bluuebunny/crossref_metadata_2025 huggingface dataset:
Gestational Intermittent Hypoxia Reduces Basal Levels of Interleukin‐1 alpha Gene Expression in Neonatal Brainstem Microglia: Implications for Respiratory Control
Authors: Knutson Andrew Owen , Ewald Andrea , Kiernan Elizabeth , Baker Tracy , Watters Jyoti
Published: June 2021

The in utero environment strongly impacts the developing fetus, and perturbations during this critical developmental window can have long lasting, negative consequences on offspring physiology. Intermittent hypoxia, a hallmark of obstructive sleep apnea, causes profound inflammation, is common during the third trimester of pregnancy, and is rising in parallel with the obesity epidemic. Although maternal immune activation is well‐known to influence fetal brain development and microglial immune activities, the consequences of gestational intermittent hypoxia (GIH) on microglia in CNS regions essential for respiratory neural control have not been studied. Given the important role of microglia in brain development during the first 2 postnatal weeks of life, and the importance of the critical period in postnatal respiratory development, we evaluated inflammatory gene expression in brainstem microglia in 14 day old (P14) rat pups whose dams were exposed to intermittent hypoxia (2 minutes alternating between 21% O‐2/10.5% O‐2) or normoxia (alternating between 21% O2/21% O2; GNX) for 8hrs/day during gestational days 10–21. Microglia were immunomagnetically isolated from the brainstems of GNX and GIH P14 pups, and inflammatory gene expression was analyzed by qRT‐PCR. While there were sex‐dependent differences in the basal expression of several key inflammatory cytokine genes in brainstem microglia, we focus here on interleukin‐1 alpha (IL‐1α). The expression of IL‐1α was 3.5‐fold higher in GNX female microglia than in male (p=0.014; N=5 each), indicating a strong sexual dimorphism in the expression of this cytokine in normal brainstem microglia. Very interestingly however, IL‐1α mRNA levels were significantly reduced by GIH only in female microglia (p=0.03; N=5 each), although they approximated those in GNX male microglia. IL‐1α is a unique cytokine in that it is an alarmin‐ a molecule that is released early after insult that signals tissue damage and activates the immune system. It has not been specifically studied in the respiratory neural control system to our knowledge, but the downregulation of IL‐1α by GIH in female brainstem microglia may reflect a compensatory response that is absent in males to combat the inflammatory uterine environment caused by maternal intermittent hypoxia. Studies are currently underway to further investigate the role of IL‐1α in respiratory neural control.

Support or Funding Information

Supported by NS085226, HL105511, and Wisconsin Alumni Research Foundation UW2020 grant

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Electrical activation of phrenic afferent neurons evokes phrenic motor plasticity following cervical spinal cord injury
Authors: Streeter Kristi A. , Wollman Lila B. , Fusco Anna , Poirier Thomas , Salminen Jake , Fuller David
Published: June 2021

Anatomical data from our laboratory indicate that phrenic afferent fibers can project across the spinal midline and neurophysiological data indicate that electrical activation of phrenic afferents can increase contralateral phrenic motor output. We have also observed that following chronic unilateral C2 hemisection (C2Hx) phrenic nerve afferent fibers undergo significant anatomical remodeling. Here we tested the hypothesis that following chronic C2Hx, activation of ipsilateral (same side as injury) phrenic afferent neurons would induce contralateral (opposite to injury) phrenic motor plasticity. Twelve weeks after unilateral C2Hx (n=9) or C2 laminectomy (n=8), adult Sprague‐Dawley rats were anesthetized, vagotomized, and ventilated to enable phrenic motor output to be studied under controlled conditions. The phrenic nerve ipsilateral to C2Hx or laminectomy was electrically stimulated using a bipolar electrode while contralateral phrenic motor output was recorded. Rats received 30 minutes of inspiratory triggered stimulation (90μA, 40pps, 1ms pulse width) and contralateral phrenic motor output was recorded for one hour. Analysis of contralateral burst amplitude using a two‐way repeated measures ANOVA revealed a significant effect of time (F3,45=9.505, P<0.0001), but not treatment (C2Hx vs. laminectomy, F1,15=0.1577, P=0.6969). Thus, phrenic burst amplitude was significantly changing over the 60 minute post‐stimulation, and both experimental groups had increased phrenic burst amplitude during this period (P<0.05 vs. pre‐stimulation baseline). These results indicate that electrical activation of phrenic nerve afferent fibers can induce a sustained increased (facilitation) of contralateral phrenic motor output after spinal cord injury. The response was not statistically different in the laminectomy group, which indicates that the phrenic afferent‐induced facilitation does not require conditions induced by the spinal cord injury. The ability of phrenic afferent neurons to evoke phrenic motor plasticity after spinal cord injury suggests that these afferent pathways could be important to rehabilitation of the diaphragm motor system post‐injury.

