bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Fructose on Uric Acid Metabolism
Authors: Theytaz Fanny , Egli Léonie , Rodriguez Yaiza Cordero , Campos Vanessa , Schneiter Philippe , Tappy Luc
Published: June 2021

Uric acid (UA) has been proposed to contribute to diet‐induced insulin resistance. We studied UA metabolism during an oral fructose challenge (0.2 g oral fructose/kg FFM every hour for 9 hours). Blood and urine UA concentrations were measured, UA excretion and clearance were calculated in two groups of healthy male subjects: 1) 8 subjects after 6 days on either a low fructose diet (LF) or a hypercaloric diet with 3g/kg/day fructose (HyperFr); 2) 7 subjects after 4 days on either LF or an isocaloric 30% fructose diet (IsoHFr).

Fasting UA (μmol/L)
Post‐fructose UA (μmol/L)
UA clearance (mL/min)
UA excretion (μmol/min)
Fasting HOMA‐IR
Fasting TG (mmol/L)

LF
389 ± 16
391 ± 14
9.3 ± 0.5
3.6 ± 0.2
2.2 ± 0.4
0.7 ± 0.0

HyperFr
458 ± 25*
456 ± 22*
7.5 ± 0.3*
3.4 ± 0.1
3.2 ± 0.5*
1.5 ± 0.2*

LF
334 ± 18
339 ± 18
9.1 ± 1.1
3.0 ± 0.3
2.6 ± 0.3
0.6 ± 0.1

IsoHFr
359 ± 23
361 ± 22
7.5 ± 0.9*
2.6 ± 0.2
3.1 ± 0.5
1.0 ± 0.2*

P < 0.05 vs LF

Oral fructose did not significantly increase UA concentration in any condition; HyperFr increased fasting UA concentration, due to a decreased UA clearance; HyperFr and IsoHFr increased fasting TG, HyperFr increased HOMA‐IR but these effects were not related to increased UA.

We conclude that short term fructose has little effects on UA production but decreases UA clearance. Fructose‐induced metabolic alterations are unlikely to be mediated by UA.

Swiss National Science Foundation supported this work.
Paternal folate deficiency influences hepatic DNA methylation, IGF‐1, IGF‐2 and IGF‐1R expression in the rat pup
Authors: Mejos Karen Kay Rosario , Lim Eun Mi , Kim Hye Won , Chang Namsoo
Published: June 2021

We investigated the effect of paternal folate deficiency on the hepatic folate content, DNA methylation, insulin‐like growth factors 1 and 2 (IGF‐1 and IGF‐2) and IGF‐1 receptor (IGF‐1R) expressions, as well as serum homocysteine (Hcy) level in the 3‐ week‐old pups. After 4 weeks of intervention with folic acid‐deficient (D) or folic acid‐supplemented (S) diet, paternal (P) and maternal (M) rats were mated and grouped as PSxMS, PSxMD, PDxMS, and PDxMD. Pups were sacrificed at day 21 of lactation. Folate content, DNA methylation and IGF expressions were analyzed in the liver, while Hcy level was analyzed in the serum of the pups. Liver folate content was markedly reduced in PDxMS group, while PSxMD group decreased as much as the level of PDxMD group (P<0.0001). Serum Hcy levels were elevated in PSxMD and PDxMD groups (P<0.0001). Hepatic DNA methylation was decreased in PSxMD and PDxMS groups as much as that in PDxMD group (P<0.0001). Hepatic IGF‐1, IGF‐2 and IGF‐1R expressions were downregulated in PDxMD and PDxMS groups, followed by PDxMS group, as compared to PSxMS group (P<0.05; P<0.01; P<0.01). These data indicate that paternal folate deficiency at mating, despite adequate maternal folate status, can influence hepatic folate content, global DNA methylation, as well as IGF‐1, IGF‐2 and IGF‐1R expressions in the pup. This research was supported by the BSRP through the NRF of Korea (2011–0003072), and BK21.
Bioactive compounds and antioxidant property of Korean traditional tea
Authors: Yang Hye‐Ran , Yi Yun‐Jeong , Park Ju‐Sung , Jo Han‐Bin , Kim Jung‐Hun , Chae Young‐Zoo
Published: June 2021

The objective of this study was to assess the bioactive compounds and antioxidant property in Korean traditional tea. Ten types of seventy tea samples were purchased from local markets in Seoul. The tea samples were homogenized and prepared by 1% extract with 90□ distilled water. A spectophotometry was used to measure the total polyphenol content at 765nm and total flavonoid content at 415nm. The free radical‐scavenging activity was analyzed by DPPH to assess the antioxidative property. The total polyphenol content showed the highest in green tea as 105.2±16.9(mg/g gallic acid equivalent) followed by persimmon leaf tea as 53.9±24.0. Mulberry leaf tea, chrysanthemum tea, brown rice green tea and eucommia bark tea showed moderate ranging from 30.9~46.9. The total flavonoid content showed the highest in chrysanthemum tea as 7.74±2.60(mg/g quercetin equivalent). Mulberry tea, persimmon leaf tea and eucommia bark tea showed 4.72±1.94, 4.56±1.27 and 4.11±2.34, respectively. The antioxidative property by DPPH showed high in persimmon leaf tea, green tea and brown rice tea ranging from 84.2 to 89.2(%). The antioxidative property was significantly correlated with the total polyphenol compound(p<0.001). We conclude that Korean traditional teas such as chrysanthemum tea, persimmon leaf tea, mulberry tea, eucommia bark tea and green tea are the good source of bioactive compounds and have high antioxidant activity as well.
Sweet potato cultivar flesh color and compositional effects on glycemic index
Authors: Allen Jonathan C. , Sun Wen , Truong Van Den
Published: June 2021

