bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Effects of Sex and Genotype on the Population Pharmacokinetics and Pharmacodynamics Modeling and Simulation of Low Dose Epinephrine and Cardiac Output
Authors: Eugene Andy Roger , Joyner Michael 
Published: November 2023

OBJECTIVEMen and women differ in cardiac output. We hypothesize a sex by genotype interaction may exist during a low‐dose adrenaline infusion affecting the β2 adrenergic receptor.METHODSSubjects: Ten males (mean ± SD: age=27.8±6.6, height=178.5±8.0cm, weight=83.9 ±12.4kg, BMI=26.3±2.9kg/m^2, BSA=2.0±0.2) and fourteen females (mean ± SD: age=26.3±5.9, height=164.3±7.0cm, weight=60.8±6.2kg, BMI=22.5±2.1kg/m^2, BSA=1.7±0.1) were studied. Three males were homozygous for Arginine (Arg/Arg) and 7 males were homozygous for Glycine (Gly/Gly) at position 16. In the female cohort, eight females were Arg/Arg and six females were Gly/Gly, at position 16. Procedure: A 1‐hour epinephrine infusion dosed at 5ng/kg/min was administered. BP was measured via an arterial catheter and HR via EKG. Stroke volume and Cardiac output were estimated via Modelflow and TPR was calculated. Plasma samples were collected at time: 0, 30, 45, 60, and 70 minutes and catecholamines measured using HPLC with electrochemical detection. Population Pharmacokinetic‐Pharmacodynamic Analysis: Plasma epinephrine concentrations and cardiac output responses were analyzed using the Nonlinear Mixed Effects (NLME) Stochastic Approximation Expectation‐Maximization (SAEM) algorithm in MATLAB® SimbiologyTM (version 2015a, Mathworks, Natick, MA). The Visual Predictive Check was conducted using the R statistical software (version 3.2.2, The R Foundation for Statistical Computing, Vienna, Austria).RESULTSEpinephrine pharmacokinetics were well‐described using a one‐compartment model with an ‘effect compartment’ and elimination from the central compartment. The population mean estimates for the volume of distribution and elimination rate were 22.81 L (CV=27.52%) and 8.77 L/hour (13.00%), respectively. Cardiac Output was modeled using the Hill Stimulation Equation and resulted in mean population estimates of E0=4.94 L/min (13.56%) for baseline, Emax=34.86 L/min (38.61%), and EC50=2486.23 ng/L (CV=5.54%). Bodyweight (mean=70kg) and Sex:Genotypes were the main covariates for the model. A visual predictive check revealed adequate central tendency for the linked PK/PD model. Dosing (300ng/kg/hour for a 70kg individual) simulations resulted in a PK/PD profile stratified for the population mean and Sex:Genotype covariates. Plasma Concentration‐Response curves produced subpopulation (Male Arg/Arg, Male Gly/Gly, Female Arg/Arg, and Female Gly/Gly) differences.CONCLUSIONBased on the plasma concentration‐response curves, the interaction of sex and genotype influences the ability to increase cardiac output during an infusion of low‐dose epinephrine.Support or Funding InformationNIH T32 Clinical Pharmacology Fellowship Grant GM008685‐17.
Genetic Inhibition of Chac1 Leads to Dysregulation of Body Composition
Authors: Crawford Rebecca R , Prescott Eugenia T , Mungrue Imran N 
Published: November 2023

