat strains (P = 0.51), but in all strains increased 28% (P = 0.02) after surgery with no further changes after hemorrhage. Such data suggest liver HO‐1 may be involved in cytoprotective effects after the stressor of surgery, but do not provide evidence for a strain‐dependent involvement in liver function post hemorrhage that might affect differential survival.
Calcineurin‐NFAT signaling regulates atrogin‐1 and MuRF1 via miR‐23a during glucocorticoid induced muscle atrophy
Authors: Hudson Matthew B , Woodworth-Hobbs Myra E , Zheng Bin , Gooch Jennifer L , Price S Russ
Published: June 2021

MicroRNAs play a critical role in biological processes including muscle atrophy. MicroRNA‐23a (miR‐23a) negatively regulates the expression of two atrophy‐related E3 ubiquitin ligases, atrogin‐1 and MuRF1, in skeletal muscle and cultured muscle cells. During atrophy miR‐23a is reduced in muscle cells. Although it was recently shown that miR‐23a expression is positively regulated by NFATc3, the mechanism of miR‐23a suppression during atrophy remains unknown. Previously, we found that the activity of calcineurin (Cn), a calcium‐activated phosphatase that regulates NFATc proteins, is decreased by diabetes. Since diabetes causes muscle atrophy, and glucocorticoids are required for this response, we investigated how the glucocorticoid dexamethasone (DEX) affects Cn activity, NFATc3 signaling, and miR‐23a expression. C2C12 or L6 myotubes were treated with 100 uM DEX to induce atrophy. Within 1 h of treatment, Cn activity was reduced and less NFATc3 was present in the nucleus. Further, the level of miR‐23a was also decreased within 30 minutes. After 48 h, expression of the NFATC3 target gene, MCIP1.4, and miR‐23a were decreased. Expression of atrogin‐1 and MuRF1 were also increased 48 h after DEX addition. Collectively, these findings indicate the Cn‐NFAT signaling pathway may play an important role in the regulation of atrogin‐1 and MuRF1 by suppressing miR23a during glucocorticoid induced muscle atrophy.

Supported by the National Institutes of Health awarded to M.B. Hudson (T32 DK007656) and the American Heart Association to S.R. Price (7660020)
Enhanced Exercise Capacity in Adenylyl Cyclase Type 5 Knockout Mimics Chronic Exercise Training
Authors: Lai Lo , Yan Lin , Park Ji Yeon , Dillinger Jean-Guillaume , Tian Bin , Houtkooper Riekelt , Auwerx Johan , Vatner Dorothy E , Vatner Stephen F
Published: June 2021

Exercise training improves skeletal muscle strength, affects muscle fiber types and increases exercise endurance, leading to prolonged longevity. Adenylyl cyclase type 5 knockout (AC5 KO) mice exhibit prolonged longevity and demonstrate increased exercise capacity. AC5 KO mice were able to run significantly longer than WT in both distance (817 ± 41m vs. 569±26m) and time (37.4±1.0min vs. 30.8±0.8min). The goal of this investigation was to determine whether AC5 KO mice share similar features with chronic exercise training. AC5 KO mice, like exercise training in WT, demonstrated more oxidative slow‐twitch fibers. Using RNA deep sequencing analysis, we found similar gene expression patterns in skeletal muscle between AC5 KO mice and the exercise‐trained WT mice. There were 72 genes (24%) commonly up‐regulated and 103 genes (27%) commonly down‐regulated between AC5 KO and WT exercise‐trained mice; they shared similar gene profiles in 27 different biological processes, including muscle contraction and metabolic related processes. Thus, AC5 KO mice, like exercise training, not only exhibit increased longevity but also share mechanisms resulting in improved skeletal muscle function and exercise endurance.
Functional characterization of novel tumor suppressor protein Sav1 in cancer cell proliferation and epithelial‐mesenchymal transition
Authors: Sakai Nobuya , Shibata Katsushi
Published: June 2021

Recent genetic screens of fly mutants and molecular analysis have revealed that the Hippo pathway controls both cell proliferation and apoptosis. Also, the Hippo pathway is reported to play a critical role in regulating tumorigenesis and epithelial‐mesenchymal transition (EMT). Specifically, adaptor protein Sav1 is the key component of the Hippo pathway; however its pathophysiological role in human cancer cells remains largely unknown. In this study, we found that ectopic expression of Sav1 induces apoptosis in human cancer cells and inhibits their growth and survival. In contrast, inhibition of Sav1 expression by shRNA failed to promote the human cancer cell proliferation and EMT. Moreover, we found that transcriptional co‐activator YAP and TAZ, the effector proteins of the Hippo pathway, are phosphorylated in Sav1 knockdown cells by similar extent to control cells. Taken together, although Sav1 is an essential component of the Hippo pathway, our results raise the possibility of Sav1‐independent hippo pathway activation in human cancer cells.
Dairy intake and obesity risk among teens
Authors: Nezami Manijeh , Siapco Gina , Sabate Joan
Published: June 2021

