bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of strength vs. endurance exercise on myocardial function and remodeling (1154.8)
Authors: Garza Michael , Wason Emily , Zhang John
Published: June 2021

Effects of strength vs. endurance training on myocardial function and remodeling in post‐MI rats Michael A. Garza, Emily A. Wason, John Q. Zhang, Department of Health and Kinesiology, The University of Texas at San Antonio TX After Myocardial Infarction (MI), increased plasma volume (PV) attributes to the progressive decline in cardiac function by exacerbating left ventricular (LV) dilation; however, compelling evidence suggests that endurance exercise training, despite eliciting a marked increase in PV, beneficially preserves post‐MI cardiac function. Contrarily, strength exercise training, which promotes concentric myocardial hypertrophy and has no effect on PV, may be more therapeutic in post‐MI applications; therefore, we investigated for the first time the effects of strength vs. endurance exercise training on myocardial function and remodeling in post‐MI rats. MI was surgically induced on 7‐wk‐old Sprague‐Dawley rats by ligation of the coronary artery. The survivors were assigned to 4 groups (n=8/group): Sham (no MI, no exercise), MI‐Sed (MI, no exercise), MI‐End (MI+endurance exercise), and MI‐St (MI+strength exercise). Endurance and strength exercise training using a rodent treadmill or an 85° inclined ladder, respectively, began 1‐wk post‐MI and lasted for 10‐wks. Although fractional shortening (FS%) was well preserved in both exercise trained groups compared to the MI‐Sed group, LV end‐diastolic dimension was significantly lower in the MI‐St group compared to the MI‐End group (1.03±0.01 vs. 1.21±0.01 cm, p<0.05). Furthermore, pressure‐volume analysis data illustrated that dP/dt max values were significantly higher in the MI‐St group compared to the MI‐End group. Our data indicate that strength training may be more beneficial than endurance training at preserving post‐MI cardiac function and attenuating LV dilation.
Cardiac hypertrophy and oxidative metabolism in novel congenic leptin receptor deficient BBDR.cg‐lepr.cp rats (1155.10)
Authors: Gomez Maria F. , Silvola Johanna , Berglund Lisa M. , Kiugel Max , Åkesson Lina , Knuuti Johani , Roivainen Anne , Lernmark Åke , Nuutila Pirjo , Saraste Antti
Published: June 2021

Congenic BBDR.cg‐lepr.cp rats generated by introgression of the Koletsky leptin receptor mutation into the BioBreeding Diabetes Resistant (BBDR) rat develop obesity and diabetes mellitus, known risk factors for heart failure. Here we studied cardiac function and myocardial oxidative metabolism in these rats by non‐invasive imaging. Myocardial glucose utilization (18F‐fluorodeoxyglucose uptake) and oxygen consumption (washout constant for 11C‐acetate derived from monoexponential fitting) were measured by positron emission tomography (PET); left ventricle (LV) mass, systolic function and cardiac output by echocardiography. Compared with non‐diabetic littermates, diabetic rats were obese (body weight 463±36 vs. 706±65 g, p<0.01), hyperglycemic (6±1 vs. 22±10 mM, p<0.01), had elevated blood pressure (136±5 vs. 151±13 mmHg, p=0.02), comparable systolic function (fractional shortening 49 vs. 48%), but higher LV mass (0,6±0,1 vs. 0,9±0,1 g, p<0.01). Diabetic rats had lower fasting myocardial glucose uptake (p=0.04) and lower efficiency of myocardial forward work (LV work / oxygen consumption * myocardial mass; 69000±8000 vs. 54000±12000 mmHg L/min; p=0.03), despite having comparable resting myocardial oxygen consumption in fasting state. Results suggest that BBDR.cg‐lepr.cp rats should prove a useful new model to study the adverse effects of obesity and diabetes on cardiac metabolism.

Grant Funding Source: Supported by: VR 2011‐3900; EFSD, SSMF, the SUMMIT consortium (IMI‐2008/115006).
Toll‐like receptor 2 activation increases contractile responses in rat corpus cavernosum (1158.6)
Authors: Stallmann‐Jorgensen Inger , Wenceslau Camilla , Ogbi Safia , Webb R. Clinton
Published: June 2021

Erectile dysfunction (ED) affects about 30 million US men and is recognized as a sign of heightened cardiovascular disease (CVD) risk. Inflammation in the vasculature could be the link between ED and CVD. Activation of innate immune toll‐like receptors can trigger vascular inflammation. Toll‐like receptor 2 (TLR2) has been implicated in CVD, but whether TLR2 signaling contributes to penile vascular dysfunction is unknown. We hypothesized that a synthetic TLR2 ligand, Pam3CSK4, would increase contraction to phenylephrine (PE) in rat corpus cavernosum (CC). The CC of adult Sprague Dawley rats was isolated, cleaned, cut into muscle strips, and incubated with 100 ng/mL Pam3CSK4 (Pam3) or vehicle (CON) for 6 h and subsequently mounted on a myograph for isometric force measurements. Contraction to 80 mM KCl confirmed CC viability and force (mN) data were normalized to KCl contraction (%KCl). Western blotting was used for protein determination. Data analyses were performed using Two‐way ANOVA and unpaired t‐tests with α‐level set at 0.05. Pam3 compared to CON showed higher contractile responses to PE across the 10uM‐1mM concentration range (mean differences in force ranged from 51.15 to 67.18 %KCl; p<0.05, RM ANOVA, n=4‐5). Pam3 showed a higher maximal response to PE than CON (Pam3: 205.5±8.5 vs. CON: 138.4±16.8 % KCl; p<0.05, t‐test). The p‐IKBα:total IkBα ratio was greater in Pam3 vs. CON (Pam3: 2.5 fold‐change over CON; p<0.05, t‐test, n=4). In conclusion, a TLR2 ligand increases contractile responses to PE in CC, suggesting that this pattern recognition receptor plays a role in CC. TLR2 may be a link between ED and sterile inflammation.

