bluuebunny/crossref_metadata_2025_split huggingface dataset:
Suppression of the gut microbiome with broad‐spectrum antibiotic cocktail reverses age‐related arterial dysfunction in mice
Authors: Richey James , Cuevas Lauren , Neilson Andrew , Smithson Andrew , Gilley Andrew , Seals Douglas , Gioscia‐Ryan Rachel 
Published: November 2023

Aging is a primary risk factor for cardiovascular diseases (CVD), driven largely by the development of arterial dysfunction, characterized by impaired endothelial function and stiffening of the large elastic arteries secondary to oxidative stress. Increasing evidence suggests a role for the gut microbiome in modulating host physiology, as dysregulation of the abundance and type of gut microbes can have systemic consequences, including promotion of oxidative stress and production of adverse gut microbe‐dependent metabolites such as trimethylamine n‐oxide (TMAO). TMAO is causally linked to atherosclerosis and independently predictive of CVD risk. However, the potential role of the gut microbiome in modulating arterial function with primary aging is unknown. We assessed endothelial function (carotid artery endothelium‐dependent dilation [EDD] to acetylcholine), arterial stiffness (aortic pulse‐wave velocity [aPWV]), circulating levels of TMAO, and aortic markers of oxidative stress (via electron paramagnetic resonance [EPR] and Western blot) in young (YC; 6 mo; n=5), old (OC; ~27 mo; n=5) and old antibiotic (Abx)‐treated mice (OA; n=4; 3‐wk broad‐spectrum Abx cocktail in drinking water to suppress endogenous gut microbes). Plasma TMAO was dramatically reduced with Abx treatment (OC: 14.7 ±5.3 vs. OA: 0.8 ±0.2 μM, p <0.05), indicating gut microbe suppression. Abx treatment reversed the age‐related impairment in peak EDD (OC: 69.2 ±6.4, p<0.05 vs. YC: 90.4 ±6.9 and OA: 83.5 ±3.9 %) and the age‐associated elevation in aPWV (OC: 487 ±30, p <0.05 vs. YC: 373 ±14 and OA: 360 ±47 cm/s). Improved arterial function with Abx was accompanied by reduced arterial oxidative stress, as indicated by attenuation of the age‐related increase in aortic superoxide production (EPR; OC: 9859 ±6086, p<.05 vs. YC: 2983 ±1711 and p=0.11 vs. OA: 6057 ±1806 AU) and augmentation of antioxidant enzyme extracellular superoxide dismutase expression (OC: 2.7 ±0.11, p =0.06 vs OA: 3.3 ±.32 AU). Our results identify the gut microbiome as an important mediator of age‐related arterial dysfunction and oxidative stress, and suggest that therapeutic strategies targeting the gut microbiome may hold promise for preserving arterial function with aging, and reducing risk of CVD.Support or Funding InformationSupported by: NIH F31AG047784, R01HL107120, R01AG013038
Oxidized Low‐Density Lipoproteins Enhance Endothelial Barrier Function
Authors: Zhang Chongxu , Crystal Crystal , Meliton Lucille , Dudek Steven , Levitan Irena 
Published: November 2023

Oxidized modifications of low‐density lipoprotein (OxLDL) are known to contribute to the formation of atherosclerotic plaques and early endothelial dysfunction. Earlier studies showed that exposure to oxLDL results in the disruption of the endothelial barrier suggesting that it may contribute to the initiation of the disease. An important constraint of these studies, however, was that oxLDL was generated by copper oxidation, an artificial process that does not occur in vivo and that may generate oxLDL species with chemical and biological properties different from those in vivo. In this study, therefore, we compared two types of oxLDL: LDL oxidized by copper sulfate (Cu‐oxLDL) or LDL oxidized by lipoxygenase (LPO‐oxLDL), a physiological process that is responsible for oxLDL generation in vivo. Surprisingly, we found that both, Cu‐oxLDL and LPO‐oxLDL transiently enhance the barrier function of Human Aortic Endothelial cells (HAECs). Specifically, endothelial permeability of HAECs was first measured using Electric Cell‐substrate Impedance Sensing (ECIS), a well‐established method to assess endothelial barrier function. Our results show that exposure to 100 μg/ml LPO‐oxLDL resulted in 40% increase in the resistance of HAECs monolayer, an effect that peaked at 2 hours and dissipated after 20 hours. Exposure to Cu‐oxLDL had a similar but smaller effect: the resistance of HAECs monolayer increased by 10% after 2 h and dissipated after 20 hours. No further change was observed at longer exposures. To verify these observations, we used an alternative method, by measuring the leak of a fluorescent FITC‐dextran (40 kDa) in the trans‐well system. Exposure to both Cu‐oxLDL and LPO‐oxLDL resulted in a ~50% decrease of HAECs permeability to FITC‐dextran. We further tested if ROS play a role in the oxLDL‐induced enhancement of HAECs barrier function using MnTMPyP, a cell‐permeable ROS scavenger. Our data show that MnTMPyP attenuated the effects of both Cu‐oxLDL and LPO‐oxLDL on HAECs permeability. In conclusion, our data suggest that oxLDL may have a protective effect on endothelial barrier function and that this effect is mediated by ROS. Further studies are needed to evaluate the role of this process to vascular permeability in vivo.Support or Funding InformationThis study is supported by NIH grants HL‐073965 and HL‐083298 to I.L. and HL‐079356 to K.W.
Sympathoadrenal activity, blood pressure and depression in Mexican children 10–14 years old with type 2 diabetes mellitus risk factors
Authors: Fernandez Ana Cecilia , Flores Constantino , Esquivel Aurora , Martinez Beatriz Elina , Fernando Shane , Pina Alexandra Soto , Ramos Roxana Elina Valdés 
Published: November 2023