Childhood obesity is associated with a higher chance of a lifetime of obesity & disability in adulthood. Evidence suggests that dairy at recommended levels could be beneficial in weight maintenance. Our aim was to determine if dairy consumption is associated with obesity risk among teens. We conducted a cross‐sectional study among 255 teens (120 males, 135 females) ages 12– 18 years who reported their food intake through a web‐based food frequency questionnaire. Trained dietitians measured anthropometrics. Association between dairy intake—total dairy, cheese, milk, and dairy desserts—on obesity indices (BMI, waist‐to‐ hip ratio [W/H]) for all teens, and body composition (fat mass [FM], fat‐free mass [FFM]) for gender groups, were determined by ANOVA. Groups by dairy intake categories (zero, low, medium, and high) have similar ages. Dairy intake was not associated with BMI. Intakes of total dairy, milk, and cheese were positively associated with W/H (p‐trend for all < .01); high intake was significantly different from medium/low intake (total dairy, 0.81 vs. 0.77; milk, 0.82 vs. 0.78; cheese, 0.81 vs. 0.78). FFM of females was 39.3 kg for high vs. 41.9 kg for low intake (p<.05) while W/H increased with increasing total dairy and milk intake for males (p<.05) but not for females. We conclude that dairy has a neutral effect on BMI but high intake (3+ svgs/d) may potentially increase central adiposity particularly for males
Associations between Knowledge and Attitudes about Sports Drinks and Sports Drink Intake among U.S. Youth
Authors: Zytnick Deena , Park Sohyun , Onufrak Stephen J.
Published: June 2021

Despite recommendations by the American Academy of Pediatrics to limit sports drink (SD) intake, SD intake has recently risen among youth. This cross‐sectional study examined the associations between caregivers’ and youths’ health‐related knowledge and attitudes about SD with SD intake among 815 U.S. youth (12–17 years) using 2011 YouthStyles and HealthStyles Survey data on youth and their caregivers. Multivariable logistic regression analysis was used to estimate adjusted odds ratios (OR) and 95% confidence intervals (CI) for youth drinking sports drinks ≥1 time/week. About 1 in 5 youth consumed sports drinks ≥1 time/week. Among youth, nearly half agreed that sports drinks are healthy drinks for children, compared with 20% of their caregivers. About 1 in 3 caregivers agreed that children need sports drinks for hydration. The adjusted odds of youth drinking sports drinks ≥1 time/week were significantly higher among youth of caregivers who agreed that children needed sports drinks for hydration (OR=3.12, 95% CI=1.74, 5.57 vs. disagreed) and among youth of caregivers who agreed that sports drinks are good, healthy drinks for children (OR=2.78, 95% CI=1.46, 5.27 vs. disagreed). However, youth knowledge and attitudes about sports drink were not associated with their sports drink intake. Our findings suggest that parental sports drink education may help reduce youths’ sports drink intake.
The Ability of Spices to Increase Vegetable Intake among Overweight Adults, Measured by a Universal Eating Monitor
Authors: Li Zhaoping , Brahe Lena K , Zerlin Alona , Rheinwald‐Jones Alexis , Krak Michael , Thames Gail , Heber David
Published: June 2021

Introduction

The intake of vegetables in the US remains below the recommendation in the Dietary Guidelines for Americans; particularly intake of cruciferous vegetables is often low, due to their bitter taste. The aim of this ongoing study is to examine if added spice mixtures can offset taste aversions and increase the intake of different vegetables including the cruciferous vegetables broccoli and cauliflower.

Methods

Twenty healthy overweight adults (BMI: 25–30 kg/m2) with a daily intake of less than three servings of vegetables are enrolled, ensuring equality between sexes and between high and low restraint eaters, defined by the Three Factor Eating Questionnaire (TFEQ‐R21). At a total of 10 visits, a random selected vegetable, with or without added spices, is served in quantities sufficient to test intake, and a computer‐based system modified from the Universal Eating Monitor (UEM) is used to measure total food intake (g), meal duration (min) and eating rate (g/min), and to obtain VAS scores to assess sensory and hedonic qualities of the vegetable, and ratings of appetite and mood.

Results

Method feasibility and preliminary observations have been obtained. Final statistical analysis is pending.

Perspective

The UEM method can give valuable information on whether simple approaches as addition of spices, potentially can increase vegetable intake as recommended by the Dietary Guidelines for Americans.
Decreasing physical activity is linked with increased obesity in Henan province, China
Authors: Zhang Ding , Zhang Shufang , Zhan Xuan , Chao Feng , Du Shufa
Published: June 2021

Few studies explored the reasons for the rapid increases in overweight plus obesity (BMI ≥ 25) in Henan, one of the largest provinces in China with >; 100 million populations. This study's goal was to analyze the dynamic changes in physical activity (PA) and the association between PA and BMI ≥ 25. A subsample from the China Health and Nutrition Survey was used. Multinominal logistic regression was used to assess the association between PA and BMI ≥ 25. PA levels significantly decreased and screen time significantly increased with constant improvement in transportation and technology in Henan province. As a result, overweight and obesity (BMI ≥ 25) more than tripled from below 10% in 1989 to 35% in 2009 and over 40% in urban areas, even though energy intake decreased by 25% during the same period. Decreased PA significantly increased the risk of overweight and obesity, controlled for age, sex, PA at baseline, and energy intake. Promoting PA and healthy lifestyle should be considered as the major health promotion strategy in Henan province.
Effect of Eurycoma longifolia on Stress Hormones and Psychological Mood State in Moderately Stressed Subjects
Authors: Talbott Shawn , Talbott Julie , George Annie , Pugh Michael
Published: June 2021

