bluuebunny/crossref_metadata_2025 huggingface dataset:
Inhibitory effects of myricitrin on oxidative stress‐induced endothelial damage and early atherosclerosis in ApoE‐/‐ mice (1146.5)
Authors: Sun Guibo , Qin Meng , Meng Xiangbao , Sun Xiaobo
Published: June 2021

We evaluated the cytoprotective effect of myricitrin on Atherosclerosis (AS) by assessing oxidative stress‐induced vascular endothelial cell (VEC) injury. The in vivo study using an ApoE−/−mouse model of AS demonstrated that myricitrin treatment protects against VEC damage and inhibits early AS plaque formation. This effect is associated with the antioxidative effect of myricitrin, as observed in a hydrogen peroxide (H2O2)‐induced rat model of artery endothelial injury and primary cultured human VECs. Myricitrin treatment also prevents and attenuates H2O2‐induced endothelial injury. Further investigation of the cytoprotective effects of myricitrin demonstrated that myricitrin exerts its function by scavenging for reactive oxygen species, as well as reducing lipid peroxidation, blocking NO release, and maintaining mitochondrial transmembrane potential. Myricitrin treatment also significantly decreased H2O2‐induced apoptosis in VECs, which was associated with significant inhibition of p53 gene expression, activation of caspase‐3 and the MAPK signaling pathway, and alteration of the patterns of pro‐apoptotic and anti‐apoptotic gene expression. The resulting indicates that myricitrin may prevent the apoptosis induced by oxidative stress injury.

Grant Funding Source: The present work was supported by the Key Projects of the National Science and Technology Pillar Pro
The role of microRNA‐21 in anesthetic‐mediated cardioprotection (1155.9)
Authors: Olson Jessica , Yan Yasheng , Twaroski Danielle , Canfield Scott , Kikuchi Chika , Kriegel Alison , Bai Xiaowen , Liang Mingyu , Bosnjak Z.
Published: June 2021

In this study, we investigate the role of microRNA‐21 in anesthetic preconditioning, and its disruption in diabetic models. Anesthetic‐mediated cardioprotection has been shown to decrease myocardial infarct size after ischemia‐reperfusion injury. This response is drastically attenuated in diabetic patients. Many cell signaling pathways have been investigated in this phenomenon; however, the role of microRNA remains unknown. MicroRNAs are short, non‐coding nucleotide sequences that negatively regulate gene expression through degradation or suppression of messenger RNA.

Using qRT‐PCR, our lab has shown a continuous upregulation in microRNA‐21 after isoflurane exposure that appears to play an important role in cardioprotection through its actions on programmed cell death protein 4. This powerful protective cell signaling pathway is disrupted in multiple models of diabetes, including induced pluripotent stem cell‐derived cardiomyocytes from patients with type 2 diabetes, and in patient‐derived cardiomyocytes exposed to high glucose. Our data indicate an important role of microRNA‐21 in isoflurane‐induced cardioprotection and the impairment of this pathway by diabetic conditions. Further investigation may suggest new therapeutic targets for reducing cardiovascular morbidity and mortality in high‐risk patients.

Grant Funding Source: Supported by NIH Grants RO1HL034708 and P01GM06673 for Zeljko J. Bosnjak.
Effect of prostate cancer on skeletal muscle mitochondrial regulation and function following exercise training in a rodent model (1159.3)
Authors: Nguyen Linda , McCullough Danielle , Joseph Anna‐Maria , Behnke Bradley , Adhihetty Peter
Published: June 2021

Cancer afflicts numerous primary tissues and is often associated with secondary skeletal muscle atrophy and wasting, known as cachexia. Mitochondrial abnormalities contribute to muscle atrophy/dysfunction in various diseases, and experimental perturbations (i.e. exercise) augmenting mitochondrial content tend to improve muscle but whether this occurs in prostate cancer is unknown. We used an orthotopic prostate cancer model, injecting AT‐1 adenocarcinoma cells (tumor‐bearing; TB) or saline (non‐tumor bearing; NTB) into the prostate of young (5 mo) rats, and assigned a sedentary (Sed) or exercise (7 weeks; Ex) protocol (n=5‐10/group). Exercise did not alter tumor size (4.12 g TB‐Sed; 4.3 g TB‐Ex), nor was there tumor‐associated atrophy in muscles (SOL, EDL, Pl, TA). As expected, training induced mitochondrial biogenesis by increasing (P<0.05) COX activity, cytochrome c, and electron transport complexes (30%, 3.3‐fold, 1.8‐fold, respectively) in NTB animals while the TB group had a significantly blunted response. Interestingly, tumor presence per se did not alter mitochondrial content/regulation but tended to reduce (~25%) mitochondrial respiration and elevate (~2.5‐fold) mitochondrial free radical production, and exercise did not evoke improvements. Our data suggests prostate cancer impairs exercise‐induced mitochondrial biogenesis and impairs mitochondrial function in skeletal muscle.
Mitochondrial oxidative capacity and function in human white, beige and brown adipose tissue (1160.6)
Authors: Porter Craig , Chondronikola Maria , Chao Tony , Saraf Manish , Børsheim Elisabet , Herndon David , Sidossis Labros
Published: June 2021

Our understanding of mitochondrial oxidative capacity (oxphos) and function in brown adipose tissue (BAT) is derived from cell and murine models. Here, we determined mitochondrial oxphos and function in white adipose tissue from healthy individuals (WAT, n=9), beige adipose tissue from severely burned children (BeAT, n=8), and BAT from healthy individuals (n=3). Mitochondrial respiration was determined following the addition of 1) substrates; 2) ADP; 3) succinate; and 4) oligomycin. Thereafter, the ratios of coupled to leak and uncoupled to coupled respiration were calculated. Oxphos was higher in BAT (14.3±6.1 pmol/mg/sec; P<0.001) vs. both WAT (1.1±0.2 pmol/mg/sec) and BeAT (2.8±0.4 pmol/mg/sec). Oxphos was also significantly higher in BeAT vs. WAT (P<0.001). The ratio of coupled/leak respiration was lower in BAT vs. WAT and BeAT (P<0.01), whereas the ratio of uncoupled/coupled respiration was higher BAT and BeAT vs. WAT (P<0.05). BAT and BeAT are similar with regards to oligomycin sensitivity, suggesting a more thermogenic phenotype than WAT. However, as oxphos is higher and ADP sensitivity lower in BAT vs. BeAT, suggests that BAT is functionally distinct from BeAT in humans.

