bluuebunny/crossref_metadata_2025 huggingface dataset:
Hemodilution Improves Shear‐Mediated Transduction of Vasodilatory Signals in Human Cerebral and Systemic Circulations
Authors: Hoiland Ryan Leo , Tremblay Josh , Flück Daniela , Willie Chris , Smith Kurt J , Tymko Mike M , Howe Connor A , Donnelly Joseph , Stembridge Mike , Patrician Alex , Rieger Matt , Hansen Alex , Coombs Geoff , Santoro Antoinette , Green Daniel , MacLeod David , Ainslie Philip
Published: June 2021

Shear stress (SS) regulates blood flow within the systemic and cerebral circulation. For example, in clinical populations (e.g. hemochromatosis), endothelium‐dependent flow‐mediated dilation (FMD) is improved and impaired by increases and decreases in whole blood viscosity (WBV), respectively. We tested the hypothesis that reductions in WBV would attenuate both cerebrovascular CO2 reactivity and brachial FMD in healthy males (n=9). Internal carotid (ICA) and brachial artery (BA) blood flow, as well as cerebrovascular CO2 reactivity and FMD, were measured prior to and following isovolumic hemodilution with 5% human serum albumin (20% removal/replacement of blood volume). Hemodilution reduced hematocrit (42.7±2.5 vs. 34.7±2.0 %; P<0.01) and WBV (3.6±0.2 vs. 2.7±0.2 cP; P<0.01). Resting ICA blood flow increased by 19% (328.7±66.3 vs. 389.9±91.0 mL · dL−1; P<0.01) while SS was unaltered (13.4±3.2 vs. 12.5±2.6 dyn · cm−2; P=0.17). BA blood flow (41.0±18.9 vs. 54.6±34.1 mL · min−1; P=0.31) and SS (2.54±1.15 vs. 3.00±2.83 dyn · cm−2; P=0.66) were unaltered following hemodilution. Despite a similarly unaltered SS area under the curve stimulus (733.4±296.6 vs. 996.1±571.1 au3; P=0.20), BA FMD increased by 130% (3.9±2.3 vs. 9.0±4.3%; P=0.02). In contrast, however, neither absolute [24.3±7.4 vs. 30.1±13.5 ΔCBF (mL/dL) · ΔmmHg PaCO2; P=0.10] or relative [7.6±3.1 vs. 8.5±4.1 %ΔCBF · mmHg PaCO2; P=0.28) CO2 reactivity were altered following hemodilution despite a reduced SS stimulus throughout the reactivity test (main effect, P<0.01). Therefore, despite the differing influence of hemodilution on cerebral and systemic circulations, both were more responsive for a given SS stimulus following hemodilution.

Support or Funding Information

Ryan L. Hoiland was supported by a Natural Sciences and Engineering Research Council of Canada Post Graduate Scholarship. Dr. David MacLeod is supported through the Duke University Human Physiology & Pharmacology Laboratory. Prof. Philip Ainslie is supported by the Natural Sciences and Engineering Research Council of Canada and Canada Research Chairs.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Sodium Nitroprusside Induced Vasodilatation Encompasses Cerebral Blood Flow in Young Men
Authors: Olesen Niels Damkjar , Fischer Mads , Secher Niels Henry
Published: June 2021

Purpose

Sodium nitroprusside (SNP) reduces blood pressure by vasodilatation, but is reported to lower cerebral blood flow (CBF). We evaluated the influence of SNP on CBF when mean arterial pressure (MAP) was reduced by 20% and by 40%, while keeping MAP ≥ 50 mmHg.

Methods

In 19 healthy men (age 24 ± 4 years; mean ± SD) right internal carotid (ICA) and vertebral artery (VA) blood flow was evaluated by duplex ultrasound. Cerebral CO2 reactivity was determined during hyperventilation and CBF ((ICA + VA flow) × 2) also ‘corrected’ according to reduction in arterial CO2 tension. Evaluation of MAP was by brachial artery catheterisation and total peripheral resistance was derived by pulse contour analysis (Modelflow). Analysis was by a repeated measure mixed model and comparison of the relative change in ICA vs. VA flow was by paired t‐test. Values are presented as mean ± SD or median (IQR) and changes as mean (95% CI). The study was registered at clinicaltrials.gov (NCT03317652) prior to subject enrolment.

Results

Three subjects developed presyncopal symptoms during the large reduction in MAP and data obtained at that time was not included in the analysis. Infusion of SNP at 2.0 μg kg–1 min–1 (1.5–2.5) reduced MAP by 17 ± 5% and at 8.6 μg kg–1 min–1 (6.0–9.4) by 31 ± 6% (both P < 0.0001) as total peripheral resistance decreased from 17 ± 4 to 10 ± 2 and 7 ± 1 l min−1 mmHg−1 (both P < 0.001). The PaCO2 decreased from 5.5 ± 0.3 to 5.2 ± 0.4 and 4.9 ± 0.6 kPa (both P < 0.001) at the low and high SNP rate. With no ‘correction’ for change in PaCO2, ICA flow increased at the low infusion rate (from 336 ± 66 to 365 ± 69 ml min−1; P = 0.013) with no change in VA flow and CBF while ICA and VA vascular conductance increased with increasing SNP rate. With ‘correction’ for the reduction in PaCO2, ICA flow increased similarly at the two levels of MAP with maintained VA flow with a larger increase in ICA than VA flow (16 ± 14% vs. 5 ± 21%; P = 0.023) during moderate reduction in MAP. Thus, CBF increased by 50 (95% CI: 27–72) and 50 ml min−1 (95% CI: 26–73; both P < 0.001) at the two rates of SNP infusion.