Increased physical or emotional responses to stress may result in increased cardiovascular disease and Type 2 Diabetes Mellitus (T2DM) risk factors. The consequent raise in blood pressure may be a direct effect of catecholamines by sympathetic stimulation, but its relation to T2DM risk is not well known. Our aim was to evaluate sympathoadrenal activity and blood pressure in children with low and high T2DM risk. This was a cross‐sectional descriptive study with children from public schools with at least one risk factor: family history (FH) of T2DM; FH of hypertension; presence of Acantosis Nigricans; fasting capillary glucose 100–126 mg/dL; or BMI ≥85th percentile. Data collection included anthropometric and blood pressure measurements, blood samples and Infant Depression Inventory (CDI‐2). Data were analyzed by sex using descriptive statistics and linear regression model. The sample consisted of 116 children (52 girls and 64 boys). FH of T2DM was higher among girls compared with boys (78.84% vs. 65.62%, p < 0.05). Presence of depression and mean CDI‐2 scores were higher among girls (26.92% and 56.35±12.81) compared with boys (13.11% and 53.56±11.42) (p < 0.05). Mean systolic blood pressure was higher among boys compared with girls (104.81±11.45 mm Hg vs. 103.18±13.86 mm Hg; p < 0.001) and mean diastolic blood pressure was higher for girls (67.64 ± 10.47 mm Hg vs. 65.96 ± 12.65 mm Hg; p < 0.001). Concentrations of plasma total and fractionated catecholamines were lower in girls compared with boys: 511.63±168.91 pg/ml vs. 652.42±174.56 pg/ml for total catecholamines; 67.98±49.49 pg/ml vs. 104.54±77.24 pg/ml for epinephrine; 435.65±143.44 pg/ml vs. 535.54±144.96 pg/ml for norepinephrine; and 18.00±19.78 pg/ml vs. 19.20±11.59 pg/ml for dopamine, respectively. In summary, girls have a lower sympathetic activity, lower systolic blood pressure and higher depression scores compared with boys, and may be associated to their hormonal condition.Support or Funding InformationFondo Semilla Universidad Autonoma del Estado de Mexico and University of North Texas Health Science Center
Loss of local Ca2+ signaling networks in the endothelium in diet induced obesity
Authors: Hong Kwangseok , Cope Eric L , Marziano Corina , Sonkusare Swapnil K 
Published: November 2023