CHAC1 is a gamma‐glutamylcyclotransferase downstream of ATF4 in the Unfolded Protein Response. CHAC1 degrades glutathione, the primary, intracellular antioxidant, and decreases Notch signaling. Notch is the receptor for a well‐conserved signaling pathway that is essential for development and proper maintenance of adult tissues, such as mucle and bone. Due to the importance of glutathione and Notch, it is likely that CHAC1 is critical for cell function and development. Chac1−/− mice were generated to elucidate the effects of Chac1 in vivo; however, knockout of Chac1 is lethal. Interestingly, Chac1+/− mice have decreased body weight, suggesting Chac1 is important in body composition regulation.To dissect the underlying cause for reduced body mass in Chac1+/− mice, four metrics were analyzed: food intake, fat mass, muscle mass, and bone function. Analysis of food intake illustrates that there is no change in food intake; thus, food intake does not account for the decrease in body weight, but does suggest a misregulation of energy balance. Abdominal fat pad weight is not consistently changed at any 6, 13, or 33 weeks of age ages, suggesting no changes in fat mass. Chac1+/− mice of both sexes have decreased gastrocnemius weights at 6 weeks and 33 weeks of age, suggesting decreased muscle mass as the cause of the reduced body weight. Finally, markers of osteoblasts were analyzed in the femur of male and female Chac1+/− mice versus control. Markers for osteoblasts, such as Runx2 and Col1a1, are decreased in Chac1+/− mice at 6 weeks. These data suggest that there is a decrease in osteoblast differentiation and decreased bone density.Overall, these data illustrate that genetic inhibition of Chac1 in mice leads to multiple changes in body composition, including lower muscle mass and changes in bone development, demonstrating the importance of Chac1 in the proper regulation of muscle and bone. Furthermore, Chac1 may play an important role in the progression of muscle and bone pathology in conditions such as osteoporosis, aging, and muscle wasting.Support or Funding InformationNIH #HL09470; COBRE P30GM106392; Louisiana Board of Regents Fellowship #LESQSF(2012‐17)‐GF‐08 to RRC
2‐Methoxyestradiol protect against isoproterenol‐induced cellular hypertrophy in the human ventricular cardiomyocytes, RL‐14 cells, through MAPK‐ and NF‐κB‐dependent mechanisms
Authors: Almaayah Zaid Hussein , El‐Kadi Ayman O.S. 
Published: November 2023

Accumulating data supported the evidence that 2‐methoxyestradiol (2ME) is a biologically active metabolite and mediates multiple effects on the cardiovascular systems that are largely independent of estrogen receptor. 2ME is a major cytochrome P450 1B1 metabolite and has been reported to have a vasoprotective and anti‐inflammatory actions. However, whether 2ME would inhibit isoproterenol (ISO)‐induced cellular hypertrophy has not been investigated yet. Therefore, the overall objectives of the present study are to elucidate the potential anti‐hypertrophic effect of 2ME in the human ventricular cardiomyocyte, RL‐14 cells, and to explore the mechanism(s) involved. For this purpose, RL‐14 cells were treated with 100 μM ISO in the presence and absence of 200 nM 2ME. Thereafter, the cellular hypertrophy markers and cell volume were determined using real‐time polymerase chain reaction and phase contrast imaging, respectively. Phosphorylated mitogen activated protein kinases (MAPK) levels and nuclear factor kappa B (NF‐κB) binding activity were determined using a commercially available kits. Our results showed that 2ME significantly inhibited the ISO‐induced cellular hypertrophy in RL‐14 cells as evidenced by a decrease in the induction of β‐myocin heavy chain/α‐myocin heavy chain and cell volume. Mechanistically, the protective effect of 2ME against ISO‐induced cellular hypertrophy was mediated through a significant inhibition of the phosphorylated p38 and ‐Jun NH2‐terminal kinases (JNK)‐induced by ISO, whereas it normalizes the ISO‐mediated inhibition of extracellular‐regulated kinases1/2 (ERK1/2) signaling pathway. Furthermore, 2ME inhibited the ISO‐induced NF‐κB binding activity. In conclusion, our study provides the first evidence that 2ME attenuate ISO‐induced cellular hypertrophy through MAPK‐ and NF‐κB‐dependent mechanisms.Support or Funding InformationThis work was supported by a grant from the CIHR to A.O.S.E. Z.H.M. is the recipient Izaak Walton Killam Scholarship and Alberta Innovates‐Health solution Scholarship.
Fibroblast Growth Factor 21 Deficiency Attenuates DSS‐induced Acute Colitis Through Activation Of Intestinal Epithelial Cell Stat3‐mediated Pathway
Authors: Liu Liming , Zhao Cuiqing , Dryden Gerald , McClain Craig , Feng Wenke 
Published: November 2023