Sweet potatoes are rich in dietary fiber, minerals, vitamins and bioactive compounds such as β‐carotene, phenolics and anthocyanins that provide distinctive skin and flesh colors. Although high in carbohydrate, sweet potatoes usually have moderate (56–69) glycemic index (GI). This study aimed to 1) investigate GI of different commercial cultivars of sweet potatoes; 2) determine how the GI is impacted by specific plant components. Eight sweet potato cultivars with white, yellow, orange, or purple flesh were analyzed for moisture, ash, fat, protein, dietary fiber, β‐carotene, total phenolics and anthocyanin contents by AOAC methods. Orange‐fleshed sweet potato ‘Evangeline’ had the highest β‐carotene with 116.56 μg/g, and purple sweet potato ‘Stokes’ had the highest total anthocyanin (6.35 mg/g) and total phenolics (3.07 mg of chlorogenic acid equivalent/g). The normalized GI determined by 10 human subjects was lowest, 65.8 ± 22.9, for Stokes and highest, 80.0 ± 18.14, for O'Henry (white) although there were no significant differences among cultivars (P= 0.780), and no correlation of pigment (β‐carotene, anthocyanins, total phenols) concentration with normalized GI was found. The data indicate that color or macronutrient content of different sweet potato cultivars does not significantly affect GI. Support: North Carolina SweetPotato Commission
Effects of dietary fiber on body mass index: a systematic review of cross‐sectional studies, prospective cohort studies and randomized controlled trials
Authors: Korczak Renee , Slavin Joanne L
Published: June 2021

The purpose of this review is to provide an updated discussion on the scientific evidence regarding dietary fiber and body weight or body mass index (BMI). A PubMed search with medical subject headings (MESH) was conducted in January 2012. Certain search terms were used to identify articles that matched our criteria and these were related to fiber OR whole grain AND body weight OR adiposity OR body fat OR BMI. In total, 547 articles were found and of these, 360 articles were eliminated based on title and 160 eliminated based on the abstract. Altogether, 28 studies were included that were published in the year 2000 or later. Seven are cross‐sectional, six prospective cohort and fifteen randomized controlled trials. Altogether, the epidemiological data shows that intake of dietary fiber is associated with a lower BMI or body weight; and the results from some randomized controlled trials are also favorable. The results demonstrate that supplementing with viscous and soluble fibers such as glucomannan, guar gum, alginate, and Konjacmannan significantly (p<0.001) reduced body weight for men and women. The level of fiber supplemented to achieve this varied from 3–18g/day. In conclusion, recent prospective and cross‐sectional data demonstrates that intake of fiber is related to a lower body weight or BMI; and the results from randomized controlled trials are promising. Future intervention studies are required to further elucidate this relationship.
Acute toxicity of lotus (Nelumbo Nucifera) seed ethanol extract in ICR mice
Authors: You Jeong Soon , Kim Sung Hoon , Lee Yun Ju , Kim So Young , Zhao Xu , Chang Kyung Ja
Published: June 2021

Lotus (Nelumbo Nucifera) is widely distributed in Korea, China, India and Japan area and lotus seed has been used as a folk medicine. The purpose of this study was to evaluate acute toxicity information of lotus seed ethanol extract (LSEE) in ICR mice. Twelve mice of each sex were randomly assigned to 3 groups of 4 mice each and were administered singly by gavages at doses of 0, 2000 and 5000 mg LSEE/kg body weight. After single oral administration, sings of toxicity such as behavioral changes and mortality were observed every hour for the first 6 hours and every day for 14 days. At the end of the 14th day experiment period, all mice were sacrificed. There was no difference in body weight change, diet intake, water consumption and organs weights such as liver, kidney, lung and spleen among different dose groups. At doses of 2000 and 5000 mg LSEE/kg body weight, mortality, macroscopic changes of internal organs and abnormal behavioral changes were not observed. The results showed that LSEE did not produce any signs of toxicity and the LD50 and approximate LD of LSEE in both female and male ICR mice were considered as over 5,000 mg/kg body weight. This research was supported by the Globalization of Korean Foods R&D program, funded by MIFAFF, Republic of Korea
Effect of a Korean, 2010 Dietary Guidelines for Americans, and typical American diet on fecal microbiota composition of overweight adults
Authors: Solano‐Aguilar Gloria I , Kang MinSook , Schroeder Natalia , Lakshman Sukla , Vinyard Bryan , Ha Grace , Kim Yangsuk , Park Younghee , Kim Haengran , Yates Allison , Caballero Benjamin
Published: June 2021

Kimchi and jang, a fermented Korean food, has the potential to affect microbiota, which may possibly alter chronic disease‐related pathologies. A dietary intervention was designed to compare the effect of a Korean diet (KD) (62% carbohydrate and 20% fat, containing 120g kimchi and 15g jang/d); a 2010 Dietary Guidelines diet for Americans (DGA) (57% carbohydrate and 26% fat); and a typical American diet (TD) (58% carbohydrate and 33% fat) on the composition of fecal microbiota. Thirty‐one volunteers with a BMI ≥25kg/m2 and an LDL‐C ≥130 mg/dL participated in a randomized crossover design trial in which every diet was consumed for four‐weeks, separated by ten‐day wash‐out periods. Relative differences in bacterial abundance in feces for total bacteria, Bifidobacterium, Lactobacillus, Bacteroides fragilis, E. coli, and Lactobacillus sakei species was measured by real time PCR. Mean values for bacterial abundance changes within each dietary period were estimated. Consumption of KD increased abundance of total bacteria and Lactobacillus species with a six‐fold increase in Lactobacillus sakei when compared to DGA or TD diets while TD and KD consumption reduced Bifidobacterium species when compared to the DGA diet. These results indicate that the lower fat Korean diet with fermented foods induced detectable changes in Lactobacillus species typically associated with health benefits.
Anti‐stress Effect of Enzyme‐Treated Asparagus extract (ETAS)
Authors: Kudo Shotaro , Sato Atsuya , Ito Tomohiro , Homma Kohei , Nishioka Hiroshi
Published: June 2021

Heat shock proteins (HSP) are known as stress‐relieving proteins that protect cells against various stresses. We have developed a product from asparagus named ETAS, possess HSP70 inducing activity. Studies were conducted to evaluate anti‐stress effects of ETAS in vitro and in vivo.