Support or Funding Information

K99HL143207‐01 (KS), F32NS095620‐01 (KS), T32HL134621‐01A1 (LBW), SPARC OT2 OD023854 (DDF)

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Glutamate Receptor Plasticity in Brainstem Respiratory Nuclei Following Chronic Hypercapnia in Goats
Authors: Burgraff Nicholas , Buchholz Kirstyn , Neumueller Suzanne , Pan Lawrence , Hodges Matthew , Forster Hubert
Published: June 2021

Patients that retain CO2 with respiratory diseases such as chronic obstructive pulmonary disease (COPD) have worse prognoses and higher mortality rates than those with equal impairment of lung function without hypercapnia. However, little is known about the effects of chronic hypercapnia on the neurochemical mechanisms controlling brainstem respiratory nuclei (BRN). Common mechanisms of neuroplasticity involve changes in glutamate receptor expression/phosphorylation to modulate synaptic strength and network excitability, driven by changes in both AMPA (GluR) and NMDA (GluN) glutamate receptors. Accordingly, herein we tested the hypothesis that changes occur in glutamatergic signaling within the BRN during exposure to chronically elevated inspired CO2 (InCO2) induced hypercapnia. Healthy goats were euthanized after either 24 hours or 30 days of chronic exposure to 6% InCO2 or room air. The brainstems were extracted for western blot analyses to assess GluR and GluN receptor expression and phosphorylation state within the BRN. Compared to room air control goats, the following significant (P<0.05) changes were found after 24 hours of exposure to chronic hypercapnia: 1) AMPA receptor expression was greater, and NMDA receptor expression lower within the rostral solitary complex. 2) NMDA receptor expression/phosphorylation and APMA receptor phosphorylation were lower within the rostral ventrolateral medulla (VLM), while AMPA receptor expression/phosphorylation were greater in the caudal VLM. 3) AMPA receptor expression/phosphorylation were lower within the rostral retrotrapezoid nucleus. And, 4) NMDA receptor expression was greater within the caudal Raphe nucleus. The data indicate that within 24 hours of chronic hypercapnia changes have occurred in four BRN in GluR/GluN signaling which may contribute to an attenuated CO2‐induced hyperpnea and attenuated CO2 chemoreflex between 1 and 24 hours of hypercapnia (J. Physiol. 2018). GluR/GluN changes found at 24 hours of hypercapnia had returned to control levels after 30 days of hypercapnia. However, compared to room air control goats, the following significant (P<0.05) changes were found following 30 days of hypercapnia: 1) NMDA receptor phosphorylation was greater in the caudal ventral respiratory column, and 2) AMPA receptor expression was greater in the caudal RTN. The changes in GluR/GluN signaling between 24 hours and 30 days of chronic InCO2 may contribute to a sustained hyperpnea and normalization of the CO2 chemoreflex at 30 days.

Support or Funding Information

‐Department of Veteran Affairs ‐NIH Grant 007852

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Viral‐Induced Systemic Inflammation Undermines Respiratory Motor Plasticity
Authors: Hocker Austin D , Huxtable Adrianne G
Published: June 2021

Systemic inflammation arises from varied stimuli and elicits distinct inflammatory profiles, yet we know little about the effects of different inflammatory stimuli on respiratory motor plasticity. Bacterial‐induced systemic inflammation undermines respiratory motor plasticity in the form of phrenic long‐term facilitation (pLTF), induced by acute intermittent hypoxia (AIH). pLTF is evoked by distinct cellular mechanisms, such as the Q‐pathway (induced by moderate AIH, PaO2 35–45 mmHg) and the S‐pathway (induced by severe AIH, PaO2 25–35 mmHg). The Q‐pathway is undermined by bacterial‐induced inflammation at 3 and 24 hours, while the S‐pathway is resistant. However, the effects of viral‐induced systemic inflammation on pLTF are unknown. Since viral‐induced inflammation is common, we tested the hypothesis that inflammation induced by a viral mimetic polyinosinic:polycitidylic acid (polyIC) would undermine Q‐pathway‐evoked pLTF, but not S‐pathway‐evoked pLTF. PolyIC dose‐response experiments (0.25 – 0.75 mg/kg, i.p.) revealed 0.75 mg/kg polyIC (i.p.) was sufficient to undermine Q‐pathway‐evoked pLTF 24 hours post‐polyIC (17 ± 15% change from baseline, n=5, p > 0.05). However, at 3 hours, polyIC (0.75 mg/kg, i.p.) was not sufficient to undermine Q‐pathway‐evoked pLTF (67 ± 21%, n=5, p < 0.0001), suggesting the temporal actions of viral‐induced systemic inflammation differ from bacterial‐induced systemic inflammation. Confirming the role of inflammatory signaling after polyIC (0.75 mg/kg, 24 hours, i.p.) in impairing pLTF, a non‐steroidal anti‐inflammatory (ketoprofen, 12.5 mg/kg, i.p., 3 hours) restored Q‐pathway‐evoked pLTF (64 ± 24%, n=5, p < 0.0001), and was not different from saline controls (55 ± 13%, n=5, p = 0.4711). Additionally, S‐pathway‐evoked pLTF was insensitive to polyIC‐induced inflammation (0.75 mg/kg, i.p.; 72 ± 25%, n=5, p < 0.0001) and was not different from saline controls (65 ± 32%, n=4, p = 0.6291). Our results suggest the inflammatory‐impairment of Q‐pathway‐evoked pLTF is not stimulus specific and confirm the inflammatory‐resistance of S‐pathway‐evoked pLTF. These data support the hypothesis that S‐pathway‐evoked plasticity could compensate for Q‐pathway impairments during inflammation. Thus, in situations where respiratory motor plasticity may be beneficial, for example, as a therapeutic tool to improve motor function after incomplete spinal cord injury, inflammation likely undermines Q‐pathway‐evoked plasticity and strategies targeting S‐pathway‐evoked plasticity may improve therapeutic outcomes.