Grant Funding Source: Supported by NIH
Overloading‐associated upregulation of interleukin‐6 in heat shock transcription 1‐null mice (1163.12)
Authors: Goto Katsumasa , Koya Tomoyuki , Nishizawa Sono , Nakai Akira , Sugiura Takao , Ohira Yoshinobu , Yoshioka Toshitada
Published: June 2021

Hypertrophic stimuli, such as mechanical stretch, up‐regulate heat shock proteins (HSPs) that are mediated by heat shock transcription factor 1 (HSF1)‐associated stress response in mammalian skeletal muscles. However, a physiological significance of HSF1‐associated stress response in loading‐associated muscle hypertrophy is still unclear. The purpose of this study was to investigate the effects of HSF1‐deficiency on loading‐associated skeletal muscle hypertrophy by using HSF1‐null mice. Functional overloading on left soleus was performed by cutting the distal tendons of gastrocnemius muscles for 4 weeks. Hypertrophy of soleus muscle in HSF1‐null mice was partially depressed. On the other hand, overloading‐related up‐regulation of IL‐6 mRNA was enhanced in HSF1‐null mice. Evidences from this study suggested that HSF1 and HSF1‐associated stress response may play an important role in loading‐induced muscle hypertrophy via the regulation of inflammatory cytokines. This study was supported, in part, by JSPS KAKENHI Grants Numbers 22240071, 24650411, 24650407 and the Promotion and Mutual Aid Corporation for Private Schools of Japan.
Glucocorticoids reduce muscle atrophy‐related microRNAs via exosomal microRNA packaging (1163.4)
Authors: Hudson Matthew , Woodworth‐Hobbs Myra , Rahnert Jill , Zheng Bin , Price S.
Published: June 2021

Several microRNAs, including miR‐23a and miR‐182, participate in skeletal muscle atrophy by regulating the level of key atrophy‐inducing proteins. We recently found that the intracellular levels of these microRNAs are reduced in C2C12 myotubes within 1‐2 hours of addition of the glucocorticoid dexamethasone (Dex). The purpose of this study was to investigate the mechanism underlying the rapid decrease in the intracellular levels of these microRNAs. We tested the hypothesis that miR‐23a and miR‐182 are incorporated into exosomes and exported from myotubes following glucocorticoid treatment. Administration of Dex (1µM) to C2C12 myotubes for 6 h in exosome‐free culture media resulted in decreased intracellular miR‐23a and miR‐182. Isolation and quantitation of exosomal miR‐23a and miR‐182 from media revealed an increase in both microRNAs. Interestingly, the total number of exosomes in the culture media of control and Dex‐treated cells was not different indicating Dex did not increase exosome export. Levels of miR‐23a and miR‐182 were decreased in gastrocnemius muscle of rats undergoing atrophy due to streptozotocin‐induced diabetes. MiR‐23a and miR‐182 in urinary exosomes from diabetic rats were also reduced, suggesting that their levels in urine reflect the levels in muscle during the persistent atrophic state. These findings identify a novel mechanism by which muscle can rapidly reduce the level of intracellular microRNAs, and demonstrate that exosomal microRNA packaging is a specific and highly regulated process.

Grant Funding Source: Supported by NIH T32 DK007656 (MBH) and NIH DK95610, VA Merit X01BX001456 (SRP)
Dietary sodium nitrate supplementation restores blood flow regulation in Becker muscular dystrophy (1165.1)
Authors: Nelson Michael , Rader Florian , Tang Xiu , Stabler Thomas , Allen Jason , Victor Ronald
Published: June 2021

Chronic administration of a nitric oxide‐donating drug fully corrects abnormal blood flow regulation in the mdx mouse model of dystrophinopathy. As a first step to clinical translation, we treated 6 men with Becker muscular dystrophy with a single oral dose of sodium nitrate‐ a simple, exogenous inorganic nitric oxide donor. We measured reflex vasoconstriction (ΔHb02, near infrared spectroscopy; evoked by lower body negative pressure) at rest and during rhythmic handgrip exercise, before and 3 hours after ~8.4 mmol of oral sodium nitrate. Before treatment, blood flow regulation was impaired in BMD, because handgrip exercise caused no attenuation of reflex vasoconstriction (ΔHbO2:‐17±2 vs. ‐16±2 %, rest vs. HG). Remarkably, sodium nitrate supplementation more than doubled plasma nitrate and nitrite levels, and restored exercise‐induced attenuation of reflex vasoconstriction (ΔHbO2: ‐18±1 vs. ‐11±2; P <.001, rest vs. HG). Moreover, the exercise‐induced increase in forearm muscle blood flow, as measured by Doppler ultrasound, nearly tripled after sodium nitrate supplementation (Δ from baseline: 102 + 19% before treatment compared to 271 + 39 % after treatment), despite having no effect on basal flow. Taken together, these data indicate that oral sodium nitrate can recapitulate the normal regulation of blood flow in exercising dystrophic skeletal muscle, which is normally achieved by sarcolemmal nNOS.
Blood pressure responses to skeletal muscle contraction relative to salt sensitivity in humans and rats (1165.11)
Authors: Matthews Evan , Stocker Sean , Brian Michael , Wenner Megan , Edwards David , Farquhar William
Published: June 2021

Salt sensitivity of blood pressure (BP) is linked to increased mortality. Salt sensitive (SS) rats display exaggerated BP responses to muscle afferent stimulation, a finding not yet studied in humans. We hypothesized that SS adults would have greater BP responses to muscle contraction than salt resistant (SR) adults. To define salt sensitivity status, a median split of 24hr mean BP (MAP) responses (%∆) to dietary sodium (20 mmol/d x 7 d to 300 mmol/d x 7 d sodium) was used in 12 adults and resulted in 6 SS (6.4±1.5 %∆) and 6 SR (‐0.1±1.6 %∆ p<0.05). Static handgrip (HG; 2 min 40% maximal voluntary contraction) was performed during normal sodium intake. MAP responses to HG tended to be greater in SS than SR (30.2±5.1 vs. 16.7±4.0 %∆, p=0.06). Salt induced %∆MAP was correlated to HG %∆MAP (r=0.658 p<0.05). Parallel experiments in Dahl SS (DSS, n=4) & Dahl SR (DSR, n=4) rats fed 0.1% NaCl confirms that stimulation of sciatic afferent nerves (500uA, 5Hz, 1ms pulse) produce greater increases in MAP (SS 26±4; SR 15±2 mmHg, p<0.05). Additionally we found greater renal sympathetic nerve activity (SS 175±12; SR 147±8 %, p<0.05). These preliminary data suggest greater BP responses to muscle contraction in SS humans & rats due to greater sympathetic activity; this may be a factor in the poorer CV outcomes in SS adults.

