bluuebunny/crossref_metadata_2025 huggingface dataset:
Post‐MI Cardiac Remodeling and Malfunction in Mice Are Exacerbated by Cardiomyocyte‐restricted Ablation of the Uchl1 Gene
Authors: Wu Penglong , Li Yifan , Liu Jinbao , Wang Xuejun
Published: June 2021

Background

Ubiquitination is reversible and the reversed process, known as deubiquitination, is catalyzed by deubiquitinases (DUBs). UCHL1 is a DUB known to express highly and play an essential role in the nervous tissue; however, the (patho) physiological significance of UCHL1 in cardiomyocytes remains undefined. To fill this gap, we performed the present study, testing the hypothesis that UCHL1 in cardiomyocytes is dispensable for cardiac development but plays an important role in maintaining proteostasis in diseased hearts.

Methods and Results

Cardiomyocyte‐restricted Uchl1 knockout (CKO) was achieved by coupling Uchl1flox/flox with transgenic Myh6‐Cre in mice. Littermate mice with a genotype of Uchl1flox/flox, Uchl1flox/+, or transgenic Myh6‐Cre were used as the control (Ctl). By 2 months of age, the CKO did not cause discernible abnormal phenotype, with myocardial total ubiquitinated proteins and proteasomal DUBs (USP14 and UCH37) remaining unchanged. Myocardial infarction (MI) was then surgically induced in 2–3 months old mixed‐sex Ctrl or CKO mice and characterized at 4‐weeks post‐MI. Compared with sham controls, significant increases in myocardial UCHL1 proteins but not USP14 and UCH37 were detected in Ctl MI but not in CKO MI, demonstrating that post‐MI myocardial UCHL1 upregulation occurs primarily in cardiomyocytes. Echocardiography revealed significantly greater left ventricular (LV) internal diameters and smaller ejection fraction (EF) and fractional shortening in CKO MI vs. Ctrl MI. LV pressure‐volume relationship analyses also revealed significantly reduced EF, cardiac output, stroke work, and minimum dP/dt in CKO MI vs. Ctrl MI. Western blot analyses showed that MI induced significant increases in total myocardial ubiquitin conjugates and the increases were more pronounced in CKO MI.

Conclusions

UCHL1 in cardiomyocytes is dispensable for cardiac development but is upregulated in post‐MI hearts and protects against post‐MI cardiac remodeling and malfunction likely through supporting cardiac capability of maintaining proteostasis under a stress condition.

Support or Funding Information

This work is supported in part by NIH grants HL072166, HL085629, and HL13166.

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Evaluating Cardiorespiratory Responses to Slow Breathing in Young Healthy Individuals: FitBit “Relax Mode” versus RESPeRATE
Authors: Jette Evan D. , Adler Tessa E. , Niro Frank , Coovadia Yasmine , Jensen Dennis , Usselman Charlotte W.
Published: June 2021

Device‐guided slow breathing has been tested in clinical populations (e.g., hypertension, type II diabetes) with the goal of reducing blood pressure (BP) via a sensitization of the baroreflex. The FitBit's “Relax Mode” and the RESPeRATE device are commercially available devices which acutely reduce an individual's respiration rate and, by extension, BP. To the best of our knowledge no studies have directly compared the cardiorespiratory effects of these devices. The purpose of this study was to compare acute respiratory and BP responses to the RESPeRATE device (RESP), the FitBit's Relax Mode (FB). We hypothesized that RESP would result in greater decreases in respiratory rate than FB, leading to larger decreases in BP. We evaluated the responses to a single bout of RESP (15 min) and FB (5 min) in young (mean±SD age: 23±1 y), healthy (BMI: 23±3 kg/m2; mean arterial BP [MAP]: 82±8 mmHg) individuals (n=2 men, n=3 women). To normalize the duration of the stimuli, we compared the mean of the responses to FB to the mean of the last 5 min of RESP; the order of devices was randomized between subjects. Both devices were effective in reducing respiration rate from baseline (RESP: 11.1±3.5 to 5.6±0.7 breaths/min; FB: 11.2±1.8 to 7.3±0.3; main effect of slow breathing: p<0.01; effect of device: p=0.4). In contrast, tidal volume expansion increased from baseline during slow breathing (RESP: 0.70±0.33 to 1.41±0.50 L; FB: 0.61±0.17 to 1.20±0.59; main effect of slow breathing: p<0.01; effect of device: p=0.6). However, there was no change in minute ventilation from baseline levels (RESP: 7.0±1.8 to 7.8±3.0 L/min; FB: 6.7±1.8 to 8.7±4.2; main effect of slow breathing: p=0.1; effect of device: p=0.9), suggesting that the subjects did not hyperventilate during either slow breathing condition. MAP decreased from baseline during slow breathing (RESP: 82±8 to 80±8 mmHg; FB: 82±8 to 81±7; main effect of slow breathing: p=0.01; effect of device: p=0.9). Conversely, a significant slow breathing by device interaction (p=0.05) revealed that diastolic BP (DBP) was reduced from baseline only in the RESP condition (69±7 to 67±8 mmHg, p<0.01); FB was not associated with a reduction in DBP (69±8 to 69±8 mmHg, p=0.2). Our preliminary data indicated that while RESP reduced respiratory rate similarly to the FB, RESP may be more effective than FB at acutely reducing DBP in young healthy adults.

Support or Funding Information

This project was supported by a Natural Sciences and Engineering Research Council Discovery Grant (CWU). TEA & YC were supported by the McGill Department of Kinesiology and Physical Education Graduate Excellence Fellowship.