Eurycoma longifolia is a medicinal plant commonly called Tongkat ali (TA) and “Malaysian ginseng.” TA roots are a traditional “anti‐aging” remedy and modern supplements are intended to improve libido, energy, sports performance and weight loss. Previous studies have shown properly‐standardized TA to stimulate release of free testosterone, improve sex drive, reduce fatigue, and improve well‐being.

We assessed stress hormones and mood state in 63 subjects (32 men and 31 women) screened for moderate stress and supplemented with a standardized hot‐water extract of TA root (PhystaTM, Biotropics Malaysia) or Placebo for 4 weeks.

Significant (p<0.05) improvements were found in the Physta group for Tension (−11%), Anger (−12%), and Confusion (−15%). Stress hormone profile (salivary cortisol and testosterone) was significantly (p<0.05) improved by Physta supplementation, with reduced cortisol exposure (−16%) and increased testosterone status (+37%). These results indicate that daily supplementation with Tongkat ali (Physta) improves stress hormone profile and certain mood state parameters, suggesting that this “ancient” remedy may be an effective approach to shielding the body from the detrimental effects of “modern” chronic stress.

This study was funded by Biotropics Malaysia and conducted by SupplementWatch
HMB Attenuates A Loss of Myofiber Cross‐Sectional Area during Prolonged Exercise with Calorie Restriction by Enhancing Regenerative Capacity
Authors: Park Bong‐Sup , Henning Paul C , Khamoui Andy V , Jo Edward , Lee Sang‐Rok , Zourdos Michael C , Kim Do‐Houn , Yeh Ming‐Chia , Kim Jeong‐Su
Published: June 2021

β‐hydroxy‐β‐methylbutyrate (HMB) has shown to attenuate loss of muscle mass and function. However, the efficacy of HMB during catabolism generated by prolonged exercise with calorie restriction has yet been addressed. Therefore, the present study investigated the impact of HMB on myofiber cross sectional area (CSA) and molecular regulators during a 6‐wk normal or catabolic condition. C57BL/6 male mice (Age= 6 wks) were divided into 4 groups (10/group): ALT=ad libitum+trained (1h/d for 3d/wk), ALTH=ALT+HMB (0.5 g/kg BW/day), C=caloric restricted (−30%)+trained (6hrs/d, 6d/wk) and CH=C+HMB. After the experimental period, the gastrocnemius muscles were isolated and analyzed histologically for myofiber number and CSA. Protein levels of atrogin‐1, myogenin, and phosphorylated Akt (pAkt) were determined by western blot. One‐way ANOVA was used and significance was set at p<0.05. Mean myofiber CSA (μm2) of the gastrocnemius in C was significantly lower than the ALT and ALTH (−38%), and CH (−35%), while the fiber number per field CSA was 35% higher in C than CH. Myogenin levels were significantly lower only in C compared to ALT and ALTH, while no group differences were detected for atrogin‐1 and pAkt. Our findings demonstrate the potential mechanisms of HMB action in enhancing regenerative capacity and attenuating the loss of myofiber CSA during prolonged exercise with low calorie intake.
Pressure overload amplifies IL‐18 signaling in a rabbit model of myocardial hypertrophy and failure
Authors: Yoshida Tadashi , Srinivas Mummidi , Friehs Ingeborg , del Nido Pedro J. , Somanna Naveen , Valente Anthony J. , Chandrasekar Bysani
Published: June 2021

Sustained inflammation plays a causal role in the development and progression of LVH and its transition to failure. We hypothesized that pressure overload (PO) amplifies interleukin (IL)‐18 signaling during LVH and failure, and IL‐18 is a potent pro‐hypertrophic cytokine.

Results

Using a rabbit model, we report that PO by constriction of the descending thoracic aorta induces LVH. Monitoring by echocardiography indicates compensated hypertrophy at 4 weeks (Mass/Volume ratio: 1.7±0.11) and ventricular dilatation indicative of failure at 6 weeks (M/V ratio: 0.7±0.04). We cloned rabbit IL‐18, IL‐18Rα and β, and IL‐18BP full‐length cDNA, and show that PO, while enhancing IL‐18 and IL‐18R expression in hypertrophied and failing hearts, markedly attenuated expression levels of the IL‐18 antagonist IL‐18 binding protein. In vitro, cyclical mechanic stretch (10% cyclic equibiaxial stretch, 1 Hz) induced hypertrophy of cardiomyocytes (CaM) and enhanced IL‐18, IL‐18Rα and ANP‐1 expression. Treatment with rhIL‐18 induced its own expression and that of IL‐18Rα via AP‐1, and CaM hypertrophy via PI3K/Akt/GATA4.

