bluuebunny/crossref_metadata_2025 huggingface dataset:
Main effects of light sources, photoperiods, and genetic strains on blood physiological variables of broilers grown to heavy weights.
Authors: Olanrewaju Hammed A. , Purswell Joseph L. , Collier Stephanie D. , Branton Scott L.
Published: June 2021

Effects of light sources, photoperiods, and genetic strains on blood physiological variables of broilers grown to heavy weights were investigated in 2 trials. The experimental design was a 4 × 2 × 2 factorial consisting of 4 light sources [incandescent (ICD, standard), compact fluorescent (CFL), neutral light emitting diode (Neutral‐LED), and cool poultry specific filtered LED (Cool‐PSF‐LED)], 2 photoperiods (Regular/intermittent [2L:2D], and Short [8L:16D], and 2 genetic strains (Ross × Ross 708, Cobb 700). In each trial, 480 (240 males/240 females) 1‐d‐old chicks of each strain from different commercial hatcheries were equally and randomly distributed into 16 environmental control rooms (30 males + 30 females/room) at 50% RH. Each room was randomly assigned one of 16 treatments from d 1 to 56 d of age. Birds were provided similar diets. Feed and water were provided ad libitum. Venous blood samples were collected on d 14, 28, 42, and d 56 of age and analyzed immediately. Cool‐PSF‐LED light sources had significant (P ≤ 0.05) effects on BW, Hb, Hct, electrolytes, angap, and mOsm in comparison with birds reared under ICD, but all these changes were still within the normal acid‐base homeostasis and physiological ranges. Also, the short photoperiod significantly (P ≤ 0.05) reduced BW, pH level, pO2, sO2, and Ca2+, with significantly (P ≤ 0.05) elevated pCO2, Hct, Hb, and McHc concentrations. Acid‐base regulation during short photoperiod exposure had not deteriorated despite higher pCO2 that consequently decreased blood pH due to a respiratory acidosis. In addition, Cobb 700 had significantly (P ≤ 0.05) increased BW, pCO2, Hct, Hb, Ca2+, Cl−, McHc, and angap along with significantly (P ≤ 0.05) reduced pH level, pO2, HCO3−, and glucose in comparison with Ross × Ross 708. Plasma corticosterone was not affected by light sources, photoperiod, genetic strain or their interaction, indicating that exposure of broiler chickens to the short photoperiod markedly affects some physiological blood variables without inducing stress in modern broilers grown to heavy weights. It was concluded that the 3 LED light bulbs evaluated may be suitable for replacement of ICD along with the regular/intermittent photoperiod for commercial poultry facilities to reduce energy costs and optimize production efficiency without compromising the welfare of broilers grown to heavy weights.

Support or Funding Information

None

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Role of cGMP and EDHF Pathways in Hydrogen Sulfide‐induced Vasorelaxation in the Human Artery
Authors: Yuan Chao , Hou Hai‐Tao , Chen Huan‐Xin , Wang Jun , Wang Zheng‐Qing , Chen Tie‐Nan , Novakovic Aleksandra , Marinko Marija , Yang Qin , He Guo‐Wei
Published: June 2021

Background

Endogenous H2S generated by mercaptopyruvate sulfurtransferase (MPST) coupled with cysteine aminotransferase (CAT) in endothelium as a physical vasodilator and blood pressure regulator may play an important protective role in the pathogenesis of coronary heart disease. The present study aimed to investigate the role of cGMP and endothelium‐derived hyperpolarizing factor (EDHF) in H2S‐induced vasorelaxation in the human internal mammary artery (IMA).

Methods

In the human IMA segments from 54 patients undergoing coronary artery bypass grafting, the acetylcholine (ACh)‐induced relaxation and the effect of CAT inhibitor (aminooxyacetic acid [AOAA] and L‐aspartate) and KCa channel blocker or KATP channel blocker were studied in a myograph. Enzyme‐linked Immunosorbent Assay for PDE5A and western blotting analysis for eNOS and p‐eNOSser1177 were performed. Methylene blue assay was used to quantify the contents of H2S.

Results

The maximal relaxation induced by ACh was significantly attenuated by AOAA or L‐aspartate, Iberiotixin (BKCa channel blocker) (P<0.01), or IKCa channel blocker plus SKCa channel blocker (TRAM‐34+Apamin) (P<0.01), or KATP channel blocker (Glibenclamide) (P<0.01). The H2S donor NaHS increased eNOS phosphorylation at its activating site S1177 and down‐regulated PDE5A activity. Incubation with ACh for 4 hours significantly increased the H2S concentration.

Conclusions

We for the first time demonstrated in the human IMA that endogenous H2S could be produced under the stimulation of ACh and that CAT is one of the key enzymes in production of H2S in the endothelial cell of the IMA. H2S may activate eNOS to produce NO that activates PKG and may also inhibit PDE5A activity; both enhance the cGMP pathway‐mediated relaxation. Further, H2S as a potential EDHF directly stimulates KCa channels to induce vasodilatation. These findings may provide new therapeutical targets for the treatment of vasospasm of coronary artery bypass grafting vessels and provide a pharmacological basis for the development of new vasodilator drugs.

Support or Funding Information

Supported by grants from the National Natural Science Foundation of China (81170148 & 81641017), Zhejiang Provincial Natural Science Foundation (LY15H020008), & Tianjin Binhai Key Platform for Creative Research Program (2012‐BK110004), Binhai New Area Health Bureau (2012BWKZ008, 2016BWKY007, 2016BWKZ003).

