bluuebunny/crossref_metadata_2025 huggingface dataset:
Antioxidant Properties of Coriandrum Sativum (Coriander)
Authors: Davar Vinti , Rathi Sonali , Dua Anita
Published: June 2021

Antioxidants prevent the damage done to cells by free radical‐molecules that are released during the normal metabolic process of oxidation. Some of these free radicals include reactive oxygen free radicals species (ROS), reactive hydroxyl radicals (OH), the superoxide anion radical (O2), hydrogen peroxides (H2O2) and peroxy (ROO) which generates metabolic products that attack lipids in cell membranes or DNA. These are associated with several types of biological damage, DNA damage; carcinogenesis and cellular degeneration related to aging and also contribute to heart disease and arthritis. Spice coriander reduces fever and promotes a feeling of coolness. It is highly beneficial in the deficiency of vitamin A, B1, B2, C and iron. High concentration of polyphenol and other bio reactive components are reported in this spice. The present study was aimed to determine the antioxidant properties of coriander. The antioxidant activity of polyphenolic extracts of Coriandrum Sativum was evaluated in vitro with the systronic Spectrophotometer at 517nm based on the reduction of the stable DPPH free radical. Total phenolic content extracted from the coriander spice sample was 240.0 mg GAE/g dry weight of the spice as estimated by Folin's reagent and calculated with standard curve prepared with gallic acid by the same procedure. Antioxidant activity measured from coriander as DPPH free radical scavenging activity was dose dependent. Incubation of 10μl of extract in DPPH free radical solution eradicated free radicals and caused decrease in OD of 0.01. Antioxidants present in coriander extract were able to protect DNA damage against hydroxyl ion caused by (ferrous sulphate + H2O2 + ascorbate) Fenton's reaction. The study indicate coriander is one of the most effective spice in terms of antioxidant properties and can serve as natural source to develop the free radical scavengers and antioxidant agents.
Broccoli seedlings prevent glucose‐induced inflammation of peripheral blood mononuclear cells in humans
Authors: Meijer Kees , de Jong Ingrid , Koehorst Martijn , Priebe Marion , Roelofsen Han , Vonk Roel
Published: June 2021

We studied the effect of anti‐inflammatory components in vegetables on postprandial inflammation using broccoli seedlings (Broccocress®, Koppert Cress BV, Monster, The Netherlands), which are rich in the isothiocyanate sulforaphane (SFN). In an NF‐κB reporter cell line, increasing concentrations of 2–15 μM SFN lead to inhibition of TNFα‐stimulated NF‐κB activation up to 98% (p<0.05). Five healthy subjects ingested a load of 75 gram glucose with or without a smoothie of broccoli seedlings (45 min. prior to glucose). NF‐κB activation in the nuclear fraction of peripheral blood mononuclear cells was determined by ELISA. 75 gram glucose leads to a 36.5% ± 20.3% increase in NF‐κB activation. In combination with the smoothie, NF‐κB was decreased by 64.8% (p<0.005) and 29.3% ± 9.3% (p<0.005) compared to high‐glucose‐induced and basal NF‐κB levels, respectively. The level of NF‐κB activation correlated to blood glucose levels after the oral glucose load, but not when the smoothie was ingested as well. SFN could be detected in plasma after 1.5 hrs. Total SFN (free SFN plus conjugated SFN) correlated to inhibition of NF‐κB. This suggests that broccoli seedlings are effective in reducing metabolic inflammation in humans.

Grant Funding Source: Food Nutrition Delta project # FND09002
Kaempferol supplementation enhances insulin sensitivity via regulation of plasma cytokine level and hepatic transcriptional response
Authors: Shin Su-kyung , Cho Yun-young , Kwon Eun-young , Jung Un Ju , Park Yong Bok , Choi Myung-sook
Published: June 2021

Obesity‐induced inflammation plays a pathogenic role in development of insulin resistance, and cytokines is linked to inflammation. Kaempferol (KF) is a dietary flavonoid and is well‐known for its anti‐oxidant properties. However, little is known about effect of KF on inflammation‐related insulin resistance. In this study, we investigated the effect of KF on insulin resistance, plasma cytokine and hepatic inflammation‐related gene transcript levels in high‐fat fed mice. Thirty‐nine male C57BL/6J mice (4‐ week‐old) were randomly divided into 3 groups and were fed normal diet, high‐fat diet (HFD, 20% fat) and HFD + 0.02% (w/w) KF for 16 weeks. KF decreased plasma glucose levels, HOMA‐IR and improved glucose tolerance compared to the HFD group. KF also decreased plasma IL‐6, TNF‐¥á, MCP‐1, resistin and PAI‐1 levels. Microarray analysis revealed hepatic Cfd, Prc1, Saa1, MmP13, Cd63, Vcam1, Cyp2b9 and Cyp2b13 mRNA that potentially connects obesity and its related inflammation were down‐regulated by KF supplementation. Our findings suggest that KF is one of bioactive component for improving insulin resistance by decreasing plasma cytokine levels as well as pro‐inflammatory gene expression in liver.
Association between ferritin, transferrin receptor and retinol biomarkers obtained from dried blood spots and anthropometric measures in Kenyan children
Authors: Haddad Ella H. , Ndiku Mueni , Haddad Victoria H. , Bahjri Khaled , Sabaté Joan
Published: June 2021

Micronutrient deficiencies continue to be a problem in Africa and dried blood spot (DBS) specimens provide a practical means to explore their causes. This study examined the association of DBS biomarker data with age and anthropometric measurements. DBS specimens were collected from 369 children aged 0–59 months residing in four randomly selected locations in the Ukambani region of Kenya. A 0.635 cm disk was punched from the DBS on the collection card and extracted with buffer. Ferritin and transferrin receptor were assayed by ELISA and retinol by HPLC. Anthropometric measures obtained on site were used to compute malnutrition indices (z‐scores) using EPI INFO 2000. With increasing age, DBS concentration of ferritin decreased (P=0.02), transferrin receptor increased (P<0.001) and retinol showed no change. There were significant positive correlations between ferritin and weight‐for‐height, weight‐for‐age and height‐for‐age z scores, whereas transferrin receptor was negatively correlated to weight‐for‐height and height‐for‐age z scores (P<0.05). In conclusion, values for ferritin and transferrin receptor varied with age and were correlated to anthropometric measures whereas those of retinol did not show similar outcomes.