Conclusions

PO enhances IL‐18 and its receptor expression in hypertrophied and failing hearts. Since IL‐18BP expression is markedly inhibited, our results indicate a positive amplification in IL‐18 inflammatory signaling, and suggest IL‐18 as a potential therapeutic target in LVH and failure.
Low respiratory quotients in chow‐fed male bonnet macaque monkeys as an indicator of metabolic stress due to single cage housing
Authors: Rising Russell , Lin Jack
Published: June 2021

Objective

Determine the metabolic affects of previously group housed male monkeys residing in single cage housing (SCH).

Methods

After two months of SCH, 16 adult male bonnet macaque (M. radiata) monkeys (11.0 ± 1.9 kg, modified BMI = 40.0 ± 7.0 kg/crown‐rump length, m2 and 14.5 ± 3.1 years old) were each placed in the primate Enhanced Metabolic Testing Activity Chamber (EMTAC Inc. Santa Barbara, CA) for 22‐hour measurements of energy intake (kcal/kg) and expenditure (EE; kcal/kg/min), along with the respiratory quotient (RQ;VCO2/VO2). All were fed monkey chow #5038 (LabDiet Inc., Richmond, IN) ad‐libitum under a 12/12 hour light/dark cycle. Metabolic data were divided into day (8‐hours), night (12‐hours) and morning periods (2‐hours). For data analysis (SPSS Ver. 13), monkeys were divided into stressed and non‐stressed groups based on their RQ being above or below 0.70, respectively.

Results

When compared to their non‐stressed counterparts, stressed monkeys exhibited a lower 22‐hour mean RQ (0.66 ± 0.03 vs. 0.78 ± 0.05; p<0.05) as well as that during the day (0.69 ± 0.04 vs. 0.81 ± 0.03; p<0.05), dark (0.63 ± 0.02 vs. 0.77 ± 0.07; p<0.05) and morning (0.67 ± 0.03 vs. 0.77 ± 0.07; p<0.05) periods. Moreover, stressed monkeys had a greater EE during the morning period (4.1 ± 0.6 vs. 3.5 ± 0.3 kcal/kg; p<0.05) when compared to their non‐stressed counterparts. Finally, energy intake was reduced in the stressed (7.0 ± 8.5) compared to non‐stressed (27.0 ± 12.2) monkeys.

Conclusion

Besides the low energy intake, the EMTAC enabled the detection of abnormal metabolic changes associated with the apparent stress of long term SCH.
Prolonged NLRP3 inflammasome activation enhances the secretion of autophagy‐derived vesicles containing LC3II in murine dendritic cells
Authors: Russo Hana Marie , Dubyak George R.
Published: June 2021

Autophagy provides a brake on overall NLRP3 inflammasome activation while also promoting non‐classical Il‐1β export in the early phases of inflammasome activation. The mechanism of autophagy dependent non‐classical secretion in response to NLRP3 inflammasome activation is unclear. To investigate this process, bone marrow derived dendritic cells from wild‐type C57BL/6 mice were primed with LPS and then stimulated with ATP to activate P2X7R channels and the downstream NLRP3 inflammasome. Cell lysates and extracellular (EC) fractions were then processed for western blot analysis of LC3II, a marker of the autophagosome. A prolonged ATP stimulus resulted in increased secretion of both non‐lipidated LC3I and lipidated LC3II. To characterize secreted LC3II‐containing vesicles, EC samples were fractionated by differential centrifugation to isolate total, microvesicle‐free, and exosome‐free EC supernatants. Western blot analysis revealed that the majority of LC3II is present in the total EC supernatant, less is present in the microvesicle‐free EC supernatant, and LC3II is not present in the exosome‐free EC supernatant. LCI levels were equivalent in all EC fractions. Thus, prolonged NLRP3 inflammasome activation enhances the secretion of autophagy‐derived vesicles that are similar in size to microvesicles or exosomes. (Support: NIH‐R01‐GM36387)
R‐type Ca2+ channels and inhibitory neuromuscular transmission in the gastrointestinal tract
Authors: Rodriguez‐Tapia Eileen , Galligan James
Published: June 2021

Enteric inhibitory neuromuscular transmission relaxes gut smooth muscle via nitric oxide (NO) and purinergic mechanisms. In the guinea pig ileum, R‐type Ca2+ channels couple to release of NO while P/Q‐ and N‐type Ca2+ channels couple to release of the purine. In the current studies we tested the hypothesis that R‐type Ca2+ channels also couple selectively to NO release in the mouse colon by studying relaxations and inhibitory junction potentials (IJPs).

Methods

Longitudinal muscle relaxations were studied using an in vitro organ bath system and intracellular recordings were conducted to study IJPs. Both responses were evoked using electrical field stimulation. The effects of drugs applied to the organ bath solution were investigated.

Results

The R‐type Ca2+ channel blocker, NiCl2 (1–50 micromolar) did not alter neurogenic relaxation (10 Hz, 1s stimulus train) of the mouse distal colon. However, NiCl2 (50 micromolar) reduced the peak response and integrated areal of the IJP (1–60 Hz, 200 ms stimulus train).