Conclusion

Infusion of SNP reduces MAP by vasodilatation and by determination of ICA and VA flow in young men vasodilatation encompasses the brain and more so ICA than VA. The results indicate that CBF is controlled not only by its perfusion pressure when blood pressure is reduced.

Support or Funding Information

This study was supported by the University of Copenhagen.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Hypo‐phosphorylated hnRNPK promotes migration of triple negative breast cancer cells through an Aurora‐A‐independent manner
Authors: Tsai Hsin‐Yu , Lin Chao‐Hsiung
Published: June 2021

HnRNPK, a member of heterogeneous nuclear ribonucleoprotein (hnRNP) family, is well known as a poly(C)‐binding protein that participates in RNA processing and translational regulations. Importance of hnRNPK in tumorigenesis has been implicated by its persistent amplification in a wide range of cancers, whereas diverse post‐transcriptional modifications (PTMs) of hnRNPK also have been shown to regulate its protein function. We previously reported a novel Aurora‐A‐mediated phosphorylation of hnRNPK, but the cellular function of such phosphorylation remains unknown. Because Aurora‐A has been known as an oncogenic kinase and promotes transformation, growth and migration of cancer cells, we further investigated the functional role of hnRNPK phosphorylation in MDA‐MB‐231 cell line, a triple negative breast cancer cell with amplification of Aurora‐A. Accordingly, two stable clones replacing endogenous hnRNPK with either phosphorylation‐defective or phosphorylation‐mimic mutants were established, namely MDA‐MB‐231‐SA and MDA‐MB‐231‐SD. To determine whether such hnRNPK phosphorylation participates in the Aurora‐A‐mediated migration signaling, migration ability was compared between the hnRNPK phosphorylation‐defective and phosphorylation‐enhancing cells. Our results showed that migration ability of MDA‐MB‐231‐SA cells is higher than the control MDA‐MB‐231 cells but migration ability of MDA‐MB‐231‐SD cells is less than control, suggesting that Aurora‐A‐mediated hnRNPK phosphorylation does not promote cell migration but instead suppresses it, likely through an Aurora‐A‐independent manner. Therefore, it is proposed that such hnRNPK phosphorylation is not only mediated by Aurora‐A amplification but also regulated by other factors. It has been shown that different PTMs of hnRNPK are able to crosstalk with each other, and synergistically influence protein functions. My data showed that such Aurora‐A‐mediated phosphorylation was inhibited by arginine methylation of hnRNPK, whereas cell migration was decreased upon deficiency of hnRNPK arginine methylation in MDA‐MB‐231 cells. Further verification of migration‐associated signaling pathway showed that levels of EMT‐related proteins, Twist and β‐catenin, and RNA levels of MMP family were increased in MDA‐MB‐231‐SA cells. In conclusion, our results imply that a hypo‐phosphorylated status of hnRNPK may promote cell migration through hnRNPK‐β‐catenin‐MMP pathway.

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 AN AEROBIC PHYSICAL EXERCISE SESSION ON INFLAMMATORY MARKERS IL‐6, IL‐10 AND TNF‐alpha IN PATIENTS WITH CHRONIC RENAL DISEASE (DRC) STAGE 3.
Authors: Pinto Walter Pereira , Rezende Rafael Andrade , Júnior Armando Morales , De Oliveira Barguena Renato , Dalboni Maria Aparecida , Tinucci Tais
Published: June 2021

Introduction

Loss of renal function results in serum accumulation of toxic substances in chronic kidney disease (CKD) patients. These substances increase the inflammatory response, which in turn contributes to the pathophysiology of cardiovascular disease in this population.

It has been described in the general population that aerobic physical exercise is capable of exerting anti‐inflammatory effects. However, the impact of physical exercise in CKD stage 3 patients (CKD3; creatinine clearance 29–69 ml/min) is unclear. Thus, the objective of this study was to evaluate the effects of a session of aerobic exercise on inflammation markers in CKD stage 3 patients.

Methods

10 subjects with CKD3, (55 ± 6 years, creatinine clearance between 29 and 69 ml/min/1.73 m2), and 10 subjects with normal renal function (51 ± 5 years creatinine clearance> 100 ml/min/1.73m2) were selected to performed aerobic exercise (cycle ergometer, 45 min, 50% VO2peak). Before and after the sessions, blood samples were collected for analysis of the inflammatory markers: TNF‐alpha, IL‐6 and IL‐10.

Statistical analysis

The normality of the data was tested by the Shapiro‐Wilk test. Data were compared through two‐factor ANOVA (groups × times) for parametric data, and the FRIEDMAN test used for non‐parametric comparisons. A significant difference was considered when p <0.05. The software used was IBM SPSS STATISTICS 24.0.

Results

Aerobic physical exercise reduced IL‐6 levels in the CKD3 group (2.13 ± 0.36 vs. 1.86 ± 0.45; p = 0.04). IL‐10 levels increased after an aerobic exercise session compared to the control group (p <0.001). Physical exercise had no effect on TNF‐alpha levels (P> 0.05).