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Cerebrovascular Regulation During an Insulin‐Glucose Challenge: Contribution of Nitric Oxide
Authors: Ward Aaron T. , Carter Katrina J. , Sauder Christina J. , Kellawan J. Mikhail , Weiben Oliver , Schrage William G.
Published: June 2021

While it is known that cerebral blood flow (CBF) is regulated by various chemical factors, such as arterial CO2, the role of nitric oxide (NO) in this regulation is unclear. NO production can be increased via numerous stimuli, including insulin. However, the CBF response to an insulin surge has yet to be fully examined. Additionally, the potential contribution of NO to an insulin surge remains poorly understood. Therefore, we tested the hypotheses that a) an insulin‐glucose challenge will increase CBF, and b) these effects will be attenuated by NO synthase inhibition (L‐NMMA). Four healthy adults (2 male, 2 female; age 21±1 yrs, height: 175±7 cm, weight: 61±4 kg) completed two visits (saline control vs. L‐NMMA) under fasted conditions (>10 hours) in a single‐blind placebo‐controlled study. CBF was measured via 4D MRI utilizing phase‐contrast vastly‐undersampled isotropic projection reconstruction (PC VIPR) at baseline and 60 mins following ingestion of a 75g Oral Glucose Tolerance Test (OGTT). L‐NMMA was infused at 36 mg/kg/hr for 5 min prior to baseline measurements with subsequent infusion at 1 mg/kg/hr for 60 min. Saline infusion was matched to L‐NMMA infusion rates. CBF was quantified as the sum of flow from both internal carotid arteries and the basilar artery. Hemodynamics (HR, MAP, ETCO2) and glucose were monitored. Cerebrovascular conductance (CVC) was calculated as CBF÷MAP. HR, MAP, and ETCO2 were similar between conditions and between time points (all p>0.05). Plasma glucose increased significantly from baseline to 60 mins (p<0.05) and did not differ between groups (p>0.05). CBF (saline 782±120 mL/min vs. L‐NMMA 700±106 mL/min) and CVC (saline 8.7±1.4 mL/min/mmHg vs. LNMMA 8.2±1.0 mL/min/mmHg), a difference of ~11% and ~7%, respectively, did not differ at baseline (p>0.05). During OGTT, CBF (saline 723±146 mL/min vs. L‐NMMA 694±138 mL/min) and CVC (saline 8.6±1.7 mL/min/mmHg vs. LNMMA 8.0±1.6 mL/min/mmHg) were similar between conditions (p>0.05) and did not change over time (p>0.05). L‐NMMA trended to reduce CBF (p=0.087) and CVC (p=0.057) overall. These data suggest that CBF does not significantly increase following an insulin‐glucose challenge. However, NO may mediate basal CBF regulation in healthy adults, suggesting additional endothelial‐mediated regulation of the cerebrovasculature.

Support or Funding Information

ADA 1‐16‐ICTS‐099

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Reconstitution of Autophagy Improves Vascular Reactivity in Spontaneously Hypertensive Rats
Authors: McCarthy Cameron G. , Wenceslau Camilla F. , Martinez‐Quinones Patricia , Calmasini Fabiano B. , Webb R. Clinton
Published: June 2021

The accumulation of misfolded‐aggregated proteins is linked to an increasing number of degenerative diseases, including hypertension. Although protein damage and misfolding are an inevitable consequence of normal cellular function, multiple proteostasis mechanisms are devoted to the repair or clearance of damaged proteins in order to prevent proteotoxicity. Autophagy is the constitutive and basally active recycling mechanism responsible for protein quality control. Previously, our data has suggested decreased autophagy in conduit and resistance arteries from spontaneously hypertensive rats (SHR); however, direct measurement of autophagic activity, as well as the proteotoxic consequences of undegraded, misfolded protein has not been performed. Furthermore, the effects of reconstituting autophagic activity on vascular reactivity are currently unknown. We hypothesized that mesenteric resistance arteries (MRA) from adult (14 weeks old) SHR would have decreased autophagic activity in lysosomes extracted from arteries and this would be associated with increased misfolded protein oligomers. Therefore, we further hypothesized that upregulation of autophagy via mammalian target of rapamycin (mTOR) inhibition would decrease contraction and improve relaxation in isolated MRA from SHR mounted on wire myographs. We observed that the activity of acid phosphatase, the major acid hydrolase in lysosomes, from arterial lysosomes (pooled mesenteric arteries and aorta) was decreased in SHR (μmol/min, Wistar: 0.51±0.06 vs. SHR: 0.24±0.02, p<0.05). This diminished arterial autophagic activity was observed in conjunction with the increased presence of insoluble protein deposition. Specifically, SHR MRA contained increased fibrillar amyloid oligomers, especially along the endothelium monolayer, as indicated by Congo red staining (Figure 1). When autophagy was reconstituted in isolated MRA via mTOR inhibition with Everolimus (EV; first generation mTOR inhibitor) for 1 hr, we observed that the maximum contraction to phenylephrine was reduced [Emax (mN), Vehicle: 19.8±0.5 vs. EV (0.1 nM): 10.7±0.5 vs. EV (0.1 μM): 8.5±1.0, p<0.05] and the contraction to high concentrations acetylcholine was prevented [LogEC50, Vehicle: −6.9±0.1 vs. EV (0.1 nM): −9.2±0.4 vs. EV (0.1 μM): −8.2±0.1, p<0.05]. Overall, these data reveal that SHR have impaired arterial lysosomal activity and this is associated with the accumulation of misfolded proteins. As a result, reconstituting arterial autophagic activity improved vascular function and could be a novel therapeutic treatment for proteotoxicity in hypertension.

