bluuebunny/crossref_metadata_2025_split huggingface dataset:
The myocardial inflammasome and heart failure with reduced ejection fraction
Authors: MacLaren Janna , Freeburg Lisa , Samani Stephanie , Churillo Amelia , Barlow Shayne , Jones Traci , Shazly Tarek , Spinale Francis 
Published: May 2023

Background: Left ventricular (LV) injury, particularly myocardial infarction (MI), is a leading cause of heart failure with reduced ejection fraction (HFrEF). However, whether and to what degree activation of the innate immune system, such as the NOD-LRR pyrin-containing protein 3 (NLRP3) inflammasome, occurs post-MI and the development of HFrEF remains unclear. This study tested the central hypothesis that LV myocardial induction of NLRP3 occurs and causes downstream activation of proinflammatory cytokines, notably interleukin-18 (IL-18). Methods and Results Pigs (n=6, 25kg) underwent an intracoronary occlusion (90 mins) followed by reperfusion and LV function (echocardiography) and myocardial sampling performed at 28 days post-MI. Age and weight matched pigs (n=6) served as controls. All results are reported as mean ± SEM. LV ejection fraction (EF) decreased (64.2 ± 5.1 vs. 44.6 ± 3.8 %, p<0.05) and end diastolic volume (EDV) increased (49.4 ± 1.2 vs.68.5 ± 11.6 mL, p<0.05) - consistent with the HFrEF phenotype. LV myocardial NLRP3 expression (rtPCR, 1.14 ± 0.28 vs. 61.55 ± 26.55 fold change, p<0.05), protein levels (digital immunoblot, 1271 ± 646 vs. 9177 ± 2491 pixels, p<0.05), and activity (caspase-1;YVAD-FAC substrate; 147 ± 122 vs.398 ± 58 slope of the fluorescence/time relation, p<0.05) were all increased. These results identified that NLRP3 at the mRNA level yielded functional inflammasome activation, and IL-18 mRNA levels (rtPCR) increased concordantly (1.05 ± 0.17 vs. 16.65 ± 7.20 fold change, p<0.05). Conclusions: While exogenous inflammatory pathways have been identified post-MI and with HFrEF, the unique findings of this study were clear demonstration that the innate immune system, the inflammasome, is also induced with a potent downstream induction of IL-18. These findings suggest that the inflammasome, notably NLRP3, as a potential therapeutic target in the context of ischemic HFrEF. This work was supported in part by National Institutes of Health grant R01HL130972-01A1 (F.G.S.) & R01HL5949 (F.G.S.) as well as a Merit Award from the Veterans Health Administration, BX000168-10A1 (F.G.S.) & BX005320 (F.G.S.). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.
Acute and reversible modulation of kidney proximal tubule endocytic capacity by fluid shear stress
Authors: Lackner Emily , Shipman Katherine , Long Kimberly , Cowan Isabella , Weisz Ora 
Published: May 2023