HeLa cells were treated with ETAS and the HSP70 expressions were measured. Those expression levels were increased with ETAS in a concentration‐dependent manner (p<0.05).

ETAS was orally administered to Slc:ddY mice (6‐week old, male) for 10 days. For the last 3 days during ETAS administration, mice were subjected to sleep‐deprivation stress, and serum concentration of corticosterone was measured. The concentration was significantly reduced by ETAS.

A placebo‐controlled, double‐blind clinical study was also carried out. Healthy volunteers were divided into ETAS (150 mg/day) and placebo groups (each 10 subjects). In order to assess anti‐stress effect, the balance and activity of autonomic nerve were measured by Pulse Analyzer Plus (TAS9) before and after administration. The parameters were significantly improved in the ETAS group.

Active ingredients of ETAS were also analyzed, and new molecule is identified that induces HSP70 expression.

In conclusion, ETAS enhanced the HSP70 expressions in cells, resulting in attenuation of stress in mice and human. It was suggested that ETAS functions in cytoprotection.
WNT5a‐mediated tumor suppression of esophageal adenocarcinoma in vitro
Authors: Moore Tami , Lyros Orestis , Nie Linghui , Jovanovic Nebojsa , Medda Rituparna , Perkins Tiffani , Otterson Mary , Shaker Reza
Published: June 2021

Background

The incidence of esophageal adenocarcinoma (EAC) has increased over the last decade while its prognosis still remains poor. Barrett's esophagus (BE) is the only known precursor of EAC while the underlying molecular mechanisms are unknown. Wnt5a is a member of the non‐transforming WNT family whose role in carcinogenesis is still ambiguous. Wnt5a functions through ROR2 receptor and exhibits tumor suppression in colorectal cancer. We investigated the role of Wnt5a in esophageal adenocarcinoma.

Methods

Gene and protein expression of Wnt5a and ROR2 were analyzed in human esophageal tissues (healthy, BE, and EAC) and various esophageal cell lines by qRT‐PCR and immunohistochemistry respectively. Cell proliferation, survival and migration were assessed in OE33 cancer cells following rWnt5a treatment. Western blotting determined GSK3 β‐phosphorylation. Nuclear β‐catenin localization and Axin2 & Cyclin D1 gene expression were also determined.

Results

Wnt5a was down‐regulated or sustained whereas ROR2 was overexpressed in BE and EAC tissues compared to healthy controls. Same findings were confirmed in vitro. rWnt5a inhibited cell proliferation, survival, and migration in OE33 cells in a dose‐dependent manner. rWnt5a inhibited GSK3β phosphorylation but did not alter β‐catenin activity.

Conclusions

Wnt5a mediates tumor suppression in OE33 cells. ROR2 receptor may mediate this effect.
Expression of MDR‐transporter, ABCB5, in Merkel cell carcinoma
Authors: Lezcano Cecilia , Kleffel Sonja , Laga Alvaro C , Zhan Qian , DoRosario Andrew , Frank Markus H , Wang Linda , Murphy George F , Schatton Tobias
Published: June 2021

Merkel cell carcinoma (MCC) is a rare and aggressive cutaneous neuroendocrine neoplasm notoriously refractory to chemotherapy. We have previously found that the multidrug resistance (MDR) transporter, ABCB5, mediates drug resistance in human colonic adenocarcinoma and melanoma where it also defines stem‐like cells responsible for tumor initiation and self‐renewal. The aim of this study was to evaluate the possible role of ABCB5 in MCC. Primary and metastatic MCCs (n=74) were assessed for ABCB5, and mRNA expression and immunoreactivity was confirmed in all cases. Of note, co‐expression of ABCB5 with stem cell markers SOX2 and CD271 was documented in a subset of MCC cells in human tissue, while CD44 and ABCB5 defined separate cell populations. ABCB5+ cells were enriched in patient biopsies after chemotherapy, consistent with relative chemoresistance of this tumor cell subset. In cell line‐derived MCC xenografts in NSG mice, tumors formed by WaGa and MKL‐1 cells demonstrated increased ABCB5 expression after administration of etoposide or carboplatin. In summary, MCCs express ABCB5, and this biomarker may have functional significance regarding both chemoresistance and tumorigenic potential. NIH P50CA93683, Dermatology Foundation Career Development Award and BWH Dermatology new investigator funding.
The Role of FcRn in Monoclonal Antibody Serum Uptake from the Intestine in Suckling Rat Pups
Authors: Cooper Philip R , Kliwinski Connie , Perkinson Robert , Mabus John , Giles‐Komar Jill , Hornby Pamela
Published: June 2021

The neonatal Fc Receptor (FcRn) in intestinal epithelium is the primary mechanism for transfer of maternal immunoglobulin G (IgG) from suckled milk to serum, but the factors contributing to this rapid uptake are poorly understood. Therefore, the pharmacological characteristics of IgG monoclonal antibody (mAb) and its interactions with FcRn in the intestinal environment in rats were investigated.

Binding affinities to rat FcRn at pH 6.0 and off‐rates of pre‐bound mAb wild type (WT) and variants at pH 7.4 were determined. In anesthetized rats, systemic levels of human (h)IgG were determined after regional intestinal delivery of hIgG variants. Quantification of full‐length mAb in serum, rat FcRn mRNA expression in regions of intestine, and mAb epithelial localization was measured.

High serum levels of hIgG were detected 90 min after duodenal delivery in 2‐week, but not 4–8 week old rats. Serum levels of variants correlated with off‐rates, not FcRn affinity. Serum levels of WT mAb, administered to different regions of intestine, correlated with rFcRn mRNA regional expression.

