bluuebunny/crossref_metadata_2025_split huggingface dataset:
CD‐14 expression in hepatic tissue of horses with laminitis
Authors: McGeachy Matthew , Carlisle Katherine , Garza Frank , Stokes Ashley Michelle 
Published: June 2021

Researchers hypothesize that laminitis in horses, due to introduction of bacterial components (i.e. endotoxins) into the systemic circulation from GI disturbance, signal an innate immune/inflammatory response via the Toll‐Like Receptor (TLR) Signaling Pathway. TLR‐4 is predominantly responsible for the response to G‐ bacteria and we found this gene was upregulated 3‐fold in laminitic horses compared to controls. The co‐receptor, Cluster of Differentiation 14 (CD‐14), transports endotoxins TLR‐4. We hypothesize that upregulation of TLR‐4 may correlate with expression of CD‐14.Equine CD‐14 expression was measured using TaqMan RT‐PCR in liver samples from normal, cases with metabolic disease, and those with naturally acquired or experimentally‐induced laminitis. The primers and probe for equine CD‐14 were designed from the NCBI published equine CD‐14 gene sequences (AF200416, NM 001081927). Data is expressed as ΔΔCT (Critical Temperature units).CD‐14 decreased 0.3561 fold from that of normal horses. Horses with metabolic predispositions for laminitis had a 9.8758 fold increase in CD‐14 expression. Decreased CD‐14 in laminitic horses may not directly correlate with TLR‐4 up‐regulation; therefore more studies need to be performed to understand the potential role of CD‐14 as it relates to laminitis pathogenesis. Funding by the LSU Equine Health Studies Program.
Sca‐1 positive pancreatic progenitor cells as a cell transplant therapy for treatment of Diabetes Mellitus
Authors: Samuelson Lisa Lynn , Gerber David 
Published: June 2021

ObjectiveWe propose a stem cell antigen 1 (Sca1) positive pancreatic progenitor cell (Sca‐PPC) for the treatment of Diabetes Mellitus.MethodsCells were isolated from pancreata of 2 week old mice using mechanical and enzymatic digestion. Pancreatic cells were purified for Sca 1 expression and cultured under select conditions. Cells were analyzed by RT‐PCR and Western blot for transcription factors and protein expression. ELISA assays were performed to determine insulin production by the Sca‐PPCResultsSca‐PPC were viable and capable of being maintained in culture through seven passages. RT‐PCR demonstrates that the cells maintained the expression of Preproinsulin I and II, Ngn3, Nkx2.2, Nkx6.1, Ins2 and Ptf1 up to passage number 7. Western blot analysis shows the cells are positive for Insulin receptor alpha, PDX1, Ngn3, and amylase through the same passages. ELISA for insulin production demonstrates a basal production of insulin from the Sca‐PPC in maintenance cultures.ConclusionSca‐1 positive pancreatic progenitor cells demonstrate a pancreatic genotype and phenotype in culture. These cells also demonstrate an ability to produce insulin in culture. Sca‐PPCs offer a potential cell type that can be used for the treatment of diabetes.
Cyclic GMP stimulating actions of a novel fully humanized designer natriuretic peptide, CBB‐NP, in human aortic endothelial cells as compared to the native natriuretic peptides
Authors: Lee Candace Y.W. , Huntley Brenda K , Burnett John C 
Published: June 2021