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Epidural stimulation improves cerebral autoregulation and autonomic cardiac control in humans with spinal cord injury
Authors: Saleem Saqib , Darrow David A , Netoff Theoden I , Tzeng Yu‐Chieh , Samadani Uzma , Krassioukov Andrei , Phillips Aaron
Published: June 2021

Spinal cord injury (SCI) results in impaired cerebrovascular buffering of blood pressure changes and cardiovagal baroreflex sensitivity. These impairments appear to be at least partially the result of disrupted spinal autonomic pathways after SCI, and likely contribute to high rates of unstable blood pressure control, orthostatic intolerance, vascular‐cognitive impairment and high risk of stroke in this population. Acute spinal cord epidural electrical stimulation has recently been shown to activate the sympathetic nervous system. We therefore reasoned that acute epidural spinal cord stimulation could improve cerebrovascular buffering of blood pressure as well as baroreflex functionality after SCI. We tested this hypothesis by assessing the beat‐by‐beat relationships between heart rate, mean arterial blood pressure, and middle cerebral artery blood velocity in several individuals with SCI at rest and with acute epidural electrical stimulation after surgical implantation. We found epidural stimulation acutely improved cerebrovascular buffering of blood pressure and cardiovagal baroreflex function in people with SCI, raising the possibility that this intervention may be a viable therapy for improving cerebrovascular health in this population.

Sponsors:

Minnesota State Office of Higher Education.

Natural Sciences and Engineering Research Council of Canada

Canadian Institutes of Health Research

Clinical Neurosciences Pilot Research Fund Program

Libin Cardiovascular Institute

Hotchkiss Brain Institute

Compute Canada

Support or Funding Information

Natural Sciences and Engineering Research Council of Canada, Canadian Institutes of Health Research, Libin Cardiovascular Institute, Hotchkiss Brain Institute, Compute Canada

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Heart Rate Differences in Males and Females during Similar Physiological Work
Authors: Trujillo Elizabeth , Rascon Jozelyn , Maddox Jessica , Morales‐Acuna Francisco J , Gurovich Alvaro N
Published: June 2021

Physiological work refers to the amount of energy that is expended during exercise and it is related to exercise intensity. In general, exercise intensity assessment includes heart rate (HR), rate of perceived exertion (RPE), power output (PO), oxygen consumption (VO2), and blood lactate (BL) levels. These measurements are used for both males and females to evaluate exercise intensity despite their physiological differences. The purpose of this study was to determine if there are differences between sexes in different exercise intensity models when using the same physiological work. Thirty young, healthy individuals (15 males) were recruited with ages ranging from 19 to 33 y. The individuals were scheduled for two (2) lab visits within 48–72 hours of each other. A graded exercise test (GXT) on a stationary bike was conducted during the first visit. At the end of each stage, the RPE, PO, VO2, and BL were taken. After the GXT was completed, peak PO and VO2max were recorded. BL during the GXT was used to determine 3 5‐min steady‐state workloads (low: 0–2 mmol/l; medium: 2–4 mmol/l; and high: >4 mmol/l) as physiological work for the second test. The measures obtained at the end of each steady‐state physiological workload were HR, %HRmax (HR/(220‐age)), RPE, PO, %POmax, VO2, %VO2max, and BL. A two‐way repeated measurements ANOVA was performed to compare all exercise intensity variables obtained during the second test between males and females (α=0.05). Females had higher HR and %HR than males in all 3 physiological workloads (116±14 vs. 97±14 bpm and 68.7±7.5 vs. 59.4±8.8%, 143±16 vs. 128±20 bpm and 84.9±6.2 vs. 75.4±6.7%, and 164±16 vs. 149±17 bpm and 97.0±3.7 vs. 91.1±7.3%, respectively, all p<0.05). Interestingly, females had a higher %VO2max only during the lower physiological workload (554.±9.8 vs. 45.6±8.4%, p<0.05). Throughout the stages of Low (0–2mmol/l), Medium (2–4mmol/l), and High (>4mmol/l) physiological workloads %PO, RPE, and BL did not differ between sexes. Unlike previous reports, our study found that RPE was similar for both sexes within the same %PO. Our data demonstrates that HR and %HR should not be used interchangeable in males and females, especially when physiological work rate is the critical factor for increased performance.

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
High Intensity Training Impacts on Prostate Cancer Induced Cardiac Atrophy in a Pre‐Clinical Model
Authors: Baumfalk Dryden Ray , Opoku‐Acheampong Alexander , Caldwell Jacob , Ade Carl , Musch Timothy , Behnke Bradley
Published: June 2021

Background

Recent evidence suggests prostate cancer independent of treatment has atrophic effects on whole heart and left ventricular (LV) mass which are associated with reduced endurance exercise capacity. In conjunction, preliminary evidence has shown that moderate exercise training mitigated cardiac mass loss in prostate tumor‐bearing rats. Using a pre‐clinical orthotopic model of prostate cancer, we tested the hypothesis that high intensity training could prevent the associated cardiac atrophy seen in prostate cancer. We also investigated whether high intensity training would attenuate any detriments seen in LV function with prostate cancer.

