bluuebunny/crossref_metadata_2025 huggingface dataset:
The Impact of Chronic Omega‐3 Polyunsaturated Fatty Acids Supplementation and Aerobic Training on Oxidative Stress Markers in Obese Women
Authors: Koozehchian Majid S. , Abdi Ahmad , Mehrabani Javad , Maryam Kaveh B , Earnest Conrad P.
Published: June 2021

PURPOSE

Increased intake of omega‐3 polyunsaturated fatty acids (n−3 PUFA) appear to have antioxidant properties. The purpose of this study was to examine the chronic effect of n−3 PUFA supplementation and aerobic training on oxidative stress markers in obese women.

METHODS

We performed a randomized, placebo‐controlled, double‐blind design on 43 obese women (48.5±2y; 39.7±5% body fat, 33.8±3 kg/m2, Supplement [SUP] n=11, Aerobic Training [AT] n=12, Supplement‐Aerobic Training [SAT] n=11, and Placebo [PLA] n=9). Oxidative stress markers including total antioxidant capacity (TAC), catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx) were measured at baseline and at week 8. All participants were asked to maintain their normal dietary intake throughout study. Participants in AT and SAT groups were required to follow an aerobic training program which was 45‐min running on the treadmill with 45–65% HRmax (3 d/wk) for an 8‐wk period, while the SUP and PLA groups did not perform any training program. Participants received either 4 g of fish oil (56% docosahexaenoic acid (DHA) and 28% eicosapentaenoic acid (EPA) or placebo (olive oil) in four divided doses per day for an 8‐week period. Data were analyzed by GLM and presented as mean (SD).

RESULTS

We observed a significant increase in serum TAC in SUP and SAT groups, but not in AT and PLA groups (p<0.04). The level of CAT was significantly higher only in SAT, but not in any other groups (p<0.01). We did not observe any significant change in serum SOD and GPx levels among the groups (p>0.05).

CONCLUSION

The present findings suggest that 4 g/day of fish oil for an 8‐week period, increase the activity of TAC and antioxidant enzymes. Fish oil supplementation might be considered as a protective strategy to improve the status of antioxidant defense system in obese women.

Support or Funding Information

This study was not funded.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Exploring Perception and Acceptance of Edible Insects as a Protein Source
Authors: Atakan S. Sinem , Wansink Brian
Published: June 2021

Edible insects are increasingly getting attention as an attractive source of protein due to their high protein quality and sustainability of their production compared to traditional sources of meat. However, consumers, especially Western consumers, may be aversive to eating insects (Tan et al., 2015). In order to encourage consumers towards sustainable sources of protein, it is crucial to examine the factors that shape consumers perception of edible insects.

The goal of this research is to understand which factors affect acceptance of different protein sources, more specifically insect protein. In order to do so, we compared perceptions of protein bars with one of the three labels (insect, soy, or whey) in an exploratory experiment (N=78).

The experiment was a 3 (protein type: whey vs. soy vs. insect) × 2 (order: evaluate‐taste vs. taste‐evaluate) between subjects design. In the experiment, one third of the participants were told that the protein bar sample they received had 10 grams of protein vs. soy protein vs. insect protein. All of the samples were from identical protein bars and had only regular whey protein. In addition, half of the participant first tasted the sample and then evaluated the sample (taste‐evaluate condition). The other half first evaluated the sample, then tasted it, and then evaluated the bar again (evaluate‐taste condition).

In the taste‐evaluate condition, all the three samples had identical evaluations. Participants did not indicate any differences in terms of taste or texture among the three protein sources when they sampled the bar before they answered the questions. They all thought that they would enjoy the protein bar at similar levels. However, in the evaluate first and then taste condition, contradictory to what previous research suggests, the sample protein bar with the insect protein label had higher evaluations in terms of both expected and actual taste. Simply labeling the protein bar sample as having insect protein enhanced its evaluations.

The results from our study challenge the common belief that Western consumers are likely to reject eating insects. Future studies will explore which specific factors encourage consumers to evaluate foods with insect protein as more favorable.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Role of Melanocortin‐4 Receptor Activation in Hypertension Induced by Chronic Intermittent Hypoxia
Authors: Maok Sydney P. , da Silva Alexandre A. , Hall John E. , do Carmo Jussara M.
Published: June 2021