Support or Funding Information

NIH (K99GM118885 and P01HL134604).

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Hypertension in serotonin‐deficient male rats is associated with reduced sympathetic drive to the vasculature
Authors: Magnusson Jennifer L. , Cummings Kevin J.
Published: June 2021

Serotonin (5‐hydroxytryptamine, 5‐HT) neurons have widespread projections to autonomic regions of the brainstem and spinal cord. However, the specific role of central 5‐HT in the autonomic regulation of arterial blood pressure (BP) is unclear. We have previously shown that in quiet wakefulness (QW) and rapid‐eye‐movement (REM) sleep, adult male rats deficient in tryptophan hydroxylase 2 (TPH2−/−), and hence lacking central 5‐HT, have increased BP compared to wild‐type (WT) controls. The BP of female TPH2−/− rats is the same as WT. The current study sought to clarify the mechanism by which a loss of central 5‐HT leads to increased BP. We hypothesized that a loss of central 5‐HT increases sympathetic vascular tone. Using femoral arterial catheters along with electroencephalography and electromyography, we confirmed the elevated BP of adult (5–8 month old) male TPH2−/− rats (n=14) compared to male WT littermates (n=17), during QW (TPH2−/−: 123 vs WT: 115 mmHg; p=0.006) and REM sleep (TPH2−/−: 128 vs WT: 117 mmHg; p=0.002), but not during non‐rapid‐eye movement sleep (NREM) (TPH2−/−: 120 vs WT: 115 mmHg; p=0.068). In contrast, the BP of female TPH2−/− rats (n=15) was the same as WT littermates (n=12) (TPH2−/−: 119, 117, 123 vs WT: 112, 113, 115 mmHg in QW, NREM and REM, respectively) (p>0.05). To determine the influence of central 5‐HT on cardiac vagal drive and sympathetic vasculature tone, we injected atropine methyl nitrate (1 mg/kg; i.v.) and hexamethonium (HEX, 30 mg/kg; i.v.) into a subset of rats (n=5 male TPH2−/− and 5 WT; n= 9 female THP2−/− and 8 WT), and measured the maximum increase in heart rate (HR) and nadir in BP, respectively, during subsequent QW. The atropine‐induced increase in HR and BP experienced by male and female TPH2−/− rats was not significantly different than in WT littermates. Unexpectedly, male TPH2−/− rats had a reduced drop in BP following HEX compared to male WT (p=0.004), a phenotype not observed in female TPH2−/− rats. Our data suggest that a loss of central 5‐HT decreases sympathetic vascular tone in males only. While the mechanism(s) that contribute to the hypertension of male TPH2−/− rats remains unresolved, the potential interaction between central 5‐HT and components of the renin‐angiotensin‐aldosterone and vasopressin systems is worth exploring.

Support or Funding Information

Funding for this research was provided by an American Heart Association Scientist Development Grant (14SDG18560022; PI: KJC) and a Ruth L. Kirschstein National Research Service Award (NRSA) Individual Predoctoral Fellowship (F31) to JLM.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Fructose‐induced salt‐sensitive hypertension increases aortic stiffness and induces changes in systemic and renal hemodynamics
Authors: Komnenov Dragana , Gaudette Joshua , Zenner Zachary , Chen Haiping , Rossi Noreen
Published: June 2021

When high fructose consumption is accompanied by high salt consumption, such as occurs in a typical Western diet, hypertension ensues and the exact mechanism still remains to be identified. Although it has been shown that at least part of the mechanism involves sodium retention by the small intestine and the proximal tubule of the kidney, and reduced renal nitric oxide production, the full spectrum of mechanisms of fructose‐induced salt‐sensitive hypertension and its impact on cardiovascular co‐morbidities remains unknown. The objective of this work was to delineate the longitudinal changes in systemic and renal hemodynamics as a consequence of fructose‐ and salt‐enriched diet. Our central hypothesis is that elevated fructose in the diet predisposes to salt‐sensitive hypertension and initiates changes in both renal and systemic hemodynamics. Previously we found that rats fed 20% fructose for one week develop salt sensitive hypertension within two weeks of high‐salt feeding (4% NaCl). In the present work, using echocardiography we found that fructose‐fed rats displayed increased stroke volume (190.1 ± 9.4 μL vs 145.7 ± 5.8 μL, p < 0.05) and increased left ventricular mass index (1.03 ± 0.06 vs 0.75 ± 0.06), while relative wall thickness remained unchanged. These results are indicative of left ventricular remodeling consistent with eccentric hypertrophy. This is further corroborated by diastolic diameter (6.8 ± 0.2 mm vs 5.9 ± 0.3 mm). Fructose‐fed rats on a high salt (F+HS) diet showed signs of increased aortic stiffness, since the distention to vasodilator phenylephrine was reduced in the ascending aorta (7.1 ± 1.0% from baseline vs 18.2 ± 1.3% from baseline, p<0.05) for the same increase in blood pressure, a result that was not observed in fructose fed rats that were on an normal salt diet (F+NS; 16.1± 2.9%, p < 0.05 vs F+HS). The observed increase in stiffness in the ascending aorta of F+HS rats is likely due to an increase in collagen deposition compared to F+NS and control rats. Finally, we wanted to determine whether the changes in systemic hemodynamics and parameters of cardiac function were paralleled by changes in renal hemodynamics. We measured renal resistive index (RRI) using ultrasound and found that it was elevated in F+HS rats compared to F+NS and control rats. Taken together, these results point to the apparent role of dietary fructose in inducing salt‐sensitive hypertension that is accompanied by increased aortic stiffness and concomitant changes in systemic and renal hemodynamics.