Funded by the Federico Foundation, Switzerland.
An examination of wealth and food security in four countries
Authors: Crookston Benjamin , Gray Bobbi , Gash Megan , Kim Jaewhan , Brett John , Hamad Rita
Published: June 2021

Our objective was to determine whether wealth as measured through a common set of indicators of assets or as measured through the use of the Progress out of Poverty Index (PPI) was positively associated with food security in four countries. We used data from over 9000 participants from previous studies conducted in Peru, Bolivia, Mali, and India that used an adapted version of the US Household Food Security Scale. Additionally, various wealth indicators were captured for each location. Factors associated with food security included PPI score, savings, income, education and assets (e.g., TV, electricity and number of rooms in home, etc.). However, the effect and significance of these factors varied by location. Food security appears to be strongly associated with a variety of wealth indicators, but the indicators of influence are not consistent across countries. Efforts to better understand how changes in wealth and assets impact food security are needed.
Metabolic Regulation of Epigenetic Processes
Authors: Domann Frederick E
Published: June 2021

The normal development and function of organisms requires concerted changes in gene activity. While changes in gene activity are often attributed to mutations or changes in DNA sequence, it has become apparent that epigenetic processes also play a critical role in controlling gene expression during both normal and pathophysiological conditions. Genome wide changes in epigenetic marks such as DNA methylation and histone modifications have been observed in both development and cancer. These epigenetic alterations normally silence or activate gene expression during development, but loss of epigenomic integrity during carcinogenesis leads to aberrant epigenetic control of gene expression and ultimately contributes to cancer; however, the process leading to this epigenetic switch in cancer remains unknown. Carcinogenesis is also associated with metabolic reprogramming that increases mitochondrially derived reactive oxygen species, creates an atypical redox state, adapts to hypoxia, and changes the fundamental means by which cells produce energy. We will summarize the influence of these metabolic perturbations on epigenetic processes. Metabolic defects affect epigenetic enzymes by limiting availability of the cofactors like S‐adenosylmethionine. Increased production of reactive oxygen species alters DNA methylation and histone modifications in tumor cells by oxidizing DNMTs and HMTs, or through direct oxidation of nucleotide bases. Lastly, hypoxia, the Warburg effect and increased glutamine consumption in cancer influences histone acetylation and methylation by affecting the activity of sirtuins and histone demethylases as well as potentially the TET family of 5‐methylcytosine hydroxylases. We anticipate that the regulatory mechanisms described herein will play increasingly large roles in our understanding of human health as epigenetics research progresses.
In Vivo 129 Murine Model of Salmonella Infection is a Powerful Tool to Examine Human Clinical Isolates
Authors: Harrington Jane , Eckmann Lars , Guiney Donald
Published: June 2021

Non‐typhoidal Salmonella are the leading causative agents of bacterial gastroenteritis in immuno‐competent hosts; however, Salmonella are also associated with typhoid‐like systemic infection in immuno‐compromised patients. Identification of Salmonella from stool samples of HIV+ patient suggests that bacterial genomic variations might contribute to the course of disease, in addition to immune status of the patient.

We have developed a novel mouse model to examine essential factors required for systemic infection with Salmonella clinical isolates. The “highly virulent” strain, UC17, was isolated from an HIV+ patient with bacteremia. The “low virulent” strain, UC9, was cultured from a stool sample of an HIV+ patient presenting acute gastroenteritis. In vitro analysis of SpvB expression (a known virulence factor) showed that UC17 expresses abundant SpvB levels and UC9 expresses low levels of SpvB. We have observed greater infection rates in liver and spleen by UC17, as compared to UC9, with the 129 mouse model(NRAMP+). We have generated SpvR knockouts (positive regulator of spvB) in the UC9 and UC17 parental backgrounds and co‐infected 129 mice with WT/spvR knockout sets to verify that SpvB is a required virulence factor for in vivo murine infection. This model has the potential to serve as an effective experimental approach to examine the key determinants for Salmonella infection in humans.
Allosteric Modulation of Cannabinoid CB1 Receptor
Authors: Ross Ruth A. , Baillie Gemma L. , Pertwee Roger G.
Published: June 2021

ORG27569, an allosteric modulator of the cannabinoid CB1 receptor increases the binding affinity of CB1 receptor agonists but reduces the agonist signalling efficacy. Allosteric modulators can have differential effects on various signalling pathways. The aim of the present study was to investigate the effect of ORG27569 on various agonist‐induced CB1 receptor signalling pathways.