Conclusion

R‐type Ca2+ channels couple to release of inhibitory neurotransmitters in the guinea pig and mouse gastrointestinal tract. The relationship between IJPs and relaxation of the mouse colon is not clear.
Initial characterization of histamine H2‐receptor overexpressing mice
Authors: Neumann Joachim , Köhler Friederike , Kirchhefer Uwe , Höft Andy , Buchwalow Igor , Gergs Ulrich
Published: June 2021

Histamine is known to have positive inotropic and positive chronotropic effects in the human heart. The involvement of histamine receptors in human heart failure is controversial. However, some lines of evidence suggest that the histamine H2‐ receptor is downregulated in end‐stage heart failure and its blockade is beneficial for the patient. Therefore, we set out to generate transgenic mice which overexpress the human H2‐ receptor, labeled with a C‐terminal His tag, specifically in the heart by means of the α‐myosin heavy‐chain promoter. We obtained one line of animals where histamine was able to increase contractility in isolated left atrial preparations or isolated perfused hearts or in vivo using left ventricular echocardiography. Of importance, this effect could be blocked by cimetidine, a H2‐receptor antagonist. In contrast, histamine was inactive in preparations from littermate wild type animals. The EC50 for the inotropic and chronotropic effects in atrial preparations amounted to about 10−6M (n=6–8). The effect was accompanied by an increase in the phosphorylation state of serine 16 on phospholamban and this effect could be completely blocked by cimetidine. Immunohistochemisty revealed that the transgene using an anti His antibody was located mainly to the sarcolemma. In summary, we have generated a novel model system to study the functional role of the human histamine H2‐ receptor in a mammalian model.
An investigation of metabotropic glutamate receptor 5 negative allosteric modulators in physiological and behavioral indicators of anxiety and cognition in rodents
Authors: Moon Joshua , McGinnis Dina , Smith Deborah L , Graf Radka , Hughes Zoe , Grimwood Sarah , Miller Emily , Trapa Patrick , Shaffer Christopher L , Siok Chester J
Published: June 2021

Negative allosteric modulators (NAMs) of the metabotropic glutamate receptor type 5 (mGluR5) have been proposed as potential anxiolytic therapeutics. However, evidence from rodent studies suggests that at high doses they may also cause cognitive disruption (Ballard et al., 2005). The stimulated hippocampal theta EEG model in rats has been proposed to be predictive of both anxiolytic activity and cognitive enhancement or disruption (McNaughton et al., 2007). We used this assay to test three mGluR5 NAMs (AFQ056 and two novel, structurally distinct compounds) for signs of anxiolytic activity and cognitive disruption. These studies were supported by rat in vivo receptor occupancy (RO), mouse stress‐induced hyperthermia (SIH) to assess anxiety, and rat radial arm maze (RAM) to evaluate spatial working memory. Consistent with predicted anxiolytic activity, all three compounds lowered stimulated theta frequency without affecting theta power or overt oscillatory activity at RO levels which reduced SIH. At ≥80% RO, which afforded RAM disruptions, theta power was lowered or disrupted. While previous studies of stimulated hippocampal theta have compared class effects of anxiolytic or cognitively impairing agents, this is the first study linking RO to both electrophysiological properties and behavioral effects, further demonstrating the value of the stimulated theta assay for characterizing novel mechanisms. Sponsored by Pfizer, Inc.
Reduction in peripheral blood beta arrestin1 levels during major depressive disorder in reproductive women
Authors: Nayyar Tultul , Alam Farzana , Richie William , Ansah Twum A , Bailey Rahn K
Published: June 2021

OBJECTIVE

Women are twice as likely as men to develop major depressive disorder (MDD) during their reproductive years. G protein coupled receptor (GPCR) signaling mechanism has been implicated in both the pathogenesis and treatment of MDD. Beta arrestin (β‐AR)‐1 protein plays regulatory role in the GPCR signaling. We studied the relationship between the severities of MDD and the protein levels of β‐AR1, G protein subunits (Gαs and Gαi) in the peripheral blood mononuclear leukocytes (PBMC) of women during reproductive ages.

DESIGN AND METHODS

Non‐pregnant women with MDD were evaluated with Mini‐ International Neuropsychiatric Interview for Axis I Diagnostic and Statistical Manual of Mental Disorders, 4th edition, criteria (DSMIV‐TR). The severity of depression were determined by the 17‐item Hamilton Depression Rating Scale (HDRS) at two time points: (i) during depression (before taking any antidepressants/therapy) and (ii) at 8 weeks after clinical treatment with antidepressants/therapy. The protein levels of β‐AR1, Gαs and Gαi in PBMC were determined by ELISA.

RESULTS

Significant inverse correlation between β‐arrestin‐1, Gαs, Gαi protein levels in the PBMC and the HDRS score were obtained.