Methods

Dunning R‐3327 AT‐1 prostate cancer cells (1×105) were cultured and harvested for injection in 0.1ml of physiological saline solution in the ventral lobe of 5–6‐month‐old male Copenhagen rats (n=24). These animals were randomized into 2 groups, Tumor Bearing Exercise (TBEX, n=15) or Tumor Bearing Sedentary (TBS, n=8). After 5 days of recovery, TBEX animals began exercise on a treadmill at 25m/min with a 15° incline for 45–60 min/day based on tolerance for 18±2 days. Pre‐surgery (Pre), and post exercise training (Post) animals underwent echocardiographic evaluation using the parasternal short axis view to examine ventricle dimensions via a commercially available system (Vivid S6, GE Health Care).

Results

There were no significant differences in tumor mass between groups (TBEX 3.4±0.7g, TBS 2.9±0.6g p=0.31), or body weights (TBEX 317±5g, TBS 333±7g p=0.20). Heart to body mass ratio was lower in SEDTB group compared to EXTB (2.3±0.1mg/g, 2.5±0.1mg/g, p=0.04). LV to body mass ratio was also lower in the SEDTB group (1.64±0.1mg/g, 1.81±0.1mg/g, p=0.04). There were no significant differences for Pre‐measures of LV function between groups. From Pre‐Post EXTB had significant increases in SV (0.64±0.04ml, 0.76±0.05ml, p=0.03) while SEDTB had no significant difference (0.68±0.03ml, 0.69±0.03ml, p=0.96).

Conclusion

This study suggests that high‐intensity exercise can improve LV function and increase LV mass, versus sedentary counterparts, with prostate cancer. Given cardiac dysfunction often manifests with conventional anti‐cancer treatments, a short‐term high‐intensity training program, prior to treatment, may improve patient outcome.

Support or Funding Information

American Cancer Society (RSG‐14‐150‐01‐CCE)

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Cognitive and Vascular effects of Exercise in patients with Alzheimer's Disease
Authors: Pedrinolla Anna , Fonte Cristina , Smania Nicola , Schena Federico , Venturelli Massimo
Published: June 2021

Object

To investigate exercise‐induced effect on cognitive and vascular functions in people with Alzheimer's Disease (AD) and compare it with the standard cognitive therapy.

Methods

Fifty‐five people with AD (77.6±6.2 years; 23.5±4.8 MMSE) were recruited and randomly assigned to Cognitive Treatment (CT, n=23) or Exercise Treatment (ET, n=22). All subjects performed 72 treatment sessions lasting 90 minutes, 3 times a week. ET included: moderate to high intensity aerobic and strength training. CT included multi‐modal stimuli (visual, verbal, auditive). Before (T0) and after (T1) the 6‐month treatment global cognitive function was measured by means of Mini‐Mental State Examination (MMSE). Vascular function was measured by means of Flow‐Mediated Dilation (FMD, %) and Passive‐Limb movement (PLM, calculating the variation in blood flow: ΔPeak; and Area Under the Curve: AUC) tests. A blood sample was also taken and analyzed for Vascular Endothelial Growth Factor (VEGF)

Results

MMSE did not change after CT nor ET and post‐treatment between‐groups (BG) difference (Diff. of means) were not found. CT group did not exhibit any change in vascular function while ET group significantly increased FMD% (3.64, p=0.003; BG Diff. of means: 4.615, p<0.001), Δpeak (135.88, p=0.004; BG Diff. of means: 160.46, p<0.001) and AUC (38.16, p=0.050; BG Diff. of means: 62.36, p=0.002). VEGF increased significantly in ET group only (8.97, p=0.047; BG Diff. of means: 12.7, p=0.004).

Conclusion

Results from this study show that both, standard cognitive therapy and exercise help in preserving cognitive function in people with AD. However, only exercise seems to offer the appropriate stimuli to improve also vascular function in this population. Importantly, exercise has a polyhedral and multi‐situ action since the whole organism, brain included, must respond adaptatively when activated during exercise. Most of the exercise‐induced responses include upregulation of growth factors at muscular, vascular and cerebral level as well.

Support or Funding Information

This work was supported by PRIN 2010KL2Y73

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
The Effects of Chronic Electrical Stimulation Evaluation Functional and Electrical Properties of Muscle in a Small Group of Patients with Congenital Muscle Disorders
Authors: Vasylieva Oksana , Sader Abbas
Published: June 2021

Background

In the case of Congenital Muscle Disorders like Myotonic Dystrophy type 1 (DM1) the rehabilitative interventions have always been aimed at muscle strengthening, increasing of fatigue resistance and improving of aerobic metabolism efficiency whereas the electrical membrane fault has always been addressed pharmacologically. Neuromuscular electrical stimulation (NMES) is a useful therapeutic tool in sport medicine and in the rehabilitation of many clinical conditions characterized by motor impairment such as stroke, cerebral palsy and spinal cord injury.

The aim of our pilot study was to evaluate the effects of chronic electrical stimulation both on functional and electrical properties of muscle in a small group of patients with condenital muscle disorders.

Materials and methods

five DM1 patients and one patient with Congenital Myotonia (CM) performed a home electrical stimulation of the tibialis anterior muscle lasting 15 days with a frequency of two daily sessions of 60 minutes each. Muscle strength was assessed according to the MRC scale (Medical Research Council) and functional tests (10 Meter Walking Test, 6 Minutes Walking Test – MWT and Timed Up and Go Test – TUG test) were performed. We analyzed the average rectified value of sEMG signal amplitude (ARV) to characterize the sarcolemmal excitability.

Results

After the treatment an increase of muscle strength in those DM1 patients with a mild strength deficit was observed. In all subjects an improvement of 10 MWT was recorded. Five patients improved their performance in the 6 MWT. In TUG test 4 out of 6 patients showed a slight reduction in execution time. All patients reported a subjective improvement when walking. A complete recovery of the normal increasing ARV curve was observed in 4 out of 5 DM1 patients; the CM patient didn't show modification of the ARV pattern.