The proximal tubule (PT) of the kidney is comprised of cells that are uniquely specialized for efficient apical uptake of albumin and other proteins that escape the glomerular filtration barrier. These proteins bind to the multiligand receptors megalin and cubilin and are internalized via clathrin-dependent endocytosis into apical early endosomes that rapidly mature into larger apical vacuoles (AVs). Dissociated ligands are delivered from AVs to lysosomes for degradation, while receptors are collected into dense apical tubules for recycling to the cell surface. When cells are grown under continuous fluid shear stress (FSS), the endocytic uptake is approximately 9-fold greater than static cells. Additionally, cells cultured in this manner rapidly and reversibly adjust their endocytic capacity in response to changes in FSS. We hypothesize flow-dependent modulation of endocytic capacity enables PT cells in vivo to preserve uptake efficiency in response to changes in glomerular filtration. We are combining biochemical, imaging, and mathematical modeling approaches to determine the mechanism(s) by which cells chronically and acutely modulate endocytic uptake. Increased levels of megalin transcripts (~2x) and protein (~4x) is insufficient to account for the large increase in endocytic uptake observed in cells cultured under FSS vs static conditions. We used cell surface biotinylation experiments to compare the fraction of megalin at the surface, the fraction endocytosed, and the half-life of surface-tagged megalin under FSS and static conditions. These data were used to adapt a kinetic model that describes kinetics of megalin biosynthesis, trafficking, and degradation in cells. Overall, the cells grown under FSS have a greater endocytic rate and recycling rate compared with static grown cells. By contrast, megalin degradation is faster than recycling in static-grown cells. Colocalization of megalin with known markers of apical compartments will enable us to extend our model to determine whether changes in endosomal maturation rates contribute to these differences. Additionally, cells cultured under continuous FSS rapidly and reversibly adjust their endocytic capacity in response to changes in shear stress. We hypothesize flow-dependent modulation of endocytic capacity enables PT cells in vivo to preserve uptake efficiency in response to changes in glomerular filtration. We are currently adapting our model to determine how acute changes in shear stress trigger alterations in endocytic uptake. National Institute of Health: 5T32GM133353-03, R01 DK118726, R01 DK125049 This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.
Inflammatory response to radiation exposure of immune cells
Authors: Didier Kaylin , Sanchez Sophie , Forsberg Matthew , Shahi Ankita , Wannebo Brett , Capitini Christian , Schrage William 
Published: May 2023

Background: The purpose of this study was to determine the effect of radiation on the inflammatory signaling response of immune cells. Radiation exposure can increase the risk of developing cardiovascular disease (CVD), which is likely initiated as an inflammatory process. In turn, inflammation initiates atherosclerosis via endothelial cell damage and subsequent immune cell infiltration. We hypothesized that CD14+ immune cells will exhibit an amplified inflammatory response, as demonstrated by larger increases in inflammatory cytokine expression 24 hours post radiation exposure. Methods: Human venous blood was collected from 6 healthy young adults (28 ± 5 years, 22.4 ± 0.7 BMI, 3 Male) using an institutional review board (IRB)-approved protocol. Women were studied in days 1-5 of menstrual cycle. Peripheral blood mononuclear cells (PBMCs) were harvested by density gradient separation. PBMCs were re-suspended and incubated with anti-human CD14 microbeads for 15 minutes at 4°C. After washing unbound antibody, cell separation was done using an autoMACS Pro Separator. CD14+ immune cells were incubated in plates, exposed to 4 gray (Gy) of x-ray radiation, and then incubated for 24 hours. CD14+ immune cells were exposed to 20ng/ml of TNF-α for 30 mins. The culture media was recovered, centrifuged at 100 × g for 1 minute to remove any floating cell debris and assayed for secreted factors, specifically for IL-1β, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12p70, IL-13, INF-γ, and TNF-α. Cytokine responses to radiation were analyzed by paired t-tests. Differences in sex were analyzed by two-way repeated measures ANOVA (Condition x Sex). Results: Radiation exposure (4 Gy) did not change the levels of IL-1β (p=0.15), IL-2 (p=0.13), IL-4 (p=0.16), IL-6 (p=0.18), IL-8 (p=0.35), IL-10 (p=0.18), IL-12p70 (p=0.15), IL-13 (p=0.27), INF-γ (p=0.12), and TNF-α (p=0.14). TNF-α stimulated expression levels of IL-1β (p=0.15), IL-2 (p=0.16), IL-4 (p=0.36), IL-6 (p=0.72), IL-8 (p=0.89), IL-10 (p=0.87), IL-12p70 (p=0.43), IL-13 (p=0.24), and INF-γ (p=0.21) were not different post radiation. There was no sex difference in inflammatory cytokine expression post radiation (p>0.2) or TNF-α stimulation post radiation (p>0.1). Conclusion: These data suggest that expression of inflammatory signals of CD14+ immune cells are not different after exposure to acute radiation (4 Gy x-ray). Further studies are needed to investigate whether increased exposure (duration and/or dose) to radiation could lead to increases in inflammatory cytokines in the adaptive immune response. Translational Research Institute for Space Health through NASA Cooperative Agreement NNX16AO69A and NIH R01 HL150361 This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.
Inflammatory cytokine elaboration following secondhand smoke exposure is mediated in part by RAGE signaling
Authors: Curtis Katrina , Homer Kyle , Wendt Ryan , Chang Ashley , Van Ry Pam , Arroyo Juan , Reynolds Paul 
Published: May 2023