Grant Funding Source: Supported by NIH (P50‐GM60338, RO1‐GM05668), NIDRR (H133P110012) and SHC (84090, 84080) grants
Cav1.1 controls ATP release to elicit gene expression in adult muscle fibers (1164.12)
Authors: Jorquera Gonzalo , Valladares Denisse , Piétri‐Rouxel France , Allard Bruno , Jacquemond Vincent , Jaimovich Enrique , Casas Mariana
Published: June 2021

In adult muscle fibers, Cav1.1 acts as voltage sensor for both excitation‐contraction coupling and the activation of a signaling cascade that regulates gene expression. We have shown that ATP is released through pannexin‐1 channels after electrical stimulation at 20 Hz, having a key role in the induction of transcriptional changes related to fast‐to‐slow muscle fiber phenotype transition. Myotubes lacking the Cav1.1α1 subunit displayed almost no ATP release after electrical stimulation. ATP release and gene transcription was also altered in adult muscle fibers knock‐down for Cav1.1α1.

In dystrophic fibers, there was also an increase in basal ATP release, but a default in the stimulation‐dependent increase in ATP release and transcription activation observed in control fibers. This can be interpreted as uncoupling between electrical stimulation and ATP release in dystrophic muscles.

All these data suggest that Cav1.1 controls ATP release trough Pannexin‐1 channels, activating it after low stimulation frequencies and blocking ATP release during resting conditions. The loss of this control perturbs the normal transcriptional response to electrical activity of adult muscle fibers and may play a role in the etiology of muscular dystrophy.

Grant Funding Source: ACT 1111, FONDECYT 1110467, UINICIA 0212M, CNRS‐CONICYT EDC24748
The nuclear receptor ERRα is essential for skeletal muscle metabolic adaptations to endurance training (1164.2)
Authors: LaBarge Samuel , McDonald Marisa , Hamilton Angelica , Turcotte Lorraine , Huss Janice
Published: June 2021

The aim of the present study is to test the hypothesis that the Estrogen‐related Receptor α (ERRα) is essential for exercise‐mediated metabolic adaptations and that AMPK activates the ERRα pathway. Muscle‐specific ERRα‐/‐ (M‐ERRα‐/‐) and M‐ERRαWT (WT) mice were subjected to 8wks of treadmill training or 1wk daily AICAR administration. In M‐ERRα‐/‐ skeletal muscle citrate synthase (CS) activity was lower ~30% and mitochondrial density was reduced compared to WT. Basal expression of transcripts involved in electron transport (ETC) and β‐oxidation were reduced by 25‐60%. AICAR treatment induced ERRα and β‐oxidation gene expression in WT mice. Exercise training upregulated transcripts involved in mitochondrial biogenesis and ETC, including mitochondrial transcription factor A and cytochrome c, in WT mice. No induction was seen in M‐ERRα‐/‐ mice. In run‐to‐exhaustion (RTE) trials trained WT mice had a greater increase in running distance than M‐ERRα‐/‐ mice (+250% vs +50%) relative to sedentary groups. After RTE blood lactate was elevated in trained M‐ERRα‐/‐ mice (>12mmol/L), similar to sedentary mice, suggesting the training effects on muscle aerobic capacity was blunted. Consistently, succinate dehydrogenase and CS activities were increased in trained WT but not M‐ERRα‐/‐ muscles. Our data suggest that ERRα is involved in AMPK‐mediated skeletal muscle metabolic adaptation following exercise training…
High salt intake and aldosterone independently augment the exercise pressor reflex in rats (1165.10)
Authors: Mizuno Masaki , Downey Ryan , Mitchell Jere , Smith Scott , Vongpatanasin Wanpen
Published: June 2021

Evidence suggests the exercise pressor reflex (EPR) is overactive in hypertension. However, the underlying mechanisms are poorly understood. The purpose of this study was to determine whether excessive salt intake and/or chronic administration of aldosterone potentiates EPR function in rats. Changes in renal sympathetic nerve activity (RSNA) and mean arterial pressure (MAP) to stimulation of the EPR were assessed in vehicle and aldosterone treated (4 weeks via osmotic mini‐pump) Sprague‐Dawley rats given either water or saline (elevated salt load) to drink. Compared to vehicle/water‐treated rats, contraction induced stimulation of the EPR evoked significantly greater increases in RSNA in vehicle/saline, aldosterone/water and aldosterone/saline‐treated animals (39±11, 98±19, 110±20, and 154±29%/kg, respectively, P<0.01). A similar MAP response profile was likewise produced. The sympathetic and pressor responses to passive muscle stretch and intra‐arterial capsaicin administration were also augmented in the vehicle/saline group and aldosterone treated rats, suggesting both mechano‐ and metaboreflex sensitization. In conclusion, our data provide the first direct evidence for both high salt intake and aldosterone as major contributors to the neural mechanisms underlying the exaggerated rise in sympathetic activity and blood pressure during exercise in hypertension. Supported by NIH HL‐113738

Grant Funding Source: Supported by NIH HL‐113738
Effect of hindlimb unloading on sympathetic vasoconstriction in resting and contracting skeletal muscle (1165.3)
Authors: Just Timothy , Jendzjowsky Nicholas , DeLorey Darren
Published: June 2021