The suckling rat pup intestine is an ideal mechanistic model of FcRn‐IgG mediated transcytosis. While binding affinity to FcRn is important for obtaining serum levels, a variant with a faster off‐rate at pH 7.4 than WT resulted in greater serum levels.
Dynamic control of Allosteric Inhibitor Specificity for RGS4
Authors: Storaska Andrew John , Vashitsh Harish , Neubig Richard R
Published: June 2021

G‐protein coupled receptors (GPCRs) are critically regulated through downstream protein‐protein interactions including Regulator of G‐protein signaling (RGS)‐proteins. They suppress GPCR output by enhancing the rate of GTP hydrolysis on the Gα subunit. A nM potency inhibitor (CCG‐50014) is several hundred‐fold selective for RGS4 over other RGS proteins. Like previous RGS inhibitors, CCG‐50014 depends on covalent cysteine modification for activity. Two key cysteines‐(95 and 148) are buried in an allosteric site. We hypothesized that inhibitor interaction at cys 95 or 148 alters the packing of alpha helices 4, 5, 6 and 7 to disrupt G‐protein binding. Consistent with this hypothesis, HSQC‐NMR experiments using RGS4 containing only Cys 95, in the presence of CCG‐50014, shows perturbations clustering in the helix bundle and in the G‐protein binding site. Molecular dynamics simulations predict motions that would provide inhibitor access to the buried allosteric cysteines, and open a novel cryptic pocket into which small molecules could be targeted. Binding of CCG‐50014 likely stabilizes a more open confirmation resulting in disruption of the G‐protein binding interface. Differences among RGS proteins involving these conformational transitions may drive the observed inhibitor selectivity for RGS4. (Supported by NIH T32 GM007767 and R01DA023253)
Modulation of Regulator of G‐Protein Signaling 4 (RGS4) Activity by Covalent Modification of 4Hydroxy‐2‐nonenal (4HNE)
Authors: Monroy Carlos Aaron , Roman David
Published: June 2021

Regulators of G‐protein signaling (RGS) proteins are a family of proteins that act as GTPase accelerating proteins (GAPs) through their interaction with Gα subunits, including Gαo, Gαi, and Gαq but not Gαs. This increased rate of hydrolysis of GTP to GDP temporally regulates G‐protein coupled receptor (GPCR) signaling. A member of this family, RGS4, has been implicated in several neurological disorders including Parkinson's Disease (PD). A hallmark of PD is the induction of oxidative stress within dopaminergic neurons. In this study, we evaluate the role of lipid peroxidation products, using 4‐hydroxy‐2‐nonenal (4HNE) as a model, in regulating RGS4 activity within neurons. Utilizing transfected RGS4 in HEK293T cells, we evaluated whether RGS4 is readily modified by physiologically relevant concentrations of 4HNE by immuonoprecipitation of RGS4 from 4HNE treated cells. Further examination of recombinant RGS4 by mass spectrometry, revealed that RGS4 is readily modified at several cysteine residues by 4HNE, including C148. Modification at this residue has been shown to be a critical site for allosteric regulation of RGS4. This is confirmed through a malachite green based phosphate generation assay we developed to observe the GAP activity of RGS4 on its native binding partner Gαi. Research support provided by the Pharmacological Sciences Training Grant (NIH/NIGMST32GM067795).
The role of hippocampal α2‐containing GABAA receptors in benzodiazepine‐induced anxiolysis
Authors: Engin Elif , Smith Kiersten S. , Keist Ruth , Crestani Florence , Fritschy Jean‐Marc , Rudolph Uwe
Published: June 2021

While the hippocampus was granted a central role in the neurobiology of anxiety in early theories, later findings shifted the attention to other structures and left the role of hippocampus in anxiety and anxiolysis a controversial subject. α2‐containing GABAA receptors mediate benzodiazepine‐induced anxiolysis in models of unconditioned anxiety and conditioned fear. To investigate whether the α2‐containing GABAA receptors within hippocampal circuits contribute to this effect, we generated mice that lack these receptors selectively in the pyramidal cells of the CA1 or the CA3, or in the granule cells of the dentate gyrus (CA1‐ KO, CA3‐KO and DG‐KO, respectively). In models of unconditioned anxiety, such as the elevated plus maze, CA1‐KO mice showed diazepam‐induced anxiolysis similar to wild types. This effect, however, was abolished in CA3‐KO and DG‐KO mice. Conversely, in models of conditioned fear, such as fear‐potentiated startle, CA1‐KO mice failed to show the anxiolytic effects of diazepam, while CA3‐KO and DG‐KO were comparable to wild types. Our findings suggest that the inhibition of the trisynaptic hippocampal pathway is required for diazepam anxiolysis in unconditioned anxiety models, while the inhibition of the CA1 output to entorhinal cortex and downstream structures is required for diazepam‐induced reduction of conditioned fear.
Allicin inhibits metastasis of MCF‐7 cells by inhibition of VCAM‐1 expression
Authors: LEE Chung Gi , Pyo Suhkneung
Published: June 2021

Adhesion molecules play a key role in tumour development and are involved in processes that allow cancer cell migration, tissue invasion and metastasis formation. Allicin, the major component of Garlic (Allium sativum) was examined for the ability to inhibit metastasis and the mechanism of the inhibition of metastasis in human breast cancer cells. Western blot analysis showed that cells pretreated with various concentrations of allicin (0.1–10 ng/ml) resulted in decrease in the levels of VCAM‐1 and p65 expression, whereas ER‐α expression was increased by allicin in TNF‐α‐treated cells. Allicin treatment also inhibited p65‐ER‐α complex formation induced by TNF‐α. In addition, cell migration and invasion assays showed that allicin inhibited the migration and invasion of MCF‐7 cells. Taken together, the present data suggest that allicin inhibits the migration and invasion of MCF‐7 cells, and the effect is likely associated with inhibition of p65‐ER‐α complex formation and downregulation of VCAM‐1 expression.
The possible antidotal effect of alpha‐lipoic acid against acetaminophen induced hepatotoxicity in rats
Authors: El‐Moselhy Mohamed Ahmed , El‐Shazly Shimaa Mostafa , Barakat Waleed Adel
Published: June 2021