Grant Funding Source: Supported by NIH R01 HL104106, NIH R01HL113270 and AHA EIA, & ACSM Foundation Research Grant.
Neuromuscular remodeling and neuromuscular junction instability in human diabetic neuropathy (1168.1)
Authors: Allen Matti , Stashuk Daniel , Doherty Timothy , Kimpinski Kurt , Rice Charles
Published: June 2021

Diabetic polyneuropathy (DPN) is a progressive axonopathy marked by loss of motor fibers, compensatory collateral reinnervation and reduced stability of neuromuscular transmission. Our objective was to assess the degree of reinnervation and motor unit instability in patients with DPN using decomposition‐based quantitative electromyography (DQEMG). Additionally, relationships between motor unit stability and muscle function were examined. The tibialis anterior (TA) muscle was tested in twelve patients with DPN (65 ± 15 yrs) and 12 age‐matched controls (63 ± 15 yrs). DQEMG was used to analyze surface and intramuscular EMG signals recorded from the TA during moderate voluntary dorsiflexion contractions. Individual motor unit action potential (MUP) trains were identified and analyzed for: MUP size (peak to peak amplitude, area), complexity (turns, fiber dispersion) and stability (near fiber jiggle). DPN patients featured larger (+45% MUP area), more complex (+40% fiber dispersion), and less stable (+30% near fiber jiggle) MUPs (p<0.05). No significant relationships were found between MUP stability and muscular denervation, or strength. MUP complexity and instability were positively related in DPN patients (r=0.46; p<0.05) and controls (r=0.37; p<0.05). DPN is associated with neuromuscular remodeling which leads to increasingly impaired neuromuscular transmission that is detectable using DQEMG.

Grant Funding Source: NSERC
Immunohistochemical evidence of nNOS containing fibres in the cardiac ventricle of the rabbit (1169.4)
Authors: Brack Kieran , Saburkina Inga , Rysevaite Kristina , Gukauskiene Ligita , Batten Trevor , Grubb Blair , Pauziene Neringa , Ng G. Andre , Pauza Dainius
Published: June 2021

Vagal stimulation (VS) is a popular novel therapy in heart failure where its potential in ventricular arrhythmia prophylaxis is highlighted by animal studies showing that VS protects against ventricular fibrillation through nitric oxide (NO). This implies that there are vagal nerves containing neuronal nitric oxide synthase (nNOS) in the ventricle but, anatomical evidence is absent. Our aim was to characterise the phenotype of intrinsic cardiac nerves in the rabbit using immunohistochemistry for tyrosine hydroxylase (TH), choline acetyltransferase (ChAT) and nNOS (n=6). In the atrial and ventricular walls (Figure), TH, ChAT and nNOS positive nerve fibers and cell bodies exist. ChAT and nNOS positive structures predominate in the atria in large and small ganglia. nNOS positive somata and nerve fibers were present within ventricular epi‐ and endo‐cardial nerves, along Purkinje fibers and within the myocardium. The distribution of TH, ChAT and nNOS nerve fibers within epicardial nerve bundles on the anterior (A) and posterior (P) aspects of the left ventricle varied. TH fibres predominate over ChAT and nNOS (TH ‐ 64% (A) 68% (P); ChAT ‐ 10% (A) 8% (P); nNOS ‐ 10% (A) 10% (P)). In summary, we show the first direct evidence of nitrergic nerves within the rabbit intrinisc cardiac nervous system, in particular within the cardiac ventricle, implicating the key role that nitric oxide plays in neurocardiac control.

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Grant Funding Source: Supported by Research Council of Lithuania and the British Heart Foundation
Ghrelin suppresses cardiac sympathetic tone following acute myocardial infarct ő mechanistic insight (1169.5)
Authors: Schwenke Daryl , Joe Natalie , Tsuchimochi Hirotsugu , Shirai Mikiyasu
Published: June 2021

Acute myocardial infarction (MI) initiates an increase in cardiac sympathetic nerve activity (SNA), which exacerbates ventricular remodelling and cardiac dysfunction. Ghrelin, a growth hormone‐releasing peptide, is effective at preventing this adverse increase in SNA, although the underlying mechanisms remain unknown. In this study we aimed to determine whether ghrelin could directly inhibited sympathetic tone within the brain, following acute MI. Cardiac SNA was continuously recorded in urethane‐anaesthetized rats for three hours following ligation of the left anterior descending coronary artery. Rats received an intracerebroventricular injection of either ghrelin (5 µg/kg) or placebo immediately after the MI. SNA remained stable in sham rats. Acute MI induced a maximal 420% increase in SNA, which was significantly attenuated, but not completely prevented, in those rats that received a central injection of ghrelin. These results suggest that ghrelin acts centrally within the brain to suppress SNA following acute MI. However, the fact that central ghrelin did not completely prevent the adverse increase in SNA, as previously reported for subcutaneous‐injected ghrelin, suggests that ghrelin may also act peripherally, e.g. cardiac vagal afferent fibers, to further prevent an increase in cardiac SNA following MI ‐ a hypothesis that warrants further investigation.
Distribution of α‐adrenergic receptors in the arteriolar network of the rat gastrocnemius (1170.13)
Authors: Murray Natasha , Heckle Tanner , Jasperse Samara , Moore Alex , Jasperse Jeffrey
Published: June 2021