Conclusion

When compared CKD3 with healthy individuals, patients with CKD3 are more inflamed. However, in this study the aerobic exercise decreased IL‐6 (pro‐inflammatory) and increased IL‐10 (anti‐inflammatory) in these patients. In conclusion, aerobic physical exercise played an anti‐inflammatory effect in CKD stage 3 patients, suggesting that this practice may to benefit this population.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Empagliflozin Inhibits NHE3 Activity in the Proximal Tubule of Normotensive and Hypertensive Rats
Authors: Borges Flávio Araújo , Silva Corina Albuquerque , Crajoinas Renato Oliveira , Castelo‐Branco Regiane Cardoso , Luchi Weverton Machado , Girardi Adriana Castello Costa
Published: June 2021

Background

A growing body of evidence suggests an interplay between extracellular volume and glucose homeostasis. NHE3 is the main pathway for Na reabsorption in the proximal tubule (PT). The sodium glucose cotransporter SGLT2 reabsorbs most of the glucose filtered by the kidneys and colocalizes with NHE3 in the apical membrane of PT. Thus, we tested the hypothesis that SGLT2 and NHE3 functionally interact. Given that SGLT2 inhibitors confer blood‐pressure lowering effects in T2DM patients, we also tested the hypothesis that the antihypertensive effects of SGLT2 inhibitors may be associated with PT NHE3 inhibition.

Methods

The acute and long‐term effects of the SGLT2 inhibitor empagliflozin on PT NHE3 activity were determined by in vivo stationary microperfusion in fourteen‐week‐old male Wistar rats and SHR‐treated rats. Additionally, twelve‐week‐old SHRs were treated with empagliflozin (10 mg/kg/day) or vehicle (control) for two weeks. Tail‐cuff blood pressure and renal function were measured before (baseline) and after treatment (post‐treatment). NHE3 expression and phosphorylation levels were evaluated by immunoblotting.

Results

Empagliflozin acutely inhibited PT NHE3 activity in both Wistar (1.73 ± 0.07 vs. 2.55 ± 0.14 nmol/cm2.s, P < 0.001) and SHR (0.82 ± 0.07 vs. 1.21 ± 0.10 nmol/cm2.s, P < 0.01). Blood pressure (BP) of empagliflozin‐treated SHR was lower than baseline levels (176 ± 4 vs. 194 ± 4 mm Hg, P < 0.01) whereas no change in BP was observed in vehicle‐treated SHR (194 ± 6 vs. 192 ± 5 mm Hg). Compared to baseline, empagliflozin‐treatment enhanced cumulative urinary flow, calcium, sodium and glucose excretion whereas in vehicle‐treated SHR these parameters remained unchanged. Lower BP in empagliflozin‐treated SHR was associated with lower PT NHE3 activity (0.67 ± 0.10 vs. 1.18 ± 0.10 nmol/cm2.s, P < 0.001). No differences were observed on renal cortical NHE3 protein expression or NHE3 phosphorylation levels between the two groups of rats.

Conclusion

These results suggest that NHE3 and SGLT2 functionally interact in the PT. Inhibition of NHE3 by SGLT2 inhibitors may underlie, at least in part, the antihypertensive effect of empagliflozin.

Support or Funding Information

FAPESP

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Mulberry extract protects from diet‐induced obesity in association with modulation of gut microbiota in mice
Authors: Song Haizhao
Published: June 2021

Mulberry, a natural source of flavonoids, phenolics and anthocyanins, has been widely used in edible food and medicine due to its pharmacological effect. Growing evidence indicates that gut microbiota contributes to obesity, type II diabetes and many other related metabolic disorders. The present study was designed to evaluate the influence of the mulberry water extract (ME) on high‐fat diet induced obesity and determine whether the beneficial effects of ME are associated with the modulation of gut microbiota. Forty‐five male C57BL/6J mice were divided into three groups and fed with low‐fat diet, high‐fat diet or high‐fat diet plus ME administration of 300 mg/kg/day for 15 weeks. 16S rDNA sequencing was performed to analyze the composition of gut microbiota. Our results showed that dietary ME reduced HFD‐induced body weight gain and ameliorated adipose tissue hypertrophy and insulin resistance. Moreover, metagenomic analysis indicated that ME supplement significantly changed the ratio of Firmicutes and Bacteroidetes at the phylum level.

In conclusion, ME protects from diet‐induced obesity and its related metabolic disorders, which is associated with the modulation of gut microbiota in mice. These findings suggested a dietary choice of mulberry in the nutrition therapy of obesity and its metabolic disorders.

Support or Funding Information

National Natural Science Foundation of China (Grant No. 31701031) China Postdoctoral Science Foundation (Grant No. 2016M601006)

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Correlation between Promoter CpG Methylation and mRNA Levels of Genes Regulated by Fatty Acids in Muscle Cells and Adipocytes
Authors: Alam Md Masudul , Cheng Elliott , Li Yi
Published: June 2021

In obesity and type 2 diabetes, adipose and muscle tissues are significantly affected. It has been demonstrated that many of the changes are associated with gene expression. We tried to study the involvement of epigenetic modifications in mediating gene expression induced by hyperlipidemia. L6 Muscle cells and differentiated 3T3L1 adipocytes were treated with saturated and polyunsaturated fatty acids to mimic hyperlipidemia condition. After treatments, methylation sequencing was done to identify the methylated regions of the genomic DNA samples from the cells. In combination with validated DNA microarray data, we have found an inverse correlation between DNA CpG methylation in the promoter region and the mRNA level of a number of genes including FADS3, PPARγ, RASA2, MEF2C. At present we are individually validating the methylation status of the genes and studying the signaling pathways mediating in methylation of these genes.