Support or Funding Information

HL141249

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Mitochondrial‐targeted antioxidant drugsas therapeutically tools for apnea of prematurity: intermittent hypoxia and sex dimorphism
Authors: Soliz Jorge , Arias Christian , Marcouiller François , Laouafa Sofien , Bairam Aida , Joseph Vincent
Published: June 2021

Immaturity of the brainstem network system that controls breathing leads to apnea of prematurity (AoP). While AoP is a developmental (and thus self‐resolving) disorder, it is not the apnea but the associated decrease of arterial oxygen levels (Intermittent Hypoxemia ‐ IH) what is detrimental for neural maturation. IH induces mitochondrial dysfunction, increased production of reactive oxygen species (ROS), and oxidative stress, thus promoting higher breathing instability, delayed neural maturation and prolonged hospitalization. We hypothesized that the mitochondrial‐targeted antioxidant drug MitoTEMPO, by restoring mitochondrial dysfunction, protects newborns against the consequences of IH induced by AoP. Moreover, keeping in mind that male sex is an important risk factor for several respiratory diseases in preterm neonates experiments were performed in male and female newborn rats exposed to IH during postnatal days (P) 3–10. During this time, animals were daily injected (i.p.) with vehicle or MitoTEMPO (10–12 pups/group). At P10 the frequency of apneas at rest were measured (as an index of respiratory dysfunction) by plethysmography. Next, the cortex tissue was collected, and a high‐resolution Oxygraph‐2k was used to evaluate the mitochondrial bioenergetics and ROS (H2O2) production using saponin‐permeabilized tissue punches of 1.5–3 mg weight. Our preliminary results obtained in male animals showed that mitoTEMPO: 1) restored the IH‐mediated increase of apneic events, 2) restored the IH‐mediated decrease of mitochondrial respiration of complex I (NADH‐linked respiration), and complex II (FADH2‐linked respiration), and 3) decreased the IH‐mediated increase of mitochondrial H2O2. Surprisingly, no impact of IH and/or the treatment with mitoTEMPO was observed in female animals. We conclude that neonatal IH leads to respiratory disturbances in male animals only. Moreover, our results suggest that antioxidant drugs may be used as new therapeutical tools for apnea of prematurity in males.

Support or Funding Information

Jorge Soliz is funded by the Canadian Institutes of Health Research (CIHR – Catalyst grant sex as a variable in biomedical research‐IC118777). The salary of Jorge Soliz is supported by Laval University. The Canadian Foundation for Innovations (FCI – 32986) supported the acquisition of state‐of‐the art equipment in Jorge Soliz lab.

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
The Effects of TNFα on Mitochondria Morphology are Mediated by Endoplasmic Reticulum Stress in Human Airway Smooth Muscle Cells
Authors: Yap John Qian , Chen Xujiao , Delmotte Philippe , Sieck Gary
Published: June 2021

Airway inflammation is a key trigger for asthma, and pro‐inflammatory cytokines such as TNFα mediate the airway hyperreactivity and remodeling characteristic of asthma. In various diseases, inflammation leads to an increase in mitochondrial fission, associated with decreased expression of mitochondrial fusion proteins, such as Mfn2. Mitochondrial fission is generally coupled with mitochondrial biogenesis and cell proliferation. Some studies in other cell types suggest that mitochondrial fission may be a result of the accumulation of unfolded or misfolded proteins i.e., endoplasmic reticulum (ER) stress. ER stress activates three intracellular pathways to induce a homeostatic response to restore normal ER function. The IRE1α pathway is activated by autophosphorylation and splices XBP1 mRNA. Previous studies have shown that the XBP1 has downstream effects on mitochondrial proteins. In this study we hypothesized that TNFα induces activation of the IRE1α pathway which leads to a decrease in Mfn2 expression. hASM cells were isolated from lung specimen incidental to patient surgery. The patients were normal as evaluated by the clinical pathologist (no history of asthma or COPD). hASM cells were stimulated with TNFα (20 ng/ml) for 1, 3, 6, 12 or 24 h. Expression of total and phosphorylated IRE1α, Mfn2 and cleaved and uncleaved XBP1 were evaluated by Western blot. RNAscope® was used to measure Mfn2 mRNA expression in hASM cells transfected with non‐phosphorylatable IREα (DeltaP‐IRE1α; GFP tagged) compared to non‐transfected cells. Results were analyzed by 2‐way ANOVA with Bonferroni analysis when justified. We found that exposure of hASM cells to TNFα activated the IRE1α/XBP1 pathway and decreased Mfn2 expression in a time dependent fashion. In addition we found that TNFα exposure in cells expressing the inactive DeltaP‐IRE1α did not lead to a significant decrease in Mfn2 expression. Our results suggest that the IRE1α/XBP1 pathway may be involved in the regulation of mitochondrial fission, mitochondrial biogenesis and cell proliferation.