BackgroundCBB‐NP is a novel fully humanized designer natriuretic peptide (NP) integrating the 17‐amino‐acid ring of human C‐type NP (CNP) with the N‐ and the C‐termini of human B‐type NP (BNP). CBB‐NP exerted natriuretic, diuretic, renal‐preserving and cardiac‐unloading actions in anesthetized dogs. In this investigation, we compared for the first time the cGMP stimulating actions of CBB‐NP vs human atrial NP (ANP), BNP and CNP in human aortic endothelial cells (HAEC).MethodsCBB‐NP was synthesized (SPKMVQGSGCFGLKLDRIGSMSGLGCKVLRRH with a disulfide bond joining the C residues). HAEC were incubated with ANP, BNP, CNP or CBB‐NP for 10 min (10−6 M). Cyclic GMP was quantified by RIA.ResultsCBB‐NP and CNP increased cGMP (pmol/mL) vs control (0.108±0.020 and 0.174±0.036 vs 0.001±0.001, P<0.01 and <0.001, respectively). CBB‐NP elicited a greater cGMP response vs ANP (0.027±0.002, P<0.05), whereas comparable responses were observed vs BNP and CNP. When the native NPs were compared, a greater cGMP stimulating response was detected with CNP vs ANP and BNP (P<0.001 and <0.01, respectively).ConclusionsThe novel designer NP, CBB‐NP, stimulates cGMP in human aortic endothelial cells to a comparable extent as compared to the native BNP and CNP. Moreover, its cGMP stimulating action is greater than that of ANP. The therapeutic potential of CBB‐NP in models of cardiovascular diseases warrants further investigation.Supported by NIH, HFSA and ASCPT
Sexually Diergic Hypothalamic‐Pituitary‐Adrenal (HPA) Responses to Single‐Dose Nicotine, Continuous Nicotine by Osmotic Mini‐Pumps, and Nicotine Withdrawal by Single‐Dose Mecamylamine in Rats
Authors: Gentile Natalie E. , McKlveen Jessica M. , Czambel R. Kenneth , Karwoski Tracy E. , Rubin Robert T. , Rhodes Michael E. 
Published: June 2021

HPA responses to acute doses of nicotine (NIC) are sexually diergic: Female rats have higher adrenocorticotropic hormone (ACTH) and corticosterone (CORT) responses than males. We determined HPA responses in male and female rats following: 1) single‐doses of NIC, 2) a single‐dose of NIC immediately following continuous NIC for 2 weeks, and 3) NIC withdrawal by single‐dose mecamylamine (MEC). Blood sampling occurred before and after MEC and NIC administrations. ACTH and CORT were determined by RIA.Male vs. female HPA responses to single‐dose NIC support previous findings: Female ACTH and CORT responses were greater than male responses. The sex difference to single‐dose NIC remained following continuous NIC, and HPA responses in both sexes were significantly lower in magnitude and duration. The sex difference remained following NIC withdrawal by MEC; as well, the HPA responses were significantly higher in magnitude and duration than in the continuous NIC groups. These results suggest that sexually diergic HPA responses to NIC are reduced and transient following continuous NIC administration, but are enhanced and sustained following NIC withdrawal. The present study may have implications for determining associations among stress, habituation of the HPA axis to chronic NIC use, and NIC withdrawal.
ETB receptor activation changes ETB receptor location in venous but not aortic smooth muscle cells
Authors: Tykocki Nathan Roger , Watts Stephanie W. 
Published: June 2021

Endothelin (ET‐1) is a 21‐amino acid peptide that acts as a potent endogenous vasoconstrictor, and is produced by vascular endothelial cells. ET‐1 activates two G‐protein coupled receptor subtypes: ETA and ETB. In arteries, ETA receptor stimulation causes contraction and ETB stimulation causes relaxation. Although ETA stimulation also causes contraction in veins, ETB stimulation can cause either contraction or relaxation. Since ETB receptors cause contraction in veins but not arteries, we hypothesize that venous smooth muscle ETB receptors will relocate within cells in ways arterial ETB receptors do not.Explants of aortic and venous smooth muscle cells (SMC) were cultured from freshly dissected rat thoracic aorta and vena cava. Cells were exposed to vehicle or the ETB receptor agonist Sarafotoxin‐6c (S6c) (100 nM) for 30 minutes prior to immunofluorescent labeling of ETA receptors, ETB receptors, and nuclei. Untreated aortic and venous SMC expressed ETA and ETB receptors, without significant difference in receptor mean fluorescence. In the presence of S6c, mean ETB receptor fluorescence was significantly greater in nuclei of venous SMC when compared to aortic SMC (137.6±9.4 vs. 96.3±11.5). S6c did not alter ETA or ETB whole‐cell fluorescence in aortic and venous SMC. These findings imply a role of activated ETB receptors in S6c‐induced signaling in venous smooth muscle cells.
Increased oxidative stress in cardiovascular center of brain stem causes sympatho‐excitation in dietary‐induced obesity rat
Authors: Konno Satomi , Hirooka Yoshitaka , Kishi Takuya , Ito Koji , Araki Shuuichiro 
Published: June 2021