Support or Funding Information

VA Merit Award to N.F.R.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Effect of Lowering Blood Pressure on Circulating Danger‐Associated Molecular Patterns in Hypertensive Adults
Authors: Stockelman Kelly A. , Bammert Tyler D. , Dow Caitlin A. , Diehl Kyle J. , Garcia Vinicius P. , Greiner Jared J. , Stauffer Brian L. , DeSouza Christopher A.
Published: June 2021

Elevated blood pressure is associated with increased circulating concentrations of danger‐associated molecular patterns (DAMPs), specifically high‐mobility group box 1 (HMGB1) and heat shock protein 72 (Hsp72). HMGB1 and Hsp72 are prototypical DAMPs that initiate sterile inflammation, drive inflammatory processes and promote atherogenesis. The mechanisms responsible for the increase in circulating HMGB1 and Hsp72 levels in adults with elevated blood pressure is currently unknown. In addition, it is currently unknown whether reducing blood pressure in these individuals results in a concomitant reduction in HMGB1 and Hsp72. Accordingly, the aim of this study was to determine the effects of lowering blood pressure on circulating levels of HMGB1 and Hsp72 in hypertensive adults. To address this aim, we studied 34 middle‐aged adults: 10 normotensive (6M/4F; age: 58±2 yr; BMI: 28.0±1.5 kg/m2; BP: 112/68±2/1 mmHg) and 24 hypertensive (15M/9F; age: 58±1 yr; BMI: 29.5±0.8 kg/m2; BP: 141/88±1/1 mmHg). Within the hypertensive group, 12 received nebivolvol (5 mg/d; 7M/5F; BP: 142/87±2/2 mmHg) and 12 received metoprolol succinate (100 mg/day; 8M/4F BP: 140/89±2/2 mmHg) for 12 weeks. Plasma concentrations of HMGB1 and Hsp72 were determined by enzyme immune‐assay before and after each intervention. Circulating concentrations of both HMGB1 (80.0±3.4 vs 69.5±4.3 ng/mL) and Hsp72 (1.6±0.4 vs 0.8±0.1 ng/mL) were higher (20% and 100%, respectively) in the hypertensive compared with normotensive group. Blood pressure was lowered (P<0.05) to a similar extent (~15 mmHG, systolic) by both nebivolol (125/78±3/2 mmHg) and metoprolol (127/79±3/2 mmHg). However, there was no significant change in circulating HMGB1 or Hsp72 in either the nebivolol (79.9±3.7 vs 81.9±2.5 ng/mL; 1.7±0.7 vs 2.4±1.0 ng/mL) or metoprolol (79.7±6.0 vs 76.0±5.2 ng/mL; 1.5±0.5 vs 1.5±0.5 ng/mL). In summary, although both nebivolol and metorprolol significantly reduced blood pressure, circulating levels of HMGB1 and Hsp‐72 were not significantly affected. These data suggest that: 1) beta‐blockers do not affect circulating DAMPS; and 2) elevations in HMGB1 and Hsp72 in hypertensive adults are not causally‐related to blood pressure.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Effects of Essential Oil of Blepharocalyx salicifolius on Cardiovascular Function of Rats
Authors: MOREIRA CLECI MENEZES , Fernandes Maquelen Blanco , Santos Karolina Torres , Schneider Leandro Alves , Da Silva Sue Elle Berro , Sant'Anna Liane Santariano , Paula Fávero Reisdorfer
Published: June 2021

Some studies reported that herbal interventions with Blepharocalyx salicifolius minimized the high blood pressure in animals. Thus the aim of this study was to evaluate the cardiovascular effects of essential oil from the leaves of the plant. Wistar Kyoto (WKY) and Spontaneously Hypertensive Rats (SHR) with 60 days old were subjected to daily injection of essential oil (10 mg/Kg ip.). At the end of 30 days, the animals were anesthetized, the carotid artery was catheterized to hemodynamic measurements and total blood was collected by puncturing. The cardiovascular measurements performed were systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate, myocardial contractility parameters, angiotensin converting enzyme (ACE) activity and myosin ATPase. The hearts were dissected for left ventricle removal, the papillary muscle was used to assess myocardial contractility and tissue to myosin ATPase and ACE activity determinations. The oil was obtained by hydrodistillation in a Clevenger apparatus and analyzed by GC‐FID and GC‐MS. Molecular modelling studies were performed on components of essential oil of B. salicifolium and Angiotensin I‐Converting Enzyme (ACE‐I) in order to support the understanding of the biological activity. The project was approved by the Ethics Committee for Animal Use from UNIPAMPA under number 05/2016. We identified 34 compounds in the essential oil, the sesquiterpenes representing the largest fraction of the essential oil with 55.9% of constitution, and the main component was the spathulenol with 11.6%. We observed an antihypertensive effect attributed the decrease in SBP and DBP (12% and 23%) in SHR treated with essential oil. The myocardial contractility parameters evaluated by isometric force, sarcoplasmic reticulum activity, inotropic response to the calcium, assessment β‐adrenergic response and strength of tetanic contractions, and serum ACE activity were not modified by the essential oil treatment. However, the myosin ATPase activity was increased 51.6% in SHR and the cardiac ACE activity was decreased 41.5% in SHR and 49% in WKY. Molecular modelling studies were performed on the four main components of essential oil, such as limoneme, viridoflorol, santoline triene and spathulenol. The data suggest the spathulenol, that was the higher concentration component in essential oil, could be the main compound inducing the of ACE‐I activity inhibition. The results obtained in this study reveal the antihypertensive action of B. salicifolius essential oil in SHR and the potential interaction with Renin Angiotensin System without impairment of cardiac function.