Support or Funding Information

Supported by NIH grant HL126451 (GCS)

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Novel Protease‐Activated Receptor‐2 Antagonist Blocks Allergen‐induced Airway Epithelial Cell Signaling In vitro and Asthma Symptoms In vivo
Authors: Rivas Candy Mavis , Addison Kenneth , Yee Michael , Ledford Julie , DeFea Kathryn , Price Theodore , Vagner Josef , Boitano Scott A.
Published: June 2021

Protease‐activated receptor‐2 (PAR2) is a G protein‐coupled receptor that can self‐activate upon proteolysis of the extracellular amino terminus. Tethered ligand binding leads to receptor activation and stimulation of both β‐arrestin/MAPK and Gαq‐Ca2+ dependent signaling. PAR2 is expressed by the airway epithelium and thus is poised to encounter proteases found within asthma‐inducing environmental allergens. Studies using activating peptides or PAR2 knock out cells/animals demonstrate a key role for PAR2 in animal models of asthma. Recently, our lab has developed C391, a potent PAR2 antagonist that has shown to be effective in blocking peptidomimetic‐ and trypsin‐induced PAR2 signaling in vitro as well as inflammatory pain in vivo. Here we show that C391 competitively binds PAR2 (using a Time Resolved Fluorescence binding assay) and evaluate the ability for C391 to block the protease‐containing asthma‐associated allergen (Alternaria alternata)‐induced signaling in cultured human airway epithelial cells (16HBE14o‐) and A. alternata‐induced asthma symptoms in a murine model. We demonstrate that micromolar concentrations of C391 block A. alternata‐induced Ca2+ signaling (digital imaging microscopy), A. alternata‐induced MAPK signaling (In Cell Western) and A. alternata‐induced β‐arrestin signaling (Bioluminescence Resonance Energy Transfer). In an eight‐day murine model of A. alternaria‐sensitization and challenge, we next evaluated the ability for C391 to block asthma associated symptoms. We demonstrate that C391 effectively attenuates inflammation (bronchoalveolar lavage and histochemical analyses), mucus production and goblet cell hyperplasia (histochemical analysis) and airway hyperresponsiveness (Forced Oscillation Technique analysis with Flexivent) in both C57Bl/6 and BALB‐C mice. To our knowledge, this is the first demonstration of pharmacological block of PAR2 to block allergen‐induced asthma symptoms in vivo. These data support further development of PAR2 antagonism as a potential first‐in‐class allergic asthma drug.

Support or Funding Information

American Physiological Society: William Townsend Porter Pre‐doctoral Fellowship (CMR) NIH AI140257 (SB)NIH NS098826 (TP JV SB)

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Sex Differences in the Diameter of Extra‐parenchymal Airways in a Large Cohort of Healthy Adult Non‐smokers
Authors: Cross Troy J , Wheatley Courtney , Wentz Robert , Levin David L , Bartholmai Brian J , Johnson Bruce D
Published: June 2021

Growing evidence suggests that the larger conducting airways are smaller in women than men; however, evidence of this sex‐difference in airway geometry is yet to be demonstrated in a large cohort of adult, healthy non‐smokers. Furthermore, it is not known whether these sex differences persist after airway size is adjusted for its allometric relationship with absolute lung size.

Purpose

We examined the effect of sex on airway size in a large cohort of non‐smoking healthy adults after adjusting for the possible confounding effect of absolute lung size.

Methods

A total of 133 (75 men; 58 women) non‐smoking adults (50 ± 18 yrs) with normal pulmonary function (>80% pred.) participated in this study. Full thoracic CT scans were obtained in each participant during a breath‐hold at full inflation. Commercial software was used to automatically segment airways and assign 32 anatomical labels ranging from the 0th to the 5th generation. Intraluminal hydraulic diameters (Dh) were obtained for each airway. An allometric relationship was assumed between Dh and absolute lung size, as given by: Dh = TLVβ·ek, where TLV is the total lung volume at full inflation, β is the allometric scaling exponent, and k allowed for proportional effects of confounding variables. This allometric equation was log‐log transformed such that it could be examined using linear regression: e.g., ln(Dh) = β·ln(TLV) + k. Sex, age and their interaction were allowed to contribute to both β and k as covariates. The model also included a term for reconstructed voxel size. Model averaging was used to provide parameter estimates of the log‐log transformed allometric equation.

Results

The allometric exponent, β, assigned to TLV was significant for all 32 anatomically labelled airways (P < 0.05); neither sex nor age affected β. On the other hand, sex and age were significant mediators of k for the extra‐parenchymal airways only (Trachea, RMB, LMB, BronInt, see Figure 1, P < 0.05).

Conclusions

Our findings indicate that sex differences in Dh remain present despite accounting for the allometric relationship between airway and lung size (see Figure 1). Importantly, however, this sex‐difference in airway size is seemingly confined to the extra‐parenchymal airways.

Support or Funding Information

This work was supported by NIH Grant HL71478.

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Divergent effects of sex and aging on the intrinsic physiology of substantia nigra dopamine neurons
Authors: Howell Rebecca Dean , Lopez Sergio Dean Dominguez , Parikh Ishita , Beckstead Michael
Published: June 2021

The largest population of dopamine‐producing neurons is in the ventral midbrain. Within this region, the neurons located in the substantia nigra are necessary for the initiation of voluntary movement. The degeneration of substantia nigra dopamine neurons is involved in the etiology for Parkinson's disease, a disease characterized by progressive loss of motor and cognitive functions. The biggest risk factor for Parkinson's disease is age, with most cases occurring after age 60. Moreover, Parkinson's is almost 2 times more prevalent in men than in women. While much research in Parkinson's has focused on the mechanisms underlying the dopamine neuron degeneration, very little work has considered the influence of normal aging on dopamine neurons which may contribute to disease risk and presentation.