The receptor for advanced glycation end products (RAGE) is a key contributor to the immune and inflammatory response in a myriad of diseases. RAGE is a transmembrane pattern recognition receptor with special interest in pulmonary anomalies due to its naturally abundant expression in the lungs. Our previous studies demonstrated a role for RAGE in inflammation following acute exposure to secondhand smoke (SHS). However, chronic inflammatory mechanisms associated with RAGE have yet to be fully elucidated. In this study, we address the impact of long-term SHS exposure on RAGE signaling. RAGE knockout (RKO) and wild type (WT) mice were exposed to SHS five times weekly via a nose-only delivery system (Scireq Scientific, Montreal, Canada) for six months. SHS animals were compared to mice exposed to room air only. Immunoblot and colorimetric high throughput FACE assays (Active Motif) were used to assess phospho-AKT and NF-κB, respectively. A mouse cytokine antibody array (Abcam) was used to screen secreted cytokines in bronchoalveolar lavage fluid (BALF). Phospho-AKT was decreased and NF-κB was elevated in both groups of SHS exposed mice, with RKO+SHS mice demonstrating tempered outcomes for both intermediates compared to WT+SHS exposed mice. BALF contained increased levels of pro-inflammatory cytokines including IFNγ, IL-13, MIP-1γ and Eotaxin1 in exposed groups and diminished secretion was observed in exposed RKO mice. These results validate a role for RAGE in the mediation of chronic pulmonary inflammatory responses and suggest AKT signaling as a viable pathway of RAGE dependent inflammatory responses. Additional characterization of RAGE-mediated pulmonary responses to prolonged exposure will provide valuable insight into cellular mechanisms of lung diseases such as chronic obstructive pulmonary disease. This work was supported by funding from the National Institutes of Health (NIH 1R15-HL152257, PRR and JAA). This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.
Stellate Ganglion Sympathetic postganglionic efferent innervation in the flat-mount of the whole heart of rats: Anterograde Tracing
Authors: Chen Jin , Bendowski Kohlton , Madas Jazune , Zhang Yuanyuan , Cheng Zixi 
Published: May 2023

The autonomic nervous system (sympathetic and parasympathetic) plays an essential role in controlling cardiac functions. Previously, we used anterograde tracing to examine the vagal afferent and efferent (preganglionic) innervations of the normal heart, their anatomical remodeling and their functional changes in disease models of rats and mice. In addition, we used vesicular acetylcholine transporter (VAChT, a parasympathetic marker;) and tyrosine hydroxylase (TH, a sympathetic marker,) to determine the parasympathetic and sympathetic postganglionic innervation of the whole heart (atria and ventricles). Immunohistochemical labeling with TH is useful for determining the broad distribution of sympathetic efferent axons in the heart. However, it is difficult to distinguish its extrinsic and intrinsic origins using TH labeling. Furthermore, the topographical organization and morphological terminal structures of cardiac sympathetic postganglionic efferent axons from the stellate ganglia (SG) remains unknown. To address this we anterogradely labeled individual sympathetic postganglionic axons projecting to the heart, using tracer Dextran-Biotin microinjections into the right SG of Sprague-Dawley rats (male, n=6, 3-6 months). Fourteen days after the injection, animals were euthanized, and their hearts were dissected into the left/right atria (LA and RA) and ventricles and prepared as flat-mounts. The tracer-labeled axons were digitized and analyzed using The Neurolucida 3D tracing system and imaged using a Zeiss M2 Imager. We found that stellate sympathetic neurons had projections to the LA and RA and left and right ventricles. Individual sympathetic axons formed complex arbors of varicose neurites in the areas of the sinoatrial node (SAN) and atrioventricular node (AVN) as well as the other areas of the atria and throughout the ventricles. Sympathetic axons also innervated blood vessels. Using the Neurolucida Digitization and Tracer system, we determined the regional density and characterized different types of axons. Some axons formed relatively simple terminal structures with only a few branches, whereas other axons produced very complex terminals with extensive branching. For the first time, we anterogradely labeled the sympathetic postganglionic axons and characterized their terminal architecture in the whole heart. These results will provide an anatomical foundation for future study This study was supported by NIH HEAL/SPARC U01 NS113867-01 and NIH R15HL137143-01A1. This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.
Chronic binge alcohol alters hepatic expression of metabolic genes in SIV-infected female rhesus macaques
Authors: Gallegos Eden , Molina Patricia , Simon Liz 
Published: May 2023