We hypothesized that hindlimb unloading (HU) would increase sympathetic vasoconstrictor responsiveness and diminish nitric oxide (NO) mediated inhibition of sympathetic vasoconstriction in resting and contracting skeletal muscle. Sprague‐Dawley rats (n=21) were randomized to sedentary time‐control (S; n = 9) or HU (n = 12) groups for 21d. Rats were anesthetized and instrumented for stimulation of the lumbar sympathetic chain and measurement of femoral vascular conductance (FVC). Sympathetic stimulations were delivered at 2Hz and 5Hz at rest and during contraction of the triceps surae muscles at 60% of maximal contractile force before and after NO synthase blockade (L‐NAME; 5mg·kg‐1 IV). The percentage decrease in FVC in response to sympathetic stimulation was not different (P > 0.05) between groups at rest (HU: 2Hz: ‐29 ± 10%; 5Hz: ‐50 ± 12%; S: 2Hz: ‐26 ± 10%, 5Hz: ‐44 ± 8%) and during contraction (HU: 2Hz: ‐9 ± 4%; 5Hz: ‐22 ± 7%; S: 2Hz: ‐7 ± 5%; 5Hz:‐18 ± 7%). In the presence of L‐NAME the vasoconstrictor response was not different (P > 0.05) between groups at rest (HU: 2Hz: ‐43 ± 7%; 5Hz: ‐63 ± 10%; S: 2Hz: ‐42 ± 8%; 5Hz: ‐57 ± 6%) and during contraction (HU: 2Hz: ‐12 ± 3%; 5Hz: ‐24 ± 6%; S: 2Hz: ‐12 ± 4%; 5Hz: ‐28 ± 8%). We conclude that HU does not alter sympathetic vasoconstrictor responsiveness or NO mediated inhibition of sympathetic vasoconstriction in resting and contracting skeletal muscle.

Grant Funding Source: Supported by NSERC, Canada.
Ketorolac attenuates the blood pressure response to dynamic exercise in peripheral arterial disease patients (1165.5)
Authors: Muller Matthew , Drew Rachel , Sinoway Lawrence
Published: June 2021

Humans with peripheral arterial disease (PAD) have an augmented exercise pressor reflex (EPR) but the metabolites responsible for this augmented response are unknown. We tested the hypothesis that intravenous infusion of ketorolac (a COX inhibitor) would attenuate the rise in mean arterial blood pressure (MAP) and heart rate (HR) in response to low‐intensity plantar flexion exercise in humans with PAD. Six PAD patients underwent four minutes of one‐legged rhythmic plantar flexion (30 contractions/min) in the supine posture. The workload began at 0.5 kg and progressed by 0.5 kg each minute. MAP and HR were measured on a beat‐by‐beat basis; changes from baseline in response to exercise were determined for both control and ketorolac conditions. Ketorolac did not affect resting MAP (97 ± 3 versus 94 ± 4 mmHg) or HR (58 ± 2 versus 55 ± 2 bpm). During the first 20 seconds of exercise with the most diseased leg, ΔMAP was significantly attenuated with ketorolac (2 ± 2 mmHg) as compared to control (8 ± 2 mmHg) but ΔHR was similar (7 ± 2 versus 6 ± 1 bpm). During the second and third minutes of exercise, ΔMAP was also significantly attenuated under ketorolac. These data indicate that prostaglandins contribute to the augmented EPR in patients with PAD. Because this response occurred at very low workloads, we speculate that muscle mechanoreceptors are sensitized by cycolooxyegnase products under conditions of chronic limb ischemia.

Grant Funding Source: Supported by NIH P01 HL096570 (LIS) and UL1 TR000127 (LIS)
Group III/IV muscle afferents are important for the pressor response to dynamic exercise in healthy humans (1165.9)
Authors: Vianna Lauro , Barbosa Thales , Fernandes Igor , Magalhães Nisval , Cavalcanti Ismar , Secher Niels , Nóbrega Antonio
Published: June 2021

The onset of dynamic exercise typically exhibits a triphasic blood pressure (BP) response, consisting of an initial rise (0‐3s) followed by a transient drop below resting levels (4‐10s) and then a sustained increase (>10s). We investigated the role of skeletal muscle afferents in modulating the dynamics of BP at the onset of exercise. Beat‐to‐beat BP (brachial artery), heart rate (HR), stroke volume (SV), cardiac output (CO) were continuously monitored in 8 healthy men (28±3 yr) while performing leg cycling exercise (80W) under control (CTRL) and lumbar intrathecal fentanyl (FENT) (impairing cephalad projection of opioid receptor sensitive muscle afferents). To evaluate whether cephalad migration of fentanyl affected cardiovascular control centers, we assessed the pressor response to handgrip exercise in both conditions. At the exercise onset, mean BP increased from baseline in the first 3s (+5±1 mmHg, P<0.05) and decreased to a nadir at 10s (‐4±3 mmHg, P<0.05). Fentanyl did not affect BP response during the first 10s, but blunted its increase thereafter (CTRL: +9±3 vs. FENT: 0±2 mmHg at 50s; P<0.05). HR, SV and CO responses to exercise were not affected by fentanyl. Similar mean BP responses to static handgrip in both conditions indicated that cephalad migration of fentanyl was avoided. Our findings demonstrate an important contribution of group III/IV muscle afferent fibers to BP response to leg cycling exercise.

Grant Funding Source: Supported by the Brazilian Science Without Borders Program
Pyridostigmine enhances vagal influence to the heart but increases renal sympathetic nerve activity in anesthetized rats (1169.14)
Authors: Aguiar Carlos Alberto , Santos Fernanda , Salgado Helio , Fazan Rubens
Published: June 2021

We evaluated effect of acute blockade of plasma acetylcholinesterase with pyridostigmine (PYR) on cardiac sympatho‐vagal balance and on electrical activity of the renal sympathetic nerve (RSN) in anesthetized rats.

Cardiac sympathetic and vagal tone were assessed in urethane anesthetized rats by heart rate (HR) responses to propranolol (2 mg/kg, N=14) or methyl‐atropine (1 mg/kg, N=18), respectively, 60 min after treatment with PYR (0.25 mg/kg iv) or saline.

Other rats, also under urethane anesthesia, were instrumented for AP and RSN activity recordings. After basal recording the rats received PYR (0.25 mg/kg, iv N=6) or saline (N=4) and the experiment last for 1h.

PYR elicited a prompt bradycardia (‐73±6 bpm) that partially recovered, but HR remained lower (387±7 vs 445±9 bpm), 1h after treatment. Sympathetic tone was lower (31±6 vs 69±7 bpm) and vagal tone was higher (86±7 vs 44±5 bpm) in rats treated with PYR.