Obesity is often associated with chronic intermittent hypoxia (CIH), increased sympathetic nervous system (SNS) activity and hypertension (HT). We previously demonstrated that melanocortin 4 receptors (MC4R) play a key role in regulating blood pressure (BP) in obesity and other conditions associated with increased SNS activity. In this study we examined if activation of CNS MC4R contributes to CIH‐induced HT. Wild‐type (WT, n=6), obese MC4R knockout (MC4R‐KO, n=5) and lean pair‐weighted (PW) MC4R‐KO (n=5) rats were instrumented with telemetry probes for measurement of mean arterial pressure (MAP) and heart rate (HR) 24‐hrs/day. The rats were exposed to CIH (8 hrs/day from 8:00–16:00 hours for 7 consecutive days). CIH significantly reduced food intake in obese MC4R‐KO rats by 50% leading to net cumulative reduction of −108±13 g compared to a −33±3 g cumulative food intake reduction in control WT rats. Food intake was kept at baseline values and was not altered by CIH in PW‐MC4RKO rats. Body weight was reduced by 7.5, 12.0 and 3.5 % in obese MC4R‐KO, WT and lean PW‐MC4R‐KO rats, respectively. CIH did not significantly alter plasma glucose concentration in MC4R‐KO or WT rats. However, CIH reduced plasma leptin concentration in obese MC4R‐KO rats (12±2 vs. 18±2 ng/mL during control period) while increasing leptin concentration in WT rats (1.8±0.5 vs. 0.9±0.1 ng/mL). CIH reduced fasting insulin concentration in WT rats (7±2 vs. 15±3 mU/mL) but did not alter insulin in MC4R‐KO rats (67±7 vs. 71±14 mU/mL). Baseline MAP was higher in obese and lean PW‐MC4R‐KO compared to WT rats (114±4, 112±2 and 107±2 mmHg), and CIH significantly increased MAP by approximately 11, 6 and 9 mmHg, respectively. Baseline HR was not different in obese MC4R‐KO and control rats (314±3 and 321±5 bpm), but lean PW‐MC4R‐KO had significantly lower HR (291±8 bpm). These results suggest that obesity and CNS melanocortin system may interact in complex ways to elevate BP during CIH. (NHLBI‐PO1HL51971, NIGMS P20GM104357)

Support or Funding Information

Department of Physiology and Biophysics and Mississippi Center for Obesity Research. University of Mississippi Medical Center, Jackson, MS.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Chronic Intermittent Hypoxia Causes Cellular Hypoxia in the Hippocampus
Authors: Khuu Maggie A. , Nallamothu Thara , Garcia Alfredo J.
Published: June 2021

The hippocampus is a brain structure frequently affected in individuals suffering from sleep apnea. Although hypoxia is a well‐recognized environmental change that negatively impacts hippocampal neurophysiology, it is unclear whether brief periods of hypoxia experienced during sleep apnea are sufficient for producing cellular hypoxia. We conducted immunohistochemical studies in tissue harvested from mice (P30–P50) exposed to 0 or 10 days of intermittent hypoxia (IH) to address this issue. Staining for protein adducts of reductively activated 2‐nitroimidazoles was used as marker for cellular hypoxia. Our ongoing experiments indicate that IH causes an increase in the number of hypoxic cells restricted primarily to the granular cell layer and subgranular zone of the dentate gyrus. While these findings suggest that cellular hypoxia caused by IH exposure may not be widespread throughout the hippocampus, we propose that increased cellular hypoxia in the dentate gyrus may contribute to changes in adult neurogenesis and synaptic plasticity in this area critical to cognition.

Support or Funding Information

Faculty Diversity Career Advancement Grant

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Bromine Exposure In Pregnant Mice May Reduce VEGF Signaling Via Increased Circulating VEGF Decoy Receptor sFlt‐1
Authors: Lambert James , Aggarwal Saurabh , Ford David , Patel Rakesh , Jilling Tamas , Matalon Sadis
Published: June 2021

Inhalation of oxidant gas and vapor like the halogen bromine (Br2) may pose an increased threat to pregnant women and their unborn fetuses. We recently published that pregnant (P) C57Bl/6 mice exposed to 600 ppm Br2 for 30 minutes on gestational day 14.5 (E14.5) exhibited increased mortality, lung injury, and blood pressure at E18.5 when compared to similarly exposed non‐pregnant (NP) mice. Additionally, fetuses of Br2‐exposed pregnant mice displayed severe growth restriction, which cumulatively indicated a preeclampsia‐like phenotype. Administration of the phosphodiesterase 5 (PDE5) inhibitor tadalafil abrogated or significantly mitigated these effects in Br2‐exposed pregnant mice but had no effect on non‐pregnant counterparts. We hypothesize that exposure to Br2 via inhalation in pregnant mice results in placental damage and subsequent release of anti‐angiogenic molecules into maternal circulation resulting in systemic endothelial dysfunction and a vasoconstrictive environment mediated by dysfunctional VEGF signaling. Firstly, we have identified significant increases at 0.5 h post‐Br2 exposure of circulating brominated fatty acids and fatty acid aldehydes (2‐BrPA and 2‐BrPALD) as well as their glutathionylated species at 6h. These may serve as potential biomarkers and/or mediators of Br2‐inhalation induced systemic injury. Furthermore, preliminary results indicate aortas incubated ex vivo in the presence of 2‐BrPA and 2‐BrPALD are more sensitive to the vasoconstricting agent phenylephrine and less sensitive to the vasodilator acetylcholine. Similarly, aortas pregnant mice exposed to Br2 are less sensitive to acetylcholine when compared with similarly exposed non‐pregnant mice. Secondly, utilizing time‐course measurements, we have identified increases in the circulating VEGF decoy receptor sFlt‐1 beginning at 72h post‐exposure in pregnant mice. No increase is observed in similarly exposed non‐pregnant mice (PBr272h 7280.3 ± 1592 vs NPBr272h 1233.5 ± 1063 pg/mL p≤0.001). Additionally, this time point also coincides with a pregnancy specific increase in lung edema/injury as evidenced by lung wet:dry weight ratios (P Br272h 4.68 ± 0.10 vs NP Br272h 4.22 ± 0.04 p≤0.05). Lastly, supplementation of exogenous VEGF‐121 intended to overcome the effects of increased circulating sFlt‐1 improves both survival and weight gain profiles of pregnant mice exposed to Br2 as well as their fetuses. This study implicates diminished VEGF signaling in pregnancy specific Br2 inhalation injury contributing to increased blood pressures, lung injury and subsequent mortality.