BackgroundActivation of the sympathetic nerve activity (SNA) induced by leptin acting on the pituitary‐hypothalamic pathway plays a central role of hypertension in metabolic syndrome (MetS). However, the role of the cardiovascular center in the brain stem (rostral ventrolateral medulla; RVLM) in SNA and the mechanism involved in MetS are not understood. The aim of this study was to determine if oxidative stress in the RVLM in MetS is increased thereby causing hypertension.Methods and ResultsMale Sprague‐Dawley rats were fed on a moderately high‐fat diet and segregated into obesity‐prone (OP, n=5) and obesity‐resistant (OR, n=5) groups based on their body weight (BW) after 13 weeks. Adiponectin in blood sample and visceral fatty mass were measured as an indicator of MetS. Blood pressure (BP), hearts rate (HR), urinary norepinephrine excretion (UNE), body weight, and amount of visceral fat mass were significantly higher and adiponectin was significantly lower in OP than in OR. Thiobarbituric acid‐reactive substances (TBARS) levels in the RVLM were significantly higher in OP than in OR. (7.2±0.8μmol/g wet wt vs 2.2±1.9μmol/g wet wt, n=3 for each, p<0.05).ConclusionOxidative stress in the RVLM of OP was increased associated with BP, HR, and UNE elevation and the changes in MetS markers. Increased oxidative stress in the RVLM may increase SNA thereby leading to hypertension in MetS.
Purinergic modulation of rhythmic preBötzinger Complex (preBötC) activity; isolating the glial compartment
Authors: Zwicker Jennifer D , Hahn Leanne B , Huxtable Adrianne G , Fang Sheena , Baker Glen B , Posse de Chaves Elena , Funk Greg D 
Published: June 2021

Analyses of rhythmic medullary slices from neonatal SD rats suggest that glial cells contribute to the P2Y1 receptor (R) excitation of preBötCinspiratory networks (Huxtable et al. this session), in part through activation of glial P2Rs. In this study we established primary cultures of glial cells from the ventral respiratory column (VRC) to directly test their ATP sensitivity, and assess whether this sensitivity might modulate neuronal activity through the subsequent release of gliotransmitters. Cultures were produced from the ventral half of 300 µm transverse preBötC sections or preBötC punches that were grown in sorbitol‐based media, and characterized as glial by presence of mRNA and immunostaining for GFAP, S100β, but not NSE (mRNA) or NF160 (immuno). Fluo‐4 Ca2+ imaging revealed that ATP (0.01 mM, n=20) or the P2Y1R agonist MRS 2365 (0.001 mM, n=20) caused 3.5‐5 fold increases in fluorescence that were reversibly reduced to 80 and 60% of control, respectively, by the P2Y1R antagonist, MRS 2279 (0.5 mM). HPLC data suggested that compared to saline, ATP (50 µM) increased the release of glutamate (30%), aspartate (50%) and taurine (100%).These data confirm that glial cells from the VRC are sensitive to ATP and P2Y1R activation, and that ATP‐evoked release of amino acid gliotransmitters may contribute to the modulatory effects of ATP on inspiratory rhythm. Supported by CIHR, NSERC, CIHR‐MFN, AHFMR, CFI, ASRA.
P2Y1 receptor‐mediated potentiation of XII motoneuron (MN) inspiratory motor output in neonatal rat
Authors: Alvares Tucaaue , Huxtable Adrianne G , Ireland Matthew F , Lorier Amanda R , Funk Gregory D 
Published: June 2021