BackgroundFibroblast growth factor 21 (FGF21) is a novel metabolic regulator in glucose and lipid metabolism. Recent studies showed that FGF21 is also induced by inflammatory stimuli. However, its role in inflammatory bowel disease (IBD) has not been examined.MethodsExperimental IBD model was induced by adding 2.5% (wt/vol) dextran sulfate sodium (DSS) into drinking water for 3, 5 and 7 days, respectively, in FGF21 knockout (KO) and wide type (WT) mice. Mouse colon tissues were analyzed for colitis severity and inflammatory cell infiltration. FGF21 and inflammatory makers were determined in serum and tissues samples. The T84 intestinal epithelial cell line was used for additional in vitro studies.ResultsIn WT mice treated with DSS induced an elevation in serum FGF21 and a significant body weight loss in a time dependent manner. Gene expression studies showed that liver and epididymal white adipose tissues were the major sources of circulation FGF21. Surprisingly, the body weight loss and colitis severity were significantly attenuated in FGF21 KO mice. Further analysis showed that FGF21 KO mice had less colon shortening, histological damage, less neutrophil infiltration compared to WT mice. FGF21 deficiency decreased DSS treatment‐increased serum concentrations of IL‐6, TNF‐α and IL‐1β and their mRNA levels in colon tissues. Colonic epithelial cell proliferation, examined by BrdU staining, was increased in the KO mice. DSS treatment caused a decrease in epithelial cell proliferation and Paneth and Goblet cell numbers in WT mice, which were attenuated in the KO mice. Importantly, FGF21 depletion dramatically increased signal transducer and activator of transcription‐3 (STAT3) activation in intestinal epithelial cells, along with a decreased suppressor of cytokine signaling‐3 (Socs3) expression. FGF21 pretreatment inhibited IL6‐induced STAT3 phosphorylation in human intestine epithelial T84 cells.ConclusionCirculating levels of FGF21 were increased in acute colitis in mice. FGF21 deficiency attenuated DSS induced acute colitis, which is likely mediated by the inhibitory effect of FGF21 on IL‐6‐induced‐STAT3 activation in intestinal epithelial cells.Support or Funding InformationThis research was supported by the NIH and Veterans Administration.
Adherens Junction Proteins in Cochlear Lateral Wall Capillaries are Altered by Loud Sound‐induced Stress to the Ear
Authors: Yu Qing , Foster Sarah , Dziennis Suzan , Wilson Teresa , Nuttall Alfred L 
Published: November 2023

BackgroundThe capillaries of the cochlear lateral wall are part of the blood‐labyrinth‐barrier (BLB) that separates the inner ear fluid from systemic circulation. The BLB controls the exchange of solutes, protein, and water, and plays an essential role in maintaining inner ear homeostasis and the endocochlear potential. Compromise of the BLB's integrity is a contributing factor in various hearing disorders including presbycusis, noise‐induced hearing loss, and autoimmune inner ear disease. This crucial barrier's function relies on endothelial cell‐cell junctions including those formed by the adherens junction (AJ) proteins. However, the mechanisms which regulate the function of AJs in the cochlear lateral wall capillaries remain largely unknown.ObjectiveTo characterize the role of AJ protein complexes and the associated signaling pathways in modulating the integrity of lateral wall capillaries under normal and loud sound‐induced stress conditions.Methods and ResultsThe spiral ligament and stria vascularis were isolated from the cochlea of 10 week old CBA/CaJ mice and immunolabeled for VE‐cadherin, β‐catenin, and FAK. Confocal imaging revealed that the fluorescent signals for VE‐cadherin and β‐catenin overlapped at endothelial cell to cell contacts whereas FAK revealed nuclear, cytoplasmic, and focal adhesion distribution without overlap with VE‐cadherin. To evaluate the dynamic changes of VE‐cadherin and its associated signaling pathway components under stress conditions, we exposed the CBA/CaJ mice to loud sound (106 dB SPL, 8–16 kHz, 2 hours). The following immunofluorescence analysis of the capillaries revealed an increase of specific phosphorylation sites for β‐catenin and FAK in the endothelial cells of noise exposed mice. Airyscan imaging showed alterations of the AJ proteins at the cell membrane as well as increased translocation of FAK to the endothelial cell‐cell junctions.ConclusionsAdherens junctions are dynamic structures that allow for rapid and specific responses to changes in the perivascular microenvironment. Loud sound‐induced alterations of AJ components and intracellular partners may reduce the integrity of the BLB. Unraveling the molecular mechanisms and signaling pathways that modulate the function of AJ complexes will contribute to the future discovery of breakthrough therapeutic treatments that maintain inner ear barrier integrity.Support or Funding InformationSupported by grants 5R01DC000105 (ALN) and P30DC005983.
Ex Vivo Validation of Intravascular Ultrasound/Photoacoustic Tissue Characterization
Authors: Kole Ayeeshik , Hui Jie , Cao Yingchun , Wang Pu , Cheng Ji‐Xin , Sturek Michael 
Published: November 2023