Support or Funding Information

This research is supported by grant SC3GM116737 from the NIGMS of the NIH to Y. Li.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Responses of Muscle Satellite Cells to Lemon Myrtle Supplementation Combined with Electrical Stimulation in Disuse‐induced Skeletal Muscle Atrophy
Authors: Takuwa Miho , Matsumoto Tomohiro , Hirabayashi Takumi , Ikeji Takuya , Ono Kohei , Honda Shinichi , Yamamoto Ayumi , Kondo Hiroyo , Fujino Hidemi
Published: June 2021

Disuse condition leads to decrease fiber cross‐sectional area and satellite cell activity in skeletal muscle. Transcutaneous electrical stimulation (ES) can suppress unloading‐induced muscle atrophy, but not prevent. Lemon myrtle (LM), one of herbs, could activate muscle satellite cells in our previous study. Therefore, the preventive effects of the lemon myrtle supplementation on muscle atrophy were investigated. In addition, we determined the activation in muscle satellite cells, the number of myonuclei, and the prevention of disuse‐induced muscle atrophy by the combination of LM supplementation and ES. Wistar rats were divided into 5 groups; control (CON), hindlimb unloading (HU), HU + LM, HU + ES and HU + LM + ES groups. The experiment period was 14 days. Unloading condition resulted in a decrease in the fiber cross‐sectional area (FCSA). The FCSA was significantly increased in HU + LM + ES group than in the other three groups (HU, HU + LM and HU + ES). In addition, the expression levels of Pax 7, MyoD and myogenin were higher in HU + LM + ES group compared with the other three groups (HU, HU + LM and HU + ES). Furthermore, the number of myonuclei were significantly decreased in HU, HU + LM and HU + ES groups than in CON group although there was no significant difference between in HU + LM + ES group and CON group. These results suggest that the combination of lemon myrtle supplementation and electrical stimulation suppressed the reduction of the fiber cross‐sectional area compared with lemon myrtle supplementation or electrical stimulation alone, and these alterations were accompanied with an increase in the number of myonuclei associated with the activation of muscle satellite cells.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Age‐Related Changes in Resting State Connectivity of Brain Areas Related to Appetite, Mood and Food Homeostasis in Response to Glucose Ingestion
Authors: Peters Riccarda , White David , Pipingas Andrew , Scholey Andrew
Published: June 2021

Objective

Aging is associated with decreases in appetite and energy intake. Appetite regulation is a complex system and age‐related changes in the brain response to food is not completely understood.

The aim of this study was to investigate the influence of a glucose load on resting state functional connectivity of brain regions involved in the regulation of appetite, motivation and reward processes as well as energy homeostasis in aging. We further investigated the relationship of changes in functional connectivity to changes in subjective mood and appetite as well as to measures of cerebral metabolic rate of oxygen consumption (CMRO2).

Method

In a randomized, double‐blind, crossover trial, 32 adults (16 young and 16 elderly) completed two counterbalanced testing sessions. Participants received a 25g glucose load in one session and a matched placebo in the other. Participants underwent resting state fMRI, blood glucose levels were monitored and mood and appetite were taken via self‐report at several time points. Seed‐based connectivity analyses were performed to assess resting state connectivity to the whole brain from seeds in the striatum (caudate, putamen, amygdala, thalamus) and the hypothalamus.

Results

Significant treatment by age‐group interactions were found between putamen and inferior frontal gyrus, and from thalamus to parietal operculum and middle temporal gyrus. Elderly participants exhibited increased functional connectivity to these clusters. Changes in resting state connectivity from thalamus were correlated with changes in perceived hunger after glucose ingestion in the elderly group.

Further, increased connectivity between hypothalamus and posterior cingulate and medial frontal cortex, core regions in the default mode network, were observed in the elderly group, which were correlated with changes in CMRO2.

Conclusion

These findings suggest that a glucose load modulates brain connectivity related to appetite, mood and food homeostasis differently in younger and older healthy adults. Our findings have implications for the understanding of how the brain's response to energy intake changes in aging.

Support or Funding Information

This study was funded by an Australian Research Council (ARC) Grant.

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 8 Months of E‐cigarette Exposure on Cytokine expression in Mice
Authors: Pitzer Christopher , Breit Matthew , Hoskinson Hannah , Aboaziza Eiman , Mashall Kent , Burrage Emily , Chantler Paul , Bryner Randall , Olfert I. Mark
Published: June 2021

Introduction

Electronic cigarettes (E‐cigs) are gaining popularity in the United States and worldwide. Little is currently known about the effects of chronic E‐cigarette exposure on cytokine expression throughout the body.

Methods

C57BL/6 female mice were randomly assigned to cappuccino flavored E‐vapor (18 mg/ml nicotine, N=12) or filtered air (N=13) exposed groups. Animals were exposed 4 hours per day, 5 days per week for 8 months. After exposure major organs including lung, serum, and gastrocnemius were removed and flash frozen for cytokine analysis. Lung and skeletal muscle (i.e. gastrocnemius muscle) were homogenized with Tris‐HCL‐ buffer. Total protein from homogenates and serum were analyzed with the Bradford method and equal concentrations of total protein were analyzed using a Meso Scale Discovery U‐Plex kit according to manufacturer's instructions. Cytokines analyzed included: vascular endothelial growth factor (VEGF), Interleukin (IL)‐6, IL‐5, IL‐4, tumor necrosis factor‐ alpha (TNF‐α), IL‐1β, IL‐15, IL‐ 10, interferon gamma (IFN‐γ) and granulocyte‐macrophage colony‐stimulating factor (GM‐CSF).