Support or Funding Information

NIEHS CounterACT ‐5U01ES026458 02, 1 U01 ES027697 01, Ruth L. Kirschstein National Research Service Award Institutional Training Grant ‐ T32HL007918.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Sleep Deprivation and Sympathetic Neural Control in Older Adults
Authors: Fonkoue Ida T. , Greenlund Ian M. , Schwartz Christopher E. , Smoot Carl A. , Mokhlesi Babak , Carter Jason R.
Published: June 2021

Epidemiological studies have suggested a link between sleep deprivation and hypertension, and that this link is stronger in women. Our laboratory recently reported that baseline sympathetic neural responses to total sleep deprivation (TSD) were different in young men and women, with a greater shift towards sympathetic predominance in young women. Postmenopausal women are at high risk for hypertension. In the present study, we hypothesize that TSD will alter sympathetic neural activity in older adults, with greater sympathoexcitation in postmenopausal women. Nine participants between the ages of 55 and 75 years (9 women and 7 men) participated in the study. Subjects were tested twice one month apart, once after 24‐hour TSD and once after normal sleep. Wrist actigraphy was worn 5 days prior to each testing to confirm normal sleep patterns. We recorded muscle sympathetic nerve activity (MSNA; microneurography), beat‐to‐beat blood pressure (finger plethsmography), and heart rate (electrocardiogram) during 5 min of supine, awake rest. TSD elicited divergent MSNA responses in older men and women. Specifically, MSNA burst frequency increased in postmenopausal women (31±3 to 35±3 burst/min), but not older men (39±3 to 36±4 burst/min; time × condition, p = 0.036). This shift towards sympathetic predominance in women was also observed when MSNA was quantified as burst incidence (time × condition, p = 0.034). TSD did not alter baseline mean arterial pressure (men, 89±5 to 87±3 mmHg; women, 84±4 to 84±3) or heart rate (men, 55±3 to 55±4 beats/min; 58±3 to 60±4 beats/min) in either group (time, p>0.05; time × condition, p> 0.05). In summary, 24‐hour TSD elicits divergent MSNA responses in older men and women, with greater sympathoexcitation in postmenopausal women. These findings provide new mechanistic insight into reported links between sleep deprivation and hypertension.

Support or Funding Information

Funding support from the National Institutes of Health (HL‐122919) and Portage Health Foundation.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Influence of Liposome Encapsulated Vitamin C on the Cardiac Autonomic Response To A High‐Calorie Meal
Authors: Bell Christopher , Hanson Moriah Ruth , Fleck Joshua Robert , Grimm Nathan Carlisle
Published: June 2021

Oxidative stress is adversely associated with heart rate variability and may be favorably modified with ingestion of antioxidants. The purpose of this study was to determine if prior ingestion of liposome encapsulated vitamin C favorably modifies the cardiac autonomic response to a high‐calorie meal. Ten young healthy adults (age: 26 ± 2 years, body mass index: 24.0 ± 1.4 kg/m2; blood pressure: 113/68 ± 3/2 mmHg; mean ± SE) ingested either a placebo or 5 g of liposome encapsulated vitamin C. Two hours later, they ingested a high‐calorie liquid meal (979 kcal; 30% fat, 64% carbohydrate, 6% protein). Circulating vitamin C concentrations, blood pressure and heart rate variability were measured over 6‐hours. Compared with placebo (0.7 ± 0.1 mg/dL), liposome encapsulated vitamin C ingestion appreciably increased circulating vitamin C (peak: 3.3 ± 0.1 mg/dL; P<0.01); concentrations remained high at 6‐hours (2.0 ± 0.1 mg/dL). Systolic blood pressure was increased following the meal however the magnitude of increase was lower with prior liposome encapsulated vitamin C (time × treatment interaction: P=0.019). Heart rate variability (standard deviation of R‐to‐R interval) was greater in the placebo compared with liposome encapsulated vitamin C (main effect: 104 ± 3 vs. 94 ± 3 ms; P=0.04) and decreased 1‐hour after the meal (main effect: 102 ± 5 vs. 87±5 ms; P=0.02); liposome encapsulated vitamin C did not influence this response (P=0.563). Similarly, the LF/HF ratio was greater with liposome encapsulated vitamin C compared with placebo (main effect: 7.3 ± 1.4 vs. 12.0 ± 1.4; P=0.041). Liposome encapsulated vitamin C appreciably increased circulating vitamin C concentration, favorably modified the systolic blood pressure response to a high‐calorie meal while potentially unfavorably modifying the heart rate variability response.

Support or Funding Information

Empirical Labs

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
TONIC GLUTAMATE NEUROTRANSMISSION BY NMDA RECEPTORS IN PARAVENTRICULAR NUCLEUS IS INCREASED IN CONSCIOUS RATS INDUCED TO 6‐OHDA PARKINSONISM
Authors: Martins‐Pinge Marli Cardoso , Amorim Eric Diego Turossi , Rodrigues Ananda Totti , Ariza Deborah , Crestani Carlos Cesar
Published: June 2021

