bluuebunny/crossref_metadata_2025 huggingface dataset:
Mitochondrial respiratory function in the vasculature with advancing age: Examining the link to vasodilatory dysfunction.
Authors: Park Soung Hun , Kwon Oh Sung , park Song‐Young , Andtbacka Robert H. I. , Hyngstrom John R. , Richardson Russell S.
Published: June 2021

Background

Unlike cardiac and skeletal muscle, the role of mitochondria in the vasculature is still unclear. Therefore, this study sought to document mitochondrial respiratory function in the vasculature with advancing age and examine the link to age‐related vasodilatory dysfunction.

Methods

Skeletal muscle feed arteries (SMFAs) were harvested from young (30±6yrs, n=4) and old (69±8yrs, n=20) subjects. Mitochondrial respiratory function was assessed in permeablized smooth muscle fibers and vasodilation in SMFAs was assessed in response to flow‐induced shear stress, acetylcholine (ACh), and sodium nitroprusside (SNP).

Results

Complex I+II, state 3 respiration was significantly lower in the old (young: 12.13±0.48, old: 8.41±0.68 pmol/s/mg), while state 4 was significantly higher in the old (young: 4.69±0.2, old: 7.59±0.67 pmol/s/mg). The respiratory control ratio (RCR), state 3/state 4 respiration, was also significantly attenuated in the old (young: 2.6±0.17, old: 1.19±0.09). Endothelium‐dependent vasodilation was attenuated in the old whether induced by flow (young: 103±6, old: 46±5 %; P<0.01) or ACh (young: 110±12, old: 53±4 %; P<0.01), while endothelial‐independent vasodilation was not altered by age. Thus, there was significant correlation between state 3 respiration and flow‐mediated (r=0.61, P<0.01) and ACh‐dependent vasodilation (r=0.62, P<0.01), but not with the SNP‐dependent response. State 4 respiration was negatively correlated only with ACh‐dependent vasodilation (r=−0.45, P<0.05). RCR also exhibited a strong positive correlation with flow‐mediated (r=0.77, P<0.001) and ACh‐dependent vasodilation (r=0.81, P<0.001), but not the SNP‐dependent response.

Conclusions

Advancing age results in altered mitochondrial respiratory capacity and these changes in mitochondrial function are strongly linked to age‐related endothelial dysfunction in SMFAs.

Support or Funding Information

The National Heart, Lung, and Blood Institute at the National Institute of Health (PO1 HL1091830) and the Veteran's Administration Rehabilitation Research and Development Service (E6910‐R, E1697‐R, E1433‐P, E9275‐L and E1572‐P).

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Identifying Pathways for Apolipoprotein A2 Actions on Respiratory Rhythmogenesis
Authors: Strohl Kingman Perkins , Azzam Sausan , Saleh Dania
Published: June 2021

Objectives

Apolipoprotein A2 (ApoA2) appears has a deterministic role on respiratory stability in the mouse (Gillombardo et al 2017). One roadblock to understanding its brain mRNA and protein effects is a lack of fundamental information on how this HDL‐cholesterol factor might act in the CNS. To address this gap, here we utilized a label‐free proteomics approach and conducted a brain proteome analysis to define protein perturbations and dysregulated pathways comparing ApoA2 presence (Apoa2‐WT) or absence (Apoa2‐KO).

Methods

Eight WT and 8 KO provided desanguinated CNS samples which were lysed (FASPed), and subjected to trypsin digestion. Each sample was analyzed by LC‐MS/MS via LTQ Orbitrap Elite mass spectrometer. Differential quantification of peptides was performed using Rosetta Elucidator. Peptide and protein assignments were made using peptide and protein teller algorithms (FDR <2%). ANOVA was performed comparing peptide intensities across groups. Protein fold changes were determined by dividing the average protein intensity for each peptide in each group. Significant proteins (P‐value ≤ 0.05 and fold change (FC) with ≤‐2 and ≥+2) were imported into Crosstalker for network and pathway analyses.

Results

Our quantitative proteomic analysis identified and quantified a total of 6307 peptides of which, 2995 peptides were statistically significant at p 0.05 using one‐way ANOVA. Of those, 1150 peptides mapping to 298 unique proteins were differentially expressed across groups based on two cutoff criteria: (1) two or more peptides (P ≤0.05) per protein, and (2) each peptide has a fold change of ±2 or greater. Network and pathway analyses of the differentially expressed proteins identified significant pathways (P ≤0.05) associated with the ApoA2 presence or absence. Notable alterations were peptides related to mitochondrial function and metabolism (citric acid cycle and respiratory electron transport, integration of energy metabolism, mitochondrial protein import, mitochondrial biogenesis), RNA, amino acids and carbohydrate metabolism, as well as neuronal signaling.

Conclusions

Our work identified altered peptide distributions representing proteins affecting pathways in energy homeostasis, cellular bioenergetics, and neuronal (neurotransmitters) systems related to Apoa2 loss at a cellular level.

