bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sink or swim: Early dive behavior in Weddell seal (Leptonychotes weddellii) pups
Authors: Weitzner Emma , Pearson Linnea E. , Tomanek Lars , Whoriskey Sophie , Liwanag Heather E.M. 
Published: June 2021

Weddell seals (Leptonychotes weddellii) are a model species for studying diving physiology. However, Weddell seal pups are not born with the elite diving capabilities of their adult counterparts and must develop their skills so they can survive into adulthood. Previous research has excluded an examination of pups' initial diving attempts. The aim of this study was to investigate the development of diving capabilities throughout ontogeny, beginning at 1 week of age, to create a more complete trajectory of development. To do this, we examined the dive behavior and blood oxygen stores of Weddell seal pups over the first seven weeks of life. Flipper‐mounted time‐depth recorders (Lotek LAT1800XLFP) were attached to 1‐week‐old Weddell seal pups (n=8) in Erebus Bay, Antarctica, and were recovered when the pups were 7 weeks of age. Time spent in the water, maximum dive depth, dive duration, bottom time, and post‐dive interval were calculated to characterize dive behavior. Blood samples were collected from three of these pups at 1 week, 3 weeks, 5 weeks, and 7 weeks of age. We measured hematocrit, hemoglobin, and red blood cell counts for all blood samples to assess age‐related changes in blood oxygen stores. Time spent in the water and number of dives per day both significantly increased as pups got older (P < 0.0001). The time pups spent in the water per day ranged between 1 min and 21 h. Although the maximum dive depths for pups ranged between 3 m and 14.78 m, the majority of “dives” were less than 2 m. Hematocrit, hemoglobin, and red blood cell counts also increased throughout early development. Correlations between dive behavior and hematology indicate dive behavior, rather than age, is a better predictor of oxygen storage development. Based on these data, we conclude early experience in the water is an important driver of physiological development in dependent Weddell seal pups. New swimmers may prioritize acclimatization to the water and strengthening their swimming muscles over attempting deeper foraging dives.Support or Funding InformationThis project was funded by a grant from the National Science Foundation (#1543539).This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Intrinsic anti‐inflammatory properties of serum in deep‐diving seals
Authors: Hindle Allyson G. , Bagchi Aranya , Batten Annabelle , Levin Milton , Allen Kaitlin N. , Huckstadt Luis A. , Costa Daniel P. , Zapol Waren M. , Buys Emmanuel S. 
Published: June 2021

Diving seals are repeatedly exposed to hypoxia‐reoxygenation and other pro‐inflammatory stimuli such as shear stresses in alveoli from lung collapse and re‐expansion. Moreover, they have a known hyperlipidemic status, which is associated with vascular inflammatory stress in humans and mice. To investigate potential protective strategies in free‐living populations of deep‐diving seals, we examined baseline levels of cytokine biomarkers, as well as the inflammatory response of IL6 gene expression in seal blood cells exposed to an endotoxin (LPS, lipopolysaccharide, 1–1000ng/mL). Despite aspects of their basic physiology that predisposes other mammals to inflammatory stress, cytokine production in healthy Weddell seals (adults and pups) and Northern elephant seals (adults only) following LPS incubation was blunted (10–100X increase in plasma IL6), compared to human samples assayed under the same conditions (>1000X increase). These plasma samples, further assayed using a cytokine panel validated for pinnipeds, revealed that many cytokines were below detectable levels in Weddell seals, with only IL6, IL10 and TNFα exhibiting a dose‐response to LPS. Under isolated, in vitro conditions, Weddell seal monocytes maintained the expected, robust response to stimulation with LPS endotoxin. However, when this response was compared under typical cell culture conditions (using media supplemented with FBS) versus media supplemented with an equivalent amount of Weddell seal serum (WSS), IL6 expression from stimulated monocytes exposed to WSS declined significantly (LPS dose*serum‐type 2way repeated‐measures ANOVA across all doses: F1,6= 8.5, p=0.027 for FBS vs WSS), as did cytokines detected in the cell culture media. To further elucidate the potential anti‐inflammatory properties of seal serum, we repeated the experiment comparing FBS to de‐complemented WSS in RAW cells, a mouse macrophage line. These results validated our findings from seal monocytes, demonstrating that mouse cytokine expression (IL6, TNFα, and Mcp1), was consistently reduced in cells cultured with WSS compared to FBS. Finally, we confirmed that these results held in RAW cells exposed to other TLR ligands, including Pam‐3‐Cys, Poly I:C and CpG DNA (TNFα expression in WSS<FBS, p=0.0001 in each experiment). These findings suggest that seal serum innately possesses anti‐inflammatory properties, which may protect these deep divers from naturally occurring inflammatory challenges such as dive‐induced hypoxia‐reoxygenation and lung collapse.Support or Funding InformationFunded by the National Science Foundation (Office of Polar Programs).This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Mechanisms for Oxygen‐Mediation of Body Size
Authors: Harrison Jon Fewell , Campbell Jacob B. , Lundquist Taylor , Callier Viviane , Cogley Theodore , Fox Trevor , Greenlee Kendra J. 
Published: June 2021