Parkinson's disease (PD) is a progressive neurodegenerative disease that manifests itself clinically after reaching an advanced pathological stage. In addition to the motor signals, PD patients present cardiovascular changes that appear to be accompanied by alterations in the autonomic nervous system. Recent data have shown that rats induced to Parkinsonism through bilateral administration of 6‐hydroxydopamine (6‐OHDA) in the substantia nigra pars compacta (SNpc) showed lower mean arterial pressure (MAP) and heart rate (HR) compared to their controls, as reduction in sympathetic modulation. The paraventricular nucleus of the hypothalamus (PVN) is an important structure for the integration of autonomic function and blood pressure (BP) control in the different behavioral and pathological situations. Thus, the aim of this study was to evaluate the role of PVN excitatory pathways in the cardiovascular and autonomic regulation during Parkinsonism induced by 6‐OHDA. Male Wistar rats were anesthetized and two guide cannulas were implanted into the PVN. 6‐OHDA or sterile saline was bilaterally administered directly into the SNpc. After 6 days and twenty‐four hours before the experiments, the animals were anesthetized and a polyethylene catheter was inserted into the abdominal aorta through the femoral artery and externalized dorsally to record MAP and HR in the conscious state. Administration of bicuculline (gabaA antagonist) in the PVN in sham group promoted an increase in MAP (Bic: 123 ± 7, baseline: 109 ± 5 mmHg) and HR (Bic: 435 ± 22, baseline: 355 ± 11 bpm). In the 6‐OHDA group, bicuculline exacerbated the increases in MAP and HR observed (MAP, 136 ± 3 mmHg; FC, 487 ± 8 bpm). Additionally, NBQX (non‐NMDA receptor inhibitor) did not promote changes in MAP and HR of the sham group, just as in 6‐OHDA group. On the other hand, microinjection of LY235959 (inhibitor of NMDA glutamate receptor) in the PVN of the sham group did not promote cardiovascular alterations, but in the 6‐OHDA group there was a decrease in MAP (LY: 83 ± 4, baseline: 98 ± 5 mmHg) and HR (LY: 251 ± 12, Baseline: 310 ± 14 bpm). Confirmation of 6‐OHDA lesion was observed by decreased levels (at least 70%) of dopamine in striatum. Our data suggest a role of NMDA receptors in the PVN, on tonic cardiovascular control of 6‐OHDA Parkinsonism in rats.

Support or Funding Information

Fundação Araucária; Capes (fellowship to EDTA); CNPq (Research fellowship to MCMP and CCC)

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Intense Fear Induces Low‐Frequency Oscillation of Cerebral Blood Flow, Arterial Pressure, and Sympathetic Nerve Activity in Conscious Rats
Authors: Miki Kenju , Akiyama Yumiko , Ukita Hiroka , Nagao Kana , Kataoka Shizuka , Yoshimoto Misa
Published: June 2021

A traumatic event, such as disaster, causes intense fear, which potentially leads to an increase in occurrence of cerebrovascular diseases. Little information is available regarding why intense fear causes cerebrovascular diseases. The present study aimed to measure cerebral blood flow, arterial pressure, and sympathetic nerve activity during intense fear conditioning in conscious rats. Wistar rats were chronically instrumented with a probe made with glass fiber for measuring hippocampal cerebral blood flow. Electrodes for measurements of renal (RSNA) and lumbar sympathetic nerve activity (LSNA) were inserted, as well as for an electroencephalogram, electromyogram, and electrocardiogram. A catheter was inserted for measuring systemic arterial pressure. Standard fear‐conditioning trials, in which a tone was paired with a brief electrical shock (5 mA, 2 s), were performed in rats two times per day over 3 days. Oscillation of arterial pressure with an amplitude of 15.7 mmHg and frequency of 0.075 Hz was induced by exposing a tone without electrical shock in fear‐conditioned rats. Arterial pressure oscillation was associated with synchronized oscillation of hippocampal cerebral blood flow, RSNA, and LSNA. Coherence between arterial pressure and hippocampal cerebral blood flow, RSNA, and LSNA was significantly increased at low frequency (0–1 Hz) compared with naive rats. These data suggest that intense fear can trigger disorder of sympathetic regulation of arterial pressure, causing low‐frequency oscillation of arterial pressure and synchronized changes in cerebral blood flow. This may be one of the causes of cerebrovascular disease induced by intense fear.

Support or Funding Information

JSPS Grant

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Effect of High Fat High Fructose Diet on Peripheral Immune Cell Trafficking into the Brain in CCR2 Mouse Model
Authors: Sniffen Lindsey J. , Eidson Lori N. , Herrick Mary K. , MacPherson Kathryn P. , de Sousa Rodrigues Maria E. , Tansey Malu G.
Published: June 2021