Results of previous studies examining adrenergic receptor subtype distribution have varied. The purpose of this study was to determine the distribution of adrenergic receptor subtypes throughout the arterial tree of the rat gastrocnemius muscle. Feed arteries (FA) and first (1A), second (2A), and third (3A) order arterioles from the gastrocnemius muscle of male Sprague‐Dawley rats were isolated and cannulated for videomicroscopic study. Cumulative dose‐response curves (10‐9 to 10‐4 M) were performed using the non‐selective agonist norepinephrine (NE), α1‐agonist phenylephrine (PE), and α2‐agonist UK14304 (UK) to determine constrictor responses. All branch orders constricted similarly to NE and PE (% constriction in FA: NE = 75.4% ± 5.4, PE =70.1% ± 6.6; 1A: NE = 91.1% ± 2.1, PE= 83.7% ± 2.8; 2A: NE= 92.4% ± 2.4, PE= 88.8% ± 2.3; 3A: NE = 81.3% ± 8.7, PE= 79.3% ± 5.0). No branch order constricted significantly to UK or to the β‐agonist isoproterenol. Constrictor responses to NE and PE were abolished by the α1‐antagonist prazosin (10‐7 M) in all branch orders. Neither the α2‐antagonist rauwolscine (10‐6 M) nor the β‐antagonist propranolol (10‐6 M) reduced constriction in any branch order. These results indicate that constrictor responses to NE are mediated almost entirely by α1‐adrenergic receptors in all examined branch orders of the rat gastrocnemius with little to no contribution from α2‐adrenergic receptors.
Sickle cell transgenic (HbSS) mice lungs produce greater inflammatory mediators with downregulation of dilator proteins (1175.10)
Authors: Bernal Gilberto , Husain Sumair , Opene Micahel , Hillery Cheryl , Belcher John , Ibe Basil
Published: June 2021

Sickle cell chronic lung disease is one of the notable causes of death in patients with sickle cell disease (SCD). Prevention and treatment of acute chest syndrome (ACS) constitutes a major concern in clinical management of SCD. Some lung complications in SCD result from direct or indirect effect of pulmonary microvascular occlusion by sickle erythrocytes and their adhesion to the vascular endothelium. Vasoactive eicosanoids are released resulting in inflammatory response. Studies with HbSS mice have enhanced knowledge of SCD pathology, but the biochemical mechanisms of initiation and progression of ACS is not well understood. We hypothesized that lungs of SCD patients are under greater inflammatory stress due to decreased expression of anti‐inflammatory proteins and metabolites, but greater inflammatory proteins and metabolites. We studied baseline expression of 5‐Lox, cysLT1 as well as PKA, COX1 and COX2 and CREB and measured Leukotrienes and PGI2 release by lungs of HbSS mice and transgenic HbAA mice. HbSS mice lungs expressed 40‐60% more 5‐Lox and CysLT1, but 40‐70% less COX1/COX2 and CREB proteins; produced 68% greater LTs, but PGI2 was not detected. Expression of PKA was not different. The data suggest that SCD lungs are under greater inflammatory stress which may trigger ACS and sustain sickle cell chronic lung disease in SCD patients.

Grant Funding Source: LA Biomed Seed grant 520522
Ca2+ entry via transient receptor potential vanilloid channel 4 mediates ventilation‐induced lung vascular barrier failure (1176.3)
Authors: Michalick Laura , van der Giet Markus , Liedtke Wolfgang , Kuebler Wolfgang
Published: June 2021

Study objective: High tidal volume ventilation causes lung vascular barrier failure, yet underlying mechanisms are unclear. Here, we tested whether endothelial Ca2+ influx via mechanosensitive TRPV4 may contribute to stretch‐induced pulmonary hyperpermeability in vivo and ex vivo. Next, we probed for the role of putative upstream (serum/glucocorticoid‐regulated kinase (SGK) 1) and downstream (Ca2+‐activated K+ channels) regulators of TRPV4 in this scenario.

Methods: Mice were ventilated for 2 h with low (7 ml/kg) and high (20 ml/kg) tidal volumes (LVT/HVT) in vivo. Isolated‐perfused lungs were inflated with 5 or 15 cmH2O (LPIP/HPIP) and [Ca2+]i was quantified by real‐time imaging with or without pharmacological inhibition of SGK1, TRPV4 or Ca2+‐activated K+ channels.

Results: TRPV4 deficiency or inhibition by HC‐067047 protected from HVT‐induced lung injury in vivo, and attenuated the endothelial Ca2+ response to HPIP ex vivo. Involvement of SGK1 and Ca2+‐activated K+ channels was evident as reduced lung hyperpermeability in HVT mice following inhibition by GSK650394 (SGK1), apamin or charybdotoxin.

Conclusions: Activation of TRPV4 by HVT mediates endothelial Ca2+ influx and promotes lung injury and barrier failure via a signaling pathway that involves both SGK1 and Ca2+‐activated K+ channels, which may present new targets for the prevention or treatment of stretch‐induced vascular pathologies.

Grant Funding Source: Supported by an operational grant of the Deutsche Forschungsgemeinschaft to W.M.K.
Hypothyroidism affects dopamine D2 modulation of metabolism, body temperature, and breathing frequency in young female hamsters (1178.1)
Authors: Padilla Tania , Schlenker Evelyn
Published: June 2021

Previous work from our laboratory showed that administration of 1 mg/kg bromocriptine (B), a D2 receptor agonist, stimulated body temperature, metabolism and ventilation in older hypothyroid females, but depressed these variables in older euthyroid female hamsters without affecting the expression of D2 receptors in various brain regions. This project investigated how hypothyroidism (induced by administration of propylthiouracil in drinking water) affected body temperature, ventilation and metabolism in young euthyroid and hypothyroid female hamsters following administration of vehicle and B. We hypothesized that the physiological responses of 2 month old females to B (1mg/kg) would be similar to those observed in older hypothyroid female hamsters. Results indicated that administration of 1 mg/kg B had little effect on breathing in young euthyroid and hypothyroid female hamsters. A higher dose, 3 mg/kg B, decreased body temperature and frequency of breathing in euthyroid hamsters, but stimulated metabolic rate and caused a post‐hypoxic frequency decline in hypothyroid hamsters. In conclusion, young female hypothyroid hamsters exhibited a lower sensitivity to B and also differences in frequency of breathing, body temperature and metabolic responses to B compared to previous responses observed in older hypothyroid female hamsters.