Coronary heart disease is the leading cause of death in the United States and incidence is projected to increase by 18% by 2030. Yet, there remains a pressing clinical need for tools to detect vulnerable atherosclerotic plaques that can rupture and lead to major adverse cardiac events. Plaques that are considered most vulnerable for rupture are thin‐capped fibroatheromas, which are grossly defined by hallmarks of a thin fibrous cap, a large lipid‐rich necrotic core, inflammatory infiltrate, and positive remodeling. These plaques are often structurally non‐obstructive to moderately obstructive, thus asymptomatic and clinically unidentifiable with routine angiography and stress testing. Rather, their vulnerability is a product of their chemical composition. Here, we present a dual‐mode intravascular catheter which is capable of producing co‐registered cross‐sectional images of vessel wall morphology and lipid content, via ultrasound and photoacoustic modes, respectively. A prototype design of the catheter was used to image a formalin‐fixed carotid artery harvested from a miniature Ossabaw swine with metabolic syndrome. Preliminary results suggest the catheter was able to detect a moderately obstructive fibrocalcific plaque identified by gross inspection. A dense pattern of superficial calcium was demonstrated by intense echogenic signal with acoustic shadowing of the ultrasound signal peripheral to the deposit and a lipid‐rich core underlying this was shown by strong photoacoustic signal. In addition, a fresh carotid artery harvested from a healthy domestic swine served as a negative control in which we observed a clean lumen with no detectable photoacoustic signal. These findings will be compared to gold standard histopathology and future studies will be extended to include interrogation of fresh, post‐mortem atherosclerotic coronary arteries from humans obtained at autopsy.Support or Funding InformationIUPUI Graduate Imaging Research Fellowship, NIH T32 GM077229, HL125385
Molecular Mechanism of Tethers and Slings in CD4+ T cells
Authors: Abadier Michael , Ley Klaus 
Published: November 2023

Leukocyte recruitment towards the site of injury is a tightly regulated multi‐step process initiated by rolling along the luminal surface of inflamed endothelium in the presence of high shear flow. The interaction of endothelial P‐selectin‐to‐P‐selectin glycoprotein ligand (PSGL)‐1 constitutively expressed in leukocytes mediates leukocyte rolling by rapid formation and breakage of selectin‐to‐ligand bonds to balance the hydrodynamic drag forces exerted by blood shear stress. Once pulling forces due to the high shear exceed a critical threshold, tethers and slings become essential to support leukocyte rolling. Slings, recently discovered by our group, are long cell adhesive structures derived from long tethers. Here, we polarized naïve T cells towards distinct lineages of CD4+ effector T cells (Th1, Th2, Th17 and Treg). Considering the critical role of functional PSGL‐1 for T cell rolling, we tested functional PSGL‐1 by P‐selectin‐Fc binding in flow cytometry. PSGL‐1 in Th1, Th17 and Treg is functional in 70–80% of cells, but only in 10–20% of Th2 cells and 0% of Naïve CD4 T cells. To visualize the dynamic process of T cell rolling, we performed live cell imaging under high shear stress (>5 dyn/cm2). Interestingly, the rolling speed of Th2 cells was significantly higher when compared to the other T cell subsets. This was mirrored by observing tethers and slings in Th1, Th17, Treg but to a lesser extent in Th2. Surprisingly, some of the few Th1 or Th17 cells bearing non‐functional PSGL‐1 were able to form tethers and slings, suggesting that functional PSGL‐1 binding to P‐selectin allows for T cell rolling at reduced speed but might not be the sole requirement for tether and sling formation. To identify the molecular and cellular requirements for tether and sling formation, Naïve CD4+ T cells and neutrophils will be used as negative and positive controls, respectively. By developing gene expression maps we will identify the differentially regulated genes during T cell lineage differentiation. Upregulated genes in Th1, Th17 and Treg, but not in Th2, are excellent candidates for being involved in tether and sling formation.Support or Funding InformationSwiss National Science Foundation and P01 HL078784/NIH
Soluble guanylate cyclase activation during ischemic injury in mice protects against post‐ischemic inflammation at the mitochondrial level
Authors: Wang Derek , Jones Allan , Wang Walter , Wang Meifang , Korthuis Ronald 
Published: November 2023