Recent studies about the gut‐brain axis suggest that high fat high fructose (HFHF) consumption is associated with chronic peripheral inflammation due to disruption of gut flora. Some evidence suggests that chronic peripheral inflammation may increase blood‐brain barrier (BBB) permeability. This may lead to increase in neuroinflammation and development of neurodegenerative diseases. The current study aims to observe the relationship between HFHF diet and BBB trafficking. We hypothesize that peripheral inflammation induced by HFHF diet will increase BBB permeability allowing for increased peripheral monocyte trafficking to the brain. To test this hypothesis, a mouse with red fluorescent protein (RFP) driven by the chemokine receptor 2 (CCR2), was treated with HFHF or control diet (CD) for five weeks to induce chronic inflammation. CCR2 is expressed on peripheral monocytes and to a lesser degree on microglia in the brain. To differentiate between resident microglia and brain infiltrating peripheral monocytes, tissue sections were stained with CD169, a marker specific for peripheral monocytes. Brain sections from CCR2‐RFP mice were stained by immunofluorescence in the hippocampal areas of CA1, CA3, and the dentate gyrus as these areas are affected in the neurodegenerative Alzheimer's Disease. CD169 and CCR2 stained cells were quantified using mean intensity to determine the effects of diet on infiltrating peripheral monocytes. In CA3, CCR2 CD mice presented with significantly decreased CCR2 and CD169 mean intensity as compared with WT CD mice (p=0.048, p=0.03). This may be because the Tg only has one allele of CCR2, permitting less trafficking than WT mice, which have two alleles. In CA1, there was a main effect of diet such that Tg HFHF treated mice showed a significant decrease in CD169 mean intensity compared to Tg CD (p=0.02). The low number of animals, the old age of the animals, and the time treated with diet may have impacted our findings. The current data did not support our hypothesis that HFHF diet increases peripheral trafficking across the BBB. Future directions include repeating this experiment with more animals, and treating the animals with HFHF diet for a longer period.

Support or Funding Information

Work was funded by the NIH NIA RO1 RF1AG051514 (MGT) and the APS IOSP Fellowship.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Hyperoxia‐Induced Bronchopulmonary Dysplasia in Neonatal Rats Acutely and Chronically Alters the Control of Breathing
Authors: Mouradian Gary Charles , Argote‐Alvarez Santiago , Thuku Gabriel , Gorzek Ryan , Brannon Avonlea , Mui Amanda , Konduri Girija Ganesh , Hodges Matthew
Published: June 2021

Infants born prematurely have immature lungs, and the neural mechanisms that control breathing are still developing. Premature infants often require supplemental oxygen therapy (hyperoxia) which acutely improves oxygen saturation but consequently leads to bronchopulmonary dysplasia (BPD; chronic lung disease in infants). Whether hyperoxia‐induced BPD also exacerbates the control of breathing is unknown. Thus, the major objective of this study was to elucidate the short and long‐term effects of hyperoxia‐induced BPD on the control of breathing. Sprague Dawley rat pups were exposed to room air (21% O2/Bal. N2) or hyperoxia (90% O2/Bal. N2) from postnatal day 0–10 (P0–10) and ventilation measured during room air (20 min) and hypoxic (10 min; 12% O2/Bal. N2) conditions at P10, 12, 14, 17, 21, 43, and 60 using plethysmography to test the hypothesis that hyperoxia‐induced BPD would decrease breathing stability and impair development of key brainstem respiratory nuclei. By P20, hyperoxic treated pups had significantly (p<0.05) reduced inspiratory (33%) and expiratory flow rates (24%) compared to control (normoxic‐reared) pups, consistent with BPD and pulmonary histologic data from prior publications. Minute ventilation in hyperoxia‐treated pups was significantly decreased (−20% of control) at P10 but increased thereafter while breathing room air (+50% of control; P12–14), and increased ~25% under hypoxic conditions (P12–14, 60, p<0.05). These changes were initially driven by significant increases in breathing frequency (P12–17; +20–46%) and later by increased tidal volume (P43–60; 50%). Room air and hypoxia breathing frequency variability was significantly lower by 20–35% from P10–21 and elevated by 70% at P60, respectively. Moreover, the cumulative histograms of breathing frequencies binned every 10 breaths/min were significantly different in room air and hypoxia conditions across all ages in hyperoxic pups compared to control pups. Preliminary analyses indicated tidal volume variability across room air and hypoxia is also significantly elevated acutely (P10) by 100% and chronically (P60) by 250% in hyperoxic pups compared to control pups. Additional preliminary data indicate increased expression of an astrocytic marker (GFAP) throughout brainstem respiratory nuclei in P60 rats perinatally treated with hyperoxia, consistent with astrogliosis. These data demonstrate significant and lasting anatomical and physiological changes to the brainstem and the neural control of breathing in a rat model of BPD, suggesting additional potential pathologies in human BPD patients.

Support or Funding Information

Children's Hospital of Wisconsin Research Institute

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Developmental consequences of intra‐uterine exposure to cannabinoids: impact on the ventilatory system of newborns rats
Authors: Patrone Luis Gustavo A. , Bicego Kenia C. , Gargaglioni Luciane H.
Published: June 2021

The endocannabinoid system is already present in the central nervous system in the early stages of embryonic development, including in areas responsible for respiratory control. Cannabis sativa (marijuana) is the illicit drug most commonly used during pregnancy. However, the relationship between marijuana use and ventilatory problems in the offspring is uncertain. Therefore, the present study evaluated the effects of exposure to cannabinoids during the gestational period on the respiratory control system in P6–7 and P12–13 male rats. To this end, osmotic pumps were implanted subcutaneously in pregnant female rats at embryonic day 0 and delivered vehicle or CB1 receptor agonist (WIN55,212–2, 0.5 mg/Kg/day) for 21 days. Ventilation (VE) of newborn was recorded during normocapnia and hypercapnia (7% CO2), as well as the O2 consumption (VO2). Our data showed a 15% increase of hypercapnic ventilatory response in P6–7 WIN‐treated animals during 7% CO2 due to a higher respiratory frequency and an increase of the respiratory equivalent. For P12–13 rats, WIN‐treated animals showed a hyperventilation (VE/VO2) in basal conditions and an increase hypercapnic ventilatory response (~20%) due to an increase in both tidal volume and respiratory frequency. No difference in VO2 was observed between groups for both ages. Our results suggest that a chronic and over activation of endocannabinoid system during gestation alters basal ventilation and CO2‐drive to breathing during neonatal period.