Conclusions

NMES determined a clear‐cut improvement of both the muscular weakness and the sarcolemmal excitability alteration in our small group of DM1 patients. Therefore this rehabilitative approach, if confirmed by further extensive studies, could be considered early in the management of muscular impairment in these patients. An attractive hypothesis to explain our encouraging result could be represented by a functional inhibition of small conductance calcium‐activated potassium channels expressed 3 (SK3) in muscle of DM1 subjects.

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Effect of the Menstrual Cycle on Vasodilatory Responses to Standard and Enhanced Flow‐ Mediated Dilation Stimuli
Authors: Khaksar Ava , Adler Tessa Evangeline , Coovadia Yasmine , Usselman Charlotte Willemina
Published: June 2021

Flow‐mediated dilation (FMD) is a clinical index of endothelial health that has not revealed consistent differences between the sexes or the phases of the menstrual cycle, both of which are known to affect endothelial function. Since estradiol varies with the menstrual cycle and up‐regulates nitric oxide, a primary mediator of the FMD response, it is surprising that past studies have not revealed consistent associations between FMD and menstrual cycle phase. It may be that the standard FMD is not sensitive enough to reflect the subtle changes in endothelial function which occur across the menstrual cycle. Recent data suggest that enhanced FMD stimuli provide a potential means for detecting subtle changes in endothelial function that are not observed using the standard FMD. We hypothesized that an enhanced FMD stimulus, as elicited by 3 min of forearm occlusion concomitant with isometric handgrip exercise at 30% of maximal voluntary contraction (IEFMD), will be more responsive to menstrual cycle‐induced changes in estradiol (and therefore vasodilatory responsiveness) than the standard 5‐min FMD in young healthy women. We compared reactive hyperemic responses (%FMD) between FMD protocols (i.e. standard FMD vs. IEFMD) in eumenorrheic women (n: 4; age: 21±1.4 yrs, range: 19–22 yrs, BMI: 23.3±3.2 kg/m2, range: 20.5–26.4 kg/m2, cycle length: 29.8±1.7 days, range: 28–32 days) during the low‐estradiol early follicular phase of the menstrual cycle (EF; days 1–5) and the high‐estradiol late follicular phase (LF; days 10–14). As expected, we observed a greater %FMD in response to the IEFMD relative to the standard FMD in the EF phase (19.4±4.6% vs. 9.0±1.6% respectively, p<0.05). Similarly, in the LF phase we observed a trend toward a greater %FMD in the IEFMD versus the standard FMD (13.5±5.8% vs. 7.0±0.04%, p=0.1). However, a two‐way ANOVA demonstrated no main effect of menstrual cycle phase (p=0.5), or FMD stimulus (p=0.7) on %FMD (phase x stimulus interaction: p=0.9). Therefore, these preliminary data do not support our hypothesis that an enhanced FMD stimulus involving isometric handgrip exercise is more sensitive than the standard FMD in detecting changes in endothelial function across menstrual cycle phases in young healthy women.

Support or Funding Information

This project was supported by a Natural Sciences and Engineering Research Council Discovery Grant (CWU). TEA & YC were supported by the McGill Department of Kinesiology and Physical Education Graduate Excellence Fellowship.

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
The Effects of Prolonged Mechanical Ventilation on Diaphragm Arteriolar Response to Alpha‐Adrenergic Agonists
Authors: Horn Andrew Gary , Baumfalk Dryden R , Opoku‐Acheampong Alexander B , Kunkel Olivia N , Caldwell Jacob T , Poole David C , Behnke Bradley J
Published: June 2021

Introduction

Mechanical ventilation (MV) is a life‐saving intervention and is employed in Intensive Care Units across the world. Previous work has shown a substantial time‐dependent reduction in diaphragmatic blood flow and O2 delivery with MV that may contribute to ventilator‐induced diaphragm dysfunction. However, the precise mechanism responsible for these alterations in blood flow are unknown. Given the reduction in diaphragm blood flow with prolonged MV, we tested the hypothesis that prolonged MV (e.g. 6 hours) enhances diaphragm arteriole contractile responses to alpha‐adrenergic agonists.

Methods

Female Sprague Dawley rats (5–8 mo) were divided into spontaneous breathing (SPB; n= 10) and MV (n= 3). Following SPB and 6 hours of MV, diaphragm arterioles (~200mm diameter, ~2mm in length) were isolated, cannulated, and pressurized to develop spontaneous tone. Thereafter, contractile responses to cumulative doses of norepinephrine (NE) and phenylephrine (PE) (10−9 to 10−4M) were determined.

Results and Conclusion

From this preliminary data, vasoconstrictor responses to NE, and PE in diaphragm arterioles were not different after prolonged MV (% max constriction, NE=23.3± 20.47, PE=16.8± 16.41 compared to SPB (% max constriction, NE= 37.5± 16.71 (P = 0.27); PE= 38.03± 21.76 (P =0.098). Between SPB and MV % max constriction with NE, there was mean difference of 14.2%, and 21.2% with PE. Additional studies are under way to increase the sample size herein. These investigations will seek to resolve the impact of prolonged MV on the diaphragm resistance vasculature and responsiveness to these (i.e. NE, PE) and other vasoactive mediators such as Angiotensin‐II and Endothelin‐1 that may be upregulated with MV as well as potential structural alterations.

