bluuebunny/crossref_metadata_2025_split huggingface dataset:
Aggregation of Insulin on Langmuir Monolayers
Authors: Saulcy Kate , Crans Debbie C. , Sostarecz Audra Goach 
Published: June 2021

The polypeptide hormone, insulin, is known to aggregate into a hexamer in the presence of zinc ions. The Langmuir monolayer technique can be used to examine the transition between active monomeric insulin molecules and the hexameric form which is more difficult for the body to use. Distinctive isotherm characteristics for both monomeric insulin and hexameric insulin were observed. Zinc (II) chloride is added to the model membrane system to create hexamers of insulin. Conditions of the system are altered to learn about the dependence of insulin's molecular conformation on factors such as pH and concentration. Chelating agents, such as (ethylenediaminetetraacetic acid) EDTA and citrate are added to effectively remove the zinc ion from the solution and observe the behavior of the insulin molecules. With the addition of EDTA to the monolayer of zinc exposed insulin, monomeric isotherm characteristics were noted, indicating the removal of zinc from the insulin hexamer and the creation of monomeric insulin. These molecular conformational changes affect the function of the insulin molecule in the human body.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Age‐Related Loss of Mitochondrial Glutathione Exacerbates Vulnerability to Redox‐Cycling Challenge
Authors: Thomas Nicholas , Shay Kate , Butler Judy , Kelley Amanda , Hagen Tory 
Published: June 2021

In order to determine the role of mitochondrial GSH (mGSH) loss in increased susceptibility to xenobiotic insult with age, markers of mitochondrial function were measured in intact and digitonin‐permeabilized hepatocytes from young and old F344 rats under a redox cycling (300 μM menadione) challenge. While the rate of mGSH loss under menadione challenge was similar in both age groups, a 47% decline in initial mGSH levels with age resulted in a 50% loss of mGSH in old rat hepatoctyes versus 28% in young within 10 minutes of exposure. Examination of mitochondrial membrane potential (Δψm), which is acutely regulated by mGSH content, showed a 21% basal loss with age. Additionally, within five minutes of menadione challenge, Δψm in young was not markedly reduced but had collapsed in old rat hepatocytes. Further characterization demonstrated that basal respiration and respiratory reserve capacity, indicators of cellular bioenergetic capacity, were both significantly reduced upon menadione treatment in old rat hepatocytes but not in young. Examination of proton leak, complex I, and complex II contributions to mitochondrial oxygen consumption rates under menadione challenge revealed no marked effect in young rat hepatocytes, while old rat hepatocytes demonstrated a significant loss in complex I activity as well as increases in proton leak and a compensatory increase in complex II activity. These data clearly demonstrate an age‐related increase in mitochondrial susceptibility to a redox‐cycling challenge, particularly in complex I, and provide a plausible mechanism that links this vulnerability to mGSH perturbations.Support or Funding InformationN.T. is supported by an NIH grant. Title: CAM RESEARCH TRAINING IN NEUROSCIENCE & STRESS; number: 2T32AT002688.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Osteopenia in a Spontaneous Mouse Model of Systemic Lupus Erythematosus
Authors: Lotinun Sutada , Atjanasuppat Korakot , Visitchanakun Peerapat , Saiworn Worasit , Pisitkun Prapaporn , Leelahavanichkul Asada 
Published: June 2021