ORG27569 (100 nM) markedly reduced the efficacy of CP55940 in the [35S]GTPγS binding assay, β arrestin assay and cyclic AMP assay. In contrast, 1μM ORG2759 had no significant effect on the efficacy of CP55940 in pERK assay. These data provide evidence that cannabinoid CB1 receptor allosteric modulators can preferentially impact various signalling pathways.
Scaffolding of the cofilin pathway by β‐arrestins
Authors: Lin Alice , DeFea Kathryn
Published: June 2021

β‐arrestin‐1 (β1) is a key mediator of G‐protein‐coupled receptor (GPCR) signal termination and G‐protein‐independent signaling. Our lab uncovered the role for β‐arrestins in the control of actin dynamics downstream of the GPCR, protease‐activated receptor‐2 (PAR2), via regulation of cofilin activity. Here, we demonstrate that β1 can form at least 2 scaffolding complexes that regulate cofilin activity, one with cofilin and its phosphatase CIN, and another with its upstream negative regulator, LIM kinase (LIMK). Previous studies have demonstrated that β1 scaffolding of cofilin with CIN facilitates cofilin dephosphorylation by bringing substrate and phosphatase together. The studies presented here demonstrated that β1 also directly inhibits LIMK1 activity which further contributes to cofilin dephosphorylation. Combining the results from sandwich immunoassay, spot peptide array, bioluminescence resonance energy transfer (BRET) and in vitro kinase assay, we prove that β1 facilitates cofilin activation by directly binding both LIMK1 and cofilin. We have identified putative sites of interaction for both LIMK and cofilin on β1 between residues 146–182. These data elucidate suggesting a novel cofilin activation mechanism by which β1 enhances cofilin dephosphorylation by specifically binding to LIMK and preventing phosphorylation and inactivation of cofilin.
Gender differences in aortic endothelial function of streptozotocin‐induced diabetic rats: possible involvement of protein kinase C beta and nitric oxide production
Authors: Han Xiaoyuan , Anderson Leigh , Rahimian Roshanak
Published: June 2021

Little is known of the interaction between diabetes and gender in the vasculature. The objective of this study was to investigate whether there are gender differences in rat aortic endothelial function in streptozotocin (STZ, 60mg/kg, iv)‐induced diabetes and the roles of protein kinase C beta (PKCβ) and nitric oxide (NO). Endothelium‐dependent vasodilatation (EDV) to acetylcholine (ACh; 10−8 to 10−5M) was measured in aortic rings precontracted with phenylephrine (PE; 2μM) before and after pretreatment with LY341684 (1μM), a selective PKCβ inhibitor. Constrictor response curves to PE (10−8 to 10−5M) were also generated before and after incubation with L‐NAME (200μM), an endothelial nitric oxide synthase inhibitor. STZ‐induced diabetes impaired aortic EDV to ACh only in females. Inhibition of PKCβ increased the sensitivity to ACh in both control and diabetic male rats. However, PKCβ inhibition enhanced the sensitivity to ACh only in aorta taken from diabetic female rats. Addition of L‐NAME resulted in a significant potentiation of the contractile responses to PE in all groups. However, aorta from control females had a greater maximal potentiation of the PE responses than others. These data suggest that the predisposition of female rat aorta to vascular injury in diabetes is possibly due to differences in enhanced PKCβ activation and decreased basal NO production (supported by NIH/NIDCR).
Expression of TNF‐R1 and Fas in coronary arterioles of type 2 diabetic mice
Authors: Yokoo Hiroki , Yamamoto Seiji , Hattori Yuichi
Published: June 2021

Hyperglycemia‐triggered endothelial cell apoptosis may be a critical event in the process of diabetic cardiovascular complications. We hypothesized that coronary arteriolar endothelium may significantly express TNF‐R1 and Fas, both of which are cell surface death receptors that transmit apoptotic signals initiated by death ligands, in type 2 diabetic mice. Type 2 diabetic mice were generated by administering streptozotocin with the use of the antidiabetic protective action of nicotinamide. Immunofluorescence staining showed appreciable expression of TNF‐R1 and Fas in the intimal surface of coronary arterioles. Overlap images with CD31 indicated that these death receptors were expressed on coronary artery endothelium. No positive staining for the death receptors was found in age‐matched control mice. Circulating TNF‐alpha levels were elevated in diabetic mice. In cultured human coronary arterial endothelial cells, high glucose‐induced up‐regulation of TNF‐R1 and Fas expression was masked in the presence of TNF‐alpha and high glucose‐induced apoptosis was significantly inhibited by treatment with TNF‐R1 neutralizing peptide. We suggest that hyperglycemia up‐regulates coronary expression of TNF‐R1 and Fas in conjunction with increased TNF‐alpha secretion, which could promote endothelial cell apoptosis and thereby contribute to coronary arterial endothelial dysfunction.
Regulator of G Protein Signaling 2 (RGS2) regulates pulmonary vasoconstriction
Authors: Jain Neha , Tu Yaping , Abel Peter W
Published: June 2021

RGS2 proteins selectively regulate Gq coupled GPCR signaling which inhibits the downstream pathways that causes vasoconstriction and cardiovascular remodeling. RGS2 homozygous knockout (KO) mice have elevated systemic blood pressure associated with enhanced constriction of peripheral blood vessels. Our goal was to determine if RGS2 KO would also cause enhanced constriction of pulmonary blood vessels and cardiac hypertrophy. For our studies we used RGS2 KO and wild‐type (WT) mice. Heart weight to body weight ratio (HW/BW) was used to estimate cardiac hypertrophy. Vascular constriction was measured in pulmonary arteries using precision cut lung slices and videomorphometric analysis of pulmonary artery luminal area. HW/BW ratio was greater in RGS2 KO (5.3 mg/gm) compared to WT (4.6 mg/gm) mice. Dose‐response curves for the Gq coupled GPCR agonists serotonin and U46619 were generated in pulmonary arteries of lung slices from RGS2 KO and WT mice. Maximal constriction caused by serotonin and U46619 was increased by 23% and 18%, respectively, in the RGS2 KO compared to WT mice. Agonist potency in causing constriction was not different. These data show that RGS2 regulates heart weight and GPCR mediated constriction of the pulmonary vasculature and suggests that RGS2 dysregulation may play a role in cardiac and pulmonary vascular disease. Supported by American Asthma Foundation.
Modulation of Norepinephrine and Neuropeptide Y release by Angiotensin‐(1‐7) from the mesenteric arterial bed of the rat: Role of Cyclooxygenase
Authors: Murray Jessica Maria , Macarthur Heather , Westfall Thomas C.
Published: June 2021