This study aimed to investigate the possible curative effect of α‐lipoic acid (α‐LA) against acetaminophen (APAP)‐induced hepatotoxicity and the mechanisms underling this possible effect. Animals divided into following groups APAP (1.5 g/kg/i.p.), N‐acetylcysteine (NAC) (1200 mg/kg, i.p.), simultaneously with APAP, NAC 1.5 h after APAP, α‐LA (20mg/Kg) simultaneously with APAP, α‐LA 1.5 h after APAP and Control. APAP administration elevates serum hepatic enzymes, Malondialdehyde (MDA), NADPH oxidase expression and NF‐κB activity and decreased the reduced glutathione (GSH). Furthermore, Nrf2, HO‐1, glutathione synthase and cystathionine‐beta‐synthase (CBS) gene expression was significantly decreased. Co‐administration of either α‐LA or NAC either simultaneously or 1.5 h after APAP administration ameliorated APAP induced alterations in hepatic enzymes, MDA and NF‐κB activity. Furthermore, administration of α‐LA or NAC restores Nrf2, HO‐1, glutathione synthase and (CBS) gene expression and GSH to nearly normal levels, moreover NF‐kB activity and NADPH oxidase gene expression were significantly lowered. Histopathological examination revealed conservation of liver integrity of treated groups compared to APAP‐treated rats alone. In conclusion, such beneficial effect of α‐LA may be conducted through its antioxidant and anti‐inflammatory effect and its ability to enhance glutathione synthesis.
Nerve growth factor reduces amiloride‐sensitive Na+ transport in human airway epithelial cells
Authors: Shimko Michael J , Zaccone Eric J , Thompson Janet A , Schwegler‐Berry Diane , Willard Patsy A , Fedan Jeffrey S.
Published: June 2021

Nerve growth factor (NGF) is over‐expressed in patients with lung inflammatory diseases including airway virus infections. Optimum airway surface liquid (ASL), controlled by epithelial cells, is essential for normal lung function. NGF has been shown to affect ion transport properties of neurons, but no information is available as to the effect NGF has on ion transport of airway epithelial cells. To investigate if NGF can alter epithelial ion transport, we established human primary cultured epithelial cells in air‐interface that demonstrates desirable in situ morphology and ion transport function. These cells were placed in an Ussing chamber to obtain transepithelial voltage (Vt), short‐circuit current (Isc), transepithelial resistance (Rt), and to measure responses to known ion transport inhibitors. Cells had an average Vt of −7.1 mV, Isc of 5.9 μA, and Rt of 750 μΩ×cm2. Amiloride (apical, 3.5×10−5 M) decreased total Isc by 52%. When cells were first treated with 1 ng/ml NGF prior to the addition of amiloride, amiloride reduced total Isc by 38%. The addition of NGF (apical, 1 ng/ml) to the bath reduced the total Isc by 4.5 %. These results indicate that NGF reduces Na+ transport in airway epithelial cells. This could result in an increase in ASL height. Support provided by NIOSH.
Maternal but not paternal fat mass is positively associated with infant fat mass at age 2 weeks
Authors: Andres Aline , Shankar Kartik , Cleves Mario A , Badger Thomas M
Published: June 2021

Maternal programming of fetal metabolism has been demonstrated in animal studies, while clinical studies have shown an association between pre‐pregnancy body mass index (BMI) and anthropometric measures in infants. Here we report on the association between infant body composition at age 2 weeks and parental total body fat mass (FM) measured during the first trimester of pregnancy. Body composition was assessed using air displacement plethysmography technology (PeaPod® and BodPod®). Gestational weight gain was assessed throughout pregnancy and categorized according to the 2009 Institute of Medicine recommendations as adequate or excessive. After controlling for excessive gestational weight gain, maternal FM (%) in 40 infant/mother pairs was significantly associated with infant FM (r=0.343, p=0.03), whereas maternal BMI was not associated with infant FM (r=0.307, p=0.06). Among the 29 fathers who agreed to be part of the study, neither paternal FM (%) nor paternal BMI was associated with infant FM at age 2 weeks (r=0.105, p=0.6 and r=0.099, p=0.6, respectively). These data suggest that higher maternal fat mass pre‐pregnancy can affect adipose deposition in utero, whereas paternal FM does not seem to play a role in programming of fetal adipose deposition. Funded by USDA‐ARS CRIS # 6251–51000‐005–03S.
Impaired pancreatic function contributes to the age‐dependent development of metabolic syndrome in female intrauterine growth restricted rats.
Authors: Intapad Suttira , Brown Andrew D. , Tull FL , Fahling Joel M. , Dasinger John Henry , Ojeda Norma B. , Alexander Barbara T.
Published: June 2021

Birth weight is inversely related to impaired metabolic health. The female intrauterine growth restricted (IUGR) rat exhibits an age‐dependent increase in blood pressure associated with a marked increase in body fat and leptin. Whether increased adiposity is associated with glucose intolerance; however, and the mechanism(s) involved are unknown. Thus, this study tested the hypothesis that age‐dependent increases in fat program glucose intolerance in female IUGR due to alterations in the glucose sensor. Insulin release in response to an oral glucose tolerance test (OGTT), an insulin tolerance test (ITT) and pancreatic glucose transporter 2 (GLUT2) protein expression were measured at one year of age in female control and IUGR rats. Female IUGR demonstrated a significant impairment in glucose tolerance associated with a delay and marked reduction in insulin release (P<0.05); an ITT revealed that female IUGR had higher insulin sensitivity (P<0.05). Although pancreas weight did not differ, pancreatic GLUT2 protein expression adjusted to β‐actin was approximately 4‐fold lower (P<0.05) in IUGR versus control. Thus, the underlying mechanism of impaired metabolic health in female IUGR may involve a decrease in pancreatic GLUT2 expression resulting in a reduction in glucose‐simulated insulin secretion in response to elevated blood glucose leading to glucose intolerance. HL074927; HL51971; AHA12POST11980021.
Sodium storage during high salt intake is not dependent upon endothelin B receptors
Authors: Speed Joshua S , Titze Jens M , Pollock David M
Published: June 2021