Grant Funding Source: Supported by the UDiscover program at the University of South Dakota and APS STRIDE grant
The obesity epidemic as a result of maternal effects and phenotypic evolution (1179.3)
Authors: Archer Edward
Published: June 2021

Objective: This research provides a reinterpretation and synthesis of existing evidence for a novel theory of the etiology of the obesity epidemic and the increased prevalence of energy contingent chronic non‐communicable diseases.

Theory: Over the past century, socio‐environmental evolution (e.g., decreased pathogenic load, thermoneutral environments, reduced physical labor, and enhanced nutrition) engendered decrements in maternal energy expenditure and metabolic control that increased the availability of energy substrates to the intrauterine milieu. This perturbation of mother‐conceptus energy partitioning resulted in population‐wide cumulative maternal effects and the consequent evolution of human energy metabolism (i.e., intensified fetal insulin production and increments in hyperplastic adiposity). With each successive generation, these anatomic and physiologic alterations led to increments in the competitive dominance of adipocytes over other tissues (e.g., myocytes) in the acquisition and sequestering of nutrient‐energy during post‐prandial periods. By the late 20th century, a metabolic tipping point was reached in which the post‐prandial insulin response was so intense (via enhanced beta‐cell mass and function), and the relative number of adipocytes so magnified, that the sequestering of nutrient‐energy as lipid was inevitable, and obesity unavoidable.
Gap between nutrition behaviour and knowledge in Australian first year, post‐graduate medical students (118.3)
Authors: Nowson Caryl , Perlstein Robyn , Macfarlane Susie , McCoombe Scott
Published: June 2021

We aimed to assess reported nutrition practices and knowledge of recommendations and identify if there is a mismatch between practice and nutritional knowledge of 1st year medical students. Students answered questions in two nutritional population health lectures (50 min each) using an audience response system. Approximately 52% of enrolled students attended the 2 lectures (n=83, n=54, respectively) and the response rate ranged from 27% ‐ 62%. 93% and 66% respectively, knew the recommended number of serves of fruit and vegetables/day, but only 44% and 12% respectively, consumed the recommended amounts. 47% reported not using salt in cooking and 76% did not use salt at the table. Therefore, although more than half the students knew the recommended daily servings of vegetable less than 2 students in 10 consumed the recommended amounts. In contrast salt usage patterns exhibited a greater alignment with guidelines. This discrepancy between knowledge and nutritional choices could provide relevant learning opportunities for students to develop an appreciation of the challenges of food behaviour change and develop skills in providing effective support to empower patients to make positive lifestyle changes.
Gd3+ and Gd3+‐containing contrast agents affect human ENaC activity in Xenopus ocytes (1181.14)
Authors: Knoepp Fenja , Clauss Wolfgang , Fronius Martin
Published: June 2021

In lungs, activity of epithelial sodium‐channel (ENaC) is crucial for regulating the volume and composition of epithelial lining fluid, since dysfunction of this process is associated with diseases, e.g. pulmonary oedema. This study examined a potential impact of Gd3+, a core‐part of nebulized contrast‐agents used for magnetic‐resonance‐imaging (MRI) of lungs, on activity of human ENaC (hENAC). hENaC was expressed in Xenopus laevis oocytes and membrane currents (IM) were recorded by Two‐Electrode‐Voltage‐Clamp measurements.Gd3+ dose‐dependently affected hENaC activity. 0.1mM decreased (17±1 %), whereas 0.5mM induced an increase of IM (27±4 %). Activation by 0.5mM Gd3+ was due to an interference with self‐inhibition (SI) of hENaC (control: 40±3 %; Gd3+: 25±4 %) whereas 0.1mM did not affect SI (control: 32±8 %; Gd3+: 33±7 %). Interestingly, the cysteine modifying compound MTSEA prevented ENaC activation by 0.5mM Gd3+ (the effect by 0.1mM was not affected), whereas histidine‐modifying DEPC prevented inhibition by 0.1mM Gd3+ and did not affect the Gd3+ induced activation. Gd‐DTPA, a Gd3+‐containing contrast agent, showed comparable effects to 0.1mM. These results argue for multiple Gd3+‐binding sites that differentially affect ENaC activity and demonstrate that Gd3+ containing contrast agents can directly interfere with ENaC activity.

Grant Funding Source: FK is supported by a scholarship from the university of Giessen
Cell phone based peer counselling can support exclusive breastfeeding: a randomized controlled trial in Kenya (119.5)
Authors: Sellen Daniel , Mbugua Samwel , Webb‐Girard Aimee , Lou Wendy , Duan Wenming , Kamau‐Mbuthia Elizabeth
Published: June 2021

Objective: To test whether exposure to community‐based continuous cell phone based peer support (CPS) or monthly peer‐led support groups (PSG) increases adoption and duration of exclusive breastfeeding (EBF), as compared to current standard of facility‐based support (Control).

Methods: We randomized low‐income women attending antenatal care at a large hospital to receive one of three support strategies from late pregnancy (32‐26 weeks) to 3 months postpartum: CPS, PSG or Control. We compared EBF estimated by maternal 24 h recall of infant foods at 3 months age by intervention group.