Ang‐(1‐7) produces a significant decreasein the nerve stimulation (NS)‐induced release of the sympathetic nervous system cotransmitters NE and NPY, as well as perfusion pressure of the mesentericarterial bed of the rat. These effects are greater in mesenteric beds obtained from Spontaneously Hypertensive Rats (SHR) compared to its normotensive control, Wistar‐Kyoto rats (WKY). We examined the hypothesis that the Ang‐(1‐7) induced inhibition of sympathetic neurotransmission is mediated at least in part by prostacyclin (PGI2). Experiments were performed using mesenteric beds obtained from 10–12 week old SHR and WKY rats. The effect of Ang‐(1‐7) on the NS‐evokedrelease of NE and NPY was determined before and after the administration of the COX inhibitor Indomethacin (to prevent PGI2 synthesis) and the IP receptor antagonist CAY 10441. A reversal of the attenuation of NE and NPY release by Ang‐(1‐7) was observed in the presence of Indomethacin in both SHR and WKY. A trend was observed suggesting CAY10441 is partially reversing the attenuation of NE and NPY release from SHR mesenteric beds, but not WKY. The attenuation of perfusion pressure by Ang‐(1‐7) was reversed by both Indomethacin and CAY10441 in SHR, but not in WKY. These data suggest a role of PGI2 mediating vasodilation and the inhibition of sympathetic neurotransmission by Ang‐(1‐7). (Supported by HL60260 and NIGMS008306)
Uroguanylin Promotes Eletroencephalographic Changes in Rat Brain
Authors: Fonteles Manassés Claudino , Teixeira Maria Daniele Azevedo , Nascimento Nilberto Robson Falcão , do Vale Otoni Cardoso
Published: June 2021

Uroguanylin (UGN) is an STa‐like peptide that acts on membrane guanylate cyclase receptors of intestine and kidney, regulating electrolyte and water epithelial transport. Recent reports demonstrate the expression of guanylate cyclase C in the central nervous system. We have probed the effect of UGN administered through intracisternal infusion of this peptide at the concentrations of 2.5μM/ min and 7.5 μM/min in order to evaluate modifications of mean absolute amplitude of electroencephalographic spectra (EEG), number of spikes and sharp waves per minute, as well as absolute amplitude of those spikes and sharp waves of the EEG in anesthetized Wistar rats. Uroguanylin or saline administration lasted for 30 minutes and previously to that, EEG was recorded during 10 min and throughout the infusion periods, with another 10 min EEG registration at the final phase of the protocol. The present results demonstrate that 2.5 and 7.5 μM/min intracisternal infusion of UGN significantly enhances mean absolute amplitude of spikes and sharp waves (p=0.03). There was also an increase in the number of spikes and sharp waves per minute. No statistical significance was observed on absolute alpha and theta spectra amplitude. The present data suggest that UGN acts on bioelectrogenesis of cortical cells by inducing hypersynchronic firing of neurons. This effect was blocked by nedocromil, suggesting that UGN acts by increasing the activity of chloride channels and points out for the presence of a possible functional guanylin receptor in the brain, as demonstrated recently (Gong et al., Science. 2011,333:1642–6).
Free radicals are important for dendritic growth in rat embryonic sympathetic neurons
Authors: Chandrasekaran Vidya , Lea Charlotte , Lein Pamela
Published: June 2021

Dendritic growth and retraction are important hallmarks of neuronal growth and injury respectively. It is therefore important to elucidate the regulators of dendritic growth. Previous studies have shown that a family of proteins known as Bone morphogenetic proteins (BMPs) promote dendritic growth in sympathetic neurons and enhance dendritic outgrowth in central neurons. In this study, we identified free radical mediated signaling as potential regulator of dendritic growth in sympathetic neurons. Cultured sympathetic neurons from E21 rat pups were treated with BMP‐7 (5 ng/ml or 50 ng/ml), with or without antioxidants. Some of the antioxidants examined in this study include Diphenylene iodinium (DPI), Nordihydroguiaretic acid (NGA), Vitamin C, Vitamin E, and Desferroxamine (DFO). Our results showed that BMP‐7 induced dendritic growth was inhibited by antioxidants in a dose dependent manner, without affecting axonal growth or cell numbers. Furthermore, DPI and DFO induced dendritic retraction whereas NGA prevented further growth of existing dendrites. These results suggest that low levels of free radicals are beneficial for maintenance of dendrites in sympathetic neurons. We are currently exploring the possible connections between BMP signaling and free radical signaling in sympathetic neurons. (Supported by the Saint Mary's College Summer Research Program)
Low nitric oxide bioavailability predicts better responses to sildenafil in patients with erectile dysfunction
Authors: Muniz Jaqueline Jóice , Lacchini Riccardo , Sertório Jonas Tadeu Cau , Junior Alceu Afonso Jordão , Nobre Yuri Túlio Dantas Andrez , Martins Antônio Carlos Pereira , Tanus-Santos José Eduardo
Published: June 2021

The aim of this study was to assess if levels of markers of nitric oxide (NO) formation and oxidative stress are associated to responses to sildenafil in patients with erectile dysfunction (ED). We studied 28 health controls, 26 patients with ED (ED group), and 18 patients with ED and diabetes mellitus (ED/DM group). The five‐item version of International Index for Erectile Function (5‐IIEF) questionnaire was used to assess the erectile function, and sildenafil responsiveness was assessed as the change of 5‐IIEF score (after sildenafil minus before sildenafil). Levels of whole blood nitrite, antioxidants markers (ferric reducing ability of plasma; FRAP and glutathione; GSH), oxidative stress markers (thiobarbituric acid reactive substance; TBARS and carbonyl) were determined. While we found a negative correlation between whole blood nitrite level and the responses to sildenafil in both ED groups, FRAP correlated negatively with the responses to sildenafil only in the ED/DM group. No other significant differences were found. Our finding show evidence that low NO bioavailability predicts better responses to sildenafil in patients with ED, with or without DM. Supported by CNPq and FAPESP
Fyn Inhibition by prenylated pholyphenols Leads to Antioxidant Effect through LKB1 Activation
Authors: Lee Chan Gyu , Kim A Young , Ryu Jae Ha , Kim Sang Geon
Published: June 2021