Support or Funding Information

Sao Paulo Research Foundation (FAPESP) and National Council for Scientific and Technological Development (CNPq)

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Reduced HIF1a Signaling Enhances Apneas During Perinatal Development
Authors: Garcia Alfredo J. , Moody Elissa J. , Xiao Jason
Published: June 2021

Immature neonatal breathing is characterized by the occurrence of periodic apneas that disrupt the breathing rhythm and cause intermittent hypoxia (IH). IH has been proposed as a factor that facilitates the development of respiratory control allowing for the transition from unstable to stable breathing rhythms where apneas no longer occur. In adults, IH increases hypoxia inducible factor 1a (HIF1a) signaling that remodels respiratory control and augments peripheral chemoreflexes. However, it is unclear whether HIF1a signaling contributes to the stabilization of immature neonatal breathing during the first days of perinatal life. To address this, we used whole body plethysmography to track perinatal development of breathing beginning at postnatal day zero (P0) in mice heterozygous for hypoxia inducible factor 1a (HIF1a+/−) and wildtype littermates (WT). At P0 we observed unstable breathing rhythms characterized by periodic apneas in both genotypes. However, in HIF1a+/− (n=4) apnea number was 50% greater and apnea duration was 172% longer when compared to the WT (n=3). Our ongoing experiments suggest that the switch to stable breathing rhythms occurs between postnatal days three and four. Our findings indicate that HIFa signaling is important to the of the neonatal breathing rhythm.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Functional Impact of Diaphragm Muscle Sarcopenia in Fischer 344 Rats
Authors: Sarrafian Tiffany L. , Khurram Obaid U. , Fogarty Matthew J. , Bhatt Arjun , Mantilla Carlos B. , Sieck Gary C.
Published: June 2021

The diaphragm muscle (DIAm) is the primary inspiratory muscle responsible for force generation across a range of ventilatory and higher force airway clearance behaviors throughout life. Our laboratory has previously reported DIAm sarcopenia, the age‐related atrophy and weakening of skeletal muscle, in multiple rodent models. Interestingly, in Fischer 344 rats, there is an increase in body mass from 6 to 24 months of age, which is greater in females (~140%) than in males (~110%), suggesting potential sex‐related differences in the manifestation of sarcopenia. Transdiaphragmatic pressure (Pdi) measurements provide information about force generation in vivo across a range of motor behaviors. The purpose of this study was to evaluate if there are sex‐related differences in DIAm sarcopenia, and if such differences translate to a functional impact on Pdi generation. We hypothesized that because of differences in weight gain, DIAm sarcopenia is more pronounced in male vs. female Fischer 344 rats, and that there is a greater impact of sarcopenia on maximum Pdi generated by bilateral phrenic nerve stimulation (Pdimax). Since Pdi generated across a range of ventilatory motor behaviors only requires <50% Pdimax, we also hypothesize that sarcopenia does not impair Pdi generation during ventilatory behaviors. Compared to 6‐month old rats, DIAm sarcopenia was apparent in ‐24‐month old rats of both sexes with a 30% reduction in maximum specific force. There was also a ~20% decrease in the cross‐sectional area of type IIx and/or IIb fibers with age, and this reduction was more pronounced in male rats. Thus, these mixed results do not entirely support our hypothesis of more pronounced DIAm sarcopenia in male rats. However, DIAm sarcopenia was associated with a ~30% decrease in Pdimax that was comparable between male and female rats. Importantly, the Pdi generated during ventilatory behaviors was unaffected by DIAm sarcopenia, even during more forceful ventilatory efforts induced by complete oropharyngeal airway occlusion. Although ventilatory behaviors are preserved with aging, a reduction in Pdimax indicates an impaired ability of the DIAm to generate higher force expulsive airway clearance behaviors necessary for maintaining airway patency.

Support or Funding Information

NIH R01‐AG044615 and T32‐HL105355

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Respiratory EMG responsiveness to hypercapnic hypoxia in mdx mice
Authors: Murphy Kevin Humphrey , Burns David Patrick , Lucking Eric , O'Halloran Ken
Published: June 2021

Duchenne muscular dystrophy (DMD) is a fatal neuromuscular disease characterised by the absence of the structural protein dystrophin. Respiratory failure is the leading cause of premature death in DMD. Although respiratory insufficiency is recognized as a hallmark of DMD, respiratory control is relatively understudied. We hypothesized that enhanced drive in accessory respiratory motor pathways preserves ventilatory capacity compensating for severe respiratory muscle weakness.

We utilised the C57BL/10ScSn‐Dmdmdx/J (mdx) mouse model. Respiratory flow recordings were performed in freely‐behaving wild‐type (WT, n=9) and mdx (n=7) mice at ~8 weeks of age using whole‐body plethysmography to determine ventilation (VE), oxygen consumption (VO2) and carbon dioxide production (VCO2). Baseline recordings were performed in normoxia, followed by chemostimulation using hypercapnic hypoxic gas challenge (FiO2=0.10; FiCO2=6; balance N2). In urethane (1.6 g/kg) anaesthetised WT (n=13) and mdx (n=14) mice, diaphragm, intercostal and genioglossus EMG and motor unit recordings were performed during baseline conditions and in response to chemostimulation.