Hypoxic‐rearing reduces the adult body size of animals, but the mechanisms responsible remain poorly understood. Holometabolous insects are important models for understanding the regulation of body size. Here we focus on how hypoxic rearing reduces final body size of Drosophila melanogaster. Larval D. melanogaster approximately triple their body mass during the last larval instar. We tested the hypothesis that functional hypoxia develops over time within the instar. Later instar animals had higher whole‐body copy numbers of HIFalpha and HIFbeta RNA and greater quantities of HIFalpha protein (Westerns), providing clear evidence that HIF signaling emerges late in the instar. Later‐instar animals also had greater expression of lactate dehydrogenase genes, and higher capacities for production of lactate, though not higher levels of whole‐body lactate, suggesting that functional hypoxia is not so extreme as to trigger anaerobic metabolism. However, CO2 emission rates increased in response to hyperoxia in late but not early‐instar larvae, providing strong evidence of oxygen limitation of metabolism. Hyperoxia reduced, and hypoxia elevated the RNA copy number of prolyl hydroxylase (whole body), a downstream target of HIF‐signaling. In sum, late‐instar normoxic‐reared larvae experience functional hypoxia, and whole‐body HIF‐signaling is increased with hypoxic‐rearing. Next, to understand the link between functional hypoxia and developmental transitions, we tested whether HIF signaling in the prothoracic glands (which produce ecdysone, aka molting hormone) affects development rate or adult size, using the GAL4‐UAS system to reduce or increase HIF signaling in this endocrine gland. Knockdown of HIF signaling in the prothoracic glands strongly delayed pupariation in 10% but not 21% oxygen atmospheres. Thus HIF‐signaling in the prothoracic gland appears to be an important factor in triggering Drosophila pupariation at a smaller body size in hypoxia, but we found no evidence that this is a key pathway for of the control of molting and size in normoxia.Support or Funding InformationSupported by NSF IOS 1256745.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Analgesic effects of intravenous morphine, fentanyl, sufentanil, and ketamine in a novel rat model of extremity trauma
Authors: Xiang Lusha , Ryan Kathy , Klemcke Harold , Hinojosa‐Laborde Carmen 
Published: June 2021