Background: Alcohol-related liver injury includes steatosis, fibrosis, and inflammation, which can culminate in alcoholic hepatitis and cirrhosis. The pre-clinical alterations in gene expression underlying these pathophysiological changes are ill-defined. Chronic binge alcohol (CBA) consumption produces marked alterations in metabolic processes and our studies show this is accentuated in chronic infection such as in HIV. This study tested the hypothesis that CBA disrupts expression of hepatic genes involved in glycolytic, gluconeogenic, and lipid turnover pathways in rhesus macaques infected with simian immunodeficiency virus (SIV). Methods: Female rhesus macaques were administered CBA (13-14g ethanol/kg/week, n=7) or vehicle (VEH, n=8) starting 3 months prior to SIV infection. All animals were treated with anti-retroviral therapy starting at 2.5 months post-SIV infection and sacrificed at 14.5 months and liver samples obtained for histological analysis, determination of gene expression by qPCR, triglyceride content by colorimetric assay, and pyruvate kinase activity by a colorimetric enzymatic assay. Results: Expression of lipid handling genes including perilipin 1, peroxisome proliferator-activated receptor γ (PPARγ), carbohydrate responsive binding protein (CHREBP), and acetyl-CoA carboxylase B were higher in CBA-treated compared to VEH-treated macaques. Expression of glycolytic (phosphofructokinase) and gluconeogenic (pyruvate carboxylase) enzymes including aldolase A was increased in the CBA group compared to VEH. No changes were observed in expression of the β-oxidation regulatory protein PPARα. Triglyceride content and pyruvate kinase activity were not significantly different between the groups. Conclusions: These results show significant CBA-mediated alteration of mRNA expression of lipid handling genes that could reflect increased lipid turnover despite lack of alterations in hepatic triglyceride content. Future studies will confirm the findings with protein expression of the differentially regulated genes and levels of non-esterified fatty acid in the liver. Supported by T32AA007577 & P60AA009803. This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.
Increased asprosin in epididymal adipose tissue as a potential contributor to impaired vascular function in obese mice.
Authors: Shah Prachi , Maddie Nicole , Carrillo-Sepulveda Maria Alicia 
Published: May 2023

Vascular complications, such as impaired vasodilation, are a major problem that obese individuals face. In obesity, epididymal white adipose tissue (eWAT) expands, undergoes phenotypic changes, and begins to secrete a variety of adipokines that can metabolically regulate other organs and tissues including the cardiovascular system. Human studies report high levels of asprosin, a newly discovered adipokine secreted by WAT, in obesity. In this study, we hypothesize that obesity increases asprosin expression in eWAT which correlates to vascular complications.Eight-week-old male C57BL/6 mice were randomized into two experimental groups. The control group (n=7) received a standard chow diet (5% fat, 48.7% carbohydrates [3.2% sucrose]) and the Western Diet (WD) group (n=11) received a WD (40% fat, 43% carbohydrates [34% sucrose]) for 39 weeks. Obesity was confirmed by increased body weight (45.39 ± 1.98 g vs. 29.21 ± 0.79 g controls, p< 0.05) and increased BMI (0.45 ± 0.12 kg/m2 vs. 0.32 ± 0.01 kg/m2 controls, p< 0.05). At terminal experiments, eWAT was collected for histological and biochemical analysis. As expected, obese mice exhibited a greater amount of eWAT in comparison to the control group (2.69 ± 0.14 mg/g vs. 0.58 ± 0.06 mg/g controls, p< 0.05). Histological analysis of eWAT stained with H&E revealed that obesity induced a significant increase in adipocyte's size (10543.47 ± 694.06 μm2 vs.1726.64 ± 152.20 μm2 controls, p< 0.05) and infiltration of inflammatory cells surrounding adipocytes. Strikingly, greater asprosin expression was detected in eWAT from WD group in comparison to the control group (1.3 fold of increase, p<0.005). To assess whether asprosin has vascular effects, mesenteric arteries from control C57BL/6 mice were acutely incubated with pharmacological concentration of asprosin followed by vascular studies assessed by wire myograph. Our preliminary results show that asprosin impairs endothelium-dependent vasodilation (Emax:72.95% ± 7.38 vs. 93.33% ± 1.33 controls, n=3).The novelty of our results show that asprosin has a negative effect in vascular function. Our findings imply that eWAT may be a tissue contributing to the high levels of asprosin in obese individuals, further suggesting asprosin as a culprit of obesity-associated vascular dysfunction in obese males. This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.
Hypothalamic PVN astrocytes fail to properly set glutamate tone in obese mice contributing to impaired glucose metabolism in this condition
Authors: Kirchner Matthew , Herrera Moro Chao Daniela , Pham Cuong , Li Dongdong , Martin Claire , Luquet Serge , Stern Javier 
Published: May 2023