Support or Funding Information

Supported by VA Research Serve Merit Award and the NIH

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Similar alterations of DNA oxidation levels following prolonged exercise in adolescent boys and girls matched for aerobic capacity
Authors: Yasuda Nobuo , Tanioka Toshihiro
Published: June 2021

The purpose of this study was to investigate effects of endurance exercise on oxidative DNA damage in adolescent boys and girls matched for aerobic capacity. Aerobically trained adolescent boys (B; n = 15, age: 15.1 ± 1.7 years, height: 165.8 ± 6.9 cm, body weight: 58.4 ± 12.1 kg, body mass index: 21.1 ± 3.2 kg/m2, body fat: 13.1 ± 6.0 %, peak oxygen uptake relative to fat free mass: 77.1 ± 8.5 VO2peak/kg FFM/min) and girls (G; n = 14, age: 14.6 ± 1.0 year, height: 156.3 ± 3.1 cm, body weight: 52.1 ± 4.3 kg, body mass index: 21.3 ± 1.6 kg/m2, body fat: 23.7 ± 5.1 %, peak oxygen uptake relative to fat free mass: 71.8 ± 6.1 VO2peak/kg FFM/min [mean±SD]) matched for peak oxygen uptake relative to fat free mass were enrolled as the participants. Urinary samples were taken at the 2‐hour period before (pre) and after (immediately post and post 24–26 hours) 60 min of cycling exercise at 65%VO2peak, followed by the analysis of urinary 8‐hydroxy‐2′‐deoxyguanosine (8‐OHdG: a potential biomarker of whole body DNA damage and repair) determined with high performance liquid chromatography with electrochemical detection. Two‐way (time × sex) analysis of variances demonstrated no significant main effects for time, sex or interaction (Pre: 3.7 ± 1.8, Post: 4.2 ± 1.9, Post 24–26h: 3.9 ± 1.4 for B; Pre: 3.8 ± 0.9, Post: 4.1 ± 1.3, Post 24–26h: 3.6 ± 0.9 ng/mg creatinine for G) regarding urinary 8‐hydroxy‐2′‐deoxyguanosine level. These results of the present study suggest that no detrimental DNA damage can be observed after prolonged moderate exercise in aerobically trained boys and girls, potentially because of the enhanced antioxidant defense responses. Furthermore, the pubertal boys and girls appear to have similar DNA oxidation responses at the whole‐body level when normalized to peak oxygen uptake relative to fat free mass.

Support or Funding Information

Supported partly by funds from the Grant‐in‐Aid for Scientific Research (C) (Grant No.16K01606) and Futaba Electronics Memorial Research Foundation (2016–29) in Japan.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Exercise Training Improves Metaboreflex Control of Sympathetic Nerve Activity in Obstructive Sleep Apnea
Authors: Guerra Renan Segalla , Goya Thiago T. , Silva Rosyvaldo F. , Barbosa Eline R.F. , Lima Marta F. , Lorenzi‐Filho Geraldo , Negrão Carlos Eduardo , Ueno‐Pardi Linda Massako
Published: June 2021

BACKGROUND

We have recently demonstrated that patients with obstructive sleep apnea(OSA) have abnormal muscle metaboreflex control of muscle sympathetic nerve activity(MSNA).

OBJECTIVE

To test the hypothesis that exercise training (ET) would improve muscle metaboreflex control of MSNA in patients with OSA.

METHODS

41 individuals with OSA(polysomnography), age = 51±1 years, BMI = 29.5±0.6 kg/m2, were randomly divided into untrained (n=21), and trained (n=20) groups. Heart rate, blood pressure, and MSNA(microneurography) were continuously measured during 4 min at rest, 3 min of handgrip static exercise (30% maximal voluntary contraction), and 2 min post handgrip muscle ischemia(PHMI). The metaborreflex sensitivity was evaluated as the difference in MSNA between first and second min PHMI and resting period. ET program was conducted for six months, three session/week. Each session consisted of 45 min of cycle ergometer, 10 min of local strengthening exercise, and 5 min of cool down.

RESULTS

Baseline age, BMI, exercise capacity, and hemodynamic variables were similar between groups. Likewise, the exercise and PHMI responses were not different between groups. Of note, MSNA returned to baseline during the PHMI period in both groups, which is an indicative of impaired muscle metaboreflex control. ET significantly increased exercise capacity. ET reduced MSNA levels at rest (36±3 vs. 25± 2 bursts/min), and during exercise (43±4 vs. 32± 3 bursts/min). More interestingly, MSNA remained elevated during PHMI in comparison to rest period in the exercise‐trained individuals (29±2 vs. 25± 2 bursts/min). No change in the untrained patients was found.

CONCLUSIONS

ET decreases sympathetic nerve activity during moderate handgrip exercise and improves muscle metaboreflex control of MSNA in patients with OSA.

Supported by FAPESP # 2010/15064‐6

Support or Funding Information

FAPESP # 2010/15064‐6

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Reliability and Validity of NIRS Mitochondrial Capacity Protocol in Human Skeletal Muscle
Authors: La Mantia Anna M. , Neidert Leslie E. , Kluess Heidi A.
Published: June 2021