Systemic lupus erythematosus (SLE), a chronic inflammatory autoimmune disease, is characterized by loss of B‐cell tolerance to autoantigens. SLE patients are at increased risk for osteoporosis. Mice lacking Fc gamma receptor IIb (Fc©RIIB) exhibit SLE and its restoration rescues the disease. To determine whether deletion of Fc©RIIB induces osteopenia, we analyzed a skeletal phenotype of Fc©RIIB knockouts at 3, 6 and 10 months old. The analysis of anti‐dsDNA antibodies indicated that mice deficient in Fc©RIIB developed spontaneous SLE at 6 months of age. μCT analysis showed that deletion of Fc©RIIB had no effect on cortical and cancellous bone at 3 months of age. In contrast, 6‐ and 10‐month‐old Fc©RIIB −/− males were osteopenic and a severity of bone loss increased with disease duration. Deletion of Fc©RIIB decreased cortical bone area and cancellous bone volume with increased structural model index. Histomorphometry indicated a decrease in cancellous bone volume, trabecular thickness and trabecular number with concomitant increase in trabecular separation in Fc©RIIB−/− males. Ablation of Fc©RIIB increased osteoclast number without any change in osteoblast number. A skeletal phenotype was milder in females. Deletion of Fc©RIIB increased osteoclast differentiation but did not alter alkaline phosphatase activity and mineralization. Breaking strength parameters, including J, Imax, Imin, Imin/Cmin, and Imax/Cmax were decreased in Fc©RIIB deficient mice compared to WT controls. Our data indicate that Fc©RIIB contributes to the regulation of bone turnover and homeostasis subsequent to SLE and that absence of Fc©RIIB induces osteopenia and decreases breaking strength.Support or Funding InformationThe Ratchadapisek Sompoch Endowment Fund (2014, CU‐57‐091‐IC) and the Faculty of Dentistry, Chulalongkorn UniversityThis abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Group A Streptococcus Prevents Acidification of the Phagolysosome: Role of Lysosomal Leakage
Authors: Zhang Robert , Snipper Joshua , Zheng Kelvin , No Hyewon , Okumura Cheryl 
Published: June 2021

Group A Streptococcus (GAS) is a Gram‐positive bacterium that is among the top 10 causes of infection‐related mortality in humans, with infections ranging from minor illnesses such as pharyngitis, to life threatening diseases such as necrotizing fasciitis and streptococcal toxic shock syndrome. As the first response to infection, the innate immune system recruits leukocytes such as macrophages to the site of GAS infection, which are able to phagocytose GAS. Once GAS is inside the phagosome, the lysosome fuses with the phagosome to form the phagolysosome. To degrade pathogens such as GAS, the phagolysosome reduces its internal pH to activate proteolytic enzymes. To monitor this process, we infected THP‐1 macrophages with M1 serotype GAS transformed with a plasmid (pWASABI) that expresses a pH‐sensitive green fluorescent protein that is degraded at low pH. Our results showed that GAS expressing pWASABI has a persistent fluorescent signal when bacteria were present in phagolysosomes. In comparison, the non‐pathogenic Gram‐positive species Lactococcus lactis expressing pWASABI had an appropriate decreased fluorescence signal. These results suggest that GAS inhibits the acidification of the phagolysosome. To further confirm the pH of the phagolysosome, we stained infected macrophages with Lysotracker, an acidotropic fluorescent dye. The preliminary results of this experiment confirmed that phagolysosomes containing GAS are not acidified. Previous research has suggested that pore‐forming toxins such as streptolysin O (SLO) and streptolysin S (SLS) induce phagolysosomal leakage of protons. To examine this, we transformed a mutant strain lacking SLO (ΔSLO) with pWASABI. Our preliminary results showed no difference in fluorescence signal when the ΔSLO strain was present in phagolysosomes, suggesting that SLO may not be inducing lysosomal leakage. We are currently exploring whether pore formation by SLS plays a role in lysosomal leakage. The results of these experiments will help provide a clearer image of the molecular mechanism of innate immune resistance of GAS, and may aid in the development of therapeutics aimed to enhance the innate immune system's ability to degrade GAS.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Discriminative Stimulus Effects of Gabapentin
Authors: Zuidema Michael Ryan , Galbo Lindsey Kay , Lekander Alex Duncan , Esterline Lea , Prus Adam Joseph 
Published: June 2021