A progressive increase in RSN activity, with no change in BP, was observed after treatment with PYR (40±3, 81±26 and 87±6% at 20, 40 and 60 min after PYR). No change in RSN activity was observed in rats treated with saline.

Acute treatment with PYR was effective in enhance parasympathetic and reduce sympathetic tonic influence to the heart. Nevertheless, RSN recording revealed an acute increase in sympathetic nerve traffic elicited by PYR.

Grant Funding Source: Supported by FAPESP, CAPES, CNPq.
A pulse‐based diet and exercise training in women with polycystic ovarian syndrome: effects on body composition, blood lipids and reproductive measures (117.5)
Authors: McBreairty Laura , Zello Gordon , Rooke Julianne , Serrao Shani , Pierson Roger , Chizen Donna , Chilibeck Philip
Published: June 2021

Polycystic ovarian syndrome (PCOS) is an endocrine disorder that predisposes women to an increased risk of heart disease, diabetes, infertility and endometrial cancer with an annual cost of $4 billion in the United States. We hypothesized that a pulse‐based diet (e.g. beans, lentils) would have a positive effect on body composition as analyzed by dual energy X‐ray absorptiometry, reproductive measures and serum lipid profiles. Twenty‐five women with PCOS aged 18‐35y with a mean BMI of 31 were randomly assigned to groups receiving a pulse‐based diet (n=14) or the National Cholesterol Education Program (NCEP) therapeutic lifestyle changes (TLC) diet (n=11) for 16 wks while participating in an exercise program. Following the intervention, both groups lost body mass (p<0.05; Pulse ‐2.4 vs TLC ‐3.0 kg), percent fat mass (Pulse ‐1.0 vs TLC ‐1.6 %) and trunk fat mass (Pulse ‐1.0 vs TLC ‐1.7 kg). No changes were observed in lean body mass between groups. Both dietary interventions also resulted in more women exhibiting regular menstrual patterns (p<0.001) and a tendency towards a decreased antral follicle count in the right ovary (p=0.06); however, only the pulse diet reduced total cholesterol to HDL ratio (4.2 to 3.8 p<0.005). As hypothesized, a pulse‐based diet reduced body fat, and improved reproductive measures and serum lipid profiles. Thus, early diagnosis and dietary/exercise interventions are important in alleviating both the personal health and economic costs associated with PCOS.

Grant Funding Source: Supported by the Saskatchewan Pulse Growers and Agriculture Agri‐Food Canada (Cluster Program)
The aqueous calyx extract of Hibiscus sabdariffa may lower blood pressure and pulse rate by sympathetic nervous system‐dependent mechanism(s) (1170.11)
Authors: Mojiminiyi Frank , Aliyu Buhari , Oyeniyi Yinka , Isezuo Simeon , Alada AbdulRasak
Published: June 2021

This study tested the hypothesis that the hypotensive effect of the aqueous calyx extract of Hibiscus sabdariffa (HS) may be sympathetically mediated. Following ethical approval and informed consent, the cold pressor test (CPT) was performed in 20 healthy subjects before and after the oral administration of 15mg/Kg HS. The blood pressure (BP) and pulse rate (PR) responses were measured digitally. Mean arterial pressure (MAP; taken as representative BP) was calculated. Experiments were performed in accordance with the Principles of the Declaration of Helsinki. Results are expressed as mean ±SEM. P<0.05 was considered significant. CPT done in the absence of HS resulted in a significant rise in BP and PR (111.1 ± 2.1mmHg and 100.8 ± 2.0/min) from the basal values (97.9±1.9mmHg and 87.8±2.1/min; P<0.0001 respectively). In the presence of HS however, these fell significantly (101.5±1.8mmHg and 92.4±2.0/min; P<0.0001 respectively). These results suggest that the hypotensive effect of HS may be due to an attenuation of the discharge of the sympathetic nervous system.

Grant Funding Source: Personal Funds
Effect of device guided slow deep breathing on central sympathetic outflow and arterial baroreflex sensitivity in young healthy individuals (1170.4)
Authors: Shantsila Alena , Adlan Ahmed M , Lip Gregory , Pickering Anthony , Paton Julian , Fisher James
Published: June 2021

We sought to investigate whether device guided slow deep breathing (SDB; RESPeRATE©) influences muscle sympathetic nerve activity (MSNA) and spontaneous baroreflex sensitivity in young healthy individuals. Following a 10 min supine baseline period, 9 men (29±7 years, body mass index 24±2 kg/m2; mean±SD) undertook 10 min of SDB while respiratory frequency (strain gauge pneumobelt), partial pressure of end‐tidal carbon dioxide (PETCO2), blood pressure (BP; finger photoplethymography), heart rate (HR; ECG) and MSNA (microneurography) were continuously monitored. Indices of arterial baroreflex control of the heart (sequence technique) and MSNA burst incidence were calculated. Respiratory rate was reduced from 12±2 to 6.2±0.7 breaths/min (P<0.001) during SDB, while PETCO2 (P=0.50), and mean BP (P=0.40) were unchanged. SDB significantly reduced MSNA burst incidence (i.e., percentage of cardiac cycles associated with a MSNA burst) from 25 (20‐38) to 20 (18‐33) (median and interquartile range; P=0.04). Neither cardiac (systolic BP‐RR interval; P=0.26) or sympathetic (P=0.95) baroreflex sensitivity were changed with SDB. Thus, reductions in MSNA burst incidence with device guided SDB in young healthy individuals appear not to be secondary to a change in baroreflex sensitivity, but may reflect an increase in lung inflation afferent input and/or a reduction in central respiratory‐sympathetic coupling.