To establish reliability of a near‐infrared spectroscopy (NIRS) mitochondrial capacity protocol and assess validity using heating and cooling interventions. We recruited 13 young, healthy participants (men=8, women=5), who were asked to attend four visits. Two of the visits consisted of a protocol which included a series of blood pressure occlusions proximal to the NIRS probe and electrical stimulation to the vastus lateralis (thigh), gastrocnemius (calf) and flexor carpi radialis (forearm), to establish reliability. Participants returned 24 hours after visit 2 to participate in one of two treatments, heating (40° Celsius) or cooling (15.6° Celsius) of the thigh, calf and forearm muscle also using the same protocol as above. The order of the visits was counterbalanced. The between day reliability coefficient of variation in the forearm (CV) was 3% and the time constants (TC) average was 42.5 ± 8.9 seconds (s). The within day CV in the forearm was 4.5%, calf 5.5% and thigh was 4.6% (n=13). The within day cold treatment testing CV for reliability in the forearm was 5.9%, calf 4.3% and thigh 4.4% and for the within day hot treatment testing CV in the forearm was 6.4%, calf 5.3% and thigh 4.6%. In the forearm (41.5 ± 2.4 s) and calf (51.6 ± 2.0 s), cold increased the mitochondrial capacity time constant however heat caused a decrease (p<0.05). Similarly, in the thigh (27.2 ± 1.2 s), heat decreased mitochondrial capacity (p<0.05), but cold was not different from control. These results suggest that the NIRS mitochondrial capacity has good within and between day reliability in all three muscles. Mitochondrial capacity time constants are increased by cold and decreased by heating in the forearm and calf, which suggests good construct validity. This study suggests the possibility of the involvement of NIRS in a clinical setting to monitor muscle health as well as utilize hot and cold treatment results to better understand the properties of the muscle's mitochondrial capacity.

Support or Funding Information

This work was supported and funded by The School of Kinesiology at Auburn 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.
Do Graduated Compression Garments Enhance Whole‐body Heat Loss During an Extreme Heat Exposure in Older Adults?
Authors: D'Souza Andrew W. , Notely Sean R. , Meade Robert D. , Kenny Glen P.
Published: June 2021

Graduated compression garments worn on the lower limbs are commonly used in clinical settings to enhance blood circulation and have been shown to elicit elevations in whole‐body heat loss relative to a control condition (no compression) in young men during post‐exercise recovery in the heat (Am J Physiol 2010;299:R119). To date, it remains unknown whether these garments can enhance heat dissipation in heat vulnerable older adults. Relative to their younger counterparts, older adults demonstrate an impaired ability to increase whole‐body heat loss during an extreme heat exposure. Consequently, these individuals store more heat, leading to potentially dangerous increases in body temperature (Temperature (Austin) 2017;4:79). The use of compression garments may help alleviate the level of thermal strain in these individuals. We therefore sought to determine whether lower limb graduated compression garments would enhance whole‐body heat dissipation and reduce body heat storage relative to a control condition (i.e., no compression) in older adults during passive heat exposure. To evaluate this possibility, we assessed changes in whole‐body heat exchange and heat storage in 6 older (mean ± SD: 69 ± 6 years) adults (4 men, 2 women) during a 2‐hour extreme heat exposure (40°C, ~10 %RH) on two separate occasions (separated by ≥48 h). In both trials, participants sat in a semi‐recumbent position wearing a graduated compression garment (SCD Express Sleeves; Kendall, Mansfield, MA) on each leg containing three bladders that either delivered intermittent graded compression (ankle: 45 mmHg, calf: 40 mmHg, thigh: 30 mmHg; Compression trial) or no compression (Control trial) throughout each exposure. Trials were administered in a balanced order. Wholebody heat loss and metabolic heat production were measured continuously by direct and indirect calorimetry, respectively. Body heat storage was quantified as the temporal summation of heat production and loss. Metabolic heat production (Compression: 98 ± 10 W vs. Control: 94 ± 13 W), evaporative heat loss (135 ± 20 W vs. 134 ± 23 W), dry heat exchange (−48 ± 19 W vs. −52 ± 12 W), and net (total) heat loss (89 ± 14 W vs. 82 ± 14 W), were similar between the Compression and Control trials (all P>0.05). Consequently, cumulative body heat storage did not differ between conditions (Compression: 85 ± 11 kJ; Control: 85 ± 24 kJ, P=0.98). Our preliminary findings suggest that graduated compression garments do not enhance whole‐body heat loss in older adults during exposure to hot ambient conditions.

Support or Funding Information

The Canadian Institutes of Health Research (funds held by Dr. Glen Kenny).

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Acute Heat Exposure Results in an Appropriate Initial Decrease in Core Body Temperature in Subjects with Higher Levels of Spinal Cord Injury, but the Thermal Homeostatic Response to More Prolonged Heat Exposure is Insufficient
Authors: Kumar Nina S. , Graham Marin , Leung Patricia , Tittley Tishina D. , Tascione Oriana F. , Bauman William A. , Handrakis John P.
Published: June 2021

Study Objective

To determine the initial (30 minutes) and more prolonged (60 & 90 minutes) response to heat exposure in individuals with higher levels of spinal cord injury (Hi‐SCI; ≥thoracic level‐4).

Methods

Sixteen persons with Hi‐SCI (C4‐T4, AIS A‐B) and 16 age and body mass index‐matched AB controls were acclimated in a 27°C baseline (BL) room before being transitioned to a 35°C chamber for 90 minutes (Heat Challenge). Tcore (rectal temperature) was continuously measured throughout the Heat Challenge, and sweat rates of the upper extremities (SRUE) and lower extremities (SRLE) were measured at BL and then at 30‐minute intervals.