Preconditioning with BAY 60‐2770, a selective activator of oxidized soluble guanylate cyclase (sGC), was shown to protect against postischemic reperfusion (I/R) injury in wild type (WT) and heme‐oxygenase‐1 KO (HO‐1−/−) mice. Here a similar effect occurred when administered during ischemia; as measured by reduced leukocyte rolling and adhesion to intestinal venules, as well as prevention of increased TNF‐α and circulating neutrophil levels that accompany I/R. We hypothesized that a component of BAY 60‐2770 protection involves maintenance of mitochondrial membrane integrity during I/R. Measures on isolated mucosal cells of Calcein fluorescence and JC‐1 fluorescence ratio were reduced by I/R, indicating formation of mitochondrial permeability transition pores (mPTP). These indices remained at control levels following treatment with BAY 60‐2770 as well as cyclosporin A and SB 216763. Western blots of mucosal cells from WT and HO‐1−/− indicated that glycogen synthase kinase‐3β (GSK‐3β) phosphorylation on serine9 (inhibitory site) was reduced following I/R alone (increased GSK‐3β activity), and increased (reduced GSK‐3β activity) following treatment with BAY 60‐2770. Studies by others have associated phosphorylation of the GSK‐3β substrate, cyclophilin D (pCyPD) with mPTP formation. We observed an increase in pCyPD after I/R, whereas BAY 60‐2770 treatment of sham and I/R groups reduced pCyPD. In conclusion, selective activation of oxidized sGC of WT and HO‐1−/− during ischemia protects against I/R induced inflammatory processes and preserves mucosal integrity in part by reducing pCyPD production and mPTP formation.Support or Funding InformationNIH R01‐AA022108 and P01‐HL ‐095486. Bayer Schering Pharma AG provided BAY 60‐2770 as a gift
Mast Cells‐Dependent Compromised Response of Aged Mesenteric Lymphatic Vessels and Surrounding Tissues to the Acute Inflammatory Challenge
Authors: Skoog Hunter , Dusio Giuseppina F. , Tobin Richard , Zawieja David C. , Newell‐Rogers M. Karen , Gashev Anatoliy A. , Nizamutdinova Irina Tsoy 
Published: November 2023

Mesenteric lymphatic vessels (MLVs), being located at the border between the biologically aggressive environment of the gut lumen and inner compartments of the abdomen have not been studied in depth as an active component of the anti‐inflammatory defense system of the body. Aging creates several challenges for lymphatic vessels by altering their ultrastructure, contractility and consequently lymph flow as well as their microenvironment. We found an increase in number and degree of basal activation of mast cells (MC) nearby aged mesenteric lymphatic vessels. Such, as we predicted, will delimit ability of aged mesenteric tissue to respond to acute inflammatory challenge. In current study we attempted to establish mechanistic links between the aging‐associated changes in functional status of MCs and the altered responses of mesenteric tissue and MLVs to acute inflammatory insult. We used in vivo model of induction of acute peritoneal inflammation by lipopolysaccharide (LPS) treatment (24 hours after single IP injection of LPS in dose of 10 mg/kg body weight into adult (9‐mo) and aged (24‐mo) F‐344 rats). Analysis of data obtained by studies based on ruthenium red staining of MCs and by flow cytometry‐based measurements demonstrate that LPS‐induced degranulation of MCs in aged mesentery is greatly diminished. Latter co‐exists with basal activation of NF‐κB signaling in aged MLVs and mesenteric tissue therefore additional LPS‐induced NF‐κB activation is also reduced. Furthermore both mast cell stabilization by Cromolyn, or application of mixture of Histamine H1–H4 receptor blockers, are able to prevent the NF‐κB activation in mesentery/MLVs. NF‐κB, as hallmark of aging‐associated low‐grade inflammation, controls the release of pro‐inflammatory cytokines. To identify the corresponding aging‐associated differences, 24 hours after LPS injection we compared blood and mesenteric tissue (including MLVs) samples from adult and aged rats for 27 major pro‐inflammatory cytokines, using a Multiplex cytokine assay system (kit RECMAG65K27PMX, Millipore, US). The obtained results show that there is an elevation of NF‐κB‐dependent pro‐inflammatory cytokines in aged mesentery/MLVs with imbalance of Th1/Th2 cytokine profile and subsequent changes in T and B cells populations. Cumulatively, our data indicate that pre‐existing activation of MCs in aged mesentery by MLVs linked to its altered response to LPS, associated with histamine/NF‐κB‐dependent specific changes in cytokine levels. Latter can contribute to imbalance of immune cells profile and decreased ability of the aged immune system to respond to acute inflammatory challenge in peritoneal compartment of the body.Support or Funding InformationNIH/NIDDK 1R56DK099161