Results: Participant flow was adequate for power (753 women enrolled, 81% of eligible; 504 infants completed, including twins, 66.6%). Both interventions were associated with a higher proportion of EBF CPS: 90.9%, PSG: 82.8%, Control: 78.2%, p=0.007). Pairwise comparisons of 24 h EBF indicated a significant association of CPS with an 12.7% higher prevalence than Control (90.9 versus 78.2, a 16.2% greater EBF response rate than Control; Chi‐square = 9.8201, p=0.0017) and an 8.1% higher prevalence than PSG (90.9 versus 82.8, a 9.8% greater EBF response rate than PSG; Chi‐square = 4.5768, p=0.0324). Differences could not be attributed to baseline indicators, dropout rates or biases, prevalence and timing of breastfeeding initiation, or EBF prevalence one week after birth. They may be attributed to the frequency of advice.

Conclusions: Cell phone based counselling approaches can be at least as effective in supporting EBF as peer support group and facility‐based approaches.

Supported by Bill & Melinda Gates Foundation to FHI 360, through the Alive & Thrive Small Grants Program managed by UC Davis; Global Alliance for Improved Nutrition; Canada Research Chair program award.
3‐Methylhistidine and cardiolipin as biomarkers of zinc deficiency (122.3)
Authors: Nkrumah‐Elie Yasmeen , Choi Jaewoo , Kirkwood Jay , Stevens Fred , Tanguay Robert , Chung Carolyn , King Janet , Brown Kenneth , Ho Emily
Published: June 2021

The global epidemic of zinc deficiency is likely contributing to the development of chronic disorders such as cancer, insulin resistance, and immune dysfunction, though reliable biomarkers for human zinc deficiency are not currently available. To discover novel indicators of zinc deficiency in humans, untargeted metabolomic and lipidomic profiles were assessed from plasma samples collected during a controlled feeding trial in healthy men to induce zinc depletion at baseline (2 wk, 11mg Zn/d), zinc‐depletion (0.6mg Zn/d for 1 wk and 4mg Zn/d for 5 wk), and zinc‐repletion (4 wk, 11mg Zn/d). 3‐methylhistidine, an indicator of human muscle catabolism, was confirmed as the most significantly increased (8‐fold change, P<0.0001) metabolite resulting from zinc depletion, which may indicate endogenous mechanisms for maintaining plasma zinc homeostasis. Lipidomic analysis indicated that dietary zinc deficiency resulted in 5‐fold decreases in sphingomyelin (P=0.039) and phosphatidylcholine (P=0.0298) species, with a 10‐fold increase in cardiolipin (P=0.03766). Elevated levels of cardiolipin and zinc deficiency have both been associated with hyperthyroidism. Thus, this research is significant not only in its identification of clinical biomarkers of zinc deficiency, but may also contribute to unraveling the mechanisms associated with dietary zinc deficiency and health outcomes.

Grant Funding Source: Supported by: USANA Health Sciences, T32 ES007060 & P30 ES000210
Building a bird: ontogenetic and evolutionary construction of the avian body plan (13.2)
Authors: Heers Ashley
Published: June 2021

In the process of invading aerial media, birds and their dinosaur ancestors have undertaken some of the most dramatic transformations in vertebrate history. Flight is the most challenging form of locomotion, and extant flight‐capable adult birds have many anatomical traits that are presumably adaptations or exaptations for meeting such demands. Immature birds lack these hallmarks of flight capacity, yet in many species juveniles must navigate the same hazardous environment as adults. How is this accomplished? Here, I explore ontogenetic relationships between anatomy and performance, and show that flight‐incapable juveniles transition to flight‐capable adults via stages that incrementally improve locomotor performance and culminate in flight capacity. Developing birds reach refugia by flap‐running up slopes or over water and supplementing their incipient wings with their legs, until the wings can fully support body weight during flight. Such cooperative use of wings and legs acts as a developmental bridge that allows juveniles to transition from leg‐based terrestrial locomotion, to wing‐and‐leg‐based locomotion, to wing‐based aerial locomotion. Many of the anatomical changes occurring during this transition are also observed in theropod dinosaurs during the evolution of flight. Thus developing birds offer important insight into both ontogenetic and evolutionary construction of the avian bauplan.
Food habits of residents who live near corner stores (132.3)
Authors: Young Taylor , Swanson Ann , Craven Tara , Martin Donna , Gibson Cheryl
Published: June 2021

Background. Working alongside small retail establishments, the Jackson County MO Healthy Corner Store Initiative aims to increase availability of healthy food items in communities with limited healthy food access. Food habit surveys were conducted in neighborhoods surrounding 4 targeted corner stores. Methods. Several strategies were used to distribute the food habit survey within the targeted areas, including mailed surveys, door‐to‐door canvassing, at focus group discussions, and online. Sample size estimates were calculated utilizing census data with consideration of abandoned and vacant households. Survey items included 24 questions about demographic characteristics and food behaviors. Results. A total of 423 food habit surveys were collected. The most important factors participants indicated when deciding where to purchase food were price (32%) and quality of food (26%). About one‐third of participants reported that they consumed only one serving of fruit and two servings of vegetables a day. Major barriers to fruit and vegetable consumption included price (40%) and spoilage time (41%). More than 60% of participants reported purchasing fruit and vegetables at least once a week, with 40% having to travel only 5 to 10 minutes to purchase items. Discussion. Overall, responses to the food habit surveys indicate that individuals are not eating adequate amounts of fruits and vegetables, although the vast majority reported not having to travel far to purchase items. Changing the perception of corner stores by offering a wider variety of low‐cost and high quality foods may enhance healthy food intake among residents.