Endothelial cells (ECs) play a crucial role in regulating vascular function. Weakening of local Ca2+ signaling networks in the ECs leads to the loss of endothelial vasodilation in hypertension (Sonkusare et al., Science Signaling, 2014). There is increasing evidence that obesity is also associated with a loss of endothelial function. The objective of this study was to determine the impact of diet‐induced obesity (DIO) on the local Ca2+ signaling networks that regulate endothelial vasodilation. We recently showed that elementary Ca2+ influx events through endothelial TRPV4 (transient receptor potential vanilloid 4) channels (TRPV4 Ca2+ sparklets) dilate mesenteric arteries (MAs) via Ca2+‐sensitive, intermediate conductance K+ (IK) channels (Sonkusare et al., Science, 2012). Moreover, muscarinic receptor agonist carbachol (CCh) dilates MAs via activation of TRPV4 sparklets at myoendothelial projections (MEPs), an interaction that requires MEP‐localized A kinase anchoring protein 150 (AKAP150). Diameter studies were performed in 3rd order mouse MAs constricted by intravascular pressure (80 mm Hg) and Ca2+ events were recorded in the slit‐open, pinned down MAs using a spinning disk confocal imaging system. After 8–10 weeks of high‐fat diet feeding, the vasodilations to CCh (0.3–10 μM) and GSK1016790A (TRPV4 channel agonist, 3–30 nM) were attenuated in the DIO mice. The activity of TRPV4 sparklets, recorded as the fluorescence integral of all the sparklet sites per field of view (~14 ECs), was 4‐fold lower in the DIO mice compared to the mice fed with a normal diet. Whereas 90% of MEPs showed identifiable AKAP150 staining in the control mice, only 32% MEPs showed AKAP150 staining in the DIO mice. These results support the concept that a loss of AKAP150 from the MEPs and resulting TRPV4 channel dysfunction may be responsible for impaired endothelial vasodilation in the DIO mice.Support or Funding InformationFunded by NIH award HL121484 to SKS.
Fibrocyte markers are increased in the pudendal artery of spontaneously hypertensive rats (SHR)
Authors: Ogbi Safia , Webb R. Clinton 
Published: November 2023

Erectile dysfunction is associated with the presence of hypertension and its incidence increases with the severity and duration of blood pressure elevation. In hypertension, vascular dysfunction and corpus cavernosum dysfunction are characterized by similar hallmark alterations, such as decreased relaxation and augmented contractile responses, vascular inflammation and remodeling. Fibrocytes are bone marrow derived mesenchymal progenitor cells that have recently been linked with fibrosis and vascular remodeling and are increased in hypertension. We hypothesized that fibrocytes contribute to pudendal artery remodeling in the spontaneously hypertensive rat (SHR). Pudendal arteries were isolated from male SHR and normotensive Wistar‐Kyoto control rats (WKY). Co‐staining for pro‐collagen and CD45, markers of fibrocytes, were observed in pudendal arteries using confocal microscopy. Protein expression of pro‐collagen and CD45 was also quantified by western blotting. Our results indicate that protein expression of fibrocyte markers, as well as co‐staining, were increased in the pudendal artery of SHR compared to WKY. These data suggest that fibrocyte‐induced vascular dysfunction in the pudendal artery could be associated with ED in hypertension. Therefore, fibrocytes can be a putative target for novel therapeutic approaches of this condition.Support or Funding InformationAmerican Heart Association
Cannabinoid Receptor Type‐1 Regulates Inflammation and Insulin Resistance in Metabolic Endotoxemia
Authors: Grunewald Zachary Ian 
Published: November 2023

BackgroundCirculating endotoxin, or lipopolysaccharide (LPS), is a suggested trigger of obesity‐associated inflammation and insulin resistance. In rodents, chronic low‐level administration of LPS induces weight gain, inflammation and insulin resistance, inducing metabolic endotoxemia. Additionally, obesity is associated with over‐activation of the endocannabinoid system, promoting insulin resistance. Interestingly, LPS has been shown to regulate endocannabinoid synthesis. We hypothesized that metabolic endotoxemia promotes inflammation and insulin resistance via a cannabinoid receptor type‐1 (CB1R) dependent pathway.MethodsMale Wistar rats fed a chow diet were implanted with mini‐osmotic pumps delivering a low dose of LPS (n=20, 12.5 μg/kg/hr) or saline (n=10) continuously for 6 weeks (42 days). 10 rats receiving LPS were injected with a CB1R antagonist (SR141716, ip 3μg/g) daily. Rats were pair‐fed to the level of the LPS + CB1R antagonist group (CB1Rx) to control for differences in body weight. Glucose tolerance (OGTT, 2g/kg) and insulin sensitivity (ITT, 0.75u/kg) were measured after 5 weeks of treatment. Insulin was given 1 hour prior to sacrifice (n=5/group). RT‐PCR, ELISA assays, and western blot was used to determine experimental outcomes.ResultsAfter 6 weeks, pair‐feeding was successful to control for body weight and energy intake differences. LPS administration was sufficient to alter insulin sensitivity. However, alterations to both glucose and insulin sensitivity were further exacerbated in the CB1Rx group. Circulating LPS binding protein was elevated in the CB1Rx group only. Serum adiponectin was reduced in both groups receiving LPS infusion compared to control. Liver, visceral and periaortic adipose tissue, and muscle exhibited a pro‐inflammatory phenotype in LPS and LPS + CB1Rx treated animals. Liver total AKT/PKB was reduced in the CB1Rx group only. p‐AKT (T308) was reduced in the LPS treated group and further reduced in the CB1Rx group. Insulin degrading enzyme was partially attenuated with CB1Rx treatment compared to LPS treatment alone.ConclusionsOur findings oppose our hypothesis that LPS induces inflammation and insulin resistance via a CB1R dependent pathway. Rather, inhibition of CB1R further exacerbates the inflammatory and insulin resistant state induced by chronic low‐level LPS administration. Moreover, our findings suggest that CB1R may play a role in regulating the pro‐inflammatory and insulin resistant phenotype associated with obesity. Thus, these findings suggest that CB1R inhibition may not be a beneficial strategy towards the treatment of obesity‐associated inflammation and insulin resistance.Support or Funding InformationFunding for this project came from 1) UGA Junior Faculty Research Grant for Claire de La Serre, 2) Kappa Omicron Nu Eileen C. Maddex Master's Fellowship for Zachary I. Grunewald
Periodic Blue Light Exposure Activates Microglial Kinases and Alters Gene Expression
Authors: Cheng Kevin P , Williams Justin C , Watters Jyoti J. 
Published: November 2023