Recent evidence suggests that the skin is a buffer to prevent changes in blood pressure by acting as a reservoir for sodium (Na+), and lack of this Na+ storing ability results in salt sensitive hypertension. We hypothesize that endothelin‐1, an important regulator of salt and water balance, mediates the skin's ability to store Na+ during a high salt intake, and rats lacking a functional Endothelin B receptor (ET‐B) have a reduction in the skin's ability to store salt, thereby contributing to salt sensitive hypertension observed in this model. After 1 week of a high salt diet (4% NaCl), blood pressure was significantly elevated in ET‐B deficient (ET‐B def) rats vs. wild type (WT) on normal salt (NS), a response that was exacerbated by increasing salt intake (98.7 ±3.1 mmHg for WT vs. 125.0±4.1 mmHg for ET‐B def on NS, 106.3±1.7 mmHg for WT vs. 142.1±3.6 mmHg for ET‐B on HS). Using an ashing technique to measure electrolyte content of the body, we found that increasing salt intake significantly elevated skin Na/water ratio, but there was no difference between wild type and ET‐B deficient rats (.101±.001 WT on NS, .114±.002 WT on HS, .099±.001 ET‐B def on NS, and .113±.002 ET‐B def on HS, mmol/ml). These data confirm skin sodium storage in rats on a high salt diet, but suggest that the endothelin B receptor is not important in regulating this process and thus does not account for salt sensitive hypertension in ET‐B receptor deficient rats.
Influence of age on respiratory modulation of muscle sympathetic nerve activity and blood pressure in humans
Authors: Shantsila Alena , McIntyre David B , Lip Gregory Y.H. , Paton Julian F.R. , Fadel Paul J , Pickering Anthony E , Fisher James P
Published: June 2021

We sought to determine the influence of age on respiratory related bursting of muscle sympathetic nerve activity (MSNA) and the coupling of MSNA to the rhythmic fluctuations in blood pressure (BP) which occur with the respiratory cycle (Traube‐Hering Waves; THW). Recordings of MSNA (microneurography), BP (Finometer) and respiration (pneumobelt) were obtained in 10 young (22±1 yr, mean±SE) and 10 older (58±2 yr) healthy men with a similar BMI (~25 kg/m2), while supine and breathing normally. Following correction for nerve conduction delays, respiratory cycle triggered averaging of MSNA and BP was performed. MSNA burst incidence was higher in older individuals (P<0.05, ANOVA), but similarly reduced in the inspiratory to post‐inspiratory period in young and older subjects (18±3 and 37±5 bursts•100 heart beats−1) compared to mid‐to‐late expiration (26±4 and 47±5 bursts•100 heart beats−1 in young and older). A significant positive correlation between MSNA and THW magnitude was observed in 90% of young but only 40% of older subjects. Thus, while the cyclic inhibition of MSNA during respiration is preserved in older individuals, the association between MSNA and THW is less robust. Supported by BHF.
Cardiac fibrosis and diastolic dysfunction are highly correlated in a mouse chronic pressure‐overload model
Authors: Olzinski Alan , Bao Weike , DeLong Drew , Lenhard Steve , Wright Fe , Coatney Robert , Jucker Beat , Eisennagel Stephen , Needle Saul , Wang Tao , Schnackenberg Christine
Published: June 2021

The purpose of this study was to determine which measurements of diastolic dysfunction are most correlated with cardiac fibrosis. Mice were subjected to Sham (n=7) or transverse aortic constriction (TAC, n=6) for 10 weeks, examined by speckle‐tracking echocardiography and left ventricle (LV) pressure catheter, and portions of the LV were processed for biomarkers and histological analysis. In TAC mice as compared to Sham, Masson's Trichrome staining revealed an increase in fibrosis by 800% (P<0.01); with the majority of the collagen located in the mid‐wall of the myocardium. LV insoluble collagen hydroxyproline (HDXP) increased by 99% (P<0.01); and the collagen cross‐linker pyridinoline (PYD) increased by 100% (P<0.001). Tau was increased by 46% (P<0.01) and diastolic radial and circumferential strain rates were decreased by 41% and 44%, respectively (both P<0.01). The correlations between PYD and diastolic dysfunction were: r = 0.79, 0.76, and 0.85 for Tau, radial and circumferential strain rates, respectively. Similar correlations were observed for HDXP and diastolic dysfunction. In summary, cardiac fibrosis and diastolic dysfunction are highly correlated in the mouse TAC model with diastolic circumferential strain rate better correlated with cardiac fibrosis, possibly due to the majority of the fibrosis being located in the mid‐wall, where myofibers are aligned circumferentially.
ETA subtype receptor sensitivity to testosterone contributes to microvascular dysfunction in PCOS
Authors: Stachenfeld Nina , Wenner Megan , Taylor Hugh S
Published: June 2021

Hyperandrogenism and endothelial dysfunction are hallmarks of Polycystic Ovary Syndrome (PCOS). We hypothesized that testosterone (T)‐related inhibition of endothelium‐mediated vasodilation in women with PCOS occurs via the ETA receptor. For 11 days we suppressed sex hormones with a gonadotropin releasing hormone antagonist (GnRHa) in women with (PCOS, n=6, 23.2±0.7 y, 35.4±1.7 kg/m2) and without (C, n=7, 22.0±1.6 y, 34.1±1.1 kg/m2) PCOS; we added testosterone (T, 2.5 mg/day) for days 8–11. On days 4 and 11, we measured cutaneous vascular conductance (CVC) with laser Doppler flowmetry during local heating and microdialysis infusions of an ETA (BQ‐123) or ETB (BQ‐788) receptor antagonist. Compared to GnRHa, during T ETA block enhanced heat‐induced vasodilation in PCOS (ΔCVC 1.74±0.23, Δ2.15±0.18 for GnRHa, T P< 0.05), with no T effect in C. In both groups, ETB block blunted heat‐induced vasodilation, but less so with T than GnRHa (PCOS: ΔCVC 1.29 ±0.32, 0.84±0.27; C: ΔCVC 0.95±0.21, 0.51±0.13, GnRHa, T P< 0.05). The increased CVC with ETA blockade indicates removal of vasoconstrictor tone and suggests T contributes to constriction via an ETA receptor mechanism in PCOS. HL093450
A single bout of aerobic exercise prevents the transient endothelial dysfunction induced by mental stress in men with metabolic syndrome
Authors: Sales Allan Robson Kluser , Fernandes Igor A , Rocha Natalia G , Garcia Vinicius P , Costa Lucas S , Silva Bruno M , da Nóbrega Antonio C L
Published: June 2021