Support or Funding Information

PPSUS/FAPERGS

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Dual Gain and Loss of Cullin 3 Function Mediates Familial Hyperkalemic Hypertension
Authors: Cornelius Ryan J. , Zhang Chong , Erspamer Kayla J. , Singer Jeffrey D. , Yang Chao‐Ling , Ellison David H.
Published: June 2021

Familial hyperkalemic hypertension is caused by mutations in with‐no‐lysine (WNK) kinases, or in proteins that mediate their degradation, kelch‐like 3 (KLHL3) and cullin 3 (Cul3). While the mechanisms by which WNK and KLHL3 mutations cause the disease are now clear, the effects of the disease‐causing Cul3Δ403–459 mutation remain controversial. Possible mechanisms including hyperneddylation, altered ubiquitin ligase activity, decreased association with the COP9 signalosome (CSN), and enhanced binding and degradation of KLHL3 have all been postulated. Here, we systematically evaluated the effects of Cul3Δ403–459 using cultured kidney cells. First, using co‐immunoprecipitation, we identified that the catalytically active CSN subunit JAB1 does not associate with the deleted Cul3 4HB domain, but instead with the adjacent α/β1 domain, indicating that resulting secondary structural effects underlie impaired binding. Inhibition of deneddylation, with JAB1 siRNA, increased Cul3 neddylation, but did not mimic the effects of Cul3Δ403–459 with respect to KLHL3 and WNK4, indicating that hyperneddylation is not essential. Next, we prevented Cul3 neddylation by introducing a point mutation at the neddylation site (K712R). The neddylation‐deficient Cul3Δ403–459 K712R construct was still able to significantly degrade KLHL3, indicating that this degradation has both ubiquitin ligase‐dependent and ‐independent components. Pharmacological inhibition of the degradative pathways showed that proteasomal degradation of KLHL3 was enhanced by Cul3Δ403–459; however, autophagic degradation was also upregulated by the Cul3 mutant. Finally, to evaluate whether deficient substrate adaptor was responsible for the disease, we restored KLHL3 to wild type (WT) Cul3 levels. In the absence of WT Cul3, WNK4 was not degraded, demonstrating that Cul3Δ403–459 itself cannot degrade WNK4; conversely, when WT Cul3 was present, as in diseased humans, WNK4 degradation was restored. In conclusion, deletion of exon 9 from Cul3 generates a protein that is itself ubiquitin ligase‐defective, but also capable of enhanced autophagocytic KLHL3 degradation, thereby exerting dominant‐negative effects on the WT allele.

Support or Funding Information

NIH R01 DK51496, NIH T32 DK067864, VA 1I01BX002228‐01A1, AHA 16POST3064003, NIH F32 DK112531, National Natural Science Foundation of China 81570634 and 81770706

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Effects of hyperglycemia on remodeling of acute myocardial infarction in rats
Authors: Ruiz Gabriela Megumi , de Souza Alcione Lescano , de Souza Leandro Ezequiel , De Angelis Katia , Curi Rui , Irigoyen Maria Cláudia , Malfitano Christiane
Published: June 2021

Acute myocardial infarction (MI) remodeling consequences for cardiac function were investigated in diabetes (hyperglycemia) induced by streptozotocin (STZ) in rats. The measurements were performed after 15 days of STZ induction (50 mg/kg iv) and/or 48hs of MI. The following parameters were evaluated: levels of FFA, TG (in plasma and the left ventricle–LV) and glycogen in the LV, the cardiac remodeling, the autonomic nervous system activity, and the oxidative stress in the LV. The Wistar rats (n=8 per group) were divided into 4 groups: control (C); control infarcted (CI); diabetic (D); diabetic infarcted (DI). After 15 days of STZ, the MI was induced by left coronary artery occlusion (□ 25% MI area between the CI and DI groups). The CI group had increased: end‐posterior wall thickness (LVPW), interventricular septum thickness the relative wall thickness and reduced LV cavity, as consequence of cardiac remodeling and increased LV mass. The D group had reduced LVPW (0.11 ± 0.001 cm) as compared with the C (0.13 ± 0.003 cm). DI group had increased LVPW (0.14 ± 0.005 cm). The systolic function was not different between groups. However, the D and CI group exhibited increased isovolumetric relaxation time (IVRT ms): D: 34 ± 1; CI: 30 ± 2.4 vs C: 23 ± 0.7 and The E‐wave desaceleration (ms) was increased in D: 50 ± 0.9 vs C: 40 ± 0.6, having diastolic dysfunction in diabetic rats but there was no impairment in MI (DI: 35 ± 2.3). The variance of heart rate (HRV m2) was reduced by diabetes (D: 18 ± 2.5; DI: 25 ± 3) vs the C group (81 ± 3), as well as the low (LF) and high (HF) frequency bands (sympathetic and vagal components). The MI increased in non‐diabetic rats the HRV (CI: 99 ± 14) and the LF (m2) (CI: 1.8 ± 0.5 vs D: 0.6 ± 0.1; DI: 1 ± 0.2). The variance of blood pressure (mmHg) was reduced by diabetes (D: 8.6 ± 0.7; DI: 5.3 ± 0.6) as compared to C (24 ± 3) and CI (18 ± 3) and the LF were increased only in the CI group (2.7 ± 0.17) vs DI group (1 ± 0.2). The MI increased in non‐diabetic rats the lipid peroxidation (1156 ± 125) vs C: 645 ± 111; D: 945 ± 117; DI: 894 ± 112) and both the MI groups increased the anion superoxide, however, only DI had increased antioxidant enzyme activities (catalase, glutathione peroxidase, superoxide dismutase) improving the redox balance after MI. DI group had reduced TG (1.4 ± 0.19) and glycogen (43 ± 7) content in the LV that was increased before the MI (D: 5.4 ± 0.9 vs C: 1.1 ± 0.2; D: 316 ± 79 vs C: 20 ± 5, respectively mg/g of LV). Therefore, the hyperglycemia previous to ischemia promoted a more efficient metabolic response on remodeling and cardiac function with improved oxidative balance.