The potential side effects of blue light used in either optogenetic and/or in vivo imaging applications in the CNS are poorly understood. Previously we reported that periodically delivered blue light (450nm, 25–100 mJ/cm2 in a single 1 second pulse per minute for 6 hours) altered the basal expression levels of a subset of genes in primary murine microglia that do not express exogenous light‐responsive proteins. However, the mechanism whereby blue light induces these changes, or whether they are temporary and/or reversible, remains unknown. Here we demonstrate that blue light‐induced changes in microglial gene expression are evident up to at least 18 hours following the cessation of light exposure, suggesting that constant light delivery is not necessary to observe long‐lasting effects. To further understand the mechanism underlying these gene expression changes, we tested the ability of blue light to activate the AMP‐activated protein kinase (AMPK) and Protein Kinase B (AKT) pathways, two signaling cascades known to exert strong downstream transcriptional effects on inflammatory and cell survival related genes. Preliminary data suggest that both pathways may play a role in the effects of blue light in microglia. These results demonstrate that long‐term optogenetic and in vivo imaging applications may have previously unappreciated off‐target effects as they may alter the basal gene expression profiles and kinase activity of all light‐exposed cells, not only of those optogenetically targeted.Support or Funding InformationThis work was supported by a DARPA HIST grant.
Theobromine, the primary methylxanthine found in Theobroma cacao, can pass through the blood‐brain barrier in mice
Authors: Sugimoto Naotoshi , Katakura Masanori , Matsuzaki Kentaro , Ohno‐Shosaku Takako , Yachie Akihiro , Shido Osamu 
Published: November 2023

Theobromine, a caffeine derivative, is the primary methylxanthine produced by Theobroma cacao. We previously showed that theobromine has anti‐tumor effect and inhibits the cell growth of a glioma cell line derived from human malignant glioma [1]. Glioma is a cancer of brain. So, for exerting the anti‐tumor effect, theobromine must pass though the blood‐brain barrier.Here, we investigate whether theobromine could pass though the blood‐brain barrier in mice. All animal experiments were performed in accordance with the Guidelines for Animal Experimentation of Shimane University Faculty of Medicine, which were compiled from the Guidelines for Animal Experimentation of the Japanese Association for Laboratory Animal Science. Mice were divided into two groups. First group mice had a normal diet, and second group mice had a diet supplemented with 0.05% of theobromine for 30 days. We show that theobromine is detected in cortex as well as plasma in mice that had the diet with theobromine. These results suggest that theobromine can pass through the blood‐brain barrier in mice.Support or Funding InformationThis work was supported in part by the Grants‐in‐Aid for Science and Culture of Japan (25282021).
Chondrocyte Metabolic Flexibility and Early‐Stage Osteoarthritis in Mice Fed a High‐Fat Diet
Authors: Donovan Elise , Hudson Joanna , Kinter Mike , Griffin Timothy 
Published: November 2023