Inspiratory rhythm generating networks in the preBötzinger Complex (preBötC) are ~100‐fold more sensitive to ATP than XII MNs that control airway patency. This is believed to reflect in part that the effects of ATP in the preBötC are primarily mediated by P2Y1Rs while P2XRs receptors dominate the actions of ATP in XII MNs. However, the effects of P2Y1R signaling on XII motor output and MN properties have not been examined. To address this deficit, we applied nerve and whole‐cell recording techniques to rhythmic medullary slices of neonatal rat.Local application of MRS2365 (P2Y1R agonist) to the XII nucleus of rhythmic slices increased tonic discharge and evoked 22±2 (0.1 mM) and 33±4% (1 mM, n=16) increases in inspiratory burst amplitude. MRS2365 also increased the frequency and amplitude of spontaneous PSCs in non‐inspiratory and inspiratory MNs alike. In inspiratory MNs, it also increased the charge transferred per inspiratory cycle (12±6%, n=5). The increase in synaptic activity was superimposed on a small, slow, inward current that was similar in all XII MNs, averaging 27±7 pA (1 mM, n=10). Following block action potentials with TTX, MRS2365 had no effect on membrane current or resistance.These data suggest that P2Y1Rs do not directly affect XII MN membrane properties, but potentiate inspiratory XII nerve output by specifically modulating synaptic function.Supported by CIHR, NSERC, CIHR‐MFN, AHFMR, CFI, ASRA.
Absence of cocaine sensitization in OVX female rats is not due to cocaine dosage
Authors: Torres‐Diaz Yvonne Marie , Arroyo Yaria , Segarra Annabell C 
Published: June 2021

Female rats show higher locomotor activity in response to cocaine than males. Estradiol is partly responsible for this enhanced cocaine‐induced hyperactivity. The present study was designed to determine the dose and/or length of exposure to cocaine necessary to induce behavioral sensitization in ovariectomized female rats. Rats were ovariectomized, half received a Silastic implant filled with estradiol benzoate (OVX‐EB); the other half received an empty implant (OVX). For 5 consecutive days rats received a daily cocaine injection (10, 15 or 30 mg/kg). On days 1, 5, and 13 animals were tested for their locomotor response to cocaine. Another group of animals received a repeated cocaine exposure of 10 days. Their locomotor response to cocaine was recorded on days 1, 5, 10, and 18. Manipulations of dose and length of exposure to cocaine did not induce behavioral sensitization in OVX rats. These results show that estradiol is necessary for female rats to develop behavioral sensitization to cocaine.Support contributed by: NIH grants: U54NS39405 (SNRP); SO6‐GM08224 (MBRS/SCORE); and R25GM61838 (MBRS/SCORE)
Source and level of protein fed to mice may affect their intestinal mucin production
Authors: Habiyambere Bupe Martha , Onyango Edward M 
Published: June 2021

Mucins are large heavily glycosylated proteins which form the major component of mucus that protects epithelial surfaces of ducts in the body. The effect of the source and level of dietary protein on mucin production and intestinal mucosal morphology was investigated in mice. Thirty two male weanling ICR Swiss mice were randomized into 4 groups of 8 mice each. The four groups of mice were randomly assigned to four diets whose sources of protein were either from plant or animal origin and the level of each protein source was either 10% or 20% crude protein. Mice were provided the respective diets for 14 days and euthanized on the fifteenth day. Jejunal sections of their intestines were removed, fixed in methacarn, embedded in paraffin, sectioned and stained with alcian blue‐periodic acid Schiff (AB‐PAS) stain to visualize mucins and quantify the goblet cells. AB‐PAS stained jejunal sections showed an increase in mucus in mice fed diets containing proteins of animal origin. The number of goblet cells was higher in diets containing protein of animal origin (p<0.05). The increase in goblet cell number was greater for the higher protein level. The length of the villi did not seem to vary among the four different diets. It is concluded that the source and level of protein fed to mice may be influencing their intestinal mucin production.Research was supported by East Tennessee State University.
The anti‐oxidative damage effect of semen cuscutae on the liver mitochondria of aging mice
Authors: Wei Xiao‐Dong , Wang Zhi‐Jun , Wang Shu‐Qiu , Ou Qin , Zhang Tao , Zhang Peng‐Xia , Wang Xian‐Gang , Kang Yu‐Ming 
Published: June 2021