Results

The lungs of E‐cig exposed mice had 54% less VEGF compared to air exposed controls. IL‐6 was reduced by 57% in serum, but IL‐6 increased 994% in the skeletal muscle of E‐cig exposed mice compared to air exposed controls. IL‐10 was reduced by 87% in the gastrocnemius muscle of E‐cig exposed mice compared to air exposed control mice. No significant differences in the remaining factors (i.e. IL‐5, IL‐4, TNF‐α, IL‐1β, IL‐15, IFNγ, GM‐CSF) were identified between E‐cig and air groups in any of the other organs/tissues tested.

Discussion

The results of this study have implications for immune system response time and muscle growth/regeneration. IL‐6 is important for initiating immune system responses, decreases in its expression may lead to increased frequency or duration of infections by viruses or bacteria. IL‐10 in muscle has been shown to influence macrophages to increase anabolic capability of the muscle. Decreases in VEGF may indicate altered angiogenic potential, changes in muscle permeability and/or increased potential of apoptosis in the lung. Long‐term exposure to E‐cig vapor results in changes in cytokines and growth factors that may negatively influence immune and angiogenic potential.

Support or Funding Information

NIH P20GM103434 (West Virginia IDeA Network for Biomedical Research Excellence) and Marshall‐WVU Health Cooperative Award

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Metformin Restores Doxorubicin Induced Reduction in Complex II Respiration in C2C12 Skeletal Muscle Myotubes
Authors: Harley Jackson S , Mackay Amy D , Hancock Chad R
Published: June 2021

Doxorubicin (DOX) is a widely used chemotherapeutic drug that blocks cell proliferation, but is limited because of its cardio‐toxic effects. Current research is directed towards finding treatments that reduce the cardio‐toxic effects without compromising the chemotherapeutic properties of DOX. Recent studies have shown that the negative effects of doxorubicin could be due to a disruption of mitochondrial energy metabolism, causing an increase in harmful free radicals. Metformin (MET), a highly prescribed drug for insulin resistance, has been shown to suppress the negative side effects associated with DOX, possibly by decreasing free radical damage. In this study, mitochondrial respiratory function was evaluated in order to further understand the effects of DOX treatment with or without the addition of MET. Given that MET is known to inhibit complex I of the electron transport chain, we wanted to examine the combined effects of DOX and MET on mitochondrial respiration. C2C12 mouse skeletal muscle myotubes were pretreated with 0.5 uM DOX and/or 0.5 mM MET for 16 hours. Consistent with the known inhibitory effect of MET on complex I, there was a 27% (p< .05) higher complex I mediated respiration rate in cells treated with DOX compared to DOX + MET. Interestingly DOX showed a 21% (p<.05) decrease in complex II respiration when compared to DOX + MET. Furthermore when comparing the difference between complex I respiration and complex II respiration, DOX treatment was 42% (p<.01) lower than the DOX + MET treatment. Even in the light of the direct inhibition of complex I by MET, there was an improvement in complex II mediated respiration in cells treated with MET. These results suggest that MET limits the damage caused by DOX treatment in tissues.

Support or Funding Information

Mentoring Environment Grant, Brigham Young University

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Nucleolar Matrix Metalloproteinase‐2 Regulates rRNA Transcription
Authors: Garcia‐Vilas Javier , Ali Mohammad , Ilarraza Ramses , Hendzel Michael , Schulz Richard
Published: June 2021

Gene expression in eukaryotic cells is a tightly regulated process, from pre‐transcriptional through post‐transcriptional stages. A major control point in gene expression is ribosome synthesis, since it executes mRNA translation and also regulates their stability. Genes encoding ribosomal proteins and ribosomal RNA (rRNA) are physically located and transcribed in specialized structures within the nucleus known as nucleoli. We previously reported that the protease matrix metalloproteinase‐2 (MMP‐2) was located inside the nucleus but its role there remains elusive.

Confocal microscopy studies in our lab showed an accumulation of MMP‐2 in nucleoli in U‐2OS human osteosarcoma cells, suggesting a role in rRNA transcription. We found that MMP‐2 co‐localizes with nucleoli markers fibrillarin and nucleophosmin, and is located in active rRNA transcription sites within nucleoli of U‐2OS cells pulsed with 5‐fluorouridine (5‐FU).

Chromatin immunoprecipitation (ChIP) assays showed an enrichment of MMP‐2 in the rRNA gene promoter region. We also found evidence of MMP‐2‐mediated proteolysis of purified histones (H1, H2A, H2B, H3 and H4), in a concentration‐dependent manner. Interestingly, we identified histone H3 to be the most susceptible to MMP‐2 activity and found at least one MMP‐ 2 cleavage site in the N‐terminal tail of histone H3.

The N‐terminal tail of histone H3 is the location of a large number of known post‐translational modifications that are involved in the regulation of DNA relaxation and transcription, RNA splicing and DNA repair. Emerging evidence indicates that one of the mechanisms behind this is the proteolytic removal of the N‐terminal tail of histone H3 by a yet uncharacterized protease. Therefore, we sought to elucidate if nucleolar MMP‐2 has proteolytic activity on recombinant histone H3. We incubated MMP‐2 immunoprecipitated from isolated nucleoli with recombinant histone H3, in presence or absence of the MMP‐2 preferring inhibitor ARP‐100. Our data revealed that nucleolar MMP‐2 has proteolytic activity on histone H3 and is sensitive to ARP‐ 100.