Grant Funding Source: Supported by CDC
Red meat and colorectal cancer: a quantitative update on the state of the science (136.4)
Authors: Alexander Dominik , Weed Douglas
Published: June 2021

The potential relationship between red meat consumption and colorectal cancer (CRC) has been the subject of scientific debate, resulting in a high degree of uncertainty among scientists, public health practitioners, and the general public. Thus, our objective was to update the state of the science on this complex topic by conducting a systematic quantitative assessment of the literature. Data from twenty‐seven independent prospective cohort studies were meta‐analyzed using random‐effects models, and sources of potential heterogeneity were examined through sub‐group and sensitivity analyses. In addition, a comprehensive evaluation of potential dose‐response patterns was conducted. In the meta‐analysis of all cohorts, a weakly elevated summary relative risk was observed (1.11, 95% CI: 1.03‐1.19), however, statistically significant heterogeneity was present. In general, summary associations were attenuated (closer to the null and less heterogeneous) in models that isolated red meat (from processed meat), adjusted for more relevant factors, analyzed women only, and were conducted in countries outside of the U.S. Furthermore, no clear patterns of dose‐response were apparent. Overall, the statistical evidence appears to be weakening over time. In conclusion, based on this updated analysis with a comprehensive evaluation of associations by intake levels, the state of the science on red meat consumption and colorectal cancer is not supportive of an independent association given the weak associations, heterogeneity, inability to disentangle effects from other dietary and lifestyle factors, lack of a clear dose‐response effect, and weakening evidence over time.
Serum C‐peptide is positively associated with the presence of colorectal adenomas (136.7)
Authors: Comstock Sarah , Xu Diana , Hortos Kari , Kovan Bruce , McCaskey Sarah , Pathak Dorothy , Fenton Jenifer
Published: June 2021

Activation of the insulin ‐‐ insulin‐like growth factor (IGF) signaling axis is hypothesized to increase colon cancer risk. The aim of this study was to determine if serum factors related to insulin or insulin signaling were associated with advanced colon polyps in males. 126 men (48 ‐ 65 yr) were recruited at time of colonoscopy, and blood was collected. Odds ratios were determined using logistic regression for polyp number and polytomous logistic regression for polyp severity. 29% of the men in our study had a tubular adenoma. Participants with C‐peptide levels above 3.3ng/ml were 3.8 (CI: 1.3 ‐ 11.1) times more likely than those with C‐peptide levels less than 1.8ng/ml to have a tubular adenoma. For each category increase in C‐peptide, an individual was 2.0 (CI: 1.2 ‐ 3.4) times more likely to have a tubular adenoma than no polyp. Those individuals with serum soluble receptor for advanced glycation end products (sRAGE) greater than 120.4pg/ml were 0.3 (CI: 0.1 ‐ 0.9) times less likely than those with sRAGE lower than 94.5pg/ml to have 蠅3 polyps than no polyps. For each category increase in sRAGE, an individual was 0.5 (CI: 0.3 ‐ 0.9) times less likely to have 蠅3 polyps than no polyps. Other factors, such as insulin growth factor binding proteins, were not associated with polyp presence or severity in this population. Serum C‐peptide levels are a potential biomarker of polyp severity in white males.

Grant Funding Source: Supported by NCI 1R03CA142000 and MSU CTSI
Sulforaphane improves MARCO expression, bacterial clearance and survival in post‐influenza bacterial pneumonia (145.1)
Authors: Kobzik Lester , Wu Muzo , Deloid Glen , Thimmulappa Rajesh , Biswal Shyam
Published: June 2021

Mechanisms that increase susceptibility for post‐influenza bacterial pneumonia include down‐regulation of the alveolar macrophage (AM) scavenger receptor MARCO by interferon‐γ (IFN‐γ), leading to diminished bacterial clearance. Since MARCO expression can be increased by NRF2 signaling, we tested whether the NRF2‐inducer sulforaphane (SFN) can up‐regulate MARCO expression and improve bacterial clearance after influenza. Human AM‐like monocyte‐derived macrophages (HMDMs) were treated with IFN‐γ (10‐50 IU/ml, 24h) to simulate influenza infection, followed by sulforaphane (SFN, 10µM) for 24h before quantitation of MARCO expression or challenge with green fluorescence protein (GFP)‐expressing S. aureus. Scanning cytometry was used to quantitate MARCO surface labeling and uptake of bacteria. C57/BL6 mice were inoculated i.n. on day 0 with 3500PFU of PR8 influenza virus, and on day 7 with 500 CFU of S. pneumoniae serotype 3. Mice were injected with SFN 25 or 50 mg/kg, or PBS daily from day 6 to 9 after influenza infection. Bacterial clearance was measured on day 1 after S. pneumoniae infection using lung lavage samples. IFN‐γ down‐regulated MARCO expression (p<0.001) of HMDMs and impaired phagocytosis of S. aureus (p<0.001, n=4). SFN added after IFN‐γ significantly improved MARCO expression (p=0.003) and S. aureus phagocytosis (p=0.05), an effect that was inhibited by scavenger receptor blockers poly(I) (p=0.001) or MARCO blocking peptide (P<0.001). In vivo, sulforaphane‐treated mice showed improved bacterial clearance (e.g. 84%, 95% reduction in SFN‐treated mice in 2 trials) and a significantly higher survival rate compared to PBS‐treated mice (75.0% vs. 12.5%, n = 8/grp, p=0.022). Therapeutic targeting of the NRF2 pathway may be beneficial to reduce risk or severity of secondary bacterial pneumonia after influenza.

Grant Funding Source: Supported by ES00002
Optimization of the nucleocapsid protein sequences of human measles virus and canine distemper virus to human and canine codon usage bias increases sequence identity and protein expression (145.3)
Authors: Uhl Elizabeth , Osborn Michelle , Michel Frank , Hogan Robert
Published: June 2021

Amino acids are coded for by two to six different RNA codons and frequency of codon use, known as codon usage bias (CUB), varies between species. Since viruses do not have tRNAs, the translation of viral proteins depends upon utilization of host tRNA, and is impacted by the host’s CUB. We are investigating the importance of codon usage in morbilliviral host adaptation and pathogenicity. Previously we determined that human CUB had significantly higher relative adaptiveness for 6 of 7 CDV proteins than canine CUB. For this study we constructed nucleic acid sequences for HMV and CDV N proteins that were optimized to human and canine CUB. For both viral N proteins, the human and canine codon optimized sequences had increased nucleic acid and codon identity compared to wild type. In addition, codon optimization of the CDV N protein to either the human or canine CUB increased its nucleic acid identity to the wild type (WT) HMV N protein from 66.3% (HMV WT vs CDV WT) to 71.8% (Human CUB vs WT) and 72.2% (Canine CUB vs WT). Finally, protein expression from human and canine CUB optimized HMV and CDV N protein nucleic acid sequences transfected into human (293 HEK) cells was increased over that of the WT constructs. These results indicate that further adaptation of HMV and CDV to the mammalian CUB could potentially enhance viral expression.