In this work, we performed whole cell patch clamp recordings in brain slices to study the changes in intrinsic firing properties of dopamine neurons in C57BL/6 mice across ages (4, 12, 18, ≥24 months) and compared between sexes. In addition, we assessed open field locomotion in these mice and performed a quantitative comparison of the numbers of substantia nigra dopamine neurons. Interestingly, we found a progressive decline in dopamine neuron function and number in males with age, while neurons in females remained largely unaffected. Behaviorally, there was a decrease in the distance travelled and speed of the mice with age, with females exhibiting higher activity levels at young ages. The effects of age and sex were further evaluated by comparing the transcriptomic profile of the substantia nigra pars compacta in these mice. The impairments in dopamine neuron function and locomotor activity in males that occurs with age may represent a vulnerability to further insults that could underlie the susceptibility to neurodegenerative processes like those seen in Parkinson's disease.

Support or Funding Information

NIH grant (R01AG052606)

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
The Effects of Lavender Essential Oils on the Anxious Behavior of Zebrafish
Authors: Moore Jennifer Lindsey , Kasper Sherry Oden
Published: June 2021

In the United States, anxiety disorders are becoming increasingly prominent, affecting as many as 30% of Americans with more cases found each year. Currently, lavender essential oils are being utilized by people to relieve anxiety symptoms although there is little research to validate the scientific basis for the relief of symptoms. Some research has indicated that lavender in essential oils can inhibit the serotonin reuptake transporter similar to the mechanism of action for many oral antidepressants. Zebrafish have become an accepted model for anxious behavior due to their visible and inherent diving behavior when presented with negative stimuli. In addition, zebrafish share 82% of the genes associated with mental disorders in humans and have similar endocrine responses such as the release of cortisol. To test the effect of lavender essential oil on the anxious behavior, zebrafish were exposed to a stressful stimulus and given varying doses of lavender oil to determine their shoaling behavior. In addition, to determine the effects on endocrine response, cortisol levels were tested in each condition. We have found that lavender essential oils decrease diving behavior in zebrafish compared with those who are untreated. Therefore, the goal of the research was to exhibit the relief of anxious symptoms with the treatment of lavender oil in zebrafish by documenting their behavioral changes when treated with lavender essential oils compared with anxious behavior in those with no treatment.

Support or Funding Information

None

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Contributions of mitochondrial dysfunction to baroreflex and cardiac dysregulation in hepatic encephalopathy
Authors: Wu Jacqueline C.C. , Tsai Ching‐Yi
Published: June 2021

Hepatic encephalopathy (HE) is a common neurocognitive complication of acute and chronic liver failure and is associated with 50–90% mortality without liver transplantation. Despite a highly challenging clinical problem, systematic evaluations of the cellular mechanisms of HE‐related mortality are still lacking. Clinical studies showed that the degree of baroreflex dysregulation is related to the severity of HE. At the cellular level, oxidative stress resulting from mitochondrial dysfunction in brain stem nuclei in the baroreflex circuit, including nucleus tractus solitarii (NTS) and rostral ventrolateral medulla (RVLM), and in the heart are known to result baroreflex dysregulation and cardiac dysfunction. This study investigated whether the same mechanism underlies the high mortality in HE. An azoxymethane (AOM)‐induced acute liver failure model of HE employing C57BL/6 mouse was used. Diffusion tensor imaging (DTI) or magnetic resonance spectroscopy (MRS) of the brain stem was performed, together with blood pressure, heart rate and indices of baroreflex recorded by radiotelemetry. Animals died within 24–30 h after AOM (100 μg/g, ip) injection. DTI further revealed that the connectivity between the NTS and nucleus ambiguus (NA), the origin of the vagal innervation of the heart, was progressively disrupted though sustained, concurrent with impaired but persistent cardiac vagal baroreflex. On the other hand, the connectivity between NTS and RVLM was progressively disrupted until its disappearance, coincidental with the abolition of baroreflex‐mediated sympathetic vasomotor tone that signifies brain death clinically. Results from 31P MRS obtained from mouse brain stem showed reduced ratio between phosphocreatine and γATP, indicating mitochondrial dysfunction in HE. Furthermore, there was a decrease in cardiac contractility, alongside an elevation of reactive oxygen species and necrotic cell death and a reduction in ATP level in the NTS or RVLM. Our results showed that impairment of baroreflex and cardiac function takes place during the progression towards death in HE, and bioenergetic failure, oxidative stress and necrotic cell death are the culprits.

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Adenosine A2a Receptor Mediated‐inhibitory Effects of Electroacupuncture on Sympathoexcitatory Reflexes Are Associated with Opioids in the Rostral Ventrolateral Medulla of Rats
Authors: Guo Zhi‐Ling , Samaniego Tracy , Malik Shaista
Published: June 2021