Grant Funding Source: Supported by British Heart Foundation
Capsaicin induced cough and urge‐to‐cough in elderly individuals with NTM (1178.6)
Authors: Tsai Hsiu‐Wen , Fennelly Kevin , Wheeler Hegland Karen , Adams Sherry , Condrey Jillian , Hosford Jennifer , Davenport Paul
Published: June 2021

Mycobaterium avium complex infection is a type of nontuberculous mycobacterial (NTM) infections have been reported often occurred in elderly, white, thin and principally nonsmoking women. It has been postulated that such disease in woman is related to the way they cough. They often cough quietly and covertly, thereby the clearance of sputum is suppressed. In this study, we hypothesized that NTM subjects may have decreased cough sensitivity as measured by a higher threshold for inducing cough and the Urge‐to‐Cough compared to controls. Female, white and elderly NTM and control subjects were recruited in the study. Four concentrations of capsaicin (50, 100, 200, 500 uM) plus placebo (0 uM capsaicin) were presented to the subject three times each in a blinded‐randomized block order. Each capsaicin presentation was separated approximately 1 min. At the end of each capsaicin presentation, subjects were asked to rate their Urge‐to‐Cough using the modified Borg scale from 1 (no Urge‐to‐Cough) to 10 (maximum Urge‐to‐Cough). Cough response was defined as single or multiple coughs elicited by capsaicin inhalation. There was no significant difference in cough response. NTM subjects showed lower Urge‐to‐Cough at the lowest capsaicin concentration compared to control subjects (p<0.05). There were no significant differences in the Urge‐to‐Cough score between NTM and control subjects when the capsaicin concentration was greater than 50 uM. The result suggests that NTM subjects have lower Urge‐to‐Cough sensitivity to low concentration capsaicin compared to control subjects. This result may explain why they have a reduced cough when the stimulus is relatively small.
The carbon dioxide reserve is reduced and chemoreflex sensitivity is increased in the morning compared to the evening and afternoon in participants with sleep apnea (1178.7)
Authors: El Chami Mohamad , Syed Ziauddin , Shaheen David , Ivers Blake , Badr M. Safwan , Lin Ho‐Sheng , Mateika Jason
Published: June 2021

Purpose: Clinical studies have indicated that breathing instability in patients with sleep apnea is increased in the morning independent of sleep stage. Upper airway collapsibility and chemoreflex responses to hypoxia/hypercapnia have a major influence on breathing stability during sleep. Thus we hypothesized that these parameters would be greater in the morning compared to the evening and afternoon.

Methods: Five participants with sleep apnea slept for 3 hours in the evening, morning and afternoon while upper airway patency was maintained with positive airway pressure. Intermittently the pressure was reduced for a period of 3‐5 breaths until the airway collapsed. On a separate occasion the protocol was repeated and the threshold (i.e. apneic threshold) and sensitivity of the chemoreflex response to carbon dioxide was determined by applying 3‐minute periods of mechanical ventilation followed by 5 minutes of recovery.

Results: Upper airway collapsibility was not significantly greater in the morning compared to the other sessions (1.87 ± 2.48 vs. ‐ 0.22 ± 1.10 cmH2O). However, chemoreflex sensitivity was greater (2.38 ± 0.36 vs.1.88 ± 0.33 L/min/mmHg, p = 0.05) and carbon dioxide (CO2) values that demarcated the apneic threshold (morning: 38.24 ± 0.36 vs. afternoon/evening: 38.09 ± 0.88 mmHg) were closer to resting values in the morning compared to the other sessions (Δ CO2:1.85 ± 0.20 vs. 3.02 ± 0.19 mmHg, p = 0.001).

Conclusions: Increased breathing instability in the morning may be a consequence of alterations in chemoreflex properties that vary across the 24 hr cycle.

Grant Funding Source: Supported by VA Merit Award (2I01CX000125‐05A1) (JHM)
Ultrasonic diagnosis of hip dysplasia in rachitic pathology in infants (1180.14)
Authors: Karabekova R. , Gorobtsova A. , Shakeeva A. , Seidakhmetov M.
Published: June 2021

Objective: to identify the signs of hip dysplasia in a large clinical material along with the symptoms of rickets (sweating, alopecia of the occipital region of the head, muscular hypotonia, irritability child).

Materials: 935 children were observed at the CCH No 2 in Astana for 2010 with hip joint pathology, of whom up to 6 months, 56.6% after 6 months ‐ 32,6% to be conservative treatment and 10.8% children received surgical treatment.

Results: Ultrasonography in 35.8% children 2‐3 months of age revealed a sharp flattening of the bone and bone bay window roof (angle d ranged between 34 ‐39), cartilaginous portion of the acetabulum has been shifted cranial ossification nucleus head femur was missing. At the age of 4‐5 months during treatment in the stirrups Pavlik appeared signs of the formation of the femoral head in the form of separate small “clumps” in 46.5% children in the remaining 36.5%, these terms are shifted to 6‐7 months of age (the angle d 48‐52). Only by 9‐10 months gradually underwent a process of mergers and the formation of a homogeneous core of ossification center of the femoral head (the angle d approaching 56‐58), cartilaginous portion of the roof of the acetabulum was relatively short. By the year 33% of patients the size of the hip bone formation were reduced, and only 67% of patients taking shape hip well‐formed, bone bay took a rectangular shape, cartilaginous part of the femoral head is completely covered).
Autologous cell sheet engineering: an animal product‐free approach (1180.23)
Authors: Wood Andrew , Sota Hiroyuki , Oliva‐Vilana Joan , Bardag‐Gorce Fawzia , Thropay Jacquelyn , Pan Derek , Niihara Yutaka
Published: June 2021

While ex vivo expanded autologous cell sheet shows promise in replacing impaired corneal epitheliums; the engineering issues of using xenogeneic products during cell expansion remain to be addressed. To eliminate animal products, this study explores the use of two chemically defined media used sequentially for expansion and differentiation, where submerged and air‐exposure techniques are used respectively. The cells in the xenogeneic product‐free condition expanded well and reached confluency however only a single layer of basal cells was created. To resolve this issue, we found that the addition of 1 mM Ca2+ helps induce differentiation. However, air‐exposure could cause the apical surface to become dry and keratinized. To overcome this downside, a few drops of PBS as a moistener, were applied to the surface. The modified culture with this preventive technique successfully yielded non‐keratinized, multi‐stratified cell sheets that are morphologically similar to cell sheets engineered with the conventional method. These observations were confirmed by H&E staining. Moreover, the sheet maintained the normal phenotypes; the basal cells stained positive for ΔN‐p63, Ki67 and PCNA, while the apical cells were stained for K3 and K13. The chemically defined non‐xenogeneic media showed promise in becoming a safe alternative for the epithelium production.