Support or Funding Information

NIH (1 R15 HL137156‐01A1)

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Effect of time of day on heat‐induced hyperventilation and cerebrovascular response during exercise in the heat
Authors: Tsuji Bun , Nakane Akari , Ohno Mizuki , Inoue Yukiko
Published: June 2021

Hyperthermia during exercise leads to increases in minute ventilation independently of metabolic factors. This heat‐induced hyperventilation results in excessive elimination of CO2 from the body, leading to reduced arterial CO2 pressure (PaCO2) and the resultant cerebral hypoperfusion, which may underlie central fatigue during hyperthermia and impaired exercise performance in the heat. We recently reported that time of day has no effect on time course of hyperventilatory response during exercise in the heat, despite the higher core temperatures in the evening (Tsuji et al. Am J Physiol 2016). This was likely due to diurnal variation in the control of ventilation in response to rising core temperature. However, it remains unclear whether cerebrovascular response during exercise in the heat is affected by time of day. This study thus examined the effect of time of day on respiratory and cerebrovascular responses during prolonged exercise in the heat. Eleven healthy subjects performed a cycle exercise at 50% of peak oxygen uptake in the heat (35°C ambient temperature and 40% relative humidity) in the morning (0830) and evening (1830). The exercise was terminated when the exercise duration reached 60 min, esophageal temperature reached 39.0°C or the subject could no longer pedal at 60 rpm. Esophageal temperature and mean arterial pressure were significantly higher in the evening than morning (both P < 0.01), but time of day had no significant effect on minute ventilation, estimated PaCO2, middle cerebral artery blood velocity and cerebral vascular conductance. The ventilatory sensitivity to rising core temperature (i.e., slope of the esophageal temperature‐ventilation relation) was significantly greater in the evening than morning. However, sensitivities of PaCO2 and cerebrovascular responses to rising core temperature were unaffected by time of day. In conclusion, present results suggest that time of day has no effect on the time course of hyperventilation, PaCO2 and cerebral blood flow response during prolonged exercise in the heat.

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
ROS‐mediated NRF2 Activity in Rats Exposed to Acrolein
Authors: Joseph Mathew , Haydari Sedi , Ranganna Kasturi , Newaz Mohammad A. , Yousefipour Zivar
Published: June 2021

Objectives

Environmental exposure to acrolein has been linked to impaired vascular reactivity and development of cardiovascular diseases. Generation of free radicals and formation of adduct with critical proteins have been proposed as the possible mechanisms involved but the precise mechanism of acrolein mediated vascular alteration remains elusive. Peroxisome proliferator‐activated receptor gamma (PPARγ) has been implicated in the pathology of diseases involving inflammation. The nuclear factor erythroid 2‐related factor 2 (Nrf2) is an important regulator of adaptive response to oxidative stress. Nrf2 activity is regulated partially through Keap1 protein. Keap1 binding to Nrf2 will keep the transcription factor in the cytoplasm. This study hypothesizes that exposure of rats to acrolein alters activation of Nrf2 through modification of Keap1 and/or modification of Nrf2.

Design and method

Male Sprague‐Dawley rats (200–250 gm) were exposed to acrolein (1 mg/kg, gavage, 1 week) alone or in combination with rosiglitazone (Roz: PPARγ ligand; 10 mg/kg, gavages, 10 days). At the end of the treatment period, animals were sacrificed and isoprostane level was measured in urine as an indication of oxidative damage. ELISA and western blot analysis were used to measure changes in the expression/activity of Nrf2, Keap1 and HO‐1 in liver tissue.

Results

Our results indicated increased generation of ROS in rats treated with acrolein. Addition of rosiglitazone ameliorated the effect of acrolein on ROS generation. Acrolein increased expression/activity of Nrf2 and HO‐1, while reduced expression of Keap1. Addition of rosiglitazone further increased expression/activity of Nrf2 and HO‐1 and reduced Keap1.

Conclusions

Based on present data we are concluding that effect of acrolein on rat is partially due to the increased generation of ROS and subsequent alterations of Nrf2, Keap1 and HO‐1. These changes were further amplified with addition of rosiglitazone.

Support or Funding Information

National Institute Of General Medical Sciences of the National Institutes of Health, Award Number SC3GM103746.

Research Center in Minority Institutions (RCMI), Molecular Biology Core facility of TSU.

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Effect of Photobiomodulation on Erythema and Edema following Dental Prophylaxis in Dogs
Authors: Watson Andrea H , Brundage Cord M
Published: June 2021

Photobiomodulation has been documented as a mitigator of wound erythema and edema in human and veterinary patients. To determine the effect of photobiomodulation therapy in male and female canine (Canis lupus familiaris) patients following routine dental prophylaxis, a low energy GaAlInP diode laser with a continuous 650 nm wavelength and 100 mW power output was used. Immediately following the dental procedure, each canine patient received irradiation (10 J/cm2) based on one of three randomly assigned treatment groups. One group (n = 7) received four treatment points of irradiation on the gingiva of the right upper and lower dental arcade, another group (n = 8) received four treatment points of irradiation on the gingiva of the left upper and lower dental arcade, and the other group (n = 9) received a mock gingiva treatment without irradiation. Erythema and edema along the gingival surface of each canine was scored 24 hours after treatment by a blinded veterinary evaluator. Using a composite evaluation there was significantly higher inflammation scores of the lower right dental arcade for the untreated control group relative to both the left side treated group (p = 0.025) and the right side treated group (p = 0.017). When looking at erythema specifically, there was significant reduction in erythema in the left side treated group relative to the control group (p = 0.049) for the lower left dental arcade. When comparing males and females, males had higher erythema (p = 0.034) and edema (p = 0.014) scores as well as composite inflammation (p = 0.026) score than females in the left side treated group at the location of the left dental arcade. No other sex associated differences were noted. Despite patient variability in this clinical study, receiving a single photobiomodulation treatment demonstrated a minor to discernible reduction in erythema and edema following canine dental prophylaxis.