The involvement of MMP‐2 in rRNA gene expression in the nucleolus is a major novel mechanism by which intracellular may MMP‐2 regulate cell function via histone proteolysis.

Support or Funding Information

Canadian Institutes of Health Research (CIHR) grants FDN‐143299 (to RS) and MOP‐119515 (to MH)

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Behavioral Assessment of Mice with Mitochondrial CaMKII Inhibition
Authors: de la Rosa‐González Nicole , Joiner Mei‐ling
Published: June 2021

Oxidative stress is thought to be the common underlying mechanism that leads to cellular dysfunction and demise in Parkinson's disease. Recent studies indicate that mitochondrial CaMKII (mtCamKII) activation is responsible for excess Ca2+ uptake under stress conditions, which ultimately leads to increased levels of cell death due to over‐production of reactive oxygen species. Inhibition of mtCaMKII, by CaMKIIN, has been established to decrease cell death under stress conditions in tissues such as the heart. It remains unidentified if inhibition of mtCaMKII in the Substantia nigra can counteract the loss of dopaminergic neurons, a hallmark of Parkinson's disease. To start addressing this interrogant, we utilized the 6‐OHDA unilateral lesion of the Substantia nigra model in mice expressing CaMKIIN, the inhibitor of mtCaMKII. Assessment of cell viability, using the Trypan blue exclusion test of cell viability, as well as confocal imaging of mitochondrial shape of SH‐SY5Y cell line, was performed to validate functionality of 6‐ OHDA. After 2 weeks, training motor impairment assays including rotarod, pole descent, inverted grid and footprint analysis were performed. Preliminary results validated the detrimental effects of 6‐OHDA on SH‐SY5Y cells and showed that mtCaMKIIN‐expressing mice were slower in the pole descent test. Thus, the 6‐OHDA unilateral lesion of the Substantia nigra model in mice shows great promise to assess level of motor impairment in mice expressing mtCaMKIIN, that way, assessing if inhibition of mtCaMKII is protective against cell death.

Support or Funding Information

Special thanks to the lab's of Dr.'s Amy Lee, Ryan Boudreau and Nandakumar Narayanan, the Interdisciplinary Summer Undergraduate Research Program (ISURP), the PRISE program and the CCOM Office of Cultural Affairs and Diversity Initiatives. This project was supported by NIH (AL: NS084190, DC009433) and a Carver MRIG (MAJ).

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Expression of myogenic regulatory factors is not different between whole muscle and isolated human muscle satellite cells following eccentric contractions
Authors: Fortino Stephen A , Nederveen Joshua P , Joanisse Sophie , Baker Jeff M , Snijders Tim , McGlory Christopher , McKay Bryon R , Kumbhare Dinesh , Parise Gianni
Published: June 2021

Skeletal muscle satellite cells (SC) play an important role in muscle repair following injury. The regulation of SC activity is governed by myogenic regulatory factors (MRF), including MyoD, Myf5, myogenin and MRF4. The mRNA expression of these MRF in humans following muscle damage has been predominately measured in whole muscle homogenate. Whether the temporal expression of MRF in whole muscle homogenate accurately reflects SC specific expression of MRF remains largely unknown. Fourteen young men (21±0.5 yrs) performed 300 unilateral eccentric contractions (180 deg·s−1) of the knee extensors on a Biodex dynamometer. Percutaneous muscle biopsies from the vastus lateralis were taken prior to (Pre) and 48h post‐exercise. Fluorescence‐activated cell sorting (FACS) analysis was utilized to purify a population of NCAM+ muscle SC from the whole muscle homogenate. 48h post‐eccentric exercise, MyoD mRNA expression increased in whole muscle homogenate (~2.0‐fold, p<0.05) and in isolated SC (~2.2‐fold, p<0.05). Myf5 mRNA expression increased in whole muscle homogenate (~3.0‐fold, p<0.05) and in isolated SC (~3.2‐fold, p<0.05). Myogenin mRNA expression increased in whole muscle homogenate (~1.9‐fold, p<0.05) and in isolated SC (~12.0‐fold, p<0.05). MRF4 mRNA expression was not increased in 48h post‐exercise whole muscle homogenate or in isolated SC (p>0.05). These results suggest that the temporal mRNA expression of MRF in a population of isolated muscle SC accurately reflects the expression observed in whole muscle homogenate. Whole muscle homogenate represents a reliable proxy for the temporal expression of MRF in human muscle satellite cells.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
HIGH RESISTANCE OF CHICKEN EMBRYO RED BLOOD CELLS TO ACID ACTION
Authors: Mischenko Alexander , Lebedeva Elena , Golovko Vladimir
Published: June 2021

In this paper, the results of the comparative studies of the resistance of Gallus gallus chicken embryo and human erythrocytes are presented to acid action.

Methods

Red blood cells from decapitated 10–12 day‐old chicken embryos (5±0.6 g) and human donor blood were used in the experiments. The cells were isolated by centrifugation and washed three times with 145 μmol/l NaCl solution. The hemolysis was performed using: a) Mcllvein buffer solution (MBS) (0.31 g/l Na2HPO4 and 1.87 g/l citric acid, pH = 2.5); b) 0.1 N HCl. The optical density (D) was registered by using photocolorimeter at λ=540 nm. The part of the experiments was made by using isotonic 145 μmol/l choline chloride solution. The experiments were carried out at 18–20°C; the reliability of the differences was evaluated with the Van der Waerden test.