Gabapentin (Neurontin) is synthetic analog of GABA that functions as a voltage‐gated calcium channel (VDCC) blocker and is FDA approved for the management of neuropathic pain and seizure disorders. While not a controlled substance, gabapentin misuse is associated with illicit opioid use, suggesting, along with anecdotal reports, that gabapentin may elicit positive subjective effects. The present study was conducted to examine the subjective effects of gabapentin using rats (N=10) trained to discriminate a 30.0 mg/kg dose of gabapentin (60 min pretreatment time) versus saline in a two‐choice drug discrimination task. The discrimination was acquired in all 10 animals (M = 67.4 sessions, +/− 7.2 SEM). A time course assessment using the gabapentin training dose revealed full substitution (> 80% Gabapentin‐appropriate responding) at 30 and 60 minutes post‐injection. In addition to the training dose, full substitution also occurred for a 60 and 120 mg/kg dose of Gabapentin. Full substitution was shown for the barbiturate and GABAA receptor positive modulator pentobarbital and for the gabapentin analog and VDCC blocker pregabalin. Partial substitution was shown with the psychostimulant d‐amphetamine and the anxiolytic drug and 5‐HT1A partial agonist buspirone. The present findings demonstrate gabapentin's discriminative stimulus effects appear to be primarily mediated by GABAA receptors and VDCC blockade and partially mediated by dopamine and 5‐HT receptors. Full substitution by pentobarbital and partial substitution by amphetamine suggests the potential for positive subjective effects produced by gabapentin.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
A nanotechnology system for augmenting the intranasal delivery of oxytocin
Authors: Murnane Kevin Sean , Oppong‐Damoah Aboagyewaah , Zaman Rokon Uz , D'Souza Martin 
Published: June 2021

Neuropeptides such as oxytocin (OT) have shown promise as treatments for many central nervous system (CNS) disorders, such as Dravet Syndrome and Autism Spectrum Disorder (ASD). The primary barriers to the use of OT as a treatment for ASD are that, due to its size and hydrophicity, it does not cross the blood brain barrier (BBB) and penetrate the CNS, and that it is rapidly metabolized in the blood stream, with a half‐life of 1–6 minutes following IV administration. Ongoing studies are attempting to overcome its poor brain penetrance using intranasal delivery of OT. Although the development of intranasal delivery of OT has been a seminal advance in ASD research, this administration method is an inefficient means of transferring drug to the brain and requires frequent dosing (because of the short half‐life of OT). As such, there is legitimate concern regarding the long‐term effects of high‐dose and frequent daily administration of intranasal OT. We have collected compelling data showing that a nanotechnology is a promising means of augments the brain penetrance of OT and protecting OT from metabolism and sustaining its delivery. We have found that our nanoscale drug carriers do not exhibit in vitro or in vivo toxicity, have sizes on the order of 100–200nm (which is highly amenable to brain delivery), increase the brain penetrance of an IR‐marker (of similar molecular size to OT) using bioimaging, engender stronger prosocial effects than OT alone given intranasally, and exhibit sustained release effects both in vitro and in vivo. Although we have focused on the development of intranasal OT, we believe that this new technology will be applicable to many other neuropeptides (such as neuropeptide Y) that may have promise for ASD and other disorders because of their anti‐inflammatory, neuroprotective, and/or anti‐seizure effects.Support or Funding InformationThis work was supported by R21NS100512.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Synthesis and Evaluation of Bioactive Estrogen Conjugated Naphthalimides
Authors: Skubic Kristin , Arnatt Christopher K. 
Published: June 2021

Small molecule DNA intercalators as antineoplastic agents, for breast cancers, have gained a significant amount of success within recent years. Therefore, previously tested naphthalimide compounds were coupled to an estrogen receptor antagonist in offering a useful method in delivering cytotoxic drugs selectively to sites expressing high levels of estrogen receptors. A series of novel conjugate compounds incorporating a linker, with an anhydride component and a diamine component, joining estrogen and known potent naphthalimides were synthesized to demonstrate apoptotic effects with antiproliferative activity in breast cancer cell lines. These conjugates are promising compounds for further studies in treatment of estrogen receptor positive breast cancers. Calculated LD50 values for the antiproliferation assays illustrate a clear structure‐activity relationship for this conjugated naphthalimide‐estrogen series.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Altered mitochondrial dynamics contributes to endothelial dysfunction in hypertension
Authors: Li Guohua , Wu Jie , Hou Zuoxu , Zhang Xing , Gao Feng 
Published: June 2021