The goal of the current study was to establish a rat model of extremity trauma (ET)for prehospital pain research and validate it using different pain behaviors and analgesics applied via intravenous (IV) injection. Male Sprague Dawley rats (11–13 wk) were briefly anesthetized using isoflurane and ET was induced via clamping there trofemoral tissue groups for 30 sec using an L‐shaped hemostat, followed by closed fibula fracture using a 15‐gauge needle. Rats regained consciousness within 5 minutes after ET. Pain responses to thermal hyperalgesia (paw withdrawal latency of injured hindlimb, PWL), mechanical allodynia (paw withdrawal pressure of injured hindlimb, PWP), and weight bearing (WB) were determined prior to and 90 minutes after ET. Morphine (2 mg/kg), fentanyl (10 μg/kg), sufentanil (1 μg/kg), ketamine (5 mg/kg), or vehicle(saline) was then administered via IV injection, followed by PWL, PWP, WB, and TF assessments at 10, 40, 80, and 120 minutes after analgesic injection. Ninety minutes after ET, the PWL, PWP, and WB were significantly decreased by 61 ± 4%, 64 ± 8%, and 65 ± 4%, respectively, compared to baseline values. These pain behaviors were steadily maintained throughout the 3–4 hours of observation. Compared with the saline‐treated group, opioid analgesics significantly increased PWL during more than 80 minutes, with sufentanil exhibiting the highest analgesic effect. An increase in PWL was only observed at 10 minutes after ketamine injection. PWP was transiently increased with opioid analgesics for 10 to 40 minutes but was not changed with ketamine. WB was improved with opioid analgesics for atleast 2 hours but only for up to 80 minutes after ketamine injection. The ET model includes long bone fracture and soft tissue injury but no fixation surgery, mimicking prehospital extremity trauma, and produces acute, steady, and reproducible trauma‐related pain behaviors. Our model is clinically relevant regarding the pain behaviors and established responses to common analgesics.Support or Funding InformationThis study was funded by the US Army Clinical and Rehabilitative Medicine Research Program, Joint Program Committee 8, Applied Pain Research Award.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Sex Specific Differences in Cardiac Fibrosis
Authors: Conger Autumn , Milburn Gregory , Blair Cheavar , Guglin Maya , Wells Gretchen , Waikel Rebekah , Campbell Kenneth 
Published: June 2021

Cardiovascular disease is the leading causes of death in America, which prompted a concerted effort to better understand the causes and to develop innovative therapies. The etiology of heart disease is complex and depends on several factors such as age, race, and sex, but previous research conducted contains gaps, as it often did not look for a difference between these groups. This study aims to fill one aspect of this research gap by examining sex‐specific differences in cardiac fibrosis in failing and non‐failing human hearts. Cardiac fibrosis is a result of cardiac remodeling and causes decreased heart function post cardiac damage. A previous study, conducted in our lab, used Nanostring analysis to examine sex‐specific differences in the expression of genes related to fibrosis. The results of this study showed certain gene expressions were specific to sex or had an interaction between the sex and heart failure status. Several of these genes were regulators of collagen, a common type of cardiac fibrosis. We continued this study by quantifying collagen in human heart samples, collected from heart transplants and non‐viable organ donors. These samples were stained using an established picrosirius red staining technique, turning the collagen tissue red and normal cardiac tissue yellow. These samples were then quantified using a k‐means cluster, via a program written in the lab, to eliminate any bias in determining red and yellow tissue. The results are pending as there are still samples left to be completed. We hope to continue pursuing this line of inquiry into sex‐specific differences in heart disease by examining passive stiffness, of which collagen is a major component.Support or Funding InformationPenny Warren Award for Clinical and Translational ResearchAHA 15GRNT2546003(Campbell:PI)NIH UL1 TR000117 (Campbell: Core Leader)NSF 1538754 (Campbell: Co‐I)NIH R01 HD090642 (Campbell: PI of sub‐contract)NIH U01 HL133359 (Campbell: Co‐PI)This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Shifting Nitrogen Balance Induces Arousal from Hibernation in Arctic Ground Squirrels
Authors: Rice Sarah A , D'Alessandro Angelo , Barati Zeinab , Gehrke Sarah , Reisz Julie A , Drew Kelly 
Published: June 2021