Supported by Emmaus Life Sciences, Inc. and CellSeed, Inc.
TRPV1 channel activity triggered by hyperosmotic stimulation increases phosphorylated NOS activity in rat supraotic slices (1182.10)
Authors: Khachaturov Andranik , Tosonian Shawnt , Beitzel Christy , Curras‐Collazo Margarita
Published: June 2021

Magnocellular neuroendocrine cells (MNCs) in the supraoptic (SON) and paraventricular nucleus (PVN) of the hypothalamus release vasopressin (VP) from axons and somata/dendrites in response to hyperosmotic stimulation. Transient receptor potential vanilloid 1 (TRPV1) channels mediate osmosensory transduction and axonal neurosecretion in SON MNCs. Our lab has shown that osmotic‐stimulated somatodendritic VP responses occur in a TRPV1‐ and NOS‐dependent manner. Since TRPV1 activation may result in NO production, our current study examined the interaction between TRPV1 and NO synthase (NOS) under hyperosmotic conditions. Acutely dissected SON slices were prepared from adult male Holtzman rats perfused with sucrose‐enriched aCSF under deep anesthesia. Slices were treated with hyperosmotic stimulation in the presence and absence of TRPV1 antagonist SB366791 (1.5 μM) and later post‐fixed. Using double‐label immunohistochemistry for phosphorylated stimulatory residue of neuronal NOS (p‐nNOS ser1412) and combined VP‐neurophysin (PS41) and oxytocin‐neurophysin (PS38) we found elevated p‐nNOS immunoreactivity in MNCs under hyperosmotic conditions but not always in the presence of SB366791, suggesting that increased NO signaling may occur downstream of TRPV1 channel activity. By analogy to other neuroendocrine systems p‐nNOS ser1412 may participate in neuropeptide secretion perhaps by coupling with NMDAr on MNCs. We also immunoprobed for downstream signaling partners of NOS and found expression of sGC (beta subunit), an enzyme that converts GTP to cGMP.

We conclude that hyperosmotic stimulation activates TRPV1 channels that produce stimulatory phosphorylation of nNOS leading to somatodendritic release of VP from supraoptic MNCs.

Grant Funding Source: Supported by American Physiological Society
Comparing cerebral blood flow velocity and cerebral blood flow measures between transcranial Doppler ultrasound and phase contrast magnetic resonance imaging during hypercapnia and hypocapnia (1183.2)
Authors: Coverdale Nicole , Gati Joe , Opalevych Oksana , Perrotta Amanda , Shoemaker J. Kevin
Published: June 2021

To test the hypothesis that middle cerebral artery (MCA) diameter remains stable across physiologic stimuli, the cross‐sectional area (CSA) of the MCA was assessed using high‐field magnetic resonance imaging (MRI) (3T, T2 images) during hypercapnia (HC) and hypocapnia (HO). Estimates of cerebral blood flow velocity (CBV) collected with transcranial Doppler (TCD) ultrasound and phase contrast (PC) MRI were also compared with subsequent calculation of cerebrovascular reactivity (CVR). End‐tidal carbon dioxide (ETCO2) levels were manipulated through hyperventilation (30 breaths/min) and inhalation of 6% CO2 gas. The CSA increased from 5.5 ± 0.9 to 6.4 ± 1.2 mm2 (p<0.001; n=16) during HC and decreased from 5.7 ± 1.0 to 5.1 ± 0.8 mm2 (p<0.001; n=14) during HO. During HC CBV increased from 68 ± 9 to 85 ± 15 cm/s (p=0.003, n=7) measured with TCD and from 64 ± 10 to 85 ± 15 cm/s (p=0.002, n=7) measured with PC, while there was a decrease from 69 ± 8 to 55 ± 16 cm/s (p = 0.02, n=7) with TCD and from 61 ± 8 to 51 ± 8 cm/s (p = 0.02, n=7) during HO. Cerebrovascular reactivity during HC was 2.42 ± 3.98 cm/s/mmHg for TCD and 2.87 ± 1.63 cm/s/mmHg for PC (p = 0.70). Cerebrovascular reactivity during HO was ‐1.67 ± 1.37 cm/s/mmHg for TCD and ‐0.92 ± 1.17 cm/s/mmHg for PC (p = 0.11). Therefore, CSA of the MCA is not constant across this range of ETCO2. Further, TCD and PC provide similar estimates of absolute CBV and CVR during HO and HC.

Grant Funding Source: Supported by the Canadian Institutes of Health Research
Alternateday fasting versus daily calorie restriction for weight loss and cardio‐protection (120.6)
Authors: Trepanowski John , Kroeger Cynthia , Klempel Monica , Calvo Yolian , Varady Krista
Published: June 2021

Background: Alternate‐day fasting (ADF) has been shown to reduce body weight and improve coronary heart disease (CHD) risk parameters in overweight and obese humans. Whether ADF produces greater improvements in these parameters compared to traditional calorie restriction (CR) remains unknown.

Methods: Overweight and obese subjects (n = 25) were randomized to 1 of 3 groups for 24 weeks: 1) ADF (feed day: 125% of energy needs, alternated with a fast day: 25% of energy needs; all meals provided); 2) CR (75% of energy needs every day; all meals provided); 3) Control (100% of energy needs every day; self‐selected diet).

Results: ADF and CR resulted in similar (p > 0.05 relative to each other) reductions in body weight 8.3 ± 1.5% and 7.2 ± 1.2%, respectively; both p < 0.02 relative to control), fat mass (14.0 ± 2.2% and 15.2 ± 1.8%, respectively; both p < 0.02 relative to control), and visceral fat (0.51 ± 0.11 kg and 0.38 ± 0.12 kg, respectively; both p < 0.01 relative to control). Fat‐free mass did not change in any group (p > 0.05). Plasma lipids, glucose, insulin, C‐reactive protein, and systolic and diastolic blood pressure did not change in either intervention group relative to the control group (p > 0.05 for each) over the 24‐week trial.