Results

At BL, the average Tcore of the Hi‐SCI group was lower than that of the AB group (36.8±0.45°C vs. 37.35±0.27°C; p=0.0003, respectively). From BL to 30 minutes of Heat Challenge, in both Hi‐SCI and AB groups, a significant decrease (p<0.001) in Tcore (Hi‐SCI and AB: 36.57±0.47°C; 37.07±0.20°C, respectively) was accompanied by increases in SRUE for both Hi‐SCI and AB groups (63.77±83.15%; p=0.008 and 202.98±412.47%; p=0.068, respectively). SRLE also increased in the AB group from BL to 30 minutes (138.25±227.96%; p=0.028). From 30–60 minutes of Heat Challenge in the Hi‐SCI group, SRUE increased significantly (32.34±54.53%; p=0.031), but SRLE did not. From 60–90 minutes of Heat Challenge in the Hi‐SCI group, SRUE and SRLE failed to increase, which was associated with progressive increases in Tcore to BL values at 60 minutes (36.74±0.45°C) and above BL values at 90 minutes (37.01±0.45°C vs. 36.8±0.45°C; p=0.01). In the AB group, both SRUE and SRLE incrementally and significantly increased at each 30 minute interval of Heat Challenge, and Tcore remained lower than the BL value at 90 minutes (37.17±0.23 vs. 37.35±0.27°C; p=0.003).

Conclusions

In the Hi‐SCI group, we speculate that during the first 30 minutes of Heat Challenge, residual sympathetic sudomotor control allowed for increased SRUE, which resulted in a dip in Tcore that was similar to the dip observed in the AB group. However, because of limited sympathetic integrity in the upper and lower extremities, persons with Hi‐SCI were unable to mount a meaningful increase in SRUE from 60–90 minutes or in SRLE from BL to 90 minutes. The insufficient thermal homeostatic response to more prolonged Heat Challenge in the Hi‐SCI group resulted in a Tcore rise above BL values. Thus, prolonged exposure (>60 minutes) to elevated ambient temperatures poses a risk to persons with higher levels of SCI.

Support or Funding Information: Department of Veterans Affairs Rehabilitation Research and Development Service (I21RX001734).

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Identification of Novel mRNA Transcripts in the Sympathetic Stellate Ganglia using RNA Sequencing
Authors: Bardsley Emma N. , Davis Harvey , Ajijola Olujimi A. , Buckler Keith J. , Ardell Jeffrey , Shivkumar Kalyanam , Paterson David J.
Published: June 2021

Introduction

Sympathetic hyperactivity is a key feature of human hypertension as well as animal models of disease. In the spontaneously hypertensive rat (SHR), a genetic‐based model of hypertension, dysautonomia occurs prior to increases in blood pressure.

Aim

In this study, we aimed to establish the genetic changes in post‐ganglionic sympathetic neurons (PGSNs) obtained from SHR rats and to confirm the presence of these transcripts in stellate ganglia from human donor patients.

Method

PGSNs were obtained from 16‐week normotensive Wistar rats and age‐matched hypertensive SHR with known sympathetic hyper‐responsiveness. RNA sequencing was used to investigate the transcriptomic changes within the cardiac sympathetic stellate ganglia in disease.

Results

RNAseq data were analysed using a Salmon‐DESeq2 pipeline1,2. We observed 768 differentially expressed mRNA transcripts in SHR compared with Wistar PGSNs, using the Benjamini‐Hochberg adjusted p<0.01 level. Gene ontology (GO) analysis of the rat dataset revealed extracellular ligand‐gated ion channels (GO:0005302) to be the most over‐represented ‘molecular function’ GO group. There were 15 differentially expressed genes in SHR stellate neurons within this group; including nicotinic, purinergic, glutamatergic, serotonergic, GABAergic and glycinergic receptor subunits. The presence of these transcripts was confirmed using qRT‐PCR in stellate ganglia obtained from human and rat.

Conclusion

RNAseq transcriptomics has revealed differential gene expression profiles in PGSNs obtained from SHR and normotensive Wistar rats. These key transcripts were also present in human stellate ganglia. Taken together, these genes require further investigation for their role in sympathetic hyperactivity and dysautonomias.

Support or Funding Information

This project was funded by the Wellcome Trust OXION initiative (105409/Z/14/Z), the British Heart Foundation, NIH SPARC (OT2OD023848) and new innovator (DP2HL142045) initiatives.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Bilirubin Induces the Burning of Fat via the Nuclear Receptor PPARα
Authors: Gordon Darren M. , John Kezia , Trabbic Christopher J. , Luniwal Amarjit , Hankins Michael W. , Baum Justin , Stec David E. , Hinds Terry D.
Published: June 2021

Deposition fat in adipocytes has become key to understanding how obesity and insulin resistance impact morbidity and mortality. Several studies have shown a decreased amount of body fat in patients with increased plasma bilirubin, which was previously only thought to be a potent antioxidant. Increasing plasma bilirubin levels have been shown to play an integral role in weight loss and are preventive of diabetes as well as cardiovascular events. Our current studies reveal this phenomenon is potentially due to bilirubin binding to the fat burning nuclear receptor peroxisome proliferative‐activated receptor alpha (PPARα) to increase transcriptional activity. We have previously shown that wild‐type and PPARα knockout (KO) mice on a high‐fat diet that were treated with PPARα ligand fenofibrate or bilirubin, had lost the response in the KO mice. Also, the impact of bilirubin on glucose lowering ability as well as weight loss was reduced in the PPARα KO mice. To determine the mechanistic role of the bilirubin‐PPARα axis, we treated adipocytes with biliverdin, a precursor of bilirubin, and known PPARα agonist WY 14,643, and identified by chromatin immunoprecipitation (ChIP) that bilirubin‐PPARα activates the uncoupling protein UCP1 to induce the burning of fat. These all point to the importance and newfound role that bilirubin plays in the burning of fat in adipose to reduce accumulation via binding to PPARα.