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Isoalantolactone inhibits LPS‐induced inflammatory responses in macrophages
Authors: Wang Ping‐Chun , Li Chia‐Yang
Published: June 2021

Isoalantolactone (ISO) is a main sesquiterpene lactone isolated from Inula helenium, which has been reported to have anti‐inflammatory and anti‐oxidative effects. However, the effect of ISO on LPS‐induced inflammatory responses has not been extensively studied. Herein we examine the anti‐inflammatory effects of ISO by LPS‐activated murine macrophages, J774A.1 cells. Cell viability was examined by MTT assay. The production of nitric oxide (NO) was analyzed using Griess reagent assay. The expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase‐2 (COX‐2) was detected by Western blot. The secretion of pro‐inflammatory cytokines including tumor necrosis factor‐alpha (TNF‐α) and interleukin‐6 (IL‐6) was determined using ELISA. Our experimental results showed that dose of ISO under 10 μM had no toxicity in J774A.1 cells. To avoid the toxic effect of ISO, the dose of ISO used in this study was less than or equal to 10 μM. Our experimental results indicated that ISO inhibits the production of NO, decreases the expression of iNOS and COX‐2, and attenuated the secretion of TNF‐α and IL‐6 in J774A.1 cells. Collectively, our experimental results demonstrated that ISO suppresses LPS‐induced inflammatory responses in macrophages. These results suggest that ISO might has potential against LPS‐induced overactive inflammation.

Support or Funding Information

This study was supported by the Ministry of Science and Technology, Taiwan, R.O.C. (Grant No. MOST 107‐2320‐B‐037‐019).

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Renal collecting duct plasticity revealed by intercalated cell lineage tracing
Authors: Picard Nicolas , Hennings J. Christopher , Godefroy Marion , Trepiccione Francesco , Huebner Antje K. , Eladari Dominique , Huebner Christian
Published: June 2021

The connecting tubule and collecting duct in the distal nephron play an essential role for acid‐base and NaCl homeostasis. Their epithelium comprises two main cell types, i.e. principal cells and intercalated cells (IC). At least two types of IC, type A‐IC and type B‐IC are distinguished. While A‐IC express the V‐type ATPase at their apical side, it localizes basolaterally in B‐IC. Thus, A‐IC can actively secrete H+, while B‐IC can mediate bicarbonate secretion via apical pendrin. Adaptation to a change in acid/base status is partly achieved by varying the numbers of A‐IC and B‐IC cells. For example, a chronic metabolic acidosis or LiCl administration promote an increase in A‐IC while the number of B‐IC is decreased. Based on these findings it is assumed that the plasticity of the distal nephron might be explained in part by a conversion of B‐IC into A‐IC or principal cell to A‐IC or vice versa.

To test this hypothesis, we crossed a mouse reporter line with a Cre‐line either specific for A‐ or B‐IC. The expression of Cre‐recombinase results in the excision of a floxed STOP cassette, thus, inducing constitutive expression of TdTomato. In both mouse models, TdTomato positive cells were characterized by confocal microscopy and immunostaining with IC and principal cell markers. In untreated adult mice, the fluorescent tag was restricted to each IC population with no leakiness in PC or other renal epithelial cells. In chronic metabolic acidosis induced by NH4Cl loading or during LiCl treatment, no transition of B‐IC TdTomato+ cells to A‐IC was observed. In a similar setting of metabolic alkalosis, A‐IC tomato‐td mice did not transform in B‐IC when challenged with NaHCO3 load. In the recovery of LiCl treatment in A‐IC tagged mouse, we could detect that some principal cells acquire the TdTomato mainly in the medullary collecting duct.

In conclusion, A‐ and B‐IC lineage tracing in the mouse suggest that conversion either from A‐to B‐IC or from B‐ to A‐IC does not occur in the adult mouse kidney. We observed the transition from A‐IC to principal cells in the medulla which suggests a particular plasticity between this two cell types.

Support or Funding Information

NP is funded by Agence National Recherche grant ANR‐16‐CE14‐0031 and ANR‐15‐CE14‐0024. CH is funded by DFG grant HU 800/7‐2

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Intercalated Cell Claudin‐4 knockout mice display abnormal renal sodium and potassium conservation and hypercalciuria
Authors: Cordat Emmanuelle , Ullah AKM Shahid , Fernandes Daphne , Dimke Henrik , Alexander R. Todd
Published: June 2021

Distal Renal tubular acidosis is a disease characterized by the inability to acidify the urine below a pH of 5.5, metabolic acidosis, hypokalemia and hyperchloremia. It is caused by mutations in genes encoding the v‐B1‐H+‐ATPase, the cytosolic carbonic anhydrase II or the kidney anion exchanger 1 (kAE1) in the renal collecting duct (CD). We recently discovered that kAE1 physically and functionally interacts with the tight junction protein claudin‐4 (Cldn‐4). This protein is expressed in principal (PC) and intercalated cells (IC) and forms a paracellular chloride pore and sodium barrier. With the aim to decipher the physiological role of the kAE1/Cldn‐4 interaction, we generated and characterized IC‐specific Cldn‐4 KO mouse. The knockout mice displayed a 30% reduction in Cldn‐4 abundance in isolated CD, in agreement with the reported IC/PC ratios. Although the KO animals developed normally and did not display an obvious phenotype, they presented a higher urinary calcium concentration at steady state than control animals. Feeding the mice a low NaCl diet caused the Cldn‐4 KO animals to have a more alkaline and dilute urine than control animals. Upon acid challenge, the Cldn‐4 KO mice excreted less urinary sodium and potassium compared with control animals. These results suggest that tight junction Cldn‐4 contributes to the maintenance of appropriate electrolyte and acid‐base balance.