Plethysmographic recordings revealed that during chemostimulation, minute ventilation (VE) is equivalent in WT and mdx mice, highlighting a considerable ventilatory reserve in young mdx despite substantial diaphragm muscle weakness. Moreover, diaphragm, intercostal and genioglossus EMG responsiveness to hypercapnic hypoxia was equivalent in WT and mdx mice.

Despite substantial diaphragm weakness and evidential muscle fibre damage and remodelling, freely behaving mdx mice can achieve enhanced ventilation during chemostimulation to levels equivalent to that of WT animals. We found no evidence of enhanced activity in respiratory muscle EMGs. Assessment of the motor unit population will allow for the comparison of the phenomena of rate coding and recruitment during increased respiratory muscle activation. Our study suggests that respiratory muscle weakness in young mdx does not compromise ventilator behaviour but is likely to have considerable impact on airway protective behaviours.

Support or Funding Information

Department of Physiology, University College Cork, Cork, Ireland

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Impact of Intralingual AAVrh10‐miRSOD1 Injection on Respiratory Function in SOD1G93A Mice
Authors: Lind Lori A. , Johnson Katherine A. , McCall Angela L. , Mueller Christian , Brown Robert H. , Lever Teresa E. , Elmallah Mai K. , Nichols Nicole L.
Published: June 2021

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease in which patients normally succumb to the disease within 5 years of onset. Death is usually a result of impaired respiratory function due to loss of motor neurons that control upper airway muscles and/or the diaphragm. The motor neurons that control upper airway muscles and thereby airway patency are found in the brainstem in a region called the hypoglossal motor nucleus. One cause of ALS is a mutation in the superoxide dismutase‐1 (SOD1) gene that results in the buildup of SOD1 protein in neurons. For this subset of patients, reducing expression of the mutated gene may slow the progression of the disease. The purpose of this study was to determine if delivering a microRNA against SOD1 (miRSOD1) to the hypoglossal motor nucleus of mice that overexpress mutant SOD1 (SOD1G93A) would increase respiratory function. Thus, we hypothesized that intralingual injection of AAV‐miRSOD1 into SOD1G93A mice would knockdown mutant SOD1 in hypoglossal motor neurons and improve respiration. Six‐week‐old male and female mice received intralingual injections of either AAVrh10‐miRSOD1 or vehicle (phosphate buffered saline). Starting at 13 weeks of age, respiratory parameters at baseline and in response to hypoxia (11% O2) + hypercapnia (7% CO2) were studied in miRSOD1‐injected SOD1G93A mice (n=11), vehicle‐injected SOD1G93A mice (n=12), and vehicle injected wild‐type mice (n=17) via whole‐body plethysmography every other week until the SOD1G93A mice reached end‐stage (20% body weight loss). Minute ventilation during hypoxia + hypercapnia and mean inspiratory flow at baseline were significantly reduced (p<0.05) in vehicle‐injected but not miRSOD1‐injected SOD1G93A mice as compared to wild‐type mice. miRSOD1 injections also extended survival in females by ~1 week; although this did not reach statistical significance, we suggest that any increase in survival could be clinically significant. In conclusion, this study indicates that intralingual miRSOD1 treatment restored respiratory function to wild‐type levels (potentially via increasing upper airway patency) and is worthy of further exploration as a possible therapy to preserve respiratory capacity in ALS patients. Future directions include studying the vector genome expression and SOD1 knock down in local and systemic tissues to understand the degree of transduction. In addition, we will measure the impact of intralingual miRSOD1 on swallowing and upper airway function.

Support or Funding Information

Supported by NIH R21 NS098131‐02 and K99/R00 HL119606

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Developmental Nicotine Exposure: Diaphragm Contractility and Neuromuscular Transmission in Neonatal Rats
Authors: DeLucia Claire M. , Whalen Mikayla , Fregosi Ralph F.
Published: June 2021

Developmental nicotine exposure (DNE) results in chronic desensitization of nicotinic acetylcholine receptors (nAChRs) in the brain. Due to the presence of nAChRs at the neuromuscular junction, we investigated whether DNE alters the fatigability and/or neuromuscular transmission (NT) in neonatal rat diaphragm. Neonatal rat (P1–P12) phrenic nerve‐hemidiaphragm preparations were excised and secured in a dish perfused with warmed (37°C), oxygenated Krebs solution. Force production was measured during both supramaximal muscle or phrenic nerve stimulation. Fatigue was induced using five minutes of repeated stimulation (0.2 ms pulse duration) delivered to the muscle or nerve at 40Hz, in 330ms trains every 2 seconds. To quantify NT, repeated trains were applied to the nerve with superimposed muscle stimulation every 15 seconds for five minutes. When collapsed across all postnatal ages, there were no significant differences in NT. In DNE animals, force fell to 51.26 ±3.26% of baseline (n=13), while in unexposed animals force fell to 53.79 ±4.37% of baseline (n=12; p=0.644). Five minutes of either nerve only or muscle only stimulation also resulted in similar rates of force decline in DNE and unexposed control animals. In addition, no differences in contractile properties evoked with supramaximal muscle stimulation were found between DNE and unexposed animals, including peak force, time to peak, or ½ relaxation time. Taken together, our preliminary results suggest DNE does not alter diaphragm neuromuscular transmission, fatigability, or contractility in neonatal rats studied in the first two weeks of life, though early developmental effects cannot be ruled out.