Conclusion: ADF and CR produce similar weight loss, and neither diet appears to modulate CHD risk. These findings are limited by small sample size, however, and warrant further investigation.
Level of cytoplasmic thioredoxin reductase 1 in prostate tissue is associated with prostate cancer Gleason score, total antioxidant capacity and erythrocyte glutathione peroxidase activity (136.2)
Authors: Vance Terrence , Azabdaftari Gissou , Pop Elena , Lee Sang Gil , Su L. Joseph , Fontham Elizabeth , Bensen Jeannette , Mohler James , Chen Ming‐Hui , Koo Sung , Chun Ock
Published: June 2021

Thioredoxin reductase 1 (TrxR1) is a member of the thioredoxin system, and a ubiquitous protein disulfide reductase involved in various intracellular inflammatory and oxidative processes. This study was conducted to determine the association between prostate tissue expression of TrxR1 levels and prostate cancer (PCa) Gleason score, dietary total antioxidant capacity (TAC), and erythrocyte glutathione peroxidase (GPx) activity using data from PCaP, a study of incident PCa among African and Caucasian Americans. Cytoplasmic and nuclear TrxR1 levels were measured using immunohistochemical staining of PCa on diagnostic biopsy sections from 55 men and visually scored in a blinded fashion by a pathologist (slides scored 0 to 3, with larger numbers indicating greater intensity of staining). Associations between PCa Gleason score and cytoplasmic TrxR1 levels of benign and malignant cells, and the difference in TrxR1 level between benign and malignant cells (ΔTrxR1), were determined using Fisher’s Exact test, α=0.05. TrxR1 was associated with dietary TAC (p<0.05) in benign cells and GPx (p<0.05) in malignant cells; ΔTrxR1 was found positively associated with Gleason score (p<0.05). These results warrant additional research on oxidative stress and prostate carcinogenesis.

Acknowledgement: The authors thank the staff, advisory committees and research subjects participating in the North Carolina‐Louisiana Prostate Cancer Project (PCaP) study for their important contributions.

Grant Funding Source: Support by NIH Cancer Epidemiology Small Grant #1R03CA159421‐01A1 and DOD DAMD 17‐03‐2‐0052
Regulatory T cells dynamically regulate selectin ligand function during multiple challenge contact hypersensitivity (146.12)
Authors: Hickey Michael , Abeynaike Latasha , Deane James , Westhorpe Clare , Issekutz Andrew
Published: June 2021

Regulatory T cells (Tregs) play critical roles in regulation of T cell‐mediated inflammation, and in organs such as the skin, this is dependent on their expression of selectin ligands required for rolling in peripheral microvessels. However, whether there are differences in the molecules used by Tregs and pro‐inflammatory T cells to undergo rolling remains unclear. Here we used spinning disk confocal microscopy of Foxp3‐GFP mice to visualize rolling of endogenous Tregs in dermal postcapillary venules. Tregs were observed to undergo infrequent but consistent rolling interactions under resting and inflamed conditions. Despite this, during inflammation, Tregs were able to adhere efficiently, comprising 40% of the total adherent CD4+ T cell population at the peak of the response. In a multiple challenge model of contact sensitivity, rolling of both Tregs and conventional CD4+ T cells was mostly dependent on overlapping contributions of P‐ and E‐selectin. However, shortly after a second challenge, rolling of Tregs but not conventional T cells became P‐selectin‐independent, an effect associated with a reduction in their capacity to bind P‐selectin in vitro. These findings demonstrate that Treg selectin‐binding capacity and the molecular basis of Treg rolling in the peripheral microvasculature can be regulated dynamically in a multiple challenge model of inflammation.
CD47 contributes to neutrophil recruitment (146.2)
Authors: Azcutia Veronica , Croce Kevin , Herter Jan , Newton Gail , Mayadas Tanya , Luscinskas Francis
Published: June 2021

Leukocyte recruitment plays a key role in an inflammatory response. CD47 associates “in cis” with β1, β2 and β3 integrins. CD47 also interacts “in trans” with Signal Regulatory Proteins (SIRP‐α and ‐γ) and thrombospondin (TSP). CD47 plays an important but incompletely understood role in the innate and adaptive immune responses. Neutrophil recruitment in CD47KO mice is reduced in models of peritonitis, lung injury and dermal air pouch inflammation, but the exact contribution(s) of CD47 to neutrophil (PMN) extravasation is unclear. Here we report that in the TNF‐α‐stimulated cremaster muscle microcirculation, PMN rolling velocity is elevated compared to WT (17.8±1.5μm/s vs. 14.3±1.0μm/s, respectively; p<0.05), whereas there was no difference between WT and CD47KO mice in CXCL1‐induced arrest. Also, PMN transendothelial migration (TEM) is reduced by 30% in CD47KO mice compared to WT mice (p<0.05). In vitro flow chamber assays demonstrate reduced adhesion (30% reduction vs. WT; p<0.05) and TEM (60% reduction vs. WT; p<0.05) of CD47KO PMN compared to WT PMN across WT TNF‐activated murine endothelium. We have previously reported that CD47 physically interacts with β2 integrins and regulates integrin affinity on T cells (Azcutia et al., Mol Biol Cell 2013). These previous observations and our current results suggest that CD47 plays a role in PMN recruitment through the regulation of β2 integrin adhesive function.