Fyn, a kinase activated by oxidative stress, may play an important role in diverse pathological processes. This study investigated the effect of Fyn inhibition on LKB1‐mediated AMPK activation and cellular antioxidant capacity, and the effects of prenylated polyphenols (Prenyl‐PP) on the events. Prenyl‐PPs had an antioxidant effect, as indicated by diminished production of H2O2 and increased cell viability more potently than non‐prenlyated polyphenols, such as tupichinol and resveratrol. Treatment of HepG2 cells with Prenyl‐PP diminished mitochondrial permeability transition and superoxide production elicited by severe oxidative stress. Prenyl‐PP treatment activated LKB1, leading to the activation of AMPK responsible for the protection of mitochondria. Our in vitro and in cell kinase assays supported the ability of Prenyl‐PP to inhibit Fyn phosphorylation. The inhibitory role of Fyn in LKB1‐dependent AMPK activation was strengthened by the results of Fyn overexpression or knockdown experiments. SU6656 (a Fyn inhibitor) treatment exerted a similar effect. Furthermore, Prenyl‐PP treatment antagonized Fyn phosphorylation increased by oxidative stress, which was accompanied by the restoration of LKB1 activity. Our results demonstrate that the inhibition of Fyn contributes to LKB1‐mediated AMPK activation, thereby enhancing antioxidant effect, and which was accomplished by prenyl‐PP treatment.
Recruitment of dynamic cerebral artery endothelial Ca2+ signals by the TRPA1 channel activator AITC
Authors: Taylor Mark Stephen , Qian Xun , Francis Michael , Earley Scott , Solodushko Viktoriya
Published: June 2021

Real‐time regulation of vascular tone by endothelial Ca2+ signals is a crucial determinant of blood flow. Recent findings suggest that transient receptor potential (TRP) channels, particularly TRPA1, may play a key role in activating endothelial Ca2+‐dependent effectors in cerebral arteries to promote acute vasodilation. In the current study, we employed high‐speed confocal imaging and a novel analysis algorithm to evaluate the impact of TRPA1 channel activation on Ca2+ signals in the endothelium of rat cerebral arteries and assess its relationship to vasodilation. We found that endothelial cells of rat cerebral arteries exhibit widespread basal Ca2+ dynamics (44 ± 6 events at 26 ± 3 distinct sites per minute in a 3.6×104 μm2 field). The TRPA1 activator allyl isothiocyanate (AITC) increased Ca2+ signals in a concentration dependent manner, primarily by soliciting new events at distinct sites along the intima (56 ± 5% and 52 ± 4% increase in events and sites, respectively, at 60 μM). These stimulated events corresponded spatially with TRPA1 channel densities within holes in the internal elastic lamina (IEL) and were blocked by the TRPA1‐specific inhibitor HC‐030031. The concentration‐dependent expansion of Ca2+ events in response to AITC correlated precisely with the dilation of pressurized cerebral arteries (p = 0.93 by F‐test comparison of nonlinear regression curve fits). Correspondingly, AITC caused rapid endothelium‐dependent suppression of pro‐contractile asynchronous Ca2+ waves in subintimal smooth muscle cells. The current findings suggest that factors evoking stimulation of TRPA1 channels trigger and expand discrete Ca2+ signal‐effector coupling sites along the endothelium to evoke graded cerebral artery vasodilation. Supported by NIH R01 HL085887 and R01 HL091905.
P2Y2 Receptor Dependent Modulation of Microvascular Barrier Function
Authors: Harvey Joseph , Erb Laurie , Huxley Virginia , Weisman Gary , Garrad Richard , Wang Jianjie
Published: June 2021

That P2Y2 nucleotide receptor (P2Y2R) is critical to endothelial‐dependent inflammatory vascular responses including leukocyte recruitment and filtration was revealed by abolishment of inflammatory responses in P2Y2R‐deficient mice. The role of P2Y2R in the mediation of microvascular permeability, however, remains to be investigated. Both in vivo and in vitro approaches were used to test the hypothesis that P2Y2R activation would increase vascular permeability. We measured in vivo cremaster venular permeability to albumin (Ps) in response to UTP, a P2Y2R agonist, in wild type (WT) and P2Y2R‐deficient mice. UTP (10− 5M) induced 5.2 ± 1.7‐fold (n=5) transient increase in cremaster venular Ps from basal levels in WT mice; this response was absent (Ptest/Pcontrol = 0.92 ±0.07, n=4) in the P2Y2R‐deficient mice. The increased Ps in response to UTP in WT mice was inhibited by the ROCK blocker, Y27632 (10−5 M). We established primary cultured microvascular endothelial cells (EC) derived from the same origin as cremaster microvessels to test the signaling mechanisms underlying P2Y2R‐dependent modulation of Ps. The level of focal adhesion kinase (FAK) expression and phosphorylated FAK at tyrosine‐397 increased in EC following UTP treatment. The findings demonstrate that P2Y2R activation elevates vascular Ps, which is consistent with the hypothesis. The UTP‐induced increase in Ps is mediated by RhoA‐ROCK pathway and is also associated with reorganization of cell‐matrix adhesion.
Adenosine and NO blockade decreases skeletal muscle interstitial pH during hypoxia
Authors: MacLean David A , Fabris Sergio , Smith Ashley
Published: June 2021