It has been largely demonstrated that electroacupuncture (EA) lowers high blood pressure (BP). However, mechanisms underlying EA's effects on elevated BP remain unclear. Our previous studies have shown that EA attenuates reflex elevation in BP induced by gastric distension (GD) through its influence on rostral ventrolateral medulla (rVLM). Although adenosine is released during neuronal activation in the rVLM, its role in acupuncture‐cardiovascular regulation is unknown. Adenosine A2a rVLM receptors are known to contribute to depressor responses. The action of A2a receptor stimulation in the central nervous system may be regulated through an opioid mechanism. However, it is uncertain whether in the rVLM this putative action occurs. We hypothesized that adenosine in the rVLM contributes to EA modulation of sympathoexcitatory reflexes through an A2a‐opioid receptor mechanism. Repeated GD every 10 min was performed in Sprague‐Dawley male rats under ketamine and α‐chloralose anesthesia. EA (2 Hz, 0.5 ms, 1–4 mA) or sham‐EA (identical procedures as EA without electrical stimulation) was applied at the P5‐6 acupoints, overlying the median nerve, for 30 min after establishing two consistent reflex responses to GDs. We observed that EA (n=5) but not sham‐EA (n=5) at P5‐6 markedly (P<0.05) reduced GD‐induced elevations in BPs. EA modulation of sympathoexcitatory cardiovascular responses was reversed significantly after rVLM microinjection of an A2a receptor antagonist, SCH 58261 (1 mM in 50 nl; n=8; P<0.05), but not by the vehicle (5% dimethylsulfoxide; n=6). Furthermore, microinjection of an A2a receptor agonist, CGS‐21680 (0.4 mM in 50 nl) into the rVLM enhanced EA's inhibitory action (n=8; P<0.05). Blockade of opioid receptors with naloxone (0.1 μM in 50 nl) in the rVLM reversed EA's inhibitory effects on GD‐induced pressor responses and blunted the CGS‐21680‐associated enhancement of EA inhibition (n=6; P<0.05). Neurons labeled with adenosine A2a receptors were co‐localized with neurons stained with enkephalin as well as delta‐opioid receptors in the rVLM. These data suggest that the involvement of rVLM adenosine A2a receptors in EA modulation of GD‐induced pressor reflexes is, at least in part, dependent on the presence of opioids.

Support or Funding Information

NCCIH grant, R01 AT009347

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Profiling RNA‐Associated Proteins for Vasopressin‐Mediated Translation in Kidney Collecting Duct Cells
Authors: Jung Hyun Jun , Yang Chin‐Rang , Knepper Mark A
Published: June 2021

Vasopressin‐mediated gene expression changes in the renal collecting duct has been intensively studied over the last decade. Prior studies were focused on transcriptional regulation as a mechanism of regulation of transport by vasopressin. However, post‐transcriptional regulation at the RNA level has not been studied. To identify vasopressin‐mediated RNA modulators, 1) a comprehensive list of RNA‐associated proteins was curated, and 2) vasopressin‐regulated genes from this list were identified using RNA‐seq in mouse mpkCCD cells exposed to vasopressin for various times.

The curated database of RNA‐associated proteins was generated by mining information from multiple databases as follows. RNA processing‐related proteins were identified from Gene Ontology (GO) ‘Molecular Function’ and ‘Biological Process’, KEGG pathway, RNA modification database and Reactome. In addition, proteins that have RNA‐binding domains were identified from five different databases (RBPDB, ATtRACT, RBPmap, InterPro and UniProt). A total of 1369 proteins are listed in the current database of RNA‐associated proteins (https://hpcwebapps.cit.nih.gov/ESBL/Database/RNAprocessing_Proteins/). Among these proteins, 646 proteins have known RNA‐binding domain structures and 723 proteins were identified with annotated molecular functions related to RNA processing. 371 proteins were identified by both criteria.

RNA‐seq was carried out in mpkCCD cells treated with the vasopressin analog dDAVP (10−10 M) for 3, 6 and 12 h. Relative transcript abundance was estimated using transcripts per million (TPM) and change of transcript abundance was presented as Log2 of the dDAVP:vehicle TPM ratio at each time point. Interestingly, we found that transcript abundance of genes coding for ribosomal proteins (60S ribosomal proteins and 40S ribosomal proteins) and translation initiation proteins (eukaryotic translation initiation factors) were extensively changed by dDAVP at all time points. These results indicate that vasopressin‐mediated gene expression includes changes mediated by abundance changes of translation‐associated proteins. Beyond this, the current study provides new resources for further study of RNA‐associated processes in the kidney.

Support or Funding Information

The work was supported by the Division of Intramural Research, National Heart, Lung, and Blood Institute projects ZIA‐HL001285 (to MAK) and ZIA‐HL006129 (to MAK).

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Saudi Population's Adherence to the Healthy Food Palm: A Cross‐sectional Study
Authors: Halawani Reham , Jaceldo‐Siegl Karen , Heskey Celine , Bahjri Khaled
Published: June 2021

Background

The Healthy Food Palm (HFP) was developed based on the culture and eating habits of Saudi Arabians to preserve and enhance nutrient adequacy and improve health by emphasizing foods and food groups that attenuate the risk of chronic diseases. Limited work has been done to assess the diet quality of Saudi Arabians based on the HFP. Therefore, our objective was to assess adherence to the guidelines among Saudi Arabians.

Methods

A total of 612 Saudi males and females, aged 18 and above, were enrolled in this cross‐sectional study. Demographics and social eating practices were obtained using an online questionnaire. Anthropometric measurements including height, weight, and waist circumference of all participants were also obtained. We applied the HFP recommendations for intake of eight food groups using 24‐hour dietary recall (24HDR) and developed a scoring system to assess the adherence of the participants to this dietary guideline. The scoring was based on those that met the guidelines (within recommended range) and those who did not meet the guidelines (below and above recommended range). Two 24HDR were initially obtained from the study subjects. However, only 248 (41%) completed the second 24‐hour recall. Since the percent agreement in adherence to the food groups for both recalls was high (77%), we used the first recall. Descriptive statistics were obtained for all socio‐demographic factors, health characteristics, and the participants' adherence to HFP.