Support or Funding Information

FAPESP, CNPq, and CAPES supported this research.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Fto deficiency reduces infarct size and improves heart function after acute myocardial infarction
Authors: Wehmöller Melanie , Gorressen Simone , Semmler Dominik , Rüther Ulrich
Published: June 2021

Obesity is one of the major risk factors that can lead to a myocardial infarction and can negatively influence subsequent cardiac remodeling. The onset of obesity is related to different genetic variants of the fat mass and obesity associated gene (Fto). Fto deficient mice were protected from obesity and showed an improved glucose tolerance under a high fat diet. In addition, it is known that Fto acts as an m6A RNA demethylase, whereby it can influence mRNA stability and translation. In a first approach, we used Fto deficient mice to perform an ischemic/reperfusion (I/R) model. At 24 h after reperfusion, Fto deficient mice already had a smaller infarct size compared to their wild type littermates. Over a time period of three weeks, the heart function was investigated by echocardiography. Three weeks after reperfusion, Fto deficient mice showed a preserved heart function and had reduced collagen scar formation compared to wild‐type control mice. Initial molecular studies indicated a reduction of the mTORC1 pathway and consequently a down regulation of S6K phosphorylation. For a first approach of therapeutic intervention, we used the Fto inhibitor rhein, which binds the active center of Fto and thereby inhibits its demethylase activity. Wild type mice were pre‐treated with rhein or the solvent over three weeks before the I/R procedure was performed. The rhein‐treated mice showed a significant reduction in the infarct size compared to the solvent treated littermates. In this study, we demonstrated that Fto deficiency can modulate the outcome of a myocardial infarction by improving left ventricular function and reduction of the infarct size.

Support or Funding Information

Supported by the Deutsche Forschung Gesellschaft (DFG) as Part of the SFB 1116 (project number 236177352)

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
TREATMENT WITH HYPERBARIC OXYGENATION AFTER 6 HOURS OF AN ACUTE MYOCARDIAL INFARCTION IN RATS
Authors: Juan‐Dominguez Vania Don , Rios‐Garcia Eduardo Castillo , Gutierrez‐Martinez Luis Alberto , Guevara‐Balcazar Gustavo , Castillo‐Hernandez Maria Carmen
Published: June 2021

Acute myocardial infarction has been placed in the leading cause of death in the world. Coronary interventionism is the gold standard in the treatment of AMI, however its therapeutic window is very limited. The decrease in the area of myocardial infarction and hemodynamic improvement have been reported with the use of HBO therapy in the ongoing AMI, as well as angiogenesis, decreased inflammation and useful as ischemic preconditioning.

Methodology

An experimental study was designed to determine the effect of HBO on the rat cardiomyocyte after 6 hours of an AMI induced by ligation of the anterior descending coronary. The HBO was administered through a 100% hyperbaric chamber, at 2 ATA, for one hour daily. The size of the infarcted area was macroscopically measured, and antioxidant enzymes were evaluated. Six groups were compared.

Results

A statistically significant decrease of the infarcted area was obtained from the 3rd session of HBO. Regarding oxidative stress, significant results were obtained for TBARS, TAS and 3‐NT from the 5th session with HBO.

Conclusion

Hyperbaric oxygen therapy shows a beneficial effect after 3 days of the induction of AMI, this is reflected by a decrease in the infarcted area; and after the 5th day reflected by a decrease in TBARS and 3‐NT.

Support or Funding Information

SIp, COFAA, IPN

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
AT1 Receptor Blockade Improves Mitochondrial Activity in Insulin Resistant but not Type II Diabetic Hearts
Authors: Thorwald Max Andrew , Rodriguez Ruben , Nakano Daisuke , Nishiyama Akira , Ortiz Rudy
Published: June 2021

Hyperglycemia increases the risk of oxidant overproduction in the heart through activation of a multitude of pathways. Oxidation of mitochondrial enzymes may impair their function resulting in accumulation of intermediates and reverse electron transfer, contributing to mitochondrial dysfunction. Furthermore, the renin‐angiotensin system (RAS) becomes inappropriately activated during metabolic syndrome, increasing oxidant production through NAPDH assemblage. To test the acute effects of an oral glucose tolerance test (oGTT) on the insulin resistant and type II diabetic hearts, 16 and 25 week old animals were given a glucose tolerance test prior to dissection. Adult male rats were randomly assigned to three groups prior to dissection (n= 5–8 animals/group/time point): 1) Long Evans Tokushima Otsuka (LETO; lean strain‐control), 2) insulin resistant, obese Otsuka Long Evans Tokushima Fatty (OLETF), and 3) OLETF + angiotensin receptor blocker (ARB; 10 mg olmesartan/kg/d x 6–8 weeks). Hearts were collected at T0, T60, and T120 minutes post‐glucose infusion and at T0, T180, and T360 in 25‐week‐old animals. Aconitase activity was not changed between LETO and OLETF rats at T0, but was increased five‐fold with ARB treatment. At T60 aconitase activity was decreased 69% in OLETF from LETO, but ARB treatment increased activity six‐fold. AT 25 weeks of age aconitase activity was two‐fold higher in OLETF compared to LETO and remained unchanged through T360. ARB treatment lowered this activity to LETO levels at T0 only. Complex I activity had no detectable difference between LETO and OLETF in 16 week old animals; however, ARB increased activity by 50%. However, in 25 week old animals complex I was lowered 32% from LETO and ARB treatment had no effect on complex I activity. At T60, complex II activity was decreased 30% from LETO in OLETF rats, and ARB treatment increased complex II activity by 79%. In 25 week old animals OLETF rats had increased complex II activity at T180 by 34%, which then was restored to baseline by T360. ARB treatment increased activity by 26%, but maintained this increase over the 6 hour span. These data demonstrate the protective effects of AT1 blockade on cardiac mitochondrial function during the manifestation of insulin resistance, but demonstrate that its protective effects diminish as animals transition into a frank diabetic stage.