To evaluate the anti‐oxidation effect and the effect of ethanol extract of semen cuscutae (EESC) on the expression of mRNA of subunit CO I of complex IV of respiratory chain in mitochondria of D‐gal induced‐mice. Seventy mice were divided into 5 groups randomly: young, aging, and three different administration groups of 15, 30 and 45 days. The activity of manganese superoxide dismutase (Mn‐SOD), complex I and complex IV, and the content of MDA, the damage of mitochondrial DNA (mtDNA) and the expression of mRNA of subunit CO‐I were all examined for each group. Compared with young group, the activity of complex‐I, complex IV and SOD in mitochondrion of liver decreased, while the content of MDA and the expression level of mRNA of subunit CO‐I increased in aging group, and there were loss of mtDNA fragments in aging group. We found that EESC increases the activity of Mn‐SOD, complex I and complex IV, but decreases the loss of mtDNA and the expression of mRNA of subunit CO I.ConclusionThe EESC can increase the activity of antioxidase and the ability of eliminating free radical of mitochondrion in liver, and can decrease the content of free radical metabolite and the loss of mtDNA. It has a certain degree of anti‐aging effect. The more days of administration, the better the effect.
Vascular Remodeling of Mesenteric Resistance Arteries in Diabetic Mice
Authors: Souza Flavia Moreira , Katz Paige S. , Stewart James A. , Vassallo Dalton V. , Lucchesi Pamela A. 
Published: June 2021

AimsLittle is known about Type 2 diabetes‐induced structural remodeling of mesenteric resistance arteries. This study compared structural differences in small mesenteric resistance arteries in diabetic (db/db) and control (Db/db) mice.MethodsVessels were isolated from 16wk old mice and structural properties were assessed by pressure myography. Mean arterial pressure (MAP) was measured in vivo by telemetry. Western blot analysis and gelatin zymography were used to assess the expression and activity of matrix regulatory proteins.ResultsMAP was similar between control and db/db mice. Fasting blood glucose levels were higher in db/db mice (505±28 mg/dl) vs. control (115±10, p<0.001). The lumen diameter (121±5.5 μm vs. 77.8±5.5, p<0.001 at 75 mmHg) and media cross‐sectional area were significantly increased in db/db compared to control, respectively, suggesting hypertrophic outward remodeling. Cross‐sectional compliance was significantly larger in the diabetic arteries at 50 and 75 mmHg. The stress‐strain curve was shifted to the right in mesenteric arteries from diabetic mice compared with controls. The expression of the matrix regulatory proteins MMP‐9, MMP‐12, TIMP‐1, TIMP‐2, TGF‐β and PAI‐1 were increased in db/db arteries, while MMP‐2 activity was decreased.ConclusionsThese data suggest that diabetic mesenteric resistance arteries undergo hypertrophic outward remodeling, increased vessel compliance and reduced stiffness that was associated with ECM turnover secondary to an imbalance between pro and anti‐fibrotic factors. Supported by COBRE P20RR18766 and HL56046 (PAL) and CAPES (DV).
Chronic intermittent hypoxia and acetaminophen induce synergistic liver injury
Authors: Polotsky Vsevolod Y , Savransky Vladimir , Reinke Christian , Jun Jonathan , Bevans‐Fonti Shannon , Li Jianguo , Myers Allen C , Torbenson Michael 
Published: June 2021