Support or Funding Information

This work was funded by the Canadian Institutes of Health Research, the Kidney Foundation of Canada, the Women and Children's Health Research Institute (supported by the Stollery Children's Hospital Foundation), Alberta Innovates and the Canada Foundation for Innovation

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
The Evolution of Air‐breathing Revised
Authors: Damsgaard Christian , Baliga Vikram B.
Published: June 2021

The evolution of air‐breathing represents one the most pronounced changes in the cardio‐respiratory physiology of vertebrates. While a lot is known about the physiological transitions required for air‐breathing evolution, there is limited information available on the evolutionary dynamics in breathing mode. Previous analyses suggest 34–67 independently origins of air‐breathing within extant vertebrates, but nothing is known about when in geological time air‐breathing originated or if air‐breathing has been secondarily lost. This study aimed to 1) provide more robust estimates on the number of air‐breathing origins, 2) identify if air‐breathing has been secondarily lost within clades of air‐breathing fishes, and 3) identify the timing of these events. To do this, we used an updated list of air‐breathing fishes, a fully resolved, time‐calibrated fish phylogeny and Bayesian phylogenetic comparative methods. We show that air‐breathing evolved 74–80 times within extant vertebrates, which is significantly higher the previously proposed 34–67 independent origins. Further, we show strong support for 7 secondary losses of air‐breathing, where pure water‐breathing was adapted from an air‐breathing ancestor. Finally, we show that the majority of air‐breathing clades radiated within the last 65 million years. This study adds novel dimensions to the evolution of air‐breathing and identifies an unprecedented evolutionary plasticity in breathing mode, where air‐breathing has been gained and lost repeatedly during the evolutionary history of vertebrates.

Support or Funding Information

Christian Damsgaard is supported by the Carlsberg Foundation.

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Time of Year Has No Effect on Indicators of Insulin Resistance in Fasting Horses
Authors: Martinez‐Flores Brenda , Harms Abigail Rachel , Mofatt Cheyenne N. , Paquin Zachary W. , Guild Ayla , Johnson Kathryn M.S.
Published: June 2021

Laminitis is a severe equine lameness associated with obesity and obese‐related conditions, such as insulin resistance. Extremely painful, laminitis typically manifests in horses in the spring and/or summer. It is unclear if insulin resistance is the mechanism that initiates the seasonal onset of laminitis or even if insulin resistance is altered seasonally in horses. To determine if insulin resistance varies throughout the year in horses, blood was collected via the jugular vein, from overnight fasted horses (n=35), from four different breeds with varying known risks for obesity‐related conditions and laminitis, (stock horses, n=11; draft/draft crosses horses, n=7; Saddlebreds, n=7; and Welsh ponies, n=10) every 60 days for a year (September 2015–July 2016). Fasting insulin resistance was determined by plasma glucose to insulin ratio (GIR=[fasting plasma glucose]/[fasting plasma insulin]) and quantitative insulin sensitivity check index (QUICKI=1/(log[fasting plasma glucose]+log[fasting plasma insulin])), with lower levels of each indicating increased insulin resistance. Neither time of year (MANOVA, F5,23=0.911, p=0.491; F5,23=1.28, p=0.307) nor breed (F5,27=0.417, p=0.091; F5,27=2.43, p=0.087) had an effect on GIR and QUICKI. Therefore, no difference in insulin resistance was detected in fasting horses throughout the year. GIR and QUICKI are commonly used in clinical settings; however, it is possible that these indicators may not accurately reflect the insulin status in horses, due to the fasted states required by these measurements. Other metrics of insulin sensitivity may need to be implemented to determine if insulin resistance is a precursor to the onset of seasonal laminitis.

Support or Funding Information

This work was supported by the Biomedical Scholars program at Beloit College.

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Differential Effects of Morphine on a Dispersed Respiratory Network to Induce Respiratory Depression in Awake Mice
Authors: Varga Adrienn G. , Reid Brandon T. , Kieffer Brigitte L. , Levitt Erica S.
Published: June 2021

Respiratory depression is the main cause of death from an opioid overdose. The reduction in respiratory rate is the result of activation of mu opioid receptors in respiratory centers, such as the pontine Kölliker‐Fuse nucleus and the medullary pre‐Bötzinger complex. The goal of this study was to directly compare the relative contribution of opioid‐sensitive neurons in the Kölliker‐Fuse nucleus and the pre‐Bötzinger complex to respiratory depression caused by systemic administration of the opioid agonist morphine in adult mice. We conditionally knocked out mu opioid receptors using virally mediated Cre expression in mice with floxed mu opioid receptors. Whole‐cell patch clamp recordings in acute brain slices showed that this approach successfully eliminates mu opioid receptor‐mediated outward currents from Kölliker‐Fuse nucleus neurons. Next, using plethysmography, we found that deletion of mu opioid receptors from either the Kölliker‐Fuse nucleus or pre‐Bötzinger complex attenuated the decrease in respiratory rate induced by an analgesic dose of morphine (10mg/kg). Administration of high doses of morphine (30mg/kg and 100mg/kg) resulted in reduced respiratory rates similar to that observed in control animals. Morphine administration also caused an increased level of irregularity in the breathing pattern with short intervals of fast and slow breathing and an increased number of apneas. These effects were dependent on the administered dose of morphine, as well as the location of mu opioid receptor removal. Our results indicate that multiple pontine and medullary respiratory groups differentially contribute to morphine‐induced respiratory depression, and none are entirely responsible for the effects of morphine.