Results

The hemolytic resistance of the chick embryo erythrocytes was higher than of human erythrocytes. The lag phase value, the time to 50% hemolysis (t50) and the time to complete hemolysis increased twice (p<0.05). The D value remained high after the completion of hemolysis. We believe that the effect of acid on the erythrocyte nucleus led to the decondensation and swelling of chromatin, causing an increase in optical density. The replacement of NaCl with choline chloride did not affect the resistance of human erythrocytes and led to an increase in the chick embryo resistance (p<0.05). In particular, the hemolytic start time (t0) and the end time (tend) were increased by 16% (p <0.05) and 21% (p <0.05) respectively. The results of these experiments showed that Na+/H+ exchange couldn't lead to an increase in the acid resistance of chick embryo erythrocytes. The calculations indicated that at the anion exchanger density of 2760 copies/μm2 and 8,300 copies/μm2 in chicken and human erythrocytes, respectively. The amount of anion exchangers was 1.2 × 106 copies per human erythrocyte and 6.3 × 105 copies per chick embryo erythrocyte. This is a in good agreement with the 2‐fold increased resistance of the chicken embryo erythrocytes compared to the human erythrocytes.

Thus, the high resistance of chicken erythrocytes in comparison with human erythrocytes can be associated with a lower density of anion exchangers in the chicken red blood cells membrane.

Support or Funding Information

The study was supported by project № AAAA‐A17‐117012310152‐2

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Prior Menopausal Hormone Treatments And Association of Peripheral Markers of Neurovascular Unit Integrity And β‐amyloid in The Brains of Menopausal Women
Authors: Jayachandran Muthuvel , Lahr Brian D , Bailey Kent R , Lowe Val J , Kantarci Kejal , Miller Virginia M
Published: June 2021

Background

Break down of the blood brain barrier and activation of brain cells are implicated in progression of deposition of β‐amyloid that is associated with the pathophysiology of Alzheimer's disease. A previous study from our group indicated that deposition of β‐amyloid may be reduced in the brains of menopausal women treated with transdermal 17β‐estradiol. This study aimed to determine the association of peripheral microvesicles carrying markers of cells of the neurovascular unit with β‐amyloid in the brains of menopausal women and if the association was affected by prior menopausal hormone treatments (MHT).

Methods

Menopausal women previously enrolled in the Kronos Early Estrogen Prevention Study at Mayo Clinic underwent β‐amyloid positron emission tomography (PET) imaging of their brains 3 years following treatment with either placebo (PL, n=29), transdermal 17β‐estradiol (tE2; n=21), or oral conjugated equine estrogen (oCEE; n=17) for 4 years. Microvesicles (MV) were isolated from peripheral venous blood by differential centrifugation and analyzed by flow cytometry using fluorophore conjugated antibodies directed toward total tau, β‐amyloid 1‐42 (Ab1‐42), neuron specific class III β‐tubulin (Tuj1), microglia ionized calcium adaptor molecule 1(Iab‐1), glial fibrillar acid protein (GFAP), and low density lipoprotein receptor‐related protein 1. Principal components analysis was used to reduce the dimensionality of the 6 brain markers to 2 principal components (PCs). Proportional odds ordinal logistic regression analysis was used to regress deposition of β‐amyloid on the 2 PCs with and without adjustment for MHT group.

Results

Number of blood MV positive for Ab1‐42 differed significantly among MHT groups (median [IQR]: 6.06 [2.11, 12.55] in the PL; 2.49 [0.73, 3.59] in the tE2 and 4.96 [0.83, 10.31] in the oCEE; P=0.036). The first 2 PCs explain 58% of the variance of the 6 markers. PC#1 represented a contrast between MV‐Iab‐1 and the MV‐GFAP and MV‐Tuj1. In multivariable models, brain β‐amyloid load positively associated with the first PC after adjustment for MHT (P= 0.006).

Conclusion

MV derived from cells of the neurovascular unit can be detected in peripheral blood, and, when combined into summary scores, showed an association with deposition of β‐amyloid in the brain that is independent of MHT.

Support or Funding Information

Supported by grants from NIH P50 AG044170 and the Mayo Foundation

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Linkage between hypothalamic homeostatic and midbrain motivation circuits and habenula enabling sex steroid modulation of motivation and behavior
Authors: Zhang Limei , Hernández Vito S , Emery Andrew C , Eiden Lee E
Published: June 2021

It is well‐established that the lateral habenula (LHb) plays a key role in integrating a variety of neural circuits associated with reward and aversive behaviors, yet there is limited information about how neuronal circuits within the LHb might serve to coordinate motivational, hormonal and homeostatic states to elicit environmentally appropriate behaviors.

We have identified a population of phenotypically GABAergic cell type in the medial division of the LHb (LHbM) that is apparently also endowed with estrogen responsivity, i.e., cells express Esr1 mRNA, and are immunopositive for ERα. These neurons express receptors for vasopressin, serotonin, dopamine and orexin, and project (as identified by in vivo juxtacellular labeling) both locally within LHb and to midbrain cell groups including those in dorsal raphe and impingent upon ventral tegmental area (VTA). They also appear to receive afferents from midbrain reward (dopamine and serotonin) and hypothalamic water and energy homeostasis (vasopressin and orexin) cell groups: these afferents are excitatory (VGLUT2‐expressing) and capable of converting testosterone to estrogen (express aromatase, or estrogen synthase at both the soma and the axon terminals). We have also demonstrated dynamic changes in LHbM VGAT+ cell density that are dependent upon gonadal functional status, and closely correlate with changes in hormone‐dependent vasopressinergic input, and with motivational behavior in response to predator and forced swim stressors.