Support or Funding Information

M. Thorwald and R. Rodriguez were supported by NIH NCMHD9T37MD001480. R.M. Ortiz was partially supported by NIH NHLBIK02HL103787. Research was partially funded by NIH NHLBIR01HL091767.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Insulin Signaling Displayed a Differential Tissue Specific Response to Low Dose Dihydrotestosterone in Female Mice
Authors: Andrisse Stanley , Wu Sheng
Published: June 2021

Hyperandrogenemia and hyperinsulinemia are believed to play prominent roles in polycystic ovarian syndrome (PCOS). We explored the effects of low dose dihydrotestosterone (DHT) on insulin signaling in metabolic and reproductive tissues in a female mouse model. Insulin resistance in the energy storage tissues is associated with type 2 diabetes. Insulin signaling in the ovaries and pituitary either directly or indirectly stimulates androgen production. Energy storage and reproductive tissues were isolated and molecular assays were performed. Livers and WAT from DHT mice displayed lower mRNA and protein expression of insulin signaling intermediates. However, ovaries and pituitaries of DHT mice exhibited higher expression levels of insulin signaling genes/proteins. Insulin‐stimulated p‐AKT levels were blunted in the livers and WAT of the DHT mice but increased or remained the same in the ovaries and pituitaries compared to controls. Glucose uptake decreased in liver and WAT but was unchanged in pituitary and ovary of DHT mice. Plasma membrane GLUTs were decreased in liver and WAT but increased in ovary and pituitary of DHT mice. Skeletal muscle insulin signaling genes were not lowered in DHT mice compared to control. DHT mice did not display skeletal muscle insulin resistance. Insulin‐stimulated glucose transport increased in skeletal muscles of DHT mice compared to controls. DHT mice were hyperinsulinemic (HI). However, the differential mRNA and protein expression pattern was independent of hyperinsulinemia in cultured hepatocytes and pituitary cells. These findings demonstrate a differential effect of DHT on the insulin‐signaling pathway in energy storage versus reproductive tissues independent of hyperinsulinemia.

Support or Funding Information

This work was supported by the National Institutes of Health (Grants R00‐HD068130 04 to S.W. and 5T32DK007751‐18 to S.A.). Technical support was provided by the Integrated Physiology Core of the Baltimore DRTC (P30DK079637). Disclosure Summary: The authors have nothing to disclose.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Undiagnosed Kidney Injury in Uninsured and Underinsured Diabetic African American Men and Putative Role of Meprin Metalloproteasses in Renal Pathology
Authors: Cao Lei , Jegede Olugbemiga Ebenezer , Harrison Scott Henry , Newman Robert Howard , Ongeri Elimelda Moige
Published: June 2021

Diabetes is a leading cause of chronic kidney disease. African Americans are disproportionately burdened by diabetic kidney disease (DKD) and end stage renal disease (ESRD). Disparities in DKD have genetic and socioeconomic components, yet its prevalence in African Americans is not adequately studied. The current study evaluated undiagnosed DKD in uninsured and underinsured African American men in Greensboro, North Carolina. Participants consisted of three groups: non‐diabetic controls, diabetic patients without known kidney disease, and diabetic patients with diagnosed DKD. Our data reveal undiagnosed kidney injury in a significant proportion of the diabetic patients, based on urinary albumin to creatinine ratio (ACR) which is the gold standard clinical test for DKD. The sensitivity of multiple other kidney injury biomarkers, namely kidney injury molecule‐1 (KIM‐1), cystatin C, and neutrophil gelatinase‐associated lipocalin (NGAL), were also tested in the current study through comparison to ACR. Compared with the normoalbuminuria group (ACR<30 mg/g), only the macroalbuminuria (ACR>300 mg/g) and not the microalbuminuria (300 mg/g>ACR>30 mg/g) group showed increased plasma levels for cystatin C, and increased urinary levels for KIM‐1, cystatin C and NGAL. Also, for plasma, plasma KIM‐1 showed higher levels in the microalbuminuria group than the normoalbuminuria group. In summary, plasma KIM‐1 showed the highest sensitivity in response to increased ACR in the African American subpopulation in our study. We also found the urinary levels of two metalloproteases, meprin A and meprin B, and two of their targets, nidogen‐1 and monocytes chemoattractant protein‐1, increased with severity of kidney injury, which suggests a role for meprin metalloproteases in the pathophysiology of DKD in this subpopulation. Our study has overall revealed undiagnosed kidney injury in a significant proportion of uninsured and underinsured diabetic African American men in the City of Greensboro, North Carolina, and demonstrates a need for more aggressive tests to assess kidney injury in uninsured diabetic patients to facilitate early diagnosis and targeted interventions that could slow progression to ESRD.