Results

Our results showed that overall level of adherence to HFP is 26%. For the vegetables, dairy, fruits, grains, water, protein and sugar groups, the majority of participants reported intake below the recommended range (98%, 91%, 88%, 88%, 78%, 62% and 54% of subjects respectively). For the fat group, most subjects (98%) met the recommended intake. When compared to the males, the intake of females was lower than the recommended range. Other groups with intake lower than the recommended range were undergraduate students, single individuals, and those with a normal BMI.

Conclusions

In this study, the results show that Saudi Arabians do not adhere to HFP. Educational interventions should be planned to improve diet quality.

Support or Funding Information

None

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Determining Risk Factors for Triple Whammy AKI using Computational Models of Long‐ Term Blood Pressure Regulation
Authors: Leete Jessica , Ahmed Sameed , Lopez Hernandez Francisco J , Layton Anita
Published: June 2021

Concurrent use of diuretics, angiotensin converting enzyme inhibitors (ACEI)/angiotensin receptor blockers (ARB), and nonsteroidal anti‐inflammatory drugs (NSAIDs) increases the risk of acute kidney injury (AKI). AKI resulting from use of all three drugs is referred to as “triple whammy”. Diuretics and ACEI/ARB are often prescribed in tandem for the treatment of hypertension while some NSAIDs, such as ibuprofen, are available over the counter. As such, concurrent treatment with all three drugs is common.

To address the critical need to better understand the mechanisms behind the increased risk of AKI and to identify potential risk factors, we use computational models of long‐term blood pressure regulation we developed previously. We hypothesize that individual variations in tubuloglomerular feedback, renal sympathetic nervous activity, and vasoactive hormones such as angiotensin II will determine whether or not triple whammy patients develop AKI. Other circumstances that we hypothesize to influence AKI development include hypertension, salt ingestion and sensitivity, and genetic polymorphisms in enzymes (ACE) or receptors (angiotensin type 1).

The computational models used include variables describing the heart and circulation, kidney function, sodium and water reabsorption in the nephron, and the renin angiotensin system (RAS) and is fit separately for male and female humans.

Support or Funding Information

This research was supported by the Canada 150 Research Chair program and by the National Institutes of Health: National Institute of Diabetes and Digestive and Kidney Diseases, grant R01DK106102.

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Increased exposure to acrylamide compromises the integrity of the gastric mucosa
Authors: Ige Abayomi , Martins Osah , Emediong Idara , Odetola Anthony , Adele Bernard , Adewoye Elsie
Published: June 2021

Acrylamide maybe formed in food cooked at very high temperature. Its role on gastric mucosa defenseis not fully elucidated. Hence the role of acrylamide consumption on gastric mucosal integrity was investigated. Fifty‐four animals (150–200g) were divided into 3 groups of 18 rats: Group 1 ‐ control (distilled water 0.2ml), Groups 2 (7.5mg/kg acrylamide) and 3 (15mg/kg acrylamide). All treatments were done orally for 28 days. Post‐treatment, gastric juice (modified pylorus ligation method) was obtained per group (n=5) and analysed for gastric acidity. Gastric antioxidants status (superoxide dismutase, glutathione, catalase, lipid peroxidation), tissue bicarbonate and prostaglandins‐E2 were assayed per group (n=5). Blood was collected via cardiac puncture for haematological indices and gastric mucus content was evaluated per group (n=5). Cell counts (parietal and mucous) and gastric histology was evaluated per group (n=3) using haematoxylin and eosin (H&E) and Periodic acid Schiff (PAS) stains. Mucus content, bicarbonate, prostaglandins‐E2, superoxide dismutase, glutathione, catalase, mucous cell count were reduced (p<0.05) in the acrylamide groups compared to control. Gastric acidity, nitric oxide, parietal cell count and lipid peroxidation were increased (p<0.05) in the acrylamide groups compared to control. White blood cell count in group 2 was increased but decreased in group 3 compared to control (p<0.05). Acrylamide treatment groups had gastric epithelial cells with poor architecture, lamina propria and submucosa inflammatory cell infiltration. Vascular congestion and limited production of mucus was observed. This study suggests that acrylamide consumption causes a dose‐dependent degeneration of gastric mucosa integrity via reductions in gastric protective factors which thus predisposes the gastric mucosa to erosions and lesions.