Hibernators, such as arctic ground squirrels (AGS), undergo brief periods of euthermy (termed interbout arousals) where they radically change their physiological and metabolic state. These interbout arousals rebalance metabolic and nitrogen homeostasis. A key metabolic characteristic of a hibernation bout is a progressive increase in glutamine in liver, representing an increase in nitrogen load, which is resolved over the interbout arousal. We hypothesized that increasing the nitrogen load over a bout of torpor would induce arousal. We tested the impact of increased nitrogen load on timing of arousal and metabolic profile by blinded infusion of ammonium acetate at 6 and 30 mg/kg/hr for a 12 hour period early in a torpor bout. Sodium acetate (6 and 30 mg/kg/hr) and saline served as controls. Plasma was sampled at 0, 6, 12, 30 hour from infusion start and at points defined as mid and late torpor. We monitored the core body temperature and rate of oxygen consumption to assess the hibernation state of the animal. The metabolic impact of exogenous nitrogen load was tracked over time in plasma with ultra high‐performance liquid chromatography mass spectrometry (UHPLC‐MS) metabolomics.Infusion with the highest concentration of ammonium acetate resulted in a shorter bout length than infusion with saline (Table 1). The effect of infusions on metabolic profiles is pending analysis. In conclusion, results support the hypothesis that nitrogen load limits torpor bout length. Further work is needed to determine if shifting nitrogen balance in hibernation mimics endogenous mechanisms which naturally induce arousal.This work was performed in conformance with the FASEB Statement of Principles for animals used in research.Support or Funding InformationThis work was supported by the NSF award number 1258179 and NIH 20GM103395.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Valproate Prevents a Cytosolic vH+ATPase Subunit Insertion on Insulin Granule Membrane and Compromises Insulin Release in Min6 Cells
Authors: Yedulla Nikhil , Naik Akshata R. , Kokotovich Keith M. , Yu Wenxi , Greenberg Miriam L. , Jena Bhanu P. 
Published: June 2021

The vacuolar proton pump, vH+ATPase transfers protons (H+) across cell membranes which helps maintain pH gradient within cells necessary for various cellular functions. It is a two‐part pump containing a membrane (V0) and a soluble cytosolic (V1) domain with each domain consisting of multiple subunits. In secretory cells, such as neurons, vH+ATPase acidifies synaptic vesicles, which is essential for neurotransmitter uptake, storage and exocytosis. Valproate, an FDA approved, anti‐ epileptic drug has been shown to disturb vH+ATPase function in yeasts, by inhibiting myo‐inositol phosphatase (MIPS), the first and the rate‐limiting enzyme in inositol biosynthesis leading to inositol depletion. Additionally, vH+ATPase is present on the membrane of insulin secreting granules (ISG) within pancreatic β cells. Several studies have suggested vH+ATPase requirement for insulin maturation within ISGs. Further, pancreatic islets containing a mutant vH+ATPase isoform exhibit compromised insulin release function, however, the mechanism is unknown. Here, we demonstrate that clinical dose of valproate (1mM) significantly reduced glucose‐ stimulated insulin secretion in mouse pancreatic insulinoma (Min6) cells. Moreover, valproate caused maximal inositol depletion in Min6 cells after 5 hours of incubation with the drug. Dual immunofluorescence staining of valproate‐treated Min6 cells demonstrates almost no localization of one of the cytosolic subunits of vH+ATPase (subunit C) on ISGs, unlike in control. These results conclude that inositol depletion in Min6 cells caused by valproate precludes insertion of vH+ATPase subunit C on ISG membrane, rendering the ISGs less competent for glucose‐stimulated insulin secretion.Support or Funding InformationWork presented in this article was supported in part by the National Science Foundation grants EB00303, CBET1066661 (BPJ); the WSU Interdisciplinary Biomedical Systems Fellow‐ ship and Graduate Research Assistantship (ARN). All authors critically analyzed results and proof read the manuscript. The authors declare no competing financial interests or conflicts.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Ergogenic effects and potential synergism of combined doxapram and acetazolamide in hypoxic rats
Authors: Schroeder Thies , Hamilton Karyn , Irwin David 
Published: June 2021