Support or Funding Information

Source of Funding: This research was supported by the National Heart, Lung, and Blood Institute of the National Institutes of Health under Award Number K01HL125445 (T.D.H.).

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
MafB Overexpression Enhances Functional Beta Cell Mass
Authors: Leifer Aaron H. , Tessem Jeffery Sivert
Published: June 2021

Both Type 1 and Type 2 diabetes are characterized by loss of beta cell function and cell number. Therefore, any cure for diabetes will require increasing a patient's functional beta cell mass. Given that beta cell proliferation is extremely low after adolescence, we have sought to determine genetic mechanisms that can result in beta cell proliferation. Recent work has shown that the beta cell transcription factor Nkx6.1, which is essential for beta cell development, is sufficient to enhance glucose‐stimulated insulin secretion, improve beta cell survival and enhance beta cell proliferation. Additional studies have shown similar results for the transcription factor Pdx1. Given these results, we hypothesized that other transcription factors essential for beta cell development may have similar effects on enhancing functional beta cell mass. Here we present data that the transcription factor MafB, which is expressed in early stages of beta cell development, when overexpressed maintains glucose‐stimulated insulin secretion and cell survival, while enhancing beta cell proliferation. These data suggest that MafB may be useful in the process of expanding functional beta cell mass as a treatment for both major forms of diabetes.

Support or Funding Information

This research was funded by a BYU ORCA Grant to AHL.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
SGLT2 inhibition decreases oxygen consumption and increases oxygen tension in diabetic rats
Authors: Liu Zhizhao , Hall Elanore , Singh Prabhleen
Published: June 2021

Introduction

Diabetes is a major cause of chronic kidney disease. Recent data reports that sodium‐glucose cotransporter 2 (SGLT2) inhibitor, empagliflozin (EMPA), slows down the progression of diabetic nephropathy in type 2 diabetes mellitus. Here we investigate the effects of empagliflozin on kidney function, renal oxygen tension and oxygen consumption in streptozotocin‐induced diabetic rats (type 1 diabetes mellitus) to understand the underlying protective mechanism of empagliflozin on kidney disease.

Method

Age‐matched male Wistar rats were randomly divided into four groups: control, control+EMPA (30 mg/kg/day oral gavage), diabetes, and diabetes+EMPA. Two weeks later, GFR was estimated by clearance of 3H‐inulin. Total renal blood flow (RBF) was measured using an ultrasound probe placed around the left renal artery. Blood gas parameters and total oxygen consumption were analyzed on samples drawn from the left renal vein and femoral artery. In another set of experiments, intrarenal oxygen tension was measured in the renal cortex and medulla by oxygen microsensor.

Results

Compared with controls, diabetes displayed a slight higher RBF, decreased arterial oxygen saturation (85% VS. 92%) and decreased oxygen partial pressure (65 mmHg VS. 81 mmHg). Oxygen consumption increased in diabetes compared to controls (0.31 ml/min VS. 0.16 ml/min), and oxygen tension in renal cortex (39 mmHg VS. 54 mmHg) and medulla (35 mmHg VS. 40 mmHg) were lower in diabetes. Empagliflozin prevented the diabetes induced‐alterations in oxygen consumption (0.21 ml/min), and restored the decreased oxygen tension in renal cortex (45 mmHg), not in renal medulla (35 mmHg). Empagliflozin reduced 48% of the insulin requirement with 14% lower blood glucose level in diabetic groups.

Conclusion

Empagliflozin prevents diabetes‐induced alteration in kidney oxygen metabolism by reducing proximal renal glucose reabsorption which reduced total renal oxygen consumption while increased renal cortex oxygen tension. Empagliflozin reduced blood glucose levels in a T1DM animal model. These improvements provide insights into the mechanisms by which empagliflozin reduces the rates of clinically relevant renal end points. Additional molecular mechanisms and mitochondrial function in response to SGLT2 inhibition in diabetes is being investigated.

Support or Funding Information

American Diabetes AssociationVA Merit Award
The β‐ and γ Epithelial Na+ Channel (ENaC) Subunits Modulate the Shear Force Activation
Authors: Baldin Jan‐Peter Markus , Fronius Martin
Published: June 2021

The epithelial sodium channel (ENaC) is expressed in the kidney and vasculature and is important for blood pressure regulation. In the kidney and vasculature, ENaC is exposed to mechanical force such as shear force (SF) caused by the urine or blood flow. Canonical ENaC consists of three homologous subunits: α, β, γ and studies have shown that α‐ENaC plays an important role for the ability of the channel to respond to SF. Further evidence suggests that β‐and γ‐ENaC alone may be involved in mechanotransduction processes in arteries. Since little is known about the function of individual ENaC subunits and their regulation by SF, this project aims to characterize the role of β‐ and γ‐ENaC for SF sensation.

Human ENaCs were expressed as homotrimers (α, β or γ alone) or heterotrimers (αβ, αγ or βγ) in Xenopus oocytes. Two‐electrode voltage‐clamp experiments were performed to measure ENaC activity in response to a fluid stream used for the application of SF. SF responses were normalized and expressed as percentage.