Grant Funding Source: Supported by NIH HL‐36028 and AHA fellowship 11POST7730055.
Is beta‐arrestin related to muscarinic receptor uncoupling in Alzheimer's disease? (153.4)
Authors: Potter Pamela , Bills Matthew , Killpack Luke , Hamada Matthew , Jones Douglas , Sue Lucia , Beach Thomas
Published: June 2021

The purpose of this study was to characterize the mechanism underlying muscarinic receptor uncoupling in patients with Alzheimer’s disease. We found previously that muscarinic receptors were uncoupled from G‐ proteins in brains of patients with Alzheimer’s disease, as well as in non‐demented controls with substantial β‐amyloid deposition and neuritic plaque formation1. We also have found that as plaque levels and β‐amyloid increased, levels of the G‐protein coupled receptor kinase GRK‐2 were significantly decreased, and Gq/11 protein was shifted from the cytosol to the membrane fraction. In the current study, levels of β‐arrestin, a protein involved in receptor recycling, were examined in four groups: patients diagnosed with Alzheimer’s (AD), age matched controls with many plaques (MP), age matched controls with sparse plaques (SP), and age‐matched controls with no plaques (NP). The amount of plaque formation was correlated with loss of cholinergic neurons as assessed by choline acetyltransferase (ChAT) activity. Levels of signal transduction markers were measured using Western blot. Levels of β‐amyloid were measured using ELISA. We found that β‐arrestin levels were decreased in both non‐demented groups with neuritic plaques as well as in those with Alzheimer’s disease, compared to the control group. It is likely that alterations in GRK, coupled with a decrease in β‐arrestin, could impair muscarinic receptor recycling. Loss of recycling could lead to downregulation or uncoupling of the receptors. Thus, it may be very important to attempt to circumvent impairment of signal transduction by addressing cholinergic dysfunction in treatment of Alzheimer’s disease.

1. Potter PE, Rauschkolb PK, Pandya Y, Sue LI, Sabbagh MN, Walker DG, Beach TG. Acta Neuropathol. 122:49‐60, 2011 2. Beach, T.G., Potter, P.E., Kuo, Y.‐M., Emmerling, M.R., Durham, R.A., Webster, S.D., Walker, D.G., Sue, L.I., Scott, S., Layne, K.J. and Roher, A.E. Neurosci. Lett. 283, 9‐12, 2000
Quiet but powerful: the role of the enteric nervous system in the pathophysiology of gastrointestinal disease (214.1)
Authors: Gershon Michael
Published: June 2021

The enteric nervous system (ENS) is large, complex, and uniquely able to function independently of the CNS. The ENS is also essential and, when defective, causes disorders of gastrointestinal (GI) motility, secretion, inflammation, and/or infection. Although the ENS is neural crest‐ and the CNS is neural tube‐derived, many developmental processes and molecules are common to both systems. Disruptions of GI function thus frequently occur together with cognitive/behavioral abnormalities as components of disorders (such as Parkinson's and autism) that affect both ENS and CNS. Serotonin (5‐HT) is a molecule that both gut and CNS express. Enteric 5‐HT is stored in enteroendocrine (EC) cells and neurons and participates in peristaltic reflexes, secretion, crypt cell proliferation, GI inflammation, neurotransmission, ENS development, and neurogenesis. EC cell and neuronal 5‐HT biosynthesis depend, respectively on tryptophan hydroxylase 1 (TPH1) and TPH2. A high affinity 5‐HT transporter (SERT) inactivates both mucosal and neuronal 5‐HT. Selective deletion of the TPH’s has enabled roles of EC cell and neuronal 5‐HT to be distinguished. Studies of mice that lack SERT, or which express SERT mutations associated with human disorders, confirm that enteric 5‐HT is multifunctional and link 5‐HT to the pathogenesis of GI manifestations of autism and functional GI disease.
Transdifferentiation of hypertrophic chondrocytes during endochondral bone repair by activation of pluripotent stem cell programs (216.1)
Authors: Bahney Chelsea , Hu Diane , Ferro Federico , Taylor Aaron , Miclau Ted , Marcucio Ralph
Published: June 2021

The majority of bone fractures heal by endochondral ossification, where bone forms secondarily to cartilage. Mechanistically bone repair is presumed to parallel endochondral ossification during development. Dogma holds that chondrocytes mature to hypertrophy, undergo apoptosis, and bone forms by invading osteoprogenitors. However, we have data to suggest chondrocytes transform directly into bone during regeneration. Consequently, we propose an alternate hypothesis where transdifferentiation of chondrocytes into osteocytes plays a direct role in endochondral bone regeneration. Using lineage tracing to follow cartilage transplanted into segmental bone defects created in murine tibiae, we demonstrate the vast majority of osteocytes are cartilage derived. Hypertrophic chondrocytes in the fracture callus are mineralized and express classic bone markers, without significant apoptosis. Instead some “transitioning” chondrocytes express Oct4A and sox‐2, suggesting that activation of the pluripotent programs may facilitate phenotypic transformation. Histologically this process appears coordinated by the invading vasculature and mineralization of cartilage can be fully recapitulated in vitro using endothelial cell conditioned medium. Taken together, these data suggest that there may be significant differences between endochondral ossification during bone development and repair.

Grant Funding Source: NIH NRSA F32 (Bahney), MTF Junior Investigator Award (Bahney), NIH #AR053645 & AR057 (TM)
Effects of maternal obesity on breastmilk composition and infant growth (247.7)
Authors: Panagos Patoula , Matthan Nirupa , Sen Sarbattama
Published: June 2021

Human and animal studies have suggested that maternal body composition and diet affects breastmilk (BM) composition, but there is no data on the effect of maternal obesity on BM composition. Hypothesis: BM composition of obese (Ob) mothers differs and predisposes their infants to increased adiposity and accelerated infant growth compared to lean control (Lc) mothers. Methods: This was a single center, prospective, case control study. BM was collected between 6 and 10 weeks postpartum from Lc (BMI 18‐25 kg/m2) and Ob (BMI >30 kg/m2) mothers. Results: BM from Ob mothers had increased saturated FA and trans FA and decreased monounsaturated FA and polyunsaturated FA content (p<0.05 by the Mann Whitney U test). FA’s with pro‐inflammatory properties (palmitic, docosatetranoic, and stearidonic acids) were increased, and those with anti‐inflammatory properties (gondoic, erucic, nervonic acids) were decreased, in BM from Ob mothers compared to Lc mothers. Total protein, lactose, fat, and calories of BM did not differ between the two groups. Ob infants were heavier, had a larger head circumference, and increased body fat at birth (p<0.05). This trend continued at two months of age, approaching statistical significance. Data analysis is ongoing; 29/42 samples and subjects have been analyzed. Micronutrient analysis is pending. Conclusions: Maternal obesity confers a pro‐inflammatory in utero and post natal environment which may contribute to the predisposition to obesity throughout the offspring lifespan.