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Lung epithelial PDIA3 plays a critical role in influenza infection
Authors: Chamberlain Nicolas , Mihavics Bethany , Nakada Emily , Bruno Sierra , Heppner David , Chapman David , Hoffman Sidra , Siddesha Jalahalli , van der Vliet Albert , Suratt Benjamin , Dienz Oliver , Alcorn John , Anathy Vikas
Published: June 2021

RATIONALE

The influenza A virus (IAV) causes severe respiratory illness in humans. Current treatments are rapidly becoming ineffective due to the emergence of viral resistance to available therapies. Given the impact of IAV on human health and health care costs there is an urgent need to explore novel targets for treatments to control IAV. Previous work has demonstrated infection with IAV induces endoplasmic reticulum (ER) stress, effectuating the unfolded protein response (UPR), a highly conserved cellular stress response that seeks to restore normal ER homeostasis. It has also been shown that interactions with host ER based protein disulfide isomerases (PDIs) are upregulated during the UPR and are required for specific IAV proteins to reach their functional conformations in vitro. The viral proteins hemagglutinin (HA) and neuraminidase (NA) both contain numerous disulfide bonds necessary for their function. Our results demonstrate both HA and NA interact with PDIA3; a chaperone responsible for the catalysis and isomerization of disulfide bonds. However it is unknown whether these host‐viral protein interactions are required during active infection in vivo and whether PDIA3 represents a putative therapeutic target during H1N1 infection.

OBJECTIVE

To investigate the role of host PDIA3 in the establishment of H1N1 infection and development of subsequent immunopathology.

METHODS

The impact of PDIA3 in IAV infection was examined using lung epithelial specific PDIA3 knockout mice and various inhibitors of PDIs in isolated primary mouse tracheal epithelial cells (MTEC).

RESULTS

We found that the conditional deletion of PDIA3 in our mouse model resulted in a significant decrease in the number of inflammatory‐immune cells in bronchoalveolar lavage fluid and a marked decrease in IAV‐mediated methacholine induced airway hyperresponsivness, illustrating that PDIA3 plays a significant role in influenza‐induced immunopathology. Interestingly, our data further show that deletion of PDIA3 in vivo affected production of IAV proteins HA and NA. Moreover, We also observed significant alterations in the oxidative folding of HA as well as decreases in IAV induced proinflammatory cytokines in MTECs treated with the PDI inhibitors in vitro.

CONCLUSIONS

These data suggest that lung epithelial PDIA3 plays a critical role in the establishment of IAV infection and propagation of the virus, and illustrate the potential of utilizing PDIA3 as a target for future anti‐viral therapies.

Support or Funding Information

NIH R01 HL12238 (VA) NIH T32 HL076122 (NC) Department of Pathology and Laboratory Medicine (UVM) Startup Fund (VA)

This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Pannexin 1 and a Venous‐specific Purinergic Cascade Induces Endothelial Leak in Response to TNFα
Authors: Comstra Heather Skye , Begandt Daniela , Molina Samuel , Krüger Nenja , Biwer Lauren , Johnstone Scott R. , Lohman Alexander , Good Miranda E. , DeLalio Leon J. , Bacon Hannah , Isakson Brant E. , Koval Michael
Published: June 2021

Disruption of the endothelial barrier by pro‐inflammatory cytokines is a complication of multiple diseases, including sepsis that can result in tissue edema. To assess the effect of TNFα on native endothelial permeability, we customized an Ussing chamber to record electrophysiological measurements of ex vivo mesenteric mouse venules or arterioles that were treated with either DMSO vehicle control or 50ng/ml TNFα for 30 minutes. Venules showed a TNFα‐dependent decrease in transendothelial electrical resistance (TEER), whereas arterioles did not. An in situ microvessel perfusion system also demonstrated preferential increases in fluorescein permeability in TNFα treated venules versus arterioles. Human umbilical and saphenous vein (HUVEC and HSaVEC) cells cultured on Transwell permeable supports showed a comparable decrease in TEER in response to TNFα; cultured aortic and coronary arterial (HAoEC and HCoEC) endothelial cells did not. At tight junctions, we found that in addition to claudin‐1 and claudin‐5, venous endothelial cells also expressed claudin‐11. Upon addition of TNFα, venous claudin protein expression was significantly reduced. To investigate molecular mechanisms underlying the differential effect of TNFα on venous and arterial cells, we targeted pannexin 1 (PANX1) channel activity using the antagonists mefloquine and spironolactone in vitro and in venules from conditional PANX1 knockout mice and found that in all cases TNFα‐induced permeability was eliminated. Further analysis of purinergic signaling in venous endothelium revealed that the ectonucleotidase CD39 is expressed at higher levels in veins than arteries and that addition of the CD39‐antagonist ARL67156 abolished TNFα‐induced permeability in venules from wildtype mice. Coupled with expression of CD73, this result suggests that ATP released by PANX1 is metabolized to adenosine as an autocrine signal produced in response to TNFα. Consistent with adenosine signaling, TNFα‐induced permeability was impaired in venules isolated from wildtype mice in the presence of A2A and A2 antagonists as well as in venules from A2A knockout mice. Our results demonstrate that targeting the purinergic signaling pathway mitigates TNFα‐induced permeability in venous cells. These findings offer multiple possibilities for pharmacological interventions aimed at preventing and treating increased vascular permeability during inflammation.

Support or Funding Information

R01 AA025854

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