AimsImpaired mitochondrial dynamics is implicated in cardiovascular diseases. Alterations in mitochondrial dynamics and reactive oxygen species production have been shown to be associated with the development of hypertension. However, the role of mitochondrial dynamics in endothelial dysfunction during the development of hypertension remains unknown.MethodsEffects of mitochondrial fission inhibitor mdivi‐1 on vascular contraction and relaxation were examined on mesenteric arteries isolated from WKY or SHR rats. Mitochondrial networks in aortic endothelia were assessed using transmission electron microscope, and further evaluated with laser confocal after labeling with 100 nmol/L MitoTracker Green FM. In vitro, effects of Angiotensin□(10−6 M, 24 h) on mitochondrial morphology in HUVECs were investigated.ResultsPretreatment with mdivi‐1 inhibited PE‐induced mesenteric artery constriction in WKY rats, and the inhibitory effect of mdivi‐1 was attenuated on endothelium‐denuded mesenteric arteries. Then we observed mitochondrial fragmentation, increased mitochondrial reactive oxygen species production and increased expression of dynamin‐related protein 1 (Drp1) in aortic endothelial cells from SHR rats. Mdivi‐1 pretreatment ameliorated acetylcholine induced mesenteric artery relaxation in SHR rats. In cultured HUVECs exposed to Angiotensin□, we observed a similar loss of mitochondrial networks and increased expression of Drp1. Altered mitochondrial dynamics was associated with increased mitochondrial reactive oxygen species production and a marked impairment of insulin‐stimulated activation of endothelial nitric oxide synthase and endothelial autophagy. Silencing Drp1 with siRNA blunted Angiotensin□induced alterations in mitochondrial networks, reactive oxygen species production, endothelial nitric oxide synthase activation and endothelial autophagy.ConclusionsThese findings show that up‐regulation of Drp1 during hypertension exacerbates endothelial dysfunction by increasing mitochondrial reactive oxygen species and subsequently inhibiting endothelial nitric oxide synthase activation and autophagy.Support or Funding InformationThis study was supported by the grants from the National Natural Science Foundation of China (Grant Nos. AWS16J018, 81670253)This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Pharmacological inhibition of TRPV4 channels protects against early renal hypoperfusion induced by ischemia‐reperfusion in neonatal pigs
Authors: Soni Hitesh , Peixoto‐Neves Dieniffer , Olushoga Michael A. , Adebiyi Adebowale 
Published: June 2021

Renal ischemia‐reperfusion (IR) remains a significant cause of acute kidney injury (AKI) in neonates. Early renal vasoconstriction in ischemic AKI induces hypoperfusion and a rapid decline in kidney function. Mechanisms that underlie post‐ischemic renal hypoperfusion are poorly understood, but possibilities include alterations in ion channel‐mediated renal vasoregulation. Here, we show that pharmacological activation of TRPV4 channels promotes renal vasoconstriction and hypoperfusion in neonatal pigs. Bilateral renal ischemia followed by short‐term reperfusion increased TRPV4 channel protein expression and activity in preglomerular microvessels and vascular smooth muscle cells (SMCs), respectively. Renal IR caused oliguria and elevated serum or urine levels of AKI biomarkers. Renal IR also increased renal vascular resistance (RVR) and attenuated renal blood flow and glomerular filtration rate in the pigs. However, TRPV4 channel blockers HC 067047 and RN 1734 mitigated renal IR‐induced oliguria, hypoperfusion, and alterations in AKI biomarkers. Furthermore, renal IR increased serum angiotensin II (ANG II) concentration, but not renal vascular expression of type 1 ANG II receptors in the pigs. TRPV4 channel blockade reduced ANG II‐induced renal vasoconstriction, RVR increase, and renal hypoperfusion in the pigs. Together, our data suggest that increased renal vascular SMC TRPV4 channel expression, ANG II‐induced TRPV4 activation, and subsequent increase in RVR contribute to hypoperfusion and kidney insufficiency elicited by renal IR in neonatal pigs. We propose that multimodal signaling by renal vascular SMC TRPV4 channels regulates neonatal renal hemodynamics in health and disease.Support or Funding InformationR01DK101668This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Evolution of Naturally High Plasma Glucose Concentrations in Birds
Authors: Basile Anthony J. , Jarrett Catherine L. , Witt Christopher C. , Sweazea Karen L. 
Published: June 2021