The hypothalamus is key in the control of energy balance, but strategies targeting hypothalamic neurons have failed to provide viable options to treat most metabolic diseases. Conversely, the role of astrocytes in systemic metabolic control has remained largely unexplored. Here, we show that obesity promotes anatomically restricted exacerbated Ca2+ activity in hypothalamic paraventricular nucleus (PVN) astrocytes. Bidirectional chemogenetic manipulation of astrocyte Ca2+ activity in lean mice stimulated or inhibited the activity of neighboring parvocellular neurons. Importantly, these effects translated into bidirectional regulation of sympathetic activity, glucose metabolism, and energy balance. We found that the astrocyte-mediated effects on PVN neurons were blocked by the glutamate receptor blocker kynurenic acid, and the astrocyte glutamate transport blocker TBOA, suggesting that the astrocyte-neuron signaling and the effects on glucose metabolism involved the astrocytic control of ambient glutamate levels. Notably, we found that TBOA alone stimulated neurons in lean mice but failed to evoke a response in obese mice. This suggests that the astrocyte glutamate transporter activity is impaired in obese mice. Finally, we found that chemogenetic inhibition of astrocyte Ca2+ activity in obese mice improved glucose metabolism in this condition. Together, our results indicate that exacerbated astrocyte Ca2+ activity leads to impaired glutamate transporter activity, standing as a likely mechanism contributing to altered PVN neuronal activity and glucose homeostasis during this condition. Collectively, these findings highlight a yet unappreciated role for astrocytes in the direct control of systemic metabolism and suggest potential targets for anti-obesity strategy. NHLBI F32 HL158172 (MKK) NHLBI HL090948 (JES) NINDS NS094640 (JES) This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.
The Proliferative and Functional Roles of CEBP/A in Ins-1 832/13 Cells and Primary Rat Islets
Authors: Ellsworth Peter , Herring Jacob , Elison Weston , Leifer Aaron 
Published: May 2023

The beta cell transcription factor Nkx6.1, when overexpressed in primary rodent and human islets, is sufficient to enhance beta cell proliferation, increase insulin secretion and enhance cell survival. We have sought to define the transcriptional targets of Nkx6.1 that allow for its ability to increase functional beta cell mass. We have shown that Nkx6.1 induces expression of the transcription factor CEBP/A. CEBP/A overexpression is sufficient to induce proliferation of Ins-1 832/13 cells and primary rat islets. CEBP/A overexpression enhances glucose stimulated insulin secretion from primary rat islets, while decreasing total insulin content. Finally, CEBPa overexpression protects Ins-1 832/13 cells from thapsigargin and glucolipotoxicity induced cell death but fails to protect against etoposide and camptothecin induced cell death. These data suggest that CEBP/A may play a critical role in Nkx6.1 mediated expansion of functional beta cell mass through a endoplasmic reticulum stress-mediated pathway. This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.