Homotrimeric α‐ENaC showed an activation of 46 ± 7.4 (Mean ± SEM, p < 0.0001, n = 19) in response to SF, whereas homotrimeric β‐ or γ‐ENaCs did not respond to SF. In heterotrimeric αβ‐ENaC channels the activation by SF was 17 ± 3 (p < 0.0001, n = 19) and in heterotrimeric αγ‐ENaC 222 ± 35 (p < 0.0001, n = 17). Heterotrimeric βγ‐ENaC did not respond to SF.

Homotrimeric α‐ENaC form a functional channel that responds to SF whereas β‐ and γ‐ENaC did not. Heterotrimeric αβ‐ENaC showed a lower SF responds, whereas αγ‐ENaC showed a higher responds to SF. This experiments identify a modulatory role of β‐ and γ‐ENaC for the activation in response to SF. Therefore, ENaC dysfunction is observed in hypertension may be due to changes in β‐ and γ‐ENaC expression that could influence its activity in response to SF caused by the urine or blood flow.

Support or Funding Information

University of Otago Doctoral Scholarship

Department of Physiology

Royal Society Te Aparangi ‐ Marsden Fund

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Characterization of Urinary Exosomes from Diabetic Hypertensive db/db Mice
Authors: Schramm Whitney , Tuna Kubra , Chacko Kevin , Sanchez Victor , Ahmed Hamzah , Liu Lauren , Alli Abdel
Published: June 2021

Hypertension can occur before or after the onset of type 2 diabetes mellitus. The db/db mouse model is commonly used to study type 2 diabetes mellitus and its comorbidities including obesity and hypertension. Diabetic db/db mice develop salt‐sensitive hypertension after salt loading. Urinary exosomes are nano‐sized vesicles derived from cell types within the kidney that contain lipids, proteins, and nucleic acids. Recent studies showed urinary exosomes are useful biomarkers for kidney associated diseases including hypertension. We hypothesized the production of urinary exosomes is augmented and that their cargo is altered during the development of salt‐sensitive hypertension. Metabolic cage studies were performed to collect urine for the isolation of urinary exosomes from diabetic db/db mice and wild‐type littermate mice before and after salt‐loading. Western blot analysis was performed using validated antibodies to probe for the exosomal markers flotillin‐1, Hsp70, and annexin V in urinary exosomal lysates. NanoSight analysis showed an increase in the concentration of urinary exosomes from salt‐loaded, diabetic, hypertensive db/db mice and Western blot analysis revealed the enrichment of ENaC and MARCKS in these exosomes compared to non‐salt loaded diabetic db/db mice or healthy wild‐type littermate mice after salt‐loading. Future studies will investigate the physiological role of exosomal MARCKS in the development of diabetes associated hypertension.

Support or Funding Information

This research was supported by a National Institutes of Health grant K01 DK099617 (to A. A. Alli).

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
A Mathematical Approach for Gas Exchange in the Lungs; Balance Between Ventilation and Perfusion
Authors: PIZANO ALEJANDRO , CALVACHI PAOLA , GIRÓN FELIPE , CORDOVEZ JUAN MANUEL
Published: June 2021

Introduction

Chronic pulmonary diseases and respiratory infections remain as one of the most morbid and deadliest diseases in the world. Airway and environment play an important role in the etiology of these pathologies. The balance between oxygen and carbon dioxide exchange is the pillar of the respiratory system. The aim of this project is to understand the gas exchange in the lungs using a mathematical model that describes the dynamics in each alveoli, in order to evaluate the relationship between ventilation and perfusion.

Methods

A mathematical model was design based on the alveoli gas exchange and its relationship between ventilation and perfusion (V/Q). So, the lungs were divided into 9 segments, each one with different ratio according to their relative exchange area and the anatomical and physiological characteristics. The model assumed mass balance for O2 and CO2 and ideal gas law. Parameters for the model were determined according to data obtained in the literature. The model was implemented in MATLAB (The MathWorks®, Inc.) and the equations were solved to steady state.

Results

The model predicted gas concentrations and flows in different lung segments. There was an evident strong association between V/Q, and its mechanisms to compensate. The model showed the behavior of lungs with and without disease. One of the most important outcomes was the evidence of enviromental influence (i.e. altitude, polution) in the imparment of the small airways and its association with the cardiovascular system.

Conclusion

The mathematical model was helpful to understand the gas exchange dynamics. The model can be used to predict the interaction between ventilation and perfusion under different conditions, giving the possibility to estimate the efficacy of medical intervention. It can also shed some light on how to prevent and decrease the incidence of lung diseases.

Support or Funding Information

Research Group in Mathematical and Computational Biology (BIOMAC), Department of Biomedical Engineering, Universidad de los Andes, Colombia.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Developmental Differences in the Contribution of PKCβ Signaling to Chronic Hypoxia‐Induced Pulmonary Arterial Tone
Authors: Yan Simin , Sheak Joshua R. , Jernigan Nikki L. , Walker Benjimen R. , Resta Thomas C.
Published: June 2021