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Retrieval Practice Enhances the Recall and Transfer of Learning of Physiology Information
Authors: Dobson John , Linderholm Tracy
Published: June 2021

It is well‐documented that retrieval practice can improve the recall of both simple and complex information when compared to more common methods of learning such as repeated studying (i.e., reading). Recent evidence also indicates that retrieval practice can improve higher orders of thinking, such as the ability to critically evaluate research articles (Dobson, Linderholm and Perez, 2018) and transfer of learning (Butler, 2010). One aim of this study was to investigate the effects of retrieval practice on transfer of learning with physiology information. A second aim was to compare recall and transfer of physiology information following retrieval practice versus a judgment of learning task (JOL) that may be easier for students to utilize on their own. Participants were randomly assigned to learn three short (~500 words) physiology texts using each of the following strategies: 1. studying a text four times (SSSS), 2. studying and then retrieving a text two times (SRSR), and 3. studying a text four times while completing multiple JOL during the second and fourth repetitions (SJSJ). Recall and transfer of learning were assessed one week after the participants learned the texts, and the results were analyzed using repeated measures ANOVAs. The SRSR strategy resulted in significantly greater recall than the SSSS strategy (21.35 ± 1.08 vs. 17.35 ± 0.86, p<0.05), and both the SRSR and SJSJ strategies facilitated significantly greater transfer than the SSSS strategy (44.60 ± 2.55 and 41.79 ± 2.63, respectively, vs. 36.07 ± 2.40, p<0.05). These results indicate that retrieval practice may enhance both recall and higher order thinking about physiology information and that covert retrieval, as experienced in a JOL task, may provide similar benefits.

Support or Funding Information

None

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Using Primary Research Literature as a Teaching Tool in an Undergraduate Human Anatomy and Physiology Course
Authors: Marvar Sarah Knight , Doperalski Adele
Published: June 2021

The level of exposure of science undergraduate students to primary literature is varied, despite evidence that it is a useful tool to teach factual information and critical thinking skills1. Reading and interpreting primary literature is a skill that is required in many scientific careers and these skills which are developed when analyzing primary literature are transferable to many areas. In an undergraduate Human Anatomy and Physiology course we incorporated weekly discussions and presentations of primary research articles as a tool to accomplish our course goals. These course goals included exploring current research in the physiology of organ systems being studied as well as developing critical thinking on a topic. In our course students were required to read a total of five primary research articles selected by the course instructors. Students were then required to write a brief 100‐word synopsis of each article prior to class. Then each week in class, students took turns in small groups to be responsible for leading a class discussion of the article. Students were responsible for discussing articles five times during the semester and leading the article discussion once during the semester. Students perceptions of the complexity and usefulness of the exercise were surveyed at the beginning and at the end of the semester.

We observed that at the start of the semester 50% of students felt confident in presenting and leading a discussion on a primary research article, compared with 67% at the end of the semester. Just 17% expected to enjoy the exercise, whereas at the end of the semester 32% reported having enjoyed it. At the start of the semester 85% of students believed that developing skills in reading primary research literature was important for their future careers. We found the level of understanding of primary literature and quality of discussion to vary greatly between students.

In conclusion we propose that the development of skills in reading primary research literature in undergraduate students enrolled in a Human Anatomy and Physiology course are valuable. We found that the students felt that the skills developed during this exercise are useful for their intended future careers and they enjoyed the exercise more than they expected. Our future plans include finding ways to improve upon student satisfaction and enjoyment of the activity.

This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Cashew gum protects the intestinal mucosa from morphological changes promoted by the aggression of 5‐Fluorouracil
Authors: Cerqueira Gilberto Santos , Leal Luzia Kalyne Almeida Santos Moreira , de Souza Pimentel Paulo Vitor Santos , de Santos Souza Luan Kelves Miranda , de Sousa Fideles Lázaro , Feitosa Amanda Alves , de Miranda João Antônio Leal
Published: June 2021

Intestinal mucositis is a frequent complication in the treatment of cancer with the chemotherapeutic agent 5‐fluorouracil (5‐FU). So far there is still no effective treatment of this condition. Cashew gum (CG) has been reported as a potent anti‐inflammatory. The present study aimed to evaluate the effect of Cashew gum (Anacardium occidentale L.) on 5‐fluorouracil‐induced intestinal mucositis in Swiss mice. The mice (25–30g) were secreted into 5 groups (n = 6): Saline group (NaCl 0.9%), 5‐FU group, CG group (90mg/kg CG, vo), CLX group (Celecoxib ip), CLX + CG group (Celecoxib ip, 90mg/kg GC). All animals except Saline group received 5‐FU at the concentration of 450mg/kg in the first experimental protocol. Duodenal portions were removed for evaluation of mucositis by histopathological and immunohistochemical analysis for cyclooxygenase‐2 (COX‐2). The results of the histopathological analysis demonstrated that 5‐FU promoted structural alterations of the intestinal mucosa, evidenced by the reduction of villi height, deepening of the crypts, and intense inflammatory infiltrate, in comparison to the Salina group, characterized by the integrity of the villi and crypts and absence of inflammatory infiltrate. CG animals showed a significant reversal of the effects promoted by antineoplastic in the villi, crypts and inflammatory cells infiltration in comparison to the 5‐FU group. CLX group, as well as CLX + GC, were able to significantly prevent (p <0.05) destruction of crypts, shortening of villi with cellular vacuolization, and inflammatory infiltrate. Regarding the immunoblotting for expression of COX‐2, it can be observed that the saline group showed subtle immunostaining when compared to the 5‐FU group (p <0.05), in which intense and generalized immunostaining was observed. In the CG, CLX and CLX + CG groups, there was a decrease in the immunostaining when compared to the 5‐FU lesion group. In addition, the amount of COX‐2‐immunolabelled cells in the CLX + CG group was lower than the CG treated group. It is concluded that CG prevented the intestinal mucosa promoted by the 5‐FU antineoplastic, in addition to decreasing the expression of the COX‐2 enzyme, an important element in the onset and exacerbation of inflammation.

Support or Funding Information

This study received funding of CNPQ and CAPES

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