Support or Funding Information

This work was supported by National Institutes of Health Grants DA038069 (E.S.L.) and DA05010 (B.L.K.). A.G.V. was funded by the UF Breathing Research and Therapeutics Training Program (T32 HL134621) and the Center for Respiratory Research and Rehabilitation.

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Translocation of bone marrow‐derived cells contribute to PVN neuroinflammation in hypoxia‐induced PH
Authors: Oliveira Aline Cristina , Kim Seungbum , Sharma Ravindra K. , Wodrich Brigitte , Kunta Avaneesh , Bryant Andrew , Zubcevic Jasenka , Richards Elaine M. , Raizada Mohan K.
Published: June 2021

Background

Pulmonary hypertension is a devastating disease characterized by elevated pressures in the pulmonary arterial circulation leading to right heart failure. Our previous studies have indicated that PH is not only a lung disease but a systemic disease and an altered brain‐gut‐lung axis is involved in the pathogenesis and progression of the disease.

Aim

This study was designed to explore the contribution of bone marrow‐derived cells to neuroinflammation in hypoxia‐induced PH model

Methods

Green fluorescent protein (GFP) bone marrow (BM) chimeric mice (C57BL6 strain) were generated by transplanting GFP BM cells into lethally irradiated WT mice. 3 months later, subjects were exposed to chronic hypoxia (10%O2) or Normoxia for 4 weeks in a ventilated chamber (n=6–10/group). An Millar pressure catheter was used to measure pulmonary hemodynamics, microglial cells specifically stained with Iba1 and migration of BM‐derived cells were also evaluated.

Results

Hypoxia induced an increase in right ventricular (RV) systolic pressure (RVSP: Normoxia (N):22.12 ± 2 mmHg vs Hypoxia (H):32.7 ± 2, p<0.001) and RV hypertrophy (RVH:N: 0.139 ± 0.09 vs H:0.201 ± 0.01, p<0.001) in chimera mice. Besides the lungs, PH also induced an increase in BM‐derived cells in the paraventricular nucleus of hypothalamus (PVN) (N 2.599:±1VsH:10.29 ±2, p<0.001) and the jejunum (N 11.08:±0.26VsH:12.65 ±0.35, p<0.001).

Conclusion

Exposure of chimeric mice with GFP bone marrow cells to chronic hypoxia illustrate the translocation of these cells into organs we have recently described to be associated with PH; the brain and gut. This data indicates that BM‐ derived cells may contribute to the dysfunctional brain‐gut‐lung axis observed in PH.

Support or Funding Information

This research is supported by NIH grant HL102033.

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Regulation of Aquaporin 1 Expression by Hypoxia‐Inducible Factors (HIFs) in Pulmonary Arterial Smooth Muscle Cells (PASMCs)
Authors: Yun Xin , Jiang Haiyang , Shimoda Larissa
Published: June 2021

Prolonged exposure to hypoxia is a common cause of pulmonary hypertension (PH), the pathophysiology of which is characterized by sustained active vasoconstriction and pulmonary vascular remodeling. Studies have shown that HIFs, hypoxia responsive transcription factors, contribute to the development of PH. Three HIF family members have been identified, HIF‐1, HIF‐2, and HIF‐3, of which HIF‐1 and HIF‐2 are the best studied. We have shown that the water channel, aquaporin 1 (AQP1), is expressed in PASMCs and that AQP1 levels are elevated during hypoxia and mediate hypoxia‐induced cell proliferation and migration. The AQP1 promoter contains a HIF binding site, and links between HIF‐1 and AQP1 have been reported in cancer cells, suggesting AQP1 might be a direct HIF target. Thus, we wanted to determine whether either HIF‐1 or HIF‐2 regulates AQP1 in PASMCs. DMOG, which inhibits HIF protein degradation, was used to mimic hypoxia. PASMCs acutely incubated with DMOG exhibited a time‐dependent increase in the levels of AQP1 protein, but not mRNA, whereas both the protein and mRNA levels of a canonical HIF target, GLUT1, were increased. Since we previously reported a link between HIFs and intracellular calcium concentration ([Ca2+]i), as well as a link between [Ca2+]iand AQP1 protein levels, we next determined whether the effects of DMOG on AQP1 were mediated by an increase in [Ca2+]i. Incubation with DMOG caused an increase in [Ca2+]iin PASMCs that was partially prevented by selectively inhibiting either HIF‐1 or HIF‐2. Both inhibitors also partially blocked the DMOG‐induced upregulation of AQP1 protein. When applied together, inhibitors of both HIFs completely blocked the effects of DMOG on [Ca2+]iand AQP1 expression. Thus, our results demonstrate that, in PASMCs, AQP1 protein can be upregulated by both HIF‐1 and HIF‐2, not as a direct target for HIF transcriptional regulation, but rather by a mechanism involving protein accumulation secondary to HIF‐dependent increases in [Ca2+]i.

Support or Funding Information

HL126514

18POST34030262

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.