Grant Funding Source: Supported by Department of Defense Threat Reduction Agency
Interrogation of novel biomarkers for the treatment of inflammatory diseases: Raf‐1 kinase inhibitor protein as a case study (146.10)
Authors: Wright Kyle , Vella Anthony
Published: June 2021

Through cutting edge proteomics, our lab has identified Raf‐1 kinase inhibitor protein (RKIP), a molecule previously described as a regulator of MAPK and NF‐κB signaling, as a new potential therapeutic target for immune regulation of inflammatory disorders. We are currently investigating the breadth and mechanism of RKIP function within the immune system, and how this can be applied to future therapeutic intervention. Experimentally, we have illustrated that RKIP is critical for T cell receptor signaling and IFNγ production from antigen‐specific T cells in a model of systemic inflammatory response syndrome (SIRS). This was evidenced by a 50% reduction in IFNγ+ T cells in RKIP‐/‐ mice after SIRS initiation and a 70% reduction in IFNγ from wild type T cells after blockade of RKIP with a small molecule inhibitor. Additionally, RKIP seems to play a role in proper toll‐like receptor (TLR) signaling in antigen presenting cells (exemplified by its rapid downregulation on immunoblot after stimulation with TLR ligands), and is necessary for maintaining the type I interferon signaling architecture in B cells as we observed a 2‐4 fold decrease in important transcripts by RNAseq in RKIP‐/‐ B cells (Table I). Taken together, our data suggest that RKIP is a critical player in driving cytokine responses from immune cells and provides a potential new target for the development of future therapeutics against inflammatory diseases.

Table I: RKIP‐/‐ B cells have an altered Type I Interferon signature by RNASeq

Gene
Location
Log2(change)
Fold Change
p value

Traf3
chr. 12
‐1.56
‐2.95
.0027

Irf3
chr. 7
‐1.86
‐3.63
.0027

Irf5
chr. 6
‐1.27
‐2.41
.0017

Irf7
chr. 7
‐1.93
‐3.81
.0018

Ifnar1
chr. 16
‐1.26
‐2.39
.0030

Grant Funding Source: Supported by grants from NIH (RO1 AI042858, Project 3 PO1 AI05172, and T32 AI007080)
Plasma metabolomic profiling in adults with cystic fibrosis and cystic fibrosis‐related diabetes (248.1)
Authors: Alvarez Jessica , Frediani Jennifer , Jones Dean , Grossmann Ruth , Uppal Karan , Tangpricha Vin , Ziegler Thomas
Published: June 2021

Background: Advances in metabolomics enable broad exploration of metabolism in cystic fibrosis (CF) and cystic fibrosis‐related diabetes (CFRD).

Methods: Plasma from 30 CF adults hospitalized for pulmonary symptoms (15 with CFRD) and 17 healthy controls were analyzed by high‐resolution LC‐MS. Data was analyzed in R using an in‐house pipeline that performs log2‐transformation, quantile normalization, FDR analysis using limma, and hierarchal clustering analysis (HCA). The METLIN Database was used to match ions to known metabolites. A targeted metabolome‐wide association study (MWAS) with serum 25‐hydroxyvitamin D (25(OH)D) levels was also done.

Results: Of 11,736 metabolites, 4,522 significantly differed between CF and controls (q = 0.01). HCA revealed 55 distinct metabolomic clusters differentiating CF and control subjects. Derivatives of vitamin D3 and several acylcarnitines were lower in CF. MWAS identified 268 metabolites associated with serum 25(OH)D levels, including octanoylcarnitine (r = 0.51, P = 0.01). A total of 74 metabolites significantly differentiated CF patients ± CFRD (q = 0.05), including coenzyme A and ATP.

Conclusions: Plasma metabolomic profiling can distinguish adults with or without CF and CF patients ± CFRD; other metabolites are linked with vitamin D status. These pilot data suggest fatty acid β‐oxidation pathways may be perturbed in certain CF patients.

Grant Funding Source: Supported by National Institutes of Health (T32 DK007298‐32S1, K23 AR054334, and K24 RR023356).
Teens and greens: the effect of vegetable‐based smoothies on adolescent health and school performance (251.8)
Authors: Lefkowitz Sarah , Rockway Susie
Published: June 2021

Teens and Greens: The Effect of Vegetable‐Based Smoothies on Adolescent Health and School Performance S Lefkowitz, S Rockway Capital Brands, 11755 Wilshire Blvd; LA CA 90025 ABSTRACT
Background: Children who eat breakfast are more likely to meet nutritional needs and perform better in school and on tests, yet many skip breakfast and do not meet their RDI for vegetable intake.

Purpose: Introduce vegetables to high school students at breakfast by giving a variety of fresh produce and high‐powered blenders to make healthy, palatable smoothies.

Design: Pre‐post design, 43 students from a local high school volunteered for a 3‐month pilot study. An RD met and encouraged students daily to make their own smoothie, ideally with 2 C veggies. Outcome measures were body composition, lipids and change in nutrient intake. Qualitative data were obtained at baseline and end of study via surveys regarding students’ views of health, focus and performance in school.

Results: Of the 43 students, 21 completed. Waist circumference decreased by 3% on average; plasma HDL increased in 14 students, TC dropped 9% in 7 students. Energy improved in 13 students. Ten percent had better grades. Afternoon lethargy dropped from 35% to 22%. Change in nutrient profiles of smoothies: Total kcal decreased from 293 to 247; veg servings increased from 1.75 to 2.25; CHO decreased from 58 to 40.5g; protein intake increased 1g, fat increased from 6 to 8.5 g and no change in fiber intake.

Conclusion: A daily vegetable‐based smoothie improved energy levels, focus, lipid profiles and body image in participating high school students.