CONCLUSION

The levels of β‐AR1 in PBMC of patients with MDD may potentially serve as a biochemical marker for the affective state of these patients. Research supported by 8 U54 RR026140 03(NIMHD).
The preventive and therapeutic efficacy of finasteride and dutasteride in TRAMP mice
Authors: Opoku‐Acheampong Alexander Boadu , Unis Dave , Beck Amanda P , Henningson Jamie , Lindshield Brian L
Published: June 2021

The Prostate Cancer Prevention Trial and Reduction by Dutasteride of Prostate Cancer Events trial found that the 5α‐reductase (5αR) inhibitors finasteride and dutasteride, respectively, decreased prostate cancer prevalence but also increased the incidence of high‐grade tumors. Because finasteride only inhibits 5αR2, we hypothesized that finasteride would not be as efficacious in preventing prostate cancer development in C57xFVB TRAMP mice as dutasteride, which inhibits both 5αR1 and 5αR2. Six week old mice were randomized to a control AIN93G or pre‐and post‐finasteride and dutasteride diet (83.3 mg drug/kg diet) groups (n =30–33) that began at 6 and 12 weeks of age, respectively, and terminated at 20 weeks of age. The pre‐and post‐groups were designed to test the preventive and therapeutic efficacy of the drugs, respectively. Final body weights were decreased in the pre‐dutasteride group and genitourinary tract weights were decreased in pre‐finasteride, pre‐and post‐dutasteride groups. The incidence of low‐grade and high‐grade PIN as the most severe lesions in the anterior and dorsal lobes of the dutasteride groups increased and decreased, respectively. There was also an increased incidence of poorly differentiated cancer as the most severe lesion in the dorsal lobe of pre‐dutasteride and both finasteride groups. There are some commonalities between our findings and trial results reported previously.
A new strategy to block tumor angiogenesis by inhibiting endocannabinoid inactivation
Authors: El‐Azab Mona , Ammar Ramy , Abdel‐Hamid Medhat , Moustafa Yasser
Published: June 2021

Angiogenesis is a key process in the promotion of cancer. Endocannabinoids are endogenous compounds known to mediate psychotropic effects by stimulating the cannabinoid receptor type‐1 (CB1). The present study was carried out to investigate the antiangiogenic effect of the endocannabinoid reuptake inhibitor, OMDM‐2, in comparison with the direct cannabinoid agonist, R‐methanandamide in Ehrlich ascites carcinoma (EAC)‐bearing mice. Solid tumors were induced by intradermal injection of EAC cells that were used for the evaluation of tumor vascular volume using Evan's blue. In addition, tumor weight, serum transforming growth factor‐β1 (TGF‐β1), and its intra‐tumoral receptor (CD‐105) were determined as a time course on days 7, 14, and 21 postinoculation. OMDM‐2 (5 mg/kg, i.p.) significantly reduced the percentage of angiogenesis as efficaciously as R‐Met (0.5 mg/kg, i.p.). On day 7, the treatment with R‐Met or OMDM‐2 significantly down‐regulated CD‐105 expression as evaluated immunohistochemically. Both treatments impeded tumor growth as evident by significant reduction in tumor weight along the study period. The combination with CB‐1 receptor antagonist, NIDA 41020 (0.7 mg/kg, i.p.), counteracted all the previous effects in R‐Met‐treated group but not in OMDM‐2‐treated group. Interestingly, on day 7, the treatment with R‐Met or OMDM‐2 significantly increased serum levels of TGF‐β1, an effect that was not antagonized in both groups by pre‐treatment with NIDA 41020. In conclusion, we have provided for the first time data on the possible in vivo use of OMDM‐2 as an anti‐cancer drug to be an alternative to direct cannabinoid receptor agonists to avoid their CB1‐mediated psychotropic side effects.
Effects of Ethanol Extract of Gastrodia elata Blume on High‐Fructose induced Metabolic syndrome
Authors: Kho Min Chul , Lee Yoon Jung , Ahn You Mee , Choi Yoon Hee , Kim A Young , Kang Dae Gill , Lee Ho Sub
Published: June 2021

Metabolic syndrome including insulin resistance, dyslipidemia and hypertension is a cluster of risk factor of cardiovascular disease. Gastrodia elata Blume (EGB), a widely used traditional herbal medicine, was reported with anti‐inflammatory and anti‐diabetes activity. Aim in the present study was to investigate that ethanol extract of EGB ameliorate metabolic signs of 65% high‐fructose diet induced metabolic syndrome. Treatment with EGB (100 mg/kg/day for 8 weeks) was significantly suppressed the increments of epididymal fat weight, blood pressure, plasma triglyceride, leptin and total cholesterol levels. EGB treatment also elevated HDL cholesterol and oral glucose tolerance. Staining with HE and Oil‐red‐O demonstrated marked increase of adipocyte size and hepatic accumulation of triglycerides, and these increases were prevented by EGB. EGB amelorated endothelial dysfunction by down‐regulation of ET‐1 and adhension molecules in the aorta. In addition, EGB suppressed mRNA expression of the cytokines related with hepatic proinflammation. Moreover, EGB induced markedly up‐regulation of AMPKα phosphorylation in the liver, muscle and fat. These results indicate that EGB ameliorates obesity, insulin resistance, dyslipidemia, hypertension and fatty liver in HF diet rats. Take together, Gastrodia elata Blume might be a beneficial therapeutic approach for metabolic syndrome.
Genotype‐phenotype relationship in patients affected by novel CLCNKB mutations
Authors: Andrini Olga , Keck Mathilde , Blanchard Anne , Vargas‐Poussou Rosa , Lourdel Stéphane , Teulon Jacques
Published: June 2021