Blood glucose is a circulating fuel source for animals. However, species vary in glucose requirements due to distinct fuel physiology. Birds naturally have higher plasma glucose concentrations (PGlu) by a factor of 1.5–2 compared to mammals when adjusted for body mass. Currently, the physiological and evolutionary cause of the high PGlu is unknown. The goal of this study was to begin to elucidate the evolution of high PGlu in birds by comparing PGlu between Aves and Mammalia as well as analyzing the phylogenetic distribution of PGlu among avian species. Data were collected for PGlu and body mass for 284 species (Aves = 163, Mammalia = 121) housed at The Phoenix Zoo in Arizona. We used these data to 1) examine the relationship between body mass and PGlu in Aves and Mammalia, 2) examine inter‐order differences in PGlu within Aves, and 3) examine the maximum‐likelihood ancestral state for glucose in Aves. Consistent with prior studies, birds maintain the highest PGlu among vertebrates (16.20 mM/L ± 0.26, p < 0.05). Further, PGlu was negatively correlated with body mass for Aves (Linear Regression, p<0.05). A similar negative correlation for mammals was not observed within this data set. The highest and lowest PGlu in birds were Coraciiformes (22.35 ± 1.17 mM/L) and Struthioniformes (10.58 ± 0.63 mM/L), respectively (one‐way ANOVA, p<0.05). As Coraciiformes are small (~0.21kg) and Struthioniformes are large (~64kg), these variations in PGlu may be explained by the relationship between body mass and PGlu presented above. This was confirmed by phylogenetic generalized linear model analyses, which showed that body mass alone explained PGlu within bird species. Collectively, these data allow us to better understand the evolution of PGlu within birds. Future research aims to determine the physiological mechanisms driving the differences in PGlu among avian species.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
TNFSF14 inhibits neutrophil extracellular trap formation in neutrophil‐like HL‐60 cells.
Authors: Petreaca Melissa , Kloczkowski Breanna 
Published: June 2021

Tissue injury and infection induce a rapid inflammatory response, in which inflammatory cells, primarily neutrophils, leave the blood vessels and move into the affected tissue. Upon their arrival in this tissue, neutrophils use a variety of methods to kill potential pathogens, including phagocytosis, the generation of reactive oxygen species (ROS) that non‐specifically damage microbes, and formation of neutrophil extracellular traps (NETs) that trap microbes in an anti‐microbial environment. In addition to eliminating potential pathogens, ROS and NETs damage host tissues, promoting a positive feedback loop of tissue damage and inflammation that normally ends during the resolution of inflammation. The resolution of inflammation is associated with the inhibition of neutrophil recruitment and function, as well as induction of neutrophil apoptosis. Previous studies comparing wound healing in wild type and knockout mice found that the cytokine TNFSF14 is necessary for timely resolution of inflammation in mouse wounds, though the mechanism remains unclear. TNFSF14 could promote the resolution of inflammation by reducing cytokine production in the affected tissue, increasing neutrophil apoptosis, and/or reducing pro‐inflammatory neutrophil functions, such as ROS production and NET formation. In this study, we investigated whether TNFSF14 decreases HL‐60 neutrophil‐like cell production of ROS or NETs in response to multiple stimuli, using fluorimetry of DCF‐DA‐stained HL‐60 cells to quantify ROS production and fluorimetry of Sytox Green‐stained extracellular DNA to quantify NET formation. We found that, while TNFSF14 does not inhibit ROS production in these cells, it does decrease NET formation in response to PMA and LPS, suggesting that TNFSF14 may promote the resolution of inflammation through its inhibition of NET formation.Support or Funding InformationResearch start‐up and faculty development funding from DePauw UniversityThis abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.