The present study examined the effects that blocking local adenosine and nitric oxide production has on skeletal muscle interstitial pH and H+ during hypoxia. Eight anesthetized rats had two microdialysis fibers inserted into the gastrocnemius muscle of each leg and perfused with Ringers (control) or 500 μM AOPCP (5′ectonucleotidase inhibitor) plus 10 mM L‐NAME (NOS inhibitor). Following baseline collections (20 min with saline, Baseline 1), all the probes were perfused with the both blockers for (20 min, Baseline 2) followed by 20 min of hypoxia (inhalation of 10.5% O2) and recovery. The perfusion of the blockers resulted in a decrease (P<0.05) in skeletal muscle interstitial pH and a reciprocal increase (P<0.05) in interstitial H+during normoxia (Baseline 2) and these changes were further exaggerated during hypoxia as well as recovery (Figures)1. These data clearly demonstrate that blocking local vasodilators most likely resulted in a decrease in local tissue blood flow and an accumulation of H+, which is further elevated under anaerobic conditions such as hypoxia.
Infrared Contrast Imaging (IRCI): A New Visualization Technology for Vascular, Metabolic and Physiological Monitoring
Authors: Sostek Ronald Yale
Published: June 2021

A new technology has been utilized to see vascular flow, metabolic activity and physiological events through the use of a new infrared imaging technique‐irci. This powerful new emmision IR technology can visualize without contrast agents vascular activity in organisms, organs and tissue. This technique has been used to see infarct areas in the heart; visualize organ perfusion paths in kidney and lungs and can identify areas with diminshed or increased vascullar flow as deep as 1.5cm into tissue without stains, dyes or contrast agents. It also is ideal for visualizing non visible contrasted events like the coating and distribution of aerosols, the physical mixing of two fluids into each other in real time.
Peripheral Sensory Function Enhanced Using Stochastic Noise Stimulation
Authors: Serrador Jorge , O'Laighin Gearóid , McIntosh Caroline , O'Tuathail Claire , Quinlan Leo R , Dinneen Sean F , Breen Paul
Published: June 2021

Peripheral neuropathy is common with both aging and disease. This sensory loss can impair the ability to feel trauma or forces during gait increasing the risk of falling, tissue damage, foot ulceration and amputation. We hypothesized that we could improve peripheral tactile sensation in the entire plantar aspect of the foot by applying subsensory electrical noise stimulation to the sensory nerve supplying this area.

We applied imperceptible levels of electrical stochastic noise stimulation to a region of the tibial nerve above the ankle. Vibrotactile perception improved in both young and older individuals despite age related neuropathy in the older group. Both groups improved ~16% despite differences in baseline levels. All sites tested showed improvement, indicating that all sensory neurons on the plantar aspect of the foot and travelling down the tibial nerve were affected to a comparable degree.

These are the first data to demonstrate that modulation of axon properties with applied electrical noise can improve neural transmission and perception of tactile stimuli. We suggest that the improvement in perception is due to changes in neural synchrony, a hypothesis that is supported by a developed computational model. Currently there are no treatment options for loss of sensory function and this work may have significant implications in the development of treatment models for neurodegenerative conditions.
Acute dietary salt loading impairs endothelial‐dependent dilation in normotensive‐salt resistant adults
Authors: DuPont Jennifer J , Greaney Jody L , Wenner Megan M , Lennon-Edwards Shannon L , Farquhar William B , Edwards David G
Published: June 2021

In humans, the effects of salt consumption on endothelial function have not been separated from the effects on blood pressure (BP). We sought to determine whether acute salt loading adversely affects endothelial function in normotensive salt‐resistant individuals. We hypothesized that brachial artery flow‐mediated dilation (FMD) would be impaired during a high salt diet in the absence of a change in BP. Fourteen healthy adults with salt‐resistant BP were studied (9M,5F; age 33±2.4 years). After a control run‐in diet, subjects were randomized to a 7 day high salt (HS) (350 mmol/day) and a 7 day low salt (LS) (20 mmol/day) diet (controlled feeding study). Salt‐resistant BP was defined as a change in 24 hour mean BP of ≤ 5 mmHg from the LS to the HS diet. FMD was measured in each subject on the last day of each diet. 24 hour mean BP was unchanged between the LS and the HS diet (LS: 85±1, HS: 85±2 mmHg). Sodium excretion significantly increased during the HS diet (LS: 29±9, HS: 231±16 mmol/24hr, p < 0.05). FMD was significantly impaired on the HS diet (LS: 10.3±0.9, HS: 7.3±0.7%, p < 0.05). These data suggest that in normotensive salt‐resistant adults, a high salt diet impairs endothelial‐dependent dilation independent of changes in arterial BP.

Supported by 2 P20 RR016472‐11 and HL104106.
Augmented coronary vasoconstriction to epicardial perivascular adipose tissue in metabolic syndrome
Authors: Kohr Meredith , Lai Xianyin , Moberly Steven P , Berwick Zachary C , Witzmann Frank A , Tune Johnathan D
Published: June 2021