Mental stress induces transient endothelial dysfunction and the association with metabolic syndrome (MetS) may increase the risk for the development of atherosclerosis. Given the beneficial impact of exercise on endothelium function, we hypothesized that a single session of aerobic exercise would prevent the endothelial dysfunction induced by mental stress in men with MetS. Thus, 14 men with MetS (36 ± 4 yrs) initially had their endothelial function assessed through the flow‐mediated dilation (FMD) of the brachial artery (Doppler ultrasound). Subjects were then submitted to a mental stress test (Stroop color), which was followed by either 40 min of leg cycling exercise (80% of the anaerobic threshold) or no exercise in two different sessions. FMD was performed again at 30 and 60 min after exercise (EX) or control (CT), with a mental stress stimulus in between. Mental stress reduced FMD at 30 and 60 min (baseline: 7.7 ± 1.0%; 30 min: 5.0 ± 0.9%; 60min: 3.8 ± 0.8%; p < 0.05) in the CT, whereas EX prevented the endothelial dysfunction caused by mental stress (baseline: 7.4 ± 0.9%; 30 min: 6.2 ± 1.0%; 60 min: 9.3 ± 1.1%; p >; 0.05). In a subgroup (n = 3) where mental stress was not performed, FMD increased at 60 min after the exercise, while no changes were observed in the CT. In conclusion, a single aerobic exercise session prevented the mental stress‐induced endothelial dysfunction in men with MetS.

Supported by FAPERJ, FINEP and CNPq.
Sex Related Differences in Vasodilator Responsiveness to Hypoxia at Rest and During Exercise
Authors: Shepherd John R. A. , Joyner Michael J. , Casey Darren P.
Published: June 2021

β‐adrenergic receptor activation causes a substantial portion of hypoxic vasodilation at rest and during forearm exercise. Recent evidence suggests that β‐receptors are either more sensitive or upregulated in young women vs. men. Therefore, we examined whether sex influences hypoxic vasodilation in 31 subjects (15F/16M; 26± 1 yr). We also examined whether potential sex related differences existed in a group of older adults (6F/5M; 61± 2 yr). All subjects performed forearm exercise at 10% and 20% of maximum under normoxic and hypoxic (80% arterial O2 saturation) conditions. Forearm vascular conductance (FVC; ml/min/100 mmHg) was calculated from blood flow (ml/min) and blood pressure (mmHg). At rest young females demonstrated a greater vasodilator response to hypoxia compared to men (39 ± 12% vs. 13 ± 6%, P < 0.05). The compensatory vasodilator response to hypoxia exercise (% change in ΔFVC compared to respective normoxic exercise trial) was also greater in young womenat 10% (46 ± 8% vs. 29 ± 5%, P < 0.05) and 20% exercise (38 ± 6% vs. 23 ± 4%, P < 0.05). Interestingly the compensatory vasodilator responses between older women and men were similar at 10% (28 ± 6% vs. 28 ± 10%, P = 0.99) and 20% exercise (13 ± 6% vs. 15 ± 7%, P = 0.84), respectively. Our data suggest that the compensatory vasodilator response to hypoxic exercise is greater in young women compared to men. However, sex specific differences appear to be lost with aging.
ATP acts via P2Y1 receptors in the preBötzinger Complex in vivo to attenuate the secondary hypoxic respiratory depression
Authors: Rajani Vishaal , Zwicker Jennifer D. , Pagliardini Silvia , Funk Gregory D.
Published: June 2021

The ventilatory response to hypoxia comprises an initial increase in ventilation followed by a secondary depression that can be life‐threatening in premature infants. The mechanisms underlying the kinetics and magnitude of this secondary depression are not known, but ATP released within the ventrolateral medulla acts via purinergic (P2) receptors to attenuate this depression. We explored the hypothesis developed from analysis of the rhythmic medullary slice preparation that ATP acts via P2Y1 receptors in the preBötzinger Complex (preBötC, a critical site for inspiratory rhythm generation) to mediate this attenuation. Adult, urethane‐anesthetized, spontaneously‐breathing, vagotomized rats were exposed to 10% O2 (90% N2) for 5 min immediately following local unilateral injection of vehicle (0.2μl HEPES buffer) or 500 μM MRS2279 (P2Y1 receptor antagonist) into the preBötC. Respiratory frequency (fR) and minute ventilation (VE) increased rapidly by ~40% in both groups. fR fell to baseline levels in the control group but to 0.8 of baseline in the MRS2279‐injected animals. VE fell to levels that were 20% above baseline in the control group but to baseline in the MRS2279 group. Data suggest that during hypoxia endogenously‐released ATP acts via P2Y1 receptors in the preBötC to reduce the magnitude of the secondary hypoxic respiratory depression. Supported by CIHR, AIHS, CFI, WCHRI and ALA.
Pulmonary vascular reactivity with ageing
Authors: Pugh Keith , Balanos George
Published: June 2021

Sleep apnoea (SA) and pulmonary hypertension are closely linked and SA is also a common condition in older people. It is possible that if ageing is associated with greater hypoxic pulmonary vasoconstriction (HPV) older SA patients could be at greater risk of developing pulmonary hypertension because of repeated intermittent hypoxia.