Background

The CLCNKB gene encodes for ClC‐Kb, a renal Clchannel expressed in the basolateral membrane of the distal nephron. Mutations occurring in CLCNKB gene are the molecular cause of classic Bartter syndrome (cBS) type III, an autosomal recessive disorder characterized by salt‐wasting tubulopathy.

Aim

Functional characterization of 6 novel ClC‐Kb mutants and their implication in the cBS phenotype.

Methods

Characterization of ClC‐Kb mutants using heterologous expression systems. Protein abundance, surface expression and Clcurrents were collected.

Results

G246R, G424E and L439P did not carry any current whereas the others mutants showed a variable reduction of the current with respect to WT (L81P 50%; R351P 67% and V170M 63%). We investigated the sensitivities to external H+ and Ca2+, two biophysical properties of CLC‐Kb, in mutants showing residual activity. We observed no difference in half‐maximal pH inhibition (pKa) and in the stimulating effect of external Ca2+ ([Ca2+]ext ) for L81P and R351P as compared to WT. In contrast, there was a dramatic alteration in both pKa and sensitivity to [Ca2+]ext for V170M. Regarding surface expression, the mutants fell into 2 categories: (i) impaired surface expression: G246R, G424E and L439P; (ii) reduction of the plasma membrane expression: L81P, V170M and R351P.

Conclusions

Reduced targeting to the membrane and/or lower stability of the membrane protein is the main functional consequence of these mutations. V170M showed an altered pHext and [Ca2+]ext sensitivity. This feature can partially explain the mild phenotype of cBS, the partial impairment of plasma membrane targeting being compensated by a higher activity of the mutated channel under physiological conditions.
Effect of Poria cocos on hypertonic stress‐induced water channel expression and apoptosis in renal collecting duct cells
Authors: Lee So Min , Lee Yun Jung , Yoon Jung Joo , Li Bin , Lee Yong Pho , Kim Dae Hwan , Kang Dae Gill , Lee Ho Sub
Published: June 2021

Aquaporin‐2 (AQP2), a family of water channels, plays an important role in the urinary concentrating process and regulation of water balance in the kidney. The dried sclerotia of Poria cocos Wolf (WPC) has been used for chronic edema and nephrosis. This study was conducted to evaluate the effects of WPC on hypertonic stress (175 mM NaCl)‐induced AQP2 expression and apoptosis in murine inner medullary collecting duct cell line (mIMCD‐3). WPC significantly attenuated the hypertonicity‐induced AQP2 protein and mRNA levels and blocked the apical membrane insertion of AQP2 in a concentration‐dependent manner. Tonicity‐responsive enhancer binding protein (TonEBP) mRNA was also recovered by WPC under hypertonic stress. Furthermore, pretreatment with WPC presented the similar effect with KT5720 which was decreased hypertonic stress‐induced AQP2 expression. On the other hand, WPC significantly recovered hypertonic stress‐injured mIMCD‐3 viability and cell number. WPC markedly inhibited hypertonic stress‐induced Bax or caspase‐3 expression, whereas Bcl‐2 expression was increased. Besides, WPC attenuated the hypertonicity‐induced morphological changes in nuclei, resulting in anti‐apoptotic effect. Thus, these data suggests that WPC has beneficial effects on the therapeutic approach to renal disorder.
Increases in renal medullary 20‐HETE formation oppose the development of hypertension and improves pressure natriuresis in CYP4A1 transgenic Dahl S rats
Authors: Murphy Sydney , Fan Fan , Baker Rodney , Roman Richard
Published: June 2021

A genetic deficiency in renal 20‐HETE formation contributes to the development of hypertension in Dahl (S) rats. We hypothesized upregulation of CYP4A protein expression and renal 20‐HETE production improves pressure natriuresis and attenuates the development of hypertension in the S rat. Utilizing a sleeping beauty transposon construct, we generated CYP4A1 transgenic Dahl S rats. Introgression of the CYP4A1 gene, responsible for the formation of 20‐HETE, into the S genetic background, significantly increased CYP4A protein expression and 20‐HETE production by 3 and 2 fold in the kidneys of transgenic CYP4A1 rats fed high salt (HS) diet compared to S rats. MAP (177±10 mmHg) and proteinuria (295±22 mg/day) increased in S rats fed HS diet for 4 weeks, but only rose to 139±5 mmHg and 175±22 mg/day (p<0.05) in CYP4A1 transgenic rats. Pressure natriuretic and diuretic responses were 2 fold higher in CYP4A1 transgenic rats. Chronic inhibition of outer medullary 20‐HETE synthesis by renal medullary infusion of HET0016 (1 mg/kg/day) rescued the hypertensive phenotype in CYP4A1 transgenic rats (173±10 mmHg and 401±37 mg/day). These results indicate upregulation of CYP4A protein expression and 20‐HETE production attenuates the development of hypertension and renal injury and improves pressure natriuresis response in CYP4A1 transgenic Dahl S rats. AHA11POST7520052, HL36279, HL29587
Renal effects produced by microinjection of kappa opioid agonist into the bed nuclei of the stria terminalis (BST)
Authors: Franklin Cynthia , Rangel Yolanda , Fortepiani Lourdes , Toney Glenn , Gottlieb Helmut
Published: June 2021