This investigation was designed to delineate the mechanisms and potential adipocytokine factors by which epicardial perivascular adipose tissue (PVAT) influences coronary smooth muscle function in the setting of the Metabolic Syndrome (MetS). We performed isometric tension studies on isolated coronary arteries from lean and MetS Ossabaw swine before and after the addition of PVAT to the tissue baths. The addition of PVAT (0.1 to 1.0g) increased active tension development in both lean and MetS swine. This effect was augmented with MetS PVAT (~2‐fold at 0.3g) and dependent on the quantity of PVAT added to the bath. Interestingly, active tension development of arteries pre‐constricted with KCl (20 mM) or PGF2α (10μM) was further amplified by the addition of PVAT from both lean and MetS swine. PVAT‐mediated increases in active tension development were similar in endothelium intact vs. denuded arteries and were reversed by diltiazem (10μM). LC‐MS/MS of lean and MetS coronary PVAT supernatants revealed 41 proteins significantly upregulated and 51 downregulated by the MetS. These data indicate that epicardial PVAT predominantly produces vasoconstrictor factors that act via Cav1.2 channels in vascular smooth muscle. Differential protein expression in the PVAT may be responsible for augmented vascular responses in the MetS.
TRPC Channels In Ca2+ Regulation And Endothelial Function During Cardioplegic Exposure
Authors: Yang Qin , Huang Jun-Hao , He Guo-Wei , Underwood Malcolm J , Yu Cheuk-Man
Published: June 2021

Elevation of [Ca2+]i is essential to endothelial function and depolarization of endothelial membrane results in a reduction of Ca2+ influx. We studied whether canonical transient receptor potential channels (TRPC), i.e., TRPC3, is involved in [Ca2+]i dysregulation and endothelial dysfunction caused by depolarizing cardioplegia. [Ca2+]i was measured in porcine coronary endothelial cells (PCECs) and relaxation was studied in porcine small coronary arteries. Ca2+ influx and Ca2+ influx via TRPC3 were decreased in PCECs exposed to hyperkalemic solutions (10, 20 or 120 mM K+) in a concentration‐dependent manner and similar reductions occurred in cardioplegic exposure (ST, HTK or UW solution). The reduction was prevented by TRPC3/6/7 activator OAG. Hyperkalemic or cardioplegic solutions decreased EDHF‐mediated relaxation that was restored by OAG‐addition (in 20 mM K+: 52.5±4.0% vs. 67.2±4.3%; in ST: 52.2±4.8% vs. 65.0±4.8%; p<0.01). We conclude that the decrease of Ca2+ influx via TRPC3 is involved in endothelial [Ca2+]i reduction caused by depolarizing cardioplegia. TRPC activation restores Ca2+ influx and prevents EDHF impairment. This study may provide new insight for improvement of cardioplegic solutions.

Supported by GRF CUHK4789/09M; CUHK2041688; China Nat'l Ministry of Sci. & Tech. 2009DFB30560 & 2010CB529502(973); Tianjin Municipal Sci. & Tech. Commission 09ZCZDSF04200 & 10JCYBJC26400.
Identification of Assessory Proteins Needed for ENaC Assembly and Function
Authors: Rodrigues Roberta , Ybanez Raquel , Booth Rachell E
Published: June 2021

The epithelial sodium channel (ENaC) is a sodium transporting protein channel composed of three subunits, alpha, beta and gamma with a stoichiometric ratio of 1:1:1. ENaC regulates sodium reabsorption within the distal nephron and is essential for maintaining fluid homeostasis. ENaC dysfunction causes blood pressure disorders as seen with pseudohypoaldosteronism and Liddle's syndrome, which lead to hypotension and hypertension, respectively. Although there are several known activators and inhibitors of ENaC, including the sterol aldosterone and the peptide hormone arginine vasopressin, the role of other intracellular proteins affecting ENaC assembly is unclear. Our current studies utilize the yeast deletion strain library in conjunction with ENaC expression to identify accessory proteins that are crucial for ENaC assembly and function. Yeast strains expressing mouse ENaC demonstrate salt‐sensitivity (growth inhibition), while strains expressing ENaC and lacking SUR4, ERV1, EMP24 or ULA1 showed a reduction in salt‐sensitivity suggesting that they directly affect ENaC function or assembly. Supported by Research Corporation (CC6313) and NIH‐NIGMS (R15GM086798).
Steviol, an aglycone of natural sweetener stevioside, slows MDCK cyst progression by reducing activity and expression of CFTR chloride channels
Authors: Yuajit Chaowalit , Muanprasat Chatchai , Chatsudthipong Varanuj
Published: June 2021

Pathogenesis of polycystic kidney disease (PKD) involved cAMP‐stimulated chloride secretion into cyst lumen. The present study was aimed to investigate an inhibitory effect and detailed mechanisms of steviol and its derivatives on cyst growth and cyst formation using Madin Darby canine kidney (MDCK) cyst models. Among 4 steviol‐related compounds, steviol was found to be the most potent compound that inhibited both MDCK cyst growth and formation. Steviol at 100 μM reversibly inhibited cyst growth and cyst formation by 38.3% and 72.4 %, respectively. Steviol at doses up to 200 μM had no cytotoxic effect on MDCK cells. Determined by Ussing chamber experiments, steviol acutely inhibited forskolin‐stimulated apical chloride current in MDCK monolayers by ~40%. Interestingly, prolonged treatment (2–24 hours) with steviol produced 50–80% inhibition of forskolin‐stimulated apical chloride current across MDCK monolayers in dose and time‐dependent manners. In addition, treatment with steviol significantly reduced cystic fibrosis transmembrane conductance regulator (CFTR) expression in MDCK cells. These findings suggest that steviol retarded MDCK cyst progression, in part, by reducing both CFTR activity and expression. Steviol and related compounds represent promising natural plant‐based drug candidates for polycystic kidney disease.