These findings provide a neurochemical and neuroanatomical basis for convergent projecting pathways to LHbMC that employ a localized neurosteroid signaling mechanism to convey altered homeostasic and gonadal hormone status to habenular output controlling motivated behaviors.

Magnocellular vasopressinergic neurons of the paraventricular nucleus (PVN) have been observed to send projections not only to the lateral habenula (Zhang et al., 2016) but also to the central nucleus of the amygdala (Hernández et al., 2016). As for the habenular projections, vasopressinergic terminals in amygdala arising from cell bodies in PVN synapse upon GABAergic neurons, and are involved in the linkage of water and thirst homeostatic balance to anxiety and stress coping (Hernández et al., 2016). We are currently examining whether or not vasopressinergic projections to the lateral habenula and to the central amygdala are the same, or distinct neuronal sub‐populations, and whether or not amygdalar target neurons, like those in lateral habenula, are endowed with estrogen responsivity as well.

Support or Funding Information

Supported by: CONACYT‐CB‐238744 (LZ), PAPIIT‐IN216918 (LZ) and MH002386 (LEE).

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Genetic Missense Variants at the EGLN1 Locus Associated with High‐Altitude Adaptation in Tibetans are Rare in Andeans
Authors: Lawrence Elijah S. , Heinrich Erica C. , Wu Lu , Villafuerte Francisco C. , Simonson Tatum S.
Published: June 2021

High‐altitude populations have been challenged by chronic hypoxia for many generations and demonstrate some of the most rapid evolution observed in humans. Genome‐wide scans have brought to light numerous hypoxic‐response candidate genes that are associated with distinct traits in these populations. One example is EGLN1, which shows signals of selection in Tibetan and Andean populations and has been linked to hemoglobin concentration in Tibetans living at high altitude. EGLN1 encodes the hypoxia‐inducible factor (HIF) prolyl hydroxylase 2 (PHD2) protein, which serves as an oxygen‐sensitive regulator of HIF transcription factor activity. We examined the frequencies of two single nucleotide polymorphisms (SNPs) (rs186996510, rs12097901) in the first exon of EGLN1, previously identified at high frequencies and having a gain‐of‐function effect in Tibetans, in a cohort of Quechua Andeans resident at high altitude and individuals of Himalayan (Tibetan, Nepali) ancestry resident at sea level. The minor C allele of rs186996510 is rare among Andeans (0.95%; 1/105) and Nepalese (5.9%; 1/17) but present in 50% (3/6) of Tibetans (X2=36.6, p<0.0001). The minor G allele of rs12097901 was found at 6.6% (7/106) in Andeans, 11.8% (2/17) in Nepalese, and 50% (3/6) in Tibetans (X2=12.8, p<0.002). Two female sea‐level, Tibetan participants with the minor C allele rs186996510 both had significantly lower hematocrit values than the other sea‐level women (F(1,7)=8.8, p=0.025). These genomic differences suggest that despite the identification of an adaptive genetic signal at this locus in both Andean and Tibetan populations, the EGLN1 variants previously reported in Tibetans are very rare in Andeans.

Support or Funding Information

This study was supported by an NIH NRSA Individual Postdoctoral Fellowship (Parent F32) to ECH (F32HL131218), NIH TL1TR001443 to LW, a University of California, San Diego Ledell Family Undergraduate Research Scholarship award for Science and Engineering to ESL, and NIH R00HL118215 and American Physiological Society Giles F. Filley Memorial Award to TSS. The content is solely the responsibility of the authors and does not necessarily represent the official views of the NIH. The UPCH team was supported by a Wellcome Trust PHTM grant (107544/Z/15/Z) to FCV.

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 Pharmacological Characterization of Riluzole on Anxiety and Memory
Authors: Rossi Grace , Rahyab Marjon , Hindieh Jennifer , Nuzzo Arianna , Visquerra Vanessa , Gelles Janine
Published: June 2021

Riluzole is a novel medication that is presently investigated in the field of ALS research since it is a chemical that is known to promote plasticity. The present study plans to investigate the effects of Riluzole on memory in the PTSD model of anxiety in CD‐1 mice. Prior to any manipulation, all subjects were placed on an elevated plus maze (EPM) for 5 minutes in order to obtain baseline data for anxiety. After baseline data was collected, stress was induced in all animals by individually exposing to an aggressor for 5 minutes for 7–10 consecutive days. Mice were reexamined for anxiety by returning to them on the EPM. Continuing further, only anxious mice were used in the study. Twenty mice were given Riluzole (5mg/kg,i.p). All mice were tested on a spatial memory task (the Morris Water Maze) on the 10th day of exposure to the bully mouse. The goal was to investigate the effects of Riluzole on spatial memory after a fear‐provoking experience (exposure to an aggressor mice). After the 10th day of exposing the mice to aggressor mice all mice had significantly higher anxiety levels. Riluzole had limited effects on spatial memory in the anxiety mice. Empirical evidence suggests male and female's spatial memory differ. Further investigation will examine if the findings generalize to female mice as well.

Support or Funding Information

The present study was supported by LIU‐Post Monetary Grant.

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