Support or Funding Information

This study was supported by the Minority Men's Health Initiative (MMHI) through NIH/NIMHD Center Award # U54MD008621 (CFDA 93.307), Sub‐Awards # HU140400 (to RHN and EMO) and HU150006 (to EMO and SHH); and the NIH/NIGMS Award Number SC3GM102049 to EMO.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Countdown before voluntary exercise induces muscle vasodilation with decreased muscle sympathetic nerve activity in humans
Authors: Manabe Kazumasa , Masuki Shizue , Ogawa Yu , Uchida Koji , Kamijo Yoshi‐ichiro , Kataoka Yufuko , Sumiyoshi Eri , Aida Takamichi , Nose Hiroshi
Published: June 2021

We examined whether countdown (CD) before voluntary bicycle ergometer exercise induced cerebro‐cardiovascular responses and, if so, whether these responses to CD were altered by postural change from the semi‐recumbent to supine position. Young men (n=14) performed voluntary cycle exercise in the semi‐recumbent position while middle cerebral artery blood flow velocity (CBF; Doppler ultrasonography), heart rate (HR), blood pressure (finger photoplethysmography), oxygen consumption rate (VO2), oxygen saturation in the right thigh muscle (StO2; near‐infrared spectrometry), cardiac output (CO; cZ method) and total peripheral resistance (TPR) were measured. The subjects repeated 8 trials, intermitted by more than 5‐min rest. In 4 trials randomly selected from 8 trials, the onset of exercise was signaled by a 30‐sec CD, whereas in the remaining 4 trials, exercise was started without CD. We found that CD increased CBF, HR, CO, mean blood pressure, and VO2 sequentially, decreasing TPR with increased StO2. To assess efferent signals causing vasodilation and the effects of posture change from the semi‐recumbent to supine position, other groups of subjects underwent the same exercise protocol but using only right leg in the semi‐recumbent (n=10) or supine (n=8) positions while muscle sympathetic nerve activity (MSNA; microneurography) and StO2 were measured in the left and right leg, respectively. We found that CD decreased MSNA burst frequency and total MSNA (both, P<0.05), which were significantly correlated with the increase in StO2 (both, P<0.001). However, these responses to CD were nearly abolished by the postural change. Thus, CD before starting voluntary exercise induced cerebro‐cardiovascular responses from central system to effector organs in a sequential manner in the semi‐recumbent position, but these responses were minimized while in the supine position.

Support or Funding Information

This study was supported by grants from the Japan Society for the Promotion of Science (24689014 and 15H04680).

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
THE ROLE OF MITOCHONDRIAL OXIDATIVE STRESS IN THE PATHOPHYSIOLOGY OF PREECLAMPSIA
Authors: Vaka Venkat Ramana , McMaster Kristen , Ibrahim Tarek , Cornelius Denise , Amaral Lorena , Wallace Kedra , LaMarca Babbette
Published: June 2021

Introduction

Preeclampsia (PE), is characterized by new onset hypertension and is associated with placental ischemia and oxidative stress. Placental ischemia is believed to be the initial event in the development of PE. Mitochondria are the major source of oxidative stress, the mitochondrial (mt) dysfunction leads to decreased respiration and increased mitochondrial reactive oxygen species (mtROS). The goal of our study is to determine if mt dysfunction and mtROS play a role in the pathology of PE. We hypothesize that PE placenta exhibit greater mt dysfunction and mtROS locally and peripherally which contribute to decreased mt respiration and in turn the development of hypertension during pregnancy.

Methods

Normal pregnant (NP) and PE patients were consented to collect placentas after delivery at the University of Mississippi Medical Center. Placentas were collected immediately after delivery and mitochondria were isolated using differential centrifugation. Mt function was assessed by studying respiration using complex I and II substrates, glutamate/malate and succinate respectively. Respiration measurements included: basal state (isolated mitochondria with no substrates), state 2 (glutamate and malate as complex I substrates), state 3 (ADP stimulated), leak state (oligomycin induced ATP synthase inhibition), and maximal state (FCCP stimulated uncoupled) were obtained using Oxygraph‐2k. MtROS production in human umbilical vein endothelial cells (HUVEC) was determined by bioassays using mitosox, a mitochondrial targeted dye, and flow cytometry. Mitochondrial targeted antioxidant, mitoQ was added to confirm the role of mitochondria in the production of ROS. Data are expressed as mean±SEM, statistical analysis included student t test or one way ANOVA and Bonferroni post hoc test.

Results

Placental complex I mediated state 3 (177±52 vs. 299±81 pmol/sec/mg,) and uncoupled (290±60 vs. 509±171 pmol/sec/mg) respiration rates; placental complex II mediated state 3 (229±53 vs. 404±44) and uncoupled (270±58 vs. 533±127, p<0.05) respiration rates were reduced in PE (n=6) vs. NP (n=6) mitochondria. HUVECs incubated with PE serum (n=8) show increased mtROS vs. NP serum (n=8) (92±1 vs 83±3, p<0.05) and was significantly reduced with mitoQ (n=6, 79±2, p<0.05 vs. PE).

Conclusion

The reduction in placental mt respiration indicate mitochondrial dysfunction in PE patients. Increased mtROS in HUVECs indicate the importance of circulating factors to stimulate mtROS in the vascular cells. Reduction in mtROS in HUVECs incubated with mitoQ indicate that targeting mitochondrial oxidative stress could be a therapeutic strategy to improve vascular function and could be a potential benefit to treating PE.

Support or Funding Information

RO1HD067541(BL)/Office of Research, UMMC.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.