Hypoxemia is a potentially life‐threatening condition that can arise from various conditions, but there is a general lack of effective acute treatments. Voluntary increase of breathing frequency can increase blood oxgen concentrations, however, this does not work during sleep or unconsciousness. Pharmaceutical enhancement of breathing rates is available, but confounded by severe side effects related to respiratory alkalosis. We hypothesized that the addition of a mildly acidifying drug, such as acetazolamide, would be feasible and beneficial, if combined with a respiratory stimulant, such as doxapram. To test the hypothesis, we measured the ability of rats to run in a hypobaric athmosphere of approx. 4,267m/10% O2, after drug injection. Both high (20 mg/kg) and low (10 mg/kg) concentrations of doxapram significantly increased exercising endurance in rats (Log rank test, using a forced exercise wheel model, with or without acetazolamide (5/20 mg/kg) present. Neither low or high acetazolamide improved hypoxic exercise capacity. In an awake hemodynamic rat model, we found that acetazolamide decreased blood pH by approx. 0.05, and doxapram increased it by 0.03 pH points, however, subsequent injection of the respectively other drug normalized blood pH to a common level within 90 minutes. Although both drugs increased blood pO2 independent of each other, addition of the respective other drug did not induce any further increase in pO2. None of the drugs significantly changed pCO2. We conclude that the combination of doxapram and acetazolamide are potentially safe and efficacious in counteracting hypoxemia in rats, caused by hypoxic environments or other factors. Because they cancel out each others effects on blood pH, they might synergize in their ergogenicity of counteracting hypoxemia.Support or Funding InformationDARPA, Prime Award Number N66001‐10‐C‐2134This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Investigating Peptide Assembly in a Membrane Environment
Authors: Gessel Megan , Kober Megan , Maxwell Zoe , Swain Samantha 
Published: June 2021

ObjectiveThis study seeks to determine how the properties of a lipid membrane influence protein folding and assembly in model systems using hydrogen‐detuerium exchange mass spectrometry (HDX‐MS).MethodsThe folding and assembly of small model peptides in large unilamellar vesicles (LUVs) have been investigated using HDX‐MS. We currently have results for the 13‐residue, cationic peptide indolicidin in LUVs prepared with 1,2‐Dioleoyl‐sn‐glycero‐3‐phosphocholine (DOPC) or 1,2‐Dioleoyl‐sn‐glycero‐3‐phosphoglycerl (DOPG).ResultsOur HDX‐MS results indicate that free indolicidin is fully deuterated at all measured time points, including the shortest (30s). Results with LUVs show differences between LUVs made of DOPC (a zwitterionic phospholipid) and DOPG (an anionic phospholipid). Indolicidin mixed with DOPC LUVs has slightly less deuterium incorporation (~3 fewer deuterium), compared to the free peptide in the absence of LUVs. Indolicidin with DOPG LUVs shows additional protection from hydrogen‐deuterium exchange (~5 fewer deuterium), compared to free indolicidin. Preliminary MS/MS experiments suggest that HDX protection occurs at the C‐terminal end of indolicidin.ConclusionsEvidence from several studies shows that MPs fold into their “correct” structures even in certain lipid‐free environments, suggesting that the membrane may not be required for proper MP folding. However, many researchers go to great lengths to mimic the physical and chemical environment of the membrane and claim that characteristics including curvature, fluidity, and symmetry are significant. Overall, we plan to investigate three model peptides known to insert into the membrane and oligomerize to form membrane‐active structures. The model peptides represent different structural classes and their individual structures have already been well‐characterized by traditional biophysical methods.Our results with free indolicidin are consistent with the fact that, in solution, indolicidin remains in a monomeric form and adopts an extended, linear structure. The results with LUVs indicate that the peptide does interact with both types of LUVs. More protection from HDX occurs with the DOPG LUVs, suggesting that the protein may be embedding itself deeper into the DOPG (anionic) LUVs, compared to DOPC (zwitterionic) LUVs. The surface charge of the model membrane may affect the peptide's ability to associate with the membrane. The MS/MS results suggest that the peptide's C‐terminus may be responsible for insertion into both LUV types. We are currently varying the model membranes to examine the effects of fluidity and curvature, as well.Support or Funding InformationThis work was supported by a Major Research Instrumentation grant (MRI1531435) from the National Science Foundation and a grant from the Murdock Charitable Trust.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.