This work was supported by the Thailand Research Fund and the Office of the Higher Education Commission and Mahidol University under the National Research Universities Initiative.
Atg6 deficiency exacerbates glucose intolerance in mice on high‐fat diet
Authors: Greene Nicholas Perry , Lira Vitor A , Yan Zhen
Published: June 2021

Autophagy is critical in clearing damaged organelles (i.e. mitochondria) and aggregate proteins for the maintenance of metabolic homeostasis, and is dependent on the function of autophagy related protein 6 (Atg6). To test the hypothesis that autophagy is required for the maintenance of glucose tolerance under the condition of high‐fat diet (HFD) we subjected Atg6 heterozygous knockout mice (Atg6+/−) and wild type (WT) littermates to either normal chow (NC) or 45% HFD beginning at 12wks of age for a period of 8wks. At the conclusion of 8wks HFD, mice were subjected to intraperitoneal glucose tolerance test (GTT, 1.5g glucose/kg body weight) with blood glucose measured before and at 30, 60, and 120min following injection. No difference was seen in GTT between Atg6+/− and WT mice on NC, while Atg6+/− mice on HFD demonstrated a 42% greater mean integrated area under the curve than that of WT mice on HFD (2.35 vs. 1.65mg/dL*min*104) with no difference in body weight between genotypes. These findings demonstrate that deficiency of Atg6 exacerbates HFD‐induced glucose intolerance in mice and provides new insight to the relevance of basal autophagy for the maintenance of whole‐body metabolic homeostasis.
High fat feeding alters vasoconstrictor responsiveness in rat skeletal muscle by increasing inducible nitric oxide synthase activity
Authors: Richards Stephen Michael , Bussey Carol T , Keske Michelle A , Rattigan Stephen
Published: June 2021

In insulin resistance endothelin‐1 (ET‐1) levels are consistently increased, but opinion is divided whether ET‐1 vasoconstrictor responsiveness is enhanced or impaired. We examined vascular responses to ET‐1 in rats made insulin resistant by high fat feeding, using the isolated, pump‐perfused hindlimb. Male Sprague‐Dawley rats were fed a high‐fat diet for 4 weeks, resulting in an 81% increase in epididymal fat pad weight, accompanied by increased fasting plasma insulin, but not glucose. Vasoconstriction by ET‐1 (1 or 3nM) was reduced by the high‐fat diet. Treatment with the nitric oxide (NO) synthase inhibitor NG‐nitro‐L‐arginine methyl ester (L‐NAME) significantly increased ET‐1 vasoconstriction in both normal and high‐fat fed animals to the same level. In the presence of 1400W, a specific inhibitor of the inducible NOS (iNOS) isoform, ET‐1 reactivity in high‐fat fed rats was restored to that of rats on normal chow. These findings support the notion that high fat feeding increases muscle iNOS activity, which opposes ET‐1 vasoconstriction. The increased NO bioavailability is likely to alter the balance between constriction and dilation in insulin resistance, contributing to the impaired endothelial function commonly observed.
Fasting hyperglycemia blunts the regression of impaired glucose tolerance in older adults after lifestyle modification
Authors: Malin Steven K. , Kirwan John P.
Published: June 2021

Lifestyle modification (LM) delays the progression from prediabetes to type 2 diabetes (T2D), but no study has determined the efficacy of LM on glucose metabolism in different prediabetes subtypes.

Methods

Older (65.1 ± 0.6yr) obese adults with impaired fasting glucose (IFG; n=12), impaired glucose tolerance (IGT; n=9), and combined glucose intolerance (IFG+IGT = CGI; n=22) were compared to normal glucose tolerant (NGT; n=15) and T2D (n=18) groups after 12 weeks of LM (60 min/d for 5d/wk at ~85% HRmax). An oral glucose tolerance test was used to assess glucose levels. Insulin sensitivity (euglycemic hyperinsulinemic: 40 mU/m2·min−1) and β‐cell function (glucose induced insulin secretion corrected for insulin sensitivity) were also assessed.

Results

LM reduced weight and improved aerobic fitness and β‐cell function similarly across groups (p < 0.05). LM lowered fasting glucose levels in IFG, CGI and T2D (p < 0.05) and 2‐hour glucose levels in IGT, CGI and T2D (p < 0.05). However, 2‐hour glucose levels were not normalized in adults with CGI compared to IGT (p < 0.05). Insulin sensitivity was improved approximately 40% in IFG and IGT, but only 17% in CGI.

Conclusion

After 12‐ weeks, lifestyle modification may not be sufficient to normalize 2‐ hour glucose levels in adults with CGI. Given the high risk of progressing to T2D, adults with CGI may require more aggressive therapies to prevent diabetes. Support: RO1 AG12834 (J.P.K).
Differential effects of a High‐Fructose diet or a High‐Fat/High‐Sucrose diet on the mitochondrial ROS production and respiration in rat liver and skeletal muscle
Authors: Couturier Karine , Le Guen Marie , Coudray Charles , Feillet-Coudray Christine , Wrutniak-Cabello Chantal , Cabello Gérard , Dubouchaud Hervé
Published: June 2021

We studied the alterations of the mitochondrial function in response to various hypercaloric diets, and their relation with the occurrence of obesity and/or metabolic syndrome. Male Wistar rats were fed with either standard diet (Control), High‐Fructose (HF) or High‐Fat/High Sucrose (HF/HS) for 6 weeks. Rats under HF/HS displayed increase in body weight, insulin resistance, liver steatosis, and in visceral adiposity when compared to control. In HF/HS, TBARs, AOPP, and antioxidative enzymes were higher in plasma and muscle when compared to control. HF diet but not HF/HS diet was associated to a lower oxygen consumption by liver isolated mitochondria under non phosphorylating conditions whatever the substrate used excepting palmitoyl‐carnitine, compared to control (−30 to −60%). We also report a higher citrate synthase activity in liver tissue in the same condition (+53%) compared to control diet. Activities of complexes II and III are lower in HF and in HF/HS compared to control. H2O2 release by liver isolated mitochondria was higher in HF with succinate as a substrate, compared to the control suggesting alterations of both complex I and III. These results suggest that the type of diet has different effects on mitochondrial function that could related to the obesity and insulin resistance states.

This work was supported by the French Agence Nationale pour la Recherche (ANR : project MitHyCal).