Obstructive sleep apnea (OSA) leads to chronic intermittent hypoxia (CIH) during sleep. OSA has been associated with liver injury. Our goal was to examine whether CIH increases liver injury induced by acetaminophen (APAP) treatment. C57BL/6J mice were exposed to CIH or intermittent air (IA) for 4 weeks while being treated with APAP i.p. (200 mg/kg) or normal saline daily. A combination of CIH and APAP caused liver injury with increases in serum alanine aminotransferase, aspartate aminotransferase (AST), gamma glutamyl transferase and total bilirubin levels, whereas CIH alone induced only elevation in serum AST levels. APAP alone did not affect serum levels of liver enzymes. Histopathology revealed hepatic necrosis and increased apoptosis in mice exposed to CIH and APAP, whereas the liver remained intact in all other groups. Mice exposed to CIH and APAP exhibited decreased hepatic glutathione and a five‐fold increase in nitrotyrosine levels. APAP or CIH alone had no effect on either glutathione or nitrotyrosine. A combination of CIH and APAP caused marked increases in monocyte chemoattractant protein‐1 and macrophage inflammatory protein‐2, which were not observed in mice exposed to CIH or APAP alone. We conclude that CIH and chronic APAP treatment lead to synergistic liver injury, which may have clinical implications for patients with OSA.Funded by NHLBI R01 HL088095
Trafficking of Silica Nanoparticles Across the Alveolar Epithelial Barrier
Authors: Fazlollahi Farnoosh , Beier C. , Yacobi N. R. , Marchelletta R. , Kim Y. H. , Brutchey R. , Hamm‐Alvarez S. , Borok Z. , Kim K. J. , Crandall E. D. 
Published: June 2021

Polystyrene nanoparticles (PNP) translocate across primary cultured rat alveolar epithelial cell monolayers (RAECM) in a surface charge‐ and size‐dependent manner. In this study, we investigated interactions of fluorescently labeled silica nanoparticles (SNP, 42 and 105 nm) with RAECM. Effects of apical 176 µg/mL SNP on transmonolayer resistance (Rt) and equivalent short‐circuit current (Ieq) were measured as functions of time. SNP fluxes (apical‐to‐basolateral) were determined in the presence and absence of the caveolin‐ or clathrin‐mediated endocytosis inhibitors methyl‐β ‐cyclodextrin (MβC) or chlorpromazine (CHL), respectively. Results showed that: i) SNP did not elicit changes in Rt and Ieq for up to 24 hr, ii) 42 nm SNP flux >105 nm SNP flux, iii) fluxes of negatively charged 20 and 100 nm PNP were 60‐80 fold less than fluxes of 42 and 105 nm SNP, iv) neither MβC nor CHL affected SNP fluxes, and v) confocal microscopy after exposure to SNP for 24 hr revealed intracellular localization of SNP. These data indicate that: (1) SNP do not injure RAECM, (2) translocation of SNP is transcellular and size‐dependent, (3) SNP translocation is much faster than comparably‐sized PNP translocation, and (4) SNP trafficking does not appear to take place via endocytosis pathways requiring clathrin or caveolin. We conclude that nanoparticle interactions with alveolar epithelium are at least in part composition‐dependent.Funded by: NIH & Hastings Foundation
β1Pix suppresses the activity of the epithelial Na+ channel through 14‐3‐3 binding
Authors: Pavlov Tengis S , Chahdi Ahmed , Sorokin Andrey , Staruschenko Alexander 
Published: June 2021

β1Pix has been identified as a p21‐activated kinase (Pak)‐interacting exchange factor and serves as a guanine nucleotide exchange factor (GEF) for Rac1 and Cdc42. Furthermore, it was shown that βPix can bind 14‐3‐3 proteins and act as a scaffolding protein. We demonstrate here that βPix is highly expressed in immortalized mouse collecting duct mpkCCDc14 cells. Additionally we have shown that β1Pix expression markedly decrease ENaC activity. Coexpression of β1Pix with ENaC decreased amiloride‐sensitive current density in CHO cells from 365 ± 35 to 158 ± 29 pA/pF. This effect did not occur through GEF activity of β1Pix because coexpression of Rac1 with ENaC markedly increased channel activity and coexpression of wild type and constitutively active (G12V) Cdc42 had no effect on ENaC activity. Moreover Δ602‐611 β1Pix construct which did not bind 14‐3‐3 but retained GEF activity had no effect on ENaC activity. In contrast, β1Pix (L238R,L239R) mutant which has no GEF activity decreased current density to the similar extent as wild type β1Pix. Thus, we can conclude that ß1Pix decreases ENaC activity via 14‐3‐3 recruitment but not through GEF activity.Supported by NIH, AHA and ASN.