Vasoconstriction contributes to the pathogenesis of chronic hypoxia (CH)‐induced pulmonary hypertension in both neonates and adults. Although reactive oxygen species (ROS) have been implicated in this response in both age groups, it is not clear whether the subcellular source of ROS and signaling mechanisms involved are similar between adults and neonates. Based on preliminary data from our laboratory in neonatal rats, we hypothesized that PKCβ and mitochondrial ROS mediate enhanced basal pulmonary arterial tone following CH in both neonatal and adult rats. To test our hypothesis, we measured basal tone by videomicroscopy in isolated, pressurized small pulmonary arteries [~150 μm inner diameter (i.d.)] from normoxic and CH (12 d, 0.5 atm for neonates; 4 wk, 0.5 atm for adults,) rats following administration of the PKCβ inhibitor, LY‐333,531 (10 nM), the mitochondrial‐targeted antioxidant, MitoQ (1 μM), or vehicle. All experiments were performed in the presence of the nitric oxide (NO) synthase inhibitor Nω‐nitro‐L‐arginine (300 μM) to evaluate vascular smooth muscle tone independent of influences of endogenous NO. Pulmonary arterial tone was calculated as the percent difference in i.d. between Ca2+‐free and Ca2+‐containing conditions. Our results indicate that exposure to CH significantly (P < 0.05) enhanced basal tone in both neonatal and adult rats as compared to normoxic animals. Whereas LY‐333,531 significantly attenuated basal tone development in arteries from neonatal CH rats, PKCβ inhibition was without effect in arteries from either CH or normoxic adult animals. In contrast, MitoQ eliminated CH‐dependent increases in basal tone in arteries from both neonatal and adult rats. These findings suggest the contribution of PKCβ to regulation of CH‐induced basal pulmonary arterial tone is developmentally regulated, being important in neonates but not adults. Furthermore, mitochondrial ROS appear to be critically involved in basal tone development in pulmonary arteries from both neonatal and adult CH rats, with potential significance to the etiology of CH‐induced pulmonary hypertension.

Support or Funding Information

This work was supported by NIH grants R01 HL132883 (to T.C. Resta) and F31 HL131334 (to J.R. Sheak).

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Implementing a Dissection‐based Human Anatomy Laboratory Manual: An Assessment of Students' Use, Perceived Usefulness, and Resulting Laboratory Preparedness
Authors: Forster Victoria N. , Marrelli Kristina M. , Jadeski Lorraine C.
Published: June 2021

The University of Guelph provides year‐round dissection‐ and prosection‐based human anatomy courses to undergraduate students; the combined enrolment in laboratory‐based courses exceeds 1000 students per academic year. Given such large enrolment numbers, an ongoing challenge is to continue to provide a very high level of human anatomy education to students with current resources. Consequently, various educational tools are being developed to enhance the current human anatomy program. To specifically target the course and laboratory learning objectives, a dissection‐based human anatomy laboratory manual has been created and is under further development, with the goal of promoting student preparedness and self‐sufficiency in the laboratory. Detailed cadaveric, dissection‐based images with clear and simple dissection instructions are the fundamental qualities of the manual. This resource also incorporates active learning exercises including drawing, colouring, and labelling components. A pilot edition of the manual was released to students enrolled in the third‐year dissection‐ and prosection‐based courses in the fall semester of 2017 (HK*3401 and HK*3501). Data pertaining to the students' use and perceived usefulness of the manual, as well as their perceived preparedness for laboratory periods have been collected. Analysis of these data is ongoing, and will be used to gain insight for the future development of subsequent editions of the manual.

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 Resveratrol Reduces Bone Fracture Risk Associated with Neurodegenerative Disease
Authors: Alkhouli Mustafa F. , Hung Jun , Squire Michaela , Anderson Miranda , Castro Monica , Al‐Nakkash Layla , Broderick Tom L. , Plochocki Jeffrey H.
Published: June 2021

Neurodegenerative disorders like Alzheimer's disease are associated with significant decreases in bone mineral density (BMD) and elevated fracture risk in comparison to healthy individuals of the same age. Low BMD is largely attributable to decreased physical activity and systemic inflammation related to neurodegenerative processes. Here, we test the hypothesis that treatment with moderate exercise and resveratrol, a natural polyphenolic phytostilbene with anti‐inflammatory effects, will improve fracture resistance in a mouse model for Alzheimer's disease. Our 4‐month study examined bone mechanical and histological properties in 7‐month‐old male wild type mice (C57BL/6, n=10) and (age‐matched) neurologically compromised mice that express regulatory genes affecting amyloid‐beta plaque formation (3xTg‐AD, n=28). 3xTg‐AD mice were divided into groups treated with treadmill running 1 hour 5 days/week, 3g/100g dietary resveratrol, both, or neither (n=7 per group). We find treatment with exercise and resveratrol, in combination and alone, significantly improved ultimate force and post‐yield displacement in three‐point bending tests of the tibia (P < 0.05). We also find combined exercise and resveratrol treatment improved cross‐sectional geometric resistance to loading and maintenance of BMD in the tibia (P < 0.05). Bone stiffness was correlated with corrected total tissue fluorescence, an indicator of bone quality that measures advanced glycation end product accumulation in the tissue (r = 0.41, P < 0.01). Our findings suggest exercise and resveratrol may provide benefits to bone health in individuals with neurodegenerative‐related bone loss.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Forelimb Myology of the Kinkajou (Potos flavus)
Authors: Ahrens Heather E. , Walker Allison M.
Published: June 2021