6 young and 6 older participants (mean age ± S.D = 20.4 ± 0.5 and 56.5 ± 2.6 years, respectively) undertook two protocols. A hypoxia protocol consisted of 5 min isocapnic euoxia (PETO2 = 100 mmHg, PETCO2 = 1 mmHg >; normal) followed by 20 min isocapnic hypoxia (PETO2 = 50 mmHg, PETCO2 = 1 mmHg >; normal), followed by a further 5 min isocapnic euoxia. A control protocol consisted of 30 min isocapnic euoxia. During both protocols pulmonary artery pressure (PAP) and cardiac output were measured continuously using Doppler echocardiography.

Baseline PAP was greater in older participants (21.6 ± 0.7 mmHg vs. 19.2 ± 1.1 mmHg, p <0.05). During hypoxia PAP rose more in older participants than in younger (13.3 ± 1.3 mmHg vs. 8.3 ± 1.0 mmHg, respectively, p<0.001). Cardiac output was similar between the two groups (p>;0.05). All data are mean ± SEM.

Our results support the hypothesis that HPV is more pronounced in older people. A greater HPV response to intermittent hypoxia during the night could play a role in the development of pulmonary hypertension in older SA patients.
Transient receptor potential channels (TRPC) contribute to an enhanced endothelial cell proliferation and irreversible vascular remodeling associated with the development of pulmonary arterial hypertension (PAH)
Authors: Sundivakkam Premanand , Tang Haiyang , Fernandez Ruby , Drennan Abigail , Yuan Jason X.‐J.
Published: June 2021

Disordered pulmonary arterial endothelial cell (PAEC) growth underlies the formation of angio‐proliferation and intimal lesions, obliterating the small pulmonary arteries (PAs), resulting in irreversible structural alterations, or pulmonary vascular remodeling in pulmonary arterial hypertension (PAH) patients.

Objective

To demonstrate that transient receptor potential channel (TRPC6) contributes to PAEC proliferation and in the development of PAH.

Results

PAEC isolated from Idiopathic PAH (IPAH) patients showed an enhanced VEGF‐induced [Ca2+]cyt and proliferation. In parallel, TRPC6 (mRNA and protein) expression was markedly up regulated in IPAH compared to normal subjects. Interestingly, knockdown of TRPC6 in IPAH‐PAEC using siRNA significantly attenuated VEGF‐induced rise in [Ca2+]cyt and proliferation. Deletion of either TRPC6 (TRPC6−/−) or TRPC4 (TRPC4−/−) abolished thapsigargin‐induced store Ca2+ release‐activated Ca2+ entry (SOCE) in mice PAEC. In addition, TRPC6−/− mice showed significant abrogation of hypoxia‐induced changes in the right ventricular systolic pressure and right ventricular hypertrophy suggesting its role in vascular remodeling associated with PAH.

Conclusion

Our studies provide a comprehensive picture of TRPC6‐mediated Ca2+ entry mechanisms in contributing to an increased PAEC proliferation and vascular remodeling associated with PAH.
The C‐terminal tail of Aquaporin 1(AQP1) is Required for Migration and Proliferation of Pulmonary Arterial Smooth Muscle Cells (PASMCs)
Authors: Lai Ning , Lade Julie M , Leggett Kyle , Undem Clark , Crow Michael , Yun Xin , Shimoda Larissa A
Published: June 2021

Both PASMC proliferation and migration are important contributors to the vascular remodeling that occurs during the development of pulmonary hypertension. AQP1 is a member of the water channel family of proteins. We previously demonstrated that AQP1 is expressed in and mediates migration and proliferation of PASMCs; however, the mechanism by which AQP1 controls these responses is unclear. The C‐terminal tail of AQP1 contains putative calcium and protein binding sites. Thus, we wanted to explore whether the C‐terminal tail of AQP1 was required for migration and proliferation. Rat PASMCs were harvested from distal pulmonary arteries enzymatically and plated onto culture dishes. Proliferation and migration were measured using BrdU incorporation and transwell filters. PASMCs were treated with 50 ifu/cell for 4 h with an adenoviral construct expressing green fluorescent protein (AdGFP), the control for infection, wild‐type AQP1 (AdAQP1) or AQP1 lacking the entire cytoplasmic C‐terminal tail (AdAQP1CT). Compared to AdGFP cells, infection with AdAQP1 or AdAQP1CT increased total and surface AQP1 protein levels and the rate of change in cell volume in response to hypotonic challenge to a similar level. Infection with AdAQP1, but not AdAQP1CT, increased migration and proliferation. Our results suggest that AQP1 controls proliferation and migration in PASMCs via a mechanism that includes the C‐terminal tail but is independent of water transport.
Loud sound induced hearing loss is prevented by methylene blue
Authors: Wilson Teresa M , Omelcheko Irina , Foster Sarah , Nuttall Alfred L
Published: June 2021

Rationale

Methylene blue (MB), a powerful synthetic redox compound that readily crosses the blood‐brain barrier, is currently in use as a treatment for methemoglobinemia and is being examined as a treatment for other human ailments including Alzheimer's disease. MB. In low doses, MB acts as an electron cycler in the mitochondrial electron transport chain facilitating oxidative respiration and greatly reducing superoxide production. Additionally, MB has been shown to directly inhibit the activity of both inducible and constitutive forms of nitric oxide synthetase (NOS).

Objective

To determine whether MB can protect against noise induced hearing loss.

Methods and Results

Male CBA/CaJ (8 weeks old) mice (n=5/group) were injected with MB (0.5 mg/kg IP) or water at 24 and 1 hr prior to exposure to the moderately damaging noise level of 110 dB SPL, 4–45 kHz for 3 hrs. At 1 and 2 weeks, Auditory Brain Stem Response and Distortion Product Otoacoustic Emission were measured. The effect of MB on NOS and NADPH oxidase activities was also measured. The results revealed that prior treatment with MB provided significant protection against noise induced hearing loss across all measured frequencies and greatly reduced reactive free radical production.

Conclusion

Here, we show that low dose MB can prevent hearing loss due to loud sound exposure.

Supported by grants 5R01DC000105 (ALN) and P30DC005983.