IntroductionObesity is a primary risk factor for osteoarthritis (OA). However, how chondrocyte metabolism changes in response to a high‐fat diet (HFD) and the mechanisms by which obesity initiates and promotes pro‐catabolic changes in chondrocytes that lead to OA are not fully understood. The objective of this study was to better understand the initiating cellular factors associated with OA pathogenesis in high‐fat diet (HFD)‐induced obese mice by examining changes in the expression of chondrocyte metabolic pathway components.MethodsMale C57BL/6J mice (n = 10–12 per diet per time point) were fed either a HFD (60% kcal fat) or a control diet (Ctr; 10% kcal fat) beginning at 6 weeks of age. Knee OA histopathology was examined using a modified Mankin OA scoring system following 20, 32, and 46 weeks of HFD feeding. In the 32‐week cohort, chondrocyte intracellular lipid accumulation was measured by oil red O staining. In an additional cohort of animals at 20 weeks (n = 3–5), mRNA and protein were isolated from knee articular cartilage to examine chondrocyte transcriptional and protein expression changes.ResultsHFD for 20 weeks increased osteophyte formation (p = 0.03) and tidemark duplication (p = 0.03) but did not increase the modified Mankin OA score, which was only significantly increased after 46 weeks on the HFD (p = 0.02). Because early osteoarthritic changes were observed by 20 weeks of HFD feeding, we examined cartilage transcriptional changes at this time point. None of the extracellular matrix genes (Aggrecan, Col10, Col2a) or matrix degrading proteases (Mmp9, Mmp13, Adamts5) were differentially expressed in HFD animals compared to Ctr at this time point, consistent with the histology. Cpt1a gene (1.4 fold increase, p = 0.03) and protein (1.87 fold increase, p = 0.04) expression were increased in the HFD group, suggesting increased transport of fatty acids into the mitochondria for oxidation. Of the 16 glycolysis related proteins examined, 62% were decreased in HFD animals (outside the reference gene CV range of 0.94 – 1.06), and of the 15 β‐oxidation proteins examined, 63% were increased in HFD animals. After 32 weeks of HFD, the percentage of chondrocytes containing lipid droplets remained unchanged.ConclusionHFD did not alter lipid droplet accumulation but did increase Cpt1a gene and protein expression, and there was a general trend for an increase in β‐oxidation proteins and a decrease in glucose metabolism proteins. These data suggest that in response to HFD chondrocyte lipid uptake and flux are increased while glucose utilization is likely decreased; these metabolic changes preceded HFD induced cartilage degradation.Support or Funding InformationSupported by the NIH and Arthritis Foundation.
Carbohydrate Mouth Rinsing Enhances Late‐Exercise Sprint Performance in Fatigued Cyclists
Authors: Roberson Paul , D'Lugos Andrew , Vining Caitlin , Pataky Mark , Baur Daniel , Saunders Michael , Luden Nicholas 
Published: November 2023

PURPOSEThere is good evidence that mouth rinsing with carbohydrate (CHO) solutions can enhance endurance performance (≥30 min). The impact of CHO on sprint performance has been less consistent, suggesting that CHO may confer benefits in conditions of ‘metabolic strain’. To test this hypothesis, the current study examined the impact of late exercise mouth rinsing on sprint performance. Secondarily, we investigated the effects of a protein mouth rinse (PRO) on performance.METHODSEight trained male cyclists participated in 3 trials consisting of 120 min of fixed load cycling (55% Wmax) followed by a 30‐km computer simulated time trial, during which only water was provided. Following 15 min of passive recovery, 10 min of fixed load cycling (3‐min at 35% Wmax, 7‐min at 55% Wmax) was performed. This was immediately followed by a 2‐km time trial. Subjects rinsed for 5 sec with 25mL of CHO, PRO, or PLA at min 5:00 and 14:30 of passive recovery, and min 8:00 of the 10‐min fixed load. Magnitude‐based inferential statistics were used to analyze the mouth rinse effects on 10‐min fixed load heart rate, glucose, lactate, RPE, and 2‐km time trial performance.RESULTSCHO ‘likely’ enhanced performance vs. PLA (4.8%). Further, CHO ‘likely’ elevated heart rate (3.8%) and glucose (5.8%) during Sub vs. PLA. All other comparisons were ‘unclear’.CONCLUSIONThese data clearly demonstrate that sprint performance is enhanced by CHO, but not PRO, under challenging metabolic conditions. The elevated heart rate and blood glucose levels following the rinse protocol suggest that the performance gain with CHO may have been mediated though an enhanced excitatory response.Support or Funding InformationSupported by a Faculty Research Grant from James Madison University College of Health and Behavior Studies