The highly arboreal kinkajou (Carnivora: Procyonidae) exhibits many characteristics representative of its locomotor function, including hind foot reversal, diagonal sequence gait, and a prehensile tail. Detailed examination of the myology of P. flavus will aid in the understanding of the terrestrial‐arboreal locomotor gradient and can provide potential phylogenetic characters clarifying musteloid relationships. Here, we present the dissection of the forelimb of a fresh‐frozen male kinkajou and document the musculature via description and muscle maps. Noteworthy findings include the absence of m. biceps brachii caput breve, fused m. extensor carpi radialis, and a distinct humeral origin of the m. flexor digitorum superficialis. The latter finding contradicts a more recent suggestion that identification of a humeral origin was due to oversight and outdated nomenclature. Overall, the kinkajou resembles our primary comparative taxon, the closely‐allied and arboreal red panda (Ailurus fulgens). Similarities include the two insertion sites of the m. latissimus dorsi and the arrangement of the deep extensor compartment. This new description of the kinkajou is an important step in evaluating phylogenetic and functional patterns in the myology of carnivorans. However, further dissection of representatives of additional taxonomic and locomotor groups is necessary to differentiate what is typical of arboreal taxa from ancestral musteloid characteristics.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Molecular Mechanism of Transcriptional Regulation by Chromatin Reader Transcription Factor 19 (TCF19) during Metabolic Stress
Authors: Sen Sabyasachi , Das Chandrima
Published: June 2021

Changing nutritional environment confers epigenetic memories that often pre‐dispose the human body to certain metabolic disorders. Histone post‐translational modifications (PTMs), and their selective recognition by reader domain containing proteins constitute a transcription regulatory network that helps in maintaining cellular metabolic homeostasis, although the exact mechanism is still unclear. Here we have studied a novel glucose sensing and endoplasmic reticulum (ER) stress‐responsive transcription regulator, TCF19, which regulates transcription of key metabolic and stress‐responsive genes through recognition of histone PTMs. Through biochemical and biophysical techniques, we have found that TCF19 Plant Homeodomain (PHD) finger has a unique preference for the lysine 4 trimethylation of histone H3, which is a transcription activation modification. Using siRNA mediated TCF19 depletion in human hepatoma cell line HepG2 and primary human hepatocyte‐like cell HepaRG, we observed a global effect on metabolic pathways and interestingly the gluconeogenic genes were significantly upregulated. Through endogenous immunoprecipitation, we found that TCF19 interacts with components of a histone deacetylase complex NuRD (Nucleosome Remodelling and Deacetylase) and Chromatin immunoprecipitation studies indicate their co‐recruitment onto promoters of gluconeogenic genes under high glucose conditions, suggesting that the observed repression is possibly mediated in concert with NuRD complex. In‐depth analysis revealed that TCF19 also represses gluconeogenesis in response to insulin stimulation in both HepG2 and HepaRG cells. Deletion mutants of TCF19 lacking the PHD finger were unable to repress gluconeogenesis in response to insulin, underscoring the importance of histone modification mediated regulation of insulin action. We have also observed that TCF19 associates with several other transcription regulators of metabolic genes which have an important role in ER stress and cell survival and has been widely linked to type 2 diabetes progression. Overall, our study presents a novel transcription regulator that integrates metabolic (glucose), as well as hormonal (insulin) signal. These findings seek to expand our understanding of the role of epigenetic changes in metabolic regulation, and in the long run, provide an opportunity for therapeutic intervention to treat metabolic disorders like diabetes.

Support or Funding Information

The study was supported by research grant entitled Biomolecular Assembly, Recognition and Dynamics (BARD) (Grant 12‐R&D‐SIN‐5.04‐0103) by the Department of Atomic Energy (DAE), Govt. of India

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Pathogenesis Related Protein 5 Expression is Induced by 1,4‐dimethylnaphthalene treatment of Potato Meristems
Authors: Pirritano Maria , Campbell Michael
Published: June 2021

The agricultural compound 1,4‐dimethyl naphthalene (DMN) can be used to inhibit sprouting and prolong the storage of Solanum tuberosum. Potatoes treated with DMN exhibit characteristics that enable greater crop yields, including pathogen response, water retention, and greater shelf life. However, the molecular mode of action as to how DMN brings about these changes within the potato is not well understood. Two years of RNA‐seq data demonstrate extensive changes in gene expression within potato samples treated with DMN at different times throughout the year. Significant changes have been highlighted among a particular group of genes located on chromosome one. This group of genes codes for a pathogenesis‐related‐protein, PR5. As an extracellular protein, PR5 has an extensive signal transduction that responds to pathogens and abiotic stress. Among the PR5 family is a group of cytosine‐rich proteins called osmotins. Osmotin is a ubiquitous protein among several plant species and serves as a useful molecular marker for the systemic acquired resistance response, which is analogous to the innate immune system in plants. Gene expression measurements were taken over a six month period, during which dormancy was naturally breached. RNA‐seq data reveals 2‐3 fold increases between measurements taken before and as dormancy was breaking. After dormancy was breached, PR5 gene expression continued to rise significantly in comparison to previous measurements. These trends in gene regulation imply that the PR5 expression proceeds concurrently with sprout growth in DMN treated potatoes, and are related to the systemic changes seen from the outside of the potato. Phylogenetic analysis reveals the PR5 genes with the greatest changes in expression (7865 and 7870) demonstrate the greatest homology among their transcripts. Current analysis is being done using qPCR primers directed towards genes 7865 and 7870. Expression levels from qPCR should mirror the RNA‐seq data, in addition to demonstrate more immediate expression following DMN treatment. It has been hypothesized that gene expression spikes in prominent PR5 genes (7865 and 7870) will signify a broad molecular mode of action DMN plays inside S.tuberosum.

Support or Funding Information

Supported in part by a grant from the 1,4‐Group, Meridian, ID.

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