Intracerebroventricular (ICV) injection of the kappa opioid agonist, U‐50448H (U50), produces a marked diuresis, antinatriuresis, and an increase in renal sympathetic nerve activity (RSNA). The dorsomedial BST has been show to express kappa opioid receptors (KOR) that project to the hypothalamic areas involved in water homeostasis, therefore we examined if injection of U50 into the BST would produce similar effects on renal function.

Methods

Rats anesthetized with urethane‐chloralose were instrumented to record arterial blood pressure (ABP), heart rate (HR) and RSNA. Catheters were placed in a femoral vein for drug delivery and infusion of isotonic saline (25 μl/min) and in the urinary bladder for urine collection. Urine was sampled during two 10 min control and six 10 min periods starting 10 min after injection of U50 or vehicle to the BST.

Results

U50 significantly increased urine excretion (n=8, P<0.05) without changing HR, mean ABP, urinary sodium excretion or RSNA. Injections of saline (n=8) were without affect.

Conclusion

The ability of U50 to increase urine outflow without effecting sodium excretion and RSNA raises the possibility that BST neurons could be an important substrate through which drugs targeting Kappa opioid receptors could selectively facilitate water excretion in sodium retaining diseases such as salt‐sensitive hypertension. This work was supported by 5SC2 HL104639.
Immunofluorescence identifies the α1 subunit of the GABAA receptor on spinally projecting neurons in rostral ventrolateral medulla
Authors: Dombrowski Maryetta Donna , Llewellyn‐Smith Ida J , Mueller Patrick J
Published: June 2021

The rostral ventrolateral medulla (RVLM) is important for sympathetic control of the cardiovascular system. RVLM neurons are known to be under strong tonic γ‐amino‐butyric acid (GABA)‐ mediated inhibition, presumably due to activation of GABAA receptors. This investigation aimed to demonstrate that GABAA receptors are present on spinally projecting RVLM neurons. Male Sprague‐Dawley rats were injected bilaterally with cholera toxin B (CTB) at spinal cord segment T9/T10. Double immunofluorescent labeling identified immunoreactivity for CTB (green, FITC) and the GABAA α1 receptor subunit (red, Cy3) in RVLM. Of 179 CTB‐immunoreactive RVLM neurons (n=4 rats), 176 (98.3%; range among rats, 95.9–99.1%) contained immunoreactivity for the GABAAα1 receptor subunit. Our data show that virtually all bulbospinal RVLM neurons express GABAAα1. These anatomical observations support the involvement of RVLM GABAA receptors in inhibitory control of sympathetic outflow arising from the lower thoracic spinal cord. (R01‐HL096787‐S1; NHMRC 1025031; R01‐ HL096787).
Carotid baroreflex control of heart rate is enhanced during whole‐body heat stress
Authors: Krnjajic Davor , Butts Cory L , Warren W Shane , Samels Mitchel R , Keller David M
Published: June 2021

Whole‐body heat stress (WBH) reduces orthostatic tolerance. While impaired carotid baroreflex (CBR) function during WBH has been reported, study design considerations may limit interpretation of previous findings. We sought to test the hypothesis that CBR function is unaltered during WBH. CBR function was assessed in ten subjects using 5‐sec trials of neck pressure (45, 30 and 15 Torr) and neck suction (−20, −40, −60 and − 80 Torr) during normothermia (NT) and passive WBH (Δ core temp ~1 °C). Analysis of stimulus response curves (4‐parameter logistic model) for CBR control of heart rate (CBR‐HR) and mean arterial pressure (CBR‐MAP), as well as separate 2‐way ANOVA of the hypo‐ and hypertensive stimuli (factor 1: thermal condition, factor 2: chamber pressure) were performed. For CBR‐HR, maximal gain was increased during WBH (−0.73±0.37) compared to NT (−0.39±0.11, p=0.03). In addition, the CBR‐HR responding range was increased during WBH (32±15) compared to NT (18±8 bpm, p=0.03). Separate analysis of hypertensive stimulation revealed enhanced HR responses during WBH at −40, −60 and −80 Torr (condition*chamber pressure interaction, p=0.049) compared to NT. For CBR‐MAP, both logistic analysis and separate 2‐way ANOVA revealed no differences during WBH. Therefore, despite marked orthostatic intolerance observed during WBH, CBR control of heart rate (enhanced) and arterial pressure (no change) is well‐preserved.